개의 표재성 농피증으로부터 분리된 Staphylococcus intermedius에 대한 0.1%(w/v) 키토산의 항균효과를 조사하였다. In vitro에서 0.1% 키토산이 S. intermedius에 대한 항균효과를 나타내기 위한 접촉시간과 키토산 용액의 pH가 미치는 영향을 조사하였다. In vivo에서 10두의 개의 피부에 인공적으로 S. intermedius를 접종하여 0.1% 키토산, 2.5% benzoyl peroxide, 0.5% chlorhexidine, 키토산-benzoyl peroxide 혼합용액, 키토산-chlorhexidine 혼합용액의 항균효과를 modified detergent cup scrub technique을 이용하여 비교하였다. In vitro에서 접종액의 내의 세균수는 $6.08{pm}0.20CFU/ml$ 이었으며 pH 4.5 용액의 경우 10분, 30분, 120분의 접촉시간 후 각각 $3.57{pm}0.51,;2.82{pm}0.24,;2.40{pm}0.17CFU/ml$로 감소하였다. 동일한 각각의 접촉시간후 pH 5.0 용액은 $4.22{pm}0.08,;3.44{pm}0.41,;3.16{pm}0.09$, pH 5.5 용액은 $4.75{pm}0.14,;4.32{pm}0.08,;3.53{pm}0.33$, pH 5.9 용액은 $5.57{pm}0.36,;5.02{pm}0.42,;4.87{pm}0.12CFU/ml$로 감소하였다. 따라서 pH에 따라 정도의 차이는 있었으나 모든 키토산 용액은 10분의 접촉시간후 현저한 항균효과를 나타내었으며 (p<0.05) pH 4.5에서 가장 높게 나타났다. In vivo에서 접종액내의 세균수는 $6.61{pm}0.30CFU/cm^2$ 이었으며 키토산은 $3.25{pm}0.98$, benzoyl peroxide는 $0.68{pm}1.13$, chlorhexidine은 $3.14{pm}0.55$, 키토산-benzoyl peroxide은 $0.48{pm}0.56$, 키토산-chlorhexidine은 $2.55{pm}0.88CFU/ml$로 각각 현저히 감소하였다 (p<0.01). 0.1% 키토산 단독보다는 소량의 benzoyl peroxide 또는 chlorhexidine을 혼합용액의 항균효과가 현저히 증가하였다. 따라서 0.1%키토산은 S. intermedius에 대하여 in vitro 및 in vivo에서 항균효과를 나타내었으며 개의 화농성 농피증의 국소제제로 적용가능성이 있을 것으로 사료된다.
The antibacterial efficacy of 0.1% (w/v) chitosan solution against Staphylococcus intermedius isolated from a dog with superficial pyoderma was evaluated in vitro and in vivo. The exposure time for the 0.1% chitosan solutions at different pH to be able to eliminate the bacterial cells and the effect of pH of the solutions on antibacterial activity was tested at the same time in vitro. The antibacterial activity of chitosan was compared to other antibacterial agents including 2.5% benzoyl peroxide, 0.5% chlorhexidine acetate, 0.1% chitosan solution combined with 2.5% benzoyl peroxide and chitosan combined with 0.5% chlorhexidine using a modified detergent scrub quantitative technique in 10 adult mongrel dogs in vivo. They were able to eliminate a number of bacteria after the exposure time of 10 minutes at varying degrees according to the pH of the solutions. The antibacterial activity of chitosan was inversely affected by pH with higher activity at lower pH value. The 0.1% chitosan solution was also efficacious against Staphylococcus intermedius in vivo. The combinations of chitosan with benzoyl peroxide and with chlorhexidine were shown to exert higher activity when compared to those of chitosan alone and benzoyl peroxide or chlorhexidine alone. The 0.1% chitosan solution was considered to be efficacious against Staphylococcus intermedius isolated from a dog with superficial pyoderma in both in vivo and in vitro and have a potential for the clinical applications in the treatment or pyoderma in dogs.
