Life cycle and pathogenicity of Eimeria strakonicensis n.sp. (Apicomplexa: Eimeriidae) in experimentally infected common voles (Microtus arvalis)

Abstract

The oocysts of Eimeria strakonicensis n.sp. are described from the feces of the common vole, Microtus arvalis. Sporulated oocysts were broadly ellipsoidal and measured 28.3 × 25.2 μm. The oocyst wall was composed of a yellowish rough outer layer and colourless smooth inner layer. The sporulated oocysts contained a compact blackberry-like residuum. The sporocysts, with a small Stieda body, measured 11.5 × 9.5 μm. Sporulation was completed within 7 days at 20–23 °C. Endogenous development of E. strakonicensis was found to take place in the middle and posterior jejunum. Asexual development comprised two generations of meronts, which were seen at 3 and 4 days postinfection. The first fully developed macrogametes, microgametes, and oocysts were seen at 5 days postinfection. The prepatent period was 5 days and the patent period was 3–4 days. The pathological changes caused by E. strakonicensis consisted of villous atrophy, crypt hyperplasia, and inflammatory infiltration of the lamina propria of the middle and posterior jejunum. During the acute phase, the villous tips were eroded and numerous trophozoites of Spironucleus sp. and Giardia sp. and necrotic debris filled the cryptal and intestinal lumina.