Virulence determinants in Escherichia coli associated with recurrent cystitis in sexually active women

Agarwal

Journal of Medical Microbiology

et al. 2014

Self Cite

Escherichia coli is the most common pathogen causing acute cystitis in sexually active women. Human faeces are generally considered the primary reservoir for infection and the faecalperineal-urethral pathway is the accepted route of infection. Two theories have been proposed for the pathogenesis of acute cystitis: (1) special pathogenicity, where uropathogenic E. coli (UPEC) encoding special virulence factors causes infection; and (2) prevalence, wherein ordinary faecal E. coli causes infection by simple mass action. The aim of this study was to compare concurrent urinary E. coli isolates from women with acute cystitis with their own dominant faecal, vaginal E. coli isolates; thus, these patients served as their own control. E. coli isolates from 80 women were analysed by phylotyping, virulence profiling (for 15 putative virulence genes) and enterobacterial repetitive intergenic consensus (ERIC) PCR. A virulence score was calculated for each isolate based on the number of virulence genes detected. Four host ecological groups of E. coli were created on the basis of ERIC PCR: group UVF, where vaginal and faecal isolates yielded the infecting urine clone; group UV, where only vaginal isolates yielded the infecting urine clone; group UF, where faecal isolates yielded the infecting urine clone; and group U, where the infecting urine clone was distinct. In the majority of cases the infecting E. coli clone from urine was also the dominant faecal clone (56.3 %; groups UVF and UF possessing high virulence scores of 4.6 and 3.9, respectively), indicating that both mechanisms play a role in pathogenesis. Non-dominant yet virulent faecal clones or an external source of E. coli seems a possibility in the UV group (13.7 %, VF score 4.8). In 30 % of patients (U group) the infecting urine clone was non-dominant and possessed a low virulence score (2.7); suggesting a possible role for host factors in establishing infection.

Section: Discussionsupporting

confidence: 93%

Section: Methodsmentioning

confidence: 99%

Role of special pathogenicity versus prevalence theory in pathogenesis of acute cystitis caused by Escherichia coli

Agarwal

Journal of Medical Microbiology

et al. 2014

Self Cite

“…Moreover, three moderate-biofilm producing isolates were belonged to the D (n=1) and B2 (n=2) phylogroups. In this study, the phylogroups B2 was predominant among E. coli isolates from pyelonephritis as exhibited in previous studies [33][34][35]. From our results and scarce previous studies it is concluded that the adhesive factors have an important role in the colonization, biofilm formation and dissemination of strains in the body.…”

Section: Discussionsupporting

confidence: 86%

Detection of virulence factors, phylogroups, serogroups and biofilm formation among CTX-M-1 positive Escherichia coli isolated from patients with pyelonephritis

Mostafavi¹,

Peerayeh²,

Mobarez³

et al. 2018

biomedicalresearch

Objectives: Urinary tract infections are among the most frequent infections caused by Escherichia coli isolates. The aims of this study were determination of antibiotic susceptibility and detection of virulence genes, phylogroups, serogroups and biofilm formation of E. coli isolates from patients with pyelonephritis. Methods: A total of 20 E. coli isolates were isolated from pyelonephritis. The antimicrobial susceptibility test was performed for eleven antibiotic disks. The biofilm formation assay was performed with Microtitre Tissue Plate (MTP) assay. The CTX-M1 gene and virulence genes including fimH, fyuA, traT, iutA, papII, kpsMII, ompT, ibeA, sfa, iroN, iucD, afaC, papI and papIII and also phylogroups and serogroups were detected with specific primers. Results: In the biofilm assay, one isolate produced strong biofilm. Among virulence encoding genes, 19 (95%) isolates amplified the all fimH, fyuA and traT genes, followed by iutA (90%, n=18), papII (75%, n=17), kpsMII (60%, n=12), ompT (55%, n=11), ibeA (30%, n=6), sfa (20%, n=5), and iroN=iucD=afaC=15%, (n=3), but none for papI and papIII. The majority (50%, n=10) of E. coli isolates from pyelonephritis belonged to the phylogroup B2, followed by phylogroups D and A (each equal to 20%, n=4) and B1 (10%, n=2). Seroproups included O25 (20%, n=4), O1 (15%, n=3), O4=O18=O75 (each equal to 10%, n=2), and O2=O12=O15=O16=1 (0.05%). Conclusion: The adhesive virulence factors play a critical role in the pathogenesis of pyelonephritis as their prevalence was high. Continued and vigilant surveillance is necessary to monitor the dissemination of antimicrobial resistance in uropathogens.

“…Biofilms are a layer of bacteria attached to biological tissues or artificial device surfaces, and biofilms have been reported to have several advantages for the survival of bacteria: increased capacity of bacterial conjugation ( 38 ), increased interspecific metabolic cooperation ( 39 ), and increased needs for higher concentrations of antibiotics ( 40 ). A study focused on E. coli associated with recurrent cystitis showed that recurrent infection isolates had better biofilm formation capability than single infection isolates ( 41 ), although this difference was not significant.…”

Section: Discussionmentioning

confidence: 99%

Clinical and Microbiological Characteristics of Recurrent Escherichia coli Bacteremia

et al. 2021