1
|
Miranda GS, Rodrigues JGM, Silva JKADO, Camelo GMA, Silva-Souza N, Neves RH, Machado-Silva JR, Negrão-Corrêa DA. New challenges for the control of human schistosomiasis: The possible impact of wild rodents in Schistosoma mansoni transmission. Acta Trop 2022; 236:106677. [PMID: 36063905 DOI: 10.1016/j.actatropica.2022.106677] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2022] [Revised: 08/27/2022] [Accepted: 09/01/2022] [Indexed: 11/17/2022]
Abstract
Schistosomiasis is a neglected parasitic disease caused by digenean trematodes from the genus Schistosoma that affects millions of people worldwide. Despite efforts to control its transmission, this disease remains active within several endemic regions of Africa, Asia, and the Americas. In addition to the deficits in sanitation and educational structure, another major obstacle hindering the eradication of schistosomiasis is the ability of Schistosoma spp. to naturally infect multiple vertebrate hosts, particularly wild rodents. Due to climate change and other anthropogenic disturbances, contact between humans and wild animals has increased, and this has contributed to more frequent interactions between Schistosoma species that typically infect different hosts. This new transmission dynamic involving Schistosoma spp., humans, wild rodents, and livestock could potentially increase the frequency of Schistosoma hybridization and the establishment of new genotypes and strains. Although it is not currently possible to precisely measure how this biological phenomenon affects the epidemiology and morbidity of schistosomiasis, we speculate that these Schistosoma variants may negatively impact control strategies, treatment regimens, and disease burden in humans. In the present study, we discuss the natural infections of wild rodents with Schistosoma spp., the role of these animals as Schistosoma spp. reservoirs, and how they may select hybrids and strains of Schistosoma mansoni. We also discuss measures required to shed light on the actual role of the wild rodents Nectomys squamipes and Holochilus sciureus in the transmission and morbidity of schistosomiasis in Brazil.
Collapse
Affiliation(s)
- Guilherme Silva Miranda
- Department of Parasitology, Institute of Biological Sciences, Federal University of Minas Gerais, Avenida Antônio Carlos 6627, Campus Pampulha, Belo Horizonte, MG CEP: 31270-010, Brazil; Department of Biology, Federal Institute of Education, Science and Technology of Maranhão, São Raimundo das Mangabeiras, Brazil
| | - João Gustavo Mendes Rodrigues
- Department of Parasitology, Institute of Biological Sciences, Federal University of Minas Gerais, Avenida Antônio Carlos 6627, Campus Pampulha, Belo Horizonte, MG CEP: 31270-010, Brazil
| | - Jeferson Kelvin Alves de Oliveira Silva
- Department of Parasitology, Institute of Biological Sciences, Federal University of Minas Gerais, Avenida Antônio Carlos 6627, Campus Pampulha, Belo Horizonte, MG CEP: 31270-010, Brazil
| | - Genil Mororó Araújo Camelo
- Department of Parasitology, Institute of Biological Sciences, Federal University of Minas Gerais, Avenida Antônio Carlos 6627, Campus Pampulha, Belo Horizonte, MG CEP: 31270-010, Brazil
| | - Nêuton Silva-Souza
- Department of Chemistry and Biology, State University of Maranhão, São Luis, Brazil
| | - Renata Heisler Neves
- Department of Microbiology, Immunology and Parasitology, Faculty of Medical Sciences, Biomedical Center, University of the State of Rio de Janeiro, Rio de Janeiro, Brazil
| | - José Roberto Machado-Silva
- Department of Microbiology, Immunology and Parasitology, Faculty of Medical Sciences, Biomedical Center, University of the State of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Deborah Aparecida Negrão-Corrêa
- Department of Parasitology, Institute of Biological Sciences, Federal University of Minas Gerais, Avenida Antônio Carlos 6627, Campus Pampulha, Belo Horizonte, MG CEP: 31270-010, Brazil.
| |
Collapse
|
2
|
Rey O, Webster BL, Huyse T, Rollinson D, Van den Broeck F, Kincaid-Smith J, Onyekwere A, Boissier J. Population genetics of African Schistosoma species. INFECTION GENETICS AND EVOLUTION 2021; 89:104727. [PMID: 33486128 DOI: 10.1016/j.meegid.2021.104727] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/11/2020] [Revised: 01/09/2021] [Accepted: 01/13/2021] [Indexed: 02/06/2023]
Abstract
Blood flukes within the genus Schistosoma (schistosomes) are responsible for the major disease, schistosomiasis, in tropical and sub-tropical areas. This disease is predominantly present on the African continent with more than 85% of the human cases. Schistosomes are also parasites of veterinary importance infecting livestock and wildlife. Schistosoma population genetic structure and diversity are important characteristics that may reflect variations in selection pressures such as those induced by host (mammalian and snail) environments, habitat change, migration and also treatment/control interventions, all of which also shape speciation and evolution of the whole Schistosoma genus. Investigations into schistosome population genetic structure, diversity and evolution has been an area of important debate and research. Supported by advances in molecular techniques with capabilities for multi-locus genetic analyses for single larvae schistosome genetic investigations have greatly progressed in the last decade. This paper aims to review the genetic studies of both animal and human infecting schistosome. Population genetic structures are reviewed at different spatial scales: local, regional or continental (i.e. phylogeography). Within species genetic diversities are discussed compared and the compounding factors discussed, including the effect of mass drug administration. Finally, the ability for intra-species hybridisation questions species integrities and poses many questions in relation to the natural epidemiology of co-endemic species. Here we review molecularly confirmed hybridisation events (in relation to human disease) and discuss the possible impact for ongoing and future control and elimination.
Collapse
Affiliation(s)
- O Rey
- Univ. Montpellier, CNRS, IFREMER, UPVD, IHPE, F-66000 Perpignan, France
| | - B L Webster
- Wolfson Wellcome Biomedical Laboratories, Department of Life Sciences, Natural History Museum, London SW7 5BD, United Kingdom; London Centre for Neglected Tropical Disease Research, Imperial College London School of Public Health, London W2 1PG, United Kingdom
| | - T Huyse
- Department of Biology, Royal Museum for Central Africa, Leuvensesteenweg 13, B-3080 Tervuren, Belgium; Laboratory of Biodiversity and Evolutionary Genomics, Department of Biology, KU Leuven, Ch. Deberiotstraat 32, B-3000 Leuven, Belgium
| | - D Rollinson
- Wolfson Wellcome Biomedical Laboratories, Department of Life Sciences, Natural History Museum, London SW7 5BD, United Kingdom; London Centre for Neglected Tropical Disease Research, Imperial College London School of Public Health, London W2 1PG, United Kingdom
| | - F Van den Broeck
- Department of Microbiology, Immunology and Transplantation, Rega Institute for Medical Research, University of Leuven, Leuven, Belgium; Department of Biomedical Sciences, Institute of Tropical Medicine, Antwerp, Belgium
| | - J Kincaid-Smith
- Centre for Emerging, Endemic and Exotic Diseases (CEEED), Department of Pathobiology and Population Sciences (PPS), Royal Veterinary College, University of London, Hawkshead Campus, Herts AL9 7TA, United Kingdom
| | - A Onyekwere
- Univ. Montpellier, CNRS, IFREMER, UPVD, IHPE, F-66000 Perpignan, France
| | - J Boissier
- Univ. Montpellier, CNRS, IFREMER, UPVD, IHPE, F-66000 Perpignan, France.
