Ceftaroline as Salvage Monotherapy for Persistent MRSA Bacteremia

Short versus long duration of ceftaroline combination therapy and outcomes in persistent or high-grade MRSA bacteremia: A retrospective single-center study

BACKGROUND

Methicillin-resistant Staphylococcus aureus (MRSA) is associated with high mortality rates. Despite antibiotic therapy, persistent bacteremia is challenging to treat. Combination therapy with ceftaroline has emerged as a potential treatment option; however, the optimal duration and clinical implications after bacteremia clearance are unknown.

METHODS

This retrospective cohort study examined patients with high-grade or persistent MRSA bacteremia who were treated with ceftaroline combination therapy at the University of New Mexico Hospital between January 2014 and June 2021. Patients were categorized into short- (<7 days) or long-duration (≥7 days) groups based on the duration of combination therapy after bacteremia clearance. Outcomes included 30-day all-cause mortality, bacteremia recurrence, post-bacteremia clearance length of stay, and adverse events.

RESULTS

A total of 32 patients were included in this study. The most common sources of bacteremia were bone/joint and endovascular (28.1%, 9/32 each). The median duration of combination therapy after clearance was seven days (IQR 2.8, 11). Patients in the long-duration group had a lower Charlson comorbidity index (1.0 vs 5.5, p = 0.017) than those in the short-duration group. After adjusting for confounders, there was no significant difference in the 30-day all-cause mortality between the groups (AOR 0.17, 95% CI 0.007-1.85, p = 0.18). No association was found between combination therapy duration and recurrence (OR 2.53, 95% CI 0.19-inf, p = 0.24) or adverse drug events (OR 3.46, 95% CI 0.39-74.86, p = 0.31). After controlling for total hospital length of stay, there was no significant difference in the post-bacteremia clearance length of stay between the two groups (p = 0.37).

CONCLUSIONS

Prolonging ceftaroline combination therapy after bacteremia clearance did not significantly improve outcomes in patients with persistent or high-grade MRSA bacteremia. The limitations of this study warrant cautious interpretation of its results. Larger studies are needed to determine the optimal duration and role of combination therapy for this difficult-to-treat infection.

Managing Antimicrobial Resistance in the Emergency Department

(Basic awareness and understanding of antimicrobial resistance and prevailing mechanisms can aid emergency physicians in providing appropriate care to patients with infections due to a multidrug-resistant organism (MDRO). Empiric treatment of MDRO infections should be approached with caution and guided by the most likely pathogens based on differential diagnosis, severity of the illness, suspected source of infection, patient-specific factors, and local antibiotic susceptibility patterns. Newer broad-spectrum antibiotics should be reserved for critically ill patients where there is a high likelihood of infection with an MDRO.).

Systematic review of ceftaroline fosamil in the management of patients with methicillin-resistant Staphylococcus aureus pneumonia

Methicillin-resistant Staphylococcus aureus (MRSA) is responsible for an array of problematic community- and healthcare-acquired infections, including pneumonia, and is frequently associated with severe disease and high mortality rates. Standard recommended treatments for empiric and targeted coverage of suspected MRSA in patients with community-acquired pneumonia (CAP) and hospital-acquired pneumonia (HAP), including ventilator-associated pneumonia (VAP), are vancomycin and linezolid. However, adverse events such as acute kidney injury and Clostridium difficile infection have been associated with these antibiotics. Ceftaroline fosamil is a β-lactam/extended-spectrum cephalosporin approved for the treatment of adults and children with CAP and complicated skin and soft tissue infections. Ceftaroline has in vitro activity against a range of common Gram-positive bacteria and is distinct among the β-lactams in retaining activity against MRSA. Due to the design of the pivotal randomised controlled trials of ceftaroline fosamil, outcomes in patients with MRSA CAP were not evaluated. However, various reports of real-world outcomes with ceftaroline fosamil for pneumonia caused by MRSA, including CAP and HAP/VAP, been published since its approval. A systematic literature review and qualitative analysis of relevant publications was undertaken to collate and summarise relevant published data on the efficacy and safety of ceftaroline fosamil in patients with MRSA pneumonia. While relatively few real-world outcomes studies are available, the available data suggest that ceftaroline fosamil is a possible alternative to linezolid and vancomycin for MRSA pneumonia. Specific scenarios in which ceftaroline fosamil might be considered include bacteraemia and complicating factors such as empyema.

