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Isabelle Desportes-livage - One of the best experts on this subject based on the ideXlab platform.

  • The genes encoding cAMP-dependent protein kinase catalytic subunit homologues of the microsporidia Encephalitozoon intestinalis and E. cuniculi: molecular characterisation and phylogenetic analysis
    Parasitology international, 2004
    Co-Authors: Leila Equinet, Isabelle Desportes-livage, Christian P. Vivarès, Marc Thellier, Eric Bapteste, Meryem Ouarzane-amara, Christian Doerig
    Abstract:

    A gene encoding a protein kinase was identified by homology-based PCR amplification in Encephalitozoon intestinalis, a microsporidian parasite pathogenic to humans, and its orthologue has been identified by database mining in the genome of the related species E. cuniculi, whose sequence has been recently published. Phylogenetic analysis revealed that the proteins encoded by these genes are homologues of the cAMP-dependent protein kinase catalytic subunits (PKAc). Southern blot analysis indicated that the EiPKAc gene is present in two copies in the E. intestinalis genome, whereas the E. cuniculi orthologue (EcPKAc) is a single copy gene. RT-PCR data showed that the EiPKAc gene is expressed in at least one of the intracellular stages during infection of the mammalian host cell by E. intestinalis.

  • A new monoclonal antibody enzyme-linked immunosorbent assay to measure in vitro multiplication of the microsporidium Encephalitozoon intestinalis.
    Journal of Microbiological Methods, 2003
    Co-Authors: Nicolas Bouladoux, Sylvestre Biligui, Isabelle Desportes-livage
    Abstract:

    Microsporidia are obligate intracellular eukaryotic parasites that infect a wide range of hosts, including invertebrates and vertebrates. Microsporidia have emerged as important opportunistic pathogens of humans with the onset of the AIDS pandemic. The potential impact of these infections in human pathology has required the development of antiparasitic strategies, based on the search for molecules having an effect on the development and/or the multiplication of microsporidia. This creates a demand for a simple and reliable in vitro technique for measuring the multiplication of microsporidia. We developed a new monoclonal antibody (MAb) enzyme-linked immunosorbent assay (ELISA) technique and measured the growth of Encephalitozoon intestinalis in an in vitro culturing system using this method. The monoclonal antibody is specific for a coat protein of E. intestinalis sporogonic stages produced in parasitophorous vacuole. An anti-mouse antibody labeled with peroxidase was used as conjugate. This ELISA is a suitable, specific and semiquantitative technique for measuring the spread of E. intestinalis. It is easy to perform and required 5 h from start to end. A good correlation was observed when the ELISA data were compared with the manual microscopic counts of parasitophorous vacuoles obtained after immunofluorescent assay (IFA). Moreover, the ELISA method proved more accurate than the immunofluorescent assay. In summary, the ELISA system described in this study provides a simple reliable assay for measuring the spread of microsporidia in vitro and may prove valuable for the screening of putative interesting antimicrosporidial compounds.

  • Evaluation of an Immunofluorescent-Antibody Test Using Monoclonal Antibodies Directed against Enterocytozoon bieneusi and Encephalitozoon intestinalis for Diagnosis of Intestinal Microsporidiosis in Bamako (Mali)
    Journal of clinical microbiology, 2002
    Co-Authors: O. Alfa Cisse, Sylvestre Biligui, Isabelle Desportes-livage, A. Ouattara, Marc Thellier, Isabelle Accoceberry, D. Minta, O. Doumbo, M. A. Thera, Martin Danis
    Abstract:

    A 2-month study was carried out in Mali to evaluate an immunofluorescent-antibody test (IFAT) using monoclonal probes specific for Enterocytozoon bieneusi or Encephalitozoon intestinalis. Sixty-one human immunodeficiency virus (HIV)-seropositive adult patients and 71 immunocompetent children were enrolled. Microsporidia were detected in stools from 8 of 61 patients (13.1%) seropositive for HIV. A single species, E. bieneusi, was identified. All the children were negative for microsporidia. The sensitivity and specificity of IFAT were 100% compared with those of PCR, which was used as the “gold standard.” Moreover, species identification by IFAT was more rapid and less expensive than that by PCR. These results show the suitability of IFAT for detection of microsporidia in developing countries.

