Curing of an R factor Escherichia coli by trimethoprim

R factor 1818, which we have shown previously to be eliminated by thymine starvation, was cured from three strains of Escherichia coli K-12 by overnight exposure to trimethoprim. Elimination was abolished in the presence of added thymine or thymidine, which suggests that curing is the result of the...

Full description

Saved in:
Bibliographic Details
Published in:Antimicrobial agents and chemotherapy 1973-06, Vol.3 (6), p.670
Main Authors: Pinney, R J, Smith, J T
Format: Article
Language:English
Subjects:
Amino Acids - metabolism
Chloramphenicol - pharmacology
Drug Resistance, Microbial
Escherichia coli - drug effects
Extrachromosomal Inheritance - drug effects
Thymine - metabolism
Trimethoprim - pharmacology
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:R factor 1818, which we have shown previously to be eliminated by thymine starvation, was cured from three strains of Escherichia coli K-12 by overnight exposure to trimethoprim. Elimination was abolished in the presence of added thymine or thymidine, which suggests that curing is the result of the induction of thymineless conditions by trimethoprim. Starvation of the required amino acids proline and histidine had little effect on elimination, whereas methionine deprivation enhanced it. R factor curing was abolished by the presence of chloramphenicol, and it is concluded that protein synthesis is required for elimination to occur. It is suggested that elimination may result from the activity of a nuclease which is synthesized or induced during both direct thymine starvation and by trimethoprim treatment.
ISSN:0066-4804
DOI:10.1128/AAC.3.6.670