Successful phage-antibiotic therapy of P. aeruginosa implant-associated infection in a Siamese cat.

Antibiotic-resistant pathogens are a growing global issue, leading to untreatable infectious diseases in both humans and animals. Personalized bacteriophage (phage) therapy, the use of specific anti-bacterial viruses, is currently a leading approach to combat antibiotic-resistant infections. The implementation of phage therapy has primarily been focused on humans, almost neglecting the impact of such infections on the health and welfare of companion animals. Pets also have the potential to spread resistant infections to their owners or the veterinary staff through zoonotic transmission. Here, we showcase personalized phage-antibiotic treatment of a cat with a multidrug-resistant Pseudomonas aeruginosa implant-associated infection post-arthrodesis surgery. The treatment encompassed a tailored combination of an anti-P. aeruginosa phage and ceftazidime, precisely matched to the pathogen. The phage was topically applied to the surgical wound while the antibiotic was administered intramuscularly. After two treatment courses spanning 7 and 3 weeks, the surgical wound, which had previously remained open for five months, fully closed. To the best of our knowledge, this is the first case of personalized phage therapy application in felines, which provides further evidence of the effectiveness of this approach. The successful outcome paves the way for personalized phage-antibiotic treatments against persistent infections therapy in veterinary practice.

Lytic bacteriophages induce the secretion of antiviral and proinflammatory cytokines from human respiratory epithelial cells.

Phage therapy is a therapeutic approach to treat multidrug-resistant (MDR) infections that employs lytic bacteriophages (phages) to eliminate bacteria. Despite the abundant evidence for its success as an antimicrobial in Eastern Europe, there is scarce data regarding its effects on the human host. Here, we aimed to understand how lytic phages interact with cells of the airway epithelium, the tissue site that is colonized by bacterial biofilms in numerous chronic respiratory disorders. Using a panel of Pseudomonas aeruginosa phages and human airway epithelial cells (AECs) derived from a person with cystic fibrosis (CF), we determined that interactions between phages and epithelial cells depend on specific phage properties as well as physiochemical features of the microenvironment. Although poor at internalizing phages, the airway epithelium responds to phage exposure by changing its transcriptional profile and secreting antiviral and proinflammatory cytokines that correlate with specific phage families. Overall, our findings indicate that mammalian responses to phages are heterogenous and could potentially alter the way that respiratory local defenses aid in bacterial clearance during phage therapy. Thus, besides phage receptor specificity in a particular bacterial isolate, the criteria to select lytic phages for therapy should be expanded to include mammalian cell responses.

Mesenchymal stem cell-based adjunctive therapy for Pseudomonas aeruginosa-induced keratitis: A proof-of-concept in-vitro study.

PURPOSE: Pseudomonas aeruginosa-induced keratitis is one of the most severe and challenging forms of corneal infection, owing to its associated intense inflammatory reactions leading to corneal necrosis and dense corneal scar with loss of vision. Since mesenchymal stem cells (MSCs) are reported to possess antimicrobial and immunomodulatory properties, they can be tested as an adjuvant treatment along with the antibiotics which are the current standard of care. This study aims to investigate the anti-bacterial and immunomodulatory roles of human bone marrow MSC-derived conditioned medium (MSC-CM) in P. aeruginosa-infected human corneal epithelial cells (HCECs) in vitro. METHODS: The effect of MSC-CM on the growth of clinical isolates of P. aeruginosa was evaluated by colony-forming unit assay. The expression of inflammatory cytokines (IL-6 and TNF-α) and an antimicrobial peptide (Lipocalin 2) in lipopolysaccharide-treated MSCs and HCECs was analyzed through ELISA. Corneal epithelial repair following infection with P. aeruginosa was studied through scratch assay. RESULTS: Compared to control (P. aeruginosa (5*105) incubated in DMEM (1 ml) at 37 °C for 16 h), MSC-CM significantly: i) inhibits the growth of P. aeruginosa (159*109 vs. 104*109 CFU/ml), ii) accelerates corneal epithelial repair following infection with P. aeruginosa (9% vs. 24% closure of the wounded area after 12 h of infection), and iii) downregulates the lipopolysaccharide-induced expression of IL-6, TNF-α and Lipocalin 2 in HCECs. A combination of MSC-CM with an antibiotic, Ciprofloxacin moderately regulated the expression of IL-6, TNF-α, and Lipocalin 2. CONCLUSION: MSC-CM holds promise as an adjunctive therapeutic approach for P. aeruginosa-induced corneal epithelial damage.

