Abundance and distribution of bacteria carrying sltll gene in natural river water

Direct in situ PCR with HNPP/Fast Red TR was used to enumerate bacteria carrying the sltII gene in river water. By direct in situ PCR with a sltII-specific EVS primer, 10(2)-10(5) cells ml(-1) of bacteria carrying the sltII gene were detected from all sampling sites, except the site nearest to the source of the river, while 10(2)-10(4) cells ml(-1) of Escherichia coli O157:H7 were detected using a direct fluorescent antibody staining method. These results indicate that such bacteria are commonly distributed in natural river water. Direct ii? situ PCR with HNPP/Fast Red TR is a useful tool for detecting cells carrying specific genes, such as verotoxin-producing bacteria in natural environments.