Inhibitory effect of deoxyribonucleaseⅠ against Cutibacterium acnes biofilms / 中华皮肤科杂志

ABSTRACT

Objective:To investigate the inhibitory effect of deoxyribonuclease Ⅰ (DNaseⅠ) on Cutibacterium acnes biofilms. Methods:Cutibacterium acnes biofilms were constructed, and then were divided into 4 groups (negative control group, 5, 10 and 20 U/ml DNase Ⅰ groups) to be treated with DNase Ⅰ at different concentrations of 0, 5, 10 and 20 U/ml respectively. The biofilm viability was evaluated by tetrazolium salt colorimetric assay, the biofilm content was determined by crystal violet staining-based semi-quantitative analysis, the biofilm structure was observed by confocal laser scanning microscopy, and the live/dead bacteria ratio was calculated. One-way analysis of variance was used to analyze differences between groups. Results:After the treatment with DNase Ⅰ, the biofilm viability was significantly inhibited in the 5, 10 and 20 U/ml DNaseⅠ groups (1.882 ± 0.421, 1.653 ± 0.287, 1.473 ± 0.154, respectively) compared with the negative control group (2.668 ± 0.245), and the inhibitory effect was gradually enhanced with the increase in concentrations of DNase Ⅰ ( F = 9.68, P = 0.005). Crystal violet semi-quantitative analysis showed that the biofilm content was also significantly lower in the 5, 10 and 20 U/ml DNaseⅠ groups (1.039 ± 0.003, 0.489 ± 0.079, 0.147 ± 0.034, respectively) than in the negative control group (1.359 ± 0.071), and the higher the DNase Ⅰ concentration, the lower the biofilm content ( F = 174.40, P < 0.001). Confocal laser scanning microscopy showed that the biofilm structure was destroyed in the 5, 10 and 20 U/ml DNase Ⅰ groups compared with the negative control group, and the higher the DNase Ⅰ concentration, the more severe the destruction of biofilm structure. Additionally, the live/dead bacteria ratio was significantly lower in the 5, 10 and 20 U/ml DNaseⅠ groups (2.303 ± 0.457, 1.534 ± 0.526, 1.263 ± 0.354, respectively) than in the negative control group (4.475 ± 0.146), and the ratio decreased with the increase in concentrations of DNase Ⅰ ( F = 56.75, P < 0.000 1) . Conclusion:DNase Ⅰ had a destructive effect on the structure of Cutibacterium acnes biofilms, and could inhibit their viability.