| |
Collapse
|
3
|
Gu MJ, Li YW, Emery AM, Li SZ, Jiang YZ, Dong HF, Zhao QP. The genetic variation of different developmental stages of Schistosoma japonicum: do the distribution in snails and pairing preference benefit the transmission? Parasit Vectors 2020; 13:360. [PMID: 32690109 PMCID: PMC7372819 DOI: 10.1186/s13071-020-04240-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2020] [Accepted: 07/15/2020] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Schistosoma japonicum is a waterborne parasite that causes schistosomiasis in humans and in more than 40 animal species. Schistosoma japonicum shows distinct genetic differentiation among geographical populations and multiple hosts, but the genetic diversity of different developmental stages of S. japonicum from is less studied. Such studies could elucidate ecological mechanisms in disease transmission by analysing feedbacks in individual physiology and population state. METHODS After infection using cercariae from a pool of snails shedding together (Method I) and infection using mixed equal numbers of cercariae from individually shed snails (Method II), different developmental stages of S. japonicum were genotyped with microsatellite loci, including 346 cercariae, 701 adult worms and 393 miracidia. Genetic diversity and molecular variation were calculated at different population levels. Kinships (I') among cercariae at intra-snail and inter-snail levels were evaluated. Genetic distance (Dsw) was compared between paired and unpaired worms, and partner changing was investigated through paternity identification for miracidia. RESULTS The cercaria clones in individual snails varied from 1 to 8 and the kinship of cercariae within individual snails was significant higher (P < 0.001) than that among different snails after deleting near-identical multi-locus genotypes (niMLGs). The allelic diversity of worms in Method I was lower (P < 0.001) than that in Method II, and allele frequency among mice in Method I was also less consistent. The parents of some miracidia were worms that were not paired when collected. The Dsw between each female of paired and unpaired males was much larger (P < 0.001) than that between the female and male in each pair. CONCLUSIONS Most of the infected snails contained multiple miracidia clones. The aggregation of genetically similar S. japonicum miracidia in individual snails and the unbalanced distribution of miracidia among snails suggests a non-uniform genetic distribution of cercariae among snails in the field. This further influenced the genetic structure of adult worms from infections with different cercariae sampling methods. Schistosoma japonicum in mice can change paired partner, preferring to mate with genetically similar worms. These characteristics provide implications for understanding the balance in genetic diversity of S. japonicum related to the transmission of schistosomiasis.
Collapse
Affiliation(s)
- Meng-Jie Gu
- Department of Parasitology, School of Basic Medical Sciences, Wuhan University, Wuhan, 430071 Hubei China
| | - Yan-Wei Li
- Department of Parasitology, School of Basic Medical Sciences, Wuhan University, Wuhan, 430071 Hubei China
- Hubei Provincial Center for Disease Control and Prevention, Wuhan, 430072 Hubei China
| | - Aidan M. Emery
- Department of Life Sciences, Natural History Museum, Cromwell Road, London, SW7 5BD UK
| | - Shi-Zhu Li
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention, National Center for Tropical Diseases Research, WHO Collaborating Center for Tropical Diseases, Key Laboratory of Parasite and Vector Biology, Ministry of Health, Shanghai, 200025 China
| | - Yong-Zhong Jiang
- Hubei Provincial Center for Disease Control and Prevention, Wuhan, 430072 Hubei China
| | - Hui-Fen Dong
- Department of Parasitology, School of Basic Medical Sciences, Wuhan University, Wuhan, 430071 Hubei China
| | - Qin-Ping Zhao
- Department of Parasitology, School of Basic Medical Sciences, Wuhan University, Wuhan, 430071 Hubei China
| |
Collapse
|
4
|
Blanton RE. Population Structure and Dynamics of Helminthic Infection: Schistosomiasis. Microbiol Spectr 2019; 7:10.1128/microbiolspec.ame-0009-2019. [PMID: 31325285 PMCID: PMC6650164 DOI: 10.1128/microbiolspec.ame-0009-2019] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2019] [Indexed: 11/20/2022] Open
Abstract
While disease and outbreaks are mainly clonal for bacteria and other asexually reproducing organisms, sexual reproduction in schistosomes and other helminths usually results in unique individuals. For sexually reproducing organisms, the traits conserved in clones will instead be conserved in the group of organisms that tends to breed together, the population. While the same tools are applied to characterize DNA, how results are interpreted can be quite different at times (see another article in this collection, http://www.asmscience.org/content/journal/microbiolspec/10.1128/microbiolspec.AME-0002-2018). It is difficult to know what the real effect any control program has on the parasite population without assessing the health of this population, how they respond to the control measure, and how they recover, if they do. This review, part of the Microbiology Spectrum Curated Collection: Advances in Molecular Epidemiology of Infectious Diseases, concentrates on one approach using pooled samples to study schistosome populations and shows how this and other approaches have contributed to our understanding of this parasite family's biology and epidemiology. *This article is part of a curated collection.
Collapse
Affiliation(s)
- Ronald E Blanton
- Center for Global Health and Diseases, Department of Pathology, Case Western Reserve University, Cleveland, OH 44120
| |
Collapse
|
5
|
Sanches Palasio RG, Zanotti-Magalhães EM, Tuan R. Genetic diversity of the freshwater snail Biomphalaria tenagophila (d’Orbigny, 1835) (Gastropoda: Hygrophila: Planorbidae) across two coastal areas of southeast Brazil. FOLIA MALACOLOGICA 2018. [DOI: 10.12657/folmal.026.019] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
|
6
|
Thiele EA, Corrêa-Oliveira G, Gazzinelli A, Minchella DJ. Elucidating the temporal and spatial dynamics of Biomphalaria glabrata genetic diversity in three Brazilian villages. Trop Med Int Health 2013; 18:1164-73. [PMID: 23911082 DOI: 10.1111/tmi.12164] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVE The freshwater snail Biomphalaria glabrata is the principal intermediate host for the parasite Schistosoma mansoni within Brazil. We assessed the potential effects of snail population dynamics on parasite transmission dynamics via population genetics. METHODS We sampled snail populations located within the confines of three schistosome-endemic villages in the state of Minas Gerais, Brazil. Snails were collected from individual microhabitats following seasonal periods of flood and drought over the span of 1 year. Snail spatio-temporal genetic diversity and population differentiation of 598 snails from 12 sites were assessed at seven microsatellite loci. RESULTS Average genetic diversity was relatively low, ranging from 4.29 to 9.43 alleles per locus, and overall, subpopulations tended to exhibit heterozygote deficits. Genetic diversity was highly spatially partitioned among subpopulations, while virtually, no partitioning was observed across temporal sampling. Comparison with previously published parasite genetic diversity data indicated that S. mansoni populations are significantly more variable and less subdivided than those of the B. glabrata intermediate hosts. DISCUSSION Within individual Brazilian villages, observed distributions of snail genetic diversity indicate temporal stability and very restricted gene flow. This is contrary to observations of schistosome genetic diversity over the same spatial scale, corroborating the expectation that parasite gene flow at the level of individual villages is likely driven by vertebrate host movement.
