Antimicrobial resistance in bacteria isolated from cases of abortions and other infections in horses of organized farms in north india and discussion on usage of antimicrobials in equines as per oie standards

Antimicrobials are most important tools in the health management of equines affected with different diseases, as primary or secondary bacterial infections are generally involved along with viral infections. However, given the situation of emergence of rapid antimicrobial resistance (AMR) among bacteria, it is important to analyze the situation of AMR in animals. The information regarding bacterial isolates, infectious disease conditions among equine in field and their antimicrobial susceptibility pattern is generally unavailable. This small study, therefore, compiles antimicrobial sensitivity data of bacterial isolates obtained from field cases of abortions, respiratory and ocular cases in Thoroughbred and Marwari horses, attended in Delhi, Rajasthan and Haryana. Samples from horses suffering from these disease conditions were collected and processed in laboratory for bacterial isolation. The antimicrobial susceptibility testing of identified bacterial isolates was carried out by disc-diffusion assay. Bacterial isolates identified included those belonging to genera Streptococcus spp., Staphylococcus spp., Aeromonas spp., Bordetella spp., Escherichia spp., Klebsiella spp., Enterobacter spp. and Acinetobacter species. Out of all Gram-negative isolates, nine (56%) isolates were resistant to at least one antimicrobial tested. We report detection of multidrug resistant Escherichia coli isolate from equine, which emphasizes the need to increase surveillance on antimicrobial resistant bacteria in equines. The OIE has categorized the Veterinary Important Antimicrobials under OIE List of Antimicrobials of Veterinary Importance, from which the antimicrobials of importance for equines practice has been discussed.