High antimicrobial resistance in Salmonella spp. and Escherichia coli isolates from swine fecal samples submitted to a veterinary diagnostic laboratory in Colombia

Background: Commensal microflora such as Escherichia coli and Enterococcus spp. are representative indicators of antimicrobial resistance (AMR) they part the normal intestinal can acquire disseminate AMR to pathogenic or zoonotic bacteria like Salmonella Objective: To investigate state among E. spp., potential pathogens in humans, isolated from cecal contents pigs submitted a veterinary diagnostic laboratory Colombia 2016 2019. Methods: Susceptibility testing was conducted using Kirby-Bauer disk diffusion method according Clinical Laboratory Standards Institute guidelines for zone diameter breakpoints. An strain (ATCC 25922) used quality control organism. Isolates showing three more classes were classified multidrug-resistant (MDR) defined by joint group European Centre Disease prevention Control Center Prevention USA. Results: A total 112 192 colonies 557 samples received between In order decreasing frequency, resistant tetracycline (100%), sulfamethoxazol-trimethoprim (97.5%), amoxicillin (86.4%), enrofloxacin (82.6%), tylosin (82.1%), doxycycline (59%), neomycin (50%), ciprofloxacin (45.5%), ceftiofur (35%), gentamicin (30%), tilmicosin (29%), fosfomycin (12.5%). When compared with coli, generally same agents slightly less (between 10-30%) eight antimicrobials tested. showed <20% antimicrobials, follows: (17%), (16%), (14%). Multi-resistance occurred 68.7% (77/112) 70.3% (135/192) isolates. Resistance alarming all critically important tested: fluoroquinolones (enrofloxacin, ciprofloxacin), (thirdgeneration cephalosporin), macrolides (tylosin). Conclusions: According our results, there is high level multidrug It necessary implement nationwide monitoring program Colombia, together proper prescribing pigs. The indiscriminate use growth promoters swine industry generating widespread bacterial should be discontinued.