1
|
Taghipour A, Ghodsian S, Jabbari M, Rajabpour V, Bahadory S, Malih N, Solhjoo K, Zibaei M, Abdoli A. The global epidemiology of Microsporidia infection in birds: A systematic review and meta-analysis. INTERNATIONAL JOURNAL OF ENVIRONMENTAL HEALTH RESEARCH 2024; 34:2180-2196. [PMID: 37266992 DOI: 10.1080/09603123.2023.2219988] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/05/2023] [Accepted: 05/25/2023] [Indexed: 06/03/2023]
Abstract
This study aimed to assess the global status and genetic diversity of Microsporidia infection in different birds. An online search was conducted in international databases from 1 January 1990 to 30 June 2022. A total of 34 articles (including 37 datasets) were included for the final meta-analysis. The pooled global prevalence of Microsporidia infection in birds was 14.6% (95% CI: 11.6-18.1). The highest prevalence of Microsporidia was found in wild waterfowl which was 54.5% (28.1-78.6). In terms of detection methods, the pooled prevalence was estimated to be 21.2% (95% CI: 12.1-34.4) and 13.4% (95% CI: 10.3-17.3) for using microscopic and molecular detection methods, respectively. Enterocytozoon bieneusi was the most common pathogen (24/31; 77.42% of the studies) according to PCR-based methods, and genotype D was the highest reported genotype (nine studies). In conclusion, designing strategies for the control and prevention of Microsporidia infection in birds should be recommended.
Collapse
Affiliation(s)
- Ali Taghipour
- Zoonoses Research Center, Jahrom University of Medical Sciences, Jahrom, Iran
| | - Sahar Ghodsian
- Department of Parasitology and Mycology, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Mahdi Jabbari
- Department of Microbiology, Faculty of Basic Science, Tabriz Branch, Islamic Azad University, Tabriz, Iran
| | - Vahid Rajabpour
- Zoonoses Research Center, Jahrom University of Medical Sciences, Jahrom, Iran
- Student Research Committee, Jahrom University of Medical Sciences, Jahrom, Iran
| | - Saeed Bahadory
- Department of Parasitology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran
| | - Narges Malih
- Global Health Research Group, University of the Balearic Islands (UIB), Palma, Spain
- Social Determinants of Health Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Kavous Solhjoo
- Zoonoses Research Center, Jahrom University of Medical Sciences, Jahrom, Iran
- Department of Parasitology and Mycology, Jahrom University of Medical Sciences, Jahrom, Iran
| | - Mohammad Zibaei
- Department of Parasitology and Mycology, School of Medicine, Alborz University of Medical Sciences, Karaj, Iran
- Evidence-Based Phytotherapy and Complementary Medicine Research Center, Alborz University of Medical Sciences, Karaj, Iran
| | - Amir Abdoli
- Zoonoses Research Center, Jahrom University of Medical Sciences, Jahrom, Iran
- Department of Parasitology and Mycology, Jahrom University of Medical Sciences, Jahrom, Iran
| |
Collapse
|
2
|
Ángeles-Argáiz RE, Aguirre-Beltrán LFL, Hernández-Oaxaca D, Quintero-Corrales C, Trujillo-Roldán MA, Castillo-Ramírez S, Garibay-Orijel R. Assembly collapsing versus heterozygosity oversizing: detection of homokaryotic and heterokaryotic Laccaria trichodermophora strains by hybrid genome assembly. Microb Genom 2024; 10:001218. [PMID: 38529901 PMCID: PMC10995626 DOI: 10.1099/mgen.0.001218] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2023] [Accepted: 03/01/2024] [Indexed: 03/27/2024] Open
Abstract
Genome assembly and annotation using short-paired reads is challenging for eukaryotic organisms due to their large size, variable ploidy and large number of repetitive elements. However, the use of single-molecule long reads improves assembly quality (completeness and contiguity), but haplotype duplications still pose assembly challenges. To address the effect of read length on genome assembly quality, gene prediction and annotation, we compared genome assemblers and sequencing technologies with four strains of the ectomycorrhizal fungus Laccaria trichodermophora. By analysing the predicted repertoire of carbohydrate enzymes, we investigated the effects of assembly quality on functional inferences. Libraries were generated using three different sequencing platforms (Illumina Next-Seq, Mi-Seq and PacBio Sequel), and genomes were assembled using single and hybrid assemblies/libraries. Long reads or hybrid assemby resolved the collapsing of repeated regions, but the nuclear heterozygous versions remained unresolved. In dikaryotic fungi, each cell includes two nuclei and each nucleus has differences not only in allelic gene version but also in gene composition and synteny. These heterokaryotic cells produce fragmentation and size overestimation of the genome assembly of each nucleus. Hybrid assembly revealed a wider functional diversity of genomes. Here, several predicted oxidizing activities on glycosyl residues of oligosaccharides and several chitooligosaccharide acetylase activities would have passed unnoticed in short-read assemblies. Also, the size and fragmentation of the genome assembly, in combination with heterozygosity analysis, allowed us to distinguish homokaryotic and heterokaryotic strains isolated from L. trichodermophora fruit bodies.
Collapse
Affiliation(s)
- Rodolfo Enrique Ángeles-Argáiz
- Posgrado en Ciencias Biológicas, Universidad Nacional Autónoma de México, Circuito de los Posgrados s/n, Ciudad Universitaria, Delegación Coyoacán, Ciudad de México, México, C.P. 04510, Mexico
- Instituto de Biología, Universidad Nacional Autónoma de México, Tercer Circuito s/n, Ciudad Universitaria, Delegación Coyoacán, Ciudad de México, México, C.P. 04510, Mexico
- Red de Manejo Biotecnológico de Recursos, Instituto de Ecología A. C. Carretera antigua a Coatepec 351, Col. El Haya, Xalapa, Veracruz, México, C.P. 91612, Mexico
| | - Luis Fernando Lozano Aguirre-Beltrán
- Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México, Avenida Universidad s/n, Universidad Autónoma del Estado de Morelos, Cuernavaca, Morelos, México, C.P. 62210, Mexico
| | - Diana Hernández-Oaxaca
- Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México, Avenida Universidad s/n, Universidad Autónoma del Estado de Morelos, Cuernavaca, Morelos, México, C.P. 62210, Mexico
- Red de Biodiversidad y Sistemática, Instituto de Ecología A. C. Carretera antigua a Coatepec 351, Col. El Haya, Xalapa, Veracruz, México, C.P. 91073, Mexico
| | - Christian Quintero-Corrales
- Posgrado en Ciencias Biológicas, Universidad Nacional Autónoma de México, Circuito de los Posgrados s/n, Ciudad Universitaria, Delegación Coyoacán, Ciudad de México, México, C.P. 04510, Mexico
- Instituto de Biología, Universidad Nacional Autónoma de México, Tercer Circuito s/n, Ciudad Universitaria, Delegación Coyoacán, Ciudad de México, México, C.P. 04510, Mexico
| | - Mauricio A. Trujillo-Roldán
- Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, Tercer Circuito s/n, Ciudad Universitaria, Delegación Coyoacán, Ciudad de México, México, C.P. 04510, Mexico
- Centro de Nanociencias y Nanotecnología, Universidad Nacional Autónoma de México, Km 107 carretera Tijuana-Ensenada, Ensenada, Baja California, Mexico, C.P. 22860, Mexico
| | - Santiago Castillo-Ramírez
- Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México, Avenida Universidad s/n, Universidad Autónoma del Estado de Morelos, Cuernavaca, Morelos, México, C.P. 62210, Mexico
| | - Roberto Garibay-Orijel
- Instituto de Biología, Universidad Nacional Autónoma de México, Tercer Circuito s/n, Ciudad Universitaria, Delegación Coyoacán, Ciudad de México, México, C.P. 04510, Mexico
| |
Collapse
|
3
|
Khalaf A, Lawniczak MKN, Blaxter ML, Jaron KS. Polyploidy is widespread in Microsporidia. Microbiol Spectr 2024; 12:e0366923. [PMID: 38214524 PMCID: PMC10845963 DOI: 10.1128/spectrum.03669-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2023] [Accepted: 12/15/2023] [Indexed: 01/13/2024] Open
Abstract
Microsporidia are obligate intracellular eukaryotic parasites with an extremely broad host range. They have both economic and public health importance. Ploidy in microsporidia is variable, with a few species formally identified as diploid and one as polyploid. Given the increase in the number of studies sequencing microsporidian genomes, it is now possible to assess ploidy levels across all currently explored microsporidian diversity. We estimate ploidy for all microsporidian data sets available on the Sequence Read Archive using k-mer-based analyses, indicating that polyploidy is widespread in Microsporidia and that ploidy change is dynamic in the group. Using genome-wide heterozygosity estimates, we also show that polyploid microsporidian genomes are relatively homozygous, and we discuss the implications of these findings on the timing of polyploidization events and their origin.IMPORTANCEMicrosporidia are single-celled intracellular parasites, distantly related to fungi, that can infect a broad range of hosts, from humans all the way to protozoans. Exploiting the wealth of microsporidian genomic data available, we use k-mer-based analyses to assess ploidy status across the group. Understanding a genome's ploidy is crucial in order to assemble it effectively and may also be relevant for better understanding a parasite's behavior and life cycle. We show that tetraploidy is present in at least six species in Microsporidia and that these polyploidization events are likely to have occurred independently. We discuss why these findings may be paradoxical, given that Microsporidia, like other intracellular parasites, have extremely small, reduced genomes.
