Results of a double-blind, randomized trial of ceftobiprole treatment of complicated skin and skin structure infections caused by gram-positive bacteria

Efficacy and Safety of Antibiotics in the Treatment of Methicillin-Resistant Staphylococcus aureus (MRSA) Infections: A Systematic Review and Network Meta-Analysis

BACKGROUND

Vancomycin is a first-line drug for the treatment of MRSA infection. However, overuse of vancomycin can cause bacteria to become resistant, forming resistant strains and making infections more difficult to treat. This study aimed to evaluate the efficacy and safety of different antibiotics in the treatment of MRSA infections and to compare them, mainly with vancomycin, to find better vancomycin alternatives.

METHODS

All studies were obtained from the PubMed and Embase databases from inception to 13 April 2023. The three comprehensive indicators of clinical cure success rate, clinical microbiological success rate, and adverse reactions were evaluated, and the clinical cure success rates of three disease types, complex skin and skin structure infections (cSSSIs), complex skin and soft tissue infections (cSSTIs), and pneumonia, were analyzed in subgroups. All statistical analyses were performed using R and STATA 14.0 software for network meta-analysis.

RESULTS

A total of 38 trials with 6281 patients were included, and 13 drug treatments were evaluated. For MRSA infections, the results of network meta-analysis showed that the clinical success rates of linezolid, the combination of vancomycin and rifampin, and the combination of minocycline and rifampin were better than that of vancomycin (RR 1.71; 95%-CI 1.45-2.02), (RR 2.46; 95%-CI 1.10-5.49) (RR, 2.77; 95%-CI 1.06-7.21). The success rate of clinical microbiological treatment with vancomycin was inferior to that with telavancin (RR 0.74; 95%-CI 0.55-0.99). Linezolid had a higher rate of adverse reactions than teicoplanin (RR 5.35; 95%-CI 1.10-25.98). Subgroup analysis showed that vancomycin had a lower clinical success rate than linezolid in the treatment of MRSA-induced cSSSIs, cSSTIs, and pneumonia (RR 0.59; 95%-CI 0.44-0.80) (RR 0.55; 95%-CI 0.35-0.89) (RR 0.55; 95%-CI 0.32-0.93).

CONCLUSIONS

This systematic review and NMA provide a new comparison framework for the clinical treatment of MRSA infection. The NMA suggests that linezolid may be the antibiotic of choice for the treatment of MRSA infections, with the ability to improve clinical and microbiological success rates despite its disadvantage in terms of adverse effects. At the same time, the combination of minocycline and rifampicin may be the most effective drug to treat MRSA-induced cSSSIs, tedizolid may be the best drug to treat MRSA-induced cSSTIs, and the combination of vancomycin and rifampicin may be the most effective treatment for MRSA-induced pneumonia. More high-quality studies are still needed in the future to further identify alternatives to vancomycin.

TRIAL REGISTRATION

PROSPERO registration number CRD42023416788.

Ceftobiprole mono-therapy versus combination or non-combination regimen of standard antibiotics for the treatment of complicated infections: A systematic review and meta-analysis

OBJECTIVE

Various bacteria produce complicated infections that are difficult to treat worldwide. Ceftobiprole is effective against resistant Gram-positive and Gram-negative bacteria.

METHODS

This review assessed effectiveness and safety of ceftobiprole monotherapy for severe infections. A systematic review and meta-analysis of randomized controlled trials comparing clinical cure, microbiological cure, and safety of ceftobiprole alone to a combination or non-combination antibiotic regimen was conducted. Until December 20, 2022, we searched a major databases.

RESULTS

This study includes 4168 patients from six trials. Ceftobiprole and comparator-received patients had similar clinical responses for all patient population. Also, the eradication rate of all organisms and specific pathogenic bacteria in microbiologically examined patients was comparable between the groups. Ceftobiprole induced more gastrointestinal side events than comparable drugs, mostly nausea [OR 1.91 (1.26-2.90), p=<0.01]. While skin-related adverse events were significantly associated with comparator antibiotics [6 trials, 4062 patients; OR 0.77 (0.60-0.99), p=0.03].

CONCLUSION

Ceftobiprole monotherapy is effective and safe for severe infections caused by Gram-positive or Gram-negative bacteria.

Treatment of MRSA Infection: Where are We?

Staphylococcus aureus is a leading cause of septicemia, endocarditis, pneumonia, skin and soft tissue infections, bone and joint infections, and hospital-acquired infections. In particular, methicillin-resistant Staphylococcus aureus (MRSA) is associated with high morbidity and mortality, and continues to be a major public health problem. The emergence of multidrug-resistant MRSA strains along with the wide consumption of antibiotics has made anti-MRSA treatment a huge challenge. Novel treatment strategies (e.g., novel antimicrobials and new administrations) against MRSA are urgently needed. In the past decade, pharmaceutical companies have invested more in the research and development (R&D) of new antimicrobials and strategies, spurred by favorable policies. All research articles were collected from authentic online databases, including Google Scholar, PubMed, Scopus, and Web of Science, by using different combinations of keywords, including 'anti-MRSA', 'antibiotic', 'antimicrobial', 'clinical trial', 'clinical phase', clinical studies', and 'pipeline'. The information extracted from articles was compared to information provided on the drug manufacturer's website and Clinical Trials.gov (https://clinicaltrials.gov/) to confirm the latest development phase of anti-MRSA agents. The present review focuses on the current development status of new anti-MRSA strategies concerning chemistry, pharmacological target(s), indications, route of administration, efficacy and safety, pharmacokinetics, and pharmacodynamics, and aims to discuss the challenges and opportunities in developing drugs for anti-MRSA infections.

Safety and effectiveness of fifth generation cephalosporins for the treatment of methicillin-resistant staphylococcus aureus bloodstream infections: a narrative review exploring past, present, and future

INTRODUCTION

Methicillin-resistant Staphylococcus aureus (MRSA) bloodstream infection (BSI) is a major issue in healthcare, since it is often associated with endocarditis or deep site foci. Relevant morbidity and mortality associated with MRSA-BSIs forced the development of new antibiotic strategies; in particular, this review will focus the attention on fifth-generation cephalosporins (ceftaroline/ceftobiprole), that are the only ß-lactams active against MRSA.

AREAS COVERED

The review discusses the available randomized controlled trials and real-world observational studies conducted on safety and effectiveness of ceftaroline/ceftobiprole for the treatment of MRSA-BSIs. Finally, a proposal of MRSA-BSI treatment flowchart, based on fifth-generation cephalosporins, is described.

EXPERT OPINION

The use of anti-MRSA cephalosporins is an acceptable choice either in monotherapy or combination therapy for the treatment of MRSA-BSIs due to their relevant effectiveness and safety. Particularly, their use may be advisable in combination therapy in case of severe infections (including endocarditis or persistent bacteriemia) or in monotherapy in subjects at higher risk of drugs-induced toxicity with older regimens. On the contrary, caution should be taken in case of suspected/ascertained central nervous system infections due to inconsistent data regarding penetration of these drugs in cerebrospinal fluid and brain tissues.

Cefto Real-Life Study: Real-World Data on the Use of Ceftobiprole in a Multicenter Spanish Cohort

BACKGROUND

Ceftobiprole is a fifth-generation cephalosporin that has been approved in Europe solely for the treatment of community-acquired and nosocomial pneumonia. The objective was to analyze the use of ceftobiprole medocaril (Cefto-M) in Spanish clinical practice in patients with infections in hospital or outpatient parenteral antimicrobial therapy (OPAT).

