Bacteriophage Cocktail for the Prevention of Multiple-Antibiotic-Resistant and Mono-Phage-Resistant Vibrio coralliilyticus Infection in Pacific Oyster (Crassostrea gigas) Larvae

Optimizing bacteriophage treatment of resistant Pseudomonas

Phage therapy is increasing in relevance as an alternative treatment to combat antibiotic resistant bacteria. Phage cocktails are the state-of-the-art method of administering phages in clinical settings, preferred over monophage treatment because of their ability to eliminate multiple bacterial strains and reduce resistance formation. In our study, we compare monophage applications and phage cocktails to our chosen method of phage sequential treatments. To do so, we isolated four novel bacteriophages capable of infecting Pseudomonas alcaligenes T3, a close relative of P. aeruginosa, and characterized them using sequencing and transmission electron microscopy. While investigating monophage treatments, we observed that different phage concentrations had a strong impact on the timing and amount of resistance formation. When using phage cocktails, we observed that P. alcaligenes were capable of forming resistance in the same timespan it took them to become resistant to single phages. We isolated mutants resistant to each single phage as well as mutants exposed to phage cocktails, resulting in bacteria resistant to all four phages at once. Sequencing these mutants showed that different treatments yielded unique single nucleotide polymorphism mutation patterns. In order to combat resistance formation, we added phages one by one in intervals of 24 h, thus managing to delay resistance development and keeping bacterial growth significantly lower compared to phage cocktails.IMPORTANCEWHO declared antimicrobial resistance a top threat to global health; while antibiotics have stood at the forefront in the fight against bacterial infection, the increasing number of multidrug-resistant bacteria highlights a need to branch out in order to address the threat of antimicrobial resistance. Bacteriophages, viruses solely infecting bacteria, could present a solution due to their abundance, versatility, and adaptability. For this study, we isolated new phages infecting a fast-mutating Pseudomonas alcaligenes strain capable of forming resistance within 30 h. By using a sequential treatment approach of adding one phage after another, we were able to curb bacterial growth significantly more compared to state-of-the-art phage cocktails.

Controlling of foodborne pathogen biofilms on stainless steel by bacteriophages: A systematic review and meta-analysis

This study investigates the potential of using bacteriophages to control foodborne pathogen biofilms on stainless steel surfaces in the food industry. Biofilm-forming bacteria can attach to stainless steel surfaces, rendering them difficult to eradicate even after a thorough cleaning and sanitizing procedures. Bacteriophages have been proposed as a possible solution, as they can penetrate biofilms and destroy bacterial cells within, reducing the number of viable bacteria and preventing the growth and spread of biofilms. This systematic review and meta-analysis evaluates the potential of bacteriophages against different biofilm-forming foodborne bacteria, including Cronobacter sakazakii, Escherichia coli, Staphylococcus aureus, Pseudomonas fluorescens, Pseudomonas aeruginosa and Listeria monocytogenes. Bacteriophage treatment generally causes a significant average reduction of 38 % in biofilm formation of foodborne pathogens on stainless steel. Subgroup analyses revealed that phages are more efficient in long-duration treatment. Also, applying a cocktail of phages is 1.26-fold more effective than applying individual phages. Phages at concentrations exceeding 107 PFU/ml are significantly more efficacious in eradicating bacteria within a biofilm. The antibacterial phage activity decreases substantially by 3.54-fold when applied at 4 °C compared to temperatures above 25 °C. This analysis suggests that bacteriophages can be a promising solution for controlling biofilms in the food industry.

Bacteriophages to control Vibrio alginolyticus in live feeds prior to their administration in larviculture

AIMS

This study aimed to evaluate the efficiency of two phages [VB_VaC_TDDLMA (phage TDD) and VB_VaC_SRILMA (phage SRI)] alone and in a cocktail to control Vibrio alginolyticus in brine shrimp before their administration in larviculture.

