Abstract: A rapid technique is disclosed for the identification of enteric bacteria which elaborate cholera-related heat-labile enterotoxin antigens which have the ability to cause diarrheal disease in man or animals. The invention includes a sensitized carrier particle for use as a reagent in an agglutination test for heat-labile enterotoxins and the use of said reagent in immunological determinations.

Abstract: Vibrio cholerae, Ogawa serotype, El Tor biotype, are subjected to the mutagenic N-methyl-N'-nitro-n-nitrosoguanidine (NTG). First generation mutants are screened for toxin production, and in particular the absence of "A" or enzymatically active subunit production and production of B (binding) subunit. Putative A.sup.- B.sup.+ mutants are again exposed to NTG and screened for the A.sup.- B.sup.+ characteristics. The formula of the native toxin molecule is usually A.sup.+ B.sup.+.sub.5-6, the formula for the molecule produced by the selected second generation mutant is A.sup.- B.sup.+.sub.5-6. This mutant strain is used for production of a live attenuated vaccine which can be administered orally. The mutant has been found to induce immunity, in an experimental model system, against subsequent challenge with virulent cholera vibrios.

Abstract: A microbial growth medium for the isolation and rapid detection of Neisseria gonorrhoeae and Neisseria meningitidis, having incorporated therein an iron-dextran complex in a quantity sufficient to stimulate maximum colony growth.