Infectious Multiple Drug Resistance in the Enterobacteriaceae
Abstract
A new method for the detection of plasmid DNA in clinical isolates has been developed. The method requires only small culture volumes and can detect plasmid genomes ranging from 1 x 10 to the 6th power to 300 x 10 to the 6th power daltons in mass. Moreover, the plasmid DNA is isolated in sufficient amount of purity so that multiple examinations of the molecular characteristics of the plasmid DNA is possible. Plasmids, Vir, common to E. coli strains associated with sepsis have been characterized. The plasmids from wild-type E. coli were tagged with antibiotic resistance genes and transferred to laboratory strains of E. coli K-12. The plasmids possess a molecular mass of 92 x 10 to the 6th power daltons and were members of the F incompatibility complex. The preliminary molecular and genetic data suggest that the structural genes encoding a Vir-specific antigen/toxin may reside upon a transposable element. Specific DNA sequences encoding for either E. coli heat stable toxin (ST) or heat labile toxin have been isolated. The entire DNA sequence of the cistron encoding the B subunit of LT has been determined. The translated sequence shows 80% similarity to the known amino acid sequences of the B unit of cholera toxin (CT). On the other hand, on the basis of DNA-DNA hybridization studies, LT and CT have diverged so that they show roughly 18% base sequence mismatching.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jun 01, 1980
- Accession Number
- ADA146338
Entities
People
- Stanley Falkow
Organizations
- University of Washington