[Elimination of multiple drug resistance of intestinal bacteria in white mice in vivo with proflavine and rimactan].

Albino mice, infected with 0.4 cu. cm of 10(10) microbial cells (S. Heidelberg), were treated with proflavin (0.4 cu. cm of a 0.3% solution) and rimactan rifamycin SV (0.4 cu. cm of a 0.4% solution). Proflavin was given singly and four times, daily, in the course of four days, and rimactan was applied four times. Given in a single dose proflavin was found to prolong twice as long the life span of albino mice infected with S. heidelberg. When injected four times it lowered considerably the mortality rate among the animals, the percent of survivals being 62. It was shown to hinder the transmission of multidrug resistance to the normally existing intestinal microflora. It also eliminated the multidrug resistance that intestinal bacteria had acquired in the course of the first several days of drug application. The action of rifamycin proved stronger: 83% of the albino mice treated survived. It eliminated the markers of resistance--both the acquired ones and those carried by the normal recipients (intestinal bacteria)--that substantiated multidrug resistance as well as some of the markers of the donor itself (S. heidelberg).