Collapse
Affiliation(s)
- Amjad Khalaf
- Tree of Life, Wellcome Sanger Institute, Cambridge, United Kingdom
| | | | - Mark L. Blaxter
- Tree of Life, Wellcome Sanger Institute, Cambridge, United Kingdom
| | - Kamil S. Jaron
- Tree of Life, Wellcome Sanger Institute, Cambridge, United Kingdom
| |
Collapse
|
4
|
Weng M, Zhang X, Xin Z, Xue S, Zhang Q, Li A, Zhang J. Morphological characterization and genetic diversity of a new microsporidium, Neoflabelliforma dubium n. sp. from the adipose tissue of Diaphanosoma dubium (Crustacea: Sididae). Front Cell Infect Microbiol 2023; 13:1125394. [PMID: 36779184 PMCID: PMC9911548 DOI: 10.3389/fcimb.2023.1125394] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2022] [Accepted: 01/16/2023] [Indexed: 01/28/2023] Open
Abstract
We reported a new microsporidium Neoflabelliforma dubium n. sp. from the adipose tissue of Diaphanosoma dubium in China. The infected daphnids generally appeared opaque due to the presence of numerous spore aggregates located in the adipose tissue. All developmental stages were in direct contact with the host cell cytoplasm. Multinucleate sporogonial plasmodia developed into uninucleate sporoblasts by rosette-like fashion. Mature spores were pyriform and monokaryotic, measuring 4.02 ± 0.24 (3.63-4.53) µm long and 2.27 ± 0.15 (2.12-2.57) µm wide (N = 40). The polaroplast was bipartite with a tightly packed anterior lamellae and a loosely aligned posterior lamellae. Isofilar polar filament was coiled 9-11 turns and arranged in 2-3 rows. The phylogenetic analysis based on the obtained SSU rDNA sequence indicated that the N. dubium n. sp. clustered with the freshwater oligochaete-infecting N. aurantiae to form an independent monophyletic group, positioned at the base of Clade 4. In addition, we analyzed the genetic diversity in three N. dubium n. sp. isolates based on the rDNA (SSU rDNA, ITS and LSU rDNA) and Rpb1 gene. The genetic variation among the rDNA sequences was not distinct, however, high nucleotide diversity could be observed in Rpb1 gene, and a wide variety of Rpb1 haplotypes were identified within each isolate. Genetic recombination detected in the Rpb1 sequences presumes cryptic sexual process occurring in N. dubium n. sp. Statistical evolutionary analyses further indicated that the purifying selection eliminated mutations in the Rpb1 gene.
Collapse
Affiliation(s)
- Meiqi Weng
- The Laboratory of Aquatic Parasitology, School of Marine Science and Engineering, Qingdao Agricultural University, Qingdao, China
- Key Laboratory of Aquaculture Diseases Control, Ministry of Agriculture and State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China
- College of Advanced Agricultural Sciences, University of Chinese Academy of Sciences, Beijing, China
| | - Xintong Zhang
- The Laboratory of Aquatic Parasitology, School of Marine Science and Engineering, Qingdao Agricultural University, Qingdao, China
| | - Zhaozhe Xin
- The Laboratory of Aquatic Parasitology, School of Marine Science and Engineering, Qingdao Agricultural University, Qingdao, China
| | - Sijia Xue
- The Laboratory of Aquatic Parasitology, School of Marine Science and Engineering, Qingdao Agricultural University, Qingdao, China
| | - Qianqian Zhang
- Key Laboratory of Aquaculture Diseases Control, Ministry of Agriculture and State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China
| | - Aihua Li
- Key Laboratory of Aquaculture Diseases Control, Ministry of Agriculture and State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China
| | - Jinyong Zhang
- The Laboratory of Aquatic Parasitology, School of Marine Science and Engineering, Qingdao Agricultural University, Qingdao, China
- Laboratory for Marine Biology and Biotechnology, Pilot National Laboratory for Marine Science and Technology (Qingdao), Qingdao, Shandong, China
- *Correspondence: Jinyong Zhang,
| |
Collapse
|
5
|
Williams BAP, Williams TA, Trew J. Comparative Genomics of Microsporidia. EXPERIENTIA SUPPLEMENTUM (2012) 2022; 114:43-69. [PMID: 35543998 DOI: 10.1007/978-3-030-93306-7_2] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
The microsporidia are a phylum of intracellular parasites that represent the eukaryotic cell in a state of extreme reduction, with genomes and metabolic capabilities embodying eukaryotic cells in arguably their most streamlined state. Over the past 20 years, microsporidian genomics has become a rapidly expanding field starting with sequencing of the genome of Encephalitozoon cuniculi, one of the first ever sequenced eukaryotes, to the current situation where we have access to the data from over 30 genomes across 20+ genera. Reaching back further in evolutionary history, to the point where microsporidia diverged from other eukaryotic lineages, we now also have genomic data for some of the closest known relatives of the microsporidia such as Rozella allomycis, Metchnikovella spp. and Amphiamblys sp. Data for these organisms allow us to better understand the genomic processes that shaped the emergence of the microsporidia as a group. These intensive genomic efforts have revealed some of the processes that have shaped microsporidian cells and genomes including patterns of genome expansions and contractions through gene gain and loss, whole genome duplication, differential patterns of invasion and purging of transposable elements. All these processes have been shown to occur across short and longer time scales to give rise to a phylum of parasites with dynamic genomes with a diversity of sizes and organisations.
Collapse
Affiliation(s)
| | - Tom A Williams
- School of Biological Sciences, University of Bristol, Bristol, UK
| | - Jahcub Trew
- School of Biosciences, University of Exeter, Exeter, UK
| |
Collapse
|
6
|
Abstract
DNA repair is an important component of genome integrity and organisms with reduced repair capabilities tend to accumulate mutations at elevated rates. Microsporidia are intracellular parasites exhibiting high levels of genetic divergence postulated to originate from the lack of several proteins, including the heterotrimeric Rad9–Rad1–Hus1 DNA repair clamp. Microsporidian species from the Encephalitozoonidae have undergone severe streamlining with small genomes coding for about 2,000 proteins. The highly divergent sequences found in Microsporidia render functional inferences difficult such that roughly half of these 2,000 proteins have no known function. Using a structural homology-based annotation approach combining protein structure prediction and tridimensional similarity searches, we found that the Rad9–Rad1–Hus1 DNA clamp is present in Microsporidia, together with many other components of the DNA repair machinery previously thought to be missing from these organisms. Altogether, our results indicate that the DNA repair machinery is present and likely functional in Microsporidia.
Collapse
|
7
|
Sparse Evidence for Giardia intestinalis, Cryptosporidium spp. and Microsporidia Infections in Humans, Domesticated Animals and Wild Nonhuman Primates Sharing a Farm-Forest Mosaic Landscape in Western Uganda. Pathogens 2021; 10:pathogens10080933. [PMID: 34451397 PMCID: PMC8398676 DOI: 10.3390/pathogens10080933] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2021] [Revised: 07/18/2021] [Accepted: 07/21/2021] [Indexed: 11/16/2022] Open
Abstract
Zoonotic pathogen transmission is considered a leading threat to the survival of non-human primates and public health in shared landscapes. Giardia spp., Cryptosporidium spp. and Microsporidia are unicellular parasites spread by the fecal-oral route by environmentally resistant stages and can infect humans, livestock, and wildlife including non-human primates. Using immunoassay diagnostic kits and amplification/sequencing of the region of the triosephosphate isomerase, small ribosomal subunit rRNA and the internal transcribed spacer genes, we investigated Giardia, Cryptosporidium, and microsporidia infections, respectively, among humans, domesticated animals (livestock, poultry, and dogs), and wild nonhuman primates (eastern chimpanzees and black and white colobus monkeys) in Bulindi, Uganda, an area of remarkably high human-animal contact and spatial overlap. We analyzed 137 fecal samples and revealed the presence of G. intestinalis assemblage B in two human isolates, G. intestinalis assemblage E in one cow isolate, and Encephalitozoon cuniculi genotype II in two humans and one goat isolate. None of the chimpanzee and colobus monkey samples were positive for any of the screened parasites. Regular distribution of antiparasitic treatment in both humans and domestic animals in Bulindi could have reduced the occurrence of the screened parasites and decreased potential circulation of these pathogens among host species.
