Escherichia coli variants in periprosthetic joint infection: diagnostic challenges with sessile bacteria and sonication.

Details

Serval ID
serval:BIB_305A4113E24A
Type
Article: article from journal or magazin.
Collection
Publications
Institution
Title
Escherichia coli variants in periprosthetic joint infection: diagnostic challenges with sessile bacteria and sonication.
Journal
Journal of Clinical Microbiology
Author(s)
Sendi P., Frei R., Maurer T.B., Trampuz A., Zimmerli W., Graber P.
ISSN
1098-660X[electronic], 0095-1137[linking]
Publication state
Published
Issued date
2010
Volume
48
Number
5
Pages
1720-1725
Language
english
Notes
Publication types: Case Reports ; Journal Article ; Research Support, Non-U.S. Gov't
Publication Status: ppublish
Abstract
The diagnostic yield of prosthetic joint-associated infection is hampered by the phenotypic change of bacteria into a sessile and resistant form, also called biofilm. With sonication, adherent bacteria can be dislodged from the prosthesis. Species identification may be difficult because of their variations in phenotypic appearance and biochemical reaction. We have studied the phenotypic, genotypic, and biochemical properties of Escherichia coli variants isolated from a periprosthetic joint infection. The strains were collected from synovial fluid, periprosthetic tissue, and fluid from the explanted and sonicated prosthesis. Isolates from synovial fluid revealed a normal phenotype, whereas a few variants from periprosthetic tissue and all isolates from sonication fluid showed different morphological features (including small-colony variants). All isolates from sonication fluid were beta-galactosidase negative and nonmotile; most were indole negative. Because of further variations in biochemical properties, species identification was false or not possible in 50% of the isolates included in this study. In contrast to normal phenotypes, variants were resistant to aminoglycosides. Typing of the isolates using pulsed-field gel electrophoresis yielded nonidentical banding patterns, but all strains were assigned to the same clonal origin when compared with 207 unrelated E. coli isolates. The bacteria were repeatedly passaged on culture media and reanalyzed. Thereafter, most variants reverted to normal phenotype and regained their motility and certain biochemical properties. In addition, some variants displayed aminoglycoside susceptibility after reversion. Sonication of an explanted prosthesis allows insight into the lifestyle of bacteria in biofilms. Since sonication fluid also reveals dislodged sessile forms, species identification of such variants may be misleading.
Keywords
Aged, Aminoglycosides/pharmacology, Anti-Bacterial Agents/pharmacology, Bacterial Adhesion, Bacterial Typing Techniques, Biofilms/growth & development, Cluster Analysis, DNA Fingerprinting, Drug Resistance, Bacterial, Electrophoresis, Gel, Pulsed-Field, Escherichia coli/classification, Escherichia coli/genetics, Escherichia coli Infections/diagnosis, Escherichia coli Infections/microbiology, Escherichia coli Proteins/metabolism, Genotype, Humans, Indoles/metabolism, Male, Phenotype, Prostheses and Implants/microbiology, Prosthesis-Related Infections/microbiology, Sonication, Specimen Handling/methods, beta-Galactosidase/metabolism
Pubmed
Web of science
Open Access
Yes
Create date
21/01/2011 14:06
Last modification date
20/08/2019 13:15
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