DETECTION OF VIBRIO-CHOLERAE AND V-MIMICUS HEAT-STABLE TOXIN GENE SEQUENCE BY PCR

Previously the heat-stable enterotoxin in Vibrio cholerae and V. mimic us has been detected by suckling mouse assay, a non-specific approach, and by DNA probes, a time-consuming method. This report describes a p olymerase chain reaction (PCR) procedure for the detection of the stn (NAG-ST) and sto (O1-ST) gene sequences that is rapid and specific, al lowing toxin gene molecular characterisation. A total of 34 V. cholera e and V. mimicus isolates was examined for ST and CT genes. The NAG-ST gene sequence was amplified in 13 of 22 non-O1/non-O139 V. cholerae a nd three of five V. mimicus strains. A new enterotoxin gene sequence p attern was found with MseI and TagI restriction endonuclease PCR fragm ent digestion of two V. cholerae isolates, in addition to the pattern anticipated from the Genbank sequence, and found with the other ST+. T hese results show that ST-PCR detection is useful for the characterisa tion of V. cholerae and V. mimicus.