Enterotoxigenic Klebsiella pneumoniae in acute childhood diarrhoea.

K. pneumoniae strains recovered as pure or predominant isolate from stool specimens of 50 children below three years of age, presenting with acute watery diarrhoea, were studied for heat-labile enterotoxin production. Twenty three (46%) of the 50 crude toxin concentrates showed positivity in rabbit ileal loops and skin permeability tests. Antigenically 17 (34%) and 20 (40%) of the toxin extracts reacted with immuno-purified anti H-LT antibody in latex particle agglutination and immuno-dot blot assays respectively. Polyacrylamide-gel electrophoresis, Western-blotting and enzyme-immunoassay revealed heat-labile enterotoxin and its subunits in 19 (68%) of 28 extracts tested. In 5 of 10 strains tested the toxigenicity could be transferred to recipient Escherichia coli J-35 in plasmid transfer experiments. Klebsiella induced enterotoxigenic diarrhoea and produced a heat-labile toxin which seems to be biologically, antigenically and possibly genetically related to the heat-labile toxin of the cholera-coli family.