Epidemiological characteristics and influencing factors of Blastocystis hominis infection among children with diarrhea under five years of age in Guangzhou City / 中国血吸虫病防治杂志

Objective To investigate the prevalence and influencing factors of Blastocystis hominis infection among children with diarrhea under five years of age in Guangzhou City. Methods Children with diarrhea under 5 years of age admitted to Guangzhou Children’s hospital, Guangzhou Maternity and Child Healthcare Hospital and Guangzhou Women and Children’s Medical Center during the period between January 1 and December 31, 2020, were enrolled. Participants’ demographics, living environments and health status were collected using questionnaire surveys. Stool samples were collected from participants and nucleic acid was extracted. B. hominis infection was identified using PCR assay and sequence alignment, and the factors affecting B. hominis infection among children with diarrhea under 5 years of age were identified using univariate analysis and multivariate logistic regression analysis. Results A total of 684 children with diarrhea under 5 years of age were enrolled, including 468 male children and 216 female children, with a mean age of (1.79 ± 1.12) years. The overall prevalence of B. hominis infection was 4.97% [34/684, 95% confidential interval (CI): (3.59%, 6.86%)] among participants, and there was no significant difference in the prevalence of B. hominis infection between children with chronic [7.52% (20/266), 95% CI: (4.92%, 11.33%)] and acute diarrhea [3.35% (14/418), 95% CI: (2.01%, 5.54%)] (χ2 = 5.983, P = 0.014). Multivariate logistic regression analysis identified keeping pet [odds ratio (OR) = 6.298, 95% CI: (2.711, 14.633)], drinking non-tap water [OR = 4.522, 95% CI: (1.769, 11.561)], lactose intolerance [OR = 4.221, 95% CI: (1.043, 17.087)], antibiotic use [OR = 0.125, 95% CI: (0.017, 0.944)] and chronic diarrhea [OR = 2.172, 95% CI: (1.018, 4.637)] as factors affecting B. hominis infection among children with diarrhea under 5 years of age in Guangzhou City. Conclusions B. hominis infections is detected in children with diarrhea under five years of age in Guangzhou City. Improving home environments and pet-keeping hygiene is recommended to reduce the likelihood of B. hominis infection among children.

Molecular detection and subtyping of Blastocystis sp. in pigs in Anhui Province / 中国血吸虫病防治杂志

Objective To investigate the prevalence and subtype distribution of Blastocystis sp. in pigs in Anhui Province. Methods A total of 500 stool samples were collected from large-scale pig farms in Bozhou, Anqing, Chuzhou, Hefei, Fuyang, and Lu’an cities in Anhui Province from October to December 2015. Blastocystis was detected in pig stool samples using a PCR assay based on the small subunit ribosomal RNA (SSU rRNA) gene, and positive samples were subjected to sequencing and sequence analysis. Blastocystis subtypes were characterized in the online PubMLST database, and verified using phylogenetic tree created with the neighbor-joining algorithm in the Meta software. Results The prevalence of Blastocystis infection was 43.2% (216/500) in pigs in 6 cities of Anhui Province, and all pig farms were tested positive for Blastocystis. There was a region-specific prevalence rate of Blastocystis (17.2% to 50.0%) (χ2 = 26.084, P < 0.01), and there was a significant difference in the prevalence of Blastocystis sp. among nursery pigs (39.6%), preweaned pigs (19.1%), and growing pigs (62.3%) (χ2 = 74.951, P < 0.01). Both online inquiry and phylogenetic analysis revealed ST1, ST3, and ST5 subtypes in pigs, with ST5 as the predominant subtype. Conclusion The prevalence of Blastocystis sp. is high in pigs in Anhui Province, with three zoonotic subtypes identified, including ST1, ST3, and ST5.

Progress of researches on Blastocystis hominis infection among patients with inflammatory bowel disease and irritable bowel syndrome / 中国血吸虫病防治杂志

Blastocystis is a common unicellular intestinal protozoa in humans and animals, and the most common clinical manifestations of infections include abdominal pain and diarrhea. Based on the sequence of the small-subunit ribosomal RNA (SSU rRNA) gene, 28 subtypes of B. hominis (ST1 to ST17, ST21 and ST23 to ST32) have been characterized. Previous studies have demonstrated that B. hominis infection is strongly associated with inflammatory bowel disease (IBD), irritable bowel syndrome (IBS) and other intestinal diseases, which threatens the health and quality of life among patients with B. hominis infection and is considered as an important public health problem. This review summarizes the progress of researches on B. hominis infection among IBD and IBS patients during the past 20 years, so as to provide insights into management of blastocystosis in China.

