Open access peer-reviewed chapter

Current Status of Antimicrobial Resistance and Prospect for New Vaccines against Major Bacterial Bovine Mastitis Pathogens

Written By

Oudessa Kerro Dego

Submitted: September 14th, 2020 Reviewed: September 28th, 2020 Published: October 19th, 2020

DOI: 10.5772/intechopen.94227

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Economic losses due to bovine mastitis is estimated to be $2 billion in the United States alone. Antimicrobials are used extensively in dairy farms for prevention and treatment of mastitis and other diseases of dairy cattle. The use of antimicrobials for treatment and prevention of diseases of dairy cattle needs to be prudent to slow down the development, persistence, and spread of antimicrobial-resistant bacteria from dairy farms to humans, animals, and farm environments. Because of public health and food safety concerns regarding antimicrobial resistance and antimicrobial residues in meat and milk, alternative approaches for disease control are required. These include vaccines, improvements in housing, management practices that reduce the likelihood and effect of infectious diseases, management systems and feed formulation, studies to gain a better understanding of animal behavior, and the development of more probiotics and competitive exclusion products. Monitoring antimicrobial resistance patterns of bacterial isolates from cases of mastitis and dairy farm environments is important for treatment decisions and proper design of antimicrobial-resistance mitigation measures. It also helps to determine emergence, persistence, and potential risk of the spread of antimicrobial-resistant bacteria and resistome from these reservoirs in dairy farms to humans, animals, and farm environments.


  • antimicrobial resistance
  • vaccines against mastitis
  • bovine mastitis
  • bacterial mastitis pathogens
  • bacterial pathogens
  • current status

1. Introduction

1.1 Antibiotic use in dairy farms and antimicrobial resistance

Economic losses due to bovine mastitis is estimated to be $2 billion in the United States alone [1]. Most studies showed that there is no widespread, emerging resistance among mastitis pathogens [2, 3, 4] in dairy farms. Some studies showed that the antimicrobial resistance of mastitis pathogens varies with dairy farms and bacterial species within and among dairy farms [4, 5, 6, 7, 8, 9]. However, antimicrobial resistance patterns of human pathogenic bacteria and their resistome in dairy farms might be of significant concern.

On average, starting from calving (giving birth) dairy cow is milked (in lactation) for about 300 days and then dried off (stop milking) for about 60 days before they calve again. Under the ideal dairy farming condition, a dairy cow should become pregnant within 60 days of calving, and the lactation cycle continues (Figure 1). The goal of a dry period is to give them a break from milking so that milk-producing cells regenerate, multiply, and ready for the next cycle of lactation. The incidence of intramammary infection (IMI) by bacteria is high during the early dry period and transition periods [10]. In general, for a dairy cow, a transition period, also known as the periparturient period, is a time range from three weeks before parturition (non-milking time) until three weeks after calving (milking time). It is a transition time from non-milking to milking.

Figure 1.

Antimicrobials usage patterns during the lactation cycle. DIM: Days in milk, yellow star: Peak lactation at 60 DIM, green bars: Energy demand that requires the mobilization of body energy reserve at the expense of losing bodyweight, red bumps showed increased usage of antimicrobials.

Dairy cows are susceptible to mastitis during early non-lactating (dry period) and transition periods [11, 12], especially new infection with environmental pathogens (Streptococcus spp. and coliform) are highest during the first two weeks after drying off and last two weeks before calving [13] compared to contagious mastitis pathogens such as S. aureus [14]. The incidence of intramammary infection is high during the early dry period because of an absence of hygienic milking practices such as pre-milking teat washing and drying [15], pre- and post-milking teat dipping in antiseptic solutions [16, 17], that are known to reduce teat end colonization by bacteria and infection. An udder infected during the early dry period usually manifests clinical mastitis during the transition period [18] because of increased production of parturition inducing immunosuppressive hormones [19], negative energy balance [12], and physical stress during calving [20].

Cows are naturally protected against intramammary infections during the dry period by physical barriers such as the closure of teat opening by smooth muscle (teat sphincter) and the formation of a keratin plug, fibrous structural proteins (scleroproteins) [21, 22], in the teat canal produced by teat canal epithelium [23]. Keratin contains a high concentration of fatty acids, such as lauric, myristic, and palmitoleic acids, which are associated with reduced susceptibility to infection and stearic, linoleic, and oleic acids that are associated with increased susceptibility to infection. Keratin also contains antibacterial proteins that can damage the cell wall of some bacteria by disrupting the osmoregulatory mechanism [23]. However, the time of teat canal closure varies among cows. Some studies showed that 50% of teat canals were classified as closed by seven days after drying off, 45% closed over the following 50–60 days after drying off, and 5% had not closed by 90 days after dry off [24]. Teats that do not form a plug-like keratin seal are believed to be most susceptible to infection. Infusion of long-acting antimicrobials into the udder at drying-off (dry cow therapy) has been the major management tool for the prevention of IMI during the dry period, as well as to clear IMI established during the previous lactation [24].

In the United States and many other countries at the end of lactation (at drying off), all cows regardless of their health status, are given an intramammary infusion of long-acting antimicrobials (blanket dry cow therapy) to prevent IMI by bacteria during the dry period [3, 25]. Because of increased concern on the use of blanket dry cow therapy for its role in driving antimicrobial resistance, selective dry cow therapy (intramammary infusion of antimicrobials into only quarters that have tendency or risk of infection) has been under investigation [26, 27]. Some recent studies showed that the use of bacteriological culture-based selective dry cow therapy at drying-off did not negatively affect cow health and performance during early lactation [26, 27]. In general, dairy farms are one of the largest users of antimicrobials including medically important antimicrobials [28]. Some of the antimicrobials used in dairy farms include beta-lactams (penicillins, Ampicillin, oxacillin, penicillin-novobiocin), extended-spectrum beta-lactams (third-generation cephalosporins, e.g., ceftiofur), aminoglycosides (streptomycin), macrolides (erythromycin), lincosamide (pirlimycin), tetracycline, sulfonamides, and fluoroquinolones [28, 29, 30]. Antimicrobials are also heavily used in dairy farms for the treatment of cases of mastitis [3, 25, 31] and other diseases of dairy cows such as metritis, retained placenta, lameness, diarrhea, pneumonia, [32, 33, 34, 35, 36] and neonatal calf diarrhea [37]. Over 90% of dairy farms in the US infuse all udder quarters of all cows with antimicrobial regardless of their health status [7, 25, 38]. According to dairy study in 2007 that was conducted in 17 major dairy states in the United States, 85.4% of farms use antibiotics for mastitis, 58.6% for lameness, 55.8% for diseases of the respiratory system, 52.9% for diseases of reproductive system, 25% for diarrhea or gastrointestinal infections and 6.9% for all other health problems [3, 25]. Cephalosporins were the most widely used antibiotics for the treatment of mastitis, followed by lincosamides and non-cephalosporin beta-lactam antibiotics [3, 25]. The two most commonly used antibiotics for dry cow therapy are Penicillin G/dihydrostreptomycin and cephalosporins [3, 25]. Antimicrobials were administered for the prevention and treatment of mastitis and other diseases of dairy cattle mainly through intramammary infusion and intramuscular route (USDA APHIS, 2009a). Antimicrobials infused into the mammary glands can be excreted to the environment through leakage of milk from the antimicrobial-treated udder or absorbed into the body and enter the blood circulation and biotransformed in the liver or kidney and excreted from the body through urine or feces into the environments [39, 40, 41, 42]. Similarly, antimicrobials administered through parenteral routes for the treatment of acute or peracute mastitis or other diseases of dairy cows will enter the blood circulation and biotransformed in the liver or kidney and excreted from the body through urine or feces into the environments [39, 40, 41, 42]. Therefore, both parenteral and intramammary administration of antibiotics has a significant impact on other commensals or opportunistic bacteria in the gastrointestinal tract of dairy cows and farm environments.

In addition to the use of antimicrobials for the prevention and treatment of mastitis and other diseases of dairy cattle, some farms also feed raw waste milk or pasteurized waste milk from antibiotic-treated cows to dairy calves. Feeding of raw waste milk or pasteurized waste milk from antibiotic-treated cows to calves increases pressure on gut microbes such as E. coli to became antimicrobial-resistant [43, 44, 45]. Aust et al. [43] showed that the proportion of antimicrobial-resistant E. coli, especially cephalosporin-resistant E. coli isolates, was significantly higher in calves fed waste milk or pasteurized waste milk from antimicrobial treated cows than calves fed bulk tank milk from non-antibiotic treated cows. However, pasteurized waste milk from cows not treated with antimicrobials is acceptable to be feed to young calves [43] but it is not known if pasteurization prevents the transfer of antimicrobial-resistant genes to microbes in the calve’s gut. Some studies also showed that feeding pasteurized waste milk from antimicrobial treated cows to calves increased the presence of phenotypic resistance to ampicillin, cephalothin, ceftiofur, and florfenicol in fecal E. coli compared with milk replacer-fed calves [45]. However, the presence of resistance to sulfonamides, tetracyclines, and aminoglycosides was common in dairy calves regardless of the source of milk, suggesting other driving factors for resistance development [45]. It has been suggested that antimicrobial residues present in waste milk have a non-specific effect at a lower taxonomical level [44]. Collectively, these non-prudent antimicrobials usage practices in dairy farms expose a large number of animals in dairy farms to antimicrobials and also increases the use of antimicrobials in dairy farms, which in turn creates intense pressure on microbes in animals’ body especially commensal and opportunistic microbes in the gastrointestinal tract and farm environments. Some of these commensal bacteria in the animal body are serious human pathogens (e.g., E. coli 0157:H7). Staphylococcus aureus is one of the pathogens with a known ability to develop antimicrobial resistance and established S. aureus infections are persistent and difficult to clear. The failure to control these infections leads to the presence of reservoirs in the dairy herd, which ultimately leads to the spread of the infection and the culling of the chronically infected cows [46, 47].

Monitoring antimicrobial resistance patterns of bacterial isolates from cases of mastitis is important for treatment decisions and proper design of mitigation measures. It also helps to determine emergence, persistence, and potential risk of the spread of antimicrobial-resistant bacteria and resistome to human, animal, and environment [48, 49]. The prudent use of antimicrobials in dairy farms reduce emergence, persistence, and spread of antimicrobial-resistant bacteria and resistome from dairy farms to human, animal, and environment.

1.2 Transmission of antimicrobial-resistant bacteria from dairy farms to human

Most studies showed that there is no widespread, emerging resistance among mastitis pathogens [2, 3, 4] in dairy farms. However, dairy farms may serve as a source of antimicrobial-resistant human pathogenic bacteria. Extensive use of third-generation cephalosporins (3GCs) in dairy cattle for the prevention and treatment of mastitis [3, 25, 28] and other diseases of dairy cattle [31, 32] can result in the carriage of extended-spectrum beta-lactamase producing Enterobacteriaceae (ESBL Ent) [50, 51]. Third- and fourth-generation cephalosporins are commonly used for the treatment of invasive Gram-negative bacterial infections in humans [52, 53, 54]. In 2017, there were an estimated 197,400 cases of ESBL Ent among hospitalized patients and 9100 estimated deaths in the US alone [55]. Among Enterobacteriaceae, Escherichia coli (E. coli) is the most common bacteria that reside in the gut as normal microflora or opportunist pathogen of animals and humans. However, certain pathogenic strains can cause diseases such as mastitis in cattle, neonatal calf diarrhea in calves and hemorrhagic enteritis, and more life-threatening conditions such as hemolytic uremic syndrome and urinary tract infections in humans. New strains of multi-drug resistant foodborne pathogens that produce extended-spectrum beta-lactamases that inactivate nearly all beta-lactam antibiotics have been reported [30]. Ceftiofur is the most common 3GC used in dairy cattle operations [56]. The 3GCs are also critically important antibiotics for the treatment of serious infections caused by Enterobacteriaceae such as Escherichia coli (E. coli) and Salmonella spp. in humans [57, 58]. The use of structurally and chemically similar antibiotics in dairy cattle production and human medicine may lead to co-resistance or cross-resistance [52, 53, 54]. Some of the species of Gram-negative environmental mastitis pathogens, such as E. coli, Klebsiella pneumoniae, Acinetobacter spp., Pseudomonas spp., Enterobacter spp. are the greatest threat to human health due to the emergence of strains that are resistant to all or most available antimicrobials [59, 60].

