Daptomycin use in patients with osteomyelitis: a preliminary report from the EU-CORE(SM) database

Oritavancin Versus Daptomycin for Osteomyelitis Treatment After Surgical Debridement

INTRODUCTION

Weekly intravenous (IV) oritavancin and daily daptomycin were compared in an outpatient setting following extensive surgical debridement for treating patients with osteomyelitis.

METHODS

This was a retrospective, observational study of patients diagnosed with acute osteomyelitis. Exclusion criteria were the use of Gram-negative antibiotic therapy, use of antibiotics for more than 48 h prior to oritavancin or daptomycin or prior use of > 2 doses of oritavancin or more than 4 weeks of daptomycin. Clinical success was resolution or improvement of symptoms and no further treatment. Data were analyzed with Chi-square test or Fisher's exact test.

RESULTS

Consecutive outpatients (n = 150) with acute osteomyelitis who were treated with oritavancin or daptomycin (1:1) following extensive surgical debridement were identified. Staphylococcus aureus was the most common pathogen (n = 117). No patient in either group received prior antibiotic therapy (previous 30 days) or was hospitalized within 90 days prior to surgical debridement. Twenty-one (28%) patients prescribed oritavancin had chronic kidney disease, seven of whom were receiving hemodialysis or peritoneal dialysis. Compared to oritavancin, patients prescribed daptomycin had higher rates of all-cause readmission [odds ratio (OR) 2.89; p < 0.001], more infection-related readmission (OR 3.19; p < 0.001), and greater likelihood of receiving antibiotics post-discontinuation of initial therapy (OR 2.13; p < 0.001). Repeat surgical debridement was required for 68.0% with daptomycin vs. 23.1% with oritavancin (p < 0.001).

CONCLUSIONS

Oritavancin demonstrated a significantly higher rate of clinical success compared to daptomycin, with lower all-cause and infection-related readmissions, reduced need for repeat surgical debridement, and fewer additional antibiotic requirements.

Comparison of the efficacy and safety of standard- and high-dose daptomycin: A systematic review and meta-analysis

AIMS

Standard doses of daptomycin at 4 and 6 mg/kg were used for the treatment of skin and soft tissue for infections and bacteraemia, respectively. However, increased doses of daptomycin are recommended for complicated infections by Gram-positive organisms.

METHODS

A systematic review was conducted using 4 databases. We compared treatment success between standard-dose (SD, 4-6 mg/kg) and high-dose (HD, >6 mg/kg) daptomycin in patients with all-cause bacteraemia, complicated bacteraemia, infective endocarditis, osteomyelitis and foreign body/prosthetic infection as the primary outcome. We also compared the success between SD and HD2 (≥8 mg/kg) daptomycin treatments in patients with these diseases as the secondary outcome. The incidence of creatine phosphokinase (CPK) elevation was evaluated as safety.

RESULTS

In patients with complicated bacteraemia and infective endocarditis, the treatment success was significantly lower in the SD group than in the HD group (odds ratio [OR] 0.48, 95% confidence interval [CI] 0.30-0.76 and OR 0.50, 95% CI 0.30-0.82) and HD2 group (OR 0.38, 95% CI 0.21-0.69 and OR 0.30, 95% CI 0.15-0.60), respectively. A significant difference was demonstrated only in the HD2 group in patients with bacteraemia, including simple infection. SD did not decrease the success rate for the treatment of osteomyelitis and foreign body/prosthetic infection. The incidence of elevated CPK was significantly lower in SD group than in HD group.

CONCLUSION

SD daptomycin was associated with significantly lower treatment success than HD in patients with complicated bacteraemia/infective endocarditis. The CPK elevation should be considered in patients treated with high daptomycin doses.

Incidence of elevated creatine phosphokinase between daptomycin alone and concomitant daptomycin and statins: a systematic review and meta-analysis

AIM

The present systematic review and meta-analysis evaluated the incidence of elevated creatine phosphokinase (CPK) levels between daptomycin alone and concomitant daptomycin and statin use.

METHODS

We searched the PubMed, Web of Sciences, Cochrane Library, and ClinicalTrials.gov databases. We analysed the incidence of elevated CPK between daptomycin alone and concomitant daptomycin and statins among studies defining CPK elevation as levels ≥ the upper limit of normal (ULN) or ≥ 5 times ULN. We also analysed the incidence of rhabdomyolysis between the groups. We then calculated the odds ratios (ORs) and 95% confidence intervals (CIs) based on the included studies.