Pseudomonas aeruginosa ventricular assist device infections: findings from ineffective phage therapies in five cases.

Left ventricular assist devices (LVAD) are increasingly used for management of heart failure; infection remains a frequent complication. Phage therapy has been successful in a variety of antibiotic refractory infections and is of interest in treating LVAD infections. We performed a retrospective review of four patients that underwent five separate courses of intravenous (IV) phage therapy with concomitant antibiotic for treatment of endovascular Pseudomonas aeruginosa LVAD infection. We assessed phage susceptibility, bacterial strain sequencing, serum neutralization, biofilm activity, and shelf-life of phage preparations. Five treatments of one to four wild-type virulent phage(s) were administered for 14-51 days after informed consent and regulatory approval. There was no successful outcome. Breakthrough bacteremia occurred in four of five treatments. Two patients died from the underlying infection. We noted a variable decline in phage susceptibility following three of five treatments, four of four tested developed serum neutralization, and prophage presence was confirmed in isolates of two tested patients. Two phage preparations showed an initial titer drop. Phage biofilm activity was confirmed in two. Phage susceptibility alone was not predictive of clinical efficacy in P. aeruginosa endovascular LVAD infection. IV phage was associated with serum neutralization in most cases though lack of clinical effect may be multifactorial including presence of multiple bacterial isolates with varying phage susceptibility, presence of prophages, decline in phage titers, and possible lack of biofilm activity. Breakthrough bacteremia occurred frequently (while the organism remained susceptible to administered phage) and is an important safety consideration.

PqsA mutation-mediated enhancement of phage-mediated combat against Pseudomonas aeruginosa.

Phage therapy is a potential approach in the biocontrol of foodborne pathogens. However, the emergence of phage resistance and the narrow host range of most phage isolates continue to limit the antimicrobial efficacy of phages. Here, we investigated the potential of the pqsA gene, encoding the anthranilate-CoA ligase enzyme, as an adjuvant for phage therapy. The knockout of the pqsA gene significantly enhanced the bactericidal effect of phages vB_Pae_QDWS and vB_Pae_S1 against Pseudomonas aeruginosa. Under phage infection pressure, the growth of the PaΔpqsA was significantly inhibited within 8 h compared to the wild-type PAO1. Furthermore, we found that altering phage adsorption is not how PaΔpqsA responds to phage infection. Although pqsA represents a promising target for enhancing phage killing, it may not be applicable to all phages, such as types vB_Pae_W3 and vB_Pae_TR. Our findings provide new material reserves for the future design of novel phage-based therapeutic strategies.

Bacteriophages for bronchiectasis: treatment of the future?

PURPOSE OF REVIEW: Bronchiectasis is a chronic respiratory disease characterized by dilated airways, persistent sputum production and recurrent infective exacerbations. The microbiology of bronchiectasis includes various potentially pathogenic microorganisms including Pseudomonas aeruginosa which is commonly cultured from patients' sputum. P. aeruginosa is difficult to eradicate and frequently exhibits antimicrobial resistance. Bacteriophage therapy offers a novel and alternative method to treating bronchiectasis and can be used in conjunction with antibiotics to improve patient outcome. RECENT FINDINGS: Thirteen case reports/series to date have successfully used phages to treat infections in bronchiectasis patients, however these studies were constrained to few patients ( n  = 32) and utilized personalized phage preparations and adjunct antibiotics. In these studies, phage therapy was delivered by inhalation, intravenously or orally and was well tolerated in most patients without any unfavourable effects. Favourable clinical or microbiological outcomes were seen following phage therapy in many patients. Longitudinal patient follow-up reported regrowth of bacteria and phage neutralization in some studies. There are five randomized clinical controlled trials ongoing aiming to use phage therapy to treat P. aeruginosa associated respiratory conditions, with limited results available to date. SUMMARY: More research, particularly robust clinical trials, into how phages can clear respiratory infections, interact with resident microbiota, and how bacteria might develop resistance will be important to establish to ensure the success of this promising therapeutic alternative.

Resistance, mechanism, and fitness cost of specific bacteriophages for Pseudomonas aeruginosa.