The resistance of Enterobacteriaceae to 3GC is mainly mediated by the production of extended-spectrum beta-lactamase enzymes (ESBLs) that breakdown 3GC [61]. E. coli is one of the most frequently isolated Enterobacteriaceae carrying ESBL genes (blaCTX-M, blaSHV, blaTEM, and blaOXA ) families [62, 63, 64]. These ESBL genes are usually carried on mobile plasmids along with other resistance genes such as tetracycline, quinolones, and aminoglycosides. E. coli resides in the gastrointestinal tract of cattle as normal or opportunistic microflora, but some strains (for e.g., 0157:H7) cause serious infection in humans [58], indicating that cattle could serve as a reservoir of ESBLs producing E. coli (ESBLs E. coli) for human.

In the US, the occurrence of ESBLs E. coli in the dairy cattle was reported a decade ago from Ohio [52] and few previous studies reported the occurrence and an increase in the trend of ESBLs E. coli in the dairy cattle production system [52, 53, 65, 66, 67]. However, recent studies increasingly showed the rise of ESBLs E. coli in the cattle [51, 52, 65, 67]. Similarly, reports from the Center for Disease Control (CDC) showed a continuous increase in the number of community-associated human infections caused by ESBLs-producing Enterobacteriaceae [55]. This CDC report showed a 9% average annual increase in the number of hospitalized patients from ESBLs pathogens in six consecutive years (from 2012 to 2017). As a result, the human health sector tends to blame dairy farms that routinely use the 3GC for the rise of ESBLs pathogens such as E. coli [55, 68]. However, despite the general believe of possibility of transmission of antimicrobial-resistant bacteria from dairy farms to humans directly through contact or indirectly through food chain, there was no clear evidence-based data that showed the spread of antimicrobial-resistant bacteria from the dairy production system to humans. The opinion of the scientific community on the factors that drive the emergence and spread of antimicrobial-resistant bacteria also varies [69]. Transmission of an antimicrobial-resistant pathogen to humans could occur if contaminated unpasteurized milk and/or undercooked meat from culled dairy cows due to chronic mastitis is consumed [70]. So it is crucial to pasteurize milk or cook meat properly to reduce the risk of infection by antimicrobial-resistant bacteria [71]. It is not known, if pasteurization or proper cooking prevents the transfer of resistant genes from milk or meat to commensal or opportunistic bacteria in the human gastrointestinal tract (GIT), or the GIT of calves fed pasteurized waste milk. Mechanisms of antibiotic resistance gene transfer from resistant to susceptible bacteria are not well known, and killing resistant pathogens alone may not be good enough to prevent the transfer of the resistance gene. Non-prudent use of antimicrobials in dairy farms increases selection pressure, which could result in the emergence, persistence, and horizontal transfer of antimicrobial-resistant determinants from resistant to non-resistant bacteria. Bacteria exchange resistance genes through mobile genetic elements such as plasmids, bacteriophages, pathogenicity islands, and these genes may ultimately enter bacteria pathogenic to humans or commensal or opportunistic bacterial pathogens. The prudent use of antimicrobials in dairy farms requires identification of the pathogen causing mastitis, determining the susceptibility/resistance of the pathogen, and proper dose, duration, and frequency of treatment to ensure effective concentrations of the antibiotic to eliminate the pathogen.


2. Prospects for effective vaccines against major bacterial mastitis pathogens

Despite decades of research to develop effective vaccines against major bacterial bovine mastitis pathogens such as Staphylococcus aureus, Streptococcus uberis, and E. coli, the effective intramammary immune mechanism is still poorly understood, perpetuating reliance on antibiotic therapies to control mastitis in dairy cows. Dependence on antimicrobials is not sustainable because of their limited efficacy [46, 47] and increased risk of emergence of antimicrobial-resistant bacteria that pose serious public health threats [4, 72, 73, 74]. Neither of the two currently available commercial Bacterin vaccines against S. aureus (Table 1), Lysigin® (Boehringer Ingelheim Vetmedica, Inc., St. Joseph, MO) in the USA and Startvac® (Hipra, Girona, Spain) in Europe and other countries, confer protection from new intramammary infection under field trials as well as under controlled experimental challenge studies [75, 76, 77, 78, 79, 80, 81].

Mastitis Pathogen Vaccine Vaccine component Protective effect Reference
S. aureus Lysigin® Bacterin: Somatic antigen containing phage types I, II, III, IV with different strains of S. aureus Reduced SCC, clinical mastitis, and chronic IMI [85, 86, 87]
Field-based studies concluded no such effect [80, 81, 88, 89, 90]
Startvac® Bacterin: E. coli J5 and S. aureus CP type 8 with SAAC Decreased duration of IMI, transmissibility of S. aureus, coliforms, and CNS [77]
Use of the vaccine was not associated with a decrease in mastitis [75]
Bestvac® Vs Startvac herd-specific autologous vaccine compared with Startvac® Both vaccines decreased herd prevalence of S. aureus mastitis but no other differences in terms of improvement of udder health [78]
Whole-cell lysate Bacterin encapsulated in biodegradable microspheres Induced antibodies that were more opsonic for neutrophils and inhibited adhesion to mammary epithelium. [91]
Whole-cell lysate from two strains Bacterin from two strains (α and α + β hemolytic) plus supernatants from non-hemolytic strain Vaccinated cows had 70% protection from infection compared to less than 10% protection in control cows [92]
MASTIVAC I Whole-cell lysate Improved udder health in addition to specific protection against S. aureus infection [93]
Live pathogenic S. aureus through IM route Live pathogenic S. aureus Induce activation of immune cells in mammary gland and blood [94]
Fibronectin binding protein and clumping factor A DNA primed and protein boosted Induced cellular and humoral immune responses that provide partial protection against S. aureus [95]
Protein A of S. aureus with the green fluorescent protein DNA Induced humoral and cellular immune responses [96]
Plasmid encoding bacterial antigen β-gal DNA Induced humoral and cellular immune responses [97]
Polyvalent S. aureus Bacterin Bacterin Eliminated some cases of chronic intramammary S. aureus infections [88]
Lysigin® with three-isolates based experimental Bacterin Bacterin Lysigin reduced the clinical severity and duration of clinical disease. None of the experimental Bacterins has significant effects [80]
Polyvalent S. aureus Bacterin Bacterin + antibiotic therapy S. aureus intramammary infection cure rate increased [89]
Whole-cell lysate Whole-cell trivalent vaccine containing CP types 5, 8 and 336 with FIA or Alum adjuvants Elicited antibody responses specific to the 3 capsular polysaccharides [98]
CP conjugated to a protein and incorporated in polymicrospheres and emulsified in FIA CP types 5, 8 and 336 Cows in both groups produced increased concentrations of IgG1, IgG2 antibodies, hyperimmune sera from immunized cows increased phagocytosis, decreased bacterial adherence to epithelial cells [99]
Polysaccharide-protein conjugates in FIA Polysaccharide-protein conjugate
SASP or SCSP Surface proteins Induced partial protection [100]
Vaccination with Efb and LukM Induced increased titers in serum and milk [101]
Inactivated Bacterin Bacterin Partial protection [102]
S. uberis Commercial
UBAC® Extract from biofilm-forming strains of S. uberis Reduce clinical signs, bacterial count, temperature, daily milk yield losses and increased the number of quarters with isolation and somatic cell count <200,000 cells/mL of milk [84]
Killed S. uberis cells Bacterin Reduced numbers of homologous S. uberis in milk [103]
Killed bacterial cells Bacterin of S. uberis and S. agalactiae Parenteral vaccination has no effect on streptococcal mastitis [104, 105]
Live S. uberis/ cutaneous route Live S. uberis Some protective effect only on the homologous strain [106]
GapC or chimeric CAMP factor Protein Reduction in inflammation [107]
PauA protein Partial protection [108]
Coliform Commercial
E. coli J5
J Vac®
Endovac-bovi® (IMMVAC)
Bacterin Reduce bacterial counts in milk, duration of IMI and resulted in fewer clinical symptoms [82, 83, 109, 110, 111]

Table 1.

Commercialized and experimental vaccines against major bovine mastitis pathogens.

SAAC: slime associated antigenic complex, SASP: Staphylococcus aureus surface proteins, SCSP: Staphylococcus chromogenes surface proteins, CP: Capsular polysaccharide, GapC: Glyceraldehyde-3-phosphate dehydrogenase C, pauA: plasminogen activator protein, FIA: Freund’s incomplete adjuvant, Efb: fibrinogen-binding protein, LukM: leukocidin subunit M.

There are four commercial vaccines against E. coli mastitis which include 1) the Eviracor®J5 (Zoetis, Kalamazoo, MI), [82, 83], 2) Mastiguard®, 3) J-VAC® (Merial-Boehringer Ingelheim vet medical, Inc., Duluth, GA) and 4) ENDOVAC-Bovi® (IMMVAC) (Endovac Animal Health, Columbia, MO) (Table 1). The Endovac-bovi® is a cross-protective vaccine made of genetically engineered R/17 mutant strain of Salmonella typhimurium and the core somatic antigen mutant J-5 strain of E. coli combined with an immune-potentiating adjuvant (IMMUNEPlus®). Endovac-bovi significantly reduces diseases caused by Gram-negative bacteria producing various endotoxins and protects against E. coli mastitis and other endotoxin-mediated diseases caused by E. coli, Salmonella, Pasteurella multocida, and Mannheimia hemolytica. The UBAC® (Hipra, Amir, Spain) [84] is a recently developed vaccine against S. uberis mastitis with label claim of partial reduction in clinical severity of S. uberis mastitis.

2.1 Intramammary immune mechanisms

Intramammary immunity can be induced locally in the mammary gland or systemically in the body and cross from the body into the mammary glands. Mammary gland pathogen that enters through teat opening interact with host innate defense system primarily with macrophages in the mammary gland. Macrophages recognize invading pathogens through its pattern recognition receptors (PRR) which binds to pathogen associated molecular patterns (PAMPs) and engulf and break down the foreign pathogen into small peptides and load on to MHC-II molecules move to the supramammary lymph nodes and display on its surface to the T cells. Naïve T cells bind with peptide on MHC-II molecule through its T- cell receptor and become activated and start secreting cytokines, which further stimulate B-cells to produce antibodies. Antibody produced by B-cells released into the blood circulation and depending on type of antibody may be released to the site of infection (e.g., IgG) and opsonize the infecting pathogen and subject them to destruction by opsonophagocytic mechanisms. Antibodies may also remain on mucosal surfaces (e.g., IgA) and bind to invading pathogens and prevent them from binding to host cells or tissue and thereby prevent colonization and infection.

