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6. Comparison of molecular diagnostic approaches for the detection and differentiation of the intestinal protist Blastocystis sp. in humans

Author

Šloufová Martina, Lhotská Zuzana, Jirků Milan, Petrželková Klára J., Stensvold C. Rune, Cinek Ondřej, and Pomajbíková Kateřina Jirků

Subjects
blastocystis, conventional-pcr, qpcr, sensitivity, quantification, ngs, Infectious and parasitic diseases, RC109-216
Abstract

Blastocystis is the most commonly found intestinal protist in the world. Accurate detection and differentiation of Blastocystis including its subtypes (arguably species) are essential to understand its epidemiology and role in human health. We compared (i) the sensitivity of conventional PCR (cPCR) and qPCR in a set of 288 DNA samples obtained from stool samples of gut-healthy individuals, and (ii) subtype diversity as detected by next-generation sequencing (NGS) versus Sanger sequencing. Real-time PCR resulted in more positive samples than cPCR, revealing high fecal load of Blastocystis based on the quantification curve in most samples. In subtype detection, NGS was largely in agreement with Sanger sequencing but showed higher sensitivity for mixed subtype colonization within one host. This fact together with use of the combination of qPCR and NGS and obtaining information on the fecal protist load will be beneficial for epidemiological and surveillance studies.

Published
2022
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8. Mitochondrial localization of human frataxin is necessary but processing is not for rescuing frataxin deficiency in Trypanosoma brucei

Author

Long, Shaojun, Jirků, Milan, Ayala, Francisco J, and Lukeš, Julius

Subjects
Vector-Borne Diseases, Infectious Diseases, Underpinning research, 1.1 Normal biological development and functioning, Good Health and Well Being, Amino Acid Sequence, Animals, Animals, Genetically Modified, Cell Line, Cytosol, Humans, Iron-Binding Proteins, Iron-Sulfur Proteins, Mitochondria, Molecular Sequence Data, Trypanosoma brucei brucei, mitochondria protein processing, kinetoplastida, evolutionary conservation, function rescue, import
Abstract

Trypanosoma brucei, the agent of human sleeping sickness and ruminant nagana, is the most genetically tractable representative of the domain Excavata. It is evolutionarily very distant from humans, with a last common ancestor over 1 billion years ago. Frataxin, a highly conserved small protein involved in iron-sulfur cluster synthesis, is present in both organisms, and its deficiency is responsible for Friedreich's ataxia in humans. We have found that T. brucei growth-inhibition phenotype caused by down-regulated frataxin is rescued by means of human frataxin. The rescue is fully dependent on the human frataxin being imported into the trypanosome mitochondrion. Processing of the imported protein by mitochondrial processing peptidase can be blocked by mutations in the signal peptide, as in human cells. Although in human cells frataxin must be processed to execute its function, the same protein in the T. brucei mitochondrion is functional even in the absence of processing. Our results illuminate remarkable conservation of the mechanisms of mitochondrial protein import and processing.

Published
2008

9. Evolutionary and geographical history of the Leishmania donovani complex with a revision of current taxonomy

Author

Lukeš, Julius, Mauricio, Isabel L, Schönian, Gabriele, Dujardin, Jean-Claude, Soteriadou, Ketty, Dedet, Jean-Pierre, Kuhls, Katrin, Tintaya, K Wilber Quispe, Jirků, Milan, Chocholová, Eva, Haralambous, Christos, Pratlong, Francine, Oborník, Miroslav, Horák, Aleš, Ayala, Francisco J, and Miles, Michael A

Subjects
Infectious Diseases, Biotechnology, Genetics, Vector-Borne Diseases, Good Health and Well Being, Animals, Biological Evolution, Genetic Markers, Genetic Speciation, Geography, Leishmania donovani, Time Factors, Leishmania infantum, leishmaniasis, parasitic protozoa, phylogeny, population genetics
Abstract

Leishmaniasis is a geographically widespread severe disease, with an increasing incidence of two million cases per year and 350 million people from 88 countries at risk. The causative agents are species of Leishmania, a protozoan flagellate. Visceral leishmaniasis, the most severe form of the disease, lethal if untreated, is caused by species of the Leishmania donovani complex. These species are morphologically indistinguishable but have been identified by molecular methods, predominantly multilocus enzyme electrophoresis. We have conducted a multifactorial genetic analysis that includes DNA sequences of protein-coding genes as well as noncoding segments, microsatellites, restriction-fragment length polymorphisms, and randomly amplified polymorphic DNAs, for a total of approximately 18,000 characters for each of 25 geographically representative strains. Genotype is strongly correlated with geographical (continental) origin, but not with current taxonomy or clinical outcome. We propose a new taxonomy, in which Leishmania infantum and L. donovani are the only recognized species of the L. donovani complex, and we present an evolutionary hypothesis for the origin and dispersal of the species. The genus Leishmania may have originated in South America, but diversified after migration into Asia. L. donovani and L. infantum diverged approximately 1 Mya, with further divergence of infraspecific genetic groups between 0.4 and 0.8 Mya. The prevailing mode of reproduction is clonal, but there is evidence of genetic exchange between strains, particularly in Africa.

