Accession Number : ADB960220

Title :   Infectious Multiple Drug Resistance in the Enterobacteriaceae.

Descriptive Note : Annual progress rept. 1 Jun 73-31 May 74,

Corporate Author : WASHINGTON UNIV SEATTLE

Personal Author(s) : Falkow, Stanley

Report Date : MAY 1974

Pagination or Media Count : 28

Abstract : Genetic and Molecular studies of R-plasmids have shown that their genome is clearly divisible into three distinct regions. The tra region concerned with conjugation functions is conserved to a high degree among plasmids of the same compatibility group. Another region, inc is of small size and concerned with the ability of a plasmid to coexist with other extrachromosomal elements. The third region, the non-essential region is highly variable and contains genes concerned with antibiotic resistance, enterotoxin production,colicin production other characteristics of evolutionary advantage. Many of the genes of the non-essential region reside upon well-defined short segments of DNA which are capable of being translocated from plasmid to plasmid. The most common form of plasmid-mediated ampicillin resistance, TEM, was shown to be present upon an identical sequence of DNA on many different R factors isolated from various enteric species through-out the world. The translocation of specific blocks of genes appears to be a major mechanism for the observed genetic variability in plasmids and the rapid wide dissemination of antibiotic resistance among many enter species.

Descriptors :   *DRUG TOLERANCE, ENTEROBACTERIACEAE, THERAPY, PLASMIDS, ENTEROTOXINS, GENETICS.

Subject Categories : Pharmacology

Distribution Statement : APPROVED FOR PUBLIC RELEASE