Desiccation-Tolerance of Mycobacterium avium , Mycobacterium intracellulare , Mycobacterium chimaera , Mycobacterium abscessus and Mycobacterium chelonae .

Desiccation-tolerance of cells of four strains of Mycobacterium chimaera and individual strains of Mycobacterium avium , Mycobacterium intracellulare , Mycobacterium abscessus , and Mycobacterium chelonae were measured by two methods. The survival of water-acclimated cells both in filter paper and on the surface of stainless-steel coupons were measured. In filter paper at 40% relative humidity at 25 °C, survival of patient isolates of M. avium and M. chimaera cells was 28% and 34% after 21 days of incubation, whereas it was 100% for the Sorin 3T isolate of M. chimaera . On stainless-steel biofilms after 42 days of incubation at 40% relative humidity at 25 °C, survival of water-acclimated cells of M. intracellulare was above 100%, while M. chelonae cells did not survive beyond 21 days, and survival of water-acclimated cells of M. avium and M. abscessus was 18% and 14%, respectively. On stainless-steel coupons, survival of patient and Sorin 3T isolates of M. chimaera was quite similar, specifically between 14% and 28% survival, after 42 days of incubation at 40% relative humidity at 25 °C. The experiments would support the hypothesis that some nontuberculous mycobacterial species are relatively desiccation-tolerant, whereas others are not. Further, long-term survival of the two M. chimaera strains is consistent with the presence of that species in Sorin 3T heater-coolers shipped throughout the world.