Elimination by Ethidium Bromide of Antibiotic Resistance in Enterobacteria and Staphylococci

Abstract

SUMMARYEthidium bromide, a trypanocidal drug affecting nucleic acid synthesis, was found to be a powerful agent in eliminating some antibiotic resistance in bacteria. In staphylococci, penicillinase production was eliminated in mercury-resistant organisms, but not in mercury-sensitive ones. Among enterobacteria, two resistance factors showing the same resistance pattern were differently eliminated, and correlation between elimination and transfer of resistance factors was not always observed. F'-lac+ factor was also eliminated by ethidium bromide in Escherichia coli ~1 2 .Elimination of antibiotic resistance was observed generally at high frequency, and could be better reproduced than with acridine dyes.

Identification of multiple-resistance (R) and colicinogeny (Col) plasmids in an epidemicSalmonella agonaserotype in Rio de Janeiro

“…Pla,smid curing Treatment of cultures with ethidium bromide (Bouanchaud, Scavizzi & Chabbert, 1969), acridine orange (Watanabe & Fukasawa, 1961) or SDS/high temperature (Hill & Carlisle, 1981) were the methods used to obtain plasmid curing.…”

SPECIFIC INHIBITION BY ETHIDIUM BROMIDE OF MITOCHONDRIAL DNA SYNTHESIS IN PHYSARUM POLYCEPHALUM

“…However, the heterogeneity of the molecules and the variable number of single-strand breaks suggested that the isolated mDNA was the degradative product of a larger, possibly circular species . Finally, bacterial episomes, which are eliminated by EtBr (Bouanchaud, Scavizzi, and Chabbert, 1969), are probably coded by closed circular DNA . Thus, available data are consistent with the proposition that the synthesis of closed circular DNA is more sensitive to EtBr than the synthesis of linear DNA .…”

Staphylococcal Penicillinase Plasmids: Studies on the Reversion of a Temperature-sensitive Replication Mutant to Temperature Stability

“…Growth of plasmid-containing strains of Staphylococcus aureus in the presence of ethidium bromide results in loss of the plasmid (Bouanchaud, Scavizzi & Chabbert, 1968). The experiment on stability was repeated in the presence of 9 x I O -~ M-ethidium bromide.…”