Biological characteristics and whole genome analysis of Pseudomonas aeruginosa phage vB_PaS_IME307

Abstract

Objective To determine the biological properties and whole genome characteristics of a phage against P. aeruginosa isolated from sewage samples as the host strain Pa175. Methods Double-layer agar plate and plaque method were used for phage isolation and identification. The obtained phage was purified through PEG 8000 concentration and NaCl precipitation. The phage was further purified with sucrose gradient centrifugation, stained by phosphotungstic acid negative staining. Transmission electron microscopy was employed to observe its morphology. After its DNA was extracted by using proteinase K/SDS, whole genome sequencing was performed and the results were analyzed by bioinformatics. Results A lytic P. aeruginosa phage was obtained and then named as vB_PaS_IME307, which can form transparent plaque with halo, with a whole genome size of 51 545 bp. Transmission electron microscopy showed that the head of vB_ PaS_ IME307 was icosahedral shape, with a diameter of 66±2 nm and a tail length of 116±2 nm. Phylogenetic tree analysis revealed that IME307 was belonged to Mccleskeyvirinae virus genus, Siphoviridae family. The phage was maintained of high activity at pH value from 4.0 to 11.0 and temperature below 60 ℃. The infection cycle was about 60 min, including 10 min incubation period and 50 min outbreak period. The outbreak was 150 PFU/cell. Conclusion vB_ PaS_ IME307 is of host specificity, good tolerance to temperature and pH valule, and has the potential to prevent and treat P. aeruginosa infection.

Keywords

• pseudomonas aeruginosa
• phage
• biological characteristics
• genomic analysis