Investigation of antistaphylococcal activity of collagen dressing containing bacitracin

In the present paper the anti-bacterial effect of bacitracin released from the collagen-based dressing and penetrating to the Staphylococcus aureus-colonised polyurethane sponge was assessed. The bacteria-colonised sponge, regarded as the "in vitro model of an infected wound", was used as a modification of the previously utilised by us analogous experimental systems. In addition, kinetics of the penetration of bacitracin from the collagen dressing to the sponge was estimated. The results indicate that in spite of the fact that the amount of bacitracin in the polyurethane sponge exceeded the minimal bactericidal concentration (MBC), not all bacteria from the S. aureus species colonising the sponge could be killed. Moreover, it appeared that in order to efficiently eradicate the sponge-adherent staphylococci the concentration of bacitracin 50-fold higher than the MBC value must be used.