Molecular diagnosis of intestinal protozoa in young adults and their pets in Colombia, South America.

Intestinal parasitic infections have been considered a relevant public health problem due to the increased incidence worldwide. In developing countries, diarrhea and gastrointestinal symptoms cause impaired work capacity in adults and delayed rate growth in children. Enteric infections of unknown etiology can often lead to misdiagnosis, increased transmission, and morbidity. The aim of this study was to determine the prevalence of intestinal parasites in a young adult population and their pets. Stool samples from 139 university students and 44 companion animals were subjected to microscopy diagnosis using wet mounts, concentration by zinc sulphate flotation and staining techniques (Kinyoun and trichrome stain). Molecular diagnosis of protozoa was also performed by conventional PCR. The mean age was 24 years, 54% individuals were female, 46% were men, and 66% had at least one pet. The overall prevalence for at least one parasite was 74.8% and the rate of polyparasitism was 37.5%. Eighty-three patients (59.7%) were positive for Blastocystis spp., followed by Cryptosporidium spp. 24.5%, Endolimax nana 13.6%, Entamoeba dispar/E. moshkovskii 7.8% and Giardia intestinalis 1.4%. Molecular diagnosis substantially improved Cryptosporidium spp. and Blastocystis spp. detection and allowed to distinguish E. histolytica from commensals in the Entamoeba complex. Student's pets were also examined for parasitism. Samples from 27 dogs, 15 cats, one rabbit and one hen were analyzed, and parasites were detected in 30 (68.2%) as follows: Cryptosporidium spp. (24) Giardia spp. (4), hookworm (3), Endolimax nana (2) and Toxoplasma gondii (1). Overall, university students showed high prevalence of parasitism and polyparasitism suggesting exposure to parasite infected animals and contaminated environments. Cryptosporidium spp. was the predominant pathogen in human and domestic animals, and it was only detected by PCR, pointing out the need for sensitive tests in diagnosis and surveillance. Control strategies to prevent the effects of parasitic infections in young population should consider pets as reservoirs and transmission source.

Parasitosis intestinales y medidas antropométricas en preescolares del cantón de Portoviejo, Ecuador / Intestinal parasites and anthropometric measurements in preschoolers from the canton of Portoviejo, Ecuador

Las enteroparasitosis son un problema de salud pública a nivel global con mayor impacto en los países subdesarrollados asociadas a condiciones de vida inadecuadas. La población infantil es más suceptible para desarrollar sintomatología provocando cuadros disentéricos, vomitos, síndrome de mal absorción, lo que influye en deficiencia de nutrientes y vitaminas, como consecuencia retraso en el crecimiento, malnutrición, trastornos del desarrollo físico y cognitivo. Se realizó una investigación epidemiológica, de corte transversal para estimar la prevalencia de parásitos instestinales y las diferencias en relación a las medidas antropométricas, en 283 escolares de la Capital de la provincia de Manabí. Las variables peso, talla parada, circunferencia de brazo izquierdo, pliegues de tríceps y subescapular, índice de masa corporal, área magra y área grasa fueron seleccionadas para establecer la relación. El coproparasitológico se realizó con el método directo (solución salina 0,9% y Lugol) y Kato Katz. Los resultados mostraron 62,54% de prevalencia, sin distingo de sexo, ni edad. Blastocytis spp., la especie más frecuente, confirmándose el comportamiento epidemiológico a nivel mundial a expensa de los protozoarios, con presencia de especies comensales (E. nana) relacionada con el fecalismo. A pesar de la alta prevalencia, no se observó diferencia significativa entre variables antropométricas analizadas en los escolares parasitados y no parasitados. Se infiere que es debido al tipo de especies y la intensidad de la infestación. Se recomienda realizar campañas de educación sanitaria y promover hábitos de higiene, así como dirigir investigaciones para determinar el papel epidemiológico del agua de consumo y las enteroparasitosis(AU)

Enteroparasitosis is a global public health problem with the greatest impact in underdeveloped countries associated with inadequate living conditions. The child population is more susceptible to developing symptoms causing dysentery, vomiting, malabsorption syndrome, which influences nutrient and vitamin deficiency, resulting in growth retardation, malnutrition, physical and cognitive development disorders. A cross-sectional epidemiological investigation was carried out to estimate the prevalence of intestinal parasites and the differences in relation to anthropometric measurements, in 283 schoolchildren from the capital of the province of Manabí. The variables weight, standing height, left arm circumference, triceps and subscapular folds, body mass index, lean area, and fat area were selected to establish the relationship. Coproparasitology was performed with the direct method (saline solution 0.9% and Lugol) and Kato Katz. The results showed 62.54% prevalence, regardless of sex or age. Blastocytis spp., the most frequent species, confirming the epidemiological behavior worldwide at the expense of protozoa, with the presence of commensal species (E. nana) related to fecalism. Despite the high prevalence, no significant difference was observed between the anthropometric variables analyzed in parasitized and non-parasitized schoolchildren. It is inferred that it is due to the type of species and the intensity of the infestation. It is recommended to carry out health education campaigns and promote hygiene habits, as well as to conduct research to determine the epidemiological role of drinking water and enteroparasitosis(AU)

