Search Results (68)

Bacteriophages are being revisited as programmable platforms for therapy, diagnostics, and biocontrol. Their value, however, depends on the setting. Therapeutic phages must do more than lyse bacteria in vitro: they need to reach infection sites, persist long enough to act, reduce bacterial burden, and limit resistance under clinically relevant conditions. Diagnostic platforms are judged by another standard, including sensitivity, specificity, matrix tolerance, and stable signal readout. Food, agricultural, and environmental applications instead rely on formulation stability, host specificity, scalable delivery, and ecological safety. This review summarizes the biological and engineering principles that support phage-based platforms, and then evaluates therapeutic, diagnostic, and nonclinical uses through an application-specific evidence framework. For therapy, we focus on evidence hierarchy, active phage exposure, immune clearance, persistence, infection spread, and host-resistance-bypass phenotypes. Recent studies on high-persistence and hyper-aggressive phages suggest that dissemination, plaque expansion, and resistance-bypass behavior should be considered during early candidate selection. Phage cocktails, antibiotic combinations, and engineered phages remain useful, but they should be treated as adaptive strategies rather than universal solutions. Overall, phage technologies require validation frameworks that link biological function with manufacturing quality, regulatory feasibility, and meaningful clinical or environmental endpoints. Full article

Background: Escherichia coli remains a critical multidrug-resistant nosocomial pathogen, driving interest in bacteriophage-based biocontrol. The genus Kayfunavirus (family Autotranscriptaviridae) exhibits obligately lytic replication cycles and favorable biosafety profiles, yet each new phage requires comprehensive genomic characterization to expand therapeutic candidate pools. This study aimed to isolate and genomically characterize a novel Kayfunavirus from an environmental reservoir in Vietnam. Methods: Escherichia phage vB_EcoA-Sparklingdew was isolated from Can Tho River water using host E. coli AgE9. The genome was assembled using SPAdes. The termini were resolved with PhageTerm. The annotation was done via the Pharokka pipeline and HHpred. Taxonomic classification was performed using taxMyPhage, VIRIDIC intergenomic comparisons, and maximum likelihood phylogeny of concatenated structural proteins. Results: The complete genome comprises a 37,944 bp linear dsDNA molecule (49.9% GC), encoding 51 open reading frames in a predominantly unidirectional arrangement. Key features include a virion-encoded T7-like RNA polymerase, a 723-residue T7-like DNA polymerase, a canonical lysis triad, and two putative tailspike proteins. A 212 bp direct terminal repeat and coverage profiles support a headful (pac) packaging mechanism. Comprehensive screening confirmed the absence of lysogeny, virulence, and antibiotic resistance determinants. A single synonymous SNP indicated high clonal purity. Intergenomic identity peaked at 87.7% against ICTV references, confirming placement in a novel species. Conclusions: Phage Sparklingdew represents a strictly lytic Kayfunavirus with a compact genomic architecture. Its favorable safety profile and absence of temperate markers support further evaluation for targeted therapeutic applications against pathogenic E. coli. Full article

Salmonella enterica serovar Enteritidis is a leading cause of foodborne zoonoses worldwide. The rapid emergence of multidrug-resistant (MDR) strains has compromised traditional antimicrobial therapies, necessitating the development of biosafe alternatives such as bacteriophages. This study aimed to isolate and comprehensively characterize novel lytic bacteriophages targeting multidrug-resistant Salmonella enterica subspecies enterica serovar Enteritidis isolates from Lebanon. In this study, four novel Salmonella phages, EDA02, EDA03, EDA05, and EDA06, were isolated from wastewater and poultry effluents in Lebanon. The isolates were characterized using host range profiling, one-step growth kinetics, and physicochemical stability assays. Comprehensive whole-genome sequencing (WGS) and phylogenetic analyses were performed to assess their genomic safety and taxonomic placement. Phages EDA03 and EDA06 exhibited the broadest intra-serovar lytic activity within the tested panel, infecting up to 72% and 67% of the MDR isolates, respectively. One-step growth analysis revealed latent periods of 30–40 min, with burst sizes ranging from 6.0 to 150 phages/infected cell. All four phages demonstrated robust stability across pH 4.7–10.3 and temperatures from 4 °C to 50 °C. WGS revealed genome sizes ranging from 42.3 kb to 108.8 kb, with no identified genes associated with lysogeny, virulence, or antimicrobial resistance. Phylogenomic analysis assigned all isolates to the family Straboviridae, with <95% intergenomic similarity to their closest RefSeq relatives, supporting their classification as novel species. The isolated phages demonstrate substantial lytic activity and environmental resilience under the tested conditions. Their complementary lytic profiles, environmental resilience, and genomic safety support their further evaluation as biocontrol candidates. This study represents the first genomic and phenotypic characterization of anti-Salmonella Enteritidis phages from Lebanon. These findings support the development of phage-based interventions for food safety and antimicrobial resistance mitigation in resource-limited settings. Full article

