Microbiological and immunological studies on buffalo subclinical mastitis
Abstract
A total of 1356 quarter milk samples of 344 apparently healthy buffaloes from three organised dairy farms were screened for subclinical mastitis. Following IDF criteria, highest prevalence of subclinical mastitis was 6.67% in Government livestock farm followed by 5.83% in Hitech farm, 2.77% in LUVAS farm (April month) and lowest 1.43% in LUVAS farm (December month). Milk microbiome revealed that out of 114 staphylococci, 43.85% were S. aureus, and out of 61 streptococci, S. dysgalactiae (62.29%), S. agalactiae (27.86%) and S. uberis (9.83%) which were characterised phenotypically and confirmed by PCR assay using 16S rRNA specific primers. Among coagulase negative staphylococci (64), S. epidermidis was found most prevalent organisms followed by S. capitis, S. haemolyticus, S. hycius, S. chromogenes, S. simulans, S. saprophyticus. Antimicrobial sensitivity of isolates varied in different farms which depend on the use of antimicrobials and strains prevalent at that farm.
In the present study, relative expression of proinflammatory cytokines revealed highest fold change in expression of TNFα followed by IL-1β, IL-6 and IFN-γ in milk of buffaloes with subclinical mastitis as compared to healthy ones. Lowest up regulation of IFN-γ was due to association of Gram positive bacteria. Significant increase in concentration of haptoglobin, milk amyloid A, lactate dehydrogenase and N-acetyl-β-D-glucosaminidase enzymes, pH, electrical conductivity, Na, Cl and significant decrease of Ca, Fe, Se, Zn, protein and fat values was observed in milk of subclinically mastitic buffaloes. All the parameters found better and reliable indicator of subclinical mastitis depending upon the availability of the reagents, kits and economy, can be used for screening of animals for subsequent bacteriological culture.
Description
Keywords
Buffalo, Subclinical mastitis, Proinflammatory cytokines, Acute phase protein, Enzyme, Minerals and trace elements