  • In vitro activities of two antimitotic compounds, pancratistatin and 7-deoxynarciclasine, against Encephalitozoon intestinalis, a microsporidium causing infections in humans.
    Antimicrobial agents and chemotherapy, 2001
    Co-Authors: Meryem Ouarzane-amara, Dominique Mazier, Jean-françois Franetich, Christian Doerig, George R. Pettit, Laurent Meijer, Isabelle Desportes-livage
    Abstract:

    The antiparasitic effect of a collection of compounds with antimitotic activity has been tested on a mammalian cell line infected with Encephalitozoon intestinalis, a microsporidian causing intestinal and systemic infection in immunocompromised patients. The antiparasitic effect was evaluated by counting the number of parasitophorous vacuoles detected by immunofluorescence. Out of 526 compounds tested, 2 (pancratistatin and 7-deoxynarciclasine) inhibited the infection without affecting the host cell. The 50% inhibitory concentrations (IC(50)s) of pancratistatin and 7-deoxynarciclasine for E. intestinalis were 0.18 microM and 0.2 microM, respectively, approximately eightfold lower than the IC(50)s of these same compounds against the host cells. Electron microscopy confirmed the gradual decrease in the number of parasitophorous vacuoles and showed that of the two life cycle phases, sporogony was more sensitive to the inhibitors than merogony. Furthermore, the persistence of meronts in some cells apparently devoid of sporonts and spores indicated that the inhibitors block development rather than entry of the parasite into the host cell. The occurrence of binucleate sporoblasts and spores suggests that these inhibitors blocked a specific phase of cell division.

  • Dissemination of Encephalitozoon intestinalis, a causative agent of human microsporidiosis, in IFN-gamma receptor knockout mice.
    Parasite immunology, 2001
    Co-Authors: Youssef El Fakhry, Isabelle Desportes-livage, Abderrahim Achbarou, Jean-françois Franetich, Dominique Mazier
    Abstract:

    The dissemination of Encephalitozoon intestinalis, a microsporidium causing intestinal diseases and systemic infection in humans, was investigated in IFN-gamma Ro/o mice. Although lesions were seen in organs of autopsied animals, the parasites were rarely detected using histological examination. Nevertheless, infection of the duodenum, liver, kidneys and lungs was demonstrated by polymerase chain reaction. This method also enabled the detection of the parasite in the brain and the heart. The development of E. intestinalis in RK13 cell cultures to which cell suspensions from liver, kidney, lung or brain of infected IFN-gamma Ro/o mice were added, confirmed the spread of intestinal microsporidiosis to these organs. No dissemination was observed in wild-type mice. These results confirm those of previous studies and emphasize the low morbidity of the infection in IFN-gamma Ro/o mice and confirm the role of IFN-gamma in the control of E. intestinalis infection. These mice infected with E. intestinalis offer important information about this interesting and important parasitic disease of man and animals.

Jean-michel Molina - One of the best experts on this subject based on the ideXlab platform.

  • Inhibitory activity of human immunodeficiency virus aspartyl protease inhibitors against Encephalitozoon intestinalis evaluated by cell culture-quantitative PCR assay.
    Antimicrobial agents and chemotherapy, 2005
    Co-Authors: Jean Menotti, Claudine Sarfati, Francis Derouin, Maud Santillana-hayat, Bruno Cassinat, Jean-michel Molina
    Abstract:

    Immune reconstitution might not be the only factor contributing to the low prevalence of microsporidiosis in human immunodeficiency virus (HIV)-infected patients treated with protease inhibitors, as these drugs may exert a direct inhibitory effect against fungi and protozoa. In this study, we developed a cell culture-quantitative PCR assay to quantify Encephalitozoon intestinalis growth in U-373-MG human glioblastoma cells and used this assay to evaluate the activities of six HIV aspartyl protease inhibitors against E. intestinalis. A real-time quantitative PCR assay targeted the E. intestinalis small-subunit rRNA gene. HIV aspartyl protease inhibitors were tested over serial concentrations ranging from 0.2 to 10 mg/liter, with albendazole used as a control. Ritonavir, lopinavir, and saquinavir were able to inhibit E. intestinalis growth, with 50% inhibitory concentrations of 1.5, 2.2, and 4.6 mg/liter, respectively, whereas amprenavir, indinavir, and nelfinavir had no inhibitory effect. Pepstatin A, a reference aspartyl protease inhibitor, could also inhibit E. intestinalis growth, suggesting that HIV protease inhibitors may act through the inhibition of an E. intestinalis-encoded aspartyl protease. These results showed that some HIV protease inhibitors can inhibit E. intestinalis growth at concentrations that are achievable in vivo and that the real-time quantitative PCR assay that we used is a valuable tool for the in vitro assessment of the activities of drugs against E. intestinalis.

