Microscopio and PCR-based detection of microsporidia spores in human stool samples

Abstract Microsporidia are obligate intracellular fungi with a remarkable ability to infect a wide range of invertebrate and vertebrate hosts. Namely, Enterocytozoon bieneusi is the most frequently microsporidia reported worldwide, and mainly associated with chronic diarrea and wasting syndrome in AIDS patients. Microscopy and PCR-based detection techniques are effective for diagnosis and identification of species and genotypes; however, these methods should be standardized in each laboratory. In this study, we performed microscopy and nested PCR techniques with PCR product sequencing to detect E. bieneusi in human stool samples. These techniques, if applied together, might prove useful for diagnosis and future epidemiological studies of intestinal microsporidiosis in Argentina.

Resumen Los microsporidios son hongos intracelulares obligados con una notable capacidad para infectar una amplia gama de hospedadores invertebrados y vertebrados. Enterocytozoon bieneusi es el microsporidio más frecuentemente reportado en todo el mundo, principalmente tricrómicaasociado con diarrea crónica y síndrome debilitante en pacientes con sida. Las técnicas dedetección basadas en microscopía y PCR son útiles para el diagnóstico y la identificación deespecies y genotipos, pero estos métodos deben estar estandarizados en cada laboratorio.En este estudio evaluamos técnicas de microscopía y PCR anidada, con secuenciación de losproductos, para detectar E. bieneusi en muestras de heces humanas. Estas técnicas, usadas con-juntamente, podrían ser útiles para su aplicación en el diagnóstico de microsporidiosis intestinaly para realizar estudios epidemiológicos de esta afección en Argentina.

Occurrence of zoonotic Enterocytozoon bieneusi in cats in Brazil / Ocorrência de Enterocytozoon bieneusi zoonótico em gatos no Brasil

Abstract Enterocytozoon bieneusi is an opportunistic intestinal pathogen that infects humans and a wide variety of animals worldwide. Our aim in this study was to investigate the occurrence of E. bieneusi in a domestic cat population in Campo Grande, Mato Grosso do Sul, Brazil. Sixty fecal samples from diarrheic cats were subjected to polymerase chain reaction (PCR) and the amplicons were sequenced for identification. E. bieneusi was detected in two samples (3.3%), both identified as genotype D. This genotype has already been reported in animals and humans and is considered a zoonotic genotype. Our findings represent the first report of E. bieneusi in domestic cats in Brazil, reinforcing the importance of identifying this agent as a source of infection in animals and humans.

Resumo Enterocytozoon bieneusi é um patógeno intestinal oportunista que infecta humanos e uma variedade de animais em todo o mundo. O objetivo no presente estudo foi investigar a ocorrência de E. bieneusi em uma população de gatos domésticos em Campo Grande, Mato Grosso do Sul, Brasil. Sessenta amostras fecais de gatos diarréicos foram submetidas a reação em cadeia da polimerase (PCR) e os produtos de amplificação foram sequenciados para identificação molecular. E. bieneusi foi detectado em duas amostras (3,3%), ambos identificados como genótipo D. Esse genótipo tem sido relatado em animais e humanos e é considerado um genótipo zoonótico. Nossos resultados representam a primeira descrição de E. bieneusi em gatos domésticos no Brasil, reforçando a importância desse agente como fonte de infecção para animais e humanos.

Enterocytozoon bieneusi detected by molecular methods in raw sewage and treated effluent from a combined system in Brazil

BACKGROUND Enterocytozoon bieneusi are the most common microsporidia associated with different clinical manifestations such as diarrhoea, respiratory tract inflammation and acalculous cholecystitis, especially in immunocompromised patients. Infection usually occurs by ingestion of food and water contaminated with spores, but can also result from direct contact with spores through broken skin, eye lesions, and sexual transmission, depending on the microsporidian species. Although there are reports of E. bieneusi found in humans and animals in Brazil, there are no published studies of environmental samples examined by molecular methods. OBJECTIVES The purpose of this study was to verify the presence of E. bieneusi in raw sewage and treated effluent from a combined system by molecular methods. METHODS Raw sewage and treated effluent samples collected from a combined system were analysed for the presence of E. bieneusi using the internal transcriber spacer (ITS) region of E. bieneusi by nested polymerase chain reaction. FINDINGS The analysis revealed E. bieneusi presence and a novel genotype (EbRB) in one raw sewage sample and one treated effluent. MAIN CONCLUSIONS The presence of E. bieneusi in final effluent indicates that the combined system may not remove microsporidian spores. This study is the first report of E. bieneusi in environmental samples in Brazil.

