Long-Term Safety of Topical Bacteriophage Application to the Frontal Sinus Region

Staphylococcus aureus and biofilms: transmission, threats, and promising strategies in animal husbandry

Staphylococcus aureus (S. aureus) is a common pathogenic bacterium in animal husbandry that can cause diseases such as mastitis, skin infections, arthritis, and other ailments. The formation of biofilms threatens and exacerbates S. aureus infection by allowing the bacteria to adhere to pathological areas and livestock product surfaces, thus triggering animal health crises and safety issues with livestock products. To solve this problem, in this review, we provide a brief overview of the harm caused by S. aureus and its biofilms on livestock and animal byproducts (meat and dairy products). We also describe the ways in which S. aureus spreads in animals and the threats it poses to the livestock industry. The processes and molecular mechanisms involved in biofilm formation are then explained. Finally, we discuss strategies for the removal and eradication of S. aureus and biofilms in animal husbandry, including the use of antimicrobial peptides, plant extracts, nanoparticles, phages, and antibodies. These strategies to reduce the spread of S. aureus in animal husbandry help maintain livestock health and improve productivity to ensure the ecologically sustainable development of animal husbandry and the safety of livestock products.

Bacteriophages: Status quo and emerging trends toward one health approach

The alarming rise in antimicrobial resistance (AMR) among the drug-resistant pathogens has been attributed to the ESKAPEE group (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumanii, Pseudomonas aeruginosa, Enterobacter sp., and Escherichia coli). Recently, these AMR microbes have become difficult to treat, as they have rendered the existing therapeutics ineffective. Thus, there is an urgent need for effective alternatives to lessen or eliminate the current infections and limit the spread of emerging diseases under the "One Health" framework. Bacteriophages (phages) are naturally occurring biological resources with extraordinary potential for biomedical, agriculture/food safety, environmental protection, and energy production. Specific unique properties of phages, such as their bactericidal activity, host specificity, potency, and biocompatibility, make them desirable candidates in therapeutics. The recent biotechnological advancement has broadened the repertoire of phage applications in nanoscience, material science, physical chemistry, and soft-matter research. Herein, we present a comprehensive review, coupling the substantial aspects of phages with their applicability status and emerging opportunities in several interdependent areas under one health concept. Consolidating the recent state-of-the-art studies that integrate human, animal, plant, and environment health, the following points have been highlighted: (i) The biomedical and pharmacological advantages of phages and their antimicrobial derivatives with particular emphasis on in-vivo and clinical studies. (ii) The remarkable potential of phages to be altered, improved, and applied for drug delivery, biosensors, biomedical imaging, tissue engineering, energy, and catalysis. (iii) Resurgence of phages in biocontrol of plant, food, and animal-borne pathogens. (iv) Commercialization of phage-based products, current challenges, and perspectives.

Phage therapy: a revolutionary shift in the management of bacterial infections, pioneering new horizons in clinical practice, and reimagining the arsenal against microbial pathogens

The recent approval of experimental phage therapies by the FDA and other regulatory bodies with expanded access in cases in the United States and other nations caught the attention of the media and the general public, generating enthusiasm for phage therapy. It started to alter the situation so that more medical professionals are willing to use phage therapies with conventional antibiotics. However, more study is required to fully comprehend phage therapy's potential advantages and restrictions, which is still a relatively new field in medicine. It shows promise, nevertheless, as a secure and prosperous substitute for antibiotics when treating bacterial illnesses in animals and humans. Because of their uniqueness, phage disinfection is excellent for ready-to-eat (RTE) foods like milk, vegetables, and meat products. The traditional farm-to-fork method can be used throughout the food chain to employ bacteriophages to prevent food infections at all production stages. Phage therapy improves clinical outcomes in animal models and lowers bacterial burdens in numerous preclinical investigations. The potential of phage resistance and the need to make sure that enough phages are delivered to the infection site are obstacles to employing phages in vivo. However, according to preclinical studies, phages appear to be a promising alternative to antibiotics for treating bacterial infections in vivo. Phage therapy used with compassion (a profound understanding of and empathy for another's suffering) has recently grown with many case reports of supposedly treated patients and clinical trials. This review summarizes the knowledge on the uses of phages in various fields, such as the food industry, preclinical research, and clinical settings. It also includes a list of FDA-approved bacteriophage-based products, commercial phage products, and a global list of companies that use phages for therapeutic purposes.