The bacteriophage is an effective adjunct to existing antibiotic therapy; however, in the course of bacteriophage therapy, host bacteria will develop resistance to bacteriophages, thus affecting the efficacy. Therefore, it is important to describe how bacteria evade bacteriophage attack and the consequences of the biological changes that accompany the development of bacteriophage resistance before the bacteriophage is applied. The specific bacteriophage vB3530 of Pseudomonas aeruginosa (P. aeruginosa) has stable biological characteristics, short incubation period, strong in vitro cleavage ability, and absence of virulence or resistance genes. Ten bacteriophage-resistant strains (TL3780-R) were induced using the secondary infection approach, and the plaque assay showed that vB3530 was less sensitive to TL3780-R. Identification of bacteriophage adsorption receptors showed that the bacterial surface polysaccharide was probably the adsorption receptor of vB3530. In contrast to the TL3780 parental strain, TL3780-R is characterized by the absence of long lipopolysaccharide chains, which may be caused by base insertion of wzy or deletion of galU. It is also intriguing to observe that, in comparison to the parent strain, the bacteriophage-resistant strains TL3780-R mostly exhibited a large cost of fitness (growth rate, biofilm formation, motility, and ability to produce enhanced pyocyanin). In addition, TL3780-R9 showed increased susceptibility to aminoglycosides and chlorhexidine, which may be connected to the loss and down-regulation of mexX expression. Consequently, these findings fully depicted the resistance mechanism of P. aeruginosa to vB3530 and the fitness cost of bacteriophage resistance, laying a foundation for further application of bacteriophage therapy.IMPORTANCEThe bacteriophage is an effective adjunct to existing antibiotic therapy; However, bacteria also develop defensive mechanisms against bacteriophage attack. Thus, there is an urgent need to deeply understand the resistance mechanism of bacteria to bacteriophages and the fitness cost of bacteriophage resistance so as to lay the foundation for subsequent application of the phage. In this study, a specific bacteriophage vB3530 of P. aeruginosa had stable biological characteristics, short incubation period, strong in vitro cleavage ability, and absence of virulence or resistance genes. In addition, we found that P. aeruginosa may lead to phage resistance due to the deletion of galU and the base insertion of wzy, involved in the synthesis of lipopolysaccharides. Simultaneously, we showed the association with the biological state of the bacteria after bacteria acquire bacteriophage resistance, which is extremely relevant to guide the future application of therapeutic bacteriophages.

Exploiting lung adaptation and phage steering to clear pan-resistant Pseudomonas aeruginosa infections in vivo.

Pseudomonas aeruginosa is a major nosocomial pathogen that causes severe disease including sepsis. Carbapenem-resistant P. aeruginosa is recognised by the World Health Organisation as a priority 1 pathogen, with urgent need for new therapeutics. As such, there is renewed interest in using bacteriophages as a therapeutic. However, the dynamics of treating pan-resistant P. aeruginosa with phage in vivo are poorly understood. Using a pan-resistant P. aeruginosa in vivo infection model, phage therapy displays strong therapeutic potential, clearing infection from the blood, kidneys, and spleen. Remaining bacteria in the lungs and liver displays phage resistance due to limiting phage adsorption. Yet, resistance to phage results in re-sensitisation to a wide range of antibiotics. In this work, we use phage steering in vivo, pre-exposing a pan resistant P. aeruginosa infection with a phage cocktail to re-sensitise bacteria to antibiotics, clearing the infection from all organs.

Characterization of a new Pseudomonas aeruginosa Queuovirinae bacteriophage.

The ESKAPEE pathogen Pseudomonas aeruginosa is a common cause of chronic wound and cystic fibrosis lung infections, as well as acute burn and nosocomial infections. Many of these infections are recalcitrant to conventional antibiotic therapies due to both traditional antibiotic resistance mechanisms and antimicrobial tolerance. Recent successes with bacteriophage (phage) therapy to treat chronic human P. aeruginosa infections have led to a renewed interest in isolating and characterizing new P. aeruginosa phages. Here, we isolated and characterized a new lytic phage (termed PIP, pili-infecting phage) capable of infecting P. aeruginosa PA14. PIP is a tailed phage with an icosahedral head and flexible tail containing a genome that is 57,462 bp in length. Phylogenetic analysis reveals that PIP belongs to the subfamily Queuovirinae and genus Nipunavirus but is highly divergent in gene content from known Nipunaviruses. By isolating and characterizing a P. aeruginosa strain that spontaneously evolved resistance to PIP, we show that the receptor for PIP is Type IV pili. In summary, we isolated a new P. aeruginosa phage species with a unique genome, thus increasing the diversity of phages known to infect this important human pathogen.IMPORTANCEThe opportunistic pathogen Pseudomonas aeruginosa causes both acute and chronic human infections. These infections are notoriously difficult to treat due to both antibiotic resistance and antibiotic tolerance. The increasing frequency of antibiotic failure in P. aeruginosa infections has led scientists to explore other treatment options, including bacteriophage (phage) therapy. To this end, there has been a significant effort to identify new Pseudomonas phages. Here, we isolated and characterized a bacteriophage (termed PIP, pili-infecting phage) that infects P. aeruginosa PA14. Examination of the PIP genome revealed that this phage represents a new species in the subclass Queuovirinae. The isolation and characterization of spontaneous PA14 mutants that are resistant to PIP infection revealed Type IV pili as the PIP receptor. Ultimately, this study characterizes a new species of Pseudomonas phage, thus enhancing the known diversity of phages that infect this important pathogen.

