Tomasz Jagielski1, Zofia Bakuła2, Katarzyna Roeske2, Michał Kamiński2, Agnieszka Napiórkowska3, Ewa Augustynowicz-Kopeć3, Zofia Zwolska3, Jacek Bielecki2. 1. Department of Applied Microbiology, Institute of Microbiology, Faculty of Biology, University of Warsaw, I. Miecznikowa 1, 02-096 Warsaw, Poland t.jagielski@biol.uw.edu.pl. 2. Department of Applied Microbiology, Institute of Microbiology, Faculty of Biology, University of Warsaw, I. Miecznikowa 1, 02-096 Warsaw, Poland. 3. Department of Microbiology, National Tuberculosis and Lung Diseases Research Institute, Płocka 26, 01-138 Warsaw, Poland.
Abstract
OBJECTIVES: To determine the prevalence of isoniazid resistance-conferring mutations among multidrug-resistant (MDR) isolates of Mycobacterium tuberculosis from Poland. METHODS: Nine genetic loci, including structural genes (katG, inhA, ahpC, kasA, ndh, nat and mshA) and regulatory regions (i.e. the mabA-inhA promoter and oxyR-ahpC intergenic region) of 50 MDR M. tuberculosis isolates collected throughout Poland were PCR-amplified in their entirety and screened for mutations by direct sequencing methodology. RESULTS: Forty-six (92%) MDR M. tuberculosis isolates had mutations in the katG gene, and the katG Ser315Thr substitution predominated (72%). Eight (16%) isolates (six with a mutated katG allele) had mutations in the inhA promoter region and two such isolates also had single inhA structural gene mutations. Mutations in the oxyR-ahpC locus were found in five (10%) isolates, of which all but one had at least one additional mutation in katG. Mutations in the remaining genetic loci (kasA, ndh, nat and mshA) were detected in 12 (24%), 4 (8%), 5 (10%) and 17 (34%) MDR isolates, respectively. All non-synonymous mutants for these genes harboured mutations in katG. One isolate had no mutations in any of the analysed loci. CONCLUSIONS: This study accentuates the usefulness of katG and inhA promoter mutations as predictive markers of isoniazid resistance. Testing only for katG 315 and inhA -15 mutations would detect isoniazid resistance in 84% of the MDR M. tuberculosis sample. This percentage would increase to 96% if the sequence analysis was extended to the entire katG gene. Analysis of the remaining genetic loci did not contribute greatly to the identification of isoniazid resistance.
OBJECTIVES: To determine the prevalence of isoniazid resistance-conferring mutations among multidrug-resistant (MDR) isolates of Mycobacterium tuberculosis from Poland. METHODS: Nine genetic loci, including structural genes (katG, inhA, ahpC, kasA, ndh, nat and mshA) and regulatory regions (i.e. the mabA-inhA promoter and oxyR-ahpC intergenic region) of 50 MDR M. tuberculosis isolates collected throughout Poland were PCR-amplified in their entirety and screened for mutations by direct sequencing methodology. RESULTS: Forty-six (92%) MDR M. tuberculosis isolates had mutations in the katG gene, and the katG Ser315Thr substitution predominated (72%). Eight (16%) isolates (six with a mutated katG allele) had mutations in the inhA promoter region and two such isolates also had single inhA structural gene mutations. Mutations in the oxyR-ahpC locus were found in five (10%) isolates, of which all but one had at least one additional mutation in katG. Mutations in the remaining genetic loci (kasA, ndh, nat and mshA) were detected in 12 (24%), 4 (8%), 5 (10%) and 17 (34%) MDR isolates, respectively. All non-synonymous mutants for these genes harboured mutations in katG. One isolate had no mutations in any of the analysed loci. CONCLUSIONS: This study accentuates the usefulness of katG and inhA promoter mutations as predictive markers of isoniazid resistance. Testing only for katG 315 and inhA -15 mutations would detect isoniazid resistance in 84% of the MDR M. tuberculosis sample. This percentage would increase to 96% if the sequence analysis was extended to the entire katG gene. Analysis of the remaining genetic loci did not contribute greatly to the identification of isoniazid resistance.
Authors: B Molina-Moya; G Kazdaglis; A Lacoma; C Prat; A Gómez; R Villar-Hernández; E García-García; L Haba; J Maldonado; S Samper; J Ruiz-Manzano; J Domínguez Journal: J Clin Microbiol Date: 2016-02-10 Impact factor: 5.948
Authors: T Jagielski; A Brzostek; A van Belkum; J Dziadek; E Augustynowicz-Kopeć; Z Zwolska Journal: Eur J Clin Microbiol Infect Dis Date: 2014-07-20 Impact factor: 3.267
Authors: Michelle L T Ang; Siti Z Zainul Rahim; Paola Florez de Sessions; Wenwei Lin; Vanessa Koh; Kevin Pethe; Martin L Hibberd; Sylvie Alonso Journal: Front Microbiol Date: 2017-04-25 Impact factor: 5.640