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In the present study, we compared the genetic variability of fragments from the internal transcribed spacer region (ITS) and the small subunit ribosomal DNA (SSUrDNA) as nuclear markers, in contrast with the ribosomal protein large two (rpl2) loci, placed in the mitochondrion-related organelles (MROs) within and among human fecal samples with Blastocystis. Samples were analyzed using polymerase chain reaction (PCR)-sequencing, phylogenies, and genetics of population structure analyses were performed. In total, 96 sequences were analyzed, i.e., 33 of SSUrDNA, 35 of rpl2, and 28 of ITS. Only three subtypes (STs) were identified, i.e., ST1 (11.4%), ST2 (28.6%), and ST3 (60%); in all cases, kappa indexes were 1, meaning a perfect agreement among ST assignations. The topologies of phylogenetic inferences were similar among them, clustering to each ST in its specific cluster; discrepancies between phylogeny and assignment of STs were not observed. The STRUCTURE v2.3.4 software assigned three subpopulations corresponding to the STs 1-3, respectively. The population indices were consistent with those previously reported by other groups. Our results suggest the potential use of the ITS and rpl2 genes as molecular markers for Blastocystis subtyping as an alternative approach for the study of the genetic diversity observed within and between human isolates of this microorganism.
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Blastocystis sp. is a common eukaryotic microorganism that colonizes the intestinal tract of several animals, including humans, although its role as a pathogen is still unclear. In the present study, we report the prevalence and risk factors associated with Blastocystis infection in scholars from a rural community in Mexico. A cross-sectional observational study was carried out on schoolchildren aged 3 to 15 years old; fecal samples were analyzed by culture, Faust technique, and molecular analysis. In addition, a structured questionnaire was applied to identify possible risk factors. Of the 177 samples obtained, Blastocystis sp. was the microorganism that presented the highest frequency (n=78, 44%), and included the following subtypes (STs): ST1 (n=43, 56.5%), ST2 (n=18, 23.6%), and ST3 (n=15, 19.7%); Blastocystis STs were not identified in two cases. No associating factors were found between Blastocystis infection or among STs vs. symptoms. During bivariate analysis, no statistically significant risk factors were found, except for the variable of "eating sweets, snacks, and handmade food on the way home" (p=0.04). Therefore, it is plausible to conclude that schoolchildren become infected with Blastocystis sp. mainly outside their homes, perhaps by eating contaminated handmade food on their way to or from school; however, this variable should be evaluated in detail in future studies.
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Infecciones por Blastocystis , Blastocystis , Animales , Humanos , Niño , Preescolar , Adolescente , Blastocystis/genética , Infecciones por Blastocystis/epidemiología , Población Rural , México/epidemiología , Estudios Transversales , Heces , Prevalencia , Factores de Riesgo , Filogenia , Variación GenéticaRESUMEN
Infection with Blastocystis sp. has been reported in free-living and captive non-human primates (NHPs); however, surveys on Blastocystis sp. from north-western South America are scarce. This study aimed to identify Blastocystis sp. in free-ranging NHPs living in Colombia. A total of 212 faecal samples were collected from Ateles hybridus, Cebus versicolor, Alouatta seniculus, Aotus griseimembra, Sapajus apella, and Saimiri cassiquiarensis. Smears and flotation were used for morphological identification. For samples microscopically classified as positive for Blastocystis sp., we used conventional PCR to amplify and sequence two regions of the SSU rRNA gene and used Maximum Likelihood methods and Median Joining Network analyses for phylogenetic analyses. Via microscopy, 64 samples were Blastocystis sp. positive. Through molecular analyses, 18 sequences of Blastocystis sp. subtype 8 (ST8) were obtained. Strain and allele assignment together with a comparative phylogenetic approach confirmed that the sequences were ST8. Alleles 21, 156, and 157 were detected. Median Joining network analyses showed one highly frequent haplotype shared by specimens from Colombia and Peru and close relationships between haplotypes circulating in NHPs from Colombia, Ecuador, Brazil, and Mexico. This survey could support the elaboration of a more accurate epidemiological picture of the Blastocystis sp. infecting NHPs.
