Case Report: successful use of phage therapy in refractory MRSA chronic rhinosinusitis

Phage therapy: A novel approach to combat drug-resistant pathogens

Antibiotic-resistant infections, such as those caused by the overuse of antibiotics, have greatly strained healthcare systems. Among them, drug-resistant bacteria ESKAPE (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter species) are typical and common. Enterococcus faecalis and Escherichia coli are of equal concern. These pathogens often have higher pathogenicity than the same strains, and resistance has reduced treatment options, so new treatment options are needed to address these pathogens. This review analyzes recent studies related to phage therapy for the treatment of bacterial infections in various parts of the human body (e.g., alcoholic liver disease, skin, and soft tissues, respiratory tract, gastrointestinal tract, urinary system, etc.), to better understand the potential role of phage therapy as a non-antibiotic strategy for the treatment of infections caused by drug-resistant bacteria. In addition, this review introduces a series of products related to phage therapy and points out potential research directions for phage therapy in clinical applications. This paper elucidates the basic mechanism of human infection by some drug-resistant bacteria and the therapeutic effect of phage therapy against drug-resistant bacteria. It popularizes the understanding of phage therapy and provides a reference for research on its use for drug-resistant bacterial infections.

Characterization of novel phages KPAФ1, KP149Ф1, and KP149Ф2 for lytic efficiency against clinical MDR Klebsiella pneumoniae infections

Phage therapy offers a promising approach to the increasing antimicrobial resistance of Klebsiella pneumoniae. This study highlights three novel lytic bacteriophages-KPAФ1, KP149Ф1, and KP149Ф2- targeting multidrug-resistant (MDR) K. pneumoniae. These phages belong to the Myoviridae and Podoviridae family and demonstrate their efficacy and stability across a wide range of temperatures (up to 60°C) and pH levels (pH 4 to 11). Genomic analysis reveals that they are free from virulence, toxicity, and antimicrobial resistance genes, making them promising candidates for therapeutic use. Among these phages, KPAФ1 showed the highest lytic activity with a 26.15% lysis against MDR K. pneumoniae isolates. Additionally, a phage cocktail comprising all three phages improved lytic efficacy to 32.30%. This study also examined the antimicrobial resistance profiles of K. pneumoniae isolates, emphasizing the critical need for alternative treatments. By effectively targeting resistant strains, these phages offer a potential candidacy to be used as a viable alternative or a complementary antimicrobial agent to traditional antibiotics, opening up the possibility for advanced phage-based therapies. The promising results from this study pave the way for developing new treatments that could significantly improve patient care and outcomes from the growing issue of resistant bacterial infections.

Synergistic effects of zP-1 phage and ampicillin against methicillin-resistant Staphylococcus aureus isolated from hospital staff

BACKGROUND

Methicillin-resistant Staphylococcus aureus (MRSA) strains are a major cause of hospital-acquired infections, exacerbated by increasing antibiotic resistance.

AIM

This study aimed to isolate bacteriophages targeting MRSA and evaluate their antimicrobial activity in combination with antibiotics.

METHODS

Nasal samples from hospital staff (n = 50) were used to isolate MRSA strains, and sewage samples were processed for phage isolation using the double agar overlay technique. The microtitration plate method evaluated the synergistic effects of isolated phages and antibiotics.

RESULTS

Out of 50 samples, 11 MRSA strains were positive, showing high resistance to multiple antibiotics, including oxacillin (95%), and vancomycin (85%). Phage zP-1, belonging to the Myoviridae family, exhibited > 90% lytic activity, stable across temperatures (20-50 °C) and pH (6-8). A statistically significant synergistic effect was observed at a MIC of 0.137 μg/ml for gentamicin (p-value 0.02).

CONCLUSION

These findings suggest that phage-antibiotic synergy may offer a promising strategy to combat MRSA infections, warranting further in vivo studies to assess its clinical potential.

Bacteriophage Therapy for Chronic Mastoiditis

OBJECTIVE

To provide the first description of intratympanic bacteriophage therapy for chronic mastoiditis from multidrug-resistant Pseudomonas aeruginosa in the United States.

PATIENTS

A 47-year-old woman with chronic mastoiditis in the setting of ciliary dysfunction from cystic fibrosis and immunosuppression from lung transplantation.

INTERVENTIONS

Ten concurrent parenteral and intratympanic doses of two custom phages targeting P. aeruginosa followed by IV antibiotic therapy.

MAIN OUTCOME MEASURES

Resolution of infection confirmed by symptomatology, cultures, and imaging.

RESULTS

At 5 months after phage treatment, the patient reported resolution of otorrhea, headaches, and hearing impairment. Subsequent cultures showed no growth.

CONCLUSIONS

Bacteriophages can enhance antibiotic activity in cases of drug-resistant chronic mastoiditis.

