Trypanosoma vivax nos tecidos testicular e epididimário de ovinos experimentalmente infectados

Abstract

Four adult sheep (number 1, 2, 3 and 4), all males, were inoculated intravenously with 1ml of blood containing 1.25x10 5 trypomastigotes of Trypanosoma vivax, and Sheep 5, 6, 7 and 8 were used as control. After infection, clinical exams considering rectal temperature, respiratory and cardiac frequencies, and parasitaemia were recorded daily for a 30-day experiment period. Blood samples were obtained for 5-day intervals to hematocrit analysis. At the end of the experimental period, the sheep were orquiectomized. Testes and epididymides from these animals were studied anatomopathologically. Samples from these tissues of Sheep 1, 4 and 5 were taken to polymerase chain reaction (PCR). Clinical parameters remained for the infected group above the values observed in the control group during the experimental period. Parasitaemia was observed on day 3 post-infection, and the highest values occurred between day 6 and 10, and day 15 and 18 post-infection. Sheep 1 and 4 showed severe anemia on day 25 post-infection. All sheep of the infected group showed flabby and palid testes. Histologically, moderate to severe testicular degeneration, multifocal epididymitis and hyperplasia of epididymal epithelium were observed. The result of T. vivax PCR analysis in the testes and epididymal tissues was positive in 100% of the samples of the experimentally infected sheep. Epididymal and testicular lesions associated with the presence of the parasite in these tissues, shown by PCR, suggest the participation of T. vivax in the pathophysiological mechanism of reproductive damage.

Non-Invasive In Vivo Study of the Trypanosoma vivax Infectious Process Consolidates the Brain Commitment in Late Infections

“…Noteworthy, the progressive increase of bioluminescence observed in testis (R5) is suggestive that parasites can pass through Sertoli cell barrier during infection and thus contribute to reproductive disorders in the seminiferous tubules, as already suggested in reports with host infected with T. vivax and T.b. brucei [27], [40]–[42] …”

Tissue tropism in parasitic diseases

“…Despite some early disagreement on whether T. vivax could colonize tissues [26,67], parasites have clearly been observed in ruptured blood vessels [68], in the extravascular spaces between myocardial fibres, swimming through extravascular fluid (oedema) [58,69], in the aqueous humour of the eye, in the CNS [57], in the dermis [48], circulating in the lymphatic vasculature following tsetse inoculation [70] and in other major organs [60]. More recently, parasites have been shown by polymerase chain reaction (PCR) in the reproductive system of both male and female experimentally infected goats [64,66]. It is worth noting that T. vivax infections may have a milder impact on the skin than T. congolense , an observation supported by lower parasite load in the dermis (5–10 T. vivax mm −2 compared with 150–250 T. congolense mm −2 ), and reduced vascular congestion and oedema at the chancre [48].…”

Studies on Comparative Hematological and Biochemical Changes in Yankasa Sheep Experimentally Infected with Trypanosoma vivax and Trypanosoma congolense Field Isolates of Nigerian Origin

“…It was observed that the initial leukocytosis is as a result of massive mobilization of the body defensive cells in response to the infection but as the disease lingers, leucopenia sets in because most of the cells might have been destroyed thereby decreasing the cells population. Consequently, leucopenia is a consistent finding in the chronic form of trypanosomosis because of the immunosuppressive action of the parasites [24,25].…”