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Blastocystis sp. is a widespread microorganism that colonizes the intestinal tract of several animals, including human beings, while its pathogenic role in humans is still under debate. The objective of the present study was to describe the frequency of Blastocystis sp. subtypes (STs) and their genetic variation within and among samples recovered from scholars inhabiting two rural villages with tropical climates and compare this information with previously documented data from arid and temperate zones in Mexico. Blastocystis sp. positive samples and ST identification were achieved by coprological analysis screening and Polymerase Chain Reaction-sequencing, respectively. Classical population genetics indexes (nucleotide diversity (π), haplotype polymorphism (θ), gene flow (Nm), genetic differentiation (ST), and Tajima's D) were calculated by comparing the sequences here obtained (n = 42) and those from previous studies from the arid (n = 80) and temperate (n = 61) climates from Mexico. Although Blastocystis sp. was the parasite most frequently found between 33% and 26% in both communities, only STs 1-3 were found. Haplotype network inference of Blastocystis sp. STs showed different haplotype profiles among STs vs. climate zones, although no specific haplotypes were identified for any particular climatic zone. Population genetics indexes showed different values within STs and climate zones (π and θ values ranged from 0.004 to 0.147; Nm > 4 and ST from 0.006 to 0.12). Our results show that Blastocystis sp. subtypes exhibit a different genetic variability profile according to the climate zone, suggesting a balancing process between the genetic variability within the Blastocystis sp. subtype and the number of haplotypes identified in each climate.
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Infecciones por Blastocystis , Blastocystis , Animales , Humanos , Blastocystis/genética , Infecciones por Blastocystis/epidemiología , Infecciones por Blastocystis/parasitología , Variación Genética , Heces/parasitología , Haplotipos , FilogeniaRESUMEN
The enteric protist Blastocystis has a worldwide distribution, however its prevalence in the human population is still underestimated, especially in developing countries where proper diagnosis is not performed in the routine of clinical laboratories. In this study, we aimed to assess the frequency, genetic diversity, and spatial distribution of Blastocystis isolates detected in fecal samples referred to a clinical laboratory for routine examination in inner São Paulo State, Brazil. A total of 348 leftover stool samples available for disposal from female and male individuals with age ranging from 3 months to 88 years were analyzed by both microscopic examination and PCR/sequencing of the SSU rRNA gene. The overall frequency of Blastocystis sp. was 31% (108/348), including 20.1% (70/348) and 31% (108/348) by microscopic examination and PCR/sequencing, respectively. Significant association was found only between Blastocystis infection and age, since the highest rate of positive samples was detected among 5-9 years old individuals (p < 0.0001). In addition, spatial distribution revealed a wide distribution of the positive samples, however they were densely concentrated in more populated areas. Seven subtypes were identified, namely ST1 (40.7%), ST2 (9.2%), ST3 (45.3%), ST4 (0.9%), ST6 (1.8%), ST7 (0.9%) and ST9 (0.9%). The intra-subtype analysis revealed a total of 25 different alleles previously reported. Here, the findings lead us to highlight the following aspects: (1) the identification of a ST9 isolate is a relevant finding since it is considered a very rare subtype in human infections as well as this is the first report in Brazil; (2) the high frequency of Blastocystis in fecal samples submitted for examination in a clinical laboratory points to the need to consider its search in routine parasitological examinations, (3) the spatial distribution of Blastocystis infection was not homogeneous but concentrated in more populated areas where the access for population to diagnostic services in healthcare is likely to be easier and, (4) the genetic variability of Blastocystis isolates suggests exposure of inhabitants living in inner municipalities to different sources of contamination involving anthroponotic and zoonotic transmission pathways.
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Infecciones por Blastocystis , Blastocystis , Blastocystis/genética , Infecciones por Blastocystis/diagnóstico , Infecciones por Blastocystis/epidemiología , Brasil/epidemiología , Niño , Preescolar , ADN Protozoario/genética , Heces , Femenino , Variación Genética , Humanos , Laboratorios Clínicos , Masculino , Filogenia , PrevalenciaRESUMEN
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.
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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.
