Isolation and characterization of vibriophage vB_Vc_SrVc9: an effective agent in preventingVibrio campbelliiinfections in brine shrimp nauplii (Artemia franciscana)

Abstract

Aims This study describes the physicochemical and genomic characterization of phage vB_Vc_SrVc9 and its potential for phage therapy application against a pathogenic Vibrio campbellii strain. Methods and Results A lytic phage vB_Vc_SrVc9 against V. campbellii was isolated from shrimp farm sediment, and characterized physicochemical and genomically. The use of vB_Vc_SrVc9 phage increased the survival in brine shrimp Artemia franciscana and reduced presumptive V. campbellii to nondetectable numbers. Genomic analysis showed a genome with a single contig of 43·15 kb, with 49 predicted genes and no tRNAs, capable of recognizing and generating complete inhibition zones of three Vibrio sp. Conclusions To our knowledge vB_Vc_SrVc9 is a lytic phage that could be used against Vibrio infections, reducing vibrio presence without any apparent impact over the natural microbiota at the family level in 28 libraries tested. Significance and Impact of the Study vB_Vc_SrVC9 is a novel phage and ecofriendly alternative for therapeutic applications and biotechnological purposes because is stable at different environmental conditions, has the potential to eliminate several strains, and has a short latent period with a good burst size. Therefore, the use of phages, which are natural killers of bacteria, represents a promising strategy to reduce the mortality of farmed organisms caused by pathogenic bacteria.

Characterization of the Novel Phage vB_VpaP_FE11 and Its Potential Role in Controlling Vibrio parahaemolyticus Biofilms

“…In terms of biological characteristics, FE11 was stable at a relatively broad temperature range between 20 and 50 • C, while phage vB_Vc_SrVc9 was only stable at 20−40 • C, which both phages were located in the same evolutionary branch [51]. For the UV test, FE11 was completely inactivated by UV irradiation for 20 min, but vB_Vc_SrVc9 was more sensitive and basically inactivated after 1 min.…”

Characterization and complete genome sequence of bacteriophage vB_Vc_SrVc2, a marine phage that infects Vibrio campbellii

“…Using hepatopancreas of shrimps with AHPDN signs, the isolation of phage vB_Vc_SrVc2 was performed as previously described in [14] using the standardized procedure described by [15] with slight modi cations. Using a positive lytic zone, the sample was diluted using serial dilutions to obtain individual phage plaques according to [15].…”

“…Vibrio campbellii strain (CIBGEN-002) was used for phage isolation [14], and other Vibrio strains V. parahaemolyticus (CIBGEN-001), V. campbellii (CIBGEN-003), and V. alginolyticus (CIBGEN-004) were used for host range assay, e ciency of plating, and killing curves only. All strains are available at Genomic Laboratory's collection of CIBNOR.…”

“…Killing curve assay was performed to evaluate the growth inhibition due to vB_Vc_SrVc2 phage presence over every bacterial strain (Table 1), using the method previously described by [14] but using a multiplicity of infection of 0.01 (MOI = 0.01) for this time.…”

“…Phage stability was tested in different values of temperature, salinity, UV radiation, and chloroform exposition. Exposition time and values of every variable was performed using the method of [14]. In all cases, serial dilutions were prepare to determinate nal phage concentrations with double-agar plate assay [15].…”