Molecular Characterization of Enterocytozoon bieneusi in Domestic Rabbits (Oryctolagus cuniculus) in Northeastern China

A study of 426 rabbits from 3 cities in Jilin province (Changchun City and Jilin City) and Liaoning province (Shenyang City) was conducted between May and June 2015. The overall prevalence of E. bieneusi in rabbits was 0.94% (4/426), with 0% (0/116), 1.72% (3/174), and 0.74% (1/136) in Jilin, Changchun, and Shenyang City, respectively. Only 3 farms (farm 1 and farm 3 in Changchun City, farm 8 in Shenyang City) were PCR-positive for E. bieneusi. Moreover, rabbits of more than 6 months (1.72%) had the highest E. bieneusi prevalence, followed by rabbits of 4-6 months (1.26%), 2-3 months (0.58%), and less than 1 month (0%). Analysis of ITS gene of E. bieneusi suggested that all 4 E. bieneusi isolates were genotype D, and were classified as group 1a. The present results first demonstrated the existence of zoonotic E. bieneusi in domestic rabbits in China. Effective control measures should be implemented to prevent E. bieneusi infection in domestic rabbits, other animals, and humans.

Cryptosporidium spp., Giardia intestinalis, and Enterocytozoon bieneusi in Captive Non-Human Primates in Qinling Mountains

Non-human primates (NHPs) are confirmed as reservoirs of Cryptosporidium spp., Giardia intestinalis, and Enterocytozoon bieneusi. In this study, 197 fresh fecal samples from 8 NHP species in Qinling Mountains, northwestern China, were collected and examined using multilocus sequence typing (MLST) method. The results showed that 35 (17.8%) samples were positive for tested parasites, including Cryptosporidium spp. (3.0%), G. intestinalis (2.0%), and E. bieneusi (12.7%). Cryptosporidium spp. were detected in 6 fecal samples of Macaca mulatta, and were identified as C. parvum (n=1) and C. andersoni (n=5). Subtyping analysis showed Cryptosporidium spp. belonged to the C. andersoni MLST subtype (A4, A4, A4, and A1) and C. parvum 60 kDa glycoprotein (gp60) subtype IId A15G2R1. G. intestinalis assemblage E was detected in 3 M. mulatta and 1 Saimiri sciureus. Intra-variations were observed at the triose phosphate isomerase (tpi), beta giardin (bg), and glutamate dehydrogenase (gdh) loci, with 3, 1, and 2 new subtypes found in respective locus. E. bieneusi was found in Cercopithecus neglectus (25.0%), Papio hamadrayas (16.7%), M. mulatta (16.3%), S. sciureus (10%), and Rhinopithecus roxellana (9.5%), with 5 ribosomal internal transcribed spacer (ITS) genotypes: 2 known genotypes (D and BEB6) and 3 novel genotypes (MH, XH, and BSH). These findings indicated the presence of zoonotic potential of Cryptosporidium spp. and E. bieneusi in NHPs in Qinling Mountains. This is the first report of C. andersoni in NHPs. The present study provided basic information for control of cryptosporidiosis, giardiasis, and microsporidiosis in human and animals in this area.

Prevalencia de Encephalitozoon intestinalis y Enterocytozoon bieneusi en pacientes VIH positivos de Maracaibo, Venezuela / Prevalence of Encephalitozoon intestinalis and Enterocytozoon bieneusi in HIV positive patients to Maracaibo, Venezuela

Los microsporidios pueden provocar infecciones emergentes y oportunistas en individuos inmunocomprometidos de todo el mundo. Se realizó éste estudio para identificar las especies de microsporidios intestinales presentes en pacientes con VIH-SIDA del Servicio Autónomo Hospital Universitario de Maracaibo (SAHUM). Se recolectaron 50 muestras fecales de individuos con diagnóstico confirmado de VIH durante los años 2007-2008; se obtuvieron las cifras de CD4 de solo 42 pacientes. Las muestras se analizaron mediante PCR separadas para la identificación de Encephalitozoon intestinalis y Enterocytozoon bieneusi. Las especies de microsporidios presentaron un 36% de prevalencia, 10 pacientes presentaron Encephalitozoon intestinalis, 4 Enterocytozoon bieneusi y 4 ambas especies. Se determinó una relación inversamente proporcional y estadísticamente significativa entre el contaje de CD4 y la presencia de microsporidios en la muestra fecal. Es destacable la elevada prevalencia de especies de microsporidios observada en los pacientes VIH estudiados, donde predominó E. intestinalis.

Microsporidioses are considered emerging and opportunistic infections in immunocompromised individuals worldwide. The purpose of this study was to identify the species of intestinal microsporidia in patients with HIV-AIDS from the Servicio Autónomo Hospital Universitario de Maracaibo, Venezuela (SAHUM). Fecal samples were collected from 50 patients with confirmed diagnosis of HIV, during the years 2007 and 2008; the CD4 values were obtained from 42 patients. The samples were analyzed by separate PCRs to identify Encephalitozoon intestinalis and Enterocytozoon bieneusi. Microsporidia species showed a 36% prevalence: ten patients had Encephalitozoon intestinalis, four Enterocytozoon bieneusi and four both species. An inverse and statistically significant relationship between the CD4 count and the presence of microsporidia in the fecal sample was also found. It is remarkable the high prevalence of microsporidia species observed in the HIV patients studied, with a predominance of E. intestinalis.