METHODS

This retrospective, observational, multicenter study included patients treated from 1 September 2021 to 31 December 2022.

RESULTS

A total of 249 individuals were enrolled, aged 66.6 ± 15.4 years, of whom 59.4% were male with a Charlson index of four (IQR 2-6), 13.7% had COVID-19, and 4.8% were in an intensive care unit (ICU). The most frequent type of infection was respiratory (55.8%), followed by skin and soft tissue infection (21.7%). Cefto-M was administered to 67.9% of the patients as an empirical treatment, in which was administered as monotherapy for 7 days (5-10) in 53.8% of cases. The infection-related mortality was 11.2%. The highest mortality rates were identified for ventilator-associated pneumonia (40%) and infections due to methicillin-resistant Staphylococus aureus (20.8%) and Pseudomonas aeruginosa (16.1%). The mortality-related factors were age (OR: 1.1, 95%CI (1.04-1.16)), ICU admission (OR: 42.02, 95%CI (4.49-393.4)), and sepsis/septic shock (OR: 2.94, 95%CI (1.01-8.54)).

CONCLUSIONS

In real life, Cefto-M is a safe antibiotic, comprising only half of prescriptions for respiratory infections, that is mainly administered as rescue therapy in pluripathological patients with severe infectious diseases.

New Antibiotics for Staphylococcus aureus Infection: An Update from the World Association of Infectious Diseases and Immunological Disorders (WAidid) and the Italian Society of Anti-Infective Therapy (SITA)

Staphylococcus aureus is an extremely virulent pathogen that is capable of quickly evolving and developing antibiotic resistance. To overcome this problem, new antibiotics have been developed. Some of these have been licenced for use in clinical practice, mainly for the treatment of adults with acute skin and soft tissue infections, in addition to both community-acquired pneumonia (CAP) and nosocomial pneumonia (hospital-acquired bacterial pneumonia and ventilator-associated bacterial pneumonia). In this paper, the main characteristics and clinical use of new licenced anti-staphylococcal drugs have been discussed. In vitro studies have demonstrated that some new anti-staphylococcal antibiotics have better antimicrobial activity and, at least in certain cases, more favourable pharmacokinetic properties and higher safety and tolerability than the presently available anti-staphylococcal drugs. This suggests that they may have a potential use in reducing the risk of failure of S. aureus therapy. However, an in-depth analysis of microbiological and clinical studies carried out with these new drugs seems to indicate that further studies need to be conducted before the problem of resistance of S. aureus to the antibiotics available today can be completely solved. Considering the overall available research, the drugs that are active against S. aureus appear to present a great therapeutic opportunity for overcoming resistance to traditional therapy. There are advantages in the pharmacokinetic characteristics of some of these drugs and they have the potential to reduce hospital stays and economic costs associated with their use.

Off-label use versus formal recommendations of conventional and novel antibiotics for the treatment of infections caused by multidrug-resistant bacteria

The infections caused by multidrug- and extensively drug-resistant (MDR, XDR) bacteria, including Gram-positive cocci (GPC, including methicillin-resistant Staphylococcus aureus, MDR-Streptococcus pneumoniae and vancomycin-resistant enterococci) and Gram-negative bacilli (GNB, including carbapenem-resistant [CR] Enterobacterales, CR-Pseudomonas aeruginosa and XDR/CR-Acinetobacter baumannii complex) can be quite challenging for physicians with respect to treatment decisions. Apart from complicated urinary tract and intra-abdominal infections (cUTIs, cIAIs), bloodstream infections and pneumonia, these difficult-to-treat bacteria also cause infections at miscellaneous sites (bones, joints, native/prosthetic valves and skin structures, etc.). Antibiotics like dalbavancin, oritavancin, telavancin and daptomycin are currently approved for the treatment of acute bacterial skin and skin structural infections (ABSSSIs) caused by GPC. Additionally, ceftaroline, linezolid and tigecycline have been formally approved for the treatment of community-acquired pneumonia and ABSSSI. Cefiderocol and meropenem-vaborbactam are currently approved for the treatment of cUTIs caused by XDR-GNB. The spectra of ceftazidime-avibactam and imipenem/cilastatin-relebactam are broader than that of ceftolozane-tazobactam, but these three antibiotics are currently approved for the treatment of hospital-acquired pneumonia, cIAIs and cUTIs caused by MDR-GNB. Clinical investigations of other novel antibiotics (including cefepime-zidebactam, aztreonam-avibactam and sulbactam-durlobactam) for the treatment of various infections are ongoing. Nevertheless, evidence for adequate antibiotic regimens against osteomyelitis, arthritis and infective endocarditis due to several GPC and MDR-GNB is still mostly lacking. A comprehensive review of PubMed publications was undertaken and the formal indications and off-label use of important conventional and novel antibiotics against MDR/XDR-GPC and GNB isolates cultured from miscellaneous sites are presented in this paper.

Pharmacokinetics/pharmacodynamics of ceftobiprole in patients on extracorporeal membrane oxygenation

INTRODUCTION

Due to its bacteriological spectrum and efficacy in skin and soft tissue infections, ceftobiprole may be of interest for extracorporeal membrane oxygenation (ECMO) cannula-related infection. It is unknown whether ceftobiprole pharmacokinetics (PK) are changed by ECMO.

METHODS

A retrospective monocentric cohort study was performed of 35 patients with suspected ECMO-related cannula infections (28 on ECMO, seven after ECMO removal), who received ceftobiprole as empiric treatment and had ceftobiprole blood levels measured at trough, peak and CT50 (50% of the dosing interval). Ceftobiprole blood levels of the 28 patients on ECMO were compared with those of the seven patients without ECMO. Factors associated with low ceftobiprole trough levels were also explored.

RESULTS

Among the 35 patients included, 29 had a confirmed cannula-related infection and 48 pathogens were isolated. Ceftobiprole MIC was determined in 29 of these 48, and 23 (79%) were susceptible to ceftobiprole. Ceftobiprole blood levels (at trough, peak and CT50) were similar in ECMO and non-ECMO patients. Moreover, in patients whose pathogens responsible for infection were susceptible to ceftobiprole, 94% had a ceftobiprole trough level above the MIC. Ceftobiprole blood levels were decreased in patients with acute renal failure requiring renal replacement therapy (RRT) and in those with increased renal clearance (defined as creatinine clearance > 130 mL/min), independent of ECMO. No other factor was associated with modification of ceftobiprole PK/pharmacodynamics (PK/PD).

CONCLUSIONS

The ceftobiprole PK/PD was no different in patients during ECMO or after its withdrawal. Factors associated with decreased ceftobiprole blood levels were patients requiring RRT and those with increased renal clearance.

Current and emerging drug treatment strategies to tackle invasive community-associated methicillin-resistant Staphylococcus aureus (MRSA) infection: what are the challenges?

INTRODUCTION

Community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) infections represent a leading cause of purulent skin and soft tissue infections in some geographical regions. Traditionally, 'old antibiotics' such as trimethoprim-sulfamethoxazole, tetracyclines, clindamycin, chloramphenicol,vancomycin, and teicoplanin have been used to treat these infections, but these were often associated with low efficacy and excessive side effects and toxicity, especially nephrotoxicity. Along with the development of new compounds, the last decade has seen substantial improvements in the management of CA-MRSA infections.

