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PubMed2026

Are Staphylococcus aureus fracture-related infections clonal, and what are the implications for bacteriophage therapy?

Fracture related infections (FRI) are a devastating complication of orthopedic trauma care, most commonly caused by Staphylococcus aureus. The organisms' ability to form biofilms complicates conventional antibiotic therapy and drives demands for novel therapeutics. One promising novel approach is bacteriophage therapy, however this therapeutic has a narrow host range. Thus, understanding whether S. aureus FRIs are clonal or polyclonal is crucial for development of bacteriophage therapy. Consequently, the aim, of this study, was to evaluate 15 S. aureus clinical FRI isolates to determine clonality. For each individual FRI, eight colonies underwent whole-genome sequencing and results were compared to a reference strain to determine genomic variants. Isolates from each individual patient demonstrated greater than 92% shared genomic variants and over a 98% overlap with a merged variant profile, indicating clonal infections across all 15 FRIs. Furthermore, we assessed bacteriophage K activity to the planktonic states of the isolates for which there was similar activity against each individual FRI but different activity amongst the 15 FRI isolates. Lastly, we evaluated variations of genes associated with bacteriophage attachment receptors glycosylation (tarS, M, P) in which there were identical sequences across colonies for each individual FRI, indicating limited intra-infection variation in glycosylation potential of this receptor. This data supports that S. aureus FRI are clonal infections which typically have uniform bacteriophage attachment receptor glycosylation profiles within individual infections. These findings are vital for the development of bacteriophage therapy, suggesting that a single S. aureus colony is sufficient to conduct in vitro testing to determine bacteriophage activity to planktonic forms of S. aureus FRI in vivo. Yet further similar studies evaluating sessile heterogeneity are warranted. Nonetheless, the foundation of knowledge seen here supports further translational research and refinement of bacteriophage therapeutic strategies for S. aureus FRI.

Bacteriophage therapy↗
PubMed2026

First UK use of bacteriophage therapy with DAIR for chronic Staphylococcus aureus prosthetic joint infection.

BACKGROUND: Chronic Staphylococcus aureus prosthetic joint infection (PJI) remains difficult to manage when surgical revision and long-term antibiotics are not feasible. Bacteriophage therapy is emerging as a potential adjunct, though experience in orthopedic infections, particularly in the United Kingdom, is limited. CASE SUMMARY: We report the first UK case of intra-articular bacteriophage therapy administered alongside debridement, antibiotics, and implant retention (DAIR) for chronic methicillin-sensitive Staphylococcus aureus knee PJI. An 81-year-old man with multiple comorbidities developed persistent infection following revision knee arthroplasty, with recurrent sinus formation despite multiple surgical washouts and prolonged suppressive antibiotics. Major revision surgery and amputation were not viable options. Following a multidisciplinary review through the UK Clinical Phage Network, targeted phage therapy was pursued as salvage treatment. Phage susceptibility testing identified an active lytic phage (ISP). The patient underwent open DAIR with intra-articular phage administration, adjunctive local antibiotics, short-course intravenous antimicrobials, and subsequent oral suppressive therapy. Two further intra-articular phage doses were administered postoperatively. Initial sinus closure occurred, but recurrence developed within 4 weeks. At 18 months, symptoms were partially improved with better mobility and reduced inflammation, though one sinus tract persisted. No significant adverse effects were observed. Whole-genome sequencing of pretreatment isolates demonstrated a predominantly ST5 S. aureus genotype with conserved biofilm-associated virulence genes and limited antimicrobial resistance in addition to clonal diversification consistent with chronic biofilm infection. CONCLUSION: This case demonstrates the feasibility and safety of intra-articular phage therapy during DAIR in a UK setting but highlights biological, logistical, and pharmacological factors that may limit efficacy in advanced chronic PJI.

Staphylococcus aureus↗
PubMedDate not supplied

[Bacteriophage therapy of septic complications of orthopaedic surgery (author's transl].

Seven septic cases have been treated by bacteriophage; two infections after insertion of a hip prosthesis, two septic arthritis of the knee, one osteomyelitis of the tibia, one septic non-union of the femur and one septic complication following Harrington rodding. Only specific phages were used in association with several types of surgical procedure. The technique of treatment is described. All cases were long-term infections with resistant organisms. Results were good in five, fair in one and one case was a failure. It is concluded that phage therapy may be helpful in the treatment of long-term infections.

