Prevalence and Antibiotic Resistance Pattern of Extended Spectrum β-Lactamase- (ESBL-) Producing Gram Negative Bacilli isolated from Clinical Samples of hospitalized Patients in a hospital in Gorgan

Antibiotic resistance among gram-negative bacilli is currently one of the major challenges for the health system in developing countries. The aim of this study was to determine the frequency and antibiotic resistance pattern of common ESBL-producing gram negative bacilli isolated from clinical specimens of hospitalized patients in Falsafi Hospital in Gorgan.

In this descriptive cross-sectional study, during October to December 2016, clinical samples of hospitalized patients including urine, blood and wound specimens were examined for the presence of common Gram-negative bacilli. Then the drug resistance pattern of the isolates and the production of ESBLs were determined by disk diffusion and phenotypic methods.

Of 154 clinical samples, 100 samples were positive for gram-negative bacilli and 50 isolates of Escherichia coli, 38 isolates of Pseudomonas aeruginosa and 12 isolates of Klebsiella pneumoniae were identified. All the isolates were resistant to ampicillin and co-trimoxazole antibiotics. 17% of the isolates were phenotypically ESBL positive and this enzyme had the highest frequency among K. pneumoniae isolates (41.6%).

The results of this study, in line with the results of other researchers, indicate high prevalence of ESBL in clinical isolates of K. pneumoniae. Therefore, third-generation cephalosporins are not recommended in treatment of infections caused by K. pneumonia as the first line drug.