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Beesley NJ, Cwiklinski K, Allen K, Hoyle RC, Spithill TW, La Course EJ, Williams DJL, Paterson S, Hodgkinson JE. A major locus confers triclabendazole resistance in Fasciola hepatica and shows dominant inheritance. PLoS Pathog 2023; 19:e1011081. [PMID: 36701396 PMCID: PMC9904461 DOI: 10.1371/journal.ppat.1011081] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2022] [Revised: 02/07/2023] [Accepted: 12/22/2022] [Indexed: 01/27/2023] Open
Abstract
Fasciola hepatica infection is responsible for substantial economic losses in livestock worldwide and poses a threat to human health in endemic areas. The mainstay of control in livestock and the only drug licenced for use in humans is triclabendazole (TCBZ). TCBZ resistance has been reported on every continent and threatens effective control of fasciolosis in many parts of the world. To date, understanding the genetic mechanisms underlying TCBZ resistance has been limited to studies of candidate genes, based on assumptions of their role in drug action. Taking an alternative approach, we combined a genetic cross with whole-genome sequencing to localise a ~3.2Mbp locus within the 1.2Gbp F. hepatica genome that confers TCBZ resistance. We validated this locus independently using bulk segregant analysis of F. hepatica populations and showed that it is the target of drug selection in the field. We genotyped individual parasites and tracked segregation and reassortment of SNPs to show that TCBZ resistance exhibits Mendelian inheritance and is conferred by a dominant allele. We defined gene content within this locus to pinpoint genes involved in membrane transport, (e.g. ATP-binding cassette family B, ABCB1), transmembrane signalling and signal transduction (e.g. GTP-Ras-adenylyl cyclase and EGF-like protein), DNA/RNA binding and transcriptional regulation (e.g. SANT/Myb-like DNA-binding domain protein) and drug storage and sequestration (e.g. fatty acid binding protein, FABP) as prime candidates for conferring TCBZ resistance. This study constitutes the first experimental cross and genome-wide approach for any heritable trait in F. hepatica and is key to understanding the evolution of drug resistance in Fasciola spp. to inform deployment of efficacious anthelmintic treatments in the field.
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Affiliation(s)
- Nicola J. Beesley
- Veterinary Parasitology, Infection, Veterinary and Ecological Sciences, University of Liverpool, Liverpool, United Kingdom
- * E-mail: (NJB); (JEH)
| | - Krystyna Cwiklinski
- Veterinary Parasitology, Infection, Veterinary and Ecological Sciences, University of Liverpool, Liverpool, United Kingdom
| | - Katherine Allen
- Veterinary Parasitology, Infection, Veterinary and Ecological Sciences, University of Liverpool, Liverpool, United Kingdom
| | - Rebecca C. Hoyle
- Veterinary Parasitology, Infection, Veterinary and Ecological Sciences, University of Liverpool, Liverpool, United Kingdom
| | - Terry W. Spithill
- Department of Animal, Plant and Soil Sciences and Centre for AgriBioscience, La Trobe University, Bundoora, Australia
| | | | - Diana J. L. Williams
- Veterinary Parasitology, Infection, Veterinary and Ecological Sciences, University of Liverpool, Liverpool, United Kingdom
| | - Steve Paterson
- Centre for Genomic Research, Infection, Veterinary and Ecological Sciences, University of Liverpool, Liverpool, United Kingdom
| | - Jane E. Hodgkinson
- Veterinary Parasitology, Infection, Veterinary and Ecological Sciences, University of Liverpool, Liverpool, United Kingdom
- * E-mail: (NJB); (JEH)
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New Insights Into the Genetic Variability of Fasciola Hepatica (Trematoda) in Algeria and Relationships with Other Geographic Regions Revealed By Mitochondrial DNA. Helminthologia 2022; 59:152-164. [PMID: 36118371 PMCID: PMC9444205 DOI: 10.2478/helm-2022-0021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2022] [Accepted: 07/14/2022] [Indexed: 11/21/2022] Open
Abstract
This study aims to investigate the level of genetic variability of Fasciola hepatica flukes isolated from cattle in Algeria and to determine the phylogenetic and phylogeographic relationships with sequences isolated worldwide. Mitochondrial (Cytochrome c Oxidase subunit I gene - COI) and nuclear markers (Internal Transcribed Spacers of nuclear ribosomal DNA - ITS) for 24 F. hepatica flukes isolated from 12 cattle in North Algeria were characterised. Only two haplotypes were obtained for the COI gene, resulting in a low level of genetic variation. The analysis of variation among the COI sequences isolated from around the world did not show high levels of genetic divergence, and the phylogenetic analysis revealed a genetic similarity among F. hepatica isolates from different areas of the world. The analysis of the ITS region showed a low level of variability, which prevented obtaining informative phylogenetic and phylogeographic results. The present study also revealed that specimens of F. hepatica are genetically similar in different hosts, indicating that the genetic structure among populations of this parasite is not influenced by the host species. The low levels of genetic variation for COI and ITS regions among fluke isolates from all continents are consistent with a common origin for the flukes’ worldwide distribution.
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Do aspermic (parthenogenetic) Fasciola forms have the ability to reproduce their progeny via parthenogenesis? J Helminthol 2021; 95:e36. [PMID: 34284831 DOI: 10.1017/s0022149x21000328] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Across Far East Asia, aspermic Fasciola forms are found endemically. They have abnormal spermatogenesis and oogenesis, and it is presumed that their progeny are produced parthenogenetically and clonally. Because of this, they are also termed parthenogenic Fasciola forms. Currently, there is no evidence that they do indeed reproduce parthenogenetically and clonally. In this study, the multilocus genetic type (MLG) in 12 microsatellite markers of adult flukes and their subsequent progeny larvae were analysed using two laboratory aspermic Fasciola triploid strains. The MLGs of adults and their larvae were identical for all markers evaluated, suggesting that these strains reproduce their progeny clonally. The deviation between theoretical and actual frequency within the larvae genotype of the Fh_6 locus resulted in the inability for self-fertilization within individual adult flukes. These findings strongly suggested that aspermic Fasciola forms reproduce their progeny by means of parthenogenesis, possibly gynogenesis.
