Comparative Pathology of the Natural infections byMycobacterium bovisand byMycobacterium capraein Wild Boar (Sus scrofa)

Abstract

Summary The potential role of wild animals in the maintenance and spread of tuberculosis (TB) infection in domestic livestock is of particular importance in countries where eradication programs have substantially reduced the incidence of bovine tuberculosis but sporadic outbreaks still occur. Mycobacterium bovis is the agent mainly isolated in wildlife in Spain, but recently, infections by Mycobacterium caprae have increased substantially. In this study, we have analysed 43 mandibular lymph nodes samples containing TB‐like lesions from 43 hunted wild boar from Madrid and Extremadura (central and south‐western regions of Spain). After isolation, identification and typing of Mycobacterium tuberculosis complex isolates, we found that 23 mandibular lymph nodes involved M. caprae infections and 20 M. bovis. The lesions were compared for histopathology (different granuloma stage and number of multinucleated giant cells (MNGCs)), and acid‐fast bacilli (AFBs) were quantified in the Ziehl‐Neelsen‐stained slides. Granulomas produced by M. caprae showed more stage IV granulomas, more MNGCs and higher AFBs counts than those induced by M. bovis. In conclusion, lesions caused by M. caprae would be more prone to the excretion of bacilli, and infected animals result as a high‐risk source of infection for other animals.

Long-Term Assessment of Wild Boar Harvesting and Cattle Removal for Bovine Tuberculosis Control in Free Ranging Populations

“…But other factors may also determine lesion pattern. Garcia-Jimenez and cols., for example, described a higher load of mycobacteria in lesions caused by M. caprae (scarce in our study), which could result in higher excretion rates and, subsequently, exposure for other individuals in the population [47]. Additionally, genetic factors have been related to the ability of both wild boar to limit infection (host resistance) and Mycobacterium bovis to circumvent host immune responses and establish infection (pathogen mechanisms of virulence) [48].…”

Non-tuberculous Mycobacteria in Wild Boar (Sus scrofa) from Southern Spain: Epidemiological, Clinical and Diagnostic Concerns

“…Necropsy examination of all animals was performed in the field with detailed macroscopic inspection of lymph nodes and abdominal and thoracic organs (García‐Jiménez et al., ). Mandibular lymph nodes were selected as the most suitable for microbiological isolation.…”

Goats challenged with different members of the Mycobacterium tuberculosis complex display different clinical pictures

“…Similarly, mice infected with a diversity of M. bovis strains isolated from different host species had different survival probabilities and clinical pictures (Aguilar et al, 2009). In natural infections it has been observed that the genotype of the species included in the MTC may affect disease outcome in human beings (Malik and GodfreyFaussett, 2005), and in animal hosts such as the Eurasian wild boar (Sus scrofa) (Garcia-Jimenez et al, 2013). However, experimental MTC infection in goats has only been reported using either M. bovis or M. caprae (Perez et al, 2012;Gonzalez-Juarrero et al, 2013 …”