Factores de riesgo y parasitosis intestinal en niños menores de 10 años de la olla común / Risk factors and intestinal parasitosis in children under 10 years of age from the common pot

Diversos factores de riesgos pueden condicionar las prevalencias de parasitosis intestinales en niños. Como objetivo se propuso determinar los factores de riesgo y parasitosis intestinal en niños menores de 10 años de la Olla Común ubicada en Villa Mara del Triunfo-Perú durate el año 2022. La investigación fue descriptiva-experimental y correlativa con una muestra de 160 niños <10 años de ambos sexos. Como instrumento de recolección se aplicó un cuestionario con preguntas dicotómicas para conocer las prácticas de higiene de los niños y se efectuó la recolección y procesamiento de muestras con técnicas de Solución Salina S.S.F al 85%, Lugol, Método de Kato y Método de concentración-Flotación de Faust. Para analizar los datos se utilizó Microsoft Excel y el software SPSS, estadística descriptica y hallar tablas de frecuencias y porcentajes y Prueba de correlación entre los elementos de riesgo y la frecuencia de signos de los parásitos. Como resultado, el cálculo estadístico con el método de Spearman mostró una concordancia positiva con el coeficiente de correlación 0,725 y con un valor de 0,001<0,05; donde los niveles de factores de riesgo en los infantes mostraron que el 31,3% se encontraban en riesgo bajo con un nivel bajo de síntomas y sin evidencia de parásitos intestinales, el 18,8% en riesgo medio y el 12,5% en riesgo alto y un nivel alto de síntomas y parasitosis intestinal confirmado; la mayoría de los niños se encuentran en un entorno de bajo riesgo. Se hace necesario e indispensable continuar con invesigaciones en zonas adyacentes(AU)

Various risk factors can condition the prevalence of intestinal parasitosis in children. The objective was to determine the risk factors and intestinal parasitosis in children under 10 years of age from the Common Pot located in Villa Mara del Triunfo-Peru during the year 2022. The research was descriptive-experimental and correlative with a sample of 160 children <10 years of both sexes. As a collection instrument, a questionnaire with dichotomous questions was applied to know the hygiene practices of the children and the collection and processing of samples was carried out with techniques of Saline Solution S.S.F at 85%, Lugol's, Kato's Method and Concentration-Flotation Method. of Faust. To analyze the data, Microsoft Excel and the SPSS software were used, descriptive statistics and finding tables of frequencies and percentages and a correlation test between the risk elements and the frequency of signs of the parasites. As a result, the statistical calculation with the Spearman method showed a positive agreement with the correlation coefficient 0.725 and with a p value of 0.001<0.05; where the levels of risk factors in infants showed that 31.3% were at low risk with a low level of symptoms and no evidence of intestinal parasites, 18.8% at medium risk and 12.5% at high risk and a high level of symptoms and confirmed intestinal parasitism; most children are in a low-risk environment. It is necessary and essential to continue with investigations in adjacent areas(AU)

Unravelling the Phylogeny of a Common Intestinal Protist: Intrageneric Diversity of Endolimax.

Endolimax nana is a common endobiont of the human intestine, but members of the genus have also been reported in non-human hosts and in non-intestinal organs. Limited information is available regarding the genetic diversity of Endolimax, which is necessary to delineate species, host specificity and potential differences in clinical impact on the host. Here, we used cloning of PCR products followed by Sanger sequencing and next-generation PacBio Sequencing to obtain Endolimax-related nuclear ribosomal gene sequences and undertook a phylogenetic analysis to gain additional insight into the taxonomy of Endolimax and related organisms. The new sequences confirmed that E. nana forms a discrete clade within the Archamoebae and is related to Endolimax piscium and Iodamoeba. However, we identified substantial sequence divergence within E. nana and evidence for two distinct clades, which we propose to name E. nana ribosomal lineage 1 and E. nana ribosomal lineage 2. Both of the sequencing approaches applied in the study helped us to improve our understanding of genetic diversity across Endolimax, and it is likely that wider application of next-generation sequencing technologies will facilitate the generation of Endolimax-related DNA sequence data and help complete our understanding of its phylogenetic position and intrageneric diversity.