Published
2007

10. Wild chimpanzees are infected by Trypanosoma brucei

Author

Jirků, Milan, Votýpka, Jan, Petrželková, Klára J., Jirků-Pomajbíková, Kateřina, Kriegová, Eva, Vodička, Roman, Lankester, Felix, Leendertz, Siv Aina J., Wittig, Roman M., Boesch, Christophe, Modrý, David, Ayala, Francisco J., Leendertz, Fabian H., and Lukeš, Julius

Published
2015
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12. A Cross-Sectional Study on the Occurrence of the Intestinal Protist, Dientamoeba fragilis, in the Gut-Healthy Volunteers and Their Animals

Author

Jirků, Milan, primary, Kašparová, Andrea, additional, Lhotská, Zuzana, additional, Oborník, Miroslav, additional, Brožová, Kristýna, additional, Petrželková, Klára J., additional, Samaš, Peter, additional, Kadlecová, Oldřiška, additional, Stensvold, Christen Rune, additional, and Jirků, Kateřina, additional

Published
2022
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31. How many species of whipworms do we share? Whipworms from man and other primates form two phylogenetic lineages

Author

Universidad de Sevilla. Departamento de Microbiología y Parasitología, Doležalová, Jana, Oborník, Miroslav, Hajdušková, Eva, Jirků, Milan, Petrželková, Klára Judita, Bolechová, Petra, Cutillas Barrios, Cristina, Callejón Fernández, Rocío, Jaroš, Josef, Beránková, Zuzana, Modrý, David, Universidad de Sevilla. Departamento de Microbiología y Parasitología, Doležalová, Jana, Oborník, Miroslav, Hajdušková, Eva, Jirků, Milan, Petrželková, Klára Judita, Bolechová, Petra, Cutillas Barrios, Cristina, Callejón Fernández, Rocío, Jaroš, Josef, Beránková, Zuzana, and Modrý, David

Abstract

The whipworms, i.e. parasitic nematodes of the genus Trichuris Roederer, 1761, infect a variety of mammals. Apparently low diversity of primate-infecting species of Trichuris strongly contrasts with the high number of species described in other mammalian hosts. The present study addresses the diversity of whipworms in captive and free-ranging primates and humans by analysing nuclear (18S rRNA, ITS2) and mitochondrial (cox1) DNA. Phylogenetic analyses revealed that primate whipworms form two independent lineages: (i) the Trichuris trichiura (Linnaeus, 1771) clade comprised of genetically almost identical whipworms from human and other primates, which suggests the ability of T. trichiura to infect a broader range of primates; (ii) a clade containing primarily Trichuris suis Schrank, 1788, where isolates from human and various primates formed a sister group to isolates from pigs; the former isolates thus may represent of more species of Trichuris in primates including humans. The analysis of cox1 has shown the polyphyly of the genera Trichuris and Capillaria, Zeder, 1800. High sequence similarity of the T. trichiura isolates from humans and other primates suggests their zoonotic potential, although the extent of transmission between human and other non‐human primates remains questionable and requires further study

Published
2015

36. The benign helminth Hymenolepis diminuta ameliorates chemically induced colitis in a rat model system.

Author

Yurchenko, Vyacheslav, Lukeš, Julius, Jirků Pomajbíková, Kateřina, Jirků, Milan, Levá, Jana, Sobotková, Kateřina, Morien, Evan, and Parfrey, Laura Wegener

Subjects
COLITIS treatment, HYMENOLEPIS diminuta, IMMUNE response, LABORATORY rats, SULFONIC acids, INTERLEUKIN-4
Abstract

The tapeworm Hymenolepis diminuta is a model for the impact of helminth colonization on the mammalian immune system and a candidate therapeutic agent for immune mediated inflammatory diseases (IMIDs). In mice, H. diminuta protects against models of inflammatory colitis by inducing a strong type 2 immune response that is activated to expel the immature worm. Rats are the definitive host of H. diminuta , and are colonized stably and over long time periods without harming the host. Rats mount a mild type 2 immune response to H. diminuta colonization, but this response does not generally ameliorate colitis. Here we investigate the ability of different life cycle stages of H. diminuta to protect rats against a model of colitis induced through application of the haptenizing agent dinitrobenzene sulphonic acid (DNBS) directly to the colon, and monitor rat clinical health, systemic inflammation measured by TNFα and IL-1 β , and the gut microbiota. We show that immature H. diminuta induces a type 2 response as measured by increased IL-4, IL-13 and IL-10 expression, but does not protect against colitis. In contrast, rats colonized with mature H. diminuta and challenged with severe colitis (two applications of DNBS) have lower inflammation and less severe clinical symptoms. This effect is not related the initial type 2 immune response. The gut microbiota is disrupted during colitis and does not appear to play an overt role in H. diminuta -mediated protection. [ABSTRACT FROM AUTHOR]

Published
2018
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