Non-01 Vibrio Cholerae in Thailand: Homology with Cloned Cholera Toxin Genes

摘要

We examined 281 non-01 Vibrio cholerae isolates from Thailand for homology with genes coding for cholera toxin. Five isolates from environmental sources were homologous with the cholera toxin gene probe and produced both the A and B subunits of cholera toxin. To determine whether non-01 Vibrio cholerae isolated from patients with diarrhea, their close contacts or environmental sources in Thailand contained nucleotide sequences coding for cholera toxin (CT) or Escherichia coli heat-lable toxin (LT), we examined isolates with radio-labeled segments of DNA coding for the A and B fragments of CT and for LT. Culture supernatants of isolates that hybridized with the CT and LT gene probes were further examined in a GM-1 enxyme-linked immunoabsorbent assay (ELISA) with monoclonal antibodies to the A and B subunits of CT. We examined V. cholerae isolates from human and environmental sources. Isolates from humans and animals were recovered from stools or rectal swabs incubated on thiosulfate-citrate-bile salts media at 37 C overnight. Non-01 V. cholerae was isolated from water and food in the homes of persons with diarrhea. Isolates from flies were collected during a study conducted to identify enteric pathogens on flies in a village in northeastern Thailand.