Bactericidal effects of polyhexamethylene biguanide against intracellular Staphylococcus aureus EMRSA-15 and USA 300
Bactericidal effects of polyhexamethylene biguanide against intracellular Staphylococcus aureus EMRSA-15 and USA 300
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DOI：
10.1093/jac/dkv474
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发表时间：
2016-05-01
影响因子：
5.2
通讯作者：
Good, Liam
中科院分区：
文献类型：
--
作者：
Kamaruzzaman, Nor Fadhilah;Firdessa, Rebuma;Good, Liam
金黄色葡萄球菌引起的皮肤感染的治疗受到获得性抗生素耐药性以及病原体和宿主细胞内药物递送不良的限制。在此，我们研究了六种局部使用的抗菌剂和一种阳离子聚合物聚六亚甲基双胍 (PHMB) 对细胞内 MSSA 菌株 RN4420 和 MRSA 菌株 EMRSA-15 和 USA 300 的抗菌活性。测定了抗菌剂对 MSSA 和 MRSA 菌株的 MIC，以及 使用受感染的角质形成细胞测定那氟沙星和 PHMB 对抗细胞内 MRSA 的作用。荧光素标记的 PHMB (PHMB-FITC) 用于研究 PHMB 的摄取、与细胞内 EMRSA-15 的共定位以及角质形成细胞中的保留。使用动力抑制剂 dynasore 研究了角质形成细胞摄取 PHMB 的机制。庆大霉素、那氟沙星和 PHMB 对 MRSA 的 MIC 最低。 10 mg/L 的那氟沙星可杀死 80% 的细胞内 EMRSA-15，但对 USA 300 无效。4 mg/L 的 PHMB 几乎可杀死 100% 的细胞内 EMRSA-15 和 USA 300。PHMB 进入角质形成细胞，与细胞内 EMRSA-15 共定位，并被细胞保留超过 5 小时。 PHMB 的摄取及其细胞内抗菌活性受到动力抑制剂 dynasore 的抑制。PHMB 通过与角质形成细胞内的病原体直接相互作用来杀死细胞内 MRSA，并且宿主细胞的进入是动力依赖性的。
The treatment of skin infections caused by Staphylococcus aureus is limited by acquired antibiotic resistance and poor drug delivery into pathogen and host cells. Here, we investigated the antibacterial activities of six topically used antimicrobials and a cationic polymer, polyhexamethylene biguanide (PHMB), against intracellular MSSA strain RN4420 and MRSA strains EMRSA-15 and USA 300.The MICs of antimicrobials were determined for MSSA and MRSA strains, and the bactericidal activities of nadifloxacin and PHMB against intracellular MRSA were determined using infected keratinocytes. Fluorescein-tagged PHMB (PHMB-FITC) was used to study PHMB uptake, co-localization with intracellular EMRSA-15 and retention in keratinocytes. The mechanism(s) of PHMB uptake into keratinocytes were studied using a dynamin inhibitor, dynasore.Gentamicin, nadifloxacin and PHMB showed the lowest MICs for MRSA. Nadifloxacin at 10 mg/L killed 80% of intracellular EMRSA-15, but was not effective against USA 300. PHMB at 4 mg/L killed almost 100% of intracellular EMRSA-15 and USA 300. PHMB entered keratinocytes, co-localized with intracellular EMRSA-15 and was retained by the cells for over 5 h. PHMB uptake and its intracellular antibacterial activities were inhibited by the dynamin inhibitor, dynasore.PHMB kills intracellular MRSA via direct interaction with pathogens inside keratinocytes and host cell entry is dynamin dependent.