Prevalence of Vibrio cholerae with heat-stable enterotoxin (NAG-ST) and cholera toxin genes; restriction fragment length polymorphisms of NAG-ST genes among V. cholerae O serogroups from a major shrimp production area in Thailand.
A total of 148 Vibrio cholerae isolates from a major shrimp production area in Southern Thailand were examined by colony hybridisation for genes encoding heat-stable enterotoxin (NAG-ST) and cholera toxin (CT). Only non-O1 V. cholerae strains were found to harbour NAG-ST (14 of 146) whereas no strains hybridised with the CT probe. NAG-ST-positive V. cholerae non-O1 strains were isolated from shrimp farms situated close to urban areas. Five different O serogroups were found among NAG-ST positive non-O1 strains. Southern blot and restriction endonuclease analysis of NAG-ST-positive strains revealed a high degree of genetic divergence. A total of seven classes of enterotoxin gene patterns were found with HindIII and EcoRI restriction endonucleases. Enterotoxin gene patterns correlated with O-antigen expression in 84% of isolates tested. In combination with other molecular techniques Southern blot analysis with an NAG-ST oligonucleotide probe could be useful for studying the molecular epidemiology of V. cholerae non-O1 strains.
Dalsgaard
A
A
Department of Veterinary Microbiology, Royal Veterinary and Agricultural University, Frederiksberg, Denmark.
Serichantalergs
O
O
Shimada
T
T
Sethabutr
O
O
Echeverria
P
P
D000818:Animals; D015139:Blotting, Southern; D002772:Cholera Toxin / Q000235:genetics*; D015342:DNA Probes; D004269:DNA, Bacterial / Q000032:analysis; D033364:Decapoda / Q000382:microbiology; D004768:Enterotoxins / Q000235:genetics*; D005243:Feces / Q000382:microbiology; D005516:Food Microbiology; D005798:Genes, Bacterial; D006801:Humans; D012150:Polymorphism, Restriction Fragment Length; D017747:Seafood; D012703:Serotyping; D013785:Thailand; D014734:Vibrio cholerae / Q000145:classification / Q000235:genetics*; D014871:Water Microbiology
D015342:DNA Probes; D004269:DNA, Bacterial; D004768:Enterotoxins; C037420:stN protein, Vibrio cholerae; D002772:Cholera Toxin