The Safety of Bacteriophages in Treatment of Diseases Caused by Multidrug-Resistant Bacteria

Given the urgency due to the rapid emergence of multidrug-resistant (MDR) bacteria, bacteriophages (phages), which are viruses that specifically target and kill bacteria, are rising as a potential alternative to antibiotics. In recent years, researchers have begun to elucidate the safety aspects of phage therapy with the aim of ensuring safe and effective clinical applications. While phage therapy has generally been demonstrated to be safe and tolerable among animals and humans, the current research on phage safety monitoring lacks sufficient and consistent data. This emphasizes the critical need for a standardized phage safety assessment to ensure a more reliable evaluation of its safety profile. Therefore, this review aims to bridge the knowledge gap concerning phage safety for treating MDR bacterial infections by covering various aspects involving phage applications, including phage preparation, administration, and the implications for human health and the environment.

Pathophysiology and management of Staphylococcus aureus in nasal polyp disease

INTRODUCTION

Staphylococcus aureus (S. aureus) is a common pathogen that frequently colonizes the sinonasal cavity. Recent studies demonstrated the essential role of Staphylococcus aureus in the pathophysiology of uncontrolled severe chronic rhinosinusitis with nasal polyps (NP) by initiating an immune response to the germ and its products, resulting in type 2 inflammation.

AREAS COVERED

This review aims to summarize the evidence for the role of S. aureus in the development of NP disease including S. aureus-related virulence factors, the pathophysiologic mechanisms used by S. aureus, and the synergistic effects of S. aureus and other pathogens. It also describes the current management of S. aureus associated with NPs as well as potential therapeutic strategies that are used in clinical practice.

EXPERT OPINION

S. aureus is able to damage the nasal mucosal epithelial barrier, impair the clearance of the host immune system, and trigger adaptive and innate immune reactions which lead to the formation of inflammation and nasal polyp growth. Further studies should focus on the development of novel therapeutic strategies, such as biologics, bacteriophages, probiotics, and nanomedicine, which could be used to treat S. aureus and its immunological consequences in the future.

Examining the effects of Salmonella phage on the caecal microbiota and metabolome features in Salmonella-free broilers

Bacteriophages selectively infect and kill their target bacterial host, being a promising approach to controlling zoonotic bacteria in poultry production. To ensure confidence in its use, fundamental questions of safety and toxicity monitoring of phage therapy should be raised. Due to its high specificity, a minimal impact on the gut ecology is expected; however, more in-depth research into key parameters that influence the success of phage interventions has been needed to reach a consensus on the impact of bacteriophage therapy in the gut. In this context, this study aimed to investigate the interaction of phages with animals; more specifically, we compared the caecum microbiome and metabolome after a Salmonella phage challenge in Salmonella-free broilers, evaluating the role of the phage administration route. To this end, we employed 45 caecum content samples from a previous study where Salmonella phages were administered via drinking water or feed for 24 h from 4, 5 to 6-weeks-old broilers. High-throughput 16S rRNA gene sequencing showed a high level of similarity (beta diversity) but revealed a significant change in alpha diversity between broilers with Salmonella-phage administered in the drinking water and control. Our results showed that the phages affected only a few genera of the microbiota's structure, regardless of the administration route. Among these, we found a significant increase in Streptococcus and Sellimonas in the drinking water and Lactobacillus, Anaeroplasma and Clostridia_vadinBB60_group in the feed. Nevertheless, the LC-HRMS-based metabolomics analyses revealed that despite few genera were significantly affected, a substantial number of metabolites, especially in the phage administered in the drinking water were significantly altered (64 and 14 in the drinking water and feed groups, respectively). Overall, our study shows that preventive therapy with bacteriophages minimally alters the caecal microbiota but significantly impacts their metabolites, regardless of the route of administration.

Novel antimicrobial agents for combating antibiotic-resistant bacteria

Antibiotic therapy has become increasingly ineffective against bacterial infections due to the rise of resistance. In particular, ESKAPE pathogens (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter species) have caused life-threatening infections in humans and represent a major global health threat due to a high degree of antibiotic resistance. To respond to this urgent call, novel strategies are urgently needed, such as bacteriophages (or phages), phage-encoded enzymes, immunomodulators and monoclonal antibodies. This review critically analyses these promising antimicrobial therapies for the treatment of multidrug-resistant bacterial infections. Recent advances in these novel therapeutic strategies are discussed, focusing on preclinical and clinical investigations, as well as combinatorial approaches. In this 'Bad Bugs, No Drugs' era, novel therapeutic strategies can play a key role in treating deadly infections and help extend the lifetime of antibiotics.

