Samantha Flores-Treviño1, Rayo Morfín-Otero2, Eduardo Rodríguez-Noriega2, Esteban González-Díaz2, Héctor Raúl Pérez-Gómez2, Soraya Mendoza-Olazarán1, Isaías Balderas-Rentería3, Gloria María González4, Elvira Garza-González5. 1. Servicio de Gastroenterología, Hospital Universitario Dr. José Eleuterio González, Universidad Autónoma de Nuevo León, Monterrey, Nuevo León, Mexico. 2. 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. 3. Laboratorio de Ingeniería Genética y Genómica, Facultad de Ciencias Químicas, Universidad Autónoma de Nuevo León, Monterrey, Nuevo León, Mexico. 4. Departamento de Microbiología, Facultad de Medicina, Universidad Autónoma de Nuevo León, Monterrey, Nuevo León, Mexico. 5. 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.
Abstract
INTRODUCTION: 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.
INTRODUCTION: 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: Thales Alves Campelo; Paulo Rafael Cardoso de Sousa; Lucas de Lima Nogueira; Cristiane Cunha Frota; Paulo Renato Zuquim Antas Journal: Access Microbiol Date: 2021-08-02