Dinámica de la evolución de las formas de Blastocystis spp. en un medio de cultivo simple / Dynamics of the evolution of the forms of Blastocystis spp. in a simple culture medium

Resumen Blastocystis spp. es un parásito muy frecuente en materia fecal humana, pero la naturaleza polimórfica y el número de Blastocystis en la muestra pueden complicar su detección por microscopía. El objetivo del trabajo fue describir la dinámica de los morfotipos de Blastocystis a corto plazo en un medio de cultivo simple y determinar su aplicabilidad para utilizarlo como complemento del análisis coproparasitológico y para estudios morfológicos, bioquímicos y moleculares del parásito. Se sembraron 10 muestras de materia fecal con Blastocystis en un medio Pavlova adaptado, se examinaron diariamente por examen microscópico durante 6 días y se registraron las formas y el recuento. El desarrollo fue regular y abundante y las formas fueron de tamaños variables y claramente identificables. El cultivo ensayado puede ser útil para la detección de Blastocystis cuando existan dudas diagnósticas por microscopía, para estudios de sensibilidad y especificidad diagnóstica o cuando se requiera aumentar la carga para realizar otros estudios.

Abstract Blastocystis spp. is a very frequent parasite in human fecal matter, but the polymorphic nature and the number of Blastocystis in a sample can complicate its detection by microscopy. The objective of the present work was to describe the dynamics of Blastocystis morphotypes in the short term in a simple culture medium and to determine its applicability to use it as a complement to coproparasitological analysis and for morphological, biochemical and molecular studies of the parasite. Ten stool samples with Blastocystis were cultured in an adapted Pavlova medium and examined during 6 days by microscopy to record the forms and the count. The development was regular and abundant and the shapes were of variable sizes and clearly identifiable. The tested culture could be used for the detection of Blastocystis when microscopic diagnosis is dubious, for studies of diagnostic sensitivity and specificity or when it is necessary to increase the load to perform other studies.

Resumo Blastocystis spp. é um parasita muito frequente nas fezes humanas, mas a natureza polimórfica e o número de Blastocystis na amostra podem complicar a sua detecção através do microscópio. O objetivo do trabalho foi descrever a dinâmica dos morfotipos de Blastocystis no curto prazo em um meio de cultura simples e determinar sua aplicabilidade para ser utilizado como complemento da análise coproparasitológica e para estudos morfológicos, bioquímicos e moleculares do parasita. Foram semeadas dez amostras de fezes com Blastocystis em um meio Pavlova adaptado e examinadas diariamente através de exame microscópico durante 6 dias, registrando as formas e fazendo recontagem. O desenvolvimento foi regular e abundante e as formas foram de tamanhos variáveis e claramente identificáveis. A cultura testada pode ser útil para a detecção de Blastocystis quando houver dúvidas diagnósticas por microscopia; para estudos de sensibilidade e especificidade diagnóstica ou quando for necessário aumentar a carga para a realização de outros estudos.

Análisis retrospectivo de un protozoo emergente en México: Blastocystis spp

Blastocystis spp. es el protista intracelular que en los últimos años ha infectado a más de mil millones de personas a nivel mundial. Sin embargo, el aumento en la prevalencia en México y su potencial patógeno son inciertos, por lo que este microorganismo aún se encuentra bajo investigación. Principalmente a nivel pediátrico, la blastocistosis es estudiada con mayor atención, debido a que destaca sobre otros agentes en diversos estudios realizados mundialmente y en México. El objetivo de este trabajo fue mediante revisión bibliográfica, evidenciar la frecuencia y su transición parasitaria como el agente más prevalente en la actualidad, pese a que no se asocia a sintomatología clínica.

Blastocystis spp. is the intracellular protist that in recent years has infected more than a billion people worldwide. However, the increase in prevalence in Mexico and its pathogenic potential are uncertain, so this microorganism is still under investigation. Mainly at the pediatric level, blastocystosis is studied with greater attention, due to the fact that it stands out over other agents in various studies carried out worldwide and in Mexico. The objective of this work was to show the frequency and its parasitic transition as the most prevalent agent today through a bibliographic review, despite the fact that it is not associated with clinical symptoms.

Eficacia y tolerabilidad de Nitazoxanida para parasitismo intestinal en escolares atendidos en el Centro de Salud de la Universidad del Quindío / Efficacy and tolerability of Nitazoxanide for intestinal parasitism in schoolchildren treated at the Health Center of the University of Quindío

Resumen Objetivo: Describir la efectividad del tratamiento antiparasitario intestinal brindado a niños de cuatro a nueve años atendidos en el centro de Salud de la Universidad del Quindío entre Julio de 2017 a marzo de 2018. Materiales y métodos: Estudio observacional prospectivo. Se extrajeron datos de historias clínicas de pacientes con rango de edad de 4 a 9 años, quienes consultaron en el Centro de Salud de la Universidad del Quindío y se diagnosticaron mediante coprológico con blastocistosis o giardiasis. Se seleccionaron las historias cuyo tratamiento fuese Nitazoxanida y tuviesen un coprológico control postratamiento. Se presentan estadísticas descriptivas; porcentaje de eficacia y tolerabilidad. Resultados: De 15 niños tratados con Nitazoxanida, respondieron al tratamiento 10, en quienes no se hallaron parásitos en el coprológico control. Con una eficacia del 83,3% (IC95% 60 - 100) en blastocistosis, 57,1% (IC95% 32 - 82%) en giardiasis. Conclusión: Se evidenciaron resultados porcentuales similares a los reportados en la literatura, siendo más eficaz en blastocisotisis que en giardiasis.

