title: Clarifying the Cryptic Host Specificity of Blastocystis spp. Isolates from Alouatta palliata and A. pigra Howler Monkeys.
abstract: Although the presence of cryptic host specificity has been documented in Blastocystis, differences in infection rates and high genetic polymorphism within and between populations of some subtypes (ST) have impeded the clarification of the generalist or specialist specificity of this parasite. We assessed the genetic variability and host specificity of Blastocystis spp. in wild howler monkeys from two rainforest areas in the southeastern region of Mexico. Fecal samples of 225 Alouatta palliata (59) and A. pigra (166) monkeys, belonging to 16 sylvatic sites, were analyzed for infection with Blastocystis ST using a region of the small subunit rDNA (SSUrDNA) gene as a marker. Phylogenetic and genetic diversity analyses were performed according to the geographic areas where the monkeys were found. Blastocystis ST2 was the most abundant (91.9%), followed by ST1 and ST8 with 4.6% and 3.5%, respectively; no association between Blastocystis ST and Alouatta species was observed. SSUrDNA sequences in GenBank from human and non-human primates (NHP) were used as ST references and included in population analyses. The haplotype network trees exhibited different distributions: ST1 showed a generalist profile since several haplotypes from different animals were homogeneously distributed with few mutational changes. For ST2, a major dispersion center grouped the Mexican samples, and high mutational differences were observed between NHP. Furthermore, nucleotide and haplotype diversity values, as well as migration and genetic differentiation indexes, showed contrasting values for ST1 and ST2. These data suggest that ST1 populations are only minimally differentiated, while ST2 populations in humans are highly differentiated from those of NHP. The host generalist and specialist specificities exhibited by ST1 and ST2 Blastocystis populations indicate distinct adaptation processes. Because ST1 exhibits a generalist profile, this haplotype can be considered a metapopulation; in contrast, ST2 exists as a set of local populations with preferences for either humans or NHP.
authors.affiliation: Departamento de Zoologia y Antropologia Fisica, Facultad de Veterinaria, Universidad de Murcia, Murcia, España.|Departamento de Ecologia del Paisaje y Cambio Global, Centro de Investigacion para la Conservacion y Aprovechamiento de Recursos Tropicales, Universidad Juarez Autonoma de Tabasco, Villahermosa, Tabasco, Mexico.
authors.forename: Claudia
authors.initials: C
authors.lastname: Villanueva-Garcia
authors.affiliation: Departamento de Ecologia del Paisaje y Cambio Global, Centro de Investigacion para la Conservacion y Aprovechamiento de Recursos Tropicales, Universidad Juarez Autonoma de Tabasco, Villahermosa, Tabasco, Mexico.
authors.forename: Elias Jose
authors.initials: EJ
authors.lastname: Gordillo-Chavez
authors.affiliation: Hospital General "Dr. Manuel Gea Gonzalez", Secretaria de Salud, Ciudad de Mexico, Mexico.
authors.forename: Eduardo
authors.initials: E
authors.lastname: Lopez-Escamilla
authors.affiliation: Departamento de Produccion Agricola y Animal, Universidad Autonoma Metropolitana, Unidad Xochimilco, Ciudad de Mexico, Mexico.
authors.forename: Emilio
authors.initials: E
authors.lastname: Rendon-Franco
authors.affiliation: Departamento de Produccion Agricola y Animal, Universidad Autonoma Metropolitana, Unidad Xochimilco, Ciudad de Mexico, Mexico.
authors.forename: Claudia Irais
authors.initials: CI
authors.lastname: Muñoz-Garcia
authors.affiliation: Departamento de Ecologia del Paisaje y Cambio Global, Centro de Investigacion para la Conservacion y Aprovechamiento de Recursos Tropicales, Universidad Juarez Autonoma de Tabasco, Villahermosa, Tabasco, Mexico.
authors.forename: Lilia
authors.initials: L
authors.lastname: Gama
authors.affiliation: Hospital General "Dr. Manuel Gea Gonzalez", Secretaria de Salud, Ciudad de Mexico, Mexico.
authors.forename: Williams Arony
authors.initials: WA
authors.lastname: Martinez-Flores
authors.affiliation: Escuela Nacional de Ciencias Biologicas, Instituto Politecnico Nacional, Ciudad de Mexico, Mexico.
authors.forename: Nayeli
authors.initials: N
authors.lastname: Gonzalez-Rodriguez
authors.affiliation: Hospital General "Dr. Manuel Gea Gonzalez", Secretaria de Salud, Ciudad de Mexico, Mexico.
authors.forename: Mirza
authors.initials: M
authors.lastname: Romero-Valdovinos
authors.affiliation: Departamento de Ecologia del Paisaje y Cambio Global, Centro de Investigacion para la Conservacion y Aprovechamiento de Recursos Tropicales, Universidad Juarez Autonoma de Tabasco, Villahermosa, Tabasco, Mexico.
authors.forename: Hilda
authors.initials: H
authors.lastname: Diaz-Lopez
authors.affiliation: Departamento de Zoologia y Antropologia Fisica, Facultad de Veterinaria, Universidad de Murcia, Murcia, España.
authors.forename: Jose
authors.initials: J
authors.lastname: Galian
authors.affiliation: Departamento de Ecologia Evolutiva, Instituto de Ecologia, Universidad Nacional Autonoma de Mexico, Ciudad de Mexico, Mexico.
authors.forename: Guiehdani
authors.initials: G
authors.lastname: Villalobos
authors.affiliation: Hospital General "Dr. Manuel Gea Gonzalez", Secretaria de Salud, Ciudad de Mexico, Mexico.
authors.forename: Pablo
authors.initials: P
authors.lastname: Maravilla
authors.affiliation: Hospital General "Dr. Manuel Gea Gonzalez", Secretaria de Salud, Ciudad de Mexico, Mexico.
authors.forename: Fernando
authors.initials: F
authors.lastname: Martinez-Hernandez
mesh_terms: D000508:Alouatta; D000818:Animals; D016844:Blastocystis / Q000145:classification / Q000235:genetics / Q000472:pathogenicity*; D016776:Blastocystis Infections / Q000821:virology*; D004275:DNA, Ribosomal / Q000235:genetics; D005243:Feces / Q000469:parasitology; D006239:Haplotypes / Q000235:genetics; D058507:Host Specificity; D006801:Humans; D008297:Male
chemical_list: D004275:DNA, Ribosomal