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Beesley NJ, Attree E, Vázquez-Prieto S, Vilas R, Paniagua E, Ubeira FM, Jensen O, Pruzzo C, Álvarez JD, Malandrini JB, Solana H, Hodgkinson JE. Evidence of population structuring following population genetic analyses of Fasciola hepatica from Argentina. Int J Parasitol 2021; 51:471-480. [PMID: 33581141 PMCID: PMC8113023 DOI: 10.1016/j.ijpara.2020.11.007] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2020] [Revised: 11/03/2020] [Accepted: 11/03/2020] [Indexed: 12/03/2022]
Abstract
320 Argentinian Fasciola hepatica were genotyped using a panel of microsatellites. Overall there was high genotypic richness: 263 distinct genotypes were identified. Population structuring of F. hepatica was evident across Argentina. Within these sub-populations there is largely random mating. Transmission of clonemates occurs: clonal parasites accounted for 26.6% of all parasites.
Fasciola hepatica, the liver fluke, is a trematode parasite that causes disease of economic importance in livestock. As a zoonosis this parasite also poses a risk to human health in areas where it is endemic. Population genetic studies can reveal the mechanisms responsible for genetic structuring (non-panmixia) within parasite populations and provide valuable insights into population dynamics, which in turn enables theoretical predictions of evolutionary dynamics such as the evolution of drug resistance. Here we genotyped 320 F. hepatica collected from 14 definitive hosts from four provinces in Argentina. STRUCTURE analysis indicated three population clusters, and principal coordinate analysis confirmed this, showing population clustering across provinces. Similarly, pairwise FST values amongst all four provinces were significant, with standardised pairwise FST (F′ST) ranging from 0.0754 to 0.6327. Therefore, population genetic structure was evident across these four provinces in Argentina. However, there was no evidence of deviation from Hardy–Weinberg equilibrium, so it appears that within these sub-populations there is largely random mating. We identified 263 unique genotypes, which gave a clonal diversity of 82%. Parasites with identical genotypes, clones, accounted for 26.6% of the parasites studied and were found in 12 of the 14 hosts studied, suggesting some clonemate transmission.
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Affiliation(s)
- Nicola J Beesley
- Veterinary Parasitology, Institute of Infection, Veterinary and Ecological Sciences, University of Liverpool, Liverpool, UK.
| | - Elizabeth Attree
- Veterinary Parasitology, Institute of Infection, Veterinary and Ecological Sciences, University of Liverpool, Liverpool, UK
| | - Severo Vázquez-Prieto
- Universidad de Los Lagos, Osorno, Chile; Vicerrectoría de Investigación y Postgrado, Universidad Católica del Maule, Talca, Chile.
| | - Román Vilas
- Departamento de Zoología, Genética y Antropología Física, Facultad de Biología, Universidad de Santiago de Compostela, Santiago de Compostela, Spain
| | - Esperanza Paniagua
- Laboratorio de Parasitología, Departamento de Microbiología y Parasitología, Facultad de Farmacia, Universidad de Santiago de Compostela, Santiago de Compostela, Spain; Instituto de Investigación en Análisis Químicos y Biológicos (IAQBUS), Universidad de Santiago de Compostela, Santiago de Compostela, Spain
| | - Florencio M Ubeira
- Laboratorio de Parasitología, Departamento de Microbiología y Parasitología, Facultad de Farmacia, Universidad de Santiago de Compostela, Santiago de Compostela, Spain; Instituto de Investigación en Análisis Químicos y Biológicos (IAQBUS), Universidad de Santiago de Compostela, Santiago de Compostela, Spain
| | - Oscar Jensen
- Centro de Investigación en Zoonosis, Sarmiento, Chubut, Argentina
| | - Cesar Pruzzo
- Facultad de Ciencias Veterinarias, Universidad Nacional de la Plata (UNLP), La Plata, Argentina
| | - José D Álvarez
- Cátedra de Enfermedades Parasitarias, Facultad de Ciencias Veterinarias, Universidad Nacional del Nordeste (UNNE), Corrientes, Argentina
| | - Jorge Bruno Malandrini
- Laboratorio de Anatomía y Fisiología Animal, Facultad de Ciencias de la Salud, Universidad Nacional de Catamarca, San Fernando del Valle de Catamarca, Argentina
| | - Hugo Solana
- Laboratorio de Biología Celular y Molecular, Centro de Investigación Veterinaria de Tandil (CIVETAN), CONICET, Facultad de Ciencias Veterinarias, Universidad Nacional del Centro de la Provincia de Buenos Aires (UNCPBA), Tandil, Argentina
| | - Jane E Hodgkinson
- Veterinary Parasitology, Institute of Infection, Veterinary and Ecological Sciences, University of Liverpool, Liverpool, UK
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Ohari Y, Matsuo K, Yoshida A, Nonaka N, Sato H, Itagaki T. Genetic diversity and population structure analyses based on microsatellite DNA of parthenogenetic Fasciola flukes obtained from cattle and sika deer in Japan. Parasitol Res 2021; 120:1341-1350. [PMID: 33554278 DOI: 10.1007/s00436-021-07061-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2020] [Accepted: 01/18/2021] [Indexed: 11/24/2022]
Abstract
Understanding the population structure of Fasciola flukes in domestic and wild animals is important for determining the extent of cross-infection between them. Although the parthenogenetic Fasciola flukes in Japan have been shown to comprise five genetic types based on the ribosomal internal transcribed spacer 1 (ITS1) and mitochondrial NADH dehydrogenase subunit 1 (nad1) regions, these genetic regions are not suitable for analyzing their population structure. In the present study, the genetic diversity and population structure of the parthenogenetic Fasciola flukes in Japan were studied using microsatellite DNA, ITS1, and nad1 regions. A total of 144 parthenogenetic Fasciola flukes, obtained from cattle and sika deer in 16 localities, were individually analyzed using PCR-RFLP for ITS1, PCR-direct sequence analysis for nad1, and post-labeling PCR and capillary electrophoresis for microsatellite DNA regions. The flukes showed higher genetic diversity in the microsatellite DNA regions than ITS1 and nad1. The population structures of parthenogenetic Fasciola flukes were unclear, however, it was suggested that the flukes are more diverse populations. We hypothesized that their distribution throughout Japan is closely related to livestock movement dependent on human activity. Moreover, it is considered that cross-infection of the flukes between cattle and sika deer possibly has occurred in the past.
