Search Results (91)

This study demonstrates the feasibility of using a T7 phage display platform to deliver a library of tick antigens as a vaccine to disrupt tick feeding in cattle. Cattle were vaccinated at three-week intervals via intradermal and intramuscular routes with a cocktail of male and female Amblyomma americanum T7 phage display cDNA libraries, with and without adjuvant. ELISA and Western blot analyses confirmed that vaccinated cattle mounted immune responses directed against phage-displayed tick proteins rather than the T7 phage backbone. Vaccine-induced antibodies recognized both native tick salivary gland proteins and selected recombinant salivary proteins, indicating effective antigen presentation and biologically relevant immunity with binding to native tick saliva proteins. The adjuvanted formulation elicited significantly stronger immune responses than phage-only immunization. Immunized cattle exhibited robust immune memory, evidenced by a pronounced anamnestic response following tick infestation. This immunity translated into measurable anti-tick effects, including reduced tick feeding efficiency and blood ingestion. Tick reproductive success was severely compromised, with larval hatching declining from 54% in ticks fed on control cattle to 4% in ticks fed on immunized cattle. This study establishes a practical and scalable T7 phage-displayed whole-tick antigen platform capable of inducing durable anti-tick immunity in cattle. Full article

Cronobacter sakazakii is a formidable foodborne pathogen that poses a severe, often fatal threat to neonates and immunocompromised individuals, with contaminated powdered infant formula as the primary transmission vehicle. Infections can lead to devastating conditions, such as meningitis, necrotizing enterocolitis, and sepsis, with alarmingly high mortality rates. Clinical management is hampered by the lack of standardized treatment guidelines and the emergence of antibiotic resistance. However, ongoing research into its molecular pathogenesis continually covers novel targets for intervention. In this review, we synthesize recent advances in our understanding of the sophisticated mechanisms that enable C. sakazakii to cause disease. We argue that its virulence hinges on a multi-faceted strategy, including efficient host invasion and tissue penetration via outer membrane proteins, sophisticated immune evasion tactics for intracellular survival, a repertoire of regulated virulence determinants, resilient biofilm formation, and robust stress response systems that ensure environmental persistence. As research continues to decipher these intricate host–pathogen interactions, we highlight promising future directions, including the development of rapid on-site diagnostics, the application of effective biocontrol strategies like phage therapy and probiotics, and the formulation of targeted therapeutic regimens. Ultimately, integrating these multifaceted insights is paramount to developing comprehensive strategies for preventing and controlling the global health burden imposed by C. sakazakii. Full article

Background/Objectives: Bacteriophages offer a promising alternative to conventional antibiotics. However, their therapeutic efficacy is often limited by instability in harsh environmental conditions, particularly within the gastrointestinal tract. This study aimed to isolate lytic bacteriophages from wastewater and evaluate the protective capacity of sodium alginate encapsulation against various stressors to enable effective oral delivery. Methods: Four distinct lytic phages (As, Ec, Pa, Gc) were isolated from wastewater and characterized by Transmission Electron Microscopy (TEM) and PCR, confirming their families (Siphoviridae, Podoviridae, Myoviridae). These phages demonstrated potent lytic activity against diverse bacterial pathogens, including Aeromonas hydrophila, Escherichia coli, Pseudomonas aeruginosa, and Glutamicbacter creatinolyticus. The phages were encapsulated in 5% sodium alginate via an extrusion method. Stability was assessed under extreme pH (2.0 and 13), at elevated temperature (up to 80 °C), and in simulated gastrointestinal transit. Results: Encapsulation efficiency exceeded 95%. Unencapsulated phages were completely inactivated at pH 2.0 within 10 min, whereas encapsulated phages maintained significant viability (3.06–3.43 log PFU/mL). Encapsulation also significantly enhanced phage survival under extreme alkaline conditions and elevated temperatures. In simulated gastrointestinal transit, encapsulated phages exhibited superior recovery (2.50 log PFU/mL) compared to their free counterparts (≤1 log PFU/mL). Long-term storage evaluations over three months further confirmed the robust stability of the encapsulated formulations at both 4 °C and 21 °C. Conclusions: Sodium alginate encapsulation effectively shields bacteriophages from severe environmental degradation, particularly acidic gastric stress, enhancing their potential for oral delivery. These findings support the development of stable, formulated phage products for diverse practical applications in phage therapy to combat antimicrobial resistance. 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

