Personalized bacteriophage therapy outcomes for 100 consecutive cases: a multicentre, multinational, retrospective observational study.

In contrast to the many reports of successful real-world cases of personalized bacteriophage therapy (BT), randomized controlled trials of non-personalized bacteriophage products have not produced the expected results. Here we present the outcomes of a retrospective observational analysis of the first 100 consecutive cases of personalized BT of difficult-to-treat infections facilitated by a Belgian consortium in 35 hospitals, 29 cities and 12 countries during the period from 1 January 2008 to 30 April 2022. We assessed how often personalized BT produced a positive clinical outcome (general efficacy) and performed a regression analysis to identify functional relationships. The most common indications were lower respiratory tract, skin and soft tissue, and bone infections, and involved combinations of 26 bacteriophages and 6 defined bacteriophage cocktails, individually selected and sometimes pre-adapted to target the causative bacterial pathogens. Clinical improvement and eradication of the targeted bacteria were reported for 77.2% and 61.3% of infections, respectively. In our dataset of 100 cases, eradication was 70% less probable when no concomitant antibiotics were used (odds ratio = 0.3; 95% confidence interval = 0.127-0.749). In vivo selection of bacteriophage resistance and in vitro bacteriophage-antibiotic synergy were documented in 43.8% (7/16 patients) and 90% (9/10) of evaluated patients, respectively. We observed a combination of antibiotic re-sensitization and reduced virulence in bacteriophage-resistant bacterial isolates that emerged during BT. Bacteriophage immune neutralization was observed in 38.5% (5/13) of screened patients. Fifteen adverse events were reported, including seven non-serious adverse drug reactions suspected to be linked to BT. While our analysis is limited by the uncontrolled nature of these data, it indicates that BT can be effective in combination with antibiotics and can inform the design of future controlled clinical trials. BT100 study, ClinicalTrials.gov registration: NCT05498363 .

Phage therapy: breathing new tactics into lower respiratory tract infection treatments.

Lower respiratory tract infections (LRTIs) present a significant global health burden, exacerbated by the rise in antimicrobial resistance (AMR). The persistence and evolution of multidrug-resistant bacteria intensifies the urgency for alternative treatments. This review explores bacteriophage (phage) therapy as an innovative solution to combat bacterial LRTIs. Phages, abundant in nature, demonstrate specificity towards bacteria, minimal eukaryotic toxicity, and the ability to penetrate and disrupt bacterial biofilms, offering a targeted approach to infection control. The article synthesises evidence from systematic literature reviews spanning 2000-2023, in vitro and in vivo studies, case reports and ongoing clinical trials. It highlights the synergistic potential of phage therapy with antibiotics, the immunophage synergy in animal models, and the pharmacodynamics and pharmacokinetics critical for clinical application. Despite promising results, the article acknowledges that phage therapy is at a nascent stage in clinical settings, the challenges of phage-resistant bacteria, and the lack of comprehensive cost-effectiveness studies. It stresses the need for further research to optimise phage therapy protocols and navigate the complexities of phage-host interactions, particularly in vulnerable populations such as the elderly and immunocompromised. We call for regulatory adjustments to facilitate the exploration of the long-term effects of phage therapy, aiming to incorporate this old-yet-new therapy into mainstream clinical practice to tackle the looming AMR crisis.

Making the leap from technique to treatment - genetic engineering is paving the way for more efficient phage therapy.

Bacteriophages (phages) are viruses specific to bacteria that target them with great efficiency and specificity. Phages were first studied for their antibacterial potential in the early twentieth century; however, their use was largely eclipsed by the popularity of antibiotics. Given the surge of antimicrobial-resistant strains worldwide, there has been a renaissance in harnessing phages as therapeutics once more. One of the key advantages of phages is their amenability to modification, allowing the generation of numerous derivatives optimised for specific functions depending on the modification. These enhanced derivatives could display higher infectivity, expanded host range or greater affinity to human tissues, where some bacterial species exert their pathogenesis. Despite this, there has been a noticeable discrepancy between the generation of derivatives in vitro and their clinical application in vivo. In most instances, phage therapy is only used on a compassionate-use basis, where all other treatment options have been exhausted. A lack of clinical trials and numerous regulatory hurdles hamper the progress of phage therapy and in turn, the engineered variants, in becoming widely used in the clinic. In this review, we outline the various types of modifications enacted upon phages and how these modifications contribute to their enhanced bactericidal function compared with wild-type phages. We also discuss the nascent progress of genetically modified phages in clinical trials along with the current issues these are confronted with, to validate it as a therapy in the clinic.

