Genetic Evaluation ofE. coliStrains Isolated from Asymptomatic Children with Neurogenic Bladders

Abstract

This study was conducted to describe the genetic profiles of E. coli that colonize asymptomatic pediatric neurogenic bladders. E. coli was isolated from 25 of 80 urine samples. Patients were excluded if they presented with symptomatic urinary tract infection or received treatment with antibiotics in the preceding three months. Multiplex PCR was performed to determine E. coli phylotype (A, B1, B2, and D) and the presence of seven pathogenicity islands (PAIs) and 10 virulence factors (VFs). E. coli strains were predominantly of the B1 and B2 phylotype, with few strains in the A or D phylotype. The PAIs IV536, ICFT073, and IICFT073 had the highest prevalence: 76%, 64%, and 48%, respectively. The PAIs II536, IJ96, and IIJ96 were less prevalent: 28%, 20%, and 24%, respectively. The most prevalent VF was vat (40%), while the least prevalent VFs were sfa (8%) and iha (12%). None of the strains carried the VF fyuA, which is very common in uropathogenic E. coli (UPEC). The genetic profiles of E. coli in this cohort seem to be more similar to UPEC than to commensal E. coli. However, they appear to have reduced virulence potential that allows them to colonize asymptomatically.

Pathogenic features of urinary Escherichia coli strains causing Asymptomatic Bacteriuria during Pregnancy

“…In this study, E. coli isolates were highly resistant to nalidixic acid, trimethoprim/sulfamethoxazole and ampicillin by more than 70%, and sensitivity values above 80% were found to imipenem, aztreonam and nitrofurantoin. Findings are in line with the earlier studies in Iran [6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23]. The findings of previous studies as well our current findings indicate that ESBL and AmpC-β-lactamase-producing isolates are typically resistant to others antibiotics such as trimethoprim/sulfamethoxazole and fluoroquinolones [13].…”

“…DNA was extracted from one single colony of each isolate by incubation in a final volume of 100 μL of distilled water at 95 °C for 10 min followed by centrifugation. PCR was used to detect thirteen genes encoding virulence determinants that are usually associated with the E. coli strains responsible for extraintestinal infections: including (fmH, papC, sfa/focDE, sfaS, kpsMTII, ecpA, ecpR-B, hlyA, cnf-1, papGII, iutA , tratT, and fyuA), genes [5][6][7][8][9][10][11][12][13][14]. Also PCR screening was used for the presence of different beta-lactamase genes (bla TEM , bla SHV , bla CTXM ) (15).…”

“…Phylogenetic analyses have shown that E. coli strains falls into four main phylogenetic groups (A, B1, B2, and D), each of which has a unique panel of genes that characterize its own evolutionary pattern. Various studies have exhibited that groups B2 and D are proportionately higher in pathogenic samples and usually more virulent, whereas groups A and B1 tend to be found at higher rates in commensal samples [9,10].However, there are few studies on virulence factor genes (VFGs), antimicrobial resistance and pattern of phylogenetic groups amongst the E. coli isolated from asymptomatic pregnant women in Iran. The objective of our study was investigated the prevalence of virulence genes, antimicrobial resistance, and its relationship with phylogenetic groups among E. coli strains isolated from asymptomatic pregnant women who referred to Hafez hospital, Shiraz, Iran.…”

On the potential role of intestinal microbial community in hepatocarcinogenesis in chronic hepatitis B

“…It also seems to be a harmless commensal that uses its host for a continuous source of nutritive, existing, and survivor. However, E. coli with a notable phenotypic variety of intestinal and extra intestinal pathogenic strains are associated with over 2 million human deaths per year . The genetic structures of commensal E. coli are shaped by the various host and environmental characteristics that determine bacterial adaptation .…”

“…However, E. coli with a notable phenotypic variety of intestinal and extra intestinal pathogenic strains are associated with over 2 million human deaths per year. 39,40 The genetic structures of commensal E. coli are shaped by the various host and environmental characteristics that determine bacterial adaptation. 41 E. coli strains can be classified into four main phylogenetic groups A, B1, B2 and D which differ in some features such as genome size and plasticity, virulence, and antibiotic resistance profiles.…”