Background/Objectives: Methicillin-resistant Staphylococcus aureus (MRSA) continues to pose a significant challenge for infection prevention, particularly because of its ability to persist on surfaces and form resilient biofilms. Although bacteriophages have attracted renewed interest as alternatives or complements to chemical disinfectants, their applied use requires careful assessment of antimicrobial performance, formulation tolerance, and genomic context. Methods: Staphylococcus-infecting bacteriophages were isolated from environmental sources and examined against reference Staphylococcus isolates. Two phage isolates, designated MRSA-W3 and SA-W2, displayed lytic activity against a broad subset of clinical MRSA strains. Using a time-resolved agar-based infection assay, phage exposure resulted in a multiplicity-of-infection-dependent decline in viable MRSA populations. Results: Time-resolved infection assays revealed a multiplicity-of-infection-dependent reduction in viable MRSA, with a pronounced decrease observed approximately 40 min post-infection. At this time point, phage-treated cultures showed a reduction of 1.2–1.8 log₁₀ CFU/mL relative to untreated controls (mean Δlog₁₀ = 1.5; 95% CI, 1.1–1.9), while control cultures remained stable. Quantitative biofilm assays demonstrated that both phages reduced biofilm biomass compared with untreated conditions, with inhibition values ranging from 20% to 45% across isolates (p ≤ 0.05), reflecting strain-dependent but reproducible effects. Assessment of formulation compatibility indicated that both phages retained infectivity following exposure to sodium dodecyl sulfate, Triton X-100, and Tween 80, whereas ethanol (≥10%) and higher concentrations of dimethyl sulfoxide were associated with rapid loss of activity. In surface disinfection models, selected phage–surfactant formulations achieved a maximum reduction of 2.18 log₁₀ CFU/cm² compared with untreated controls (p ≤ 0.05). Infection-coupled whole-genome sequencing of MRSA-infecting phage MRSA-W3 produced a high-quality assembly (99.99% completeness; 0.13% contamination) and revealed a mosaic genome containing incomplete prophage-like regions, which were interpreted conservatively as evidence of shared phage ancestry rather than active temperate behavior. Conclusions: Therefore, these findings suggest that bacteriophage-based approaches may be feasible for MRSA surface decontamination, while clearly emphasizing the need for context-specific validation before practical implementation. Full article

Antimicrobial resistance (AMR) remains a major clinical challenge, with Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter species (ESKAPE) accounting for a substantial share of multidrug-resistant (MDR) infections worldwide. These organisms undermine antibiotic efficacy through reduced permeability, surface shielding, biofilm formation, and rapid genetic adaptation, mechanisms that primarily restrict effective exposure at infection sites. Bacteriophages, phage-derived enzymes, and Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR)-based antimicrobials provide selective and mechanistically distinct alternatives to conventional antibiotics, but their performance in vivo is often limited by instability in physiological environments, immune neutralization, uneven tissue distribution, and insufficient access to bacteria protected by biofilms or surface-associated barriers. This narrative review examines how nanotechnology-based delivery systems can address these constraints. We first outline the delivery-relevant biological barrier characteristic of ESKAPE pathogens, then summarize the therapeutic potential and inherent limitations of whole phages, phage-derived enzymes, and CRISPR-based antimicrobials when used without formulation. Major nanotechnology platforms for antibacterial delivery are reviewed, followed by analysis of how nano-enabled systems can improve stability, localization, and persistence of these biological agents. A pathogen-aware integration framework is presented that links dominant barriers in each ESKAPE pathogen to the biological modality and nano-enabled delivery strategy most likely to enhance exposure at infection sites. Translational challenges, regulatory considerations, and emerging directions, including responsive delivery systems and personalized approaches, are also discussed. Overall, nano-enabled phage-based therapeutics represent a realistic and adaptable strategy for managing MDR ESKAPE infections. Therapeutic success depends on both continued discovery and engineering of antibacterial agents and effective delivery design. Full article

Microbial resistance to antibiotics necessitates the development of alternative treatments to address the challenges posed by severe bacterial infections. Bacteriophages are regaining clinical relevance, but the effectiveness of phage therapy depends directly on the route of administration and the carrier used. This review provides a critical overview of the therapeutic potential of phages, emphasizing different strategies for delivery to the site of infection. We focus on the preclinical and clinical data on phage therapies using various routes of administration, such as oral, intravenous, inhalation, topical, and local administration to joints and bones. In view of different phage formulations, including liquid suspension, phages immobilized in polymers or liposome-based carriers, we highlight the potential challenges and obstacles that may affect phage stability and bioavailability and limit the successful outcome of therapy. This review serves to enhance the understanding of the integration of materials engineering with clinical practice and production standardization, to address these issues. Additionally, a clear knowledge of the bacteriophage and pharmacokinetics of phage preparations is necessary to implement safe and efficacious bacteriophage treatment in the era of antimicrobial resistance. Full article

