Study of antibiotic resistance pattern and ESBls in Pseudomonas aeruginosa isolates obtained from hospitalized patients from Amiralmonenin hospital, Zabol, southeast of Iran

Introduction and objectives: Pseudomonas aeruginosa is an opportunistic pathogen of human and animals that causes different kind of infections. The aim of this study is detection of the antibiotic resistance pattern and the ESBLs in P. aeruginosa local isolates which were obtained from hospitalized patients in Amiralmonenin hospital, Zabol, Iran. Materials and methods: Study population were included, 80 local isolates of P .aeruginosa that had been cultivated from patients bedridden in Amiralmonenin hospital during 2017-2018. This research is a cross-sectional descriptive-analytic study. P. aeruginosa isolates were identified by biochemical tests and sensitivity to antibiotics was measured by disk diffusion method. Combined Disk Diffusion method (CDD) was used to detect ESBLs (Extended Spectrum- beta Lactamases) in these isolates. ESBL genes were screened by PCR method. Results: The results obtained from CDD test showed that among the 80 isolate of P .aeruginosa, 32 samples (40%) were ESBL positive. Resistance to Azithromycin was 72.5%, Amoxicillin 97.9%, Amoxiclav 90%, Imipenem 0%, Gentamicin 50%, Cotrimoxazole 75%, Ciprofloxacin 28.8%, Cefotaxime 52.5%, Cefalexin 81.3% Ceftriaxone 60%, Ceftazidime 75% and Nitrofurantoin 75%. ESBL genes including, bla(shv), bla(ctxm1)، bla(ctxm2), bla(ctxm3) and bla(oxa) were existed in 15.6% of isolates. bla(ctxm3) gene were the most prevalent ESBL gene (84.4%) in compare to the others and bla(ctxm2) gene was not detected in any isolate. Conclusion: The results of the study indicated high rate of the resistance to various classes of antibiotics among the P. aeruginosa isolates. Therefore, it could be concluded that detection of antibiotic resistance pattern of the P. aeruginosa isolates have to be done before any antibiotic prescription in any infection attributed to this pathogen.

Keywords:

Pseudomonas aeruginosa , antibiotic resistance , Extended spectrum β-lactamases (ESBL)