Salvage treatment of methicillin-resistant staphylococcal endocarditis with ceftaroline: a multicentre observational study

Ceftaroline Fosamil for the Treatment of Methicillin-Resistant Staphylococcus Aureus Bacteremia: A Real-World Comparative Clinical Outcomes Study

BACKGROUND AND OBJECTIVE

Methicillin-resistant Staphylococcus aureus (MRSA) bacteremia results in substantial morbidity and mortality. As current treatments often lead to unsatisfactory outcomes, evidence guiding alternative treatment options is needed. This study evaluated real-world clinical outcomes of ceftaroline fosamil for the treatment of MRSA bacteremia.

METHODS

This retrospective study included adults hospitalized with MRSA bacteremia between 2011 and 2019. Patients were classified according to treatment with ceftaroline fosamil (ceftaroline), vancomycin, or daptomycin: Group 1, ceftaroline; Group 2, vancomycin or daptomycin (without ceftaroline); Group 3, combination therapy with ≥ 2 of these three agents. Clinical outcomes were compared using propensity-score-adjusted odds ratios (ORs) from logistic regression models.

RESULTS

Overall, 24,479 patients were included (Group 1, n = 532; Group 2, n = 21,555; Group 3, n = 2392). Mean age was 59.6, 60.8, and 57.4 years in Groups 1, 2, and 3, respectively. Mean post-index treatment length of stay was 8.8, 8.8, and 8.0 days, respectively. The most frequent line of therapy was ceftaroline first-line (42.1%), vancomycin or daptomycin first-line (95.4%), and combination therapy third-line or later (67.8%) in Groups 1, 2, and 3, respectively. Compared with Group 2, Groups 1 and 3 had similar favorable clinical responses {odds ratio [OR] = 1.18 [95% confidence interval (CI) 0.98-1.44], p = 0.08; OR = 1.20 [95% CI 0.97-1.47], p = 0.09, respectively} and were less likely to switch treatment (both p < 0.001). Compared with Group 2, Group 1 was more likely to undergo 30-day all-cause readmission [OR = 1.38 (95% CI 1.06-1.80), p = 0.02], whereas this was less likely for Group 3 [OR = 0.77 (95% CI 0.58-1.00), p = 0.05].

CONCLUSIONS

Patients receiving ceftaroline more often had favorable clinical responses than those receiving vancomycin or daptomycin monotherapy. In the absence of large-scale randomized controlled trials, these real-world data provide insights into the potential role of ceftaroline for treating MRSA bacteremia.

In vitro Activity of Ceftaroline Against Isolates of Gram-Positive Bacteria from Patients with Bloodstream Infections Collected as a Part of ATLAS Between 2017 and 2020

Purpose

To assess the in vitro activity of ceftaroline and a panel of comparator agents against isolates of Gram-positive bacteria, including Staphylococcus aureus, Streptococcus pneumoniae, β-hemolytic streptococci, and coagulase-negative staphylococci (CoNS) from blood collected in Africa and Middle East (AfME), Asia Pacific (APAC), Europe, Latin America (LATAM), and North America from 2017 to 2020 as a part of the Antimicrobial Testing Leadership and Surveillance (ATLAS) program.

Methods

Susceptibility and minimum inhibitory concentration were determined using broth microdilution for all antimicrobial agents by a central reference laboratory according to the Clinical and Laboratory Standards Institute (CLSI) and European Committee on Antimicrobial Susceptibility Testing (EUCAST) guidelines.

Results

Ceftaroline showed good activity (susceptibility ≥89.8%, MIC90 0.008-2 mg/L) against all Gram-positive isolates tested. All isolates of methicillin-susceptible S. aureus, penicillin-susceptible S. pneumoniae, S. agalactiae, S. dysgalactiae, and S. pyogenes were susceptible to ceftaroline (MIC90 0.008-0.25 mg/L). Ceftaroline susceptibility for MRSA isolates was 89.8% globally (MIC90 2 mg/L). Among the comparator agents, all isolates were susceptible to vancomycin, except S. epidermis (susceptibility, 99.9%). Among other agents, daptomycin, linezolid, and tigecycline showed potent activity (susceptibility ≥97.9%, MIC90 0.03-2 mg/L) against all isolates tested.

Conclusion

Ceftaroline showed potent in vitro activity against global bloodstream isolates of Gram-positive bacteria collected between 2017 and 2020. Monitoring and surveillance of global as well as regional longitudinal trends of resistance rates among Gram-positive isolates causing bloodstream infections are important to limit the spread of AMR, establish stewardship measures, and manage and appropriately treat infections.

New Antimicrobials and New Therapy Strategies for Endocarditis: Weapons That Should Be Defended

The overall low-quality evidence concerning the clinical benefits of different antibiotic regimens for the treatment of infective endocarditis (IE), which has made it difficult to strongly support or reject any regimen of antibiotic therapy, has led to a discrepancy between the available guidelines and clinical practice. In this complex scenario, very recently published guidelines have attempted to fill this gap. Indeed, in recent years several antimicrobials have entered the market, including ceftobiprole, ceftaroline, and the long-acting lipoglycopeptides dalbavancin and oritavancin. Despite being approved for different indications, real-world data on their use for the treatment of IE, alone or in combination, has accumulated over time. Furthermore, an old antibiotic, fosfomycin, has gained renewed interest for the treatment of complicated infections such as IE. In this narrative review, we focused on new antimicrobials and therapeutic strategies that we believe may provide important contributions to the advancement of Gram-positive IE treatment, providing a summary of the current in vitro, in vivo, and clinical evidence supporting their use in clinical practice.

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.