Bacteriophages and bacterial extracellular vesicles, threat or opportunity?

Emergence of antimicrobial-resistant bacteria (AMR) is one of the health major problems worldwide. The scientists are looking for a novel method to treat infectious diseases. Phage therapy is considered a suitable approach for treating infectious diseases. However, there are different challenges in this way. Some biological aspects can probably influence on therapeutic results and further investigations are necessary to reach a successful phage therapy. Bacteriophage activity can influence by bacterial defense system. Bacterial extracellular vesicles (BEVs) are one of the bacterial defense mechanisms which can modify the results of bacteriophage activity. BEVs have the significant roles in the gene transferring, invasion, escape, and spreading of bacteriophages. In this review, the defense mechanisms of bacteria against bacteriophages, especially BEVs secretion, the hidden linkage of BEVs and bacteriophages, and its possible consequences on the bacteriophage activity as well phage therapy will be discussed.

Protocol for phage matching, treatment, and monitoring for compassionate bacteriophage use in non-resolving infections.

Phage therapy has re-emerged as a promising treatment for non-resolving infections. Given the lack of approved phage treatments, there is a need to establish a compassionate use pipeline. Here, we present a protocol for phage matching, treatment, and monitoring for compassionate bacteriophage use in non-resolving infections. We describe steps for consultation and request implementation, evaluating and comparing different aspects of phage activity, and phage production. We then detail procedures for multidisciplinary meetings, ethics approvals, phage therapy, and follow-up. For complete details on the use and execution of this protocol, please refer to Onallah et al.1,2.

Comparison of bacterial species and clinical outcomes in patients with diabetic hand infection in tropical and nontropical regions.

Hand infection is a rare complication in patients with diabetes. Its clinical outcomes depend on the severity of hand infection caused by bacteria, but the difference in bacterial species in the regional disparity is unknown. The purpose of this study was to explore the influence of tropical and nontropical regions on bacterial species and clinical outcomes for diabetic hand. A systematic literature review was conducted using PubMed, EMBASE, Web of Science, and Google Scholar. Moreover, the bacterial species and clinical outcomes were analyzed with respect to multicenter wound care in China (nontropical regions). Both mixed bacteria (31.2% vs. 16.6%, p = 0.014) and fungi (7.5% vs. 0.8%, p = 0.017) in the nontropical region were significantly more prevalent than those in the tropical region. Staphylococcus and Streptococcus spp. were dominant in gram-positive bacteria, and Klebsiella, Escherichia coli, Proteus and Pseudomonas in gram-negative bacteria occupied the next majority in the two regions. The rate of surgical treatment in the patients was 31.2% in the nontropical region, which was significantly higher than the 11.4% in the tropical region (p = 0.001). Although the overall mortality was not significantly different, there was a tendency to be increased in tropical regions (6.3%) compared with nontropical regions (0.9%). However, amputation (32.9% vs. 31.3%, p = 0.762) and disability (6.3% vs. 12.2%, p = 0.138) were not significantly different between the two regions. Similar numbers of cases were reported, and the most common bacteria were similar in tropical and nontropical regions in patients with diabetic hand. There were more species of bacteria in the nontropical region, and their distribution was basically similar, except for fungi, which had differences between the two regions. The present study also showed that surgical treatment and mortality were inversely correlated because delays in debridement and surgery can deteriorate deep infections, eventually leading to amputation and even death.