Bacteriophage (phage) therapy, including monophage preparations, phage cocktails, engineered phages, and phage-derived enzymes, has re-emerged as a potential option for difficult-to-treat and biofilm-associated infections in the context of rising antimicrobial resistance. Recent scientific and regulatory developments, such as the 2024 World Health Organization Bacterial Priority Pathogens List and the introduction of the European Pharmacopoeia general chapter 5.31 on phage therapy medicinal products, highlight the growing interest in establishing quality, safety, and governance standards for clinical implementation. This narrative review provides an overview of current clinical applications of phage therapy, drawing on published case reports, case series, early-phase clinical studies, and regulatory experiences across different healthcare settings. Clinical use has been reported in respiratory, urinary tract, musculoskeletal, cardiovascular, and device-associated infections, particularly in cases involving multidrug-resistant pathogens, often in combination with antibiotics. At the same time, the biological characteristics of phages, such as strain specificity, adaptive composition of phage cocktails, and the need for individualized formulations, pose significant regulatory and translational challenges. Access to phage therapy currently relies on heterogeneous regulatory mechanisms, including compassionate use programmes, magistral preparations, named-patient pathways, and other national frameworks. Overall, phage therapy represents a promising strategy for selected infections, but its broader clinical adoption will depend on harmonized regulatory approaches, robust quality standards, and the generation of stronger clinical evidence to support safe and scalable use. Full article

Background/Objectives: Phages show efficacy against multidrug-resistant Pseudomonas aeruginosa, but limited host ranges require combining them in cocktails. In this work, we characterized 25 P. aeruginosa phages, developed therapeutic cocktails active against diverse clinical isolates, and tested phage efficacy in a mouse incisional wound model. Methods/Results: These phages represent seven genera, and genomic and phenotypic analyses indicate that 24/25 are lytic and suitable for phage therapy. Phage host ranges on a diversity panel of 156 P. aeruginosa strains that included 106 sequence types varied from 8% to 54%, and together the 24 lytic phages were active against 133 strains (85%). All of the phages reduced bacterial counts in biofilms. A cocktail of five lytic phages, WRAIR_PAM1, covered 56% of the strain panel, protected 100% of mice from lethal systemic infection (vs. 20% survival in the saline-treated group), and accelerated healing of infected wounds. An improved five-phage cocktail, WRAIR_PAM2, was formulated by a rational design approach (using phages with broader host ranges, more complementing activity, relatively low resistance background, and compatibility in mixes). Conclusions: WRAIR_PAM2 covered 76% of highly diverse clinical isolates and demonstrated significant efficacy against topical and systemic P. aeruginosa infection, indicating that it is a promising therapeutic candidate. Full article

Background/Objectives: Periodontal disease is a condition marked by the destruction of tooth-supporting tissues, driven by an exaggerated immune response to an unbalanced dental biofilm. Conventional treatments struggle due to antimicrobial resistance and the biofilm’s protective extracellular matrix. This study evaluates the potential of bacteriophages as an innovative strategy for managing periodontal disease. Methods: This research employed a qualitative approach using Discursive Textual Analysis, with IRAMUTEQ version 0.8 alpha 7 (Interface de R pour les Analyses Multidimensionnelles de Textes et de Questionnaires) software. The search was conducted in the Orbit Intelligence and PubMed databases, for patents and scholarly articles, respectively. The textual data underwent Descending Hierarchical Classification, Correspondence Factor Analysis, and Similarity Analysis to identify core themes and relationships between words. Results: The analysis revealed an increase in research and patent filings concerning phage therapy for periodontal disease since 2017, emphasizing its market potential. The primary centers for intellectual property activity were identified as China and the United States. The study identified five focus areas: Genomic/Structural Characterization, Patent Formulations, Etiology, Therapeutic Efficacy, and Ecology/Phage Interactions. Lytic phages were shown to be effective against prominent pathogens such as Fusobacterium nucleatum and Enterococcus faecalis. Conversely, the lysogenic phages poses a potential risk, as they may transfer resistance and virulence factors, enhancing pathogenicity. Conclusions: Phage therapy is a promising approach to address antimicrobial resistance and biofilm challenges in periodontitis management. Key challenges include the need for the clinical validation of formulations and stable delivery systems for the subgingival area. Future strategies, such as phage genetic engineering and data-driven cocktail design, are crucial for enhancing efficacy and overcoming regulatory hurdles. Full article