Ceftaroline: Systematic Review of Clinical Uses and Emerging Drug Resistance

OBJECTIVE

To assess the success rates of off-label uses of ceftaroline for infections caused by methicillin-resistant Staphylococcus aureus (MRSA) and evaluate emerging ceftaroline resistance.

DATA SOURCES

We queried PubMed/MEDLINE, with the search term "Ceftaroline." Articles were restricted to the English language and year of publication (January 1, 2009-January 31, 2022).

STUDY SELECTION AND DATA EXTRACTION

Clinical trials, observational studies, and case reports that reported efficacy, safety, pharmacokinetics, use in MRSA infections other than acute bacterial skin infection and community-acquired pneumonia, and ceftaroline resistance were selected.

DATA SYNTHESIS

The search pooled 103 publications and all abstracts were reviewed. Forty-six articles that reported efficacy, safety, pharmacokinetics, or off-label use in multiple patients and 7 articles on ceftaroline resistance are used in this review. Ceftaroline has been approved for treatment of acute skin/soft tissue infection and community-acquired pneumonia. Ceftaroline's efficacy in off-label infections ranged from 66.7% to 87.3% depending on the types of infection. There were 14 documented cases of ceftaroline resistance associated with PBP2a changes.

RELEVANCE TO PATIENT CARE AND CLINICAL PRACTICE

Case series and observational studies have documented success with ceftaroline alone or in combination with vancomycin or daptomycin for treatment of MRSA bone and joint, endovascular, diabetic foot infections, and bacteremia from other causes.

CONCLUSION

Despite the lack of randomized controlled trials, ceftaroline is used as salvage therapy for different MRSA infections. The data from case series and observational studies are promising but ceftaroline should be used judiciously as ceftaroline-resistant MRSA begin to emerge.

A review of recent advances in the treatment of adults with complicated urinary tract infection

INTRODUCTION

Complicated urinary tract infections (cUTIs) entail diverse clinical conditions that could be managed differently and not necessarily with premature empiric therapy. Since multidrug-resistant organisms (MDROs) are widely spreading worldwide, the possibility of encountering these resistant bacteria is inevitably part of the daily life of physicians who manage cUTIs.

AREAS COVERED

The advances in the management of cUTIs are explored, illustrating: 1) a proposed therapeutical approach to cUTIs within the antimicrobial stewardship context; 2) evidence regarding novel antibiotics targeting MDROs. Evidence research has been performed through MEDLINE/PubMed using appropriate keywords and terms regarding cUTIs published before June 2022.

EXPERT OPINION

Novel antimicrobial drugs are available in the clinicians' armamentarium. Selecting the optimal therapy for suitable patients may be challenging given the multifaceted group of cUTIs. Carbapenems use is widely increasing, the role of old β-lactam/β-lactamase inhibitors is constantly revised, and novel drugs lack real-life studies. Understanding the different ranges of the complexity of patients affected by cUTIs may help select the most suitable antibiotic for every single case. More multicentric observational studies targeting cUTIs are needed to elucidate the appropriate drug based on patient characteristics and presentations, providing stronger recommendations for cases encountered in everyday clinical practice.

In vitro activity of ceftaroline and other antimicrobial agents against Gram positive bacterial isolates: Descriptive study from a university hospital

PURPOSE

Ceftaroline is a novel antibiotic approved by USA Food and Drug Administration (FDA) for the treatment of acute bacterial skin and skin structure infections (ABSSSI) and community-acquired bacterial pneumonia (CABP). It has potent in vitro activity against Staphylococci, including methicillin-resistant strains, whose incidence is increasing worldwide and they are often difficult to treat. The present study was done to investigate the susceptibility of methicillin-resistant Staphylococcus aureus (MRSA) and methicillin-resistant coagulase-negative Staphylococcus (MR-CoNS) to ceftaroline and other antimicrobial agents in patient samples and to evaluate clinical profile of these patients.

METHODS

All consecutive, nonduplicate isolates of MRSA and MR-CoNS recovered from patient samples between June 2020 to December 2020 were included in the study. Species identification was done by Matrix Assisted Laser Desorption Ionization Time of Flight Mass Spectromtery (MALDI-TOF-MS) (BioMérieux, France). Antimicrobial sensitivity of ceftaroline and other comparator antimicrobials was done as per the Clinical and Laboratory Standards Institute (CLSI, 2020). Statistical Package for the Social Sciences (IBM-SPSS) software (Version 25) was used for statistical study.

RESULTS

Total 134 clinical isolates of the study consisted of MR-CoNS (115 isolates; 85.8%) and MRSA (19 isolates; 14.2%).89.5% MRSA isolates were sensitive to ceftaroline. 44.3% and 32.2% MR-CoNS isolates had ceftaroline MIC ≤1 ​μg/ml and MIC ​= ​2-4 ​μg/ml respectively.

CONCLUSIONS

Ceftaroline exhibited potent in vitro activity against both MRSA and MR-CoNS in the study.

Novel Cephalosporins in Septic Subjects and Severe Infections: Present Findings and Future Perspective

In past decade, cephalosporins have developed significantly, and data regarding novel cephalosporins (i.e., ceftobiprole, ceftaroline, ceftolozane/tazobactam, ceftazidime/avibactam, and cefiderocol) within septic and bacteremic subjects are rising. These compounds generally offer very promising in vitro microbiological susceptibility, although the variability among gram-negative and -positive strains of different cohorts is noticed in the literature. We require further pharmacological data to measure the best dose in order to prevent sub-therapeutic drug levels in critically ill patients. These new compounds in theory are the sparing solution in the Enterobacteriales infection group for different antimicrobial classes such as aminoglycosides notably within endovascular and GNB-bacteremias, as well as colistin and carbapenem-sparing strategies, favoring good safety profile molecules. Moreover, new cephalosporins are the basis for the actual indications to open up new and exciting prospects for serious infections in the future. In future, patients will be addressed with the desirable approach to sepsis and serious infections in terms of their clinical situation, inherent features of the host, the sensitivity profile, and local epidemiology, for which evidence of the use of new cephalosporin in the treatment of severe infections will fill the remaining gaps.

