Biological Characteristics And Genomic Analysis of A Novel Bacteriophage BUCT609 Infecting Stenotrophomonas Maltophilia

Abstract

Stenotrophomonas maltophilia is widely distributed in nature and has a high isolation rate in nosocomial infections. Due to its potential application and important role in clinical practice, the relevant studies of S.maltophilia have received much attention. S.maltophilia phage BUCT609 (GenBank: MW960043) was isolated from hospital sewage with S.maltophilia strain No. 3015 as a host. Morphologically, it can be inferred as Podoviridae phage from the result of transmission electron microscopy (TEM). The electron microscopy also shows that the phage has an isometric capsid ~50 nm in diameter. The one-step growth curve demonstrated that the incubation period of 10 min and the burst size is 382 pfu/cell when its optimal multiplicity of infection (MOI) is 0.01. Phage BUCT609 had a high survival rate at pH 3 to 10 and tolerant temperature from 4 ℃ to 55 ℃. Next-Generation Sequencing (NGS) results demonstrated that its complete genome is linear double-stranded DNA of 43145 bp in length, and the GC content is 58 %. It has very little resemblance to other phages. The BlastN analysis shows that the genome of phage BUCT609 shares 22 % homology with S.maltophilia phage Ponderosa (GenBank: MK903280.1), and it encodes 56 putative proteins, of which only 25 have annotated function. Phage BUCT609 with a relatively large burst size and excellent survival ability in a wide pH and temperature range, suggests BUCT609 is a potential alternative for multi-drug resistance S.maltophilia therapy.