Contribution of multiplex real time PCR for detection and differentiation of Enterocytozoon bieneusi and Encephalitozoon intestinalis in fecal samples of immunocompromised patients

Intestinal microsporidiosis is among the most frequent opportunistic diseases in immunocompromised patients. Routine diagnosis is generally performed by light microscopy of stained fecal samples. While unequivocal non-molecular species identification, important for cases management, is achievable only through electron microscopy. This study aimed to evaluate the contribution of multiplex real time PCR for simultaneous detection and differentiation of Enterocytozoon bieneusi and Encephalitozoon intestinalis in stool specimens of patients with immunosuppressive conditions. Stool samples were obtained from 78 immunocompromised patients suffering from diarrhea. The samples were screened for intestinal microsporidiosis by light microscopy using Weber's modified trichrome stain. The samples were subjected to multiplex real time PCR using Enterocytozoon bieneusi [E. bieneusi] primers and a probe specific on the internal transcribed spacer [ITS] sequence. Encephalitozoon intestinalis [E. intestinalis] primers and probe were specific for the small ribosomal subunit RNA gene sequence. Of 78 samples, 20 [25.6%] were detected positive by multiplex real time PCR. E. intestinalis was identified in 8 cases [40%], E. bieneusi in 7 [35%], and both species in 5 [25%]. Light microscopy detected a total of 22 samples [28.2%], 7 of which did not show the belt-like structure characteristic for microsporidial spores [empty-looking spores]. Compared to real time PCR, light microscopy had 75% sensitivity, 87.9% specificity, 68.2% PPV, 91.1% NPV and 84.6% accuracy in detection of microsporidia. No significant difference was found regarding the detection of E. intestinalis, E. bieneusi or both species by microscopy. Multiplex real time PCR proved to be more effective than classical trichrome stain for simultaneous identification and differentiation between E. bieneusi and E. intestinalis

Prevalence des infections opportunistes digestives parasitaires a Kinshasa (Republique Democratique du Congo). Resultats d'une enquete preliminaire chez 50 patients au stade SIDA

En Republique Democratique du Congo (RDC); comme dans de nombreux pays africains; le sida et son cortege d'infections opportunistes sont une cause majeure de morbidite et de mortalite. A Kinshasa; on estime entre 4 et 5le taux de prevalence de sujets infectes par le VIH; soit plus de 200 000 personnes (chiffres du Programme National de Lutte contre le Sida; PNLS 2005). A ce jour; faute de personnels formes et de moyens diagnostiques adaptes; aucune enquete n'a encore ete menee sur la prevalence des parasites opportunistes digestifs dans la population des patients infectes par leVIH; prealable indispensable a la mise en place d'une politique de soin adaptee. Une enquete preliminaire a ete realisee a Paris sur 50 echantillons de selles de 50 patients malades du sida; hospitalises dans 3 hopitaux de references de Kinshasa. Onze patients (22) avaient une symptomatologie digestive avec un syndrome diarrheique. La realisation des examens specialises a mis en evidence 2 cas d'infection digestive par des parasitoses opportunistes (4); une a Cryptosporidium sp. et une a Enterocytozoon bieneusi; premier cas decrit dans la litterature en RDC

Prevalence des infections opportunistes digestives parasitaires a Kinshasa (Republique Democratique du Congo); resultats d'une enquete preliminaire chez 50 patients au stade sida

En Republique Democratique du Congo (RDC); comme dans de nombreux pays africains; le sida et son cortege d'infections opportunistes sont une cause majeure de morbidite et de mortalite. A Kinshasa; on estime entre 4 et 5le taux de prevalence de sujets infectes par le VIH; soit plus de 200 000 personnes (chiffres du Programme National de Lutte contre le Sida; PNLS 2005).A ce jour; faute de personnels formes et de moyens diagnostiques adaptes; aucune enquete n'a encore ete menee sur la prevalence des parasites opportunistes digestifs dans la population des patients infectes par leVIH; prealable indispensable a la mise en place d'une politique de soin adaptee. Une enquete preliminaire a ete realisee a Paris sur 50 echantillons de selles de 50 patients malades du sida; hospitalises dans 3 hopitaux de references de Kinshasa. Onze patients (22) avaient une symptomatologie digestive avec un syndrome diarrheique. La realisation des examens specialises a mis en evidence 2 cas d'infection digestive par des parasitoses opportunistes (4); une a Cryptosporidium sp. et une a Enterocytozoon bieneusi; premier cas decrit dans la litterature en RDC

Detection of Enterocytozoon bieneusi (Microsporidia) by polymerase chain reaction (PCR) using species-specific primer in stool samples of HIV patients.

