LONG-TERM SURVIVAL OF BORDETELLA-BRONCHISEPTICA IN LAKEWATER AND IN BUFFERED SALINE WITHOUT ADDED NUTRIENTS

Bordetella bronchiseptica grew from small inocula, and retained viabil ity for at least 24 weeks, in unsupplemented lakewater or phosphate-bu ffered saline. From washed inocula of around 10(3) colony-forming unit s/ml, there was growth at both 10-degrees-C and 37-degrees-C to give 1 0(6)-10(7) colony-forming units/ml. At 10-degrees-C, these counts were maintained with little diminution up to week 24 when observations cea sed. In the tests at 37-degrees-C, two of three strains tested showed similar retention of viability. These results suggest that B. bronchis eptica may exist as hitherto unsuspected reservoirs of infection in fr eshwater habitats.