Intramammary infection (IMI) leads to increased somatic cell count in the milk or mammary secretion. Somatic cells are mainly white blood cells such as granulocytes (neutrophils, eosinophils, and basophils), monocytes or macrophages, and lymphocytes, which are recruited to the mammary glands in response to mammary gland infection to fight off infection. A small proportion of mammary epithelial cells that produce milk are also shed through milk and are included in the somatic cell count. So, somatic cells are white blood cells and mammary epithelial cells. Milk somatic cell count (SCC) increases when there is mammary gland infection (IMI) because of an inflammatory response to clear infection. In general, SCC is also an indicator of milk quality [112, 113, 114, 115, 116] because if there are few mammary pathogenic bacteria in the gland, the inflammatory response is less, and somatic cells recruitment into the gland is also low and vice versa. Bulk tank milk (BTM) is milk collected from all lactating dairy cows in a farm into a tank or multiple tanks. So BTSCC is somatic cell counts obtained from milk sample collected from a tank.

Intramammary infection may progress to clinical or subclinical mastitis [117]. Clinically infected udder usually treated with antimicrobial, whereas subclinically infected udder may not be diagnosed immediately and treated but remained infected and shedding bacteria through milk throughout lactation. The proportion of cure following treatment of mastitis varies and the variation in cure rate is multi-factorial including cow factors (age or parity number, stage of lactation, and duration of infection, etc.), management factors (detection and diagnosis of infection and time from detection to treatment, availability of balanced nutrition, sanitation, etc.), factors related to antimicrobial use patterns (type, dose, route, frequency, and duration), and pathogen factors (type, species, number, pathogenicity or virulence, resistance to antimicrobial, etc.) [46, 118].

The dilution of effector humoral immune responses by large volume of milk coupled with the ability of mastitis causing bacteria to develop resistance to antimicrobials makes the control of mastitis very difficult. Therefore, the development of an alternative preventive tool such as a vaccine, which can overcome these limitations, has been a crucial focus of current research to decrease not only the incidence of mastitis but also the use of antimicrobials in dairy cattle farms. Most vaccination strategies against mastitis have focused on the enhancement of humoral immunity. Development of vaccines that induce an effective cellular immune response in the mammary gland has not been well investigated. The ability to induce cellular immunity, especially neutrophil activation and recruitment into the mammary gland, is one of the key strategies in the control of mastitis, but the magnitude and duration of increased cellular recruitment into the mammary gland leads to a high number of somatic cells and poor-quality milk. So, effective balanced humoral and cellular immunity that clear intramammary infection in a short period of time is required. Several vaccine studies were conducted over the years under controlled experimental and field trials. The major bacterial bovine mastitis pathogens that have been targeted for vaccine development are S. aureus, S. uberis, and E. coli [119]. Most of these experimental and some commercial vaccines are Bacterins which are inactivated whole organism, and some vaccines contained subunits of the organism such as surface proteins [100], toxins, or polysaccharides.

2.2 Vaccine trials against Staphylococcus aureus mastitis

Staphylococcus aureus is one of the most common contagious mastitis pathogens, with an estimated incidence rate ranging from 43–74% [25, 38, 56, 120, 121]. Staphylococcus chromogenes is another increasingly reported coagulase-negative Staphylococcus species with an estimated quarter incidence rate of 42.7% characterized by high somatic cell counts [122, 123, 124, 125, 126, 127, 128]. In a study on conventional and organic Canadian dairy farms, coagulase-negative Staphylococcus species were found in 20% of the clinical samples [129]. Recently, mastitis caused by coagulase-negative Staphylococcus species increasingly became more problematic in dairy herds [125, 127, 130, 131].

Several staphylococcal vaccine efficacy trials showed that vaccination with Bacterin vaccines induced increased antibody titers in the serum and milk that are associated with partial protection [75, 76, 77, 80, 132, 133, 134] or no protection at all [78, 79, 81]. However, effective intramammary immune mechanisms against staphylococcal mastitis is still poorly understood. None of the commercially available Bacterin vaccines protects new intramammary infection [75, 77, 80, 81]. Dependence on antibiotics for the prevention and treatment of mastitis is not sustainable because of limited success [46, 47] and the emergence of antimicrobial-resistant bacteria that are major threat to human and animal health [72, 73, 74].

Despite several mastitis vaccine trials conducted against S. aureus mastitis [7577, 80, 88, 89, 91, 93, 94, 95, 97, 98, 99, 133] all field trials have either been unsuccessful or had limited success. There are two commercial vaccines for Staphylococcus aureus mastitis on the market, Lysigin® (Boehringer Ingelheim Vetmedica, Inc., St. Joseph, MO) in the United States and Startvac® (Hipra S.A, Girona, Spain) in Europe and Canada [78]. None of these vaccines confer protection under field trials as well as under controlled experimental studies [75, 77, 80, 81]. Several field trials and controlled experimental studies have been conducted testing the efficacy of Lysigin® and Startvac®, and results from those studies have shown some interesting results, namely a reduced incidence, severity, and duration of mastitis in vaccinated cows compared to non-vaccinated control cows [75, 76, 77]. Contrary to these observations, other studies failed to find an effect on improving udder health or showed no difference between vaccinated and non-vaccinated control cows [7879]. None of these Bacterin-based vaccines prevents new S. aureus IMI [75, 77, 80, 81]. Differences found in these studies are mainly due to methodological differences (vaccination schedule, route of vaccination, challenge model, herd size, time of lactation, etc.) in testing the efficacy of these vaccines. It is critically important to have a good infection model that mimics natural infection and a model that has 100% efficacy in causing infection. Without a good challenge model, the results from vaccine efficacy will be inaccurate.

The Startvac® (Hipra, Girona, Spain) is the commercially available vaccine in Europe and is a polyvalent vaccine that contains E. coli J5 and S. aureus strain SP140 [119]. In a field trial, Freick et al. [78] compared the efficacy of Startvac® with Bestvac® (IDT, Dessau-Rosslau, Germany) another herd-specific autologous commercial vaccine in a dairy herd with a high prevalence of S. aureus and found that the herd prevalence of S. aureus mastitis was lower in the Startvac® and Bestvac® vaccinated cows compared to the control cows. However, there were no other differences in terms of improvement of udder health. These authors [78] concluded that vaccination with Startvac® and Bestvac® did not improve udder health. In another field efficacy study on Startvac® in the UK, Bradley et al. [75] found that Startvac® vaccinated cows had clinical mastitis with reduced severity and higher milk production compared to non-vaccinated control cows [75].

Similarly, Schukken et al. [77] evaluated effect of Startvac® on the development of new IMI and the duration of infections caused by S. aureus and CNS. These authors [77] found that vaccinated cows had decreased incidence rate and a shorter duration of S. aureus and CNS mastitis. Piepers et al. [76], also tested the efficacy of Startvac® through vaccination and subsequent challenge with a heterologous killed S. aureus strain and found that the inflammatory response in the vaccinated cows was less severe compared to the control cows. These authors [76] suggested that Startvac® elicited a strong Th2 immune response against S. aureus in vaccinated cows and was more effective at clearing bacteria compared to the control cows. Contrary to these observations, Landin et al. [135], evaluated the effects of Startvac® on milk production, udder health, and survival on two Swedish dairy herds with S. aureus mastitis problems and found no significant differences between the Startvac® vaccinated and non-vaccinated control cows on the health parameters they evaluated.

An experimental S. aureus vaccine made up of a combination of plasmids encoding fibronectin-binding motifs of fibronectin-binding protein (FnBP) and clumping factor A (ClfA), and plasmid encoding bovine granulocyte-macrophage-colony stimulatory factor, was used as a vaccine with a subsequent challenge with bacteria to test its protective effects [95]. These authors (Shkreta et al. 2004) found that their experimental vaccine-induced immune responses in the heifers that were partially protective upon experimental challenge [95]. Another controlled experimental vaccine efficacy study was conducted on the slime associated antigenic complex (SAAC) which is an extracellular component of Staphylococcus aureus, as vaccine antigen in which one group of cows were vaccinated with a vaccine containing a low amount of SAAC and another group with a high amount of SAAC and the unvaccinated group served as a control [136]. Upon intramammary infusion (challenge) with S. aureus, no difference in the occurrence of mastitis among all three groups despite the fact that the vaccine with high SAAC content induced higher production of antibodies compared to the vaccine with a low amount of SAAC [136]. Similarly, Pellegrino et al. [137], vaccinated dairy cows with an avirulent mutant strain of S. aureus and subsequently challenged with S. aureus 20 days after the second vaccination which resulted in no significant differences in the number of somatic cell count (SCC) or number of bacteria shedding through milk despite increased IgG antibody titer in the vaccinated cows compared to the control cows.

Some of the constraints affecting the successful development of effective mastitis vaccines are strain variation, the presence of exopolysaccharide (capsule, slime, biofilm) layer in most pathogenic strains of bacteria (Staph. aureus, Strep. uberis) which does not allow recognition of antibody-coated bacteria by phagocytic cells, dilution of immune effectors by milk [138, 139], the interaction between milk components and immune effectors [140] that reduce their effectiveness, and the ability of most mastitis-causing bacteria to attach and internalize into mammary epithelial cells. Furthermore, evaluation of mastitis vaccines is complicated by the absence of uniform challenge study models, and lack of uniform route(s) of vaccination, time of vaccination, adjuvants, and challenge dose. There is an increasing need for development of better vaccines that overcome these problems. Most mastitis vaccines are killed whole bacterial cells (Bacterin) vaccines [75, 77, 80, 88, 89, 91, 92, 93, 94, 95, 97, 98, 99] that are difficult to improve because of difficulty to specifically identify an immunogenic component that induced partial or some protective effect. In this regard, some of the current efforts to use a mixture of purified surface proteins as vaccine antigens [100] to induce immunity than killed whole bacterial cells (Bacterin) is encouraging. A better understanding of natural and acquired immunological defenses of the mammary gland coupled with detailed knowledge of the pathogenesis of each mammary pathogen should lead to the development of improved methods of reducing the incidence of mastitis in dairy cows.

2.3 Vaccine trials against Streptococcus uberis

S. uberis is ubiquitous in the cow’s environment accounting for a significant number of mastitis cases. It is found on-farm in water, soil, plant material, bedding, flies, hay, and feces [141]. As such, S. uberis is remarkably adaptable, affecting lactating and dry cows, heifers, and multiparous cows, causing clinical or subclinical mastitis, and even being responsible for persistent colonization without an elevation in the somatic cell count [142, 143]. It has been described as an environmental pathogen [108, 144, 145, 146] with potential as a contagious pathogen [142, 143, 147]. S. uberis has ability to persist within the mammary gland which lead to chronic mastitis that is difficult to treat [148]. Coliform bacteria are a major cause of clinical mastitis [149, 150]. A vaccine that prevents S. uberis mastitis is not available, control measures are limited to the implementation of good management practices. Recently vaccine efficacy trial with extract of biofilm-forming strains of S. uberis (UBAC®) (Hipra, Amir, Spain), was reported to reduce clinical severity [84]. It is not clear what kind of adative immunity is induced by UBAC® S. uberis vaccine [84] and it only conferred partial reduction in clinical severity of mastitis. Multiple intramammary vaccinations of dairy cows with killed S. uberis cells resulted in the complete protection from experimental infection with the homologous strain [103]. Similarly, subcutaneous vaccination of dairy cows with live S. uberis followed by intramammary booster vaccination with S. uberis cell surface extract protected against challenge with the homologous strain but was less effective against a heterologous strain [106]. Vaccination with S. uberis glyceraldehyde phosphate dehydrogenase C (GapC) protein induced immune responses that confer a significant reduction in inflammation post-challenge [107, 151]. The pauA is a plasminogen activator and also binds active protease plasmin [152]. It has been postulated that acquisition of plasmin may promote invasion [153]. Vaccination of dairy cows with PauA induced increased antibody titers that conferred reduction in clinical severity [154]. However, mutation of pauA did not alter ability to grow in milk or to infect lactating bovine mammary glands. It appears that the ability to activate plasminogen through PauA does not play a major role in pathogenesis of S. uberis to either grow in milk or infect bovine mammary gland [155].