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Humanos , Infecciones por Blastocystis/diagnóstico , Infecciones por Blastocystis/epidemiología , Blastocystis/genética , Filogenia , Variación Genética , Brasil/epidemiología , Prevalencia , ADN Protozoario , HecesRESUMEN
Blastocystis sp. is a commonly reported intestinal parasite with a worldwide distribution. Phylogenetic analyses describe at least 17 subtypes for this parasite, and nine of them have been found in humans. However, the prevalence and some epidemiological characteristics of this parasitic infection in rural communities are not well known. The objective of this cross-sectional study was to evaluate the prevalence, subtypes, and epidemiological factors related to Blastocystis sp. Infection in children from of a small rural community in the central area of Panama. For this, 66 fecal samples from children (1 to 12â¯years old), were initially analyzed for the presence of parasites by a formalin-ethyl acetate/concentration method. Molecular detection and identification of Blastocystis sp. subtypes were carried out by amplification and sequencing of a partial fragment of the small-subunit ribosomal RNA gene. Using data from a questionnaire, analyses of epidemiological conditions potentially associated with Blastocystis sp. transmission were also conducted. Microscopic diagnostics showed that 33.3% (22/66) of the analyzed samples presented entero-parasites. Among them, Blastocystis sp. was the most prevalent, with 21.2% (14/66), followed by the E. histolytica/dispar/moshkovskii complex 4.5% (3/66), Giardia lamblia 1.5% (1/66) and Strongyloides stercoralis 1.5% (1/66). PCR-based analyses detected a prevalence of Blastocystis sp. infection of 74.2% (49/66) in apparently healthy children. Phylogenetic analysis revealed two different subtypes of this parasite: ST1 with 42.2% (28/66) infected, and ST3 with 31.8% (21/66) infected. In addition, recent diarrhea was significantly associated with Blastocystis sp. infection. None of the other risk factors evaluated was statistically associated with infection. These results highlight the need to further investigate clinical, epidemiological, and genetic characteristics of Blastocystis sp. infections in this community.
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Blastocystis sp. is an intestinal protozoan commonly found in fecal samples of many animal species, including humans, but poorly studied in transplant candidates. The aim of this study was to evaluate the occurrence and molecular identification of Blastocystis sp. in fecal samples from transplant candidates. A polymerase chain reaction was performed using specific primers for Blastocystis ribosomal DNA. The DNA sequences obtained were aligned and compared with other sequences from the GenBank and MLST databases. The analyzed samples showed a positivity of 16% (24 of 150) for Blastocystis sp. The highest occurrence was observed in renal transplant candidates (31.4%), followed by hepatic transplant candidates (10.4%) and candidates for bone marrow transplantation (5.9%). Subtype (ST) 3 (45.8%) was the most prevalent among the isolates, followed by ST1 (37.5%), ST2 (12.5%), and ST7 (4.2%). This is the first study of molecular identification Blastocystis sp. in transplant candidates. Our results confirmed that ST3 was the most common subtype in transplant candidates and reinforce the importance of new studies to investigate of Blastocystis sp. in these patients.
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Blastocystis sp. is described as an enteric protist prevalent in fecal samples from humans and animals; its pathogenicity and epidemiology are still controversial. Currently, it has been associated with intestinal diseases such as irritable bowel syndrome and clinical manifestations of allergic skin, such as chronic urticaria. In the context of urticaria, it is still uncertain whether this organism is directly related to the allergic manifestation or just a common component of the intestinal microbiota. This study aimed to evaluate the occurrence and molecular diversity of Blastocystis sp. in individuals with urticaria from a dermatology outpatient clinic, São Paulo, Brazil. Fecal samples of 58 patients with urticaria were examined using parasitological methods; and subsequently tested by polymerase chain reaction using Blastocystis-specific primers. The subtypes (STs) and alleles (a) were determined using BLASTn and MLST tools. ST1, ST2, ST3, ST4, ST6 and mixed infection (ST1 + ST3) were identified in the patients with urticaria; ST1 (a4), ST3 (a34 and a36) and ST4 (a42) were the most prevalent. Our molecular analyses allowed an initial description of Blastocystis subtypes in patients with urticaria from São Paulo city, Brazil.
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Blatocystis sp. un parásito unicelular, anaerobio y de gran variabilidad genética del intestino de animal y del ser humano de distribución mundial y el de mayor prevalencia entre las zoonosis intestinales que ha estado inmerso en controversias y revisiones por su taxonomía, características morfológicas, ciclo de vida y papel patógeno. Por tanto, el objetivo del presente escrito es la consolidación de información sobre estos y otros aspectos de Blatocystis sp. producto de la revisión de la literatura científica. Se trata de un estudio documental. Los datos encontrados fueron agrupados en 8 capítulos a saber: tipificación, comportamiento epidemiológico, ciclo de vida y morfología parasitaria, patogenia, manifestaciones clínicas, diagnóstico, tratamiento y reflexiones finales. En esta revisión se actualizan aspectos relativos a Blatocystis sp. con el objeto de mostrar las tendencias del conocimiento sobre esta parasitosis como base esencial de las estrategias de promoción y prevención que adoptan los países contra Blatocystis sp.