Nematodes in the genus Oscheius (Rhabditidae) have traditionally been regarded as free-living bacteriophagous or necromenic associates of insects. Over the past two decades, however, multiple Oscheius species and isolates have been shown to express facultative pathogenicity toward insects and, in some cases, parasitism of mollusks. This has stimulated interest in Oscheius as a complementary group of biological control agents that may function under conditions limiting classical entomopathogenic nematodes (EPNs) of the genera Steinernema and Heterorhabditis. Here, we synthesize current knowledge on Oscheius taxonomy and diversity, life-history strategies, bacterial associations and virulence mechanisms, evidence for control of insect and mollusk pests, and recent advances in chemo-ecology relevant to host finding. We emphasize that Oscheius represents a continuum of ecological strategies, and we adopt conservative terminology in which “entomopathogenic” is reserved for Oscheius species/isolates that meet operational criteria of insect pathogenicity. Finally, we highlight key barriers to wider implementation—strain variability, bacterial partner instability, non-target and community effects, and production/quality control needs—and propose research priorities for the development of robust, field-reliable Oscheius-based biocontrol. Full article

Bacteriophages (phages) offer a targeted biocontrol solution, but their direct application is hampered by environmental instability. To address this, we developed a novel, food-grade microcapsule system for phage delivery using layer-by-layer (LbL) self-assembly of zein and carboxymethyl chitosan (CMCS). Lytic phages targeting specific spoilage bacteria were successfully encapsulated via electrostatic interactions. Characterization confirmed the formation of a multilayer structure, driven primarily by hydrogen bonding and electrostatic forces between the wall materials. The microencapsulation markedly enhanced phage stability against thermal (60 °C and 70 °C) and extreme pH (2.0, 12.0) stresses and provided a controlled release profile in a simulated fish exudate. When applied to fresh-cut sea bass (Lateolabrax japonicus), the phage-loaded microcapsules (CMCS3), constructed via a three-layer zein/CMCS LbL assembly, significantly delayed the pH rise during refrigerated storage, maintaining a final pH of 6.28 compared to 7.28 in the control group after 5 days. The microcapsules also effectively suppressed microbial growth (total viable count (TVC) was maintained below 6 log CFU/g) and controlled lipid oxidation (thiobarbituric acid reactive substances (TBARS) values were kept at 0.62 mg malondialdehyde/kg) while better preserving texture and color stability compared to free phages. This zein/CMCS-based LbL system presents a promising strategy for advancing phage-based biopreservation in aquatic products through enhanced physical protection, sustained release, and improved stress tolerance. Full article

Seafood products are highly perishable and particularly susceptible to contamination by pathogenic and spoilage microorganisms, including Listeria monocytogenes, Vibrio spp., Salmonella spp., and Escherichia coli. Conventional control strategies in seafood processing and storage largely rely on chemical preservatives and thermal treatments, which may negatively affect sensory quality and increasingly conflict with consumer demand for minimally processed, “clean-label” foods. In this context, bacteriophages, viruses that specifically infect and lyse bacterial hosts, have emerged as natural, targeted, and environmentally sustainable biocontrol agents for food safety applications. This review provides a comprehensive assessment of bacteriophage applications in seafood processing and storage, with particular emphasis on their mechanisms of action, host specificity, and ability to selectively reduce pathogenic bacteria without compromising nutritional or sensory attributes. Recent advances in phage-based technologies, including phage cocktails, immobilized phage systems, and genetically engineered phages, are discussed in relation to their efficacy against major seafood-associated pathogens under both laboratory and industrial conditions. Key challenges limiting large-scale implementation such as phage resistance development, regulatory considerations, stability during processing and storage, and consumer perception are critically evaluated. In addition, the review highlights emerging evidence on the synergistic use of bacteriophages with complementary preservation strategies, including natural antimicrobials and innovative packaging systems. Overall, this review underscores the potential of bacteriophage-based interventions as practical and sustainable tools to enhance seafood safety, extend shelf life, and support modern seafood processing practices aligned with evolving regulatory and consumer expectations. Full article

