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FEMS Microbiology Reviews May 2012The microsporidia are a diverse phylum of obligate intracellular parasites related to the fungi that cause significant and sometimes life-threatening disease in... (Review)
Review
The microsporidia are a diverse phylum of obligate intracellular parasites related to the fungi that cause significant and sometimes life-threatening disease in immune-compromised hosts, such as AIDS and organ transplant patients. More recently, their role in causing pathology in immune-competent populations has also been appreciated. Interestingly, in several instances, the microsporidia have been shown to persist in their hosts long term, causing at opposite ends of the spectrum either an intractable chronic diarrhea and wasting in patients with advanced-stage AIDS or asymptomatic shedding of spores in healthy populations. Much remains to be studied regarding the immune response to these pathogens, but it seems clear that CD8+ T cells are essential in clearing infection. However, in the infection models examined thus far, the role for CD4+ T cells is unclear at best. Here, we discuss the possible reasons and ramifications of what may be a weak primary CD4+ T cell response against Encephalitozoon cuniculi. Given the central role of the CD4+ T cell in other models of adaptive immunity, a better appreciation of its role in responding to microsporidia may provide insight into the survival strategies of these pathogens, which allow them to persist in hosts of varied immune status.
Topics: CD4-Positive T-Lymphocytes; CD8-Positive T-Lymphocytes; Chronic Disease; Host-Pathogen Interactions; Humans; Microsporidia; Microsporidiosis
PubMed: 22126330
DOI: 10.1111/j.1574-6976.2011.00318.x -
Scientific Reports Jan 2020Cryptosporidium spp. and Enterocytozoon bieneusi are two well-known protist pathogens which can result in diarrhea in humans and animals. To examine the occurrence and...
Cryptosporidium spp. and Enterocytozoon bieneusi are two well-known protist pathogens which can result in diarrhea in humans and animals. To examine the occurrence and genetic characteristics of Cryptosporidium spp. and E. bieneusi in pet red squirrels (Sciurus vulgaris), 314 fecal specimens were collected from red squirrels from four pet shops and owners in Sichuan province, China. Cryptosporidium spp. and E. bieneusi were examined by nested PCR targeting the partial small subunit rRNA (SSU rRNA) gene and the ribosomal internal transcribed spacer (ITS) gene respectively. The infection rates were 8.6% (27/314) for Cryptosporidium spp. and 19.4% (61/314) for E. bieneusi. Five Cryptosporidium species/genotypes were identified by DNA sequence analysis: Cryptosporidium rat genotype II (n = 8), Cryptosporidium ferret genotype (n = 8), Cryptosporidium chipmunk genotype III (n = 5), Cryptosporidium rat genotype I (n = 4), and Cryptosporidium parvum (n = 2). Additionally, a total of five E. bieneusi genotypes were revealed, including three known genotypes (D, SCC-2, and SCC-3) and two novel genotypes (RS01 and RS02). Phylogenetic analysis revealed that genotype D fell into group 1, whereas the remaining genotypes clustered into group 10. To our knowledge, this is the first study to report Cryptosporidium spp. and E. bieneusi in pet red squirrels in China. Moreover, C. parvum and genotype D of E. bieneusi, previously identified in humans, were also found in red squirrels, suggesting that red squirrels may give rise to cryptosporidiosis and microsporidiosis in humans through zoonotic transmissions. These results provide preliminary reference data for monitoring Cryptosporidium spp. and E. bieneusi infections in pet red squirrels and humans.
Topics: Animals; China; Cryptosporidiosis; Cryptosporidium; DNA, Ribosomal Spacer; Enterocytozoon; Feces; Female; Humans; Male; Microsporidiosis; Pets; Phylogeny; RNA, Ribosomal; Sciuridae; Sequence Analysis, DNA; Zoonoses
PubMed: 31974403
DOI: 10.1038/s41598-020-57896-w -
BMC Infectious Diseases Jan 2022Intestinal microsporidiosis is an opportunistic infection associated with persistent diarrhea among HIV/AIDS patients. In Yemen, however, its epidemiology is unknown....
