Phylogenetic and genetic population analyses of Amblyomma ovale (Parasitiformes: Ixodidae) from Brazil and Central America

Autores
Lado, Paula; Ogrzewalska, María; Lemos, Elba R.S.; Pasini-Martins, Matheus; Szabó, Matías P.J.; Nava, Santiago; Labruna, Marcelo B.
Año de publicación
2026
Idioma
inglés
Tipo de recurso
artículo
Estado
versión publicada
Descripción
Amblyomma ovale is a widespread hard tick in Neotropics and it is an important vector of pathogens, particularly Rickettsia parkeri strain Atlantic rainforest, which causes a spotted fever illness in humans. Adult ticks primarily parasitize medium and large mammals, such as carnivores, while larvae and nymphs feed on small mammals and occasionally on birds. In Brazil, the species is found in all six major biomes (Amazon, Atlantic forest, Cerrado, Caatinga, Pantanal, Pampa), and is generally found in humid, forested areas. Despite its broad range, large-scale genetic studies have been lacking. This study analyzed the genetic diversity and population structure of A. ovale using five gene markers (four mitochondrial, one nuclear) in 57 specimens from Brazil (five biomes) plus Panama and Belize. High haplotype diversity was found for all markers, with numerous unique haplotypes and many biome-specific groupings. Phylogenetic analyses (maximum parsimony and maximum likelihood) revealed two major genetic clusters: one predominantly from Atlantic forest A region and another comprising samples from Atlantic forest B, other Brazilian biomes, and Central America. The nuclear marker (ITS2) exhibited low polymorphism and did not mirror mitochondrial patterns. This different pattern between mitochondrial and nuclear markers could be attributed to the over-resolution of mtDNA that can occur because the small inbreeding effective population size (Ne) of the mitochondrial genes may lead to coalescence of mtDNA lineages that are only temporarily isolated. Population genetic analyses (AMOVA and FST) revealed significant structuring among most regional populations, but no strong correlation between geographic and genetic distances (no isolation by distance). Neutrality tests indicated possible population expansion in the Atlantic forest B group. Overall, A. ovale exhibits high genetic diversity with some biome-linked clustering, especially between Atlantic forest subregions, as evidenced by mitochondrial markers. The tick’s broad host range and high movement may reduce isolation, thereby maintaining gene flow across regions. Given the public health importance of A. ovale as a vector of spotted fever, understanding this genetic variation could inform disease ecology and risk in different biomes.
EEA Rafaela
Fil: Lado, Paula. Ohio State University. Department of Evolution, Ecology, and Organismal Biology; Estados Unidos
Fil: Ogrzewalska, María. Oswaldo Cruz Foundation. Instituto Oswaldo Cruz. Laboratory of Respiratory, Exanthematic, Enteric Viruses and Viral Emergencies; Brasil
Fil: Lemos, Elba R.S. Oswaldo Cruz Foundation. Instituto Oswaldo Cruz. Laboratório de Hantaviroses e Rickettsioses; Brasil
Fil: Pasini-Martins, Matheus. Universidade de São Paulo. Faculdade de Medicina Veterinária e Zootecnia. Departamento de Medicina Veterinária Preventiva e Saúde Animal; Brasil.
