title: Comparison of the genetic variability of Blastocystis subtypes between human carriers from two contrasting climatic regions of México.
abstract: Blastocystis sp. is an anaerobic intestinal microorganism commonly identified in the feces of several animals, including humans. Blastocystis exhibits high genetic polymorphism and at least 17 subtypes (ST) have been identified; ST1-ST3 are frequently found in the Americas. Furthermore, in vitro assays have shown that temperature and humidity can affect the viability of Blastocystis cysts. In this study, we describe the genetic variability and genetic differentiation among and within Blastocystis STs in adults and children from the cities of Hermosillo and Morelia cities, which represent arid and humid subtropical climatic regions of México, respectively. Phylogenetic and genetic diversity was assessed by analyzing a region of the small subunit ribosomal DNA (SSU rDNA) gene as a marker. Blastocystis ST3 and ST1 were associated with children from Hermosillo and Morelia, respectively. An analysis of the nucleotide diversity (π) and haplotype polymorphism (θ) indexes showed that they were similar within each ST, but different between ST1 and ST3. Interestingly, the group of symptomatic carriers from Hermosillo showed scarce mean nucleotide diversity compared to the asymptomatic carriers (0.0039±0.0030 and 0.0329±0.0286, respectively). Furthermore, the gene flow and genetic differentiation indexes between the children and adults suggested that the Blastocystis haplotypes in the adult carriers were "highly mobile" among humans, while the haplotypes found in the children were more isolated and genetically differentiated between them.
authors.affiliation: Departamento de Ciencias Químico Biológicas, Universidad de Sonora, Blvd. Luis Encinas y Rosales S/N, Col. Centro, Hermosillo 83000, Sonora, Mexico.
authors.forename: Isaac
authors.initials: I
authors.lastname: Villegas-Gómez
authors.affiliation: Departamento de Ciencias Químico Biológicas, Universidad de Sonora, Blvd. Luis Encinas y Rosales S/N, Col. Centro, Hermosillo 83000, Sonora, Mexico; Hospital General "Dr. Manuel Gea González", Calzada de Tlalpan 4800, Ciudad de México 14080, Mexico.
authors.forename: Fernando
authors.initials: F
authors.lastname: Martínez-Hernández
authors.affiliation: Departamento de Ciencias Químico Biológicas, Universidad de Sonora, Blvd. Luis Encinas y Rosales S/N, Col. Centro, Hermosillo 83000, Sonora, Mexico.
authors.forename: Alejandro
authors.initials: A
authors.lastname: Urrea-Quezada
authors.affiliation: Departamento de Ciencias Químico Biológicas, Universidad de Sonora, Blvd. Luis Encinas y Rosales S/N, Col. Centro, Hermosillo 83000, Sonora, Mexico.
authors.forename: Mariana
authors.initials: M
authors.lastname: González-Díaz
authors.affiliation: Servicio de Infectología, Hospital Infantil del Estado de Sonora, Hermosillo 83100, Sonora, Mexico.
authors.forename: María
authors.initials: M
authors.lastname: Durazo
authors.affiliation: Laboratorio de Inmunología, Centro de Investigación en Alimentación y Desarrollo A. C., Hermosillo 83304, Sonora, Mexico.
authors.forename: Jesús
authors.initials: J
authors.lastname: Hernández
authors.affiliation: Hospital Infantil de Morelia "Eva Samano de López Mateos", Bosque Cuauhtémoc s/n, Morelia 58000, Michoacán, Mexico.
authors.forename: Guadalupe Erendira
authors.initials: GE
authors.lastname: Orozco-Mosqueda
authors.affiliation: Departamento de Ecología Evolutiva, Instituto de Ecología, Universidad Nacional Autónoma de México, Ciudad de México 04510, Mexico.
authors.forename: Guiehdani
authors.initials: G
authors.lastname: Villalobos
authors.affiliation: Hospital General "Dr. Manuel Gea González", Calzada de Tlalpan 4800, Ciudad de México 14080, Mexico.
authors.forename: Pablo
authors.initials: P
authors.lastname: Maravilla
authors.affiliation: Departamento de Ciencias Químico Biológicas, Universidad de Sonora, Blvd. Luis Encinas y Rosales S/N, Col. Centro, Hermosillo 83000, Sonora, Mexico. Electronic address: olivia.valenzuela@unison.mx.
authors.forename: Olivia
authors.initials: O
authors.lastname: Valenzuela
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D016844:Blastocystis / Q000145:classification* / Q000235:genetics*; D016776:Blastocystis Infections / Q000453:epidemiology* / Q000469:parasitology*; D002353:Carrier State; D002648:Child; D002675:Child, Preschool; D002980:Climate; D005260:Female; D014644:Genetic Variation; D005838:Genotype; D006239:Haplotypes; D006801:Humans; D007223:Infant; D008297:Male; D008800:Mexico / Q000453:epidemiology; D008875:Middle Aged; D010802:Phylogeny; D011110:Polymorphism, Genetic; D012335:RNA, Ribosomal / Q000235:genetics; D017422:Sequence Analysis, DNA; D055815:Young Adult
chemical_list: D012335:RNA, Ribosomal
keywords: Blastocystis sp.; Ecozones; Haplotype polymorphism; Landscape epidemiology; Nucleotide diversity