Blastocystis hominis: A species of parasitic protozoa found in the intestines of humans and other primates. It was classified as a yeast in 1912. Over the years, questions arose about this designation. In 1967, many physiological and morphological B. hominis characteristics were reported that fit a protozoan classification. Since that time, other papers have corroborated this work and the organism is now recognized as a protozoan parasite of humans causing intestinal disease with potentially disabling symptoms.Blastocystis: A genus of protozoa of the suborder BLASTOCYSTINA. It was first classified as a yeast but further studies have shown it to be a protozoan.Blastocystis Infections: Infections with organisms of the genus BLASTOCYSTIS. The species B. hominis is responsible for most infections. Parasitologic surveys have generally found small numbers of this species in human stools, but higher positivity rates and organism numbers in AIDS patients and other immunosuppressed patients (IMMUNOCOMPROMISED HOST). Symptoms include ABDOMINAL PAIN; DIARRHEA; CONSTIPATION; VOMITING; and FATIGUE.Protozoan Infections: Infections with unicellular organisms formerly members of the subkingdom Protozoa.Intestinal Diseases, Parasitic: Infections of the INTESTINES with PARASITES, commonly involving PARASITIC WORMS. Infections with roundworms (NEMATODE INFECTIONS) and tapeworms (CESTODE INFECTIONS) are also known as HELMINTHIASIS.Feces: Excrement from the INTESTINES, containing unabsorbed solids, waste products, secretions, and BACTERIA of the DIGESTIVE SYSTEM.Eukaryota: One of the three domains of life (the others being BACTERIA and ARCHAEA), also called Eukarya. These are organisms whose cells are enclosed in membranes and possess a nucleus. They comprise almost all multicellular and many unicellular organisms, and are traditionally divided into groups (sometimes called kingdoms) including ANIMALS; PLANTS; FUNGI; and various algae and other taxa that were previously part of the old kingdom Protista.Helminthiasis: Infestation with parasitic worms of the helminth class.Metronidazole: A nitroimidazole used to treat AMEBIASIS; VAGINITIS; TRICHOMONAS INFECTIONS; GIARDIASIS; ANAEROBIC BACTERIA; and TREPONEMAL INFECTIONS. It has also been proposed as a radiation sensitizer for hypoxic cells. According to the Fourth Annual Report on Carcinogens (NTP 85-002, 1985, p133), this substance may reasonably be anticipated to be a carcinogen (Merck, 11th ed).Diarrhea: An increased liquidity or decreased consistency of FECES, such as running stool. Fecal consistency is related to the ratio of water-holding capacity of insoluble solids to total water, rather than the amount of water present. Diarrhea is not hyperdefecation or increased fecal weight.Staphylococcus hominis: A species of STAPHYLOCOCCUS similar to STAPHYLOCOCCUS HAEMOLYTICUS, but containing different esterases. The subspecies Staphylococcus hominis novobiosepticus is highly virulent and novobiocin resistant.SikkimPrevalence: The total number of cases of a given disease in a specified population at a designated time. It is differentiated from INCIDENCE, which refers to the number of new cases in the population at a given time.Dientamoeba: A genus of minute EUKARYOTES that are characterized by the preponderance of binucleate over uninucleate forms, the presence of several distinct granules in the karyosome, and the lack of a cystic stage. It is parasitic in the large intestine of humans and certain monkeys.Dientamoebiasis: Gastrointestinal infection with organisms of the genus DIENTAMOEBA.Entamoeba histolytica: A species of parasitic protozoa causing ENTAMOEBIASIS and amebic dysentery (DYSENTERY, AMEBIC). Characteristics include a single nucleus containing a small central karyosome and peripheral chromatin that is finely and regularly beaded.

Isolate resistance of Blastocystis hominis to metronidazole. (1/34)

Isolates of Blastocystis hominis from infected immigrant workers from Indonesia, Bangladesh and infected individuals from Singapore and Malaysia were assessed for growth pattern and degree of resistance to different concentrations of metronidazole. Viability of the cells was assessed using eosin-brillian cresyl blue which stained viable cells green and nonviable cells red. The Bangladeshi and Singaporean isolates were nonviable even at the lowest concentration of 0.01 mg/ml, whereas 40% of the initial inoculum of parasites from the Indonesian isolate at day one were still viable in cultures with 1.0 mg/ml metronidazole. The study shows that isolates of B. hominis of different geographical origin have different levels of resistance to metronidazole. The search for more effective drugs to eliminate th parasite appears inevitable, especially since surviving parasites from metronidazole cultures show greater ability to multiply in subcultures than controls.  (+info)

Intestinal blockage by carcinoma and Blastocystis hominis infection. (2/34)

