Genotypic characterization of hospital Enterococcus faecalis strains using multiple-locus variable-number tandem-repeat analysis

Department of Food Hygiene and Consumer Health Protection, Faculty of Veterinary Medicine, Wrocław University of Environmental and Life Sciences, Wrocław, Poland.
Letters in Applied Microbiology (Impact Factor: 1.66). 05/2009; 49(1):79-84. DOI: 10.1111/j.1472-765X.2009.02629.x
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The level of genetic diversity and relationships between the specific genotypes and the distribution of virulence determinants among Enterococcus faecalis strains isolated from patients hospitalized in different wards of two hospitals were investigated.
Fifty-six clinical strains of E. faecalis, isolated from patients hospitalized in the period of 1999-2004 in several wards in Wrocław (Poland), were analysed by multiple-locus variable-number tandem-repeat analysis (MLVA). Analysis of seven genomic loci identified 40 novel genotypes among the analysed E. faecalis strains, with two major genomic groups, designated I and II, distinguished at a cut-off of 35%. With a similarity cut-off of 85.7%, the genotypes could be combined into 12 clusters (C1-C12), containing at least two isolates. The remaining 18 MLVA types were represented by a single isolate.
Based on the data obtained by MLVA, it was found that (i) many E. faecalis isolates recovered from patients from the wards whose location allowed the potential transmission of micro-organisms, belonged to closely related MLVA types and (ii) possible relationships between specific E. faecalis genotype and the virulence factors lipase, haemolysin and esp gene can exist.
Our study confirms that MLVA is a suitable method for the epidemiological study of E. faecalis and for the first time shows possible relationships between specific genotypes and such virulence determinants, i.e. lipase, haemolysin and esp gene.

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Available from: Maciej Ugorski, Dec 03, 2014
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    • "Surprisingly, in our study the occurrence of esp was not significantly associated with UTI isolates, although a role of Esp protein as urovirulence factor has been demonstrated [21]. However , the percentage of strains bearing esp was similar to that reported in other studies for Enterococcus faecalis [16] [18] [20]. Since the first studies on esp and its role in bacterial adhesion have been published [22] [23], several conflicting results have been reported. "
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