rats immunized with escherichia coli heat-labile ( lt ) enterotoxin , either in the form of the holotoxin derived from a transformed k-12 strain or the polymyxin-release form obtained from human strains which produce lt toxin alone ( lt+/st- [ st is heat-stable toxin ) ] or together with st toxin ( lt+/st+ ) , were challenged with viable organisms of 10 different serotypes , 5 lt+/st- and 5 lt+/st+ .
C0014372
enterotoxin
C0040549
toxin