title: In house reverse line hybridization assay for rapid detection of susceptibility to rifampicin in isolates of Mycobacterium tuberculosis.
abstract: We developed a Reverse Hybridization Assay (RHA) slightly modified from the Rifoligotyping assay and analyzed the presence of mutations in a specific region of rpoB gene in 157 isolates (90 rifampin-resistant and 67 rifampin sensitive) of Mycobacterium tuberculosis from patients attended in South and Southeast region of Brazil. Comparing to standardized drug susceptibility testing results, the sensitivity and specificity of the RHA was respectively 93% (95% IC: 86.6%-97.2%) and 100% respectively. Additionally, a high agreement (kappa coefficient 95%) between the RHA assay and sequencing was obtained. Among the 90 rifampicin-resistant isolates, RHA identified point mutations in the following codons: 42 isolates (46.6%) in 531; 29 isolates (32.2%) in 526, 6 isolates (6.7%) in 516, 3 isolates (3.3%) in 522, 2 isolates (2.2%) in 515, 514, 513 and 1 isolate (1.1%) in 511, 524 and 525. Mutations in different codons were simultaneously identified in 8 isolates (8.9%). The RHA used in the present study had a high accuracy and can be rapidly performed. However, more reproducible hybridization conditions should be looked for to increase reliability of mutant probe interpretation.
authors.affiliation: Universidade Federal do Rio de Janeiro, Brazil.
authors.forename: Simone G
authors.initials: SG
authors.lastname: Senna
authors.forename: Harrison M
authors.initials: HM
authors.lastname: Gomes
authors.forename: Marta O
authors.initials: MO
authors.lastname: Ribeiro
authors.forename: Afrânio L
authors.initials: AL
authors.lastname: Kristki
authors.forename: Maria Lucia R
authors.initials: ML
authors.lastname: Rossetti
authors.forename: Philip N
authors.initials: PN
authors.lastname: Suffys
mesh_terms: D000995:Antitubercular Agents / Q000494:pharmacology*; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D024881:Drug Resistance, Bacterial; D005838:Genotype; D006801:Humans; D008826:Microbial Sensitivity Tests / Q000379:methods; D009169:Mycobacterium tuberculosis / Q000187:drug effects* / Q000235:genetics / Q000254:growth & development / Q000302:isolation & purification; D009693:Nucleic Acid Hybridization / Q000379:methods*; D017354:Point Mutation; D016133:Polymerase Chain Reaction; D012293:Rifampin / Q000494:pharmacology*; D017422:Sequence Analysis, DNA; D014376:Tuberculosis / Q000382:microbiology
chemical_list: D000995:Antitubercular Agents; D004269:DNA, Bacterial; D012293:Rifampin