Biochemical characteristics & secretory activity of Aeromonas species isolated from children with gastroenteritis in Chennai.

An attempt was made to delineate the phenotypic markers for the detection of enterotoxigenic strains of Aeromonas. Eighteen Aeromonas species comprising one isolate of A. hydrophila, six isolates of A. sobria and 11 isolates of A. caviae were obtained from 379 children suffering from acute diarrhoea in Chennai. Nine of these isolates inclusive of three A. sobria and six A. caviae were found to produce secretory response in vitro in the rabbit intestinal mucosa mounted in the Ussing chambers as revealed by significant increases in the short circuit current. Eleven strains hydrolysed aesculin, 8 fermented arabinose, 6 produced acetyl methyl carbinol, 14 produced lysine decarboxylase, 3 fermented salicin, 9 produced beta-haemolysin, 9 produced CAMP-like factor and only two isolates took up congo red dye. None of these phenotypic traits were found to correlate with the in vitro secretory activity.