S. uberis expresses several surface associated proteins such as S. uberis adhesion molecule (SUAM) and extracellular matrix binding proteins, which allow it to adhere to and internalize into mammary epithelial cells, successfully inducing IMI [156, 157, 158]. The S. uberis adhesion molecule (SUAM) plays a central role in the adherence of S. uberis to mammary epithelial cells [159, 160, 161, 162]. Vaccination of dairy cows with SUAM induced strong immune resposes in vaccinated cows [163]. The immune serum from SUAM vaccinated cows prevented S. uberis adhesion and invasion into mammary epithelial cells in vitro [163]. In vivo infusion of mammary quarters of dairy cows with S. uberis pre-incubated with immune-serum from SUAM vaccinated cows reduced clinical severity [164]. The SUAM gene deletion mutant strain is less pathogenic to mammary epithelial cells [165] and to dairy cows [159]. Controlled experimental efficacy studies using SUAM as vaccine antigen to control S. uberis mastitis showed that SUAM is immunogenic but the induced immunity was not protective. Following experimental IMI challenge with S. uberis, clinical signs emerged at about 48 h, along with increased levels of inflammatory cytokines including TNF-α, IL-1β, IL-6, and IL-8 in milk at 60 h post-infection [166]. Adaptive immune response cytokines such as IFN-γ promotes a cell-mediated immune response by enhancing functions such as macrophage bacterial killing, antigen presentation, cytotoxic T cell activation, and increased IgG2 levels. The IL-4 expression is associated with the antibody-mediated response, which is generally linked to parasite resistance, allergic reactions, and increased levels of IgG1 [167, 168]. This partial protection by the SUSP vaccine can be improved with dose optimization, appropriate adjuvant, route of injection, and timing of vaccination.

In conclusion, it is clear that Bacterin vaccines have some protective effect against homologous strains, and single surface protein is not effective. Therefore; use of multiple surface proteins may induce better immunity that prevents clinical disease and production losses.

2.4 Vaccine trials against E. coli mastitis

Coliform bacteria are a major cause of clinical mastitis [149, 150]. Coliforms include the genera Escherichia, Klebsiella, and Enterobacter [169]. Eighty to ninety percent of coliform intramammary infection (IMI) develop clinical mastitis, and 10% will be severe and could lead to death [150]. E. coli usually infects the mammary glands during the dry period and progresses to inflammation and clinical mastitis during the early lactation with local and sometimes severe systemic clinical manifestations.

Iron is an essential nutrient for the growth of coliforms [170]. However, free iron is limited in the bovine milk because most iron is bound to citrate and to a lesser extent to lactoferrin, transferrin, xanthine oxidase, and some caseins [171] and maintained at concentrations below levels required to support coliform growth [172]. To overcome this limited iron source, coliforms express multiple iron transport systems [173], which include synthesis of siderophores (e.g., enterobactin, aerobactin, ferrichrome) that bind iron with high affinity [174], the expression of iron-regulated outer membrane proteins (IROMP) that binds to ferric siderophore complexes to transport into bacterial cell and enzymes to utlize the chelated iron [173]. The siderophores are too large (600 to 1200 Da) to pass through the porin channels of the bacterial outer membrane [175, 176]. Therefore, the siderophores require specific IROMP to enable their passage across the bacterial outer membrane into the periplasm [177, 178]. The enterobactin is a siderophore with the highest affinity for iron, and it is produced by most pathogenic E. coli and Klebsiella spp. [179, 180, 181]. The aerobactin is another siderophore that was detected in only 12% of E. coli isolated from mastitis cases [182]. Enterobactin is the primary siderophore of Escherichia coli and many other Gram-negative bacteria [183]. Coliform bacteria also developed the ability to take up iron directly from naturally occurring organic iron-binding acids, including citrate [173, 184]. The citrate iron uptake system requires ferric dicitrate for induction [184]. More than 0.1 mM citrate is required for the induction of this system under iron-restricted conditions [184]. The ferric citrate transport system is the major iron acquisition system utilized by E. coli [173] to grow in the mammary gland. The mammary gland is an iron-restricted environment, and bovine milk contains approximately 7 mM citrate [185] which is ideal for induction of ferric citrate transport sytem.

Ferric enterobactin receptor, FepA, is an 81 kDa iron regulated outer membrane protein (IROMP), that binds to ferric enterobactin complex to transoport iron into the bacterial cell [186, 187]. Vaccination of dairy cows with FepA elicited an increased immunological response in serum and milk [188]. Bovine IgG directed against FepA inhibited the growth of coliform bacteria by interfering with the binding of the ferric enterobactin complex [189]. Ferric citrate receptor, FecA, is an 80.5-kDa IROMP that is responsible for the binding of ferric dicitrate [190] and transport into the bacterial cell. The FecA, is conserved among coliforms isolated from cases of naturally occurring mastitis [191]. The iron-regulated outer membrane proteins, FepA and FecA are ideal vaccine candidates because they are surface exposed, antigenic, and conserved among isolates from IMI.

Immunization of dairy cows with FepA induced significantly higher serum and whey anti-FepA IgG titers than in E. coli J5 vaccinates [188]. Results of in vitro growth inhibition studies demonstrated that antibody specific for blocking ferric enterobactin-binding site (anti-FepA) inhibited the growth of E. coli in vitro [192]. Cows immunized with FecA did have increased antibody titers in serum and mammary secretions compared with E. coli J5 immunization and unimmunized control cows [193, 194]. Antibody purified from colostrum inhibited the growth of E. coli when cultured in synthetic media modified to induce FecA expression [193]. Despite their antigenicity, the use of either FepA or FecA alone were not sufficient to prevent mastitis. The FecA and FepA are antigenically distinct [191].

Intramammary infection with E. coli induced expression and release of pro-inflammatory cytokines such as TNF-alpha, IL-8, IL-6, and IL-1 [195, 196]. Recently it has been shown with mouse mastitis models that IL-17A and Th17 cells are instrumental in the defense against E. coli IMI [197, 198]. However, the role of IL-17 in bovine E. coli mastitis is not well defined. Results of a recent vaccine efficacy study against E. coli mastitis suggested that cell-mediated immune response has more protective effect than humoral response [199]. The cytokine signaling pathways that lead to efficient bacterial clearance is not clearly defined.

The four coliform vaccines which include 1) J-5 Bacterin® (Zoetis, Kalamazoo, MI) [82, 83], 2) Mastiguard®, 3) J Vac® (Merial-Boehringer Ingelheim vet medical, Inc., Duluth, GA) and 4) Endovac-bovi® (IMMVAC) (Endovac Animal Health, Columbia, MO). Of the four coliform vaccines, J-5 Bacterin® and Mastiguard® are believed to have the same component, which is J5 Bacterin. The J Vac® is a different bacterin-toxoid. The Endovac-Bovi® contains mutant Salmonella typhimurium bacterin toxoid. All coliform mastitis vaccine formulations use gram-negative core antigens to produce non-specific immunity directed against endotoxin (LPS) [119]. The efficacy of these vaccines has been demonstrated in both experimental challenge trials and field trials in commercial dairy herds [109, 110, 111]. The principle of these bacterins is based upon their ability to stimulate the production of antibodies directed against common core antigens that gram-negative bacteria share. These vaccines are considered efficacious even though the rate of intramammary infection is not significantly reduced in vaccinated animals because they significantly reduce the clinical effects of the infection. Experimental challenge studies have demonstrated that J5 vaccines are able to reduce bacterial counts in milk and result in fewer clinical symptoms [109]. Vaccinated cows may become infected with gram-negative mastitis pathogens at the same rate as control animals but have a lower rate of development of clinical mastitis [111], reduced the duration of IMI [110], reduced production, culling, and death losses [200, 201].

There is an increasing need for the development of effective vaccines against major bacterial bovine mastitis pathogens. A better understanding of the natural and acquired immunological defenses of the mammary gland coupled with detailed knowledge of the pathogenesis of each mammary pathogen should lead to the development of improved methods of reducing the incidence of mastitis in dairy cows (Table 1).


