Open AccessPersistence of Mycobacterium avium subsp. paratuberculosis at a Farm-Scale Biogas Plant Supplied with Manure from Paratuberculosis-Affected Dairy Cattle
Author(s) -
Iva Slaná,
Radka Pribylova,
Alena Králová,
I. Pavlík
Publication year - 2011
Publication title -
applied and environmental microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.552
H-Index - 324
eISSN - 1070-6291
pISSN - 0099-2240
DOI - 10.1128/aem.02407-10
Subject(s) - paratuberculosis , biology , mycobacterium , manure , microbiology and biotechnology , dairy cattle , mycobacterium avium subsp. paratuberculosis , veterinary medicine , bacteria , agronomy , zoology , medicine , genetics
In this study, products from all steps of anaerobic digestion at a farm-scale biogas plant supplied with manure from paratuberculosis-affected dairy cattle were examined and quantified for the presence of the causal agent of paratuberculosis,Mycobacterium avium subsp.paratuberculosis , using culture and quantitative real-time PCR (qPCR). ViableM. avium subsp.paratuberculosis cells were detected using culture in fermentors for up to 2 months; the presence ofM. avium subsp.paratuberculosis DNA (101 cells/g) was demonstrated in all anaerobic fermentors and digestate 16 months after initiation of work at a biogas plant, using IS900 qPCR.F57 qPCR was able to detectM. avium subsp.paratuberculosis DNA (102 cells/g) at up to 12 months. According to these results, a fermentation process that extended beyond 2 months removed all viableM. avium subsp.paratuberculosis cells and therefore rendered its productM. avium subsp.paratuberculosis free. However,M. avium subsp.paratuberculosis DNA was found during all the examined periods (more than 1 year), which could be explained by either residual DNA being released from dead cells or by the presence of viable cells whose amount was under the limit of cultivability. As the latter hypothesis cannot be excluded, the safety of the final products of digestion used for fertilization or animal bedding cannot be defined, and further investigation is necessary to confirm or refute this risk.