Distribution of lag-1 Alleles and Sequence-Based Types among Legionella pneumophila Serogroup 1 Clinical and Environmental Isolates in the United States
| Autor: | Robert F. Benson, Brian G. Shelton, Ellen Brown, Thomas H. Taylor, Barry S. Fields, Nicole T. Alexander, Natalia A. Kozak |
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| Rok vydání: | 2009 |
| Předmět: |
DNA
Bacterial Microbiology (medical) Serotype Genotype Molecular Sequence Data Legionella pneumophila Microbiology Bacterial Proteins Acetyltransferases Gene Order Environmental Microbiology Prevalence medicine Humans Amino Acid Sequence Typing Serotyping Legionella pneumophila Serogroup 1 Alleles Molecular Epidemiology Molecular epidemiology biology Antibodies Monoclonal Outbreak Bacteriology Sequence Analysis DNA bacterial infections and mycoses medicine.disease biology.organism_classification Antibodies Bacterial Virology United States Bacterial Typing Techniques Legionnaires' disease Legionnaires' Disease Sequence Alignment |
| Zdroj: | Journal of Clinical Microbiology. 47:2525-2535 |
| ISSN: | 1098-660X 0095-1137 |
| DOI: | 10.1128/jcm.02410-08 |
| Popis: | Approximately 84% of legionellosis cases are due to Legionella pneumophila serogroup 1. Moreover, a majority of L. pneumophila serogroup 1 clinical isolates react positively with monoclonal antibody 2 (MAb2) of the international standard panel. Over 94% of the legionellosis outbreaks investigated by the Centers for Disease Control and Prevention are due to this subset of L. pneumophila serogroup 1. To date, there is no complete explanation for the enhanced ability of these strains to cause disease. To better characterize these organisms, we subtyped 100 clinical L. pneumophila serogroup 1 isolates and 50 environmental L. pneumophila serogroup 1 isolates from the United States by (i) reactivity with MAb2, (ii) presence of a lag-1 gene required for the MAb2 epitope, and (iii) sequence-based typing analysis. Our results showed that the MAb2 epitope and lag-1 gene are overrepresented in clinical L. pneumophila serogroup 1 isolates. MAb2 recognized 75% of clinical isolates but only 6% of environmental isolates. Similarly, 75% of clinical isolates but only 8% of environmental isolates harbored lag-1 . We identified three distinct lag-1 alleles, referred to as Philadelphia, Arizona, and Lens alleles, among 79 isolates carrying this gene. The Arizona allele is described for the first time in this study. We identified 59 different sequence types (STs), and 34 STs (58%) were unique to the United States. Our results support the hypothesis that a select group of STs may have an enhanced ability to cause legionellosis. Combining sequence typing and lag-1 analysis shows that STs tend to associate with a single lag-1 allele type, suggesting a hierarchy of virulence genotypes. Further analysis of ST and lag-1 profiles may identify genotypes of L. pneumophila serogroup 1 that warrant immediate intervention. |
| Databáze: | OpenAIRE |
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