Plesiomonas Gastroenteritis in Texas

To the Editor.— Plesiomanas shigelloides is a straight, motile gramnegative bacillus of the family Vibrionaceae. It is widespread in tropical and subtropical environments and has been isolated from ponds and rivers, as well as fish and oysters. Although the pathogenicity of P shigelloides has been questioned, the organism has been isolated in the absence of other pathogens from stools of more than 100 persons with gastroenteritis. Recent laboratory studies have indicated that this organism can produce an enterotoxin. 1,2 Thus, the emerging consensus is that it can cause gastroenteritis in immunocompetent patients. Although accummulated evidence suggests that P shigelloides is an intestinal pathogen, the source(s) of illness has only been hypothesized. Rutala et al 3 reported an outbreak of gastrointestinal tract illness associated with a North Carolina oyster roast. In that outbreak, P shigelloides was isolated from a single stool specimen as well as an oyster harvested from the same