Characterization of a Lytic Bacteriophage against Pseudomonas syringae pv. actinidiae and Its Endolysin

Abstract

Pseudomonas syringae pv. actinidiae (Psa) is a phytopathogen that causes canker in kiwifruit. Few conventional control methods are effective against this bacterium. Therefore, alternative approaches, such as phage therapy are warranted. In this study, a lytic bacteriophage (PN09) of Psa was isolated from surface water collected from a river in Hangzhou, China in 2019. Morphologically, PN09 was classified into the Myoviridae family, and could lyse all 29 Psa biovar 3 strains. The optimal temperature and pH ranges for PN09 activity were determined as 25 to 35 °C and 6.0 to 9.0, respectively. The complete genome of PN09 was found to be composed of a linear 99,229 bp double-stranded DNA genome with a GC content of 48.16%. The PN09 endolysin (LysPN09) was expressed in vitro and characterized. LysPN09 was predicted to belong to the Muraidase superfamily domain and showed lytic activity against the outer-membrane-permeabilized Psa strains. The lytic activity of LysPN09 was optimal over temperature and pH ranges of 25 to 40 °C and 6.0 to 8.0, respectively. When recombinant endolysin LysPN09 was combined with EDTA, Psa strains were effectively damaged. All these characteristics demonstrate that the phage PN09 and its endolysin, LysPN09, are potential candidates for biocontrol of Psa in the kiwifruit industry.

A Single Catalytic Endolysin Domain Plychap001: Characterization and Application to Control Vibrio parahaemolyticus and Its Biofilm Directly

“…Next, the stability of recombinant Plychap001 was evaluated by various tests. When simultaneously treated with EDTA, the tested cells were more sensitive to Plychap001 ( Figure 4 A), indicating that EDTA could enhance the efficiency of Plychap001, which is consistent with Lysqdvp001 [ 21 ] and some other Gram-negative endolysins [ 33 , 34 ]. Moreover, the lytic effect of Plychap001 was not inhibited when reaction solutions contained different concentrations of NaCl (even up to 500 mM) ( Figure 4 B), which is even more applicative due to the marine halophilic characteristics of V. parahaemolyticus [ 35 ].…”

Endolysin, a Promising Solution against Antimicrobial Resistance

“…Similarly, the lytic activity of the endolysin LysPN09 from P. syringae pv. actinidiae phage PN09 was improved at the presence of 1 mM EDTA [ 48 ]. Secondly, the edible ε-poly-L-lysine (EPL) can be used as an outer-membrane permeabilizer for some endolysins targeting food-borne pathogens.…”

“…actinidiae phage PN09 showed lytic activity against Psa strains. When LysPN09 was coupled with EDTA, Psa strains were effectively damaged, indicating that LysPN09 is a potential candidate for biocontrol of Psa in the kiwifruit industry [ 48 ]. The production of transgenic crops that express endolysins to provide defense against pathogenic bacteria is one proposed strategy.…”

Genomic Analysis of Lytic Phage V09 that Targets Pathogenic Vibrio Parahaemolyticus

“…Staphylococcus aureus strain ATCC 29213, Pseudomonas aeruginosa strain CMCC 10104, Escherichia coli strain BL21 (DE3), Escherichia coli strain DH5α, Pseudomonas syringae pv. actinidiae strain SCJY02-1 [11], and Salmonella derby strain 58 [12] were used to determine the host range of phage V09. The V. parahaemolyticus, Staphylococcus aureus, Pseudomonas aeruginosa, and Escherichia coli strains were cultured in Luria Bertani (LB) liquid medium (Oxoid Ltd., London, England) at 37°C at 150 revolutions per minute (rpm) in a shaking incubator, whereas Pseudomonas syringae pv.…”