METHODS AND RESULTS

Phages were isolated from seawater samples and characterized by host spectrum, growth parameters, adsorption rate, genomic analysis, and inactivation efficiency. Both phages belong to the Caudoviricetes class and lack known virulence or antibiotic-resistance genes. They exhibit specificity, infecting only their host, V. alginolyticus CECT 521. Preliminary experiments in a culture medium showed that phage TDD (reduction of 5.8 log CFU ml-1 after 10 h) outperformed phage SRI (reduction of 4.6 log CFU ml-1 after 6 h) and the cocktail TDD/SRI (reduction of 5.2 log CFU ml-1 after 8 h). In artificial marine water experiments with Artemia franciscana, both single phage suspensions and the phage cocktail, effectively inactivated V. alginolyticus in culture water (reduction of 4.3, 2.1, and 1.9 log CFU ml-1 for phages TDD, SRI, and the phage cocktail, respectively, after 12 h) and in A. franciscana (reduction of 51.6%, 87.3%, and 85.3% for phages TDD, SRI, and the phage cocktail, respectively, after 24 h). The two phages and the phage cocktail did not affect A. franciscana natural microbiota or other Vibrio species in the brine shrimp.

CONCLUSIONS

The results suggest that phages can safely and effectively control V. alginolyticus in A. franciscana prior to its administration in larviculture.

Coral mucus as a reservoir of bacteriophages targeting Vibrio pathogens

The increasing trend in sea surface temperature promotes the spread of Vibrio species, which are known to cause diseases in a wide range of marine organisms. Among these pathogens, Vibrio mediterranei has emerged as a significant threat, leading to bleaching in the coral species Oculina patagonica. Bacteriophages, or phages, are viruses that infect bacteria, thereby regulating microbial communities and playing a crucial role in the coral's defense against pathogens. However, our understanding of phages that infect V. mediterranei is limited. In this study, we identified two phage species capable of infecting V. mediterranei by utilizing a combination of cultivation and metagenomic approaches. These phages are low-abundance specialists within the coral mucus layer that exhibit rapid proliferation in the presence of their hosts, suggesting a potential role in coral defense. Additionally, one of these phages possesses a conserved domain of a leucine-rich repeat protein, similar to those harbored in the coral genome, that plays a key role in pathogen recognition, hinting at potential coral-phage coevolution. Furthermore, our research suggests that lytic Vibrio infections could trigger prophage induction, which may disseminate genetic elements, including virulence factors, in the coral mucus layer. Overall, our findings underscore the importance of historical coral-phage interactions as a form of coral immunity against invasive Vibrio pathogens.

Isolation, characterization, and genome analysis of a broad host range Salmonella phage vB_SenS_TUMS_E4: a candidate bacteriophage for biocontrol

Salmonella enteritidis is one of the most important foodborne pathogens that cause numerous outbreaks worldwide. Some strains of Salmonella have become progressively resistant to antibiotics, so they could represent a critical threat to public health and have led to the use of alternative therapeutic approaches like phage therapy. In this study, a lytic phage, vB_SenS_TUMS_E4 (E4), was isolated from poultry effluent and characterized to evaluate its potential and efficacy for bio-controlling S. enteritidis in foods. Transmission electron microscopy revealed that E4 has a siphovirus morphotype, with an isometric head and non-contractile tail. Determining the host range showed that this phage can effectively infect different motile as well as non-motile Salmonella enterica serovars. The biological characteristics of E4 showed that it has a short latent period of about 15 min and a large burst size of 287 PFU/cell, and is also significantly stable in a broad range of pHs and temperatures. The E4 whole genome contains 43,018 bp and encodes 60 coding sequences (CDSs) but no tRNA genes. Bioinformatics analysis revealed that the genome of E4 lacks any genes related to lysogeny behavior, antibiotic resistance, toxins, or virulence factors. The efficacy of phage E4 as a bio-control agent was assessed in various foodstuffs inoculated with S. enteritidis at 4°C and 25°C, and the resulting data indicated that it could eradicate S. enteritidis after a very short time of 15 min. The findings of the present study showed that E4 is a hopeful candidate as a bio-control agent against S. enteritidis and has the potential to be used in various foodstuffs.

Interactions of Vibrio phages and their hosts in aquatic environments

Bacteriophages (phages) are viruses that specifically infect bacteria. These viruses were discovered a century ago and have been used as a model system in microbial genetics and molecular biology. In order to survive, bacteria have to quickly adapt to phage challenges in their natural settings. In turn, phages continuously develop/evolve mechanisms for battling host defenses. A deeper understanding of the arms race between bacteria and phages is essential for the rational design of phage-based prophylaxis and therapies to prevent and treat bacterial infections. Vibrio species and their phages (vibriophages) are a suitable model to study these interactions. Phages are highly ubiquitous in aquatic environments and Vibrio are waterborne bacteria that must survive the constant attack by phages for successful transmission to their hosts. Here, we review relevant literature from the past two years to delve into the molecular interactions of Vibrio species and their phages in aquatic niches.

