Zhang Yuetian, Feng Ruizhang, Li Lixia, Zhou Xun, Li Zhengwen, Jia Renyong, Song Xu, Zou Yuanfeng, Yin Lizi, He Changliang, Liang Xiaoxia, Zhou Wanhai, Wei Qin, Du Yonghua, Yan Kuan, Wu Zili, Yin Zhongqiong
Natural Medicine Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, 611130, China.
Key Lab of Aromatic Plant Resources Exploitation and Utilization in Sichuan Higher Education, Yibin University, Yibin, 644000, China.
Curr Microbiol. 2018 Sep;75(9):1214-1220. doi: 10.1007/s00284-018-1512-2.
Streptococcus agalactiae, a highly contagious mastitis pathogen, caused huge economic losses; meanwhile, repeated use of antibiotics results in the emergence of serious antibiotic residues and drug resistance. Therefore, it is in great need to develop ecologically sustainable antimicrobial agents. In the study, the minimal inhibitory concentration (MIC), minimal bactericidal concentration (MBC), and action mechanism of terpinen-4-ol against S. agalactiae was investigated to evaluate antibacterial activity of terpinen-4-ol. Results showed the MIC and MBC of terpinen-4-ol were 98 and 196 µg/mL, respectively. Time-kill curves displayed that the antibacterial activity of terpinen-4-ol was in a concentration-dependent manner. Transmission electron micrographs showed that the cell membrane and wall of S. agalactiae were damaged, and plasmolysis and chromatins were inconspicuous. Release of Ca and Mg proved that terpinen-4-ol could increase cell membrane permeability. And the release of lactate dehydrogenase (LDH) suggested that cell wall was destroyed. Sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and 4',6-diamidino-2-phenylindole (DAPI) staining results showed that terpinen-4-ol could affect the synthesis of protein and DNA. These results suggested that terpinen-4-ol might be used as candidate for treating S. agalactiae infection.
无乳链球菌是一种具有高度传染性的乳腺炎病原体，会造成巨大的经济损失；与此同时，抗生素的反复使用导致了严重的抗生素残留和耐药性问题的出现。因此，迫切需要开发具有生态可持续性的抗菌剂。在本研究中，对松油烯-4-醇针对无乳链球菌的最低抑菌浓度（MIC）、最低杀菌浓度（MBC）及作用机制进行了研究，以评估松油烯-4-醇的抗菌活性。结果显示，松油烯-4-醇的MIC和MBC分别为98和196 μg/mL。时间-杀菌曲线表明，松油烯-4-醇的抗菌活性呈浓度依赖性。透射电子显微镜照片显示，无乳链球菌的细胞膜和细胞壁受到损伤，质壁分离和染色质不明显。钙和镁的释放证明松油烯-4-醇可增加细胞膜通透性。而乳酸脱氢酶（LDH）的释放表明细胞壁被破坏。十二烷基硫酸钠聚丙烯酰胺凝胶电泳（SDS-PAGE）和4',6-二脒基-2-苯基吲哚（DAPI）染色结果显示，松油烯-4-醇可影响蛋白质和DNA的合成。这些结果表明，松油烯-4-醇可能作为治疗无乳链球菌感染的候选药物。