  • Development of a Real-Time PCR Assay for Quantitative Detection of Encephalitozoon intestinalis DNA
    Journal of clinical microbiology, 2003
    Co-Authors: Jean Menotti, Olivier Liguory, Claudine Sarfati, Francis Derouin, Bruno Cassinat, Jean-michel Molina
    Abstract:

    A new real-time PCR assay for quantitation of Encephalitozoon intestinalis DNA was developed which used a TaqMan fluorescent probe for specific detection. Serial dilutions of E. intestinalis spore suspensions obtained from tissue culture were used as external standards. The detection limit of the technique was 20 spores per ml, with a good interassay reproducibility (coefficient of variation of 7.1% for the suspension containing 20 spores/ml, 5.0% for the suspension containing 75 spores/ml and below 3.5% for higher concentrations). Quantitative detection of E. intestinalis DNA was similar whether the serial dilutions of spores were made in distilled water or in a stool suspension, allowing the use of the assay for stool specimens. The assay was then applied to 14 clinical specimens from 8 immunocompromised patients with proven E. intestinalis infection. The quantitation of the parasitic burden was achieved in stools, blood, urine, tissue biopsies, and bronchopulmonary specimens. The highest parasitic burdens were noted in stools, urine, and bronchopulmonary specimens, reaching 10(5) to 10(6) spores/g or ml. Dissemination of the infection was also evidenced in some patients by demonstration of E. intestinalis DNA in blood and serum. We conclude that real-time PCR is a valuable tool for quantitation of E. intestinalis burden in clinical specimens.

  • Effects of chemical and physical agents on viability and infectivity of Encephalitozoon intestinalis determined by cell culture and flow cytometry.
    Antimicrobial agents and chemotherapy, 2002
    Co-Authors: Maud Santillana-hayat, Sandra Fournier, Claudine Sarfati, Jean-michel Molina, Françoise Chau, Raphaël Porcher, Francis Derouin
    Abstract:

    We combined tissue culture and flow cytometry to assess the activities of various temperatures, chemicals, and disinfectants on the viability and infectivity of spores of Encephalitozoon intestinalis. Surfanios and benzalkonium chloride, disinfectants currently used in the hospital, were remarkably efficient in destroying spore viability and infectivity.

  • Genetic homology among thirteen Encephalitozoon intestinalis isolates obtained from human immunodeficiency virus-infected patients with intestinal microsporidiosis.
    Journal of clinical microbiology, 2000
    Co-Authors: Olivier Liguory, Sandra Fournier, Claudine Sarfati, Francis Derouin, Jean-michel Molina
    Abstract:

    The ribosomal DNA internal transcribed spacer sequences of 13 unrelated Encephalitozoon intestinalis isolates obtained from human immunodeficiency virus (HIV)-infected patients with intestinal microsporidiosis were analyzed by gene amplification and DNA sequencing. Among these isolates, we found only one genetic lineage which suggests that E. intestinalis may have a clonal distribution in HIV-infected patients.

  • Albendazole for Treatment and Prophylaxis of Microsporidiosis Due to Encephalitozoon intestinalis in Patients with AIDS: A Randomized Double-Blind Controlled Trial
    The Journal of infectious diseases, 1998
    Co-Authors: Jean-michel Molina, Isabelle Desportes-livage, Claudine Sarfati, Francis Derouin, Claude Chastang, Jérome Goguel, Jean-françois Michiels, John Horton, Jacques Modaï
    Abstract:

    A double-blind placebo-controlled trial was conducted to assess the efficacy and safety of albendazole (400 mg twice daily for 3 weeks) for the treatment of Encephalitozoon intestinalis infection in patients with AIDS. Clearance of microsporidia from the intestinal tract was obtained in 4 of 4 patients in the albendazole group versus 0 of 4 in the control group (P = .01, one-sided Fisher's exact test) and was associated with significant clinical benefit. All 4 controls subsequently cleared microsporidia following open-labeled albendazole treatment. To investigate the effect of albendazole in preventing relapse, these 8 patients were then randomly assigned to receive either albendazole (400 mg twice daily) or no treatment for the next 12 months. Albendazole significantly delayed the occurrence of relapse (P = .04, one-sided log-rank test). In human immunodeficiency virus-infected patients with E. intestinalis infection, albendazole has parasitologic and clinical efficacy and reduces the risk of relapse.

