Arthroscopic "Debridement and Implant Retention" With Local Administration of Exebacase (Lysin CF-301) Followed by Suppressive Tedizolid as Salvage Therapy in Elderly Patients for Relapsing Multidrug-Resistant S. epidermidis Prosthetic Knee Infection

Local antibiotic delivery via intra-articular catheter infusion for the treatment of periprosthetic joint infection: a systematic review

INTRODUCTION

There is an increasing interest in the use of intra-articular (IA) antibiotic infusion as a stand-alone or adjuvant therapy to standard revision surgery for periprosthetic joint infection (PJI). The objective of this systematic review is to evaluate the evidence with respect to this up-and-coming treatment modality.

METHODS

A systematic review of studies published until April 2023 was conducted using PubMed, Embase, MEDLINE and Cochrane databases. Quality assessment was performed with the National Institute of Health quality assessment tool. Inclusion criteria were adult patients (≥ 18 years) with a mean follow-up of ≥ 11 months and a score ≥ 6 on the National Institute of Health quality assessment tool. Primary outcome was eradication of infection.

RESULTS

15 articles, encompassing 631 PJIs in 626 patients, were included in the final analysis, all level IV case series. The majority was treated with single-stage revision with adjuvant IA antibiotic infusion (79.1%). The remaining PJIs were treated with stand-alone IA antibiotic infusion (12.2%), DAIR (debridement, antibiotics and implant retention) with adjuvant IA antibiotic infusion (5.7%) or two-stage revision with adjuvant IA antibiotic infusion (3.0%). Mean duration of IA antibiotic infusion was 19 days (range 3-50). An overall failure rate of approximately 11% was found. In total 117 complications occurred, 71 were non-catheter-related and 46 were catheter-related. The most common catheter-related complications were premature loss of the catheter (18/46) and elevated blood urea nitrogen (BUN) and creatinine levels (12/46).

CONCLUSIONS

Due to the lack of comparative studies the (added) benefit of IA antibiotic infusion in the treatment of PJI remains uncertain. Based on the current evidence, we would advise against using it as a stand-alone treatment. A prospective randomized controlled trial using a well-described infusion protocol is needed to see if the potential benefits justify the increased costs and potential complications of this treatment modality.

Local Antibiotic Delivery Options in Prosthetic Joint Infection

Prosthetic Joint Infection (PJI) causes significant morbidity and mortality for patients globally. Delivery of antibiotics to the site of infection has potential to improve the treatment outcomes and enhance biofilm eradication. These antibiotics can be delivered using an intra-articular catheter or combined with a carrier substance to enhance pharmacokinetic properties. Carrier options include non-resorbable polymethylmethacrylate (PMMA) bone cement and resorbable calcium sulphate, hydroxyapatite, bioactive glass, and hydrogels. PMMA allows for creation of structural spacers used in multi-stage revision procedures, however it requires subsequent removal and antibiotic compatibility and the levels delivered are variable. Calcium sulphate is the most researched resorbable carrier in PJI, but is associated with wound leakage and hypercalcaemia, and clinical evidence for its effectiveness remains at the early stage. Hydrogels provide a versatile combability with antibiotics and adjustable elution profiles, but clinical usage is currently limited. Novel anti-biofilm therapies include bacteriophages which have been used successfully in small case series.

Locally delivered antistaphylococcal lysin exebacase or CF-296 is active in methicillin-resistant Staphylococcus aureus implant-associated osteomyelitis