We detected heavy infections of Blastocystis hominis in four individuals with intestinal obstruction due to cancerous growths. After surgery, the infections spontaneously resolved, without specific chemotherapy. It appears that the B. hominis infection was coincidental and not related to the neoplastic growth. We suggest that intestinal obstruction and concomitant stool retention, plus hemorrhage from cancerous lesions, may have permitted the more abundant growth of B. hominis. This is the first report of a possible relationship between intestinal obstruction and a concomitant B. hominis infection.  (+info)

Genomic analysis of Blastocystis hominis strains isolated from two long-term health care facilities. (3/34)

The genotype Blastocystis hominis is highly polymorphic. Therefore, a genetic marker would be a powerful tool for the identification or classification of B. hominis subtypes and could be used as a means to resolve the transmission route or origin of the parasite. To this end, 32 B. hominis isolates were collected from patients and/or staff members of two long-term health care facilities (facilities A and B), and these organisms were subjected to genotype analysis based on diagnostic PCR primers and restriction fragment length polymorphism (RFLP) of small subunit rRNA gene (rDNA). Based on PCR amplification using diagnostic primers which were developed from randomly amplified polymorphic DNA analysis of known strains of B. hominis, the 32 isolates of B. hominis were classified into three different subtypes. Thirty isolates, including twenty-four that were isolated from patients and a staff member, from facility A and all isolates isolated from six patients from facility B showed the same genotype. Two of six patients of facility B had been transferred from facility A, and these two patients also had the same-genotype B. hominis that corresponded to 24 isolates from facility A. This genotype strain may have been transmitted by these two patients from facility A to facility B, suggesting human-to-human transmission. In contrast, 2 of 26 isolates from facility A showed distinct genotypes, suggesting that the colonization by these two isolates is attributable to another infectious route. These different subtypes were subjected to RFLP analysis, and the RFLP profiles were correlated with the results obtained by diagnostic PCR primers. This study presents the first molecular evidence of possible human-to-human B. hominis infection between and/or among two small communities.  (+info)

Clinical significance and frequency of Blastocystis hominis in Turkish patients with hematological malignancy. (4/34)

The effect of Blastocystis hominis (B. hominis) in both immunocompetent and immunocompromised subjects has been the subject of debate in recent years, mostly in response to its unknown pathogenicity and frequency of occurrence. We performed a non-randomised, open labelled, single institute study in our hospital in order to investigate the clinical significance and frequency of B. hominis in patients suffering from hematological malignancy (HM) who displayed symptoms of gastrointestinal diseases during the period of chemotherapy-induced neutropenia. The presence and potential role of other intestinal inclusive of parasites were also studied. At least 3 stool samples from each of 206 HM patients with gastrointestinal complaints (the HM group) were studied. These were compared with stool samples from a control group of 200 patients without HM who were also suffering from gastrointestinal complaints. Samples were studied with saline-lugol, formalin-ether, and trichome staining methods. Groups were comparable in terms of gender, age and type of gastrointestinal complaints. In the HM group, the most common parasite was B. hominis. In this group, 23 patients (13%) had B. hominis, while in the control group only 2 patients (1%) had B. hominis. This difference was statistically significant (P < 0.05). Symptoms were non-specific for B. hominis or other parasites in the HM group. The predominant symptoms in both groups were abdominal pain (87-89.5%), diarrhea (70-89.5%), and flatulence (74-68.4%). Although all patients with HM were symptom-free at the end of treatment with oral metranidazol (1,500 mg per day for 10 days) 2 patients with HM had positive stool samples containing an insignificant number of parasites (< 5 cells per field). In conclusion, it appears that B. hominis is not rare and should be considered in patients with HM who have gastrointestinal complaints while being treated with chemotherapy. Furthermore, metranidazol appears to be effective in treating B. hominis infection.  (+info)

Multiyear prospective study of intestinal parasitism in a cohort of Peace Corps volunteers in Guatemala. (5/34)