Abstract Objective: To describe the effectiveness of the intestinal antiparasitic treatment given to children ranging between 4 and 9 years old that were attended in the Health Center of the University of Quindío in the period of July 2017 and March 2018. Materials and methods: Prospective observational study. Data were extracted from medical records of patients with an age range of 4 to 9 years, who consulted at the Health Center of the University of Quindío and were diagnosed through coprological tests with Blastocystis and Giardiasis. The clinical records were selected by whose treatment was done with Nitazoxanide or Albendazole with coprological results of post-treatment check-up. Descriptive statistics are presented along with percentage of efficacy and tolerability. Results: From 15 children treated with Nitazoxanide, 10 responded to the treatment, who presented no parasites in the coprological check-up. The remaining population presented some type of parasitic infection (n = 5). With an efficiency of 83,3% (IC95% 32 - 82%) in blastocystis, and 57,1% (IC95% 32 - 82%) in giardiasis. Conclusion: Percentage results similar to those reported in the literature were evidenced, being more effective in blastocystis than in giardiasis.

Standardization of molecular techniques for the detection and characterization of intestinal protozoa and other pathogens in humans

Background: The intrinsic sensitivity limitations of basic parasitological methods, along with the particular biological characteristics of parasites, make these methods ineffective to differentiate morphologically indistinguishable species. Molecular detection and characterization techniques could be used to overcome these problems. The purpose of this work was to standardize molecular polymerase chain reaction (PCR) techniques, described in the literature, for the detection and molecular characterization of intestinal protozoa and other pathogens in humans. Methods: DNA was extracted from human or animal feces, previously washed or cultured in Boeck Drbohlav's Modified Medium. DNA extraction was performed with Machery-Nagel extraction kits. The standardization of the PCR, nested-PCR or RFLP techniques was carried out according to the literature. For each molecular technique performed, the sensitivity of the test was determined based on the minimun quantity required of DNA (sensitivity A) and the minimum quantity of life forms that the test detected (sensitivity B). Results: Sensitivity A was 10 fg for G. duodenalis, 12.5 pg for Entamoeba histolytica or Entamoeba dispar, 50 fg for Cryptosporidium spp., 225 pg for Cyclospora spp. and 800 fg or 8 fg for Blastocystis spp. after performing a 1780 bp PCR or 310 bp nested PCR, respectively. The sensitivity B was 100 cysts for G. duodenalis, 500 cysts for E. histolytica or E. dispar, 1000 oocysts for Cyclospora spp. and 3600 or four vegetatives forms for PCR or nested PCR of Blastocystis spp., respectively. Conclusions: The molecular detection of protozoa and chromist was achieved and the molecular characterization allowed the genotyping of some of the parasites such as Giardia duodenalis, Cryptosporidium spp., and Blastocystis spp. This study summarizes the molecular techniques for epidemiological studies in humans and animals, and helps in the investigation of their transmission sources in countries where intestinal parasites are a public health problem.(AU)

Identification of α-L-fucosidase (ALFuc) of Blastocystis sp. subtypes ST1, ST2 and ST3

ABSTRACT Blastocystis sp. is a common intestinal microorganism. The α-L-fucosidase (ALFuc) is an enzyme long associated with the colonization of the gut microbiota. However, this enzyme has not been experimentally identified in Blastocystis cultures. The objective of the present study was to identify ALFuc in supernatants of axenic cultures of Blastocystis subtype (ST)1 ATCC-50177 and ATCC-50610 and to compare predicted ALFuc proteins of alfuc genes in sequenced STs1-3 isolates in human Blastocystis carriers. Excretion/secretion (Es/p) and cell lysate proteins were obtained by processing Blastocystis ATCC cultures and submitting them to SDS-PAGE and immunoblotting. In addition, 18 fecal samples from symptomatic Blastocystis human carriers were analyzed by sequencing of amplification products for subtyping. A complete identification of the alfuc gene and phylogenetic analysis were performed. Immunoblotting showed that the amplified band corresponding to ALFuc (~51 kDa) was recognized only in the ES/p. Furthermore, prediction analysis of ALFuc 3D structures revealed that the domain α-L-fucosidase and the GH29 family's catalytic sites were conserved; interestingly, the galactose-binding domain was recognized only in ST1 and ST2. The phylogenetic inferences of ALFuc showed that STs1-3 were clearly identifiable and grouped into specific clusters. Our results show, for the first time through experimental data that ALFuc is a secretion product of Blastocystis sp., which could have a relevant role during intestinal colonization; however, further studies are required to clarify this condition. Furthermore, the alfuc gene is a promising candidate for a phylogenetic marker, as it shows a conserved classification with the SSU-rDNA gene.