  1. 1. DeGraves FJ, Fetrow J. 1993. Economics of mastitis and mastitis control. The Veterinary Clinics of North America Food Animal Practice 9:421-434.
  2. 2. Erskine RJ, Cullor J, Schaellibaum M. Bovine mastitis pathogens and trends in resistance to antibacterial drugs, p. In (ed),
  3. 3. Oliver SP, Murinda SE, Jayarao BM. 2011. Impact of antibiotic use in adult dairy cows on antimicrobial resistance of veterinary and human pathogens: a comprehensive review. Foodborne Pathog Dis 8:337-55.
  4. 4. Abdi RD, Gillespie BE, Vaughn J, Merrill C, Headrick SI, Ensermu DB, D’Souza DH, Agga GE, Almeida RA, Oliver SP, Kerro Dego O. 2018. Antimicrobial Resistance of Staphylococcus aureus Isolates from Dairy Cows and Genetic Diversity of Resistant Isolates. Foodborne Pathog Dis 15:449-458.
  5. 5. Erskine RJ, Walker RD, Bolin CA, Bartlett PC, White DG. 2002. Trends in antibacterial susceptibility of mastitis pathogens during a seven-year period. J Dairy Sci 85:1111-8.
  6. 6. Kalmus P, Aasmae B, Karssin A, Orro T, Kask K. 2011. Udder pathogens and their resistance to antimicrobial agents in dairy cows in Estonia. Acta Vet Scand 53:4.
  7. 7. Mathew AG, Cissell R, Liamthong S. 2007. Antibiotic resistance in bacteria associated with food animals: a United States perspective of livestock production. Foodborne Pathog Dis 4:115-33.
  8. 8. Myllys V, Asplund K, Brofeldt E, Hirvela-Koski V, Honkanen-Buzalski T, Junttila J, Kulkas L, Myllykangas O, Niskanen M, Saloniemi H, Sandholm M, Saranpaa T. 1998. Bovine mastitis in Finland in 1988 and 1995--changes in prevalence and antimicrobial resistance. Acta Vet Scand 39:119-26.
  9. 9. Saini V, McClure JT, Leger D, Keefe GP, Scholl DT, Morck DW, Barkema HW. 2012. Antimicrobial resistance profiles of common mastitis pathogens on Canadian dairy farms. J Dairy Sci 95:4319-32.
  10. 10. Bradley AJ, Green MJ. 2004. The importance of the nonlactating period in the epidemiology of intramammary infection and strategies for prevention. Vet Clin North Am Food Anim Pract 20:547-68.
  11. 11. Drackley JK. 1999. ADSA Foundation Scholar Award. Biology of dairy cows during the transition period: the final frontier? J Dairy Sci 82:2259-73.
  12. 12. Esposito G, Irons PC, Webb EC, Chapwanya A. 2014. Interactions between negative energy balance, metabolic diseases, uterine health and immune response in transition dairy cows. Animal Reproduction Science 144:60-71.
  13. 13. Barkema HW, Schukken YH, Lam TJ, Beiboer ML, Wilmink H, Benedictus G, Brand A. 1998. Incidence of clinical mastitis in dairy herds grouped in three categories by bulk milk somatic cell counts. J Dairy Sci 81:411-9.
  14. 14. Pinedo PJ, Fleming C, Risco CA. 2012. Events occurring during the previous lactation, the dry period, and peripartum as risk factors for early lactation mastitis in cows receiving 2 different intramammary dry cow therapies. J Dairy Sci 95:7015-26.
  15. 15. Gibson H, Sinclair LA, Brizuela CM, Worton HL, Protheroe RG. 2008. Effectiveness of selected premilking teat-cleaning regimes in reducing teat microbial load on commercial dairy farms. Lett Appl Microbiol 46:295-300.
  16. 16. Gleeson D, O’Brien B, Flynn J, O’Callaghan E, Galli F. 2009. Effect of pre-milking teat preparation procedures on the microbial count on teats prior to cluster application. Ir Vet J 62:461-7.
  17. 17. Dufour S, Frechette A, Barkema HW, Mussell A, Scholl DT. 2011. Invited review: effect of udder health management practices on herd somatic cell count. J Dairy Sci 94:563-79.
  18. 18. Timonen AAE, Katholm J, Petersen A, Orro T, Motus K, Kalmus P. 2018. Elimination of selected mastitis pathogens during the dry period. J Dairy Sci 101:9332-9338.
  19. 19. Mordak R, Stewart PA. 2015. Periparturient stress and immune suppression as a potential cause of retained placenta in highly productive dairy cows: examples of prevention. Acta Vet Scand 57:84.
  20. 20. Bach A. 2011. Associations between several aspects of heifer development and dairy cow survivability to second lactation. J Dairy Sci 94:1052-7.
  21. 21. Wang B, McKittrick O, Meyers MA. 2016. Keratin: Structure, mechanical properties,occurrence in biological organisms, and effortsat bioinspiration. Progress in Materials Science 76:229-318.
  22. 22. Bragulla HH, Homberger DG. 2009. Structure and functions of keratin proteins in simple, stratified, keratinized and cornified epithelia. J Anat 214:516-59.
  23. 23. Smolenski GA, Cursons RT, Hine BC, Wheeler TT. 2015. Keratin and S100 calcium-binding proteins are major constituents of the bovine teat canal lining. Vet Res 46:113.
  24. 24. Williamson JH, Woolford MW, Day AM. 1995. The prophylactic effect of a dry-cow antibiotic against Streptococcus uberis. N Z Vet J 43:228-34.
  25. 25. USDA APHIS U. 2008a. Antibiotic use on U.S. dairy operations, 2002 and 2007 (infosheet,5p,October,2008). 2008a. Availableat: Accessed 3/23/2020, (Online).
  26. 26. Rowe SM, Godden SM, Nydam DV, Gorden PJ, Lago A, Vasquez AK, Royster E, Timmerman J, Thomas MJ. 2020. Randomized controlled trial investigating the effect of 2 selective dry-cow therapy protocols on udder health and performance in the subsequent lactation. J Dairy Sci 103:6493-6503.
  27. 27. Kabera F, Dufour S, Keefe G, Cameron M, Roy JP. 2020. Evaluation of quarter-based selective dry cow therapy using Petrifilm on-farm milk culture: A randomized controlled trial. J Dairy Sci doi:10.3168/jds.2019-17438.
  28. 28. Redding LE, Bender J, Baker L. 2019. Quantification of antibiotic use on dairy farms in Pennsylvania. J Dairy Sci 102:1494-1507.
  29. 29. Leger DF, Newby NC, Reid-Smith R, Anderson N, Pearl DL, Lissemore KD, Kelton DF. 2017. Estimated antimicrobial dispensing frequency and preferences for lactating cow therapy by Ontario dairy veterinarians. Can Vet J 58:26-34.
  30. 30. Economou V, Gousia P. 2015. Agriculture and food animals as a source of antimicrobial-resistant bacteria. Infect Drug Resist 8:49-61.
  31. 31. Pol M, Ruegg PL. 2007. Treatment practices and quantification of antimicrobial drug usage in conventional and organic dairy farms in Wisconsin. J Dairy Sci 90:249-61.
  32. 32. Sawant AA, Sordillo LM, Jayarao BM. 2005. A survey on antibiotic usage in dairy herds in Pennsylvania. J Dairy Sci 88:2991-9.
  33. 33. Kelton DF, Lissemore KD, Martin RE. 1998. Recommendations for recording and calculating the incidence of selected clinical diseases of dairy cattle. J Dairy Sci 81:2502-9.
  34. 34. Dudek K, Bednarek D, Ayling RD, Kycko A, Reichert M. 2019. Preliminary study on the effects of enrofloxacin, flunixin meglumine and pegbovigrastim on Mycoplasma bovis pneumonia. BMC Vet Res 15:371.
  35. 35. Illambas J, Potter T, Cheng Z, Rycroft A, Fishwick J, Lees P. 2013. Pharmacodynamics of marbofloxacin for calf pneumonia pathogens. Res Vet Sci 94:675-81.
  36. 36. Illambas J, Potter T, Sidhu P, Rycroft AN, Cheng Z, Lees P. 2013. Pharmacodynamics of florfenicol for calf pneumonia pathogens. Vet Rec 172:340.
  37. 37. Constable PD. 2009. Treatment of calf diarrhea: antimicrobial and ancillary treatments. Vet Clin North Am Food Anim Pract 25:101-20, vi.
  38. 38. USDA APHIS U. 2008b. United States Department of Agriculture, Animal Plant Health Inspection Service National Animal Health Monitoring System. Highlights of Dairy 2007 Part III: reference of dairy cattle health and management practices in the United States, 2007 (Info Sheet 4p, October, 2008). 2008b. Available at Accessed 3/23/2020, (Online).
  39. 39. Baggot JD. 2006. Principles of antimicrobial drug bioavailability and disposition.
  40. 40. Baggot JD, Brown SA. 2006. Development and formation of veterinary dosage forms, 2nd edition ed. Marcel Dekker, New York.
  41. 41. Guardabassi L, Apley M, Olsen JE, Toutain PL, Weese S. 2018. Optimization of Antimicrobial Treatment to Minimize Resistance Selection. Microbiol Spectr 6.
  42. 42. Toutain PL, Raynaud JP. 1983. Pharmacokinetics of oxytetracycline in young cattle: comparison of conventional vs long-acting formulations. Am J Vet Res 44:1203-9.
  43. 43. Aust V, Knappstein K, Kunz HJ, Kaspar H, Wallmann J, Kaske M. 2013. Feeding untreated and pasteurized waste milk and bulk milk to calves: effects on calf performance, health status and antibiotic resistance of faecal bacteria. J Anim Physiol Anim Nutr (Berl) 97:1091-103.
  44. 44. Maynou G, Chester-Jones H, Bach A, Terre M. 2019. Feeding Pasteurized Waste Milk to Preweaned Dairy Calves Changes Fecal and Upper Respiratory Tract Microbiota. Front Vet Sci 6:159.
  45. 45. Maynou G, Migura-Garcia L, Chester-Jones H, Ziegler D, Bach A, Terre M. 2017. Effects of feeding pasteurized waste milk to dairy calves on phenotypes and genotypes of antimicrobial resistance in fecal Escherichia coli isolates before and after weaning. J Dairy Sci 100:7967-7979.
  46. 46. Barkema HW, Schukken YH, Zadoks RN. 2006. Invited Review: The role of cow, pathogen, and treatment regimen in the therapeutic success of bovine Staphylococcus aureus mastitis. J Dairy Sci 89:1877-95.
  47. 47. McDougall S, Parker KI, Heuer C, Compton CW. 2009. A review of prevention and control of heifer mastitis via non-antibiotic strategies. Vet Microbiol 134:177-85.
  48. 48. Durso LM, Cook KL. 2014. Impacts of antibiotic use in agriculture: what are the benefits and risks? Curr Opin Microbiol 19:37-44.
  49. 49. Normanno G, La Salandra G, Dambrosio A, Quaglia NC, Corrente M, Parisi A, Santagada G, Firinu A, Crisetti E, Celano GV. 2007. Occurrence, characterization and antimicrobial resistance of enterotoxigenic Staphylococcus aureus isolated from meat and dairy products. Int J Food Microbiol 115:290-6.
  50. 50. Wichmann F, Udikovic-Kolic N, Andrew S, Handelsman J. 2014. Diverse antibiotic resistance genes in dairy cow manure. MBio 5:e01017.
  51. 51. Agga GE, Schmidt JW, Arthur TM. 2016. Antimicrobial-Resistant Fecal Bacteria from Ceftiofur-Treated and Nonantimicrobial-Treated Comingled Beef Cows at a Cow-Calf Operation. Microb Drug Resist 22:598-608.
  52. 52. Wittum TE, Mollenkopf DF, Daniels JB, Parkinson AE, Mathews JL, Fry PR, Abley MJ, Gebreyes WA. 2010. CTX-M-type extended-spectrum beta-lactamases present in Escherichia coli from the feces of cattle in Ohio, United States. Foodborne Pathog Dis 7:1575-9.