Adult↗
PubMed2026

Chronic suppression of a multidrug-resistant Pseudomonas aeruginosa in prosthetic joint infection using personalized bacteriophage treatment.

Multidrug resistant (MDR) bacterial infections without antibiotic options are a public health emergency. Infections associated with medical implants serve as an example. Conventional antibiotics have limited ability to eradicate these infections as they are associated with antibiotic-tolerant biofilms. Here, we report the use of bacteriophage therapy for the treatment of a MDR, non-operable Pseudomonas aeruginosa periprosthetic joint infection that had failed multiple antibiotic and surgical interventions. Treatment with intermittent bacteriophage therapy alone without antibiotics over a 2 year time period resulted in clinical resolution of the infection, but not microbiological eradication. Bacteriophage therapy established this control, in part, by altering virulence as defined by disease severity and symptoms and disrupting biofilm. Whole genome sequencing demonstrated the continued presence of bacteriophage during treatment. This provides preliminary evidence that bacteriophage therapy can be used to treat MDR infections in salvage cases when surgical and antibiotic options do not exist.

Humans↗
PubMed2026

Genomic characterization and therapeutic potential of five broad-spectrum lytic bacteriophages against multidrug-resistant avian pathogenic Escherichia coli (APEC).

UNLABELLED: Colibacillosis, caused by avian pathogenic Escherichia coli (APEC), results in substantial economic losses in global poultry production. The emergence of multidrug-resistant (MDR) APEC poses zoonotic risks through horizontal transfer of antimicrobial resistance (AMR) genes. Bacteriophage therapy emerges as a safe alternative to antibiotherapy; however, comprehensive characterization of phages targeting MDR-APEC from diverse geographical regions remains limited. We isolated five lytic bacteriophages from poultry fecal samples collected from five Indian states and characterized them through morphological analysis, physiological stability testing, whole-genome sequencing, and in vivo efficacy assessment. Host range was determined against APEC isolates, and therapeutic potential was validated in the Galleria mellonella infection model. All phages showed Myovirus-like morphology and stability across physiologically relevant temperatures (up to 55°C-70°C) and pH conditions (3-11). Phages were classified as Escherichia phage vB_EcoM_fRPOT1, vB_EcoM_fDMYT1, vB_EcoM_fBSZT1, vB_EcoM_fUAMT1, and vB_EcoM_fPKPT2. Their genome size ranges from 170 to 356 kb, belonging to three distinct genera: Dhakavirus, Gaprivervirus, and Asteriusvirus. Genomic analysis confirmed the absence of antimicrobial resistance, virulence, toxin, or lysogeny genes. Fifty-one APEC strains were isolated, of which 23 (45.1%) were MDR. Individual phages lysed 37%-51% of tested APEC and 17%-39% of MDR strains. Three phages (fBSZT1, fUAMT1, and fPKPT2) significantly improved larval survival to 60%-80% at an MOI of 10 in G. mellonella infection models compared to the untreated control. This study establishes a well-characterized phage bank targeting MDR-APEC strains, providing a foundation for developing phage-based interventions to reduce antibiotic dependency and mitigate AMR transmission risks under the One Health framework. IMPORTANCE: The overuse of antibiotics in poultry farming has created a crisis. The multidrug-resistant (MDR) bacteria threaten both animal health and human safety through the food chain. When antibiotics fail, farmers face devastating losses, and resistant bacteria can transfer to humans through consumption or environmental contamination. Bacteriophages offer a practical solution as they kill target bacteria without harming beneficial microbes or leaving chemical residues. Our comprehensive characterization confirms that these five phages are safe and effective as they lack any resistance or toxin genes and rescue 60%-80% of infected larvae. This represents a characterized phage bank targeting the specific resistant strains in Indian poultry. By providing a validated alternative to antibiotics, this work supports sustainable food production while reducing the spread of antimicrobial resistance from farms to humans.

Animals↗
PubMed2026

Beyond antibiotics: artificial intelligence-enabled anti-infective ecosystems for next-generation precision therapeutics against antimicrobial resistance.

