Pneumocystis spp. e Histoplasma capsulatum detectados em pulmões de morcegos das regiões Sul e Centro-Oeste do Brasil

Background: Histoplasma capsulatum and Pneumocystis spp. may cause a host infection through the respiratory airway, mainly affecting the pulmonary tissue. These fungal pathogens affect a wide range of mammalian species, including humans and bats. The co-infection of bats with both organisms above has never been studied in Brazil. The aim of the present research was to detect the presence of the H. capsulatum and Pneumocystis spp. in lung samples of bat species from two states of Brazil. For this purpose, a highly sensitive nested PCR was used with specific molecular markers for each pathogen. Materials, Methods & Results: Two hundred and forty-nine bats were captured between 2007 and 2009 in caves, forests, and urban areas of Mato Grosso (MT) and Rio Grande do Sul (RS), located respectively in the Mid-Western and Southern regions. The bats were captured following the guidelines of the rabies control manual for herbivores, standardized by the Ministry of the Agriculture. Detection of Pneumocystis spp. DNA was based upon nested PCR, which amplified a portion of the mitochondrial small subunit (mtSSU) of the rRNA gene, whereas the H. capsulatum DNA was amplified employing the Hcp 100 locus. Amplification products were sequenced to confirm fungal presence in bat lungs. The amplifications results for H. capsulatum and Pneumocystis spp. were positive in 63 [25.3%, IC95% (20.1%-31.25%)] and 95 [(38,2%, IC95% (32.1%-44.52%)] samples, respectively. The greatest occurrence of Histoplasma capsulatum was observed in Desmodus rotundus (20.6%), Tadarida brasiliensis (20.6%), Histiotus velatus (19.0%) and Molossus molossus (11.1%), with the detection in the other species being lower than 7.9%, among the 24 studied bat species. For Pneumocystis spp., the detection was higher in Tadarida brasiliensis (23.1%), Desmodus rotundus (18.%), Histiotus velatus (14.7%), and Molossus molossus (11,6%), being lower than 5.3% in the other species. A co-infection with both Pneumocystis spp. and Histoplasma capsulatum was observed in 14.4% of the samples. Discussion: Results from this study revealed a high positivity in pulmonary tissue for both studied fungi. Comparing with the current and recent literature, a higher occurrence was observed for Pneumocystis spp., being lower for H. capsulatum as well as for the co-infection in the lungs of bats from both Brazilian regions. The majority of the analyzed samples were from urban area, where the occurrence of H. capsulatum was higher than that observed by the Centro de Zoonose do Estado de São Paulo, which pionerily described H. capsulatum in N. macrotis, E. glaucinus and M. Rufus species. In this study, 1.6% of the samples in those same species were positive for H. Capsulatum. Due the larger sample size from urban areas, the species Tadarida brasiliensis was the most studied for both fungi. To note, in one colony from the latter species, composed of hundreds of bats, a large amount of bat guano was observed, which favors the dispersion of fungal propaguls of H. capsulatum and a subsequent high fungal colonization detected in those animals. However, it is not possible to infer that the bats were developing the disease, since others organs like liver, spleen and intestine were not analyzed. Results from this study corroborate with the literature that report a high transmission of H. capsulatum among bats belonging to big colonies, by demonstrating a high occurrence of Histoplasma capsulatum and Pneumocystis spp., individually or in co-infection, in bats from two geographically distant Brazilian states (RS and MT).