  53. 53. Heider LC, Funk JA, Hoet AE, Meiring RW, Gebreyes WA, Wittum TE. 2009. Identification of Escherichia coli and Salmonella enterica organisms with reduced susceptibility to ceftriaxone from fecal samples of cows in dairy herds. Am J Vet Res 70:389-93.
  54. 54. Dunne EF, Fey PD, Kludt P, Reporter R, Mostashari F, Shillam P, Wicklund J, Miller C, Holland B, Stamey K, Barrett TJ, Rasheed JK, Tenover FC, Ribot EM, Angulo FJ. 2000. Emergence of domestically acquired ceftriaxone-resistant Salmonella infections associated with AmpC beta-lactamase. JAMA 284:3151-6.
  55. 55. CDC. 2019. Antibiotic Resistance Threats Report.
  56. 56. USDA APHIS U. Part III: Health Management and Bio¬security in US Feedlots, 1999. US Department of Agriculture; 2000. Available at accessed December 23, 2020 (online), p. In (ed),
  57. 57. Paterson DL, Bonomo RA. 2005. Extended-spectrum beta-lactamases: a clinical update. Clin Microbiol Rev 18:657-86.
  58. 58. Malloy AM, Campos JM. 2011. Extended-spectrum beta-lactamases: a brief clinical update. Pediatr Infect Dis J 30:1092-3.
  59. 59. Wyres KL, Holt KE. 2018. Klebsiella pneumoniae as a key trafficker of drug resistance genes from environmental to clinically important bacteria. Curr Opin Microbiol 45:131-139.
  60. 60. Wyres KL, Hawkey J, Hetland MAK, Fostervold A, Wick RR, Judd LM, Hamidian M, Howden BP, Lohr IH, Holt KE. 2019. Emergence and rapid global dissemination of CTX-M-15-associated Klebsiella pneumoniae strain ST307. J Antimicrob Chemother 74:577-581.
  61. 61. Rawat D, Nair D. 2010. Extended-spectrum beta-lactamases in Gram Negative Bacteria. J Glob Infect Dis 2:263-74.
  62. 62. Ali T, Ur Rahman S, Zhang L, Shahid M, Zhang S, Liu G, Gao J, Han B. 2016. ESBL-Producing Escherichia coli from Cows Suffering Mastitis in China Contain Clinical Class 1 Integrons with CTX-M Linked to ISCR1. Front Microbiol 7:1931.
  63. 63. Teng L, Lee S, Ginn A, Markland SM, Mir RA, DiLorenzo N, Boucher C, Prosperi M, Johnson J, Morris JG, Jr., Jeong KC. 2019. Genomic Comparison Reveals Natural Occurrence of Clinically Relevant Multidrug-Resistant Extended-Spectrum-beta-Lactamase-Producing Escherichia coli Strains. Appl Environ Microbiol 85.
  64. 64. Smet A, Martel A, Persoons D, Dewulf J, Heyndrickx M, Herman L, Haesebrouck F, Butaye P. 2010. Broad-spectrum beta-lactamases among Enterobacteriaceae of animal origin: molecular aspects, mobility and impact on public health. FEMS Microbiol Rev 34:295-316.
  65. 65. Davis MA, Sischo WM, Jones LP, Moore DA, Ahmed S, Short DM, Besser TE. 2015. Recent Emergence of Escherichia coli with Cephalosporin Resistance Conferred by blaCTX-M on Washington State Dairy Farms. Appl Environ Microbiol 81:4403-10.
  66. 66. Tragesser LA, Wittum TE, Funk JA, Winokur PL, Rajala-Schultz PJ. 2006. Association between ceftiofur use and isolation of Escherichia coli with reduced susceptibility to ceftriaxone from fecal samples of dairy cows. Am J Vet Res 67:1696-700.
  67. 67. Afema JA, Ahmed S, Besser TE, Jones LP, Sischo WM, Davis MA. 2018. Molecular Epidemiology of Dairy Cattle-Associated Escherichia coli Carrying blaCTX-M Genes in Washington State. Appl Environ Microbiol 84.
  68. 68. Thaden JT, Fowler VG, Sexton DJ, Anderson DJ. 2016. Increasing Incidence of Extended-Spectrum beta-Lactamase-Producing Escherichia coli in Community Hospitals throughout the Southeastern United States. Infect Control Hosp Epidemiol 37:49-54.
  69. 69. Turnbridge J. 2004. Antibiotic use in animals-prejudices, perceptions and realities. J Antimicrob Chemother 53:26-27.
  70. 70. Oliver SP, Boor KJ, Murphy SC, Murinda SE. 2009. Food safety hazards associated with consumption of raw milk. Foodborne Pathog Dis 6:793-806.
  71. 71. Oliver SP, Jayarao BM, Almeida RA. 2005. Foodborne pathogens in milk and the dairy farm environment: food safety and public health implications. Foodborne Pathog Dis 2:115-29.
  72. 72. Fitzgerald JR. 2012a. Human origin for livestock-associated methicillin-resistant Staphylococcus aureus. MBio 3:e00082-12.
  73. 73. Fitzgerald JR. 2012b. Livestock-associated Staphylococcus aureus: origin, evolution and public health threat. Trends Microbiol 20:192-8.
  74. 74. Holmes MA, Zadoks RN. 2011. Methicillin resistant S. aureus in human and bovine mastitis. Journal of mammary gland biology and neoplasia 16:373-382.
  75. 75. Bradley AJ, Breen J, Payne B, White V, Green MJ. 2015. An investigation of the efficacy of a polyvalent mastitis vaccine using different vaccination regimens under field conditions in the United Kingdom. Journal of dairy science 98:1706-1720.
  76. 76. Piepers S, Prenafeta A, Verbeke J, De Visscher A, March R, De Vliegher S. 2017. Immune response after an experimental intramammary challenge with killed Staphylococcus aureus in cows and heifers vaccinated and not vaccinated with Startvac, a polyvalent mastitis vaccine. J Dairy Sci 100:769-782.
  77. 77. Schukken YH, Bronzo V, Locatelli C, Pollera C, Rota N, Casula A, Testa F, Scaccabarozzi L, March R, Zalduendo D, Guix R, Moroni P. 2014. Efficacy of vaccination on Staphylococcus aureus and coagulase-negative staphylococci intramammary infection dynamics in 2 dairy herds. Journal of Dairy Science 97:5250-5264.
  78. 78. Freick M, Frank Y, Steinert K, Hamedy A, Passarge O, Sobiraj A. 2016. Mastitis vaccination using a commercial polyvalent vaccine or a herd-specific Staphylococcus aureus vaccine. Tierärztliche Praxis G: Großtiere/Nutztiere 44:219-229.
  79. 79. Landin H, Mork MJ, Larsson M, Waller KP. 2015. Vaccination against Staphylococcus aureus mastitis in two Swedish dairy herds. Acta Vet Scand 57:81.
  80. 80. Middleton JR, Ma J, Rinehart CL, Taylor VN, Luby CD, Steevens BJ. 2006. Efficacy of different Lysigin formulations in the prevention of Staphylococcus aureus intramammary infection in dairy heifers. J Dairy Res 73:10-9.
  81. 81. Middleton JR, Luby CD, Adams DS. 2009. Efficacy of vaccination against staphylococcal mastitis: a review and new data. Vet Microbiol 134:192-8.
  82. 82. Wilson DJ, Grohn YT, Bennett GJ, González RN, Schukken YH, Spatz J. 2007. Comparison of J5 vaccinates and controls for incidence, etiologic agent, clinical severity, and survival in the herd following naturally occurring cases of clinical mastitis. J Dairy Sci 90:4282-8.
  83. 83. Wilson DJ, Mallard BA, Burton JL, Schukken YH, Grohn YT. 2009. Association of Escherichia coli J5-specific serum antibody responses with clinical mastitis outcome for J5 vaccinate and control dairy cattle. Clin Vaccine Immunol 16:209-17.
  84. 84. Collado R, Montbrau C, Sitja M, Prenafeta A. 2018. Study of the efficacy of a Streptococcus uberis mastitis vaccine against an experimental intramammary infection with a heterologous strain in dairy cows. J Dairy Sci 101:10290-10302.
  85. 85. Nickerson SC, Owens WE, Tomita GM, Widel P. 1999. Vaccinating dairy heifers with a Staphylococcus aureus bacterin reduces mastitis at calving. Large Animal Practice 20:16-28.
  86. 86. Williams JM, Mayerhofer HJ, Brown RW. 1966. Clinical evaluation of a Staphylococcus aureus bacterin (polyvalent somatic antigen). Vet Med Small Anim Clin 61:789-93.
  87. 87. Williams JM, Shipley GR, Smith GL, Gerber DL. 1975. A clinical evaluation of Staphylococcus aureus bacterin in the control of staphylococcal mastitis in cows. Vet Med Small Anim Clin 70:587-94.
  88. 88. Smith GW, Lyman RL, Anderson KL. 2006. Efficacy of vaccination and antimicrobial treatment to eliminate chronic intramammary Staphylococcus aureus infections in dairy cattle. J Am Vet Med Assoc 228:422-5.
  89. 89. Luby CD, Middleton JR. 2005. Efficacy of vaccination and antibiotic therapy against Staphylococcus aureus mastitis in dairy cattle. Vet Rec 157:89-90.
  90. 90. Luby CD, Middleton JR, Ma J, Rinehart CL, Bucklin S, Kohler C, Tyler JW. 2007. Characterization of the antibody isotype response in serum and milk of heifers vaccinated with a Staphylococcus aureus bacterin (Lysigin). J Dairy Res 74:239-46.
  91. 91. O’Brien CN, Guidry AJ, Douglass LW, Westhoff DC. 2001. Immunization with Staphylococcus aureus lysate incorporated into microspheres. J Dairy Sci 84:1791-9.
  92. 92. Leitner G, Lubashevsky E, Glickman A, Winkler M, Saran A, Trainin Z. 2003. Development of a Staphylococcus aureus vaccine against mastitis in dairy cows. I. Challenge trials. Vet Immunol Immunopathol 93:31-8.
  93. 93. Leitner G, Yadlin N, Lubashevsy E, Ezra E, Glickman A, Chaffer M, Winkler M, Saran A, Trainin Z. 2003b. Development of a Staphylococcus aureus vaccine against mastitis in dairy cows. II. Field trial. Vet Immunol Immunopathol 93:153-8.
  94. 94. Rivas AL, Tadevosyan R, Quimby FW, Lein DH. 2002. Blood and milk cellular immune responses of mastitic non-periparturient cows inoculated with Staphylococcus aureus. Can J Vet Res 66:125-31.
  95. 95. Shkreta L, Talbot BG, Diarra MS, Lacasse P. 2004. Immune responses to a DNA/protein vaccination strategy against Staphylococcus aureus induced mastitis in dairy cows. Vaccine 23:114-26.
  96. 96. Carter EW, Kerr DE. 2003. Optimization of DNA-based vaccination in cows using green fluorescent protein and protein A as a prelude to immunization against staphylococcal mastitis. J Dairy Sci 86:1177-86.
  97. 97. Shkreta L, Talbot BG, Lacasse P. 2003. Optimization of DNA vaccination immune responses in dairy cows: effect of injection site and the targeting efficacy of antigen-bCTLA-4 complex. Vaccine 21:2372-82.
  98. 98. Lee JW, O’Brien CN, Guidry AJ, Paape MJ, Shafer-Weaver KA, Zhao X. 2005. Effect of a trivalent vaccine against Staphylococcus aureus mastitis lymphocyte subpopulations, antibody production, and neutrophil phagocytosis. Can J Vet Res 69:11-8.
  99. 99. O’Brien CN, Guidry AJ, Fattom A, Shepherd S, Douglass LW, Westhoff DC. 2000. Production of antibodies to Staphylococcus aureus serotypes 5, 8, and 336 using poly(DL-lactide-co-glycolide) microspheres. J Dairy Sci 83:1758-66.
  100. 100. Merrill C, Ensermu DB, Abdi RD, Gillespie BE, Vaughn J, Headrick SI, Hash K, Walker TB, Stone E, Kerro Dego O. 2019. Immunological responses and evaluation of the protection in dairy cows vaccinated with staphylococcal surface proteins. Vet Immunol Immunopathol 214:109890.