The rapid global expansion of antimicrobial resistance (AMR) threatens to undermine decades of progress in infectious disease management and highlights the limitations of conventional antibiotic-centered therapeutic strategies. Although emerging technologies-including antimicrobial peptides, bacteriophage therapy, CRISPR-based antimicrobials, microbiome therapeutics, anti-virulence approaches, nanotechnology-enabled drug delivery, and artificial intelligence (AI)-have individually demonstrated considerable promise, they are predominantly being developed as independent interventions rather than as coordinated components of an integrated therapeutic strategy. This Perspective proposes the Intelligent Anti-Infective Ecosystem (IAIE) as a conceptual systems-level framework that computationally integrates multimodal diagnostics, pathogen genomics, microbiome profiling, AI-assisted decision support, programmable precision therapeutics, ecological monitoring, and longitudinal clinical feedback within a continuously learning dynamically optimized workflow. Unlike existing paradigms that primarily optimize individual technologies or therapeutic decisions, IAIE emphasizes closed-loop coordination among complementary antimicrobial approaches to support precision-guided infection management while preserving microbiome integrity and mitigating resistance selection pressure. We further outline the core components, operational principles, translational challenges, and technology readiness of the major therapeutic platforms that could contribute to such an ecosystem, while distinguishing clinically established interventions from emerging experimental strategies. Importantly, IAIE should be interpreted as a prospective conceptual architecture rather than an existing clinical platform. Its proposed clinical value remains to be established through sequential computational, preclinical, and prospective clinical investigations using standardized microbiological, ecological, and patient-centered outcome measures. By framing antimicrobial innovation within an responsive systems perspective, IAIE provides a roadmap for future multidisciplinary research aimed at integrating artificial intelligence and systems microbiology to enable sustainable management of antimicrobial resistance.

Humans↗
PubMed2026

Genomic and functional characterization of novel therapeutic lytic bacteriophages targeting multidrug-resistant Enterobacter cloacae.

The alarming rates at which extensively drug-resistant (XDR) and pandrug-resistant (PDR) Enterobacter cloacae in hospitals are increasing has begun to severely limit treatment options, and thus the urgency for alternative interventions, including bacteriophage therapy. The purpose of the study was to isolate and molecularly characterize phages that can infect E. cloacae, and, furthermore, to assess the antimicrobial efficacy of the four novel lytic bacteriophages (MMRP1, MMRP2, MMRP3, and MMRP4) against antimicrobial-resistant E. cloacae isolates and to evaluate their potential as alternative therapeutic strategies. These novel phages were characterized by plaque morphology, transmission electron microscopy (TEM), host range testing, thermal and chloroform stability assays, bacterial reduction assays, and whole-genome sequencing (WGS). Among 27 clinical isolates, MDR, XDR, and PDR phenotypes were observed in 20 (74.1%), six (22.2%), and one (3.7%) isolates, respectively. All four phages produced clear lytic plaques (0.5-3.0 mm) with titers reaching up to 6 × 1010 PFU/mL, and the phage cocktail lysed 81.4% (22 of 27 isolates) of clinical isolates with high host specificity. TEM revealed that all four E. cloacae-infecting phages (MMRP1, MMRP2, MMRP3, and MMRP4) belong to the class Caudoviricetes, exhibiting icosahedral capsids, tailed morphology, and double-stranded DNA genomes, consistent with current ICTV classification criteria. Whole genome sequencing and comparative phylogenetic analysis further resolved the taxonomic placement of these phages at the family level, positioning MMRP1 within the family Demerecviridae and MMRP4 within the family Straboviridae. All phages were stable from -20 to 40 °C and were unaffected by exposure to chloroform. Phage cocktail reduced bacterial OD₆₀₀ to ≤ 0.3 within 4 h in the bacterial reduction test. WGS revealed large circular dsDNA genomes of ~132 kbp (MMRP1) and ~149 kbp (MMRP4), GC content of 38%, and modular architectures encoding structural, lytic, and replication gene modules. The most striking and highlighted suggestion that in vitro evaluation of MMRP1 and MMRP4 are highly recommended to more deeper future experimental studies to combat MDR E. cloacae nosocomial infections supported by genomic foundation and eventually, the possibility to be suitable for phage-engineering applications in clinical settings.

Enterobacter cloacae↗
PubMed2026

Isolation and Characterization of Lytic Bacteriophages Targeting Clinical Staphylococcus Other Than S. aureus.

