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Clinical Microbiology Reviews Oct 1996Blastocystis hominis is a unicellular organism found commonly in the intestinal tract of humans and many other animals. Very little is known of the basic biology of the... (Review)
Review
Blastocystis hominis is a unicellular organism found commonly in the intestinal tract of humans and many other animals. Very little is known of the basic biology of the organism, and controversy surrounds its taxonomy and pathogenicity. There morphological forms (vacuolar, granular, and ameboid) have been recognized, but recent studies have revealed several additional forms (cyst, avacuolar, and multivacuolar). The biochemistry of the organism has not been studied to any extent, and organelles and structures of unknown function and composition are present in the cells. Several life cycles have been proposed but not experimentally validated. The form used for transmission has not been defined. Infections with the organism are worldwide and appear in both immunocompetent and immunodeficient individuals. Symptoms generally attributed to B. hominis infection are nonspecific, and the need for treatment is debated. If treatment appears warranted, metronidazole is suggested as the drug of choice, although failures of this drug in eradicating the organism have been reported. Infection is diagnosed by light microscopic examination of stained smears or wet mounts of fecal material. Most laboratories identify B. hominis by observing the vacuolar form, although morphological studies indicate that other forms, such as the cyst form and multivacuolar form, also should be sought for diagnosis.
Topics: Animals; Antiprotozoal Agents; Blastocystis Infections; Blastocystis hominis; Disease Transmission, Infectious; Drug Therapy, Combination; Humans; Microscopy, Electron; Prevalence
PubMed: 8894352
DOI: 10.1128/CMR.9.4.563 -
Infectious Agents and Cancer Jun 2022Intestinal protozoa Blastocystis hominis and Cryptosporidium spp. are two influential factors in intestinal complications and malignancies. In present study, we... (Review)
Review
OBJECTIVE
Intestinal protozoa Blastocystis hominis and Cryptosporidium spp. are two influential factors in intestinal complications and malignancies. In present study, we estimated the pooled prevalence and odds ratio (OR) of the two parasites in colorectal cancer (CRC) patients and their possible association with the deadly disease.
METHOD
Our systematic search was conducted for published researches between January 1, 2000 and April 30, 2022 by using four international databases include Scopus, PubMed, and Web of Science as well as Google scholar search engine. The random- and fixed-effects models were used to estimate the pooled prevalence, OR, and 95% confidence interval (CI) by comprehensive meta-analysis (V2.2, Bio stat) software. Inclusion and exclusion criteria were applied.
RESULTS
Thirteen papers (seven case-control and six cross-sectional studies) for B. hominis/CRC and six papers (two case-control and four cross-sectional studies) for Cryptosporidium spp./CRC were eligible to include in data synthesis. Pooled prevalence of B. hominis and Cryptosporidium spp. in CRC patients was calculated to be 26.8% (95% CI 19.4-35.7%) and 12.7% (95% CI 6.8-22.5%), respectively. Based on case-control studies, significant difference was found between case and controls in both protozoa (B. hominis OR 2.10; 95% CI 1.39-3.18% vs. Cryptosporidium spp. OR 5.06; 95% CI 1.8-13.6%). Considering the Blastocystis subtypes, ST1 (5/6; 83.33% studies) and ST3 (5/6; 83.33% studies) had the highest number of reports in CRC patients. Regarding the Cryptosporidium species, only C. parvum and C. hominis were reported.
CONCLUSION
Given the significant prevalence of both parasites in CRC patients and their statistically significant association, there is a need to pay more attention to these two intestinal parasites in under treatment patients.
PubMed: 35715853
DOI: 10.1186/s13027-022-00447-x -
Experimental Parasitology Sep 2022Blastocystis hominis is a worldwide common enteric parasite. Its pathogenic potential has not yet been established, although many reports suggest that it may cause the...