Prevalencia de parasitosis intestinal en trabajadores de la florícola Irose de la provincia de Pichincha ­ Cantón Pedro Moncayo 2019 / Prevalence of intestinal parasitosis in workers of the irose florícola of the province of pichincha - Canton Pedro Moncayo

Las infecciones por parásitos intestinales son de ocurrencia constantes y se encuentran asociadas al incumplimiento de las medidas sanitarias por parte de la población. El objetivo de esa investigación fue establecer la prevalencia de parasitosis intestinal por protozoos y helmintos en trabajadores de la florícola iRose de la provincia de Pichincha-Cantón Pedro Moncayo mediante el examen coproparasitario realizado en el mes de agosto de 2019. Correspondió a un estudio transversal, descriptivo y de tipo observacional. La población estuvo integrada por 88 personas, quienes son trabajadores de la florícola iRose, Provincia de Pichincha, cantón Pedro Moncayo, distribuidos de la siguiente manera: 49 trabajadores del sexo masculino y 39 trabajadores del sexo femenino. La técnica de recolección de datos utilizada fue la encuesta y la observación directa y luego de obtener las muestras biológicas, la detección de parásitos intestinales se realizó mediante el método de coproparasitario en muestras heces. Los resultados evidencian presencia de protozoos en un 92.5% de las muestras estudiadas, mientras que el 7.5% presentan helmintos; mientras que el 40% de los estudios revelan quistes de endolimax nana, detectándose en el 25% de la muestra de los trabajadores de sexo masculino y con una presencia del 15% en los trabajadores del sexo femenino. Por lo que se recomienda realizar el examen coproparasitario al menos dos veces al año y paralelamente fortalecer las estrategias de promoción y prevención(AU)

Infections with intestinal parasites are of constant occurrence and are associated with non-compliance with health measures by the population. The objective of this research was to establish the prevalence of intestinal parasitosis by protozoa and helminths in la workers IRose flower farm of the province of Pichincha-Canton Pedro Moncayo through the coproparasitario examination carried out in august 2019. It corresponded to a cross-sectional, descriptive, observational study. The population was composed of 88 people, who are workers of the floricultural iRose, Province of Pichincha, canton Pedro Moncayo, distributed as follows: 49 male and 39 female workers. The data collection technique used was survey and direct observation and after obtaining biological samples, detection of intestinal parasites was performed using the coproparasitario method in fecal samples. The results showed the presence of protozoa in 92.5% of the samples studied, while 7.5% showed helminths; while 40% of studies reveal endolimax nana cysts, being detected in 25% of the sample of male workers and with a presence of 15% in female workers. Therefore, it is recommended to perform the coproparasitario examination less twice a year and in parallel strengthen strategies promotion and prevention(AU)

Contrasting microbiota profiles observed in children carrying either Blastocystis spp. or the commensal amoebas Entamoeba coli or Endolimax nana.

Recent studies have shown how intestinal parasites can modulate gut microbiota. This observation is not surprising since the human intestinal lumen, like any other niche, is a battlefield of microbial competition, and Eukaryotes can affect bacterial populations. Intestinal pathogenic protist has been associated with reshaping the microbial community structure; however, the interactions between the colonic bacterial communities and parasites like Blastocystis spp., Entamoeba coli, and Endolimax nana have been poorly studied. In this work, we studied the distal intestinal bacterial microbiota of 49 children attending 7 public daycare centers in Medellin, Colombia, and compared the bacterial microbiota structure in the presence or absence of the protists Blastocystis spp., E. coli, and E. nana. Parasite colonization was associated with an increase in bacterial richness. Moreover, Blastocystis spp. presented a positive relationship with Prevotella, since this bacterium was selectively enriched in children carrying it. Remarkably, the E. coli colonized children showed a microbial profile that was closer to uninfected controls, although some bacterial taxa displayed to be enriched. This is the case for Akkermansia, which showed to be favored in E. coli colonized individuals, while notably reduced in the Blastocystis spp. parasitized group.

Specific IgG and IgA Antibody Reactivities in Sera of Children by Enzyme-Linked Immunoassay and Comparison With Giardia duodenalis Diagnosis in Feces.

BACKGROUND: Giardia duodenalis is conventionally diagnosed in fecal samples using parasitological methods. However, sensitivity is poor when only a single sample is analyzed, due to intermittent excretion of cysts in feces. Alternatively, the serum antibodies to G. duodenalis can be used for parasite diagnosis and epidemiological studies to determine previous exposure. We compared the rate of G. duodenalis infection between serum anti-Giardia IgG and IgA antibodies and fecal examination in Brazilian children. METHODS: Fecal and serum samples were tested from 287 children at a clinical laboratory and from 187 children at daycare centers. Fecal samples were processed using conventional parasitological methods and coproantigen detection for Giardia diagnosis. Serum samples were tested using an in-house ELISA for detection of anti-Giardia IgG and IgA. RESULTS: G. duodenalis was found in 8.2% (N=39) of the 474 children analyzed. The sensitivity and specificity of ELISA were 80.0% and 90.0% for IgG and 80.0% and 83.3% for IgA, respectively. The total positivity rate of anti-Giardia IgG and IgA in the sera was 13.9% (N=66) and 23.6% (N=112). The agreement between the positivity of specific antibodies and the detection of G. duodenalis in feces was moderate for ELISA-IgG, kappa index (95% CI)=0.543 (0.422-0.664), and mild for ELISA-IgA, kappa index (95% CI)=0.283 (0.162-0.404). Among the children infected with other enteroparasites, 11.6% (N=10) and 24.4% (N=21) showed reactivity to anti-Giardia IgG and to IgA, respectively. This cross-reactivity was more frequent in samples from children infected with Endolimax nana and Entamoeba coli. CONCLUSIONS: The higher frequency of specific antibody reactivity compared with G. duodenalis diagnosis in feces could reflect continuous exposure of children to G. duodenalis infection, resulting in long-lasting immunological memory and/or cross-reactivity with other intestinal amoebas.

