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.

Microsporidia as a Potential Threat to the Iberian Lynx (Lynx pardinus).

Lynx pardinus is one of the world's most endangered felines inhabiting the Iberian Peninsula. The present study was performed to identify the presence of microsporidia due to the mortality increase in lynxes. Samples of urine (n = 124), feces (n = 52), and tissues [spleen (n = 13), brain (n = 9), liver (n = 11), and kidney (n = 10)] from 140 lynxes were studied. The determination of microsporidia was evaluated using Weber's chromotrope stain and Real Time-PCR. Of the lynxes analyzed, stains showed 10.48% and 50% positivity in urine and feces samples, respectively. PCR confirmed that 7.69% and 65.38% belonged to microsporidia species. The imprints of the tissues showed positive results in the spleen (38.46%), brain (22.22%), and liver (27.27%), but negative results in the kidneys. PCR confirmed positive microsporidia results in 61.53%, 55.55%, 45.45%, and 50%, respectively. Seroprevalence against Encephalitozoon cuniculi was also studied in 138 serum samples with a positivity of 55.8%. For the first time, the results presented different species of microsporidia in the urine, feces, and tissue samples of Lynx pardinus. The high titers of anti-E. cuniculi antibodies in lynx sera confirmed the presence of microsporidia in the lynx environment. New studies are needed to establish the impact of microsporidia infection on the survival of the Iberian lynx.

Comparative genomic analysis of the principal Cryptosporidium species that infect humans.

Cryptosporidium parasites are ubiquitous and can infect a broad range of vertebrates and are considered the most frequent protozoa associated with waterborne parasitic outbreaks. The intestine is the target of three of the species most frequently found in humans: C. hominis, C. parvum, and. C. meleagridis. Despite the recent advance in genome sequencing projects for this apicomplexan, a broad genomic comparison including the three species most prevalent in humans have not been published so far. In this work, we downloaded raw NGS data, assembled it under normalized conditions, and compared 23 publicly available genomes of C. hominis, C. parvum, and C. meleagridis. Although few genomes showed highly fragmented assemblies, most of them had less than 500 scaffolds and mean coverage that ranged between 35X and 511X. Synonymous single nucleotide variants were the most common in C. hominis and C. meleagridis, while in C. parvum, they accounted for around 50% of the SNV observed. Furthermore, deleterious nucleotide substitutions common to all three species were more common in genes associated with DNA repair, recombination, and chromosome-associated proteins. Indel events were observed in the 23 studied isolates that spanned up to 500 bases. The highest number of deletions was observed in C. meleagridis, followed by C. hominis, with more than 60 species-specific deletions found in some isolates of these two species. Although several genes with indel events have been partially annotated, most of them remain to encode uncharacterized proteins.

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.

[Modified Ziehl-Neelsen and modified Safranin staining for diagnosing Cyclospora cayetanensis]. / Coloraciones Ziehl-Neelsen y Safranina modificadas para el Diagnóstico de Cyclospora cayetanensis.

OBJECTIVE: Comparing modified Ziehl-Neelsen (ZNm) and modified Safranin (Sm) staining for detecting C. cayetanensis oocysts in stool samples. METHODS: The sample to be analysed consisted of 100 stool samples which had been previously evaluated by direct microscopic examination and concentration. Each sample was then ZNm and Sm stained. Microscope examination was used as gold standard for comparing both techniques by statistical analysis. RESULTS: There was 95% sensitivity and 90% specificity for ZNm and 98% sensitivity and 100% specificity for Sm. The Kappa index was 0.93, signifying a very good degree of agreement between the two techniques. CONCLUSIONS: The use of either of the two stains for diagnosing C. cayetanensis can be recommended due to the high sensitivity and specificity for Zm and Sm found in this study and to the high degree of agreement between them.

Coloraciones Ziehl-Neelsen y Safranina modificadas para el diagnóstico de Cyclospora cayetanensis / Modified Ziehl-Neelsen and modified Safranin staining for diagnosing Cyclospora cayetanensis

Objetivo Comparar las coloraciones Ziehl-Neelsen modificada (ZNm) y Safranina modificada (Sm) en la detección de ooquistes de C. cayetanensis en muestras de materia fecal . Metodología Se analizaron 100 muestras de materia fecal que fueron evaluadas previamente por coprológico directo y por concentración, posteriormente se realizaron las coloraciones ZNm y Sm para cada una de las muestras. Para la comparación de las dos técnicas se hicieron análisis estadísticos tomando como prueba oro el examen directo. Resultados Se encontró una sensibilidad y especificidad del 95 por ciento y 98 por ciento para ZNm y del 90 por ciento y 100 por ciento para Sm respectivamente. El índice Kappa fue de 0,93, correspondiendo a un muy buen grado de concordancia entre las dos coloraciones. Conclusiones Debido a la alta sensibilidad y especificidad encontradas en este estudio para Zm y Sm y al alto grado de concordancia entre ellas, cualquiera de las dos coloraciones puede ser utilizada para el diagnóstico de rutina de C. cayetanensis.

Objective Comparing modified Ziehl-Neelsen (ZNm) and modified Safranin (Sm) staining for detecting C. cayetanensis oocysts in stool samples. Methods The sample to be analysed consisted of 100 stool samples which had been previously evaluated by direct microscopic examination and concentration. Each sample was then ZNm and Sm stained. Microscope examination was used as gold standard for comparing both techniques by statistical analysis. Results There was 95 percent sensitivity and 90 percent specificity for ZNm and 98 percent sensitivity and 100 percent specificity for Sm. The Kappa index was 0,93, signifying a very good degree of agreement between the two techniques. Conclusions The use of either of the two stains for diagnosing C. cayetanensis can be recommended due to the high sensitivity and specificity for Zm and Sm found in this study and to the high degree of agreement between them.