Metataxomics reveals Blastocystis subtypes mixed infections in Colombian children.

Blastocystis sp., is an intestinal protist with a broad host range and a high prevalence in human populations worldwide, even in developed Western countries. The publication of conflicting evidence has divided the scientific community about the pathogenic role of this parasite. Even though, genetic studies on Blastocystis sp. revealed associations between genotypes and different pathogenic profiles. Conventionally, the detection of this parasite is based on microscopic or PCR methods, which offer meager or null performance in detecting mixed infections. In this work, we applied a metataxonomic NGS approach targeting the V4 region of the eukaryotic SSU-rRNA gene and classical phylogenetic methods. This approach allowed us to detect Blastocystis sp. in stool samples from infected children living in an urban setting in the city of Medellin attending the same daycare center. Phylogenetic analysis identified the subtypes present in the children as ST1, ST2, and ST3. Besides, mixed infections of subtypes ST1 + ST3 were spotted in 16% of the analyzed stool samples.

Evaluation of new Toxocara canis chimeric antigens as an alternative to conventional TES-Ag for anti-Toxocara antibodies detection.

Human toxocariasis is one of the neglected helminthiases and it is caused by the zoonotic roundworm species Toxocara canis and Toxocara cati. Diagnosis of human toxocariasis is based on the combination of clinical, parasitological, and epidemiological criteria, as well as serology tests that detect anti-Toxocara antibodies. Notwithstanding, due to the absence of pathognomonic symptoms and signs of the disease, serology is the key evidence to support a conclusive diagnosis. TES-ELISA is the most widely used serological test for diagnosis. However, cross-reaction of TES antigens with antibodies produced to other helminth antigens is a major drawback for its application in countries with high parasitic prevalence. T. canis recombinant antigens have been described as an alternative to native TES for diagnosis. Nevertheless, the selection of antigenic proteins is a complex process that requires validation. In this paper, we developed an eGFP carrier-based system to express and purify blocks of recombinant polypeptides of T. canis antigenic proteins. Intense cross-reaction polypeptides were detected by Immunoblot and avoided to finally produce a chimeric prototype protein. Additionally, a control chimeric protein that harbors the complete tested proteins was produced. Purified chimeric antigens were tested in ELISA and Immunoblot assays with 310 sera samples of negative and positive control individuals. Our results showed that chimeric rCHITC0 and rCHITC1 antigens (with sensitivities of 62% 58%, 38% and 16% in IB-rCHITC0, ELISA-rCHITC0, ELISA-rCHITC1 and IB-rCHITC1 respectively for OLMS) can perform better in terms of specificity (being 91%, 89%, 87% and 76% for ELISA-rCHITC1, IB-rCHITC1, ELISA-rCHITC0 and IB-rCHITC0 respectively for OLMS) than T. canis TES-ELISA (with 61% specificity), giving a higher signal with serum samples of infected individuals as well the possibility to discriminate false positive cases with other parasitic infections. Our data suggest that T. canis chimeric proteins, represent candidate antigens for phase II studies.

Multilocus Sequence Typing helps understand the genetic diversity of Cryptosporidium hominis and Cryptosporidium parvum isolated from Colombian patients.

Multilocus Sequence Typing has become a useful tool for the study of the genetic diversity and population structure of different organisms. In this study, a MLST approach with seven loci (CP47, MS5, MS9, MSC6-7, TP14, and gp60) was used to analyze the genetic diversity of Cryptosporidium hominis and Cryptosporidium parvum isolated from 28 Colombian patients. Five Cryptosporidium species were identified: C. hominis, C. parvum, Cryptosporidium felis, Cryptosporidium meleagridis, and Cryptosporidium suis. Unilocus gp60 analysis identified four allelic families for C. hominis (Ia, Ib, Id, and Ie) and two for C. parvum (IIa and IIc). There was polymorphic behavior of all markers evaluated for both C. hominis and C. parvum, particularly with the CP47, MS5, and gp60 markers. Phylogenetic analysis with consensus sequences (CS) of the markers showed a taxonomic agreement with the results obtained with the 18S rRNA and gp60 gene. Additionally, two monophyletic clades that clustered the species C. hominis and C. parvum were detected, with a higher number of subclades within the monophyletic groups compared to those with the gp60 gene. Thirteen MLG were identified for C. hominis and eight for C. parvum. Haplotypic and nucleotide diversity were detected, but only the latter was affected by the gp60 exclusion from the CS analysis. The gene fixation index showed an evolutionary closeness between the C. hominis samples and a less evolutionary closeness and greater sequence divergence in the C. parvum samples. Data obtained in this work support the implementation of MLST analysis in the study of the genetic diversity of Cryptosporidium, considering the more detailed information that it provides, which may explain some genetic events that with an unilocus approach could not be established. This is the first multilocus analysis of the intra-specific variability of Cryptosporidium from humans in South America.