[Optimization of the puncture treatment method for acute bacterial maxillary sinusitis]. / Optimizatsiya metoda punktsionnogo lecheniya ostrogo bakterial'nogo verkhnechelyustnogo sinusita.

OBJECTIVE: Optimization of the method of puncture treatment of acute bacterial maxillary sinusitis (ABMS) through the development of original devices for drainage of the maxillary sinus (MS). MATERIAL AND METHODS: Registration and comparative analysis of the results of puncture methods of treatment of 120 patients with ABMS using developed new original devices for drainage of MS with one channels and with two channels in comparison with the Kulikovsky's needle (KN) was carried out. Based on the results of the analysis, the effectiveness of the original devices was assessed. During the clinical study, patients were divided into two groups: in group I, patients underwent of the MS puncture using KN, in group II, using original devices. Groups I and II, depending on the absence or presence of a block of the natural anastomosis MS, was divided into subgroups A and B, respectively. After puncture of the MS, the pain syndrome was assessed by patients using Visual Analogue Scale (VAS) and by doctors - using Touch Visual Pain (TVP) scale. RESULTS: Our study showed that when puncturing the upper jaw with an original needle with one channels and with two channels, compared with the use of KN, there is a decrease in pain (the average VAS score was 1.5±0.3 and 1.7±0.3 points, respectively; the average TVP scale score was 0.9±0.2 and 1.8±0.3 points, respectively, the difference is significant, p≤0.05). Patients of subgroup IB were manipulated with two KN, patients of subgroup IIB manipulated using the original device with two channels without an additional needle (the average VAS score was 3.0±0.4 and 1.3±0.3 points, respectively; the average TVP scale score was 2.7±0.4 and 1.0±0.2 points, respectively, the difference is significant, p≤0.05). The doctors also assessed the devices used for puncture of the upper jaw. As a result of the study, the high efficiency and safety of using new original devices was established.

Implications of lytic phage infections inducing persistence.

Phage therapy holds much promise as an alternative to antibiotics for fighting infection. However, this approach is no panacea as recent results show that a small fraction of cells survives lytic phage infection due to both dormancy (i.e. formation of persister cells) and resistance (genetic change). In this brief review, we summarize evidence suggesting phages induce the persister state. Therefore, it is predicted that phage cocktails should be combined with antipersister compounds to eradicate bacterial infections.

Current Knowledge and Perspectives of Phage Therapy for Combating Refractory Wound Infections.

Wound infection is one of the most important factors affecting wound healing, so its effective control is critical to promote the process of wound healing. However, with the increasing prevalence of multi-drug-resistant (MDR) bacterial strains, the prevention and treatment of wound infections are now more challenging, imposing heavy medical and financial burdens on patients. Furthermore, the diminishing effectiveness of conventional antimicrobials and the declining research on new antibiotics necessitate the urgent exploration of alternative treatments for wound infections. Recently, phage therapy has been revitalized as a promising strategy to address the challenges posed by bacterial infections in the era of antibiotic resistance. The use of phage therapy in treating infectious diseases has demonstrated positive results. This review provides an overview of the mechanisms, characteristics, and delivery methods of phage therapy for combating pathogenic bacteria. Then, we focus on the clinical application of various phage therapies in managing refractory wound infections, such as diabetic foot infections, as well as traumatic, surgical, and burn wound infections. Additionally, an analysis of the potential obstacles and challenges of phage therapy in clinical practice is presented, along with corresponding strategies for addressing these issues. This review serves to enhance our understanding of phage therapy and provides innovative avenues for addressing refractory infections in wound healing.

Virulence-associated factors as targets for phage infection.

Bacterial pathogens can infect a wide range of hosts and pose a threat to public and animal health as well as to agriculture. The emergence of antibiotic-resistant strains has increased this risk by making the treatment of bacterial infections even more challenging. Pathogenic bacteria thrive in various ecological niches, but they can also be specifically targeted and killed by bacteriophages (phages). Lytic phages are now investigated and even used, in some cases, as alternatives or complements to antibiotics for preventing or treating bacterial infections (phage therapy). As such, it is key to identify factors responsible for phage specificity and efficiency. Here, we review recent advances in virulence-associated factors that are targeted by phages. We highlight components of the bacterial cell surface, effector systems, and motility structures exploited by phages and the effects of phages on cell aggregation and communication. We also look at the fitness trade-off of phage resistance.