Francis Derouin - One of the best experts on this subject based on the ideXlab platform.

  • Inhibitory activity of human immunodeficiency virus aspartyl protease inhibitors against Encephalitozoon intestinalis evaluated by cell culture-quantitative PCR assay.
    Antimicrobial agents and chemotherapy, 2005
    Co-Authors: Jean Menotti, Claudine Sarfati, Francis Derouin, Maud Santillana-hayat, Bruno Cassinat, Jean-michel Molina
    Abstract:

    Immune reconstitution might not be the only factor contributing to the low prevalence of microsporidiosis in human immunodeficiency virus (HIV)-infected patients treated with protease inhibitors, as these drugs may exert a direct inhibitory effect against fungi and protozoa. In this study, we developed a cell culture-quantitative PCR assay to quantify Encephalitozoon intestinalis growth in U-373-MG human glioblastoma cells and used this assay to evaluate the activities of six HIV aspartyl protease inhibitors against E. intestinalis. A real-time quantitative PCR assay targeted the E. intestinalis small-subunit rRNA gene. HIV aspartyl protease inhibitors were tested over serial concentrations ranging from 0.2 to 10 mg/liter, with albendazole used as a control. Ritonavir, lopinavir, and saquinavir were able to inhibit E. intestinalis growth, with 50% inhibitory concentrations of 1.5, 2.2, and 4.6 mg/liter, respectively, whereas amprenavir, indinavir, and nelfinavir had no inhibitory effect. Pepstatin A, a reference aspartyl protease inhibitor, could also inhibit E. intestinalis growth, suggesting that HIV protease inhibitors may act through the inhibition of an E. intestinalis-encoded aspartyl protease. These results showed that some HIV protease inhibitors can inhibit E. intestinalis growth at concentrations that are achievable in vivo and that the real-time quantitative PCR assay that we used is a valuable tool for the in vitro assessment of the activities of drugs against E. intestinalis.

  • Development of a Real-Time PCR Assay for Quantitative Detection of Encephalitozoon intestinalis DNA
    Journal of clinical microbiology, 2003
    Co-Authors: Jean Menotti, Olivier Liguory, Claudine Sarfati, Francis Derouin, Bruno Cassinat, Jean-michel Molina
    Abstract:

    A new real-time PCR assay for quantitation of Encephalitozoon intestinalis DNA was developed which used a TaqMan fluorescent probe for specific detection. Serial dilutions of E. intestinalis spore suspensions obtained from tissue culture were used as external standards. The detection limit of the technique was 20 spores per ml, with a good interassay reproducibility (coefficient of variation of 7.1% for the suspension containing 20 spores/ml, 5.0% for the suspension containing 75 spores/ml and below 3.5% for higher concentrations). Quantitative detection of E. intestinalis DNA was similar whether the serial dilutions of spores were made in distilled water or in a stool suspension, allowing the use of the assay for stool specimens. The assay was then applied to 14 clinical specimens from 8 immunocompromised patients with proven E. intestinalis infection. The quantitation of the parasitic burden was achieved in stools, blood, urine, tissue biopsies, and bronchopulmonary specimens. The highest parasitic burdens were noted in stools, urine, and bronchopulmonary specimens, reaching 10(5) to 10(6) spores/g or ml. Dissemination of the infection was also evidenced in some patients by demonstration of E. intestinalis DNA in blood and serum. We conclude that real-time PCR is a valuable tool for quantitation of E. intestinalis burden in clinical specimens.

  • Effects of chemical and physical agents on viability and infectivity of Encephalitozoon intestinalis determined by cell culture and flow cytometry.
    Antimicrobial agents and chemotherapy, 2002
    Co-Authors: Maud Santillana-hayat, Sandra Fournier, Claudine Sarfati, Jean-michel Molina, Françoise Chau, Raphaël Porcher, Francis Derouin
    Abstract:

    We combined tissue culture and flow cytometry to assess the activities of various temperatures, chemicals, and disinfectants on the viability and infectivity of spores of Encephalitozoon intestinalis. Surfanios and benzalkonium chloride, disinfectants currently used in the hospital, were remarkably efficient in destroying spore viability and infectivity.

