Evolutionarily distinct bacteriophage endolysins featuring conserved peptidoglycan cleavage sites protect mice from MRSA infection.
Evolutionarily distinct bacteriophage endolysins featuring conserved peptidoglycan cleavage sites protect mice from MRSA infection.
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DOI：
10.1093/jac/dku552
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发表时间：
2015-05
期刊：
影响因子：
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通讯作者：
M. Schmelcher;Yang Shen;D. Nelson;M. Eugster;Fritz Eichenseher;D. Hanke;M. Loessner;S. Dong;
中科院分区：
文献类型：
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作者：
M. Schmelcher;Yang Shen;D. Nelson;M. Eugster;Fritz Eichenseher;D. Hanke;M. Loessner;S. Dong;
鉴于金黄色葡萄球菌的耐药性增加，噬菌体内溶素[肽聚糖水解酶（PGH）]已被认为是有前途的抗菌剂。本研究的目的是确定9种酶的抗菌活性，这些酶代表了不同类型葡萄球菌PGHs中独特的同源组。方法重组表达PGHs，纯化PGHs，并在多种体外试验（酶谱、浊度降低试验和平板裂解）中测试PGHs对葡萄球菌的溶解活性。aureus和CoNS）。葡萄球菌肽聚糖中的PGH切割位点通过生化测定（Park-Johnson和Ghuysen程序）和MS分析确定。测试了这些酶根除静态S.金黄色葡萄球菌生物膜，并在小鼠模型中比较它们对抗全身性MRSA感染的功效。结果尽管肽聚糖中具有相似的模块结构和出乎意料的保守切割位点（由进化上不同的催化结构域赋予），但这些酶对许多葡萄球菌菌株（包括细胞表面突变株和耐药菌株）显示出不同程度的体外裂解活性，并证明对静态生物膜有效。在全身性MRSA感染的小鼠模型中，6种PGH提供了100%的死亡保护，在实验结束时动物没有临床体征。结论我们的结果证实了PGHs治疗S。金黄色葡萄球菌感染，并揭示了不同酶的独特的抗微生物和生物化学性质，这表明尽管肽聚糖靶位点高度保守，但潜在应用的高度多样性。
OBJECTIVES In the light of increasing drug resistance in Staphylococcus aureus, bacteriophage endolysins [peptidoglycan hydrolases (PGHs)] have been suggested as promising antimicrobial agents. The aim of this study was to determine the antimicrobial activity of nine enzymes representing unique homology groups within a diverse class of staphylococcal PGHs. METHODS PGHs were recombinantly expressed, purified and tested for staphylolytic activity in multiple in vitro assays (zymogram, turbidity reduction assay and plate lysis) and against a comprehensive set of strains (S. aureus and CoNS). PGH cut sites in the staphylococcal peptidoglycan were determined by biochemical assays (Park-Johnson and Ghuysen procedures) and MS analysis. The enzymes were tested for their ability to eradicate static S. aureus biofilms and compared for their efficacy against systemic MRSA infection in a mouse model. RESULTS Despite similar modular architectures and unexpectedly conserved cleavage sites in the peptidoglycan (conferred by evolutionarily divergent catalytic domains), the enzymes displayed varying degrees of in vitro lytic activity against numerous staphylococcal strains, including cell surface mutants and drug-resistant strains, and proved effective against static biofilms. In a mouse model of systemic MRSA infection, six PGHs provided 100% protection from death, with animals being free of clinical signs at the end of the experiment. CONCLUSIONS Our results corroborate the high potential of PGHs for treatment of S. aureus infections and reveal unique antimicrobial and biochemical properties of the different enzymes, suggesting a high diversity of potential applications despite highly conserved peptidoglycan target sites.