Bacillus cereus is a major foodborne pathogen responsible for food spoilage and foodborne illness, including strains producing emetic toxins. In this study, two bacteriophages, PBC_MG88 and PBC_MG99, were isolated from wastewater using emetic B. cereus strains as hosts and were comprehensively characterized. Both phages formed clear plaques with halos and exhibited siphovirus morphology. Host range analysis against 172 B. cereus strains showed that PBC_MG88 and PBC_MG99 infected 50 and 60 strains, respectively. One-step growth experiments revealed efficient lytic activity, with latent periods of 20–25 min and burst sizes of 59–63 PFU per infected cell. More than 90% of phage particles adsorbed to host cells within 15 min. Both phages were stable across a wide temperature range (4–55 °C) and pH values (4–11). Genome sequencing revealed ~37 kb double-stranded DNA genomes lacking antibiotic resistance or virulence genes; however, the presence of lysogeny-related genes suggests a temperate lifestyle. Comparative genomic analyses indicated that both phages represent novel species within the genus Lwoffvirus. Biofilm assays demonstrated significant inhibition of B. cereus biofilm formation and reduction of pre-established biofilms. Overall, this study expands knowledge of B. cereus phage diversity and highlights the importance of genomic characterization in phage-based biocontrol research. Full article

In the face of rising antimicrobial resistance, food insecurity, and climate change, bacteriophages are gaining renewed attention as promising biological alternatives to antibiotics across human, animal, and plant health sectors. Their high specificity, self-replicating capacity, and biodegradability make them valuable tools for combating antimicrobial or pesticide resistance and promoting sustainable biocontrol. This review discusses commonly accepted selection criteria for therapeutic phages, such as avoiding temperate types and screening for undesirable genes, while acknowledging ongoing debates and exceptions in specific clinical or ecological contexts. An overview of phage-based applications within a One Health framework is provided, spanning human medicine, veterinary practice, aquaculture, food safety and crop protection. Particular attention is given to agricultural biocontrol, where several successful plant protection strategies are highlighted, illustrating the feasibility and diversity of phage-based approaches. Despite their potential, key challenges remain regarding phage stability, formulation, and persistence under environmental conditions. Emerging innovations such as encapsulation, carrier bacteria, and protective formulations aim to enhance field performance. Furthermore, this review emphasizes the need to assess the environmental safety of phage applications, particularly their impacts on natural ecosystems, microbial communities, and ecological functions. Finally, the regulatory and policy challenges that currently limit the large-scale deployment of phages, particularly in the European Union, where they remain evaluated under conventional chemical pesticide frameworks are discussed. The development of dedicated regulatory pathways, better adapted to the specificities of phages, is argued to be essential for supporting their integration into agroecological transition strategies and next-generation antimicrobial policies. Full article

Pseudomonas syringae pv. syringae and Xanthomonas arboricola pv. juglandis are the causal agents of bacterial canker in cherry and walnut blight, respectively, which cause significant production losses worldwide. These diseases have traditionally been controlled by copper-based agrochemicals and, more recently, antibiotics. However, the prolonged use of these compounds has led to the emergence of resistant bacterial strains. The search for new, efficient, and environmentally friendly biocontrol alternatives has intensified. Phages are promising candidates due to their ability to specifically infect and lyse bacterial pathogens. Endolysin enzymes are responsible for bacterial cell wall degradation, and although they have been extensively studied in medical and veterinary contexts, their application in agriculture remains limited. In this study, 17 putative endolysins were identified from bacteriophages infecting X. arboricola pv. juglandis and P. syringae pv. syringae. Based on conserved domain analyses, 12 were classified as glycosidases, four as amidases, and one as an endopeptidase. From these, a recombinant amidase (LysP) and a recombinant glycosidase (LysX) were expressed in E. coli, purified, and evaluated as pure enzymes. Both endolysins exhibited significant antimicrobial activity, reducing P. syringae pv. syringae viability by 62–78.3% and X. arboricola pv. juglandis viability by 51.5–53.1%, respectively. These findings highlight these recombinant endolysins as promising candidates for the development of biocontrol strategies against bacterial plant pathogens. Full article

