Isolation and Characterization of Two Lytic Phages Efficient Against Phytopathogenic Bacteria From Pseudomonas and Xanthomonas Genera

Abstract

Pseudomonas syringae is a bacterial pathogen that causes yield losses in various economically important plant species. At the same time, P. syringae pv. tomato (Pst) is one of the best-studied bacterial phytopathogens and a popular model organism. In this study, we report on the isolation of two phages from the market-bought pepper fruit showing symptoms of bacterial speck. These Pseudomonas phages were named Eir4 and Eisa9 and characterized using traditional microbiological methods and whole-genome sequencing followed by various bioinformatics approaches. Both of the isolated phages were capable only of the lytic life cycle and were efficient against several pathovars from Pseudomonas and Xanthomonas genera. With the combination of transmission electron microscopy (TEM) virion morphology inspection and comparative genomics analyses, both of the phages were classified as members of the Autographiviridae family with different degrees of novelty within the known phage diversity. Eir4, but not Eisa9, phage application significantly decreased the propagation of Pst in the leaf tissues of Arabidopsis thaliana plants. The biological properties of Eir4 phage allow us to propose it as a potential biocontrol agent for use in the prevention of Pst-associated bacterioses and also as a model organism for the future research of mechanisms of phage–host interactions in different plant systems.

Isolation and Characterization of a Novel Aeromonas salmonicida-Infecting Studiervirinae Bacteriophage, JELG-KS1

“…Aeromonas phage JELG-KS1 has demonstrated a conserved modular genome organization typically seen in other subfamily Studiervirinae podophages (e.g., Chatterjeevirus ICP3 [ 85 ], Ningirsuvirus ninurta [ 86 ], Pektosvirus PP81 [ 87 , 88 ], Teseptimavirus T7 [ 89 ], Ghunavirus gh1 [ 90 ]) and tentative Studiervirinae phages such as Pseudomonas phage Eir4 [ 91 ], Hafnia phage Ca [ 92 ], etc. An open reading frame encoding a DNA-directed RNA polymerase, a hallmark of Autographiviridae podophages, was readily identifiable among the first few ORFs at the beginning of the genome, which likely represent early genes.…”

Characterization and Comparative Genomic Analysis of Three Virulent E. coli Bacteriophages with the Potential to Reduce Antibiotic-Resistant Bacteria in the Environment

“…These findings suggest the use of higher phage concentrations to compensate for the reduction of host growth. Another explanation could be the development of slow-growing phage-resistant mutants during infection [ 38 ]. Interestingly, the partial regrowth of BF17-treated bacteria occurred at much higher MOIs (>1) ( Figure 5 c).…”

Isolation, characterization, and genomic analysis of a novel bacteriophage MA9V-1 infecting Chryseobacterium indologenes: a pathogen of Panax notoginseng root rot

“…Due to this unique feature to phage, phage therapy would not directly affect the density, richness, and viability of other microorganisms living in microecology ( Wang et al, 2019 ; Federici et al, 2021 ). The growth inhibitory curve indicated that the inhibitory ability of MA9V-1 was little weaker than other phages, such as phage P. syringae Eisa9 ( Korniienko et al, 2022 ) and P. aeruginosa phage PPAY ( Niu et al, 2022 ). We hypothesized a reasonable explanation that phage MA9V-1 required a long time to complete adsorption, invasion, proliferation, maturation, and lysis, since it has a lower burst size value (only 10 PFU/cell), which made it not easy to inhibit the bacterial growth.…”