Comparative evaluation of nine different methods for detecting enterotoxin of Escherichia coli.

Nine different methods for detecting enterotoxin of Escherichia coli were studied and compared. We found rabbit ileal-loop test and suckling mouse assay were both quite accurate and reliable for detecting heat labile toxin (LT) and heat stable toxin (ST) of enterotoxigenic Escherichia coli (ETEC). Mouse ileal-loop test was simple, but its sensitivity and specificity were comparatively low. CHO cell-culture assay might be more sensitive and specific. LT-DNA probe was the most sensitive and specific method. In practical application, PIHT (plate immunohemolytic test), Biken's, SPA-CoA and ELISA methods are recognized as simple, rapid, sensitive and specific methods for detecting ETEC-LT. These methods can be selected for use in clinical laboratory.