RESUMO
Microsporidia, including Encephalitozoon intestinalis, are emerging pathogens which cause opportunistic infections in immunocompromised patients, such as those with AIDS, cancer, the elderly and people on immunosuppressive drugs. Intestinal mucosa (IM) is crucial for developing an efficient adaptive immune response against pathogenic micro-organisms, thereby preventing their colonization and subsequent infection. As immunosuppressive drugs affect the intestinal immune response is little known. In the present study, we investigated the immune response to E. intestinalis infection in the IM and gut-associated lymphoid tissue (GALT) in cyclophosphamide (Cy) immunosuppressed mice, to mimic an immunocompromised condition. Histopathology revealed lymphoplasmacytic enteritis at 7 and 14 days-post-infection (dpi) in all infected groups, however, inflammation diminished at 21 and 28 dpi. Cy treatment also led to a higher number of E. intestinalis spores and lesions, which reduced at 28 dpi. In addition, flow cytometry analysis demonstrated CD4+ and CD8+ T cells to be predominant immune cells, with up-regulation in both Th1 and Th2 cytokines at 7 and 14 dpi, as demonstrated by histopathology. In conclusion, Cy treatment reduced GALT (Peyer's plaques and mesenteric lymph nodes) and peritoneum populations but increased the T-cell population in the intestinal mucosa and the production of pro-and anti-inflammatory cytokines, which were able to eliminate this opportunistic fungus and reduced the E. intestinalis infection.
RESUMO
PURPOSE: Microsporidiosis is an opportunistic infection that produces chronic diarrhoea and cholangiopathy in patients with AIDS, mainly caused by two species of microsporidia, Enterocytozoon bieneusi and Encephalitozon intestinalis. The aim of this work was to develop an integral system for the diagnosis of microsporidiosis of the intestine and biliary tract in HIV-infected patients, comprising microscopic and molecular techniques. METHODS: The study population comprised 143 adult patients of both sexes with diagnosis of HIV infection, with chronic diarrhoea, and with or without HIV-associated cholangiopathy. Stool studies for microsporidia identification of spores were performed on each patient. A video esofagogastroduodenoscopy with biopsy collection was also carried out for routine histology and semi-thin sections stained with Azure II. Species identification was carried out by transmission electron microscopy and/or polymerase chain reaction for the species E. bieneusi and E. intestinalis. RESULTS: Out of the 143 patients a total of 12.6% (n = 18) were infected with microsporidia. Microsporidia species identified in most cases was E. bieneusi (16/18 cases), followed by E. intestinalis (4/18), all of these last ones in coinfection with E. bieneusi. CONCLUSIONS: Clinical, imaging, microscopic and molecular analyses, when applied in a systematic and integrated approach, allow diagnosis and identification of microsporidia at species level in AIDS patients with chronic diarrhoea, and with or without HIV-associated cholangiopathy.
Assuntos
Infecções Oportunistas Relacionadas com a AIDS/microbiologia , Infecções por HIV/complicações , Microsporídios/isolamento & purificação , Microsporidiose/microbiologia , Infecções Oportunistas Relacionadas com a AIDS/etiologia , Adulto , Diarreia/etiologia , Diarreia/microbiologia , Fezes/microbiologia , Feminino , Trato Gastrointestinal/microbiologia , Humanos , Masculino , Microsporídios/classificação , Microsporídios/genética , Microsporidiose/etiologia , Pessoa de Meia-Idade , Adulto JovemRESUMO
Microsporidia, including Encephalitozoon intestinalis, are emerging pathogens which cause opportunistic infections in immunocompromised patients, such as those with AIDS, cancer, the elderly and people on immunosuppressive drugs. Intestinal mucosa (IM) is crucial for developing an efficient adaptive immune response against pathogenic micro-organisms, thereby preventing their colonization and subsequent infection. As immunosuppressive drugs affect the intestinal immune response is little known. In the present study, we investigated the immune response to E. intestinalis infection in the IM and gut-associated lymphoid tissue (GALT) in cyclophosphamide (Cy) immunosuppressed mice, to mimic an immunocompromised condition. Histopathology revealed lymphoplasmacytic enteritis at 7 and 14 days-post-infection (dpi) in all infected groups, however, inflammation diminished at 21 and 28 dpi. Cy treatment also led to a higher number of E. intestinalis spores and lesions, which reduced at 28 dpi. In addition, flow cytometry analysis demonstrated CD4+ and CD8+ T cells to be predominant immune cells, with up-regulation in both Th1 and Th2 cytokines at 7 and 14 dpi, as demonstrated by histopathology. In conclusion, Cy treatment reduced GALT (Peyer’s plaques and mesenteric lymph nodes) and peritoneum populations but increased the T-cell population in the intestinal mucosa and the production of pro-and anti-inflammatory cytokines, which were able to eliminate this opportunistic fungus and reduced the E. intestinalis infection.