Antibiotic Resistance of Staphylococcus aureus Strains-Searching for New Antimicrobial Agents-Review

Inappropriate and excessive use of antibiotics is responsible for the rapid development of antimicrobial resistance, which is associated with increased patient morbidity and mortality. There is an urgent need to explore new antibiotics or alternative antimicrobial agents. S. aureus a commensal microorganism but is also responsible for numerous infections. In addition to innate resistance to β-lactam antibiotics, S. aureus strains resistant to methicillin (MRSA) often show resistance to other classes of antibiotics (multidrug resistance). The advancement of phage therapy against MRSA infections offers a promising alternative in the context of increasing antibiotic resistance. Therapeutic phages are easier to obtain and cheaper to produce than antibiotics. However, there is still a lack of standards to ensure the safe use of phages, including purification, dosage, means of administration, and the quantity of phages used. Some bacteria have developed defense mechanisms against phages. The use of phage cocktails or the combination of antibiotics and phages is preferred. For personalized therapy, it is essential to set up large collections to enable phage selection. In the future, the fight against MRSA strains using phages should be based on a multidisciplinary approach, including molecular biology and medicine. Other therapies in the fight against MRSA strains include the use of endolysin antimicrobial peptides (including defensins and cathelicidins). Researchers' activities also focus on the potential use of plant extracts, honey, propolis, alkaloids, and essential oils. To date, no vaccine has been approved against S. aureus strains.

Phage therapy: an alternative treatment modality for MDR bacterial infections

The increasing global incidence of multidrug-resistant (MDR) bacterial infections threatens public health and compromises various aspects of modern medicine. Recognising the urgency of this issue, the World Health Organisation has prioritised the development of novel antimicrobials to combat ESKAPEE pathogens. Comprising Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, Enterobacter spp. and Escherichia coli, such pathogens represent a spectrum of high to critical drug resistance, accounting for a significant proportion of hospital-acquired infections worldwide. In response to the waning efficacy of antibiotics against these resilient pathogens, phage therapy (PT) has emerged as a promising therapeutic strategy. This review provides a comprehensive summary of clinical research on PT and explores the translational journey of phages from laboratory settings to clinical applications. It examines recent advancements in pre-clinical and clinical developments, highlighting the potential of phages and their proteins, alone or in combination with antibiotics. Furthermore, this review underlines the importance of establishing safe and approved routes of phage administration to patients. In conclusion, the evolving landscape of phage therapy offers a beacon of hope in the fight against MDR bacterial infections, emphasising the imperative for continued research, innovation and regulatory diligence to realise its full potential in clinical practice.

Development and mouse model evaluation of a new phage cocktail intended as an alternative to antibiotics for treatment of Staphylococcus aureus-induced bovine mastitis

Bovine mastitis is a prevalent infectious disease in dairy herds worldwide, resulting in substantial economic losses. Staphylococcus aureus is a major cause of mastitis in animals, and its antibiotic resistance poses challenges for treatment. Recently, renewed interest has focused on the development of alternative methods to antibiotic therapy, including bacteriophages (phages), for controlling bacterial infections. In this study, 2 lytic phages, vB_SauM_JDYN (JDYN) and vB_SauM_JDF86 (JDF86), were isolated from the cattle sewage effluent samples collected from dairy farms in Shanghai. The 2 phages have a broad bactericidal spectrum against Staphylococcus of various origins. Genomic and morphological analyses revealed that the 2 phages belonged to the Myoviridae family. Moreover, JDYN and JDF86 remained stable under a wide temperature and pH range and were almost unaffected in chloroform. In this study, we prepared a phage cocktail (PHC-1) which consisted of a 1:1:1 ratio of JDYN, JDF86, and SLPW (a previously characterized phage). We found that PHC-1 showed the strongest bacteriolytic effect and the lowest frequency of emergence of bacteriophage insensitive mutants compared with monophages. Bovine mammary epithelial cells and lactating mice mastitis models were used to evaluate the effectiveness of PHC-1 in vitro and in vivo, respectively. The results demonstrated that PHC-1 treatment significantly reduced bacterial load, alleviated inflammatory response, and improved mastitis pathology. Altogether, these results suggest that PHC-1 has the potential to treat S. aureus-induced bovine mastitis and that phage cocktails can combat antibiotic-resistant S. aureus infections.

Non-antibiotic antimicrobial agents for chronic rhinosinusitis: a narrative review

OBJECTIVE

This narrative review explores alternative non-antibiotic antimicrobial agents for CRS management in adults.

METHODS

Alternative antimicrobial agents using EPOS 2020 guidelines as reference were selected, and articles dated from 2003 to 2022 in English, Portuguese, or Spanish using PubMed and EMBASE databases. The parameters analyzed included study design, evidence level, population characteristics, CRS characteristics, interventions, outcomes, sample size, randomization, blinding, and side effects. Reviews, unrelated contexts,in vitro experiments, and duplicates were excluded.