AREAS COVERED

In this review, the authors discuss the current and emerging drug treatment strategies to tackle invasive CA-MRSA infections. Articles reported in this review were selected from through literature searches using the PubMed database.

EXPERT OPINION

The availability of new drugs showing a potent in vitro activity against CA-MRSA represents a unique opportunity to face the threat of resistance while potentially reducing toxicity. All these compounds represent promising options to enhance our antibiotic armamentarium. However, data regarding the use of these new drugs in real-life studies are limited and their best placement in therapy and in terms of optimization of medical resources and balance of cost-effectiveness requires further investigation.

Efficacy and safety of optional parenteral antimicrobial therapy for complicated skin and soft tissue infections: A systematic review and Bayesian network meta-analysis

BACKGROUND

Skin and soft tissue infections (SSTIs) carry significant economic burden, as well as morbidity and mortality, especially when caused by methicillin-resistant Staphylococcus aureus. This study aims to investigate the efficacy and safety of optional antimicrobial therapy for the treatment of complicated SSTIs (cSSTIs).

METHODS

We searched PubMed, Medline (Via Ovid SP), Embase (Via Ovid SP), and the Cochrane Central Register of Controlled Trials from their inception to March 22, 2021 for randomized controlled trials (RCTs) that studied the use of optional antimicrobial therapy for cSSTIs. Citations' screening, study selection, data extraction, and risk of bias assessment were independently performed by 2 authors. The primary outcomes were clinical and microbiological treatment success, and adverse events (AEs) were also assessed.

RESULTS

A total of 48 trials covering 24,381 patients assessing 20 types of antimicrobial treatment modalities were included. Overall, omadacycline was associated with the highest beneficial effect on clinical and microbiological treatment success and with the largest rank probability based on surface under the cumulative ranking curve values, avarofloxacin was closely followed. Both had, however, omadacycline was related to moderately safety profiles. Lefamulin ranked as the best option was associated with the lowest risk of severe AEs. Subgroup analysis showed similar results. The quality of primary outcomes was moderate to low.

CONCLUSIONS

The use of omadacycline was associated with higher rates of clinical and microbiological treatment success for the treatment of cSSTIs, with a relative low risk of AEs. Due to the limitations of the included RCTs, high-quality and well-designed RCTs are needed to further confirm the results.

Diagnosis and management of infections caused by multidrug-resistant bacteria: guideline endorsed by the Italian Society of Infection and Tropical Diseases (SIMIT), the Italian Society of Anti-Infective Therapy (SITA), the Italian Group for Antimicrobial Stewardship (GISA), the Italian Association of Clinical Microbiologists (AMCLI) and the Italian Society of Microbiology (SIM)

Management of patients with infections caused by multidrug-resistant organisms is challenging and requires a multidisciplinary approach to achieve successful clinical outcomes. The aim of this paper is to provide recommendations for the diagnosis and optimal management of these infections, with a focus on targeted antibiotic therapy. The document was produced by a panel of experts nominated by the five endorsing Italian societies, namely the Italian Association of Clinical Microbiologists (AMCLI), the Italian Group for Antimicrobial Stewardship (GISA), the Italian Society of Microbiology (SIM), the Italian Society of Infectious and Tropical Diseases (SIMIT) and the Italian Society of Anti-Infective Therapy (SITA). Population, Intervention, Comparison and Outcomes (PICO) questions about microbiological diagnosis, pharmacological strategies and targeted antibiotic therapy were addressed for the following pathogens: carbapenem-resistant Enterobacterales; carbapenem-resistant Pseudomonas aeruginosa; carbapenem-resistant Acinetobacter baumannii; and methicillin-resistant Staphylococcus aureus. A systematic review of the literature published from January 2011 to November 2020 was guided by the PICO strategy. As data from randomised controlled trials (RCTs) were expected to be limited, observational studies were also reviewed. The certainty of evidence was classified using the GRADE approach. Recommendations were classified as strong or conditional. Detailed recommendations were formulated for each pathogen. The majority of available RCTs have serious risk of bias, and many observational studies have several limitations, including small sample size, retrospective design and presence of confounders. Thus, some recommendations are based on low or very-low certainty of evidence. Importantly, these recommendations should be continually updated to reflect emerging evidence from clinical studies and real-world experience.

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.

Anti-MRSA Cephalosporin versus Vancomycin-Based Treatment for Acute Bacterial Skin and Skin Structure Infection: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

This systematic review and meta-analysis of randomized controlled trials (RCTs) compared the clinical efficacy and safety of anti-MRSA cephalosporin and vancomycin-based treatment in treating acute bacterial skin and skin structure infections (ABSSSIs). PubMed, Embase, Cochrane Central Register of Controlled Trials, Turning Research into Practice, and ClinicalTrials.gov databases were searched for relevant articles from inception to 15 June 2020. RCTs comparing the clinical efficacy and safety of anti-MRSA cephalosporin with those of vancomycin-based regimens in treating adult patients with ABSSSIs were included. The primary and secondary outcomes were clinical response at the test-of-cure assessments and risk of adverse events (AEs), respectively. Eight RCTs were enrolled. The clinical response rate was not significantly different between anti-MRSA cephalosporin and vancomycin-based treatments (odds ratio [OR], 1.05; 95% CI, 0.90–1.23; I² = 0%). Except for major cutaneous abscesses in which anti-MRSA cephalosporin-based treatment was associated with a lower clinical response rate than vancomycin-based treatment (OR, 0.62; 95% CI, 0.40–0.97; I² = 0%), other subgroup analyses according to the type of cephalosporin (ceftaroline or ceftobiprole), type of infection, and different pathogens did not show significant differences in clinical response. Anti-MRSA cephalosporin-based treatment was only associated with a higher risk of nausea than vancomycin-based treatment (OR, 1.41; 95% CI, 1.07–1.85; I² = 0%). In treating ABSSSIs, the clinical efficacy of anti-MRSA cephalosporin is comparable to that of vancomycin-based treatment, except in major cutaneous abscesses. In addition to nausea, anti-MRSA cephalosporin was as tolerable as vancomycin-based treatment.

Clinical efficacy and safety of ceftobiprole in the treatment of acute bacterial skin and skin structure infection: a systematic review and meta-analysis of randomized controlled trials

Objectives: To investigate the clinical efficacy and safety of ceftobiprole for acute bacterial skin and skin structure infections (ABSSSIs).Methods: PubMed, Web of Science, EBSO, Ovid Medline, ClinicalTrial.gov and Cochrane Library were searched until 25 December 2020. Only randomized controlled trials that compared the treatment efficacy of ceftobiprole with that of other antibiotics for adult patients with ABSSSIs were included in this meta-analysis.Results: The 3 RCTs involving 2291 adult patients with ABSSSIs were included. No significant difference in clinical success, as measured by the TOC, was observed between ceftobiprole and comparators among the intention-to-treat population (OR, 1.06; 95% CI, 0.85-1.33; I² = 0%) and clinical evaluable population (OR, 1.17; 95% CI, 0.76-1.79; I² = 17%). Ceftobiprole was associated with a similar risk of adverse events (AEs) to that of comparators.Conclusions: Ceftobiprole can achieve similar clinical and microbiological responses as alternative antibiotics in patients with ABSSSIs. In addition, ceftobiprole shares a similar safety profile to comparators.

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.

