Determining the Frequency of Genes Producing Colicins Ia and V in Escherichia coli Strains Isolated from Clinical Samples of Medical Centers in Yazd City

Abstract

Introduction: Bacteriocins are peptides with antimicrobial properties. They are ribosomally synthesized and produced by both gram-positive and gram-negative bacteria. The bacteriocins produced by Escherichia coli are called colicins. Colicins in commensal bacteria inhibit the growth of pathogenic bacteria and in pathogen strains, they increase bacterial virulence. The aim of this study was to evaluate the frequency of col V and col Ia genes in Escherichia coli specimens isolated from patients with urinary tract infections in Yazd City, Iran. Methods: In this descriptive cross-sectional study, 160 Escherichia coli samples were isolated from urine specimens and identified by common biochemical tests. The amplification of col V and col Ia genes was performed by PCR method using specific primers and after sequencing, the results were analyzed using SPSS version 16 software. Results: In this study, out of 160 Escherichia coli isolates examined, calicin gene was detected in 26.9% of the isolates. The frequency of col Ia gene was 24.4% and the frequency of col V gene was 10.6%. Furthermore, in 8.12% of isolates, both genes were identified together. The frequency of isolates containing only col Ia gene was 16.2% and isolates containing only col V gene was 2.5%. Conclusion: In this study, isolates with col Ia gene showed high frequency. Most strains with col V gene also had col Ia gene. Therefore, the col V gene is often observed together with the col Ia gene.

Keywords

• escherichia coli
• bacteriocin
• colicin.