title: Molecular characterization of Mycobacterium bovis isolates from patients with tuberculosis in Baja California, Mexico.
abstract: The incidence of tuberculosis (TB) from Mycobacterium bovis in humans is likely to be underestimated and in some cases even ignored in most developing countries. This may be due to the difficulty of differentiating TB caused by either Mycobacteriumtuberculosis or M. bovis. Our objectives were to determine the prevalence of M. bovis human disease among the patients referred for study to the Tuberculosis Laboratory of the Tijuana General Hospital in Baja California, Mexico and to characterize molecularly the clinical isolates using 8 loci of MIRU-VNTR. A cross-sectional analysis of all culture-proven cases of tuberculosis was conducted during the period from January 1, 2011 through June 30, 2013. Clinical isolates that exhibited resistance to pyrazinamide (Z) were submitted for molecular analysis. A total of 2699 clinical samples were cultured during the study period and 600 (22%) that tested positive were processed for drug susceptibility for first line drugs. Sixty-four (10.7%) of the tested isolates tested were resistant to Z, and 27 (4.5%) of those were subsequently identified molecularly as M. bovis. Three of the M. bovis isolates were polyresistant to Z, isoniazid (H), ethambutol (E) and rifampicin (R) (Z+H+E, Z+E and Z+R); the rest were only resistant only to Z. VNTR typing, based on the 8 VNTR loci commonly tested for M.bovis, detected 12 allelic profiles (genotypes). The real burden of M. bovis cases among the total reported human tuberculosis cases can only be known from especially designed studies in which, during a specific period, all specimens submitted to tuberculosis diagnosis in one or more laboratories are cultured on the appropriate media and the isolated mycobacteria are analyzed to differentiate M. bovis from M. tuberculosis and other Mycobacterium species.
authors.affiliation: Facultad de Medicina y Psicología, Universidad Autónoma de Baja California, Calzada Tecnológico 14418, Mesa de Otay, 22390 Tijuana, Baja California, Mexico; Clínica de Tuberculosis, Hospital General Tijuana, ISESALUD, Avenida Centenario 10851, Zona Rio, 22320 Tijuana, Baja California, Mexico. Electronic address: rlaniado@uabc.edu.mx.
authors.forename: Rafael
authors.initials: R
authors.lastname: Laniado-Laborín
authors.affiliation: Escuela de Ciencias de la Salud, Universidad Autónoma de Baja California, Blvd. Zertuche y Blvd. de los Lagos s/n, Fracc. Valle Dorado, 22890 Ensenada, Baja California, Mexico. Electronic address: ramusal@uabc.edu.mx.
authors.forename: Raquel
authors.initials: R
authors.lastname: Muñiz-Salazar
authors.affiliation: Escuela de Ciencias de la Salud, Universidad Autónoma de Baja California, Blvd. Zertuche y Blvd. de los Lagos s/n, Fracc. Valle Dorado, 22890 Ensenada, Baja California, Mexico. Electronic address: alejandraa_ortiz@hotmail.com.
authors.forename: Rosa Alejandra
authors.initials: RA
authors.lastname: García-Ortiz
authors.affiliation: Clínica de Tuberculosis, Hospital General Tijuana, ISESALUD, Avenida Centenario 10851, Zona Rio, 22320 Tijuana, Baja California, Mexico. Electronic address: caro_vargas@uabc.edu.mx.
authors.forename: Adriana Carolina
authors.initials: AC
authors.lastname: Vargas-Ojeda
authors.affiliation: Facultad de Medicina y Psicología, Universidad Autónoma de Baja California, Calzada Tecnológico 14418, Mesa de Otay, 22390 Tijuana, Baja California, Mexico. Electronic address: villa.rosas@gmail.com.
authors.forename: Cecilia
authors.initials: C
authors.lastname: Villa-Rosas
authors.affiliation: Facultad de Medicina y Psicología, Universidad Autónoma de Baja California, Calzada Tecnológico 14418, Mesa de Otay, 22390 Tijuana, Baja California, Mexico. Electronic address: loret_@hotmail.com.
authors.forename: Lorena
authors.initials: L
authors.lastname: Oceguera-Palao
mesh_terms: D000328:Adult; D003430:Cross-Sectional Studies; D005260:Female; D005838:Genotype; D006801:Humans; D015994:Incidence; D008297:Male; D008800:Mexico / Q000453:epidemiology; D018598:Minisatellite Repeats; D058885:Multilocus Sequence Typing; D009163:Mycobacterium bovis / Q000145:classification* / Q000235:genetics* / Q000302:isolation & purification; D014376:Tuberculosis / Q000453:epidemiology* / Q000382:microbiology*; D055815:Young Adult
keywords: Bovis; Human–human transmission; MIRU-VNTR; Pyrazinamide