Persistent Methicillin-Resistant Staphylococcus aureus Bacteremia: Host, Pathogen, and Treatment

Methicillin-resistant Staphylococcus aureus (MRSA) is a devastating pathogen responsible for a variety of life-threatening infections. A distinctive characteristic of this pathogen is its ability to persist in the bloodstream for several days despite seemingly appropriate antibiotics. Persistent MRSA bacteremia is common and is associated with poor clinical outcomes. The etiology of persistent MRSA bacteremia is a result of the complex interplay between the host, the pathogen, and the antibiotic used to treat the infection. In this review, we explore the factors related to each component of the host-pathogen interaction and discuss the clinical relevance of each element. Next, we discuss the treatment options and diagnostic approaches for the management of persistent MRSA bacteremia.

Antibiotics for multidrug-resistant gram-positive bacteria

Background: Antimicrobial resistance is a major global threat to public health and is associated with increased morbidity and mortality. A few therapeutic options for the treatment of multidrug resistant (MDR) gram-positive bacteria, such as methicillin resistant Staphylococcus aureus, MDR Streptococcus pneumoniae, vancomycin resistant Enterococci, are available.Current Concepts: As a result of comprehensive efforts, a dozen novel antibiotics have been developed and approved for the treatment of MDR gram-positive bacteria in the United States and Europe over the past 15 years. However, only a few antibiotics have been introduced in the Republic of Korea. The purpose of this review is to evaluate the antibiotics that act against MDR gram-positive bacteria as a primary therapeutic option. Particularly, this review focuses on novel antibiotics, including ceftaroline, ceftobiprole, telavancin, dalbavancin, oritavancin, tedizolid, delafloxacin, omadacycline, and lefamulin.Discussion and Conclusion: Novel antibiotics against MDR gram-positive bacteria have not yet been sufficiently studied in various clinical settings, and therefore, the approved indications are limited. However, these antibiotics are expected to play a major role in the treatment of MDR gram-positive bacteria owing to their advantages, including broad anti-bacterial spectrum, rapid bactericidal effect, minimal drug-drug interaction, a favorable safety profile, availability of both intravenous and oral formulations, convenient dosing scheme, and a single dose (or once a week) regimen owing to long half-life. It is crucial to introduce these novel antibiotics in the Republic of Korea for the treatment of patients suffering from MDR bacterial infections.

Investigational agents for the treatment of methicillin-resistant Staphylococcus aureus (MRSA) bacteremia: progress in clinical trials

INTRODUCTION

Bacteremia caused by Staphylococcus aureus is common. Cases caused by methicillin-resistant S. aureus (MRSA) are particularly formidable and often lethal. The mortality associated with MRSA bacteremia has not significantly decreased over the past couple of decades and concerns regarding efficacy and toxicity of standard therapy highlight the need for novel agents and new therapeutic approaches.

AREAS COVERED

This paper explores clinical trials investigating novel therapeutic approaches to S. aureus bacteremia. There is a special focus on MRSA bacteremia. Monotherapy and combination therapies and novel antimicrobials and adjunctive therapies that are only recently being established for therapeutic use are discussed.

EXPERT OPINION

The unfavorable safety profile of combination antimicrobial therapy in clinical trials has outweighed its benefits. Therefore, future investigation should focus on optimizing duration and de-escalation protocols. Antibody and bacteriophage lysin-based candidates have mostly been limited to safety trials, but progress with these agents is demonstrated through a lysin-based agent receiving a phase III trial. Antibiotics indicated for use in treating MRSA skin infections see continued investigation as treatments for MRSA bacteremia despite the difficulty of completing trials in this patient population. Promising agents include dalbavancin, ceftobiprole, ceftaroline, and exebacase.

Select controversies in the management of methicillin-resistant Staphylococcus aureus bacteremia: answers and remaining questions from recent evidence

Methicillin-resistant Staphylococcus aureus (MRSA) bacteremia continues to cause significant morbidity and mortality despite advances in medical therapy. Vancomycin therapy remains the standard of care for most cases of MRSA bacteremia but has pharmacokinetic and pharmacodynamic limitations, dosing complications, and known toxicity. Welcomed clinical trials have recently addressed some of the controversies that plague this field, including optimization of vancomycin dosing and use of combination therapy. In this review, we discuss these trials and their implications for clinical care and future research.