Development and Evaluation of Bacteriophage Cocktail to Eradicate Biofilms Formed by an Extensively Drug-Resistant (XDR) Pseudomonas aeruginosa

Extensive and multiple drug resistance in P. aeruginosa combined with the formation of biofilms is responsible for its high persistence in nosocomial infections. A sequential method to devise a suitable phage cocktail with a broad host range and high lytic efficiency against a biofilm forming XDR P. aeruginosa strain is presented here. Out of a total thirteen phages isolated against P. aeruginosa, five were selected on the basis of their high lytic spectra assessed using spot assay and productivity by efficiency of plating assay. Phages, after selection, were tested individually and in combinations of two-, three-, four-, and five-phage cocktails using liquid infection model. Out of total 22 combinations tested, the cocktail comprising four phages viz. φPA170, φPA172, φPA177, and φPA180 significantly inhibited the bacterial growth in liquid infection model (p < 0.0001). The minimal inhibitory dose of each phage in a cocktail was effectively reduced to >10 times than the individual dose in the inhibition of XDR P. aeruginosa host. Field emission-scanning electron microscopy was used to visualize phage cocktail mediated eradication of 4-day-old multi-layers of XDR P. aeruginosa biofilms from urinary catheters and glass cover slips, and was confirmed by absence of any viable cells. Differential bacterial inhibition was observed with different phage combinations where multiple phages were found to enhance the cocktail's lytic range, but the addition of too many phages reduced the overall inhibition. This study elaborates an effective and sequential method for the preparation of a phage cocktail and evaluates its antimicrobial potential against biofilm forming XDR strains of P. aeruginosa.

Evaluation of the Antimicrobial Potential and Characterization of Novel T7-Like Erwinia Bacteriophages

The recent outbreak of blight in pome fruit plants has been a major concern as there are two indistinguishable Erwinia species, Erwinia amylovora and E. pyrifoliae, which cause blight in South Korea. Although there is a strict management protocol consisting of antibiotic-based prevention, the area and the number of cases of outbreaks have increased. In this study, we isolated four bacteriophages, pEp_SNUABM_03, 04, 11, and 12, that infect both E. amylovora and E. pyrifoliae and evaluated their potential as antimicrobial agents for administration against Erwinia-originated blight in South Korea. Morphological analysis revealed that all phages had podovirus-like capsids. The phage cocktail showed a broad spectrum of infectivity, infecting 98.91% of E. amylovora and 100% of E. pyrifoliae strains. The antibacterial effect was observed after long-term cocktail treatment against E. amylovora, whereas it was observed for both short- and long-term treatments against E. pyrifoliae. Genomic analysis verified that the phages did not encode harmful genes such as antibiotic resistance or virulence genes. All phages were stable under general orchard conditions. Collectively, we provided basic data on the potential of phages as biocontrol agents that target both E. amylovora and E. pyrifoliae.

Role of Bacteriophages in the Evolution of Pathogenic Vibrios and Lessons for Phage Therapy

Viruses of bacteria, i.e., bacteriophages (or phages for short), were discovered over a century ago and have played a major role as a model system for the establishment of the fields of microbial genetics and molecular biology. Despite the relative simplicity of phages, microbiologists are continually discovering new aspects of their biology including mechanisms for battling host defenses. In turn, novel mechanisms of host defense against phages are being discovered at a rapid clip. A deeper understanding of the arms race between bacteria and phages will continue to reveal novel molecular mechanisms and will be important for the rational design of phage-based prophylaxis and therapies to prevent and treat bacterial infections, respectively. Here we delve into the molecular interactions of Vibrio species and phages.

