Re-evaluation of merogony of aCystoisospora ohioensis-like coccidian and its distinction from gametogony in the intestine of a naturally infected dog

Abstract

Four species of Cystoisospora, C. canis, C. ohioensis, C. neorivolta and C. burrowsi are described from feces of dogs. Of these, the oocysts of C. canis are the largest and easily distinguished from the remaining three species. Oocysts of C. ohioensis, C. neorivolta and C. burrowsi are difficult to distinguish because of overlap in their sizes. However, based on endogenous developmental stages, C. ohioensis is distinct from C. neorivolta and C. burrowsi because its endogenous stages are confined to surface epithelium of intestine whereas endogenous stages of C. neorivolta and C. burrowsi are predominantly in the lamina propria. There are uncertainties regarding the endogenous stages of C. neorivolta and C. burrowsi and there is no way now to determine whether C. burrowsi and C. neorivolta are different parasites; therefore, these are referred as C. ohioensis-like organisms. Additionally, mode of division of asexual stages of coccidia of dogs is largely unknown and ultrastructural studies are lacking. In the present study, development of asexual and sexual stages of a C. ohioensis-like organism in a naturally infected dog is described by light microscopy and by transmission electron microscopy. Merozoites divided by endodyogeny/merogony. Meronts were crescent/merozoite-shaped and contained a maximum of eight nuclei. A distinctive feature of merozoites was the presence of many PAS-positive amylopectin granules that were absent or rare in immature microgamonts making it possible to distinguish them.

The transcriptome from asexual to sexual in vitro development of Cystoisospora suis (Apicomplexa: Coccidia)

“…The role of these putative proteins in merozoite biology of C. suis remains to be investigated. The commitment of type II merozoites to sexual differentiation during the final phase of asexual development is a key process during the life cycle of Apicomplexan parasites 73 . DNA binding proteins (ApiAP2 factors) are related to the APETALA family of transcription factors which play key roles in the development and environmental stress response pathways of plants 74 .…”

Parasitological and molecular investigation of consequences of raw meat feeding (BARF) in dogs and cats: implications for other pets living nearby

“…During the microscopical examination in the present study, two dogs (2.2%) were infected with Cystoisospora spp., i.e., one with C. canis and the other one is with a C. ohioensis -like species. Considering the latter, based on the morphological examination of the oocysts, it is difficult to distinguish Cystoisospora burrowsi , Cystoisospora neorivolta , and C.ohioensis , since they are similar and their size ranges overlap (Dubey 2019 ). The infection might have been associated with raw meat consumption, since monozoic tissue cyst of this protozoon can occur in paratenic hosts (Lindsay et al 2014 ).…”

Wildlife parasitology: sample collection and processing, diagnostic constraints, and methodological challenges in terrestrial carnivores

“…Intracellular forms of protozoans like Cystoisospora spp. can be detected using the mucosal wet smear method [ 223 ] or histology [ 224 ], the last being unsuitable in frozen carcasses. In addition to the direct examination, coproscopical methods can be done using feces collected from the rectum or even gastric content for the detection and identification of preimaginal parasitic forms [ 225 , 226 ].…”