The Laboratory of Bacterial Pathogenesis and Immunology, The Rockefeller University, 1230 York Ave., Box 172, New York, NY 10065, USA.
Antimicrob Agents Chemother. 2010 Apr;54(4):1603-12. doi: 10.1128/AAC.01625-09. Epub 2010 Jan 19.
Staphylococcus aureus is the causative agent of several serious infectious diseases. The emergence of antibiotic-resistant S. aureus strains has resulted in significant treatment difficulties, intensifying the need for new antimicrobial agents. Toward this end, we have developed a novel chimeric bacteriophage (phage) lysin that is active against staphylococci, including methicillin-resistant S. aureus (MRSA). The chimeric lysin (called ClyS) was obtained by fusing the N-terminal catalytic domain of the S. aureus Twort phage lysin with the C-terminal cell wall-targeting domain from another S. aureus phage lysin (phiNM3), which displayed Staphylococcus-specific binding. ClyS was expressed in Escherichia coli, and the purified protein lysed MRSA, vancomycin-intermediate strains of S. aureus (VISA), and methicillin-sensitive (MSSA) strains of S. aureus in vitro. In a mouse nasal decolonization model, a 2-log reduction in the viability of MRSA cells was seen 1 h following a single treatment with ClyS. One intraperitoneal dose of ClyS also protected against death by MRSA in a mouse septicemia model. ClyS showed a typical pattern of synergistic interactions with both vancomycin and oxacillin in vitro. More importantly, ClyS and oxacillin at doses that were not protective individually protected synergistically against MRSA septic death in a mouse model. These results strongly support the development of ClyS as an attractive addition to the current treatment options of multidrug-resistant S. aureus infections and would allow for the reinstatement of antibiotics shelved because of mounting resistance.
金黄色葡萄球菌是几种严重传染病的病原体。具有抗药性的金黄色葡萄球菌菌株的出现导致了治疗上的重大困难，加剧了对新抗菌剂的需求。为此，我们开发了一种新型的嵌合噬菌体（噬菌体）溶菌酶，对金黄色葡萄球菌有效，包括耐甲氧西林金黄色葡萄球菌（MRSA）。嵌合溶菌酶（称为 ClyS）是通过融合金黄色葡萄球菌 Twort 噬菌体溶菌酶的 N 端催化结构域与另一种金黄色葡萄球菌噬菌体溶菌酶（phiNM3）的 C 端细胞壁靶向结构域而获得的，后者显示出对金黄色葡萄球菌的特异性结合。ClyS 在大肠杆菌中表达，纯化的蛋白在体外裂解 MRSA、耐万古霉素的金黄色葡萄球菌（VISA）和甲氧西林敏感的金黄色葡萄球菌（MSSA）。在小鼠鼻腔去定植模型中，单次使用 ClyS 处理后 1 小时，MRSA 细胞的活力降低了 2 个对数级。单次腹腔内给予 ClyS 也能保护小鼠败血症模型免受 MRSA 死亡的影响。ClyS 与万古霉素和苯唑西林在体外表现出典型的协同相互作用模式。更重要的是，ClyS 和苯唑西林在单独使用时没有保护作用的剂量，在小鼠模型中协同保护免受 MRSA 败血症死亡的影响。这些结果强烈支持将 ClyS 作为治疗多药耐药金黄色葡萄球菌感染的现有治疗方案的一个有吸引力的补充，并将允许重新使用因耐药性而搁置的抗生素。
