Tian Changyu, Zhao Jiangtao, Zhang Zheng, Chen Xiao, Wei Xiao, Li Huan, Lin Weishi, Ke Yuehua, Hu Lingfei, Jiang Aimin, Feng Ruo, Yang Wenhui, Jing Ying, Yuan Jing, Luo Yanping, Zhao Xiangna
Institute of Disease Control and Prevention, China PLA, Beijing, 100071, China.
Department of Histology and Embryology, School of Basic Medical Sciences, Zhengzhou University, Zhengzhou, China.
Arch Virol. 2019 Apr;164(4):1085-1094. doi: 10.1007/s00705-019-04169-1. Epub 2019 Feb 20.
Serratia marcescens is a rod-shaped, Gram-negative bacterium causing nosocomially acquired infections. Bacteriophages are natural opponents of their pathogenic bacterial hosts and could be an alternative to traditional antibiotic treatments. In this study, two S. marcescens-specific bacteriophages, vB_SmaA_2050H1 and vB_SmaM_2050HW, were isolated from two different waste samples in China. Phage plaque assays, transmission electron microscopy, host-range determination, and one-step growth curve analyses were performed for both phages. vB_SmaA_2050H1 was classified as belonging to the family Ackermannviridae, and vB_SmaM_2050HW was classified as belonging to the family Myoviridae. One-step growth curve analysis showed that the latent and rise period of vB_SmaA_2050H1 were 80 min and 50 min, respectively, with a burst size of approximately 10 phage particles per infected cell. For vB_SmaM_2050HW, latent and rise periods of 40 min and 60 min, respectively, were determined, with a burst size of approximately 110 phage particles per infected cell. vB_SmaA_2050H1 infected 10 of the 15 (66.67%) S. marcescens strains tested, while vB_SmaM_2050HW infected 12 (80%) of the strains. Whole-genome sequencing and annotation of each of the phage genomes revealed genome sizes of 159,631 bp and 276,025 bp for vB_SmaA_2050H1 and vB_SmaM_2050HW, respectively, with the respective genomes containing 213 and 363 putative open reading frames. Sequence analysis of the genomes revealed that vB_SmaA_2050H1 is a member of the ViI-like family, while vB_SmaM_2050HW is a novel virulent bacteriophage. These findings provide further insights into the genomic structures of S. marcescens bacteriophages.
粘质沙雷氏菌是一种杆状革兰氏阴性菌，可引起医院获得性感染。噬菌体是其致病细菌宿主的天然对手，可能成为传统抗生素治疗的替代方法。在本研究中，从中国的两个不同废物样本中分离出两种粘质沙雷氏菌特异性噬菌体，即vB_SmaA_2050H1和vB_SmaM_2050HW。对这两种噬菌体都进行了噬菌斑测定、透射电子显微镜观察、宿主范围测定和一步生长曲线分析。vB_SmaA_2050H1被归类为属于阿克曼病毒科，vB_SmaM_2050HW被归类为属于肌病毒科。一步生长曲线分析表明，vB_SmaA_2050H1的潜伏期和上升期分别为80分钟和50分钟，每个感染细胞的爆发量约为10个噬菌体颗粒。对于vB_SmaM_2050HW，确定潜伏期和上升期分别为40分钟和60分钟，每个感染细胞的爆发量约为110个噬菌体颗粒。vB_SmaA_2050H1感染了所测试的15株粘质沙雷氏菌中的10株（66.67%），而vB_SmaM_2050HW感染了其中的12株（80%）。对每个噬菌体基因组进行全基因组测序和注释，结果显示vB_SmaA_2050H1和vB_SmaM_2050HW的基因组大小分别为159,631 bp和276,025 bp，各自的基因组分别包含213个和363个推定的开放阅读框。基因组序列分析表明，vB_SmaA_2050H1是类ViI家族的成员，而vB_SmaM_2050HW是一种新型烈性噬菌体。这些发现为粘质沙雷氏菌噬菌体的基因组结构提供了进一步的见解。
