Comparative analysis of amplified fragment length polymorphism and pulsed field gel electrophoresis in a hospital outbreak and subsequent endemicity of ampicillin-resistantEnterococcus faecium

Abstract

Reliable molecular methods for determination of relatedness between bacterial isolates have become increasingly important to evaluate outbreaks and endemic situations with nosocomial pathogens. In the present study Simpson's index of diversity with calculated confidence intervals was used to compare amplified fragment length polymorphism (AFLP) and pulsed field gel electrophoresis (PFGE) analysis of a hospital outbreak of ampicillin-resistant Enterococcus faecium and subsequent endemicity. The outbreak, in a Norwegian tertiary hospital, of infections caused by these enterococci started in 1995 and increased in 1996 after which the situation turned endemic. The purpose of this study was to compare the two methods in this setting and to determine the length of time during an outbreak that these methods are sufficiently valid to be of value for hospital infection control efforts. One hundred and sixty clinical isolates from urine specimens collected during the period 1995-1999 were included. The findings indicate that PFGE and AFLP are equally discriminative and could in this setting be used for typing purposes over the whole 5-year period.

Genotypic characterisation of vancomycin-resistant Enterococcus faecium isolates from haemato-oncological patients at Olomouc University Hospital, Czech Republic

“…Although macrorestriction analysis does not readily establish the degree of genetic relatedness of isolates with substantially different PFGE patterns, it is a highly reproducible typing method that is capable of distinguishing among clonal populations of VRE. Moreover, grouping of isolates by PFGE correlates well with the results obtained by other typing techniques [24,25,32]. In the present study, PFGE identified 32 unique restriction patterns with a similarity ranging from 65% to 98%, which is comparable to the high intra-species genomic variability seen in E. faecium isolates from various sources [33].…”

Emergence of CC17Enterococcus faecium: from commensal to hospital-adapted pathogen

“…Most importantly, though, there were genetic differences between VREF isolated from feces of nonhospitalized persons without infection (genogroup A) and isolates from hospitalized patients of fecal origin or from infected body sites like blood (genogroup C). Other studies confirmed the existence of these genogroups among vancomycin‐susceptible E. faecium (VSEF) isolates originating from different sources (Borgen et al , 2002; Bruinsma et al , 2002; Jureen et al , 2003, 2004; Coque et al , 2005). Furthermore, AFLP exhibited a discriminatory power comparable to PFGE and discriminated outbreak‐related isolates from other isolates (Jureen et al , 2004).…”

Detection of CC17 Enterococcus faecium in Dogs and a Comparison with Human Isolates

“…Three virulence genes, esp , hyl and acm , were also identified by PCR (Vankerckhoven et al., 2004; Camargo et al., 2006). Multilocus sequence typing and pulsed field gel electrophoresis (PFGE) were performed for the genetic comparisons (Jureen et al., 2004; Camargo et al., 2006). Sequence types (STs) and CCs were determined using http://efaecium.mlst.net, and PFGE patterns were analysed with B io N umerics software package v.6.0 (Applied Maths, Sint‐Martens‐Latem, Belgium) using Dice coefficient (optimization, 0.5%; band matching tolerance, 1%) and the unweighted pair group method using arithmetic mean (UPGMA).…”