Relationship between Hand-Washing Activity of Disinfectants and In Vitro Bactericidal Activity in the Presence of Peptone

Abstract

A study was made on the relation between in vitro bactericidal activity against Staphylococcus epidermidis which is the main bacterial flora of skin and the disinfecting activity of hand-washing with povidone-iodine, sodium hydrochloride, chloramin-T, chlorhexidine gluconate and benzalkoniumchloride. Although the bactericidal activity of povidone-iodine and sodium hydrochloride was significantly high as compared with those of the other three disinfectants, both povidone-iodine and sodium hydrochloride showed no or a little hand-washing effects. In vitro the bactericidal activity of both povidone-iodine and sodium chloride were significantly retarded by the addition of peptone in the reaction mixture. On the other hand, chloramin-T, chlorhexidine gluconate and benzalkonium chloride showed a high disinfecting activity in hand washing in spite of low in vitro bactericidal activity.Moreover, the bactericidal activity of these three disinfectants were not suppressed by the addition of peptone in the reaction mixture.These results strongly suggested that hand-washing effect of disinfectant is affected by the protein on the hand and that hand-washing activity of disinfectant should be determined by in vitro bactericidal activity in the presence of peptone.