Molecular genetic characterization of Blastocystis in primary and middle school students in Baisha Li Autonomous County, Hainan / 中国热带医学

@#Abstract: Objective　To investigate the prevalence and genetic characterization of Blastocystis in primary and middle school students in Baisha Li Autonomous County, Hainan Province, in order to understand the infection status of Blastocystis and its subtype distribution characteristics in this area. Methods　From March to November 2021, fecal samples were collected from two primary and middle schools in Baisha Li Autonomous County. Nested PCR targeting the SSU rDNA was employed in this study, sequence analysis were performed to determine the prevalence and subtype. A neighbor-joining tree was built using Mega 7. Meanwhile, the risk factors of the Blastocystis infection among different grades and genders were evaluated. Results　The infection rate of Blastocystis was 4.1% (13/314), there was no statistical difference in infection rates among genders and grades (P>0.05). Sequence analysis revealed that three Blastocystis subtypes were identified, namely ST3 (n=7), ST7 (n=4) and ST1 (n=2), all of which have zoonotic potential. Conclusions　This is the first report of the identification of Blastocystis in humans in Hainan at the subtype level, and provide the basic data for the prevention and control of Blastocystis in this area. The zoonotic subtypes identified in this area indicated more studies should be taken in humans and various animals, to better evaluate the transmission of Blastocystis and provide scientific support for the prevention and control of Blastocystis.

Blastocystis in captivated and free-ranging wild animals worldwide: a review

@#Blastocystis is the most prevalent eukaryotic gastrointestinal symbiont found in humans and animals worldwide. Increased human infection rates are associated with raising concerns about the involvement of the parasite in public health. Over the last decade, the number of linked epidemiology studies has been prudently grown. Microscopy has been used to detect the presence of protozoan and the advent of molecular techniques has made detection easier. However, due to its limited host specificity and zoonotic potential, animals, either livestock or wildlife animals, may serve as a potential reservoir for Blastocystis infection transmission. The approach utilised in this study aided in understanding the distribution and prevalence of Blastocystis in animals, particularly captivated and free-ranging wild animals worldwide due to increased interest. This review will help comprehend the epidemiological aspects, demographic, subtypes, and the zoonotic potential of Blastocystis in wildlife and captive animals.

Blastocystis spp. y su asociación con otros parásitos intestinales en niños de edad preescolar, estado Sucre, Venezuela / Blastocystis spp. and their association to other intestinal parasites in preschool children from Sucre State, Venezuela

Introducción: Blastocystis spp. es uno de los parásitos intestinales más comunes en el ser humano y su patogenicidad sigue siendo controvertida. Objetivo: Determinar la prevalencia de Blastocystis spp. y su asociación con otros parásitos intestinales a niños en edad preescolar. Métodos: Se procesaron 90 muestras fecales provenientes de niños en edad preescolar. Las técnicas copro-parasitológicas usadas fueron: examen directo con solución salina (0,85 por ciento) y lugol. Se usó la prueba chi cuadrado para demostrar la independencia entre las variables: parasitosis, sexo y edad. Se determinó el índice de afinidad de Fager para establecer las asociaciones entre los principales enteroparásitos identificados. Resultados: Se encontraron 68 niños parasitados, con 75,6 por ciento de prevalencia. No hubo diferencias significativas con respecto a la edad y el sexo (p> 0,05). Los parásitos más comunes fueron: Blastocystis spp. (45,6 por ciento), Endolimax nana (30,9 por ciento), Entamoeba coli (26,5 por ciento), y como único helminto, Enterobius vermicularis (1,5 por ciento). El 42,6 por ciento estuvo monoparasitado y 57,4 por ciento biparasitados. Los índices de afinidad (IAB) y pruebas de "t" efectuadas, señalaron asociación significativa entre Blastocystis spp. y los protozoarios E. nana y E. coli. Conclusiones: Se determina una elevada prevalencia de Blastocystis spp. y especies comensales intestinales, todas indicadoras de contaminación fecal, en que probablemente factores ambientales y socioculturales promueven su transmisión. Este tema debe continuarse y profundizarse por la connotación que ha adquirido este parásito en los debates científicos actuales, tanto en el ámbito nacional como internacional(AU)

Introduction: Blastocystis spp. are among the most common intestinal parasites affecting humans. Their pathogenicity continues to be a topic of debate. Objective: Determine the prevalence of Blastocystis spp. and their association to other intestinal parasites in preschool children. Methods: Analysis was performed of 90 stool samples from preschool children. The coproparasitological techniques used were direct examination with 0.85 percent saline solution and lugol. The chi-square test was used to show the independence between the variables parasitic infection, sex and age. Fager's affinity index was determined to establish associations between the main enteroparasites identified. Results: The study found 68 children infected with parasites, for a 75.6 percent prevalence. There were no significant differences with respect to age and sex (p> 0.05). The most common parasites were Blastocystis spp. (45.6 percent), Endolimax nana (30.9 percent) and Entamoeba coli (26.5 percent). The only helminth found was Enterobius vermicularis (1.5 percent). 42.6 percent of the children were infected with one parasite and 57.4 percent with two. The affinity index (IAB) and t tests performed revealed a significant association between Blastocystis spp. and the protozoa E. nana and E. coli. Conclusions: High prevalence was determined of Blastocystis spp. and intestinal protozoan species, all of which were indicative of fecal contamination. Environmental and sociocultural factors are likely to facilitate their transmission. This topic should continue to be addressed and examined due to the relevance of this parasite in current scientific debate, both nationally and internationally(AU)