A universal strategy to enhance photothermal conversion efficiency by regulating the molecular aggregation states for safe photothermal therapy of bacterial infections.

Photothermal therapy (PTT) has emerged as a promising approach for treating bacterial infections. However, achieving a high photothermal conversion efficiency (PCE) of photothermal agents (PTAs) remains a challenge. Such a problem is usually compensated by the use of a high-intensity laser, which inevitably causes tissue damage. Here, we present a universal strategy to enhance PCE by regulating the molecular aggregation states of PTAs within thermoresponsive nanogels. We demonstrate the effectiveness of this approach using aggregation-induced emission (AIE) and aggregation-caused quenching (ACQ) PTAs, showing significant enhancements in PCE without the need for intricate molecular modifications. Notably, the highest PCEs reach up to 80.9% and 64.4% for AIE-NG and ACQ-NG, respectively, which are nearly 2-fold of their self-aggregate counterparts. Moreover, we elucidate the mechanism underlying PCE enhancement, highlighting the role of strong intermolecular π-π interactions facilitated by nanogel-induced volume contraction. Furthermore, we validate the safety and efficacy of this strategy in in vitro and in vivo models of bacterial infections at safe laser power densities, demonstrating its potential for clinical translation. Our findings offer a straightforward, universal, and versatile method to improve PTT outcomes while minimizing cytotoxicity, paving the way for enhanced treatment of bacterial infections with safe PTT protocols.

Bacteriophages as a potential substitute for antibiotics: A comprehensive review.

Over the years, the administration of antibiotics for the purpose of addressing bacterial infections has become increasingly challenging due to the increased prevalence of antimicrobial resistance exhibited by various strains of bacteria. Multidrug-resistant (MDR) bacterial species are rising due to the unavailability of novel antibiotics, leading to higher mortality rates. With these conditions, there is a need for alternatives in which phage therapy has made promising results. Phage-derived endolysins, phage cocktails, and bioengineered phages are effective and have antimicrobial properties against MDR and extensively drug-resistant strains. Despite these, it has been observed that phages can give antimicrobial activity to more than one bacterial species. Thus, phage cocktail against resistant strains provides broad spectrum treatment and magnitude of effectivity, which is many folds higher than antibiotics. Many commercially available endolysins such as Staphefekt SA.100, Exebacase (CF-301), and N-Rephasin®SAL200 are used in biofilm penetration and treating plant diseases. The role of CMP1 phage endolysin in transgenic tomato plants in preventing Clavibacter michiganensis infection and the effectiveness of phage in protecting Atlantic salmon from vibriosis have been reported. Furthermore, phage-derived endolysin therapy, such as TSPphg phage exogenous treatment, can aid in disrupting cell walls, leading to bacterial cell lysis. As animals in aquaculture and slaughterhouses are highly susceptible to bacterial infections, effective phage therapy instead of antibiotics can help treat poultry animals, preserve them, and facilitate disease-free trade. Using bioengineered phages and phage cocktails enhances the effectiveness by providing a broad spectrum of phages and target specificity. Research is currently being conducted on clinical trials to confirm the efficacy of engineered phages and phage cocktails in humans. Although obtaining commercial approval may be time-consuming, it will be beneficial in the postantibiotic era. This review provides an overview of the significance of phage therapy as a potential alternative to antibiotics in combating resistant bacterial strains and its application to various fields and emphasizes the importance of safeguarding and ensuring treatment efficacy.

The Medicinal Phage-Regulatory Roadmap for Phage Therapy under EU Pharmaceutical Legislation.

