Department of Operative Dentistry and Endodontics, School of Stomatology, Fourth Military Medical University, Xi'an, Shaanxi, China.
J Endod. 2011 Aug;37(8):1116-20. doi: 10.1016/j.joen.2011.03.020. Epub 2011 May 8.
MTAD is a common intracanal irrigant. Although MTAD inhibits Enterococcus faecalis in root canals, its bactericidal effect against E. faecalis remains to be improved. Nisin, an antibacterial peptide, possesses a strong bactericidal effect. The study evaluated the synergetic action between MTAD and nisin against E. faecalis.
The minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) were used to measure the antibacterial activities of MTAD, MTAN (substitution of doxycycline with nisin), and MTADN (nisin in combination with doxycycline), respectively. The synergetic effect between nisin and doxycycline was evaluated by fractional inhibitory concentration (FIC) and time-killing curves. Furthermore, morphologic changes in E. faecalis were observed by scanning electron microscopy after E. faecalis was treated with MTAD, MTAN, or MTADN for 24 hours.
The MBC of MTADN against E. faecalis was lower than that of MTAD and MTAN. The combination of nisin and doxycycline had a significantly synergetic antibacterial effect on E. faecalis. Among the 3 antimicrobial treatments, MTADN caused the most severe damage to E. faecalis.
The combination of nisin and doxycycline has a synergetic antibacterial effect on E. faecalis, and MTAD in conjunction with nisin inhibits E. faecalis better than MTAD alone.
MTAD 是一种常见的根管内冲洗剂。虽然 MTAD 可以抑制根管内粪肠球菌，但仍需提高其杀菌效果。乳链菌肽是一种抗菌肽，具有很强的杀菌作用。本研究评估了 MTAD 与乳链菌肽联合应用对粪肠球菌的协同作用。
采用最低抑菌浓度（MIC）和最低杀菌浓度（MBC）分别测定 MTAD、MTAN（用乳链菌肽替代强力霉素）和 MTADN（乳链菌肽联合强力霉素）的抗菌活性。采用抑菌浓度分数（FIC）和时间杀伤曲线评估乳链菌肽与强力霉素的协同作用。扫描电镜观察粪肠球菌经 MTAD、MTAN 或 MTADN 处理 24 小时后的形态变化。
MTADN 对粪肠球菌的 MBC 低于 MTAD 和 MTAN。乳链菌肽与强力霉素联合使用对粪肠球菌具有显著的协同抗菌作用。在 3 种抗菌处理中，MTADN 对粪肠球菌的损伤最严重。
乳链菌肽与强力霉素联合使用对粪肠球菌具有协同抗菌作用，MTAD 联合乳链菌肽抑制粪肠球菌的效果优于 MTAD 单独使用。
