ARS | Publication request: Evaluation of survival of Mycobacterium avium subsp. paratuberculosis (Map) in ciliates isolated from Johne’s positive cow.

Submitted to: Annual Johne's Disease Integrate Program Conference
Publication Type: Abstract Only
Publication Acceptance Date: February 8, 2007
Publication Date: April 2, 2007
Citation: Cook, K.L., Janaki, L., Berk, S.G. 2007. Evaluation of survival of Mycobacterium avium subsp. paratuberculosis (Map) in ciliates isolated from Johne’s positive cow.. Annual Johne's Disease Integrate Program Conference.

Technical Abstract: Introduction: Persistence of Mycobacterium avium subsp. paratuberculosis (Map) in farm environments is not well understood. Previously we examined the ability of amoebae from a cow’s watering trough to sequester and enhance growth of Map and found that one amoeba species released vesicles containing viable intact Map. Ciliates, common in water and moist soils, may behave similarly; and their vesicles may protect the bacteria from environmental conditions. The purpose of the present investigation was to obtain ciliates from a watering trough of a cow that was Johne’s positive, and to examine their interactions with Map. Methods: Water and biofilm from a trough used by a cow with Johne’s disease was processed to enrich for protozoa. A ciliate species tentatively identified as a Tetrahymena sp. was isolated and used, along with a previously isolated strain of Tetrahymena from moist field soil. The ciliates were co-cultured with two strains of Map, ATCC strain 700535, derived from a cow with Johne’s disease, and another strain isolated from the jejunum of the cow that used the watering trough. Confocal microscopy was used to visualize fluorescent acid-fast (A-F)-stained Map in the ciliates and in their expelled vesicles, which were enumerated with a hemacytometer. Results: Vesicles with intact A-F bacteria were produced by each ciliate species with either Map strain in less than 24 h. The bacteria were viable, as determined by the BacLight Live/Dead stain. There were no statistically significant differences in the numbers of vesicles produced by either ciliate strain feeding on either Map strain. The average number of vesicles produced by the ciliates in 24 h ranged from to per individual ciliate. Such vesicles may protect bacteria from harsh environmental conditions. Conclusion: These results suggest that ciliated protozoa in the farm environment may play a role in persistence or protection of Map populations.