Characterization of non-membrane-damaging cytotoxin of non-toxigenic Vibrio cholerae O1 and its relevance to disease.
The non-membrane-damaging cytotoxin which causes dramatic cell rounding of cultured HeLa cells was purified to homogeneity from a clinical strain (WO5) of non-toxigenic Vibrio cholerae O1 Inaba belonging to the E1 Tor biotype. The purified protein has a denatured molecular weight of 35 kDa and a native molecular weight of approximately 37 kDa indicating the monomeric nature of the protein. The 15 N-terminal amino acid sequence of non-membrane-damaging cytotoxin showed complete homology to the hemagglutinin protease previously purified and characterized from V. cholerae O1. Purified non-membrane-damaging cytotoxin from V. cholerae O1 was immunologically and biochemically identical to that previously purified from V. cholerae O26. Non-membrane-damaging cytotoxin was found to be enterotoxic in rabbit ileal loop assay inducing accumulation of non-hemorrhagic fluid at 100 micrograms and elicited a concentration dependent increase in short circuit current and tissue conductance of rabbit ileal mucosa mounted on Ussing chambers. A significant serum immunoglobulin G response against non-membrane-damaging cytotoxin was elicited by patients infected with V. cholerae O139 but not with V. cholerae O1. These properties make non-membrane-damaging cytotoxin a potential virulence factor of V. cholerae which should be taken into consideration while making live, attenuated recombinant vaccine strains against cholera.
Mitra
R
R
National Institute of Cholera and Enteric Diseases, Calcutta, India.
Saha
P K
PK
Basu
I
I
Venkataraman
A
A
Ramakrishna
B S
BS
Albert
M J
MJ
Takeda
Y
Y
Nair
G B
GB
D000818:Animals; D000918:Antibody Specificity; D001426:Bacterial Proteins / Q000737:chemistry / Q000302:isolation & purification / Q000502:physiology*; D002364:Caseins / Q000378:metabolism; D002771:Cholera / Q000097:blood / Q000382:microbiology*; D003603:Cytotoxins / Q000737:chemistry / Q000302:isolation & purification / Q000502:physiology*; D010450:Endopeptidases / Q000378:metabolism; D006367:HeLa Cells; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood; D007413:Intestinal Mucosa / Q000187:drug effects*; D051379:Mice; D008807:Mice, Inbred BALB C; D011817:Rabbits; D014734:Vibrio cholerae / Q000737:chemistry* / Q000276:immunology
D001426:Bacterial Proteins; D002364:Caseins; D003603:Cytotoxins; D007074:Immunoglobulin G; C026018:azocasein; D010450:Endopeptidases