We conducted a prospective, longitudinal study in a cohort of 36 Peace Corps volunteers (PCVs) in Guatemala to study the incidence and natural history of intestinal parasitic infections during the PCVs' >2-year overseas stay. PCVs collected stool specimens at least monthly and when ill with gastrointestinal symptoms. Of the 1,168 specimens tested, 453 (38.8%) were positive for at least one parasite and 48 (4.1%) were positive for a pathogenic parasite. A median interval of 187 days (range, 14 to 752 days) elapsed before the first documented parasitic infection, and the median intervals from arrival until subsequent infections (e.g., second or third) were >300 days. The PCVs had 116 episodes of infection with 11 parasites, including up to 4 episodes per PCV with specific nonpathogens and Blastocystis hominis. The incidence, in episodes per 100 person-years, was highest for B. hominis (65), followed by Entamoeba coli (31), Cryptosporidium parvum (17), and Entamoeba hartmanni (17). The PCVs' B. hominis episodes lasted 6,809 person-days (28.7% of the 23,689 person-days in the study), the E. coli episodes lasted 2,055 person-days (8.7%), and each of the other types of episodes lasted <2% of the person-days in the study. Gastrointestinal symptoms were somewhat more common and more persistent, but not significantly so, in association with pathogen episodes than with B. hominis and nonpathogen episodes. Although infections with pathogenic parasites could account for only a minority of the PCVs' diarrheal episodes, the continued acquisition of parasitic infections throughout the PCVs' >2-year stay in Guatemala suggests that PCVs repeatedly had fecal exposures and thus were at risk for infections with both parasitic and nonparasitic pathogens throughout their overseas service.  (+info)

Ribodemes of Blastocystis hominis isolated in Japan. (6/34)

To determine if genetic diversity of Blastocystis hominis exists in Japan, we monitored 64 B. hominis-infected people: 39 asymptomatic people whose infections were detected during routine medical check-ups (32 Japanese and 7 non-Japanese) and 25 patients with gastrointestinal symptoms who visited the outpatient clinics of St. Luke's International Hospital (19 Japanese and 6 non-Japanese). We detected 6 known and 2 new riboprint patterns in isolates from the infected people. There were no differences in the distribution of ribodemes between isolates from Japanese and non-Japanese people, similar to that in other countries. However, we noted a possible relationship between ribodeme type and pathogenicity. The results suggest that ribodemes I, III, and VI may be responsible for gastrointestinal symptoms.  (+info)

Epidemiological survey of Blastocystis hominis in Huainan City, Anhui Province, China. (7/34)

AIM: To provide scientific evidence for prevention and controlling of blastocystosis, the infection of Blastocystis homonis and to study its clinical significance in Huainan City, Anhui Province, China. METHODS: Blastocystis homonis in fresh stools taken from 100 infants, 100 pupils, 100 middle school students and 403 patients with diarrhea was smeared and detected with method of iodine staining and hematoxylin staining. After preliminary direct microscopy, the shape and size of Blastocystis homonis were observed with high power lens. The cellular immune function of the patients with blastocystosis was detected with biotin-streptavidin (BSA). RESULTS: The positive rates of Blastocystis homonis in fresh stools taken from the infants, pupils, middle school students and the patients with diarrhea, were 1.0 % (1/100), 1.0 % (1/100), 0 % (0/100) and 5.96 % (24/403) respectively. Furthermore, the positive rates of Blastocystis homonis in the stool samples taken from the patients with mild diarrhea, intermediate diarrhea, severe diarrhea and obstinate diarrhea were 6.03 % (14/232), 2.25 % (2/89), 0 % (0/17) and 12.31 % (8/65) respectively. The positive rates of Blastocystis homonis in fresh stools of male and female patients with diarrhea were 7.52 % (17/226) and 3.95 % (7/177) respectively, and those of patients in urban and rural areas were 4.56 % (11/241) and 8.02 % (13/162) respectively. There was no significant difference between them (P>0.05). The positive rates of CD(3)(+), CD(4)(+), CD(8)(+) in serum of Blastocystis homonis-positive and-negative individuals were 0.64+/-0.06, 0.44+/-0.06, 0.28+/-0.04 and 0.60+/-0.05, 0.40+/-0.05 and 0.30+/-0.05 respectively, and the ratio of CD(4)(+)/CD(8)(+) of the two groups were 1.53+/-0.34 and 1.27+/-0.22. There was significant difference between the two groups (P<0.05, P<0.01). CONCLUSION: The prevalence of Blastocystis hominis as an enteric pathogen in human seems not to be associated with gender and living environment, and that Blastocystis hominis is more common in stool samples of the patients with diarrhea, especially with chronic diarrhea or obstinate diarrhea. When patients with diarrhea infected by Blastocystis hominis, their cellular immune function decreases, which make it more difficult to be cured.  (+info)

Clinical characteristics and endoscopic findings associated with Blastocystis hominis in healthy adults. (8/34)

