Infecção por Sarcocystis spp., Toxoplasma gondii e Neospora caninum em aves: ocorrência e detecção molecular

Abstract

Parasites from de genus Sarcocystis, Toxoplasma and Neospora which belong to the Apicomplexa phylum cause infection in birds. Birds feeding habits as consumption of food touching the soil enhances the probability of cysts ingestion and because of that they indirectly demonstrate the parasites that are contaminating the environment. Birds are intermediate hosts and when they are killed and ingested they became infection sources to definitive hosts. Studies have showed that these parasites infect birds but the role of birds in protozoa life cycles remains unclear. Therefore, the objective of this study was to check the occurrence and the molecular detection of Sarcocystis spp., Toxoplasma gondii and Neospora caninum in tissues from naturally infected birds. Tissue samples (brains, hearts and chest muscle) were collected from birds destined to necropsy at the Avian Pathologies Diagnosis Central Laboratory (LCDPA) of the Federal University of Santa Maria (UFSM). Birds were free-living, domestic or originating from conservatories or maintainer and died from different causes. Samples were submitted to DNA extraction, PCR amplification of the 18S rRNA gene to Sarcocystis spp., NC5 gene to N. caninum and repetitive gene 529 base pares for T. gondii. Positive samples were sequenced and compared with sequences in GenBank. This thesis was organized in two chapters based on birds’ tissue samples availability to parasites analyses. In chapter one, samples were collected from 65 birds (65 brains and 65 hearts) and analyzed for Sarcocystis spp., T. gondii and N. caninum. N. caninum DNA was detected in two birds (02/65 – 3.07%), in brain sample of a Rupornis magnirostris and in brain and heart samples of a Dendrocygna bicolor. DNA from Sarcocystis spp. was detected in three birds (03/65 – 4.62%), in brain of a Nymphicus hollandicus, brains and hearts of a Amazona aestiva and a Paroaria coronata. T. gondii DNA was not detected in any tissues. No mixed infections were observed. In chapter two, chest muscles were collected from 89 birds which were held in captivity aiming Sarcocystis detection. Five amplified sequences (5.61%) detected in Cyanoliseus patagonus (1), Psittacula krameri (1), Pyrrhura frontalis (2) e Ramphastos dicolorus (1) showed 100% identity with Sarcocystis spp. The diversity of hosts species naturally infected analyzed by molecular methods showed Sarcocystis and Neospora infecting different birds’ species and probably these birds are involved in protozoa epidemiology.