Blastocystis sp., Parasite Associated with Gastrointestinal Disorders: An Overview of its Pathogenesis, Immune Modulation and Therapeutic Strategies.

Blastocystis sp. is a unicellular parasitic microorganism commonly found in the gastrointestinal tracts of humans and animals. It causes symptomatic or asymptomatic infection and its route of transmission is via fecal-oral. High prevalence of Blastocystis infection in developing countries is usually due to poor hygiene practices, exposure to animals infected with the parasite and intake of contaminated water or food. Blastocystis infected individuals often suffer from diarrhea, abdominal pain, nausea, and stomach bloating. Even though pathogenicity of Blastocystis is unclear, it is commonly associated with irritable bowel syndrome. In this review, we have analysed the evidence that shows the association between this microorganism and gastrointestinal disorders. There have been a number of studies which showed that the pathogenicity of Blastocystis is related to its different STs. The pathogenicity is speculated to be due to cysteine proteases formation which stimulates mucosal cells to release interleukin-8 which has been associated with extreme dehydration and gut inflammation. In vitro studies on human colonic epithelial cells revealed that incubation of Blastocystis modulated the host immune response by stimulating the formation of pro-inflammatory cytokines and granulocyte macrophage colonystimulating factor. Metronidazole is found to be the first-line drug of choice. Another treatment option is the combination therapy with trimethoprim/sulfamethoxazole.

SURVEY OF HOUSE RAT INTESTINAL PARASITES FROM SURABAYA DISTRICT, EAST JAVA, INDONESIA THAT CAN CAUSE OPPORTUNISTIC INFECTIONS IN HUMANS.

The purpose of this study was to investigate the prevalence of house rat zoonotic intestinal parasites from Surabaya District, East Java, Indonesia that have the potential to cause opportunistic infection in humans. House rat fecal samples were collected from an area of Surabaya District with a dense rat population during May 2015. Intestinal parasites were detected microscopically using direct smear of feces stained with Lugol's iodine and modified Ziehl-Neelsen stains. The fecal samples were also cultured for Strongyloides stercoralis. Ninety-eight house rat fecal samples were examined. The potential opportunistic infection parasite densities found in those samples were Strongyloides stercoralis in 53%, Hymenolepis nana in 42%, Cryptosporidium spp in 33%, and Blastocystis spp in 6%. This is the first report of this kind in Surabaya District. Measures need to be taken to control the house rat population in the study area to reduce the risk of the public health problem. Keywords: zoonotic intestinal parasites, opportunistic infection, house rat, densely populated area, Indonesia

Prevalencia de parasitosis intestinales en unidades educativas de Ciudad Bolívar, Venezuela / Prevalence of intestinal parasites in educational units from Ciudad Bolívar, Venezuela

Introducción: Las parasitosis intestinales a nivel mundial son un problema de salud pública que afecta a los países en las zonas tropicales. Un grupo muy vulnerable a padecer este tipo de infección son los niños. El objetivo de la presente investigación fue determinar la prevalencia general de parásitos intestinales en las Unidades Educativas de Ciudad Bolívar, entre los años 2009 - 2013. Materiales y Métodos: Fueron obtenidos los trabajos de grado sobre el tema del Departamento de Parasitología y Microbiología y así se recolectaron datos sobre edad, sexo, tipo de parasito, especies y asociaciones parasitarias y poder calcular así dicha prevalencia general. Resultados: Se encontró una prevalencia general de 63,1% sin predilección por la edad o sexo. Los tipos de parásitos más prevalentes fueron los protozoarios con 83,5%. Las especies más prevalentes fueron Blastocystis spp con 39,7%, Entamoeba coli con 15,3%, y Giardia intestinalis con 13,4%. Las asociaciones parasitarias más frecuentes Blastocystis sppconEndolimax nana (21,1%) yBlastocystis sppcon Entamoeba coli. (7,4%). Discusión: Los resultados de este estudio guardan relación con estudios realizados a nivel nacional como internacional, con respecto a las prevalencias de parasitosis, el predominio de protozoarios sobre helmintos en los últimos años, y la indistinción de la infección parasitaria con respecto al género. Conclusiones: La prevalencia aquí estudiada a manera general es alta, se recomienda seguir haciendo este tipo de estudios en escuelas para denotar el impacto de estas infecciones en niños y la consecuencia que esto conlleva.