  • Genetic homology among thirteen Encephalitozoon intestinalis isolates obtained from human immunodeficiency virus-infected patients with intestinal microsporidiosis.
    Journal of clinical microbiology, 2000
    Co-Authors: Olivier Liguory, Sandra Fournier, Claudine Sarfati, Francis Derouin, Jean-michel Molina
    Abstract:

    The ribosomal DNA internal transcribed spacer sequences of 13 unrelated Encephalitozoon intestinalis isolates obtained from human immunodeficiency virus (HIV)-infected patients with intestinal microsporidiosis were analyzed by gene amplification and DNA sequencing. Among these isolates, we found only one genetic lineage which suggests that E. intestinalis may have a clonal distribution in HIV-infected patients.

  • Albendazole for Treatment and Prophylaxis of Microsporidiosis Due to Encephalitozoon intestinalis in Patients with AIDS: A Randomized Double-Blind Controlled Trial
    The Journal of infectious diseases, 1998
    Co-Authors: Jean-michel Molina, Isabelle Desportes-livage, Claudine Sarfati, Francis Derouin, Claude Chastang, Jérome Goguel, Jean-françois Michiels, John Horton, Jacques Modaï
    Abstract:

    A double-blind placebo-controlled trial was conducted to assess the efficacy and safety of albendazole (400 mg twice daily for 3 weeks) for the treatment of Encephalitozoon intestinalis infection in patients with AIDS. Clearance of microsporidia from the intestinal tract was obtained in 4 of 4 patients in the albendazole group versus 0 of 4 in the control group (P = .01, one-sided Fisher's exact test) and was associated with significant clinical benefit. All 4 controls subsequently cleared microsporidia following open-labeled albendazole treatment. To investigate the effect of albendazole in preventing relapse, these 8 patients were then randomly assigned to receive either albendazole (400 mg twice daily) or no treatment for the next 12 months. Albendazole significantly delayed the occurrence of relapse (P = .04, one-sided log-rank test). In human immunodeficiency virus-infected patients with E. intestinalis infection, albendazole has parasitologic and clinical efficacy and reduces the risk of relapse.

Claudine Sarfati - One of the best experts on this subject based on the ideXlab platform.

  • Inhibitory activity of human immunodeficiency virus aspartyl protease inhibitors against Encephalitozoon intestinalis evaluated by cell culture-quantitative PCR assay.
    Antimicrobial agents and chemotherapy, 2005
    Co-Authors: Jean Menotti, Claudine Sarfati, Francis Derouin, Maud Santillana-hayat, Bruno Cassinat, Jean-michel Molina
    Abstract:

    Immune reconstitution might not be the only factor contributing to the low prevalence of microsporidiosis in human immunodeficiency virus (HIV)-infected patients treated with protease inhibitors, as these drugs may exert a direct inhibitory effect against fungi and protozoa. In this study, we developed a cell culture-quantitative PCR assay to quantify Encephalitozoon intestinalis growth in U-373-MG human glioblastoma cells and used this assay to evaluate the activities of six HIV aspartyl protease inhibitors against E. intestinalis. A real-time quantitative PCR assay targeted the E. intestinalis small-subunit rRNA gene. HIV aspartyl protease inhibitors were tested over serial concentrations ranging from 0.2 to 10 mg/liter, with albendazole used as a control. Ritonavir, lopinavir, and saquinavir were able to inhibit E. intestinalis growth, with 50% inhibitory concentrations of 1.5, 2.2, and 4.6 mg/liter, respectively, whereas amprenavir, indinavir, and nelfinavir had no inhibitory effect. Pepstatin A, a reference aspartyl protease inhibitor, could also inhibit E. intestinalis growth, suggesting that HIV protease inhibitors may act through the inhibition of an E. intestinalis-encoded aspartyl protease. These results showed that some HIV protease inhibitors can inhibit E. intestinalis growth at concentrations that are achievable in vivo and that the real-time quantitative PCR assay that we used is a valuable tool for the in vitro assessment of the activities of drugs against E. intestinalis.

