Isolation and the genetic study of antibiotic-resistant Escherichia coli strains in the urine of patients referred to Ahvaz Veterans Clinic

Introduction & Objectives: Escherichia coli strains, which produce extended-spectrum β-lactamases (ESBLs), have caused many therapeutic problems due to their resistance to various antibiotics. This study aimed to isolate and determine the pattern of antibiotic resistance of different strains of this bacterium based on the presence of resistant genes including TEM, CTX-M, and SHV in the urine of patients referred to Ahvaz Veterans Clinic.Materials & Methods: 70 Escherichia coli strains were identified and isolated from urine samples of patients and then identified by staining and biochemical analyses. The antimicrobial susceptibility test was performed by the disk diffusion method based on CLSI standards. The presence of SHV, CTX-M, and TEM was shown using Multiplex-PCR, and Rep-PCR also applied to determine the genetic relations between resistance strains.Results: The results among the 11 studied antibiotics showed that the highest and lowest of antibiotic resistance were related to the Nalidixic acid and Cefixime in 72.85 and 64.28% of the strains, respectively, and the Imipenem in 11.24% of the strains. In addition, the frequency of CTX-M, TEM, and SHV genes between resistant strains was 31.42, 12.85, and 57.14%, respectively. These three genes were not present simultaneously in any of the studied strains, but 18 strains had two resistant genes in their genomes. A total of 52 different genetic patterns were found in the resistant strains of Escherichia coli.Conclusion: The results indicate the expansion of the Escherichia coli strains which produce ESBLs and thus the increase of Escherichia coli antibiotic-resistance in the patients' urine. Therefore, the antibiotic treatment of urinary tract infections caused by Escherichia coli in medical centers should be done with more care and after genetic analysis to prevent the increase of such dangerous resistant strains in the community and especially in hospitals.

کلیدواژه ها:

Antibiotic resistance ، ESBLs ، Escherichia coli ، Ahwaz