Paracoccidioides spp

From Dog
Paracoccidioides brasiliensis. Cultured at 37°C. Two views of a 15-day culture.[1]

Paracoccidioides spp are a dimorphic species of yeast which reside in tropical and subtropical soils[2].

In humans, Paracoccidioides causes a severe systemic mycosis (Lobo's disease), endemic in Latin America. A similar situation is perceived in these countries, where serological surveys have found more than 50% of urban dogs are seropositive to exposure to this yeast[3].

Co-infection of dogs by Leishmania brasiliensis is common and may amplify this serological picture[4]. Dogs susceptible to developing leishmaniasis could be also more susceptible to developing paracoccidioidomycosis[5].

The ecological niche or exact habitat of the fungus Paracoccidioides brasiliensis is not known, and few isolates have been obtained from the environment[6].

Infections in dogs are thought to be naturally acquired via inhalation.

Species which are pathogenic in dogs include:

  • Paracoccidioides brasiliensis

Clinical signs are usually non-specific, although weight loss, hepatomegaly and cervical lymphadenopathy are consistent findings[7][8].

Diagnosis is based on clinical findings and postmortem findings of granulomas in the lungs, spleen and liver[9].

Definitive diagnosis requires culturing, ELISA[10], Western blot[11], immunohistochemistry, and histopathology of popliteal lymph nodes.

Itraconazole is the drug of choice, with extended treatments for up to 2 years.

References

  1. Lupi O et al (2005) Tropical dermatology: fungal tropical diseases. J Am Acad Dermatol 53(6):931-951
  2. Franco M et al (2000) A critical analysis of isolation of Paracoccidioides brasiliensis from soil. Med Mycol 38(3):185-191
  3. Fontana FF et al (2010) Seroepidemiological survey of paracoccidioidomycosis infection among urban and rural dogs from Uberaba, Minas Gerais, Brazil. Mycopathologia 169(3):159-165
  4. Silveira LH et al (2006) Serological detection of antibodies against Paracoccidioides brasiliensis in dogs with leishmaniasis. Mycopathologia 162(5):325-329
  5. Lemesre JL et al (2005) Protection against experimental visceral leishmaniasis infection in dogs immunized with purified excreted secreted antigens of Leishmania infantum promastigotes. Vaccine 23:2825–2840
  6. Costa PF et al (2010) Characteristics of environmental Paracoccidioides brasiliensis isolates. Mycopathologia 169(1):37-46
  7. Ricci G et al (2004) Canine paracoccidioidomycosis. Med Mycol 42(4):379-383
  8. de Farias MR et al (2011) Paracoccidioidomycosis in a dog: case report of generalized lymphadenomegaly. Mycopathologia 172(2):147-152
  9. Ono MA et al (2003) Experimental paracoccidioidomycosis in dogs. Med Mycol 41(3):265-268
  10. Eisele RC et al (2004) Immune response in dogs experimentally infected with Paracoccidioides brasiliensis. Med Mycol 42(6):549-553
  11. Canteros CE et al (2010) Endemic fungal pathogens in a rural setting of Argentina: seroepidemiological study in dogs. Rev Iberoam Micol 27(1):14-19