This Article Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services 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 HighWire Citing Articles via Google Scholar Google Scholar Articles by Bernander, S. Articles by Lundholm, M. Search for Related Content PubMed PubMed Citation Articles by Bernander, S. Articles by Lundholm, M.

 Previous Article  |  Next Article 

Journal of Clinical Microbiology, June 2003, p. 2503-2508, Vol. 41, No. 6
0095-1137/03/$08.00+0     DOI: 10.1128/JCM.41.6.2503-2508.2003
Copyright © 2003, American Society for Microbiology. All Rights Reserved.

A Hospital-Associated Outbreak of Legionnaires' Disease Caused by Legionella pneumophila Serogroup 1 Is Characterized by Stable Genetic Fingerprinting but Variable Monoclonal Antibody Patterns

Sverker Bernander,^1* Kerstin Jacobson,¹ Jürgen Herbert Helbig,² Paul Christian Lück,² and Monica Lundholm^3,

Department of Clinical Microbiology, Karolinska Hospital, and Microbiology and Tumor Biology Center, MTC, Karolinska Institute, Stockholm,¹ Department of Clinical Microbiology, Uppsala University Hospital, Uppsala, Sweden,³ Institut Medizinische Mikrobiologie und Hygiene, Medizinische Fakultät TU Dresden, Dresden, Germany²

Received 15 October 2002/ Returned for modification 19 November 2002/ Accepted 7 March 2003

An outbreak of 18 pneumonia cases caused by Legionella pneumophila serogroup 1 occurred at a Swedish university hospital 1996 to 1999. Eight clinical isolates obtained by culture from the respiratory tract were compared to 20 environmental isolates from the hospital and to 21 epidemiologically unrelated isolates in Sweden, mostly from patients, by using pulsed-field gel electrophoresis (PFGE), amplified fragment length polymorphism analysis (AFLP), and monoclonal antibody (MAb) typing. All patients and most environmental isolates from the outbreak hospital belonged to the same genotypic cluster in both PFGE and AFLP. This genotype was distinctly different from other strains, including a cluster from a second hospital in a different part of the country. The MAb subtype of the outbreak clone was Knoxville except for three isolates that were Oxford. A variation in the MAb reactivity pattern was also found in a second genotypic cluster. These changes in the MAb reactivity pattern were due to the absence or presence of the lag-1 gene coding for an O-acetyltransferase that is responsible for expression of the lipopolysaccharide epitope recognized by MAb 3/1 of the Dresden Panel. In all MAb 3/1-positive strains, the lag-1 gene was present on a genetic element that was bordered by a direct repeat that showed a high degree of sequence homology. Due to this homology, the lag-1 gene region seemed to be an unstable element in the chromosome. MAb patterns are thus a valuable adjunct to genotyping methods in defining subgroups inside a genotypic cluster of L. pneumophila sg 1.

Deceased.

This article has been cited by other articles:

• Ratzow, S., Gaia, V., Helbig, J. H., Fry, N. K., Luck, P. C. (2007). Addition of neuA, the Gene Encoding N-Acylneuraminate Cytidylyl Transferase, Increases the Discriminatory Ability of the Consensus Sequence-Based Scheme for Typing Legionella pneumophila Serogroup 1 Strains. J. Clin. Microbiol. 45: 1965-1968 [Abstract] [Full Text]  
• Fernandez-Moreira, E., Helbig, J. H., Swanson, M. S. (2006). Membrane Vesicles Shed by Legionella pneumophila Inhibit Fusion of Phagosomes with Lysosomes.. Infect. Immun. 74: 3285-3295 [Abstract] [Full Text]  
• Scaturro, M., Losardo, M., De Ponte, G., Ricci, M. L. (2005). Comparison of Three Molecular Methods Used for Subtyping of Legionella pneumophila Strains Isolated during an Epidemic of Legionellosis in Rome. J. Clin. Microbiol. 43: 5348-5350 [Abstract] [Full Text]