Bacteriophage therapy is a promising approach to treating bacterial infections. Research and development of bacteriophage therapy is intensifying due to the increase in antibiotic resistance and the faltering development of new antibiotics. Bacteriophage therapy uses bacteriophages (phages), i.e., prokaryotic viruses, to specifically target and kill pathogenic bacteria. The legal handling of this type of therapy raises several questions. These include whether phage therapeutics belong to a specially regulated class of medicinal products, and which legal framework should be followed with regard to the various technical ways in which phage therapeutics can be manufactured and administered. The article shows to which class of medicinal products phage therapeutics from wild type phages and from genetically modified (designer) phages do or do not belong. Furthermore, the article explains which legal framework is relevant for the manufacture and administration of phage therapeutics, which are manufactured in advance in a uniform, patient-independent manner, and for tailor-made patient-specific phage therapeutics. For the systematically coherent, successful translation of phage therapy, the article considers pharmaceutical law and related legal areas, such as genetic engineering law. Finally, the article shows how the planned legislative revisions of Directive 2001/83/EC and Regulation (EC) No 726/2004 may affect the legal future of phage therapy.

Bacteriophage-Host Interactions and the Therapeutic Potential of Bacteriophages.

Healthcare faces a major problem with the increased emergence of antimicrobial resistance due to over-prescribing antibiotics. Bacteriophages may provide a solution to the treatment of bacterial infections given their specificity. Enzymes such as endolysins, exolysins, endopeptidases, endosialidases, and depolymerases produced by phages interact with bacterial surfaces, cell wall components, and exopolysaccharides, and may even destroy biofilms. Enzymatic cleavage of the host cell envelope components exposes specific receptors required for phage adhesion. Gram-positive bacteria are susceptible to phage infiltration through their peptidoglycan, cell wall teichoic acid (WTA), lipoteichoic acids (LTAs), and flagella. In Gram-negative bacteria, lipopolysaccharides (LPSs), pili, and capsules serve as targets. Defense mechanisms used by bacteria differ and include physical barriers (e.g., capsules) or endogenous mechanisms such as clustered regularly interspaced palindromic repeat (CRISPR)-associated protein (Cas) systems. Phage proteins stimulate immune responses against specific pathogens and improve antibiotic susceptibility. This review discusses the attachment of phages to bacterial cells, the penetration of bacterial cells, the use of phages in the treatment of bacterial infections, and the limitations of phage therapy. The therapeutic potential of phage-derived proteins and the impact that genomically engineered phages may have in the treatment of infections are summarized.

Safety and efficacy of phage application in bacterial decolonisation: a systematic review.

Colonisation by bacterial pathogens typically precedes invasive infection and seeds transmission. Thus, effective decolonisation strategies are urgently needed. The literature reports attempts to use phages for decolonisation. To assess the in-vivo efficacy and safety of phages for bacterial decolonisation, we performed a systematic review by identifying relevant studies to assess the in-vivo efficacy and safety of phages for bacterial decolonisation. We searched PubMed, Embase (Ovid), MEDLINE (Ovid), Web of Science, and the Cochrane Library to identify relevant articles published between Jan 1, 1990, and May 12, 2023, without language restrictions. We included studies that assessed the efficacy of phage for bacterial decolonisation in humans or vertebrate animal models. This systematic review is registered with PROSPERO, CRD42023457637. We identified 6694 articles, of which 56 (51 animal studies and five clinical reports) met the predetermined selection criteria and were included in the final analysis. The gastrointestinal tract (n=49, 88%) was the most studied bacterial colonisation site, and other sites were central venous catheters, lung, nose, skin, and urinary tract. Of the 56 included studies, the bacterial load at the colonisation site was reported to decrease significantly in 45 (80%) studies, but only five described eradication of the target bacteria. 15 studies reported the safety of phages for decolonisation. No obvious adverse events were reported in both the short-term and long-term observation period. Given the increasing life-threatening risks posed by bacteria that are difficult to treat, phages could be an alternative option for bacterial decolonisation, although further optimisation is required before their application to meet clinical needs.

