Iranian Journal of Medical Microbiology (Jan 2019)
Molecular Identification and Serotyping of Isolates of Verotoxin Producing Escherichia coli Isolated from Urinary Tract Infection in Samples of Patients Referred to Health Centers in Khoy
Abstract
Background and Aims: Urinary tract infections are among the most common infectious diseases. The bacterium of Escherichia coli, which produces verotoxin venom, is one of the most common causes of urinary tract infections. The aim of this study was to identify the molecular and serotyping of the isolates of E. coli producing verotoxin from the urinary tract infection in patients referred to the health centers in Khoy. Materials and Methods: 200 urine samples of people suspected to urinary tract infection were identified by using standard culture and biochemical methods of E. coli. The bacterium was isolated in term of the susceptibility pattern to antibiotics and was studied using disc diffusion method. To do Serotyping, strains with polyvalent antisera were tested. DNA was isolated from bacteria after extraction. The Verotoxin producing isolates were identified by Multiplex PCR. Results: 78 urine samples were identified as E. coli. E. coli isolates had the most antibiotic resistance to ampicillin and had the highest susceptibility to Norfloxacin. In serotyping, Group 3 had the most common strains of E. coli. Among the samples that were studied using Multiplex PCR and specific primers, stx1 genes were observed in 3 isolated isolates and stx2 genes were observed in 16 isolated isolates and both stx1 and stx2 were seen in 9 isolates. Conclusions: Serotypes of O25, O78, O103, O118, O124, O145, O157 and O164 were the most frequent infection-specific serotypes. The frequency of E. coli strains with stx2 gene producing verotoxin was more than stx1. High resistance to ampicilin is probably due to the excessive consumption of these antibiotics. Norfloxacin can be an appropriate choice for the treatment.
