The Genomes, Proteomes, and Structures of Three Novel Phages That Infect the Bacillus cereus Group and Carry Putative Virulence Factors
The Genomes, Proteomes, and Structures of Three Novel Phages That Infect the Bacillus cereus Group and Carry Putative Virulence Factors
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DOI：
10.1128/jvi.01364-14
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发表时间：
2014-10-01
影响因子：
5.4
通讯作者：
Breakwell, Donald P.
中科院分区：
文献类型：
--
作者：
Grose, Julianne H.;Belnap, David M.;Breakwell, Donald P.
本文报道了三种新的噬菌体JL、Shanette和Basilisk感染蜡样芽孢杆菌并携带可能参与其发病机制的基因的研究结果。我们分析了寄主范围和重叠侵染能力，绘制了它们的基因组图，并用质谱仪和透射电子显微镜表征了噬菌体的结构。JL和Shanette基因组有96%的相似性，分别包含217个开放阅读框(ORF)和220个ORF，而Basilisk有一个无关的基因组，包含138个ORF。质谱仪显示JL和Basilisk的噬菌体颗粒蛋白分别为23和15，而通过序列分析预测分别只有11和4个。结构蛋白的同源性表明，JL和Shanette是Myoviridae家族的成员，这一点在电子显微镜下得到证实。第三个噬菌体Basilisk只与未鉴定的噬菌体相似，是一种无关的虹吸病毒。这种新型噬菌体的低温电子显微镜显示T=9的二十面体衣壳结构，尽管缺乏序列相似性，但主要衣壳蛋白(MCP)很可能与噬菌体HK97 MCP具有相同的折叠。这些噬菌体基因组编码了几个可能的毒力因子，包括与碲抗性有关的TERC和TerD。对所有三个噬菌体的寄主范围分析支持蜡样芽胞杆菌组内这些因子的遗传转移，包括蜡样芽胞杆菌、炭疽杆菌和苏云金芽胞杆菌。本研究为了解这三种噬菌体和其他相关噬菌体以及它们在蜡样芽孢杆菌群细菌致病性中的作用提供了基础。蜡样芽孢杆菌类细菌包括几种人类和植物病原体，包括蜡样芽孢杆菌、炭疽杆菌和苏云金杆菌。噬菌体与其细菌宿主的进化密切相关，并经常提供毒力因子，这使得对蜡样芽胞杆菌噬菌体的研究对了解致病菌株的进化具有重要意义。在这里，我们提供了三个新的蜡状芽胞杆菌噬菌体，两个高度相关的肌病毒(JL和Shanette)和一个不相关的剑状病毒(Basilisk)的详细研究结果。寄主范围和重复感染的详细特征，以及基因组、蛋白质组和结构分析的结果，揭示了几个可能的毒力因素以及这些噬菌体感染不同病原物种的能力。
This article reports the results of studying three novel bacteriophages, JL, Shanette, and Basilisk, which infect the pathogen Bacillus cereus and carry genes that may contribute to its pathogenesis. We analyzed host range and superinfection ability, mapped their genomes, and characterized phage structure by mass spectrometry and transmission electron microscopy (TEM). The JL and Shanette genomes were 96% similar and contained 217 open reading frames (ORFs) and 220 ORFs, respectively, while Basilisk has an unrelated genome containing 138 ORFs. Mass spectrometry revealed 23 phage particle proteins for JL and 15 for Basilisk, while only 11 and 4, respectively, were predicted to be present by sequence analysis. Structural protein homology to well-characterized phages suggested that JL and Shanette were members of the family Myoviridae, which was confirmed by TEM. The third phage, Basilisk, was similar only to uncharacterized phages and is an unrelated siphovirus. Cryogenic electron microscopy of this novel phage revealed a T = 9 icosahedral capsid structure with the major capsid protein (MCP) likely having the same fold as bacteriophage HK97 MCP despite the lack of sequence similarity. Several putative virulence factors were encoded by these phage genomes, including TerC and TerD involved in tellurium resistance. Host range analysis of all three phages supports genetic transfer of such factors within the B. cereus group, including B. cereus, B. anthracis, and B. thuringiensis. This study provides a basis for understanding these three phages and other related phages as well as their contributions to the pathogenicity of B. cereus group bacteria.IMPORTANCEThe Bacillus cereus group of bacteria contains several human and plant pathogens, including B. cereus, B. anthracis, and B. thuringiensis. Phages are intimately linked to the evolution of their bacterial hosts and often provide virulence factors, making the study of B. cereus phages important to understanding the evolution of pathogenic strains. Herein we provide the results of detailed study of three novel B. cereus phages, two highly related myoviruses (JL and Shanette) and an unrelated siphovirus (Basilisk). The detailed characterization of host range and superinfection, together with results of genomic, proteomic, and structural analyses, reveal several putative virulence factors as well as the ability of these phages to infect different pathogenic species.