Microbiome therapeutics: exploring the present scenario and challenges

Human gut-microbiome explorations have enriched our understanding of microbial colonization, maturation, and dysbiosis in health-and-disease subsets. The enormous metabolic potential of gut microbes and their role in the maintenance of human health is emerging, with new avenues to use them as therapeutic agents to overcome human disorders. Microbiome therapeutics are aimed at engineering the gut microbiome using additive, subtractive, or modulatory therapy with an application of native or engineered microbes, antibiotics, bacteriophages, and bacteriocins. This approach could overcome the limitation of conventional therapeutics by providing personalized, harmonized, reliable, and sustainable treatment. Its huge economic potential has been shown in the global therapeutics market. Despite the therapeutic and economical potential, microbiome therapeutics is still in the developing stage and is facing various technical and administrative issues that require research attention. This review aims to address the current knowledge and landscape of microbiome therapeutics, provides an overview of existing health-and-disease applications, and discusses the potential future directions of microbiome modulations.

Phage Treatment Trial to Eradicate LA-MRSA from Healthy Carrier Pigs

The increase of livestock-associated methicillin-resistant Staphylococcus aureus (LA-MRSA) causes a threat to human health. LA-MRSA can be transmitted from animals to animal caretakers, which may further spread MRSA to communities and health care facilities. The objective of this work was to study the efficacy of phage treatment in the eradication of LA-MRSA from healthy carrier pigs. A total of 19 MRSA -positive weanling pigs were assigned to a test (n = 10) and a control group (n = 9). A phage cocktail containing three Staphylococcus phages, or a control buffer was administered to the nares and skin of the pigs three times every two days, after which the phage and MRSA levels in nasal and skin swab samples were monitored for a three-week period. The sensitivity of the strains isolated during the follow-up period to the phage cocktail and each phage individually was analyzed and the pig sera were tested for antibodies against the phages used in the cocktail. The phage treatment did not cause any side effects to the pigs. Phages were found in the skin and nasal samples on the days following the phage applications, but there was no reduction in the MRSA levels in the sampled animals. Phage-resistant strains or phage-specific antibodies were not detected during the experiment. The MRSA load in these healthy carrier animals was only 10-100 CFU/swab or nasal sample, which was likely below the replication threshold of phages. The effectiveness of phage treatment to eradicate MRSA from the pigs could thus not be (reliably) determined.

Bacteriophages as tools for biofilm biocontrol in different fields

Microbial biofilms are difficult to control due to the limited accessibility that antimicrobial drugs and chemicals have to the entrapped inner cells. The extracellular matrix, binds water, contributes to altered cell physiology within biofilms and act as a barrier for most antiproliferative molecules. Thus, new strategies need to be developed to overcome biofilm vitality. In this review, based on 223 documents, the advantages, recommendations, and limitations of using bacteriophages as 'biofilm predators' are presented. The plausibility of using phages (bacteriophages and mycoviruses) to control biofilms grown in different environments is also discussed. The topics covered here include recent historical experiences in biofilm control/eradication using phages in medicine, dentistry, veterinary, and food industries, the pros and cons of their use, and the development of microbial resistance/immunity to such viruses.

The Safety and Toxicity of Phage Therapy: A Review of Animal and Clinical Studies

Increasing rates of infection by antibiotic resistant bacteria have led to a resurgence of interest in bacteriophage (phage) therapy. Several phage therapy studies in animals and humans have been completed over the last two decades. We conducted a systematic review of safety and toxicity data associated with phage therapy in both animals and humans reported in English language publications from 2008-2021. Overall, 69 publications met our eligibility criteria including 20 animal studies, 35 clinical case reports or case series, and 14 clinical trials. After summarizing safety and toxicity data from these publications, we discuss potential approaches to optimize safety and toxicity monitoring with the therapeutic use of phage moving forward. In our systematic review of the literature, we found some adverse events associated with phage therapy, but serious events were extremely rare. Comprehensive and standardized reporting of potential toxicities associated with phage therapy has generally been lacking in the published literature. Structured safety and tolerability endpoints are necessary when phages are administered as anti-infective therapeutics.

The Potential Role of Bacteriophages in the Treatment of Recalcitrant Chronic Rhinosinusitis

Chronic rhinosinusitis is a common condition affecting 5-12% of the general population worldwide. In a limited number of cases, the disease is recalcitrant to medical and surgical interventions, causing a major impact on physical, social and emotional well-being and increasing pressure on healthcare systems. Biofilm formation and dysbiosis caused by Staphylococcus aureus and Pseudomonas aeruginosa play a role in the pathogenesis of recalcitrant chronic rhinosinusitis. In these cases, a promising treatment alternative is the application of bacteriophages, which are viruses that infect and lyse bacteria. In this review, we appraise the evidence for the use of bacteriophages in the treatment of recalcitrant chronic rhinosinusitis. Additionally, (dis)advantages of bacteriophages and considerations for implementation of phage therapy in otorhinolaryngology practice will be discussed.