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Affiliation(s)
- Yuma Ohari
- Laboratory of Veterinary Parasitology, Faculty of Agriculture, Iwate University, 3-18-8 Ueda, Morioka, 020-8550, Japan.,Department of Pathogenetic Veterinary Science, United Graduate School of Veterinary Sciences, Gifu University, 1-1 Yanagido, Gifu, 501-1193, Japan
| | - Kayoko Matsuo
- Hida Regional Livestock Hygiene Service Center, 305 Mikkatyo, Takayama, Gifu, 506-0102, Japan.,Faculty of Applied Biological Sciences, Gifu University, 1-1 Yanagido, Gifu, 501-1193, Japan
| | - Ayako Yoshida
- Laboratory of Veterinary Parasitic Diseases, Department of Veterinary Sciences, Faculty of Agriculture, University of Miyazaki, 1-1 Gakuen-Kibanadai-Nishi, Miyazaki, 889-0075, Japan.,Centre for Animal Diseases Control (CADIC), University of Miyazaki, 1-1 Gakuen-Kibanadai-Nishi, Miyazaki, Japan
| | - Nariaki Nonaka
- Laboratory of Veterinary Parasitic Diseases, Department of Veterinary Sciences, Faculty of Agriculture, University of Miyazaki, 1-1 Gakuen-Kibanadai-Nishi, Miyazaki, 889-0075, Japan.,Centre for Animal Diseases Control (CADIC), University of Miyazaki, 1-1 Gakuen-Kibanadai-Nishi, Miyazaki, Japan
| | - Hiroshi Sato
- Laboratory of Parasitology, Joint Faculty of Veterinary Medicine, Yamaguchi University, 1677-1 Yoshida, Yamaguchi, 753-8515, Japan
| | - Tadashi Itagaki
- Laboratory of Veterinary Parasitology, Faculty of Agriculture, Iwate University, 3-18-8 Ueda, Morioka, 020-8550, Japan. .,Department of Pathogenetic Veterinary Science, United Graduate School of Veterinary Sciences, Gifu University, 1-1 Yanagido, Gifu, 501-1193, Japan.
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Vázquez AA, Sabourin E, Alda P, Leroy C, Leray C, Carron E, Mulero S, Caty C, Hasfia S, Boisseau M, Saugné L, Pineau O, Blanchon T, Alba A, Faugère D, Vittecoq M, Hurtrez-Boussès S. Genetic diversity and relationships of the liver fluke Fasciola hepatica (Trematoda) with native and introduced definitive and intermediate hosts. Transbound Emerg Dis 2020; 68:2274-2286. [PMID: 33068493 DOI: 10.1111/tbed.13882] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2020] [Revised: 10/06/2020] [Accepted: 10/13/2020] [Indexed: 12/14/2022]
Abstract
Fasciolosis is a worldwide spread parasitosis mainly caused by the trematode Fasciola hepatica. This disease is particularly important for public health in tropical regions, but it can also affect the economies of many developed countries due to large infections in domestic animals. Although several studies have tried to understand the transmission by studying the prevalence of different host species, only a few have used population genetic approaches to understand the links between domestic and wildlife infections. Here, we present the results of such genetic approach combined with classical parasitological data (prevalence and intensity) by studying domestic and wild definitive hosts from Camargue (southern France) where fasciolosis is considered as a problem. We found 60% of domestic hosts (cattle) infected with F. hepatica but lower values in wild hosts (nutria, 19%; wild boars, 4.5%). We explored nine variable microsatellite loci for 1,148 adult flukes recovered from four different populations (non-treated cattle, treated cattle, nutria and wild boars). Populations from the four groups differed, though we found a number of migrants particularly non-treated cattle and nutria. Overall, we detected 729 different multilocus genotypes (from 783 completely genotyped individuals) and only 46 genotypes repeated across samples. Finally, we experimentally infected native and introduced intermediate snail hosts to explore their compatibility with F. hepatica and assess the risks of fasciolosis expansion in the region. The introduced species Galba truncatula and Pseudosuccinea columella attained the higher values of overall compatibility in relation to the European species. However, concerning the origin, sympatric combinations of G. truncatula were more compatible (higher prevalence, intensity and survival) than the allopatric tested. According to our results, we should note that the assessment of epidemiological risks cannot be limited to a single host-parasite system, but should focus on understanding the diversity of hosts in the heterogeneous environment through space and time.
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Affiliation(s)
- Antonio A Vázquez
- MIVEGEC, University of Montpellier, CNRS, IRD, Montpellier, France.,Laboratory of Malacology, Institute of Tropical Medicine "Pedro Kourí", Havana, Cuba
| | - Emeline Sabourin
- MIVEGEC, University of Montpellier, CNRS, IRD, Montpellier, France
| | - Pilar Alda
- MIVEGEC, University of Montpellier, CNRS, IRD, Montpellier, France.,Laboratorio de Zoología de Invertebrados I, Departamento de Biología, Bioquímica y Farmacia, Universidad Nacional del Sur, Bahía Blanca, Argentina
| | - Clémentine Leroy
- MIVEGEC, University of Montpellier, CNRS, IRD, Montpellier, France
| | - Carole Leray
- Institut de Recherche de la Tour du Valat, Arles, France
| | - Eric Carron
- MIVEGEC, University of Montpellier, CNRS, IRD, Montpellier, France
| | - Stephen Mulero
- MIVEGEC, University of Montpellier, CNRS, IRD, Montpellier, France.,IHPE UMR 5244, University of Perpignan, Perpignan, France
| | - Céline Caty
- Institut de Recherche de la Tour du Valat, Arles, France
| | - Sarah Hasfia
- MIVEGEC, University of Montpellier, CNRS, IRD, Montpellier, France
| | - Michel Boisseau
- MIVEGEC, University of Montpellier, CNRS, IRD, Montpellier, France
| | - Lucas Saugné
- MIVEGEC, University of Montpellier, CNRS, IRD, Montpellier, France
| | - Olivier Pineau
- Institut de Recherche de la Tour du Valat, Arles, France
| | | | - Annia Alba