Endolimax nana and urticaria.

Endolimax nana is a commensal protozoan of the colon. We report a case of chronic urticaria associated with E. nana in a 34-year-old Italian woman. The patient suffered from abdominal pain, diarrhoea and weight loss. The disease appeared after a trip to Vietnam. Laboratory examinations showed mild blood eosinophilia. Three coproparasitological examinations were positive for cysts of E. nana. The patient was successfully treated with two courses of metronidazole (2 g/day for 10 days each). No antihistamines were used. Three coproparasitological examinations, carried out at the end of the therapy, were negative. Follow up (six months) was negative. E. nana can be responsible for very rare cases of abdominal pain, diarrhoea, polyarthritis and urticaria.

Biodiversity of protists and nematodes in the wild nonhuman primate gut.

Documenting the natural diversity of eukaryotic organisms in the nonhuman primate (NHP) gut is important for understanding the evolution of the mammalian gut microbiome, its role in digestion, health and disease, and the consequences of anthropogenic change on primate biology and conservation. Despite the ecological significance of gut-associated eukaryotes, little is known about the factors that influence their assembly and diversity in mammals. In this study, we used an 18S rRNA gene fragment metabarcoding approach to assess the eukaryotic assemblage of 62 individuals representing 16 NHP species. We find that cercopithecoids, and especially the cercopithecines, have substantially higher alpha diversity than other NHP groups. Gut-associated protists and nematodes are widespread among NHPs, consistent with their ancient association with NHP hosts. However, we do not find a consistent signal of phylosymbiosis or host-species specificity. Rather, gut eukaryotes are only weakly structured by primate phylogeny with minimal signal from diet, in contrast to previous reports of NHP gut bacteria. The results of this study indicate that gut-associated eukaryotes offer different information than gut-associated bacteria and add to our understanding of the structure of the gut microbiome.

Frecuencia de contaminación por enteroparásitos en pasamanos de autobuses de Barquisimeto, Venezuela / Enteric Parasite Contamination Frequency on Bus Handrails in Barquisimeto, Venezuela / Frequência da contaminação por enteroparasitos em corrimãos de ônibus em Barquisimeto, Venezuela

Introducción. La contaminación enteroparasitaria en autobuses por parte de usuarios infectados con malas conductas sanitarias potencia el riesgo de infección del resto de los pasajeros con el subsecuente peligro del desarrollo de patologías gastrointestinales. Por esto se evaluó la frecuencia de contaminación de autobuses con el fin de aportar datos que son desconocidos en Venezuela e inexistentes en Latinoamérica. Metodología. El trabajo fue descriptivo, transversal, con muestra no probabilística y accidental, donde la obtención de la muestra consistió en frotar el pasamanos de cada autobús (100 vehículos examinados) tres veces con un hisopo impregnado en solución salina isotónica 0.85%, resuspendiendolo en un tubo de ensayo con 10 ml de solución salina. La muestra se centrifugó a 3000 rpm por diez minutos para luego observar el sedimento al microscopio. Resultados. El 16% de las muestras presentaron contaminación, encontrándose solo dos especies de enteroparásitos, Blastocystis spp. (14% del total de muestras examinadas) y Endolimax nana (5%). Discusión. La abundancia del potencial patógeno Blastocystis sp., se relaciona con lo descrito en exámenes de heces de habitantes de Barquisimeto y del estado Lara, demostrando que los usuarios enfermos con malas conductas higiénicas convierten a los autobuses en un foco de infección que debe ser controlado. Conclusión. La falta de aseo constante en unidades de transporte público y la ausencia de conciencia sanitaria de algunos pasajeros infectados facilitan la transmisión de enteroparásitos endémicos potencialmente productores de enfermedades gastrointestinales. Cómo citar: Traviezo, L. Frecuencia de contaminación por enteroparásitos en pasamanos de autobuses de Barquisimeto, Venezuela. MedUNAB. 2020;23(3):434-440 doi: doi.org/10.29375/01237047.3913

