Molecular evidence of Mycobacterium avium subspecies paratuberculosis (MAP) shedding in the invasive American mink (Neogale vison) in southern Chile.

Mycobacterium avium subsp. paratuberculosis (MAP) is the causative agent of Johne's disease (paratuberculosis), a chronic enteritis affecting domestic and wild ruminants worldwide. While MAP transmission primarily occurs among livestock, increasing attention has been given to the role of wildlife in the maintenance and spread of this pathogen. Invasive species, such as the American mink (Neogale vison), may serve as unexpected source of infection or mechanical vectors for MAP, especially in regions where wildlife and domestic animals share habitats. In this study, we performed a specific MAP-IS900 real-time PCR assay to detect bacterial DNA in mesenteric lymph nodes (MesLN) (n = 401) and colonic/rectal fecal swabs (n = 346) from minks in Los Ríos region, Chile. We detected MAP DNA in 16 % and 10 % of minks in MesLN and fecal swabs, respectively, while 4 % of minks were MAP qPCR-positive in both MesLN and fecal swab samples. Considering specimens with known sex and age, we detected MAP DNA in 22 % of minks in either MesLN or fecal swabs, where 21 % of males and 22 % of females were MAP qPCR-positives, and 15 % of juveniles, 25 % of subadults, and 21 % of adults were MAP DNA-positive in at least one sample type. Our study is the first report on MAP detection in this non-ruminant carnivore in Chile, raising further questions about interspecies transmission dynamics and the potential environmental dissemination of this bacterial agent. These findings highlight the need for broader surveillance strategies that incorporate wildlife, particularly invasive species, into MAP control programs.