Blastocystis sp. a single-celled, anaerobic parasite of great genetic variability in the intestine of animals and humans of worldwide distribution and the one with the highest prevalence among intestinal zoonoses that has been immersed in controversies and reviews due to its taxonomy, morphological characteristics, life cycle and role pathogen. Therefore, the objective of this paper is the consolidation of information on these and other aspects of Blastocystis sp. product of the review of the scientific literature. It is a documentary study. The data found were grouped into 8 chapters: typification, epidemiological behavior, life cycle and parasitic morphology, pathogenesis, clinical manifestations, diagnosis, treatment and final reflections. In this review, aspects related to Blastocystis sp. in order to show the current trends of knowledge about this parasitism as an essential basis of the promotion and prevention strategies that countries adopt against Blastocystis sp.
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Enteroparasitosis presents high prevalence in developing countries, and is frequent among children, and those with disabilities present even higher susceptibility. The present study evaluated 156 children with neurological disorders to whose parents or guardians an epidemiological questionnaire was applied with a view to identifying risk factors. Stool samples were processed using Ritchie modified by Young, Faust et al., Lutz and Baermann-Moraes techniques. Thirteen samples (8.3%) were positive, being Blastocystis sp. the most frequent parasite (46.2%). Higher positivity was observed for protozoa, especially non-pathogenic. A statistically significant association was only found between the educational level of the mother and positivity for enteroparasites. Among positive children, the habit of placing their hands and objects in their mouths and the consumption of raw vegetables was more frequent. The results show the existence of care and sanitation minimizing the acquisition of intestinal parasite diseases. It is important to alert parents and caregivers about personal hygiene, water and food quality, as well as the environment, considering that transmission of these parasites occurs via the fecal-oral route, in association with multiple factors.
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Trastornos del Neurodesarrollo , Parásitos , BlastocystisRESUMEN
Blastocystis sp. es uno de los parásitos del humano más frecuentemente identificados en el laboratorio clínico durante el estudio parasitológico de las muestras de heces. En esta revisión se actualizan los aspectos relativos a la diversidad genética y especificidad del huésped, la taxonomía, caracterización molecular, formas clínicas y experiencia terapéutica en pacientes inmuno-competentes y comprometidos, sintomáticos y asintomáticos, de la consulta de la Sección de Geohelmintiasis del Instituto de Medicina Tropical de la Facultad de Medicina de la Universidad Central de Venezuela, proponiendo el secnidazol como droga de primera elección. Se analiza la presencia de Blastocystis como patógeno humano o como comensal, formando parte de la microbiota intestinal. Se considera la tendencia actual entre los diferentes grupos de investigación a mirar la blastocistosis como un problema de salud pública en lugar de una entidad clínica frecuente y se incluyen elementos que pudieran reforzar esta visión. Se incluyen las medidas que pudieran contribuir a prevenir la parasitosis. Dado que la investigación sobre este parásito progresa rápidamente, se recomienda realizar revisiones frecuentes para mantener actualizados los conceptos relacionados con su epidemiología, diagnóstico, tratamiento y prevención en el paciente inmunocompetente así como en el inmunosuprimido.
Blastocystis sp. is one of the human parasites most frequently identified in the clinical laboratory during the parasitological study of stool samples. This review updates the aspects related to genetic diversity and host specificity, taxonomy, molecular characterization, clinical forms and therapeutic experience in symptom free and symptomatic immune-competent and compromised patients who attended to the Soil Transmitted Helminth Section of the Institute of Tropical Medicine of the Faculty of Medicine of the Central University of Venezuela, proposing secnidazole as the drug of first choice. The presence of Blastocystis as human pathogen or as part of the gut microbiota, are analyzed. The current trend among the different research groups is to look at Blastocystosis as a public health problem rather than a common clinical entity and include elements that could reinforce this view. Measures that could help prevent parasitic disease are also included. Since research on this parasite is progressing rapidly, frequent reviews are recommended to keep the concepts related to its epidemiology, diagnosis, treatment and prevention updated in the immunocompetent as well as the immunosuppressed patient.