Abstract. Introduction: Staphylococcus aureus is the most common cause of orthopedic infections and can be challenging to treat, especially in the presence of a foreign body. The antistaphylococcal lysins exebacase and CF-296 have rapid bactericidal activity, a low propensity for resistance development, and synergize with some antibiotics. Methods: Rabbit implant-associated osteomyelitis was induced by drilling into the medial tibia followed by locally delivering exebacase, CF-296, or lysin carrier. A titanium screw colonized with methicillin-resistant S. aureus (MRSA) IDRL-6169 was inserted. Intravenous daptomycin or saline was administered and continued daily for 4 d. On day 5, rabbits were euthanized, and the tibiae and implants were collected for culture. Results were reported as log10 colony forming units (cfu) per gram of bone or log10 cfu per implant, and comparisons among the six groups were performed using the Wilcoxon rank sum test. Results: Based on implant and bone cultures, all treatments resulted in significantly lower bacterial counts than those of controls (P≤0.0025). Exebacase alone or with daptomycin as well as CF-296 with daptomycin were more active than daptomycin alone (P≤0.0098) or CF-296 alone (P≤0.0154) based on implant cultures. CF-296 with daptomycin was more active than either CF-296 alone (P=0.0040) or daptomycin alone (P=0.0098) based on bone cultures. Conclusion: Local delivery of either exebacase or CF-296 offers a promising complement to conventional antibiotics in implant-associated infections.

Activity of Exebacase (CF-301) against Biofilms Formed by Staphylococcus epidermidis Strains Isolated from Prosthetic Joint Infections

Staphylococcus epidermidis is one of the main pathogens responsible for bone and joint infections, especially those involving prosthetic materials, due to its ability to form biofilms. In these cases, biofilm formation, combined with increased antimicrobial resistance, often results in therapeutic failures.

Exebacase: A Novel Approach to the Treatment of Staphylococcal Infections

Lysins are bacteriophage-derived enzymes that degrade essential components of bacteria. Exebacase (Lysin CF-301) is an attractive antimicrobial agent because it demonstrates rapid bacteriolytic activity against staphylococcal species, including Staphylococcus aureus, has a low resistance profile, eradicates biofilms, and acts synergistically with other antibiotics. Combinations including exebacase and standard of care antibiotics represent an alternative to antibiotic monotherapies currently used to treat invasive staphylococcal infections. This manuscript reviews what is known about exebacase and explores how this novel agent may be used in the future to treat human bacterial pathogens.

Past and Future of Phage Therapy and Phage-Derived Proteins in Patients with Bone and Joint Infection

Phage-derived therapies comprise phage therapy and the use of phage-derived proteins as anti-bacterial therapy. Bacteriophages are natural viruses that target specific bacteria. They were proposed to be used to treat bacterial infections in the 1920s, before the discovery and widespread over-commercialized use of antibiotics. Phage therapy was totally abandoned in Western countries, whereas it is still used in Poland, Georgia and Russia. We review here the history of phage therapy by focusing on bone and joint infection, and on the development of phage therapy in France in this indication. We discuss the rationale of its use in bacterial infection and show the feasibility of phage therapy in the 2020s, based on several patients with complex bone and joint infection who recently received phages as compassionate therapy. Although the status of phage therapy remains to be clarified by health care authorities, obtaining pharmaceutical-grade therapeutic phages (i.e., following good manufacturing practice guidelines or being “GMP-like”) targeting bacterial species of concern is essential. Moreover, multidisciplinary clinical expertise has to determine what could be the relevant indications to perform clinical trials. Finally “phage therapy 2.0” has to integrate the following steps: (i) follow the status of phage therapy, that is not settled and defined; (ii) develop in each country a close relationship with the national health care authority; (iii) develop industrial–academic partnerships; (iv) create academic reference centers; (v) identify relevant clinical indications; (vi) use GMP/GMP-like phages with guaranteed quality bioproduction; (vii) start as salvage therapy; (vii) combine with antibiotics and adequate surgery; and (viii) perform clinical trials, to finally (ix) demonstrate in which clinical settings phage therapy provides benefit. Phage-derived proteins such as peptidoglycan hydrolases, polysaccharide depolymerases or lysins are enzymes that also have anti-biofilm activity. In contrast to phages, their development has to follow the classical process of medicinal products. Phage therapy and phage-derived products also have a huge potential to treat biofilm-associated bacterial diseases, and this is of crucial importance in the worldwide spread of antimicrobial resistance.