Infectious Multiple Drug Resistance in the Enterobacteriaceae
Abstract
Current methods for the detection and isolation of enterotoxigenic e. coli (ETEC) are unsuitable for assaying large numbers of isolates. An alternative method is described which is based on detection of the genes encoding the enterotoxins rather than the detection of the toxins themselves. Isolated radiolabeled fragments of DNA encoding the heat labile (LT) or heat stable (ST) toxins are used as hybridization probes for homologous DNA sequences in E. coli colonies grown and lysed in situ on nitrocellulose filters. This method was also effective for detecting the presence of EtEC in bacterial growth from directly spotted stools from patients with actue diarrhea. A study was performed in Cacca, Bangladesh in which all LT producing strains were detected by the hybridizati on method. Using a single ST probe (from a porcine E. coli) 12 of 17 ST producing strains were detected but only 3 of 26 ST+LT isolates were detected. Based on the data that were at least two heterologous ST detectable in the infant mouse assay, we cloned and sequenced an ST gene from one of the human strains from Dacca that was not detected in our initial hybridization studies. This gene is related to the porcine St gene but is clearly divergent possessing 30 different amino acids and 31% different base pairs.
Document Details
- Document Type
- Technical Report
- Publication Date
- Feb 01, 1981
- Accession Number
- ADA146461
Entities
People
- Stanley Falkow
Organizations
- University of Washington