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Blastocystis sp. es un parásito de distribución mundial, que se transmite por vía fecal-oral, colonizando el tracto gastrointestinal, tanto de animales como de humanos. Existen múltiples factores que favorecen su transmisión tales como el pobre saneamiento, el consumo de alimentos contaminados y la propagación de vectores. Este parásito ha despertado gran interés científico y clínico en los últimos años, por su potencial asociación con enfermedad; sin embargo, no ha sido posible establecer con exactitud su rol patógeno. También ha sido considerado agente oportunista, por su alta prevalencia en pacientes inmunosuprimidos, específicamente en aquellos con VIH/SIDA y cáncer. Actualmente, en el GenBank se han descrito secuencias de 33 subtipos (STs) diferentes, si bien en la literatura solo se encuentran reportados 17 subtipos hasta el momento, de los cuales 9 han sido aislados en el ser humano. Aunque buena parte de los estudios reportan a ST3 como el de mayor prevalencia, unos cuantos autores sugieren predominio de ST1 y ST4 en ciertas zonas, indicando que algunos subtipos varían dependiendo de la distribución geográfica. Varios de estos STs se han relacionado directamente con sintomatología gastrointestinal aguda y crónica e incluso con manifestaciones clínicas extraintestinales, encontrándose con mayor frecuencia el ST3 en pacientes sintomáticos, generalmente seguido de ST1 y en algunos casos de ST2. Además, se han reportado infecciones mixtas, de las cuales la más común se ha presentado entre los ST1 - ST3. En Latinoamérica, y particularmente en Colombia, se han desarrollado pocas investigaciones orientadas a identificar y definir la prevalencia, coinfección y potencial patógeno de las diferentes formas y subtipos conocidos de Blastocystis sp., por lo cual el conocimiento que se tiene hasta el momento es escaso e inespecífico, requiriéndose más estudios que permitan obtener mayor información al respecto.
Blastocystis sp. is a globally distributed parasite which is transmitted by the fecal-oral route by colonizing the gastrointestinal tract of both animals and humans. There are many factors which allow its transmiBion such as poor sanitation, the consumption of contaminated food and vectors propagation. This parasite has awakened scientific and clinical interest in recent years because of its aBociation with disease. However, its pathogen role has not been accurately established. Also, it has been considered as an opportunistic agent due to its high prevalence in immunosuppreBed patients, specifically in those with HIV / AIDS and cancer. Currently, in GenBank database the sequences of 33 different subtypes (STs) have been described even though only 17 subtypes are reported in the literature so far, from which nine have been isolated in humans. Although many studies indicate the subtype 3 (ST3) as the most prevalent, some authors suggest the predominance of ST1 and ST4 in particular areas, suggesting that some subtypes vary depending on the geographical distribution. Several of these STs have been directly related to acute and chronic gastrointestinal symptoms and even with clinical extraintestinal manifestations, being ST3 found with more frequency in symptomatic patients followed by ST1 and ST2 in some cases. Furthermore, mixed infections have been reported of which the most common has been present between ST1 - ST3. In Latin America, and particularly in Colombia, little research has been developed that aims to identify and define the prevalence, coinfection, and pathogenic potential of different forms and known subtypes of Blastocystis sp., therefore the knowledge at hand so far is scarce and unspecific, requiring more studies which allow obtaining more information about it.
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Blastocystis sp. is an anaerobic intestinal microorganism commonly identified in the feces of several animals, including humans. Blastocystis exhibits high genetic polymorphism and at least 17 subtypes (ST) have been identified; ST1-ST3 are frequently found in the Americas. Furthermore, in vitro assays have shown that temperature and humidity can affect the viability of Blastocystis cysts. In this study, we describe the genetic variability and genetic differentiation among and within Blastocystis STs in adults and children from the cities of Hermosillo and Morelia cities, which represent arid and humid subtropical climatic regions of México, respectively. Phylogenetic and genetic diversity was assessed by analyzing a region of the small subunit ribosomal DNA (SSU rDNA) gene as a marker. Blastocystis ST3 and ST1 were associated with children from Hermosillo and Morelia, respectively. An analysis of the nucleotide diversity (π) and haplotype polymorphism (θ) indexes showed that they were similar within each ST, but different between ST1 and ST3. Interestingly, the group of symptomatic carriers from Hermosillo showed scarce mean nucleotide diversity compared to the asymptomatic carriers (0.0039±0.0030 and 0.0329±0.0286, respectively). Furthermore, the gene flow and genetic differentiation indexes between the children and adults suggested that the Blastocystis haplotypes in the adult carriers were "highly mobile" among humans, while the haplotypes found in the children were more isolated and genetically differentiated between them.