  • Development of a Real-Time PCR Assay for Quantitative Detection of Encephalitozoon intestinalis DNA
    Journal of clinical microbiology, 2003
    Co-Authors: Jean Menotti, Olivier Liguory, Claudine Sarfati, Francis Derouin, Bruno Cassinat, Jean-michel Molina
    Abstract:

    A new real-time PCR assay for quantitation of Encephalitozoon intestinalis DNA was developed which used a TaqMan fluorescent probe for specific detection. Serial dilutions of E. intestinalis spore suspensions obtained from tissue culture were used as external standards. The detection limit of the technique was 20 spores per ml, with a good interassay reproducibility (coefficient of variation of 7.1% for the suspension containing 20 spores/ml, 5.0% for the suspension containing 75 spores/ml and below 3.5% for higher concentrations). Quantitative detection of E. intestinalis DNA was similar whether the serial dilutions of spores were made in distilled water or in a stool suspension, allowing the use of the assay for stool specimens. The assay was then applied to 14 clinical specimens from 8 immunocompromised patients with proven E. intestinalis infection. The quantitation of the parasitic burden was achieved in stools, blood, urine, tissue biopsies, and bronchopulmonary specimens. The highest parasitic burdens were noted in stools, urine, and bronchopulmonary specimens, reaching 10(5) to 10(6) spores/g or ml. Dissemination of the infection was also evidenced in some patients by demonstration of E. intestinalis DNA in blood and serum. We conclude that real-time PCR is a valuable tool for quantitation of E. intestinalis burden in clinical specimens.

  • Effects of chemical and physical agents on viability and infectivity of Encephalitozoon intestinalis determined by cell culture and flow cytometry.
    Antimicrobial agents and chemotherapy, 2002
    Co-Authors: Maud Santillana-hayat, Sandra Fournier, Claudine Sarfati, Jean-michel Molina, Françoise Chau, Raphaël Porcher, Francis Derouin
    Abstract:

    We combined tissue culture and flow cytometry to assess the activities of various temperatures, chemicals, and disinfectants on the viability and infectivity of spores of Encephalitozoon intestinalis. Surfanios and benzalkonium chloride, disinfectants currently used in the hospital, were remarkably efficient in destroying spore viability and infectivity.

  • Genetic homology among thirteen Encephalitozoon intestinalis isolates obtained from human immunodeficiency virus-infected patients with intestinal microsporidiosis.
    Journal of clinical microbiology, 2000
    Co-Authors: Olivier Liguory, Sandra Fournier, Claudine Sarfati, Francis Derouin, Jean-michel Molina
    Abstract:

    The ribosomal DNA internal transcribed spacer sequences of 13 unrelated Encephalitozoon intestinalis isolates obtained from human immunodeficiency virus (HIV)-infected patients with intestinal microsporidiosis were analyzed by gene amplification and DNA sequencing. Among these isolates, we found only one genetic lineage which suggests that E. intestinalis may have a clonal distribution in HIV-infected patients.

  • Albendazole for Treatment and Prophylaxis of Microsporidiosis Due to Encephalitozoon intestinalis in Patients with AIDS: A Randomized Double-Blind Controlled Trial
    The Journal of infectious diseases, 1998
    Co-Authors: Jean-michel Molina, Isabelle Desportes-livage, Claudine Sarfati, Francis Derouin, Claude Chastang, Jérome Goguel, Jean-françois Michiels, John Horton, Jacques Modaï
    Abstract:

    A double-blind placebo-controlled trial was conducted to assess the efficacy and safety of albendazole (400 mg twice daily for 3 weeks) for the treatment of Encephalitozoon intestinalis infection in patients with AIDS. Clearance of microsporidia from the intestinal tract was obtained in 4 of 4 patients in the albendazole group versus 0 of 4 in the control group (P = .01, one-sided Fisher's exact test) and was associated with significant clinical benefit. All 4 controls subsequently cleared microsporidia following open-labeled albendazole treatment. To investigate the effect of albendazole in preventing relapse, these 8 patients were then randomly assigned to receive either albendazole (400 mg twice daily) or no treatment for the next 12 months. Albendazole significantly delayed the occurrence of relapse (P = .04, one-sided log-rank test). In human immunodeficiency virus-infected patients with E. intestinalis infection, albendazole has parasitologic and clinical efficacy and reduces the risk of relapse.

