Complete Genome Sequence of Salmonella Bacteriophage SS3e

The outbreak of multidrug-resistant pathogenic bacteria made the discovery of novel control strategies necessary. Phages have regained attention for their specific lytic activity against pathogenic bacterium. A newly isolated phage infecting the clinical Escherichia coli isolates, including several multidrug-resistant strains, was isolated, and this phage showed high control effects against the tested pathogenic E. coli strains. Host range analysis revealed that although the phage exhibited broad lytic spectrum against the tested E. coli strains, it could not lyse strains from the other species. Comparative genomic analysis showed that phages had undergone at least three genome recombination events during the evolutionary process at the position of the three phage tail genes, which was reported to be associated with the host range determination of the phage. The recombinant tail proteins contained functional domains that were highly similar with genes of the Salmonella phage and genes of Pseudomonas and Neisseria. The findings of this study not only provide resources for developing phage therapy against E. coli, but also showed the highly variable genome structure of the phage.

Section: Resultsmentioning

confidence: 99%

Characterization of a newly isolated phage infecting pathogenic Escherichia coli and analysis of its mosaic structural genes

Qin

Yuan

2018

“…Following the structural components, there is a region encoding small and uncharacterized proteins, which spans about 24 kb. No genes similar to the genes for lysin or holin have yet been detected in the phiAxp-2 genome, which are responsible for host cell disruption during the burst steps of phages 15 , although the clearing of the bacterial culture at a specific time point strongly suggest that they exist.…”

Section: Resultsmentioning

confidence: 99%

“…In this study, we have characterized a Siphoviridae phage that infects the important nosocomial pathogen A. xylosoxidans . Genomic data are an important resource with which to study and engineer phages to control specific bacterial species 15 , and advances in phage genomic characterization have made phage therapy more feasible in terms of both its logistics and safety 10 . A combination of genomic sequencing and a morphological analysis showed that phiAxp-2 is a member of the family Siphoviridae , and is related to the previously sequenced phage AH2.…”

Section: Resultsmentioning

confidence: 99%

Identification and molecular characterization of bacteriophage phiAxp-2 of Achromobacter xylosoxidans

Yin

et al. 2016

A novel Achromobacter xylosoxidans bacteriophage, phiAxp-2, was isolated from hospital sewage in China. The phage was morphologically and microbiologically characterized, and its one-step growth curve, host range, genomic sequence, and receptor were determined. Its morphology showed that phiAxp-2 belongs to the family Siphoviridae. Microbiological characterization demonstrated that pH 7 is most suitable for phage phiAxp-2; its titer decreased when the temperature exceeded 50 °C; phiAxp-2 is sensitive to ethanol and isopropanol; and the presence of calcium and magnesium ions is necessary to accelerate cell lysis and improve the formation of phiAxp-2 plaques. Genomic sequencing and a bioinformatic analysis showed that phage phiAxp-2 is a novel bacteriophage, consisting of a circular, double-stranded 62,220-bp DNA molecule with a GC content of 60.11% that encodes 86 putative open reading frames (ORFs). The lipopolysaccharide of A. xylosoxidans is involved in the adsorption of phiAxp-2.

“…This article presents the sequence analysis and a detailed genome annotation of phage phiAxp-1. The genomic data constitute an important resource to study and engineer phages to control specific bacterial species 22 . The analysis showed that phiAxp-1 does not easily fit into previously established groups of dsDNA bacterial viruses and may represent a distinct branch of the Siphoviridae family.…”

Section: Discussionmentioning

confidence: 99%

Characterization of a novel Achromobacter xylosoxidans specific siphoviruse: phiAxp-1

Zhao

et al. 2016

Bacteriophages have recently been considered as an alternative biocontrol tool because of the widespread occurrence of antimicrobial-resistant Achromobacter xylosoxidans. Herein, we isolated a virulent bacteriophage (phiAxp-1) from a water sample of the Bohai sea of China that specifically infects A. xylosoxidans. Transmission electron microscopy revealed that phage phiAxp-1 belongs to the Siphoviridae. We sequenced the genome of phiAxp-1, which comprises 45,045 bp with 64 open reading frames. Most of the proteins encoded by phiAxp-1 have no similarity to sequences in the public databases. Twenty-one proteins with assigned functions share weak homology with those of other dsDNA bacteriophages infecting diverse hosts, such as Burkholderia phage KL1, Pseudomonas phage 73, Pseudomonas phage vB_Pae-Kakheti25, Pseudomonas phage vB_PaeS_SCH_Ab26, Acinetobacter phage IME_AB3 and Achromobacter phage JWX. The genome can be divided into different clusters for the head and tail structure, DNA replication and mazG. The sequence and genomic organization of bacteriophage phiAxp-1 are clearly distinct from other known Siphoviridae phages; therefore, we propose that it is a member of a novel genus of the Siphoviridae family. Furthermore, one-step growth curve and stability studies of the phage were performed, and the specific receptor of phiAxp-1 was identified as the lipopolysaccharide of A. xylosoxidans.