Ceftaroline activity against Staphylococcus aureus isolated from patients with infective endocarditis, worldwide (2010-2019)

OBJECTIVE

To evaluate the antimicrobial activity of ceftaroline against Staphylococcus aureus isolated from patients with infective endocarditis (IE).

METHODS

23,833 S. aureus isolates were collected consecutively from patients with bloodstream infections (BSI) from 2010 to 2019, via the SENTRY Antimicrobial Surveillance Program, including 396 isolates from patients with a diagnosis of IE. Isolates were collected from 340 medical centers worldwide and susceptibility tested by reference broth microdilution in a monitoring laboratory.

RESULTS

The oxacillin resistance (MRSA) rate was 29.0% among IE isolates, and was higher in North America (40.3%) than in Europe (25.4%) or the Latin America/Asia-Pacific region (LATAM-APAC; 18.6%). Ceftaroline was active against 95.2% of IE isolates (MIC50/90, 0.25/1 mg/L), with ceftaroline susceptibility higher in North America (99.2%) and LATAM-APAC (98.3%) than in Europe (92.0%). Among MRSA isolates from IE (n = 115; MIC50/90, 1/2 mg/L), ceftaroline susceptibility was 98.0% in North America, 90.9% in LATAM-APAC, and 68.5% in Europe. Among BSI isolates, MRSA rates were 43.6% in North America and 25.6% in Europe, while ceftaroline susceptibility rates were 98.1% in North America and 95.4% in Europe.

CONCLUSIONS

Ceftaroline demonstrated potent in vitro activity against a large collection of S. aureus isolates recovered from patients with BSI, including IE.

[New antibiotics for severe infections due to multidrug-resistant pathogens : Definitive treatment and escalation]

Multidrug-resistant pathogens often lead to treatment failure of antimicrobial regimens. After a period of imbalance between the occurrence/spread of resistance mechanisms and the development of new substances, some new substances have meanwhile been approved and many more are currently undergoing clinical testing. They are particularly effective against specific resistance mechanisms/pathogens and should be preserved for definitive treatment of an isolated pathogen. In the absence of alternatives reserve antibiotics, such as aztreonam and colistin have experienced a renaissance. They are again used in special infection scenarios and clinically tested in combination with new substances. Despite the introduction and development of new substances the building of resistance will at some time also render these (at least partially) ineffective. Therefore, their implementation must be carried out according to the antibiotic or infectious diseases stewardship.

Bacterial sepsis : Diagnostics and calculated antibiotic therapy

The mortality of patients with sepsis and septic shock is still unacceptably high. An effective calculated antibiotic treatment within 1 h of recognition of sepsis is an important target of sepsis treatment. Delays lead to an increase in mortality; therefore, structured treatment concepts form a rational foundation, taking relevant diagnostic and treatment steps into consideration. In addition to the assumed infection and individual risks of each patient, local resistance patterns and specific problem pathogens must be taken into account during the selection of anti-infective treatment. Many pathophysiologic alterations influence the pharmacokinetics (PK) of antibiotics during sepsis. The principle of standard dosing should be abandoned and replaced by an individual treatment approach with stronger weighting of the pharmacokinetics/pharmacodynamics (PK/PD) index of the substance groups. Although this is not yet the clinical standard, prolonged (or continuous) infusion of β‑lactam antibiotics and therapeutic drug monitoring (TDM) can help to achieve defined PK targets. Prolonged infusion is sufficient without TDM, but for continuous infusion, TDM is generally necessary. A further argument for individual PK/PD-oriented antibiotic approaches is the increasing number of infections due to multidrug-resistant (MDR) pathogens in the intensive care unit. For effective treatment, antibiotic stewardship teams (ABS teams) are becoming more established. Interdisciplinary cooperation of the ABS team with infectious disease (ID) specialists, microbiologists, and clinical pharmacists leads not only to rational administration of antibiotics, but also has a positive influence on treatment outcome. The gold standards for pathogen identification are still culture-based detection and microbiologic resistance testing for the various antibiotic groups. Despite the rapid investigation time, novel polymerase chain reaction(PCR)-based procedures for pathogen identification and resistance determination are currently only an adjunct to routine sepsis diagnostics, due to the limited number of studies, high costs, and limited availability. In complicated septic courses with multiple anti-infective therapies or recurrent sepsis, PCR-based procedures can be used in addition to treatment monitoring and diagnostics. Novel antibiotics represent potent alternatives in the treatment of MDR infections. Due to the often defined spectrum of pathogens and the practically (still) absent resistance, they are suitable for targeted treatment of severe MDR infections (therapy escalation). (Contribution available free of charge by "Free Access" [ https://link.springer.com/article/10.1007/s00101-017-0396-z ].).

New antibiotics for the treatment of infections by multidrug-resistant microorganisms

One of the current priorities of the World Health Organization is multidrug-resistant bacteria, because they are a global problem due to their rapid spread and the difficulty of their treatment. In addition, they are associated with high morbidity, mortality and high economic costs. There are multidrug-resistant bacteria, both Gram-positive and Gram-negative, including Pseudomonas aeruginosa and Acinetobacter baumannii resistant to carbapenems, enterobacteria producing carbapenemases, Staphylococcus aureus resistant to methicillin and/or with intermediate sensitivity to vancomycin, and Enterococcus faecium (and less frequently Enterococcus faecalis) resistant to vancomycin. This review will comment on the new antibiotics that have been incorporated into the therapeutic arsenal in recent years, as well as other promising antibiotics that are in their final stages of development.