Optimized preparation pipeline for emergency phage therapy against Pseudomonas aeruginosa at Yale University.

Bacteriophage therapy is one potential strategy to treat antimicrobial resistant or persistent bacterial infections, and the year 2021 marked the centennial of Felix d'Hérelle's first publication on the clinical applications of phages. At the Center for Phage Biology & Therapy at Yale University, a preparatory modular approach has been established to offer safe and potent phages for single-patient investigational new drug applications while recognizing the time constraints imposed by infection(s). This study provides a practical walkthrough of the pipeline with an Autographiviridae phage targeting Pseudomonas aeruginosa (phage vB_PaeA_SB, abbreviated to ΦSB). Notably, a thorough phage characterization and the evolutionary selection pressure exerted on bacteria by phages, analogous to antibiotics, are incorporated into the pipeline.

Correlation of Pseudomonas aeruginosa Phage Resistance with the Numbers and Types of Antiphage Systems.

Phage therapeutics offer a potentially powerful approach for combating multidrug-resistant bacterial infections. However, to be effective, phage therapy must overcome existing and developing phage resistance. While phage cocktails can reduce this risk by targeting multiple receptors in a single therapeutic, bacteria have mechanisms of resistance beyond receptor modification. A rapidly growing body of knowledge describes a broad and varied arsenal of antiphage systems encoded by bacteria to counter phage infection. We sought to understand the types and frequencies of antiphage systems present in a highly diverse panel of Pseudomonas aeruginosa clinical isolates utilized to characterize novel antibacterials. Using the web-server tool PADLOC (prokaryotic antiviral defense locator), putative antiphage systems were identified in these P. aeruginosa clinical isolates based on sequence homology to a validated and curated catalog of known defense systems. Coupling this host bacterium sequence analysis with host range data for 70 phages, we observed a correlation between existing phage resistance and the presence of higher numbers of antiphage systems in bacterial genomes. We were also able to identify antiphage systems that were more prevalent in highly phage-resistant P. aeruginosa strains, suggesting their importance in conferring resistance.

Enhancement of bactericidal effects of bacteriophage and gentamicin combination regimen against Staphylococcus aureus and Pseudomonas aeruginosa strains in a mice diabetic wound model.

Diabetic patients are more susceptible to developing wound infections resulting in poor and delayed wound healing. Bacteriophages, the viruses that target-specific bacteria, can be used as an alternative to antibiotics to eliminate drug-resistant bacterial infections. Pseudomonas aeruginosa (P. aeruginosa) and Staphylococcus aureus (S. aureus) are among the most frequently identified pathogens in diabetic foot ulcers (DFUs). The aim of this study was assessment of bacteriophage and gentamicin combination effects on bacterial isolates from DFU infections. Specific bacteriophages were collected from sewage and animal feces samples and the phages were enriched using S. aureus and P. aeruginosa cultures. The lytic potential of phage isolates was assessed by the clarity of plaques. We isolated and characterized four lytic phages: Stp2, Psp1, Stp1, and Psp2. The phage cocktail was optimized and investigated in vitro. We also assessed the effects of topical bacteriophage cocktail gel on animal models of DFU. Results revealed that the phage cocktail significantly reduced the mortality rate in diabetic infected mice. We determined that treatment with bacteriophage cocktail effectively decreased bacterial colony counts and improved wound healing in S. aureus and P. aeruginosa infections, especially when administrated concomitantly with gentamicin. The application of complementary therapy using a phage cocktail and gentamicin, could offer an attractive approach for the treatment of wound diabetic bacterial infections.

Pharmacokinetics and safety evaluation of intravenously administered Pseudomonas phage PA_LZ7 in a mouse model.

