Enterotoxicity of group F vibrios

Recently a group of organisms resembling Aeromonas hydrophila has been isolated from human diarrheal cases from marine and estuarine environment. These organisms are tentatively designated as group "F" vibrios. Live cells of 23 strains isolated from different sources were tested for their enterotoxicity in the adult rabbit ileal loop model. All but two caused fluid accumulation comparable to that obtained with Vibrio cholerae 569B. An inoculum of 10(4) viable bacteria could give rise to gut loop reaction. Culture filtrates of the 19 strains tested including one giving negative reaction with live cells also caused accumulation of fluid in loops.