Intestinal parasitic infection alters bacterial gut microbiota in children.

The study of the burden that parasites can exert upon the bacterial gut microbiota was restricted by the available technologies and their costs. Currently, next-generation sequencing coupled with traditional methodologies allows the study of eukaryotic parasites (protozoa and helminths) and its effects on the human bacterial gut microbiota diversity. This diversity can be altered by a variety of factors such as age, diet, genetics and parasitic infections among others. The disturbances of the gut microbiota have been associated with a variety of illnesses. Children population in developing countries, are especially susceptible to parasitic infections because of the lack of proper sanitation and undernutrition, allowing both, the thriving of intestinal parasites and profound alteration of the gut microbiota. In this work, we have sampled the stool of 23 children from four different children's care-centers in Medellin, Colombia, and we have identified the eukaryotic parasites by traditional and molecular methodologies coupled with microbial profiling using 16S rDNA sequencing. This mixed methodology approach has allowed us to establish an interesting relationship between Giardia intestinalis and helminth infection, having both effects upon the bacterial gut microbiota enterotypes, causing a switch from a type I to a type II enterotype upon infection.

Transcriptome profiling of the cysticercus stage of the laboratory model Taenia crassiceps, strain ORF.

Neurocysticercosis (NC) is a serious public health problem mainly in developing countries. NC caused by the cysticercus stage from cestode Taenia solium is considered by the WHO and ITFDE as a potentially eradicable disease. Definitive diagnosis of NC is challenging because of the unspecific clinical manifestations such as the non-definitive evidence presented by neuroimaging (in most cases) and the lack of definitive serological test. Taenia crassiceps (ORF strain) is a cestode closely related to T. solium and it has frequently been used as a source of antigens for immunodiagnostics. A murine model to study host immune response to infection has also been established by using T. crassiceps. Despite the extensive use of T. crassiceps for research, molecular information for this cestode is scarce in public databases. With the aim of providing more extensive information on T. crassiceps biology, an RNA-seq experiment and subsequent bioinformatic transcriptome processing of this cestode parasite mRNA in its cysticercus stage were carried out. A total of 227,082 read/ESTs were sequenced using the 454-GS FLX Titanium technology and assembled into 10,787 contigs. This transcriptome dataset represents new and valuable molecular information of the cestode T. crassiceps (ORF). This information will substantially improve public information and will help to achieve a better understanding of the biology of T. crassiceps and to identify target proteins for serodiagnosis and vaccination.

Valoración clínica y parasitológica del tití gris (Primates: Cebidae: Saguinus leucopus) en dos poblaciones naturales presentes en San Carlos y San Rafael (Antioquia, Colombia) / Clinical and parasitological evaluation of White-footed Tamarins (Primates: Cebidae: Saguinusleucopus) from two free-range populations located in San Carlos and San Rafael (Antioquia, Colombia) / Valoração clínica e parasitológica do sagui cinza (Primates: Cebidae: Saguinus leucopus) em duas populações naturais que se encontram em San Carlos e San Rafael (Antioquia, Colômbia)