BACKGROUND
Intestinal microsporidiosis is an opportunistic infection associated with persistent diarrhea among HIV/AIDS patients. In Yemen, however, its epidemiology is unknown. Therefore, this study determined its prevalence and predictors among HIV/AIDS patients receiving antiretroviral therapy (ART) in Sana'a city, the capital of Yemen.
METHODS
This cross-sectional study included 402 patients receiving ART at Al-Jomhori Educational Hospital in Sana'a from November 2019 to December 2020. Data about demographics, clinical characteristics and risk factors were collected using a pre-designed questionnaire. Stool samples were collected and examined for microsporidian spores using the Gram-chromotrope Kinyoun staining. Blood samples were also collected and used for CD4 cell counting by flow cytometry. Univariate analysis was used to test the association of patients' characteristics and risk factors with intestinal microsporidiosis. Multivariable logistic regression was then used to identify the independent predictors of infection. Statistical significance was considered at P-values < 0.05.
RESULTS
Intestinal microsporidiosis was prevalent among 14.2% (57/402) of HIV/AIDS patients and was significantly associated with diarrhea (OR 3.4, 95% CI 1.7-6.6; P = 0.001). The significant independent predictors of infection were < 200 CD4 cells/µl (AOR 3.2, 95% CI 1.5-6.9; P = 0.003), not washing hands after contacting soil (AOR 2.5, 95% CI 1.1-5.4; P = 0.026) and before eating (AOR 3.1, 95% CI 1.5-6.4; P = 0.003), eating unwashed raw produce (AOR 2.5, 95% CI 1.2-5.3; P = 0.017) and absence of indoor latrines (AOR 6.2, 95% CI 1.5-25.9; P = 0.012).
CONCLUSIONS
The prevalence of intestinal microsporidiosis among HIV/AIDS patients in Sana'a is high and comparable to that reported from several other countries, being prevalent among approximately 14.0% of patients and significantly associated with diarrhea. It could be predicted among patients who have < 200 CD4 cells/µl, have poor hand hygiene after contacting soil and before eating, usually eat unwashed raw produce, or do not possess indoor latrines. Large-scale studies on its epidemiology and predictors among HIV/AIDS patients across the country are warranted.
Topics: Cross-Sectional Studies; HIV Infections; Humans; Microsporidiosis; Prevalence; Yemen
PubMed: 34983416
DOI: 10.1186/s12879-021-07009-3 -
Journal of Clinical Microbiology Feb 2013Molecular diagnostic tools have been used increasingly in the characterization of the transmission of cryptosporidiosis and microsporidiosis in developing countries....
Molecular diagnostic tools have been used increasingly in the characterization of the transmission of cryptosporidiosis and microsporidiosis in developing countries. However, few studies have examined the distribution of Cryptosporidium species and Enterocytozoon bieneusi genotypes in AIDS patients receiving antiretroviral therapy. In the present study, 683 HIV-positive patients in the National Free Antiretroviral Therapy Program in China and 683 matched HIV-negative controls were enrolled. Cryptosporidium species and subtypes and Enterocytozoon bieneusi genotypes were detected and differentiated by PCR and DNA sequencing. The infection rates were 1.5% and 0.15% for Cryptosporidium and 5.7% and 4.2% for E. bieneusi in HIV-positive and HIV-negative participants, respectively. The majority (8/11) of Cryptosporidium cases were infections by zoonotic species, including Cryptosporidium meleagridis (5), Cryptosporidium parvum (2), and Cryptosporidium suis (1). Prevalent E. bieneusi genotypes detected, including EbpC (39), D (12), and type IV (7), were also potentially zoonotic. The common occurrence of EbpC was a feature of E. bieneusi transmission not seen in other areas. Contact with animals was a risk factor for both cryptosporidiosis and microsporidiosis. The results suggest that zoonotic transmission was significant in the epidemiology of both diseases in rural AIDS patients in China.
