A Novel Staphylococcus Podophage Encodes a Unique Lysin with Unusual Modular Design.
A Novel Staphylococcus Podophage Encodes a Unique Lysin with Unusual Modular Design.
复制标题
DOI：
10.1128/msphere.00040-17
复制
发表时间：
2017-03
期刊：
影响因子：
4.8
通讯作者：
Hatoum-Aslan A
中科院分区：
文献类型：
--
作者：
Cater K;Dandu VS;Bari SM;Lackey K;Everett GF;Hatoum-Aslan A
抗生素耐药性在细菌病原体中的传播正在引发全球公共卫生危机。耐药葡萄球菌属，特别是金黄色葡萄球菌和表皮葡萄球菌，已经出现在医院和社区环境中，强调了迫切需要新的战略来对抗葡萄球菌感染。细菌病毒（Bacterial viruses，简称MRSA）和它们用来降解细菌细胞壁的酶（溶素）显示出作为替代抗菌剂的前景;然而，只有有限种类的葡萄球菌链球菌（Staphylococcal MRSA）和它们的溶素尚未被鉴定。在这里，我们报告了一种新的葡萄球菌噬菌体Andhra的发现和表征。我们发现Andhra编码两种溶素（Andhra_gp10和Andhra_gp14），其抑制不同葡萄球菌（包括金黄色葡萄球菌和表皮葡萄球菌菌株）的生长并降解细胞壁。Andhra及其独特的溶素添加到具有治疗用途潜力的抗菌剂库中。耐药葡萄球菌，特别是金黄色葡萄球菌和表皮葡萄球菌，是医院获得性感染的主要原因。噬菌体和它们的肽聚糖水解酶（溶素）目前正在探索作为传统抗生素的替代品;然而，只有有限的葡萄球菌的噬菌体和它们的溶素的多样性尚未得到表征。在这里，我们描述了一种新的葡萄球菌噬菌体及其溶素。Andhra噬菌体是第一个报道的表皮葡萄球菌噬菌体，属于短尾病毒科。Andhra拥有18，546个核苷酸的基因组，有20个开放阅读框架。BLASTp搜索结果显示，基因产物10（gp 10）和gp 14港推定的催化结构域与预测的肽酶和酰胺酶的活动，特征功能的噬菌体溶素。我们纯化了这些蛋白质，并表明Andhra_gp10和Andhra_gp14都抑制不同葡萄球菌的生长并降解细胞壁，Andhra_gp10对测试的细胞壁底物组表现出更强大的活性。其预测的催化残基的定点诱变废除了Andhra_gp10的活性，与其C末端上存在催化性的NH3结构域一致。活性位点位置加上SH 3b细胞壁结合结构域的缺失将Andhra_gp10与迄今为止表征的大多数葡萄球菌溶素区分开来。重要的是，密切同源的Andhra_gp10存在于相关的葡萄球菌噬菌体，我们建议，这些构成一类新的噬菌体编码的溶素。总而言之，我们的研究结果揭示了一个罕见的葡萄球菌家族的生物学，同时增加了具有治疗用途潜力的抗菌药物库。细菌病原体中抗生素耐药性的传播正在引发全球公共卫生危机。耐药葡萄球菌属，特别是金黄色葡萄球菌和表皮葡萄球菌，已经出现在医院和社区环境中，强调了迫切需要新的战略来对抗葡萄球菌感染。细菌病毒（Bacterial viruses，简称MRSA）和它们用来降解细菌细胞壁的酶（溶素）显示出作为替代抗菌剂的前景;然而，只有有限种类的葡萄球菌链球菌（Staphylococcal MRSA）和它们的溶素尚未被鉴定。在这里，我们报告了一种新的葡萄球菌噬菌体Andhra的发现和表征。我们发现Andhra编码两种溶素（Andhra_gp10和Andhra_gp14），其抑制不同葡萄球菌（包括金黄色葡萄球菌和表皮葡萄球菌菌株）的生长并降解细胞壁。Andhra及其独特的溶素添加到具有治疗用途潜力的抗菌剂库中。
The spread of antibiotic resistance among bacterial pathogens is inciting a global public health crisis. Drug-resistant Staphylococcus species, especially S. aureus and S. epidermidis, have emerged in both hospital and community settings, underscoring the urgent need for new strategies to combat staphylococcal infections. Bacterial viruses (phages) and the enzymes that they use to degrade bacterial cell walls (lysins) show promise as alternative antimicrobials; however, only a limited variety of staphylococcal phages and their lysins have yet been identified. Here, we report the discovery and characterization of a novel staphylococcal phage, Andhra. We show that Andhra encodes two lysins (Andhra_gp10 and Andhra_gp14) that inhibit growth and degrade the cell walls of diverse staphylococci, including S. aureus and S. epidermidis strains. Andhra and its unique lysins add to the arsenal of antimicrobials with potential for therapeutic use. Drug-resistant staphylococci, particularly Staphylococcus aureus and Staphylococcus epidermidis, are leading causes of hospital-acquired infections. Bacteriophages and their peptidoglycan hydrolytic enzymes (lysins) are currently being explored as alternatives to conventional antibiotics; however, only a limited diversity of staphylococcal phages and their lysins has yet been characterized. Here, we describe a novel staphylococcal phage and its lysins. Bacteriophage Andhra is the first reported S. epidermidis phage belonging to the family Podoviridae. Andhra possesses an 18,546-nucleotide genome with 20 open reading frames. BLASTp searches revealed that gene product 10 (gp10) and gp14 harbor putative catalytic domains with predicted peptidase and amidase activities, characteristic functions of phage lysins. We purified these proteins and show that both Andhra_gp10 and Andhra_gp14 inhibit growth and degrade cell walls of diverse staphylococci, with Andhra_gp10 exhibiting more robust activity against the panel of cell wall substrates tested. Site-directed mutagenesis of its predicted catalytic residues abrogated the activity of Andhra_gp10, consistent with the presence of a catalytic CHAP domain on its C terminus. The active site location combined with the absence of an SH3b cell wall binding domain distinguishes Andhra_gp10 from the majority of staphylococcal lysins characterized to date. Importantly, close homologs of Andhra_gp10 are present in related staphylococcal podophages, and we propose that these constitute a new class of phage-encoded lysins. Altogether, our results reveal insights into the biology of a rare family of staphylococcal phages while adding to the arsenal of antimicrobials with potential for therapeutic use. IMPORTANCE The spread of antibiotic resistance among bacterial pathogens is inciting a global public health crisis. Drug-resistant Staphylococcus species, especially S. aureus and S. epidermidis, have emerged in both hospital and community settings, underscoring the urgent need for new strategies to combat staphylococcal infections. Bacterial viruses (phages) and the enzymes that they use to degrade bacterial cell walls (lysins) show promise as alternative antimicrobials; however, only a limited variety of staphylococcal phages and their lysins have yet been identified. Here, we report the discovery and characterization of a novel staphylococcal phage, Andhra. We show that Andhra encodes two lysins (Andhra_gp10 and Andhra_gp14) that inhibit growth and degrade the cell walls of diverse staphylococci, including S. aureus and S. epidermidis strains. Andhra and its unique lysins add to the arsenal of antimicrobials with potential for therapeutic use.