Comparison of Virulence Factors Distribution in Uropathogenic E. coli Isolates From Phylogenetic Groups B2 and D

Abstract

Background: Urinary tract infections are a significant health problem, with Escherichia coli as a primary pathogen in approximately 80% of cases. The pathogenesis of E. coli in urinary tract infections is attributed to the production of virulence factors and phylogenetic background groups. Objectives: The aim of this study was to determine differences in prevalence of virulence factors of E. coli isolates from phylogenetic groups B2 and D, collected from patients with urinary tract infections. Materials and Methods: A total of 100 E. coli isolates were identified by conventional biochemical tests from patients with urinary tracts infections (UTIs) in teaching hospitals of Zabol, Iran. DNA was extracted using the boiling method. Analysis of phylogenetic groups, along with detection of virulence factor genes was performed by the multiplex-PCR method. Associations were assessed between type 1 fimberiaencoding gene, siderophore receptor encoding genes and hemolysin encoding gene among 55 B2 group E. coli isolates and 22 D group E. coli isolates. Statistical analysis was performed using the Fisher exact test. Results: Phylogenetic analysis showed that 55 and 22 of 100 isolates belonged to the B2 and D phylogenetic groups, respectively. The hlyA, iroN, iucD and fimH genes were present in 29 (52.72%), 22 (40%), 46 (83.63%) and 55 (100%) isolates belonging to the phylogenetic group B2, whereas in 2 (9.09%), 2 (9.09%), 10 (45.45%) and 22 (100%) isolates belonging to the phylogenetic group D, respectively. The comparison showed that there was a significant difference between the presence of hlyA and iroN genes in isolates belonging to the phylogenetic group B2 and D (P ≤ 0.05). Conclusions: This study determined that strains belonging to group B2 are the most important and abundant E. coli strains causing urinary tract infections.

Phylogenetic Distribution of Virulence Genes Among ESBL-producing Uropathogenic Escherichia coli Isolated from Long-term Hospitalized Patients

“…As reported previously, most of the uropathogenic E.coli isolates belonged to the phylogenetic group B2, D [25] and most of VGs were more prevalent in phylogenetic group B2 and/or D [26][27][28][29]. In the study, the number of VGs detected varied within the phylogroups and was significantly higher in group B2 than in other three groups.…”

Prevalence of Genes Encoding Outer Membrane Virulence Factors Among Fecal Escherichia coli Isolates

“…26 The virulence genes of UPEC bacteria such as iroN, iucD and irp2 have been previously recorded from Iran. 11,12 However, according to published data, there is no information on the occurrence of these genes in FeEC isolates. The distribution of the ompT gene among the studied isolates was also similar to that in the previously reported data.…”

“…Multiple studies have been done in different parts of Iran in order to investigate the frequency of virulence genes among UPEC. [11][12][13] However, there is no information about the frequency of virulence mediators in FeEC isolated from human in Iran. Therefore, this study was conducted to examine the distribution of 8 virulence factors, including type 1 fimbriae (fimH), iron-regulated gene homologue adhesion (iha), alpha-hemolysin (hlyA), outer membrane protease (ompT), aerobactin (iucD), yersiniabactin (irp2), salmochelin receptor (iroN) and cytotoxic necrotizing factor 1 (cnf1) in E. coli strains isolated from human feces in Zabol, southeast of Iran, by using the multiplex polymerase chain reaction (PCR) method.…”

Investigation of fimH Single Nucleotide Polymorphisms (C640T and T591A) in Uropathogenic E. coli Isolated from Patients with Urinary Tract Infections

“…E. coli virulence genes are also main factors in the etiology of UTIs, as well as human susceptibility factors (1,22,23). It has been reported that the UPEC strains which cause most UTIs form a genetically different group with multiple virulence factors (24). Generally, the combination of various factors in host and pathogen has determined the individual susceptibility to UTIs.…”