Introduction. Enteroparasite contamination by infected users with poor sanitary habits in buses increases other passengers' risk of infection, with the subsequent danger of developing gastrointestinal pathologies. For this reason, bus contamination frequency was evaluated in order to provide data that is unknown in Venezuela and non-existent in Latin America. Methodology. The work was descriptive and cross-sectional, with non-probability and accidental sampling. The sample was obtained by rubbing each bus' handrail (100 examined vehicles) three times with a swab permeated with a 0.85% isotonic saline solution, resuspending it in a test tube with 10 ml of saline solution. The sample was centrifuged at 3,000 rpm for ten minutes to then observe the sediment under a microscope. Results. Sixteen percent of samples were contaminated, observing only two species of enteroparasites, Blastocystis sp. (14% of total examined samples) and Endolimax nana (5%). Discussion. The abundance of the potential pathogen, Blastocystis sp. is related to what has been described in feces exams on the inhabitants of Barquisimeto and the state of Lara, demonstrating that sick users with poor hygiene habits make buses a point of infection that must be controlled. Conclusion. The lack of constant cleaning in public transportation units and the absence of some infected passengers' sanitary awareness facilitates transmitting endemic enteroparasites that could potentially produce gastrointestinal diseases. Cómo citar: Traviezo, L. Frecuencia de contaminación por enteroparásitos en pasamanos de autobuses de Barquisimeto, Venezuela. MedUNAB. 2020;23(3):434-440 doi: doi.org/10.29375/01237047.3913

Introdução. A contaminação enteroparasitária em ônibus por usuários infectados com comportamentos sanitários inadequados aumenta o risco de infecção do resto dos passageiros com o consequente perigo de desenvolvimento de patologias gastrointestinais. Por isso, avaliou-se a frequência de contaminação de ônibus, a fim de fornecer dados até agora desconhecidos na Venezuela e inexistentes na América Latina. Metodologia. O trabalho foi descritivo, transversal, com amostra não-probabilística e acidental, em que a obtenção da amostra consistiu em esfregar o corrimão de cada ônibus (100 veículos examinados) três vezes com um cotonete impregnado em solução salina isotônica 0.85%, ressuspendendo-o em um tubo de ensaio com 10 ml de solução salina. A amostra foi centrifugada a 3,000 rpm por dez minutos para posteriormente observar o sedimento ao microscópio. Resultados. 16% das amostras apresentaram contaminação, sendo encontradas apenas duas espécies de enteroparasitas, Blastocystis sp. (14% do total das amostras examinadas) e Endolimax nana (5%). Discussão. A abundância do potencial patógeno Blastocystis sp., está relacionada ao que foi descrito em exames de fezes de moradores dos estados de Barquisimeto e Lara, mostrando que usuários doentes e com comportamentos sanitários inadequados fazem do ônibus um foco de infecção que deve ser controlado. Conclusão. A falta de limpeza constante nas unidades de transporte público e a falta de conscientização sobre a saúde de alguns passageiros infectados facilitam a transmissão de enteroparasitos endêmicos potencialmente produtoras de doenças gastrointestinais. Cómo citar: Traviezo, L. Frecuencia de contaminación por enteroparásitos en pasamanos de autobuses de Barquisimeto, Venezuela. MedUNAB. 2020;23(3):434-440 doi: doi.org/10.29375/01237047.3913

Frequência de enteroparasitos em mulheres não grávidas e seus filhos e grávidas atendidas em uma unidade de saúde / Frequency of enteroparasites in non-pregnant women and their children and pregnant women attended at a public health unit

As infecções parasitárias intestinais são amplamente distribuídas em todo o mundo e a população infantil é a mais afetada. A prevalência das infecções parasitárias intestinais materna e infantil de pacientes atendidos em uma unidade de saúde pública do município de Lagoa Santa, Minas Gerais foi avaliada pela técnica de centrífugo sedimentação em formol-éter. A positividade foi de 41,7% para gestantes, 37,3% para mães e 35,7% em crianças. Endolimax nana (17,1%) e Giardia intestinalis (17,1%) foram os parasitos mais frequentemente detectados em crianças com idade inferior a dois anos e em gestantes (33,3%). Para as mães, G. intestinalis (20,3%) foi o parasito mais prevalente seguido de Entamoeba coli (17%). A infecção simultânea de mãe e filho foi detectada em 7 das 25 crianças infectadas. Apesar das ações de educação em saúde, melhoria no nível educacional e acesso a serviços médicos, a frequência de infecções por endoparasitas permanece alta. A literatura é escassa em relação ao tema e acredita-se que a deficiência na aplicação de medidas de educação sanitária possa fazer com que mães infectadas possam contribuir para a infecção parasitária de seus filhos, assim como os filhos podem ser fonte de infecção para suas mães.

Intestinal parasitic infections are widely distributed throughout the world and children are the most affected population. The objective of the present study was to evaluate the prevalence of parasitic maternal and infant intestinal infection of patients attended at a public health unit in the municipality of Lagoa Santa, Minas Gerais. The centrifugal-sedimentation in formol-ether was the technica used for stool analysis. Positivity was observed in 41.7% for pregnant women, 37.3% for mothers and 35.7% for children. Endolimax nana (17.1%) and Giardia intestinalis (17.1%) were the most frequently detected parasites in children under two-years old and pregnant women (33.3%). For mothers, G. intestinalis (20.3%) was the most prevalent parasite followed by Entamoeba coli (17%). Simultaneous infection of mother and child was detected in 7 of 25 infected children. Despite health educations actions, improvement in educational level, and access to medical services, the frequency of endoparasite infections remains high. Literature is scarce in relation to the present theme and it is believed that infected mothers can contribute for parasitic infection of their kids, just as children can be a source of infection for their mothers.

