First insights into the genetic diversity of Mycobacterium tuberculosis isolates from HIV-infected Mexican patients and mutations causing multidrug resistance

• Published in: BMC microbiology 2010-03, Vol.10 (1), p.82-82, Article 82
• Main Authors: Lopez-Alvarez, Rocio, Badillo-Lopez, Claudia, Cerna-Cortes, Jorge F, Castillo-Ramirez, Ivan, Rivera-Gutierrez, Sandra, Helguera-Repetto, Addy C, Aguilar, Diana, Hernandez-Pando, Rogelio, Samper, Sofia, Gonzalez-y-Merchand, Jorge A
• Format: Article
• Language: English
• Subjects: AIDS-Related Opportunistic Infections - microbiology; Biological diversity; Care and treatment; Cluster Analysis; Diseases; Drug resistance; Drug resistance in microorganisms; Drug Resistance, Multiple, Bacterial; Genes; Genetic aspects; Health aspects; HIV; HIV Infections - microbiology; HIV patients; Human immunodeficiency virus; Humans; Identification and classification; Medical examination; Mexico; Mutation; Mycobacterium avium; Mycobacterium tuberculosis; Mycobacterium tuberculosis - genetics; Mycobacterium tuberculosis - isolation & purification; Polymorphism, Restriction Fragment Length; Research article; Serotyping; Tuberculosis; Tuberculosis, Multidrug-Resistant - microbiology; Tuberculosis, Multidrug-Resistant - virology
• ISSN: 1471-2180; 1471-2180
• DOI: 10.1186/1471-2180-10-82

The prevalence of infections with Mycobacterium tuberculosis (MTb) and nontuberculous mycobacteria (NTM) species in HIV-infected patients in Mexico is unknown. The aims of this study were to determine the frequency of MTb and NTM species in HIV-infected patients from Mexico City, to evaluate the genotypic diversity of the Mycobacterium tuberculosis complex strains, to determine their drug resistance profiles by colorimetric microplate Alamar Blue assay (MABA), and finally, to detect mutations present in katG, rpoB and inhA genes, resulting in isoniazid (INH) and rifampin (RIF) resistance. Of the 67 mycobacterial strains isolated, 48 were identified as MTb, 9 as M. bovis, 9 as M. avium and 1 as M. intracellulare. IS6110-RFLP of 48 MTb strains showed 27 profiles. Spoligotyping of the 48 MTb strains yielded 21 patterns, and 9 M. bovis strains produced 7 patterns. Eleven new spoligotypes patterns were found. A total of 40 patterns were produced from the 48 MTb strains when MIRU-VNTR was performed. Nineteen (39.6%) MTb strains were resistant to one or more drugs. One (2.1%) multidrug-resistant (MDR) strain was identified. A novel mutation was identified in a RIF-resistant strain, GAG --> TCG (Glu --> Ser) at codon 469 of rpoB gene. This is the first molecular analysis of mycobacteria isolated from HIV-infected patients in Mexico, which describe the prevalence of different mycobacterial species in this population. A high genetic diversity of MTb strains was identified. New spoligotypes and MIRU-VNTR patterns as well as a novel mutation associated to RIF-resistance were found. This information will facilitate the tracking of different mycobacterial species in HIV-infected individuals, and monitoring the spread of these microorganisms, leading to more appropriate measures for tuberculosis control.