Histopathology of Trypanosoma (Trypanozoon) evansi infection in Bandicoot rat. II. Brain and choroid plexus

Abstract

Bandicoot rat, Bandicota bengalensis, received intraperitoneal inoculation of Trypanosoma (Trypanozoon) evansi flagellates and showed acute disease, leading to death during the 2 nd peak of parasitaemia [14 th day post infection (pi)]. Damage in brain and choroid plexus of the infected bandicoot is studied on the 5 th , 8 th , 12 th and 14 th day post inoculation. Sign of histopathological changes in the brain and choroid plexus of the bandicoot are detected after 1 st peak of parasitaemia. Infiltration of lymphocyte and plasma cells, congestion, perivascular cuffing, gliosis and brain lesions are observed during 12 th -14 th day post intection. Multiple sclerosis, neuronophagia, focal haemorrhage, cerebral hyperplasia, oligodendrocytoma, astrocytoma and fatty degeneration of brain tissue are also found. Alteration in the ependymal cells of choroid plexus is noticed. Extensive oedema, infiltration of inflammatory cells and rupture of ventricular ependymal layer are found. Parasites are found both in the brain tissue and choroid plexus. No intracellular stage of the parasite is observed. The nature of damage in the brain tissue and choroid plexus shows similarity with the cases of African trypanosomiasis. This salivarian species cause more deleterious effect in brain much earlier in the disease course than its African relatives.

Pathological studies on experimental Trypanosoma evansi infection in Swiss albino mice

“…Hirokawa et al (1981) also reported mild superficial necrosis of intestinal mucosa in experimental T. musculi infection in mice. T. evansi is highly pathogenic to laboratory animals as observed in the previous studies also (Patel et al 1982;Uche and Jones 1992;Biswas et al 2001Biswas et al , 2010 and in the present study as trypanosomes were observed in stained tissue sections of different visceral organs of mice particularly inside the blood vessels of brain, liver, lung, heart, It was concluded that T. evansi is pathogenic for Swiss albino mice. …”

“…Congestion and edema of lungs were mainly due to inflammatory response of the lungs to the parasite resulting in vasodilatation and exudation. Biswas et al (2001Biswas et al ( , 2010) also observed similar type of changes in the lungs of rats experimentally infected with T. evansi. In contrast, Nagle et al (1980) observed no changes in the lungs of T. rhodesiense infected rabbits.…”

Biology of Trypanosoma (Trypanozoon) evansi in experimental heterologous mammalian hosts

“…These observations led the scientists ''to believe that the life cycle of these trypanosomes including a tissue phase comparable to that in Stercoraria'' (Hoare 1972). Histopathology of choroid plexus of T. evansi infected bandicoot rat also confirmed the presence of amastigote stage (Biswas et al 2010). Occurrence of amastigote and sphaeromastigote stages of T. evansi in the organ impression smear preparation as well as in tissue section in cat and monkey indicates the evolutionary relationships among the members of the subgenus Trypanozoon.…”

“…Morales and Carreno (1976) reported that T. evansi and T. brucei species could produce similar clinical and pathological lesions in laboratory animals. However both species seem to produce intravascular and extravascular lesions in their hosts (Losos and Ikede 1972;Biswas et al 2001Biswas et al , 2010Rodrigues et al 2009;Bal et al 2012). Prasad et al (2013) studied the prevalece of trypanosomiasis in certain areas of Andhra Pradesh.…”

Choroid plexus and the blood–cerebrospinal fluid barrier in disease

“…This parasite was detected in the perivascular region of the CP and in CP epithelial cells [174]. A histopathological study of brain and the CP after Trypanosoma evansi infection showed extensive edema, rupture of the CP epithelial cell layer and infiltration of the CP by inflammatory cells [175].…”