Growth-promoting effects of the hydrogen-sulfide compounds produced by Desulfovibrio desulfuricans subsp. desulfuricans co-cultured with Escherichia coli (DH5α) on the growth of Entamoeba and Endolimax species isolates from swine.

Certain Desulfovibrio sp. (anaerobic sulfate-reducing bacteria) are indigenous to swine cecum and colon, which are also common habitats for parasitic amoebae such as Entamoeba polecki and Entamoeba suis. In this study, we evaluated the growth-promoting effects of D. desulfuricans co-cultured with Escherichia coli (DH5α) and its products [e.g., hydrogen sulfide (H2S) and certain iron-sulfide (FeS) compounds] using Robinson's medium, on the 4 amoeba isolates from swine-Entamoeba polecki subtype (ST)-1, E. polecki ST-3, Entamoeba suis, and Endolimax sp., and, consequently, a continuous culture system for these amoebae was established. However, this novel culture system was required to regulate the excess H2S dissolved in the medium by increasing air space as amoeba isolates thrive only in large air spaces (30-40%). The effects of air space and H2S and FeS compounds on the growth of E. polecki ST-1 (TDP-5) were determined. E. polecki ST-1 (TDP-5) thrived well in culture bottles with an air space of 30-40% (aerobic) (H2S: ~250-400 µmoles/L), but did not grow at all in an air space < 5% (microaerobic) ( H2S:~800 µmoles/L) and in anaerobic vessels (H2S: 20-30 µmoles/L). In both H2S-depleted and FeS compound-depleted conditions, the amoebae sp. could not thrive either. It was hypothesized that an appropriate concentration of H2S and FeS compounds might function as important physiologically active components of electron carriers such as FeS and ferredoxin.

Intestinal parasitic infections and associated factors in children of three rural schools in Colombia. A cross-sectional study.

Rural children are one of the populations that are most vulnerable to gastrointestinal parasite infections. Such diseases decrease the quality of life and result in growth and cognitive delays in the long term. This cross-sectional study was conducted to determine the frequency of intestinal parasite infections among rural schoolchildren in the municipality of Apulo, Colombia. A total of 97 stool samples from children aged between 5 and 15 years were collected and examined via direct light microscopy. Microscopic examination was repeated with sediments obtained using a fecal parasite concentrator, and the Kato-Katz test was performed. Frequency of intestinal parasite infection was 100%. Endolimax nana (77.35%), Blastocystis sp. (71.1%), Giardia intestinalis (39.1%), Entamoeba coli (25.7%), and the Entamoeba histolytica/dispar/moshkovskii complex (9.2%) were the most prevalent protozoa. Trichuris trichiura was the most prevalent helminth (12.3%), followed by Enterobius vermicularis (6.15%) and Ascaris lumbricoides (5.1%). Among the analyzed associated factors, consumption of untreated water increased the risk of acquiring pathogenic intestinal parasites. Finally, because G. intestinalis was the most prevalent pathogenic protozoan, molecular analysis was conducted to establish genetic assemblages and subassemblages of Giardia through sequence-based genotyping of the glutamate dehydrogenase, triose phosphate isomerase, and beta-giardin genes. A total of 14 G. intestinalis-positive samples were genotyped, which revealed the presence of subassemblages AI (n = 1), AII (n = 7), BIII (n = 2), BIV (n = 2), and BIII/BIV (n = 1) as well as a mixed subassemblage AII + BIII (n = 1). Our results indicate that gastrointestinal parasite infections in the tested population were mainly caused by suboptimal water quality. Moreover, molecular typing of G. intestinalis suggested contamination of water by animal- and human-derived cysts.

Development and evaluation of molecular tools for detecting and differentiating intestinal amoebae in healthy individuals.

Amoebae are single-celled parasites frequently colonizing human gut. However, few molecular tools are available for accurate identification. Here, we evaluated a panel of polymerase chain reactions (PCRs) targeting Entamoeba histolytica, Entamoeba dispar, Entamoeba coli, Entamoeba hartmanni, Entamoeba polecki, Endolimax nana and Iodamoeba bütschlii. Thirty-six faecal samples (18 containing at least one amoeba species by microscopy and 18 microscopy negative for amoebae) were tested. Real-time PCRs were used for detection and differentiation of E. histolytica and E. dispar. Conventional PCR with Sanger sequencing were applied for detection and differentiation of E. coli, E. hartmanni, E. polecki, E. nana and I. bütschlii. All microscopy results were confirmed by DNA-based methods. However, more samples were positive for single and mixed amoebic species by DNA-based assays than by microscopy (22 vs 18 and 7 vs 1, respectively). DNA sequencing allowed identification of E. coli subtypes (ST1 and ST2), showed low intra-specific variation within E. hartmanni, identified two phylogenetically distinct groups within E. nana, and identified Iodamoeba at the ribosomal lineage level. Taking into account the high intra-genetic diversity within some of the species at the small subunit (SSU) rRNA gene level, amplification of SSU rRNA genes with subsequent sequencing represents a useful method for detecting, differentiating and subtyping intestinal amoebae.

