Chapters authored
Staphylococcus aureus and Dairy Udder
Staphylococcus aureus is a major causative agent of intra-mammary infections in dairy animals with potential virulence of surface components, toxins, and extracellular enzymes. About 74% quarter prevalence of S. aureus in bovine udder with overall prevalence exceeding 61% in dairy animals. About 17 different serotypes of dairy originated S. aureus have been reported with 24 virulence coding genes for leukocidins (lukED/lukM), pyrogenic toxin super antigen (PTSAg), haemolysins (hla-hlg), toxic-shock syndrome toxin (tst), enterotoxins (sea-seo, seu), exfoliative toxins (eta, etb), and genes for methicillin (mecA) and penicillin (blaZ) resistance. Attainment of refuge inside the macrophages and neutrophils is a major cause of S. aureus mastitis persistence. Mammary prebiotics and probiotics are recently being used as alternatives to antibiotic for the prevention of mastitis. Literature showed anti- staphylococcus vaccines with different results depending upon types of immunization, route of administration and adjuvant used. Studies has shown that herd specific as well as commercial S. aureus vaccines reduce new infections in dairy animals. Experiments are still in progress for the use of vaccines against S. aureus mastitis with optimal efficacy and reliability. Perhaps, there might be bright future because of highly satisfactory trial results of mastitis vaccines in the lab animals.
Part of the book: Insights Into Drug Resistance in Staphylococcus aureus
Etiology of Bovine Mastitis
Mastitis in dairy animals is the primary concern of dairy farmers, which is the most common disease that causes huge economic losses in the dairy industry. The economic losses due to mastitis are from a reduction in milk yield, condemnation of milk with antibiotic residues, veterinary treatment costs, and death. In addition, some mastitis pathogens also cause serious human diseases associated with the contamination of milk or milk products with bacteria or their toxins. Bovine mastitis is mainly caused by a wide range of environmental and contagious bacterial mastitis pathogens. Contagious pathogens are those whose main reservoir is the infected udder. Contagious pathogens mainly spread among animals during milking process whereas environmental pathogens spread from environment to udder at any time. The source of the environmental pathogens is the surrounding environment of an animal. The major contagious pathogens include Staphylococcus aureus, Streptococcus agalactiae, and Mycoplasma spp. and the minor contagious pathogens include Corynebacterium bovis and others. Major environmental pathogens include coliform bacteria (Escherichia coli, Klebsiella spp., Enterobacter spp. and Citrobacter spp.), environmental streptococci (Strep. dysgalactiae, Strep. uberis). This chapter covers detailed review of published data on contagious and environmental pathogens responsible for bovine mastitis.
Part of the book: Mastitis in Dairy Cattle, Sheep and Goats