Relação parasitemia e leucograma de gatos infectados com Trypanosoma evansi

Abstract

ResumoTrypanosoma evansi é um protozoário que causa a tripanossomose em animais de muitos países do sudeste da Ásia, África e América do Sul. Optamos por utilizar os gatos em nosso estudo, devido à facilidade de manipular os animais e a falta de estudos envolvendo a tripanossomose nesta espécie. Deste modo, o objetivo deste estudo foi investigar alterações no leucograma de felinos domésticos infectados experimentalmente por T. evansi e relacionar com a parasitemia. Foram utilizados 13 gatos, divididos em dois grupos. Sete deles foram infectados com T. evansi e o restante foram utilizados como grupo controle negativo. Os animais foram monitorados diariamente através de esfregaço sanguíneo. Nos dias 0, 7, 21, 35 e 49 de experimento, foram coletadas amostras de sangue para avaliação do leucograma. O pico de parasitemia ocorreu cinco dias após inoculação, após este período o número de parasitos reduziu e manteve-se com picos irregulares, variando de zero a três tripomastigotas/campo. Na pesquisa foi verificado aumento (P < 0,05) do número de leucócitos totais (dia 49), bastonetes (dia 35), neutrofilos segmentados (dia 49) e monócitos (dias 7, 35 e 49) e redução de linfocitos e eosinofilos (dias 21, 35 e 49). Gatos infectados com T. evansi apresentam leucocitose, neutrofilia, monocitose, linfopenia e eosinopenia. Porém, não foi verificado relação entre os picos de parasitemia e alteração no número de globulos brancos circulantes, com execção dos monócitos no dia 7. Palavras-chave: Tripanossomose, felinos, sistema imunológico, parasitismo AbstractTrypanosoma evansi is a protozoan which causes trypanosomosis in livestock in many countries of Southeast Asia, Africa and South America. We chose to use cats in our study due to the facility to handle the animals and the lack of studies involving the trypanosomosis in this species. The aim of this study was to analyze the leukogram of domestic cats experimentally infected with T. evansi and its correlation to the parasitemia. Thirteen animals were divided into two groups. Seven animals were infected with T. evansi and six were used as negative control. Parasitemia was estimated daily by microscopic examination of smears. Blood samples for leukogram were collected at days 0, 7, 21, 35 and 49. The

Co-Infection and Wild Animal Health: Effects of Trypanosomatids and Gastrointestinal Parasites on Coatis of the Brazilian Pantanal

“…Species in the order Carnivora show varied responses to T . evansi infection regarding the number of circulating neutrophils [ 65 , 71 , 72 ], and reasons underpinning this variation are not known. Coatis also showed a reduced number of eosinophils, which may be a consequence of acute infection [ 12 ].…”

“…Eosinopenia (low number of eosinophils) was reported in cats experimentally infected with T . evansi [ 72 ], but the same was not observed in dogs [ 65 , 71 ]; indeed, interpretation of such results is troublesome, as eosinophil reference values for many species may be zero cells per mm 3 of blood.…”

Biochemical and physiological parameters associated with Trypanosoma evansi prevalence in wild capybaras (Hydrochoerus hydrochaeris)

“…Previous results on leukocytes and counts of each cell type, both in naturally and experimentally infected mammal hosts, have been varied. For example, Olifiers et al (2015) reported that coatis naturally infected by T. evansi also showed a reduced number of eosinophils and neutrophils; dogs showed a decrease in circulating leukocyte counts during infection (Aquino et al 2002), while cats, horses and guinea pigs exhibited an increase (Monzón et al 1991;Silva et al 2010). Our results suggest a cellular immunological debilitation (since all leukocyte populations tended to be lower in infected individuals) at the expense of antibody production (infected capybaras showed higher levels of gamma-globulins than those not infected, see above).…”