Metabolismo intermediario de Blastocystis spp / Intermediate metabolism of Blastocystis spp

Blastocystis es un stramenopile o cromista, pleomórfico no móvil. Se han identificado diecinue-ve subtipos de este organismo (ST1-ST19). Tiene una presencia a nivel mundial. Este microor-ganismo tiene un metabolismo intermediario anaeróbico. Un aspecto interesante de la bioquími-ca de este stramenopile está dado por la presencia de organelas similares a mitocondrias con un conjunto de rutas: cadena de fosforilación oxidativa incompleta, ciclo de Krebs parcial, metabo-lismo de ácidos grasos (anabolismo y catabolismo), metabolismo de aminoácidos y ensamblaje de proteínas con centros hierro/azufre. El tratamiento se ha basado tradicionalmente en metroni-dazol y otros imidazoles. Sin embargo, hay un número creciente de cepas resistentes a esos medicamentos. La reciente obtención del genoma nuclear y los estudios bioquímicos, proteómi-cos, metabolómicos, interactómicos permitirán el desarrollo racional de nuevos fármacos curati-vos. El objetivo de esta revisión es describir el metabolismo de Blastocystis spp

Blastocystis is a stramenopile or chromist, nonmobile pleomorphic. Nineteen subtypes of this organism (ST1-ST19) have been identified worldwide. This microorganism has an intermediate anaerobic metabolism. An interesting aspect of the biochemistry of this stramenopile is given by the presence of mitochondrial-like organelles with a set of pathways: incomplete oxidative phos-phorylation chain, partial Krebs cycle, fatty acid metabolism (anabolism and catabolism), amino acid metabolism and protein assembly with iron / sulfur centers. Treatment has traditionally been based on metronidazole and other imidazoles. However, there are a growing number of strains resistant to these drugs. The recent obtaining of the nuclear genome and the biochemical, proteomic, metabolomic and interactomic studies will allow the rational development of new curative drugs. The objective of this review is to describe the metabolism of Blastocystis spp.

Blastocystis: estudio coproparasitológico, clínico-epidemiológico y de prevalencia de subtipo 3 en pacientes de hospitales de Bahía Blanca, Argentina / Blastocystis: coproparasitological, clinical-epidemiological and prevalence study of subtype 3 in patients from hospitals in Bahía Blanca, Argentina

Resumen Blastocystis es el parásito unicelular del intestino del hombre y de otros animales más prevalente en seres humanos. Presenta gran variedad genética con múltiples subtipos (ST). Aunque se ha asociado a desórdenes intestinales y extraintestinales, su patogenicidad es discutida. Se analizaron 461 muestras de materia fecal de pacientes sintomáticos (n=380) y asintomáticos (n=81) de hospitales de Bahía Blanca, Argentina; se solicitó consentimiento informado y se completó una ficha epidemiológica. Se realizaron análisis coproparasitológicos, morfometría, recuento y tipificación de Blastocystis ST3 por PCR. La población fue: 57,3% de sexo femenino y 42,7% masculino. La prevalencia de Blastocystis fue de 31% y de Blastocystis ST3 62%. Se hallaron formas vacuolares, granulares y quísticas; las vacuolares fueron las más frecuentes. En el 64,8% de las muestras los Blastocystis fueron pequeños y escasos. El 88,4% de los pacientes sintomáticos presentó trastornos gastrointestinales, el 4% urticaria y el 7,6% fiebre, anemia y bajo peso. El 66,7% de los pacientes con urticaria presentó Blastocystis. La presencia de síntomas se asoció significativamente con Blastocystis (p<0,002). No se hallaron asociaciones estadísticas entre Blastocystis, la edad, el sexo, la disponibilidad de agua potable, de cloacas y el contacto con animales. Dentro de los síntomas sólo se encontró asociación estadística de Blastocystis con urticaria (p<0,007). No hubo asociación entre Blastocystis ST3 y sintomatología. Los resultados destacan la alta prevalencia de Blastocystis y de Blastocystis ST3, la necesidad de hacer un coproparasitológico minucioso, su asociación estadística con urticaria y la importancia de no ignorarlo en el proceso salud-enfermedad.

