Investigation of the survival characteristics of Rhodococcus coprophilus and certain fecal indicator bacteria

Abstract

Rhodococcus coprophilus and Clostridium perfringens survived in fresh water samples held at 5, 20, and 30°C for over 17 weeks, whereas Escherichia coli and fecal streptococci disappeared after 5 weeks at all three temperatures. R. coprophilus survived for more than 8 months in sterilized sewage and deionized water at all three temperatures, whereas in normal sewage held at 20°C, the survival time was 12 to 26 weeks. In samples held at 30°C, survival times were shorter, probably because of interbacterial competition or protozoal predation. The results indicate that R. coprophilus may be a useful indicator of the presence of remote fecal pollution of farm animal origin, but not of recent pollution, when enumerated alone in polluted waters or wastewaters.