The use of gene probes, immunoassays and tissue culture for the detection of toxin in Vibrio cholerae non-O1.
Vibrio cholerae non-O1 strains were screened for the presence of cholera enterotoxin (CT) genes by means of digoxigenin-labelled polynucleotide CTA and CTB probes. In-vitro production of CT was investigated by the Y1 mouse adrenal cell assay, enzyme-linked immunosorbent assay (ELISA) and a commercial, reversed passive latex agglutination (RPLA) kit. Only two (0.25%) of 790 strains tested gave positive results with the CTA and CTB probes. The production of other bacterial cytotoxin(s) made it impossible to use the characteristic cell-rounding effect on Y1 cells for the detection of CT. CT production by the probe-positive strains was confirmed by the immunoassays. Two hundred and fifty-two of the 788 probe-negative strains were tested by both cell assay and immunoassays. Of these, 90% produced cytotoxin(s) in the cell assay. In addition, 37% gave positive results in CT-ELISA, but negative results with LT-ELISA and VET-RPLA. These results indicate the presumed presence of a toxin in V. cholerae non-O1 that is able to bind GM1 and react with antisera to CT, but which is not identical to CT.
Said
B
B
Laboratory of Enteric Pathogens, Central Public Health Laboratory, London.
Scotland
S M
SM
Rowe
B
B
D002460:Cell Line; D003470:Culture Media; D015342:DNA Probes; D004768:Enterotoxins / Q000096:biosynthesis* / Q000235:genetics; D004797:Enzyme-Linked Immunosorbent Assay; D006801:Humans; D007841:Latex Fixation Tests; D009693:Nucleic Acid Hybridization; D014734:Vibrio cholerae / Q000235:genetics / Q000378:metabolism*
D003470:Culture Media; D015342:DNA Probes; D004768:Enterotoxins; C037420:stN protein, Vibrio cholerae