Fil: Szabó, Matías P.J. Universidade Federal de Uberlandia. Faculdade de Medicina Veterinaria. Laboratório de Ixodologia; Brasil
Fil: Nava, Santiago. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Rafaela. Instituto de Investigación de la Cadena Láctea (IDICAL); Argentina
Fil: Nava, Santiago. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigación de la Cadena Láctea (IDICAL); Argentina
Fil: Nava, Santiago. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Rafaela; Argentina
Fil: Labruna, Marcelo B. Universidade de São Paulo. Faculdade de Medicina Veterinária e Zootecnia. Departamento de Medicina Veterinária Preventiva e Saúde Animal; Brasil
Fuente
Veterinary Parasitology 348 : Article: 110902. (December 2026)
Materia
Garrapata
Análisis Filogenético
Genética de Poblaciones
Brasil
América Central
Ticks
Amblyomma
Phylogenetic Analysis
Population Genetics
Brazil
Central America
Amblyomma ovale
Nivel de accesibilidad
acceso abierto
Condiciones de uso
http://creativecommons.org/licenses/by-nc-sa/4.0/
Repositorio
INTA Digital (INTA)
Institución
Instituto Nacional de Tecnología Agropecuaria
OAI Identificador
oai:localhost:20.500.12123/27709
Acceder
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oai_identifier_str oai:localhost:20.500.12123/27709
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network_name_str INTA Digital (INTA)
spelling Phylogenetic and genetic population analyses of Amblyomma ovale (Parasitiformes: Ixodidae) from Brazil and Central AmericaLado, PaulaOgrzewalska, MaríaLemos, Elba R.S.Pasini-Martins, MatheusSzabó, Matías P.J.Nava, SantiagoLabruna, Marcelo B.GarrapataAnálisis FilogenéticoGenética de PoblacionesBrasilAmérica CentralTicksAmblyommaPhylogenetic AnalysisPopulation GeneticsBrazilCentral AmericaAmblyomma ovaleAmblyomma ovale is a widespread hard tick in Neotropics and it is an important vector of pathogens, particularly Rickettsia parkeri strain Atlantic rainforest, which causes a spotted fever illness in humans. Adult ticks primarily parasitize medium and large mammals, such as carnivores, while larvae and nymphs feed on small mammals and occasionally on birds. In Brazil, the species is found in all six major biomes (Amazon, Atlantic forest, Cerrado, Caatinga, Pantanal, Pampa), and is generally found in humid, forested areas. Despite its broad range, large-scale genetic studies have been lacking. This study analyzed the genetic diversity and population structure of A. ovale using five gene markers (four mitochondrial, one nuclear) in 57 specimens from Brazil (five biomes) plus Panama and Belize. High haplotype diversity was found for all markers, with numerous unique haplotypes and many biome-specific groupings. Phylogenetic analyses (maximum parsimony and maximum likelihood) revealed two major genetic clusters: one predominantly from Atlantic forest A region and another comprising samples from Atlantic forest B, other Brazilian biomes, and Central America. The nuclear marker (ITS2) exhibited low polymorphism and did not mirror mitochondrial patterns. This different pattern between mitochondrial and nuclear markers could be attributed to the over-resolution of mtDNA that can occur because the small inbreeding effective population size (Ne) of the mitochondrial genes may lead to coalescence of mtDNA lineages that are only temporarily isolated. Population genetic analyses (AMOVA and FST) revealed significant structuring among most regional populations, but no strong correlation between geographic and genetic distances (no isolation by distance). Neutrality tests indicated possible population expansion in the Atlantic forest B group. Overall, A. ovale exhibits high genetic diversity with some biome-linked clustering, especially between Atlantic forest subregions, as evidenced by mitochondrial markers. The tick’s broad host range and high movement may reduce isolation, thereby maintaining gene flow across regions. Given the public health importance of A. ovale as a vector of spotted fever, understanding this genetic variation could inform disease ecology and risk in different biomes.EEA RafaelaFil: Lado, Paula. Ohio