Abstract Blastocystis is the unicellular parasite of the intestine of man and other animals,most prevalent in humans. It has a great genetic variety with multiple subtypes (ST). Although it has been associated with intestinal and extraintestinal disorders, its pathogenicity remains unclear. Four hundred and sixty one stool samples from symptomatic (n=380) and asymptomatic(n=81) patients from hospitals in Bahía Blanca, Argentina were analysed; informed consent was requested and an epidemiological file was completed. Coproparasitological analysis, morphometry, counting and typing of Blastocystis ST3 were performed by PCR. The population was: 57.3% female and 42.7% male.The prevalence of Blastocystis was 31.0% and that of Blastocystis ST3 62%. Vacuolar, granular and cystic forms were found, with vacuolar forms being the most frequent. Blastocystis were small and scarce in 64.8% of the samples. Most of the symptomatic patients (88.4%) presented gastrointestinal disorders, urticaria 4% and fever, anemia and low weight 7.6%; 66.7% of the urticaria patients presented Blastocystis. The presence of symptoms was significantly associated with Blastocystis (p<0.002). No statistical associations were found between Blastocystis, age, sex, availability of drinking water, sewage, and contact with animals. Within the symptoms, only statistical association of Blastocystis with urticaria was found (p<0.007). There was no association between Blastocystis ST3 and symptomatology. The results highlight the high prevalenceof Blastocystis and Blastocystis ST3, the need for a thorough coproparasitology, their statistical association with urticaria and the importance of not ignoring it in the health-disease process.

Resumo Blastocystis é o parasita unicelular do intestino do homem e outros animais, mais prevalente em seres humanos. Apresenta grande variedade genética com múltiplos subtipos (ST). Embora tenha sido associada a distúrbios intestinais e extraintestinais, sua patogenicidade é debatida. Foram analisadas 461 amostras de fezes de pacientes sintomáticos (n=380) e assintomáticos (n= 81) de hospitais de Bahía Blanca, Argentina; foi solicitado consentimento informado e preenchida uma ficha epidemiológica. Foram realizadas análises coproparasitológicas, morfometria, contagem e tipificação de Blastocystis ST3 por PCR. A população era: 57,3% sexo feminino e 42,7% masculino. A prevalência de Blastocystis foi de 31,0% e de Blastocystis ST3 62%. Foram encontradas formas vacuolares, granulares e císticas, sendo as vacuolares as mais frequentes. Em 64,8% das amostras, os Blastocystis foram pequenos e escassos; 88,4% dos pacientes sintomáticos apresentaram distúrbios gastrointestinais, 4% urticária e 7,6% febre, anemia e baixo peso; 66,7% dos pacientes com urticária apresentaram Blastocystis. A presença de sintomas foi associada significativamente com Blastocystis (p˂0,002). Não foram encontradas associações estatísticas entre Blastocystis, a idade, sexo, a disponibilidade de água potável, de esgoto e o contato com animais. Dentro dos sintomas, só foi encontrada associação estatística de Blastocystis com urticária (p˂0,007). Não houve associação entre Blastocystis ST3 e sintomatologia. Os resultados destacam a alta prevalência de Blastocystis e Blastocystis ST3, a necessidade de fazer um coproparasitologico minucioso, sua associação estatística com urticária e a importância de não ignorá-lo no processo saúde-doença.

Dolor abdominal crónico en un niño con Blastocystis hominis: a propósito de un caso / Chronic abdominal pain in a child with Blastocystis hominis: case report

RESUMEN El Blastocystis sp. es un parásito frecuente en el humano, identificado por el laboratorio en muestras de heces fecales. Se presentó el caso de un paciente de 5 años atendido en consulta de Gastroenterología en el Hospital Pediátrico Docente Provincial Eliseo Noel Caamaño, de Matanzas, por presentar dolor abdominal, heces pastosas, náuseas y vómitos desde hacía un año. Llevó tratamiento con ranitidina, omeprazol y domperidona, sin mejoría clínica. Se realizó estudio coproparasitológico en muestras de heces fecales seriadas, con la presencia del Blastocystis hominis. Se indicó tratamiento con metronidazol, sin mejoría clínica, y posteriormente se indicó como alternativa la nitazoxanida. Se evaluó a los 15 días, sin sintomatología y con negativización de las heces fecales seriadas. Resulta frecuente el desconocimiento y la poca importancia que los profesionales sanitarios muestran ante esta infestación, aunque cada vez más se confirma la participación del parásito en manifestaciones clínicas (AU).

ABSTRACT Blastocystis sp. is a frequent parasite in humans, identified in the laboratory in samples of fecal feces. The case of a 5-year-old patient is presented; he assisted the consultation of Gastroenterology in the Provincial Teaching Pediatric Hospital Eliseo Noel Caamaño in Matanzas, suffering abdominal pain, mash feces, nauseas and vomits for one year, and was treated with ranitidine, omeprazole and domperidone without clinical improvement. A coproparasitological study was carried out in serial fecal feces samples with the presence of Blastocystis hominis. Treatment with metronidazole was indicated without clinical improvement and them, as an alternative, nitazoxanide was indicated. He was evaluated at 15 days without symptoms and with negative serial fecal feces. The ignorance and the little importance that health professionals show towards this infestation are frequent, although more and more frequently it is confirmed the participation of the parasite in clinical manifestations (AU).

