title: Clinical outcome of Mycobacterium abscessus infection and antimicrobial susceptibility testing.
abstract: OBJECTIVE
  Mycobacterium abscessus is the most resistant and rapidly growing mycobacterium and causes a wide range of clinical infectious diseases. The relationship between antimicrobial susceptibility and clinical outcome needs to be further evaluated.
  
  
  METHODS
  Forty M. abscessus isolates were obtained from clinical specimens of 40 patients at the Taichung Veterans General Hospital from January 2006 to December 2008. Antimicrobial susceptibility testing was performed using the broth microdilution method according to the recommendations of the National Committee for Clinical Laboratory Standards. The clinical manifestations and outcomes were reviewed from medical records.
  
  
  RESULTS
  Twenty-two patients were diagnosed with M. abscessus infection. Cough (86.3%), hemoptysis (31.8%) and fever (18.1%) were the most common symptoms. The radiographic findings included reticulonodular opacities (50.0%), consolidation (31.8%) and cavitary lesions (18.1%). The 40 isolates were susceptible to amikacin (95.0%), cefoxitin (32.5%), ciprofloxacin (10.0%), clarithromycin (92.5%), doxycycline (7.5%), imipenem (12.5%), moxifloxacin (22.5%), sulfamethoxazole (7.5%) and tigecycline (100%). The rate of treatment failure was 27.3% at the end of the 12(th) month after the start of treatment, although these patients were treated with a combination of clarithromycin and other antimicrobial agents.
  
  
  CONCLUSIONS
  M. abscessus is naturally susceptible to clarithromycin and amikacin, variably susceptible to cefoxitin and imipenem, and resistant to most other antimicrobial drugs. Combination therapy with clarithromycin, amikacin and other active antimicrobial agents may lead to clinical improvement; however, the rate of treatment failure is still high.
authors.affiliation: Department of Internal Medicine, Taichung Veterans General Hospital, Taichung, Taiwan. ychuang@vghtc.gov.tw
authors.forename: Yi-Ching
authors.initials: YC
authors.lastname: Huang
authors.forename: Meei-Fang
authors.initials: MF
authors.lastname: Liu
authors.forename: Gwan-Han
authors.initials: GH
authors.lastname: Shen
authors.forename: Chin-Fu
authors.initials: CF
authors.lastname: Lin
authors.forename: Chih-Chuan
authors.initials: CC
authors.lastname: Kao
authors.forename: Po-Yu
authors.initials: PY
authors.lastname: Liu
authors.forename: Zhi-Yuan
authors.initials: ZY
authors.lastname: Shi
mesh_terms: D000583:Amikacin / Q000494:pharmacology / Q000627:therapeutic use; D000900:Anti-Bacterial Agents / Q000494:pharmacology* / Q000627:therapeutic use*; D017291:Clarithromycin / Q000494:pharmacology / Q000627:therapeutic use; D024881:Drug Resistance, Bacterial; D006801:Humans; D008171:Lung Diseases / Q000175:diagnosis / Q000188:drug therapy / Q000382:microbiology; D008826:Microbial Sensitivity Tests; D009165:Mycobacterium Infections, Nontuberculous / Q000175:diagnosis / Q000188:drug therapy* / Q000382:microbiology*; D009170:Nontuberculous Mycobacteria / Q000187:drug effects* / Q000302:isolation & purification; D016896:Treatment Outcome
chemical_list: D000900:Anti-Bacterial Agents; D000583:Amikacin; D017291:Clarithromycin