Detection of virulence factors in culturable Escherichia coli isolates from water samples by DNA probes and recovery of toxin-bearing strains in minimal o-nitrophenol-beta-D-galactopyranoside-4-methylumbelliferyl-beta-D-g luc uronide media.
A total of 449 Escherichia coli isolates in treated and raw water sources were submitted to DNA-DNA hybridization using seven different DNA probes to detect homology to sequences that code for Shiga-like toxins I and II; heat-stabile and heat-labile toxins, adherence factors EAF and eae, and the fimbrial antigen of entero-hemorrhagic E. coli. Fifty-nine (13%) of the isolates demonstrated homology with one or more specific DNA probes. More than 50% of the isolates in treated water were not recovered in MMO-4-methylumbelliferyl-beta-D-glucuronide media designed for detection of this indicator.
Martins
M T
MT
Department of Microbiology, University of Sao Paulo, Brazil.
Rivera
I G
IG
Clark
D L
DL
Olson
B H
BH
D001427:Bacterial Toxins / Q000235:genetics*; D003470:Culture Media; D015342:DNA Probes; D004768:Enterotoxins / Q000235:genetics*; D004926:Escherichia coli / Q000235:genetics / Q000254:growth & development / Q000302:isolation & purification* / Q000472:pathogenicity*; D005618:Fresh Water; D005798:Genes, Bacterial; D006923:Hymecromone / Q000031:analogs & derivatives* / Q000378:metabolism; D010105:Oxygenases / Q000378:metabolism; D013045:Species Specificity; D013862:Thiogalactosides / Q000378:metabolism*; D014774:Virulence; D014871:Water Microbiology
D001427:Bacterial Toxins; D003470:Culture Media; D015342:DNA Probes; D004768:Enterotoxins; D013862:Thiogalactosides; C010256:o-nitrophenol beta-thiogalactoside; D006923:Hymecromone; C034888:4-methylumbelliferyl glucuronide; D010105:Oxygenases; C021555:methane monooxygenase