Genotyping of ESBL-Producing E. coli from Food-producing Animals, Animal Food Products and Humans in South-West, Nigeria

Abstract

Extended-spectrum beta-lactamase- (ESBL-) producing Escherichia coli strains are emerging globally in both humans and animals. The use of antibiotics in animal production and treatment has led to this phenomenon.  This study aimed at determining the resistance patterns of E. coli isolates from humans, food-producing animals, and their food products in South-western Nigeria. The prevalence and distribution of antibiotic-resistant E. coli in three categories were evaluated: Animals (goats, pigs, poultry, cattle, sheep), Humans (butchers, meat sellers, animal farm workers, buyers), and Animal food products (milk, cheese, beef, chicken, yogurt) from selected animal farms in South-west Nigeria.Out of a total number of 280 samples that were collected, 216 E. coli strains were isolated. The prevalence of isolated E. coli from humans (96%) was higher than that from animals (89%) and about 38.8% were isolated from animal food products. Out of the 216 E. coli isolates that were obtained from the different sources, 60 (27.8%) were multiple drug-resistant and were also ESBL- positive. Seven resistance genes were amplified in the multi-drug resistant Escherichia coli isolates: TEM (61.7%), CTX-M-15 (51.7%), AAC-6-LB (43.3%), CTX-M-1 (38.3%), CTX-M-9 (33.3%), CTX-M-2 (21.7%) and SHV (11.7%). The results suggest the need for continuous surveillance of antibiotic resistance to curtail the spread of resistance bacteria.