State University. Department of Evolution, Ecology, and Organismal Biology; Estados UnidosFil: Ogrzewalska, María. Oswaldo Cruz Foundation. Instituto Oswaldo Cruz. Laboratory of Respiratory, Exanthematic, Enteric Viruses and Viral Emergencies; BrasilFil: Lemos, Elba R.S. Oswaldo Cruz Foundation. Instituto Oswaldo Cruz. Laboratório de Hantaviroses e Rickettsioses; BrasilFil: Pasini-Martins, Matheus. Universidade de São Paulo. Faculdade de Medicina Veterinária e Zootecnia. Departamento de Medicina Veterinária Preventiva e Saúde Animal; Brasil.Fil: Szabó, Matías P.J. Universidade Federal de Uberlandia. Faculdade de Medicina Veterinaria. Laboratório de Ixodologia; BrasilFil: Nava, Santiago. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Rafaela. Instituto de Investigación de la Cadena Láctea (IDICAL); ArgentinaFil: Nava, Santiago. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigación de la Cadena Láctea (IDICAL); ArgentinaFil: Nava, Santiago. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Rafaela; ArgentinaFil: Labruna, Marcelo B. Universidade de São Paulo. Faculdade de Medicina Veterinária e Zootecnia. Departamento de Medicina Veterinária Preventiva e Saúde Animal; BrasilElsevier2026-09-09T11:09:26Z2026-09-09T11:09:26Z2026-12info:eu-repo/semantics/articleinfo:eu-repo/semantics/publishedVersionhttp://purl.org/coar/resource_type/c_6501info:ar-repo/semantics/articuloapplication/pdfhttp://hdl.handle.net/20.500.12123/27709https://www.sciencedirect.com/science/article/pii/S03044017260022190304-40171873-2550https://doi.org/10.1016/j.vetpar.2026.110902Veterinary Parasitology 348 : Article: 110902. (December 2026)reponame:INTA Digital (INTA)instname:Instituto Nacional de Tecnología AgropecuariaengBrazil .......... (nation) (World, South America)1000047Mesoamerica .......... (general region) (World, North and Central America)7016739info:eu-repo/semantics/openAccesshttp://creativecommons.org/licenses/by-nc-sa/4.0/Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International (CC BY-NC-SA 4.0)2026-09-24T11:43:47Zoai:localhost:20.500.12123/27709instacron:INTAInstitucionalhttp://repositorio.inta.gob.ar/Organismo científico-tecnológicoNo correspondehttp://repositorio.inta.gob.ar/oai/requesttripaldi.nicolas@inta.gob.arArgentinaNo correspondeNo correspondeNo correspondeopendoar:l2026-09-24 11:43:48.779INTA Digital (INTA) - Instituto Nacional de Tecnología Agropecuariafalse
dc.title.none.fl_str_mv Phylogenetic and genetic population analyses of Amblyomma ovale (Parasitiformes: Ixodidae) from Brazil and Central America
title Phylogenetic and genetic population analyses of Amblyomma ovale (Parasitiformes: Ixodidae) from Brazil and Central America
spellingShingle Phylogenetic and genetic population analyses of Amblyomma ovale (Parasitiformes: Ixodidae) from Brazil and Central America
Lado, Paula
Garrapata
Análisis Filogenético
Genética de Poblaciones
Brasil
América Central
Ticks
Amblyomma
Phylogenetic Analysis
Population Genetics
Brazil
Central America
Amblyomma ovale
title_short Phylogenetic and genetic population analyses of Amblyomma ovale (Parasitiformes: Ixodidae) from Brazil and Central America
title_full Phylogenetic and genetic population analyses of Amblyomma ovale (Parasitiformes: Ixodidae) from Brazil and Central America
title_fullStr Phylogenetic and genetic population analyses of Amblyomma ovale (Parasitiformes: Ixodidae) from Brazil and Central America
title_full_unstemmed Phylogenetic and genetic population analyses of Amblyomma ovale (Parasitiformes: Ixodidae) from Brazil and Central America
title_sort Phylogenetic and genetic population analyses of Amblyomma ovale (Parasitiformes: Ixodidae) from Brazil and Central America
dc.creator.none.fl_str_mv Lado, Paula
Ogrzewalska, María
Lemos, Elba R.S.
Pasini-Martins, Matheus
Szabó, Matías P.J.
Nava, Santiago
Labruna, Marcelo B.
author Lado, Paula
author_facet Lado, Paula
Ogrzewalska, María
Lemos, Elba R.S.
Pasini-Martins, Matheus
Szabó, Matías P.J.
Nava, Santiago
Labruna, Marcelo B.
author_role author
author2 Ogrzewalska, María
Lemos, Elba R.S.
Pasini-Martins, Matheus
Szabó, Matías P.J.
