1
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Shaw S, Cohn IS, Baptista RP, Xia G, Melillo B, Agyabeng-Dadzie F, Kissinger JC, Striepen B. Genetic crosses within and between species of Cryptosporidium. Proc Natl Acad Sci U S A 2024; 121:e2313210120. [PMID: 38147547 PMCID: PMC10769859 DOI: 10.1073/pnas.2313210120] [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: 08/04/2023] [Accepted: 11/12/2023] [Indexed: 12/28/2023] Open
Abstract
Parasites and their hosts are engaged in reciprocal coevolution that balances competing mechanisms of virulence, resistance, and evasion. This often leads to host specificity, but genomic reassortment between different strains can enable parasites to jump host barriers and conquer new niches. In the apicomplexan parasite Cryptosporidium, genetic exchange has been hypothesized to play a prominent role in adaptation to humans. The sexual lifecycle of the parasite provides a potential mechanism for such exchange; however, the boundaries of Cryptosporidium sex are currently undefined. To explore this experimentally, we established a model for genetic crosses. Drug resistance was engineered using a mutated phenylalanyl tRNA synthetase gene and marking strains with this and the previously used Neo transgene enabled selection of recombinant progeny. This is highly efficient, and genomic recombination is evident and can be continuously monitored in real time by drug resistance, flow cytometry, and PCR mapping. Using this approach, multiple loci can now be modified with ease. We demonstrate that essential genes can be ablated by crossing a Cre recombinase driver strain with floxed strains. We further find that genetic crosses are also feasible between species. Crossing Cryptosporidium parvum, a parasite of cattle and humans, and Cryptosporidium tyzzeri a mouse parasite resulted in progeny with a recombinant genome derived from both species that continues to vigorously replicate sexually. These experiments have important fundamental and translational implications for the evolution of Cryptosporidium and open the door to reverse- and forward-genetic analysis of parasite biology and host specificity.
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Affiliation(s)
- Sebastian Shaw
- Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA19104
| | - Ian S. Cohn
- Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA19104
| | - Rodrigo P. Baptista
- Department of Medicine, Houston Methodist Research Institute, Houston, TX77030
| | - Guoqin Xia
- Department of Chemistry, Scripps Research, La Jolla, CA92037
| | - Bruno Melillo
- Department of Chemistry, Scripps Research, La Jolla, CA92037
- Chemical Biology and Therapeutics Science Program, Broad Institute, Cambridge, MA02142
| | | | - Jessica C. Kissinger
- Department of Genetics, University of Georgia, Athens, GA30602
- Center for Tropical and Emerging Global Diseases and Institute of Bioinformatics, University of Georgia, Athens, GA30602
| | - Boris Striepen
- Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA19104
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2
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Adjou KT, Chevillot A, Lucas P, Blanchard Y, Louifi H, Arab R, Mammeri M, Thomas M, Polack B, Karadjian G, Dheilly NM. First identification of Cryptosporidium parvum virus 1 (CSpV1) in various subtypes of Cryptosporidium parvum from diarrheic calves, lambs and goat kids from France. Vet Res 2023; 54:66. [PMID: 37608341 PMCID: PMC10464362 DOI: 10.1186/s13567-023-01196-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2023] [Accepted: 06/23/2023] [Indexed: 08/24/2023] Open
Abstract
Cryptosporidium spp. remain a major cause of waterborne diarrhea and illness in developing countries and represent a significant burden to farmers worldwide. Cryptosporidium parvum virus 1 (CSpV1), of the genus Cryspovirus, was first reported to be present in the cytoplasm of C. parvum in 1997. Full-length genome sequences have been obtained from C. parvum from Iowa (Iowa), Kansas (KSU) and China. We aimed at characterizing the genome of CSpV1 from France and used sequence analysis from Cryptosporidium isolates to explore whether CSpV1 genome diversity varies over time, with geographical sampling location, C. parvum genetic diversity, or ruminant host species. A total of 123 fecal samples of cattle, sheep and goats were collected from 17 different French departments (57 diseased animal fecal samples and 66 healthy animal fecal samples). Subtyping analysis of the C. parvum isolates revealed the presence of two zoonotic subtype families IIa and IId. Sequence analysis of CSpV1 revealed that all CSpV1 from France, regardless of the subtype of C. parvum (IIaA15G2R1, IIaA17G2R1 and IIdA18G1R1) are more closely related to CSpV1 from Turkey, and cluster on a distinct branch from CSpV1 collected from C. parvum subtype IIaA15G2R1 from Asia and North America. We also found that samples collected on a given year or successive years in a given location are more likely to host the same subtype of C. parvum and the same CSpV1 strain. Yet, there is no distinct clustering of CSpV1 per French department or ruminants, probably due to trade, and transmission of C. parvum among host species. Our results point towards (i) a close association between CSpV1 movement and C. parvum movement, (ii) recent migrations of C. parvum among distantly located departments and (iii) incidental transmission of C. parvum between ruminants. All together, these results provide insightful information regarding CSpV1 evolution and suggest the virus might be used as an epidemiological tracer for C. parvum. Future studies need to investigate CSpV1's role in C. parvum virulence and on subtype ability to infect different species.
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Affiliation(s)
- Karim Tarik Adjou
- Laboratoire de Santé Animale, Ecole Nationale Vétérinaire d'Alfort, Anses, INRAE, UMR BIPAR, 94700, Maisons-Alfort, France.
| | - Aurélie Chevillot
- Laboratoire de Santé Animale, Ecole Nationale Vétérinaire d'Alfort, Anses, INRAE, UMR BIPAR, 94700, Maisons-Alfort, France
| | - Pierrick Lucas
- Laboratoire de Ploufragan-Plouzané-Niort, Unité Génétique virale et biosécurité, ANSES, Agence Nationale de Sécurité Sanitaire de l'Alimentation, de l'Environnement et du Travail, Ploufragan, France
| | - Yannick Blanchard
- Laboratoire de Ploufragan-Plouzané-Niort, Unité Génétique virale et biosécurité, ANSES, Agence Nationale de Sécurité Sanitaire de l'Alimentation, de l'Environnement et du Travail, Ploufragan, France
| | - Houria Louifi
- Laboratoire de Santé Animale, Ecole Nationale Vétérinaire d'Alfort, Anses, INRAE, UMR BIPAR, 94700, Maisons-Alfort, France
| | - Razika Arab
- Laboratoire de Santé Animale, Ecole Nationale Vétérinaire d'Alfort, Anses, INRAE, UMR BIPAR, 94700, Maisons-Alfort, France
| | - Mohamed Mammeri
- Laboratoire de Santé Animale, Ecole Nationale Vétérinaire d'Alfort, Anses, INRAE, UMR BIPAR, 94700, Maisons-Alfort, France
| | - Myriam Thomas
- Laboratoire de Santé Animale, Ecole Nationale Vétérinaire d'Alfort, Anses, INRAE, UMR BIPAR, 94700, Maisons-Alfort, France
| | - Bruno Polack
- Laboratoire de Santé Animale, Ecole Nationale Vétérinaire d'Alfort, Anses, INRAE, UMR BIPAR, 94700, Maisons-Alfort, France
| | - Grégory Karadjian
- Laboratoire de Santé Animale, Ecole Nationale Vétérinaire d'Alfort, Anses, INRAE, UMR BIPAR, 94700, Maisons-Alfort, France
| | - Nolwenn M Dheilly
- Anses Animal Health Laboratory, UMR1161 Virology, INRAE, Anses, ENVA, Maisons-Alfort, France.
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3
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Shaw S, Cohn IS, Baptista RP, Xia G, Melillo B, Agyabeng-Dadzie F, Kissinger JC, Striepen B. Genetic crosses within and between species of Cryptosporidium. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.08.04.551960. [PMID: 37577700 PMCID: PMC10418217 DOI: 10.1101/2023.08.04.551960] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/15/2023]
Abstract
Parasites and their hosts are engaged in rapid coevolution that balances competing mechanisms of virulence, resistance, and evasion. This often leads to host specificity, but genomic reassortment between different strains can enable parasites to jump host barriers and conquer new niches. In the apicomplexan parasite Cryptosporidium genetic exchange has been hypothesized to play a prominent role in adaptation to humans. The sexual lifecycle of the parasite provides a potential mechanism for such exchange; however, the boundaries of Cryptosporidium sex are currently undefined. To explore this experimentally, we established a model for genetic crosses. Drug resistance was engineered using a mutated phenylalanyl tRNA synthetase gene and marking strains with this and the previously used Neo transgene enabled selection of recombinant progeny. This is highly efficient, and genomic recombination is evident and can be continuously monitored in real time by drug resistance, flow cytometry, and PCR mapping. Using this approach multiple loci can now be modified with ease. We demonstrate that essential genes can be ablated by crossing a Cre recombinase driver strain with floxed strains. We further find that genetic crosses are also feasible between species. Crossing C. parvum, a parasite of cattle and humans, and C. tyzzeri a mouse parasite resulted in progeny with a recombinant genome derived from both species that continues to vigorously replicate sexually. These experiments have important fundamental and translational implications for the evolution of Cryptosporidium and open the door to reverse- and forward- genetic analysis of parasite biology and host specificity.
