Plesiomonas shigelloides : An Opportunistic Food and Waterborne Pathogen ¹

Plesiomonas shigelloides is an oxidase-positive, gram-negative rod that has been implicated as an agent of human gastroenteritis for almost 40 years. Reports of gastroenteritis associated with Plesiomonas have been increasing in recent years, although inadequacies in isolation techniques and recognition procedures have undoubtedly resulted in the underreporting of this organism in the past. Existing information indicates that P. shigelloides , while mainly an aquatic species, is widely distributed in the environment. Recent outbreaks of gastroenteritis associated with consumption of oysters contaminated with P. shigelloides have resulted in an increased awareness of this organism by public health officials.