- Laboratory of Malacology, Institute of Tropical Medicine "Pedro Kourí", Havana, Cuba.,University of Corse-Pascal-Paoli, Corte, France
| | | | - Marion Vittecoq
- MIVEGEC, University of Montpellier, CNRS, IRD, Montpellier, France.,Institut de Recherche de la Tour du Valat, Arles, France
| | - Sylvie Hurtrez-Boussès
- MIVEGEC, University of Montpellier, CNRS, IRD, Montpellier, France.,Département de Biologie-Ecologie, Faculté des Sciences, Université de Montpellier, Montpellier, France
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John BC, Davies DR, Howell AK, Williams DJL, Hodgkinson JE. Anaerobic fermentation results in loss of viability of Fasciola hepatica metacercariae in grass silage. Vet Parasitol 2020; 285:109218. [PMID: 32841785 DOI: 10.1016/j.vetpar.2020.109218] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2020] [Revised: 08/13/2020] [Accepted: 08/14/2020] [Indexed: 10/23/2022]
Abstract
The parasitic liver fluke, Fasciola hepatica, has a detrimental impact on food security and poses a welfare concern to ruminant livestock. F. hepatica metacercariae, shed from an intermediate mud snail host, encyst on vegetation and present a source of infection to grazing livestock. Feeding grass silage to ruminants is a common practice, however the role it plays in the transmission of F. hepatica remains largely unknown. Our current understanding relies on historical studies that are not representative of current silage production and did not apply molecular methods to detect F. hepatica DNA persistence within silages. This study determined the impact of specific fermentation factors, including grass dry matter (DM) content (20, 30 & 40 %), length of ensiling period and maintaining an anaerobic environment on F. hepatica metacercariae viability. In vitro excystment assays demonstrated that regardless of grass DM content, metacercariae ensiled under anaerobic conditions were not viable from two weeks post-sealing. Metacercariae recovered from ensiled grass of 20 % DM content subjected to aerobic spoilage, remained viable for up to 10 weeks. DNA of F. hepatica remained detectable for up to 10 weeks in both anaerobic and spoiled silages. This study highlights i) the importance of maintaining an anaerobic ensiling environment to eliminate the risk of F. hepatica transmission from silage and ii) an inverse relationship between grass DM content and duration of metacercariae survival within spoiled silages. Improving our understanding of trematode metacercariae survival rates within silages, especially of highly pathogenic species such as F. hepatica, allows farmers to make informed decisions regarding on-farm parasite control.
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Affiliation(s)
- Bethan C John
- Institute of Infection, Veterinary and Ecological Sciences, Department of Infection Biology and Microbiomes, University of Liverpool, Liverpool Science Park IC2, 146 Brownlow Hill, Liverpool, L3 5RF, UK.
| | - David R Davies
- Silage Solutions Ltd, Bwlch y Blaen, Pontrhydygroes, Ceredigion, SY25 6DP, UK
| | - Alison K Howell
- Institute of Infection, Veterinary and Ecological Sciences, Department of Infection Biology and Microbiomes, University of Liverpool, Liverpool Science Park IC2, 146 Brownlow Hill, Liverpool, L3 5RF, UK
| | - Diana J L Williams
- Institute of Infection, Veterinary and Ecological Sciences, Department of Infection Biology and Microbiomes, University of Liverpool, Liverpool Science Park IC2, 146 Brownlow Hill, Liverpool, L3 5RF, UK
| | - Jane E Hodgkinson
- Institute of Infection, Veterinary and Ecological Sciences, Department of Infection Biology and Microbiomes, University of Liverpool, Liverpool Science Park IC2, 146 Brownlow Hill, Liverpool, L3 5RF, UK
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Design and expression of polytopic construct of cathepsin-L1, SAP-2 and FhTP16.5 proteins of Fasciola hepatica. J Helminthol 2020; 94:e134. [PMID: 32127056 DOI: 10.1017/s0022149x20000140] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The enzyme-linked immunosorbent assay (ELISA) technique can play an important role in the early detection of fascioliasis. However, they have some diagnostic limitations, including cross-reaction with other helminths. It seems that the combination of recombinant parasite proteins as antigen can reduce these problems. Hence, the present study was aimed to design and confirm the antigenic recombinant multi-epitope (rMEP) construct of three protein epitopes (linear and conformational B-cell epitopes) of the parasite using immunoinformatic tools. For this purpose, the tertiary structures of Fasciola hepatica cathepsin-L1, saposin-like protein 2 and 16.5-kDa tegument-associated protein were predicted using the I-TASSER server. Validation of the modelled structures was performed by Ramachandran plots. The antigenic epitopes of the proteins were achieved by analysing the features of the IEDB server. The synthesized gene was cloned into the pET-22b (+) expression vector and transformed into the Escherichia coli BL21. Sodium dodecyl sulfate polyacrylamide gel electrophoresis was used to verify and analyse the expression of the rMEP protein. Western blotting was utilized to confirm rMEP protein immunogenicity in two forms, one using an anti-His tag antibody and the other with human pooled sera samples (fascioliasis, non-fascioliasis and negative control sera). Our results demonstrated that the rMEP designed for the three proteins of F. hepatica was highly antigenic, and immune-detection techniques confirmed the antigen specificity. In conclusion, the presented antigenic multi-epitope may be very helpful to develop serodiagnostic kits such as indirect ELISA to evaluate the proper diagnosis of fascioliasis in humans and ruminants.
