Changes in the colicinogenic and hemolytic activities of Escherichia isolated from man during long-term confinement.

The paper presents data obtained during the year-long medico-engineering experiment (in which three test subjects participated) with respect to changes in the Escherichia composition as judged by colicinogenic and hemolytic activity. At the beginning of the experiment colicinogenic E. coli (col/D and col/B) was found in one of the three test subjects (U-85%); he also showed the highest stability of intestinal microflora throughout the experiment. The two other test subjects (B and M) displayed colicinogenic micro-organisms of the same type plus an unidentified type only during and immediately after emergency situations. Hemolytically active E. coli was isolated from the subjects with unstable microflora under emergency situations and at the end of the experiment. The results obtained allowed to note the periodicity in predominance of Escherichia with antagonistic and hemolytic activity as related to the changes in the physiological state of the macro-organism and the rate of mechanical and possibly genetic exchange within the microbial associations in the human intestine.