Studies on Toxinogenesis in Vibrio cholerae. I. Isolation of Mutants with Altered Toxinogenicity

Abstract

Methods have been developed for the recognition of toxin production by individual colonies of Vibrio cholerae strain 569B Inaba and certain other (but not all) strains of V. cholerae. Following mutagenesis of strain 569B with nitrosoguanidine, mutants that produced less or no detectable enterotoxin were isolated. One mutant, which did not elaborate any toxin detectable in Oakley-Fulthorpe tests or in the rabbit skin test, was completely avirulent for infant rabbits, although it was prototrophic and colonized their intestines. A strain of V. cholerae biotype El Tor produced a toxin that lacked an antigenic determinant found in toxin elaborated by strain 569B Inaba.