IMPORTANCE: Phage therapy is gaining traction as an alternative to antibiotics due to the rise of multi-drug-resistant (MDR) bacteria. This study assessed the pharmacokinetics and safety of PA_LZ7, a phage targeting MDR Pseudomonas aeruginosa, in mice. After intravenous administration, the phage showed an exponential decay in plasma and its concentration dropped significantly within 24 h for all dosage groups. Although there was a temporary increase in certain plasma cytokines and spleen weight at higher dosages, no significant toxicity was observed. Therefore, PA_LZ7 shows potential as an effective and safe candidate for future phage therapy against MDR P. aeruginosa infections.

Studying Bacteriophage Efficacy Using a Zebrafish Model.

The rise of bacteria resistant to the antibiotics currently in use (multiple drug-resistant, MDR) is a serious problem for patients affected by infections. This situation is even more worrying in the case of chronic bacterial infections, such as those caused by Pseudomonas aeruginosa (Pa), in patients with cystic fibrosis (CF). As an alternative to antibiotic treatments, the use of bacteriophages (phages) to fight bacterial infections has gained increasing interest in the last few years. Phages are viruses that specifically infect and multiply within the bacteria without infecting eukaryotic cells. It is well assumed that phage therapy has a high bacterial specificity, which, unlike antibiotics, should limit the damage to the endogenous microbiome. In addition, phages can kill antibiotic-resistant bacteria and perform self-amplification at the site of the infection.The protocol detailed in this chapter describes how the antimicrobial effect of phages can be studied in vivo in the zebrafish (Danio rerio) model infected with Pa. The same procedure can be applied to test the effectiveness of several different phages killing other bacterial species and for the rapid preclinical testing of phages to be used as personalized medicine.

Identification and impact on Pseudomonas aeruginosa virulence of mutations conferring resistance to a phage cocktail for phage therapy.

IMPORTANCE: In this work, we identified the putative receptors of 16 Pseudomonas phages and evaluated how resistance to phages recognizing different bacterial receptors may affect the virulence. Our findings are relevant for the implementation of phage therapy of Pseudomonas aeruginosa infections, which are difficult to treat with antibiotics. Overall, our results highlight the need to modify natural phages to enlarge the repertoire of receptors exploited by therapeutic phages and suggest that phages using the PAO1-type T4P as receptor may have limited value for the therapy of the cystic fibrosis infection.

Human Complement Inhibits Myophages against Pseudomonas aeruginosa.

Therapeutic bacteriophages (phages) are primarily chosen based on their in vitro bacteriolytic activity. Although anti-phage antibodies are known to inhibit phage infection, the influence of other immune system components is less well known. An important anti-bacterial and anti-viral innate immune system that may interact with phages is the complement system, a cascade of proteases that recognizes and targets invading microorganisms. In this research, we aimed to study the effects of serum components such as complement on the infectivity of different phages targeting Pseudomonas aeruginosa. We used a fluorescence-based assay to monitor the killing of P. aeruginosa by phages of different morphotypes in the presence of human serum. Our results reveal that several myophages are inhibited by serum in a concentration-dependent way, while the activity of four podophages and one siphophage tested in this study is not affected by serum. By using specific nanobodies blocking different components of the complement cascade, we showed that activation of the classical complement pathway is a driver of phage inhibition. To determine the mechanism of inhibition, we produced bioorthogonally labeled fluorescent phages to study their binding by means of microscopy and flow cytometry. We show that phage adsorption is hampered in the presence of active complement. Our results indicate that interactions with complement may affect the in vivo activity of therapeutically administered phages. A better understanding of this phenomenon is essential to optimize the design and application of therapeutic phage cocktails.

Ciprofloxacin in combination with bacteriophage cocktails against multi-drug resistant Pseudomonas aeruginosa in ex vivo simulated endocardial vegetation models.