Collapse
Affiliation(s)
- Elizabeth A Thiele
- Department of Biological Sciences, Purdue University, West Lafayette, IN, USA
| | | | | | | |
Collapse
|
7
|
Zhao GH, Li J, Blair D, Li XY, Elsheikha HM, Lin RQ, Zou FC, Zhu XQ. Biotechnological advances in the diagnosis, species differentiation and phylogenetic analysis of Schistosoma spp. Biotechnol Adv 2012; 30:1381-9. [DOI: 10.1016/j.biotechadv.2012.02.008] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2011] [Revised: 01/08/2012] [Accepted: 02/08/2012] [Indexed: 11/26/2022]
|
8
|
Xu D, Sandland GJ, Minchella DJ, Feng Z. Interactions among virulence, coinfection and drug resistance in a complex life-cycle parasite. J Theor Biol 2012; 304:197-210. [PMID: 22554952 DOI: 10.1016/j.jtbi.2012.03.040] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2011] [Revised: 01/31/2012] [Accepted: 03/29/2012] [Indexed: 11/26/2022]
Abstract
Motivated by relatively recent empirical studies on Schistosoma mansoni, we use a mathematical model to investigate the impacts of drug treatment of the definitive human host and coinfection of the intermediate snail host by multiple parasite strains on the evolution of parasites' drug resistance. Through the examination of evolutionarily stable strategies (ESS) of parasites, our study suggests that higher levels of drug treatment rates (which usually tend to promote monomorphism as the evolutionary equilibrium) favor parasite strains that have a higher level of drug resistance. Our study also shows that whether coinfection of intermediate hosts affects the levels of drug resistance at ESS points and their stability depends on the assumptions on the cost of parasites paid for drug resistance, coinfection functions and parasites' reproduction within coinfected hosts. This calls for more empirical studies on the parasite.
Collapse
Affiliation(s)
- Dashun Xu
- Department of Mathematics, Southern Illinois University, Carbondale, IL 62901, USA.
| | | | | | | |
Collapse
|
9
|
Genetic differentiation of cercariae infrapopulations of the avian schistosome Trichobilharzia szidati based on RAPD markers and mitochondrial cox1 gene. Parasitol Res 2011; 110:833-41. [PMID: 21796386 DOI: 10.1007/s00436-011-2562-6] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2011] [Accepted: 07/13/2011] [Indexed: 10/17/2022]
Abstract
Avian schistosome Trichobilharzia szidati is a member of the largest genus within the family Schistosomatidae (Trematoda). Population genetic structure of Trichobilharzia spp. schistosomes, causative agents of cercarial dermatitis in humans, has not been studied yet. The knowledge of the genetic structure of trichobilharzian populations is essential for understanding the host-parasite coevolutionary dynamics and epidemiology strategies. Here we examined genetic diversity in three geographically isolated local populations of T. szidati cercariae inhabiting Russia based on nuclear (randomly amplified polymorphic DNA, RAPD) and mt (cox1) markers. We analyzed T. szidati cercariae shed from seven naturally infected snails of Lymnaea stagnalis. Using three random primers, we demonstrated genetic variation among populations, thus posing genetic structure across geographic sites. Moreover, T. szidati cercariae have been genetically structured among hosts (infrapopulations). Molecular variance analysis was performed to test the significance of genetic differentiation within and between local populations. Of total parasitic diversity, 18.8% was partitioned between populations, whereas the higher contribution (48.9%) corresponds to the differences among individual cercariae within infrapopulations. In contrast to RAPD markers, a 1,125-bp fragment of cox1 mt gene failed to provide any significant within-species structure. The lack of geographic structuring was detected using unique haplotypes which were determined in the current work for Moscow and Western Siberian local populations as well as obtained previously for European isolates (Czech Republic and Germany). All T. szidati/Trichobilharzia ocellata haplotypes were found to be mixed across their geographical origin.
Collapse
|
10
|
Jones-Nelson O, Thiele EA, Minchella DJ. Transmission dynamics of two strains of Schistosoma mansoni utilizing novel intermediate and definitive hosts. Parasitol Res 2011; 109:675-87. [PMID: 21369763 DOI: 10.1007/s00436-011-2299-2] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2010] [Accepted: 02/17/2011] [Indexed: 11/24/2022]
Abstract
The intimate host-parasite relationship mandates adaptation to the genetic and phenotypic variability of their counterparts. Here, inbred and outcrossed strains of Schistosoma mansoni were challenged with "local" and "novel" intermediate and definitive hosts to examine effects of genetic variability and novelty on infection success and dynamics. Genetically distinct lines of Biomphalaria glabrata intermediate hosts exposed to inbred and outcrossed S. mansoni larvae were assessed for differences in both snail and parasite life-history parameters. Cercariae from each parasite-snail treatment were used to infect "local" and "novel" Mus musculus definitive hosts to assess parasite infectivity and fitness. Outcrossed parasites significantly reduced snail growth, were more productive, and induced greater host mortality than inbred parasites. Mouse strain did not influence parasite infectivity or reproduction, but parasite and snail host genetic background did, affecting both sex-specific infectivity and parasite productivity. Overall, genetic background of S. mansoni and its intermediate snail host altered life history traits and transmission dynamics of the parasite throughout its life cycle.
Collapse
Affiliation(s)
- Omari Jones-Nelson
- Department of Biological Sciences, Purdue University, West Lafayette, IN 47907, USA
| | | | | |
Collapse
|
11
|
Lu DB, Rudge JW, Wang TP, Donnelly CA, Fang GR, Webster JP. Transmission of Schistosoma japonicum in marshland and hilly regions of China: parasite population genetic and sibship structure. PLoS Negl Trop Dis 2010; 4:e781. [PMID: 20689829 PMCID: PMC2914789 DOI: 10.1371/journal.pntd.0000781] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2009] [Accepted: 07/01/2010] [Indexed: 11/25/2022] Open
Abstract
The transmission dynamics of Schistosoma japonicum remain poorly understood, as over forty species of mammals are suspected of serving as reservoir hosts. However, knowledge of the population genetic structure and of the full-sibship structuring of parasites at two larval stages will be useful in defining and tracking the transmission pattern between intermediate and definitive hosts. S. japonicum larvae were therefore collected in three marshland and three hilly villages in Anhui Province of China across three time points: April and September-October 2006, and April 2007, and then genotyped with six microsatellite markers. Results from the population genetic and sibling relationship analyses of the parasites across two larval stages demonstrated that, within the marshland, parasites from cattle showed higher genetic diversity than from other species; whereas within the hilly region, parasites from dogs and humans displayed higher genetic diversity than those from rodents. Both the extent of gene flow and the estimated proportion of full-sib relationships of parasites between two larval stages indicated that the cercariae identified within intermediate hosts in the marshlands mostly came from cattle, whereas in the hilly areas, they were varied between villages, coming primarily from rodents, dogs or humans. Such results suggest a different transmission process within the hilly region from within the marshlands. Moreover, this is the first time that the sibling relationship analysis was applied to the transmission dynamics for S. japonicum. Schistosoma japonicum involves two obligatory host stages, with asexual reproduction within a molluscan host and sexual reproduction within a mammalian host. Having over 40 species of mammals suspected of being potential reservoirs complicates the transmission patterns. Understanding the complex transmission patterns is further hampered by the ethical and logistical difficulty in sampling adult worms from mammalian hosts. However, the two free-swimming larval stages, cercariae (released from a mollusc and then infective to a mammal) and miracidia (hatched from eggs passed in a mammal's faeces, and then infective to a mollusc), are available, and elucidating the genetic composition of parasites at theses two stages could provide information of infection processes. Here we sampled cercariae during April 2006, miracidia during September-October 2006, and cercariae during April 2007 in three marshland and three hilly villages in Anhui Province of China, and, using microsatellite markers, analyzed the population genetic structure and, for the first time, the familial relationships of parasites at different stages. We found contrasting population structures of parasites, and host species-associated diversities and transmission patterns of parasites between and within two regions. Moreover, we demonstrate that the successful application of sibship analyses to infection process provides an alternative approach to the dissection of transmission dynamics.
