Antimicrobial susceptibility profiling of caprine clinical mastitis pathogens in Punjab, India

Goats can serve as an efficient animal model to study antimicrobial resistance. The present study was undertaken with an aim to assess the status of antibiotic resistance associated with caprine mastitis in the Bathinda district of Punjab.

Milk samples were collected aseptically from the cases of clinical mastitis in goats followed by bacterial isolation and antibiotic susceptibility testing for amikacin, amoxicillin, amoxyclav, ampicillin, ampicillin-sulbactam, cefoperazone, cefoperazone-tazobactam, ceftizoxime, ceftriaxone, ceftriaxone-sulbactam, ceftriaxone-tazobactam, ciprofloxacin, colistin, doxycycline, enrofloxacin, erythromycin, gentamicin, moxifloxacin, ofloxacin, oxytetracycline, penicillin-G, streptomycin and tetracycline.

The antimicrobial susceptibility testing revealed resistance to multiple antibiotics including the macrolide (100%) and polymyxin (100%) group followed by the penicillins (88.89%), tetracyclines (43.75%), cephalosporins (28.57%), aminoglycosides (25.93%), and quinolones (13.33%). The resistance in penicillin (28.57%) and cephalosporin (20%) combinations was comparatively lower as compared to their individual use. Among the bacterial isolates, Escherichia coli (21.42%) were multidrug resistant to more than five antibiotics tested, whereas Bacillus species (21.42%) showed resistance to three to five antibiotics and; Staphylococcus spp. (35.71%), Streptococcus spp. (7.14%) and Corynebacterium spp. (14.28%) were resistant to less than three antibiotics tested.

As the antimicrobial susceptibility was found to vary among the goats suffering from mastitis as well as the bacteria involved, the antimicrobial susceptibility testing prior to treatment initiation would be crucial in limiting the development of resistance in goats and potentially in human beings as well.

The antimicrobial susceptibility profiling in caprine mastitis revealed the multidrug resistant bacterial isolates.