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Zhang XX, Cwiklinski K, Hu RS, Zheng WB, Sheng ZA, Zhang FK, Elsheikha HM, Dalton JP, Zhu XQ. Complex and dynamic transcriptional changes allow the helminth Fasciola gigantica to adjust to its intermediate snail and definitive mammalian hosts. BMC Genomics 2019; 20:729. [PMID: 31606027 PMCID: PMC6790025 DOI: 10.1186/s12864-019-6103-5] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2019] [Accepted: 09/13/2019] [Indexed: 01/22/2023] Open
Abstract
BACKGROUND The tropical liver fluke, Fasciola gigantica causes fasciolosis, an important disease of humans and livestock. We characterized dynamic transcriptional changes associated with the development of the parasite in its two hosts, the snail intermediate host and the mammalian definitive host. RESULTS Differential gene transcription analysis revealed 7445 unigenes transcribed by all F. gigantica lifecycle stages, while the majority (n = 50,977) exhibited stage-specific expression. Miracidia that hatch from eggs are highly transcriptionally active, expressing a myriad of genes involved in pheromone activity and metallopeptidase activity, consistent with snail host finding and invasion. Clonal expansion of rediae within the snail correlates with increased expression of genes associated with transcription, translation and repair. All intra-snail stages (miracidia, rediae and cercariae) require abundant cathepsin L peptidases for migration and feeding and, as indicated by their annotation, express genes putatively involved in the manipulation of snail innate immune responses. Cercariae emerge from the snail, settle on vegetation and become encysted metacercariae that are infectious to mammals; these remain metabolically active, transcribing genes involved in regulation of metabolism, synthesis of nucleotides, pH and endopeptidase activity to assure their longevity and survival on pasture. Dramatic growth and development following infection of the mammalian host are associated with high gene transcription of cell motility pathways, and transport and catabolism pathways. The intra-mammalian stages temporally regulate key families of genes including the cathepsin L and B proteases and their trans-activating peptidases, the legumains, during intense feeding and migration through the intestine, liver and bile ducts. While 70% of the F. gigantica transcripts share homology with genes expressed by the temperate liver fluke Fasciola hepatica, gene expression profiles of the most abundantly expressed transcripts within the comparable lifecycle stages implies significant species-specific gene regulation. CONCLUSIONS Transcriptional profiling of the F. gigantica lifecycle identified key metabolic, growth and developmental processes the parasite undergoes as it encounters vastly different environments within two very different hosts. Comparative analysis with F. hepatica provides insight into the similarities and differences of these parasites that diverged > 20 million years ago, crucial for the future development of novel control strategies against both species.
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Affiliation(s)
- Xiao-Xuan Zhang
- State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, Gansu Province, 730046, People's Republic of China
- College of Veterinary Medicine, Qingdao Agricultural University, Qingdao, Shandong Province, 266109, People's Republic of China
| | - Krystyna Cwiklinski
- National Centre for Biomedical and Engineering Science (NCBES), School of Natural Sciences, National University of Ireland, Galway, Ireland.
| | - Rui-Si Hu
- State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, Gansu Province, 730046, People's Republic of China
| | - Wen-Bin Zheng
- State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, Gansu Province, 730046, People's Republic of China
| | - Zhao-An Sheng
- College of Animal Science and Technology, Guangxi University, Nanning, Guangxi Zhuang Autonomous Region, 530005, People's Republic of China
| | - Fu-Kai Zhang
- State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, Gansu Province, 730046, People's Republic of China
| | - Hany M Elsheikha
- Faculty of Medicine and Health Sciences, School of Veterinary Medicine and Science, University of Nottingham, Nottingham, UK
| | - John P Dalton
- National Centre for Biomedical and Engineering Science (NCBES), School of Natural Sciences, National University of Ireland, Galway, Ireland.
| | - Xing-Quan Zhu
- State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, Gansu Province, 730046, People's Republic of China.
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Chikowore TJ, Zishiri OT, Mukaratirwa S. Phylogenetic analysis of Fasciola spp. isolated from slaughtered cattle in KwaZulu-Natal and Mpumalanga provinces of South Africa based on the cytochrome c oxidase subunit I mitochondrial marker. Onderstepoort J Vet Res 2019; 86:e1-e11. [PMID: 31291732 PMCID: PMC6620549 DOI: 10.4102/ojvr.v86i1.1706] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2018] [Revised: 02/11/2019] [Accepted: 02/12/2019] [Indexed: 11/16/2022] Open
Abstract
Fasciola spp. are the causative agents of fascioliasis in humans and livestock. Before the development of control and management measures, the geographical distribution of the species and patterns of infection must be considered. Because of difficulties in the phenotypic differentiation and morphometric classification of Fasciola spp., DNA molecular markers have become more useful for fluke differentiation and description of phylogenetic patterns. This study aimed to differentiate and describe the phylogenetic background of Fasciola spp. isolated from cattle slaughtered at three abattoirs in the Mpumalanga and KwaZulu-Natal provinces of South Africa. The cytochrome c oxidase I (COI) - FHCO1 (forward: 5'-TTGGTTTTTTGGGCATCCT-3') and FHCO1 (reverse: 5' -AGGCCACCACCAAATAAAAGA3') - marker was sequenced from 55 Fasciola flukes that were collected from abattoirs in catchment areas of the KwaZulu-Natal and Mpumalanga provinces. Fasciola hepatica was demonstrated to have 100% prevalence in KwaZulu-Natal and Mpumalanga (highveld), respectively, and 76% prevalence in the lowveld (Belfast area) of Mpumalanga. Two animals from the Belfast metapopulation were co-infected with both Fasciola gigantica and F. hepatica. DNA sequence analysis of all the isolates demonstrated a sequence conservation of 0.472, nucleotide diversity of 0.082 and Tajima's D of -1.100; however, it was not statistically significant (p > 0.05). Twenty-two haplotypes were identified, with 18 novel haplotypes being unique to the isolates from South Africa. Within the study samples, 12 haplotypes were isolated to a few individuals, with a haplotype diversity of 0.8957 indicating high genetic diversity. Principal coordinate analysis supported the clustering and distribution of the haplotypes, with 11.38% of the variation being attributed to coordinate 2 and 55.52% to coordinate 1. The distribution of Fasciola spp. has been demonstrated to be related to the distribution of the freshwater intermediate host snails, Lymnaea spp., as well as the relative altitude of the localities in South Africa. Information provided by this study serves as preliminary evidence for further studies on the mapping of the distribution of F. gigantica and F. hepatica in South Africa, which is key in designing control programmes for fascioliasis in humans and livestock.
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Affiliation(s)
- Tatenda J Chikowore
- Discipline of Genetics, School of Life Sciences, College of Agriculture, Engineering and Science, University of KwaZulu-Natal, Durban.