The clinical path to deliver encapsulated phages and lysins

The global emergence of multidrug-resistant pathogens is shaping the current dogma regarding the use of antibiotherapy. Many bacteria have evolved to become resistant to conventional antibiotherapy, representing a health and economic burden for those afflicted. The search for alternative and complementary therapeutic approaches has intensified and revived phage therapy. In recent decades, the exogenous use of lysins, encoded in phage genomes, has shown encouraging effectiveness. These two antimicrobial agents reduce bacterial populations; however, many barriers challenge their prompt delivery at the infection site. Encapsulation in delivery vehicles provides targeted therapy with a controlled compound delivery, surpassing chemical, physical and immunological barriers that can inactivate and eliminate them. This review explores phages and lysins' current use to resolve bacterial infections in the respiratory, digestive, and integumentary systems. We also highlight the different challenges they face in each of the three systems and discuss the advances towards a more expansive use of delivery vehicles.

Potential for bacteriophage therapy for Staphylococcus aureus pneumonia with influenza A coinfection

The ability of influenza A virus to evolve, coupled with increasing antimicrobial resistance, could trigger an influenza pandemic with great morbidity and mortality. Much of the 1918 influenza pandemic mortality was likely due to bacterial coinfection, including Staphylococcus aureus pneumonia. S. aureus resists many antibiotics. The lack of new antibiotics suggests alternative antimicrobials, such as bacteriophages, are needed. Potential delivery routes for bacteriophage therapy (BT) include inhalation and intravenous injection. BT has recently been used successfully in compassionate access pulmonary infection cases. Phage lysins, enzymes that hydrolyze bacterial cell walls and which are bactericidal, are efficacious in animal pneumonia models. Clinical trials will be needed to determine whether BT can ameliorate disease in influenza and S. aureus coinfection.

Comprehensive Evaluation of the Safety and Efficacy of BAFASAL® Bacteriophage Preparation for the Reduction of Salmonella in the Food Chain

Bacteriophages are bacterial predators, which are garnering much interest nowadays vis-à-vis the global phenomenon of antimicrobial resistance. Bacteriophage preparations seem to be an alternative to antibiotics, which can be used at all levels of the food production chain. Their safety and efficacy, however, are of public concern. In this study, a detailed evaluation of BAFASAL^® preparation was performed. BAFASAL^® is a bacteriophage cocktail that reduces Salmonella in poultry farming. In vivo acute and sub-chronic toxicity studies on rats and tolerance study on targeted animals (chicken broiler) conducted according to GLP and OECD guidelines did not reveal any signs of toxicity, which could be associated with BAFASAL^® administration. In addition, no evidences of genotoxicity were observed. The tolerance study with 100-times concentrated dose also did not show any statistically significant differences in the assessed parameters. The in vitro crop assay, mimicking normal feed storage and feed application conditions showed that BAFASAL^® reduced the number of Salmonella bacteria in experimentally contaminated feed. Moreover, reductions were observed for all examined forms (liquid, powder, spray). Furthermore, the in vivo efficacy study showed that treatment with BAFASAL^® significantly decreased Salmonella content in caeca of birds infected with Salmonella Enteritidis. Detailed examination of BAFASAL^® in terms of safety and efficacy, adds to the body of evidence that bacteriophages are harmless to animals and effective in the struggle against bacteria.

Efficacy of phage cocktail AB-SA01 therapy in diabetic mouse wound infections caused by multidrug-resistant Staphylococcus aureus

BACKGROUND

Diabetic foot ulcer (DFU) is a serious complication of diabetes mellitus. Antibiotic-resistant Staphylococcus aureus is frequently isolated from DFU infections. Bacteriophages (phages) represent an alternative or adjunct treatment to antibiotic therapy. Here we describe the efficacy of AB-SA01, a cocktail of three S. aureus Myoviridae phages, made to current good manufacturing practice (cGMP) standards, and which has undergone two phase I clinical trials, in treatment of multidrug-resistant (MDR) S. aureus infections.