Collapse
|
8
|
Wadi L, Reinke AW. Evolution of microsporidia: An extremely successful group of eukaryotic intracellular parasites. PLoS Pathog 2020; 16:e1008276. [PMID: 32053705 PMCID: PMC7017984 DOI: 10.1371/journal.ppat.1008276] [Citation(s) in RCA: 63] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Affiliation(s)
- Lina Wadi
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada
| | - Aaron W. Reinke
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada
- * E-mail:
| |
Collapse
|
9
|
Haag KL, Pombert JF, Sun Y, de Albuquerque NRM, Batliner B, Fields P, Lopes TF, Ebert D. Microsporidia with Vertical Transmission Were Likely Shaped by Nonadaptive Processes. Genome Biol Evol 2020; 12:3599-3614. [PMID: 31825473 PMCID: PMC6944219 DOI: 10.1093/gbe/evz270] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/05/2019] [Indexed: 12/14/2022] Open
Abstract
Microsporidia have the leanest genomes among eukaryotes, and their physiological and genomic simplicity has been attributed to their intracellular, obligate parasitic life-style. However, not all microsporidia genomes are small or lean, with the largest dwarfing the smallest ones by at least an order of magnitude. To better understand the evolutionary mechanisms behind this genomic diversification, we explore here two clades of microsporidia with distinct life histories, Ordospora and Hamiltosporidium, parasitizing the same host species, Daphnia magna. Based on seven newly assembled genomes, we show that mixed-mode transmission (the combination of horizontal and vertical transmission), which occurs in Hamiltosporidium, is found to be associated with larger and AT-biased genomes, more genes, and longer intergenic regions, as compared with the exclusively horizontally transmitted Ordospora. Furthermore, the Hamiltosporidium genome assemblies contain a variety of repetitive elements and long segmental duplications. We show that there is an excess of nonsynonymous substitutions in the microsporidia with mixed-mode transmission, which cannot be solely attributed to the lack of recombination, suggesting that bursts of genome size in these microsporidia result primarily from genetic drift. Overall, these findings suggest that the switch from a horizontal-only to a mixed mode of transmission likely produces population bottlenecks in Hamiltosporidium species, therefore reducing the effectiveness of natural selection, and allowing their genomic features to be largely shaped by nonadaptive processes.
Collapse
Affiliation(s)
- Karen L Haag
- Department of Genetics and Post-Graduation Program of Genetics and Molecular Biology, Federal University of Rio Grande do Sul, Porto Alegre, Brazil
| | | | - Yukun Sun
- Department of Biology, Illinois Institute of Technology
| | - Nathalia Rammé M de Albuquerque
- Department of Genetics and Post-Graduation Program of Genetics and Molecular Biology, Federal University of Rio Grande do Sul, Porto Alegre, Brazil
| | | | - Peter Fields
- Department of Environmental Sciences, Zoology, Basel University, Switzerland
| | - Tiago Falcon Lopes
- Department of Genetics and Post-Graduation Program of Genetics and Molecular Biology, Federal University of Rio Grande do Sul, Porto Alegre, Brazil
| | - Dieter Ebert
- Department of Environmental Sciences, Zoology, Basel University, Switzerland
| |
Collapse
|
10
|
Robertson LJ, Clark CG, Debenham JJ, Dubey J, Kváč M, Li J, Ponce-Gordo F, Ryan U, Schares G, Su C, Tsaousis AD. Are molecular tools clarifying or confusing our understanding of the public health threat from zoonotic enteric protozoa in wildlife? Int J Parasitol Parasites Wildl 2019; 9:323-341. [PMID: 31338293 PMCID: PMC6626983 DOI: 10.1016/j.ijppaw.2019.01.010] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2018] [Revised: 01/30/2019] [Accepted: 01/31/2019] [Indexed: 12/13/2022]
Abstract
Emerging infectious diseases are frequently zoonotic, often originating in wildlife, but enteric protozoa are considered relatively minor contributors. Opinions regarding whether pathogenic enteric protozoa may be transmitted between wildlife and humans have been shaped by our investigation tools, and have led to oscillations regarding whether particular species are zoonotic or have host-adapted life cycles. When the only approach for identifying enteric protozoa was morphology, it was assumed that many enteric protozoa colonized multiple hosts and were probably zoonotic. When molecular tools revealed genetic differences in morphologically identical species colonizing humans and other animals, host specificity seemed more likely. Parasites from animals found to be genetically identical - at the few genes investigated - to morphologically indistinguishable parasites from human hosts, were described as having zoonotic potential. More discriminatory molecular tools have now sub-divided some protozoa again. Meanwhile, some infection events indicate that, circumstances permitting, some "host-specific" protozoa, can actually infect various hosts. These repeated changes in our understanding are linked intrinsically to the investigative tools available. Here we review how molecular tools have assisted, or sometimes confused, our understanding of the public health threat from nine enteric protozoa and example wildlife hosts (Balantoides coli - wild boar; Blastocystis sp. - wild rodents; Cryptosporidium spp. - wild fish; Encephalitozoon spp. - wild birds; Entamoeba spp. - non-human primates; Enterocytozoon bieneusi - wild cervids; Giardia duodenalis - red foxes; Sarcocystis nesbitti - snakes; Toxoplasma gondii - bobcats). Molecular tools have provided evidence that some enteric protozoa in wildlife may infect humans, but due to limited discriminatory power, often only the zoonotic potential of the parasite is indicated. Molecular analyses, which should be as discriminatory as possible, are one, but not the only, component of the toolbox for investigating potential public health impacts from pathogenic enteric protozoa in wildlife.
Collapse
Affiliation(s)
- Lucy J. Robertson
- Parasitology Laboratory, Department of Food Safety and Infection Biology, Faculty of Veterinary Medicine, Norwegian University of Life Sciences, PO Box 369 Sentrum, 0102, Oslo, Norway
| | - C. Graham Clark
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, Keppel Street, London, WC1E 7HT, United Kingdom
| | - John J. Debenham
- Department of Companion Animal Clinical Sciences, Faculty of Veterinary Medicine, Norwegian University of Life Sciences, PO Box 369 Sentrum, 0102, Oslo, Norway
| | - J.P. Dubey
- United States Department of Agriculture, Agricultural Research Service, Beltsville Agricultural Research Center, Animal Parasitic Diseases Laboratory, Building 1001, Beltsville, MD, 20705-2350, USA
| | - Martin Kváč
- Institute of Parasitology, Biology Centre of the Academy of Sciences of the Czech Republic, Branišovská 31, 370 05, České Budějovice, Czech Republic
- Faculty of Agriculture, University of South Bohemia in České Budějovice, Studentská 1668, 370 05, Czech Republic
| | - Junqiang Li
- College of Animal Science and Veterinary Medicine, Henan Agricultural University, Zhengzhou, 450046, China
| | - Francisco Ponce-Gordo
- Department of Microbiology and Parasitology, Faculty of Pharmacy, Complutense University, Plaza Ramón y Cajal s/n, 28040, Madrid, Spain
| | - Una Ryan
- Centre for Sustainable Aquatic Ecosystems, College of Science, Health, Engineering and Education, Murdoch University, Murdoch, WA, 6150, Australia
| | - Gereon Schares
- Institute of Epidemiology, Friedrich-Loeffler-Institut, Federal Research Institute for Animal Health, 17493, Greifswald, Insel Riems, Germany
| | - Chunlei Su
- Department of Microbiology, University of Tennessee, Knoxville, TN, 37996-1937, USA
| | - Anastasios D. Tsaousis
- Laboratory of Molecular & Evolutionary Parasitology, RAPID Group, School of Biosciences, University of Kent, Canterbury, UK
| |
Collapse
|
11
|
Peters MJ, Suwannapong G, Pelin A, Corradi N. Genetic and Genome Analyses Reveal Genetically Distinct Populations of the Bee Pathogen Nosema ceranae from Thailand. MICROBIAL ECOLOGY 2019; 77:877-889. [PMID: 30288544 DOI: 10.1007/s00248-018-1268-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/01/2018] [Accepted: 09/25/2018] [Indexed: 06/08/2023]
Abstract
The recent global decline in Western honeybee (Apis mellifera) populations is of great concern for pollination and honey production worldwide. Declining honeybee populations are frequently infected by the microsporidian pathogen Nosema ceranae. This species was originally described in the Asiatic honeybee (Apis cerana), and its identification in global A. mellifera hives could result from a recent host transfer. Recent genome studies have found that global populations of this parasite are polyploid and that humans may have fueled their global expansion. To better understand N. ceranae biology, we investigated its genetic diversity within part of their native range (Thailand) and among different hosts (A. mellifera, A. cerana) using both PCR and genome-based methods. We find that Thai N. ceranae populations share many SNPs with other global populations and appear to be clonal. However, in stark contrast with previous studies, we found that these populations also carry many SNPs not found elsewhere, indicating that these populations have evolved in their current geographic location for some time. Our genome analyses also indicate the potential presence of diploidy within Thai populations of N. ceranae.
Collapse
Affiliation(s)
- Melissa J Peters
- Department of Biology, University of Ottawa, Ottawa, Ontario, Canada
| | | | - Adrian Pelin
- Department of Biochemistry, University of Ottawa, Ottawa, Ontario, Canada
- Center for Cancer Therapeutics, Ottawa Hospital Research Institute, Ottawa, Ontario, Canada
| | - Nicolas Corradi
- Department of Biology, University of Ottawa, Ottawa, Ontario, Canada.
| |
Collapse
|
12
|
Abstract
Microsporidia are obligate intracellular pathogens related to Fungi. These organisms have a unique invasion organelle, the polar tube, which upon appropriate environmental stimulation rapidly discharges out of the spore, pierces a host cell's membrane, and serves as a conduit for sporoplasm passage into the host cell. Phylogenetic analysis suggests that microsporidia are related to the Fungi, being either a basal branch or sister group. Despite the description of microsporidia over 150 years ago, we still lack an understanding of the mechanism of invasion, including the role of various polar tube proteins, spore wall proteins, and host cell proteins in the formation and function of the invasion synapse. Recent advances in ultrastructural techniques are helping to better define the formation and functioning of the invasion synapse. Over the past 2 decades, proteomic approaches have helped define polar tube proteins and spore wall proteins as well as the importance of posttranslational modifications such as glycosylation in the functioning of these proteins, but the absence of genetic techniques for the manipulation of microsporidia has hampered research on the function of these various proteins. The study of the mechanism of invasion should provide fundamental insights into the biology of these ubiquitous intracellular pathogens that can be integrated into studies aimed at treating or controlling microsporidiosis.
