High frequency of virulence factor genes tdh, trh, and tlh in Vibrio parahaemolyticus strains isolated from a pristine estuary.
Virulence factor genes encoding the thermostable direct hemolysin (tdh) and the thermostable direct hemolysin-related hemolysin (trh) are strongly correlated with virulence of the emergent human pathogen Vibrio parahaemolyticus. The gene encoding the thermolabile hemolysin (tlh) is also considered a signature molecular marker for the species. These genes are typically reported in very low percentages (1 to 2%) of nonclinical strains. V. parahaemolyticus strains were isolated from various niches within a pristine estuary (North Inlet, SC) and were screened for these genes using both newly designed PCR primers and more commonly used primers. DNA sequences of tdh and trh were recovered from 48% and 8.3%, respectively, of these North Inlet strains. The recovery of pathogenic V. parahaemolyticus strains in such high proportions from an estuarine ecosystem that is virtually free of anthropogenic influences indicates the potential for additional, perhaps environmental roles of the tdh and trh genes.
Department of Biological Sciences, University of South Carolina, Columbia, South Carolina, USA.
Casandra K
CK
Gutierrez West
Savannah L
SL
Klein
Charles R
CR
Lovell
D004269:DNA, Bacterial / Q000235:genetics; D063366:Estuaries; D006460:Hemolysin Proteins / Q000235:genetics*; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction; D017422:Sequence Analysis, DNA; D014736:Vibrio parahaemolyticus / Q000235:genetics* / Q000302:isolation & purification*; D037521:Virulence Factors / Q000235:genetics*; D014871:Water Microbiology
D004269:DNA, Bacterial; D006460:Hemolysin Proteins; D037521:Virulence Factors