The evaluation of beta-lactamases genes in E.coli species isolated from hospitals sewages in Ilam city

The wide application of antimicrobial agents in hospitals has led to large-scale dissemination of antibiotic-resistant bacteria in different environments. The aims of present study were to evaluation of antibiotic resistance in E.coli species isolated from Ilam hospitals wastewater and detection of extended-spectrumbeta-lactamasesblaTEM, blaSHV, blaCTX-M and FOX genes. Out of 81 E.coli species during one year period (from September 2014 to September 2015) isolated from wastewater samples given from hospitals in Ilam city. Samples were identified using routine microbiological and biochemical tests. The antibiotic resistance pattern of isolates to 14 different antibiotics has done by disk diffusion method and ESBL producing strains were characterized by phenotypic method as CLSI guideline and combination disk, phenotypic detection of AMPC producing isolates was performed using sensitivity to cefoxitin (30μg) and frequency of blaTEM, blaSHV, blaCTX-M-15 and blaFOX genes were evaluated by polymerase chain reaction (PCR). The antibiogram results showed that, the highest rates of resistance were related to amoxicillin (100%) and ampicillin-sulbactam (91.36%), and the highest rate of sensitivity were related to meropenem and imipenem (100%), among 81 species totally 30 isolates (37.3%) were detected as ESBL producing by phenotypic and double disk tests, and results of PCR showed that frequency of blaTEM, blaSHV, blaCTX-M-15 and FOX genes were 43.33%, 6.66%,20% and 4.93% respectively. The results of this survey showed that, thebacterial strains isolated from the hospital wastewater exhibited about 44% of the 4 investigated resistance genes, which could be further disseminated among environmental bacteria.

کلیدواژه ها:

Antibiotic resistance ، beta-lactamases genes ، E.coli ، Hospital sewage