Collapse
|
13
|
Quandt CA, Beaudet D, Corsaro D, Walochnik J, Michel R, Corradi N, James TY. The genome of an intranuclear parasite, Paramicrosporidium saccamoebae, reveals alternative adaptations to obligate intracellular parasitism. eLife 2017; 6. [PMID: 29171834 PMCID: PMC5701793 DOI: 10.7554/elife.29594] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2017] [Accepted: 11/06/2017] [Indexed: 12/17/2022] Open
Abstract
Intracellular parasitism often results in gene loss, genome reduction, and dependence upon the host for cellular functioning. Rozellomycota is a clade comprising many such parasites and is related to the diverse, highly reduced, animal parasites, Microsporidia. We sequenced the nuclear and mitochondrial genomes of Paramicrosporidium saccamoebae [Rozellomycota], an intranuclear parasite of amoebae. A canonical fungal mitochondrial genome was recovered from P. saccamoebae that encodes genes necessary for the complete oxidative phosphorylation pathway including Complex I, differentiating it from most endoparasites including its sequenced relatives in Rozellomycota and Microsporidia. Comparative analysis revealed that P. saccamoebae shares more gene content with distantly related Fungi than with its closest relatives, suggesting that genome evolution in Rozellomycota and Microsporidia has been affected by repeated and independent gene losses, possibly as a result of variation in parasitic strategies (e.g. host and subcellular localization) or due to multiple transitions to parasitism.
Collapse
Affiliation(s)
- C Alisha Quandt
- Department of Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, United States
| | - Denis Beaudet
- Department of Biology, University of Ottawa, Ottawa, Canada
| | | | - Julia Walochnik
- Molecular Parasitology, Institute for Specific Prophylaxis and Tropical Medicine, Medical University of Vienna, Koblenz, Germany
| | - Rolf Michel
- Laboratory of Electron Microscopy, Central Institute of the Federal Armed Forces Medical Services, Koblenz, Germany
| | | | - Timothy Y James
- Department of Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, United States
| |
Collapse
|
14
|
Abstract
Microsporidia comprise a phylum of obligate intracellular pathogens related to fungi that infect virtually all animals. Recently, the nematode Caenorhabditis elegans has been developed as a convenient model for studying microsporidia infection in a whole-animal host through the identification and characterization of a natural microsporidian pathogen of this commonly studied laboratory organism. The C. elegans natural microsporidian pathogen is named Nematocida parisii, and it causes a lethal intestinal infection in C. elegans. Comparison of the genomes of N. parisii and its closely related species Nematocida sp. 1, together with the genomes of other microsporidian species, has provided insight into the evolutionary events that led to the emergence of the large, specialized microsporidia phylum. Cell biology studies of N. parisii infection in C. elegans have shown how N. parisii restructures host intestinal cells and, in particular, how it hijacks host exocytosis for nonlytic exit to facilitate transmission. Recent results also show how the host responds to infection with ubiquitin-mediated responses, and how a natural variant of C. elegans is able to clear N. parisii infection, but only during early life. Altogether, these studies provide insight into the mechanisms of microsporidia pathogenesis using a whole-animal host.
Collapse
|
15
|
Dynamics of parasitophorous vacuoles formed by the microsporidian pathogen Encephalitozoon cuniculi. Fungal Genet Biol 2017; 107:20-23. [PMID: 28754285 DOI: 10.1016/j.fgb.2017.07.006] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2017] [Revised: 07/10/2017] [Accepted: 07/24/2017] [Indexed: 12/28/2022]
Abstract
It has been a long-standing debate if sexual development occurs in the microsporidian lineages. Previous studies, including morphological observations, ploidy analysis, and the presence of a sex-related locus, provided evidence of possible extant of sexual development. This study presents another line of evidence by monitoring the parasitophorous vacuoles (PVs) formed by Encephalitozoon cuniculi. Time lapse observations of infection cycles of E. cuniculi revealed that multiple PVs can be formed in a single host cell and the PVs in the single cell can merge (fusion) or split (fission). The dynamics of PVs may provide a route for interactions between genetically distinct microsporidian isolates during host infections.
Collapse
|
16
|
Abstract
Although at the level of resolution of genes and molecules most information about mating in fungi is from a single lineage, the Dikarya, many fundamental discoveries about mating in fungi have been made in the earlier branches of the fungi. These are nonmonophyletic groups that were once classified into the chytrids and zygomycetes. Few species in these lineages offer the potential of genetic tractability, thereby hampering the ability to identify the genes that underlie those fundamental insights. Research performed during the past decade has now established the genes required for mating type determination and pheromone synthesis in some species in the phylum Mucoromycota, especially in the order Mucorales. These findings provide striking parallels with the evolution of mating systems in the Dikarya fungi. Other discoveries in the Mucorales provide the first examples of sex-cell type identity being driven directly by a gene that confers mating type, a trait considered more of relevance to animal sex determination but difficult to investigate in animals. Despite these discoveries, there remains much to be gleaned about mating systems from these fungi.
Collapse
|
17
|
Ndikumana S, Pelin A, Williot A, Sanders JL, Kent M, Corradi N. Genome Analysis of Pseudoloma neurophilia: A Microsporidian Parasite of Zebrafish (Danio rerio). J Eukaryot Microbiol 2017; 64:18-30. [PMID: 27230544 PMCID: PMC5124540 DOI: 10.1111/jeu.12331] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2016] [Revised: 05/06/2016] [Accepted: 05/18/2016] [Indexed: 12/23/2022]
Abstract
Microsporidia are highly successful parasites that infect virtually all known animal lineages, including the model Danio rerio (zebrafish). The widespread use of this aquatic model for biomedical research has resulted in an unexpected increase in infections from the microsporidium Pseudoloma neurophilia, which can lead to significant physical, behavioral, and immunological modifications, resulting in nonprotocol variation during experimental procedures. Here, we seek to obtain insights into the biology of P. neurophilia by investigating its genome content, which was obtained from only 29 nanograms of DNA using the MiSeq technology and paired-end Illumina sequencing. We found that the genome of P. neurophilia is phylogenetically and genetically related to other fish-microsporidians, but features unique to this intracellular parasite are also found. The small 5.25-Mb genome assembly includes 1,139 unique open-reading frames and an unusually high number of transposable elements for such a small genome. Investigations of intragenomic diversity also provided strong indications that the mononucleate nucleus of this species is diploid. Overall, our study provides insights into the dynamics of microsporidian genomes and a solid sequence reference to be used in future studies of host-parasite interactions using the zebrafish D. rerio and P. neurophilia as a model.
Collapse
Affiliation(s)
- Steve Ndikumana
- Center for Advanced Research in Environment Genomic, Department of Biology, University of Ottawa, ON, Canada
| | - Adrian Pelin
- Center for Advanced Research in Environment Genomic, Department of Biology, University of Ottawa, ON, Canada
| | - Alex Williot
- Center for Advanced Research in Environment Genomic, Department of Biology, University of Ottawa, ON, Canada
| | - Justin L. Sanders
- Department of Microbiology, Oregon State University, Corvallis, Oregon 97331, USA
| | - Michael Kent
- Department of Microbiology, Oregon State University, Corvallis, Oregon 97331, USA
| | - Nicolas Corradi
- Center for Advanced Research in Environment Genomic, Department of Biology, University of Ottawa, ON, Canada
| |
Collapse
|
18
|
Maestrini G, Ricci E, Cantile C, Mannella R, Mancianti F, Paci G, D'Ascenzi C, Perrucci S. Encephalitozoon cuniculi in rabbits: Serological screening and histopathological findings. Comp Immunol Microbiol Infect Dis 2016; 50:54-57. [PMID: 28131379 DOI: 10.1016/j.cimid.2016.11.012] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2016] [Revised: 11/20/2016] [Accepted: 11/21/2016] [Indexed: 01/06/2023]
Abstract
Serological prevalence of E. cuniculi infection was assessed in 183 rabbits from central Italy. In seropositive deceased rabbits, histopathological lesions were also evaluated. Sera from 118 rabbits from 6 intensive farms, 10 rabbits from 6 family farms, 16 rabbits from a zoo, 30 rabbits from 5 research laboratories and 9 pet rabbits from 9 different owners, were tested by an enzyme-linked immunosorbent assay. Data were statistically analysed. Tissue samples from brain and kidney of 10 deceased rabbits were formalin-fixed and subsequently analysed by histopathology and immunohistochemistry. Anti-E. cuniculi antibodies were found in 129/183 (70.5%) analysed sera. At statistical analysis, E. cuniculi seropositivity was significantly higher (p<0.05) in industrial and zoo rabbits. At histology, different degrees of pathological lesions were found in serological positive (9) deceased animals. In three rabbits deceased after showing neurological signs, the severity of the lesions was interpreted as a likely cause for their death.
