Direct detection of isoniazid-resistant Mycobacterium tuberculosis in respiratory specimens by multiplex allele-specific polymerase chain reaction

Kit Hang Siu, Yuk Ho Tam, Pak Leung Ho, Ann Siew Gek Lee, Tak Lun Que, Cindy Wing Sze Tse, Kam Tong Yip, Jason Tsz Hin Lam, Vincent Chi Chung Cheng, Kwok Yung Yuen, Wing Cheong Yam

Research output: Journal article publicationJournal articleAcademic researchpeer-review

9 Citations (Scopus)


This study evaluated the feasibility of using 2 multiplex allele-specific polymerase chain reaction (MAS-PCR) assays targeting 2 mutations (codon 315 of the katG gene and the 15th nucleotide preceding the mabA-inhA operon) to directly detect isoniazid (INH)-resistant Mycobacterium tuberculosis in cultured isolates and respiratory specimens. A total of 203 M. tuberculosis isolates and 487 respiratory specimens were investigated. The MAS-PCR assays successfully amplified all M. tuberculosis isolates and acid-fast bacilli smear-positive specimens while only 49.2% of the smear-negative specimens exhibited positive MAS-PCR results. The MAS-PCR assays identified 83.4% and 79.2% of the resistant strains in the culture isolates and respiratory specimens, respectively. All the inferred genotypes were in complete accordance with subsequent DNA sequence analyses. This study suggested the application of our improved MAS-PCR protocols to provide the rapid identification of INH-resistant M. tuberculosis directly in respiratory specimens. The technical simplicity, short turnaround time, and low cost of this molecular strategy should facilitate routine diagnostic services in developing areas with a high prevalence of drug-resistant tuberculosis.
Original languageEnglish
Pages (from-to)51-58
Number of pages8
JournalDiagnostic Microbiology and Infectious Disease
Issue number1
Publication statusPublished - 1 Jan 2011
Externally publishedYes


  • INH resistance
  • KatG
  • Maba-inhA
  • Multiplex allele-specific PCR
  • Rapid diagnosis

ASJC Scopus subject areas

  • Microbiology (medical)
  • Infectious Diseases

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