Prevalence of extended-spectrum β-lactamase (ESBL)-producing Escherichia coli associated with outbreaks of food-borne gastroenteritis in Tehran

Abstract

The prevalence of antibiotic resistance has been demonstrated in various food-borne pathogens. Beta-lactam antibiotics are among the first-line antimicrobials that are normally administered in case of gastrointestinal infections. However, Escherichia coli (E. coli) and some other members of Enterobacteriaceae have indicated broad resistance against such antibiotics thanks to extended-spectrum beta-lactamase (ESBL) enzymes. In this research, 216 stool samples have been screened for ESBL-producing E. coli, using phenotypic antibiotic susceptibility tests. ESBL-producing E. coli isolates were further screened for the presence of antibiotic-resistance genes CTX-M, SHV, and TEM. Our isolation experiments resulted in 111 E. coli isolates among which 41 (36.9%) isolates were found as ESBL. Also, 51.2% of the above ESBL isolates harbored blaTEM. Furthermore, 18 (43.9%) and 2 (4.9%) of those ESBL isolates had blaCTX-M and blaSHV genes, respectively. Our results revealed a detectable prevalence of ESBL E. coli in stool samples collected during food outbreaks. Results of such researches can guide how to control the distribution of drug-resistant pathogens in various environments. In this line, the considerable prevalence of ESBL E. coli seems to have originated from the wide administration of various beta-lactam antibiotics.

Keywords

• beta-lactamase
• clavulanic acid
• drug-resistant pathogens
• food-borne infections
• gastroenteritis symptoms
• klebsiella pneumonia