Molecular Typing of Environmental and Clinical Strains of Vibrio vulnificus Isolated in the Northeastern USA

Type Article
Date 2013-12
Language English
Author(s) Reynaud Yann1, Pitchford Steven1, de Decker Sophie1, Wikfors Gary H.1, Brown Christopher L.1
Affiliation(s) 1 : NOAA, NEFSC, Milford Lab, Milford, CT 06460 USA.
Source Plos One (1932-6203) (Public Library Science), 2013-12 , Vol. 8 , N. 12 , P. e83357 (11p.)
DOI 10.1371/journal.pone.0083357
WOS© Times Cited 18
Abstract Vibrio vulnificus is a ubiquitous marine bacterium that is responsible for infections and some seafood-related illnesses and deaths in the United States, mainly in individuals with compromised health status in the Gulf of Mexico region. Most phylogenetic studies focus on V. vulnificus strains isolated in the southern United States, but almost no genetic data are available on northeastern bacterial isolates of clinical or environmental origin. Our goal in this study was to examine the genetic diversity of environmental strains isolated from commercially-produced oysters and in clinical strains of known pathogenicity in northeastern United States. We conducted analyses of a total of eighty-three strains of V. vulnificus, including 18 clinical strains known to be pathogenic. A polyphasic, molecular-typing approach was carried out, based upon established biotypes, vcg, CPS, 16S rRNA types and three other genes possibly associated with virulence (arylsulfatase A, mtlABC, and nanA). An established Multi Locus Sequence Typing (MLST) method was also performed. Phylogenetic analyses of these markers and MLST results produced similar patterns of clustering of strains into two main lineages (we categorized as 'LI' and 'LII'), with clinical and environmental strains clustering together in both lineages. Lineage LII was comprised primarily but not entirely of clinical bacterial isolates. Putative virulence markers were present in both clinical and environmental strains. These results suggest that some northeastern environmental strains of V. vulnificus are phylogenetically close to clinical strains and probably are capable of virulence. Further studies are necessary to assess the risk of human illness from consuming raw oysters harvested in the northeastern US.
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Publisher's official version 11 1018 KB Open access
Figure S1. MLST majority-rule consensus tree based on the genealogies inferred by Clonal Frame with the null hypothesis of recombination (ρ = 0). 53 KB Open access
Figure S2. Genetic representation of events indicated in Fig. 2 nodes A and B 266 KB Open access
Figure S3. Arylsulfatase A unrooted neighbor joining tree; Kimura's 2-parameter distance, 1000 bootstraps replicates. 2 MB Open access
Figure S4. Arylsulfatase A majority-rule consensus tree based on the genealogies inferred by Clonal Frame after 100000 iterations (including 50000 burn-in iterations), mutation rate θ = 5 and ... 525 KB Open access
Figure S5. MtlABC unrooted neighbor joining tree; Kimura's 2-parameter distance, 1000 bootstraps replicates. 80 KB Open access
Figure S6. MtlABC majority-rule consensus tree based on the genealogies inferred by Clonal Frame after 100000 iterations (including 50000 burn-in iterations), mutation rate θ = 5 and recombination... 45 KB Open access
Figure S7. NanA unrooted neighbor joining tree; Kimura's 2-parameter distance, 1000 bootstraps replicates. 77 KB Open access
Figure S8. NanA majority-rule consensus tree based on the genealogies inferred by Clonal Frame after 100000 iterations (including 50000 burn-in iterations), mutation rate θ = 5 and recombination... 41 KB Open access
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