Collapse
Affiliation(s)
- Giovanni Maestrini
- Dipartimento di Scienze Veterinarie, Università di Pisa, Viale delle Piagge, 2- 56124 Pisa Italy.
| | - Emanuele Ricci
- School of Veterinary Science, University of Liverpool, Liverpool, Leahurst Campus, Chester High Road, Neston, CH64 7TE, UK.
| | - Carlo Cantile
- Dipartimento di Scienze Veterinarie, Università di Pisa, Viale delle Piagge, 2- 56124 Pisa Italy.
| | - Riccardo Mannella
- Dipartimento di Fisica "Enrico Fermi", Università di Pisa, Largo Bruno Pontecorvo, 3-56127 Pisa Italy.
| | - Francesca Mancianti
- Dipartimento di Scienze Veterinarie, Università di Pisa, Viale delle Piagge, 2- 56124 Pisa Italy.
| | - Gisella Paci
- Dipartimento di Scienze Veterinarie, Università di Pisa, Viale delle Piagge, 2- 56124 Pisa Italy.
| | - Carlo D'Ascenzi
- Dipartimento di Scienze Veterinarie, Università di Pisa, Viale delle Piagge, 2- 56124 Pisa Italy.
| | - Stefania Perrucci
- Dipartimento di Scienze Veterinarie, Università di Pisa, Viale delle Piagge, 2- 56124 Pisa Italy.
| |
Collapse
|
19
|
González-Tortuero E, Rusek J, Maayan I, Petrusek A, Piálek L, Laurent S, Wolinska J. Genetic diversity of two Daphnia-infecting microsporidian parasites, based on sequence variation in the internal transcribed spacer region. Parasit Vectors 2016; 9:293. [PMID: 27206473 PMCID: PMC4875737 DOI: 10.1186/s13071-016-1584-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2016] [Accepted: 05/10/2016] [Indexed: 11/12/2022] Open
Abstract
Background Microsporidia are spore-forming obligate intracellular parasites that include both emerging pathogens and economically important disease agents. However, little is known about the genetic diversity of microsporidia. Here, we investigated patterns of geographic population structure, intraspecific genetic variation, and recombination in two microsporidian taxa that commonly infect cladocerans of the Daphnia longispina complex in central Europe. Taken together, this information helps elucidate the reproductive mode and life-cycles of these parasite species. Methods Microsporidia-infected Daphnia were sampled from seven drinking water reservoirs in the Czech Republic. Two microsporidia species (Berwaldia schaefernai and microsporidium lineage MIC1) were sequenced at the internal transcribed spacer (ITS) region, using the 454 pyrosequencing platform. Geographical structure analyses were performed applying Fisher’s exact tests, analyses of molecular variance, and permutational MANOVA. To evaluate the genetic diversity of the ITS region, the number of polymorphic sites and Tajima’s and Watterson’s estimators of theta were calculated. Tajima’s D was also used to determine if the ITS in these taxa evolved neutrally. Finally, neighbour similarity score and pairwise homology index tests were performed to detect recombination events. Results While there was little variation among Berwaldia parasite strains infecting different host populations, the among-population genetic variation of MIC1 was significant. Likewise, ITS genetic diversity was lower in Berwaldia than in MIC1. Recombination signals were detected only in Berwaldia. Conclusion Genetic tests showed that parasite populations could have expanded recently after a bottleneck or that the ITS could be under negative selection in both microsporidia species. Recombination analyses might indicate cryptic sex in Berwaldia and pure asexuality in MIC1. The differences observed between the two microsporidian species present an exciting opportunity to study the genetic basis of microsporidia-Daphnia coevolution in natural populations, and to better understand reproduction in these parasites. Electronic supplementary material The online version of this article (doi:10.1186/s13071-016-1584-4) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Enrique González-Tortuero
- Department of Ecosystem Research, Leibniz-Institute of Freshwater Ecology and Inland Fisheries (IGB), Müggelseedamm 301, 12587, Berlin, Germany. .,Berlin Centre for Genomics in Biodiversity Research (BeGenDiv), Königin-Luise-Straße 6-8, 14195, Berlin, Germany. .,Department of Biology II, Ludwig Maximilians University, Großhaderner Straße 2, 82512, Planegg-Martinsried, Germany.
| | - Jakub Rusek
- Department of Biology II, Ludwig Maximilians University, Großhaderner Straße 2, 82512, Planegg-Martinsried, Germany
| | - Inbar Maayan
- Department of Biology II, Ludwig Maximilians University, Großhaderner Straße 2, 82512, Planegg-Martinsried, Germany
| | - Adam Petrusek
- Department of Ecology, Faculty of Science, Charles University in Prague, Viničná 7, 128 44, Prague, Czech Republic
| | - Lubomír Piálek
- Department of Ecology, Faculty of Science, Charles University in Prague, Viničná 7, 128 44, Prague, Czech Republic.,Department of Zoology, Faculty of Science, University of South Bohemia, Branišovská 31, 370 05, České Budějovice, Czech Republic
| | - Stefan Laurent
- School of Life Sciences, École Polytechnique Fédérale de Lausanne (EPFL), 1015, Lausanne, Switzerland.,Swiss Institute of Bioinformatics (SIB), 1015, Lausanne, Switzerland
| | - Justyna Wolinska
- Department of Ecosystem Research, Leibniz-Institute of Freshwater Ecology and Inland Fisheries (IGB), Müggelseedamm 301, 12587, Berlin, Germany.,Department of Biology, Chemistry and Pharmacy, Institute of Biology, Free University of Berlin, Königin-Luise-Straße 1-3, 14195, Berlin, Germany
| |
Collapse
|
20
|
Hinney B, Sak B, Joachim A, Kváč M. More than a rabbit's tale - Encephalitozoon spp. in wild mammals and birds. Int J Parasitol Parasites Wildl 2016; 5:76-87. [PMID: 28560162 PMCID: PMC5439460 DOI: 10.1016/j.ijppaw.2016.01.001] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2015] [Revised: 12/23/2015] [Accepted: 01/05/2016] [Indexed: 11/25/2022]
Abstract
Within the microsporidian genus Encephalitozoon, three species, Encephalitozoon cuniculi, Encephalitozoon hellem and Encephalitozoon intestinalis have been described. Several orders of the Class Aves (Passeriformes, Psittaciformes, Apodiformes, Ciconiiformis, Gruiformes, Columbiformes, Suliformes, Podicipediformes, Anseriformes, Struthioniformes, Falconiformes) and of the Class Mammalia (Rodentia, Lagomorpha, Primates, Artyodactyla, Soricomorpha, Chiroptera, Carnivora) can become infected. Especially E. cuniculi has a very broad host range while E. hellem is mainly distributed amongst birds. E. intestinalis has so far been detected only sporadically in wild animals. Although genotyping allows the identification of strains with a certain host preference, recent studies have demonstrated that they have no strict host specificity. Accordingly, humans can become infected with any of the four strains of E. cuniculi as well as with E. hellem or E. intestinalis, the latter being the most common. Especially, but not exclusively, immunocompromised people are at risk. Environmental contamination with as well as direct transmission of Encephalitozoon is therefore highly relevant for public health. Moreover, endangered species might be threatened by the spread of pathogens into their habitats. In captivity, clinically overt and often fatal disease seems to occur frequently. In conclusion, Encephalitozoon appears to be common in wild warm-blooded animals and these hosts may present important reservoirs for environmental contamination and maintenance of the pathogens. Similar to domestic animals, asymptomatic infections seem to occur frequently but in captive wild animals severe disease has also been reported. Detailed investigations into the epidemiology and clinical relevance of these microsporidia will permit a full appraisal of their role as pathogens.