Off-label use of ceftaroline fosamil: A systematic review

Ceftaroline fosamil is a fifth-generation cephalosporin with anti-methicillin-resistant Staphylococcus aureus (MRSA) activity. It has been approved by the EMA and FDA for the treatment of adults and children with community-acquired bacterial pneumonia (CABP) and acute bacterial skin and skin structure infections (ABSSSI). However, ceftaroline fosamil has a broad spectrum of activity, and a good safety and tolerability profile, so is frequently used off-label. The aim of this systematic review was to summarize the safety and efficacy of off-label use of ceftaroline. The review was conducted according to PRISMA guidelines. MEDLINE, EMBASE and CENTRAL databases (2010-2018) were searched using as the main term ceftaroline fosamil and its synonyms in combination with names of infectious diseases of interest. A total of 21 studies with 1901 patients were included: the most common off-label indications for ceftaroline use were bacteremia (n=595), endocarditis (n=171), osteoarticular infections (n=368), hospital-acquired pneumonia (n=115) and meningitis (n=23). The most common reasons for off-label use were persistent or recurrent infection after standard treatment or non-susceptibility to vancomycin and daptomycin. Clinical success was evaluated in 933 patients, and 724 (77%) of these reached this positive outcome. Incidence of adverse events (AEs) was reported in 11 studies. In 83 (9%) cases there were AEs related to the use of ceftaroline; the most common reported AEs were nausea, vomiting, diarrhea, rash and neutropenia. The review results show that ceftaroline may be used in clinical settings other than those currently approved; however, the use of ceftaroline in these contexts deserves further investigation.

High-dose trimethoprim-sulfamethoxazole and clindamycin for Staphylococcus aureus endocarditis

OBJECTIVE

The mortality rate for Staphylococcus aureus endocarditis remains as high as 20-30% despite improvements in medical and surgical treatment. This study evaluated the efficiency and tolerance of a combination of intravenous trimethoprim-sulfamethoxazole and clindamycin (T&C) +/- rifampicin and gentamicin, with a rapid switch to oral administration of T&C.

METHODS

This before-after intervention study compared the outcomes of 170 control patients before introduction of the T&C protocol (2001-2011) with the outcomes of 171 patients in the T&C group (2012-2016). All patients diagnosed with S. aureus infective endocarditis and referred to the study centre between 2001 and 2016 were included. Between 2001 and 2011, the patients received a standardized antibiotic treatment: oxacillin or vancomycin for 6 weeks, plus gentamicin for 5 days. Since February 2012, the antibiotic protocol has included a high dose of T&C (intravenous, switched to oral administration on day 7). Rifampicin and gentamicin are also given in cases of cardiac abscess or persistent bacteraemia.

RESULTS

The two groups were slightly different. On intention-to-treat analysis, global mortality (19% vs 30%, P=0.024), in-hospital mortality (10% vs 18%, P=0.03) and 30-day mortality (7% vs 14%, P=0.05) were lower in the T&C group. The mean duration of hospital stay was significantly shorter in the T&C group (30 vs 39 days; P=0.005).

CONCLUSIONS

The management of S. aureus infective endocarditis using a rapid shift to oral administration of T&C reduced the length of hospital stay and the mortality rate.

Methicillin-Resistant Staphylococcus aureus Prosthetic Valve Endocarditis: Pathophysiology, Epidemiology, Clinical Presentation, Diagnosis, and Management

Staphylococcus aureus prosthetic valve endocarditis (PVE) remains among the most morbid bacterial infections, with mortality estimates ranging from 40% to 80%. The proportion of PVE cases due to methicillin-resistant Staphylococcus aureus (MRSA) has grown in recent decades, to account for more than 15% of cases of S. aureus PVE and 6% of all cases of PVE. Because no large studies or clinical trials for PVE have been published, most guidelines on the diagnosis and management of MRSA PVE rely upon expert opinion and data from animal models or related conditions (e.g., coagulase-negative Staphylococcus infection). We performed a review of the literature on MRSA PVE to summarize data on pathogenic mechanisms and updates in epidemiology and therapeutic management and to inform diagnostic strategies and priority areas where additional clinical and laboratory data will be particularly useful to guide therapy. Major updates discussed in this review include novel diagnostics, indications for surgical management, the utility of aminoglycosides in medical therapy, and a review of newer antistaphylococcal agents used for the management of MRSA PVE.

New treatments of multidrug-resistant Gram-negative ventilator-associated pneumonia

Ventilator-associated pneumonia (VAP) remains an important clinical problem globally, being associated with significant morbidity and mortality. As management of VAP requires adequate and timely antibiotic administration, global emergence of antimicrobial resistance poses serious challenges over our ability to maintain this axiom. Development of antimicrobials against MDR Gram-negative pathogens has therefore emerged as a priority and some new antibiotics have been marketed or approach late stage of development. The aim of this review is to analyse new therapeutic options from the point view of potential treatment of VAP. Among recently developed antimicrobials presented herein, it is obvious that we will have promising therapeutic options against VAP caused by Enterobacteriaceae excluding those producing metallo-β-lactamases, against which only cefiderocol and aztreonam/avibactam are expected to be active. Against infections caused by carbapenem non-susceptible Pseudomonas aeruginosa, ceftolozane/tazobactam and to a lesser extend ceftazidime/avibactam may cover a proportion of current medical needs, but there still remain a considerable proportion of strains which harbor other resistance mechanisms. Murepavadin and cefiderocol hold promise against this particularly notorious pathogen. Finally, Acinetobacter baummannii remains a treatment-challenge. Eravacycline, cefiderocol and probably plazomicin seem to be the most promising agents against this difficult-to treat pathogen, but we have still a long road ahead, to see their position in clinical practice and particularly in VAP. In summary, despite persisting and increasing unmet medical needs, several newly approved and forthcoming agents hold promise for the treatment of VAP and hopefully will enrich our antimicrobial arsenal in the next few years. Targeted pharmacokinetic and clinical studies in real-life scenario of VAP are important to position these new agents in clinical practice, whereas vigilant use will ensure their longevity in our armamentarium.

