Evaluation of Dormancy Modeling Systems for Consistent Viability of Dormant Mycobacterium avium subsp. paratuberculosis

Location

CSU 253/4/5

Start Date

4-4-2011 1:30 PM

End Date

4-4-2011 3:00 PM

Student's Major

Biological Sciences

Student's College

Science, Engineering and Technology

Mentor's Name

Timothy Secott

Mentor's Department

Biological Sciences

Mentor's College

Science, Engineering and Technology

Description

Mycobacterium avium subsp paratuberculosis (Mpt) causes Johne‘s disease, a fatal gastrointestinal disease that infects ruminant animals such as cows. This particularly affects the dairy industry because cows infected with the disease end up starving to death due to the result of highly inflamed gastrointestinal tissue inhibiting absorption of nutrients from the intestinal lumen. Evidence also suggests a link between Johne‘s disease and Crohn‘s disease, the human form of Johne‘s disease, which increases the importance of Mpt research. The ability of Mpt to enter a dormant state poses problems for detecting asymptomatic infections with Mpt, as these organisms cannot be reliably detected by diagnostic culture. Previous research in our laboratory has demonstrated that dormant cultures can differ widely in viability, indicating that the physiologic state of the organisms also varies widely. The development of a standardized system for investigating dormancy would improve the reliability of detecting Mpt infections. We cultured Mpt in sealed vials to restrict oxygen availability. In addition, culture medium was supplemented with different concentrations of Oxyrase, a biological reducing agent, to increase the rate of oxygen loss from cultures. Culture viability was measured by differential staining with fluorescent DNA stains that allow the enumeration of live and dead cells when measured by flow cytometry. Our preliminary results indicate no variation in the viability among the treatments used. This indicates that entry into a dormant state for laboratory investigations can be accomplished much more quickly than previously believed. The results of final testing are currently in progress.

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Apr 4th, 1:30 PM Apr 4th, 3:00 PM

Evaluation of Dormancy Modeling Systems for Consistent Viability of Dormant Mycobacterium avium subsp. paratuberculosis

CSU 253/4/5

Mycobacterium avium subsp paratuberculosis (Mpt) causes Johne‘s disease, a fatal gastrointestinal disease that infects ruminant animals such as cows. This particularly affects the dairy industry because cows infected with the disease end up starving to death due to the result of highly inflamed gastrointestinal tissue inhibiting absorption of nutrients from the intestinal lumen. Evidence also suggests a link between Johne‘s disease and Crohn‘s disease, the human form of Johne‘s disease, which increases the importance of Mpt research. The ability of Mpt to enter a dormant state poses problems for detecting asymptomatic infections with Mpt, as these organisms cannot be reliably detected by diagnostic culture. Previous research in our laboratory has demonstrated that dormant cultures can differ widely in viability, indicating that the physiologic state of the organisms also varies widely. The development of a standardized system for investigating dormancy would improve the reliability of detecting Mpt infections. We cultured Mpt in sealed vials to restrict oxygen availability. In addition, culture medium was supplemented with different concentrations of Oxyrase, a biological reducing agent, to increase the rate of oxygen loss from cultures. Culture viability was measured by differential staining with fluorescent DNA stains that allow the enumeration of live and dead cells when measured by flow cytometry. Our preliminary results indicate no variation in the viability among the treatments used. This indicates that entry into a dormant state for laboratory investigations can be accomplished much more quickly than previously believed. The results of final testing are currently in progress.

Recommended Citation

Ramberg, Nicholas. "Evaluation of Dormancy Modeling Systems for Consistent Viability of Dormant Mycobacterium avium subsp. paratuberculosis." Undergraduate Research Symposium, Mankato, MN, April 4, 2011.
https://cornerstone.lib.mnsu.edu/urs/2011/poster-session-C/12