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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 -
Biomedical Journal Sep 2023Intestinal parasitic infections are the most common infectious diseases among Southeast Asian migrant workers in Taiwan, especially for infections with Blastocystis...
BACKGROUND
Intestinal parasitic infections are the most common infectious diseases among Southeast Asian migrant workers in Taiwan, especially for infections with Blastocystis hominis. However, little is known about the impact of Blastocystis subtypes (STs) on the gut microbiota.
MATERIAL AND METHODS
We retrospectively evaluated the prevalence of intestinal parasites in a teaching hospital in Northern Taiwan in the period of 2015 to 2019. Blastocystis-positive stool specimens were collected for ST analysis by polymerase chain reaction in 2020. Intestinal microbiota analyses of different Blastocystis STs and Blastocystis-free individuals were conducted by 16S rRNA sequencing.
RESULTS
A total of 13,859 subjects were analyzed, of which 1,802 cases (13%) were diagnosed with intestinal parasitic infections. B. hominis infections were the most prevalent (n = 1546, 85.7%). ST analysis of Blastocystis-positive samples (n=150) indicated that ST1 was the most common type, followed by ST3, ST4, ST2, ST7, and ST5. Different Blastocystis STs (ST1, ST3, and ST4) were associated with distinct richness and diversity of the microbiota. Taxonomic profiles revealed that Akkermansia muciniphila was significantly enriched for all analyzed Blastocystis STs, whereas Holdemanella biformis was more abundant in the Blastocystis-free group. Additionally, Succinivibrio dextrinosolvens and Coprococcus eutactus were specifically more abundant in ST3 carriers than in non-infected individuals.
CONCLUSIONS
This study demonstrates that A. muciniphila is positively associated with all Blastocystis STs, while H. biformis was negatively associated with them. Several bacteria were enriched in specific STs, highlighting the need for further microbiota analysis at the ST level to elucidate the pathogenicity of Blastocystis.
PubMed: 37774792
DOI: 10.1016/j.bj.2023.100661 -
Clinical Microbiology Reviews Jan 1991The history of B. hominis is unique. Few infectious agents have provoked the many misconceptions that plague this enigmatic parasitic ameba. Conflicting descriptions of... (Review)
Review
The history of B. hominis is unique. Few infectious agents have provoked the many misconceptions that plague this enigmatic parasitic ameba. Conflicting descriptions of its nature and pathogenesis have continued throughout the 20th century. As seen by the greatly expanded number of reports in recent years, B. hominis is now a major subject of study, particularly for evidence of disease causation. Physicians are treating patients with intestinal disease caused by B. hominis. Many mild cases resolve in about 3 days without treatment, but others are acute and chronic disease is common. As with E. histolytica, the carrier state is often seen without symptoms. Treatment is usually with metronidazole, but emetine (for refractory infections), trimethoprim-sulfamethoxazole, and pentamidine are also effective. In fecal samples, this complex protozoan appears in a variety of cell forms which makes microscopic diagnosis difficult. As yet, no specific fluorescent-antibody test is available for diagnosis. A culture method to demonstrate the more easily recognized CB form is available, but probably not feasible for most diagnostic laboratories. The common cell forms are the CB form, the granular (mitochondria) form, and the ameba form. The unexpected size range of these forms in clinical material, from yeast size (ca. 7 microns) to giant cells of 20 to 40 microns, makes diagnosis difficult Pseudopodia may be demonstrated by the ameba form in heated microscope stage culture chambers. The anaerobic B. hominis has no cyst form. Its mitochondria are uniquely anaerobic and have no cytochrome protein or oxidative mitochondrial enzymes. Because of its many cell forms and anaerobic mitochondria, B. hominis is an organism of great interest for morphologic and biochemical study. Reproduction is asexual, usually