Veterinary Academy, Lithuanian University of Health Sciences, Kaunas, Lithuania
Increasing bacterial resistance to antibiotics is a worldwide problem, which is why external-use antiseptics are gaining attention. Chlorhexidine is one such antiseptic, it reacts with the microbial cell surface. Chitosan increases the permeability of the membranes.
Aim of this study was to assess antimicrobial efficacy of different concentration of chlorhexidine/chitosan gel in vitro.
Chlorhexidine/chitosan gel was carried in vitro using the diffusion agar method. Reference and wild strains of gram-positive microorganisms: Staphylococcus aureus (ATCC 25923), Enterococcus faecalis (ATCC 29212); as well as reference and wild strains of gram-negative microorganisms: Escherichia coli (ATCC 25922), Pseudomonas aeruginosa (ATCC 27853) were sown to Mueller-Hinton agar ([CM 0337] Oxoid LTD, Basingstoke, Hampshire, England). Three different concentration chlorhexidine/chitosan gel (0.25%; 0.5%, and 1.0%) were tested against each strain of organism.
The gel was active against all bacteria, but effectiveness was dependent on species and strain. The greatest activity was noticed against the reference strain of S. aureus (diameter of sterile zone from 26,90±0,61 mm to 29,65±0,30 mm). No significant difference between 0.5% and 1.0% concentrations.
Different concentrations of chlorhexidine/chitosan gel appeared to be effective against all bacteria strains. Whilst the increase in concentration from 0,25% to 1% increased the sterile zone in almost all cases.