Use of Ceftaroline in Hospitalized Patients with and without COVID-19: A Descriptive Cross-Sectional Study

A single-center cross-sectional study was conducted to describe the use of ceftaroline in a large teaching hospital in Northern Italy, during a period also including the first months of the coronavirus disease 2019 (COVID-19) pandemic. The primary objective was to describe the use of ceftaroline in terms of indications and characteristics of patients. A secondary objective was to describe the rate of favorable clinical response in patients with bloodstream infections (BSI) due to methicillin-resistant Staphylococcus aureus (MRSA-BSI) receiving ceftaroline. Overall, 200 patients were included in the study. Most of them had COVID-19 (83%, 165/200) and were hospitalized in medical wards (78%, 155/200). Included patients with COVID-19 pneumonia were given empirical ceftaroline in the suspicion of bacterial co-infection or superinfection. Among patients with MRSA-BSI, ceftaroline was used as a first-line therapy and salvage therapy in 25% (3/12) and 75% (9/12) of cases, respectively, and as a monotherapy or in combination with daptomycin in 58% (7/12) and 42% (5/12) of patients, respectively. A favorable response was registered in 67% (8/12) of patients. Improving etiological diagnosis of bacterial infections is essential to optimize the use of ceftaroline in COVID-19 patients. The use of ceftaroline for MRSA-BSI, either as a monotherapy or in combination with other anti-MRSA agents, showed promising rates of favorable response.

High-level ceftaroline resistance in a paediatric patient with invasive methicillin-resistant Staphylococcus aureus infection without previous ceftaroline exposure

WHAT IS KNOWN AN OBJECTIVE

Our objective is to report a paediatric case of high-level ceftaroline resistance without previous ceftaroline exposure.

CASE DESCRIPTION

A 20-month-old, 12 kg, female with invasive MRSA infection presented with high-level ceftaroline resistance with no previous ceftaroline exposure.

WHAT IS NEW AND CONCLUSION

To our knowledge, our case is the first report of high-level ceftaroline resistance evident in a paediatric patient with invasive infection due to MRSA, without history of prior ceftaroline exposure. This case illustrates the importance of weighing the risk of resistance with the benefits of use when starting therapy empirically prior to susceptibility results, even in patients without previous drug exposure.

Differential effects of antibiotics on neutrophils exposed to lipoteichoic acid derived from Staphylococcus aureus

BACKGROUND

Persistent bacteremia occurs in at least 30% of patients with Staphylococcus aureus bloodstream infection (SAB) and may be attributable to a dysregulated host immune response. Neutrophils interact with a variety of S. aureus microbial factors, including lipoteichoic acid (LTA), to activate phagocytic function in a concentration-dependent manner. Antibiotics have been shown to exert both direct antimicrobial action as well as immunomodulatory effects. In this study, we compared the effects of different anti-staphylococcal antibiotics on LTA-mediated immune activation of neutrophils.

METHODS

Neutrophils obtained from healthy volunteers were exposed to two levels of LTA (1 and 10 μg/ml) with or without addition of antibiotics from different pharmacologic classes (vancomycin, daptomycin, ceftaroline). Neutrophil function was assessed by examining phagocytic response, activation (CD11b, CD62L expression), Toll-like receptor-2 expression, cell survival and apoptosis, and CXCL8 release.

RESULTS

Differential LTA-mediated antibiotic effects on neutrophil function were observed primarily at the high LTA exposure level. Ceftaroline in the presence of 10 μg/ml LTA had the most prominent effects on phagocytosis and CD11b and CD62L expression, with trends towards increased neutrophil survival and preservation of CXCL8 release when compared to daptomycin and vancomycin with the latter significantly dampening PMN CXCL8 release.

CONCLUSIONS

Select antimicrobial agents, such as ceftaroline, exert immunostimulatory effects on neutrophils exposed to S. aureus LTA, which when confirmed in vivo, could be leveraged for its dual immunomodulatory and antibacterial actions for the treatment of persistent SAB mediated by a dysregulated host response.

Methicillin-resistant Staphylococcus aureus: an overview of basic and clinical research

Methicillin-resistant Staphylococcus aureus (MRSA) is one of the most successful modern pathogens. The same organism that lives as a commensal and is transmitted in both health-care and community settings is also a leading cause of bacteraemia, endocarditis, skin and soft tissue infections, bone and joint infections and hospital-acquired infections. Genetically diverse, the epidemiology of MRSA is primarily characterized by the serial emergence of epidemic strains. Although its incidence has recently declined in some regions, MRSA still poses a formidable clinical threat, with persistently high morbidity and mortality. Successful treatment remains challenging and requires the evaluation of both novel antimicrobials and adjunctive aspects of care, such as infectious disease consultation, echocardiography and source control. In this Review, we provide an overview of basic and clinical MRSA research and summarize the expansive body of literature on the epidemiology, transmission, genetic diversity, evolution, surveillance and treatment of MRSA.

