Genomic and biological characterization of the Vibrio alginolyticus-infecting “Podoviridae” bacteriophage, vB_ValP_IME271
As an opportunist pathogen, Vibrio alginolyticus (V. alginolyticus), causes disease in marine animals. Bacterial contamination of seafood is not uncommon, and phage therapy is considered a safe way to decontaminate such foods to control the emergence of vibriosis. Here, we report on the isolation of a new, virulent phage called vB_ValP_IME271 (designated phage IME271), which infects V. alginolyticus and was isolated from seawater. Phage IME271 displayed good pH (7–9) and temperature tolerance (< 40 °C) and had a broad host range against Vibrio isolates, including 7 strains of V. alginolyticus and11 strains of V. parahaemolyticus. The IME271 genome was sequenced and annotated, the results of which showed that this phage is a Podoviridae family member with a genome length of 50,345 base pairs. The complete genome is double-stranded DNA with a G+C content of 41.4%. Encoded within the genome are 67 putative proteins, of which only 22 coding sequences have known functions, and no tRNAs are present. The BLASTn results for IME271 showed that it only shares similarity with the Vibrio phage VPp1 (sequence identity score of 96% over 87% of the genome) whose host is V. parahaemolyticus. Comparative analysis showed that IME271 and VPp1 share a similar genomic structure, and the structural proteins are highly similar (> 95% similarity score). In summary, our work identified a new lytic Podoviridae bacteriophage, which is infective to V. alginolyticus and V. parahaemolyticus. This bacteriophage could potentially be used to control V. alginolyticus and V. parahaemolyticus infections in marine animals.
KeywordsVibrio alginolyticus Bacteriophage Biological characteristics Genome
We thank Sandra Cheesman, PhD, from Liwen Bianji, Edanz Group China (http://www.liwenbianji.cn/ac), for editing the English text of a draft of this manuscript. All authors read and approved the final manuscript.
LZ and YT conceived and designed the experiments and critically evaluated the manuscript. FL and TM isolated and identified the phage and conducted the biological characterization experiments. ZX was responsible for the data and sequence analyses and wrote the manuscript. KF, SZ, and JL collected the clinical bacteria and carried out the experiments.
This research was supported by a grant from The National Key Research and Development Program of China (2015AA020108), the National Natural Science Foundation of China (31400107 and 81621005), and the State Key Laboratory of Pathogen and biosecurity (SKLPBS1518 and 14J004).
Compliance with ethical standards
Conflict of interest
The authors declare that they have no conflict of interest.
This research does not contain any studies with human participants or animals that were performed by any of the authors.