Bactericidal activities of povidone-iodine against Mycobacterium.

Three standard strains of Mycobacterium (M. tuberculosis H37Rv, M. avium ATCC15769 and M. kansasii ATCC12478) and 15 clinical isolates of Mycobacterium (7 M. tuberculosis, 2 M. avium, 3 M. kansasii, 1 M. intracellulare, 1 M. chelonae subsp. abscessus and 1 M. gordonae) were selected in order to study the bactericidal activities of povidone-iodine (PVP-I) drug substance and a commercially available PVP-I solution (Isodine solution) against Mycobacterium. After the bacilli had been exposed to the disinfectant solution at concentrations of 0.1 or 0.02% with 2% human serum for various incubation periods from 30 to 120 s, the PVP-I drug substance was inactivated by addition of 0.5% sodium thiosulfate. In the case of the commercially available PVP-I solution, a mixture of 10% Tween 80, 3% soybean lecithin and 0.5% sodium thiosulfate was used as inactivator. It was demonstrated that the 3 standard strains were completely inactivated within 30 s by 0.1% PVP-I drug substance and that the 15 clinical isolates were almost killed by 0.1% commercially available PVP-I solution within 60 s. As a result, the commercially available PVP-I product appeared to be a useful agent as disinfectant against all the tested species of Mycobacterium.