  101. 101. Benedictus L, Ravesloot L, Poppe K, Daemen I, Boerhout E, van Strijp J, Broere F, Rutten V, Koets A, Eisenberg S. 2019. Immunization of young heifers with staphylococcal immune evasion proteins before natural exposure to Staphylococcus aureus induces a humoral immune response in serum and milk. BMC Veterinary Research 15.
  102. 102. Mellaa A, Ulloa F, Valdésd I, Olivaresa N, Ceballose A, Kruzea J. 2017. Evaluation of a new vaccine against Staphylococcus aureus mastitis in dairy herds of southern Chile. I. Challenge tria. Aust J Vet Sci 49:149-160
  103. 103. Finch JM, Hill AW, Field TR, Leigh JA. 1994. Local vaccination with killed Streptococcus uberis protects the bovine mammary gland against experimental intramammary challenge with the homologous strain. Infect Immun 62:3599-603.
  104. 104. Giraudo JA, Calzolari A, Rampone H, Rampone A, Giraudo AT, Bogni C, Larriestra A, Nagel R. 1997. Field trials of a vaccine against bovine mastitis. 1. Evaluation in heifers. J Dairy Sci 80:845-53.
  105. 105. Calzolari A, Giraudo JA, Rampone H, Odierno L, Giraudo AT, Frigerio C, Bettera S, Raspanti C, Hernandez J, Wehbe M, Mattea M, Ferrari M, Larriestra A, Nagel R. 1997. Field trials of a vaccine against bovine mastitis. 2. Evaluation in two commercial dairy herds. J Dairy Sci 80:854-8.
  106. 106. Finch JM, Winter A, Walton AW, Leigh JA. 1997. Further studies on the efficacy of a live vaccine against mastitis caused by Streptococcus uberis. Vaccine 15:1138-43.
  107. 107. Fontaine MC, Perez-Casal J, Song XM, Shelford J, Willson PJ, Potter AA. 2002. Immunisation of dairy cattle with recombinant Streptococcus uberis GapC or a chimeric CAMP antigen confers protection against heterologous bacterial challenge. Vaccine 20:2278-86.
  108. 108. Leigh JA. 1999. Streptococcus uberis: a permanent barrier to the control of bovine mastitis? Vet J 157:225-38.
  109. 109. Hogan JS, Smith KL, Todhunter DA, Schoenberger PS. 1992. Field trial to determine efficacy of an Escherichia coli J5 mastitis vaccine. J Dairy Sci 75:78-84.
  110. 110. Hogan JS, Weiss WP, Smith KL, Todhunter DA, Schoenberger PS, Sordillo LM. 1995. Effects of an Escherichia coli J5 vaccine on mild clinical coliform mastitis. J Dairy Sci 78:285-90.
  111. 111. Hogan JS, Todhunter DA, Smith KL, Schoenberger PS, Wilson RA. 1992. Susceptibility of Escherichia coli isolated from intramammary infections to phagocytosis by bovine neutrophils. J Dairy Sci 75:3324-9.
  112. 112. Gillespie BE, Lewis MJ, Boonyayatra S, Maxwell ML, Saxton A, Oliver SP, Almeida RA. 2012. Short communication: Evaluation of bulk tank milk microbiological quality of nine dairy farms in Tennessee. J Dairy Sci 95:4275-9.
  113. 113. Barbano DM, Lynch JM. 2006. Major advances in testing of dairy products: milk component and dairy product attribute testing. J Dairy Sci 89:1189-94.
  114. 114. Barbano DM, Ma Y, Santos MV. 2006. Influence of raw milk quality on fluid milk shelf life. J Dairy Sci 89 Suppl 1:E15-9.
  115. 115. Parodi P. 2004. Milk fat in human nutrition. Aust J Dairy Technol 59:3-59.
  116. 116. Jayarao BM, Pillai SR, Sawant AA, Wolfgang DR, Hegde NV. 2004. Guidelines for monitoring bulk tank milk somatic cell and bacterial counts. J Dairy Sci 87:3561-73.
  117. 117. Seegers H, Fourichon C, Beaudeau F. 2003. Production effects related to mastitis and mastitis economics in dairy cattle herds. Vet Res 34:475-91.
  118. 118. Bradley AJ, Green MJ. 2009. Factors affecting cure when treating bovine clinical mastitis with cephalosporin-based intramammary preparations. J Dairy Sci 92:1941-53.
  119. 119. Ismail ZB. 2017. Mastitis vaccines in dairy cows: Recent developments and recommendations of application. Veterinary world 10:1057.
  120. 120. Riekerink RGO, Barkema HW, Scholl DT, Poole DE, Kelton DF. 2010. Management practices associated with the bulk-milk prevalence of Staphylococcus aureus in Canadian dairy farms. Preventive veterinary medicine 97:20-28.
  121. 121. USDA APHIS U. 2009. United States Department of Agriculture, Animal Plant Health Inspection Service National Animal Health Monitoring System. Injection practices on U.S. dairy opera tions, 2007 (Veterinary Services Info Sheet 4 p, February 2009). 2009. Available at accessed March 23, 2020. (Online.)
  122. 122. Dufour S, Dohoo IR, Barkema HW, Descoteaux L, Devries TJ, Reyher KK, Roy JP, Scholl DT. 2012. Epidemiology of coagulase-negative staphylococci intramammary infection in dairy cattle and the effect of bacteriological culture misclassification. J Dairy Sci 95:3110-24.
  123. 123. Piessens V, Van Coillie E, Verbist B, Supre K, Braem G, Van Nuffel A, De Vuyst L, Heyndrickx M, De Vliegher S. 2011. Distribution of coagulase-negative Staphylococcus species from milk and environment of dairy cows differs between herds. J Dairy Sci 94:2933-44.
  124. 124. Gillespie BE, Headrick SI, Boonyayatra S, Oliver SP. 2009. Prevalence and persistence of coagulase-negative Staphylococcus species in three dairy research herds. Vet Microbiol 134:65-72.
  125. 125. Pyorala S, Taponen S. 2009. Coagulase-negative staphylococci-emerging mastitis pathogens. Vet Microbiol 134:3-8.
  126. 126. Fry PR, Middleton JR, Dufour S, Perry J, Scholl D, Dohoo I. 2014. Association of coagulase-negative staphylococcal species, mammary quarter milk somatic cell count, and persistence of intramammary infection in dairy cattle. Journal of Dairy Science 97:4876-4885.
  127. 127. Taponen S, Liski E, Heikkila AM, Pyorala S. 2017. Factors associated with intramammary infection in dairy cows caused by coagulase-negative staphylococci, Staphylococcus aureus, Streptococcus uberis, Streptococcus dysgalactiae, Corynebacterium bovis, or Escherichia coli. J Dairy Sci 100:493-503.
  128. 128. Taponen S, Pyorala S. 2009. Coagulase-negative staphylococci as cause of bovine mastitis- not so different from Staphylococcus aureus? Vet Microbiol 134:29-36.
  129. 129. Levison L, Miller-Cushon E, Tucker A, Bergeron R, Leslie K, Barkema H, DeVries T. 2016. Incidence rate of pathogen-specific clinical mastitis on conventional and organic Canadian dairy farms. Journal of dairy science 99:1341-1350.
  130. 130. Taponen S, Bjorkroth J, Pyorala S. 2008. Coagulase-negative staphylococci isolated from bovine extramammary sites and intramammary infections in a single dairy herd. J Dairy Res 75:422-9.
  131. 131. Taponen S, Koort J, Bjorkroth J, Saloniemi H, Pyorala S. 2007. Bovine intramammary infections caused by coagulase-negative staphylococci may persist throughout lactation according to amplified fragment length polymorphism-based analysis. J Dairy Sci 90:3301-7.
  132. 132. Leitner G, Yadlin N, Lubashevsy E, Ezra E, Glickman A, Chaffer M, Winkler M, Saran A, Trainin Z. 2003. Development of a Staphylococcus aureus vaccine against mastitis in dairy cows. II. Field trial. Vet Immunol Immunopathol 93:153-8.
  133. 133. Leitner G, Lubashevsky E, Glickman A, Winkler M, Saran A, Trainin Z. 2003a. Development of a Staphylococcus aureus vaccine against mastitis in dairy cows. I. Challenge trials. Vet Immunol Immunopathol 93:31-8.
  134. 134. Chang BS, Moon JS, Kang HM, Kim YI, Lee HK, Kim JD, Lee BS, Koo HC, Park YH. 2008. Protective effects of recombinant staphylococcal enterotoxin type C mutant vaccine against experimental bovine infection by a strain of Staphylococcus aureus isolated from subclinical mastitis in dairy cattle. Vaccine 26:2081-91.
  135. 135. Landin H, Mörk MJ, Larsson M, Waller KP. 2015. Vaccination against Staphylococcus aureus mastitis in two Swedish dairy herds. Acta Veterinaria Scandinavica 57:81.
  136. 136. Prenafeta A, March R, Foix A, Casals I, Costa L. 2010. Study of the humoral immunological response after vaccination with a Staphylococcus aureus biofilm-embedded bacterin in dairy cows: possible role of the exopolysaccharide specific antibody production in the protection from Staphylococcus aureus induced mastitis. Vet Immunol Immunopathol 134:208-17.
  137. 137. Pellegrino M, Giraudo J, Raspanti C, Nagel R, Odierno L, Primo V, Bogni C. 2008. Experimental trial in heifers vaccinated with Staphylococcus aureus avirulent mutant against bovine mastitis. Veterinary Microbiology 127:186-190.
  138. 138. Guidry AJ, O’Brien CN, Oliver SP, Dowlen HH, Douglass LW. 1994. Effect of whole Staphylococcus aureus and mode of immunization on bovine opsonizing antibodies to capsule. J Dairy Sci 77:2965-74.
  139. 139. Yancey RJ, Jr. 1999. Vaccines and diagnostic methods for bovine mastitis: fact and fiction. Adv Vet Med 41:257-73.
  140. 140. Russell MW, Brooker BE, Reiter B. 1977. Eelectron microscopic observations of the interaction of casein micelles and milk fat globules with bovine polymorphonuclear leucocytes during the phagocytosis of staphylococci in milk. J Comp Pathol 87:43-52.
  141. 141. Zadoks RN, Tikofsky LL, Boor KJ. 2005. Ribotyping of Streptococcus uberis from a dairy’s environment, bovine feces and milk. Vet Microbiol 109:257-65.
  142. 142. Oliver S, Almeida R, Calvinho L. 1998. Virulence factors of Streptococcus uberis isolated from cows with mastitis. Zoonoses and Public Health 45:461-471.
  143. 143. Zadoks RN, Gillespie BE, Barkema HW, Sampimon OC, Oliver SP, Schukken YH. 2003. Clinical, epidemiological and molecular characteristics of Streptococcus uberis infections in dairy herds. Epidemiol Infect 130:335-49.
  144. 144. Douglas VL, Fenwick SG, Pfeiffer DU, Williamson NB, Holmes CW. 2000. Genomic typing of Streptococcus uberis isolates from cases of mastitis, in New Zealand dairy cows, using pulsed-field gel electrophoresis. Vet Microbiol 75:27-41.
  145. 145. McDougall S, Parkinson TJ, Leyland M, Anniss FM, Fenwick SG. 2004. Duration of infection and strain variation in Streptococcus uberis isolated from cows’ milk. J Dairy Sci 87:2062-72.
  146. 146. Wieliczko RJ, Williamson JH, Cursons RT, Lacy-Hulbert SJ, Woolford MW. 2002. Molecular typing of Streptococcus uberis strains isolated from cases of bovine mastitis. J Dairy Sci 85:2149-54.
  147. 147. Phuektes P, Mansell PD, Dyson RS, Hooper ND, Dick JS, Browning GF. 2001. Molecular epidemiology of Streptococcus uberis isolates from dairy cows with mastitis. J Clin Microbiol 39:1460-6.
  148. 148. Steeneveld W, Swinkels J, Hogeveen H. 2007. Stochastic modelling to assess economic effects of treatment of chronic subclinical mastitis caused by Streptococcus uberis. J Dairy Res 74:459-67.