J. Russell Hayman - One of the best experts on this subject based on the ideXlab platform.

  • Role of host cell integrins in the microsporidium Encephalitozoon intestinalis adherence and infection in vitro.
    FEMS microbiology letters, 2017
    Co-Authors: Cory A Leonard, J. Russell Hayman
    Abstract:

    Microsporidia are obligate intracellular, spore-forming, fungal-related pathogens that employ a unique organelle, the polar tube, to transfer infectious spore contents into host cells to initiate infection. Spore adherence to host cells may provide the proximity required for polar tube/host cell interaction during in vivo infection. In previous in vitro studies, host sulfated glycosaminoglycans (GAGs) or recombinant microsporidia endospore protein (EnP1) was implicated in the pathogen adherence and infection process; however, complete ablation of spore adherence and infection could not be achieved, suggesting that additional or alternative spore and host cell determinants of adherence and infection may exist. Analysis of the Encephalitozoon intestinalis genome revealed about 100 predicted proteins containing the canonical integrin-binding motif arginine-glycine-aspartic acid (RGD); and, many pathogens have been shown to engage integrin molecules on cell surfaces. We hypothesized that host cell integrins play a role in microsporidia adherence and infection. In this study, we demonstrated that addition of exogenous integrin ligands or recombinant alpha 3 beta 1 integrin or alpha 5 beta 1 integrin to assays of E. intestinalis adherence and infection significantly reduced spore adherence and infection of host cells, supporting our hypothesis and implicating these specific integrins as putative host cell receptors for E. intestinalis spores.

  • Role of Sulfated Glycans in Adherence of the Microsporidian Encephalitozoon intestinalis to Host Cells In Vitro
    Infection and immunity, 2005
    Co-Authors: J. Russell Hayman, Timothy R. Southern, Theodore E. Nash
    Abstract:

    Microsporidia are obligate intracellular opportunistic protists that infect a wide variety of animals, including humans, via environmentally resistant spores. Infection requires that spores be in close proximity to host cells so that the hollow polar tube can pierce the cell membrane and inject the spore contents into the cell cytoplasm. Like other eukaryotic microbes, microsporidia may use specific mechanisms for adherence in order to achieve target cell proximity and increase the likelihood of successful infection. Our data show that Encephalitozoon intestinalis exploits sulfated glycans such as the cell surface glycosaminoglycans (GAGs) in selection of and attachment to host cells. When exogenous sulfated glycans are used as inhibitors in spore adherence assays, E. intestinalis spore adherence is reduced by as much as 88%. However, there is no inhibition when nonsulfated glycans are used, suggesting that E. intestinalis spores utilize sulfated host cell glycans in adherence. These studies were confirmed by exposure of host cells to xylopyranoside, which limits host cell surface GAGs, and sodium chlorate, which decreases surface sulfation. Spore adherence studies with CHO mutant cell lines that are deficient in either surface GAGs or surface heparan sulfate also confirmed the necessity of sulfated glycans. Furthermore, when spore adherence is inhibited, host cell infection is reduced, indicating a direct association between spore adherence and infectivity. These data show that E. intestinalis specifically adheres to target cells by way of sulfated host cell surface GAGs and that this mechanism serves to enhance infectivity.

  • Developmental Expression of Two Spore Wall Proteins during Maturation of the Microsporidian Encephalitozoon intestinalis
    Infection and immunity, 2001
    Co-Authors: J. Russell Hayman, Stanley F. Hayes, Joseph J Amon, Theodore E. Nash
    Abstract:

    Microsporidia are intracellular eukaryotes that infect many animals and cause opportunistic infections in AIDS patients. The disease is transmitted via environmentally resistant spores. Two spore wall constituents from the microsporidian Encephalitozoon intestinalis were characterized. Spore wall protein 1 (SWP1), a 50-kDa glycoprotein recognized by monoclonal antibody (MAb) 11B2, was detected in developing sporonts and at low levels on the surfaces of mature spores. In contrast, SWP2, a 150-kDa glycoprotein recognized by MAb 7G7, was detected on fully formed sporonts and was more abundant on mature spores than SWP1. Nevertheless, the SWPs appeared to be complexed on the surfaces of mature spores. SWP1 and SWP2 are similar at the DNA and protein levels and have 10 conserved cysteines in the N-terminal domain, suggesting similar secondary structures. The C-terminal domain of SWP2 has a unique region containing 50 repeating 12- or 15-amino-acid units that lacks homology to known protein motifs. Antibodies from mice infected with E. intestinalis recognized SWP1 and SWP2. The characterization of two immunogenic SWPs from E. intestinalis will allow the study of exospore structure and function and may lead to the development of useful tools in the diagnosis and treatment of microsporidiosis.