RESULTS

Wounds of saline-treated mice showed no healing, but expanded and became inflamed, ulcerated, and suppurating. In contrast, AB-SA01 treatment decreased the bacterial load with efficacy similar or superior to vancomycin treatment. At the end of the treatment period, there was a significant decrease (p < 0.001) in bacterial load and wound size in infected phage- and vancomycin-treated groups compared with infected saline-treated mice. In phage-treated mice, wound healing was seen similar to vancomycin treatment. No mortality was recorded associated with infections, and post-mortem examinations did not show any evident pathological lesions other than the skin wounds. No adverse effects related to the application of phages were observed.

CONCLUSION

Topical application of phage cocktail AB-SA01 is effective, as shown by bacterial load reduction and wound closure, in the treatment of diabetic wound infections caused by MDR S. aureus. Our results suggest that topical phage cocktail treatment may be effective in treating antibiotic-resistant S. aureus DFU infections.

Future topical medications in chronic rhinosinusitis

BACKGROUND

Research has progressed rapidly in recent decades to better understand the etiopathogenesis and management paradigms of chronic rhinosinusitis (CRS). Although oral antibiotics often mitigate symptoms in acute CRS exacerbations, eradication of polymicrobial biofilms and multidrug-resistant bacteria remains a challenge. The goal of this review is to summarize and discuss the potential and pitfalls of topical medications in the treatment of CRS.

METHODS

A related literature review was performed using PubMed and Scopus, with only the English database included.

RESULTS

The main therapies were selected and separated in sections. Details regarding future topical treatments of CRS were summarized and discussed.

CONCLUSION

The ease of access of the sinonasal mucosa positions CRS as a disease with high potential for local topical treatment. The ultimate adoption of topical agents will require continued expansion of our understanding of novel local targets in CRS as well as improved methods to deliver and retain the drug of interest at the site of activity.

Overexpression of AmpC Promotes Bacteriophage Lysis of Ampicillin-Resistant Escherichia coli

Infections caused by antibiotic-resistant Escherichia coli are a threat to human and animal health globally. Phage therapy has made great progress for the treatment of drug-resistant infections, but it is still unclear whether E. coli resistance to antibiotics could change the lysis ability of phages. In this study, we demonstrate that over expression of AmpC, an important β-lactamase for ampicillin resistance, promotes lysis of E. coli by phage utilizing OmpA as a receptor. E. coli strains expressing more AmpC showed higher levels of OmpA, an E. coli outer membrane protein known to serve as a receptor for T-even phages, which resulted in increased adsorption and lysis by the phage tested in this study. These data demonstrate that increased ampicillin resistance can increase the sensitivity of E. coli to some lytic phage, which provides evidence for the feasibility of synergistic application of phage and antibiotics.

Exacerbations of Chronic Rhinosinusitis-Microbiology and Perspectives of Phage Therapy

The chronically inflamed mucosa in patients with chronic rhinosinusitis (CRS) can additionally be infected by bacteria, which results in an acute exacerbation of the disease (AECRS). Currently, AECRS is universally treated with antibiotics following the guidelines for acute bacterial rhinosinusitis (ABRS), as our understanding of its microbiology is insufficient to establish specific treatment recommendations. Unfortunately, antibiotics frequently fail to control the symptoms of AECRS due to biofilm formation, disruption of the natural microbiota, and arising antibiotic resistance. These issues can potentially be addressed by phage therapy. In this study, the endoscopically-guided cultures were postoperatively obtained from 50 patients in order to explore the microbiology of AECRS, evaluate options for antibiotic treatment, and, most importantly, assess a possibility of efficient phage therapy. Staphylococcus aureus and coagulase-negative staphylococci were the most frequently isolated bacteria, followed by Haemophilus influenzae, Pseudomonas aeruginosa, and Enterobacteriaceae. Alarmingly, mechanisms of antibiotic resistance were detected in the isolates from 46% of the patients. Bacteria not sensitive to amoxicillin were carried by 28% of the patients. The lowest rates of resistance were noted for fluoroquinolones and aminoglycosides. Fortunately, 60% of the patients carried bacterial strains that were sensitive to bacteriophages from the Biophage Pharma collection and 81% of the antibiotic-resistant strains turned out to be sensitive to bacteriophages. The results showed that microbiology of AECRS is distinct from ABRS and amoxicillin should not be the antibiotic of first choice. Currently available bacteriophages could be used instead of antibiotics or as an adjunct to antibiotics in the majority of patients with AECRS.

Safety and Tolerability of Bacteriophage Therapy for Chronic Rhinosinusitis Due to Staphylococcus aureus

Importance

Staphylococcus aureus infections are associated with recalcitrant chronic rhinosinusitis (CRS). The emerging threat of multidrug-resistant S aureus infections has revived interest in bacteriophage (phage) therapy.

