JCM Accepts, published online ahead of print on 10 June 2009

This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services E-mail this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Reprints and Permissions Copyright Information Books from ASM Press MicrobeWorld Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Morand, P. C. Articles by Dumaine, V. Search for Related Content PubMed PubMed Citation Articles by Morand, P. C. Articles by Dumaine, V.

 Previous Article  |  Next Article 

J. Clin. Microbiol. doi:10.1128/JCM.00290-09
Copyright (c) 2009, American Society for Microbiology and/or the Listed Authors/Institutions. All Rights Reserved.

Specific distribution among the Enterobacter cloacae complex of strains isolated from infected orthopedic implants

Philippe C. Morand^*, Annick Billoet, Martin Rottman, Valérie Sivadon-Tardy, Luc Eyrolle, Luc Jeanne, Asmaa Tazi, Philippe Anract, Jean-Pierre Courpied, Claire Poyart, and Valérie Dumaine

Faculty of Medicine, Université Paris Descartes, Paris, France; Department of Bacteriology, Cochin Hospital AP-HP, Paris, France; Institut Cochin, INSERM U567, Paris, France; Laboratoire de Microbiologie, Hôpital Raymond Poincaré (AP-HP), Garches, France; EA 3647, Faculté de Médecine Paris-Ile de France-Ouest, Université de Versailles-Saint-Quentin en Yvelines, Garches, France; Department of Microbiology, Ambroise Paré Hospital AP-HP, Boulogne-Billancourt, France; Department of Anesthesiology, Cochin Hospital AP-HP, Paris, France; Department of Orthopedic Surgery, Cochin Hospital AP-HP, Paris, France

^* To whom correspondence should be addressed. Email: philippe.morand{at}cch.aphp.fr.

Bacteria belonging to the Enterobacter genus are frequently isolated from clinical samples but are unusual causative agents of orthopedic implant infections. Twelve genetic clusters (I to XII) and one sequence crowd (xiii) can be distinguished within the Enterobacter cloacae nomenspecies on the basis of hsp60 sequence analysis and, until now, none of these clusters could be specifically associated with a disease.

In order to investigate if specific genetic clusters would be involved in infections of orthopedic material, two series of bacterial clinical isolates, identified as "E. cloacae" using routine phenotypic methods, were collected either from infected orthopedic implants (n=21), or from randomly selected samples of diverse anatomical origins (control, n=52). Analysis of the hsp60 gene showed that genetic clusters III, VI and VIII were the most frequent in the control group, whereas cluster III was poorly represented in orthopedic implant isolates (P=0.006). On the other hand, E. hormaechei (clusters VI and VIII), but not cluster III, is predominantly associated with infections of orthopedic implants, and more specifically with hip infected material (P=0.019). These results support the hypothesis that, among the E. cloacae complex, E. hormaechei and hsp60-based cluster III are differently involved in pathogenesis, and highlight the need for more accurate routine Enterobacter identification methods.