In Vitro Survival Characteristics of Koala Chlamydiae.

Abstract

Extracellular stability of koala chlamydia type I and II, were compared with that of an avian C. psittaci strain. Koala types I and II, as well as avian psittacosis elementary bodies, survived 4 h exposure to solution of pH 4.0-10.0. Koala type I survived best at pH 7.2-7.5 whereas type II preferred pH of 7.0-7.2. Koala type I elementary bodies were inactivated after 5 min at 56 deg C, but at lower temperatures (18-23 deg C) the elementary bodies remained viable for up to 28 days. Koala type I elementary bodies survived for 2-4 days after drying, whereas avian chlamydiae survived for 4-6 days. The koala type I isolate maintained infectivity for cell culture after 3 days' exposure on the leaves of Eucalyptus tereticornis. It is concluded that the koala type I isolate is able to survive extreme conditions for significant time periods and that non-sexual transmission of this chlamydiae may be possible.