Characterization of Escherichia coli obtained from patients undergoing peritoneal dialysis and diagnosed with peritonitis in a Brazilian centre

Abstract

Purpose. This study aimed to characterize 27 Escherichia coli isolates obtained from peritoneal dialysis (PD)-related peritonitis that occurred at the University Hospital of Botucatu Medical School, Brazil, between 1997 and 2015. Methodology. These isolates were characterized regarding the occurrence of 22 virulence factor-encoding genes, antimicrobial resistance and biofilm production. We then evaluated whether these factors influenced the clinical outcome. Results. Over an 18-year period, 726 episodes of PD-related peritonitis were diagnosed, with 27 of them (3.7 %) being due to E. coli . The majority of the isolates were classified in phylogroups B1 (33.3 %), B2 (30.0 %) or F (18.0 %). fimH (100.0 %), ompT (66.7 %) and irp2 (51.9 %) were the most prevalent genes, while papA, papC, iha, sat, irp2, iucD, ireA, ibe10, ompT and kpsMTII were significantly more prevalent among isolates belonging to phylogroups B2 and F (P<0.05). Non-susceptibility to quinolones was detected in six isolates, which harboured chromosomal and/or plasmid-mediated quinolone resistance determinants, while two CTX-M extended-spectrum β-lactamase-producing E. coli were identified. Virulence factor-encoding genes (alone or in combination) and antimicrobial resistance were not associated with non-resolution outcomes. However, there was a trend for the ability to produce biofilm to be associated with treatment failure, although this association was not statistically significant. Conclusion. The E. coli isolates were heterogeneous in terms of the features investigated, and were susceptible to most of the antimicrobial drugs tested, despite the unsuccessful treatment observed in more than 50.0 % of the patients. Studies including more cases could help to clarify if biofilm production can influence the outcome in patients with PD-related peritonitis.

Characterization of Uropathogenic Escherichia coli: Distribution of Adhesin-Encoding Genes and O-Serotypes Among Ciprofloxacin Susceptible and Resistant Isolates

“…In this study, 57 and 43 isolates were susceptible and resistant to ciprofloxacin, respectively that is consistent with the finding of Alishahi et al in Estahban-Iran (23). In our study, as we expected, almost all the isolates (95%) harbored the fimH gene were consistent with some previ-ous reports (24,25). Conversely, in agreement with other published data in Iran (26), the prevalence of fimH was reported 64 percent.…”

“…The E. coli sero-grouping was determined by the amplification of the following target genes: 25 , O 75 , and O 157 as described by Clermont et al (16). In brief, the experiment was performed in two separate PCR runs, including six reverse primers representative of six O-reverse and one universal forward primer (Table 1) as described by Clermont et al (16).…”

Predictive factors of outcome following nonfermenting gram-negative bacilli peritonitis in peritoneal dialysis

“…Previous publications by our group showed a high number of virulence factors among Staphylococcus aureus lineages, some of which are associated with worse PD-related peritonitis outcome, despite their low resistance rate to methicillin [29,30]. In a previous report on PD-related Escherichia coli peritonitis episodes, we did not nd any resistant strain to amikacin or ceftazidime used as initial treatment; in contrast, only 48.1% of the episodes progressed to resolution [31]. In the same study, approximately 50% of the isolates were medium or strong bio lm producers, which tended to be associated with nonresolution, but this did not reach statistical signi cance (p=0.09) [31].…”

“…In a previous report on PD-related Escherichia coli peritonitis episodes, we did not nd any resistant strain to amikacin or ceftazidime used as initial treatment; in contrast, only 48.1% of the episodes progressed to resolution [31]. In the same study, approximately 50% of the isolates were medium or strong bio lm producers, which tended to be associated with nonresolution, but this did not reach statistical signi cance (p=0.09) [31].…”

Comparison of clinical features and outcomes in peritoneal dialysis-associated peritonitis patients with and without diabetes: A multicenter retrospective cohort study

“…Previous studies showed that the PDAP E. coli isolates exhibited a superior virulence capability[ 26 , 27 ]. However, E. coli obtained from patients with PDAP did not show a common virulence profile and exhibited diverse serotypes[ 28 ]. Difference in virulence patterns of E. coli may explain a differential distribution frequency of infection between the DM group and non-DM group.…”