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Infecciones por Blastocystis/epidemiología , Infecciones por Blastocystis/parasitología , Blastocystis/clasificación , Blastocystis/genética , Portador Sano , Clima , Variación Genética , Genotipo , Adolescente , Adulto , Anciano , Niño , Preescolar , Femenino , Haplotipos , Humanos , Lactante , Masculino , México/epidemiología , Persona de Mediana Edad , Filogenia , Polimorfismo Genético , ARN Ribosómico/genética , Análisis de Secuencia de ADN , Adulto JovenRESUMEN
Esta investigación tuvo como objetivo determinar la prevalencia de parásitos intestinales en manipuladores de alimentos de varios comedores de PDVSA; que acudieron en solicitud del certificado de salud en clínicas de PDVSA, ubicadas en la Costa Oriental del Lago. Se analizaron 166 muestras de heces, por métodos coproparasitológicos: evaluación microscópica en solución salina fisiológica al 0,85%, lugol y técnica de Ritchie. La prevalencia de enteroparásitos fue de 25,90% (43/166). Del porcentaje de parasitados 17,47% correspondió al grupo de 20 a 40 años y 8,43% al grupo mayores de 40 años. No se observó diferencia estadísticamente significativa entre edad y frecuencia de parasitosis intestinal (Chi²= 0,539; P >0,05). De acuerdo al sexo, del porcentaje casos parasitados; 15,66% correspondieron al sexo masculino y 10,24% al sexo femenino (Chi²= 0,016; P >0,05). Solo se identificaron protozoarios, destacándose Blastocystis sp. con 83,72%. El presente estudio demostró que los manipuladores de alimentos estuvieron infectados por protozoarios entéricos, la prevalencia detectada es similar a otros estudios en poblaciones parecidas.
The objective of this research was to determine the prevalence of intestinal parasites in food handlers at several PDVSA dining rooms, who requested a health certificate at PDVSA clinics on the East Lake Coast. One-hundred sixty-six stool samples were analyzed using parasitological methods: microscopic evaluation in physiological saline solution at 0.85%, Lugols solution and the Ritchie method. The prevalence of intestinal parasites was 25.90% (43/166). Of those who had parasites, 17.47% corresponded to the group of 20 to 40 years old and 8.43% to the group of 40 years or older. No statistically significant difference was observed between age and frequency of intestinal parasitosis (Chi² = 0.539, P> 0.05). According to sex, 15.66% of the parasitized cases were male and 10.24% female (Chi² = 0.016, P> 0.05). Only protozoa were identified, highlighting Blastocystis sp. with 83.72%. This study showed that food handlers were infected with enteric protozoa. The detected prevalence is similar to other studies in similar populations.
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Para determinar la prevalencia de Blastocystis sp. y su asociación con características epidemiológicas se realizó una investigación descriptiva en dos comunidades del Municipio Maracaibo del Estado Zulia. Para la recolección de datos se empleó una ficha epidemiológica; participaron 406 individuos seleccionados aleatoriamente realizándoseles a cada uno, un examen coproparasitológico directo con SSF-Lugol. Entre los estudiados predominaron los mayores de 18 años (72,1%) y el género femenino (51,4%). La prevalencia de Blastocystis sp. fue 38,9%, con mayor frecuencia de poliparasitismo (54,4%), identificándose Endolimax nana (36,1%) como especie comensal principalmente asociada, seguida de Giardia intestinalis (22,1%) entre los patógenos. Hubo asociación significativa (p<0.05) entre la prevalencia de la infección con el status de ocupación activa, hacinamiento, consumo de agua no tratada y ausencia de adecuadas condiciones para disponer y eliminar basura. Dichas variables mostraron valores OR 95% IC que evidencian su influencia como factores de riesgo, presentándose para el status de ocupación activa el mayor riesgo de infección (OR = 3,18). No se observó asociación significativa entre presencia de Blastocystis sp. con otras características epidemiológicas (p>0.05). Las limitaciones en los estándares de higiene comunal y personal son determinantes de la prevalencia de Blastocystis sp. en estas comunidades.
To determine the prevalence of Blastocystis sp. and its association with epidemiological characteristics, a cross-sectional study was conducted in two communities of the Maracaibo Municipality, State of Zulia. To collect data, an epidemiological record was used; 406 randomly selected individuals participated; for each one, a direct parasitological examination with SSF- Lugol was performed. Individuals over 18 years (72.1%) and females (51.4%) predominated. The overall prevalence of Blastocystis sp. infection was 38.9%; poly-parasitism predominated (54.4 %), identifying Endolimax nana (36.1%) as the most frequently associated commensal species, followed by Giardia intestinalis (22.1%), among the pathogens. There was significant association (p<0.05) between the prevalence of infection with active occupation status, overcrowding, untreated water consumption and lack of adequate conditions to dispose of and eliminate waste. These variables showed OR 95% CI values, which demonstrates their influence as risk factors, reporting the greatest risk of infection (OR=3.18) for the active occupation status. No significant association was noted between the presence of Blastocystis sp. and other epidemiological characteristics (p >0.05). Limitations in community and personal hygiene standards are determinants for the prevalence of Blastocystis sp. in these communities.