[Bacterial sepsis : Diagnostics and calculated antibiotic therapy]

The mortality of patients with sepsis and septic shock is still unacceptably high. An effective antibiotic treatment within 1 h of recognition of sepsis is an important target of sepsis treatment. Delays lead to an increase in mortality; therefore, structured treatment concepts form a rational foundation, taking relevant diagnostic and treatment steps into consideration. In addition to the assumed focus and individual risks of each patient, local resistance patterns and specific problem pathogens must be taken into account for selection of anti-infection treatment. Many pathophysiological alterations influence the pharmacokinetics of antibiotics during sepsis. The principle of standard dosing should be abandoned and replaced by an individual treatment approach with stronger weighting of the pharmacokinetics/pharmacodynamics (PK/PD) index of the substance groups. Although this is not yet the clinical standard, prolonged (or continuous) infusion of beta-lactam antibiotics and therapeutic drug monitoring (TDM) can help to achieve defined PK targets. Prolonged infusion is sufficient without TDM but for continuous infusion TDM is basically necessary. A further argument for individual PK/PD-oriented antibiotic approaches is the increasing number of infections due to multidrug resistant pathogens (MDR) in the intensive care unit. For effective treatment antibiotic stewardship teams (ABS team) are becoming more established. Interdisciplinary cooperation of the ABS team with infectiologists, microbiologists and clinical pharmacists leads not only to a rational administration of antibiotics but also has a positive influence on the outcome. The gold standards for pathogen detection are still culture-based detection and microbiological resistance testing for the various antibiotic groups. Despite the rapid investigation time, novel polymerase chain reaction (PCR)-based procedures for pathogen identification and resistance determination, are currently only an adjunct to routine sepsis diagnostics due to the limited number of studies, high costs and limited availability. In complicated septic courses with multiple anti-infective treatment or recurrent sepsis, PCR-based procedures can be used in addition to therapy monitoring and diagnostics. Novel antibiotics represent potent alternatives in the treatment of MDR infections. Due to the often defined spectrum of pathogens and the practically absent resistance, they are suitable for targeted treatment of severe MDR infections (therapy escalation).

Treatment strategies for persistent methicillin-resistant Staphylococcus aureus bacteraemia

WHAT IS KNOWN AND OBJECTIVE

Treatment of methicillin-resistant Staphylococcus aureus (MRSA) bacteraemia is a long-standing challenge to health care, often complicated by metastatic infections, treatment failure and mortality. When MRSA bacteraemia persists despite adequate initial treatment, current Infectious Diseases Society of America guidelines recommend evaluation and removal of possible sources of infection. In addition, a change in therapy may be considered. The objective of this review was to explore the therapeutic options for the treatment of persistent MRSA bacteraemia.

METHODS

A literature search of PubMed, MEDLINE and Google Scholar was performed using the following search terms: [methicillin-resistant Staphylococcus aureus OR MRSA] AND [bacteraemia OR bloodstream infection] AND [persistent OR persistence OR refractory OR treatment failure OR salvage] AND treatment. We evaluated relevant, adult, English-language, peer-reviewed studies published between 1985 and May 2018. In vitro and animal studies were considered as supportive of in vivo data.

RESULTS AND DISCUSSION

Randomized, controlled trials are lacking. However, case series and case reports support multiple treatment options including high-dose daptomycin in combination with an antistaphylococcal β-lactam, ceftaroline, trimethoprim-sulfamethoxazole (TMP-SMX) or fosfomycin; ceftaroline alone or in combination with vancomycin or TMP-SMX; linezolid alone or in combination with a carbapenem, or telavancin.

WHAT IS NEW AND CONCLUSION

Given the heterogeneity of the data, a preferred regimen has not emerged. Prescribers must take into consideration recent exposure, source control, and available synergy and clinical data. Further comparative trials are needed to establish a preferred regimen and the creation of a universal treatment algorithm.

Ceftaroline for the treatment of methicillin-resistant Staphylococcus aureus bacteremia

PURPOSE

The utility of ceftaroline for the treatment of methicillin-resistant Staphylococcus aureus bacteremia (MRSAB) is reviewed.

SUMMARY

Ceftaroline was originally approved for the treatment of community-acquired bacterial pneumonia (CABP) and acute bacterial skin and skin structure infections (ABSSSIs) but recently received an additional approval for the treatment of S. aureus bacteremia (SAB) associated with ABSSSIs. Ceftaroline has demonstrated efficacy for the treatment of MRSAB, including isolates with elevated minimum inhibitory concentrations to conventional therapy when used alone or in combination with other agents. In multiple studies, ceftaroline has displayed rapid bloodstream eradication, even in the setting of refractory MRSAB or infective endocarditis. The clinical resolution of MRSAB or SAB in patients who received ceftaroline ranged from 31.0% to 83.3%; studies used varying definitions for clinical resolution and included differing proportions of patients with endocarditis. The use of ceftaroline in treatment-refractory patients and assorted populations makes absolute effectiveness difficult to determine. Ceftaroline has been shown to be effective in patients who have not responded to other agents for MRSAB, making it an attractive option for such patients. Although the approved dosing regimen for ceftaroline fosamil is 600 mg every 12 hours for patients with normal renal function for the treatment of ABSSSIs and CABP, there is some debate about whether more frequent doses (i.e., every 8 hours) are needed for MRSAB.