Successful Clearance of Persistent Methicillin-Resistant Staphylococcus aureus Bacteremia with Daptomycin, Linezolid, and Meropenem Salvage Therapy

Staphylococcus aureus is one of the most virulent Gram-positive organisms responsible for a multitude of infections, including bacteremia. Methicillin-resistant Staphylococcus aureus (MRSA) is of special concern in patients with bacteremia. Due to its associated poor clinical outcomes, morbidity, and mortality, the superlative salvage regimen for persistent MRSA bacteremia remains uncertain. An 85-year-old white female presented with persistent methicillin-resistant Staphylococcus aureus (MRSA) bacteremia. Empiric antibiotic therapy with linezolid was initiated prior to blood culture results. Once MRSA bacteremia was confirmed, alternative antibiotic therapy with daptomycin was initiated. Blood cultures remained positive for MRSA despite three days of daptomycin therapy after which ceftaroline was added to the antibiotic regimen. Blood cultures remained positive for MRSA despite seven days of combination therapy with daptomycin and ceftaroline. Salvage therapy was then initiated with daptomycin, linezolid, and meropenem. One day following initiation of salvage therapy, blood cultures revealed no bacterial growth for the remainder of the length of stay. This report supports the effectiveness of salvage therapy consisting of daptomycin, linezolid, and meropenem in patients with persistent MRSA bacteremia.

Evaluation of treatment options for methicillin-resistant Staphylococcus aureus infections in the obese patient

Methicillin-resistant Staphylococcus aureus (MRSA) has emerged as a major cause of infection in both the hospital and community setting. Obesity is a risk factor for infection, and the prevalence of this disease has reached epidemic proportions worldwide. Treatment of infections in this special population is a challenge given the lack of data on the optimal antibiotic choice and dosing strategies, particularly for treatment of MRSA infections. Obesity is associated with various physiological changes that may lead to altered pharmacokinetic parameters. These changes include altered drug biodistribution, elimination, and absorption. This review provides clinicians with a summary of the literature pertaining to the pharmacokinetic and pharmacodynamic considerations when selecting antibiotic therapy for the treatment of MRSA infections in obese patients.

MRSA Spinal Epidural Abscess as a Neurosurgical and Infectious Disease Emergency with Unresolved Antimicrobial Solution

Spinal epidural abscess caused by MRSA, a life-threatening organism resistant to methicillin and other antibiotics, is a rare but important infectious pathology due to its potential damage to the spinal cord. We present the case of a 74-year-old man who hematogenously seeded his entire epidural spinal canal from C1 to sacrum with MRSA bacteria and remained infected even after maximal treatment with vancomycin and daptomycin. Ceftaroline, a new 5th generation antibiotic with recently described clearance of widespread MRSA infection in epidural complex spine infections, was added to vancomycin as dual therapy for his MRSA infection. A 74-year-old diabetic man with prior right total knee arthroplasty and MRSA infection presented with persistent bacteremia and sepsis. He was transferred to our academic center after diagnosis of entire spine epidural abscesses from C1 to sacral levels with midthoracic MRI T2 hyperintensities of the vertebral bodies and disc concerning for osteomyelitis and discitis. Despite surgery and IV vancomycin with MIC of 1, suggesting extreme susceptibility, the patient's blood cultures remained persistently bacteremic at day 5 of treatment. After 48 hours of dual antibiotic therapy with vancomycin and ceftaroline, his blood cultures came back showing no growth. The patient's outcome was unfavorable due to the advanced nature of his infection and multiple comorbidities, but his negative blood cultures after the addition of ceftaroline to his regime require further investigation into this dual therapy. Randomized controlled trials of 5th generation or combinatorial antibiotics should be considered for this disease.

Antimicrobial resistance in healthcare, agriculture and the environment: the biochemistry behind the headlines

The crisis of antimicrobial resistance (AMR) is one of the most serious issues facing us today. The scale of the problem is illustrated by the recent commitment of Heads of State at the UN to coordinate efforts to curb the spread of AMR infections. In this review, we explore the biochemistry behind the headlines of a few stories that were recently published in the public media. We focus on examples from three different issues related to AMR: (i) hospital-acquired infections, (ii) the spread of resistance through animals and/or the environment and (iii) the role of antimicrobial soaps and other products containing disinfectants in the dissemination of AMR. Although these stories stem from three very different settings, the underlying message in all of them is the same: there is a direct relationship between the use of antimicrobials and the development of resistance. In addition, one type of antimicrobial could select for cross-resistance to another type and/or for multidrug resistance. Therefore, we argue the case for increased stewardship to not only cover clinical use of antibiotics, but also the use of antimicrobials in agriculture and stewardship of our crucially important biocides such as chlorhexidine.

