Masuda K, Ohta M, Ito M, Ohsuka S, Kaneda T, Kato N
Department of Oral Surgery, Nagoya University School of Medicine, Japan.
Oral Microbiol Immunol. 1994 Apr;9(2):77-80. doi: 10.1111/j.1399-302x.1994.tb00038.x.
Tachyplesin I, a polycationic antimicrobial peptide isolated from hemocytes of horseshoe crabs, kills bacteria by disrupting the membrane potential of the cytoplasmic membrane. The present study shows that, among 36 oral streptococcal strains, 12 of 21 Streptococcus sanguis, 3 Streptococcus mutans, 9 Streptococcus salivarius and 3 Streptococcus milleri strains were susceptible to tachyplesin I, whereas 9 S. sanguis strains were resistant. Interestingly, these resistant strains include the clinical isolates from both Kawasaki disease and Behçet patients. According to the time-kill study, tachyplesin I inhibited irreversibly the growth of S. sanguis, S. mutans and S. salivarius strains within 20 min and an S. milleri strain within 80 min. Although it has been suggested that Escherichia coli cultured in rich media were more susceptible to tachyplesin I, the present results show that only 3 S. milleri strains were more sensitized to tachyplesin I in a glucose-supplemented medium, and other tested strains were not. Similarly, only 4 strains were more resistant to tachyplesin I in saline than these were in a rich medium.
鲎素I是一种从鲎血细胞中分离得到的多阳离子抗菌肽，它通过破坏细胞质膜的膜电位来杀死细菌。本研究表明，在36株口腔链球菌菌株中，21株血链球菌中的12株、3株变形链球菌、9株唾液链球菌和3株米勒链球菌对鲎素I敏感，而9株血链球菌菌株具有抗性。有趣的是，这些抗性菌株包括来自川崎病患者和白塞病患者的临床分离株。根据时间-杀菌研究，鲎素I在20分钟内不可逆地抑制了血链球菌、变形链球菌和唾液链球菌菌株的生长，在80分钟内抑制了一株米勒链球菌菌株的生长。尽管有人认为在丰富培养基中培养的大肠杆菌对鲎素I更敏感，但本研究结果表明，在添加葡萄糖的培养基中，只有3株米勒链球菌菌株对鲎素I更敏感，其他受试菌株则不然。同样，只有4株菌株在盐溶液中比在丰富培养基中对鲎素I更具抗性。