Staphylococcus spp., other than S. aureus (SOSA, formerly CoNS), are opportunistic pathogens often linked to biofilm infections on indwelling devices. Their rising antibiotic resistance highlights the need for novel therapies. Bacteriophages are promising due to their specificity and ability to inhibit cell growth and biofilm formation. In this study, lytic phages isolated from swab pools were characterized against six clinical S. epidermidis and S. warneri isolates. Two distinct groups were identified via their host range, transmission electron microscopy, and genome sequencing. Group 1 phage ΘBRJ9 belongs to genus Sepunavirus (Myoviridae), while Group 2 phage ΘBRJ18 belongs to genus Andhravirus (Podoviridae). Both showed rapid adsorption, short latent periods (20 min), and high burst sizes (79 and 60 PFU/cell). They strongly inhibited planktonic SOSA growth at MOI 10, with efficacy comparable to or better than vancomycin, and their genomes lacked lysogeny, virulence, or resistance genes. These phages display a lytic lifestyle and are candidates for targeted SOSA therapies. Future work will assess biofilm efficacy, antibiotic synergies, and in vivo performance.

Antibiotic resistance↗
PubMed2026

Precision medicine in combating antimicrobial resistance: A comprehensive review.

Antimicrobial resistance (AMR) represents one of the most pressing threats to global public health, undermining the effectiveness of modern antimicrobial therapy and challenging decades of medical progress. This comprehensive review examines the transition from broad-spectrum empirical therapy toward precision medicine as an integrated framework for improving antimicrobial use and combating AMR. Precision medicine seeks to tailor treatment decisions by combining pathogen-specific genomic and resistance data with relevant host characteristics to optimize therapy while limiting unnecessary antimicrobial exposure and the selective pressures that drive resistance. The review synthesizes advances reported from 2020, highlighting established and emerging approaches including rapid molecular diagnostics, next-generation sequencing, CRISPR-based detection, machine learning (ML)-assisted decision support, precision dosing, and targeted therapeutics such as bacteriophage therapy, antimicrobial peptides, and bacterial proteolysis-targeting chimeras. Rather than functioning as isolated technologies, these approaches achieve their greatest clinical value when integrated within antimicrobial stewardship programs and a One Health framework that recognizes the interconnected human, animal, and environmental drivers of resistance. Despite considerable progress, important challenges remain, including equitable access to advanced technologies, interpretation of increasingly complex datasets, workforce and infrastructure limitations, and evolving regulatory pathways for novel diagnostics and therapeutics. This review concludes that while precision medicine is not a standalone solution, its successful implementation will depend on coordinated integration of diagnostics, host factors, computational tools, pharmacological optimization, and stewardship strategies to improve patient outcomes while preserving the long-term effectiveness of existing antimicrobials.

Antimicrobial resistance↗
PubMed2026

Bridging the airway microbiome and targeted therapy in bronchiectasis: multi-omics insights, endotypes and emerging therapies.

Bronchiectasis is a heterogeneous chronic airway disease primarily driven by persistent infection, microbial dysbiosis and dysregulated host immunity. While culture-based microbiology has historically informed clinical management, advances in high-throughput sequencing and multi-omic technologies have transformed our understanding of the airway ecosystem, revealing that disease activity is shaped not only by individual pathogens, but by complex and dynamic host-microbe interactions. Despite the breadth of descriptive microbiome data, translation into clinically actionable diagnostics or therapies has been limited. Importantly, cross-sectional correlations between microbiota and inflammation do not establish cause and effect, underscoring the need to embed host-microbiome profiling within both longitudinal and interventional therapeutic trials. In this review, we critically appraise current microbial and host multi-omics research in bronchiectasis, integrating microbiome studies with host inflammatory, proteomic and immunophenotyping data. We highlight themes emerging across cohorts, including low microbial diversity, pathogen dominance, loss of commensal networks and neutrophil-driven inflammation, and discuss how these features align with biological endotypes associated with exacerbations and treatment response. Drawing on lessons from host-directed therapeutic successes, we examine translational roadblocks limiting microbiome-guided care. We further review emerging microbiome-modulating strategies such as pathogen-specific biologics, bacteriophage therapy, live biotherapeutic products, biofilm-targeting adjuncts and precision antibiotic stewardship. Finally, we propose a roadmap toward microbiome-informed precision medicine through harmonised methodologies, integration of host and microbial biomarkers into clinical trials, and embedding multi-omics pipelines within large international registries. Collectively, these advances have the potential to shift bronchiectasis research and clinical management towards rationally designed, precision medicine-driven therapeutic strategies.

Humans↗
PubMed2026

Isolation and genomic characterization of bacteriophage Luminis, a lytic Yuavirus infecting clinical strains of Pseudomonas aeruginosa.