Isolation and Characterization of a Novel Vibrio natriegens—Infecting Phage and Its Potential Therapeutic Application in Abalone Aquaculture

Phage-based pathogen control (i.e., phage therapy) has received increasing scientific attention to reduce and prevent the emergence, transmission, and detrimental effects of antibiotic resistance. In the current study, multidrug-resistant Vibrio natriegens strain AbY-1805 was isolated and tentatively identified as a pathogen causing the death of juvenile Pacific abalones (Haliotis discus hannai Ino). In order to apply phage therapy, instead of antibiotics, to treat and control V. natriegens infections in marine aquaculture environments, a lytic phage, vB_VnaS-L3, was isolated. It could effectively infect V. natriegens AbY-1805 with a short latent period (40 min) and high burst size (~890 PFU/cell). Treatment with vB_VnaS-L3 significantly reduced the mortality of juvenile abalones and maintained abalone feeding capacity over a 40-day V. natriegens challenge experiment. Comparative genomic and phylogenetic analyses suggested that vB_VnaS-L3 was a novel marine Siphoviridae-family phage. Furthermore, vB_VnaS-L3 had a narrow host range, possibly specific to the pathogenic V. natriegens strains. It also exhibited viability at a wide range of pH, temperature, and salinity. The short latent period, large burst size, high host specificity, and broad environmental adaptation suggest that phage vB_VnaS-L3 could potentially be developed as an alternative antimicrobial for the control and prevention of marine animal infections caused by pathogenic V. natriegens.

Phage Cocktail in Combination with Kasugamycin as a Potential Treatment for Fire Blight Caused by Erwinia amylovora

Recently, there has been an increasing number of blight disease reports associated with Erwinia amylovora and Erwinia pyrifoliae in South Korea. Current management protocols that have been conducted with antibiotics have faced resistance problems and the outbreak has not decreased. Because of this concern, the present study aimed to provide an alternative method to control the invasive fire blight outbreak in the nation using bacteriophages (phages) in combination with an antibiotic agent (kasugamycin). Among 54 phage isolates, we selected five phages, pEa_SNUABM_27, 31, 32, 47, and 48, based on their bacteriolytic efficacy. Although only phage pEa_SNUABM_27 showed host specificity for E. amylovora, all five phages presented complementary lytic potential that improved the host infectivity coverage of each phage All the phages in the cocktail solution could lyse phage-resistant strains. These strains had a decreased tolerance to the antibiotic kasugamycin, and a synergistic effect of phages and antibiotics was demonstrated both in vitro and on immature wound-infected apples. It is noteworthy that the antibacterial effect of the phage cocktail or phage cocktail-sub-minimal inhibitory concentration (MIC) of kasugamycin was significantly higher than the kasugamycin at the MIC. The selected phages were experimentally stable under environmental factors such as thermal or pH stress. Genomic analysis revealed these are novel Erwinia-infecting phages, and did not encode antibiotic-, virulence-, or lysogenic phage-related genes. In conclusion, we suggest the potential of the phage cocktail and kasugamycin combination as an effective strategy that would minimize the use of antibiotics, which are being excessively used in order to control fire blight pathogens.

Efficacy of Repeated Applications of Bacteriophages on Salmonella enterica-Infected Alfalfa Sprouts during Germination

Nontyphoidal Salmonella enterica is one of the leading pathogens for foodborne outbreaks in a multitude of food commodities, including alfalfa sprouts, which are commonly consumed raw. The food industry has commonly used chlorinated washes, but such methods may not be perceived as natural; this can be a detriment as a large portion of sprouts are designated for the organic market. A natural and affordable antimicrobial method that has been acquiring popularity is the use of bacteriophages. This study compared the efficacy of repeated daily applications and a single application of two separate bacteriophage cocktails (SE14, SE20, SF6 and SE14, SF5, SF6) against four Salmonella enterica (S. enterica) strains on germinating alfalfa sprout seeds from days 0 to 7. The results show S. Enteritidis to be the most susceptible to both cocktails with ~2.5 log CFU/mL decrease on day 0 with cocktail SE14, SF5, and SF6. S. enterica populations on all strains continued to grow even with repeated daily bacteriophage applications but in a significantly decreased rate (p < 0.05) compared with a single bacteriophage application. The extent of the reduction was dependent on the S. enterica strain, but the results do show benefits to using repeated bacteriophage applications during sprout germination to reduce S. enterica populations compared with a single bacteriophage application.

