Pathogenic potential of Blastocystis hominis in laboratory mice

Abstract

Blastocystis hominis is a ubiquitous enteric protozoan whose pathogenic potential is still controversial. This study was carried out to clarify the pathogenecity of B. hominis infection and to study the proper number of parasites for mice infection. A total of 15 albino mice were orally inoculated with B. hominis and divided according to the inoculums, 10(2), 10(5), and 4 x 10(7) B. hominis forms/100 microl saline, into three groups consisting of five mice each, GI, GII GIII, respectively. In addition with group IV (uninfected control) consisting of five mice. All mice were sacrificed 2 weeks post-infection. The results revealed that all mice of GIII and two mice of GII got the infection while all mice of GI showed a completely negative result. Histopathological examination of large intestine on highly infected group (GIII) showed that B. hominis infiltrated the lamina propria, the submucosa, and the muscle layers in the form of collection of vacuolar forms. This was accompanied by active colitis with infiltration of mixed inflammatory cells. In conclusion, this study revealed that large number of B. hominis is essential for oral infection of mice and that vacuolar forms of B. hominis can invade the lamina propria, the submucosa, and even the muscle layers.

Epidemiology and Prevalence of Blastocystis spp. in North Cyprus

“…Numbers of female and male participants were 143 (62.2%) and 87 (37.8%), respectively. Distribution of the individuals according to the age groups was nine (3.9%) for age 7-19, 76 (33%) for age 20-39, 90 (39.1%) for age [40][41][42][43][44][45][46][47][48][49][50][51][52][53][54][55][56][57][58][59], and 55 (24%) for age 60 and above. A minority of the participants (24%) were university graduates; however, most of the individuals (91.7%) had middle or high socioeconomic status.…”

“…44 It is generally accepted that Blastocystis is noninvasive however, vacuolar form of the protist was shown to invade the lamina propria, submucosal and muscular layers of the intestine, leading to inflammation and active colitis in experimentally infected mice. 45 Furthermore, the proteases of Blastocystis were suggested as a virulence factor that contributes to escape from the host immune response. 46 Blastocystis spp.…”

Recent Developments in Blastocystis Research

“…However, the studies performed to date are, in our opinion, inconclusive. For example, experimental infections of laboratory mice (Elwakil and Hewedi, 2010) resulted in tissue invasion -something never reported in humans. Another study showed increased oxidative stress in Blastocystis -infected rats (Chandramathi et al, 2010), again something not linked to human colonisation.…”

Frequency of Blastocystosis and Its Association with Clinical Symptoms in 2 Years of Surveillance at "Pedro Kourí" Institute

“…Wu et al found that Blastocystis attaches to intestinal epithelium and leads to epithelial barrier dysfunction and that drug resistance might entail a fitness cost in parasite virulence by limiting entero-adhesiveness [10]. In another study made by Wu, they found that a Blastocystis subtype (ST-7) induced enterocyte-apoptosis by activating caspases 3 and 9, suggesting the involvement of the intrinsic apoptotic pathway in pathogenesis [30].…”