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Affiliation(s)
- Sebastian Shaw
- Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA
| | - Ian S. Cohn
- Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA
| | | | - Guoqin Xia
- Department of Chemistry, Scripps Research, La Jolla, CA
| | - Bruno Melillo
- Department of Chemistry, Scripps Research, La Jolla, CA
- Chemical Biology and Therapeutics Science Program, Broad Institute, Cambridge, MA
| | | | - Jessica C. Kissinger
- Department of Genetics, University of Georgia, Athens, GA
- Center for Tropical and Emerging Global Diseases and Institute of Bioinformatics University of Georgia, Athens, GA
| | - Boris Striepen
- Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA
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Hanna JC, Corpas-Lopez V, Seizova S, Colon BL, Bacchetti R, Hall GMJ, Sands EM, Robinson L, Baragaña B, Wyllie S, Pawlowic MC. Mode of action studies confirm on-target engagement of lysyl-tRNA synthetase inhibitor and lead to new selection marker for Cryptosporidium. Front Cell Infect Microbiol 2023; 13:1236814. [PMID: 37600947 PMCID: PMC10436570 DOI: 10.3389/fcimb.2023.1236814] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2023] [Accepted: 07/10/2023] [Indexed: 08/22/2023] Open
Abstract
Introduction Cryptosporidiosis is a leading cause of diarrheal-associated morbidity and mortality, predominantly affecting children under 5 years old in low-and-middle-income countries. There is no effective treatment and no vaccine. New therapeutics are emerging from drug discovery efforts. It is critical that mode of action studies are performed alongside drug discovery to ensure the best clinical outcomes. Unfortunately, technology to identify and validate drug targets for Cryptosporidium is severely lacking. Methods We used C. parvum lysyl-tRNA synthetase (CpKRS) and DDD01510706 as a target-compound pair to develop both chemical and genetic tools for mode of action studies for Cryptosporidium. We adapted thermal proteome profiling (TPP) for Cryptosporidium, an unbiased approach for target identification. Results Using TPP we identified the molecular target of DDD01510706 and confirm that it is CpKRS. Genetic tools confirm that CpKRS is expressed throughout the life cycle and that this target is essential for parasite survival. Parasites genetically modified to over-express CpKRS or parasites with a mutation at the compound-binding site are resistant to treatment with DDD01510706. We leveraged these mutations to generate a second drug selection marker for genetic modification of Cryptosporidium, KRSR. This second selection marker is interchangeable with the original selection marker, NeoR, and expands the range of reverse genetic approaches available to study parasite biology. Due to the sexual nature of the Cryptosporidium life cycle, parental strains containing different drug selection markers can be crossed in vivo. Discussion Selection with both drug markers produces highly efficient genetic crosses (>99% hybrid progeny), paving the way for forward genetics approaches in Cryptosporidium.
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Affiliation(s)
- Jack C. Hanna
- Wellcome Centre for Anti-Infectives Research, School of Life Sciences, University of Dundee, Dundee, United Kingdom
| | - Victor Corpas-Lopez
- Wellcome Centre for Anti-Infectives Research, School of Life Sciences, University of Dundee, Dundee, United Kingdom
| | - Simona Seizova
- Wellcome Centre for Anti-Infectives Research, School of Life Sciences, University of Dundee, Dundee, United Kingdom
| | - Beatrice L. Colon
- Wellcome Centre for Anti-Infectives Research, School of Life Sciences, University of Dundee, Dundee, United Kingdom
| | - Ross Bacchetti
- Wellcome Centre for Anti-Infectives Research, School of Life Sciences, University of Dundee, Dundee, United Kingdom
| | - Grant M. J. Hall
- Wellcome Centre for Anti-Infectives Research, School of Life Sciences, University of Dundee, Dundee, United Kingdom
| | - Emma M. Sands
- Wellcome Centre for Anti-Infectives Research, School of Life Sciences, University of Dundee, Dundee, United Kingdom
| | - Lee Robinson
- Wellcome Centre for Anti-Infectives Research, School of Life Sciences, University of Dundee, Dundee, United Kingdom
| | - Beatriz Baragaña
- Wellcome Centre for Anti-Infectives Research, School of Life Sciences, University of Dundee, Dundee, United Kingdom
- Drug Discovery Unit, School of Life Sciences, University of Dundee, Dundee, United Kingdom
| | - Susan Wyllie
- Wellcome Centre for Anti-Infectives Research, School of Life Sciences, University of Dundee, Dundee, United Kingdom
| | - Mattie C. Pawlowic
- Wellcome Centre for Anti-Infectives Research, School of Life Sciences, University of Dundee, Dundee, United Kingdom
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5
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Robinson G, Pérez-Cordón G, Hamilton C, Katzer F, Connelly L, Alexander CL, Chalmers RM. Validation of a multilocus genotyping scheme for subtyping Cryptosporidium parvum for epidemiological purposes. Food Waterborne Parasitol 2022; 27:e00151. [PMID: 35498551 PMCID: PMC9043402 DOI: 10.1016/j.fawpar.2022.e00151] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2021] [Revised: 03/21/2022] [Accepted: 03/27/2022] [Indexed: 11/17/2022] Open
Abstract
Subtyping Cryptosporidium parvum for outbreak investigations or epidemiological surveillance usually relies on DNA sequence analysis of a gene coding for a 60 KDa glycoprotein (gp60). Although gp60 can be useful for allelic discrimination and to help investigate sources and routes of transmission, the presence of common subtypes and recombination during the parasite's sexual life-cycle demand a multilocus-based method for more discriminatory genotyping. While whole genome sequencing would provide the ultimate approach, it is a time consuming and expensive option for faecal parasites such as Cryptosporidium that occur at low density and are difficult to propagate routinely. In this study, we selected and evaluated a panel of previously identified variable-number tandem-repeat (VNTR) markers, to establish a multilocus genotyping scheme based on fragment sizing, appropriate for inter-laboratory surveillance and outbreak investigations. Seven VNTR markers were validated in vitro and demonstrated typeability of 0.85 and discriminatory power of 0.99. The discriminatory power was much greater than the currently used gp60 sequencing (0.74), which identified 26 subtypes, compared to 100 different MLVA profiles within the same sample set. The assay was robust, with repeatable results and reproducibility across three laboratories demonstrating the scheme was suitable for inter-laboratory comparison of C. parvum subtypes. As the majority of genotypes (79%) were unique among epidemiologically unrelated samples, there was efficiency to infer linkage, and epidemiological concordance was observed in historical outbreaks. We propose that the multilocus variable number of tandem repeats analysis scheme is suitable to assist outbreak investigations.
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6
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O'Leary JK, Sleator RD, Lucey B. Cryptosporidium spp. diagnosis and research in the 21 st century. Food Waterborne Parasitol 2021; 24:e00131. [PMID: 34471706 PMCID: PMC8390533 DOI: 10.1016/j.fawpar.2021.e00131] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2021] [Revised: 08/06/2021] [Accepted: 08/17/2021] [Indexed: 01/01/2023] Open
Abstract
The protozoan parasite Cryptosporidium has emerged as a leading cause of diarrhoeal illness worldwide, posing a significant threat to young children and immunocompromised patients. While endemic in the vast majority of developing countries, Cryptosporidium also has the potential to cause waterborne epidemics and large scale outbreaks in both developing and developed nations. Anthroponontic and zoonotic transmission routes are well defined, with the ingestion of faecally contaminated food and water supplies a common source of infection. Microscopy, the current diagnostic mainstay, is considered by many to be suboptimal. This has prompted a shift towards alternative diagnostic techniques in the advent of the molecular era. Molecular methods, particularly PCR, are gaining traction in a diagnostic capacity over microscopy in the diagnosis of cryptosporidiosis, given the laborious and often tedious nature of the latter. Until now, developments in the field of Cryptosporidium detection and research have been somewhat hampered by the intractable nature of this parasite. However, recent advances in the field have taken the tentative first steps towards bringing Cryptosporidium research into the 21st century. Herein, we provide a review of these advances.
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Affiliation(s)
- Jennifer K. O'Leary
- Department of Biological Sciences, Munster Technological University, Bishopstown Campus, Cork, Ireland
| | - Roy D. Sleator
- Department of Biological Sciences, Munster Technological University, Bishopstown Campus, Cork, Ireland
| | - Brigid Lucey
- Department of Biological Sciences, Munster Technological University, Bishopstown Campus, Cork, Ireland
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7
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Baptista RP, Cooper GW, Kissinger JC. Challenges for Cryptosporidium Population Studies. Genes (Basel) 2021; 12:894. [PMID: 34200631 PMCID: PMC8229070 DOI: 10.3390/genes12060894] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2021] [Revised: 05/28/2021] [Accepted: 06/04/2021] [Indexed: 12/31/2022] Open
Abstract
Cryptosporidiosis is ranked sixth in the list of the most important food-borne parasites globally, and it is an important contributor to mortality in infants and the immunosuppressed. Recently, the number of genome sequences available for this parasite has increased drastically. The majority of the sequences are derived from population studies of Cryptosporidium parvum and Cryptosporidium hominis, the most important species causing disease in humans. Work with this parasite is challenging since it lacks an optimal, prolonged, in vitro culture system, which accurately reproduces the in vivo life cycle. This obstacle makes the cloning of isolates nearly impossible. Thus, patient isolates that are sequenced represent a population or, at times, mixed infections. Oocysts, the lifecycle stage currently used for sequencing, must be considered a population even if the sequence is derived from single-cell sequencing of a single oocyst because each oocyst contains four haploid meiotic progeny (sporozoites). Additionally, the community does not yet have a set of universal markers for strain typing that are distributed across all chromosomes. These variables pose challenges for population studies and require careful analyses to avoid biased interpretation. This review presents an overview of existing population studies, challenges, and potential solutions to facilitate future population analyses.
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Affiliation(s)
- Rodrigo P. Baptista
- Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, GA 30602, USA;
- Institute of Bioinformatics, University of Georgia, Athens, GA 30602, USA
| | - Garrett W. Cooper
- Department of Genetics, University of Georgia, Athens, GA 30602, USA;
| | - Jessica C. Kissinger
- Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, GA 30602, USA;
- Institute of Bioinformatics, University of Georgia, Athens, GA 30602, USA
- Department of Genetics, University of Georgia, Athens, GA 30602, USA;
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8
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O'Leary JK, Blake L, Corcoran GD, Sleator RD, Lucey B. Development of a novel, high resolution melting analysis based genotyping method for Cryptosporidium parvum. Eur J Protistol 2021; 79:125799. [PMID: 34044353 DOI: 10.1016/j.ejop.2021.125799] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2020] [Revised: 04/19/2021] [Accepted: 04/26/2021] [Indexed: 12/16/2022]
Abstract
This study employed the post-real-time PCR application, high resolution melting (HRM) analysis, in order to differentiate between characterised clinical and reference Cryptosporidium parvum samples obtained from Cork University Hospital (Cork, Ireland) and the Cryptosporidium Reference Unit (Swansea, Wales). A sample set composed of 18 distinct C. parvum gp60-subtypes of the IIa gp60-subtype family (an allele family accounting for over 80% of all cryptosporidiosis cases in Ireland) was employed. HRM analysis-based interrogation of the gp60, MM5 and MS9-Mallon tandem repeat loci was found to completely differentiate between 10 of the 18 studied gp60-subtypes. The remaining eight gp60-subtypes were differentiated into three distinct groupings, with the designations within these groupings resolved to two to three potential gp60-subtypes. The current study aimed to develop a novel, reproducible, real-time PCR based multi-locus genotyping method to distinguish between C. parvum gp60-subtypes. These preliminary results support the further expansion of the multi-locus panel in order to increase the discriminatory capabilities of this novel method.
