Escherichia coli

Abstract

Extended-spectrum β-lactamase (ESBL) - producing bacteria of the Enterobacteriaceae family are considered to be one of the most frequently occurring groups of multidrug-resistant bacteria worldwide. Resistance is mediated by the production of β-lactamase enzymes having the ability to hydrolyse a variety of β- lactam antibiotics used to treat most bacterial infections. Escherichia coli is the most comprehensive ESBL-producing organism isolated and is known to cause the greatest number of infections. Recent studies in a number of European countries have identified similar ESBL-producing strains in food-producing animals, particularly in poultry meat, and in humans, indicating that the food chain is a source of spread of ESBL-mediated resistance. Since no local data is available, a pilot study was undertaken to determine the prevalence of ESBL in E. coli strains in poultry meat. One hundred (100) poultry meat samples were purchased from different outlets around Malta and Gozo to determine the prevalence of ESBL-producing E. coli in local chicken meat. ESBL-producing E. coli were isolated on MacConkey agar supplemented with 1mg/L cefotaxime. Species verification for E. coli was performed using Tryptone Bile X-Glucoronide agar, a selective chromogenic medium for E. coli. Confirmed E. coli isolates were tested for ESBL mediated resistance using the ESBL/AmpC disk diffusion test. The overall prevalence was 56% at a 95% confidence interval (46.3%, 65.7%). This first local study on ESBL-producing E. coli in poultry meat, has identified a significant prevalence of resistance that merits future, farmbased studies on antimicrobial resistance within livestock. It also emphasizes the importance of monitoring livestock for antimicrobial resistance and increasing the surveillance on veterinary antimicrobial use in farms.