Molecular characterization of Blastocystis subtypes isolated in the city of Uberaba, Minas Gerais State, Brazil

Abstract INTRODUCTION Blastocystis is an intestinal protozoan that may play a role in the pathogenicity of humans. This study aimed to (i) genetically characterize Blastocystis isolates obtained from human fecal samples and the water supply of the city of Uberaba, Minas Gerais, Brazil, and (ii) to verify the phylogenetic relationship between these isolates. METHODS Blastocystis species present in 26 fecal samples obtained from humans and animals from Uberaba were genetically characterized by polymerase chain reaction-restriction fragment length polymorphism and polymerase chain reaction-sequence-tagged sites. All amplicons were partially sequenced and/or defined according to the GenBank classification. RESULTS Polymerase chain reaction amplicons were generated from 21 human isolates and 18 water samples. The subtypes defined were ST1 (53.3%), ST3 (40.0%), and ST2 (6.7%) for human isolates; ST10 (100%) for bovine isolates; and ST5 (50.0%), ST1 (25%), and ST3 (25%) for pigs. Sequencing of polymerase chain reaction products showed a 98%-99% identity for the Blastocystis sequences deposited in GenBank, except for sequences from water samples that showed the identity of algae sequences. Phylogenetic analysis of Blastocystis sequences showed two distinct groups, one of which was principally formed by ST1, ST5, and ST10, and the other by isolates characterized as ST3 and ST7. Both clades showed human and animal sequences, reinforcing the notion that Blastocystis subtypes are not host-specific. CONCLUSIONS The data showed that Blastocystis subtypes circulating in Uberaba are ST1-ST3, ST5, and ST10, present in both humans and animals, demonstrating that the Blastocystis subtypes are not host-specific; that is, zoonotic transmission is possible.

Current status of research regarding Blastocystis sp, an enigmatic protist, in Brazil

The present study aimed to evaluate the occurrence of Blastocystis sp. in Brazilian studies over a period of years (2000-2020), as well as point out relevant aspects of this enigmatic organism. We performed a literature search using six sources of international databases. The data were divided into diagnostic by parasitological and molecular techniques, and relevant aspects. After applying the inclusion and exclusion criteria, 52 studies were included in the final analysis. The occurrence of Blastocystis sp. in Brazil ranged from 0.5% to 86.6%, as determined using parasitological techniques. The highest occurrence was in the North (27.3%) and the lowest, in the Midwest region (13.4%). In Brazil, most studies have employed molecular techniques and are concentrated in the Southeast region. The Blastocystis sp. subtype ST3 had the highest average positivity, followed by ST1 and ST2. These findings represent a panorama that reflects the reality of Brazil; thus, we believe that the effectiveness of parasitological diagnosis should be considered with regard to making an appropriate choice of technique for detecting Blastocystis sp. Additionally, we emphasize the importance of further studies in the context of molecular epidemiology with regard to this genus. Blastocystis sp. is not well understood yet, and very little information regarding this genus is available; hence, further research regarding this genus is urgently needed.

Study on the mechanisms of the intestinal tight-junction destruction caused by Blastocystis hominis infection in rats / 中国血吸虫病防治杂志

Objective To explore the mechanism of the intestinal barrier damage caused by Blastocystis hominis infections in rats. Methods Thirty SD rats were randomly divided into the control group, and the 1-, 3-, 6- and 9-week-infection groups, of 6 rats in each group. Rats in each infection group were orally infected with B. hominis trophozoites at a density of 2 × 108 parasites per rat, and the control group was given an equal volume of phosphate buffered saline solution. The 7-hour urine samples were collected 1, 3, 6 and 9 weeks post-infection for the measurement of the intestinal permeability. Then, rats were sacrificed using the cervical dislocation method, and the cecum specimens were collected for the detection of the intestinal epithelial cell permeability. The expression of tight junction-related Occludin and Claudin - 1 genes and apoptosis-related Bcl - 2 and Bax genes was quantified in cecum epithelial cells using the real-time fluorescent quantitative PCR (qPCR) assay, and cell apoptosis was detected in the rat cecum using the TdT-mediated dUTP nick-end labeling (TUNEL) assay. Results The median urinary lactolose to mannitol ratios were 0.29, 0.72, 0.44, 0.46 and 0.38 in the control group, and the 1-, 3-, 6- and 9-week-infection groups, respectively, and the difference was statistically significant (H = 12.09, P < 0.05). B. hominis invasion and epithelial injury were observed in intestinal epithelial cells of rats infected with B. hominis, and transmission electron microscopy displayed the destruction of tight junctions between intestinal epithelial cells. The relative expression of Occludin, Claudin-1, Bcl-2 and Bax genes was 1.04, 0.62, 0.71, 0.68 and 0.96; 1.03, 0.61, 0.63, 0.76 and 0.86; 1.08, 0.70, 0.75, 0.74 and 1.03; and 1.00, 1.57, 1.33, 1.35 and 1.10 in the control group and the 1-, 3-, 6- and 9-week-infection groups, respectively, and all differences were statistically significant (F = 2.86, 2.85, 3.37 and 4.45, all P values < 0.05). The median number of positive staining cells were 1.00, 13.00, 9.00, 3.50 and 1.00 in rat cecum specimens in the control group, and the 1-, 3-, 6- and 9-week-infection groups, respectively, and the difference was statistically significant (H = 22.95, P < 0.01). Conclusion B. hominis infection may cause an increase in the rat intestinal permeability through triggering the apoptosis of intestinal epithelial cells to destroy the tight junction between intestinal epithelial cells, thereby destroying the intestinal barrier function.