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Affiliation(s)
- Jennifer K O'Leary
- Department of Biological Sciences, Munster Technological University, Bishopstown, Cork, Ireland
| | - Liam Blake
- Department of Clinical Microbiology, Cork University Hospital, Wilton, Cork, Ireland
| | - Gerard D Corcoran
- Department of Clinical Microbiology, Cork University Hospital, Wilton, Cork, Ireland
| | - Roy D Sleator
- Department of Biological Sciences, Munster Technological University, Bishopstown, Cork, Ireland.
| | - Brigid Lucey
- Department of Biological Sciences, Munster Technological University, Bishopstown, Cork, Ireland
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9
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O' Leary JK, Blake L, Corcoran GD, Sleator RD, Lucey B. Increased diversity and novel subtypes among clinical Cryptosporidium parvum and Cryptosporidium hominis isolates in Southern Ireland. Exp Parasitol 2020; 218:107967. [PMID: 32858044 DOI: 10.1016/j.exppara.2020.107967] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2020] [Revised: 08/04/2020] [Accepted: 08/05/2020] [Indexed: 12/15/2022]
Abstract
Reported incidence rates of cryptosporidiosis in Ireland are consistently among the highest in Europe. Despite the national prevalence of this enteric parasite and the compulsory nature of incidence surveillance and reporting, in-depth analyses seeking to genotype clinical isolates of Cryptosporidium on an intra-species level are rarely undertaken in Ireland. This molecular epidemiology study of 163 clinical Cryptosporidium isolates was conducted in Southern Ireland, from 2015 to 2018, in order to ascertain population subtype heterogeneity. Analysis was conducted via real-time PCR amplification and gp60 gene sequencing, which successfully determined the subtype designation of 149 of the 163 (91.4%) tested isolates. Overall, 12 C. parvum and five C. hominis subtypes were identified, with the incidence of the regionally predominant C. parvum species found to primarily occur during springtime months, while C. hominis incidence was largely confined to late summer and autumnal months. Additionally, one C. parvum and four C. hominis subtypes were newly reported by this study, having not been previously identified in clinical or livestock infection in Ireland. Overall, these data give insight into the diversification of the Cryptosporidium population and emergent subtypes, while also allowing comparisons to be made with clinical epidemiological profiles reported previously in Ireland and elsewhere.
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Affiliation(s)
- Jennifer K O' Leary
- Department of Biological Sciences, Cork Institute of Technology, Bishopstown, Cork, Ireland
| | - Liam Blake
- Department of Clinical Microbiology, Cork University Hospital, Wilton, Cork, Ireland
| | - Gerard D Corcoran
- Department of Clinical Microbiology, Cork University Hospital, Wilton, Cork, Ireland
| | - Roy D Sleator
- Department of Biological Sciences, Cork Institute of Technology, Bishopstown, Cork, Ireland.
| | - Brigid Lucey
- Department of Biological Sciences, Cork Institute of Technology, Bishopstown, Cork, Ireland
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10
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Morris A, Robinson G, Swain MT, Chalmers RM. Direct Sequencing of Cryptosporidium in Stool Samples for Public Health. Front Public Health 2019; 7:360. [PMID: 31921734 PMCID: PMC6917613 DOI: 10.3389/fpubh.2019.00360] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2019] [Accepted: 11/13/2019] [Indexed: 01/24/2023] Open
Abstract
The protozoan parasite Cryptosporidium is an important cause of diarrheal disease (cryptosporidiosis) in humans and animals, with significant morbidity and mortality especially in severely immunocompromised people and in young children in low-resource settings. Due to the sexual life cycle of the parasite, transmission is complex. There are no restrictions on sexual recombination between sub-populations, meaning that large-scale genetic recombination may occur within a host, potentially confounding epidemiological analysis. To clarify the relationships between infections in different hosts, it is first necessary to correctly identify species and genotypes, but these differentiations are not made by standard diagnostic tests and more sophisticated molecular methods have been developed. For instance, multilocus genotyping has been utilized to differentiate isolates within the major human pathogens, Cryptosporidium parvum and Cryptosporidium hominis. This has allowed mixed populations with multiple alleles to be identified: recombination events are considered to be the driving force of increased variation and the emergence of new subtypes. As yet, whole genome sequencing (WGS) is having limited impact on public health investigations, due in part to insufficient numbers of oocysts and purity of DNA derived from clinical samples. Moreover, because public health agencies have not prioritized parasites, validation has not been performed on user-friendly data analysis pipelines suitable for public health practitioners. Nonetheless, since the first whole genome assembly in 2004 there are now numerous genomes of human and animal-derived cryptosporidia publically available, spanning nine species. It has also been demonstrated that WGS from very low numbers of oocysts is possible, through the use of amplification procedures. These data and approaches are providing new insights into host-adapted infectivity, the presence and frequency of multiple sub-populations of Cryptosporidium spp. within single clinical samples, and transmission of infection. Analyses show that although whole genome sequences do indeed contain many alleles, they are invariably dominated by a single highly abundant allele. These insights are helping to better understand population structures within hosts, which will be important to develop novel prevention strategies in the fight against cryptosporidiosis.
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Affiliation(s)
- Arthur Morris
- Institute of Biological, Environmental & Rural Sciences, Aberystwyth University, Aberystwyth, United Kingdom
| | - Guy Robinson
- Cryptosporidium Reference Unit, Public Health Wales Microbiology, Singleton Hospital, Swansea, United Kingdom
- Swansea University Medical School, Swansea, United Kingdom
| | - Martin T. Swain
- Institute of Biological, Environmental & Rural Sciences, Aberystwyth University, Aberystwyth, United Kingdom
| | - Rachel M. Chalmers
- Cryptosporidium Reference Unit, Public Health Wales Microbiology, Singleton Hospital, Swansea, United Kingdom
- Swansea University Medical School, Swansea, United Kingdom
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11
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Local and global genetic diversity of protozoan parasites: Spatial distribution of Cryptosporidium and Giardia genotypes. PLoS Negl Trop Dis 2017; 11:e0005736. [PMID: 28704362 PMCID: PMC5526614 DOI: 10.1371/journal.pntd.0005736] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2017] [Revised: 07/25/2017] [Accepted: 06/21/2017] [Indexed: 01/09/2023] Open
Abstract
Cryptosporidiosis and giardiasis are recognized as significant enteric diseases due to their long-term health effects in humans and their economic impact in agriculture and medical care. Molecular analysis is essential to identify species and genotypes causing these infectious diseases and provides a potential tool for monitoring. This study uses information on species and genetic variants to gain insights into the geographical distribution and spatial patterns of Cryptosporidium and Giardia parasites. Here, we describe the population heterogeneity of genotypic groups within Cryptosporidium and Giardia present in New Zealand using gp60 and gdh markers to compare the observed variation with other countries around the globe. Four species of Cryptosporidium (C. hominis, C. parvum, C. cuniculus and C. erinacei) and one species of Giardia (G. intestinalis) were identified. These species have been reported worldwide and there are not unique Cryptosporidium gp60 subtype families and Giardiagdh assemblages in New Zealand, most likely due to high gene flow of historical and current human activity (travel and trade) and persistence of large host population sizes. The global analysis revealed that genetic variants of these pathogens are widely distributed. However, genetic variation is underestimated by data biases (e.g. neglected submission of sequences to genetic databases) and low sampling. New genotypes are likely to be discovered as sampling efforts increase according to accumulation prediction analyses, especially for C. parvum. Our study highlights the need for greater sampling and archiving of genotypes globally to allow comparative analyses that help understand the population dynamics of these protozoan parasites. Overall our study represents a comprehensive overview for exploring local and global protozoan genotype diversity and advances our understanding of the importance for surveillance and potential risk associated with these infectious diseases. Infectious diseases threaten the health and well-being of wildlife, livestock and human populations and contribute to significant economic impact in agriculture and medical care. Cryptosporidium and Giardia are enteric protozoan pathogens that cause diarrhea and nutritional disorders on a global level. Using molecular analysis and a review framework we showed that species and genetic variants within genera Cryptosporidium and Giardia (including two species recently infecting humans) found in an island system are not different from other parts of the world. This similarity is likely due to high gene flow of historical and current human activity (travel and trade) and persistence of large host population sizes, such as cattle and people. We also show that, although species and genotypes are widely distributed, new variants will arise when sampling effort increase and their dispersal will be facilitated by human activity. These findings suggest that geographical distribution of species and genotypes within Cryptosporidium and Giardia parasites may yield important clues for designing effective surveillance strategies and identification of factors driving within and cross species transmission.
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Pérez-Cordón G, Robinson G, Nader J, Chalmers RM. Discovery of new variable number tandem repeat loci in multiple Cryptosporidium parvum genomes for the surveillance and investigation of outbreaks of cryptosporidiosis. Exp Parasitol 2016; 169:119-28. [PMID: 27523797 DOI: 10.1016/j.exppara.2016.08.003] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2016] [Revised: 08/09/2016] [Accepted: 08/10/2016] [Indexed: 01/28/2023]
Abstract
Cryptosporidium parvum is a protozoan parasite causing gastro-intestinal disease (cryptosporidiosis) in humans and animals. The ability to investigate sources of contamination and routes of transmission by characterization and comparison of isolates in a cost- and time-efficient manner will help surveillance and epidemiological investigations, but as yet there is no standardised multi-locus typing scheme. To systematically identify variable number tandem repeat (VNTR) loci, which have been shown to provide differentiation in moderately conserved species, we interrogated the reference C. parvum Iowa II genome and seven other C. parvum genomes using a tandem repeat finder software. We identified 28 loci that met criteria defined previously for robust typing schemes for inter-laboratory surveillance, that had potential for generating PCR amplicons analysable on most fragment sizing platforms: repeats ≥6 bp, occurring in tandem in a single repeat region, and providing a total amplicon size of <300 bp including 50 bp for the location of the forward and reverse primers. The qualifying loci will be further investigated in vitro for consideration as preferred loci in the development of a robust VNTR scheme.
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Affiliation(s)
- Gregorio Pérez-Cordón
- Cryptosporidium Reference Unit, Public Health Wales Microbiology, Singleton Hospital, Swansea, SA2 8QA, UK
| | - Guy Robinson
- Cryptosporidium Reference Unit, Public Health Wales Microbiology, Singleton Hospital, Swansea, SA2 8QA, UK; Swansea University Medical School, Grove Building, Swansea University, Singleton Park, Swansea, SA2 8PP, UK
| | - Johanna Nader
- Norwich Medical School, University of East Anglia, Norwich, UK
| | - Rachel M Chalmers
- Cryptosporidium Reference Unit, Public Health Wales Microbiology, Singleton Hospital, Swansea, SA2 8QA, UK; Swansea University Medical School, Grove Building, Swansea University, Singleton Park, Swansea, SA2 8PP, UK.
