Prevalence and Antimicrobial Resistance of Escherichia coli Isolates from Chicken Meat in Romania

SIMPLE SUMMARY: In Romania, the consumption rate of chicken meat is high, while the broiler industry is a rapidly growing sector in the country. Chicken meat is often contaminated with various pathogenic bacteria, including Escherichia coli, which remains one of the most frequent causes of common bacterial infections in both animals and humans. The aim of the current study was to evaluate the prevalence of Escherichia coli in chicken meat samples, as well as to analyze the antimicrobial susceptibility of these isolates. An overall prevalence of 30% has been determined in our study, which seems to be lower compared to prevalence rates previously reported. However, the Escherichia coli isolates recovered in the current study showed substantial resistance to multiple antibiotic classes, including fluoroquinolones and third generation cephalosporins, which is concerning. The evaluation of the prevalence and antimicrobial resistance of Escherichia coli is highly important, both for food safety reasons, as well as for analyzing its public health impact and the spread of antimicrobial-resistant bacteria to humans. ABSTRACT: The current study was conducted in order to analyze the prevalence of Escherichia coli (E. coli) in samples of chicken meat (100 chicken meat samples), as well as to evaluate the antimicrobial susceptibility of these isolates. A total of 30 samples were positive for E. coli among the collected chicken samples. Most isolates proved to be highly resistant to tetracycline (80%), ampicillin (80%), sulfamethoxazole (73.33%), chloramphenicol (70%) and nalidixic acid (60%). Strong resistance to ciprofloxacin (56.66%), trimethoprim (50%), cefotaxime (46.66%), ceftazidime (43.33%) and gentamicin (40%) was also observed. Notably, one E. coli strain also proved to be resistant to colistin. The antimicrobial resistance determinants detected among the E. coli isolates recovered in our study were consistent with their resistance phenotypes. Most of the isolates harbored the tetA (53.33%), tetB (46.66%), blaTEM (36.66%) and sul1 (26.66%) genes, but also aadA1 (23.33%), blaCTX (16.66%), blaOXA (16.66%), qnrA (16.66%) and aac (10%). In conclusion, to the best of our knowledge, this is among the first studies analyzing the prevalence and antimicrobial resistance of E. coli strains isolated from chicken meat in Romania and probably the first study reporting colistin resistance in E. coli isolates recovered from food sources in our country.