Collapse
Affiliation(s)
- Barbara Hinney
- Institute of Parasitology, Department of Pathobiology, University of Veterinary Medicine Vienna, Veterinaerplatz 1, A-1210 Vienna, Austria
| | - Bohumil Sak
- Institute of Parasitology, Biology Centre of the Academy of Sciences of the Czech Republic, v.v.i. Branišovská 31, 370 05 České Budějovice, Czech Republic
| | - Anja Joachim
- Institute of Parasitology, Department of Pathobiology, University of Veterinary Medicine Vienna, Veterinaerplatz 1, A-1210 Vienna, Austria
| | - Martin Kváč
- Institute of Parasitology, Biology Centre of the Academy of Sciences of the Czech Republic, v.v.i. Branišovská 31, 370 05 České Budějovice, Czech Republic
- Faculty of Agriculture, University of South Bohemia in České Budějovice, Studentská 13, 370 05 České Budějovice, Czech Republic
| |
Collapse
|
21
|
Pelin A, Moteshareie H, Sak B, Selman M, Naor A, Eyahpaise MÈ, Farinelli L, Golshani A, Kvac M, Corradi N. The genome of an Encephalitozoon cuniculi type III strain reveals insights into the genetic diversity and mode of reproduction of a ubiquitous vertebrate pathogen. Heredity (Edinb) 2016; 116:458-65. [PMID: 26837273 DOI: 10.1038/hdy.2016.4] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2015] [Revised: 12/10/2015] [Accepted: 12/18/2015] [Indexed: 02/07/2023] Open
Abstract
Encephalitozoon cuniculi is a model microsporidian species with a mononucleate nucleus and a genome that has been extensively studied. To date, analyses of genome diversity have revealed the existence of four genotypes in E. cuniculi (EcI, II, III and IV). Genome sequences are available for EcI, II and III, and are all very divergent, possibly diploid and genetically homogeneous. The mechanisms that cause low genetic diversity in E. cuniculi (for example, selfing, inbreeding or a combination of both), as well as the degree of genetic variation in their natural populations, have been hard to assess because genome data have been so far gathered from laboratory-propagated strains. In this study, we aim to tackle this issue by analyzing the complete genome sequence of a natural strain of E. cuniculi isolated in 2013 from a steppe lemming. The strain belongs to the EcIII genotype and has been designated EcIII-L. The EcIII-L genome sequence harbors genomic features intermediate to known genomes of II and III lab strains, and we provide primers that differentiate the three E. cuniculi genotypes using a single PCR. Surprisingly, the EcIII-L genome is also highly homogeneous, harbors signatures of heterozygosity and also one strain-specific single-nucleotide polymorphism (SNP) that introduces a stop codon in a key meiosis gene, Spo11. Functional analyses using a heterologous system demonstrate that this SNP leads to a deficient meiosis in a model fungus. This indicates that EcIII-L meiotic machinery may be presently broken. Overall, our findings reveal previously unsuspected genome diversity in E. cuniculi, some of which appears to affect genes of primary importance for the biology of this pathogen.
Collapse
Affiliation(s)
- A Pelin
- Department of Biology, Canadian Institute for Advanced Research, University of Ottawa, Ottawa, ON, Canada
| | - H Moteshareie
- Department of Biology, Carleton University, Ottawa, Ontario, Canada.,Ottawa Institute of Systems Biology, Carleton University, Ottawa, Ontario, Canada
| | - B Sak
- Institute of Parasitology, Biology Centre of the Academy of Sciences of the Czech Republic, České Budějovice, Czech Republic
| | - M Selman
- Department of Biology, Canadian Institute for Advanced Research, University of Ottawa, Ottawa, ON, Canada
| | - A Naor
- Department of Biology, Canadian Institute for Advanced Research, University of Ottawa, Ottawa, ON, Canada
| | - M-È Eyahpaise
- Department of Biology, Canadian Institute for Advanced Research, University of Ottawa, Ottawa, ON, Canada
| | - L Farinelli
- FASTERIS S.A., Ch. du Pont-du-Centenaire 109, Plan-les-Ouates, Switzerland
| | - A Golshani
- Department of Biology, Carleton University, Ottawa, Ontario, Canada.,Ottawa Institute of Systems Biology, Carleton University, Ottawa, Ontario, Canada
| | - M Kvac
- Institute of Parasitology, Biology Centre of the Academy of Sciences of the Czech Republic, České Budějovice, Czech Republic
| | - N Corradi
- Department of Biology, Canadian Institute for Advanced Research, University of Ottawa, Ottawa, ON, Canada
| |
Collapse
|
22
|
Maside X, Gómez-Moracho T, Jara L, Martín-Hernández R, De la Rúa P, Higes M, Bartolomé C. Population Genetics of Nosema apis and Nosema ceranae: One Host (Apis mellifera) and Two Different Histories. PLoS One 2015; 10:e0145609. [PMID: 26720131 PMCID: PMC4699903 DOI: 10.1371/journal.pone.0145609] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2015] [Accepted: 12/07/2015] [Indexed: 12/26/2022] Open
Abstract
Two microsporidians are known to infect honey bees: Nosema apis and Nosema ceranae. Whereas population genetics data for the latter have been released in the last few years, such information is still missing for N. apis. Here we analyze the patterns of nucleotide polymorphism at three single-copy loci (PTP2, PTP3 and RPB1) in a collection of Apis mellifera isolates from all over the world, naturally infected either with N. apis (N = 22) or N. ceranae (N = 23), to provide new insights into the genetic diversity, demography and evolution of N. apis, as well as to compare them with evidence from N. ceranae. Neutral variation in N. apis and N. ceranae is of the order of 1%. This amount of diversity suggests that there is no substantial differentiation between the genetic content of the two nuclei present in these parasites, and evidence for genetic recombination provides a putative mechanism for the flow of genetic information between chromosomes. The analysis of the frequency spectrum of neutral variants reveals a significant surplus of low frequency variants, particularly in N. ceranae, and suggests that the populations of the two pathogens are not in mutation-drift equilibrium and that they have experienced a population expansion. Most of the variation in both species occurs within honey bee colonies (between 62%-90% of the total genetic variance), although in N. apis there is evidence for differentiation between parasites isolated from distinct A. mellifera lineages (20%-34% of the total variance), specifically between those collected from lineages A and C (or M). This scenario is consistent with a long-term host-parasite relationship and contrasts with the lack of differentiation observed among host-lineages in N. ceranae (< 4% of the variance), which suggests that the spread of this emergent pathogen throughout the A. mellifera worldwide population is a recent event.
Collapse
Affiliation(s)
- Xulio Maside
- Medicina Xenómica, CIMUS, Universidade de Santiago de Compostela, Santiago de Compostela, Galicia, Spain
- Xenómica Comparada de Parásitos Humanos, IDIS, Santiago de Compostela, Galicia, Spain
- Departamento de Anatomía Patolóxica e Ciencias Forenses, Universidade de Santiago de Compostela, Santiago de Compostela, Galicia, Spain
| | - Tamara Gómez-Moracho
- Medicina Xenómica, CIMUS, Universidade de Santiago de Compostela, Santiago de Compostela, Galicia, Spain
- Xenómica Comparada de Parásitos Humanos, IDIS, Santiago de Compostela, Galicia, Spain
- Laboratorio de Patología Apícola. Centro de Investigación Apícola y Agroambiental (CIAPA), Instituto Regional de Investigación y Desarrollo Agroalimentario y Forestal (IRIAF), Consejería de Agricultura de la Junta de Comunidades de Castilla-La Mancha, Marchamalo, Guadalajara, Spain
| | - Laura Jara
- Departamento de Zoología y Antropología Física, Facultad de Veterinaria, Universidad de Murcia, Murcia, Spain
| | - Raquel Martín-Hernández
- Laboratorio de Patología Apícola. Centro de Investigación Apícola y Agroambiental (CIAPA), Instituto Regional de Investigación y Desarrollo Agroalimentario y Forestal (IRIAF), Consejería de Agricultura de la Junta de Comunidades de Castilla-La Mancha, Marchamalo, Guadalajara, Spain
- Instituto de Recursos Humanos para la Ciencia y la Tecnología (INCRECYT-FEDER), Fundación Parque Científico y Tecnológico de Albacete, Albacete, Spain
| | - Pilar De la Rúa
- Departamento de Zoología y Antropología Física, Facultad de Veterinaria, Universidad de Murcia, Murcia, Spain
| | - Mariano Higes
- Laboratorio de Patología Apícola. Centro de Investigación Apícola y Agroambiental (CIAPA), Instituto Regional de Investigación y Desarrollo Agroalimentario y Forestal (IRIAF), Consejería de Agricultura de la Junta de Comunidades de Castilla-La Mancha, Marchamalo, Guadalajara, Spain
| | - Carolina Bartolomé
- Medicina Xenómica, CIMUS, Universidade de Santiago de Compostela, Santiago de Compostela, Galicia, Spain
- Xenómica Comparada de Parásitos Humanos, IDIS, Santiago de Compostela, Galicia, Spain
- * E-mail:
| |
Collapse
|
23
|
Reinke AW, Troemel ER. The Development of Genetic Modification Techniques in Intracellular Parasites and Potential Applications to Microsporidia. PLoS Pathog 2015; 11:e1005283. [PMID: 26720003 PMCID: PMC4699923 DOI: 10.1371/journal.ppat.1005283] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Affiliation(s)
- Aaron W. Reinke
- Division of Biological Sciences, Section of Cell and Developmental Biology, University of California-San Diego, San Diego, California, United States of America
| | - Emily R. Troemel
- Division of Biological Sciences, Section of Cell and Developmental Biology, University of California-San Diego, San Diego, California, United States of America
- * E-mail:
| |
Collapse
|
24
|
Watson AK, Williams TA, Williams BAP, Moore KA, Hirt RP, Embley TM. Transcriptomic profiling of host-parasite interactions in the microsporidian Trachipleistophora hominis. BMC Genomics 2015; 16:983. [PMID: 26589282 PMCID: PMC4654818 DOI: 10.1186/s12864-015-1989-z] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2015] [Accepted: 10/06/2015] [Indexed: 12/28/2022] Open
Abstract
Background Trachipleistophora hominis was isolated from an HIV/AIDS patient and is a member of a highly successful group of obligate intracellular parasites. Methods Here we have investigated the evolution of the parasite and the interplay between host and parasite gene expression using transcriptomics of T. hominis-infected rabbit kidney cells. Results T. hominis has about 30 % more genes than small-genome microsporidians. Highly expressed genes include those involved in growth, replication, defence against oxidative stress, and a large fraction of uncharacterised genes. Chaperones are also highly expressed and may buffer the deleterious effects of the large number of non-synonymous mutations observed in essential T. hominis genes. Host expression suggests a general cellular shutdown upon infection, but ATP, amino sugar and nucleotide sugar production appear enhanced, potentially providing the parasite with substrates it cannot make itself. Expression divergence of duplicated genes, including transporters used to acquire host metabolites, demonstrates ongoing functional diversification during microsporidian evolution. We identified overlapping transcription at more than 100 loci in the sparse T. hominis genome, demonstrating that this feature is not caused by genome compaction. The detection of additional transposons of insect origin strongly suggests that the natural host for T. hominis is an insect. Conclusions Our results reveal that the evolution of contemporary microsporidian genomes is highly dynamic and innovative. Moreover, highly expressed T. hominis genes of unknown function include a cohort that are shared among all microsporidians, indicating that some strongly conserved features of the biology of these enormously successful parasites remain uncharacterised. Electronic supplementary material The online version of this article (doi:10.1186/s12864-015-1989-z) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Andrew K Watson
- Institute for Cell and Molecular Biosciences, Newcastle University, Newcastle upon Tyne, NE2 4HH, UK.
