Evaluation of the Presence and Viability of Mycobacterium bovis in Wild Boar Meat and Meat-Based Preparations.

Abstract

The aim of the present study is to provide information about the ability of Mycobacterium bovis to survive within wild boar (Sus scrofae) meat and meat-based preparations and the duration of this survival, and to consider the preservation of its infectious potential toward humans and animals. Meat samples were artificially contaminated with an M. bovis field strain and then stored at −20 °C, while two sausages batches were contaminated with the same field strain at two different concentrations, 105 CFU/g and 103 CFU/g, before storing them in proper conditions to allow for their ripening. A third sausage batch was contaminated by adding 2 g of wild boar lymph nodal tissue with active tuberculous lesions to the meat mixture. Bacteriological and biomolecular (PCR) methods were used to test the meat and sausage samples every 60 days and every 7–10 days, respectively. M. bovis was detected as still alive and viable on the frozen meat for the last test on the 342nd day, while from the sausage samples, M. bovis was isolated until 23 days after contamination. Our results indicate that M. bovis can stay alive and be viable for 23 days within sausages prepared with contaminated meat from infected wild boars. These products are usually eaten as fresh food after grilling, often cooking at a temperature that does not ensure complete inactivation of the pathogenic microorganisms present, which can pose a risk for humans to develop zoonotic tuberculosis.