A total of 269 cows in small family herds in the central region of México from different municipalities of México State were studied. Composed milk samples were obtained to detect subclinical mastitis and S. aureus infection and for characterization of phenotypes as follows: biotypes, capsular exopolysaccharide 5 and 8, ORSA/MRSA and MRSA strains; and in vitro phagocytosis neutrophil activity and apoptosis by S. aureus serotype 5. Results were evaluated by estimating proportions and chi-square test (p < 0.05). The microbial isolation rate was 46%; S. aureus isolation rate was 23.4–21.0% among cow herds; 39% of microbial isolates were in 1500–2500 cells/mL, with Wisconsin test. The phenotypes of S. aureus were: biotypes A and C are identified frequently that produce alpha and beta-hemolysin toxins, and a smaller proportion other hemolysins types. S. aureus isolates capsular serotypes 5 and 8 show differences in the in vitro neutrophil phagocytosis activity and apoptosis. The ORSA/MRSA isolates show that MRSA strains? mec A gene was confirmed by PCR. The S. aureus infection level in the dairy cow herds shows a wide municipal distribution, identifying different S. aureus pathotypes enclosed to virulence factors and MRSA to establish a potential health risk in small dairy cow herds in México.
Part of the book: Milk Production, Processing and Marketing
The dairy products industry is going toward safe milk and its products in the food market. Milk quality and food safety concern in the consumers’ health and nutrition in public health surveillance prevent food-borne diseases, food poisoning, and zoonosis risk by raw milk and fresh dairy products. The aim of this work is focused on milk microbial contamination and its impacts on milk production and dairy industry with their implications in milk product quality, food-borne diseases from raw milk, and unpasteurized milk by food-borne pathogen microbial contamination and milk and dairy product spoilage. The microbial milk contamination source comes from herd hygiene and health status, mastitis prevalence, production environment, and milking parlor and milk conserving practices in dairy farm. Moreover, these facts are implicated in milk quality and milk spoilage and unsafe dairy products. The milk production system and the dairy plant operations keep track in pasteurized milk and fresh dairy products reviewing the traceability in field situational diagnosis report.
Part of the book: Nutrition in Health and Disease