Molecular subtyping and phylogeny of Blastocystis sp. isolated from turkey (Meleagris gallopavo) populations in Penang, Malaysia

@#Most poultry farms in Malaysia preferred rearing chickens either for eggs or/and meat than turkeys. This is due to several challenges such as parasitic load and heat stress in rearing turkey. Blastocystis is one of the most common protozoan parasites infecting poultry. As no study was conducted on Blastocystis infection in turkey in Malaysia, this study aims to determine the current status, the morphological characteristics and subtyping of Blastocystis from turkey reared either in closed house or free-range system in Penang, Malaysia. It was found that the prevalence of Blastocystis sp. infection in turkeys were moderately high with 41.6% (25/60) in the closed house and 45.0% (45/100) in free-range system as infection was higher in the female turkeys with no gastrointestinal signs and symptoms. Vacuolar form was the most common form found in the in vitro culture ranged between 5 to 20 μm in diameter with a rough surface coat and undulating cell surface viewed under the scanning electron microscope. Meanwhile, the ultrastructure of the cells from turkey isolates were varies with partially expanded electron-opaque vacuoles to electron-dense in fully distended vacuoles. Interestingly, sequence analysis for 30 positive Blastocystis isolates from turkeys revealed one subtypes with three alleles namely, ST7 allele 99 (73.4%, n=22), ST7 allele 100 (23.3%, n=7) and ST7 allele 101 (3.3%, n=1). Findings from this study added to our understanding on Blastocystis infection in turkey production.

Advances in the research of comorbidity of Blastocystis hominis infections and other diseases / 中国血吸虫病防治杂志

Blastocystis hominis is a common intestinal protozoan parasite. Most individuals with B. hominis infections have no apparent clinical symptoms; however, a few patients, notably those with co-infections or impaired immune system function may present abdominal pain, diarrhea, nausea, vomiting, and even death. This paper reviews the co-infections of B. hominis and other pathogens and comorbidity of B. hominis infections and other diseases, so as to provide insights into the management of B. hominis infections.

Prevalencia de protozoarios intestinales y factores asociados en niños 3 a 7 años en la Unidad Educativa del Milenio, parroquia de Quisapincha. Ambato- Ecuador 2018 / Prevalence of intestinal protozoa and associated factors in children 3 to 7 years old at the Millennium Educational Unit, Quisapincha parish. Ambato- Ecuador 2018

La prevalencia de los parásitos intestinales presenta una mayor incidencia en los niños con respecto a los casos de los adultos. Se ha notado un crecimiento sostenido de la ocurrencia de casos de parasitosis en los niños en épocas reciente. Es por ello que el presente estudio presenta como fin estimar la prevalencia y factores asociados de protozoarios intestinales en niños 3 a 7 años en la Unidad Educativa del Milenio, parroquia de Quisapincha. Ambato- Ecuador 2018. Para lo cual el estudio se desarrolló de corte transversal, siendo una investigación de campo, la cual posee un nivel descriptivo. La población estuvo integrada por 79 niños, quienes son estudiantes de la etapa inicial, primero y segundo año de la Unidad Educativa el Milenio y sus 79 representantes. Como técnica de recolección de datos se empleó la encuesta y las muestras biológicas, como instrumentos se utilizó el cuestionario y la prueba de Graham. Como técnica de análisis de datos se contó con la tabulación y el procesamiento de los datos se realizó mediante el programa SPSS statistics 22. El resultado obtenido fue que 58 escolares resultaron parasitados lo que arroja un nivel de contagio del 73,42%, de este porcentaje de infectado los estudiantes masculinos presentan el 41,75% de los casos, mientras que las niñas obtuvieron el 31,62%. Siendo la edad con la mayor prevalencia los 6 años con un porcentaje de casos de 18,98%(AU)

in children compared to adult cases. A sustained growth in the occurrence of parasitic cases in children has been noted in recent times. That is why the present study aims to estimate the prevalence and associated factors of intestinal protozoa in children 3 to 7 years old at the Millennium Educational Unit, Quisapincha parish. Ambato- Ecuador 2018. For which the study was developed in a cross section, being a field investigation, which has a descriptive level. The population was made up of 79 children, who are students of the initial, first and second years of the Millennium Educational Unit and its 79 representatives. The data collection technique used was the survey and biological samples, as instruments the questionnaire and the Graham test were used. As a data analysis technique, tabulation was used and the data was processed using the SPSS statistics 22 program. The result obtained was that 58 schoolchildren were parasitized, which gives a contagion level of 73.42%, of this percentage of infected male students present 41.75% of cases, while girls obtained 31.62% . The age with the highest prevalence being 6 years with a percentage of cases of 18.98%(AU)