Prevalence and Antibiogram of Bacterial Pathogens from Subclinical Mastitis in Buffaloes

The present investigation was carried out to study the prevalence of bacterial pathogens responsible for subclinical mastitis in buffaloes and their antibiogram pattern to selected antibiotics. The study was carried out on lactating buffaloes maintained at the Cattle and Buffalo farm, Indian Veterinary Research Institute, Izatnagar, India. Screening for subclinical mastitis was done by California Mastitis Test (CMT) and Somatic Cell Count (SCC) in milk. The buffaloes showing CMT score ≥ 2 and SCC ≥ 0.5 million/ml of milk were considered for isolation and identifi cation of bacterial pathogens by cultural examination and requisite biochemical tests. Fifteen out of 48 lactating buffaloes were found positive for subclinical mastitis, affecting one or two quarters, giving a prevalence of 31.25%. Out of them, 9 (60%) were found positive for Staphylococcus aureus, 3 (20%) positive for Streptococcus agalactiae, 1 (7.69%) for other streptococci and 2 (13.33%) for E. coli. The antibiogram of the bacterial isolates to standard antibiotic discs determined by disc diffusion method revealed the highest sensitivity to ciprofl oxacin and enrofl oxacin followed by cefotaxime, cloxacillin, erythromycin, amoxycillin in decreasing order and least sensitivity to penicillin G. Judicious use of antibiotics based on antibiotic sensitivity and pharmacokinetics in mastitis control may reduce the chances of treatment failure and the economic losses.