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11
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John BC, Davies DR, Williams DJL, Hodgkinson JE. A review of our current understanding of parasite survival in silage and stored forages, with a focus on Fasciola hepatica metacercariae. GRASS AND FORAGE SCIENCE : THE JOURNAL OF THE BRITISH GRASSLAND SOCIETY 2019; 74:211-217. [PMID: 31244499 PMCID: PMC6582591 DOI: 10.1111/gfs.12429] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/11/2018] [Revised: 03/08/2019] [Accepted: 04/07/2019] [Indexed: 06/09/2023]
Abstract
Fasciola hepatica, the parasitic liver fluke, is a re-emerging zoonotic infection and an important cause of morbidity and mortality in ruminant livestock worldwide. A significant animal welfare concern, fasciolosis also has a detrimental impact on food security, with the effects of sub-clinical infection on growth rate and milk yield estimated to cost the UK cattle industry £40.4 million annually. It is understood that up to 50% of infective F. hepatica metacercariae may overwinter on pasture and remain viable to infect grazing livestock the following spring. However, the infection risk posed by feeding grass silage to livestock remains largely unknown as the majority of previous studies are outdated in both experimental design and analysis of ensiled metacercariae viability. Anecdotal reports of fasciolosis outbreaks in housed livestock have reignited interest in F. hepatica metacercariae survival during modern ensiling processes and more importantly if they retain viability within stored forages. Consequently, a comprehensive review of the available literature is required in order to identify knowledge gaps and highlight future research opportunities regarding the role of silage in the transmission of F. hepatica.
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Affiliation(s)
- Bethan C. John
- Institute of Infection and Global HealthUniversity of LiverpoolLiverpoolUK
| | | | | | - Jane E. Hodgkinson
- Institute of Infection and Global HealthUniversity of LiverpoolLiverpoolUK
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12
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Di Maggio LS, Tirloni L, Pinto AFM, Diedrich JK, Yates JR, Carmona C, Berasain P, da Silva Vaz I. A proteomic comparison of excretion/secretion products in Fasciola hepatica newly excysted juveniles (NEJ) derived from Lymnaea viatrix or Pseudosuccinea columella. Exp Parasitol 2019; 201:11-20. [PMID: 31022392 DOI: 10.1016/j.exppara.2019.04.004] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2018] [Revised: 03/19/2019] [Accepted: 04/12/2019] [Indexed: 12/13/2022]
Abstract
The characteristics of parasitic infections are often tied to host behavior. Although most studies have investigated definitive hosts, intermediate hosts can also play a role in shaping the distribution and accumulation of parasites. This is particularly relevant in larval stages, where intermediate host's behavior could potentially interfere in the molecules secreted by the parasite into the next host during infection. To investigate this hypothesis, we used a proteomic approach to analyze excretion/secretion products (ESP) from Fasciola hepatica newly excysted juveniles (NEJ) derived from two intermediate host species, Lymnaea viatrix and Pseudosuccinea columella. The two analyzed proteomes showed differences in identity, abundance, and functional classification of the proteins. This observation could be due to differences in the biological cycle of the parasite in the host, environmental aspects, and/or host-dependent factors. Categories such as protein modification machinery, protease inhibitors, signal transduction, and cysteine-rich proteins showed different abundance between samples. More specifically, differences in abundance of individual proteins such as peptidyl-prolyl cis-trans isomerase, thioredoxin, cathepsin B, cathepsin L, and Kunitz-type inhibitors were identified. Based on the differences identified between NEJ ESP samples, we can conclude that the intermediate host is a factor influencing the proteomic profile of ESP in F. hepatica.
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Affiliation(s)
- Lucía Sánchez Di Maggio
- Centro de Biotecnologia, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil; Unidad de Biología Parasitaria, Facultad de Ciencias, Universidad de la República Oriental del Uruguay, Montevideo, Uruguay
| | - Lucas Tirloni
- Centro de Biotecnologia, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil; College of Veterinary Medicine, Department of Veterinary Pathobiology, Texas A&M University, College Station, TX, USA
| | - Antônio F M Pinto
- Department of Molecular Medicine, The Scripps Research Institute, CA, USA
| | - Jolene K Diedrich
- Department of Molecular Medicine, The Scripps Research Institute, CA, USA
| | - John R Yates
- Department of Molecular Medicine, The Scripps Research Institute, CA, USA
| | - Carlos Carmona
- Unidad de Biología Parasitaria, Facultad de Ciencias, Universidad de la República Oriental del Uruguay, Montevideo, Uruguay
| | - Patricia Berasain
- Unidad de Biología Parasitaria, Facultad de Ciencias, Universidad de la República Oriental del Uruguay, Montevideo, Uruguay.
| | - Itabajara da Silva Vaz
- Centro de Biotecnologia, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil; Faculdade de Veterinária, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil.
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13
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Musah-Eroje M, Flynn RJ. Fasciola hepatica, TGF-β and host mimicry: the enemy within. Curr Opin Microbiol 2018; 46:80-85. [PMID: 30317150 DOI: 10.1016/j.mib.2018.09.002] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2018] [Revised: 08/29/2018] [Accepted: 09/24/2018] [Indexed: 11/16/2022]
Abstract
Helminths parasites undergo developmental changes and migration within their definitive host, in addition to establishing chronic infection. Essential to this is the evasion of host immune responses; the canonical Th2 response is effective at removing parasites resident in the intestine. Conversely, helminths also promote the development of antigen-specific anergy and regulation. This often limits pathology but allows parasite survival, parasite effectors mediating this are the subject of intense study. They may be useful as future vaccine targets or xenogenic therapeutics. Fasciola hepatica possesses a family of TGF-like molecules of which one member, FhTLM, is capable of promoting intrinsic and extrinsic effects. Here we review the extrinsic effects of FhTLM on the host macrophage and its consequences for protective immunity. This review also discusses the specificities of FhTLM in light a very recent description of a nematode TGF-β mimic and the effects of endogenous TGF-β.
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Affiliation(s)
- Mayowa Musah-Eroje
- School of Veterinary Medicine and Science, University of Nottingham, LE12 5RD, United Kingdom
| | - Robin J Flynn
- Department of Infection Biology, Institute of Infection and Global Health, University of Liverpool, L3 5RF, United Kingdom.
