Identification of uidA gene sequences in beta-D-glucuronidase-negative Escherichia coli
نویسندگان
چکیده
منابع مشابه
Heterogeneity of uidA gene in environmental Escherichia coli populations.
Previous studies have shown that Escherichia coli can be isolated from non-polluted rivers and from bromeliad axilae in pristine areas of tropical rain forests. Finding E. coli in pristine environments is unusual because this bacterium is thought to only survive in the gut of warm-blooded animals and thus its presence should indicate recent fecal contamination. The aims of this study were 1) to...
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A medium containing a chromogenic substrate was developed for the enumeration of Escherichia coli on the basis of beta-glucuronidase activity. In this medium there was an inverse linear relationship between the log initial E. coli concentration and the time taken for the color to reach a threshold optical density of 0.05. This relationship applied even when the E. coli population contained 5% b...
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The O157:H7 lineage of enterohemorrhagic Escherichia coli is a geographically disseminated complex of highly related genotypes that share common ancestry. The common clone that is found worldwide carries several markers of events in its evolution, including markers for acquisition of virulence genes and loss of physiological characteristics, such as sorbitol fermentation ability and beta-glucur...
متن کاملNegative dominant mutations of the uidR gene in Escherichia coli: genetic proof for a cooperative regulation of uidA expression.
The uidA gene is the first gene involved in the hexuronide-hexuronate pathway in Escherichia coli K-12 and is under the dual control of the uidR and uxuR encoded repressors. Point mutations affecting the uidR regulatory gene were sought to investigate the regulation of uidA. When the uidR mutant allele was on a multicopy plasmid and the wild-type allele was on the chromosome, some of the mutant...
متن کاملPhenotypic and genotypic characterization of beta-D-glucuronidase-positive Shiga toxin-producing Escherichia coli O157:H7 isolates from deer.
Beta-glucuronidase-positive (GUD+) Shiga toxin-producing Escherichia coli (STEC) O157:H7 was isolated from both an asymptomatic woman and uncooked deer meat in her possession in Hokkaido, Japan. The phenotypic and genotypic characteristics of the two isolates were identical or closely related, indicating probable transmission of the deer isolate to the woman. Moreover, several other GUD+ STEC O...
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ژورنال
عنوان ژورنال: Applied and Environmental Microbiology
سال: 1991
ISSN: 0099-2240,1098-5336
DOI: 10.1128/aem.57.1.320-323.1991