Objective

To investigate the safety, tolerability, and preliminary efficacy of ascending multiple intranasal doses of investigational phage cocktail AB-SA01 in patients with recalcitrant CRS due to S aureus.

Design, Setting, and Participants

This phase 1, first-in-humans, open-label clinical trial of multiple ascending doses was conducted at a single tertiary referral center from December 1, 2015, through September 30, 2016, with follow-up completed on December 31, 2016. Patients with recalcitrant CRS (aged 18-70 years) in whom surgical and medical treatment had failed and who had positive S aureus cultures sensitive to AB-SA01 were recruited. Findings were analyzed from February 2 through August 31, 2017.

Interventions

Three patient cohorts (3 patients/cohort) received serial doses of twice-daily intranasal irrigations with AB-SA01 at a concentration of 3 × 108 plaque-forming units (PFU) for 7 days (cohort 1), 3 × 108 PFU for 14 days (cohort 2), and 3 × 109 PFU for 14 days (cohort 3).

Main Outcomes and Measures

The primary study outcome was the safety and tolerability of intranasal AB-SA01. Safety observations included vital signs, physical examinations, clinical laboratory test results, and adverse events. The secondary outcome was preliminary efficacy assessed by comparing pretreatment and posttreatment microbiology results, disease-relevant endoscopic Lund-Kennedy Scores, and symptom scores using a visual analog scale and Sino-Nasal Outcome Test-22.

Results

All 9 participants (4 men and 5 women; median age, 45 years [interquartile range, 41.0-71.5 years]) completed the trial. Intranasal phage treatment was well tolerated, with no serious adverse events or deaths reported in any of the 3 cohorts. No change in vital signs occurred before and 0.5 and 2.0 hours after administration of AB-SA01 and at the exit visit. No changes in biochemistry were found except for 1 participant in cohort 3 who showed a decrease in blood bicarbonate levels on exit visit, with normal results of physical examination and vital signs. All biochemistry values were normalized 8 days later. No changes in temperature were recorded before, during, or after treatment. Six adverse effects were reported in 6 participants; all were classified as mild treatment-emergent adverse effects and resolved by the end of the study. Preliminary efficacy results indicated favorable outcomes across all cohorts, with 2 of 9 patients showing clinical and microbiological evidence of eradication of infection.

Conclusions and Relevance

Intranasal irrigation with AB-SA01 of doses to 3 × 109 PFU for 14 days was safe and well tolerated, with promising preliminary efficacy observations. Phage therapy could be an alternative to antibiotics for patients with CRS.

Trial Registration

http://anzctr.org.au identifier: ACTRN12616000002482.

[Bacteriophages therapy in otorhinolaryngology. History and contemporaneity]

Bacterial infections of the upper respiratory tract in the structure of the incidence of the population ranked second. Recently in practice there are more and more cases of a protracted course of the disease, chronic inflammation, as well as various kinds of complications. The abuse and misuse of antibiotics has contributed to the growth of antibiotic-resistant bacterial strains. This problem is named one of the most pressing for public health in the world. In this regard, the topical issue is the search for alternative drugs foe treating infectious diseases. Bacteriophage preparations that have a 100-year history and have gone a long way in development have shown their effectiveness as an alternative to antibiotics, and as an additional therapy in the treatment of certain bacterial infections. This review includes data from various studies available in English, as well as the results of domestic reports published in Russian scientific literature.

The dawn of phage therapy

Bacteriophages or phages, being the most abundant entities on earth, represent a potential solution to a diverse range of problems. Phages are successful antibacterial agents whose use in therapeutics was hindered by the discovery of antibiotics. Eventually, because of the development and spread of antibiotic resistance among most bacterial species, interest in phage as therapeutic entities has returned, because their noninfectious nature to humans should make them safe for human nanomedicine. This review highlights the most recent advances and progress in phage therapy and bacterial hosts against which phage research is currently being conducted with respect to food, human, and marine pathogens. Bacterial immunity against phages and tactics of phage revenge to defeat bacterial defense systems are also summarized. We have also discussed approved phage-based products (whole phage-based products and phage proteins) and shed light on their influence on the eukaryotic host with respect to host safety and induction of immune response against phage preparations. Moreover, creation of phages with desirable qualities and their uses in cancer treatment, vaccine production, and other therapies are also reviewed to bring together evidence from the scientific literature about the potentials and possible utility of phage and phage encoded proteins in the field of therapeutics and industrial biotechnology.