| | - Tom A Williams
- Institute for Cell and Molecular Biosciences, Newcastle University, Newcastle upon Tyne, NE2 4HH, UK.
| | - Bryony A P Williams
- Biosciences, College of Life and Environmental Sciences, University of Exeter, Devon, UK.
| | - Karen A Moore
- Biosciences, College of Life and Environmental Sciences, University of Exeter, Devon, UK.
| | - Robert P Hirt
- Institute for Cell and Molecular Biosciences, Newcastle University, Newcastle upon Tyne, NE2 4HH, UK.
| | - T Martin Embley
- Institute for Cell and Molecular Biosciences, Newcastle University, Newcastle upon Tyne, NE2 4HH, UK.
| |
Collapse
|
25
|
Corradi N. Microsporidia: Eukaryotic Intracellular Parasites Shaped by Gene Loss and Horizontal Gene Transfers. Annu Rev Microbiol 2015. [PMID: 26195306 DOI: 10.1146/annurev-micro-091014-104136] [Citation(s) in RCA: 71] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Microsporidia are eukaryotic parasites of many animals that appear to have adapted to an obligate intracellular lifestyle by modifying the morphology and content of their cells. Living inside other cells, they have lost many, or all, metabolic functions, resulting in genomes that are always gene poor and often very small. The minute content of microsporidian genomes led many to assume that these parasites are biochemically static and uninteresting. However, recent studies have demonstrated that these organisms can be surprisingly complex and dynamic. In this review I detail the most significant recent advances in microsporidian genomics and discuss how these have affected our understanding of many biological aspects of these peculiar eukaryotic intracellular pathogens.
Collapse
Affiliation(s)
- Nicolas Corradi
- Canadian Institute for Advanced Research, Department of Biology, University of Ottawa, Ontario, Canada K1N 6N5;
| |
Collapse
|
26
|
Pelin A, Selman M, Aris-Brosou S, Farinelli L, Corradi N. Genome analyses suggest the presence of polyploidy and recent human-driven expansions in eight global populations of the honeybee pathogen Nosema ceranae. Environ Microbiol 2015; 17:4443-58. [PMID: 25914091 DOI: 10.1111/1462-2920.12883] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2015] [Revised: 04/13/2015] [Accepted: 04/15/2015] [Indexed: 12/23/2022]
Abstract
Nosema ceranae is a microsporidian pathogen whose infections have been associated with recent global declines in the populations of western honeybees (Apis mellifera). Despite the outstanding economic and ecological threat that N. ceranae may represent for honeybees worldwide, many aspects of its biology, including its mode of reproduction, propagation and ploidy, are either very unclear or unknown. In the present study, we set to gain knowledge in these biological aspects by re-sequencing the genome of eight isolates (i.e. a population of spores isolated from one single beehive) of this species harvested from eight geographically distant beehives, and by investigating their level of polymorphism. Consistent with previous analyses performed using single gene sequences, our analyses uncovered the presence of very high genetic diversity within each isolate, but also very little hive-specific polymorphism. Surprisingly, the nature, location and distribution of this genetic variation suggest that beehives around the globe are infected by a population of N. ceranae cells that may be polyploid (4n or more), and possibly clonal. Lastly, phylogenetic analyses based on genome-wide single-nucleotide polymorphism data extracted from these parasites and mitochondrial sequences from their hosts all failed to support the current geographical structure of our isolates.
Collapse
Affiliation(s)
- Adrian Pelin
- Canadian Institute for Advanced Research, Department of Biology; University of Ottawa, Ottawa, ON, Canada
| | - Mohammed Selman
- Canadian Institute for Advanced Research, Department of Biology; University of Ottawa, Ottawa, ON, Canada
| | - Stéphane Aris-Brosou
- Departments of Biology and of Mathematics & Statistics, University of Ottawa, Ottawa, ON, Canada
| | - Laurent Farinelli
- FASTERIS S.A., Ch. du Pont-du-Centenaire 109, P.O. Box 28, Plan-les-Ouates, CH-1228, Geneva, Switzerland
| | - Nicolas Corradi
- Canadian Institute for Advanced Research, Department of Biology; University of Ottawa, Ottawa, ON, Canada
| |
Collapse
|
27
|
Desjardins CA, Sanscrainte ND, Goldberg JM, Heiman D, Young S, Zeng Q, Madhani HD, Becnel JJ, Cuomo CA. Contrasting host-pathogen interactions and genome evolution in two generalist and specialist microsporidian pathogens of mosquitoes. Nat Commun 2015; 6:7121. [PMID: 25968466 PMCID: PMC4435813 DOI: 10.1038/ncomms8121] [Citation(s) in RCA: 73] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2014] [Accepted: 04/07/2015] [Indexed: 12/14/2022] Open
Abstract
Obligate intracellular pathogens depend on their host for growth yet must also evade detection by host defenses. Here we investigate host adaptation in two Microsporidia, the specialist Edhazardia aedis and the generalist Vavraia culicis, pathogens of disease vector mosquitoes. Genomic analysis and deep RNA-Seq across infection time courses reveal fundamental differences between these pathogens. E. aedis retains enhanced cell surface modification and signalling capacity, upregulating protein trafficking and secretion dynamically during infection. V. culicis is less dependent on its host for basic metabolites and retains a subset of spliceosomal components, with a transcriptome broadly focused on growth and replication. Transcriptional profiling of mosquito immune responses reveals that response to infection by E. aedis differs dramatically depending on the mode of infection, and that antimicrobial defensins may play a general role in mosquito defense against Microsporidia. This analysis illuminates fundamentally different evolutionary paths and host interplay of specialist and generalist pathogens.
Collapse
Affiliation(s)
| | - Neil D Sanscrainte
- USDA, ARS, Center for Medical, Agricultural and Veterinary Entomology, 1600 SW 23rd Drive, Gainesville, Florida 32608, USA
| | | | - David Heiman
- Broad Institute of MIT and Harvard, Cambridge, Massachusetts 02142, USA
| | - Sarah Young
- Broad Institute of MIT and Harvard, Cambridge, Massachusetts 02142, USA
| | - Qiandong Zeng
- Broad Institute of MIT and Harvard, Cambridge, Massachusetts 02142, USA
| | - Hiten D Madhani
- Department of Biochemistry and Biophysics, University of California-San Francisco, San Francisco, California 94158, USA
| | - James J Becnel
- USDA, ARS, Center for Medical, Agricultural and Veterinary Entomology, 1600 SW 23rd Drive, Gainesville, Florida 32608, USA
| | - Christina A Cuomo
- Broad Institute of MIT and Harvard, Cambridge, Massachusetts 02142, USA
| |
Collapse
|
28
|
The Ordospora colligata genome: Evolution of extreme reduction in microsporidia and host-to-parasite horizontal gene transfer. mBio 2015; 6:mBio.02400-14. [PMID: 25587016 PMCID: PMC4313915 DOI: 10.1128/mbio.02400-14] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
UNLABELLED Microsporidia are a group of obligate intracellular parasites that are best known for their unique infection mechanism and their unparalleled levels of genomic reduction and compaction. We sequenced the genome of Ordospora colligata, a gut parasite of the microcrustacean Daphnia sp. and the closest known relative to the microsporidia characterized by the most extreme genomic reduction, the model genus Encephalitozoon. We found that the O. colligata genome is as compact as those of Encephalitozoon spp., featuring few introns and a similar complement of about 2,000 genes, altogether showing that the extreme reduction took place before the origin of Encephalitozoon spp. and their adaptation to vertebrate hosts. We also found that the O. colligata genome has acquired by horizontal transfer from its animal host a septin that is structurally analogous to septin 7, a protein that plays a major role in the endocytosis-based invasion mechanism of the fungal pathogen Candida albicans. Microsporidian invasion is most often characterized by injection through a projectile tube, but microsporidia are also known to invade cells by inducing endocytosis. Given the function of septins in other systems, we hypothesize that the acquired septin could help O. colligata induce its uptake by mimicking host receptors. IMPORTANCE The smallest known eukaryotic genomes are found in members of the Encephalitozoon genus of microsporidian parasites. Their extreme compaction, however, is not characteristic of the group, whose genomes can differ by an order of magnitude. The processes and evolutionary forces that led the Encephalitozoon genomes to shed so much of their ancestral baggage are unclear. We sequenced the genome of Ordospora colligata, a parasite of the water flea Daphnia sp. and the closest known relative of Encephalitozoon species, and show that this extreme reduction predated the split between the two lineages. We also found that O. colligata has acquired a septin gene by host-to-parasite horizontal transfer and predicted that the encoded protein folds like a septin 7, which plays a major role in endocytosis. We hypothesize that this acquisition could help O. colligata parasitize its hosts by facilitating endocytic infection, a mechanism that occurs in microsporidia but that is not yet well understood.
