Hepatic Lesions in Rabbits Infected with Encephalitozoon cuniculi Administered per Rectum

Abstract

Abstract. Microsporidia have been recognized recently as opportunistic pathogens in acquired immunodeficiency syndrome patients. In an attempt to develop an animal model of enteric microsporidiosis, adult (5 to 6 months old) male Flemish Giant rabbits from a closed New York colony were administered 5 x 10 3,5 X 10 5 , and 5 x 10 7 Encephalitozoon cuniculi per rectum. Rabbits given 5 x 10 5 and 5 x 10 7 E. cuniculi had moderate granulomatous periportal infiltrates, characterized by the presence of numerous macrophages, epithelioid cells, and a few multinucleated giant cells, lymphocytes, and plasma cells. Inflammatory cells also were seen infiltrating the tunica adventitia and tunica media of hepatic portal veins and branches of the hepatic artery. This study demonstrates that administration of E. cuniculi per rectum to rabbits results in infection that is characterized by high frequency and severity of hepatic lesions.

Immunohistochemical identification of Encephalitozoon cuniculi in phacoclastic uveitis in four rabbits

“…Conversely, in lagomorphs, encephalitozoonosis is an essentially asymptomatic, chronic disease 2,3 with a reported incidence of infection varying from 5 to 75% in laboratory rabbits 5 . Characteristic microscopic lesions associated with E. cuniculi infection in rabbits are mostly diagnosed at necropsy as small focal granulomatous lesions of brain and kidney 3,5,6 …”

Meningeal hyperaemia and myocarditis in a caged rabbit with encephalitozoonosis: Case report and literature review

“…The liver lesions in rabbits are associated with signs of hepatic failure [15]. The hepatic granulomatous reaction is usually periportal in location and also mostly characterized by lymphocytes, plasma cells, epithelioid and giants cells [18]. In this report, the periportal lesions included fibroplasia which depicted the chronic nature of the infection.…”

Encephalitozoon intestinalis infection increases host cell mutation frequency

“…Like other obligate intracellular pathogens, microsporidia exert significant stress on infected host cells. Microsporidia infection alters host cell cycle regulation [8] and can lead to development of multinucleated host cells [9,10]. Multinucleated cells also occur in human tumors and can give rise to lung metastases in nude mice [11].…”