RESUMO
Introduction: The hospital water supply is a reservoir of a variety of potentially pathogenic microorganisms that can particularly affect children and immunocompromised patients. Potentially pathogenic Microsporidium spp. have been identified in water. Microsporidiosis is an emerging parasitic and opportunistic infection in immunocompromised patients. Objective and Method: to describe an outbreak of nosocomial diarrhea due to Microsporidium, species Encephalitozoon intestinalis. Results: Seven cases of E. intestinalis associated diarrhea were reported between november 2012 and february 2013, in a unit of immunocompromised patients in L. Calvo Mackenna Children's Hospital. Microsporidium spp. was found in the hospital water supply and water reservoir tank. Secondary cases were transmitted by contact. Control measures included contact precautions, not to use faucet water for hand washing, bottled water for drinking and water reservoir tank sanitation. Conclusions: This research is about a nosocomial outbreak associated with water supply. Water quality in Chilean hospitals is an unresolved issue, especially in immunocompromised patient areas. Compliance of cleaning and disinfection of water supply systems in hospitals must be ensured.
Introducción: Los sistemas de suministro de agua potable de los hospitales constituyen un reservorio de una variedad de microorganismos potencialmente patógenos que pueden afectar especialmente a niños y pacientes inmunocomprometidos. Especies de Microsporidium spp. potencialmente patógenos para el hombre han sido identificadas en el agua potable. La microsporidiosis es una infección parasitaria oportunista en pacientes inmunocomprometidos. Objetivos y Método: Describir un brote de diarrea nosocomial por Microsporidium de la especie Encephalitozoon intestinalis. Resultados: Se registraron siete casos de diarrea por E. intestinalis, entre noviembre de 2012 y febrero de 2013, en una unidad de pacientes inmunocomprometidos del Hospital de Niños Luis Calvo Mackenna, comprobándose la presencia de Microsporidium spp. abundante en el agua potable y estanques del hospital. Los casos secundarios pudieron transmitirse por contacto. Las medidas de control fueron precauciones de contacto, no usar agua de grifos para lavado de manos, ingesta de agua envasada y desinfección de estanques. Conclusiones: Esta investigación corresponde a un brote nosocomial transmitido por agua potable. La importancia de la calidad del agua en los hospitales de nuestro país es un tema no resuelto, especialmente en áreas que atienden pacientes inmunocomprometidos. Debe asegurarse el cumplimiento de limpieza y desinfección de los sistemas de suministro de agua en los hospitales.
Assuntos
Humanos , Água Potável/microbiologia , Infecção Hospitalar/microbiologia , Surtos de Doenças , Microsporídios não Classificados/isolamento & purificação , Chile/epidemiologia , Infecção Hospitalar/diagnóstico , Infecção Hospitalar/epidemiologia , Hospedeiro Imunocomprometido , Microsporídios não Classificados/classificaçãoRESUMO
Microsporidia are a group of intracellular pathogens causing self-limited and severe diseases in immunocompetent and immunocompromised individuals, respectively. A cellular type 1 adaptive response, mediated by IL-12, IFNγ, CD4+, and CD8+ T cells has been shown to be essential for host resistance, and dendritic cells (DC) play a key role at eliciting anti-microsporidial immunity. We investigated the in vitro response of DC and DC precursors/progenitors to infection with Encephalitozoon intestinalis (Ei), a common agent of human microsporidosis. Ei-exposed DC cultures up-regulated the surface expression of MHC class II and the costimulatory molecules CD86 and CD40, only when high loads of spores were used. A vigorous secretion of IL-6 but not of IL-1ß or IL-12p70 was also observed in these cultures. Ei-exposed DC cultures consisted of immature infected and mature bystander DC, as assessed by MHC class II and costimulatory molecules expression, suggesting that intracellular Ei spores deliver inhibitory signals in DC. Moreover, Ei selectively inhibited the secretion of IL-12p70 in LPS-stimulated DC. Whereas Ei-exposed DC promoted allogeneic naïve T cell proliferation and IL-2 and IFNγ secretion in DC-CD4+ T cell co-cultures, separated co-cultures with bystander or infected DCs showed stimulation or inhibition of IFNγ secretion, respectively. When DC precursors/progenitors were exposed to Ei spores, a significant inhibition of DC differentiation was observed without shifting the development toward cells phenotypically or functionally compatible with myeloid-derived suppressor cells. Neutralization experiments demonstrated that this inhibitory effect is IL-6-dependent. Altogether this investigation reveals a novel potential mechanism of immune escape of microsporidian parasites through the modulation of DC differentiation and maturation.