CONCLUSION

Ceftaroline has been used to successfully treat SAB, including endocarditis. Therapy with ceftaroline may be considered when antibiotic resistance or previous treatment failure precludes the use of first-line agents.

Multicenter Observational Study of Ceftaroline Fosamil for Methicillin-Resistant Staphylococcus aureus Bloodstream Infections

Novel therapies for methicillin-resistant Staphylococcus aureus (MRSA) bloodstream infection (BSI) are needed in the setting of reduced antibiotic susceptibilities and therapeutic failure. Ceftaroline is a cephalosporin antibiotic with MRSA activity. Although not FDA approved for MRSA BSI, ceftaroline has generated much interest as a potential treatment option. However, detailed descriptions of its use in this setting remain limited. To address this, we conducted a retrospective, multicenter, observational study of adult patients with MRSA BSI treated with at least 72 h of ceftaroline from 2011 to 2015. Safety outcomes were examined in the overall cohort, while efficacy outcomes were examined among patients who had not cleared their BSI prior to ceftaroline initiation. Data were also stratified by ceftaroline monotherapy or combination therapy. Predictors of clinical failure on ceftaroline treatment were also sought. Overall, 211 patients were included in the safety population; Clostridium difficile infection, rash, and neutropenia occurred in 6 patients (2.8%), 7 patients (3.3%), and 3 patients (1.4%), respectively. Clinical success was observed in 86 (68.3%) of the 126 patients included in the efficacy population. The monotherapy and combination therapy subgroups had similar proportions of patients experiencing success (69.7 and 64.9%, respectively). The median BSI durations post-ceftaroline treatment were 2 days (interquartile range, 1 to 4 days) for monotherapy and 3 days (interquartile range, 1.5 to 5 days) for combination therapy. Higher acute physiology and chronic health evaluation II scores and comorbid malignancy independently predicted treatment failure. Ceftaroline appears effective for MRSA BSI as both monotherapy and combination therapy. However, comparative studies are needed to further delineate the role of ceftaroline in MRSA BSI treatment.

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.

Ceftaroline as Salvage Monotherapy for Persistent MRSA Bacteremia

OBJECTIVE

To summarize published data regarding the use of ceftaroline as salvage monotherapy for persistent methicillin-resistant Staphylococcus aureus (MRSA) bacteremia.

DATA SOURCES

PubMed (January 1980-June 2016) was searched using combinations of the search terms methicillin-resistant Staphylococcus aureus, MRSA, bacteremia, ceftaroline, refractory, and persistent Supplemental references were generated through review of identified literature citations.

STUDY SELECTION AND DATA EXTRACTION

Available English-language, full-text articles pertaining to the use of ceftaroline for persistent MRSA bacteremia (MRSAB) were included.

DATA SYNTHESIS

The PubMed search yielded 23 articles for evaluation. There are no randomized controlled trials to date-only case series and reports. Four retrospective case series detailing the use of ceftaroline as monotherapy for persistent MRSAB were included. Most patients received at least 4 days of an appropriate anti-MRSA antimicrobial prior to ceftaroline and were able to clear bacteremia within 3 days. The most common rationales for ceftaroline use were progression of disease or nonresponse to current therapy. Higher off-label dosing of ceftaroline is often utilized to achieve optimal pharmacokinetic/pharmacodynamic parameters. Adverse events are not well described due to lack of follow-up; however, neutropenia has been associated with prolonged use.

CONCLUSIONS

Treatment options for persistent MRSAB remain few and far between. Ceftaroline is an effective agent for the salvage treatment of MRSAB. Off-label doses up to 600 mg every 8 hours are often used to achieve optimal pharmacokinetic/pharmacodynamic parameters. Because of lack of follow-up in these reports, the incidence of adverse effects of prolonged use of ceftaroline is not well defined.

Methicillin-resistant Staphylococcus aureus infections: A review of the currently available treatment options

This review is the result of discussions that took place at the 5th MRSA Working Group Consensus Meeting and explores the possible treatment options available for different types of infections due to methicillin-resistant Staphylococcus aureus (MRSA), focusing on those antibiotics that could represent a valid alternative to vancomycin. In fact, whilst vancomycin remains a viable option, its therapy is moving towards individualised dosing. Other drugs, such as the new lipoglycopeptides (oritavancin, dalbavancin and telavancin) and fifth-generation cephalosporins (ceftaroline and ceftobiprole), are showing good in vitro potency and in vivo efficacy, especially for patients infected with micro-organisms with higher vancomycin minimum inhibitory concentrations (MICs). Tedizolid is an attractive agent for use both in hospital and community settings, but the post-marketing data will better clarify its potential. Daptomycin and linezolid have shown non-inferiority to vancomycin in the treatment of MRSA bacteraemia and non-inferiority/superiority to vancomycin in the treatment of hospital-acquired pneumonia. Thus, several options are available, but more data from clinical practice, especially for invasive infections, are needed to assign specific roles to each antibiotic and to definitely include them in the new antibacterial armamentarium.

Bacteremia due to Methicillin-Resistant Staphylococcus aureus: New Therapeutic Approaches

This article reviews recent clinical evidence for the treatment of methicillin-resistant Staphylococcus aureus (MRSA) bacteremia. Vancomycin remains the initial antibiotic of choice for the treatment of patients with MRSA bacteremia and endocarditis due to isolates with vancomycin minimum inhibitory concentration ≤2 μg/mL, whereas daptomycin is an effective alternative, and ceftaroline seems promising. Treatment options for persistent MRSA bacteremia or bacteremia due to vancomycin-intermediate or vancomycin-resistant strains include daptomycin, ceftaroline, and combination therapies. There is a critical need for high-level evidence from clinical trials to allow optimally informed decisions in the treatment of MRSA bacteremia and endocarditis.

