Avaliação da ocorrência e impacto de Trichomonas gallinae em aves

Abstract

Avian trichomoniasis is caused by the protozoan Trichomonas gallinae, whose main hosts are birds of the Columbidae family, which have a high prevalence of the protozoan without manifesting the disease. The continuous growth of the pigeon population and its cosmopolitan nature mean that today there is a worldwide distribution of this species, being responsible for the distribution and maintenance of the prevalence of trichomoniasis in almost the entire world. The transmission of the disease can be by direct contact, or indirect, through food or water. This indirect route is the reason why a wide variety of bird orders can be infected, very different from columbids such as falconiformes, strigiformes, passerines, piciformes, psittaciformes, gruiformes, galliformes or anseriformes. Thus, the aim of this study was to evaluate the presence of T. gallinae in passerines received at a wild animal screening center, in addition to describing a positive case of T. gallinae infection in a red-breasted toucan (Ramphastos dicolorus). For the accomplishment of this study, 300 samples were collected and analyzed for convenience, of swabs from the oral mucosa of birds of the Passeriforme order, which corresponded to 23 different species received at the Nucleus of Rehabilitation of Wild Fauna (NURFS) of the Federal University of Pelotas (UFPel ), in different seasons of the year, between March and October 2021. From all individuals, an oropharyngeal swab was performed, the material was immediately placed in a falcon tube containing Trypticase-Yeast Extract-Maltose (TYM) culture medium and sent to the Laboratory of Protozoology and Entomology (LAPEn) for incubation in a bacteriological growth oven and subsequent identification on a slide in wet mounting under an optical microscope at 40x magnification of the protozoan. Wet mounting on a slide was performed in triplicate and analyzed in its entirety. Of the 300 birds evaluated in in vitro culture for T. gallinae, 25 had inconclusive results and were submitted to PCR analysis, being negative for T. gallinae. Although no positive Passeriformes were found, the monitoring of the occurrence of this protozoan should continue, as it is known that it can cause a possible epidemic, leading to losses for the wild fauna that has endangered birds.