Assuntos
Células Dendríticas/citologia , Células Dendríticas/imunologia , Encephalitozoon/imunologia , Encefalitozoonose/imunologia , Evasão da Resposta Imune/imunologia , Interleucina-6/imunologia , Animais , Antígeno B7-2/biossíntese , Linfócitos T CD4-Positivos/imunologia , Antígenos CD40/biossíntese , Linfócitos T CD8-Positivos/imunologia , Diferenciação Celular/imunologia , Células Cultivadas , Encefalitozoonose/microbiologia , Interferon gama/imunologia , Interferon gama/metabolismo , Subunidade p35 da Interleucina-12/imunologia , Ativação Linfocitária/imunologia , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Esporos Bacterianos/imunologiaRESUMO
Con la finalidad de comparar la prevalencia de Microsporidiosis intestinal en niños con desnutrición severa y niños eutróficos de la Unidad de Recuperación Nutricional del Hospital Chiquinquirá de Maracaibo, Estado Zulia, se realizó la técnica de reacción en cadena de la polimerasa (PCR) para la identificación de Encephalitozoon intestinalis y Enterocytozoon bieneusi en las muestras de heces de 50 niños desnutridos graves y 50 niños eutróficos, cuyas edades fueron estratificadas de la siguiente manera: lactantes menores (0-11 meses), lactantes mayores (12-23 meses), preescolares (2-6 años), y escolares (7 a 12 años). De las especies de microsporidios investigadas, se evidenció Enterocytozoon bieneusi en el 14% de los niños desnutridos graves y 8% en los niños eutróficos, no se obtuvieron amplificaciones para Encephalitozoon intestinalis en los grupos estudiados; al aplicar la prueba estadística X², resultó no significativa para las variables microsporidiosis intestinal y desnutrición. Se concluye que la medida en la que se relacionan la desnutrición, y la microsporidiosis es difícil de esclarecer, ya que la desnutrición es una condición multifactorial y aún no está bien establecido cuál de estos dos factores es la causa y cual la consecuencia.
In order to compare the prevalence of intestinal microsporidiosis in children with severe malnutrition and eutrophic children at the Nutritional Recovery Unit, Chiquinquirá Hospital in Maracaibo, State of Zulia, a chain reaction technique was performed on the polymerase (PCR) to identify Encephalitozoon intestinalis and Enterocytozoon bieneusi in stool samples from 50 healthy and 50 severely malnourished children, whose ages were stratified as follows: younger infants (0-11 months), older infants (12-23 months), preschool (2-6 years) and school children (7-12 years). Of the microsporidia species investigated, Enterocytozoon bieneusi was evident in 14% of severely malnourished children and 8% of the eutrophic children. No amplifications for Encephalitozoon intestinalis were obtained in the groups studied. On applying the chi-square statistical test, the result was not significant for the variables intestinal microsporidiosis and malnutrition. Conclusions are that the extent to which malnutrition and microsporidiosis relate is difficult to clarify, because malnutrition is a multifactorial condition, and it is not yet well established which of these two factors is the cause and which is the consequence.
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Es un hecho conocido que las infecciones oportunistas por protozoos y hongos han aumentado en los últimos años, debido especialmente al aumento de las infecciones por VIH. Cryptosporidium spp., Giardia lamblia y Encephalitozoon intestinalis son protozoos y hongo, respectivamente, mundialmente reconocidos como agentes oportunistas emergentes, responsables de brotes epidémicos provocados por la ingestión de agua potable contaminada, incluso después de una correcta desinfección. La ingestión de estos protozoos puede provocar diferentes grados de enfermedad, entre aguda o leve (población sana) hasta situaciones más graves y agresivas, hasta a veces mortales (pacientes inmunocomprometidos y/o inmunodeprimidos). A pesar de ser responsables de muchos brotes epidémicos, su diagnóstico de laboratorio permanece arduo y trabajoso, incluso utilizando las nuevas técnicas desarrolladas en los últimos años. En esta revisión se resumen las consideraciones generales de estos oportunistas emergentes, así como los métodos de diagnóstico más usuales, incluso los más recientes y específicos.
Epidemiological data, regarding parasitic and fungi opportunist infections, have changed in the last years, especially due to HIV infection. Cryptosporidium spp., Giardia lamblia and Encephalitozoon intestinalis are protozoan and fungi, respectively, worldwide known as opportunistic emergent agents, being responsible by epidemic outbreaks after ingestion of contaminated water, even following a correct disinfection treatment. Its ingestion can cause different effects on individuals health, from light or acute among the healthy population, to serious, aggressive or even deadly among the immunodepressed or immunocompromised patients. Contaminated water ingestion can result in outbreaks but protozoa laboratory diagnosis still remains very laborious, even after the development of more sensitive and specific techniques in the last years. In this paper, a revision of these emergent opportunists, their main characteristics and diagnostic tools are described, including the most recent and specific techniques.
Assuntos
Humanos , Masculino , Feminino , Cryptosporidium , Giardia lamblia , Parasitos/virologia , Fatores Epidemiológicos , FungosRESUMO
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.