Antimicrobial activity of ceftaroline and comparator agents when tested against numerous species of coagulase-negative Staphylococcus causing infection in US hospitals

A total of 1593 coagulase-negative staphylococci (CoNS) considered clinically significant were collected from 71 US medical centers in 2013-2014 and tested for susceptibility by CLSI broth microdilution methods. Species identification was performed by matrix-assisted laser desorption ionization-time-of-flight mass spectrometry. Overall, 59.7% of isolates were oxacillin resistant (MRCoNS). Ceftaroline (MIC50/90, 0.25/0.5μg/mL) inhibited 99.2% of CoNS at ≤1μg/mL (susceptible breakpoint for Staphylococcus aureus), including 98.7% of MRCoNS, and the highest ceftaroline MIC value was 2μg/mL (13 isolates). Staphylococcus epidermidis represented 60.3% of the CoNS collection and was highly susceptible to ceftaroline (MIC50/90, 0.25/0.5μg/mL, 99.9% inhibited at ≤1μg/mL). All isolates of Staphylococcus capitis, Staphylococcus caprae, Staphylococcus hominis, Staphylococcus lugdunensis, Staphylococcus pettenkoferi, Staphylococcus simulans, and Staphylococcus warneri (MIC50/90, 0.06-0.25/0.25-0.5μg/mL) were inhibited at ceftaroline MIC of ≤1μg/mL. Staphylococcus haemolyticus represented only 4.8%, was atypically less susceptible to ceftaroline (MIC50/90, 0.5/2μg/mL, 87.0% inhibited at ≤1μg/mL), and accounted for 76.9% (10/13) of isolates with ceftaroline MIC >1μg/mL.

Antimicrobial Activities of Ceftaroline and Comparator Agents against Bacterial Organisms Causing Bacteremia in Patients with Skin and Skin Structure Infections in U.S. Medical Centers, 2008 to 2014

We evaluated the antimicrobial susceptibility of 1,454 organisms consecutively collected from patients with bacteremia associated with skin and skin structure infections. The most common organisms obtained wereStaphylococcus aureus(670 organisms [46.1%]),Escherichia coli(200 organisms [13.8%]), β-hemolytic streptococci (βHS) (138 organisms [9.5%]), andKlebsiella pneumoniae(109 organisms [7.5%]). The susceptibility rates for ceftaroline were 97.9% forS. aureus(95.9% among methicillin-resistantS. aureus[MRSA]), 100.0% for βHS, 86.5% forE. coli, and 89.0% forK. pneumoniae Ceftaroline and tigecycline provided the best overall coverage.

Daptomycin non-susceptible, vancomycin-intermediate Staphylococcus aureus endocarditis treated with ceftaroline and daptomycin: case report and brief review of the literature

We report a case of clearance of persistent bacteremia due to daptomycin non-susceptible, vancomycin-intermediate Staphylococcus aureus native mitral valve endocarditis with a combination of ceftaroline and daptomycin, in an 81-year-old medically complex patient who was not an operative candidate.

When sepsis persists: a review of MRSA bacteraemia salvage therapy

MRSA bacteraemia (MRSAB), including infective endocarditis, carries a high mortality rate, with up to 50% of patients failing initial therapy with vancomycin and requiring salvage therapy. Persistent MRSAB can be difficult to successfully eliminate, especially when source control is not possible due to an irremovable focus or the bacteraemia still persists despite surgical intervention. Although vancomycin and daptomycin are the only two antibiotics approved by the US FDA for the treatment of patients with MRSAB as monotherapy, the employment of novel strategies is required to effectively treat patients with persistent MRSAB and these may frequently involve combination drug therapy. Treatment strategies that are reviewed in this manuscript include vancomycin combined with a β-lactam, daptomycin-based therapy, ceftaroline-based therapy, linezolid-based therapy, quinupristin/dalfopristin, telavancin, trimethoprim/sulfamethoxazole-based therapy and fosfomycin-based therapy. We recommend that combination antibiotic therapy be considered for use in MRSAB salvage treatment.

Ventilator associated pneumonia in the ICU: where has it gone?

PURPOSE OF REVIEW

To highlight the clinical importance of ventilator-associated pneumonia (VAP) in an era of escalating antimicrobial resistance.

RECENT FINDINGS

VAP continues to be an important infection in the critically ill. The development of rapid microbiologic diagnostics and new antimicrobial agents offer opportunities for improved treatment strategies for VAP balancing the need to treat effectively in a timely manner and antimicrobial stewardship. Additionally, the new surveillance definitions for assessing the quality of care in critically ill patients (ventilator-associated events, ventilator-associated conditions, and infection-related ventilator-associated conditions) do not appear to be adequate surrogates for the identification of VAP.

SUMMARY

Clinicians caring for critically ill patients should be aware of the importance of correctly treating VAP. As new diagnostic technologies and antimicrobials become available for VAP, their incorporation into routine patient management should occur in a way that optimizes patient outcomes wherein minimizing further emergence of antimicrobial resistance.

What's new in the treatment of serious MRSA infection?

PURPOSE OF REVIEW

Vancomycin has been the cornerstone of treatment for methicillin-resistant Staphylococcus aureus (MRSA) infections. This review describes new MRSA-active antibiotics that have recently been introduced and highlights emerging resistance.

RECENT FINDINGS

Elevations in the vancomycin minimum inhibitory concentration within the susceptible range are associated with treatment failure and mortality in the treatment of MRSA infections. Ceftaroline and ceftobiprole are anti-MRSA cephalosporins and are noninferior to comparator agents in the treatment of acute bacterial skin and skin structure infections (ABSSSIs) and pneumonia. Tedizolid is more potent than linezolid, has improved pharmacokinetics and reduced toxicity and is active against cfr-containing S. aureus. Telavancin now has approval for treatment of hospital-acquired pneumonia, and recent phase 2 trial data showed similar cure rates in S. aureus bacteremia. Dalbavancin and oritavancin are administered once weekly and are noninferior to comparators for acute bacterial skin and skin structure infections. Resistance has emerged against many new anti-MRSA antimicrobials including ceftaroline. Combination therapy of β-lactams with vancomycin or daptomycin is increasing.

