Dual antibacterial mechanisms of nisin Z against Gram-positive and Gram-negative bacteria
Dual antibacterial mechanisms of nisin Z against Gram-positive and Gram-negative bacteria
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DOI：
10.1016/j.ijantimicag.2005.08.010
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发表时间：
2005-11-01
影响因子：
10.8
通讯作者：
Sonomoto, K
中科院分区：
文献类型：
--
作者：
Kuwano, K;Tanaka, N;Sonomoto, K
乳链菌肽是一种两亲性抗菌肽，由多种乳酸乳球菌亚种产生。乳酸菌。由于它具有较高的抗菌活性，对人体的毒性相对较低，已被用作食品防腐剂。已知Nisin对革兰氏阳性菌有很高的抗菌活性，但对革兰氏阴性菌没有。然而，纯化的Nisin Z对革兰氏阳性菌和革兰氏阴性菌都显示出抗菌活性。为了阐明Nisin Z的活性机制，在高盐环境中对Nisin Z和纯化的Nisin Z进行了抑菌活性测试。即使在100 mM的氯化钠存在下，Nisin Z对金黄色葡萄球菌的活性也是稳定的，表现出约2log菌落形成单位(CFU)的减少。相反，Nisin Z对相同浓度的氯化钠高度敏感，未观察到菌落形成单位的减少。此外，纯化的Nisin Z对金黄色葡萄球菌和大肠杆菌细胞质膜均有通透性。在高盐环境中，大肠杆菌的通透性显著降低，但金黄色葡萄球菌细胞膜的通透性没有明显降低。此外，万古霉素抑制Nisin Z诱导的金黄色葡萄球菌细胞膜的通透性。这些结果表明，Nisin Z利用了两种不同的抗菌活性机制：对大肠杆菌的高盐敏感机制和对金黄色葡萄球菌的高盐不敏感机制。(C)2005年Elsevier B.V.和国际化疗学会。版权所有。
Nisin, an amphipathic antibiotic peptide, is produced by a number of strains of Lactococcus lactis subsp. lactis. It has been employed as a food preservative as it has a high antibacterial activity with a relatively low toxicity for humans. Nisin is known to exert a high antibacterial activity against Gram-positive but not Gram-negative bacteria. However, purified nisin Z was found to show an antibacterial activity both against Gram-positive and Gram-negative bacteria. To clarify the mechanisms of activity, nisin Z and purified nisin Z were tested for their antibacterial activities in a high-salt environment. The activity of nisin Z against Staphylococcus aureus was stable even in the presence of NaCl at 100 mM, showing ca. 2 log colony-forming unit (CFU) reduction. In contrast, the activity of nisin Z against Escherichia coli was highly sensitive to the same concentration of NaCl, and CFU reduction was not observed. Furthermore, purified nisin Z caused the permeabilisation both of S. aureus and E. coli cytoplasmic membranes. The permeabilisation of E. coli but not S. aureus cytoplasmic membranes was remarkably reduced in a high-salt environment. Moreover, vancomycin inhibited the nisin Z-induced permeabilisation of the S. aureus cytoplasmic membrane. These results suggest that nisin Z utilises two distinct mechanisms of antibacterial activity: a high-salt-sensitive mechanism for E. coli and a high-salt-insensitive mechanism for S. aureus. (C) 2005 Elsevier B.V. and the International Society of Chemotherapy. All rights reserved.