Resumen El estudio de individuos en cautiverio de primates Neotropicales ha permitido conocer aspectos básicos de su historia natural. Sin embargo las condiciones medioambientales pueden determinar diferencias ecológicas y fisiológicas en poblaciones silvestres. En el caso del tití gris (Saguinus leucopus), primate endémico del noroccidente colombiano, diferentes parámetros fisiológicos han sido evaluados en cautiverio. Con el fin de diagnosticar el estado de salud en condiciones naturales, se evaluaron varias características externas y parámetros fisiológicos, así como la comunidad de parásitos de dos poblaciones naturales. Aunque en general no se detectaron signos de deterioro en las condiciones generales de salud, se identificaron once taxones de parásitos entre helmintos y protozoos, algunos con alta prevalencia (filarias y Trypanosoma spp). Las comunidades de parásitos en cautiverio y en estado silvestre muestran diferencias notables. Igualmente, se identificó una aparente variación entre poblaciones silvestres e incluso entre grupos sociales circundantes con respecto a los perfiles hematológicos y de química sanguínea, que sugiere diferencias en la respuesta fisiológica ante condiciones medioambientales. Ninguna de dichas variables fisiológicas pareció estar relacionada con los parásitos encontrados. Los resultados revelaron una amplia diversidad de parásitos y una elevada tasa de infecciones parasitarias en poblaciones naturales de S. leucopus, que parecen no estar asociadas con indicadores de la condición de salud. Futuros estudios deberán enfatizar en aspectos ecológicos, genéticos y demográficos que determinen las condiciones de salud de S. leucopus en su medio natural. Se recomienda que la rehabilitación de individuos en cautiverio tenga presente posibles diferencias en variables fisiológicas y epidemiológicas entre poblaciones naturales y grupos en cautiverio con el fin de restringir la transmisión de agentes infecciosos entre ...

Abstract While much of the natural history of Neotropical primates has been revealed through studies conducted in captive individuals, environmental factors may impose ecological and physiological differences in free-range populations. For the white-footed tamarin (Saguinus leucopus), a primate endemic to Northwest Colombia, physiological parameters that have been assessed in captivity still remain to be measured in free-range populations. In order to diagnose the health status of this species in a natural environment, we assessed several external traits, measured hematological and blood-chemistry values, and characterized the parasite community of two natural populations. Despite the identification of eleven different parasite taxa and wide distribution of filaria and Trypanosoma spp., we faieled to detect signs of poor health condition. Substantial differences were found between captive and free-range tamarin populations in the composition of their parasite communities. Likewise, hematological and blood-chemistry profiles differed between free-range populations and even between neighboring social groups, suggesting a role of environmental factors in the physiological response. However, none of the physiological parameters varied as a response to parasite infection. Our results revealed a high diversity of parasites and elevated rates of parasitic infections in natural populations of S. leucopus, that do not seem to be associated with indicators of health conditions. Future studies should emphasize on ecological, genetic and demographic factors that determine the health conditions of S. leucopus in the wild. Lastly, geographic variation of physiological profiles and parasite distribution, as well as epidemiological differences between captive and wild populations, should be incorporated in rehabilitation plans of captive tamarins in order to restrict the transmission of infectious agents between populations.

Resumo O estudo de indivíduos em cativeiro de primatas Neotropicais tem permitido conhecer aspectos básicos da história natural. Embora as condições ambientais podem determinar diferenças ecológicas e fisiológicas em populações silvestres. No caso do sagui cinza (Saguinus leucopus), primata endémico do noroeste colombiano, diferentes parâmetros fisiológicos tem sido avaliados em cativeiro. Com o intuito de diagnosticar o estado de saúde em condições naturais, avaliaram-se vários rasgos externos e parâmetros fisiológicos, assim como a comunidade de parasitas de duas populações naturais. Ainda que em geral não se detectassem signos de deterioro nas condições gerais de saúde, identificaram-se onze táxones de parasitas entre helmintos e protozoários, alguns com alta prevalência (filarias e Trypanosoma spp). As comunidades de parasitas em cativeiro e no estado silvestre mostram diferenças notáveis. Igualmente, identificou-se uma aparente variação entre populações silvestres e entre grupos sociais circundantes com respeito aos perfis hematológicos e de química sanguínea, que sugere diferenças na resposta fisiológica diante condições ambientais do médio. Nenhuma das mencionadas variáveis fisiológicas pareceu estar relacionada com as parasitas encontradas. Os resultados revelaram uma grande diversidade de parasitas e uma alta taxa de infecção parasitária em populações naturais de S. leucopus, que não parecem estar associados com indicadores do condição de saúde. Estudos deste tipo no futuro deveram enfatizar em aspectos ecológicos, genéticos e demográficos que determinem as condições de saúde de S. leucopus em seu médio natural. Recomenda-se que a reabilitação de indivíduos em cativeiro tenha presente possíveis diferenças em variáveis fisiológicas e epidemiológicas entre populações naturais e grupos em cativeiro com o fim de restringir a transmissão de agentes infeciosos entre populações.