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Abstract
A key part of the life cycle of an organism is reproduction. For a number of important protist parasites that cause human and animal disease, their sexuality has been a topic of debate for many years. Traditionally, protists were considered to be primitive relatives of the ‘higher’ eukaryotes, which may have diverged prior to the evolution of sex and to reproduce by binary fission. More recent views of eukaryotic evolution suggest that sex, and meiosis, evolved early, possibly in the common ancestor of all eukaryotes. However, detecting sex in these parasites is not straightforward. Recent advances, particularly in genome sequencing technology, have allowed new insights into parasite reproduction. Here, we review the evidence on reproduction in parasitic protists. We discuss protist reproduction in the light of parasitic life cycles and routes of transmission among hosts.
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Sivakumar T, Hayashida K, Sugimoto C, Yokoyama N. Evolution and genetic diversity of Theileria. INFECTION GENETICS AND EVOLUTION 2014; 27:250-63. [PMID: 25102031 DOI: 10.1016/j.meegid.2014.07.013] [Citation(s) in RCA: 137] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/25/2014] [Revised: 07/11/2014] [Accepted: 07/15/2014] [Indexed: 11/16/2022]
Abstract
Theileria parasites infect a wide range of domestic and wild ruminants worldwide, causing diseases with varying degrees of severity. A broad classification, based on the parasite's ability to transform the leukocytes of host animals, divides Theileria into two groups, consisting of transforming and non-transforming species. The evolution of transforming Theileria has been accompanied by drastic changes in its genetic makeup, such as acquisition or expansion of gene families, which are thought to play critical roles in the transformation of host cells. Genetic variation among Theileria parasites is sometimes linked with host specificity and virulence in the parasites. Immunity against Theileria parasites primarily involves cell-mediated immune responses in the host. Immunodominance and major histocompatibility complex class I phenotype-specificity result in a host immunity that is tightly focused and strain-specific. Immune escape in Theileria is facilitated by genetic diversity in its antigenic determinants, which potentially results in a loss of T cell receptor recognition in its host. In the recent past, several reviews have focused on genetic diversity in the transforming species, Theileriaparva and Theileriaannulata. In contrast, genetic diversity in Theileriaorientalis, a benign non-transforming parasite, which occasionally causes disease outbreaks in cattle, has not been extensively examined. In this review, therefore, we provide an outline of the evolution of Theileria, which includes T. orientalis, and discuss the possible mechanisms generating genetic diversity among parasite populations. Additionally, we discuss the potential implications of a genetically diverse parasite population in the context of Theileria vaccine development.
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Affiliation(s)
- Thillaiampalam Sivakumar
- National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Obihiro, Hokkaido, Japan; Veterinary Research Institute, Peradeniya, Sri Lanka
| | - Kyoko Hayashida
- National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Obihiro, Hokkaido, Japan
| | - Chihiro Sugimoto
- Division of Collaboration and Education, Research Center for Zoonosis Control, Hokkaido University, Sapporo, Hokkaido, Japan
| | - Naoaki Yokoyama
- National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Obihiro, Hokkaido, Japan.
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Li N, Xiao L, Cama VA, Ortega Y, Gilman RH, Guo M, Feng Y. Genetic recombination and Cryptosporidium hominis virulent subtype IbA10G2. Emerg Infect Dis 2014; 19:1573-82. [PMID: 24050210 PMCID: PMC3810731 DOI: 10.3201/eid1910.121361] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022] Open
Abstract
Little is known about the emergence and spread of virulent subtypes of Cryptosporidium hominis, the predominant species responsible for human cryptosporidiosis. We conducted sequence analyses of 32 genetic loci of 53 C. hominis specimens isolated from a longitudinally followed cohort of children living in a small community. We identified by linkage disequilibrium and recombination analyses only limited genetic recombination, which occurred exclusively within the 60-kDa glycoprotein gene subtype IbA10G2, a predominant subtype for outbreaks in industrialized nations and a virulent subtype in the study community. Intensive transmission of virulent subtype IbA10G2 in the study area might have resulted in genetic recombination with other subtypes. Moreover, we identified selection for IbA10G2 at a 129-kb region around the 60-kDa glycoprotein gene in chromosome 6. These findings improve our understanding of the origin and evolution of C. hominis subtypes and the spread of virulent subtypes.
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Wang R, Zhang L, Axén C, Bjorkman C, Jian F, Amer S, Liu A, Feng Y, Li G, Lv C, Zhao Z, Qi M, Dong H, Wang H, Sun Y, Ning C, Xiao L. Cryptosporidium parvum IId family: clonal population and dispersal from Western Asia to other geographical regions. Sci Rep 2014; 4:4208. [PMID: 24572610 PMCID: PMC3936226 DOI: 10.1038/srep04208] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2013] [Accepted: 02/11/2014] [Indexed: 11/26/2022] Open
Abstract
In this study, 111 Cryptosporidium parvum IId isolates from several species of animals in China, Sweden, and Egypt were subtyped by multilocus sequence typing (MLST). One to eleven subtypes were detected at each of the 12 microsatellite, minisatellite, and single nucleotide polymorphism (SNP) loci, forming 25 MLST subtypes. Host-adaptation and significant geographical segregation were both observed in the MLST subtypes. A clonal population structure was seen in C. parvum IId isolates from China and Sweden. Three ancestral lineages and the same RPGR sequence were shared by these isolates examined. Therefore, the present genetic observations including the higher nucleotide diversity of C. parvum IId GP60 sequences in Western Asia, as well as the unique distribution of IId subtypes (almost exclusively found in Asia, Europe, and Egypt) and in combination with the domestication history of cattle, sheep, and goats, indicated that C. parvum IId subtypes were probably dispersed from Western Asia to other geographical regions. More population genetic structure studies involving various C. parvum subtype families using high-resolution tools are needed to better elucidate the origin and dissemination of C. parvum in the world.
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Affiliation(s)
- Rongjun Wang
- College of Animal Science and Veterinary Medicine, Henan Agricultural University, Zhengzhou, China
| | - Longxian Zhang
- College of Animal Science and Veterinary Medicine, Henan Agricultural University, Zhengzhou, China
| | - Charlotte Axén
- Department for Animal Health and Antimicrobial Strategies, Swedish National Veterinary Institute, Uppsala, Sweden
| | - Camilla Bjorkman
- Department of Clinical Sciences, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - Fuchun Jian
- College of Animal Science and Veterinary Medicine, Henan Agricultural University, Zhengzhou, China
| | - Said Amer
- Department of Zoology, Faculty of Science, Kafr El sheikh University, Kafe El Sheikh, Egypt
| | - Aiqin Liu
- Department of Parasitology, Harbin Medical University, Harbin, China
| | - Yaoyu Feng
- School of Resource and Environmental Engineering, East China University of Science and Technology, Shanghai, China
| | - Guoquan Li
- College of Animal Science and Veterinary Medicine, Henan Agricultural University, Zhengzhou, China
| | - Chaochao Lv
- College of Animal Science and Veterinary Medicine, Henan Agricultural University, Zhengzhou, China
| | - Zifang Zhao
- College of Animal Science and Veterinary Medicine, Henan Agricultural University, Zhengzhou, China
| | - Meng Qi
- College of Animal Science and Veterinary Medicine, Henan Agricultural University, Zhengzhou, China
| | - Haiju Dong
- College of Animal Science and Veterinary Medicine, Henan Agricultural University, Zhengzhou, China
| | - Helei Wang
- College of Animal Science and Veterinary Medicine, Henan Agricultural University, Zhengzhou, China
| | - Yanru Sun
- College of Animal Science and Veterinary Medicine, Henan Agricultural University, Zhengzhou, China
| | - Changshen Ning
- College of Animal Science and Veterinary Medicine, Henan Agricultural University, Zhengzhou, China
| | - Lihua Xiao
- Division of Foodborne, Waterborne, and Environmental Diseases, National Center for Emerging and Zoonotic Infectious Diseases, Centers for Disease Control and Prevention, Atlanta, USA
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Abstract
SUMMARYEimeriais a common genus of apicomplexan parasites that infect diverse vertebrates, most notably poultry, causing serious disease and economic loss. Like all apicomplexans, eimerians have a complex life cycle characterized by asexual divisions that amplify the parasite population in preparation for sexual reproduction. This can be divided into three events: gametocytogenesis, producing gametocytes from merozoites; gametogenesis, producing microgametes and macrogametes from gametocytes; and fertilization of macrogametes by microgametes, producing diploid zygotes with ensuing meiosis completing the sexual phase. Sexual development inEimeriadepends on the differential expression of stage-specific genes, rather than presence or absence of sex chromosomes. Thus, it involves the generation of specific structures and, implicitly, storage of proteins and regulation of protein expression in macrogametes, in preparation for fertilization. InEimeria, the formation of a unique, resilient structure, the oocyst wall, is essential for completion of the sexual phase and parasite transmission. In this review, we piece together the molecular events that underpin sexual reproduction inEimeriaand use additional details from analogous events inPlasmodiumto fill current knowledge gaps. The mechanisms governing sexual stage formation and subsequent fertilization may represent targets for counteracting parasite transmission.
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Abstract
Coccidial parasites including Cryptosporidium parvum, Cyclospora cayetanensis, Neospora caninum, Toxoplasma gondii and the Eimeria species can cause severe disease of medical and veterinary importance. As many as one-third of the human population may carry T. gondii infection, and Eimeria are thought to cost the global poultry production industry in excess of US$2 billion per annum. Despite their significance, effective vaccines are scarce and have been confined to the veterinary field. As sequencing and genotyping technologies continue to develop, genetic mapping remains a valuable tool for the identification of genes that underlie phenotypic traits of interest and the assembly of contiguous genome sequences. For the coccidian, cross-fertilization still requires in vivo infection, a feature of their life cycle which limits the use of genetic mapping strategies. Importantly, the development of population-based approaches has now removed the need to isolate clonal lines for genetic mapping of selectable traits, complementing the classical clone-based techniques. To date, four coccidial species, representing three genera, have been investigated using genetic mapping. In this review we will discuss recent progress with these species and examine the prospects for future initiatives.
