Paracoccidioidomycosis infection in domestic and wild mammals by Paracoccidioides lutzii.

The research article reports on a study investigating the presence of Paracoccidioides lutzii, a type of fungus that causes systemic mycosis (a severe disease in humans and animals), in various animal populations in Rio Grande do Sul, Brazil. The study found that 21.8% of the tested animals had antibodies against the fungus, indicating potential exposure.

Introduction to Paracoccidioidomycosis and Paracoccidioides lutzii

• Paracoccidioidomycosis (PCM) is a serious disease caused by a type of fungus known as Paracoccidioides.
• The fungus is thermo-dimorphic, meaning it can change its form in response to temperature.
• PCM is prevalent in several Latin American countries, and especially endemic in Brazil.

The Need for the Study

• Despite Rio Grande do Sul being an endemic region for PCM in humans, there was limited information about the ecology of the fungus in the environment and its impact on animal populations.
• Serological studies which detect infections in animals are an excellent strategy for obtaining data about the pathogen’s spread and behaviour.

Methodology of the Study

• The study involved testing a total of 481 animals, composed of 85 wild mammals, 200 horses, and 196 domestic dogs.
• These animals were previously tested for infection by the fungus P. brasiliensis, another pathogen closely related to P. lutzii.
• Serum samples obtained from the animals were tested for the presence of anti-P. lutzii antibodies, which would indicate exposure to the fungus.

Findings of the Study

• Out of the animals tested, 105 (21.8%) were found to have IgG anti-P. lutzii antibodies, indicating an exposure to the pathogen.
• Of these, 54 had also been exposed to P. brasiliensis.
• A subset of the animals, composed of 11 horses (10.5%), 30 dogs (28.8%) and 10 wild mammals (9.5%) tested positive only for P. lutzii.
• The presence of anti-P. lutzii antibodies in the tested population suggests the fungus is present in southern Brazil, despite primarily being associated with the midwestern and southeastern regions of the country.