Nava, Santiago
Labruna, Marcelo B.
author2_role author
author
author
author
author
author
dc.subject.none.fl_str_mv Garrapata
Análisis Filogenético
Genética de Poblaciones
Brasil
América Central
Ticks
Amblyomma
Phylogenetic Analysis
Population Genetics
Brazil
Central America
Amblyomma ovale
topic Garrapata
Análisis Filogenético
Genética de Poblaciones
Brasil
América Central
Ticks
Amblyomma
Phylogenetic Analysis
Population Genetics
Brazil
Central America
Amblyomma ovale
dc.description.none.fl_txt_mv Amblyomma ovale is a widespread hard tick in Neotropics and it is an important vector of pathogens, particularly Rickettsia parkeri strain Atlantic rainforest, which causes a spotted fever illness in humans. Adult ticks primarily parasitize medium and large mammals, such as carnivores, while larvae and nymphs feed on small mammals and occasionally on birds. In Brazil, the species is found in all six major biomes (Amazon, Atlantic forest, Cerrado, Caatinga, Pantanal, Pampa), and is generally found in humid, forested areas. Despite its broad range, large-scale genetic studies have been lacking. This study analyzed the genetic diversity and population structure of A. ovale using five gene markers (four mitochondrial, one nuclear) in 57 specimens from Brazil (five biomes) plus Panama and Belize. High haplotype diversity was found for all markers, with numerous unique haplotypes and many biome-specific groupings. Phylogenetic analyses (maximum parsimony and maximum likelihood) revealed two major genetic clusters: one predominantly from Atlantic forest A region and another comprising samples from Atlantic forest B, other Brazilian biomes, and Central America. The nuclear marker (ITS2) exhibited low polymorphism and did not mirror mitochondrial patterns. This different pattern between mitochondrial and nuclear markers could be attributed to the over-resolution of mtDNA that can occur because the small inbreeding effective population size (Ne) of the mitochondrial genes may lead to coalescence of mtDNA lineages that are only temporarily isolated. Population genetic analyses (AMOVA and FST) revealed significant structuring among most regional populations, but no strong correlation between geographic and genetic distances (no isolation by distance). Neutrality tests indicated possible population expansion in the Atlantic forest B group. Overall, A. ovale exhibits high genetic diversity with some biome-linked clustering, especially between Atlantic forest subregions, as evidenced by mitochondrial markers. The tick’s broad host range and high movement may reduce isolation, thereby maintaining gene flow across regions. Given the public health importance of A. ovale as a vector of spotted fever, understanding this genetic variation could inform disease ecology and risk in different biomes.
EEA Rafaela
Fil: Lado, Paula. Ohio State University. Department of Evolution, Ecology, and Organismal Biology; Estados Unidos
Fil: Ogrzewalska, María. Oswaldo Cruz Foundation. Instituto Oswaldo Cruz. Laboratory of Respiratory, Exanthematic, Enteric Viruses and Viral Emergencies; Brasil
Fil: Lemos, Elba R.S. Oswaldo Cruz Foundation. Instituto Oswaldo Cruz. Laboratório de Hantaviroses e Rickettsioses; Brasil
Fil: Pasini-Martins, Matheus. Universidade de São Paulo. Faculdade de Medicina Veterinária e Zootecnia. Departamento de Medicina Veterinária Preventiva e Saúde Animal; Brasil.