Ninety-nine individuals with stools positive for Blastocystis hominis but negative for other parasites were identified from medical records of healthy adults who had received a physical examination at Taipei Veterans General Hospital from November 2000 to October 2002. The medical records of these 99 positive cases and 193 randomly selected controls, matched for age, sex, and date of examination, were retrospectively reviewed. The pathogenicity of B. hominis could not be demonstrated due to a lack of association with the development of gastrointestinal symptoms or pathologic findings on endoscopic examination. Multivariate analyses revealed that chronic hepatitis B infection was a predisposing condition to the acquisition of B. hominis (odd ratio = 2.848, 95% confidence interval = 1.299-6.242, P = 0.009), and concentration of urate was significantly lower in B. hominis-positive individuals (mean +/- SD = 361.64 +/- 87.44 versus 392.57 +/- 93.38 micromol/L; P = 0.009). Among the 64 individuals who underwent gastric biopsy, Helicobacter pylori was found more frequently in the individuals harboring B. hominis (19 of 26 versus 15 of 38; P = 0.017).  (+info)

  • A case report involving a 49-year old man with Hashimoto's Thyroiditis shows that eradicating Blastocystis hominis resulted in a decrease of his thyroid antibodies (3). (
  • The most common parasites are species of Cryptosporidium, Blastocystis hominis, Entamoeba, Giardia lamblia and Dientamoeba fragilis . (
  • Sedighi I, Asadi M, Olfat M, Maghsood A H. Prevalence and Risk Factors of Giardia lamblia and Blastocystis hominis Infections in Children Under Ten Years Old, Hamadan, Iran, Avicenna J Clin Microb Infec. (
  • Blastocystis hominis was the most frequently detected parasite with the prevalence of 18.5%, followed by Giardia lamblia (10.9%), Entamoeba coli (2.8%), Dientamoeba fragilis (0.8%), Iodamoeba buetschlii (0.8%), Chilomastix mesnili (0.5%), Cryptosporidium spp. (
  • The results of the study showed a high prevalence of Giardia lamblia and Blastocystis hominis in rural areas compared to urban regions. (
  • medicalrecordandaninterviewwith usedfordetectionofamoebaespecies, Thereislittleinformationaboutper- theparents.Trainednursesvisitedall Giardia lamblia and Blastocystis hominis , sistentdiarrhoeaintheIslamicRepublic thechildrenadmittedtothehospital andaformol-etherconcentrationmeth- ofIran.A7.7%prevalencewasreported withgastroenteritis.Afterabriefexpla- odforcysts.Trichromestainingand inastudyfromthewestofthecountry, nationofthestudytooneoftheparents polymerasechainreaction(PCR)was andyoungage,non-breastfeeding,use andacquiringverbalinformedconsent, performedtodifferentiate Entamoeba ofantibioticsandpresenceofmucoid adatacol ectionformwascompleted. (
  • Giardia and other protozoan infections: Dientamoeba fragilis and Blastocystis hominis the real culprint? (
  • We exhibit in this article the results obtained for 4 years on the epidemiological, clinical and biological character and opportunistic Blastocystis hominis , often overlooked in the examination of parasitological laboratories city. (
  • Approximately 70% of patients diagnosed with IBS ("Irritable Bowel Syndrome") are infected with Blastocystis Hominis. (
  • In fact, recent microbiome and metagenomics studies suggest that Blastocystis colonization is usually associated with a healthy gut microbiota, rather than with the gut dysbiosis generally observed in metabolic or inflammatory diseases such irritable bowel syndrome (IBS). (
  • I attached 2 reports one for stool test for Blastocystis hominis from Netherland. (
  • And so in order to confirm if someone has Blastocystis hominis it is necessary to do a stool test. (
  • Of course if you have health insurance that will cover a one sample stool test at a conventional lab you can start by doing this, but just keep in mind that a negative result won't necessarily rule out Blastocystis hominis. (
  • Pharmaceutical treatment to clear Blastocystis Hominis (usually "Flagyl") has generally proven to be ineffective. (
  • A number of common antibiotics available in the U.K. today are also used for the treatment of Blastocystis Hominis as well as Dientmoeba and Entamoeba Histolytica. (
  • 1996). On the other hand, B. hominis shows a diverse morphologies which include vacuolar, granular, amoeboid and cyst forms (Zierdt. (
  • Cultures of Blastocystis hominis were induced to encyst using three encystation media: (a) an encystation medium (EM) comprising yeast extract in buffered saline containing 50% horse serum, (b) an encystation medium (CEM) comprising EM conditioned with bacterial soluble products and (c) an encystation medium (TEM) containing 0.5% trypticase in EM. (
  • The original description of Blastocystis was as a yeast due to its yeast-like glistening appearance in fresh wet mounts and the absence of pseudopodia and locomotion. (
  • The aim of this study was to develop and evaluate a polymerase chain reaction (PCR) technique for the direct detection of B. hominis in human stool samples. (
  • Detection of Blastocystis hominis has been made by microscopic examination of samples by direct examination and concentration. (