The dynamic of the potential pathogenic bacteria, antibiotic-resistant bacteria, and antibiotic resistance genes in the water at different growth stages of grass carp pond

Pond aquaculture has become the most important and broadest breeding model in China, and an extremely important source of aquatic products, but the potential hazard factors of potential pathogenic bacteria (PPB), antibiotic resistance bacteria (ARB), and antibiotic resistance genes (ARGs) in aquaculture environment are largely invisible. In the present study, the bacterial communities in the larvae, juvenile, rearing, and harvesting culture stages of great grass carp (Ctenopharyngodon idellus) ponds were investigated and the structure of microbial flora analysis showed that the larvae culture stage has the highest abundance and the most dominant phyla were Proteobacteria (27.8%). A total of 123 significant Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway annotations and the relative abundance of nine bacterial phenotypes implied that the larvae culture stage had the most abundance of pathogenic potential and mobile elements. The correlation analyses of environmental factors showed that temperature, stocking density, pH, and transparency showed the significant impacts on both the distribution of microbiome and the PPB. More importantly, a total of 40 ARB were identified, and 16 ARGs have the detection rates of 100%, which revealed that they are widely distributed and highly enriched in the aquaculture production. Notably, this is the first robust report to analyze and understand the PPB, ARB, and ARGs characteristics and dynamic changes in the pond aquaculture.

A phage cocktail in controlling phage resistance development in multidrug resistant Aeromonas hydrophila with great therapeutic potential

Aeromonas hydrophila (A. hydrophila) is an opportunistic pathogen of fish-human-livestock, which poses a threat to the development of aquaculture. Lytic phage has long been considered as an effective bactericidal agent. However, the rapid development of phage resistance seriously hinders the continuous application of lytic phages. In our study, a new bacteriophage vB_ AhaP_PZL-Ah8 was isolated from sewage and its characteristics and genome were investigated. Phage vB_ AhaP_PZL-Ah8 has been classified as the member of the Podoviridae family, which exhibited the latent period was about 30 min. As revealed from the genomic sequence analysis, vB_ AhaP_PZL-Ah8 covered a double-stranded genome of 40,855 bp (exhibiting 51.89% G + C content), with encoding 52 predicted open reading frames (ORFs). The results suggested that the combination of vB_ AhaP_PZL-Ah8 and another A. hydrophila phage vB_ AhaP_PZL-Ah1 could improve the therapeutic efficacy both in vitro and in vivo. The resistance mutation frequency of A. hydrophila cells infected with the mixture phage (vB_ AhaP_PZL-Ah8+ vB_ AhaP_PZL-Ah1) was significantly lower than cells treated with single phage (P <0.01). Phage therapy in vivo showed that the survival rate in the mixture phage treatment group was significantly higher than that in single phage treatment group.

Coral holobionts and biotechnology: from Blue Economy to coral reef conservation

Corals are of ecological and economic importance, providing habitat for species and contributing to coastal protection, fisheries, and tourism. Their biotechnological potential is also increasingly recognized. Particularly, the production of pharmaceutically interesting compounds by corals and their microbial associates stimulated natural product-based drug discovery. The efficient light distribution by coral skeletons for optimal photosynthesis by algal symbionts has led to 3D-printed bionic corals that may be used to upscale micro-algal cultivation for bioenergy generation. However, corals are under threat from climate change and pollution, and biotechnological approaches to increase their resilience, like 'probiotics' and 'assisted evolution', are being evaluated. In this review, we summarize the recent biotechnological developments related to corals with an emphasis on coral conservation, drug discovery and bioenergy.

The Characterization of a Novel Phage, pPa_SNUABM_DT01, Infecting Pseudomonas aeruginosa

The bacterial genus Pseudomonas is a common causative agent of infections in veterinary medicine. In this study, we focused on Pseudomonas aeruginosa canine otitis externa isolates. Due to prolonged antibiotic treatment of otitis externa, antibiotic resistance is common and has become a major complication. Many alternatives to antibiotics have been studied, with bacteriophages emerging as the most promising alternatives. Here, we isolated and characterized a novel phage, pPa_SNUABM_DT01, by investigating its morphology, growth, lysis kinetics, and genomic characteristics. Phages have a vigorous capacity to eliminate bacterial cells through bacterial lysis. This capacity is dependent on the multiplicity of infection (MOI), but even at low MOIs, the phage successfully inhibited bacterial regrowth. The phage genome was 265,520 bp in size and comprised 312 putative open reading frames (ORFs). Comparative genome analysis demonstrated that the phage is a novel species in Myoviridae. The nucleotide similarity was moderately high compared with the Pseudomonas virus, Noxifer. However, a phylogenetic analysis and a dot plot indicated that pPa_SNUABM_DT01 is not closely related to the Phikzvirus or Noxifervirus genus but, instead, belongs to a novel one. The genome comparisons also indicate that the phage, pPa_SNUABM_DT01, could be a novel genus.