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14
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Hodgkinson JE, Cwiklinski K, Beesley N, Hartley C, Allen K, Williams DJL. Clonal amplification of Fasciola hepatica in Galba truncatula: within and between isolate variation of triclabendazole-susceptible and -resistant clones. Parasit Vectors 2018; 11:363. [PMID: 29941045 PMCID: PMC6020221 DOI: 10.1186/s13071-018-2952-z] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2018] [Accepted: 06/13/2018] [Indexed: 11/10/2022] Open
Abstract
Background Fasciola hepatica is of worldwide significance, impacting on the health, welfare and productivity of livestock and regarded by WHO as a re-emerging zoonosis. Triclabendazole (TCBZ), the drug of choice for controlling acute fasciolosis in livestock, is also the drug used to treat human infections. However TCBZ-resistance is now considered a major threat to the effective control of F. hepatica. It has yet to be demonstrated whether F. hepatica undergoes a genetic clonal expansion in the snail intermediate host, Galba truncatula, and to what extent amplification of genotypes within the snail facilitates accumulation of drug resistant parasites. Little is known about genotypic and phenotypic variation within and between F. hepatica isolates. Results Six clonal isolates of F. hepatica (3× triclabendazole-resistant, TCBZ-R and 3× triclabendazole-susceptible, TCBZ-S) were generated. Snails infected with one miracidium started to shed cercariae 42–56 days post-infection and shed repeatedly up to a maximum of 11 times. A maximum of 884 cercariae were shed by one clonally-infected snail (FhLivS1) at a single time point, with > 3000 clonal metacercariae shed over its lifetime. Following experimental infection all 12 sheep were FEC positive at the time of TCBZ treatment. Sheep infected with one of three putative TCBZ-S clones and treated with TCBZ had no parasites in the liver at post-mortem, whilst sheep each infected with putative TCBZ-R isolates had 35–165 adult fluke at post-mortem, despite TCBZ treatment. All six untreated control animals had between 15–127 parasites. A single multi-locus genotype was reported for every fluke from each of the six clonal isolates. Adult F. hepatica showed considerable variation in weight, ranging from 20–280 mg, with variation in weight evident within and amongst clonal isolates. Conclusions A genetic clonal expansion occurs within G. truncatula, highlighting the potential for amplification of drug resistant genotypes of F. hepatica. Variation in the weight of parasites within and between clonal isolates and when comparing isolates that are either susceptible or resistant to TCBZ represent inherent variation in liver fluke and cannot be attributed to their resistance or susceptibility traits.
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Affiliation(s)
- Jane E Hodgkinson
- Veterinary Parasitology, Dept Infection Biology, Institute of Infection and Global Health, University of Liverpool, Liverpool, L69 7ZJ, UK.
| | - Krystyna Cwiklinski
- Veterinary Parasitology, Dept Infection Biology, Institute of Infection and Global Health, University of Liverpool, Liverpool, L69 7ZJ, UK.,School of Biological Sciences, Medical Biology Centre, Queen's University Belfast, Belfast, BT9 7BL, UK
| | - Nicola Beesley
- Veterinary Parasitology, Dept Infection Biology, Institute of Infection and Global Health, University of Liverpool, Liverpool, L69 7ZJ, UK
| | - Catherine Hartley
- Veterinary Parasitology, Dept Infection Biology, Institute of Infection and Global Health, University of Liverpool, Liverpool, L69 7ZJ, UK
| | - Katherine Allen
- Veterinary Parasitology, Dept Infection Biology, Institute of Infection and Global Health, University of Liverpool, Liverpool, L69 7ZJ, UK
| | - Diana J L Williams
- Veterinary Parasitology, Dept Infection Biology, Institute of Infection and Global Health, University of Liverpool, Liverpool, L69 7ZJ, UK
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15
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Correa AC, De Meeûs T, Dreyfuss G, Rondelaud D, Hurtrez-Boussès S. Galba truncatula and Fasciola hepatica: Genetic costructures and interactions with intermediate host dispersal. INFECTION GENETICS AND EVOLUTION 2017; 55:186-194. [PMID: 28917540 DOI: 10.1016/j.meegid.2017.09.012] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/31/2017] [Revised: 09/12/2017] [Accepted: 09/12/2017] [Indexed: 12/07/2022]
Abstract
Antagonistic interactions between hosts and parasites are key structuring forces in natural populations. Demographic factors like extinction, migration and the effective population size shape host-parasite metapopulational dynamics. Therefore, to understand the evolution of host-parasite systems it is necessary to study the distribution of the genetic variation of both entities simultaneously. In this paper, we investigate the population genetics co-structure of parasites and hosts within a metapopulation of the liver fluke, Fasciola hepatica, and two of its intermediate hosts, the main intermediate host in Europe, Galba truncatula, and a new intermediate host, Omphiscola glabra, in Central France. Our results reveal an absence of specificity of flukes as regard to the two alternative hosts though O. glabra shows higher prevalence of F. hepatica. Host and parasites displayed contrasting population genetics structure with very small, highly inbred (selfing) and strongly isolated G. truncatula populations and much bigger, panmictic and more dispersive F. hepatica. This could indicate a local adaptation of the parasite and a local maladaptation of the host. We also unveil a parasite-mediated biased population genetics structure suggesting that infected G. truncatula disperse more; have higher dispersal survival than uninfected snails or, more likely, that immigrant snails are infected more often than local snails (local parasites are less adapted to local hosts). Finally, an absence, or at least an ambiguous signature of isolation by distance was observed in both host and parasite population. A very weak migration rate for G. truncatula provides a reasonable explanation for this ambiguous result. Alternatively, smaller sample sizes combined with modest migration rates might explain the difficulties to unveil the signal in F. hepatica.
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Affiliation(s)
- Ana C Correa
- Mivegec UMR UM, CNRS 5290 - IRD 224 Maladies Infectieuses et Vecteurs: Ecologie, Génétique, Evolution et Contrôle, Centre IRD, BP 64501, 34394 Montpellier Cedex 5, France
| | - Thierry De Meeûs
- IRD, UMR Interactions hôtes - vecteurs - parasites dans les infections par des trypanosomatidae - (Intertryp) UMR IRD 177, CIRAD 17, TA A-17/G, Campus International de Baillarguet, 34398 Montpellier Cedex 5, France.