Agrobacterium tumefaciens, a destructive pathogen causing crown gall disease, results in substantial agricultural losses. Traditional chemical and existing biocontrol methods are limited by environmental pollution, pesticide resistance, and low efficacy, while bacteriophages emerge as a promising alternative due to their high host specificity, environmental compatibility, and low resistance risk. In this study, we isolated and characterized a lytic phage (PAT-A) targeting A. tumefaciens, evaluating its biological traits, genomic features, and biocontrol potential. The host strain A. tumefaciens CL-1 was isolated from cherry crown gall tissue and identified by 16S rDNA sequencing. Phage PAT-A was recovered from orchard soil via the double-layer agar method, showing a tadpole-shaped morphology (60 nm head diameter, 30 nm tail length) under transmission electron microscopy (TEM). Nucleic acid analysis confirmed a double-stranded DNA genome, susceptible to DNase I but resistant to RNase A and Mung Bean Nuclease. PAT-A exhibited an optimal MOI of 0.01, tolerated wide pH and temperature ranges, but was sensitive to UV (titer declined after 15 min of irradiation) and chloroform (8% survival at a 5% concentration). Whole-genome sequencing revealed a 44,828 bp genome with a compact structure, and phylogenetic/collinearity analyses placed it in the Atuphduvirus genus (Autographiviridae). Biocontrol experiments on tobacco plants demonstrated that PAT-A significantly reduced crown gall incidence. Specifically, simultaneous inoculation of PAT-A and A. tumefaciens CL-1 resulted in the lowest tumor incidence (12.0%), while pre-inoculation of PAT-A 2 days before pathogen exposure achieved an incidence rate of 33.3%. In conclusion, PAT-A is a novel strictly lytic phage with favorable biological properties and potent biocontrol efficacy against A. tumefaciens, enriching phage resources for crown gall management and supporting phage-based agricultural biocontrol strategies. Full article

Shiga toxin-producing Escherichia coli (STEC) pose a significant threat to public health and effective methods of detection are needed. The use of naturally occurring bacteriophages (phages) to detect E. coli has been well documented. However, detecting multiple serotypes at the same time often required multiple phages specific to individual serotypes. To limit the burden of complex cocktails, this study aimed to engineer phages with an expanded host range that allows each phage to contribute to detection across multiple STEC serogroups. Kutterviruses, in the Ackermannviridae family, contain four tailspike proteins (TSPs), each of which confers tropism to a different bacterial strain. The modular nature of TSPs allows for mixing receptor-binding domains from diverse phage types. The host range of the Kuttervirus CBA120 was modified by replacing its native tailspike proteins (TSPs) with chimeric versions incorporating receptor-binding domains from related and unrelated phages. A structure-guided approach was utilized to overcome minimal sequence similarity between donor and recipient phages and achieve novel functional TSP chimeras. Two engineered phage variants were created that collectively detect five STEC serogroups: O26, O45, O103, O111, and O157. Spotting and luciferase assays confirmed that the replacement TSPs were functional and the phages had acquired new host ranges. This study demonstrates the feasibility of engineering Ackermannviridae phages with customized host ranges for detecting multiple STEC strains. This approach has potential applications in developing improved phage-based bacterial detection, therapy, and biocontrol. Full article

Staphylococcus aureus is a major foodborne pathogen associated with contamination of dairy and meat products, posing a persistent challenge to food safety due to its biofilm formation and resistance to multiple antibiotics. In this review, we summarize recent advances in the use of bacteriophages and phage-derived endolysins as targeted biocontrol agents against S. aureus in food systems. Bacteriophages exhibit host specificity and self-replicating capacity, while endolysins provide rapid lytic activity, minimal resistance development, and effectiveness against biofilm-embedded cells. Studies demonstrate significant microbial reductions in milk, cheese, and meat matrices, although factors such as pH, salt, and fat content can influence their efficacy. The integration of these biocontrol tools into food preservation represents a sustainable and safe alternative to conventional antimicrobials. Finally, we discuss current limitations and the need for optimizing formulations, stability, and regulatory frameworks to facilitate the adoption of phage and endolysin-based products in the food industry. Full article

