title: Characterization of phenotypic and genotypic drug resistance patterns of Mycobacterium tuberculosis isolates from a city in Mexico.
abstract: BACKGROUND
  The emergence of multidrug-resistant (MDR) Mycobacterium tuberculosis strains has become a worldwide health care problem, making treatment of tuberculosis difficult. The aim of this study was to determine phenotypic resistance and gene mutations associated with MDR of clinical isolates of Mycobacterium tuberculosis from Guadalajara, Mexico.
  
  
  METHODS
  One hundred and five isolates were subjected to drug susceptibility testing to first line drugs using the proportion and Mycobacteria Growth Indicator Tube (MGIT) methods. Genes associated with isoniazid (inhA, katG, ahpC) and rifampicin (rpoB) resistance were analyzed by either pyrosequencing or PCR-RFLP.
  
  
  RESULTS
  Resistance to any drug was detected in 48.6% of isolates, of which 40% were isoniazid-resistant, 20% were rifampicin-resistant and 19% were MDR. Drug-resistant isolates had the following frequency of mutations in rpoB (48%), katG (14%), inhA (26%), ahpC (26%). Susceptible isolates also had a mutation in ahpC (29%).
  
  
  CONCLUSIONS
  This is the first analysis of mutations associated with MDR of M. tuberculosis in Guadalajara. Commonly reported mutations worldwide were found in rpoB, katG and inhA genes. Substitution C to T in position -15 of the ahpC gene may possibly be a polymorphism.
authors: Servicio de Gastroenterología, Hospital Universitario Dr. José Eleuterio González, Universidad Autónoma de Nuevo León, Monterrey, Nuevo León, Mexico.
authors: Samantha
authors: S
authors: Flores-Treviño
authors: Hospital Civil de Guadalajara, Fray Antonio Alcalde, y el Instituto de Patología Infecciosa y Experimental, Centro Universitario de Ciencias de la Salud, Universidad de Guadalajara, Guadalajara, Jalisco, Mexico.
authors: Rayo
authors: R
authors: Morfín-Otero
authors: Hospital Civil de Guadalajara, Fray Antonio Alcalde, y el Instituto de Patología Infecciosa y Experimental, Centro Universitario de Ciencias de la Salud, Universidad de Guadalajara, Guadalajara, Jalisco, Mexico.
authors: Eduardo
authors: E
authors: Rodríguez-Noriega
authors: Hospital Civil de Guadalajara, Fray Antonio Alcalde, y el Instituto de Patología Infecciosa y Experimental, Centro Universitario de Ciencias de la Salud, Universidad de Guadalajara, Guadalajara, Jalisco, Mexico.
authors: Esteban
authors: E
authors: González-Díaz
authors: Hospital Civil de Guadalajara, Fray Antonio Alcalde, y el Instituto de Patología Infecciosa y Experimental, Centro Universitario de Ciencias de la Salud, Universidad de Guadalajara, Guadalajara, Jalisco, Mexico.
authors: Héctor Raúl
authors: HR
authors: Pérez-Gómez
authors: Servicio de Gastroenterología, Hospital Universitario Dr. José Eleuterio González, Universidad Autónoma de Nuevo León, Monterrey, Nuevo León, Mexico.
authors: Soraya
authors: S
authors: Mendoza-Olazarán
authors: Laboratorio de Ingeniería Genética y Genómica, Facultad de Ciencias Químicas, Universidad Autónoma de Nuevo León, Monterrey, Nuevo León, Mexico.
authors: Isaías
authors: I
authors: Balderas-Rentería
authors: Departamento de Microbiología, Facultad de Medicina, Universidad Autónoma de Nuevo León, Monterrey, Nuevo León, Mexico.
authors: Gloria María
authors: GM
authors: González
authors: Servicio de Gastroenterología, Hospital Universitario Dr. José Eleuterio González, Universidad Autónoma de Nuevo León, Monterrey, Nuevo León, Mexico; Departamento de Patología Clínica, Hospital Universitario Dr. José Eleuterio González, Universidad Autónoma de Nuevo León, Monterrey, Nuevo León, Mexico. Electronic address: elvira_garza_gzz@yahoo.com.
authors: Elvira
authors: E
authors: Garza-González
mesh_terms: D000995:Antitubercular Agents / Q000494:pharmacology*; D024881:Drug Resistance, Bacterial; D005838:Genotype; D006801:Humans; D008800:Mexico; D008826:Microbial Sensitivity Tests; D009169:Mycobacterium tuberculosis / Q000187:drug effects* / Q000235:genetics* / Q000302:isolation & purification; D010641:Phenotype; D014504:Urban Health
chemical_list: D000995:Antitubercular Agents
keywords: Isoniazid; Isoniazida; Multidrug-resistant; Multifarmacorresistente; Mutación; Mutation; Mycobacterium tuberculosis; Rifampicin; Rifampicina