Development of TLC Chromatographic-Densitometric Procedure for Qualitative and Quantitative Analysis of Ceftobiprole

Currently, there is still a need for broad-spectrum antibiotics. The new cephalosporin antibiotics include, among others, ceftobiprole, a fifth-generation gram-positive cephalosporin, active against Staphylococcus aureus methicillin agonist (MRSA). The main focus of the work was to optimize the conditions of ceftobiprole qualitative determination and to validate the developed procedure according to ICH guidelines. As a result of the optimization process, HPTLC Cellulose chromatographic plates as a stationary phase and a mixture consisting of ethanol:2-propanol: glacial acetic acid: water (4:4:1:3, v/v/v/v) as a mobile phase were chosen. The densitometric detection was carried out at maximum absorbance of ceftobiprole (λ = 232 nm). Next, the validation process of the developed procedure was carried out. The relative standard deviation (RSD) for precision was less than 1.65%, which proves the high compatibility of the results, as well as the LOD = 0.0257 µg/spot and LOQ = 0.0779 µg/spot values, which also confirm the high sensitivity of the procedure. The usefulness of the developed method for the stability studies of ceftobiprole was analyzed. Study was carried out under stress conditions, i.e., acid and alkaline environments, exposure to radiation imitating sunlight and high temperature (40–60 °C). It was found that cefotbiprole is unstable in an alkaline environment and during exposure to UV-VIS radiation. Moreover, the lipophilicity parameter, as a main physicochemical property of the biologically active compound, was determined using experimental and computational methods.

Ceftobiprole Perspective: Current and Potential Future Indications

Ceftobiprole combines an excellent spectrum for community-acquired pneumonia (CAP) and hospital-acquired pneumonia (HAP) pathogens, with a low/medium MDR risk, and the β-lactams' safety in frail patients admitted to the hospital in internal medicine wards which may be at high risk of adverse events by anti-MRSA coverage as oxazolidinones or glycopeptides. We aimed to report the available evidence regarding ceftobiprole use in pneumonia and invasive bacterial infections, shedding light on ceftobiprole stewardship. The clinical application and real-life experiences of using ceftobiprole for bloodstream infections, including infective endocarditis, are limited but nevertheless promising. In addition, extended-spectrum ceftobiprole activity, including Enterococcus faecalis, Enterobacteriaceae, and Pseudomonas aeruginosa, has theoretical advantages for use as empirical therapy in bacteremia potentially caused by a broad spectrum of microorganisms, such as catheter-related bacteremia. In the future, the desirable approach to sepsis and severe infections will be administered to patients according to their clinical situation, the intrinsic host characteristics, the susceptibility profile, and local epidemiology, while the "universal antibiotic strategy" will no longer be adequate.

Treatment of methicillin-resistant Staphylococcus aureus (MRSA): updated guidelines from the UK

These evidence-based guidelines are an updated version of those issued in 2008. They have been produced following a review of the published literature (2007-18) pertaining to the treatment of infections caused by MRSA. The guidelines update, where appropriate, previous recommendations, taking into account changes in the UK epidemiology of MRSA, ongoing national surveillance data and the efficacy of novel anti-staphylococcal agents licensed for use in the UK. Emerging therapies that have not been licensed for use in the UK at the time of the review have also been assessed.

No Evidence for Ceftobiprole-Induced Immune Hemolytic Anemia in Three Phase 3 Clinical Trials

Purpose

Drug-induced immune hemolytic anemia (DIIHA) is a rare but serious adverse event associated with a number of drugs, including second- and third-generation cephalosporins. A positive direct antiglobulin test (DAT) is a reliable finding in DIIHA, but positive results without evidence of hemolysis can occur, particularly in hospitalized patients. There have been no reports of hemolytic anemia in four previous Phase 3 trials or from post-marketing surveillance of the advanced-generation, broad-spectrum cephalosporin, ceftobiprole. The aim of this analysis was to review the incidence of positive DAT results and any evidence of hemolytic anemia from three recent Phase 3 trials of ceftobiprole.

Patients and Methods

Patients were enrolled in three Phase 3 randomized controlled trials: 94 pediatric patients with pneumonia received ceftobiprole in the BPR-PIP-002 trial; 335 adults with acute bacterial skin and skin structure infections received ceftobiprole in the TARGET trial; and 201 adults with Staphylococcus aureus bacteremia have been randomized 1:1 to ceftobiprole or daptomycin ± aztreonam in the ongoing ERADICATE trial. In all three trials, DAT results were obtained at baseline, and follow-up tests were performed either at the test of cure (TOC) visit (BPR-PIP-002), end-of-treatment (EOT) visit (TARGET), or both EOT and post-treatment Day 70 visits (ERADICATE).

Results

In the BPR-PIP-002 trial, five patients (all ceftobiprole treated) had a documented negative DAT result at baseline followed by a positive result at the TOC visit. One patient in the ongoing, blinded ERADICATE trial had a positive DAT result at both baseline and EOT. Results from other laboratory investigations showed no evidence of hemolytic anemia in these patients. No positive DAT results were reported in the TARGET trial.

Conclusion

No evidence of hemolytic anemia associated with ceftobiprole was observed in either adults or children across several indications in this analysis of three large Phase 3 trials.

Ceftobiprole Compared With Vancomycin Plus Aztreonam in the Treatment of Acute Bacterial Skin and Skin Structure Infections: Results of a Phase 3, Randomized, Double-blind Trial (TARGET)

BACKGROUND

The development of novel broad-spectrum antibiotics, with efficacy against both gram-positive and gram-negative bacteria, has the potential to enhance treatment options for acute bacterial skin and skin structure infections (ABSSSIs). Ceftobiprole is an advanced-generation intravenous cephalosporin with broad in vitro activity against gram-positive (including methicillin-resistant Staphylococcus aureus) and gram-negative pathogens.

METHODS

TARGET was a randomized, double-blind, active-controlled, parallel-group, multicenter, phase 3 noninferiority study that compared ceftobiprole with vancomycin plus aztreonam. The Food and Drug Administration-defined primary efficacy endpoint was early clinical response 48-72 hours after treatment initiation in the intent-to-treat (ITT) population and the European Medicines Agency-defined primary endpoint was investigator-assessed clinical success at the test-of-cure (TOC) visit. Noninferiority was defined as the lower limit of the 95% CI for the difference in success rates (ceftobiprole minus vancomycin/aztreonam) >-10%. Safety was assessed through adverse event and laboratory data collection.

RESULTS

In total, 679 patients were randomized to ceftobiprole (n = 335) or vancomycin/aztreonam (n = 344). Early clinical success rates were 91.3% and 88.1% in the ceftobiprole and vancomycin/aztreonam groups, respectively, and noninferiority was demonstrated (adjusted difference: 3.3%; 95% CI: -1.2, 7.8). Investigator-assessed clinical success at the TOC visit was similar between the 2 groups, and noninferiority was demonstrated for both the ITT (90.1% vs 89.0%) and clinically evaluable (97.9% vs 95.2%) populations. Both treatment groups displayed similar microbiological success and safety profiles.

CONCLUSIONS

TARGET demonstrated that ceftobiprole is noninferior to vancomycin/aztreonam in the treatment of ABSSSIs, in terms of early clinical response and investigator-assessed clinical success at the TOC visit.

CLINICAL TRIALS REGISTRATION

NCT03137173.

Is coverage of S. aureus necessary in cellulitis/erysipelas? A literature review

BACKGROUND

Empirical treatment of patients with cellulitis/erysipelas usually targets both streptococci and methicillin-sensitive S. aureus (MSSA). However, the recommendation to empirically cover MSSA is weak and based on low-quality evidence.