The emergence of multidrug-resistant Shiga toxin-producing Escherichia coli (STEC) poses a major challenge to public health and necessitates the development of alternative antimicrobial strategies. This study aimed to isolate and characterize five lytic bacteriophages belonging to the genus Mosigvirus and evaluate their potential as biocontrol against MDR STEC strains and their biofilms. The five bacteriophages, designated vB_EcoM-pJBB (ΦB), vB_EcoM-pJBC (ΦC), vB_EcoM-pJBJ (ΦJ), vB_EcoM-pJBK (ΦK), and vB_EcoM-pJBL (ΦL), were isolated from sewage treatment plant samples using STEC ATCC 43895 as host. Biological characterization included host range determination against 19 MDR STEC strains, one-step growth analysis, environmental stability assays, bacteriolytic activity assessment, and antibiofilm efficacy testing. Whole-genome sequencing and phylogenetic analyses were performed to determine genomic features and taxonomic classification. The phages demonstrated varying infectious capacities, lysing between six and 12 strains, with ΦL exhibiting the broadest spectrum of activity. All phages showed MOI-independent antibiofilm activity, preventing biofilm formation by approximately 70% and disrupting pre-formed biofilms by up to 80.3%. Genomic analysis revealed the absence of lysogeny markers, virulence factors, and antimicrobial resistance genes, while identifying putative depolymerase genes associated with tail fiber proteins. Phylogenetic analysis confirmed the taxonomic position of these phages within the Mosigvirus genus in the Straboviridae family. Our findings indicate that the newly identified Mosigvirus phages are promising candidates for phage-based biocontrol applications. Full article

Background/Objectives: Bacteriophages are considered promising alternatives for the treatment of multidrug-resistant (MDR) Pseudomonas aeruginosa infections. Methods: Five bacteriophages with lytic activity against MDR P. aeruginosa were isolated from lake and sewage samples and characterized for their biological properties, host range, and efficacy in biofilm and in vitro infection models. Results: The phages displayed broad host ranges, producing zones of lysis in 40–53% of MDR isolates. The average burst size was 112 ± 70 PFU per cell. All phages, either individually or in combination, inhibited biofilm formation and were capable of disrupting preformed biofilms. While treatment with single phages led to bacterial regrowth, the cocktail of all five phages achieved complete bacterial lysis with no regrowth observed. In an in vitro wound and burn infection model, the phage cocktail significantly enhanced cell proliferation and promoted healing. Transmission electron microscopy (TEM) analysis identified phage PA2 as a Myovirus based on its morphology. Conclusions: The phage isolates demonstrated strong activity in multiple in vitro models, effectively targeting both planktonic and biofilm-associated P. aeruginosa. Notably, the five-phage combination prevented the emergence of bacterial resistance, supporting its potential as a biocontrol strategy against MDR P. aeruginosa. Full article

Background: Since 2008, the kiwifruit industry has been significantly impacted by Pseudomonas syringae pv. actinidiae (Psa), the agent responsible for bacterial canker in kiwifruit. Existing treatments, such as copper-based compounds and antibiotics, have faced challenges related to resistance and soil contamination. Phage therapy is a promising and safe alternative for controlling this pathogen. This study aimed to evaluate the use of a mixture of four isolated and characterized bacteriophages as potential biocontrol agents against Psa. Methods: Trials were conducted at two locations in Chile, where Psa presence was reported during the 2019/2020 and 2020/2021 seasons, with a focus on the spring stages. Different formulations were tested each season to evaluate possible improvements in effectiveness. Pseudomonas spp. isolates obtained from epiphyte populations were characterized using morphological, biochemical (LOPAT), and molecular techniques. Results: Field trials demonstrated that the phage mixture effectively reduced the damage associated with Psa on kiwi leaves, resulting in a decrease in the Pseudomonas spp. bacterial load (42.9% for Peumo and 25% for Linares) at both locations during the first season trials. This decrease is associated with a reduction in the incidence and severity of the disease in kiwi plants in the Peumo orchard. In both seasons, bacteriophages reduce Psa symptoms in treated kiwi plants compared to untreated controls, at least at one location and evaluation. In both orchards during the first season, bacteriophages also outperformed copper- and antibiotic-based treatments used by farmers. Bacteriophage therapy is eco-friendly and safe for both applicators and consumers. Full article