by binary fission. Shizogony occurs in cultured cells. The CB appears to be an organelle whose specific purpose is for reproduction by shizogony. From 2 to 30 progeny are derived from schizogony. The ameba form reproduces by plasmotomy; it has no CB. The pathology of B. hominis infections has been studied in gnotobiotic guinea pigs in which inflammation of the intestinal mucosa and invasion of the superficial layers were seen. Only limited studies of human pathology are available. Those who have studied mucosal histopathology report inflammation and cellular changes that resolve after treatment. More study in this area is strongly indicated (32, 44, 57, 62, 67, 75). Ultrastructural details of B. hominis major forms, except for the schizont, are complete. The organism has no cell wall. The concentric CB takes up as much as 95% of the cell. The major organelles, which include multiple nuclei, Golgi apparatus, mitochondria, endoplasmic reticulum, fat, and other inclusions, are confined in two or four opposed pods in a thin band of peripheral cytoplasm between the spherical entire plasma membrane and the CB membrane. The pods buldge the CB membrane inward. There is evidence of a bacteroid endosymbiont. Education about B. hominis is needed. Entry of recent findings into new textbooks is imperative for its understanding among medical practitioners. Laboratory workers need to be aware of it for many reasons. The College of American Pathologists includes B. hominis in its proficiency testing samples and requires that it be reported from clinical samples.
Topics: Animals; Eukaryota; Humans; Intestinal Diseases, Parasitic; Mitochondria; Protozoan Infections
PubMed: 2004348
DOI: 10.1128/CMR.4.1.61 -
Scientific Reports Aug 2021Blastocystis hominis and Cystoisospora belli are considered to be common opportunistic intestinal protozoa in HIV/AIDS patients. In order to investigate the prevalence...
Blastocystis hominis and Cystoisospora belli are considered to be common opportunistic intestinal protozoa in HIV/AIDS patients. In order to investigate the prevalence and genetic characteristics of B. hominis and C. belli in HIV/AIDS patients, a total of 285 faecal samples were individually collected from HIV/AIDS patients in Guangxi, China. B. hominis and C. belli were investigated by amplifying the barcode region of the SSU rRNA gene and the internal transcribed spacer 1 (ITS-1) region of the rRNA gene, respectively. Chi-square test or Fisher's exact test were conducted to assess the risk factors related to B. hominis and C. belli infection. The prevalence of B. hominis and C. belli was 6.0% (17/285) and 1.1% (3/285) respectively. Four genotypes of B. hominis were detected, with ST3 (n = 8) and ST1 (n = 6) being predominant, followed by ST6 (n = 2) and ST7 (n = 1). Females had a statistically higher prevalence of B. hominis (11.6%) than males (4.2%). The statistical analysis also showed that the prevalence of B. hominis was significantly associated with age group and educational level. Our study provides convincing evidence for the genetic diversity of B. hominis, which indicates its potential zoonotic transmission and is the first report on the molecular characteristics of C. belli in HIV/AIDS patients in China.
Topics: Acquired Immunodeficiency Syndrome; Adult; Blastocystis; Blastocystis Infections; Blastocystis hominis; China; DNA, Protozoan; Feces; Female; Genetic Variation; Genotype; HIV-1; Humans; Isospora; Isosporiasis; Male; Middle Aged; Prevalence; Risk Factors
PubMed: 34354101
DOI: 10.1038/s41598-021-94962-3 -
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 -
Iranian Journal of Parasitology 2022sp., located in the large intestine, is one of the most common zoonotic parasites. Risk factors affect its prevalence and pathogenicity, and it causes gastrointestinal...
BACKGROUND
sp., located in the large intestine, is one of the most common zoonotic parasites. Risk factors affect its prevalence and pathogenicity, and it causes gastrointestinal disorders. Thus, this study aimed to investigate the sp. prevalence and its relationship with gastrointestinal disorders, in patients referred to laboratories, and provide some prevention strategies.