Blastocystis hominis is a worldwide common enteric parasite. Its pathogenic potential has not yet been established, although many reports suggest that it may cause the development of various gastrointestinal symptoms. The aim of the present study is to evaluate the destructive effect of different doses of cytotoxic gamma (γ) irradiation combined with and compared to metronidazole (MTZ) on Blastocystis spp. in vitro. The detection of the parasite in the stool specimen was conventionally done by light microscopic examination of direct smears, cultivation, followed by PCR-sequencing. Evaluation of γ-irradiation and MTZ effects on B. hominis was carried out by trypan blue exclusion assay, caspase activity detection, acridine orange staining, DNA fragmentation assay and transmission electron microscopic (TEM) examination. The current study demonstrated that exposure to γ-irradiation in a dose of 0.5 kGray (kGy) significantly (P < 0.05) reduced the viability of B. hominis subtype 2 by 95.2% compared to the untreated and MTZ-treated parasites (87.1%) after 48 h incubation. Combining the same dose of irradiation (0.5 kGy) with MTZ yielded a viability reduction of 94.2% and 94% after 24 and 48 h respectively, which were statistically significant (P < 0.05) compared to MTZ alone. Moreover, our results showed features of programmed cell death in the form of morphological, biochemical, and molecular changes (TEM abnormalities, caspase-like activity, and DNA fragmentation, respectively) with the high doses of γ-irradiation (0.3 and 0.5 kGy) either singly or combined with MTZ. In conclusion, cytotoxic γ-irradiation plays an important role in the inactivation of Blastocystis spp., so, it can be a promising prophylactic water-sterilizing tool against blastocystosis.
Topics: Antineoplastic Agents; Antiprotozoal Agents; Apoptosis; Blastocystis; Blastocystis Infections; Blastocystis hominis; Caspases; Feces; Humans; Metronidazole
PubMed: 35921920
DOI: 10.1016/j.exppara.2022.108341 -
Enfermedades Infecciosas Y... 1992
Review
Topics: Adult; Animals; Blastocystis Infections; Blastocystis hominis; Child; Diarrhea; Digestive System; Humans
PubMed: 1450262
DOI: No ID Found -
Surgical Infections Feb 2022
Topics: Acute Disease; Blastocystis hominis; Humans; Pancreatitis
PubMed: 34491857
DOI: 10.1089/sur.2021.225 -
Annales Academiae Medicae Stetinensis 2014Blastocystis hominis (B. hominis) is a cosmopolitan pro- tozoa which parasitizes the human large intestine. This parasite had been considered to be commensal of the... (Review)
Review
Blastocystis hominis (B. hominis) is a cosmopolitan pro- tozoa which parasitizes the human large intestine. This parasite had been considered to be commensal of the large intestine for a long time, because even an intense invasion may be asymptomatic. However, this species is now being regarded as a parasitic organism. In this paper the latest data concerning the epidemiology, diagnostics and treatment of B. hominis invasion have been cited and discussed.
Topics: Animals; Blastocystis Infections; Blastocystis hominis; Host-Parasite Interactions; Humans; Intestine, Large; Species Specificity
PubMed: 25518089
DOI: No ID Found -
Clinical Infectious Diseases : An... Jul 1995
Review
Topics: Animals; Bacteria; Bacterial Infections; Blastocystis Infections; Blastocystis hominis; Case-Control Studies; Diarrhea; Humans; Nepal; Prevalence; Prospective Studies; Travel
PubMed: 7578716
DOI: 10.1093/clinids/21.1.102 -
British Journal of Biomedical Science 2001
Topics: Animals; Blastocystis Infections; Blastocystis hominis; Humans; Parasitology
PubMed: 11788005
DOI: No ID Found -
Zhongguo Xue Xi Chong Bing Fang Zhi Za... Mar 2021is a common intestinal protozoan parasite. Most individuals with infections have no apparent clinical symptoms; however, a few patients, notably those with... (Review)
Review
is a common intestinal protozoan parasite. Most individuals with infections have no apparent clinical symptoms; however, a few patients, notably those with co-infections or impaired immune system function may present abdominal pain, diarrhea, nausea, vomiting, and even death. This paper reviews the co-infections of and other pathogens and comorbidity of infections and other diseases, so as to provide insights into the management of infections.
Topics: Blastocystis Infections; Blastocystis hominis; Comorbidity; Diarrhea; Feces; Humans
PubMed: 34791856
DOI: 10.16250/j.32.1374.2020204 -
Zhongguo Xue Xi Chong Bing Fang Zhi Za... Oct 2020is a common parasitic protozoa in human and animal intestines; however, its pathogenicity remains controversial. Construction of animal models is of great significance... (Review)
Review
is a common parasitic protozoa in human and animal intestines; however, its pathogenicity remains controversial. Construction of animal models is of great significance to investigate the pathogenicity, pathogenic mechanisms and drug screening of . Experimental animals, mode of infections, parasite strains and host immune status are important factors affecting the successful modeling of infections in animals. Hereby, we review the progress of researches on animal models of infections, and summarize the influencing factors and application of animal models of infections, in order to provides insights into the selection of animals models of infections.
Topics: Animals; Blastocystis Infections; Blastocystis hominis; Feces; Humans; Models, Animal; Virulence
PubMed: 33660484
DOI: 10.16250/j.32.1374.2020162