Sensitivity of the different tests of enterotoxigenicity of Escherichia coli and their correlation.

ABSTRACT

Enterotoxigenicity of E. coli isolates was tested in 136 cases of acute gastroenteritis. Heat labile toxin (LT) produced in-vitro was tested in rabbit ileal loop (RIL); vero cell line and Biktn plate. The results of live cultures were evaluated in RIL. The overall data of these four models were not statistically different. Elaboration of LT in these four models ranged from 14-21.4%. Out of the 20 LT producing strains 14 (70%) also revealed ST. Of the 6 positive reactors on vero cell line, appeared to produce vero toxin (VT) only. Out of 29 LT positive E. coli, 1 (3.45%) and 2 (6.89%) strains respectively revealed colonising factor antigen (CFA) I and II. The high incidence of ETEC showing both LT and ST has been highlighted in the age group 0-4 years, and its impact on nutritional status is discussed.