Topics: AIDS-Related Opportunistic Infections; Adolescent; Adult; Aged; Aged, 80 and over; Animals; Antiretroviral Therapy, Highly Active; Case-Control Studies; Child; Child, Preschool; China; Coinfection; Cryptosporidiosis; Cryptosporidium; DNA, Ribosomal Spacer; Enterocytozoon; Female; Genotype; HIV Infections; HIV-1; Humans; Infant; Male; Microsporidiosis; Middle Aged; Molecular Sequence Data; Phylogeny; Prevalence; Risk Factors; Young Adult
PubMed: 23224097
DOI: 10.1128/JCM.02758-12 -
Folia Parasitologica 1994This paper summarizes work done in this laboratory over the last two years on the cloning of microsporidian rRNA by homology PCR and its subsequent use in diagnostic... (Review)
Review
This paper summarizes work done in this laboratory over the last two years on the cloning of microsporidian rRNA by homology PCR and its subsequent use in diagnostic tests and phylogenetic studies. Using highly conserved primers in the 16S or small subunit rRNA (SSU-rRNA) these genes were cloned from human intestinal biopsies with transmission electron microscopy proven Enterocytozoon bieneusi and Septata intestinalis. The SSU-rRNA genes were then used to design and test several primer pairs for the diagnosis of microsporidian infection. Utilizing the polymerase chain reaction and primers V1 and EB450 Ent. bieneusi infected duodenal aspirates or intestinal biopsies could be detected. Using V1 and SI500 infection with S. intestinalis could be detected. In addition to diagnostic tests, phylogenetic relationships were examined using sequence data from the fragment amplified by PCR by primer 530f in the SSU-rRNA and primer 580r in the large subunit rRNA. This data supported the placement of S. intestinalis in the family Encephalitozoonidae. In addition, it confirmed that Encephalitozoon cuniculi, E. hellem and S. intestinalis are distinct organisms. These techniques have broad applications to the study of other microsporidia and the development of a molecular phylogeny.
Topics: Animals; Base Sequence; Cloning, Molecular; DNA Primers; Genes, Protozoan; Microsporida; Microsporidiosis; Molecular Sequence Data; Phylogeny; RNA, Protozoan; RNA, Ribosomal, 16S; RNA, Small Nuclear; Sequence Homology, Nucleic Acid
PubMed: 7927064
DOI: No ID Found -
Turkiye Parazitolojii Dergisi Mar 2015The members of the Microsporidia are single-celled, eukaryotic, obligate intracellular parasites. They infect a wide range of invertebrate and vertebrate hosts. The... (Review)
Review
The members of the Microsporidia are single-celled, eukaryotic, obligate intracellular parasites. They infect a wide range of invertebrate and vertebrate hosts. The studies on Microsporidia are of considerable interest because of that they cause desirable and undesirable infections in different animals. That situation requires identification of these organisms correctly. The identification of Microsporidia needs relatively more complex studies. Morphological and ultrastructural studies play important role in the identification of these organisms. In the present study, a working knowledge on the morphological and ultrastructural features of Microsporidia are given.
Topics: Animals; Microsporidia; Microsporidiosis; Spores, Fungal
PubMed: 25917585
DOI: 10.5152/tpd.2015.3738 -
Annals of Parasitology 2017Enterocytozoon bieneusi is the most commonly identified Microsporidia in humans and has also been detected worldwide in a large group of wild living and domestic... (Review)
Review
Enterocytozoon bieneusi is the most commonly identified Microsporidia in humans and has also been detected worldwide in a large group of wild living and domestic animals. The identification of E. bieneusi in wildlife has raised the question of the importance of animal reservoirs in the epidemiology of microsporidiosis and the implications of the infection with this pathogen in hosts. This review summarizes the available molecular data on the variety of E. bieneusi genotypes, both potentially zoonotic and host-specific isolated from wild living mammals and birds. In contrast to microsporidial infections of humans and domestic animals, wildlife deserves attention as a source of significant environmental reservoir of E. bieneusi.
Topics: Animals; Animals, Wild; Disease Reservoirs; Enterocytozoon; Humans; Microsporidiosis; Zoonoses
PubMed: 29396924
DOI: 10.17420/ap6304.113 -
BMC Veterinary Research Mar 2020Cryptosporidium and Enterocytozoon bieneusi are two important pathogens with zoonotic potential that cause enteric infections in a wide range of hosts, including humans....