Introduction: The intestinal parasites are a worldwide public health problem that affects countries in tropical and subtropical areas, a very vulnerable group to suffer this kind of infection are children .The objective of this investigation was determine the general prevalence of parasitism intestinal in the Educational Units from Ciudad Bolívar, between the years 2009 - 2013. Materials and Methods: For this were reviewed the degree work’s about intestinal parasitism’s in the Department of Parasitology and Microbiology , ando so data was collected about, age, sex, parasite type, species and parasitic association, and so calculate the general prevalence Results: It was found a general prevalence of 63,1% no predilection for the age or sex. The parasite types more prevalent have be the protozoan with 83, 5%. The species more prevalente heve be Blastocystis spp with 39, 7% Entamoeba coli with 15, 3%, and Giardia intestinalis 13, 4%. The parasitic association most frequent Blastocystis spp / Endolimax nana (21,1%) and Blastocystis spp / Entamoeba coli (7,4%). Discussion: The results of this study relate to the work done at national and international level regarding the prevalence of parasitosis, the predominance of protozoa with respect to helminths, and indistinction of parasitic infection with regard to gender. Conclusions: The prevalence in all years studied here assessed globally is high, it is recommended to keep doing this type of study in schools to denote the impact of these infections in children and the consequences that this entails.

Diagnóstico parasitológico e molecular de enteroparasitos entre crianças residentes e funcionários de uma institução beneficente para menores no município de Niterói-RJ, Brasil / Parasitological and molecular diagnosis of enteroparasites among resident children and employees of a child care institution at Niterói city, RJ, Brazil

Os enteroparasitos são causa importante de agravos à saúde humana e podem interferir de forma significativa no desenvolvimento infantil. Embora as formas de transmissão sejam bemdocumentadas, a desinformação e as precárias condições socioeconômicas de alguns segmentos da população ainda são fatores que contribuem para a manutenção de parasitos no País, viabilizando a transmissão. Este estudo foi realizado entre crianças residentes e funcionários de uma instituiçãofilantrópica religiosa, situada na cidade de Niterói, Rio de Janeiro, consistindo em um ciclo de palestras educativas, seguido da coleta de amostras fecais para diagnóstico coproparasitológico.Foram coletadas 68 amostras fecais frescas e encontrados enteroparasitos em 41 delas (60 por cento),sendo o Blastocystis hominis o parasito mais prevalente (44 por cento). Adicionalmente, sete amostrasforam positivas para o complexo Entamoeba histolytica/E. dispar, sendo uma confirmada como E. histolytica pelo ELISA para pesquisa de coproantígeno. Em 37 amostras de fezes foi pesquisadaa presença de E. histolytica e E. dispar pela técnica de Nested-PCR. Entre essas, 12 (32 por cento) amplificaram um fragmento de 195 pb quando utilizados primers específicos para E. dispar, não havendo amplificação de qualquer produto com os primers de E. histolytica. Estudo feito no entornoda instituição revelou acúmulo de lixo e a presença de saídas de esgoto no peridomicílio, as quais desembocavam nas proximidades da área de lazer das crianças. É possível que esses pontos sejam responsáveis pela contaminação do solo e mesmo incriminados como uma das possíveis fontes deinfestação para as crianças.

Intestinal parasites are important agents of human diseases, besides being responsible for impairingchildhood development. Although transmission is well known, lack of information and precarioussocial and economic conditions are risk factors that allow maintenance of parasite cycles, favoringtransmission. This study was carried out among resident children and employees of a Catholic Institution, located in Niterói, Rio de Janeiro, and consisted of delivering lectures and collectingfresh stool samples, which were processed through the Willis and Hoffman, Pons and Janermethods. Enteroparasites were found in 41 samples (60 percent) and Blastocystis hominis was the mostprevalent (44 percent). Additionally, in seven samples where microscopic examination was positive forthe E. histolytica/E. dispar complex an ELISA was employed to detect E. histolytica and only onereacted positively in the immunoassay. In 37 samples a Nested-PCR was carried out for detectionof E. histolytica and E. dispar and in 12 samples (32 percent) a product with 195 bp was observed usingE. dispar primers, while there was no amplification product with E. histolytica specific primers. As the Institution has a good pattern of hygiene not related with the results, a superficial analysis of its peripheral area was carried out and showed lots of garbage in the neighborhood and sewage outflowinto the play area of the Institution. We concluded that these points may be responsible for the soil contamination and could be incriminated as one of the sources of infection in the children.

Predominance of Blastocystis sp. subtype 4 in rural communities, Nepal.