  149. 149. Smith KL, Todhunter D, Schoenberger P. 1985. Environmental mastitis: Cause, prevalence, prevention1, 2. Journal of Dairy Science 68:1531-1553.
  150. 150. Smith KL, Todhunter DA, Schoenberger PS. 1985. Environmental mastitis: cause, prevalence, prevention. J Dairy Sci 68:1531-53.
  151. 151. Leigh JA. 2002. Immunisation of dairy cattle with recombinant Streptococcus uberis GapC or a chimeric CAMP antigen confers protection against heterologous bacterial challenge. M.C. Fontaine et al. [Vaccine 20 (2002) 2278-2286]. Vaccine 20:3047-8.
  152. 152. Lincoln RA, Leigh JA. 1997. Characterization of a novel plasminogen activator from Streptococcus uberis. Adv Exp Med Biol 418:643-5.
  153. 153. Leigh JA, Lincoln RA. 1997. Streptococcus uberis acquires plasmin activity following growth in the presence of bovine plasminogen through the action of its specific plasminogen activator. FEMS Microbiol Lett 154:123-9.
  154. 154. Leigh JA, Finch JM, Field TR, Real NC, Winter A, Walton AW, Hodgkinson SM. 1999. Vaccination with the plasminogen activator from Streptococcus uberis induces an inhibitory response and protects against experimental infection in the dairy cow. Vaccine 17:851-7.
  155. 155. Ward PN, Field TR, Rapier CD, Leigh JA. 2003. The activation of bovine plasminogen by PauA is not required for virulence of Streptococcus uberis. Infect Immun 71:7193-6.
  156. 156. Almeida RA, Luther DA, Park HM, Oliver SP. 2006. Identification, isolation, and partial characterization of a novel Streptococcus uberis adhesion molecule (SUAM). Vet Microbiol 115:183-91.
  157. 157. Almeida RA, Oliver SP. 2001. Role of collagen in adherence of Streptococcus uberis to bovine mammary epithelial cells. J Vet Med B Infect Dis Vet Public Health 48:759-63.
  158. 158. Almeida RA, Luther DA, Kumar SJ, Calvinho LF, Bronze MS, Oliver SP. 1996. Adherence of Streptococcus uberis to bovine mammary epithelial cells and to extracellular matrix proteins. Zentralbl Veterinarmed B 43:385-92.
  159. 159. Almeida RA, Dego OK, Headrick SI, Lewis MJ, Oliver SP. 2015. Role of Streptococcus uberis adhesion molecule in the pathogenesis of Streptococcus uberis mastitis. Vet Microbiol 179:332-5.
  160. 160. Almeida RA, Dunlap JR, Oliver SP. 2010. Binding of Host Factors Influences Internalization and Intracellular Trafficking of Streptococcus uberis in Bovine Mammary Epithelial Cells. Vet Med Int 2010:319192.
  161. 161. Almeida RA, Fang W, Oliver SP. 1999. Adherence and internalization of Streptococcus uberis to bovine mammary epithelial cells are mediated by host cell proteoglycans. FEMS microbiology letters 177:313-317.
  162. 162. Patel D, Almeida RA, Dunlap JR, Oliver SP. 2009. Bovine lactoferrin serves as a molecular bridge for internalization of Streptococcus uberis into bovine mammary epithelial cells. Veterinary microbiology 137:297-301.
  163. 163. Prado ME, Almeida RA, Ozen C, Luther DA, Lewis MJ, Headrick SJ, Oliver SP. 2011. Vaccination of dairy cows with recombinant Streptococcus uberis adhesion molecule induces antibodies that reduce adherence to and internalization of S. uberis into bovine mammary epithelial cells. Vet Immunol Immunopathol 141:201-8.
  164. 164. Almeida RA, Kerro-Dego O, Prado ME, Headrick SI, Lewis MJ, Siebert LJ, Pighetti GM, Oliver SP. 2015. Protective effect of anti-SUAM antibodies on Streptococcus uberis mastitis. Veterinary research 46:133.
  165. 165. Chen X, Dego OK, Almeida RA, Fuller TE, Luther DA, Oliver SP. 2011. Deletion of sua gene reduces the ability of Streptococcus uberis to adhere to and internalize into bovine mammary epithelial cells. Vet Microbiol 147:426-34.
  166. 166. Rambeaud M, Almeida RA, Pighetti GM, Oliver SP. 2003. Dynamics of leukocytes and cytokines during experimentally induced Streptococcus uberis mastitis. Vet Immunol Immunopathol 96:193-205.
  167. 167. Swanson KM, Stelwagen K, Dobson J, Henderson HV, Davis SR, Farr VC, Singh K. 2009. Transcriptome profiling of Streptococcus uberis-induced mastitis reveals fundamental differences between immune gene expression in the mammary gland and in a primary cell culture model. J Dairy Sci 92:117-29.
  168. 168. Moyes KM, Drackley JK, Morin DE, Bionaz M, Rodriguez-Zas SL, Everts RE, Lewin HA, Loor JJ. 2009. Gene network and pathway analysis of bovine mammary tissue challenged with Streptococcus uberis reveals induction of cell proliferation and inhibition of PPARgamma signaling as potential mechanism for the negative relationships between immune response and lipid metabolism. BMC Genomics 10:542.
  169. 169. Eberhart RJ. 1984. Coliform mastitis. Vet Clin North Am Large Anim Pract 6:287-300.
  170. 170. Weinberg ED. 1978. Iron and infection. Microbiol Rev 42:45-66.
  171. 171. Jenness R. 1974. The composition of milk, vol III. Academic Press, New York.
  172. 172. Bullen JJ, Rogers HJ, Griffiths E. 1978. Role of iron in bacterial infection. Curr Top Microbiol Immunol 80:1-35.
  173. 173. Braun V, Hantke K, Koster W. 1998. Bacterial iron transport: mechanisms, genetics, and regulation. Met Ions Biol Syst 35:67-145.
  174. 174. Neilands JB. 1984. Siderophores of bacteria and fungi. Microbiol Sci 1:9-14.
  175. 175. Nikaido H, Rosenberg EY. 1983. Porin channels in Escherichia coli: studies with liposomes reconstituted from purified proteins. J Bacteriol 153:241-52.
  176. 176. Nikaido H, Rosenberg EY. 1981. Effect on solute size on diffusion rates through the transmembrane pores of the outer membrane of Escherichia coli. J Gen Physiol 77:121-35.
  177. 177. Guerinot ML. 1994. Microbial iron transport. Annu Rev Microbiol 48:743-72.
  178. 178. Klebba PE, Rutz JM, Liu J, Murphy CK. 1993. Mechanisms of TonB-catalyzed iron transport through the enteric bacterial cell envelope. J Bioenerg Biomembr 25:603-11.
  179. 179. Neilands JB. 1981. Microbial iron compounds. Annu Rev Biochem 50:715-31.
  180. 180. Podschun R, Fischer A, Ullmann U. 1992. Siderophore production of Klebsiella species isolated from different sources. Zentralbl Bakteriol 276:481-6.
  181. 181. Tarkkanen AM, Allen BL, Williams PH, Kauppi M, Haahtela K, Siitonen A, Orskov I, Orskov F, Clegg S, Korhonen TK. 1992. Fimbriation, capsulation, and iron-scavenging systems of Klebsiella strains associated with human urinary tract infection. Infect Immun 60:1187-92.
  182. 182. Linggoood MA, Robberts M, Ford S, Parry SH, H. WP. 1987. Incidence of the Aerobactin Iron Uptake System Among Escherichiu cdi Isolates From Infections of Farm Animals Journal of General Microbiology 133:835-842.
  183. 183. Rutz JM, Abdullah T, Singh SP, Kalve VI, Klebba PE. 1991. Evolution of the ferric enterobactin receptor in gram-negative bacteria. J Bacteriol 173:5964-74.
  184. 184. Hussein S, Hantke K, Braun V. 1981. Citrate-dependent iron transport system in Escherichia coli K-12. Eur J Biochem 117:431-7.
  185. 185. Faulkner A, Peaker M. 1982. Reviews of the progress of dairy science: secretion of citrate into milk. J Dairy Res 49:159-69.
  186. 186. Murphy CK, Kalve VI, Klebba PE. 1990. Surface topology of the Escherichia coli K-12 ferric enterobactin receptor. J Bacteriol 172:2736-46.
  187. 187. Neilands JB, Bindereif A, Montgomerie JZ. 1985. Genetic basis of iron assimilation in pathogenic Escherichia coli. Curr Top Microbiol Immunol 118:179-95.
  188. 188. Lin J, Hogan JS, Aslam M, Smith KL. 1998. Immunization of cows with ferric enterobactin receptor from coliform bacteria. J Dairy Sci 81:2151-8.
  189. 189. Lin J, Hogan JS, Smith KL. 1999. Growth responses of coliform bacteria to purified immunoglobulin G from cows immunized with ferric enterobactin receptor FepA. J Dairy Sci 82:86-92.
  190. 190. Pressler U, Staudenmaier H, Zimmermann L, Braun V. 1988. Genetics of the iron dicitrate transport system of Escherichia coli. J Bacteriol 170:2716-24.
  191. 191. Lin J, Hogan JS, Smith KL. 1999. Antigenic homology of the inducible ferric citrate receptor (FecA) of coliform bacteria isolated from herds with naturally occurring bovine intramammary infections. Clin Diagn Lab Immunol 6:966-9.
  192. 192. Lin J, Hogan JS, Smith KL. 1998. Inhibition of in vitro growth of coliform bacteria by a monoclonal antibody directed against ferric enterobactin receptor FepA. J Dairy Sci 81:1267-74.
  193. 193. Takemura K, Hogan JS, Smith KL. 2004. Growth responses of Escherichia coli to immunoglobulin G from cows immunized with ferric citrate receptor, FecA. J Dairy Sci 87:316-20.
  194. 194. Takemura K, Hogan JS, Lin J, Smith KL. 2002. Efficacy of immunization with ferric citrate receptor FecA from Escherichia coli on induced coliform mastitis. J Dairy Sci 85:774-81.
  195. 195. Petzl W, Zerbe H, Gunther J, Seyfert HM, Hussen J, Schuberth HJ. 2018. Pathogen-specific responses in the bovine udder. Models and immunoprophylactic concepts. Res Vet Sci 116:55-61.
  196. 196. Petzl W, Zerbe H, Gunther J, Yang W, Seyfert HM, Nurnberg G, Schuberth HJ. 2008. Escherichia coli, but not Staphylococcus aureus triggers an early increased expression of factors contributing to the innate immune defense in the udder of the cow. Vet Res 39:18.
  197. 197. Zhao Y, Zhou M, Gao Y, Liu H, Yang W, Yue J, Chen D. 2015. Shifted T Helper Cell Polarization in a Murine Staphylococcus aureus Mastitis Model. PLoS One 10:e0134797.
  198. 198. Porcherie A, Gilbert FB, Germon P, Cunha P, Trotereau A, Rossignol C, Winter N, Berthon P, Rainard P. 2016. IL-17A Is an Important Effector of the Immune Response of the Mammary Gland to Escherichia coli Infection. J Immunol 196:803-12.
  199. 199. Herry V, Gitton C, Tabouret G, Reperant M, Forge L, Tasca C, Gilbert FB, Guitton E, Barc C, Staub C, Smith DGE, Germon P, Foucras G, Rainard P. 2017. Local immunization impacts the response of dairy cows to Escherichia coli mastitis. Sci Rep 7:3441.
  200. 200. DeGraves FJ, Fetrow J. 1991. Partial budget analysis of vaccinating dairy cattle against coliform mastitis with an Escherichia coli J5 vaccine. J Am Vet Med Assoc 199:451-5.
  201. 201. Allore HG, Erb HN. 1998. Partial budget of the discounted annual benefit of mastitis control strategies. J Dairy Sci 81:2280-92.

Written By

Oudessa Kerro Dego

Submitted: September 14th, 2020 Reviewed: September 28th, 2020 Published: October 19th, 2020