Phylogenetic analysis of Mycobacterium caprae highlights past and present epidemiological links at the Iberian Peninsula scale.

Mycobacterium caprae is linked to regular outbreaks of tuberculosis (TB) in geographically distinct caprine populations across Europe, namely Iberia where this ecovar may represent 8% of total animal TB cases, circulating in multi-host communities encompassing domestic ruminants and wildlife, representing severe financial losses. It also causes zoonotic human disease. In this work, we undertake the first phylodynamic and phylogeographic analyses of M. caprae to reconstruct past demography and transmission chains. First, we examined the worldwide diversity of M. caprae based on 229 unpublished and publicly available whole genome sequences, depicting Asian, Central-East European, and Iberian clades. Phylodynamic analyses of the SB0157 Iberian clade (n=81) positioned the most recent common ancestor in goats, around 100 years ago. Host transition events were common between goats, wild boars, and humans, possibly resulting from mixed farming, extensive management, and close human proximity, facilitating interspecific transmission. We show the spread of M. caprae on multiple scales due to local and transnational animal trade, supporting historical and sustained cross-species transmission in Iberia. We highlight the value of intersecting genomic epidemiology with molecular ecology to resolve epidemiological links and show that an EU-official eradication program in goats is utterly needed to control TB in a multi-host scenario.

Adiaspiromycoses in Wild Rodents from the Pyrenees, Northeastern Spain.

Adiaspiromycosis is a nontransmissible infectious pulmonary disease caused by the inhalation of propagules from fungal species belonging to the family Ajellomicetaceae, especially Emergomyces crescens. Adiaspiromycosis caused by E. crescens has been recorded in a broad number of species worldwide, with small burrowing mammals being considered the main hosts for this environmental pathogen. Only a handful of studies on adiaspiromycosis in European wildlife has been published to date. We assessed the occurrence of adiaspiromycosis in wild rodents (Murinae and Arvicolinae) from the central Spanish Pyrenees (NE Spain). The lungs of 302 mice and 46 voles were screened for the presence of adiaspores through histopathologic examination. Pulmonary adiaspiromycosis was recorded in 21.6% of all individuals (75/348), corresponding to 63/299 wood mice (Apodemus sylvaticus) and 12/40 bank voles (Myodes glareolus). Adiaspore burden varied highly between animals, with a mean of 0.19 spores/mm2 and a percentage of affected lung tissue ranging from <0.01% to >8%. These results show that the infection is present in wild rodents from the central Spanish Pyrenees. Although the impact of this infection on nonendangered species is potentially mild, it might contribute to genetic diversity loss in endangered species.

Experimental infection of goats with Mycobacterium microti induces subclinical pulmonary tuberculosis and mild responses to tuberculin skin tests.

Mycobacterium microti is a member of the Mycobacterium tuberculosis complex that seldom causes disease in livestock and humans. This study evaluated the effects on immunodiagnosis and the pathological findings in goats after experimental exposure by different routes and doses to M. microti. In a first experiment goats were challenged orally (PO, n = 7) or intranasally (IN, n = 7) with 104 CFU. In a second experiment, the endobronchial route was assessed, with a low dose of 102 CFU (EB-LD, n = 7) and a high dose of 105 CFU (EB-HD, n = 7) as well as the subcutaneous route (SC, n = 5). Temperature, body weight, clinical signs and immunological responses were monitored. Pathological evaluation was carried out and samples were processed for mycobacterial detection. RESULTS: demonstrated the induction of a subclinical pulmonary infection in all the EB-HD challenged animals. Infection was also confirmed in one animal of the SC group, but not in the EB-LD, PO or IN groups. Two animals belonging to the EB-HD and SC groups, respectively, showed positive results to the single intradermal tuberculin test, and another two animals of the EB-HD and EB-LD groups showed doubtful (inconclusive) results, indicating that M. microti can induce mild responses to tuberculin skin testing. No positive results were observed when defined antigens absent in M. microti (ESAT-6 and CPF-10) were used. Our results indicate that animals exposed to M. microti can yield positive results to the skin tests currently performed in livestock tuberculosis eradication campaigns and reinforce the need to use specific antigens in antemortem tests to avoid interference with M. bovis/M. caprae diagnosis.