This study compared the efficacy of three individual lytic phages, PSA_LMAPSA-2T (PSA-2T), PSA_LMAPSA-6F (PSA-6F) and PSA_LMAPSA-7F (PSA-7F) and four phage cocktails (dual and triple combinations) in inactivating Pseudomonas syringae pv. actinidiae. Phages were isolated from kiwifruit leaves and soil samples contaminated with P. syringae pv. actinidiae and characterized by host spectrum, growth parameters, adsorption rate, genomic analysis, inactivation efficiency and viability under variable environmental conditions in orchard environments (temperature, pH and solar radiation). Phage PSA-2T showed the highest in vitro efficacy, achieving a 3.2 log CFU/mL maximum reduction after 18 h, outperforming PSA-6F and PSA-7F (0.6 and 1.5 log reductions, respectively). Phage cocktails achieved reductions of 1.0–2.2 log CFU/mL, but none exceeded the performance of PSA-2T alone. Phage viability was most affected by high temperature and acidic pH, with PSA-7F showing the greatest sensitivity. Nonetheless, all phages remained stable under typical orchard conditions. Phage PSA-2T significantly reduced P. syringae pv. actinidiae levels (1.5-log CFU/mL) on artificially contaminated kiwifruit leaves after a single treatment. These results demonstrate the potential of PSA-2T and phage cocktails as sustainable alternatives to copper and antibiotics, warranting further study of repeated treatments and broad-host-range phage formulations for field use. Full article

Narrow host specificity and bacterial resistance often limit single-phage treatments. Phage cocktails address these challenges by expanding the host range, reducing resistance, and enhancing bacterial inactivation. This study aimed to develop an optimised phage cocktail targeting Escherichia coli, Salmonella enterica serovar Typhimurium, Salmonella enterica serovar Enteritidis, and Aeromonas hydrophila, key pathogens in bivalve consumption. Twelve phages were isolated, purified, and screened for bacterial inactivation using resazurin-based viability assays. Host range analysis showed that all phages infected at least one additional bacterial species, with four (phEc4, phSE1, phAh2, phAh4) targeting three of the four bacteria. Cocktail formulation aimed to maximise bacterial reduction while balancing host range expansion with factors such as the risks of resistance development and inter-phage competition. Among the tested combinations, the most effective cocktail consisted of E. coli phage phEc3, S. Typhimurium phage phST1, S. Enteritidis phage phSE1, and A. hydrophila phage phAh2. Future studies should evaluate the cocktail’s efficacy in vitro and assess both safety and performance in vivo in bivalve depuration systems. 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 global spread of carbapenem-resistant Acinetobacter baumannii (CRAB) poses a severe public health threat, driving growing interest in phage-based precision antibacterial strategies. This systematic review synthesizes recent advances in the field of A. baumannii phage. Modern taxonomy, based on whole-genome phylogeny, has reclassified the majority of A. baumannii phages into the class Caudoviricetes, revealing distinct evolutionary clades that correlate with host tropism and biological properties, superseding the traditional morphological families (Myoviridae, Siphoviridae, Podoviridae). To overcome limitations of natural phage therapy, such as narrow host range, cocktail therapies (ex vivo resistance mutation rates < 5%) and phage-antibiotic synergism (enabling antibiotic efficacy at 1/4 minimum inhibitory concentration) have significantly enhanced antibacterial efficacy. Preclinical models demonstrate that phage therapy efficiently clears pathogens in pneumonia models and promotes the healing of burn wounds and diabetic ulcers via immunomodulatory mechanisms. Technical optimizations include nebulized inhalation delivery achieving 42% alveolar deposition, and thermosensitive hydrogels enabling sustained release over 72 h. Genetic engineering approaches, such as host range expansion through tail fiber recombination and CRISPR/Cas-mediated elimination of lysogeny, show promise. However, the genetic stability of engineered phages requires further validation. Current challenges remain, including limited host spectrum, the absence of clinical translation standards, and lagging regulatory frameworks. Future efforts must integrate metagenomic mining and synthetic biology strategies to establish a precision medicine framework encompassing resistance monitoring and personalized phage formulation, offering innovative solutions against CRAB infections. Full article

Post-harvest bacterial infections pose a serious threat to modern agriculture, resulting in substantial financial losses and environmental issues. Every year, microbial spoiling causes a significant loss in fruit and vegetable production, and traditional control techniques are frequently insufficient. This review highlights novel delivery systems such as edible films and coatings while analyzing recent developments in bacteriophage-based post-harvest disease management techniques. Bacterial resistance, environmental stability, and regulatory issues restrict the use of bacteriophages, despite their high specificity, biodegradability, and low environmental impact. Phage viability in storage and the field has increased thanks to developments in formulation technologies, such as encapsulation and stabilization. The review highlights the practical implementation of phage applications in post-harvest disease management, with a particular focus on innovative delivery systems as well as integrating legal and regulatory viewpoints. By bridging scientific innovation with legal and commercial considerations, this work offers an interdisciplinary foundation for advancing sustainable, phage-based approach. Full article