Experimental Blastocystis hominis infection in laboratory mice

Abstract

Young (less than 8 weeks old) immunocompetent BALB/c mice became infected with Blastocystis hominis after inoculation of fecal cysts orally and of in vitro axenic-culture forms intracecally. This study confirmed that the fecal cyst was the form responsible for external transmission and that the mode of transmission was by the fecal-oral route. The infection was self-limiting and the infected BALB/c mice appeared normal except that some of them showed weight loss and lethargy. Both vacuolar and granular forms were found in the cecum, but only cyst forms were observed in the colon. Histological examination of the cecum and colon showed intense inflammatory-cell infiltration, edematous lamina propria, and mucosal sloughing. It is apparent that although B. hominis is not invasive, it is capable of causing pathogenesis in BALB/c mice.

Blastocystis subtypes in irritable bowel syndrome and inflammatory bowel disease in Ankara, Turkey

“…Animal models exist to study the most common enteric protozoa. Experimental infection of mice and rats with Blastocystis isolates found in humans has been reported to produce illness or death in a number of independent studies (Moe et al 1997, Yao et al 2005, Zhang et al 2006, Hussein et al 2008.…”

Development and Evaluation of a Real-Time PCR Assay for Detection and Quantification of Blastocystis Parasites in Human Stool Samples: Prospective Study of Patients with Hematological Malignancies

“…The cyst represents the smallest (2 to 5 m in diameter) form of the organism and is responsible for the environmental dissemination of the parasite. The results of in vivo experiments previously performed with mice have suggested that cysts represent the infectious stage (18,35,37), but the most common form detected during parasitological examination of feces is the vacuolar form (2 to 200 m in diameter) (41,44). The vacuolar form also represents the major parasitic stage observed in in vitro cultures of Blastocystis parasites.…”

Extreme anoxia tolerance in embryos of the annual killifishAustrofundulus limnaeus: insights from a metabolomics analysis

“…There are no reports of Blastocystis-associated dysentery, and it appears that the parasite is generally noninvasive, as indicated by endoscopy (43,76,329,330) and histology of experimentally infected animals (5,152,187). An interesting case study described Blastocystis trophozoites present in the liver abscess aspirate of a 63-year-old man with a 5-day history of fever and blood-tinged watery diarrhea (102).…”

“…Heavy infections led to diarrhea and gross cecal hyperemia. A later study involved the experimental infection of young (less than 8 weeks old) BALB/c mice with Blastocystis (152). Infections were generally self-limiting, although some mice showed weight loss, and histological examination revealed inflammatory responses and mucosal sloughing.…”

“…Upon ingestion of cysts, the parasite undergoes excystation in the large intestines and develops into vacuolar forms. Encystation occurs during passage along the large intestines and is deposited in the feces (152). The fecal cysts may be covered by a fibrillar layer that is gradually lost during cyst development (313).…”