Bactericidal activity of povidone-iodine (pvp-i) against tubercle bacilli

Antituberculous activity of antiseptics was evaluated by using a modification of a method for the determination of phenol coefficient. Bactericidal activities of 5% phenol and 99.5% ethyl alcohol agai. nst BCG and H₃₇Rv were found at a dilution of 1: 5 and those of saponated cresol solution (USP) and 100 mg/ml-PVP-I were at a dilution of 1: 500. However, 5% chlorhexidine gluconate, 10% benzar• conium chloride and 10% alkyl (aminoethyl) glycine showed no bactericidal activity against BCG and H27Rv. Bactericidal activities of the saponated cresol solution against 7 clinical isolates of tubercle bacilli • were found at a 1: 100 dilution against 2 strains, at a 1: 500 dilution against 4 strains and at a 1: 10,000 dilution against 1 strain. On the other hand, PVP-I exibited bactericidal activities against 6 of the above 7 strains at a dilution of 1: 5,000. Bactericidal activity of PVP-I against BCG was markedly decreased at lower temperature (10°C and below). Also the activity of PVP-I was decreased in the presence of human blood serum. From these data, it is evident that PVP-I is more effective than saponated cresol solution aginst tubercle bacilli at a temperature above 10°C and in the absence of proteinous substances.