Lee Jin-Kyung, Chang Seok Woo, Perinpanayagam Hiran, Lim Sang-Min, Park Yoon-Jeong, Han Seung Hyun, Baek Seung-Ho, Zhu Qiang, Bae Kwang-Shik, Kum Kee-Yeon
Department of Conservative Dentistry, Dental Research Institute, Seoul National University Dental Hospital, Seoul National University School of Dentistry, Seoul, Republic of Korea.
J Endod. 2013 Dec;39(12):1625-9. doi: 10.1016/j.joen.2013.07.035. Epub 2013 Sep 11.
The aggregation of mixed bacterial flora into sessile biofilms on root canal surfaces can be one of the causes of persistent apical periodontitis. The aim of this study was to evaluate the antibacterial efficacy of human β-defensin-3 (HBD3) peptide on multispecies biofilms by using confocal laser scanning microscopy.
Actinomyces naeslundii, Lactobacillus salivarius, Streptococcus mutans, and Enterococcus faecalis were cultured in a peptone-yeast-glucose broth, and their culture suspensions were combined in equal proportions. The mixed bacteria were inoculated on sterile coverslips placed into the wells of tissue culture plates to permit the formation of mixed species biofilm. After incubation for 3 weeks, the samples were treated for 24 hours with saline (control), saturated calcium hydroxide solution (CH), 2% chlorhexidine solution (CHX), and 50 μg/mL HBD3 solution. A commercial biofilm/viability assay kit was used to assess cell viability and analyze the 3-dimensional architecture of biofilms. The percentage of dead cells was determined from the ratio of biovolumes for the red subpopulation and the total biofilm.
Three medication groups showed a significant reduction of biovolume within the biofilms compared with the control group (P < .001). The HBD3-treated biofilms had a higher percentage of dead cells than the other medication groups (P < .05). The CH and CHX groups showed higher levels of bactericidal activity than saline (P < .05), and there was no significant difference between the 2 groups (P > .05).
HBD3 peptide exhibited more antibacterial activity against mature multispecies biofilms in vitro than either CH or CHX.
根管表面混合细菌菌群聚集成固着性生物膜可能是持续性根尖周炎的病因之一。本研究的目的是使用共聚焦激光扫描显微镜评估人β-防御素-3（HBD3）肽对多菌种生物膜的抗菌效果。
将内氏放线菌、唾液乳杆菌、变形链球菌和粪肠球菌在蛋白胨-酵母-葡萄糖肉汤中培养，其培养悬液按等比例混合。将混合细菌接种到置于组织培养板孔中的无菌盖玻片上，以形成混合菌种生物膜。培养3周后，将样品分别用生理盐水（对照组）、饱和氢氧化钙溶液（CH）、2%氯己定溶液（CHX）和50μg/mL HBD3溶液处理24小时。使用商用生物膜/活力检测试剂盒评估细胞活力并分析生物膜的三维结构。根据红色亚群和总生物膜的生物体积比确定死细胞百分比。
与对照组相比，三个用药组生物膜内的生物体积均显著减少（P <.001）。HBD3处理的生物膜死细胞百分比高于其他用药组（P <.05）。CH组和CHX组的杀菌活性水平高于生理盐水组（P <.05），两组之间无显著差异（P >.05）。
在体外，HBD3肽对成熟的多菌种生物膜的抗菌活性比CH或CHX更强。