Collapse
|
29
|
Peyretaillade E, Boucher D, Parisot N, Gasc C, Butler R, Pombert JF, Lerat E, Peyret P. Exploiting the architecture and the features of the microsporidian genomes to investigate diversity and impact of these parasites on ecosystems. Heredity (Edinb) 2014; 114:441-9. [PMID: 25182222 DOI: 10.1038/hdy.2014.78] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2014] [Revised: 07/16/2014] [Accepted: 07/21/2014] [Indexed: 12/16/2022] Open
Abstract
Fungal species play extremely important roles in ecosystems. Clustered at the base of the fungal kingdom are Microsporidia, a group of obligate intracellular eukaryotes infecting multiple animal lineages. Because of their large host spectrum and their implications in host population regulation, they influence food webs, and accordingly, ecosystem structure and function. Unfortunately, their ecological role is not well understood. Present also as highly resistant spores in the environment, their characterisation requires special attention. Different techniques based on direct isolation and/or molecular approaches can be considered to elucidate their role in the ecosystems, but integrating environmental and genomic data (for example, genome architecture, core genome, transcriptional and translational signals) is crucial to better understand the diversity and adaptive capacities of Microsporidia. Here, we review the current status of Microsporidia in trophic networks; the various genomics tools that could be used to ensure identification and evaluate diversity and abundance of these organisms; and how these tools could be used to explore the microsporidian life cycle in different environments. Our understanding of the evolution of these widespread parasites is currently impaired by limited sampling, and we have no doubt witnessed but a small subset of their diversity.
Collapse
Affiliation(s)
- E Peyretaillade
- Genomics, Clermont Université, Université d'Auvergne, EA 4678 CIDAM, Clermont-Ferrand, France
| | - D Boucher
- Genomics, Clermont Université, Université d'Auvergne, EA 4678 CIDAM, Clermont-Ferrand, France
| | - N Parisot
- 1] Genomics, Clermont Université, Université d'Auvergne, EA 4678 CIDAM, Clermont-Ferrand, France [2] CNRS, UMR 6023, LMGE, Aubière, France
| | - C Gasc
- Genomics, Clermont Université, Université d'Auvergne, EA 4678 CIDAM, Clermont-Ferrand, France
| | - R Butler
- Illinois Institute of Technology, BCHS Biology Division, Chicago, IL, USA
| | - J-F Pombert
- Illinois Institute of Technology, BCHS Biology Division, Chicago, IL, USA
| | - E Lerat
- Université de Lyon, Lyon, Université Lyon 1, CNRS, UMR 5558, Laboratoire de Biométrie et Biologie Évolutive, Villeurbanne, France
| | - P Peyret
- Genomics, Clermont Université, Université d'Auvergne, EA 4678 CIDAM, Clermont-Ferrand, France
| |
Collapse
|
30
|
Abstract
Sexual reproduction is a pervasive attribute of eukaryotic species and is now recognized to occur in many clinically important human fungal pathogens. These fungi use sexual or parasexual strategies for various purposes that can have an impact on pathogenesis, such as the formation of drug-resistant isolates, the generation of strains with increased virulence or the modulation of interactions with host cells. In this Review, we examine the mechanisms regulating fungal sex and the consequences of these programmes for human disease.
Collapse
|
31
|
Affiliation(s)
- Marianna Feretzaki
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, North Carolina, United States of America
| | - Joseph Heitman
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, North Carolina, United States of America
- Department of Medicine, Duke University Medical Center, Durham, North Carolina, United States of America
- Department of Pharmacology and Cancer Biology, Duke University Medical Center, Durham, North Carolina, United States of America
- * E-mail:
| |
Collapse
|
32
|
Variability in minimal genomes: analysis of tandem repeats in the microsporidia Encephalitozoon intestinalis. INFECTION GENETICS AND EVOLUTION 2013; 20:26-33. [PMID: 23917025 DOI: 10.1016/j.meegid.2013.07.024] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/11/2013] [Revised: 07/23/2013] [Accepted: 07/24/2013] [Indexed: 12/25/2022]
Abstract
Microsporidia are ubiquitous fungi with genomes that have undergone a strong reduction to the extreme cases of Encephalitozoon cuniculi and Encephalitozoon intestinalis. Genetic variability within species of the Encephalitozoon genus has been reported, with most of the studies based on the internal transcribed spacer (ITS) of the rDNA. However, in contrast to the picture of E. cuniculi and Encephalitozoon hellem, where different strains have been identified, no genetic variability has yet been observed in E. intestinalis. We have analysed tandem repeats included in putative coding sequences which could be used as polymorphic markers in E. intestinalis. Eight candidate loci (M2, M2A, M3, M5, M7, M7A, M8 and PTP1) were established and 9 E. intestinalis cultured strains from North America, South America and Europe were analysed. M2, M7 and PTP1 nucleotide sequences were identical among the different strains and the GenBank sequence. In contrast, we observed variants in 4 markers (M2A, M3, M7A and M8) which did not correspond to their respective reference sequences. The most noticeable finding was that with the M5 marker two genotypes were defined among the different strains studied, demonstrating genotypic variability of E. intestinalis. Although the diversity described is certainly not high, which can be explained by a lower chance of genetic variability in its minimal genome, we have demonstrated that polymorphisms actually exist in E. intestinalis. Epidemiological studies using this genetic marker should now be conducted to elucidate the genetic variability in E. intestinalis and improve our knowledge of the epidemiology of this microsporidia.
Collapse
|
33
|
Frequent occurrence of mixed Enterocytozoon bieneusi infections in humans. Appl Environ Microbiol 2013; 79:5357-62. [PMID: 23811516 DOI: 10.1128/aem.01260-13] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Enterocytozoon bieneusi (phylum Microsporidia) is a human pathogen with a broad host range. Following the sequencing of 3.8 Mb of the estimated 6-Mb E. bieneusi genome, simple sequence repeats (micro- and minisatellites) were identified. Sequencing of four such repeats from various human and animal E. bieneusi isolates identified extensive sequence polymorphism and enabled the development of a multilocus genotyping method to study the epidemiology of this pathogen. We genotyped E. bieneusi DNA extracted from 197 fecal samples originating from children with diarrhea who were residing in Kampala, Uganda. Three newly identified microsatellite markers and the internal transcribed spacer were PCR amplified, and multiple cloned amplicons for each marker were sequenced from each individual. Most microsatellite sequences were unique to the Ugandan population. Significantly, polymorphism not only was present among isolates but was also found within isolates. This observation suggests that infections with heterogeneous E. bieneusi populations are common in this region. However, the data do not exclude that some of the polymorphism originates from divergent paralogs within the genome. The frequent occurrence of multiple sequences within an isolate precluded the identification of multilocus genotypes. This observation raises the possibility that in a region in which the prevalence of E. bieneusi is high, sequencing of uncloned PCR products may not be adequate for multilocus genotyping.
Collapse
|
34
|
Complete genome sequences from three genetically distinct strains reveal high intraspecies genetic diversity in the microsporidian Encephalitozoon cuniculi. EUKARYOTIC CELL 2013; 12:503-11. [PMID: 23291622 DOI: 10.1128/ec.00312-12] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Microsporidia from the Encephalitozoonidae are obligate intracellular parasites with highly conserved and compacted nuclear genomes: they have few introns, short intergenic regions, and almost identical gene complements and chromosome arrangements. Comparative genomics of Encephalitozoon and microsporidia in general have focused largely on the genomic diversity between different species, and we know very little about the levels of genetic diversity within species. Polymorphism studies with Encephalitozoon are so far restricted to a small number of genes, and a few genetically distinct strains have been identified; most notably, three genotypes (ECI, ECII, and ECIII) of the model species E. cuniculi have been identified based on variable repeats in the rRNA internal transcribed spacer (ITS). To determine if E. cuniculi genotypes are genetically distinct lineages across the entire genome and at the same time to examine the question of intraspecies genetic diversity in microsporidia in general, we sequenced de novo genomes from each of the three genotypes and analyzed patterns of single nucleotide polymorphisms (SNPs) and insertions/deletions across the genomes. Although the strains have almost identical gene contents, they harbor large numbers of SNPs, including numerous nonsynonymous changes, indicating massive intraspecies variation within the Encephalitozoonidae. Based on this diversity, we conclude that the recognized genotypes are genetically distinct and propose new molecular markers for microsporidian genotyping.
Collapse
|