Inactivation of Mycobacterium avium ssp. paratuberculosis in cattle manure by lactic acid fermentation is dependent on carbohydrate source.

Abstract

Mycobacterium avium ssp. paratuberculosis (MAP) is an intestinal pathogen which is excreted fecally and can be spread in the environment through contaminated manure. Lactic acid fermentation (LAF) was evaluated as a method to inactivate MAP in cattle manure (CM). As carbohydrate (CHO) sources oats and saccharose (Sac) were used. After mixing, manure was incubated at 21°C for 8 weeks. The microbial shift was determined using cultural methods. The results showed different suitability of the selected CHOs for inactivation of MAP by LAF. Using squeezed oats as an additive, culturable MAP was reduced to below the detection limit after 35 and 42 days of fermentation. Additional Sac decreased the reduction time to 21 days. With Sac only addition, inactivation of MAP was not successful and bacterial counts did not differ from the negative control. Detection of IS900 genome fragments using real time-polymerase chain-reaction (PCR) showed that the number of gene copies in the manure did not decrease during the course of the experiments. This study showed that LAF is a valuable option for decontaminating CM with natural resources in the case of paratuberculosis.