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Affiliation(s)
- Emily L Clark
- Royal Veterinary College, Department of Pathology and Infectious Diseases, University of London, North Mymms AL9 7TA, UK
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Robinson G, Chalmers RM. Assessment of polymorphic genetic markers for multi-locus typing of Cryptosporidium parvum and Cryptosporidium hominis. Exp Parasitol 2012; 132:200-15. [PMID: 22781277 DOI: 10.1016/j.exppara.2012.06.016] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2012] [Revised: 06/26/2012] [Accepted: 06/29/2012] [Indexed: 11/29/2022]
Abstract
The use of high resolution molecular tools to study Cryptosporidium parvum and Cryptosporidium hominis intra-species variation is becoming common practice, but there is currently no consensus in the methods used. The most commonly applied tool is partial gp60 gene sequence analysis. However, multi-locus schemes are acknowledged to improve resolution over analysis of a single locus, which neglects potential re-assortment of genes during the sexual phase of the Cryptosporidium life-cycle. Multi-locus markers have been investigated in isolates from a variety of sampling frames, in varying combinations and using different assays and methods of analysis. To identify the most informative markers as candidates for the development of a standardised multi-locus fragment size-based typing (MLFT) scheme to integrate with epidemiological analyses, we examined the published literature. A total of 31 MLFT studies were found, employing 55 markers of which 45 were applied to both C. parvum and C. hominis. Of the studies, 11 had sufficient raw data, from three or more markers, and a sampling frame containing at least 50 samples, for meaningful in-depth analysis using assessment criteria based on the sampling frame, study size, number of markers investigated in each study, marker characteristics (>2 nucleotide repeats) and the combinations of markers generating all possible multi-locus genotypes. Markers investigated differed between C. hominis and C. parvum. When each scheme was analysed for the fewest markers required to identify 95% of all MLFTs, some redundancy was identified in all schemes; an average redundancy of 40% for C. hominis and 27% for C. parvum. Ranking markers, based on the most productive combinations, identified two different sets of potentially most informative candidate markers, one for each species. These will be subjected to technical evaluation including typability (percentage of samples generating a complete multi-locus type) and discriminatory power by direct fragment size analysis and analysed for correlation with epidemiological data in suitable sampling frames. The establishment of a group of users and agreed subtyping scheme for improved epidemiological and public health investigations of C. parvum and C. hominis will facilitate further developments and consideration of technological advances in a harmonised manner.
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Affiliation(s)
- Guy Robinson
- Cryptosporidium Reference Unit, Public Health Wales Microbiology, Singleton Hospital, Swansea SA2 8QA, UK
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20
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Abstract
We describe recent advances in the genomics and population biology of Cryptosporidium parvum and C. hominis, the causative agents of cryptosporidiosis in humans and animals. Many basic aspects of the biology of Cryptosporidium species remain to be investigated and effective drugs to control cryptosporidiosis are not available. Sequencing and annotation of the genome of C. parvum and C. hominis has uncovered unique features of the metabolism of these species. The recently sequenced genome of the gastric species C. muris is providing new insights into the evolution of the genus. Cryptosporidian sequence information has facilitated the identification of polymorphic genetic markers. Genotyping of oocysts excreted by human and animal hosts using such markers has revealed many new species and genotypes, and is leading to a better understanding of the epidemiology of cryptosporidiosis.
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Affiliation(s)
- G Widmer
- Division of Infectious Diseases, Tufts Cummins School of Veterinary Medicine, North Grafton, MA 01536, USA.
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Conrad M, Zubacova Z, Dunn LA, Upcroft J, Sullivan SA, Tachezy J, Carlton JM. Microsatellite polymorphism in the sexually transmitted human pathogen Trichomonas vaginalis indicates a genetically diverse parasite. Mol Biochem Parasitol 2010; 175:30-8. [PMID: 20813140 DOI: 10.1016/j.molbiopara.2010.08.006] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2010] [Revised: 08/19/2010] [Accepted: 08/23/2010] [Indexed: 10/19/2022]
Abstract
Given the growing appreciation of serious health sequelae from widespread Trichomonas vaginalis infection, new tools are needed to study the parasite's genetic diversity. To this end we have identified and characterized a panel of 21 microsatellites and six single-copy genes from the T. vaginalis genome, using seven laboratory strains of diverse origin. We have (1) adapted our microsatellite typing method to incorporate affordable fluorescent labeling, (2) determined that the microsatellite loci remain stable in parasites continuously cultured for up to 17 months, and (3) evaluated microsatellite marker coverage of the six chromosomes that comprise the T. vaginalis genome, using fluorescent in situ hybridization (FISH). We have used the markers to show that T. vaginalis is a genetically diverse parasite in a population of commonly used laboratory strains. In addition, we have used phylogenetic methods to infer evolutionary relationships from our markers in order to validate their utility in future population analyses. Our panel is the first series of robust polymorphic genetic markers for T. vaginalis that can be used to classify and monitor lab strains, as well as provide a means to measure the genetic diversity and population structure of extant and future T. vaginalis isolates.
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Affiliation(s)
- Melissa Conrad
- Department of Medical Parasitology, New York University Langone Medical Center, New York, NY 10010, USA
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Yang YL, Serrano MG, Sheoran AS, Manque PA, Buck GA, Widmer G. Over-expression and localization of a host protein on the membrane of Cryptosporidium parvum infected epithelial cells. Mol Biochem Parasitol 2009; 168:95-101. [PMID: 19631240 PMCID: PMC2752322 DOI: 10.1016/j.molbiopara.2009.07.004] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2009] [Revised: 06/26/2009] [Accepted: 07/13/2009] [Indexed: 12/30/2022]
Abstract
The genus Cryptosporidium includes several species of intestinal protozoan parasites which multiply in intestinal epithelial cells. The impact of this infection on the transcriptome of cultured host cells was investigated using DNA microarray hybridizations. The expression of 14 genes found to be consistently up- or down-regulated in infected cell monolayers was validated with RT PCR. Using immunofluorescence we examined the expression of Protease Activated Receptor-2, which is encoded by one of the up-regulated genes. In infected cells this receptor localized to the host cell membrane which covers the intracellular trophozoites and meronts. This observation indicates that the composition of the host cell membrane is affected by the developing trophozoite, a phenomenon which has not been described previously.
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Affiliation(s)
- Yi-Lin Yang
- Tufts Cummings School of Veterinary Medicine, Division of Infectious Diseases, 200 Westboro Road, North Grafton, MA 01536, USA
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Meta-analysis of a polymorphic surface glycoprotein of the parasitic protozoa Cryptosporidium parvum and Cryptosporidium hominis. Epidemiol Infect 2009; 137:1800-8. [PMID: 19527551 DOI: 10.1017/s0950268809990215] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
Due to its extensive polymorphism, a partial sequence of the Cryptosporidium surface glycoprotein gene gp60 has been frequently used as a genetic marker. I explored the global diversity of this protein, and compared its sequence diversity in Cryptosporidium parvum and Cryptosporidium hominis. In marked contrast to the geographical partition of C. parvum and C. hominis multi-locus genotypes, gp60 allelic groups showed no evidence of segregating in space, or of differing with respect to geographical diversity. Globally, genetic diversity of C. hominis gp60 exceeded that of C. parvum. Within C. parvum, gp60 alleles originating from human isolates were more diverse than those infecting ruminants. Phylogenetic analysis grouped gp60 sequences into a small number of relatively homogenous allelic groups, with only a small number of alleles having evolved independently. With the notable exception of a group of alleles restricted to humans, C. parvum alleles are found in ruminants and humans.
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A hundred-year retrospective on cryptosporidiosis. Trends Parasitol 2008; 24:184-9. [PMID: 18329342 DOI: 10.1016/j.pt.2008.01.002] [Citation(s) in RCA: 136] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2008] [Accepted: 01/07/2008] [Indexed: 11/23/2022]
Abstract
Tyzzer discovered the genus Cryptosporidium a century ago, and for almost 70 years cryptosporidiosis was regarded as an infrequent and insignificant infection that occurred in the intestines of vertebrates and caused little or no disease. Its association with gastrointestinal illness in humans and animals was recognized only in the early 1980s. Over the next 25 years, information was generated on the disease's epidemiology, biology, cultivation, taxonomy and development of molecular tools. Milestones include: (i) recognition in 1980 of cryptosporidiosis as an acute enteric disease; (ii) its emergence as a chronic opportunistic infection that complicates AIDS; (iii) acknowledgement of impact on the water industry once it was shown to be waterborne; and (iv) study of Cryptosporidium genomics.
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Wielinga PR, de Vries A, van der Goot TH, Mank T, Mars MH, Kortbeek LM, van der Giessen JWB. Molecular epidemiology of Cryptosporidium in humans and cattle in The Netherlands. Int J Parasitol 2007; 38:809-17. [PMID: 18054936 DOI: 10.1016/j.ijpara.2007.10.014] [Citation(s) in RCA: 123] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2007] [Revised: 10/12/2007] [Accepted: 10/16/2007] [Indexed: 10/22/2022]
Abstract
The protozoan parasite Cryptosporidium is found world-wide and can cause disease in both humans and animals. To study the zoonotic potential of Cryptosporidium in The Netherlands we isolated this parasite from the faeces of infected humans and cattle and genotyped those isolates for several different markers. The overall genotyping results showed: for humans isolates, 70% Cryptosporidium hominis, 19% Cryptosporidium parvum, 10% a combination of C. hominis and C. parvum, and 1% Cryptosporidium felis; and for cattle isolates 100% C. parvum. Analysis of the genetic variants detected for the HSP70, ML1 and GP60 markers showed: for human isolates, one C. hominis and two C. parvum variants (C. parvum and C. parvum NL) for HSP70, one C. hominis and five C. parvum variants (C1, C2, C3, and C2 NL1 and C2 NL2) for ML1, four C. hominis (mainly IbA10G2) and four C. parvum variants (mainly IIaA15G2R1) for GP60; and the cattle isolates only C. parvum (not C. parvum NL1) for HSP70, C1 and C2 for ML1, and 17 different IIa sub-types (mainly IIaA15G2R1) for GP60. Molecular epidemiological analysis of the human data showed a C. hominis peak in autumn. The majority (80%) of the human cases were children aged between 0 and 9 years and >70% of these were caused by C. hominis. Patients >25 years of age were infected mainly with C. parvum. We conclude that C. hominis IbA10G2 is found at high frequencies in autumn in humans and not in cattle. The high prevalence of C. parvum IIaA15G2R1 in both humans and cattle indicates that cattle may be a reservoir for this sub-type in The Netherlands.
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Affiliation(s)
- Peter R Wielinga
- National Institute for Public Health and the Environment (RIVM), Centre for Infectious Disease Control (Cib), Laboratory for Zoonoses and Environmental Microbiology (LZO), Antonie van Leeuwenhoeklaan 9, Bilthoven, The Netherlands.
