OBJECTIVES: The incidence of infections caused by multidrug-resistant strains of Mycobacterium tuberculosis (MDR-TB) has been increasing. Antiseptics are frequently used to prevent mycobacterial infection. The aim of this study was to determine those antiseptics that are useful against MDR-TB. DESIGN: We evaluated bactericidal activity against clinical isolates of MDR-TB in vitro. METHOD: Thirteen strains of MDR-TB were tested against povidone-iodine (PVP-I), cresol, akyldiaminoethyl glycine hydrocloride (AEG), and glutaraldehyde. After bacilli were exposed to the antiseptic solution with 2% human serum, the disinfectant was inactivated by addition of neutraliser. RESULTS: PVP-1 at a final concentration of 0.2% killed all of the strains within 120 seconds, and PVP-I at 0.1% killed 99.9% or more bacilli within 60 seconds. Most strains were killed after exposure to 0.5% cresol at 300 seconds and to 1.0% cresol at 60 seconds; 3.0% cresol killed all bacilli within 120 seconds, while 0.1%, 0.2%, and 0.5% AEG all required 60 minutes to kill 99.9% or more of the bacilli; 2.0% glutaraldehyde required 10 minutes to kill all bacilli. CONCLUSION: The bactericidal activities of antiseptics for MDR-TB were similar to those for drug-sensitive M. tuberculosis strains. PVP-I would be a useful antiseptic against MDR-TB. The bactericidal activities of glutaraldehyde are effective against MDR-TB as an antiseptic for medical equipment.
OBJECTIVES: The incidence of infections caused by multidrug-resistant strains of Mycobacterium tuberculosis (MDR-TB) has been increasing. Antiseptics are frequently used to prevent mycobacterial infection. The aim of this study was to determine those antiseptics that are useful against MDR-TB. DESIGN: We evaluated bactericidal activity against clinical isolates of MDR-TB in vitro. METHOD: Thirteen strains of MDR-TB were tested against povidone-iodine (PVP-I), cresol, akyldiaminoethyl glycine hydrocloride (AEG), and glutaraldehyde. After bacilli were exposed to the antiseptic solution with 2% human serum, the disinfectant was inactivated by addition of neutraliser. RESULTS: PVP-1 at a final concentration of 0.2% killed all of the strains within 120 seconds, and PVP-I at 0.1% killed 99.9% or more bacilli within 60 seconds. Most strains were killed after exposure to 0.5% cresol at 300 seconds and to 1.0% cresol at 60 seconds; 3.0% cresol killed all bacilli within 120 seconds, while 0.1%, 0.2%, and 0.5% AEG all required 60 minutes to kill 99.9% or more of the bacilli; 2.0% glutaraldehyde required 10 minutes to kill all bacilli. CONCLUSION: The bactericidal activities of antiseptics for MDR-TB were similar to those for drug-sensitive M. tuberculosis strains. PVP-I would be a useful antiseptic against MDR-TB. The bactericidal activities of glutaraldehyde are effective against MDR-TB as an antiseptic for medical equipment.