Detection of Trypanosoma vivax in tissues of experimentally infected goats: what is the role of adipose tissue in the life cycle of this protozoon?

Abstract

Trypanosomiasis, caused by Trypanosoma vivax, is responsible for great economic losses among livestock in Africa and South America. During the life cycle of these parasites, they may present different morphological, metabolic and physiological characteristics depending on the interactions that are encountered at each point of their life cycle. Although T. vivax is frequently reported in the circulation of its mammalian hosts, it has the ability to migrate to the tissues of these individuals. However, this characteristic is poorly understood. In this context, we aimed to investigate the presence of T. vivax and the changes caused in different tissues of experimentally infected goats. Despite the animals were not perfused before tissues collection, using different approaches, we demonstrated its presence in different samples, including in the adipose tissue and skin of infected animals. In addition, a mononuclear inflammatory reaction, mostly characterized by an infiltrate of lymphocytes, plasma cells and macrophages were observed. The results highlight the possibility that, like other trypanosomatids, T. vivax may use these tissues during its life cycle. Future studies aiming to elucidate the length of time for which T. vivax remains active in these sites, and whether it uses these sites as a refuge from trypanocidal drugs, and whether it is capable of recolonizing the blood circulation, are much needed.

Immunohistochemical diagnosis of Trypanosoma vivax in experimentally infected sheep tissues

“…The presence of parasites in these organs may be correlated with cases of congestion, edema, and necrosis described as clinical signs in sheep (Ogbaje et al, 2017, Batista et al, 2019) and cattle (Costa et al, 2020). It has recently been shown that T. vivax can also be used as a refuge for adipose tissue and skin (Machado et al, 2021). Unfortunately, these tissues were not analyzed in this work.…”

Investigation ofTrypanosoma-induced vascular damage sheds insights intoTrypanosoma vivaxsequestration

“…Findings in goats include evaluation of clinal and pathological manifestations in the central nervous system of infected goats, some of which developed meningoencephalitis and meningitis (Batista et al, 2011). descriptions of parasite presence in the skin and adipose tissue, together with mononuclear inflammatory reactions (Machado et al, 2021), and follicular degeneration in ovaries, together with enlarged lymph nodes and weight loss (Rodrigues et al, 2013). Findings in sheep include descriptions of acute testicular degeneration and hyperplasia of the epididymal epithelium (Bezerra et al, 2008).…”

“…Altogether, however, whether T. vivax can display tropism to and establish in tissues has been long debated (Machado et al, 2021 and reviewed in Silva Pereira et al, 2019). Here, we use intravital and ex vivo fluorescence microscopy to compare the organ distribution of each of the three aforementioned trypanosome species in mouse models, the vascular changes induced by them, and their impact on the expression of key blood vascular endothelial cell receptors.…”