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Huber F, da Silva S, Bomfim TCB, Teixeira KRS, Bello AR. Genotypic characterization and phylogenetic analysis of Cryptosporidium sp. from domestic animals in Brazil. Vet Parasitol 2007; 150:65-74. [PMID: 17905514 DOI: 10.1016/j.vetpar.2007.08.018] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2007] [Revised: 07/11/2007] [Accepted: 08/14/2007] [Indexed: 11/19/2022]
Abstract
The purpose of the present study was the genetic characterization, sequencing and phylogenetic analysis of 18S rDNA sequences of Cryptosporidium isolates obtained from different animal hosts in Brazil. Fecal samples containing Cryptosporidium oocysts were obtained from chickens, ducks, quails, guinea pigs, dairy calves, dogs and cats. For amplification of 18S rDNA sequences the Secondary-PCR product of the extracted DNA from fecal suspension of each studied animal was utilized. The primary genetic characterization of Cryptosporidium sp. was performed using RFLP with the enzymes SspI and VspI. DNA samples were sequenced and subjected to phylogenetic analysis. The results showed C. baileyi infecting two ducks and one quail and C. melagridis infecting one chicken. The sequences obtained from Cryptosporidium sp. infecting guinea pigs were not identified within groups of known Cryptosporidium species. The isolates found parasitizing cats and one dog were diagnosed as C. felis and C. canis, respectively. One isolate of calf origin was identified as C. parvum. The phylogenetic analysis showed clear distribution of isolates between two Cryptosporidium sp. groups according to their gastric or intestinal parasitism. A great genetic distance was observed between C. felis and C. canis from Brazil when compared to the reference sequences obtained from GenBank. The results obtained during this study constitute the first report of rDNA sequences from C. baileyi, C. meleagridis, C. felis, C. canis and C. parvum isolated in Brazil.
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Affiliation(s)
- F Huber
- Instituto Superior de Tecnologia/ Fundação de Apoio à Escola Técnica do Estado do Rio de Janeiro (FAETEC), Rua João de Lacerda S/N, Bairro Fábrica, Paracambi, RJ, CEP 26600-000, Brazil.
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Tanriverdi S, Blain JC, Deng B, Ferdig MT, Widmer G. Genetic crosses in the apicomplexan parasite Cryptosporidium parvum define recombination parameters. Mol Microbiol 2007; 63:1432-9. [PMID: 17302818 DOI: 10.1111/j.1365-2958.2007.05594.x] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Recombinant progeny lines of Cryptosporidium parvum were generated by coinfecting immunosuppressed mice with two genetically distinct isolates of C. parvum. Progeny lines were obtained from a cross of parental lines MD x TU114 through targeted propagation in mice of progeny oocysts originating from populations lacking one parental allele at one or more loci. For each infection lineage this process was repeated until only a single allele remained for each marker, indicating that the progeny line was clonal. To study genetic recombination, 16 progeny clones were genotyped at 40 loci located on each of the eight chromosomes. The inheritance of parental alleles was significantly skewed towards the more virulent parent isolate MD. A contiguous 476 kb segment of chromosome V displayed MD allele in all progeny recovered, while MD and TU114 alleles were detected at other loci throughout the genome. The absence of alleles from one parental isolate in this chromosomal region may indicate phenotypic selection for the MD allele during the generation of these lines. A range for the meiotic crossover frequency was determined on the basis of 40 markers and the number of meioses estimated to have taken place during the crossing experiment. C. parvum exhibits a high rate of recombination commensurate with other Apicomplexa.
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Affiliation(s)
- Sultan Tanriverdi
- Tufts Cummings School of Veterinary Medicine, Division of Infectious Diseases, North Grafton, MA, USA
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28
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Borges JCG, Alves LC, Faustino MADG. Criptosporidiose: uma revisão sobre a sua implicação na conservação dos mamíferos aquáticos. BIOTA NEOTROPICA 2007. [DOI: 10.1590/s1676-06032007000300010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A criptosporidiose é uma doença parasitária emergente que vem sendo relatada em diversas espécies de mamíferos, incluindo os aquáticos. Esta revisão trata da epidemiologia da infecção por Cryptosporidium spp. em mamíferos aquáticos. A idade dos animais, dose infectante e o estado imunológico podem influenciar na apresentação clínica, e quando associados a outros patógenos pode levar o animal a óbito. A contaminação dos recursos hídricos constitui um dos principais meios de disseminação do parasito, que foi identificado por diferentes técnicas de análise. A adequação das estruturas de saneamento, utilização de métodos apropriados para a inativação dos oocistos e garantia das normas de higiene pessoal constituem algumas das maneiras recomendadas para minimizar a disseminação do Cryptosporidium entre os mamíferos aquáticos.
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Tanriverdi S, Markovics A, Arslan MO, Itik A, Shkap V, Widmer G. Emergence of distinct genotypes of Cryptosporidium parvum in structured host populations. Appl Environ Microbiol 2006; 72:2507-13. [PMID: 16597950 PMCID: PMC1449037 DOI: 10.1128/aem.72.4.2507-2513.2006] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Cryptosporidium parvum is an apicomplexan parasite that infects humans and ruminants. C. parvum isolated from cattle in northeastern Turkey and in Israel was genotyped using multiple polymorphic genetic markers, and the two populations were compared to assess the effect of cattle husbandry on the parasite's population structure. Dairy herds in Israel are permanently confined with essentially no opportunity for direct herd-to-herd transmission, whereas in Turkey there are more opportunities for transmission as animals range over wider areas and are frequently traded. A total of 76 C. parvum isolates from 16 locations in Israel and seven farms in the Kars region in northeastern Turkey were genotyped using 16 mini- and microsatellite markers. Significantly, in both countries distinct multilocus genotypes confined to individual farms were detected. The number of genotypes per farm was higher and mixed isolates were more frequent in Turkey than in Israel. As expected from the presence of distinct multilocus genotypes in individual herds, linkage disequilibrium among loci was detected in Israel. Together, these observations show that genetically distinct populations of C. parvum can emerge within a group of hosts in a relatively short time. This may explain the frequent detection of host-specific genotypes with unknown taxonomic status in surface water and the existence of geographically restricted C. hominis genotypes in humans.
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Affiliation(s)
- Sultan Tanriverdi
- Division of Infectious Diseases, Tufts Cummings School of Veterinary Medicine, 200 Westboro Road, North Grafton, MA 01536, USA
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30
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Park JH, Guk SM, Han ET, Shin EH, Kim JL, Chai JY. Genotype analysis of Cryptosporidium spp. prevalent in a rural village in Hwasun-gun, Republic of Korea. THE KOREAN JOURNAL OF PARASITOLOGY 2006; 44:27-33. [PMID: 16514279 PMCID: PMC2532641 DOI: 10.3347/kjp.2006.44.1.27] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Two species of Cryptosporidium are known to infect man; C. hominis which shows anthroponotic transmission between humans, and C. parvum which shows zoonotic transmission between animals or between animals and man. In this study, we focused on identifying genotypes of Cryptosporidium prevalent among inhabitants and domestic animals (cattle and goats), to elucidate transmittal routes in a known endemic area in Hwasun-gun, Jeollanam-do, Republic of Korea. The existence of Cryptosporidium oocysts was confirmed using a modified Ziehl-Neelsen stain. Human infections were found in 7 (25.9%) of 27 people examined. Cattle cryptosporidiosis cases constituted 7 (41.2%) of 17 examined, and goat cases 3 (42.9%) of 7 examined. Species characterizations were performed on the small subunit of the rRNA gene using both PCR-RFLP and sequence analysis. Most of the human isolates were mixtures of C. hominis and C. parvum genotypes and similar PCR-RFLP patterns were observed in cattle and goat isolates. However, sequence analyses identified only C. hominis in all isolates examined. The natural infection of cattle and goats with C. hominis is a new and unique finding in the present study. It is suggested that human cryptosporidiosis in the studied area is caused by mixtures of C. hominis and C. parvum oocysts originating from both inhabitants and domestic animals.
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Affiliation(s)
- Jae-Hwan Park
- Department of Parasitology and Tropical Medicine, Seoul National University College of Medicine, and Institute of Endemic Diseases, Seoul National University Medical Research Center, Seoul, Korea
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31
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Widmer G, Yang YL, Bonilla R, Tanriverdi S, Ciociola KM. Preferential infection of dividing cells by Cryptosporidium parvum. Parasitology 2006; 133:131-8. [PMID: 16623967 DOI: 10.1017/s0031182006000151] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2006] [Revised: 02/01/2006] [Accepted: 02/09/2006] [Indexed: 11/06/2022]
Abstract
In spite of its limitations, the culture of Cryptosporidium parvum in monolayers of epithelial cells is a suitable model to study the interaction of this protozoan parasite with the host cell, to assay oocyst infectivity, and to screen drugs for anti-cryptosporidial activity. For unknown reasons, growth of Cryptosporidium in culture is limited in time and generally does not lead to the production of significant numbers of oocysts. In monolayers infected with high doses of oocysts, we observed that many cells remain uninfected, suggesting that some cells are less susceptible to the infection. Since C. parvum and the related species C. hominis lack many essential biosynthetic pathways, we tested whether the dependence of the parasite on host cell metabolites may favour the infection of cells in mitosis. The proportion of monolayer cells in stationary (G0/G1) phase and in mitosis (S/G2/M) was determined and the prevalence of infected cells in each subpopulation was quantified. Although C. parvum infects and develops in dividing and stationary cells, a significant preference for cells in S/G2/M phase was observed. Consistent with previous observations showing that C. parvum induces apoptosis in cell monolayers, infection was accompanied by a significant increase in the proportion of mitotic cells.
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Affiliation(s)
- G Widmer
- Tufts Cummings School of Veterinary Medicine, Division of Infectious Diseases, 200 Westboro Road, North Grafton, MA 01536, USA.
