Effectiveness of Cinnamon Oil Coating on K-wire as an Antimicrobial Agent against Staphylococcus Epidermidis

BACKGROUND Chronic osteomyelitis remains one of the common problems with the use of orthopaedic implants. Staphylococcus epidermidis is notorious for its biofilm formation on indwelling medical devices and is one of the most frequent pathogenic agents in chronic osteomyelitis. Cinnamon oil has been proven to be an effective antimicrobial agent against several bacteria, including S. epidermidis. The eradication of S. epidermidis and prevention of biofilm formation on medical devices are desirable outcomes. OBJECTIVE To study the antimicrobial effect of cinnamon oil coating on K-wire against S. epidermidis and to quantify the most effective concentration of cinnamon oil coating on the K-wire. METHOD The cinnamon oil was divided in ten different concentrations, from 0.002% to 1%, and subsequently applied to the Kirschner wire (K-wire). Its antimicrobial effect was determined by agar well diffusion method (MHA). Cinnamon oil coated K-wires were planted on S. epidermidis inoculated Muller-Hinton Agar (MHA) plate. The size of the zone of inhibition was recorded to the nearest mm, and this was compared to gentamycin, fosfomycin, vancomycin, netilmycin. RESULT The cream based 1% concentration cinnamon oil coating on K-wire showed the strongest antimicrobial effect on S. epidermidis inoculated MHA plate. This was evident especially in the fourth repetition, with an inhibition zone diameter (IZD) of 19 mm. In the 1% concentration repetitions, the highest mean IZD of the 4 repetitions was 14 mm (intermediate according NCCLS). The mean IZD results demonstrate that cinnamon oil has 46.3% of the effectiveness of gentamycin, 49.1% of fosfomycin, 59.6% of vancomycin, and 43.4% of netilmycin. CONCLUSION In this in-vitro study, cream based cinnamon oil coating on K-wire is effective against S. epidermidis, though less effective compared to gentamycin, fosfomycin, vancomycin and netilmycin. KEY WORDS Cinnamon oil, K-wire, antimicrobial, S.epidermidis.