Giardia intestinalis and nutritional status in children participating in the complementary nutrition program, Antioquia, Colombia, May to October 2006.

Giardia intestinalis infection is prevalent throughout the world and widely distributed in developing countries. In general, children display serious consequences to their state of health, including slow height-weight development; therefore, the main aim of this study was to determine the association between Giardia infection and the nutritional status of children who participate in the program of complementary feeding (Mejoramiento Alimentario y Nutricional de Antioquia (MANA) - Instituto Colombiano de Bienestar Familiar (ICBF)). A cross-sectional study examining the association of giardiasis with nutritional status was conducted. A total of 2035 children aged eight months to six years-old were studied. Data were collected using structured questionnaires, anthropometric measurements and laboratory analysis of blood and stool samples. Analysis of the results showed that 27.6% of children were infected with G. intestinalis, while 8.1% and 1.9% were mildly and significantly underweight, respectively, and 14.1% presented stunting. Giardiasis was statistically identified as a strong predictor of stunting in this study population.

Giardia intestinalis and nutritional status in children participating in the complementary nutrition program, Antioquia, Colombia, May to October 2006 / Giardia intestinalis e estado nutricional em crianças participantes do programa de nutrição complementar, melhoramento alimentar e nutricional da Antioquia (MANA): Instituto Colombiano de Bem-Estar Familiar (ICBF), Antióquia, Colombia, maio a outubro de 2006

Giardia intestinalis infection is prevalent throughout the world and widely distributed in developing countries. In general, children display serious consequences to their state of health, including slow height-weight development; therefore, the main aim of this study was to determine the association between Giardia infection and the nutritional status of children who participate in the program of complementary feeding (Mejoramiento Alimentario y Nutricional de Antioquia (MANA) - Instituto Colombiano de Bienestar Familiar (ICBF)). A cross-sectional study examining the association of giardiasis with nutritional status was conducted. A total of 2035 children aged eight months to six years-old were studied. Data were collected using structured questionnaires, anthropometric measurements and laboratory analysis of blood and stool samples. Analysis of the results showed that 27.6% of children were infected with G. intestinalis, while 8.1% and 1.9% were mildly and significantly underweight, respectively, and 14.1% presented stunting. Giardiasis was statistically identified as a strong predictor of stunting in this study population.

A infecção pela Giardia intestinalis está amplamente distribuída no mundo apresentando a maior prevalência nos países em desenvolvimento. Em crianças, esta parasitose pode ter conseqüências graves no estado geral de saúde assim como no ganho de peso e estatura. O objetivo desta pesquisa foi estabelecer a associação entre a infecção com Giardia e o estado nutricional das crianças beneficiárias do programa de complementação alimentar - MANA. Um estudo de corte no qual foram avaliadas 2035 crianças entre os oito meses e os seis anos de idade foi realizado. A informação foi obtida a partir de questionários estruturados, medições antropométricas e exame de fezes. Os resultados mostraram que 27,6% das crianças estavam infectadas com Giardia intestinalis, das quais 8,1% apresentaram desnutrição moderada, 1,9% desnutrição grave e 14,1% franca queda no crescimento. Em conclusão, nesta população a Giardíase foi indicador de desnutrição grave.