SUMMARY

Several new MRSA-active agents are now approved for use, although much of the data is derived from treatment of acute bacterial skin and skin structure infections or pneumonia. Further studies are required for more invasive infections, such as bacteremia and endocarditis.

Activity of ceftaroline and comparator agents tested against Staphylococcus aureus from patients with bloodstream infections in US medical centres (2009-13)

OBJECTIVES

The objective of this study was to evaluate the in vitro antimicrobial activity of ceftaroline and comparator agents tested against Staphylococcus aureus isolates causing bloodstream infection (BSI).

METHODS

A total of 4426 S. aureus isolates from patients with BSI were collected in 150 medical centres in the USA in 2009-13 and tested for susceptibility to ceftaroline and comparators by the CLSI broth microdilution method.

RESULTS

Overall, 45.5% of isolates were MRSA. Ceftaroline (MIC50/90, 0.25/1 mg/L) was active against 97.9% of S. aureus isolates at ≤1 mg/L (highest MIC, 2 mg/L). Daptomycin (MIC50/90, 0.25/0.5 mg/L), linezolid (MIC50/90, 1/2 mg/L) and vancomycin (MIC50/90, 1/1 mg/L) were active against ≥99.8% of isolates at the respective susceptible breakpoints. Susceptibility rates for clindamycin (MIC50/90, ≤0.25/>2 mg/L) and levofloxacin (MIC50/90, ≤0.5/>4 mg/L) were 80.8% and 59.2%, respectively. Against MSSA, ceftaroline (MIC50/90, 0.25/0.25 mg/L; 100.0% susceptible) was 16-, 4-8- and 4-fold more active in vitro (based on MIC50/90) than ceftriaxone (MIC50/90, 4/4 mg/L), linezolid (MIC50/90, 1/2 mg/L) and vancomycin (MIC50/90, 1/1 mg/L), respectively, and slightly more potent than daptomycin (MIC50/90, 0.25/0.5 mg/L). When tested against MRSA, ceftaroline was active against 95.4% and 100.0% of isolates at ≤1 and ≤2 mg/L, respectively. Moreover, ceftaroline retained significant activity against S. aureus with reduced susceptibility to vancomycin, daptomycin, clindamycin, levofloxacin and trimethoprim/sulfamethoxazole.

CONCLUSIONS

Ceftaroline demonstrated potent in vitro activity when tested against a large collection of contemporary (2009-13) S. aureus isolates causing BSI in US hospitals.

Diagnosis and treatment of bacteremia and endocarditis due to Staphylococcus aureus. A clinical guideline from the Spanish Society of Clinical Microbiology and Infectious Diseases (SEIMC)

Both bacteremia and infective endocarditis caused by Staphylococcus aureus are common and severe diseases. The prognosis may darken not infrequently, especially in the presence of intracardiac devices or methicillin-resistance. Indeed, the optimization of the antimicrobial therapy is a key step in the outcome of these infections. The high rates of treatment failure and the increasing interest in the influence of vancomycin susceptibility in the outcome of infections caused by both methicillin-susceptible and -resistant isolates has led to the research of novel therapeutic schemes. Specifically, the interest raised in recent years on the new antimicrobials with activity against methicillin-resistant staphylococci has been also extended to infections caused by susceptible strains, which still carry the most important burden of infection. Recent clinical and experimental research has focused in the activity of new combinations of antimicrobials, their indication and role still being debatable. Also, the impact of an appropriate empirical antimicrobial treatment has acquired relevance in recent years. Finally, it is noteworthy the impact of the implementation of a systematic bundle of measures for improving the outcome. The aim of this clinical guideline is to provide an ensemble of recommendations in order to improve the treatment and prognosis of bacteremia and infective endocarditis caused by S. aureus, in accordance to the latest evidence published.

My paper 10 years later: infective endocarditis in the intensive care unit

INTRODUCTION

Although the recent literature contains plenty of studies concerning all aspects of infective endocarditis (IE), very few focus on severe IE requiring admission to the ICU.

RESULTS

In 2004, we published a report on the clinical spectrum and prognostic factors in 228 consecutive critically ill patients with IE. Septic shock, neurological complications and immunocompromised state were independently associated with in-hospital mortality. Cardiac surgery during the acute phase of EI was associated with better survival. A lot of information has been accumulated during the past 10 years on management of IE. Although three sets of blood cultures allow the identification of about 90% of cases, culture-negative IE still remains a diagnostic challenge. Blood-polymerase chain reaction in valve tissue may yield a microbiologic diagnosis. New imaging techniques such as positron emission tomography computed tomography (PET-CT) have shown additive value in patients with an intracardiac device or valvular prosthesis. Systematic cerebral magnetic resonance imaging can lead to modification of therapeutic plans. The decision to operate and the timing of cardiac surgery should take into account the presence of congestive heart failure, neurological complications, renal failure and multiorgan dysfunction syndrome. In 2011 and 2013, we published the results of a multicentre prospective observational study of 198 ICU patients with left-sided IE and confirmed that cardiac surgery was associated with better outcome. The strongest independent predictor of post-operative mortality was the pre-operative multiorgan failure score. Neurological failure also represented a major determinant of mortality, regardless of the mechanism of neurological complication.

CONCLUSION

In the present paper, we propose algorithms to optimize the medico-surgical approach.