Nonconventional Therapeutics against Staphylococcus aureus

Staphylococcus aureus is one of the most important human pathogens that is responsible for a variety of diseases ranging from skin and soft tissue infections to endocarditis and sepsis. In recent decades, the treatment of staphylococcal infections has become increasingly difficult as the prevalence of multi-drug resistant strains continues to rise. With increasing mortality rates and medical costs associated with drug resistant strains, there is an urgent need for alternative therapeutic options. Many innovative strategies for alternative drug development are being pursued, including disruption of biofilms, inhibition of virulence factor production, bacteriophage-derived antimicrobials, anti-staphylococcal vaccines, and light-based therapies. While many compounds and methods still need further study to determine their feasibility, some are quickly approaching clinical application and may be available in the near future.

Bacteriocins and Bacteriophages: Therapeutic Weapons for Gastrointestinal Diseases?

Bacteriocins are bactericidal peptides, ribosomally synthesized, with an inhibitory activity against diverse groups of undesirable microorganisms. Bacteriocins are produced by both gram-positive and gram-negative bacteria, and to a lesser extent by some archaea. Bacteriophages are viruses that are able to infect bacterial cells and force them to produce viral components, using a lytic or lysogenic cycle. They constitute a large community in the human gut called the phageome, the most abundant part of the gut virome. Bacteriocins and bacteriophages may have an influence on both human health and diseases, thanks to their ability to modulate the gut microbiota and regulate the competitive relationship among the different microorganisms, strains and cells living in the human intestine. In this review, we explore the role of bacteriocins and bacteriophages in the most frequent gastrointestinal diseases by dissecting their interaction with the complex environment of the human gut, analyzing a possible link with extra-intestinal diseases, and speculating on their possible therapeutic application with the end goal of promoting gut health.

Bacteriophage therapy for severe infections

The rise of multiple antibiotic resistance in clinically relevant bacteria has created a global crisis with increasing burden on healthcare systems. The need to optimise alternative therapies to antibiotics, particularly in high risk nosocomial settings, is therefore immediate. Bacteriophages are specialised lethal viruses of bacteria, and an underused clinical resource for the treatment of severe infections refractory to antibiotics. Both the gaps in knowledge of bacteriophage biology, particularly the details of host-pathogen dynamic interactions, and legislative hurdles related to the regulation of natural microorganisms for therapy have delayed progress in bacteriophage clinical applications. At the Westmead Institute for Medical Research (WIMR), in collaboration with Westmead Hospital (Western Sydney Local Health District, WSLHD) and the University of Sydney (USyd), we have been investigating rational design protocols for routine bacteriophage application in clinical practice and testing bacteriophage therapeutics on patients suffering from multidrug resistant (MDR) severe infections.

Clinical Indications and Compassionate Use of Phage Therapy: Personal Experience and Literature Review with a Focus on Osteoarticular Infections

The history of phage therapy started with its first clinical application in 1919 and continues its development to this day. Phages continue to lack any market approval in Western medicine as a recognized drug, but are increasingly used as an experimental therapy for the compassionate treatment of patients experiencing antibiotic failure. The few formal experimental phage clinical trials that have been completed to date have produced inconclusive results on the efficacy of phage therapy, which contradicts the many successful treatment outcomes observed in historical accounts and recent individual case reports. It would therefore be wise to identify why such a discordance exists between trials and compassionate use in order to better develop future phage treatment and clinical applications. The multitude of observations reported over the years in the literature constitutes an invaluable experience, and we add to this by presenting a number of cases of patients treated compassionately with phages throughout the past decade with a focus on osteoarticular infections. Additionally, an abundance of scientific literature into phage-related areas is transforming our knowledge base, creating a greater understanding that should be applied for future clinical applications. Due to the increasing number of treatment failures anticipatedfrom the perspective of a possible post-antibiotic era, we believe that the introduction of bacteriophages into the therapeutic arsenal seems a scientifically sound and eminently practicable consideration today as a substitute or adjuvant to antibiotic therapy.

Microbiota and Phage Therapy: Future Challenges in Medicine

An imbalance of bacterial quantity and quality of gut microbiota has been linked to several pathologies. New strategies of microbiota manipulation have been developed such as fecal microbiota transplantation (FMT); the use of pre/probiotics; an appropriate diet; and phage therapy. The presence of bacteriophages has been largely underestimated and their presence is a relevant component for the microbiome equilibrium. As a promising treatment, phage therapy has been extensively used in Eastern Europe to reduce pathogenic bacteria and has arisen as a new method to modulate microbiota diversity. Phages have been selected and “trained” to infect a wide spectrum of bacteria or tailored to infect specific antibiotic resistant bacteria present in patients. The new development of genetically modified phages may be an efficient tool to treat the gut microbiota dysbiosis associated with different pathologies and increased production of bacterial metabolites and subsequently decrease systemic low-grade chronic inflammation associated with chronic diseases. Microbiota quality and mitochondria dynamics can be remodulated and manipulated by phages to restore the equilibrium and homeostasis of the system. Our aim is to highlight the great interest for phages not only to eliminate and control pathogenic bacterial infection but also in the near future to modulate the microbiota by adding new functions to selected bacteria species and rebalance the dynamic among phages and bacteria. The challenge for the medicine of tomorrow is to re-think and redesign strategies differently and far from our traditional thinking.