METHODS
In this descriptive-analytical study, 1,000 stool specimens were collected from patients referred to Ilam, Iran laboratories from 2018-2019. Wet mount method was conducted on samples, and suspected specimens were confirmed using trichrome staining. The demographic and clinical information was recorded in a questionnaire. Finally, the results were analyzed using the SPSS.
RESULTS
infection was detected in 81 out of 1,000 patients (8.1%) including 61 (75.3%) males and 20 (24.7%) females. and illiterate people were more at risk. The prevalence in rural was more than urban areas, and it was more in the age group of 31-50 year.
CONCLUSION
There was a significant relationship between sp. and risk factors (age, sex, level of education, and residence) and clinical symptoms (stomach ache and nausea) (<0.05), but interestingly there was no significant relationship between bloating and diarrhea.
PubMed: 36046570
DOI: 10.18502/ijpa.v17i1.9029 -
Parasites & Vectors Feb 2018Global data regarding the molecular epidemiology of Blastocystis sp. and Pentatrichomonas hominis in sheep and goats are sparse. China has one of the largest sheep and...
BACKGROUND
Global data regarding the molecular epidemiology of Blastocystis sp. and Pentatrichomonas hominis in sheep and goats are sparse. China has one of the largest sheep and goat populations in the world. In this study we investigated the occurrence of Blastocystis sp. and P. hominis in domestic sheep and goats in China, and analyzed the genetic characterization of these two parasite species.
METHODS
In total, we collected fresh fecal samples from 832 sheep and 781 goats located on seven and ten farms, respectively, in the central eastern region of China. The corresponding sequences obtained in this study were subject to molecular analysis for subtype and allele identification of Blastocystis sp., and species and genotype confirmation of P. hominis.
RESULTS
The occurrence of Blastocystis sp. was 6.0% (50/832) in sheep and 0.3% (2/781) in goats. The most predominant subtype (ST) of Blastocystis sp. in sheep was ST10 (50.0%), followed by ST14 (20%), ST5 (16%), novel sequence 1 (6%), novel sequence 4 (4%), novel sequence 2 (2%) and novel sequence 3 (2%). However, only ST1 was observed in goats. No mixed infections with different subtypes were found in this study. The 18S alleles showed allele 2 (100%) for ST1; allele 115 (75%) for ST5; and no match allele for ST5 (25%), ST10 (100%), ST14 (100%), novel sequence 1 (100%), novel sequence 2 (100%), novel sequence 3 (100%), and novel sequence 4 (100%) on the Blastocystis subtype (18S) and Sequence Typing (MLST) database. For P. hominis, two goats (0.3%) and zero sheep (0%) were identified as positive in this study. The 18S rRNA gene sequences of two P. hominis isolates from goats displayed 100% identity to type CC1, found previously in dogs, monkeys and humans.
CONCLUSIONS
These results provide the detailed data on the occurrence and molecular epidemiology of Blastocystis sp. and P. hominis in sheep and goats in China. They also contribute to and expand our knowledge of the Blastocystis sp. and P. hominis epidemiology around the world.
Topics: Animals; Blastocystis; China; DNA, Protozoan; Feces; Genotype; Geography; Goats; Molecular Epidemiology; Molecular Sequence Data; Phylogeny; Protozoan Infections, Animal; RNA, Ribosomal, 18S; Sheep; Trichomonadida
PubMed: 29454366
DOI: 10.1186/s13071-018-2671-5 -
Pharmaceutics Jun 2023Silver nanoparticles (AgNPs) are ultra-small silver particles with a size from 1 to 100 nanometers. Unlike bulk silver, they have unique physical and chemical... (Review)
Review
Silver nanoparticles (AgNPs) are ultra-small silver particles with a size from 1 to 100 nanometers. Unlike bulk silver, they have unique physical and chemical properties. Numerous studies have shown that AgNPs have beneficial biological effects on various diseases, including antibacterial, anti-inflammatory, antioxidant, antiparasitic, and antiviruses. One of the most well-known applications is in the field of antibacterial applications, where AgNPs have strong abilities to kill multi-drug resistant bacteria, making them a potential candidate as an antibacterial drug. Recently, AgNPs synthesized from plant extracts have exhibited outstanding antiparasitic effects, with a shorter duration of use and enhanced ability to inhibit parasite multiplication compared to traditional antiparasitic drugs. This review summarizes the types, characteristics, and the mechanism of action of AgNPs in anti-parasitism, mainly focusing on their effects in leishmaniasis, flukes, cryptosporidiosis, toxoplasmosis, , , and . The aim is to provide a reference for the application of AgNPs in the prevention and control of parasitic diseases.