Collapse
Affiliation(s)
- Da-Bing Lu
- Department of Infectious Disease Epidemiology, Faculty of Medicine, Imperial College, London, UK.
| | | | | | | | | | | |
Collapse
|
12
|
Korsunenko AV, Tyutin AV, Semyenova SK. Clonal and population RAPD variation of cercariae obtained from Bucephalus polymorphus sporocysts (Trematoda: Bucephalidae). RUSS J GENET+ 2009. [DOI: 10.1134/s1022795409010098] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
|
13
|
Gentile R, Oliveira G. Brazilian studies on the genetics of Schistosoma mansoni. Acta Trop 2008; 108:175-8. [PMID: 18831955 DOI: 10.1016/j.actatropica.2008.09.003] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2007] [Revised: 05/27/2008] [Accepted: 09/03/2008] [Indexed: 11/27/2022]
Abstract
The parasite Schistosoma is known to exhibit variations among species, strains and genera, such as, the levels of infectivity, pathogenicity and immunogenicity. These factors may differ among parasite populations according to the local epidemiological conditions. Diversity observed in Schistosoma mansoni from different geographical regions or within individuals of the same region can be determined by differences in the genotype of each parasite strain. However, until recently, finding adequate genetic markers to investigate infectivity or other epidemiological characteristics of a transmission area proved difficult. Several studies have been conducted to evaluate the genetic variability of S. mansoni, using different techniques. Intraspecific variability was observed in morphological characters, isoenzyme studies, mtDNA, ribosomal gene probes, random amplification of polymorphic DNA (RAPD) and microsatellites. The sequencing of the S. mansoni genome was the most important achievement concerning genetic approaches to the study of this parasite and may improve the development of drugs, vaccines and diagnostics of schistosomiasis. The knowledge of the genetic structure of schistosome populations in relation to epidemiological data and host variability is essential for the understanding of the epidemiology of the disease and the design of control strategies.
Collapse
|
14
|
Saijuntha W, Sithithaworn P, Wongkham S, Laha T, Satrawaha R, Chilton NB, Petney TN, Andrews RH. Genetic variation at three enzyme loci within a Thailand population of Opisthorchis viverrini. Parasitol Res 2008; 103:1283-7. [PMID: 18690476 PMCID: PMC2582050 DOI: 10.1007/s00436-008-1128-8] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2008] [Accepted: 07/14/2008] [Indexed: 01/23/2023]
Abstract
Genetic variation among 231 individuals of Opisthorchis viverrini from the Ban Phai District, Khon Kaen Province (Thailand) was examined at three polymorphic enzymes: enolase (ENOL), phosphoglucomutase (PGM), and triose phosphate isomerase (TPI). Four alleles were detected for TPI and PGM, whereas only two alleles were detected for ENOL. The inferred genotype frequencies for both TPI and ENOL were not significantly different from Hardy-Weinberg equilibrium. In contrast, the inferred genotype frequencies for PGM showed a significant departure from Hardy-Weinberg equilibrium, with a lack of heterozygous individuals. This heterozygote deficiency suggests non-random mating and/or potentially high self fertilization.
Collapse
Affiliation(s)
- Weerachai Saijuntha
- Walai Rukhavej Botanical Research Institute, Mahasarakham University, Mahasarakham 44150, Thailand
| | | | | | | | | | | | | | | |
Collapse
|
15
|
Abstract
The genetic control of compatibility between laboratory strains of schistosomes and their snail hosts has been studied intensively since the 1970s. These studies show (1) a bewildering array of genotype-by-genotype interactions - compatibility between one pair of strains rarely predicts compatibility with other strains, and (2) evidence for a variety of (sometimes conflicting) genetic mechanisms. Why do we observe such variable and conflicting results? One possibility is that it is partly an artifact of the use of laboratory strains that have been in culture for many years and are often inbred. Here we show that results of compatibility trials between snails and schistosomes - all derived from the same natural population - depend very much on whether one uses laboratory-cultured or field-collected individuals. Explanations include environmental effects of the lab on either host or parasite, and genetic changes in either host or parasite during laboratory culture. One intriguing possibility is that genetic bottlenecks during laboratory culture cause the random fixation of alleles at highly polymorphic loci that control the matched/mismatched status of hosts and parasites. We show that a simple model of phenotype matching could produce dose response curves that look very similar to empirical observations. Such a model would explain much of the genotype-by-genotype interaction in compatibility observed among strains.
Collapse
|
16
|
Beltran S, Galinier R, Allienne JF, Boissier J. Cheap, rapid and efficient DNA extraction method to perform multilocus microsatellite genotyping on all Schistosoma mansoni stages. Mem Inst Oswaldo Cruz 2008; 103:501-3. [DOI: 10.1590/s0074-02762008000500017] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2007] [Accepted: 07/28/2008] [Indexed: 11/21/2022] Open
|
17
|
Yin M, Hu W, Mo X, Wang S, Brindley PJ, McManus DP, Davis GM, Feng Z, Blair D. Multiple near-identical genotypes of Schistosoma japonicum can occur in snails and have implications for population-genetic analyses. Int J Parasitol 2008; 38:1681-91. [PMID: 18590733 DOI: 10.1016/j.ijpara.2008.05.015] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2008] [Revised: 05/24/2008] [Accepted: 05/29/2008] [Indexed: 11/17/2022]
Abstract
We genotyped (using 16 or 17 microsatellite loci) numerous adult Schistosoma japonicum raised in rabbits exposed to pooled cercariae from small numbers of naturally infected snails from several localities in China. As expected, duplicate multi-locus genotypes (MLGs) were found among these worms. Additionally, many more MLGs, often near-identical, were found than snails used as sources of cercariae. Explanations for these results include (i) genotyping errors, (ii) development within each infected snail of multiple sibling miracidia and (iii) somatic mutation producing genetically varied cercariae from a single miracidium. To control for genotyping errors we re-analysed samples from many individual worms, including repeating the initial PCR. Explanations invoking the development of multiple sibling miracidia within a single snail are not likely to be correct because almost all duplicate MLGs fell within same-sex clusters in a principal coordinates analysis. We would expect both sexes to be represented in a multi-miracidium infection. In addition, we exposed several snails to infection by a single miracidium. One such snail, via an experimentally infected mouse, yielded 48 adult worms. The presence of at least nine near-identical MLGs among these worms was confirmed by re-genotyping. We regard somatic mutation as the most likely explanation for our results. The implications of multiple MLGs for population-genetic studies in S. japonicum are discussed.