METHODS AND OBJECTIVE

A systematic review was conducted in PubMed and clinical trial registries to assess the role of S. aureus in cellulitis/erysipelas and the need for empirical MSSA coverage.

RESULTS

Combined microbiological and serological data, and response to penicillin monotherapy suggest that streptococci are responsible for the vast majority of cases of cellulitis/erysipelas. However, most cases are non-culturable and the specificity of microbiological and serological studies is questionable based on recent studies using molecular techniques. According to epidemiological data and three randomized controlled trials, empirical coverage of methicillin-resistant S. aureus (MRSA) is not recommended for most patients, despite the high prevalence of MRSA in many areas. If MRSA is indeed not an important cause of uncomplicated cellulitis/erysipelas, then the same may apply to MSSA. Based on indirect comparison of data from clinical studies, cure rates with penicillin monotherapy (to which most MSSA are resistant) are comparable to the cure rates reported in many studies using wider-spectrum antibiotics.

CONCLUSION

Considering the limitations of microbiological studies in identifying the pathogens responsible for cellulitis/erysipelas, treatment needs to be guided by clinical trials. Trials comparing penicillin or amoxicillin monotherapy to MSSA-covering regimens are needed to definitively answer whether empirical coverage of MSSA is needed and to identify the subset of patients that can be safely treated with penicillin or amoxicillin monotherapy.

Ceftobiprole: drug evaluation and place in therapy

Introduction: Ceftobiprole is a fifth-generation cephalosporin with a broad spectrum of antimicrobial activity, including also methicillin-resistant Staphylococcus aureus (MRSA). Ceftobiprole is approved for the treatment of community-acquired pneumonia (CAP) and hospital-acquired pneumonia (HAP), excluding ventilator-associated pneumonia, in several European and non-European countries. Areas covered: In this narrative review, we discuss the current place in therapy of ceftobiprole, both within and outside approved indications. An inductive MEDLINE/PubMed search of the available literature was conducted. Expert opinion: There are three main reasons which render ceftobiprole an attractive option for the empirical and targeted treatment of CAP and HAP: (i) its broad spectrum of activity; (ii) its activity against MRSA; (iii) its good safety profile. For these indications, ceftobiprole should be employed thoughtfully, in those scenarios in which its intrinsic advantages could be maximized. The use of ceftobiprole outside approved indications could be justified in specific scenarios, such as when other approved alternatives are ineffective, when the risk of toxicity due to other agents is unacceptable, and for salvage therapy. In the near future, ongoing phase 3 studies and further observational experiences could both enlarge the current panel of approved indications and enrich our knowledge on the use of ceftobiprole for off-label indications.

Possible clinical indications of ceftobiprole

Ceftobiprole is a fifth-generation cephalosporin approved for the treatment of adult community-acquired pneumonia and non-ventilator associated hospital-acquired pneumonia. However, its microbiological and pharmacokinetic profile is very attractive as armamentarium for empirical monotherapy treatment in other infections too. Among these, the following scenarios could be considered complicated skin and soft tissue infections, moderate-severe diabetic foot infections without bone involvement, vascular-catheter-associated-bloodstream infections, and fever without apparent focus in the hospitalized patient without septic shock or profound immunosuppression.

Assessment of Antibiotic Treatment of Cellulitis and Erysipelas: A Systematic Review and Meta-analysis

Importance

The optimum antibiotic treatment for cellulitis and erysipelas lacks consensus. The available trial data do not demonstrate the superiority of any agent, and data are limited on the most appropriate route of administration or duration of therapy.

Objective

To assess the efficacy and safety of antibiotic therapy for non-surgically acquired cellulitis.

Data Sources

The following databases were searched to June 28, 2016: Cochrane Central Register of Controlled Trials (2016, issue 5), Medline (from 1946), Embase (from 1974), and Latin American and Caribbean Health Sciences Information System (LILACS) (from 1982). In addition, 5 trials databases and the reference lists of included studies were searched. Further searches of PubMed and Google Scholar were undertaken from June 28, 2016, to December 31, 2018.

Study Selection

Randomized clinical trials comparing different antibiotics, routes of administration, and treatment durations were included.

Data Extraction and Synthesis

For data collection and analysis, the standard methodological procedures of the Cochrane Collaboration were used. For dichotomous outcomes, the risk ratio and its 95% CI were calculated. A summary of findings table was created for the primary end points, adopting the GRADE approach to assess the quality of the evidence.

Main Outcomes and Measures

The primary outcome was the proportion of patients cured, improved, recovered, or symptom-free or symptom-reduced at the end of treatment, as reported by the trial. The secondary outcome was any adverse event.

Results

A total of 43 studies with a total of 5999 evaluable participants, whose age ranged from 1 month to 96 years, were included. Cellulitis was the primary diagnosis in only 15 studies (35%), and in other studies the median (interquartile range) proportion of patients with cellulitis was 29.7% (22.9%-50.3%). Overall, no evidence was found to support the superiority of any 1 antibiotic over another, and antibiotics with activity against methicillin-resistant Staphylococcus aureus did not add an advantage. Use of intravenous antibiotics over oral antibiotics and treatment duration of longer than 5 days were not supported by evidence.

Conclusions and Relevance

In this systematic review and meta-analysis, only low-quality evidence was found for the most appropriate agent, route of administration, and duration of treatment for patients with cellulitis; future trials need to use a standardized set of outcomes, including severity scoring, dosing, and duration of therapy.

The Significant Association between Polymicrobial Diabetic Foot Infection and Its Severity and Outcomes

Background

Foot infection is a major complication of diabetes mellitus (DM) and its agents are usually polymicrobial. This study aims to describe the agent and determine the association between polymicrobial infections and the severity of diabetic foot infections (DFI) and their outcomes.

Methods

This retrospective cohort study was conducted during one year and it involved 104 patients. Their records were reviewed and assessed. The causative agents and its sensitivity pattern were noted. The results were presented as descriptive statistic and analysed.

Results

A total of 133 microorganisms were isolated with 1.28 microorganisms per lesion. The microorganism isolated were 62% (n = 83) GN (Gram-negative) and 38% (n = 50) GP (Gram-positive). GN microorganisms include Pseudomonas spp (28%), Proteus spp (11%), Klebsiella spp (8%) and E. coli (4%). Staphylococcus aureus (54%) was predominant among GP, followed by Group B Streptococci (26%) and Enterococcus spp (6%). Thirty patients (28.8%) had polymicrobial infections. The association between the quantity of microorganisms and severity of DFI was significant. Among severe DFI cases, 77.8% with polymicrobial microorganisms underwent amputation compared to 33.3% with monomicrobial infection.

Conclusion

GN microorganisms were predominantly isolated from DFIs and remained sensitive to widely used agents. Polymicrobial infections were associated with DFI severity.

Ceftobripole: Experience in staphylococcal bacteremia

Ceftobiprole is a new cephalosporin with an extended spectrum activity against the majority of microorganisms isolated in bacteremia including methicillin-susceptible (MSSA) and -resistant S. aureus (MRSA). This antibiotic has demonstrated a potent activity against MRSA in animal models of endocarditis in monotherapy but particularly in combination with daptomycin, suggesting that this combination could be a future option to improve the outcome of staphylococcal endovascular infections. In addition, the extended-spectrum ceftobiprole activity, including coagulase-negative staphylococci, Enterococcus faecalis, Enterobacteriaceae and Pseudomonas aeruginosa represents an advantage for use as empirical therapy in bacteremia potentially caused by a broad spectrum of microorganisms, such as in catheter-related bacteremia.

