ABSTRACT
Risk of gastric infection with Vibrio parahaemolyticus increases with favorable environmental conditions and population shifts that increase prevalence of infective strains. Genetic analysis of New Hampshire strains revealed a unique population with some isolates similar to outbreak-causing strains and high-level diversity that increased as waters warmed.
Subject(s)
Seawater/microbiology , Shellfish/microbiology , Vibrio parahaemolyticus/isolation & purification , DNA, Bacterial/chemistry , DNA, Bacterial/genetics , Genetic Variation , Molecular Typing , Multilocus Sequence Typing , New Hampshire , Vibrio parahaemolyticus/classification , Vibrio parahaemolyticus/geneticsABSTRACT
Although Vibrio cholerae is an important human pathogen, little is known about its populations in regions where the organism is endemic but where cholera disease is rare. A total of 31 independent isolates confirmed as V. cholerae were collected from water, sediment, and oysters in 2008 and 2009 from the Great Bay Estuary (GBE) in New Hampshire, a location where the organism has never been detected. Environmental analyses suggested that abundance correlates most strongly with rainfall events, as determined from data averaged over several days prior to collection. Phenotyping, genotyping, and multilocus sequence analysis (MLSA) revealed a highly diverse endemic population, with clones recurring in both years. Certain isolates were closely related to toxigenic O1 strains, yet no virulence genes were detected. Multiple statistical tests revealed evidence of recombination among strains that contributed to allelic diversity equally as mutation. This relatively isolated population discovered on the northern limit of detection for V. cholerae can serve as a model of natural population dynamics that augments predictive models for disease emergence.
Subject(s)
Cholera Toxin/metabolism , Ecosystem , Genetic Variation , Vibrio cholerae/classification , Vibrio cholerae/isolation & purification , Animals , Cluster Analysis , Genotype , Geologic Sediments/microbiology , Multilocus Sequence Typing , New Hampshire , Ostreidae/microbiology , Phenotype , Recombination, Genetic , Vibrio cholerae/genetics , Vibrio cholerae/pathogenicity , Virulence Factors/genetics , Water Microbiology , WeatherABSTRACT
The staphylococcal msr(A) gene, coding for a macrolide efflux protein, was identified in three new gram-positive genera and one gram-negative genus. These msr(A) genes shared 99 to 100% identity with each other and the staphylococcal gene. This study demonstrates that the msr(A) gene has a wider host range than previously reported.
