title: Frequency and Distribution of Tuberculosis Resistance-Associated Mutations between Mumbai, Moldova, and Eastern Cape.
abstract: Molecular diagnostic assays, with their ability to rapidly detect resistance-associated mutations in bacterial genes, are promising technologies to control the spread of drug-resistant tuberculosis (DR-TB). Sequencing assays provide detailed information for specific gene regions and can help diagnostic assay developers prioritize mutations for inclusion in their assays. We performed pyrosequencing of seven Mycobacterium tuberculosis gene regions (katG, inhA, ahpC, rpoB, gyrA, rrs, and eis) for 1,128 clinical specimens from India, Moldova, and South Africa. We determined the frequencies of each mutation among drug-resistant and -susceptible specimens based on phenotypic drug susceptibility testing results and examined mutation distributions by country. The most common mutation among isoniazid-resistant (INH(r)) specimens was the katG 315ACC mutation (87%). However, in the Eastern Cape, INH(r) specimens had a lower frequency of katG mutations (44%) and higher frequencies of inhA (47%) and ahpC (10%) promoter mutations. The most common mutation among rifampin-resistant (RIF(r)) specimens was the rpoB 531TTG mutation (80%). The mutation was common in RIF(r) specimens in Mumbai (83%) and Moldova (84%) but not the Eastern Cape (17%), where the 516GTC mutation appeared more frequently (57%). The most common mutation among fluoroquinolone-resistant specimens was the gyrA 94GGC mutation (44%). The rrs 1401G mutation was found in 84%, 84%, and 50% of amikacin-resistant, capreomycin-resistant, and kanamycin (KAN)-resistant (KAN(r)) specimens, respectively. The eis promoter mutation -12T was found in 26% of KAN(r) and 4% of KAN-susceptible (KAN(s)) specimens. Inclusion of the ahpC and eis promoter gene regions was critical for optimal test sensitivity for the detection of INH resistance in the Eastern Cape and KAN resistance in Moldova. (This study has been registered at ClinicalTrials.gov under registration number NCT02170441.).
authors.affiliation: Department of Medicine, University of California, San Diego, La Jolla, California, USA sgeorghi@ucsd.edu.
authors.forename: S B
authors.initials: SB
authors.lastname: Georghiou
authors.affiliation: Department of Medicine, University of California, San Diego, La Jolla, California, USA.
authors.forename: M
authors.initials: M
authors.lastname: Seifert
authors.affiliation: University of Arkansas, Fayetteville, Arkansas, USA.
authors.forename: D
authors.initials: D
authors.lastname: Catanzaro
authors.affiliation: Department of Medicine, University of California, San Diego, La Jolla, California, USA.
authors.forename: R S
authors.initials: RS
authors.lastname: Garfein
authors.affiliation: Biological and Medical Informatics Research Center, San Diego State University, San Diego, California, USA.
authors.forename: F
authors.initials: F
authors.lastname: Valafar
authors.affiliation: Microbiology and Morphology Laboratory, Institute of Phthisiopneumology, Chisinau, Moldova.
authors.forename: V
authors.initials: V
authors.lastname: Crudu
authors.affiliation: Department of Microbiology, P. D. Hinduja Hospital and Medical Research Centre, Mumbai, India.
authors.forename: C
authors.initials: C
authors.lastname: Rodrigues
authors.affiliation: Division of Molecular Biology and Human Genetics, Stellenbosch University, Stellenbosch, South Africa.
authors.forename: T C
authors.initials: TC
authors.lastname: Victor
authors.affiliation: Department of Medicine, University of California, San Diego, La Jolla, California, USA.
authors.forename: A
authors.initials: A
authors.lastname: Catanzaro
authors.affiliation: Department of Medicine, University of California, San Diego, La Jolla, California, USA.
authors.forename: T C
authors.initials: TC
authors.lastname: Rodwell
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics; D002207:Capreomycin / Q000627:therapeutic use; D024901:Drug Resistance, Multiple, Bacterial / Q000235:genetics; D007538:Isoniazid / Q000627:therapeutic use; D007612:Kanamycin / Q000627:therapeutic use; D008826:Microbial Sensitivity Tests; D008966:Moldova; D009154:Mutation; D009169:Mycobacterium tuberculosis / Q000187:drug effects / Q000235:genetics / Q000472:pathogenicity; D012293:Rifampin / Q000627:therapeutic use; D013019:South Africa; D014376:Tuberculosis; D018088:Tuberculosis, Multidrug-Resistant / Q000188:drug therapy / Q000235:genetics*
chemical_list: D001426:Bacterial Proteins; D002207:Capreomycin; D007612:Kanamycin; D007538:Isoniazid; D012293:Rifampin