Changes in Sensitivity to Acriflavine of Escherichia coli Grown in Media of Different Glucose Contents

Abstract

Organisms of E. coli K-12 strains sensitive and resistant to acriflavine were plated on media with and without acriflavine after growth in media containing different concentrations of glucose. Proportionally more organisms produced colonies, in the presence of acriflavine, after growth in media containing a high concentration of glucose than in media with lower glucose contents. The final pH value of the growth medium was low with the high glucose media. With the resistant strain, the number of bacteria which survived acriflavine increased as the final pH value of the medium from which bacteria were harvested was decreased, but the initial glucose concentration rather than the final pH value of the culture was more influential in increasing survival with the sensitive strain. The acri-flavine-binding capacity of the bacteria was affected by the initial glucose concentration of culture medium probably indirectly through a change of pH. Acriflavine sensitivity of the bacteria varied with the amount of acriflavine bound. The acriflavine-binding capacity of bacteria modified by the pH value of culture medium was stabilized in the course of several doublings of bacteria in that medium. The glucose concentration of the medium affected the acriflavine sensitivity of the sensitive strain through some mechanism other than the change of pH.