Previous Article | Next Article ![]()
Journal of Clinical Microbiology, October 2001, p. 3442-3445, Vol. 39, No. 10
Division Autonome de Médecine
Préventive Hospitalière, Centre Hospitalier Universitaire
Vaudois, Lausanne, Switzerland,1 and
Service de Microbiologie, Hôpital Erasme,
Université Libre de Bruxelles, Brussels,
Belgium2
Received 30 April 2001/Returned for modification 6 June
2001/Accepted 11 July 2001
To determine the stability of pulsed-field gel electrophoresis
(PFGE) patterns of methicillin-resistant Staphylococcus
aureus in the nosocomial setting, we analyzed isolates from
long-term carriers (>1 month) and from patients involved in
well-defined nosocomial epidemics. The number of fragment differences
between the first isolate and subsequent isolates in long-term carriers showed a bimodal distribution, with one group having 0 to 6 fragment differences and the other group having 14 to 24 fragment differences. The PFGE patterns of isolates involved in epidemics also presented a
similar bimodal distribution of the number of fragment differences. Typing these isolates with another molecular method
(inter-IS256 PCR) showed that isolates of the first
group (i.e., with 1 to 6 fragment differences) were clonally related,
whereas the second group (with 14 to 24 fragment differences) could be
considered genetically different. Among long-term carriers with
clonally related isolates, 74 of 84 (88%) of consecutive isolates
showed indistinguishable patterns, whereas 10 of 84 (12%) showed
related patterns differing by one to six fragments. Moreover, the
frequency of apparition of related patterns is higher when the time
between the first and the subsequent isolate is longer. During seven
nosocomial epidemics lasting from 1 to 15 months, only 2 of 120 isolates (1.7%) showed a pattern which was different, although
related, from the predominant one involved in each of these outbreaks.
0095-1137/01/$04.00+0 DOI: 10.1128/JCM.39.10.3442-3445.2001
Copyright © 2001, American Society for Microbiology. All rights reserved.
Epidemiological Validation of Pulsed-Field Gel
Electrophoresis Patterns for Methicillin-Resistant
Staphylococcus aureus
*
Corresponding author. Mailing address: Division
Autonome de Médecine Préventive Hospitalière, Centre
Hospitalier Universitaire Vaudois, 1011 Lausanne, Switzerland. Phone:
41-21-314-02-59. Fax: 41-21-314-02-62. E-mail:
Dominique.Blanc{at}chuv.hospvd.ch.
This article has been cited by other articles:
| Antimicrob. Agents Chemother. | Clin. Microbiol. Rev. |
|---|---|
| Clin. Vaccine Immunol. | ALL ASM JOURNALS |
|---|