Format

Send to

Choose Destination
Appl Environ Microbiol. 2004 May;70(5):2989-3004.

Survival and dormancy of Mycobacterium avium subsp. paratuberculosis in the environment.

Author information

1
Faculty of Veterinary Science, The University of Sydney, Sydney, Australia. richardw@camden.usyd.edu.au

Abstract

The survival of Mycobacterium avium subsp. paratuberculosis was studied by culture of fecal material sampled at intervals for up to 117 weeks from soil and grass in pasture plots and boxes. Survival for up to 55 weeks was observed in a dry fully shaded environment, with much shorter survival times in unshaded locations. Moisture and application of lime to soil did not affect survival. UV radiation was an unlikely factor, but infrared wavelengths leading to diurnal temperature flux may be the significant detrimental component that is correlated with lack of shade. The organism survived for up to 24 weeks on grass that germinated through infected fecal material applied to the soil surface in completely shaded boxes and for up to 9 weeks on grass in 70% shade. The observed patterns of recovery in three of four experiments and changes in viable counts were indicative of dormancy, a hitherto unreported property of this taxon. A dps-like genetic element and relA, which are involved in dormancy responses in other mycobacteria, are present in the M. avium subsp. paratuberculosis genome sequence, providing indirect evidence for the existence of physiological mechanisms enabling dormancy. However, survival of M. avium subsp. paratuberculosis in the environment is finite, consistent with its taxonomic description as an obligate parasite of animals.

PMID:
15128561
PMCID:
PMC404446
[Indexed for MEDLINE]
Free PMC Article

Supplemental Content

Full text links

Icon for HighWire Icon for PubMed Central
Loading ...
Support Center