Prevalence and genotypic identification of Cryptosporidium spp. and Enterocytozoon bieneusi in captive Asiatic black bears (Ursus thibetanus) in Heilongjiang and Fujian provinces of China.
BACKGROUND
Cryptosporidium and Enterocytozoon bieneusi are two important pathogens with zoonotic potential that cause enteric infections in a wide range of hosts, including humans. Both are transmitted from animals to humans by direct contact or through contaminated equipment. Bears are frequently found in Chinese zoos as ornamental animals as well as farmed as commercial animals, and are therefore in close contact with zoo- or farm-keepers, but the prevalence and zoonotic potential of Cryptosporidium and E. bieneusi in bears is poorly understood. In this study, we aimed to provide data on the occurrence and genetic diversity of Cryptosporidium and E. bieneusi in Asiatic black bears from Heilongjiang and Fujian, China. From May 2015 to December 2017, 218 fresh fecal specimens were collected from captive Asiatic black bears in Heilongjiang (n = 36) and Fujian (n = 182), China. Cryptosporidium and E. bieneusi were examined by PCR amplification of the partial small subunit of ribosomal DNA (SSU rDNA) and the internal transcribed spacer (ITS) region of rDNA, respectively. C. andersoni-positive isolates were subtyped through PCR analysis of the four minisatellite/microsatellite (MS1, MS2, MS3 and MS16) loci.
RESULTS
The overall prevalence of Cryptosporidium and E. bieneusi were 2.4% (4/218) and 6.4% (14/218), respectively, with 2.8% (1/36) and 22.2% (8/36) in the Heilongjiang Province, and 1.6% (3/182) and 3.3% (6/182) in the Fujian Province. Sequence analysis confirmed the presence of Cryptosporidium species: C. andersoni (n = 3) and a genotype termed Cryptosporidium rat genotype IV (n = 1). All three identified C. andersoni belonged to the MLST subtype A4, A4, A4, A1. Two known E. bieneusi genotypes D (n = 4) and SC02 (n = 10) were identified, both of which belong to zoonotic Group 1.
CONCLUSIONS
This is the first report of C. andersoni and Cryptosporidium rat genotype IV in bears. The discovery of the zoonotic potential of E. bieneusi genotype D in bears highlights its significant zoonotic potential and potential threat to human health.
Topics: Animals; China; Cryptosporidiosis; Cryptosporidium; DNA, Ribosomal; Enterocytozoon; Microsatellite Repeats; Microsporidiosis; Polymerase Chain Reaction; Prevalence; Ursidae; Zoonoses
PubMed: 32151253
DOI: 10.1186/s12917-020-02292-9 -
Indian Journal of Medical Microbiology 2020Microsporidium is a spore-forming intracellular parasite that affects a wide range of hosts including humans. The tumor necrosis factor alpha (TNF-α) plays a key role...
PURPOSE
Microsporidium is a spore-forming intracellular parasite that affects a wide range of hosts including humans. The tumor necrosis factor alpha (TNF-α) plays a key role in the immunity to infection with microsporidia. Recently, the TNF-α antagonists have proven successful in treating variable autoimmune diseases. In the current study, we aimed to investigate the impact of using TNF-α antagonists as a therapeutic regimen in the prevalence of infections with microsporidia.
MATERIALS AND METHODS
Diarrheal patients with distinct autoimmune diseases (n = 100) were assigned to the study. Patients taking anti-TNF-α medications (n = 60) were allocated to Group 1A and those undergoing non-TNF-α inhibitor treatment (n = 40) to Group 1B. Furthermore, patients with diarrhea without autoimmune disorders (n = 20) were allocated as controls. Stool specimens, 3 per patient, were collected and microscopically examined for microsporidia spores. A microsporidia-specific stool polymerase chain reaction was used to confirm the microscopic findings.
RESULTS
Microsporidia infection was identified in 28.3% (17/60), 10% (4/40), and in 5% (1/20) of patients in Group 1A, Group 1B, and in the control group, respectively. Overall, infection was significantly high in cases compared to the controls and in patients receiving TNF-α antagonists compared to patients not given TNF-α inhibitors (P < 0.05). Finally, infection was significantly higher in cases treated with TNF-α antagonists for ≥2 months compared to cases treated for <2 months of duration (P < 0.05).