RESUMEN
Se analizaron 74 muestras fecales pertenecientes a niños de ambos sexos de una institución educativa del municipio Maracaibo, estado Zulia con edades entre 3 y 11 años para determinar la prevalencia de Blastocystis sp. Cada muestra fue sometida a un examen coproparasitológico directo con solución salina 0,85%, tinción temporal de lugol y método de concentración formol-éter. La prevalencia de enteroparásitos en la población estudiada fue de 41,9%; de éstos 80,6% correspondió a Blastocystis sp. En relación a esta especie y su asociación al grupo etario, se reportó un mayor porcentaje de niños parasitados a los 10 años de edad (9,4%), mientras que el parasitismo por otras especies en toda la población estudiada presentó una prevalencia de 19,4%. La forma evolutiva vacuolar predominó, presentándose el mayor número de casos en heces pastosas. Se encontró relación significativa entre las variables parasitismo y edad, más no fue significativa al evaluar las variables parasitismo y sexo. La alta prevalencia de este protozoario en escolares plantea la necesidad de evaluar el comportamiento en la higiene alimentaria y el abastecimiento de agua.
Seventy four fecal samples obtained from children of both sexes at an educational institution of the Maracaibo Municipality, Zulia State, with ages between 3 and 11 years, were analyzed in order to determine the prevalence of Blastocystis sp. Each sample was submitted to a direct coproparasitologic examination with an 0.85% saline solution, temporal lugol staining, and formalin-ether concentration method. Enteroparasite prevalence in the population studied was 41.9%, and of these, 80.6% corresponded to Blastocystis sp. Regarding this species and its association with an age group, a higher percentage of parasitized children was reported in the 10 years age group (9.4%), while parasitism by other species in all the population studied showed a 19.4% prevalence. There was predominance of the vacuolar evolutionary form, and the highest number of cases was seen in tarry stools. There was a significant relationship between parasitism variables and age, but not in the parasitism and sex variables. The high prevalence of this protozoan in school children indicates the need of evaluating the status of food and water supply hygiene.
RESUMEN
Es importante definir criterios diagnósticos que permitan dilucidar el papel patógeno de Blastocystis sp. Se evaluó morfología y se estimó el diámetro de las formas, número de parásitos por campo y por gramo de heces y los anticuerpos IgM e IgG anti- Blastocystis sp. mediante ELISA, en sujetos con sintomatología general y portadores sanos. Se encontró 77% de muestras positivas para Blasctocystis sp, 52% provenientes de pacientes con síntomas como flatulencia 6 (24%), dolor abdominal 5 (20%), náuseas 2 (8%), diarrea 6 (24%) y estreñimiento 6 (24%). Los rangos de parásitos por campo más frecuente en sintomáticos fueron 0-3 (74%) y 10-12 (26%), mientras que 100% de los pacientes asintomáticos presentaron Blastocystis sp. en el rango 0-3. Los pacientes asintomáticos presentaron menor número de parásitos por gramo de heces, en el rango de 0-3 y el rango 7-10 con altas cargas parasitarias solo fue observado en sintomáticos. Se encontró menor cantidad de formas granulares en ambos grupos, en el rango 0-3 en sintomáticos: 85% vacuolares y 15% granulares; 76% vacuolares y 24% granulares, en asintomáticos. En el rango 10-12, 98% vacuolares y 2% de granulares, en sintomáticos. El diámetro promedio de las formas vacuolares fue 11,9±2 μm en los pacientes sintomáticos y 7,9±3,7 μm en asintomáticos. En los granulares fue 9,3±2,3 μm en sintomáticos y 8,2±0,1 μm en asintomáticos. Observándose diferencias significativas entre las formas vacuolares de ambos grupos (P=0,000026), pero no en los granulares (P=0,346). El 3,5% de los pacientes sintomáticos presentaron anticuerpos IgG anti-Blastocystis sp. El estudio morfológico empleado contribuyó en la optimización del diagnóstico, mientras que las técnicas inmunoenzimáticas resultaron de baja sensibilidad.