RESULTS

148 articles were screened; 19 articles were selected for analysis. Randomized controlled trials and cohort studies assessing non-antibiotic antimicrobial treatments for CRS were included. Xylitol demonstrated effectiveness in reducing CRS symptoms, particularly SNOT-22 scores, surpassing saline irrigation benefits. Manuka honey showed potential microbiological benefits in recalcitrant CRS, but symptomatic and endoscopic improvements remained inconclusive. Baby shampoo irrigation improved nasal mucociliary clearance and postoperative outcomes. Colloidal silver nasal irrigation showed limited efficacy in reducing CRS symptoms or endoscopic scores. Povidone-Iodine (PI) nasal irrigation yielded mixed results, with varying effects on culture negativity and SNOT-20 scores. Bacteriophage treatment exhibited promise in decreasing specific bacterial strains and cytokine levels.

CONCLUSION

Non-antibiotic antimicrobial therapies, including xylitol, manuka honey, baby shampoo, colloidal silver, PI, bacteriophages, lactoferrin, and carrageenan offer potential alternatives for CRS in adult patients. Xylitol, baby shampoo, and PI presented benefits in improving symptoms and nasal endoscopic scores, however, the number of studies is limited for conclusive recommendations and safety assessments. CRS management should adopt a comprehensive approach, particularly for non-infectious or immune-related cases, moving beyond antibiotics. Antibiotics should be reserved for confirmed bacterial infections. Overall, this review shows the importance of exploring non-antibiotic therapies to enhance the management of CRS.

Biological characterization and genomic analysis of a novel methicillin-resistant Staphylococcus aureus phage, SauPS-28

Staphylococcus aureus, a representative gram-positive bacterium, is a common infectious pathogen widely present in the natural environment. The increasing application of antibiotics is witnessing an increment in the number of clinically resistant strains (such as methicillin-resistant S. aureus [MRSA]), which has posed a great challenge to antimicrobial therapy. In this study, a novel MRSA phage, SauPS-28, was isolated from the lake water of the Guangxi Zhuang Autonomous Region. This phage has an incubation period of approximately 30 min, a lysis period of approximately 40 min, and a burst size of approximately 25 PFU/cell. The isolated phage exhibited good biological stability at a pH range of 6.0-9.0 and temperature range of 4°C-37°C. In addition, the identification of an elongated tail using transmission electron microscopy confirmed that SauPS-28 belongs to the long-tailed phage family. Whole-genome sequencing analysis revealed that SauPS-28 has a 43,286-bp-long genome with 31.03% G + C content. Moreover, SauPS-28 exhibited 95.69% sequence identity with ECel-2020k, while the query coverage was only 66%, which is a newly discovered phage. Whole-genome functional annotation results revealed that SauPS-28 had 68 open reading frames (ORFs). Of these, 30 ORFs are unknown proteins. The results suggest that SauPS-28 could be a lysogenic phage strain. This study thus provides preliminary data to conduct further in-depth analysis of the mechanism of phage-host interaction and provides a reference value for phage therapy.IMPORTANCEIn recent years, drug-resistant bacterial infections have become increasingly serious. As a kind of virus with the ability to infect and lyse drug-resistant bacteria, phage is expected to be a new therapeutic method. In this study, we isolated and purified a new methicillin-resistant Staphylococcus aureus bacteriophage SauPS-28, studied a series of biological characteristics of the bacteriophage, analyzed the genome and structural proteome data of the bacteriophage, and provided reference data for further study of the interaction mechanism between bacteriophage and host bacteria and promoted new antibacterial strategies.

Main Aspects of Pharmaceutical Development of In situ Immunobiological Drugs for Intranasal Administration

INTRODUCTION

The review presents the latest developments in the area of intranasal in situ delivery systems of immunobiological drugs (IBDs). Interest in intranasal administration for IBDs has increased significantly due to the COVID-19 pandemic. However, not only intranasal delivery of vaccines is developing, but also bacteriophages, interferons, etc. In situ systems that make a selective phase transition can be a modern solution to intranasal delivery problems caused by mucociliary clearance. In addition, smart-polymers used as the main excipients in in situ systems can be used as specific adjuvants.

METHODS

A scientific search was conducted on the PubMed database of medical publications for the period from 2000 to 2022, using the keywords "intranasal in situ vaccine"; "intranasal in situ immunization". There were analyzed in detail more than 70 scientific studies on intranasal in situ delivery of IBDs.

RESULTS AND CONCLUSIONS

Despite the large number of new studies, the potential of possibilities of intranasal in situ systems is not being realized. Based on the results of the literature review an algorithm was created for the development of in situ systems for intranasal delivery of IBDs. Such algorithms and the methods of study design organization described in the review will help to facilitate the R&D process and bring the drug to commercial market, which will help to improve the quality of medical care.

