Antimicrobial susceptibility of animal and food isolates of Salmonella enterica

Background: Bacterial resistance to one or more antimicrobials is worrisome. Aim: To determine the susceptibility to antimicrobials of Salmonella enterica isolates from animals and food, from the Laboratory of Veterinary Microbiology at the University of Concepcion. Material and Methods: The samples were isolated according to traditional microbiological methods standardized protocols. Resistance was determined by the Kirby-Bauer method and minimal inhibitory concentration (MIC), following Clinical and Laboratory Standards Institute recommendations (2008). Results: Nine sero types were identified among the 68 isolates. Strains were resistant to one or more antibiotics and 11 patterns of resistance were identified. Multidrug resistance (MDR) was observed in 20.5% of the strains tested. The most common was Oxytetracycline resistance (69.1%). In food, the predominant serotype was S. Derby (2.9%) and S. Senftenberg (2.9%), which is commonly found in food intended for animal consumption. In samples of animal origin, the predominant sero types were S. infantis (33.8%) and S. Group E (3.9;-;-) (23.5%). Conclusions: The frequency of resistance found and the impending risk that these strains could reach humans through the food chain, should prompt a follow-up study of this pathogen.