The relationship of temperature to desiccation and starvation tolerance of the Mycobacterium avium complex

Abstract.

Mycobacterium avium grew in media at 14–37 °C, and persisted at 4 °C and 42 °C. The bacteria lost approximately 90% viability after 3 months in reverse-osmosis deionized water at 4–37 °C. Cooler temperatures lowered the death rate. Death rates also decreased after a 5- to 10-day starvation adaptation period. Alterations of the steady-state levels of different mycolic acid classes, presumably to facilitate thermoadaptation, were found. Following desiccation, M. avium lost viability at a constant rate (half-life of 2.3 days). This implies that bacilli contaminating dry medical surfaces would persist for short periods of time. The remarkable stress survival exhibited by M. avium further suggests persistence in a range of environmental and clinical settings.