Collapse
Affiliation(s)
- Mingbo Yin
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention, 207 Rui Jin Rd II, Shanghai 200025, PR China
| | | | | | | | | | | | | | | | | |
Collapse
|
18
|
Thiele EA, Sorensen RE, Gazzinelli A, Minchella DJ. Genetic diversity and population structuring of Schistosoma mansoni in a Brazilian village. Int J Parasitol 2007; 38:389-99. [PMID: 17825305 PMCID: PMC2476926 DOI: 10.1016/j.ijpara.2007.07.011] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2007] [Revised: 07/07/2007] [Accepted: 07/10/2007] [Indexed: 11/20/2022]
Abstract
The digenean trematode Schistosoma mansoni is responsible for chronic schistosomiasis worldwide, and in Brazil alone an estimated 35 million people are at risk. To evaluate epidemiological patterns among human definitive hosts, we assessed genetic diversity and population subdivision of S. mansoni infrapopulations in human hosts from the highly endemic village of Virgem das Graças in the state of Minas Gerais, Brazil. We believe this is the largest such survey to date. Genetic diversity of parasites, measured over eight polymorphic microsatellite loci, was relatively high and standard measures of inbreeding indicated that the population was panmictic. Furthermore, there was no significant isolation-by-distance of parasite infrapopulations, and measures of population subdivision indicated significant but low to moderate levels of population differentiation. We conclude that patients within this village sample from a broad range of schistosome genetic diversity and effectively act as "genetic mixing bowls" for the parasites. These results contrast with those previously observed in the Brazilian village of Melqui ades and thus provide the opportunity for comparisons of environmental and epidemiological differences that are likely to influence host-parasite coevolution and parasite transmission.
Collapse
Affiliation(s)
- E A Thiele
- Department of Biological Sciences, Purdue University, West Lafayette, IN 47907, USA.
| | | | | | | |
Collapse
|
19
|
Nuchprayoon S, Junpee A, Poovorawan Y. Random amplified polymorphic DNA (RAPD) for differentiation between Thai and Myanmar strains of Wuchereria bancrofti. FILARIA JOURNAL 2007; 6:6. [PMID: 17663780 PMCID: PMC1976415 DOI: 10.1186/1475-2883-6-6] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/25/2006] [Accepted: 07/30/2007] [Indexed: 11/12/2022]
Abstract
BACKGROUND Lymphatic filariasis (LF) is a mosquito-borne disease caused by mosquito-transmitted filarial nematodes, including Wuchereria bancrofti and Brugia malayi. The Lymphatic Filariasis Elimination Program in Thailand has reduced the prevalence of nocturnally subperiodic W. bancrofti (Thai strain), mainly transmitted by the Ochlerotatus (Aedes) niveus group in Thailand to 0.57/100,000 population. However, it is estimated that more than one million Myanmar migrants with high prevalence of bancroftian filariasis have settled in the large urban cities of Thailand. These infected migrants carry the nocturnally periodic W. bancrofti (Myanmar strain) which has Culex quinquefasciatus as the main mosquito vector. Although transmissions of the Myanmar strain of W. bancrofti by the Thai Cx. quinquefasciatus has never been reported, previous study showed that Cx. quinquefasciatus could nurture the Myanmar strain of W. bancrofti to the infective stage. Thus, the potential now exists for a re-emergence of bancroftian filariasis in Thailand. The present study was undertaken in an attempt to differentiate between the Thai and Myanmar strains of W. bancrofti. METHODS The microfilarial periodicity of Thai and the Myanmar strains of W. bancrofti were determined. Comparative morphology and morphometry of microfilariae and a study of random amplified polymorphic DNA (RAPD) was performed. The Nei's genetic distance was calculated, and a phylogenetic tree was constructed using the Unweighted Pair Group Method with Arithmetic mean (UPGMA). RESULTS The Thai strain of W. bancrofti was nocturnally subperiodic, and the Myanmar strain of W. bancrofti was nocturnally periodic. The body length, cephalic space length, and cephalic space width of the Thai strain of W. bancrofti were significantly larger than those of the Myanmar strain of W. bancrofti (p < 0.05). However, an overlapping mean of these parameters made it impractical for field application. RAPD-PCR profiles showed specific bands characteristic for the Myanmar strain of W. bancrofti. The phylogenetic tree indicated two genetically distinct clusters of the Thai and Myanmar strains of W. bancrofti. DISCUSSION This study was the first report on the genetic polymorphism of the Thai and Myanmar strains of W. bancrofti. Differentiation between the Thai and Myanmar strains of W. bancrofti could not rely on morphological criteria alone. However, RAPD profiles revealed a significant diversity between the two strains. The RAPD-PCR technique was suitable for differentiating Thai and Myanmar strains of W. bancrofti. The RAPD marker could be used for epidemiological assessment of the Myanmar strains of W. bancrofti in Thailand.
Collapse
Affiliation(s)
- Surang Nuchprayoon
- Lymphatic Filariasis Research Unit, Department of Parasitology, Chulalongkorn Medical Research Center (Chula MRC), Chulalongkorn University, Bangkok 10330, Thailand
| | - Alisa Junpee
- Lymphatic Filariasis Research Unit, Department of Parasitology, Chulalongkorn Medical Research Center (Chula MRC), Chulalongkorn University, Bangkok 10330, Thailand
| | - Yong Poovorawan
- Department of Pediatrics, Faculty of Medicine, Chulalongkorn University, Bangkok 10330, Thailand
| |
Collapse
|
20
|
Gerardo NM, Caldera EJ. Labile associations between fungus-growing ant cultivars and their garden pathogens. ISME JOURNAL 2007; 1:373-84. [DOI: 10.1038/ismej.2007.57] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
|
21
|
Sorensen RE, Rodrigues NB, Oliveira G, Romanha AJ, Minchella DJ. Genetic filtering and optimal sampling of Schistosoma mansoni populations. Parasitology 2006; 133:443-51. [PMID: 16817994 DOI: 10.1017/s0031182006000552] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2006] [Revised: 04/29/2006] [Accepted: 05/01/2006] [Indexed: 11/07/2022]
Abstract
Allelic variation in 6 microsatellite markers was compared between frozen Schistosoma mansoni eggs and laboratory-passaged worms originating from the same 5 fecal samples obtained from Brazilian residents. Based on allelic richness values, the number of alleles detected per locus did not differ between egg and worm DNA templates. However, our ability to score loci differed between these DNA templates, with worms providing more scored loci per individual than eggs. Differences also existed between the worms and eggs in the identity of the specific alleles that were detected. Additionally, we observed a reduction in homozygous genotypes among laboratory-passaged worms relative to the eggs. Allelic diversity curves were calculated by genotyping all worms from a representative host sample to determine the relationship between the number of alleles detected at a locus and the number of worms genotyped. Curves for the 5 residents' worm infrapopulations for each of the loci were very similar. The equation y=19.55 x ln(x) + 9.992 explained the association between sampling effort (x) and number of alleles detected (y) with an R(2) of 0.775. In conclusion, egg DNA templates and allelic diversity curves can benefit efforts to discern the sociological, ecological and evolutionary forces impacting the genetic diversity and disease epidemiology of human schistosomes.
