title: Evaluation of the broth microdilution method using 2,3-diphenyl-5-thienyl-(2)-tetrazolium chloride for rapidly growing mycobacteria susceptibility testing.
abstract: As the incidence of nontuberculous mycobacterial infection has been increasing recently in Korea, the importance of drug susceptibility test for clinical isolates of mycobacteria has become larger. In this study we determined the antimicrobial susceptibility patterns of clinical isolates of M. fortuitum and M. abscessus in Korea, and evaluated the efficacy of a modified broth microdilution method using 2,3-diphenyl-5-thienyl-(2)-tetrazolium chloride (STC), in terms of its ability to provide accurate and easy-to-read minimal inhibitory concentration (MIC) endpoints for the susceptibility testing of rapidly growing mycobacteria. Most isolates of M. fortuitum and M. abscessus in Korea are susceptible or intermediately susceptible to amikacin, cefoxitin, ciprofloxacin, and clarithromycin. Many isolates of M. fortuitum are susceptible to doxycycline, sulfamethoxazole, and imipenem, while many M. abscessus isolates are resistant to these drugs. In the present study, the modified broth microdilution method using STC was found to be reliable, easy to read, and inexpensive for M. fortuitum and M. abscessus susceptibility testing. The modified colorimetric MIC testing method using STC was proven to be a useful surrogate for RGM antibiotic susceptibility testing.
authors.affiliation: Department of Laboratory Medicine, School of Medicine, Pusan National University, Busan, Korea.
authors.forename: Sun Min
authors.initials: SM
authors.lastname: Lee
authors.forename: Jeong man
authors.initials: Jm
authors.lastname: Kim
authors.forename: Joseph
authors.initials: J
authors.lastname: Jeong
authors.forename: Young Kil
authors.initials: YK
authors.lastname: Park
authors.forename: Gill-Han
authors.initials: GH
authors.lastname: Bai
authors.forename: Eun Yup
authors.initials: EY
authors.lastname: Lee
authors.forename: Min Ki
authors.initials: MK
authors.lastname: Lee
authors.forename: Chulhun L
authors.initials: CL
authors.lastname: Chang
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology; D002440:Cefoxitin / Q000494:pharmacology; D002626:Chemistry, Pharmaceutical / Q000379:methods; D002939:Ciprofloxacin / Q000494:pharmacology; D017291:Clarithromycin / Q000494:pharmacology; D003124:Colorimetry / Q000379:methods; D024881:Drug Resistance, Bacterial; D007723:Korea; D008826:Microbial Sensitivity Tests; D009161:Mycobacterium / Q000378:metabolism*; D019907:Mycobacterium fortuitum / Q000378:metabolism*; D013778:Tetrazolium Salts / Q000494:pharmacology*
chemical_list: C494145:2,3-diphenyl-5-thienyl-(2)-tetrazolium; D000900:Anti-Bacterial Agents; D013778:Tetrazolium Salts; D002939:Ciprofloxacin; D002440:Cefoxitin; D017291:Clarithromycin