Bacteriophages-Dangerous Viruses Acting Incognito or Underestimated Saviors in the Fight against Bacteria?

The steadily increasing number of drug-resistant bacterial species has prompted the search for alternative treatments, resulting in a growing interest in bacteriophages. Although they are viruses infecting bacterial cells, bacteriophages are an extremely important part of the human microbiota. By interacting with eukaryotic cells, they are able to modulate the functioning of many systems, including the immune and nervous systems, affecting not only the homeostasis of the organism, but potentially also the regulation of pathological processes. Therefore, the aim of this review is to answer the questions of (i) how animal/human immune systems respond to bacteriophages under physiological conditions and under conditions of reduced immunity, especially during bacterial infection; (ii) whether bacteriophages can induce negative changes in brain functioning after crossing the blood-brain barrier, which could result in various disorders or in an increase in the risk of neurodegenerative diseases; and (iii) how bacteriophages can modify gut microbiota. The crucial dilemma is whether administration of bacteriophages is always beneficial or rather if it may involve any risks.

An exploration of the value of NLR, PLR, LMR, and WBC × CRP for the diagnosis and treatment of influenza B in adults.

The aim of the study was to study the diagnostic and therapeutic utility of NLR (neutrophil-to-lymphocyte ratio), LWR (lymphocyte-to-monocyte ratio), PLR (platelet-to-lymphocyte ratio), and WBC × CRP (WBC: white cell count, CRP: C-reactive protein) in patients with influenza B. This retrospective study included 122 adult patients with influenza B, 176 adult patients with bacterial infection, and 119 adult healthy physical examinees for routine blood examination and CRP testing, calculation of NLR, LMR, PLR, and WBC × CRP for relevant statistical analysis, monitoring of NLR, LMR, PLR and WBC × CRP in patients with influenza B during relevant treatment. All indicators, except for WBC and NLR, had no statistical differences between the influenza B group, the normal control group, and the influenza B group and bacterial infection group, respectively, and showed no statistical significance for the differences between the groups. The diagnostic effect of LMR and WBC × CRP was deemed good or excellent in patients with influenza B, healthy people, and patients with a bacterial infection. Conversely, NLR and PLR could only distinguish patients with influenza B from healthy people but remained unable to identify different pathogens. Moreover, many false negatives were noted for WBC and CRP during the diagnosis of influenza B. Also, NLR, LMR, PLR, and WBC × CRP exerted a good effect in evaluating curative effect and conditions for influenza B. LMR and WBC × CRP have a relatively high value in the early diagnosis of adults suffering from influenza B. Also, NLR and PLR excelled at differentiating adult patients with influenza B from healthy people. Therefore, NLR, PLR, LMR, and WBC × CRP can all be used for disease course monitoring and efficacy evaluation.

Bacteriophage therapy and current delivery strategies for orthopedic infections: A SCOPING review.

OBJECTIVES: Interest in phages as adjunctive therapy to treat difficult infections has grown in the last decade. However, phage dosing and delivery for orthopedic infections have not been systematically summarized. METHODS: Following PRISMA-ScR guidelines, we conducted a SCOPING review through September 1st, 2023, of MEDLINE, Embase, Web of Science Core Collection, and Cochrane Central. RESULTS: In total, 77 studies were included, of which 19 (24.7%) were in vitro studies, 17 (22.1%) were animal studies, and 41 (53.2%) were studies in humans. A total of 137 contemporary patients receiving phage therapy are described. CONCLUSIONS: Direct phage delivery remains the most studied form of phage therapy, notably in prosthetic joint infections, osteomyelitis, and diabetic foot ulcers. Available evidence describing phage therapy in humans suggests favorable outcomes for orthopedic infections, though this evidence is composed largely of low-level descriptive studies. Several phage delivery devices have been described, though a lack of comparative and in-human evidence limits their therapeutic application. Limitations to the use of phage therapy for orthopedic infections that need to be overcome include a lack of understanding related to optimal dosing and phage pharmacokinetics, bacterial heterogeneity in an infection episode, and phage therapy toxicity.