Safety and tolerability of ceftobiprole

Ceftobiprole is a fifth generation cephalosporin with a series of characteristics differentiating it from other beta-lactams, including its antibacterial activity, mainly against methicillin-resistant Staphylococcus aureus, resistant Streptococcus pneumoniae and also Gram-negative microorganisms such as Pseudomonas aeruginosa. This antibiotic has been subjected to various clinical trials and the results of these have led to its approval in Spain for the treatment of nosocomial pneumonia, excluding that associated with mechanical ventilation, and community-acquired pneumonia. The results of various ceftobiprole clinical studies provide consistent information on efficacy and tolerability. Ceftobiprole as monotherapy has been shown to be non-inferior to comparator antibiotics in different settings. Information is available on its compatibility with other drugs in Y-site administration, important from the point of view of the intravenous treatment of patients who present venous access limitation. On the other hand, and in contrast to other cephalosporins, ceftobiprole presents a low risk of infection due to Clostridium difficile and, in comparison with ceftaroline, neutropenia has not been reported to present any significant issues.

Ceftobiprole medocaril for the treatment of community-acquired pneumonia

INTRODUCTION

Ceftobiprole is a novel broad-spectrum cephalosporin with excellent activity against a broad range of pathogens that are important in community-acquired pneumonia (CAP), including drug-resistant pneumococci, methicillin-resistant Staphylococcus aureus, and Pseudomonas aeruginosa. Areas covered: This article reviews the spectrum of activity, the main pharmacological and pharmacodynamic characteristics of ceftobiprole as well its clinical efficacy and safety in the treatment of CAP in adult patients. Expert opinion: Taking into account that the current treatment guidelines for CAP recommend the use of an adequate empirical therapy to improve its prognosis, ceftobiprole shows a profile of antimicrobial activity that would cover most etiological agents in patients with risk factors for infection caused by multidrug resistant organisms. The results of the pivotal clinical trial of patients hospitalized with CAP treated with ceftobiprole showed a high rate of clinical cure. The clinical tolerance of ceftobiprole in clinical trials was generally very good. These findings make ceftobiprole a good parenteral therapeutic alternative for the empirical treatment of CAP that requires hospitalization, especially in patients with risk factors for CAP caused by resistant microorganisms.

Comparative Study of Drainage and Antibiotics versus Drainage Only in the Management of Primary Subcutaneous Abscesses

BACKGROUND

Skin and soft tissue infections are common problems dealt with in emergency departments and medical offices. It is routine practice to prescribe antibiotic agents after incision and drainage of cutaneous abscesses. However, current evidence does not support prescribing oral antibiotic agents after surgical debridement. The aim of the present study was to determine the actual role of antibiotic agents after drainage of cutaneous abscesses.

PATIENTS AND METHODS

This was a prospective study of patients undergoing incision and drainage (I&D) of a subcutaneous abscess. Patients were randomly assigned either to receive antibiotic agents (group 1) or placebo (group 2) after I&D. The primary end point was resolution rate of the abscess at the seventh day. Secondary end points were pain at the seventh day and total time to full healing of the wound. P value <0.05 was considered statistically significant.

RESULTS

One hundred sixty-five patients were included for analysis. Age, gender, body mass index (BMI), and comorbidities did not differ substantially between groups. Chest and peri-anal abscesses were statistically more frequent in group 2, whereas neck abscesses were more frequent in group 1 (p = 0.02). Leukocyte count was also statistically higher in group 1 (p = 0.005). Resolution rate was 96% in group 1 and 93% in group 2, with no statistical difference between both (p = 0.28). Neither pain at seventh day nor time to full healing differed statistically between groups.

CONCLUSIONS

Antibiotic agents are not necessary for uncomplicated subcutaneous abscesses after I&D. These cases can be managed safely on an outpatient basis without any increase in morbidity.

Pharmacokinetic drug evaluation of ceftobiprole for the treatment of MRSA

INTRODUCTION

Methicillin-resistant Staphylococcus aureus (MRSA), while decreasing in overall incidence, is still a prominent concern world-wide. New agents coming to market in the last 10 years allow practitioners to optimize treatment for MRSA infections. Ceftobiprole is a cephalosporin agent with MRSA activity, currently approved in selected countries for the treatment of community-acquired pneumonia and hospital-acquired pneumonia. Areas covered: Relevant literature regarding spectrum of activity, pharmacokinetics, pharmacodynamics, and clinical trials will be discussed. Expert opinion: Ceftobiprole is an addition to a growing number of antimicrobials with activity against MRSA. Concern for appropriate dosing in critically ill patients remains due to its ineffectiveness for the treatment of ventilator-associated pneumonia (VAP). While ceftobiprole has activity against gram-negative organisms, the allowance for use of an additional agent for gram-negative infections in clinical trials limits recommendations for monotherapy for empirical treatment of HAP. Ceftobiprole's place in therapy will lie in its activity against gram positive organisms, such as Streptococcus spp. and Staphylococcus spp.

New therapeutic options for skin and soft tissue infections

PURPOSE OF REVIEW

The occurrence of methicillin-resistance in Staphylococcus aureus, that represents the most frequent cause of complicated skin and soft tissue infections (cSSTIs) worldwide, is a major concern and has been associated with increased length of stay, health care costs, and overall mortality. Although vancomycin is still considered the standard therapy in this setting, limitations of its use in clinical practice are represented by a progressive increase in methicillin-resistant S. aureus (MRSA) minimum inhibitory concentrations, drug-related toxicity, and the lack of an oral formulation. New therapeutic options for MRSA cSSTIs have recently become available, with promising implications for the management of cSSTIs in clinical practice.

RECENT FINDINGS

A number of new antimicrobials with activity against MRSA have been recently approved for the treatment of cSSTIs, and other agents are under investigation. We have reviewed the recent developments, with a specific focus on the possible advantages of new drugs for the management of cSSTIs into the everyday clinical practice.

SUMMARY

The new approved drugs for the treatment of cSSTIs are expected to offer many advantages for the management of patients with suspected or confirmed MRSA cSSTIs. The most promising features of the new compounds include the availability of oral formulations, once-weekly intravenous regimens, and broad spectra of activity.

Failure of antibiotics in cellulitis trials: a systematic review and meta-analysis

OBJECTIVES

The objectives of the study are to quantify trial-to-trial variability in antibiotic failure rates, in randomized clinical trials of cellulitis treatment and to provide a point estimate for the treatment failure rate across trials.

METHODS

We conducted a structured search for clinical trials evaluating antibiotic treatment of cellulitis, indexed in PubMed by August 2015. We included studies published in English and excluded studies conducted wholly outside of developed countries because the pathophysiology of cellulitis is likely to be different in such settings. Two authors reviewed all abstracts identified for possible inclusion. Of studies identified initially, 5% met the selection criteria. Two reviewers extracted data independently, and data were pooled using the Freeman-Tukey transformation under a random-effects model. Our primary outcome was the summary estimate of treatment failure across intent-to-treat and clinically evaluable participants.

RESULTS

We included 19 articles reporting data from 20 studies, for a total of 3935 patients. Treatment failure was reported in 6% to 37% of participants in the 9 trials reporting intent-to-treat results, with a summary point estimate of 18% failing treatment (95% confidence interval, 15%-21%). In the 15 articles evaluating clinically evaluable participants, treatment failure rates ranged from 3% to 42%, and overall, 12% (95% confidence interval, 10%-14%) were designated treatment failures.

