Simultaneous detection and differentiation of Escherichia coli populations from environmental freshwaters by means of sequence variations in a fragment of the beta-D-glucuronidase gene.

ABSTRACT: A PCR-based denaturing-gradient gel electrophoresis (DGGE) approach was applied to a partial sequence of the beta-D-glucuronidase gene (uidA) for specific detection and differentiation of Escherichia coli populations according to their uidA sequence variations. Detection of sequence variations by PCR-DGGE and by PCR with direct sequencing correlated perfectly. Screening of 50 E. coli freshwater isolates and reference strains revealed 11 sequence types, showing nine polymorphic sites and an average number of pairwise differences between alleles of the uidA gene fragments (screened fragment length, 126 bp) of 2.3%. Among the analyzed strains a range of dominating to more rarely and/or uniquely observed E. coli sequence types was revealed. PCR-DGGE applied to fecally polluted river water samp

SUBMITTER: Farnleitner AH 

PROVIDER: S-EPMC91990 | biostudies-literature | 2000 Apr

REPOSITORIES: biostudies-literature