Collapse
Affiliation(s)
- R E Sorensen
- Department of Biological Sciences, Minnesota State University Mankato, Mankato, MN 56001, USA.
| | | | | | | | | |
Collapse
|
22
|
Prugnolle F, de Meeûs T, Pointier JP, Durand P, Rognon A, Théron A. Geographical variations in infectivity and susceptibility in the host-parasite system Schistosoma mansoni/Biomphalaria glabrata: no evidence for local adaptation. Parasitology 2006; 133:313-9. [PMID: 16719959 DOI: 10.1017/s0031182006000412] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2006] [Revised: 03/24/2006] [Accepted: 03/27/2006] [Indexed: 11/06/2022]
Abstract
We investigated local adaptation in the spatially structured natural Biomphalaria glabrata/Schistosoma mansoni host-parasite system in the marshy forest focus of Guadeloupe using cross-transplantation experiments. We demonstrated strong and highly significant variations in susceptibility/infectivity of host and parasite populations, respectively, but found no evidence of local adaptation neither for S. mansoni nor for B. glabrata. Environmental as well as genetic factors are discussed to explain susceptibility/infectivity variations between both host and parasite populations. The absence of local adaptation is discussed in relation to the metapopulation dynamics of both host and parasite, in particular their relative rates of dispersal at the scale under scrutiny. Our study constitutes the first cross-transplantation experiment concerning this host-parasite system of which both hosts and parasites came directly from the wild, excluding laboratory generations and experimental host passages.
Collapse
Affiliation(s)
- F Prugnolle
- GEMI, Equipe ESS, UMR-2274 CNRS-IRD, centre IRD, 911 avenue Agropolis, BP 64501, 34394 Montpellier Cedex 5, France.
| | | | | | | | | | | |
Collapse
|
23
|
Minchella DJ. PRESIDENTIAL ADDRESS: THE ROLE OF VARIATION IN HOST-PARASITE INTERACTIONS: LINKING GENETIC DEMES AND LIFE HISTORY SCHEMES. J Parasitol 2005; 91:1246-52. [PMID: 16539000 DOI: 10.1645/ge-703.1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Affiliation(s)
- Dennis J Minchella
- Department of Biological Sciences, Purdue University, West Lafayette, Indiana 47907-2054, USA.
| |
Collapse
|
24
|
Theron A, Sire C, Rognon A, Prugnolle F, Durand P. Molecular ecology of Schistosoma mansoni transmission inferred from the genetic composition of larval and adult infrapopulations within intermediate and definitive hosts. Parasitology 2005; 129:571-85. [PMID: 15552402 DOI: 10.1017/s0031182004005943] [Citation(s) in RCA: 71] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
We investigated the genotypic composition of the digenetic parasite Schistosoma mansoni for its adult stages within the definitive host (the wild rat, Rattus rattus) and for the larval stages within the intermediate host (the snail, Biomphalaria glabrata) both collected at the same transmission site. Our analyses are based upon the recognition and distribution of 200 different multilocus genotypes generated by RAPD markers. While intramolluscan larval infrapopulations are characterized by a low infection rate (0.6 % on average) and low intra-host genetic diversity (1.1 genotype on average per infected snail), adult infrapopulations within rats showed a high infection rate (94%) and a substantial intra-host genetic diversity (34 genotypes on average) linked to high intensities (160 worms per host on average). A single definitive host bearing 105 different genotypes harboured 52 % of the total genetic diversity detected within the whole parasite population. Analysis of the genetic data allowed the identification of various ecological, behavioural and immunological factors which are likely to enhance transmission of multiple parasite genotypes towards the vertebrate hosts. From the distribution of repeated identical multilocus genotypes within the parasite population and among the hosts, we have inferred different parameters of the cercarial transmission efficiency as well as patterns and processes by which vertebrate hosts acquire infection in the field.
Collapse
Affiliation(s)
- A Theron
- Parasitologie Fonctionnelle et Evolutive, UMR 5555 CNRS-UP, CBETM, Université, 66860 Perpignan Cedex, France.
| | | | | | | | | |
Collapse
|
25
|
Gower CM, Webster JP. INTRASPECIFIC COMPETITION AND THE EVOLUTION OF VIRULENCE IN A PARASITIC TREMATODE. Evolution 2005. [DOI: 10.1111/j.0014-3820.2005.tb01014.x] [Citation(s) in RCA: 70] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
26
|
Prugnolle F, Théron A, Pointier JP, Jabbour-Zahab R, Jarne P, Durand P, Meeûs TD. DISPERSAL IN A PARASITIC WORM AND ITS TWO HOSTS: CONSEQUENCE FOR LOCAL ADAPTATION. Evolution 2005. [DOI: 10.1111/j.0014-3820.2005.tb00990.x] [Citation(s) in RCA: 90] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
|
27
|
Gower CM, Webster JP. INTRASPECIFIC COMPETITION AND THE EVOLUTION OF VIRULENCE IN A PARASITIC TREMATODE. Evolution 2005. [DOI: 10.1554/04-475] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
|
28
|
Prugnolle F, Théron A, Pointier JP, Jabbour-Zahab R, Jarne P, Durand P, de Meeûs T. DISPERSAL IN A PARASITIC WORM AND ITS TWO HOSTS: CONSEQUENCE FOR LOCAL ADAPTATION. Evolution 2005. [DOI: 10.1554/04-522] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
|
29
|
Intapan PM, Kosuwan T, Wongkham C, Maleewong W. Genomic characterization of lung flukes, Paragonimus heterotremus, P. siamensis, P. harinasutai, P. westermani and P. bangkokensis by RAPD markers. Vet Parasitol 2004; 124:55-64. [PMID: 15350661 DOI: 10.1016/j.vetpar.2004.05.023] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2003] [Revised: 04/26/2004] [Accepted: 05/05/2004] [Indexed: 10/26/2022]
Abstract
Random amplified polymorphic DNA (RAPD) markers were assayed in an attempt to discriminate among five species of Paragonimus. Genomic DNAs of two strains of Paragonimus heterotremus from two provinces in Thailand, Saraburi and Phitsanulok, as well as of P. siamensis, P. harinasutai, P. westermani and P. bangkokensis were extracted and amplified by an arbitrary primer, namely P2 (5-GTTTCGCTCC-3). RAPD patterns showed that those five species were genetically distinct, although they shared genomic DNA to some extent. This primer could also distinguish between two strains of P. heterotremus. The polymorphism observed allowed to construct a relationship dendrogram. The phylogenetic dendrogram showed that the P. heterotremus strains were closest to P. harinasutai, followed by P. siamensis, P. bangkokensis and P. westermani.
