Evaluation of ESBL genes of blaTEM, blaSHV, blaoxa and aminoglycoside gene of aadA in Escherichia coli strains isolated in Tehran and determination of antimicrobial resistance

Nowadays, the widespread use of broad-spectrum beta-lactam antibiotics has increased antibiotic resistance around the world. The aim of this study was to assess and identify genes blaTEM, blaSHV, blaoxa and blaaada in clinical isolates E.coli by Multiplex- PCR methods.
In this descriptive study, 150 stool samples from different treatment centers in Tehran were randomly gathered; and biochemical tests detected 55 E. coli. Antimicrobial susceptibility testing was performed by disk diffusion method according to CLSI. Multiple PCR assay was used to identify the genes β-lactamase. Data were analyzed by descriptive statistical analysis using SPSS version 19.
Highest sensitivity was observed to cefpodoxime and trimethoprim (90.9% and 58.1% respectively) and the maximum resistance was reported to imipenem and ciprofloxacin (76.3% and 100% respectively). PCR results showed bla oxa gene in 40 isolates (72.7%), aadA gene in 15 samples (27.2%) and concurrent blaoxa/ aadA genes in 12 isloates (21.8%). blaTEM and blaSHV genes were not identified in samples.
Antibiotic resistance to E.coli in children with diarrhea is indicated the indiscriminate use of antibiotics. Monitoring and control of drug-resistant intestinal bacteria play a major role in preventing the creation of resistant strains.