Pseudomonas aeruginosa-associated infective endocarditis represents difficult-to-treat, deep-seated infections. Phage-antibiotic combinations have shown to eradicate multi-drug resistant (MDR) P. aeruginosa, limit the development of phage resistance, and restore antibiotic sensitivity. The objective of this study was to evaluate the activity of phage-ciprofloxacin (CIP) combinations in 4-day ex vivo simulated endocardial vegetation (SEV) models against drug-resistant P. aeruginosa isolates. Two P. aeruginosa isolates, extensively drug-resistant AR351 and MDR I0003-1, were selected for their drug resistance and sensitivity to phage. Three phages [LL-5504721-AH (LL), E2005-C (EC), and 109] and CIP were evaluated alone and in combination for their activity and influence on drug and phage resistance using 24-h time-kill analysis. The three-phage cocktail (q24h) in combination with CIP (400 mg q12h) was then tested in dynamic 4-day ex vivo SEV models, with reduction of log10 CFU/mL compared using ANOVA with Bonferroni analysis. Compared to other combinations, CIP-LL-EC-109 demonstrated synergistic and bactericidal activity from starting CFU/g against AR351 and I0003-1 (-Δ5.65 and 6.60 log10 CFU/g, respectively; P < 0.001). Additionally, CIP-LL-EC-109 mitigated phage resistance, while all other therapies had a high degree of resistance to >1 phages, and all phage-containing regimens prevented CIP mean inhibitory concentration increases compared to CIP alone for both AR351 and I0003-1 at 96 h.

Topical application of Lactobacilli successfully eradicates Pseudomonas aeruginosa biofilms and promotes wound healing in chronic wounds.

Chronic wounds are difficult to treat due to the presence of biofilm which prevents wound healing. Pseudomonas aeruginosa is one of the most common pathogens found in chronic wounds and conventional treatment strategies have been ineffective in the eradication of its biofilm, without harming the surrounding healthy tissue at the same time. Here, we introduced an innovative approach applying the probiotic product Bio-K+ (containing three lactobacilli) topically as an antimicrobial and antibiofilm agent. We identified lactic acid as the main active component. While antibiotics and antiseptics such as silver-ions only demonstrated limited efficacy, Bio-K+ was able to completely eradicate mature P. aeruginosa biofilms established in an in-vitro and ex-vivo human skin model. Furthermore, it demonstrated biocompatibility in the co-culture with human dermal fibroblasts and accelerated the migration of fibroblasts in a cell migration assay promoting wound healing. To enhance clinical practicability, we introduced Bio-K+ into the hydrocolloid dressing Aquacel, achieving sustained release of lactic acid and biofilm eradication. This new treatment approach applying probiotics could represent a major improvement in the management of chronic wounds and can be extended in treating other biofilm-associated infections.

Remotely Controllable Engineered Bacteria for Targeted Therapy of Pseudomonas aeruginosa Infection.

Pseudomonas aeruginosa (P. aeruginosa) infection has become an intractable problem worldwide due to the decreasing efficacy of the mainstay therapy, antibiotic treatment. Hence, exploring new drugs and therapies to address this issue is crucial. Here, we construct a chimeric pyocin (ChPy) to specifically kill P. aeruginosa and engineer a near-infrared (NIR) light-responsive strain to produce and deliver this drug. Our engineered bacterial strain can continuously produce ChPy in the absence of light and release it to kill P. aeruginosa via remotely and precisely controlled bacterial lysis induced by NIR light. We demonstrate that our engineered bacterial strain is effective in P. aeruginosa-infected wound therapy in the mouse model, as it eradicated PAO1 in mouse wounds and shortened the wound healing time. Our work presents a potentially spatiotemporal and noninvasively controlled therapeutic strategy of engineered bacteria for the targeted treatment of P. aeruginosa infections.

Successful Bacteriophage-Antibiotic Combination Therapy against Multidrug-Resistant Pseudomonas aeruginosa Left Ventricular Assist Device Driveline Infection.

There is considerable interest in the use of bacteriophages (phages) to treat Pseudomonas aeruginosa infections associated with left ventricular assist devices (LVADs). These infections are often challenging to manage due to high rates of multidrug resistance and biofilm formation, which could potentially be overcome with the use of phages. We report a case of a 54-year-old man with relapsing multidrug-resistant P. aeruginosa LVAD driveline infection, who was treated with a combination of two lytic antipseudomonal phages administered intravenously and locally. Treatment was combined with LVAD driveline repositioning and systemic antibiotic administration, resulting in a successful outcome with clinical cure and eradication of the targeted bacteria. However, laboratory in vitro models showed that phages alone could not eradicate biofilms but could prevent biofilm formation. Phage-resistant bacterial strains evolved in biofilm models and showed decreased susceptibility to the phages used. Further studies are needed to understand the complexity of phage resistance and the interaction of phages and antibiotics. Our results indicate that the combination of phages, antibiotics, and surgical intervention can have great potential in treating LVAD-associated infections. More than 21 months post-treatment, our patient remains cured of the infection.