Isolation and characterization of a novel phage belonging to a new genus against Vibrio parahaemolyticus

Abstract

Background Vibrio parahaemolyticus is a major foodborne pathogen that contaminates aquatic products and causes great economic losses to aquaculture. Because of the emergence of multidrug-resistant V. parahaemolyticus strains, bacteriophages are considered promising agents for their biocontrol as an alternative or supplement to antibiotics. In this study, a lytic vibriophage, vB_VpaM_R16F (R16F), infecting V. parahaemolyticus 1.1997T was isolated, characterized and evaluated for its biocontrol potential. Methods A vibriophage R16F was isolated from sewage from a seafood market with the double-layer agar method. R16F was studied by transmission electron microscopy, host range, sensitivity of phage particles to chloroform, one-step growth curve and lytic activity. The phage genome was sequenced and in-depth characterized, including phylogenetic and taxonomic analysis. Results R16F belongs to the myovirus morphotype and infects V. parahaemolyticus, but not nine other Vibrio spp. As characterized by determining its host range, one-step growth curve, and lytic activity, phage R16F was found to highly effective in lysing host cells with a short latent period (< 10 min) and a small burst size (13 plaque-forming units). R16F has a linear double-stranded DNA with genome size 139,011 bp and a G + C content of 35.21%. Phylogenetic and intergenomic nucleotide sequence similarity analysis revealed that R16F is distinct from currently known vibriophages and belongs to a novel genus. Several genes (e.g., encoding ultraviolet damage endonuclease and endolysin) that may enhance environmental competitiveness were found in the genome of R16F, while no antibiotic resistance- or virulence factor-related gene was detected. Conclusions In consideration of its biological and genetic properties, this newly discovered phage R16F belongs to a novel genus and may be a potential alternate biocontrol agent.

Isolation and characterization of three novel lytic phages against K54 serotype carbapenem-resistant hypervirulent Klebsiella pneumoniae

“…To determine whether there are lipids in the viral capsid, the sensitivities of the phages to chloroform were examined. The method of chloroform susceptibility test was performed as previously described by Yubing Chen et al with slight changes (Chen et al, 2023). In brief, 1 mL phage suspension was mixed with 100 µL chloroform, the mixture was vigorously shaken for 1 min and then incubated at room temperature for 30 min.…”

Characterization of a Vibriophage Infecting Pathogenic Vibrio harveyi

“…A one-step growth experiment was performed to determine the phage's life cycle [71]. Briefly, 1 mL of early-phase host culture was infected with the phage at an MOI of 0.01 and allowed to adsorb for 15 min at room temperature in the dark.…”