فاطمه زابلی - Department of Microbiology, Science and Research Ayatollah Amoli Branch, Islamic Azad University, Amol, Iran
سیدمجتبی مهدی پور میر - Department of Biology, Science and Research Ayatollah Amoli Branch, Islamic Azad University, Amol, Iran

Background and Objectives: Escherichia coli (E.coli) is one of the most common bacteria causing urinary tract infections which has become resistant to beta-lactam antibiotics due to the acquisition of plasmids encoding extended-spectrum beta-lactamases (ESBL). Here, we investigated the phenotype and genotype of Cefotaxsim-M (CTX-M) gene among ESBL-producing Escherichia coli among urine samples of patients reffering to Yahyanejad hospital of Babol city. Methods: The present cross-sectional study was conducted among all ۱۸۴۲ patients referring to Yahyanejad hospital since June to December of ۲۰۱۵. Disc diffusion method was used to evaluate the bacterial resistance to cefotaxime, meropenem, gentamicin, amikacin, ciprofloxacin, ceftriaxone, nitrofurantoin and nalidixic acid. The resistant strains were also confirmed using a combination of cefotaxime-clavulanic acid and ceftazidime-clavulanic acid discs. The presence of CTX-M gene was evaluated among ESBL-producing strains by Real time PCR. SPSS ۲۰ software and chi-square test were used to analyze data statistically. Results: A total of ۸۴ E.coli isolates were detected in all specimens. The most sensitivities were against amikacin (۹۱.۶۷%), meropenem (۹۶.۴۳%), ampicillin/sulbactam (۹۵.۲۴%) and  piperacillin/tazobactam (۹۴.۵%). However, the highest resistancies were against nalidixic acid (۸۳%) , doxycycline/ salicilin (۷۰%), ceftriaxone (۴۶.۶۳ %) and ciprofloxacin (۵۱.۲%). Twenty-nine isolates (۳۴.۵%) produced ESBL. The CTX-M positive ESBL-producing E-coli was ۶۹%. There was a significant relationship between the presence of CTX-M gene and ESBL (P-value = ۰.۰۳). Conclusion: In the present study, the presence of beta-lactamase-producing genes (CTX-M) in E.coli strains were markedly high. Therefore, the consumption of antibiotics should be controled and further phenotypic and genotypic studies on bacterial pathogens should be conducted.

Escherichia coli, antibiotic resistance, extended-spectrum beta-lactamases, Cefotaxsim-M, اشرشیاکلی, الگوی مقاومت, مقاومت آنتی بیوتیکی, بتالاکتاماز طیف گسترده (ESBL), ژن CTX-M, Real Time-PCR