Collapse
Affiliation(s)
- P M Intapan
- Department of Parasitology, Faculty of Medicine, Khon Kaen University, Khon Kaen 40002, Thailand.
| | | | | | | |
Collapse
|
30
|
Haag KL, Ayala FJ, Kamenetzky L, Gutierrez AM, Rosenzvit M. Livestock trade history, geography, and parasite strains: the mitochondrial genetic structure of Echinococcus granulosus in Argentina. J Parasitol 2004; 90:234-9. [PMID: 15165043 DOI: 10.1645/ge-173r] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
A sample of 114 isolates of Echinococcus granulosus (Cestoda: Taeniidae) collected from different host species and sites in Argentina has been sequenced for 391 bp from the mitochondrial cytochrome c oxidase subunit I gene to analyze genetic variability and population structure. Nine different haplotypes were identified, 5 of which correspond to already characterized strains. Analysis of molecular variance and nested clade analysis of the distribution of haplotypes among localities within 3 main geographic regions indicate that geographic differentiation accounts for the overall pattern of genetic variability in E. granulosus populations. Significant geographic differentiation is also present when the sheep strain alone is considered. Our results suggest that geographic patterns are not due to actual restricted gene flow between regions but are rather a consequence of past history, probably related to the time and origin of livestock introduction in Argentina.
Collapse
Affiliation(s)
- K L Haag
- Departamento de Genética, Universidade Federal do Rio Grande do Sul, Caixa Postal 15053, CEP 91501-970 Porto Alegre, RS, Brazil.
| | | | | | | | | |
Collapse
|
31
|
Lockyer AE, Jones CS, Noble LR, Rollinson D. Trematodes and snails: an intimate association. CAN J ZOOL 2004. [DOI: 10.1139/z03-215] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Trematode parasites share an intimate relationship with their gastropod intermediate hosts, which act as the vehicle for their development and transmission. They represent an enormous economic and medical burden in developing countries, stimulating much study of snail–trematode interactions. Laboratory-maintained snail–trematode systems and in vitro cell cultures are being used to investigate the molecular dialogue between host and parasite. These dynamic and finely balanced antagonistic relationships, in which parasites strongly influence the physiology of the host, are highly specific and may occasionally demonstrate co-speciation. We consider the mechanisms and responses deployed by trematodes and snails that result in compatibility or rejection of the parasite, and the macroevolutionary implications that they may effect. Although for gastropods the fossil record gives some insight into evolutionary history, elucidation of trematode evolution must rely largely upon molecular approaches, and for both, such techniques have provided fresh and often surprising evidence of their origins and dispersal over time. Co-evolution of snails and trematodes is becoming increasingly apparent at both cellular and population levels; the implications of which are only beginning to be understood for disease control. Untangling the complex interactions of trematodes and snails promise fresh opportunities for intervention to relieve the burden of parasitic disease.
Collapse
|
32
|
Gutiérrez A, Pointier JP, Fraga J, Jobet E, Modat S, Pérez RT, Yong M, Sanchez J, Loker ES, Théron A. Fasciola hepatica: identification of molecular markers for resistant and susceptible Pseudosuccinea columella snail hosts. Exp Parasitol 2003; 105:211-8. [PMID: 14990314 DOI: 10.1016/j.exppara.2003.12.006] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2003] [Revised: 11/05/2003] [Accepted: 12/11/2003] [Indexed: 10/26/2022]
Abstract
Protein electrophoresis, RAPD-PCR and nuclear rDNA ITS sequencing were performed to search for genetic differences between Pseudosuccinea columella snails susceptible and resistant to Fasciola hepatica infection. Of the 21 enzymatic loci analyzed in both populations, none of them exhibited neither within- or between-group variation. Such an absence of enzyme polymorphism support the hypothesis of selfing as the "prevalent" mating system for this hermaphroditic species. Conversely, the RAPD profiles displayed clear differences between susceptible and resistant isolates for 17 of the 26 primers tested while no within-group variation was detected. rDNA ITS sequence analysis from snails of each isolates showed only two bases that differed between groups accounting for a 0.17% of variation confirming that susceptible and resistant snails belong to the same species. This is the first time that a genetic variation using RAPD markers is demonstrated between susceptible and resistant lymnaeid snails vis-a-vis of F. hepatica infection in absence of experimental selection.
Collapse
Affiliation(s)
- Alfredo Gutiérrez
- Laboratorio de Malacología, Instituto "Pedro Kouri", IPK Apartado 601, Marianao 13, Ciudad Habana, Cuba
| | | | | | | | | | | | | | | | | | | |
Collapse
|
33
|
Barnard CJ, Kulis K, Behnke JM, Bajer A, Gromadzka-Ostrowska J, Stachon M, Sinski E. Local variation in helminth burdens of bank voles (Clethrionomys glareolus) from ecologically similar sites: temporal stability and relationships with hormone concentrations and social behaviour. J Helminthol 2003; 77:185-95. [PMID: 12895277 DOI: 10.1079/joh2003194] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Populations of bank voles (Clethrionomys glareolus) in a fragmented forest habitat in north-east Poland showed local differences in helminth infection intensity, morphometric measures and organ weights that were consistent with differences at the same locations two years previously. Although overall intensities of infection were lower than previously, and there were some differences in the relative intensities of individual helminth species, site differences remained significant and were consistent across replicated subsites. In keeping with site differences in helminth infection and adrenal gland weight and asymmetry, voles at site 1 (high intensity infection) had higher circulating concentrations of corticosterone than those at site 2 (low intensity infection). Since males were sampled outside the breeding season, and thus non-scrotal, testosterone levels were low and did not differ between sites. As previously, voles at site 1 also showed greater hind foot asymmetry. Dyadic interactions between males from the same and different sites in the laboratory showed that males from site 1 were significantly less aggressive, especially when confronted with intruder males from site 2. There was no relationship between aggressiveness and intensity of infection overall or at site 1, but a significant negative relationship emerged at site 2. Aggression thus appeared to be downregulated at the higher intensity site independently of individual levels of infection. Terminal corticosterone concentrations were greater at site 1 and lower among residents that initiated more aggression. While corticosterone concentrations rose over the period of testing, they did not correlate with the amount of aggression initiated or received.
Collapse
Affiliation(s)
- C J Barnard
- Animal Behaviour and Ecology Research Group, School of Life and Environmental Sciences, University of Nottingham, University Park, NG7 2RD UK.
| | | | | | | | | | | | | |
Collapse
|
34
|
Curtis J, Sorensen RE, Minchella DJ. Schistosome genetic diversity: the implications of population structure as detected with microsatellite markers. Parasitology 2003; 125 Suppl:S51-9. [PMID: 12622328 DOI: 10.1017/s0031182002002020] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Blood flukes in the genus Schistosoma are important human parasites in tropical regions. A substantial amount of genetic diversity has been described in populations of these parasites using molecular markers. We first consider the extent of genetic variation found in Schistosoma mansoni and some factors that may be contributing to this variation. Recently, though, attempts have been made to analyze not only the genetic diversity but how that diversity is partitioned within natural populations of schistosomes. Studies with non-allelic molecular markers (e.g. RAPDs and mtVNTRs) have indicated that schistosome populations exhibit varying levels of gene flow among component subpopulations. The recent characterization of microsatellite markers for S. mansoni provided an opportunity to study schistosome population structure within a population of schistosomes from a single Brazilian village using allelic markers. Whereas the detection of population structure depends strongly on the type of analysis with a mitochondrial marker, analyses with a set of seven microsatellite loci consistently revealed moderate genetic differentiation when village boroughs were used to define parasite subpopulations and greater subdivision when human hosts defined subpopulations. Finally, we discuss the implications that such strong population structure might have on schistosome epidemiology.