CONCLUSIONS

Treatment failure rates vary widely across cellulitis trials, from 6% to 37%. This may be due to confusion of cellulitis with its mimics and perhaps problems with construct validity of the diagnosis of cellulitis. Such factors bias trials toward equivalence and, in routine clinical care, impair quality and antibiotic stewardship. Objective diagnostic tools are needed.

Ertapenem versus piperacillin/tazobactam for diabetic foot infections in China: a Phase 3, multicentre, randomized, double-blind, active-controlled, non-inferiority trial

OBJECTIVES

Few randomized controlled studies have compared antibiotic regimens against diabetic foot infections (DFIs) in Chinese patients. We evaluated the efficacy and safety of ertapenem versus piperacillin/tazobactam for the treatment of DFIs in Chinese patients.

METHODS

Patients with moderate to severe DFIs requiring parenteral antibiotics were randomized in a 1 : 1 ratio to receive ertapenem (1.0 g once daily) or piperacillin/tazobactam (4.5 g every 8 h) by 30 min intravenous (iv) infusions for ≥5 days. The primary outcome was favourable clinical response at discontinuation of iv therapy (DCIV). An evaluable-patient population was identified for primary analysis of non-inferiority at -15%. Safety was assessed. ClinicalTrials.gov: NCT01370616.

RESULTS

Of 565 patients randomized, 443 patients (ertapenem = 219 and piperacillin/tazobactam = 224) were clinically evaluable for primary analysis. In the clinically evaluable population, the proportions of patients with favourable clinical response at DCIV were 93.6% (205/219) and 97.3% (218/224) in the ertapenem and piperacillin/tazobactam groups, respectively (difference: -3.8%, 95% CI: -8.3%, 0.0%). Ertapenem had a significantly lower favourable clinical response rate (91.5% versus 97.2%, 95% CI for difference: -12.1%, -0.3%) at DCIV in severe DFI patients. In the modified ITT population, 88.8% (237/267) and 90.6% (241/266) of patients in the ertapenem and piperacillin/tazobactam groups, respectively, had favourable clinical responses at DCIV (difference: -1.9%, 95% CI: -7.3%, 3.3%). Microbiological eradications of causative pathogens and adverse events were similar between treatment groups.

CONCLUSIONS

Treatment with ertapenem was non-inferior to piperacillin/tazobactam in Chinese patients with DFIs. Ertapenem treatment resulted in a markedly lower rate of clinical resolution in severe DFIs.

Systemic antibiotics for treating diabetic foot infections

BACKGROUND

Foot infection is the most common cause of non-traumatic amputation in people with diabetes. Most diabetic foot infections (DFIs) require systemic antibiotic therapy and the initial choice is usually empirical. Although there are many antibiotics available, uncertainty exists about which is the best for treating DFIs.

OBJECTIVES

To determine the effects and safety of systemic antibiotics in the treatment of DFIs compared with other systemic antibiotics, topical foot care or placebo.

SEARCH METHODS

In April 2015 we searched the Cochrane Wounds Group Specialised Register; The Cochrane Central Register of Controlled Trials (CENTRAL; The Cochrane Library); Ovid MEDLINE, Ovid MEDLINE (In-Process & Other Non-Indexed Citations); Ovid EMBASE, and EBSCO CINAHL. We also searched in the Database of Abstracts of Reviews of Effects (DARE; The Cochrane Library), the Health Technology Assessment database (HTA; The Cochrane Library), the National Health Service Economic Evaluation Database (NHS-EED; The Cochrane Library), unpublished literature in OpenSIGLE and ProQuest Dissertations and on-going trials registers.

SELECTION CRITERIA

Randomised controlled trials (RCTs) evaluating the effects of systemic antibiotics (oral or parenteral) in people with a DFI. Primary outcomes were clinical resolution of the infection, time to its resolution, complications and adverse effects.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected studies, assessed the risk of bias, and extracted data. Risk ratios (RR) were estimated for dichotomous data and, when sufficient numbers of comparable trials were available, trials were pooled in a meta-analysis.

MAIN RESULTS

We included 20 trials with 3791 participants. Studies were heterogenous in study design, population, antibiotic regimens, and outcomes. We grouped the sixteen different antibiotic agents studied into six categories: 1) anti-pseudomonal penicillins (three trials); 2) broad-spectrum penicillins (one trial); 3) cephalosporins (two trials); 4) carbapenems (four trials); 5) fluoroquinolones (six trials); 6) other antibiotics (four trials).Only 9 of the 20 trials protected against detection bias with blinded outcome assessment. Only one-third of the trials provided enough information to enable a judgement about whether the randomisation sequence was adequately concealed. Eighteen out of 20 trials received funding from pharmaceutical industry-sponsors.The included studies reported the following findings for clinical resolution of infection: there is evidence from one large trial at low risk of bias that patients receiving ertapenem with or without vancomycin are more likely to have resolution of their foot infection than those receiving tigecycline (RR 0.92, 95% confidence interval (CI) 0.85 to 0.99; 955 participants). It is unclear if there is a difference in rates of clinical resolution of infection between: 1) two alternative anti-pseudomonal penicillins (one trial); 2) an anti-pseudomonal penicillin and a broad-spectrum penicillin (one trial) or a carbapenem (one trial); 3) a broad-spectrum penicillin and a second-generation cephalosporin (one trial); 4) cephalosporins and other beta-lactam antibiotics (two trials); 5) carbapenems and anti-pseudomonal penicillins or broad-spectrum penicillins (four trials); 6) fluoroquinolones and anti-pseudomonal penicillins (four trials) or broad-spectrum penicillins (two trials); 7) daptomycin and vancomycin (one trial); 8) linezolid and a combination of aminopenicillins and beta-lactamase inhibitors (one trial); and 9) clindamycin and cephalexin (one trial).Carbapenems combined with anti-pseudomonal agents produced fewer adverse effects than anti-pseudomonal penicillins (RR 0.27, 95% CI 0.09 to 0.84; 1 trial). An additional trial did not find significant differences in the rate of adverse events between a carbapenem alone and an anti-pseudomonal penicillin, but the rate of diarrhoea was lower for participants treated with a carbapenem (RR 0.58, 95% CI 0.36 to 0.93; 1 trial). Daptomycin produced fewer adverse effects than vancomycin or other semi-synthetic penicillins (RR 0.61, 95%CI 0.39 to 0.94; 1 trial). Linezolid produced more adverse effects than ampicillin-sulbactam (RR 2.66; 95% CI 1.49 to 4.73; 1 trial), as did tigecycline compared to ertapenem with or without vancomycin (RR 1.47, 95% CI 1.34 to 1.60; 1 trial). There was no evidence of a difference in safety for the other comparisons.

AUTHORS' CONCLUSIONS

The evidence for the relative effects of different systemic antibiotics for the treatment of foot infections in diabetes is very heterogeneous and generally at unclear or high risk of bias. Consequently it is not clear if any one systemic antibiotic treatment is better than others in resolving infection or in terms of safety. One non-inferiority trial suggested that ertapenem with or without vancomycin is more effective in achieving clinical resolution of infection than tigecycline. Otherwise the relative effects of different antibiotics are unclear. The quality of the evidence is low due to limitations in the design of the included trials and important differences between them in terms of the diversity of antibiotics assessed, duration of treatments, and time points at which outcomes were assessed. Any further studies in this area should have a blinded assessment of outcomes, use standardised criteria to classify severity of infection, define clear outcome measures, and establish the duration of treatment.

