Antimicrobial sensitivity and efficacy of sanitizers against the Salmonella spp. isolated from swine slaughterhouse in southern Brazil

The aim of this study was to evaluate the antimicrobial sensitivity and efficacy of three sanitizers against Salmonella spp. isolated from carcasses in swine slaughterhouse. Thirty nine of 120 samples were positive for Salmonella spp. The antimicrobials tested included: penicillin G 10 U, amoxicillin + clavulanic acid 30mcg, ampicillin 10mcg, chloramphenicol 30mcg, tetracycline 30mcg, streptomycin 10mcg, gentamicin 10mcg, neomycin 30mcg, enrofloxacin 5mcg, sulfazotrim 25mcg, sulfonamide 300mcg and trimetropim 5mcg. In the tests with sanitizers were used chlorhexidine, quaternary ammonia and peracetic acid, which were put in contact intervals of 1, 5, 10 and 15 minutes. Antimicrobial resistance was observed using penicillin (100%), tetracycline (94.9%), trimetropim (89.7%), and ampicillin (87.2%). None of the antimicrobials was 100% effective against the samples tested. Amoxicillin + clavulanic acid (86.7%), neomycin (86.7%) and chloramphenicol (64.1%) showed better antimicrobial action. In tests of efficacy of sanitizers, 0.5% peracetic acid was effective at 10 minutes (94.6%) and 15 minutes (97.3%) of contact; 1% quaternary ammonia at 10 minutes (89.2%) and 15 minutes (97.3%) and 0.5% chlorhexidine at 10 minutes (70.3%) and 15 minutes (72.8%). All samples tested were multidrug resistance and six (15.3%) showed resistance to ampicillin, chloramphenicol, streptomycin, sulfonamide and tetracycline (ACSSuT group) indicating the need to monitor the spread of antimicrobial resistance of Salmonella spp. isolated from swine. The most effective sanitizing against the bacteria tested was 0.5% peracetic acid per 15 minutes, reinforcing the need to monitor the effectiveness of products sanitizers against Salmonella spp.