BACKGROUND & OBJECTIVE: Microsporidia are obligate intracellular parasites causing infections predominantly in immunocompromised patients. Enterocytozoon bieneusi is the most important microsporidian causing chronic diarrhoea in AIDS patients. The current method used for diagnosing the microsporidia spores is based on light microscopy using stained smears, which do not differentiate spores at species level. The present study was undertaken to detect microsporidia and confirm at species level (E. bieneusi) by PCR from stool samples of HIV positive patients. METHODS: During September 2002 to April 2003, stool samples from 153 HIV-positive patients (with chronic diarrhoea n = 105; without diarrhoea n=48) were collected and examined microscopically for microsporidia spores using modified Weber's chromotrope stain. Stool samples were subjected to PCR assay using species-specific primer EBIEFI/EBIER1, which amplifies small subunit ribosomal RNA (SSU rRNA) of this microsporidian RESULTS: A total of 10 HIV positive patients with chronic diarrhoea were positive for microsporidia by microscopic analysis and confirmed as Enterocytozoon bieneusi by PCR. No false positive results were observed. A diagnostic DNA fragment of 607 bp of the unique SSU rRNA was amplified from all samples infected with E. bieneusi. INTERPRETATION & CONCLUSION: The study revealed that polymerase chain reaction is a useful tool for accurate species identification of microsporidia in stool samples, which serves the benefit of treatment to the patients.

Effects of intestinal protozoa infection on gastrointestinal transit and contractility in experimental Animals

Three groups of animals, each was orally infected with Cryptosporidium parvum oocysts, Enterocytozoon bieneusi spores or Cyclospora cayetanensis oocysts, were included in this study. At the time peak of colonization of infected animals, each group and its corresponding control were infused orally with radioactive isotope. Gastric emptying of isotope was significantly greater in infected compared with the controls in both fasted and fed states to determine the effect of each parasite on the contractility of longitudinal and circular muscle. Isometric tension of jejunal segments was recorded. The development of active tension with stretch and the dose-response curve were significantly increased in the longitudinal muscle of the infected animals compared with the controls. The circular smooth muscle did not show an increase in contractility. The results suggested that an altered gastrointestinal transit and smooth muscle contractility may be involved in the intestinal protozoa infections pathophysiology

Microsporidiosis intestinal: una visión integral / Intestinal microsporidiasis: an integral vision

La microsporidiosis intestinal es la infección del tracto digestivo alto, Enterocytozoon bieneusi y Encephalolytozoon intestinalis, pertenecientes al phylum Microspora, que en el hospedero inmunocomprometido especialmente con el síndrome de inmunodeficiencia adquirida (SIDA), produce cuadros de diarrea prolongada y malabsorción. Se revisarán sus aspectos históricos, biológicos, fisiopatológicos, inmunológicos, epidemiológicos, clínicos y de tratamiento. Método: para la elaboración de esta revisión se emplearon las bases de datos Medline y Pubmed a partir de 1981 hasta la fecha

Enterocytozoon bieneusi (microsporidia) in faecal samples from domestic animals from Galicia, Spain

In this survey we examined 87 domestic animal stool samples in order to detect the possible presence of microsporidia in animals in close contact with humans in Galicia (NW, Spain). The detection of Enterocytozoon bieneusi spores was confirmed in faecal samples from two dogs and one goat by polymerase chain reaction. None of the positive samples for microsporidia in the staining method were amplified with species-specific primers for Encephalitozoon intestinalis, E. hellem and E. cuniculi. Four rabbits faecal samples reacted with anti-E. cuniculi serum. Our results could indicate the importance of domestic animals as zoonotic reservoirs of microsporidial human infections

Using pig biliary system, in vivo propagation of Enterocytozoon bieneusi, an AIDS-related zoonotic pathogen

A microsporidian parasite Enterocytozoon bieneusi is the most common microorganism recognized in AIDS patients, and slow scientific progress is attributed to our inability to propagate the parasite. We report upon the development of a system of propagation using the pig biliary system. The parasite spores were continuously detected in the bile samples post onset of spore shedding in the gall bladder, which suggests that this organism maintain persistent infection in the biliary system and that the hepatobiliary tree may represent a reservoir of infection. In conclusion the biliary tree is an adequate niche for the propagation of E. bieneusi. This work has also resulted in the development of a procedure of ultrasound-guided cholecystocentesis for aspirating biles. This is a simple and non-surgical procedure, and creates no signs of clinical complications in the livers and the gall bladders after dozens of separate attempts. Thus, this is a very useful and safe technique for the aspiration of bile from live animals.