Virulence Gene and Pandemic Group-Specific Marker Profiling of Clinical Vibrio parahaemolyticus Isolates

Nova Research Inc., Alexandria, Virginia; National Center for Infectious Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia; Center for Bio/Molecular Science & Engineering, Naval Research Laboratory, Washington DC

^* To whom correspondence should be addressed. Email: gvora{at}cbmse.nrl.navy.mil.

	Abstract

Vibrio parahaemolyticus is a halophilic bacterium capable of causing food- and waterborne gastroenteritis, wound infections, and septicemia in humans. The organism has recently received increasing attention as the emergence of a new clone, V. parahaemolyticus O3:K6, has resulted in the first documented pandemic spread of V. parahaemolyticus. We used microarray analyses to explore the presence of known virulence factors and genetic markers thought to be specific for V. parahaemolyticus O3:K6 and its clonal derivatives. Analyses of 48 human clinical isolates collected between 1997 and 2005 revealed that the V. parahaemolyticus chromosome 2 type three secretion system is not specifically associated with pandemic strains and can be found in tdh negative (i.e. Kanagawa negative) clinical isolates. These results highlight the genetic dynamism of V. parahaemolyticus and aid in refining the genetic definition of the pandemic group members.