[Comparison of BBL Mycoprep and 2%NaOH decontamination procedures for MGIT].
OBJECTIVE
We compared the BBL Mycoprep (Becton Dickinson Japan) and home-made 2%NaOH decontamination procedures by using an equal amount of expectorated sputum in the aerosol-free 30 ml KT centrifuge tube with the rugged inner surface.


METHODS
A total of 113 sputum specimens obtained in NHO Kinki-Chuo Chest Medical Center in November 2004 were subjected to two decontamination methods. All specimens were divided into two equal portions after concentrating the sediments processed by semi-kaline protease (SAP), then decontaminated, and inoculated into MGIT. The tubes were incubated at 37 degrees C and monitored for up to forty-second days.


RESULTS
Comparing these decontamination procedures, the time of the recovery of mycobacteria strains in the 2%NaOH (mean 8 days) was significantly faster than in the BBL Mycoprep (mean 11 days). Of these, 19 specimens (16.9%) processed by the BBL Mycoprep were positive for growth of mycobacteria, and similarly 18 specimens (16.0%) processed by the 2%NaOH (p>0.5) were positive. The 19 mycobacteria recovered by the BBL Mycoprep were identified as 14 M. tuberculosis strains and 5 NTM strains. The decontamination rate was 0.9% in 2%NaOH and 6.2% in Mycoprep, however the difference was statistically not significant (p>0.5).


CONCLUSIONS
We verified that the 2%NaOH was an alternative method suitable for the digestion and decontamination procedure, and 2%NaOH was useful for the isolation and detection of mycobacteria as well.
Tomita
Motohisa
M
Department of Clinical Laboratory, National Hospital Organization Kinki-Chuo Chest Medical Center, Japan. mhtomita@kch.hosp.go.jp
Takeno
Hana
H
Yoshida
Shiomi
S
Suzuki
Katsuhiro
K
Sakatani
Mitsunori
M
D001431:Bacteriological Techniques; D003470:Culture Media; D003666:Decontamination / Q000379:methods*; D009169:Mycobacterium tuberculosis / Q000302:isolation & purification*; D012972:Sodium Hydroxide / Q000494:pharmacology*; D013183:Sputum / Q000382:microbiology*
D003470:Culture Media; D012972:Sodium Hydroxide