Enteroparasitism and Risk Factors Associated with Clinical Manifestations in Children and Adults of Jalisco State in Western Mexico

OBJECTIVES: To determine the prevalence and risk factors associated with intestinal parasites in the population of San Juan Cosala, Jalisco, Mexico. METHODS: A total of 277 samples from 104 participants were analysed using direct smear, flotation, formaldehyde/ethyl acetate, and modified Kinyoun’s acid-fast stain methods. The Graham method was applied only for samples from children under 12 years of age for the diagnosis of Enterobius vermicularis. RESULTS: The prevalence of parasite infections in the study population was 77.9% including: Entamoeba histolytica/E. dispar/E. moshkovskii/E. bangladeshi (37.5%), Giardia intestinalis (11.5%); commensals: Endolimax nana (44.2%), Entamoeba coli (27.9%), Chilomastix mesnili (6.7%) and Iodamoeba bütschlii, (2.9%); emerging intestinal protozoans: Blastocystis spp. (49%), Cryptosporidium spp. (7.7%) and Cyclospora cayetanensis (2.9%); and helminths: Enterobius vermicularis (18.3%) and Ascaris lumbricoides (5.8%). The results also showed that 58.64% of the studied population presented polyparasitism. A significant association was found between protozoan infections and housewives, and houses that were not built with concrete ceilings, brick walls and cement floors (p < 0.05). CONCLUSION: Polyparasitism was observed in over half the study population. The most prevalent parasite was Blastocystis spp, whilst the prevalence of helminths was less than that of protozoans. The risk factors for infection to intestinal parasites were being a housewife and not having solid brick, cement and concrete materials for house construction.

Prevalence of non-pathogenic types of gastrointestinal protozoa in population in Slovakia and their potential importance in the aspect of public health.

The aim of the research was to determine the prevalence of non-pathogenic protozoa circulating in the human population of Slovakia. We particularly focused on the socially deprived areas with poor sanitation conditions, as they are one of the factors affecting the transmission of these infections. Within this study, 2760 people were coprologically screened for the presence of protozoan cysts. The analyzed group comprised 1173 men and 1587 women from different regions of Slovakia. The total prevalence (2.03%) of non-pathogenic protozoa species was determined. The prevalence of Entamoeba coli was 0.80%, the prevalence of Endolimax nana 0.58%, and the prevalence of Blastocystis hominis was 0.65%. The presence of non-pathogenic protozoa was more frequent in women than that in men, in all age groups. The highest incidence of Entamoeba coli was found in children aged one month - seven years (0.79%), the lowest in the age group of 19-88 years (0.66%). Endolimax nana was most frequent in 8-18 year-olds (0.95%), where the statistical significance was found (p<0.05). The prevalence of Blastocystis hominis by the age group ranged from 0.39 to 0.95%. We did not find any statistical significance (p>0.05) for Entamoeba coli, and similarly for Blastocystis hominis associated with the sex and age. Although the circulation of non-pathogenic protozoa in the human population is far from being limited to the developing countries, their occurrence is also frequent in the population of developed countries. Despite their controversial pathogenicity, they should not be neglected, particularly in the patients with gastrointestinal symptoms.

Horizontal transmission of Endolimax piscium, causative agent of systemic amoebiasis in Senegalese sole Solea senegalensis.

Systemic amoebiasis of Senegalese sole Solea senegalensis is caused by Endolimax piscium Constenla, Padrós & Palenzuela, 2014 a cryptic parasitic member of the Archamoebae whose epidemiology is yet unknown. To test whether the parasite can be transmitted horizontally, an experimental trial by cohabitation between non-infected and infected fish was designed. Transmission of the parasite from naturally infected to healthy fish was confirmed in the experiment, with the water as the most likely route of infection. Under the conditions of the study, the infection process was remarkably slow, as parasites could be detected by in situ hybridization within the intestinal mucosa of recipient fish only after 17 wk of cohabitation, and none of the new hosts displayed clinical signs of disease. Long prepatent period and the need for additional triggering factors for the development of the clinical condition are suggested. The intestinal mucosa is proposed as the tissue where the amoeba can survive as endocommensal, but also as an invasion route from which the parasite would disperse to other organs.

Intestinal helminths and protozoan infections in patients with colorectal cancer: prevalence and possible association with cancer pathogenesis.

