Molecular epidemiology of Enterococcus sp. isolated in a university hospital in Algeria

Abstract

Background: The aim of this study was to describe the epidemiology of enterococci isolated from infections at an Algerian university hospital, and to evaluate the prevalence of vancomycin-resistant enterococci (VRE) and the clonal cluster present in this country. Methods: Patients who presented at Annaba University Hospital with Enterococcus infections were prospectively included over a 1-y period (2010). All Enterococcus sp. isolated were characterized by antibiotic resistance, van and erm genes, repetitive sequence-based polymerase chain reaction (rep-PCR), multi-locus sequence typing (MLST), and virulence genes. Results: A total of 125 Enterococcus isolates recovered from 125 patients (59% female; median age 54 y, range 2–86y) were studied. No differences in epidemiological data were observed between infections by Enterococcus faecalis vs Enterococcus faecium. However a high proportion of E. faecium were resistant to ampicillin (95%). The prevalence of VRE, corresponding to 4 vanC1-Enterococcus gallinarum, was 3.2%. A high level of genomic diversity among strains was noted, with the importance of sequence type (ST) 78 (which belongs to clonal complex (CC) 17) in E. faecium and ST317 and CC2 in E. faecalis. Conclusions: This first study on enterococci isolated in Algeria shows the low prevalence of VRE, but the presence of clonal complexes linked to VRE and vancomycin-sensitive enterococci associated with hospital infections. Moreover the high level of macrolide resistance and/or ampicillin resistance in E. faecium suggests close monitoring of the epidemiology of these strains.

Keywords::

• Clonal complex
• clonality
• Enterococcus
• MLST
• virulence

Acknowledgements

We thank Laure Vidal-Navarro for her help with this manuscript. This work was supported by INSERM, Université de Montpellier 1 and La Région Languedoc-Roussillon (“Chercheur d'Avenir” grant 2009).

Declaration of interest: The authors report no conflicts of interests. The authors alone are responsible for the content and writing of the paper.