Applications for Bacteriophage Therapy during Pregnancy and the Perinatal Period

Pregnant women and their unborn children are a population that is particularly vulnerable to bacterial infection. Physiological changes that occur during pregnancy affect the way women respond to such infections and the options that clinicians have for treatment. Antibiotics are still considered the best option for active infections and a suitable prophylaxis for prevention of potential infections, such as vaginal/rectal Streptococcus agalactiae colonization prior to birth. The effect of such antibiotic use on the developing fetus, however, is still largely unknown. Recent research has suggested that the fetal gut microbiota plays a critical role in fetal immunologic programming. Hence, even minor alterations in this microbiota may have potentially significant downstream effects. An ideal antibacterial therapeutic for administration during pregnancy would be one that is highly specific for its target, leaving the surrounding microbiota intact. This review first provides a basic overview of the challenges a clinician faces when administering therapeutics to a pregnant patient and then goes on to explore common bacterial infections in pregnancy, use of antibiotics for treatment/prevention of such infections and the consequences of such treatment for the mother and infant. With this background established, the review then explores the potential for use of bacteriophage (phage) therapy as an alternative to antibiotics during the antenatal period. Many previous reviews have highlighted the revitalization of and potential for phage therapy for treatment of a range of bacterial infections, particularly in the context of the increasing threat of widespread antibiotic resistance. However, information on the potential for the use of phage therapeutics in pregnancy is lacking. This review aims to provide a thorough overview of studies of this nature and discuss the feasibility of bacteriophage use during pregnancy to treat and/or prevent bacterial infections.

Can phage therapy solve the problem of recalcitrant chronic rhinosinusitis?

Chronic rhinosinusitis (CRS) affects 5-15% of the global population. In some patients, the infectious exacerbations of the disease are recalcitrant to medical treatment and surgery. These cases are probably associated with the presence of bacterial biofilms. Bacteriophage (phage) therapy seems to be a promising antibiofilm strategy. The efficacy of phage therapy in sinonasal infections has been demonstrated both in vitro and in animal models. In the past, phage preparations were also administered to humans with CRS with favorable outcomes and no significant side effects. Very recently, the safety and efficacy of phage therapy in otolaryngological infections has been demonstrated in pioneer Phase I/II clinical trials. This review addresses the potential of phage therapy to treat CRS. We also discuss issues that require further research.

Activity of Bacteriophages in Removing Biofilms of Pseudomonas aeruginosa Isolates from Chronic Rhinosinusitis Patients

Introduction:Pseudomonas aeruginosa infections are prevalent amongst chronic rhinosinusitis (CRS) sufferers. Many P. aeruginosa strains form biofilms, leading to treatment failure. Lytic bacteriophages (phages) are viruses that infect, replicate within, and lyse bacteria, causing bacterial death. Aim: To assess the activity of a phage cocktail in eradicating biofilms of ex vivo P.aeruginosa isolates from CRS patients. Methods: P. aeruginosa isolates from CRS patients with and without cystic fibrosis (CF) across three continents were multi-locus sequence typed and tested for antibiotic resistance. Biofilms grown in vitro were treated with a cocktail of four phages (CT-PA). Biofilm biomass was measured after 24 and 48 h, using a crystal violet assay. Phage titrations were performed to confirm replication of the phages. A linear mixed effects model was applied to assess the effects of treatment, time, CF status, and multidrug resistance on the biomass of the biofilm. Results: The isolates included 44 strain types. CT-PA treatment significantly reduced biofilm biomass at both 24 and 48 h post-treatment (p < 0.0001), regardless of CF status or antibiotic resistance. Biomass was decreased by a median of 76% at 48 h. Decrease in biofilm was accompanied by a rise in phage titres for all except one strain. Conclusion: A single dose of phages is able to significantly reduce biofilms formed in vitro by a range of P.aeruginosa isolates from CRS patients. This represents an exciting potential and novel targeted treatment for P. aeruginosa biofilm infections and multidrug resistant bacteria.