The purpose of the present study was to determine the prevalence of intestinal helminths and protozoa in colorectal cancer (CRC) patients and to evaluate the possible association between the prevalence and CRC pathogenesis. A total of 200 CRC patients and 200 residents of Tashkent, who had no complaints related to the gastrointestinal tract, were examined by triple coproscopy using a concentration method and estimations of protozoan infection intensity. Of the CRC patients tested, 144 were classified as T1-4N0M0 (without metastases) and 56 were classified as T1-4N1-2M0-1 (with metastases). Parasitological examination was performed during CRC diagnosis before and after surgery and chemotherapy. A significantly higher prevalence of Blastocystis sp., Chilomastix mesnili, Jodamoeba butschlii, and Endolimax nana was found in CRC patients than in the control population (p < 0.0001), amounting to 80, 20, 22.5, and 11.5%, respectively. The high prevalence of Blastocystis sp., as well as the patterns of infection intensity, was stable at all stages of examination. The ratio of the number of CRC patients with and without Blastocystis sp. in the T1-4N0M0 and T1-4N1-2M0-1 groups amounted to 3.3 and 7.0, respectively. The ratios for C. mesnili, E. coli, J. butschlii, and E. nana in both groups were 0.2 and 0.2, 0.07 and 0.07, 0.3 and 0.16, and 0.18 and 0.01, respectively. The prevalence of helminths and Giardia lamblia in CRC patients and the control population was not significantly different. Taken together, these data indicate a possible role for Blastocystis sp. in CRC pathogenesis. Diagnosis, treatment, and further observation of patients with Blastocystis sp. are necessary at all stages of CRC, including during diagnosis and before and after surgery and chemotherapy.

Formalin-ethyl acetate concentration, FLOTAC Pellet and anal swab techniques for the diagnosis of intestinal parasites.

The aim of this study was to compare formalin-ethyl acetate concentration and FLOTAC Pellet techniques for the diagnosis of intestinal parasites in human stool samples. The anal swab method was used for the specific detection of Enterobius vermicularis. The study was performed in children and youth from Puerto Madryn (South Argentina). A total of 174 individuals were examined using the formalin-ethyl acetate concentration technique (FECT), the FLOTAC Pellet technique with saturated sodium chloride and zinc sulphate flotation solutions and anal swabs. The performance of copromicroscopic techniques was evaluated according to sensitivity, negative predictive value and Kappa index. Overall, 39.1% of the individuals were parasitised. The most prevalent species was Blastocystis sp. (19%) followed by E. vermicularis (17.8%), Giardia lamblia (6.3%), Entamoeba coli (5.7%), Hymenolepis nana and Endolimax nana (1.1%). The FECT was the most sensitive technique for Blastocystis sp., G. lamblia and E. coli infections, whereas FLOTAC Pellet techniques were the most sensitive for H. nana diagnosis. Anal swabs detected the highest percentage of E. vermicularis infection. This was the first time that the FLOTAC Pellet technique was used to detect intestinal parasites in humans. The FECT continues to be a reliable method for detecting protozoa and the FLOTAC Pellet technique gains importance in the diagnosis of helminths. Anal swab test remains the method of choice for the detection of E. vermicularis. However, when comparing techniques, key factors as preservation methods, preservation times and flotation solutions should be taken into account.

A Cross-Sectional Study on Intestinal Parasitic Infections in Children in Suburban Public Primary Schools, Saraburi, the Central Region of Thailand.

Intestinal parasitic infection rate among school-aged children in Thailand has been decreasing. However, certain intestinal parasites remain problematic in some regions. This cross-sectional study was conducted between February and September 2016 in three suburban government primary schools (KK, BR, and HK), Saraburi, Thailand. Stool was collected from 263 asymptomatic subjects (4-15 years old), using simple direct smear, formalin-ether concentration, Boeck and Drbohlav's Locke-Egg-Serum (LES) medium culture, and agar plate culture. A self-administered questionnaire was used to collect data about lifestyle and socioeconomic status. The overall rate of intestinal parasites was 22.1% (15.6% single infection and 6.5% multiple infections). The helminths involving the digestive system found were Strongyloides stercoralis (1.5%) and Opisthorchis viverrini (0.4%). For protozoan infection, the major cause was Blastocystis hominis (17.5%). The other protozoa included Endolimax nana (4.6%), Entamoeba coli (3.4%), Entamoeba histolytica/Entamoeba dispar (1.1%), and Giardia intestinalis (0.8%). The sensitivity for the detection of B. hominis increased with the LES culture technique. The infection rate of each organism was not significantly different among the three schools except for B. hominis which showed the highest prevalence in the HK school (P = 0.001). This was correlated with the questionnaire results in which the HK school showed the highest risk of drinking contaminated water (P = 0.004). The present study emphasized the persistent problems of protozoan infections among suburban school-aged children. Lifestyle was still an important factor for intestinal parasitic infections among suburban school-aged Thai children in this study. Health education as well as routine surveillance was necessary to control the infections.