| | - Gilles Dreyfuss
- Inserm 1094, Facultés de Médecine et de Pharmacie, Limoges, 2 Rue du Docteur Raymond Marcland, 87025 Limoges, France
| | - Daniel Rondelaud
- Inserm 1094, Facultés de Médecine et de Pharmacie, Limoges, 2 Rue du Docteur Raymond Marcland, 87025 Limoges, France
| | - Sylvie Hurtrez-Boussès
- Mivegec UMR UM, CNRS 5290 - IRD 224 Maladies Infectieuses et Vecteurs: Ecologie, Génétique, Evolution et Contrôle, Centre IRD, BP 64501, 34394 Montpellier Cedex 5, France; Département de Biologie-Ecologie, Faculté des Sciences, Université Montpellier, 34095 Montpellier Cedex 5, France
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16
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Wit J, Gilleard JS. Resequencing Helminth Genomes for Population and Genetic Studies. Trends Parasitol 2017; 33:388-399. [DOI: 10.1016/j.pt.2017.01.009] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2016] [Revised: 01/11/2017] [Accepted: 01/12/2017] [Indexed: 10/20/2022]
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17
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Beesley NJ, Williams DJL, Paterson S, Hodgkinson J. Fasciola hepatica demonstrates high levels of genetic diversity, a lack of population structure and high gene flow: possible implications for drug resistance. Int J Parasitol 2016; 47:11-20. [PMID: 27940066 PMCID: PMC5264428 DOI: 10.1016/j.ijpara.2016.09.007] [Citation(s) in RCA: 61] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2016] [Revised: 09/01/2016] [Accepted: 09/07/2016] [Indexed: 11/19/2022]
Abstract
Self-fertilisation does occur but is rare in field populations of Fasciola hepatica. Some hosts harboured genotypically identical parasites (clones). The presence of clones is consistent with clonal expansion and clumped transmission. 84% of 1579 F. hepatica had unique genotypes, indicating high genetic diversity. We found high gene flow, no population structure and low self-fertilisation rate.
Fasciola hepatica, the liver fluke, is a trematode parasite of considerable economic importance to the livestock industry and is a re-emerging zoonosis that poses a risk to human health in F. hepatica-endemic areas worldwide. Drug resistance is a substantial threat to the current and future control of F. hepatica, yet little is known about how the biology of the parasite influences the development and spread of resistance. Given that F. hepatica can self-fertilise and therefore inbreed, there is the potential for greater population differentiation and an increased likelihood of recessive alleles, such as drug resistance genes, coming together. This could be compounded by clonal expansion within the snail intermediate host and aggregation of parasites of the same genotype on pasture. Alternatively, widespread movement of animals that typically occurs in the UK could promote high levels of gene flow and prevent population differentiation. We identified clonal parasites with identical multilocus genotypes in 61% of hosts. Despite this, 84% of 1579 adult parasites had unique multilocus genotypes, which supports high levels of genotypic diversity within F. hepatica populations. Our analyses indicate a selfing rate no greater than 2%, suggesting that this diversity is in part due to the propensity for F. hepatica to cross-fertilise. Finally, although we identified high genetic diversity within a given host, there was little evidence for differentiation between populations from different hosts, indicating a single panmictic population. This implies that, once those emerge, anthelmintic resistance genes have the potential to spread rapidly through liver fluke populations.
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Affiliation(s)
- Nicola J Beesley
- Veterinary Parasitology, Institute of Infection and Global Health, University of Liverpool, Liverpool L3 5RF, UK.
| | - Diana J L Williams
- Veterinary Parasitology, Institute of Infection and Global Health, University of Liverpool, Liverpool L3 5RF, UK
| | - Steve Paterson
- Centre for Genomic Research, Institute of Integrative Biology, University of Liverpool, Liverpool L69 7ZB, UK
| | - Jane Hodgkinson
- Veterinary Parasitology, Institute of Infection and Global Health, University of Liverpool, Liverpool L3 5RF, UK
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18
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Cwiklinski K, O'Neill SM, Donnelly S, Dalton JP. A prospective view of animal and human Fasciolosis. Parasite Immunol 2016; 38:558-68. [PMID: 27314903 PMCID: PMC5053257 DOI: 10.1111/pim.12343] [Citation(s) in RCA: 118] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2016] [Accepted: 06/09/2016] [Indexed: 12/17/2022]
Abstract
Fasciolosis, a food-borne trematodiasis, results following infection with the parasites, Fasciola hepatica and Fasciola gigantica. These trematodes greatly affect the global agricultural community, infecting millions of ruminants worldwide and causing annual economic losses in excess of US $3 billion. Fasciolosis, an important zoonosis, is classified by WHO as a neglected tropical disease with an estimated 17 million people infected and a further 180 million people at risk of infection. The significant impact on agriculture and human health together with the increasing demand for animal-derived food products to support global population growth demonstrate that fasciolosis is a major One Health problem. This review details the problematic issues surrounding fasciolosis control, including drug resistance, lack of diagnosis and the threat that hybridization of the Fasciola species poses to future animal and human health. We discuss how these parasites may mediate their long-term survival through regulation and modulation of the host immune system, by altering the host immune homeostasis and/or by influencing the intestinal microbiome particularly in respect to concurrent infections with other pathogens. Large genome, transcriptome and proteomic data sets are now available to support an integrated One Health approach to develop novel diagnostic and control strategies for both animal and human disease.
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Affiliation(s)
- K Cwiklinski
- School of Biological Sciences, Queen's University Belfast, Belfast, UK.
| | - S M O'Neill
- School of Biotechnology, Dublin City University, Dublin, Republic of Ireland
| | - S Donnelly
- The i3 Institute & School of Medical and Molecular Biosciences, University of Technology Sydney, Sydney, NSW, Australia
| | - J P Dalton
- School of Biological Sciences, Queen's University Belfast, Belfast, UK
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Genetic and infective diversity of the liver fluke Fasciola hepatica (Trematoda: Digenea) from Cuba. J Helminthol 2016; 90:719-725. [DOI: 10.1017/s0022149x15001029] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
AbstractIn this study we present the first approach to exploration of the genetic diversity of Cuban Fasciola hepatica populations using microsatellite markers, coupled with observed prevalence in slaughterhouses. Nine populations of flukes recovered from cows and buffalos were studied in the central-western region of Cuba. The observed infection rates of definitive hosts (bovines) were 70–100% in most cases. An important amount of polymorphism was found in the four loci explored. However, no apparent genetic differences were found between populations from different provinces or bovine species. The absence of deviations from Hardy–Weinberg equilibrium suggests a high rate of cross-fertilization between F. hepatica individuals. This result was confirmed when all multilocus genotypes were tested for clonal reproduction and only four individuals differed statistically (Psex< 0.05). High values of expected heterozygosity coupled with highly probable mixing among strains make the metapopulation genetically diversified but similar in terms of certain alleles (low FST values). These results suggest a close relationship between parasite diversity and cattle management in Cuba. Our findings should be taken into consideration by veterinary authorities to help mitigate fasciolosis transmission.
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