Methicillin Resistant Staphylococcus aureus: Molecular Mechanisms Underlying Drug Resistance Development and Novel Strategies to Combat

Antimicrobial resistance (AMR) represents a major threat to global health. Infection caused by Methicillin-resistant Staphylococcus aureus (MRSA) is one of the well-recognized global public health problem globally. In some regions, as many as 90% of S. aureus infections are reported to be MRSA, which cannot be treated with standard antibiotics. WHO reports indicated that MRSA is circulating in every province worldwide, significantly increasing the risk of death by 64% compared to drug-sensitive forms of the infection which is attributed to its antibiotic resistance. The emergence and spread of antibiotic-resistant MRSA strains have contributed to its increased prevalence in both healthcare and community settings. The resistance of S. aureus to methicillin is due to expression of penicillin-binding protein 2a (PBP2a), which renders it impervious to the action of β-lactam antibiotics including methicillin. The other is through the production of beta-lactamases. Although the treatment options for MRSA are limited, there are promising alternatives to antibiotics to combat the infections. Innovative therapeutic strategies with wide range of activity and modes of action are yet to be explored. The review highlights the global challenges posed by MRSA, elucidates the mechanisms underlying its resistance development, and explores mitigation strategies. Furthermore, it focuses on alternative therapies such as bacteriophages, immunotherapy, nanobiotics, and antimicrobial peptides, emphasizing their synergistic effects and efficacy against MRSA. By examining these alternative approaches, this review provides insights into the potential strategies for tackling MRSA infections and combatting the escalating threat of AMR. Ultimately, a multifaceted approach encompassing both conventional and novel interventions is imperative to mitigate the impact of MRSA and ensure a sustainable future for global healthcare.

Engineering of Salmonella Phages into Novel Antimicrobial Tailocins

Due to the extensive use of antibiotics, the increase of infections caused by antibiotic-resistant bacteria is now a global health concern. Phages have proven useful for treating bacterial infections and represent a promising alternative or complement to antibiotic treatment. Yet, other alternatives exist, such as bacteria-produced non-replicative protein complexes that can kill their targeted bacteria by puncturing their membrane (Tailocins). To expand the repertoire of Tailocins available, we suggest a new approach that transforms phages into Tailocins. Here, we genetically engineered the virulent Ackermannviridae phage S117, as well as temperate phages Fels-1, -2 and Gifsy-1 and -2, targeting the food pathogen Salmonella, by deleting the portal vertex or major capsid gene using CRISPR-Cas9. We report the production of Tailocin particles from engineered virulent and temperate phages able to kill their native host. Our work represents a steppingstone that taps into the huge diversity of phages and transforms them into versatile puncturing new antimicrobials.

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.

The Post-Antibiotic Era: A New Dawn for Bacteriophages

Phages are the most biologically diverse entities in the biosphere, infecting specific bacteria. Lytic phages quickly kill bacteria, while lysogenic phages integrate their genomes into bacteria and reproduce within the bacteria, participating in the evolution of natural populations. Thus, lytic phages are used to treat bacterial infections. However, due to the huge virus invasion, bacteria have also evolved a special immune mechanism (CRISPR-Cas systems, discovered in 1987). Therefore, it is necessary to develop phage cocktails and synthetic biology methods to infect bacteria, especially against multidrug-resistant bacteria infections, which are a major global threat. This review outlines the discovery and classification of phages and the associated achievements in the past century. The main applications of phages, including synthetic biology and PT, are also discussed, in addition to the effects of PT on immunity, intestinal microbes, and potential safety concerns. In the future, combining bioinformatics, synthetic biology, and classic phage research will be the way to deepen our understanding of phages. Overall, whether phages are an important element of the ecosystem or a carrier that mediates synthetic biology, they will greatly promote the progress of human society.

Phage Therapy as an Alternative Treatment Modality for Resistant Staphylococcus aureus Infections

The production and use of antibiotics increased significantly after the Second World War due to their effectiveness against bacterial infections. However, bacterial resistance also emerged and has now become an important global issue. Those most in need are typically high-risk and include individuals who experience burns and other wounds, as well as those with pulmonary infections caused by antibiotic-resistant bacteria, such as Pseudomonas aeruginosa, Acinetobacter sp, and Staphylococci. With investment to develop new antibiotics waning, finding and developing alternative therapeutic strategies to tackle this issue is imperative. One option remerging in popularity is bacteriophage (phage) therapy. This review focuses on Staphylococcus aureus and how it has developed resistance to antibiotics. It also discusses the potential of phage therapy in this setting and its appropriateness in high-risk people, such as those with cystic fibrosis, where it typically forms a biofilm.