Collapse
Affiliation(s)
- J Curtis
- Department of Biological Sciences, Purdue University, West Lafayette, IN 47907, USA
| | | | | |
Collapse
|
35
|
Moné H, Mouahid G, Shaban MA, Al Jabri AA, Boissier J, Ruppel A, Idris MA. Ecological and molecular studies on emerging schistosomiasis mansoni in Dhofar Governorate, Sultanate of Oman. Trop Med Int Health 2003; 8:269-76. [PMID: 12631319 DOI: 10.1046/j.1365-3156.2003.01024.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The recent detection of some cases of autochtonous schistosomiasis mansoni in Dhofar, Oman, prompted a search for the transmission sites. The five field surveys we conducted from November 2000 to February 2002 provided ecological data on schistosomiasis in Dhofar. Twenty-eight water bodies situated within 8-160 km from Salalah, the largest city of Dhofar and at altitudes of up to 900 m, were surveyed for freshwater snails. Biomphalaria arabica was found in 15 of them. Three sites (Tibraq, Siginitti and Arazat) had Schistosoma infected snails, the first snails shedding cercariae of this parasite ever collected in Oman. The parasite from Dhofar was analysed by Random Amplified Polymorphic DNA comparisons using 11 primers and 167 polymorphic fragments and had 87-88% similarity with Schistosoma mansoni from Guadeloupe, but only 37-38% similarity with S. rodhaini from Burundi. Thus, it is a strain of S. mansoni. During the November 2000 survey, the prosobranch snail Melanoides tuberculata was associated with B. arabica in 10 of the 13 B. arabica sites. Cercariae from other species of Digenea emerged from five of the B. arabica sites, including the three named above. This paper presents the first finding of S. mansoni in the Dhofar Governorate and represents an initial study of the biology of S. mansoni transmission. This parasite and its cycle need further biological and molecular characterization, and the clarification of its epidemiological status in Dhofar Governorate is an urgent task.
Collapse
Affiliation(s)
- Hélène Moné
- Centre de Biologie et d'Ecologie tropicale et méditerranéenne, WHO Collaborating Center, Université Perpignan, France.
| | | | | | | | | | | | | |
Collapse
|
36
|
D'Andrea PS, Fernandes FA, Cerqueira R, Rey L. Experimental evidence and ecological perspectives for the adaptation of Schistosoma mansoni Sambon, 1907 (Digenea: Schistosomatidae) to a wild host, the water-rat, Nectomys squamipes Brants, 1827 (Rodentia: Sigmodontinae). Mem Inst Oswaldo Cruz 2003; 97 Suppl 1:11-4. [PMID: 12426586 DOI: 10.1590/s0074-02762002000900003] [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: 11/22/2022] Open
Abstract
Due to the semi aquatic habits and the overlap of the geographical distribution of the water-rat, Nectomys spp., with schistosomiasis endemic areas, these wild rodents are very likely to acquire Schistosoma mansoni infection in their daily activities. The role of the water-rat in the S. mansoni cycle would be substantiated if one could prove that these rodents acquire the parasite during their own activity time, a completely independent time schedule of human activities. To pursue this goal, we performed two field experiments in the municipality of Sumidouro, State of Rio de Janeiro, Brazil, a schistosomiasis endemic area where N. squamipes is found naturally infected. One experiment was devised as a series of observations of activity time of the water-rat. The other experiment was a test of the occurrence of late transmission of S. mansoni to the water-rat. The daily activity pattern showed that the water-rat is active chiefly just after sunset. At both diurnal and late exposition essays the water-rat sentinels got infected by S. mansoni. These findings clarify ecological and behavioral components necessary to the adaptation of S. mansoni to the water-rat as a non human definitive host and the existence of a transmission cycle involving this animals as a reservoir.
Collapse
Affiliation(s)
- Paulo Sérgio D'Andrea
- Laboratório de Biologia e Controle da Esquistossomose, Departamento de Medicina Tropical, Instituto Oswaldo Cruz, Fiocruz, Rio de Janeiro, RJ, 21045-900, Brasil.
| | | | | | | |
Collapse
|
37
|
Barnard CJ, Behnke JM, Bajer A, Bray D, Race T, Frake K, Osmond J, Dinmore J, Sinski E. Local variation in endoparasite intensities of bank voles (Clethrionomys glareolus) from ecologically similar sites: morphometric and endocrine correlates. J Helminthol 2002; 76:103-13. [PMID: 12015821 DOI: 10.1079/joh2001109] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Much interest has centred recently on the role of adaptive trade-offs between the immune system and other components of life history in determining resistance and parasite intensities among hosts. Steroid hormones, particularly glucocorticoids and sex steroids, provide a plausible mechanism for mediating such trade-offs. A basic assumption behind the hypothesis, however, is that steroid activity will generally correlate with reduced resistance and thus greater parasite intensities. Here, we present some findings from a field study of bank voles (Clethrionomys glareolus) in which we have looked at associations between parasite intensities, anatomical and morphometric measures relating to endocrine function and life history variation in three local populations inhabiting similar but mutually isolated woodland habitats. In general, sites with greater parasite intensities were those in which male C. glareolus had significantly larger adrenal glands, testes and seminal vesicles for their age and body size. Females also showed a site difference in adrenal gland weight. Some aspects of site-related parasite intensity were associated with asymmetry in adrenal gland weight and hind foot length, which may have reflected developmental effects on glucocorticoid activity.
Collapse
Affiliation(s)
- C J Barnard
- Animal Behaviour and Ecology Research Group, University of Nottingham, University Park, UK.
| | | | | | | | | | | | | | | | | |
Collapse
|
38
|
Sire C, Durand P, Pointier JP, Théron A. Genetic diversity of Schistosoma mansoni within and among individual hosts (Rattus rattus): infrapopulation differentiation at microspatial scale. Int J Parasitol 2001; 31:1609-16. [PMID: 11730788 DOI: 10.1016/s0020-7519(01)00294-6] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
The distribution of genetic diversity in a local population of the trematode Schistosoma mansoni was determined within and between individual wild rats at a microspatial geographic scale of a standing water transmission site. Using RAPD markers, molecular variance and canonical correspondence analysis were performed to test the significance of genetic differentiation between infrapopulations. Of total gene diversity, 8 and 11% was partitioned between hosts trapped at few metres distance from each other. Significant temporal differentiation (2%) was also detected among schistosomes sampled at 6 month intervals with more infrapopulation pairs differentiated during the dry season of parasite transmission than during the rainy season (45 and 12%, respectively). A combination of factors such as restricted displacement of rats, patchy spatial aggregation of infected snails and limited cercarial dispersion in standing water are likely to promote the genetic differentiation observed between infrapopulations at this microgeographic scale.
Collapse
Affiliation(s)
- C Sire
- Laboratoire de Biologie Animale, UMR 5555 CNRS-UP, Centre de Biologie et d'Ecologie tropicale et méditerranéenne, EPHE, Université. 52, Av. de Villeneuve, 66860 Perpignan Cedex, France
| | | | | | | |
Collapse
|