Prevalence of class 1 and 2 integrons in multi-drug resistant Escherichia coli isolated from aquaculture water in Chaharmahal Va Bakhtiari province, Iran

Background: Integrons play important role in the spread and maintenance of antimicrobial resistance among strains of Escherichia coli (E. coli) and other species of Enterobacteriaceae. This study investigated the prevalence of class 1 and 2 integrons among E. coli strains isolated from aquaculture water of fish fields in Iran. Methods: One hundred and fifty water samples from different geographical regions in Chaharmahal Va Bakhtiari province were examined over a 2 months period. Isolation was through culture and biochemical tests. Integrons were identified through polymerase chain reaction (PCR) using oligonucleotide primers specific for class 1 and 2 integrons. Antimicrobial susceptibility testing was carried out using disc diffusion methods. Results: Eighteen percent of the water samples were positive for E. coli. All the strains were multi-drug resistant; 100% to ciprofloxacin, chloramphenicol, gentamycin, ampicillin and tetracycline and least resistant to imipenem (7.2%). Ten (50%) of the most resistant strains were positive for class 1 (40%) and class 2 (10%). Conclusions: Escherichia coli in aquaculture in Iran carried integrons class 1 and 2 which could be of public health concern since they could play a role in the spread and maintenance of antimicrobial resistance among bacterial population in the region and should be constantly monitored.

Antimicrobial resistance, Aquaculture, E. coli, Integrons, Iran