Fil: Szabó, Matías P.J. Universidade Federal de Uberlandia. Faculdade de Medicina Veterinaria. Laboratório de Ixodologia; Brasil
Fil: Nava, Santiago. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Rafaela. Instituto de Investigación de la Cadena Láctea (IDICAL); Argentina
Fil: Nava, Santiago. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigación de la Cadena Láctea (IDICAL); Argentina
Fil: Nava, Santiago. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Rafaela; Argentina
Fil: Labruna, Marcelo B. Universidade de São Paulo. Faculdade de Medicina Veterinária e Zootecnia. Departamento de Medicina Veterinária Preventiva e Saúde Animal; Brasil
description Amblyomma ovale is a widespread hard tick in Neotropics and it is an important vector of pathogens, particularly Rickettsia parkeri strain Atlantic rainforest, which causes a spotted fever illness in humans. Adult ticks primarily parasitize medium and large mammals, such as carnivores, while larvae and nymphs feed on small mammals and occasionally on birds. In Brazil, the species is found in all six major biomes (Amazon, Atlantic forest, Cerrado, Caatinga, Pantanal, Pampa), and is generally found in humid, forested areas. Despite its broad range, large-scale genetic studies have been lacking. This study analyzed the genetic diversity and population structure of A. ovale using five gene markers (four mitochondrial, one nuclear) in 57 specimens from Brazil (five biomes) plus Panama and Belize. High haplotype diversity was found for all markers, with numerous unique haplotypes and many biome-specific groupings. Phylogenetic analyses (maximum parsimony and maximum likelihood) revealed two major genetic clusters: one predominantly from Atlantic forest A region and another comprising samples from Atlantic forest B, other Brazilian biomes, and Central America. The nuclear marker (ITS2) exhibited low polymorphism and did not mirror mitochondrial patterns. This different pattern between mitochondrial and nuclear markers could be attributed to the over-resolution of mtDNA that can occur because the small inbreeding effective population size (Ne) of the mitochondrial genes may lead to coalescence of mtDNA lineages that are only temporarily isolated. Population genetic analyses (AMOVA and FST) revealed significant structuring among most regional populations, but no strong correlation between geographic and genetic distances (no isolation by distance). Neutrality tests indicated possible population expansion in the Atlantic forest B group. Overall, A. ovale exhibits high genetic diversity with some biome-linked clustering, especially between Atlantic forest subregions, as evidenced by mitochondrial markers. The tick’s broad host range and high movement may reduce isolation, thereby maintaining gene flow across regions. Given the public health importance of A. ovale as a vector of spotted fever, understanding this genetic variation could inform disease ecology and risk in different biomes.
publishDate 2026
dc.date.none.fl_str_mv 2026-09-09T11:09:26Z
2026-09-09T11:09:26Z
2026-12
dc.type.none.fl_str_mv info:eu-repo/semantics/article
info:eu-repo/semantics/publishedVersion
http://purl.org/coar/resource_type/c_6501
info:ar-repo/semantics/articulo
format article
status_str publishedVersion
dc.identifier.none.fl_str_mv http://hdl.handle.net/20.500.12123/27709
https://www.sciencedirect.com/science/article/pii/S0304401726002219
0304-4017
1873-2550
https://doi.org/10.1016/j.vetpar.2026.110902
url http://hdl.handle.net/20.500.12123/27709
https://www.sciencedirect.com/science/article/pii/S0304401726002219
https://doi.org/10.1016/j.vetpar.2026.110902
identifier_str_mv 0304-4017
1873-2550
dc.language.none.fl_str_mv eng
language eng
dc.rights.none.fl_str_mv info:eu-repo/semantics/openAccess
http://creativecommons.org/licenses/by-nc-sa/4.0/
Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International (CC BY-NC-SA 4.0)
eu_rights_str_mv openAccess
rights_invalid_str_mv http://creativecommons.org/licenses/by-nc-sa/4.0/
Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International (CC BY-NC-SA 4.0)
dc.format.none.fl_str_mv application/pdf
dc.coverage.none.fl_str_mv Brazil .......... (nation) (World, South America)
1000047
Mesoamerica .......... (general region) (World, North and Central America)
7016739
dc.publisher.none.fl_str_mv Elsevier
publisher.none.fl_str_mv Elsevier
dc.source.none.fl_str_mv Veterinary Parasitology 348 : Article: 110902. (December 2026)
reponame:INTA Digital (INTA)
instname:Instituto Nacional de Tecnología Agropecuaria
reponame_str INTA Digital (INTA)
collection INTA Digital (INTA)
instname_str Instituto Nacional de Tecnología Agropecuaria
repository.name.fl_str_mv INTA Digital (INTA) - Instituto Nacional de Tecnología Agropecuaria
repository.mail.fl_str_mv tripaldi.nicolas@inta.gob.ar
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score 12.733355

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