Evaluation of the penetration strength, bactericidal efficacy and spectrum of action of several antimicrobial creams against isolated microorganisms in a burn centre.

The antibacterial activity of eight antiseptic creams: 1 per cent silver sulphadiazine; 0.2 per cent nitrofurazone; 0.1, 0.5 and 1 per cent chlorhexidine; 2.2 per cent cerium nitrate; 10 per cent povidone iodine; and 1 per cent silver sulphadiazine with 2.2 per cent cerium nitrate were evaluated in vitro. The evaluation included the minimum inhibitory concentration (MIC) against 100 microorganisms isolated from burn patients, the chronology of the bacterial activity against Ps. aeruginosa and Staph. aureus and the penetration strength of the creams through a novel in vitro model contaminated with 17 microorganisms of different species isolated from burn patients. The results revealed that 0.5 per cent or 1 per cent chlorhexidine, 2.2 per cent cerium nitrate, and 1 per cent silver sulphadiazine with 2.2 per cent cerium nitrate were the creams which were effective at the highest dilutions. 0.5 per cent chlorhexidine and 10 per cent povidone iodine had the greater bactericidal activity. Finally, 0.2 per cent nitrofurazone showed greater penetration strength within the eschar model in comparison with the weaker penetration of 0.5 per cent and 1 per cent chlorhexidine and the absence of penetration by the rest of the antibacterial creams.