It is important to define diagnostic criteria to elucidate the pathogenic role of Blastocystis sp. Morphology was assessed and diameter of the shapes, number of parasites per field and per gram of faeces and Blastocystis sp. IgM and IgG antibodies was estimated by ELISA in subjects with constitutional symptoms and healthy carriers. Seventy percent Blasctocystis sp positive samples were found, 52% from patients with symptoms such as flatulence 6 (24%), abdominal pain 5 (20 %), nausea 2 (8%), diarrhea 6 (24%) and constipation 6 (24%). Ranges of parasites per field found more frequently in symptomatic patients were 0-3 (74%) and 10-12 (26%), while 100% of asymptomatic patients had Blastocystis sp. in the range 0-3. Asymptomatic patients showed lower number of parasites per gram feces in the range of 0-3 and the 7-10 range with high parasitic load was only observed in symptomatic. Less granular forms in both groups was found, in the range 0-3 in symptomatic patients: 85% vacuolar and 15% granular; 76% vacuolar and 24% granular in asymptomatics. In the range 10-12, 98% vacuolar and 2% granular in symptomatic patients. The average diameter of the vacuolar forms was 11.9 ± 2 μm in symptomatic patients and 7.9 ± 3.7 μm in asymptomatics . In the granular form was 9.3 ± 2.3 μm in symptomatic and 8.2 ± 0.1 μm in asymptomatics. Significant difference was found among vacuolar forms of both groups (P= 0.000026), but not in the granular form (P= 0.346). Only 3.5 % of symptomatic patients had IgG antibodies to Blastocystis sp. The morphological study employed contributed to the diagnosis optimization while immunoenzymatic techniques were of low sensitivity.
RESUMEN
El Blastocystis sp es un protozoario con alta prevalencia en Venezuela. Es controversial por su papel patógeno y su gran variabilidad genética, relacionada con la dificultad de mantenerlo en condiciones de viabilidad fuera del hospedador. Se evaluó la utilidad de los medios de cultivo in vitro RPMI1640, TB1, MBD y MBDM para mantener la viabilidad del Blastocystis sp. Se seleccionaron 97 muestras de heces, 43 (44%) de las cuales resultaron positivas solo para Blastocystis sp y de 15 de ellas se purificaron los Blastocystis sp mediante gradiente (ficol-diatrizaoato de sodio). En cada medio de cultivo y en solución salina 0,85% (SSI) se inoculó1x103 parásitos por paciente y se evaluó la viabilidad mediante coloración con azul de tripano a las 24, 48 y 72 horas. Los resultados mostraron porcentajes de viabilidad a las 24 h: en SSI de 2%, en RPMI1640 5%, en TB1 5%, MBD 24% y MBDM 40%. A las 48 h: en SSI de 3%, en RPMI1640 4%, en TB1 4%, MBD 17% y MBDM 21%. A las 72 h: en SSI 2%, en RPMI1640 2%, en TB1 2%, MBD 15% y MBDM 16%. Se observaron diferencias estadísticamente significativas después de las 24 h, entre los medios TB1, MBD y MBDM comparado con SSI. Se concluye que el medio MBDM es el que ofrece las mejores condiciones para mantener viable a Blastocystis sp por 72 h.
The protozoan Blastocystis sp is a high prevalence in Venezuela. Its role is controversial pathogen and its wide genetic variability related to the difficulty of keeping it in a position outside the host viability. We evaluated the utility of in vitro culture media RPMI1640, TB1, and MBDM MBD to maintain the vitality of Blastocystis sp. They selected 97 stool samples, 43 (44%) of which were positive for Blastocystis sp and only 15 of them were purified by gradient Blastocystis sp (ficoll-sodium diatrizaoato). In each culture medium and 0.85% saline (SSI) is inoculó1x103 parasites per patient and viability was assessed by trypan blue staining after 24, 48 and 72 hours. The results showed viability percentage at 24 hours: in SSI of 2%, 5% RPMI1640 at TB1 5%, 24% and MBDM MBD 40%. After 48 h: SSI 3% in RPMI1640 4%, 4% TB1, MBD MBDM 17% and 21%. After 72 h: SSI 2% in RPMI1640 2%, 2% TB1, MBD 15% and 16% MBDM. Statistically significant differences were observed after 24 h, between TB1 media, compared MBDM MBD and SSI. We conclude that the medium is MBDM which offers the best conditions for maintaining viable Blastocystis sp for 72 h.