title: Detection and assessment of clarithromycin inducible resistant strains among Korean Mycobacterium abscessus clinical strains: PCR methods.
abstract: BACKGROUND
  Mycobacterium abscessus group belongs to a group of rapidly growing mycobacteria (RGM) and, following Mycobacterium avium complex, is the second most common pathogen responsible for lung disease caused by nontuberculous mycobacteria (NTM). Clarithromycin is known to be the key drug in the treatment of M. abscessus group disease, but a high failure rate of treatment response is reported due to clarithromycin inducible resistance.
  
  
  METHODS
  Using the results from a clarithromycin susceptibility test we examined the proportion of clarithromycin inducible resistant M. abscessus (sensu stricto; hereafter referred to as M. abscessus) clinical strains. Also, we attempted to detect the clarithromycin resistant strains, using the amplification refractory mutation system-PCR (ARMS-PCR) and real-time PCR methods for rapid detection of single-nucleotide polymorphisms (SNPs) at position 28 (T or C) of the erm(41) gene of M. abscessus leading to resistance to clarithromycin.
  
  
  RESULTS
  Of the 157 M. abscessus clinical strains, clarithromycin susceptible, resistant, and inducible resistant strains accounted for 10.83% (n = 17), 22.29% (n = 35), and 66.88% (n = 105), respectively. Clarithromycin resistant strains were able to separate from clarithromycin susceptible strains by ARMS-PCR and real-time PCR identical to DNA sequence analysis.
  
  
  CONCLUSIONS
  Most M. abscessus clinical strains in Korea are resistant to clarithromycin, and ARMS-PCR and real-time PCR are useful tools for the rapid detection of single-nucleotide polymorphisms (SNPs) at position 28 of the erm(41) gene.
authors.affiliation: Korean Institute of Tuberculosis, Chungbuk, Korea.
authors.forename: Seung-Heon
authors.initials: SH
authors.lastname: Lee
authors.forename: Hee Kyung
authors.initials: HK
authors.lastname: Yoo
authors.forename: Seol Hee
authors.initials: SH
authors.lastname: Kim
authors.forename: Won-Jung
authors.initials: WJ
authors.lastname: Koh
authors.forename: Chang Ki
authors.initials: CK
authors.lastname: Kim
authors.forename: Young Kil
authors.initials: YK
authors.lastname: Park
authors.forename: Hee Jin
authors.initials: HJ
authors.lastname: Kim
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D015373:Bacterial Typing Techniques / Q000379:methods*; D017291:Clarithromycin / Q000494:pharmacology*; D004269:DNA, Bacterial / Q000235:genetics; D024881:Drug Resistance, Bacterial / Q000235:genetics*; D005838:Genotype; D006801:Humans; D008826:Microbial Sensitivity Tests; D009161:Mycobacterium / Q000145:classification / Q000187:drug effects* / Q000235:genetics* / Q000302:isolation & purification; D016133:Polymerase Chain Reaction; D020641:Polymorphism, Single Nucleotide / Q000235:genetics; D056910:Republic of Korea; D013997:Time Factors
chemical_list: D000900:Anti-Bacterial Agents; D004269:DNA, Bacterial; D017291:Clarithromycin
keywords: amplification refractory mutation system-PCR; clarithromycin; erm(41); real-time PCR