Bacteriophages against Vibrio coralliilyticus and Vibrio tubiashii: Isolation, Characterization, and Remediation of Larval Oyster Mortalities

Vibrio coralliilyticus and Vibrio tubiashii are pathogens responsible for high larval oyster mortality rates in shellfish hatcheries. Bacteriophage therapy was evaluated to determine its potential to remediate these mortalities. Sixteen phages against V. coralliilyticus and V. tubiashii were isolated and characterized from Hawaiian seawater. Fourteen isolates were members of the Myoviridae family, and two were members of the Siphoviridae In proof-of-principle trials, a cocktail of five phages reduced mortalities of larval Eastern oysters (Crassostrea virginica) and Pacific oysters (Crassostrea gigas) by up to 91% 6 days after challenge with lethal doses of V. coralliilyticus Larval survival depended on the oyster species, the quantities of phages and vibrios applied, and the species and strain of Vibrio A later-generation cocktail, designated VCP300, was formulated with three lytic phages subsequently named Vibrio phages vB_VcorM-GR7B, vB_VcorM-GR11A, and vB_VcorM-GR28A (abbreviated 7B, 11A, and 28A, respectively). Together, these three phages displayed host specificity toward eight V. coralliilyticus strains and a V. tubiashii strain. Larval C. gigas mortalities from V. coralliilyticus strains RE98 and OCN008 were significantly reduced by >90% (P < 0.0001) over 6 days with phage treatment compared to those of untreated controls. Genomic sequencing of phages 7B, 11A, and 28A revealed 207,758-, 194,800-, and 154,046-bp linear DNA genomes, respectively, with the latter showing 92% similarity to V. coralliilyticus phage YC, a strain from the Great Barrier Reef, Australia. Phage 7B and 11A genomes showed little similarity to phages in the NCBI database. This study demonstrates the promising potential for phage therapy to reduce larval oyster mortalities in oyster hatcheries.IMPORTANCE Shellfish hatcheries encounter episodic outbreaks of larval oyster mortalities, jeopardizing the economic stability of hatcheries and the commercial shellfish industry. Shellfish pathogens like Vibrio coralliilyticus and Vibrio tubiashii have been recognized as major contributors of larval oyster mortalities in U.S. East and West Coast hatcheries for many years. This study isolated, identified, and characterized bacteriophages against these Vibrio species and demonstrated their ability to reduce mortalities from V. coralliilyticus in larval Pacific oysters and from both V. coralliilyticus and V. tubiashii in larval Eastern oysters. Phage therapy offers a promising approach for stimulating hatchery production to ensure the well-being of hatcheries and the commercial oyster trade.

Isolation and Characterization of Six Vibrio parahaemolyticus Lytic Bacteriophages From Seafood Samples

Vibrio parahaemolyticus is a foodborne pathogen that is frequently isolated from a variety of seafood. To control this pathogenic Vibrio spp., the implementation of bacteriophages in aquaculture and food industries have shown a promising alternative to antibiotics. In this study, six bacteriophages isolated from the seafood samples demonstrated a narrow host range specificity that infecting only the V. parahaemolyticus strains. Morphological analysis revealed that bacteriophages Vp33, Vp22, Vp21, and Vp02 belong to the Podoviridae family, while bacteriophages Vp08 and Vp11 were categorized into the Siphoviridae family. All bacteriophages were composed of DNA genome and showed distinctive restriction fragment length polymorphism. The optimal MOI for bacteriophage propagation was determined to be 0.001 to 1. One-step growth curve revealed that the latent period ranged from 10 to 20 min, and the burst size of bacteriophage was approximately 17 to 51 PFU/cell. The influence of temperature and pH levels on the stability of bacteriophages showed that all bacteriophages were optimally stable over a wide range of temperatures and pH levels. In vitro lytic activity of all bacteriophages demonstrated to have a significant effect against V. parahaemolyticus. Besides, the application of a bacteriophage cocktail instead of a single bacteriophage suspension was observed to have a better efficiency to control the growth of V. parahaemolyticus. Results from this study provided a basic understanding of the physiological and biological properties of the isolated bacteriophages before it can be readily used as a biocontrol agent against the growth of V. parahaemolyticus.