Comparative efficacy of antibiotics for the treatment of acute bacterial skin and skin structure infections (ABSSSI): a systematic review and network meta-analysis

OBJECTIVE

The objective was to conduct a systematic review and network meta-analysis (NMA) of existing treatments for ABSSSI focusing on the novel lipoglycopeptide oritavancin.

METHODS

EMBASE, MEDLINE, MEDLINE in Process, CENTRAL (Cochrane), and select conferences were searched for randomized controlled trials investigating antimicrobial agents for the treatment of ABSSSI. NMA was used to estimate the odds ratios of the Test-Of-Cure (TOC) and Early Clinical Response (ECR) outcomes for treatments relative to vancomycin in the ITT populations. Sub-group analyses in MRSA and MSSA populations were conducted for TOC; sensitivity analyses investigated the use of the clinically evaluable (CE) populations and the restriction to trials following the recent FDA guidelines for clinical trials.

RESULTS

The systematic review identified 52 trials. The most commonly investigated treatments were vancomycin and linezolid; most trials reported TOC, but not ECR. The posterior mean and 95% credible intervals for odds ratios of TOC for antimicrobial agents relative to vancomycin were: linezolid (1.55; 0.91-2.57), daptomycin (2.18; 0.90-5.42), and oritavancin 1200 mg (1.06; 0.80-1.43). The odds ratio of ECR for oritavancin 1200 mg was 1.02 (0.23-4.33). In the MRSA sub-group the odds ratios relative to vancomycin for TOC were: linezolid (1.55; 0.96-2.46), daptomycin (0.74; 0.13-3.66), and oritavancin 1200 mg (0.94; 0.44-2.02). In the MSSA sub-group they were linezolid (1.36; 0.15-13.34) and oritavancin 1200 mg (0.82; 0.08-7.83). These results were robust to the sensitivity analyses.

CONCLUSIONS

This NMA provides a unified framework for the comparison of all available antimicrobial agents used in the treatment of ABSSSI and is the first to assess the ECR end-point. The results suggest equivalence of clinical efficacy between vancomycin, daptomycin, linezolid, and novel antimicrobial agents including oritavancin for the treatment of ABSSSI at TOC. The wide uncertainty margins indicate the heterogeneity of the available evidence and the need for further research.

Genotypic Characterization of Methicillin-Resistant Staphylococcus aureus Recovered at Baseline from Phase 3 Pneumonia Clinical Trials for Ceftobiprole

Baseline methicillin-resistant Staphylococcus aureus (MRSA) isolates from patients with nosocomial and community-acquired pneumonia collected during Phase 3 trials for ceftobiprole were characterized. Eighty-four unique isolates from patients enrolled in Europe (50.0%), Asia-Western Pacific region (APAC; 20.2%), North America (19.0%), Latin America (8.3%), and South Africa (2.4%) were included. Antimicrobial susceptibility testing was performed by broth microdilution and isolates screened for Panton-Valentine leukocidin. SCCmec and agr types were determined. Strains were subjected to pulsed-field gel electrophoresis and spa typing. Clonal complexes (CCs) were assigned based on spa and/or multilocus sequence typing. Most isolates were CC5-MRSA-I/II/IV (44.0%; 37/84), followed by CC8-MRSA-IV (22.6%; 19/84) and CC239-MRSA-III (21.4%; 18/84). Other MRSA formed seven clonal clusters. Isolates from North America were associated with USA100, while those from South America belonged to the Cordobes/Chilean CC. A greater clonal diversity was observed in Europe; however, each country had CC5, CC8, or CC239 as prevalent lineages. Isolates from APAC were CC5-MRSA-II (47.1%; 8/17) or CC239-MRSA-III (47.1%; 8/17). Isolates carrying SCCmec I and III had ceftobiprole MIC₅₀ values of 2 μg/ml, while those isolates with SCCmec II and IV had MIC₅₀ values of 1 μg/ml. Ceftobiprole inhibited 96% and 100.0% of the isolates at ≤2 and ≤4 μg/ml, respectively. These isolates represented common circulating MRSA clones. Ceftobiprole demonstrated in vitro activity with a slight variation of minimum inhibitory concentrations (MICs) according to SCCmec or clonal type.

Staphylococcus aureus infections: epidemiology, pathophysiology, clinical manifestations, and management

Staphylococcus aureus is a major human pathogen that causes a wide range of clinical infections. It is a leading cause of bacteremia and infective endocarditis as well as osteoarticular, skin and soft tissue, pleuropulmonary, and device-related infections. This review comprehensively covers the epidemiology, pathophysiology, clinical manifestations, and management of each of these clinical entities. The past 2 decades have witnessed two clear shifts in the epidemiology of S. aureus infections: first, a growing number of health care-associated infections, particularly seen in infective endocarditis and prosthetic device infections, and second, an epidemic of community-associated skin and soft tissue infections driven by strains with certain virulence factors and resistance to β-lactam antibiotics. In reviewing the literature to support management strategies for these clinical manifestations, we also highlight the paucity of high-quality evidence for many key clinical questions.

Ceftobiprole activity against over 60,000 clinical bacterial pathogens isolated in Europe, Turkey, and Israel from 2005 to 2010

Ceftobiprole medocaril is a newly approved drug in Europe for the treatment of hospital-acquired pneumonia (HAP) (excluding patients with ventilator-associated pneumonia but including ventilated HAP patients) and community-acquired pneumonia in adults. The aim of this study was to evaluate the in vitro antimicrobial activity of ceftobiprole against prevalent Gram-positive and -negative pathogens isolated in Europe, Turkey, and Israel during 2005 through 2010. A total of 60,084 consecutive, nonduplicate isolates from a wide variety of infections were collected from 33 medical centers. Species identification was confirmed, and all isolates were susceptibility tested using reference broth microdilution methods. Ceftobiprole had high activity against methicillin-susceptible Staphylococcus aureus (MSSA) (100.0% susceptible), methicillin-susceptible coagulase-negative staphylococci (CoNS), beta-hemolytic streptococci, and Streptococcus pneumoniae (99.3% susceptible), with MIC90 values of 0.25, 0.12, ≤ 0.06, and 0.5 μg/ml, respectively. Ceftobiprole was active against methicillin-resistant S. aureus (MRSA) (98.3% susceptible) and methicillin-resistant CoNS, having a MIC90 of 2 μg/ml. Ceftobiprole was active against Enterococcus faecalis (MIC50/90, 0.5/4 μg/ml) but not against most Enterococcus faecium isolates. Ceftobiprole was very potent against the majority of Enterobacteriaceae (87.3% susceptible), with >80% inhibited at ≤ 0.12 μg/ml. The potency of ceftobiprole against Pseudomonas aeruginosa (MIC50/90, 2/>8 μg/ml; 64.6% at MIC values of ≤ 4 μg/ml) was similar to that of ceftazidime (MIC50/90, 2/>16 μg/ml; 75.4% susceptible), but limited activity was observed against Acinetobacter spp. and Stenotrophomonas maltophilia. High activity was also observed against all Haemophilus influenzae (MIC90, ≤ 0.06 μg/ml) and Moraxella catarrhalis (MIC50/90, ≤ 0.06/0.25 μg/ml) isolates. Ceftobiprole demonstrated a wide spectrum of antimicrobial activity against this very large longitudinal sample of contemporary pathogens.