PubMed: 37513969
DOI: 10.3390/pharmaceutics15071783 -
Journal of Parasitology Research 2021is the most common intestinal parasite found in humans and many other hosts. Pathogenicity of spp. remains controversial, and it has been suggested that it may be...
is the most common intestinal parasite found in humans and many other hosts. Pathogenicity of spp. remains controversial, and it has been suggested that it may be associated with specific subtypes of the organism. This study identified the subtypes and their prevalence rates in the northeast of Iran. A total of 1878 samples were collected from the northeast of Iran from January to December 2017. The patients' demographic details were recorded. Samples were examined by a wet mount, and genomic DNA was extracted from positive samples. Also, PCR was done on the positive samples, and sequencing and phylogenetic analysis were subsequently performed. From 1878 collected stool samples, 152 (8.1%) Blastocystis samples were detected by the microscopic method. Of the 152 samples, spp. were found in 53.6% of the men and 28.9% of the women who showed clinical gastrointestinal symptoms, and a significant relationship was observed between gender and clinical symptoms ( = 0.002). A meaningful relationship was found between the season and infection with this parasite ( value = 0.003). The results of the sequencing of 22 PCR products showed the dominance of ST3, which was isolated from 10 (45.45%) patients, while ST1, ST2, and ST7 were found in 4 (18.19%), 7 (31.81%), and 1 (4.55%) patients, respectively. In this study, ST7 had a low prevalence in the northeast of Iran, and similar to previous studies, ST3 was the dominant subtype.
PubMed: 33510903
DOI: 10.1155/2021/8821885 -
Journal of Parasitic Diseases :... Mar 2022is a cosmopolitan protozoan that has been associated with several gastrointestinal disturbances involving lactose intolerance. However, the underlying pathogenic...
is a cosmopolitan protozoan that has been associated with several gastrointestinal disturbances involving lactose intolerance. However, the underlying pathogenic factors remain indistinct. 20 Swiss albino mice were utilized and assembled into four groups, each of five mice: group-I: received neither infection nor lactose (healthy control), group-II: received a single dose of 10,000 cysts of and lactose diets in a dose of 12.5 g/day/mouse for 7 consecutive days starting from day 14 p.i., group-III: non-infected mice with oral doses of lactose (12.5 g/day/mouse) for 7 consecutive days (positive control), group-IV: infected mice on lactose free diet (negative control). We investigated the histopathological changes using H&E stain.s Also, lactase enzyme activity was measured using spectrophotometry and the production of TNF-α and apoptotic events were explored via immunohistochemistry and compared in the small intestine of all groups. The active inflammatory changes in the infected animals were moderate in the form of loss of villous architecture, increased ILC (-value > 0.001) besides scattered forms of the parasite as compared to non-infected mice. There was a reduction in lactase enzyme activity p.i. The TNF-α levels were induced p.i. as compared to non-infected mice (-value > 0.001). The expression of Bax protein was upgraded, while Bcl-2 expression decreased significantly with a reverse in Bax/Bcl2 ratio in infected animals. infection appears to humble lactase enzyme activity via the induction of apoptosis in the epithelial cells of the small intestinal brush border in a TNF-α associative pathway.
PubMed: 35299913
DOI: 10.1007/s12639-021-01442-6