We report the genome of Luminis, a lytic bacteriophage isolated from wastewater using Pseudomonas aeruginosa mPAO1Δpf4Δpf6. Phage Luminis is a Yuavirus with 61,617 bp of circularly permuted dsDNA and 64.4% GC content. In addition to reference strains, Luminis plaques on two drug-resistant clinical isolates of P. aeruginosa.

Pseudomonas aeruginosa↗
PubMed2026

Complete genome sequences of Staphylococcus epidermidis phages Cicami, Sazerac, Southeast, Slasher, Spartan, and Undine.

Staphylococci are opportunistic pathogens that cause a variety of antibiotic-resistant infections, and staphylococcal viruses (phages) can be harnessed as alternative therapeutics. Here, we report genome sequences of six Staphylococcus epidermidis phages with siphovirus morphology that lack proteins associated with virulence and lysogeny. Our observations suggest potential uses in therapeutic applications.

bacteriophage therapy↗
PubMed2023

Staphylococcus aureus Prophage-Encoded Protein Causes Abortive Infection and Provides Population Immunity against Kayviruses.

Both temperate and obligately lytic phages have crucial roles in the biology of staphylococci. While superinfection exclusion among closely related temperate phages is a well-characterized phenomenon, the interactions between temperate and lytic phages in staphylococci are not understood. Here, we present a resistance mechanism toward lytic phages of the genus Kayvirus, mediated by the membrane-anchored protein designated PdpSau encoded by Staphylococcus aureus prophages, mostly of the Sa2 integrase type. The prophage accessory gene pdpSau is strongly linked to the lytic genes for holin and ami2-type amidase and typically replaces genes for the toxin Panton-Valentine leukocidin (PVL). The predicted PdpSau protein structure shows the presence of a membrane-binding α-helix in its N-terminal part and a cytoplasmic positively charged C terminus. We demonstrated that the mechanism of action of PdpSau does not prevent the infecting kayvirus from adsorbing onto the host cell and delivering its genome into the cell, but phage DNA replication is halted. Changes in the cell membrane polarity and permeability were observed from 10 min after the infection, which led to prophage-activated cell death. Furthermore, we describe a mechanism of overcoming this resistance in a host-range Kayvirus mutant, which was selected on an S. aureus strain harboring prophage 53 encoding PdpSau, and in which a chimeric gene product emerged via adaptive laboratory evolution. This first case of staphylococcal interfamily phage-phage competition is analogous to some other abortive infection defense systems and to systems based on membrane-destructive proteins. IMPORTANCE Prophages play an important role in virulence, pathogenesis, and host preference, as well as in horizontal gene transfer in staphylococci. In contrast, broad-host-range lytic staphylococcal kayviruses lyse most S. aureus strains, and scientists worldwide have come to believe that the use of such phages will be successful for treating and preventing bacterial diseases. The effectiveness of phage therapy is complicated by bacterial resistance, whose mechanisms related to therapeutic staphylococcal phages are not understood in detail. In this work, we describe a resistance mechanism targeting kayviruses that is encoded by a prophage. We conclude that the defense mechanism belongs to a broader group of abortive infections, which is characterized by suicidal behavior of infected cells that are unable to produce phage progeny, thus ensuring the survival of the host population. Since the majority of staphylococcal strains are lysogenic, our findings are relevant for the advancement of phage therapy.

Humans↗
PubMed1976

[Experience with treating complicated forms of abscessing pneumonia in children].

Under observation were 157 patients with different forms of abscessing pneumonias. Pleural complicaitons were noted in 113 patients (about 60%). The complex treatment was employed in all patients (intensive antibacterial therapy, immunotherapy, bacteriophage, administration of protein preparations, vitamin-therapy, fresh blood transfusion, artery system and by means of percutaneous catheterization of th subclavian vein. The results of the treatment are described.

Anti-Bacterial Agents↗
PubMed1975

[Clinical study of the efficacy of staphylococcal anatoxin in relation to the phage group to which the staphylococcal strains--the causative agents of infection--belong].

In comparing the bacteriophage group reference of the strains of pathogenic staphylococci isolated in case of postoperative complications from children given staphylococcus toxoid for prophylactic purpose and from control group it was found that prophylactic vaccinations of staphylococcus toxoid created the most intense immunity against staphylococci of the I bacteriophage group. There was found no significant association between the efficacy of the therapy and bacteriophage reference of staphylococci--the causative agents of the infection.