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32
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Tanriverdi S, Widmer G. Differential evolution of repetitive sequences in Cryptosporidium parvum and Cryptosporidium hominis. INFECTION GENETICS AND EVOLUTION 2006; 6:113-22. [PMID: 16503512 DOI: 10.1016/j.meegid.2005.02.002] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/19/2005] [Revised: 02/16/2005] [Accepted: 02/18/2005] [Indexed: 10/25/2022]
Abstract
Cryptosporidium parvum and Cryptosporidium hominis are two morphologically identical species of Apicomplexan protozoa infecting humans. Although the genomes of these species are 97% identical, their host range is strikingly different. C. parvum infects humans and animals and is primarily a zoonotic infection, whereas C. hominis is typically not detected in animals. The extent of genetic polymorphism in both species has been surveyed locally, but not on a larger geographical scale. Herein, a collection of unrelated C. parvum and C. hominis isolates was genotyped using multiple, randomly distributed micro- and minisatellites. In average, minisatellites, consisting of tandemly repeated sequence motifs of 6-24 basepair, were more polymorphic than microsatellites. When the average number of micro- and minisatellite alleles per locus was used as a measure of heterogeneity, no difference between C. parvum and C. hominis was found. However, the frequency distribution of alleles in both species was significantly different and in 6 of the 14 loci the size of the C. parvum and C. hominis repeats did not overlap. Assuming that C. parvum and C. hominis evolved from a common ancestor, these observations suggest a differential evolution of repeat length at these loci.
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Affiliation(s)
- Sultan Tanriverdi
- Tufts University School of Veterinary Medicine, Division of Infectious Diseases, 200 Westborough Road, North Grafton, MA 01536, USA
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33
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Lee Y, Gomez LL, McAuliffe IT, Tsang VCW. Evaluation of Cryptosporidium parvum oocyst recovery efficiencies from various filtration cartridges by electrochemiluminescence assays. Lett Appl Microbiol 2004; 39:156-62. [PMID: 15242454 DOI: 10.1111/j.1472-765x.2004.01552.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
AIMS To evaluate four types of filtration cartridges for their capacities, efficiency for capture and release of Cryptosporidium parvum oocysts for detection. METHODS AND RESULTS Filtration cartridges included in this evaluation were IDEXX Filta-Max, Gelman Envirochek HV, Corning CrypTest, and Filterite Sigma+. Various dosages of C. parvum oocysts were spiked into water samples with a wide range of turbidity (10-50 NTU). Electrochemiluminescence assays were employed to enumerate viable or total number of C. parvum oocysts in these eluates. Among the cartridges tested, Filta-Max consistently showed higher oocyst recovery efficiency, especially with large volume, highly turbid water samples. CONCLUSIONS Filta-Max filter is the best performer because of its higher oocyst recovery efficiency. SIGNIFICANCE AND IMPACT OF THE STUDY The overall sensitivities of various C. parvum oocyst detection assays in water samples can be improved if highly efficient oocyst recovery filtration cartridges such as Filta-Max are incorporated in sample preparation.
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Affiliation(s)
- Y Lee
- Immunology Branch, Division of Parasitic Diseases, National Center for Infectious Disease, Centers for Disease Control and Prevention, Public Health Services, U.S. Department of Health and Human Services, Atlanta, GA 30341, USA.
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34
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Guk SM, Yong TS, Park SJ, Park JH, Chai JY. Genotype and animal infectivity of a human isolate of Cryptosporidium parvum in the Republic of Korea. THE KOREAN JOURNAL OF PARASITOLOGY 2004; 42:85-9. [PMID: 15181350 PMCID: PMC2717348 DOI: 10.3347/kjp.2004.42.2.85] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Cryptosporidium parvum oocysts were isolated from a child suffering from acute gastroenteritis and successfully passaged in a calf and mice (designated hereafter SNU-H1) in the Republic of Korea; its molecular genotype has been analyzed. The GAG microsatellite region was amplified by a polymerase chain reaction (PCR), with a 238 base pair product, which is commonly displayed in C. parvum. The isolate was shown to be a mixture of the genotypes 1 (anthroponotic) and 2 (zoonotic). To study its infectivity in animals, 2 calves and 3 strains of mice were infected with the SNU-H1; in these animals, the propagation of both genotypes was successful. In immunosuppressed (ImSP) BALB/c and C57BL/6 mice the number of oocysts decreased after day 10 post-infection (PI); but in ImSP ICR mice, they remained constant until day 27 PI. The results show that both the C. parvum genotypes 1 and 2 can be propagated in calves and ImSP mice.
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Affiliation(s)
- Sang-Mee Guk
- Department of Parasitology and Tropical Medicine, Seoul National University College of Medicine, and Institute of Endemic Diseases, Seoul National University Medical Research Center, Seoul 110-799, Korea
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35
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Xiao L, Fayer R, Ryan U, Upton SJ. Cryptosporidium taxonomy: recent advances and implications for public health. Clin Microbiol Rev 2004; 17:72-97. [PMID: 14726456 PMCID: PMC321466 DOI: 10.1128/cmr.17.1.72-97.2004] [Citation(s) in RCA: 544] [Impact Index Per Article: 27.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
There has been an explosion of descriptions of new species of Cryptosporidium during the last two decades. This has been accompanied by confusion regarding the criteria for species designation, largely because of the lack of distinct morphologic differences and strict host specificity among Cryptosporidium spp. A review of the biologic species concept, the International Code of Zoological Nomenclature (ICZN), and current practices for Cryptosporidium species designation calls for the establishment of guidelines for naming Cryptosporidium species. All reports of new Cryptosporidium species should include at least four basic components: oocyst morphology, natural host specificity, genetic characterizations, and compliance with the ICZN. Altogether, 13 Cryptosporidium spp. are currently recognized: C. muris, C. andersoni, C. parvum, C. hominis, C. wrairi, C. felis, and C. cannis in mammals; C. baïleyi, C. meleagridis, and C. galli in birds; C. serpentis and C. saurophilum in reptiles; and C. molnari in fish. With the establishment of a framework for naming Cryptosporidium species and the availability of new taxonomic tools, there should be less confusion associated with the taxonomy of the genus Cryptosporidium. The clarification of Cryptosporidium taxonomy is also useful for understanding the biology of Cryptosporidium spp., assessing the public health significance of Cryptosporidium spp. in animals and the environment, characterizing transmission dynamics, and tracking infection and contamination sources.
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Affiliation(s)
- Lihua Xiao
- Division of Parasitic Diseases, National Center for Infectious Diseases, Centers for Disease Control and Prevention, Chamblee, Georgia 30341, USA.
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36
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Affiliation(s)
- Giovanni Widmer
- Tufts University School of Veterinary Medicine, 200 Westboro Road, North Grafton, MA 01536, USA.
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37
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Tanriverdi S, Arslan MO, Akiyoshi DE, Tzipori S, Widmer G. Identification of genotypically mixed Cryptosporidium parvum populations in humans and calves. Mol Biochem Parasitol 2003; 130:13-22. [PMID: 14550892 DOI: 10.1016/s0166-6851(03)00138-5] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Genotypic analyses of Cryptosporidium parvum oocysts have divided the species into two genotypes, referred to as type 1 and type 2. Although humans are susceptible to both types, mixed type 1/type 2 infections have rarely been identified. The paucity of mixed infections could be explained by the predominance of one type over the other in mixed infections, or by the poor sensitivity of restriction fragment length polymorphism (RFLP) analyses for detecting subpopulations. Using a type-specific real-time PCR assay capable of detecting type 1 or type 2 constituting as little as 0.01% of the population, archived and new isolates of human, bovine, and mouse origin were genotyped. Mixed type 1/type 2 infections were identified in humans and calves, including in samples previously found to be homogeneous by RFLP. Isopycnic fractionation of mixed isolates revealed that type 1 and type 2 oocysts differ in their sedimentation properties. The detection of a type 1 subpopulation in serially-propagated bovine isolates indicates that type 1 and type 2 are stably maintained during long-term passage. Together with recently reported experimental bovine and ovine type 1 infections, the persistence of type 1 subpopulation in experimentally infected animals suggests that animals may play a previously unrecognized role in the maintenance of C. parvum type 1.
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38
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Zhou L, Yang C, Xiao L. PCR-Mediated Recombination between Cryptosporidium spp. of Lizards and Snakes. J Eukaryot Microbiol 2003; 50 Suppl:563-5. [PMID: 14736163 DOI: 10.1111/j.1550-7408.2003.tb00630.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The presence or absence of genetic recombination has often been used as one of the criteria for Cryptosporidium species designation and population structure delineation. During a recent study of cryptosporidiosis in reptiles that were housed in the same room, 4 lizards were found to have concurrent infections of C. serpentis (a gastric parasite) and C. saurophilum (an intestinal parasite), and 6 snakes were concurrently infected with C. serpentis, C. saurophilum and a new Cryptosporidium as indicated by PCR-RFLP analysis of the SSU rRNA gene. DNA sequence analysis of cloned PCR products confirmed the diagnosis of mixed infections. Surprisingly, it appeared that 11 of the 22 clones (8 and 14 clones from a lizard and a snake, respectively) had chimeric sequences of two Cryptosporidium spp. BootScan analysis indicated the existence of recombinants among the cloned sequences and detection of the informative sites confirmed the BootScan results. Because the probability for genetic recombination between gastric and intestinal parasites is small, these hybrid sequences were likely results of PCR artifacts due to the presence of multiple templates. This was confirmed by PCR-sequencing analysis of single-copy templates using diluted DNA samples. Direct sequencing of 69 PCR products from 100- to 1,000-fold diluted DNAs from the same snake and lizard produced only sequences of C. serpentis, C. saurophilum and the unnamed Cryptosporidium sp. Thus, care should be taken to eliminate PCR artifacts when determining the presence of genetic recombination or interpreting results of population genetic studies.
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Affiliation(s)
- Ling Zhou
- Centers for Disease Control and Prevention, Atlanta, GA, USA
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39
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Huang K, Akiyoshi DE, Feng X, Tzipori S. Development of patent infection in immunosuppressed C57Bl/6 mice with a single Cryptosporidium meleagridis oocyst. J Parasitol 2003; 89:620-2. [PMID: 12880270 DOI: 10.1645/0022-3395(2003)089[0620:dopiii]2.0.co;2] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
The ability of Cryptosporidium meleagridis to produce patent infection was studied in adult C57BL/6 mice that were immunosuppressed with dexamethasone phosphate provided in the drinking water at a dosage of 16 microg/ml. Four days after the onset of immunosuppression, mice were orally challenged with 1, 3, 10, or 1,000 C. meleagridis TU1867 oocysts per mouse. The mice were monitored daily for 18 days postinoculation for oocyst shedding. Five of 10 mice given a single oocyst, 4 of 5 mice given 3 oocysts, and all 9 mice given either 10 or 1,000 oocysts became infected and began shedding oocysts 5-7 days after challenge and continued to shed oocysts until the end of the experiment on day 18 postchallenge. Approximately 10(7) oocysts per mouse per day were excreted, regardless of the challenge dose. Neither the noninfected, immunosuppressed nor the inoculated, nonimmunosuppressed control mice shed oocysts. The excreted oocysts were confirmed to be those of C. meleagridis by polymerase chain reaction-restriction fragment length polymorphism analysis. We show that C. meleagridis, originally classified as an avian pathogen but recently found in humans with cryptosporidiosis, can produce patent infection in mice infected with a single oocyst. Moreover, we demonstrate that the immunosuppressed C57BL/6 adult mouse is an ideal host for the propagation of clonal populations of C. meleagridis isolates for laboratory studies.
