ABSTRACT
BACKGROUND: TB is the leading cause of death from a single infectious disease, particularly among people living with HIV (PLHIV). Molecular epidemiology provides information on prevalent genotypes of Mycobacterium tuberculosis and disease transmission dynamics, which aid in TB control. Identification of mutations that confer drug resistance is essential for the rapid diagnosis of drug-resistant TB, especially in high TB burden settings, like the Philippines.METHODS: This study aimed to determine mutations in M. tuberculosis drug resistance-conferring genes and circulating genotypes in PLHIV. MIRU-VNTR (mycobacterial interspersed repetitive unit-variable number of tandem repeats) typing using a set of 24-loci and sequencing of drug resistance-conferring genes were performed in 22 M. tuberculosis isolates from TB-HIV co-infected patients.RESULTS: The prevalence of resistance to any drug was 31.8%, 18.2% for isoniazid monoresistance, 4.5% for streptomycin monoresistance and 9.1% for multidrug resistance. The identified mutations in the katG, rpoB, pncA, rpsL and gyrA genes have been reported in the literature; none was found in the inhA and embB genes. All isolates belonged to the EAI2-Manila family and were grouped into four clusters based on their phenotypic drug resistance and mutation profiles.CONCLUSION: The use of 24-loci set may be used as a more discriminatory MIRU-VNTR typing in settings where the East African-Indian lineage is predominant, like the Philippines.
Subject(s)
Coinfection , HIV Infections , Mycobacterium tuberculosis , Tuberculosis, Multidrug-Resistant , Adult , Antitubercular Agents/pharmacology , Antitubercular Agents/therapeutic use , Coinfection/drug therapy , Coinfection/epidemiology , Drug Resistance, Multiple, Bacterial/genetics , Genotype , HIV Infections/complications , HIV Infections/drug therapy , HIV Infections/epidemiology , Humans , Microbial Sensitivity Tests , Molecular Epidemiology , Mutation , Mycobacterium tuberculosis/genetics , Philippines/epidemiology , Tuberculosis, Multidrug-Resistant/drug therapy , Tuberculosis, Multidrug-Resistant/epidemiologyABSTRACT
An MPT64 antigen detection assay, the SD Bioline TB Ag MPT64 Rapid kit, was evaluated for the identification of Mycobacterium tuberculosis grown in both solid and liquid media. The rapid test showed positive results in 132 of 133 (99.2%) M. tuberculosis cultures grown on Ogawa medium and 136/143 (95.1%) cultures grown in liquid culture medium, resulting in an overall sensitivity of 97.1%. All 18 non-tuberculous mycobacteria were found to be negative by the rapid test, indicating a specificity of 100%. The rapid test seems useful for the initial confirmation of M. tuberculosis in acidfast bacilli positive cultures.
