Conservation of cholera toxin gene in a strain of cholera toxin non-producing Vibrio cholerae O1.
BT23, a Vibrio cholerae O1 E1 Tor isolate, possesses the cholera toxin (CT) gene as determined by PCR. However, CT was not detected in the culture medium by the reversed passive latex agglutination test, nor in the whole cell lysate as examined by Western blotting. The toxin-coregulated pilus (TCP) was not detected by Western blotting. This suggests the presence of defects in the regulatory cascade. toxR, toxS and toxT, members of the regulatory cascade, were examined by PCR. toxR and toxS were conserved but toxT was not. CT and TCP production was complemented by transformation of toxT. The lack of toxT was suspected to be the cause of the undetectable production of CT in strain BT23.
Honma
Y
Y
Department of Bacteriology, Faculty of Medicine, University of the Ryukyus, Okinawa, Japan. yhonma@med.u-ryukyu-ac-jp
Iwanaga
M
M
D001426:Bacterial Proteins / Q000235:genetics; D002772:Cholera Toxin / Q000235:genetics* / Q000378:metabolism*; D017931:DNA Primers; D004269:DNA, Bacterial / Q000032:analysis; D004268:DNA-Binding Proteins / Q000235:genetics; D015964:Gene Expression Regulation, Bacterial; D005816:Genetic Complementation Test; D008565:Membrane Proteins; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction; D014176:Protein Biosynthesis; D014157:Transcription Factors / Q000235:genetics; D014158:Transcription, Genetic; D014734:Vibrio cholerae / Q000235:genetics* / Q000378:metabolism*
D001426:Bacterial Proteins; D017931:DNA Primers; D004269:DNA, Bacterial; D004268:DNA-Binding Proteins; D008565:Membrane Proteins; D014157:Transcription Factors; C499324:toxR protein, Vibrio cholerae; C066719:toxR protein, bacteria; C066828:ToxS protein, Vibrio cholerae; C075626:tcpN protein, Vibrio cholerae; D002772:Cholera Toxin