Improved decontamination method for recovering mycobacteria from patients with cystic fibrosis

Eur J Clin Microbiol Infect Dis. 2002 Jul;21(7):546-8. doi: 10.1007/s10096-002-0760-y. Epub 2002 Jul 12.


In order to improve the recovery of mycobacteria from patients with cystic fibrosis, the present study evaluated a two-step decontamination procedure for clinical specimens. A total of 920 specimens obtained from 239 patients with cystic fibrosis were treated initially with N-acetyl-L-cysteine/sodium hydroxide. Of these specimens, 31 (3.3%) showed mycobacterial growth and 415 (45.1%) remained contaminated. Contaminated specimens were then subjected to a second round of decontamination, using a combination of N-acetyl-L-cysteine/sodium hydroxide and oxalic acid. Following this second decontamination, the number of specimens overgrown by microorganisms other than mycobacteria was reduced to 7.3%, and an additional 10 specimens positive for mycobacteria were found. The results suggest this two-step protocol could improve the recovery of mycobacteria from heavily contaminated specimens.

MeSH terms

  • Acetylcysteine
  • Bacteriological Techniques / methods*
  • Cystic Fibrosis / complications
  • Cystic Fibrosis / microbiology*
  • Disinfection
  • Female
  • Humans
  • Male
  • Mycobacterium / growth & development
  • Mycobacterium / isolation & purification*
  • Mycobacterium Infections / complications
  • Mycobacterium Infections / microbiology*
  • Respiratory System / microbiology
  • Sodium Hydroxide


  • Sodium Hydroxide
  • Acetylcysteine