Treatment of Staphylococcus aureus Infections

Staphylococcus aureus, although generally identified as a commensal, is also a common cause of human bacterial infections, including of the skin and other soft tissues, bones, bloodstream, and respiratory tract. The history of S. aureus treatment is marked by the development of resistance to each new class of antistaphylococcal antimicrobial drugs, including the penicillins, sulfonamides, tetracyclines, glycopeptides, and others, complicating therapy. S. aureus isolates identified in the 1960s were sometimes resistant to methicillin, a ß-lactam antimicrobial active initially against a majority S. aureus strains. These MRSA isolates, resistant to nearly all ß-lactam antimicrobials, were first largely confined to the health care environment and the patients who attended it. However, in the mid-1990s, new strains, known as community-associated (CA-) MRSA strains, emerged. CA-MRSA organisms, compared with health care-associated (HA-) MRSA strain types, are more often susceptible to multiple classes of non ß-lactam antimicrobials. While infections caused by methicillin-susceptible S. aureus (MSSA) strains are usually treated with drugs in the ß-lactam class, such as cephalosporins, oxacillin or nafcillin, MRSA infections are treated with drugs in other antimicrobial classes. The glycopeptide drug vancomycin, and in some countries teicoplanin, is the most common drug used to treat severe MRSA infections. There are now other classes of antimicrobials available to treat staphylococcal infections, including several that have been approved after 2009. The antimicrobial management of invasive and noninvasive S. aureus infections in the ambulatory and in-patient settings is the topic of this review. Also discussed are common adverse effects of antistaphylococcal antimicrobial agents, advantages of one agent over another for specific clinical syndromes, and the use of adjunctive therapies such as surgery and intravenous immunoglobulin. We have detailed considerations in the therapy of noninvasive and invasive S. aureus infections. This is followed by sections on specific clinical infectious syndromes including skin and soft tissue infections, bacteremia, endocarditis and intravascular infections, pneumonia, osteomyelitis and vertebral discitis, epidural abscess, septic arthritis, pyomyositis, mastitis, necrotizing fasciitis, orbital infections, endophthalmitis, parotitis, staphylococcal toxinoses, urogenital infections, and central nervous system infections.

Use of Ceftaroline Fosamil in Children: Review of Current Knowledge and its Application

Ceftaroline is a novel cephalosporin recently approved in children for treatment of acute bacterial skin and soft tissue infections and community-acquired bacterial pneumonia (CABP) caused by methicillin-resistant Staphylococcus aureus, Streptococcus pneumoniae and other susceptible bacteria. With a favorable tolerability profile and efficacy proven in pediatric patients and excellent in vitro activity against resistant Gram-positive and Gram-negative bacteria, ceftaroline may serve as a therapeutic option for polymicrobial infections, CABP caused by penicillin- and ceftriaxone-resistant S. pneumoniae and resistant Gram-positive infections that fail first-line antimicrobial agents. However, limited data are available on tolerability in neonates and infants younger than 2 months of age, and on pharmacokinetic characteristics in children with chronic medical conditions and those with invasive, complicated infections. In this review, the microbiological profile of ceftaroline, its mechanism of action, and pharmacokinetic profile will be presented. Additionally, clinical evidence for use in pediatric patients and proposed place in therapy is discussed.

Resistance to Non-glycopeptide Agents in Serious Staphylococcus aureus Infections

The role of vancomycin in the treatment of serious Staphylococcus aureus infections, both methicillin-susceptible and methicillin-resistant, is becoming increasingly ineffective due to increasing MIC and failure. The development of reduced vancomycin susceptibility by S. aureus to glycopeptides highlights the need for clinicians to reexamine the roles of non-glycopeptide therapy. As the use of these alternative non-glycopeptides antimicrobials increases, it will become pertinent to monitor the rates of resistance. Large surveillance programs have provided data for resistance against S. aureus for the non-glycopeptides (daptomycin, ceftaroline, tigecycline, linezolid, and tedizolid). The current published literatures suggest that worldwide resistance rates to these non-glycopeptides for serious MRSA infections are still low. Implementation of antimicrobial stewardship programs will be crucial in prevention of resistance of these antimicrobials against S. aureus.