Bacteriophage Typing↗
PubMed2025

Phage therapy for Klebsiella pneumoniae: Understanding bacteria-phage interactions for therapeutic innovations.

Klebsiella pneumoniae (KP) is a Gram-negative bacterium that commonly resides in the human gastrointestinal tract and can also act as an opportunistic pathogen and cause extra-intestinal infections. KP poses a global health threat because it causes both hospital- and community-acquired infections in immune-competent and immunocompromised hosts. These infections can be multidrug-resistant and/or hypervirulent, making KP infections difficult to treat and deadly. In the absence of effective treatments for recalcitrant KP infections, bacteriophage (phage) therapy is gaining attention as a promising alternative. In this review, we evaluate KP epidemiology and epitope diversity, discuss interactions between KP-targeting phages and their bacterial hosts from an eco-evolutionary perspective, and summarize recent efforts in phage therapy for treating KP infections. We also discuss novel approaches, including genetic engineering and machine learning, as initial steps toward developing KP-targeting phage therapy as a precision medicine approach for an emerging and dangerous pathogen.

Phage Therapy↗
PubMed1975

A review of bacteria in L-phase and their possible clinical significance.

L-phase bacteria are bacterial variants produced by adverse conditions in the environment. Although variant growth may be perpetuated for generations, the changes are not of genetic origin, but due solely to the environment which causes damage to the bacterial cell wall. Since the structure of Gram-positive and Gram-negative cell walls is fundamentally different, the degraded variant which will occur in each case will also be different. Such variants are seldom detected in routine diagnostic laboratories because they will not grow on normal media, as their optimal conditions of growth are changed. L-phase variants bear a strong resemblance to the mycoplasmas; both are resistant to penicillin, both lack characteristic bacterial cell wall constituents, and their colonial and cellular morphology are similar. Since the conditions for mycoplasma cultivation are, at this time, more clearly understood, they provide useful models for handling fragile L-phase organisms. L-phase bacteria may be readily produced in vitro by the action of penicillin, and it is theoretically possible for conversion to occur in vivo just as readily during phagocytosis, by the action of bacteriophage, antibiotic therapy, and other defence mechanisms of the host. In the clinical field, the most difficult problem is the assessment of the significance of the isolation of L-phase bacteria in the individual case because they have not been observed with certainty in the pathological process. It is probable that such organisms may be clinically significant in cases of chronic and recurrent infection, since these bacteria will survive the defence mechanisms of the host which are largely directed at the cell wall.

Anti-Bacterial Agents↗
PubMed2026

Therapeutic potential of a novel virulent bacteriophage XQ-1 against avian pathogenic Escherichia coli infection in broiler chickens.

Avian Pathogenic Escherichia coli (APEC) represents a significant subgroup within extraintestinal pathogenic Escherichia coli strains and constitutes a substantial threat to the global poultry industry. Although the negative impacts of APEC have been mitigated considerably through antibiotic use, this practice has concurrently facilitated the widespread emergence and dissemination of antibiotic-resistant APEC strains worldwide. Consequently, bacteriophage has emerged as a promising alternative to antibiotics. In the current study, a novel virulent bacteriophage, designated XQ-1, was isolated from a sewage sample collected at a broiler chickens farm in Hubei Province, China. Notably, this bacteriophage exhibited the capability to lyse multiple APEC strains, including O1, O2, and O78 serotypes. The optimal multiplicity of infection (MOI) for bacteriophage XQ-1 was determined to be 0.001, yielding a maximum viral titer of 4.73 ± 0.31 × 1011 plaque-forming units (PFU) per milliliter. This bacteriophage displayed a latent period of 30 min, and a burst period of 80 minutes, corresponding to a burst size of 348 PFU per infected cell. Additionally, bacteriophage XQ-1 retained high lytic activity across a temperature range of 4-50 °C and maintained tolerance with a pH range of 3-11. Further in vitro studies demonstrated that bacteriophage XQ-1 holds potential as an effective disinfectant capable of directly lysing APEC strain JZ-1. In chick models subjected to intraperitoneal injection, exposure to APEC resulted in 100% mortality in chicks. However, treatment with bacteriophage XQ-1 significantly improved the survival rates of infected broiler chickens, reduced organ indexes, decreased bacterial loads in the liver and heart organs, and mitigated intestinal damage caused by APEC infection. Collectively, these findings suggest that bacteriophage XQ-1 represents a promising candidate for the prevention and treatment of APEC infections in poultry.

APEC↗