Q-283. Novel Antimicrobial Formulations

V. K. Sharma, P. K. Fu;
Naval Inst. for Dent. and Biomedical Res., Great Lakes, IL.

The objective of the study is to develop new antimicrobial regimens to manage microbial growth in open wounds. Wounds occurring in military operational environments pose unique infection prevention and control challenges. Since drug resistance to available antibiotics is a persistent problem, different metal salts of fluoride and surfactants (anionic, cationic, non-ionic and zwitterionic) either alone or in combination have been tested in order to develop novel antimicrobial formulations. Microdilution Minimum Inhibitory Concentrations (MICs) assays were conducted according to the guidelines published by the Clinical Laboratory and Standards Institute. Efficacy against Gram positive and Gram negative bacteria as well as yeasts including Bacillus subtilis (ATCC 6633), Escherichia coli (ATCC 25922), Issatchenkia orientalis (ATCC 6258), Candida parapsilosis (ATCC 22019). Streptococcus mutans (ATCC 31987), S. sobrinus (ATCC 33478), S. mitis (ATCC 15913), Lactobacillus casei (ATCC 4646) and Lactobacillus acidophilus (ATCC 314) was evaluated. Formulations comprising various reagents such as CTAB, CHAPS, Tween-80, sodium dodecyl sulfate, Na2S2O5, tartaric acid, 1, 2 propanediol, and thioglycerol produced nearly three times the zones of inhibition as compared to those obtained with 200 μg/ml amoxicillin or comparable to those with 10 μg/ml gentamicin. MIC values in general were less than 2.5 to 5.12 µg/ml for most strains. Such concentrations also prevented monoculture biofilms formation in 24-well plates. Results suggest topical microbicidal efficacy against tested bacteria and yeasts. Further testing is underway for other possible antimicrobial and infection prevention applications.