Repository of Research and Investigative Information

Repository of Research and Investigative Information

Baqiyatallah University of Medical Sciences

Frequency of bla TEM, bla SHV, bla CTX-M, and qnrA among Escherichia coli isolated from urinary tract infection

(2014) Frequency of bla TEM, bla SHV, bla CTX-M, and qnrA among Escherichia coli isolated from urinary tract infection. Archives of Clinical Infectious Diseases. ISSN 23452641 (ISSN)

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Background: Escherichia coli is the most important as well as the most common bacteria causing urinary tract infections (UTIs) and its resistance to common antibiotics is increasing. Extended-spectrum beta-lactamase (ESBL) producer E. coli strains can resist against the third-generation and fourth-generation cephalosporins. Objectives: This study aimed to evaluate the resistance profile of E. coli isolated from patients with UTIs referred to Imam Khomeini and Baqiyatallah hospitals, Tehran, Iran, through phenotypic and molecular methods. Materials and Methods: During 2010-2011, 180 urine samples of patients with UTIs from Imam Khomeini and Baqiyatallah hospitals were collected. Based on the standard bacteriologic tests, E. coli isolates were identified. Resistance to common antibiotics was tested by the Kirby-Bauer method and reconfirmed by determining minimum inhibitory concentration (MIC) through microdilution method. Further phenotypic double-disk synergy test (DDST) was performed to screen the ESBL producer strains. Resistance genes related to ESBL and qnrA were evaluated by Polymerase chain Reaction (PCR). Results: A total of 100 E. coli strains were examined by antibiogram and the rates of resistance to the tested antibiotics were as follows: 100 to penicillin and amoxicillin, 77 to amoxicillin-clavulanic acid, 72 to ceftazidime, 69 to cefotaxime, 47 to cefoxitin, 46 to ceftriaxone, 43 to cephalexin, 27 to aztreonam, 53 to nalidixic acid, 51 to ciprofloxacin, and 2 to imipenem. The MIC to ciprofloxacin, cefazolin, and ceftriaxone were ≥ 0.249, ≥ 0.508, and ≥ 0.044, respectively. Moreover, 20 of E. coli isolates were ESBL-producing isolates by DDST. The frequency of bla CTX-M, bla TEM, bla SHV, and qnrA genes was 87, 82, 65, and 39, respectively. Conclusions: Considering the high prevalence of ESBL genes (bla CTX-M, 87; and bla TEM, 82), fluoroquinolones may be used as an alternative drug in treatment, although resistance to this family is increasing as well. As a result, this increasing trend should be prevented using appropriate guidelines for prescription.

Item Type: Article
Keywords: Beta-Lactamases bla CTX-M bla SHV bla TEM Escherichia coli amoxicillin amoxicillin plus clavulanic acid aztreonam beta lactamase CTX M beta lactamase SHV cefalexin cefotaxime cefoxitin ceftazidime ceftriaxone ciprofloxacin imipenem nalidixic acid penicillin derivative antibiotic resistance antibiotic sensitivity article bacterial gene bacterial strain bla CTX-M gene bla SHV gene bla TEM gene controlled study extended spectrum beta lactamase producing Escherichia coli minimum inhibitory concentration nonhuman qnrA gene
Journal or Publication Title: Archives of Clinical Infectious Diseases
Journal Index: Scopus
Volume: 9
Number: 1
Identification Number:
ISSN: 23452641 (ISSN)
Depositing User: مهندس مهدی شریفی

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