Blastocystis sp. is a common intestinal parasite. To date, there have been sporadic and scanty studies on Blastocystis sp. carried out in rural communities in Nepal. We surveyed the prevalence of Blastocystis sp. and its possible associated risk factors, and reported the predominant Blastocystis sp. subtype in two rural communities, Bolde Phediche and Bahunipati, in Nepal. Human faecal samples were collected from 241 participants, cultured using in vitro cultivation and examined for Blastocystis sp. The presence of Blastocystis sp. in faecal samples was further confirmed by polymerase chain reaction (PCR) and subsequently genotyped using subtype-specific sequence tagged site (STS) primers. There were 26.1% (63/241) of the participants that were infected by Blastocystis sp. We detected 84.1% (53/63) of Blastocystis sp. subtype 4 infections in these rural communities. The unusually high prevalence of Blastocystis sp. subtype 4 can be attributed to the rearing of family-owned animals in barns built close to their houses. Eighty one percent (51/63) of the Blastocystis sp. infected participants drank not boiled or unfiltered water. The present study revealed that Blastocystis sp. could pose a health concern to the communities and travellers to the hilly area in Nepal. Infection may be transmitted through human-to-human, zoonotic and waterborne transmissions. We provide recommendations to ensure good public health practices.

Algunas consideraciones acerca de Blastocystissp, un parásito controversial / Some considerations about Blastocystis sp, a controversial parasite / Algumas considerações sobre Blastocystis sp, Um parasita controverso

Blastocystis es un organismo unicelular, anaerobio y uno de los parásitos intestinales de mayor prevalencia a nivel mundial. Durante mucho tiempo su ubicación taxonómica fue difícil de definir. Actualmente es considerado el único parásito humano del Reino Chromista. Se le reconocen numerosas formas evolutivas (vacuolares, granulares, ameboidales, avacuolares, multivacuolares y quísticas) que conforman un ciclo vital aún en estudio. Los quistes son las formas de resistencia y transmisión. Se lo considera un parásito zoonótico con 9 subtipos que pueden tener diferentes especificidades entre hospedadores humanos y animales. Su carácter patógeno ha sido motivo también de controversia dado que puede presentar infecciones asintomáticas o sintomáticas con manifestaciones digestivas, y dérmicas, entre otras. El diagnóstico de laboratorio puede ser microscópico o mediante cultivos, serología y técnicas moleculares.

Blastocystis is an anaerobic, unicellular organism and it is one of the most prevalent among intestinal parasites. It has a worldwide distribution. Nowadays, it is considered the only human parasite that belongs to the kingdom Chromista. Many morphological forms of the parasite are known: vacuolar, granular, amoeboid, avacuolar, multivacuolar and cyst. Its life cycle is not completely understood. Cysts are the forms of resistance and transmission. It is considered a zoonotic parasite with 9 subtypes, with different specificities for human and animal hosts. Its pathogenesis is controversial because it can cause asymptomatic and symptomatic infections, with gastrointestinal and cutaneous manifestations. Laboratory diagnosis may be performed by microscopic, cultural, serological and molecular techniques.

Enteroparasitosis en indígenas de la comunidad Japrería estado Zulia Venezuela / Enteroparasites in indigenous individuals from the Japreria community Zulia state Venezuela

Las enfermedades parasitarias representan un problema médico, económico y social, afectando a todas las clases sociales, pero principalmente a los estratos socioeconómicos más bajos. Para determinar la prevalencia de enteroparásitos en la comunidad indígena Japrer¡a, ubicada en la Sierra de Perijá, Estado Zulia, Venezuela, se procesaron 191 muestras fecales correspondientes a individuos de ambos sexos con edades comprendidas entre 1 mes y 86 años. Las muestras fueron analizadas a través de los métodos coproparasitológico directo y por la técnica de concentración formol-éter. Se encontró una elevada prevalencia de enteroparásitos (82,20 por ciento) y un predominio del poliparasitismo (78,98 por ciento), con asociaciones entre especies comensales y patógenas. No se observó diferencia significativa de susceptibilidad entre la prevalencia de parásitos y el sexo (p>0,05). En cuanto al grupo etario, el estrato más afectado resultó ser el de adultos jóvenes (20-39 años; 25,48 por ciento). Las especies de protozoarios mas frecuentes fueron Blastocystis hominis (46,07 por ciento), Entamoeba coli (42,93 por ciento) y el complejo Entamoeba histolytica/Entamoeba dispar (34,0 por ciento). Entre los helmintos, Ancylostomideos (30,89 por ciento), Ascaris lumbricoides (9,95 por ciento) e Hymenolepis nana (4,19 por ciento) ocuparon los primeros lugares. La presencia incrementada de enteroparásitos se relaciona con el escaso saneamiento ambiental en esta comunidad indígena, por lo que los resultados avalan la importancia de diseñar programas de control específicos para disminuir los factores condicionantes presentes, lo cual tendr¡a impacto en el descenso de las infecciones parasitarias.

Colony growth as a step towards axenization of Blastocystis isolates.

Colonies of Blastocystis from non-axenic cultures grown in agar medium were isolated from bacterial colonies. Axenization of human and reptilian isolates of Blastocystis was achieved using antibiotic treatment to lower bacterial numbers, followed by colony growth to isolate pure parasite colonies.