Abstract
Incidences of colicinogenic strains in the Escherichia coli strains isolated from various clinical materials were examined. The incidences were higher in the order in the strains isolated from pustular materials, feces, sputa and urine. Approximately 32% of the pustular strains were found to be colicino-genic. Heat stability of these colicins were examined and incidences of the heat stable colicins were found to be higher in the strains from pustular mate-rials than the strains from any other materials. Some of the colicins which retained their activity after treatment at 100°C for 30 minutes were con-centrated and tested for the cellophane membrane permeability and the re-sistance to methanol, acid and alkaline. They were all found to be permeable through cellophane membrane and resistant to all the chemicals.