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Affiliation(s)
- Kehe Huang
- College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, Jiangsu Province, People's Republic of China
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40
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Harp JA. Cryptosporidium and host resistance: historical perspective and some novel approaches. Anim Health Res Rev 2003; 4:53-62. [PMID: 12885209 DOI: 10.1079/ahrr200352] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Cryptosporidium parvum is recognized as a major cause of diarrheal disease in neonatal bovine calves. In addition, this protozoan parasite has emerged as an important cause of disease in both immunocompromised and immunocompetent humans. Despite years of research, no consistently effective means of prevention or treatment are readily available for cryptosporidiosis in any species. Infection through ingestion of contaminated water has been widely documented; C. parvum was reported to be responsible for the largest waterborne outbreak of infectious disease in US history. In addition to its role as a primary disease agent, C. parvum has potential to initiate or exacerbate other gastrointestinal disorders, such as inflammatory bowel disease. Thus, control of C. parvum infection in both animals and humans remains an important objective. Research in our laboratory has focused on understanding mechanisms of resistance to C. parvum. We have demonstrated that acquisition of intestinal flora increases resistance to C. parvum. Substances present in the intestinal mucosa of adult animals can transfer resistance when fed to susceptible infants. Both expression of intestinal enzymes and rate of proliferation of epithelial cells may be altered following C. parvum infection. These and other changes may have profound effects on host resistance to C. parvum.
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Affiliation(s)
- James A Harp
- United States Department of Agriculture, Agricultural Research Service, National Animal Disease Center, 2300 Dayton Avenue, Ames, IA 50010, USA.
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41
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Leav BA, Mackay M, Ward HD. Cryptosporidium species: new insights and old challenges. Clin Infect Dis 2003; 36:903-8. [PMID: 12652391 DOI: 10.1086/368194] [Citation(s) in RCA: 68] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2002] [Accepted: 11/26/2002] [Indexed: 12/27/2022] Open
Abstract
Cryptosporidium species are protozoan parasites that cause mainly enteric illnesses in humans and other animals. The mode of transmission is most commonly waterborne, but other sources of infection, including foodborne and person-to-person spread, have been documented. The environmental form of the parasite is resistant to most water purification methods, including chlorination. Cryptosporidium infection usually causes a self-limited diarrheal illness but can be life-threatening in immunocompromised individuals. There is no effective therapy for cryptosporidiosis.
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Affiliation(s)
- Brett A Leav
- Division of Geographic Medicine and Infectious Diseases, Tufts-New England Medical Center, Boston, MA 02111, USA
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42
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Santos SR, Coffroth MA. Molecular genetic evidence that dinoflagellates belonging to the genus Symbiodinium freudenthal are haploid. THE BIOLOGICAL BULLETIN 2003; 204:10-20. [PMID: 12588740 DOI: 10.2307/1543491] [Citation(s) in RCA: 69] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Microscopic and cytological evidence suggest that many dinoflagellates possess a haploid nuclear phase. However, the ploidy of a number of dinoflagellates remains unknown, and molecular genetic support for haploidy in this group has been lacking. To elucidate the ploidy of symbiotic dinoflagellates belonging to the genus Symbiodinium, we used five polymorphic microsatellites to examine populations harbored by the Caribbean gorgonians Plexaura kuna and Pseudopterogorgia elisabethae; we also studied a series of Symbiodinium cultures. In 690 out of 728 Symbiodinium samples in hospite (95% of the cases) and in all 45 Symbiodinium cultures, only a single allele was recovered per locus. Statistical testing of the Symbiodinium populations harbored by P. elisabethae revealed that the observed genotype frequencies deviate significantly from those expected under Hardy-Weinberg equilibrium. Taken together, our results confirm that, in the vegetative life stage, members of Symbiodinium, both cultured and in hospite, are haploid. Furthermore, based on the phylogenetics of the dinoflagellates, haploidy in vegetative cells appears to be an ancestral trait that extends to all 2,000 extant species of these important unicellular protists.
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Affiliation(s)
- Scott R Santos
- Department of Biological Science, State University of New York at Buffalo, Buffalo, New York 14260-1300, USA
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43
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Abstract
Intestinal parasites continue to be a significant health problem in both developed and developing countries. In developed countries, protozoans are more commonly the cause of gastrointestinal infections than are helminths. Some protozoan parasites have stages in which, in addition to being resistant to chemicals used for water treatment, they are small enough to pass through commonly used filtration processes. The relatively large size of helminth eggs increases the likelihood of their removal during water filtration. The direct impact of protozoan parasites on both human and animal health is considerable, and there is some evidence that infection may contribute to the development of various forms of intestinal dysregulation as well as disseminated infection, especially in AIDS patients. Protozoans of special interest, due to either their frequency of isolation or their role as emerging pathogens, include Giardia duodenalis, Cryptosporidium parvum, Cyclospora cayetanensis, and the microsporidians, Enterocytozoon bieneusi and Encephalitozoon intestinalis.
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Affiliation(s)
- James A Harp
- U.S. Department of Agriculture, Agricultural Research Service, National Animal Disease Center, Ames, Iowa 50010, USA.
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44
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Boedeker EC. Gastrointestinal infections. Curr Opin Gastroenterol 2003; 19:1-3. [PMID: 15699886 DOI: 10.1097/00001574-200301000-00001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/10/2022]
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45
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Tanriverdi S, Tanyeli A, Başlamişli F, Köksal F, Kilinç Y, Feng X, Batzer G, Tzipori S, Widmer G. Detection and genotyping of oocysts of Cryptosporidium parvum by real-time PCR and melting curve analysis. J Clin Microbiol 2002; 40:3237-44. [PMID: 12202559 PMCID: PMC130769 DOI: 10.1128/jcm.40.9.3237-3244.2002] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Several real-time PCR procedures for the detection and genotyping of oocysts of Cryptosporidium parvum were evaluated. A 40-cycle amplification of a 157-bp fragment from the C. parvum beta-tubulin gene detected individual oocysts which were introduced into the reaction mixture by micromanipulation. SYBR Green I melting curve analysis was used to confirm the specificity of the method when DNA extracted from fecal samples spiked with oocysts was analyzed. Because C. parvum isolates infecting humans comprise two distinct genotypes, designated type 1 and type 2, real-time PCR methods for discriminating C. parvum genotypes were developed. The first method used the same beta-tubulin amplification primers and two fluorescently labeled antisense oligonucleotide probes spanning a 49-bp polymorphic sequence diagnostic for C. parvum type 1 and type 2. The second genotyping method used SYBR Green I fluorescence and targeted a polymorphic coding region within the GP900/poly(T) gene. Both methods discriminated between type 1 and type 2 C. parvum on the basis of melting curve analysis. To our knowledge, this is the first report describing the application of melting curve analysis for genotyping of C. parvum oocysts.
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Affiliation(s)
- Sultan Tanriverdi
- Department of Pediatric Hematology-Oncology, School of Medicine, Cukurova University, 01330 Adana, Turkey
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Widmer G, Lin L, Kapur V, Feng X, Abrahamsen MS. Genomics and genetics of Cryptosporidium parvum: the key to understanding cryptosporidiosis. Microbes Infect 2002; 4:1081-90. [PMID: 12191658 DOI: 10.1016/s1286-4579(02)01632-5] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
This paper focuses on recent advances in the genetics and genomics of Cryptosporidium parvum. The approach to and the relevance of sequencing the genomes of C. parvum type 1 and type 2 are discussed, as well as new insights into the genetic heterogeneity of this species.
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Affiliation(s)
- Giovanni Widmer
- Tufts University School of Veterinary Medicine, Division of Infectious Diseases, 200 Westboro Road, North Grafton, MA 01536, USA.
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Leav BA, Mackay MR, Anyanwu A, O' Connor RM, Cevallos AM, Kindra G, Rollins NC, Bennish ML, Nelson RG, Ward HD. Analysis of sequence diversity at the highly polymorphic Cpgp40/15 locus among Cryptosporidium isolates from human immunodeficiency virus-infected children in South Africa. Infect Immun 2002; 70:3881-90. [PMID: 12065532 PMCID: PMC128099 DOI: 10.1128/iai.70.7.3881-3890.2002] [Citation(s) in RCA: 142] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Cryptosporidium sp. is a significant cause of diarrheal disease, particularly in human immunodeficiency virus (HIV)-infected patients in developing countries. We recently cloned and sequenced several alleles of the highly polymorphic single-copy Cryptosporidium parvum gene Cpgp40/15. This gene encodes a precursor protein that is proteolytically cleaved to yield mature cell surface glycoproteins gp40 and gp15, which are implicated in zoite attachment to and invasion of enterocytes. The most-striking feature of the Cpgp40/15 alleles and proteins is their unprecedented degree of sequence polymorphism, which is far greater than that observed for any other gene or protein studied in C. parvum to date. In this study we analyzed nucleic acid and amino acid sequence polymorphism at the Cpgp40/15 locus of 20 C. parvum isolates from HIV-infected South African children. Fifteen isolates exhibited one of four previously identified genotype I alleles at the Cpgp40/15 locus (Ia, Ib, Ic, and Id), while five displayed a novel set of polymorphisms that defined a new Cpgp40/15 genotype I allele, designated genotype Ie. Surprisingly, only 15 of these isolates exhibited concordant type I alleles at the thrombospondin-related adhesive protein of Cryptosporidium and Cryptosporidium oocyst wall protein loci, while five isolates (all of which displayed Cpgp40/15 genotype Ic alleles) displayed genotype II alleles at these loci. Furthermore, the last five isolates also manifested chimeric genotype Ic/Ib or Ic/II alleles at the Cpgp40/15 locus, raising the possibility of sexual recombination within and between prototypical parasite genotypes. Lastly, children infected with isolates having genotype Ic alleles were significantly older than those infected with isolates displaying other genotype I alleles.
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Affiliation(s)
- Brett A Leav
- Division of Geographic Medicine and Infectious Diseases, Tufts New England Medical Center, Boston, Massachusetts 02111, USA
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