CONCLUSION
There was a significant increase in microsporidia infection in autoimmune disease patients undergoing treatment with TNF-α antagonists, and the duration of treatment is one of the risk factors. The study highlights the importance of microsporidia testing in immunocompromised patients, particularly those undergoing treatment with anti-TNF-α drugs and emphasises the need for awareness among clinicians regarding this opportunistic parasite.
Topics: Autoimmune Diseases; Case-Control Studies; Diarrhea; Feces; Female; Humans; Male; Microsporidia; Microsporidiosis; Polymerase Chain Reaction; Prospective Studies; Tumor Necrosis Factor-alpha
PubMed: 33154255
DOI: 10.4103/ijmm.IJMM_20_325 -
Parasites & Vectors Nov 2017Microsporidia are intracellular obligate parasites traditionally associated with immunosuppressed patients; their detection in immunocompetent patients has increased,...
BACKGROUND
Microsporidia are intracellular obligate parasites traditionally associated with immunosuppressed patients; their detection in immunocompetent patients has increased, highlighting their possible importance as emerging pathogens. Detection of spores in stools, urine, body fluids and tissues is difficult and immunological techniques such as immunofluorescence have proved to be a useful and reliable tool in the diagnosis of human microsporidiosis. For this reason, we have produced and characterized monoclonal antibodies (MAbs) specific for Encephalitozoon intestinalis (the second most frequent microsporidian infecting humans), and other Encephalitozoon species, that can be used in different diagnostic techniques.
RESULTS
Seven MAbs were selected in accordance with their optical density (OD). Four (4C4, 2C2, 2E5 and 2H2) were isotype IgG2a; two (3A5 and 3C9) isotype IgG3, and one Mab, 1D7, IgM isotype. The selected monoclonal antibody-secreting hybridomas were characterized by indirect immunofluorescence antibody test (IFAT), enzyme-linked immunosorbent assay (ELISA), Western blot, immunoelectron microscopy (Immunogold) and in vitro cultures. The study by IFAT showed different behavior depending on the MAbs studied. The MAbs 4C4, 2C2, 2E5 and 2H2 showed reactivity against epitopes in the wall of the spore (exospore and endospore) epitopes located in Encephalitozoon sp. spores, whereas the MAbs 3A5, 1D7 and 3C9 showed reactivity against internal epitopes (cytoplasmic contents or sporoplasm) of E. intestinalis spores. All MAbs recognized the developing parasites in the in vitro cultures of E. intestinalis. Additionally, 59 formalin-fixed stool samples that had been previously analyzed were screened, with 26 (44%) presenting microsporidian spores (18 samples with E. intestinalis and 8 samples with Enterocytozoon bieneusi). Detection of microsporidian spores by microscopy was performed using Calcofluor stain, Modified Trichrome, Quick-Hot Gram Chromotrope, as well as IFAT using MAbs 4C4, 2C2, 2E5 and 2H2. The 4 MAbs tested clearly recognized the larger spores corresponding to E. intestinalis, but showed no reactivity with Enterocytozoon bieneusi spores. The mass spectrometry and proteomic study revealed that the Mabs 4C4, 2C2, 2E5 and 2H2 recognized the Spore Wall Protein 1 (SWP1) as the antigenic target.
CONCLUSIONS
The IFAT-positive MAbs exhibited excellent reactivity against spores and developmental stages, permitting their use in human and animal diagnosis. The epitopes recognized (exospore, endospore and cytoplasmic contents) by the different MAbs developed need further study, and may reveal potential targets for vaccine development, immunotherapy and chemotherapy.
Topics: Antibodies, Monoclonal; Blotting, Western; Encephalitozoon; Encephalitozoonosis; Enterocytozoon; Feces; Fluorescent Antibody Technique; Humans; Mass Spectrometry; Microscopy; Microsporidiosis; Proteomics; Spores, Fungal
PubMed: 29121996
DOI: 10.1186/s13071-017-2503-z