title: Molecular epidemiology of Mycobacterium tuberculosis in Baja California, Mexico: A result of human migration?
abstract: The State of Baja California (BC) exhibits the highest incidence and prevalence rates of tuberculosis (TB), and multidrug-resistant TB (MDR-TB) in Mexico. However information about the circulation of M. tuberculosis lineages in BC and Mexico as a whole is limited. Here, we describe the genetic relationship and genetic diversity among M. tuberculosis clinical isolates (n=140) collected in BC between October 2009 and April 2011 with other regions of Mexico, the United States, and Latin America. All specimens were genotyped based on 24 mycobacterial interspersed repetitive units (MIRU)-variable number of tandem repeats (VNTR) loci. Population structure and minimum spanning tree (MST) analyses were used to assess the genetic diversity and distribution of BC isolates in comparison to USA and South America strains. Among the nine lineages observed, LAM, Haarlem and S were the most frequent identified in BC. Population structure analysis clustered most BC isolates (41%) into three distinctive groups that included strains from San Diego and South America, whereas other BC strains (22%) clustered with other Mexican strains. A subset of isolates (12%) seemed to be autochthonous of BC, while 25% were cosmopolitan and grouped into multiple clusters. It is highly likely that the TB genetic structure observed in BC is due to human migration. Additional studies are required to determine the mechanism involved in the phylogeographic distribution of M. tuberculosis in Mexico. Implementation of domestic molecular TB surveillance programs is required to better understand the molecular epidemiology of TB not only in the region but at the national level.
authors.affiliation: Facultad de Ciencias, Universidad Autónoma de Baja California, Ensenada, Baja California, Mexico; Red Multidisciplinaria de Investigación en Tuberculosis, Mexico. Electronic address: http://www.remitb.org.
authors.forename: Carlos A
authors.initials: CA
authors.lastname: Flores-López
authors.affiliation: Instituto de Salud Pública, Universidad Veracruzana, Xalapa, Veracruz, Mexico; Red Multidisciplinaria de Investigación en Tuberculosis, Mexico. Electronic address: http://www.remitb.org.
authors.forename: Roberto
authors.initials: R
authors.lastname: Zenteno-Cuevas
authors.affiliation: Clínica de Tuberculosis, Hospital General de Tijuana, ISESALUD, Tijuana, Baja California, Mexico; Red Multidisciplinaria de Investigación en Tuberculosis, Mexico. Electronic address: http://www.remitb.org.
authors.forename: Rafael
authors.initials: R
authors.lastname: Laniado-Laborín
authors.affiliation: WHO, Supranational Tuberculosis Reference Laboratory, Institut Pasteur de Guadeloupe, Abymes, France.
authors.forename: Yann
authors.initials: Y
authors.lastname: Reynaud
authors.affiliation: Laboratorio de Epidemiología y Ecología Molecular, Escuela de Ciencias de la Salud, Universidad Autónoma de Baja California, Ensenada, Baja California, Mexico.
authors.forename: Rosa Alejandra
authors.initials: RA
authors.lastname: García-Ortiz
authors.affiliation: Escuela Nacional de Ciencias Biologicas, Instituto Politécnico Nacional, Mexico City, Mexico; Red Multidisciplinaria de Investigación en Tuberculosis, Mexico. Electronic address: http://www.remitb.org.
authors.forename: Jorge A
authors.initials: JA
authors.lastname: González-Y-Merchand
authors.affiliation: Escuela Nacional de Ciencias Biologicas, Instituto Politécnico Nacional, Mexico City, Mexico; Red Multidisciplinaria de Investigación en Tuberculosis, Mexico. Electronic address: http://www.remitb.org.
authors.forename: Sandra
authors.initials: S
authors.lastname: Rivera
authors.affiliation: Instituto de Diagnóstico y Referencia Epidemiológicos, Mexico City, Mexico.
authors.forename: Carlos A
authors.initials: CA
authors.lastname: Vázquez-Chacón
authors.affiliation: Instituto de Diagnóstico y Referencia Epidemiológicos, Mexico City, Mexico.
authors.forename: Gilberto
authors.initials: G
authors.lastname: Vaughan
authors.affiliation: Instituto de Diagnóstico y Referencia Epidemiológicos, Mexico City, Mexico; Red Multidisciplinaria de Investigación en Tuberculosis, Mexico. Electronic address: http://www.remitb.org.
authors.forename: José Armando
authors.initials: JA
authors.lastname: Martínez-Guarneros
authors.affiliation: Laboratorio de Epidemiología y Ecología Molecular, Escuela de Ciencias de la Salud, Universidad Autónoma de Baja California, Ensenada, Baja California, Mexico.
authors.forename: Nelva Lorena
authors.initials: NL
authors.lastname: Victoria-Cota
authors.affiliation: Universidad Nacional Autónoma de Mexico, Mexico City, Mexico.
authors.forename: Mayra
authors.initials: M
authors.lastname: Cruz-Rivera
authors.affiliation: WHO, Supranational Tuberculosis Reference Laboratory, Institut Pasteur de Guadeloupe, Abymes, France.
authors.forename: Nalin
authors.initials: N
authors.lastname: Rastogi
authors.affiliation: Laboratorio de Epidemiología y Ecología Molecular, Escuela de Ciencias de la Salud, Universidad Autónoma de Baja California, Ensenada, Baja California, Mexico; Red Multidisciplinaria de Investigación en Tuberculosis, Mexico. Electronic address: ramusal@uabc.edu.mx.
authors.forename: Raquel
authors.initials: R
authors.lastname: Muñiz-Salazar
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D003430:Cross-Sectional Studies; D005260:Female; D014644:Genetic Variation; D005838:Genotype; D063426:Human Migration; D006801:Humans; D008297:Male; D008800:Mexico / Q000453:epidemiology; D008875:Middle Aged; D018598:Minisatellite Repeats; D017720:Molecular Epidemiology; D009169:Mycobacterium tuberculosis / Q000145:classification / Q000235:genetics*; D010802:Phylogeny; D014376:Tuberculosis / Q000453:epidemiology* / Q000382:microbiology*; D018088:Tuberculosis, Multidrug-Resistant / Q000453:epidemiology / Q000382:microbiology; D055815:Young Adult
keywords: Baja California; Genetic diversity; Mexico; Migration; TB-MDR; Tuberculosis