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Tesis (Doctor en Medicina de la Conservación) Financial support was given by Universidad Andres Bello project DI 313-13/R and FONDECYT 1100139 The increase in human population and domestic pets, such as dogs and cats, and introduction of species, such as American mink are generating important consequences in terms of habitat loss and pathogen pollution of ecosystems with potential to generate negative impacts in biodiversity. For this, it is essential to perform studies that illustrate the sanitary situation of Chilean native species, particularly those with serious conservation problems, like Southern river otter, to be able to understand and predict how infectious agents spread, and whether they represent a risk for the conservation of these wild species. In particular, this investigation seeks to carry out epidemiologic evaluation of four important infectious agents: Toxoplasma gondii is the etiological agent of zoonotic disease toxoplasmosis, and is associated to cat abundance and anthropogenic disturbance. The present study analyzed seroprevalence (modified agglutination test, MAT, cut-off 1:25) and presence of T. gondii DNA in American mink, Southern river otters and domestic cats in Southern Chile. Mean seroprevalence of T. gondii was 64% of 151 total animals sampled: 59% of 73 American mink, 77% of 13 Southern river otters, 68% of 65 domestic cats. Toxoplasma gondii DNA was detected in tissues from one American mink and one Southern river otter. The present study confirms the widespread distribution of T. gondii in Southern Chile, and shows a high exposure of semiaquatic mustelids and domestic cats to the parasite. Cats and anthropogenic disturbance have a role in the maintenance of T. gondii infection in ecosystems of southern Chile. 8 Parvovirus and canine distemper virus are important agents that can infect carnivores, which causes severe disease in Canidae and Mustelidae. Domestic dogs are considered a problem for public health and for conservation of endangered species, because it can transmit infections to wildlife, such as parvovirus and canine distemper virus. This study analyzed, by PCR the presence of Canine Parvovirus (CPV) and Canine Distemper Virus (CDV) in domestic dogs (n=82), American mink (n=48) and native Southern river otter (13) in the Chilean Patagonia. One dog and two minks were found positive to CPV, these samples were confirmed as CPV by sequencing; but which showed 100% identity with CPV, Feline Panleukopenia and mink Enteritis virus. Non CDV was found. Leptospirosis is an important zoonosis with worldwide distribution caused by pathogenic bacteria of the genus Leptospira. The North American mink has an important role in the environmental contamination with Leptospira, as minks live in aquatic environments and are the predators of rodents. Blood and kidney samples were obtained from 57 minks in southern Chile 39ºS to 45ºS. Pathogenic species of Leptospira were detected by PCR on 31/57 minks. To determine the species we sequenced the 16S rRNA gene on nine of the positive samples. We predicted two pathogenic species: L. interrogans (five samples) and L. borgpetersenii (four samples). This study showed that the American mink presents pathogenic species of Leptospira, and confirm important environmental contamination of Patagonian rivers and lakes with pathogenic Leptospira. |
