Abstract
Enterotoxin production by cAMP-deficient mutants of Vibrio cholerae was investigated by the latex agglutination test, CHO cell elongation system, and permeability increasing test. It was revealed that two kinds of permeability-increasing factors were produced by V. cholerae E2 and its cAMP-deficient mutant E2751. They were cholera toxin (CT) and an unknown permeability-increasing factor (PF). PF was separated from CT by DEAE-Sephacel column chromatograhy. Antiserum was prepared against partially purified PF separated by DEAE-Sephacel chromatography and used for the neutralization tests. Neutralization tests with anti CT antiserum and anti PF antiserum showed that CT and PF were entirely different immunplogically. We showed also that though cAMP is not essential for production of CT, it is required for production of this newly found PF.