RESULTS

Comparing CPK elevation defined as CPK levels ≥ ULN, a significantly higher incidence of CPK elevation was observed with concomitant daptomycin and statin use than with daptomycin alone (OR=2.55, 95% CI 1.78-3.64, p<0.00001, I² =0%). Likewise, when CPK elevation was defined as CPK levels ≥ 5 times ULN, a significantly higher incidence of CPK elevation was detected with concomitant daptomycin and statin use than with daptomycin alone (OR = 1.89, 95% CI 1.06-3.35, p=0.03, I² =48%). The incidence of rhabdomyolysis was significantly higher following concomitant daptomycin and statin use than with daptomycin alone (OR = 11.60, 95% CI 1.81-74.37, p=0.01, I² =0%).

CONCLUSIONS

The combined use of daptomycin and statins were significant risk factors for the incidence of CPK elevation defined as levels ≥ ULN or ≥ 5 times ULN and rhabdomyolysis.

Identification of Risk Factors for Daptomycin-Associated Creatine Phosphokinase Elevation and Development of a Risk Prediction Model for Incidence Probability

BACKGROUND

In this study, we investigated the risk factors for daptomycin-associated creatine phosphokinase (CPK) elevation and established a risk score for CPK elevation.

METHODS

Patients who received daptomycin at our hospital were classified into the non-elevated or elevated CPK group based on their peak CPK levels during daptomycin therapy. Univariable and multivariable analyses were performed, and a risk score and prediction model for the incidence probability of CPK elevation were calculated based on logistic regression analysis.

RESULTS

The non-elevated and elevated CPK groups included 181 and 17 patients, respectively. Logistic regression analysis revealed that concomitant statin use (odds ratio [OR], 4.45 [95% confidence interval {CI}, 1.40-14.47]; risk score 4), concomitant antihistamine use (OR, 5.66 [95% CI, 1.58-20.75]; risk score 4), and trough concentration (Cmin) between 20 and <30 µg/mL (OR, 14.48 [95% CI, 2.90-87.13]; risk score 5) and ≥30.0 µg/mL (OR, 24.64 [95% CI, 3.21-204.53]; risk score 5) were risk factors for daptomycin-associated CPK elevation. The predicted incidence probabilities of CPK elevation were <10% (low risk), 10%-<25% (moderate risk), and ≥25% (high risk) with total risk scores of ≤4, 5-6, and ≥8, respectively. The risk prediction model exhibited a good fit (area under the receiver operating characteristic curve, 0.85 [95% CI, .74-.95]).

CONCLUSIONS

These results suggested that concomitant use of statins with antihistamines and Cmin ≥20 µg/mL were risk factors for daptomycin-associated CPK elevation. Our prediction model might aid in reducing the incidence of daptomycin-associated CPK elevation.

Biofilm and its implications postfracture fixation: All I need to know

Biofilm represents an organized multicellular community of bacteria having a complex 3D structure, formed by bacterial cells and their self-produced extracellular matrix. It usually attaches to any foreign body or fixation implant. It acts as a physical protective barrier of the bacteria from the penetration of antibodies, bacteriophages, granulocytes and biocides, antiseptics, and antibiotics. Biofilm-related infections will increase in the near future. This group of surgical site infections is the most difficult to diagnose, to suppress, to eradicate, and in general to manage. Multispecialty teams involved in all stages of care are an effective way to improve results and save resources and time for the benefit of patients and the health system. Significant steps have occurred recently in the prevention and development of clever tools that we can employ in this everlasting fight with the bacteria. Herein, we attempt to describe the nature and role of the "biofilm" to the specific clinical setting of surgical site infections in the field of orthopaedic trauma surgery.

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

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

Daptomycin to bone and joint infections and prosthesis joint infections: a systematic review

Backgroud

Daptomycin has been used in bone and joint infections (BJI) and prosthesis joint infections (PJI) considering spectrum of activity and biofilm penetration. However, the current experience is based on case reports, case series, cohorts, and international surveys. The aim of this systematic review was to evaluate studies about daptomycin treatment efficacy in BJI/PJI compared to other antibiotic regimens.

Methods

PubMed, LILACS, Scielo and Web of Science databases were searched for articles about daptomycin and treatment of BJI and PJI from inception to March 2018. Inclusion criteria were any published researches that included patients with BJI treated with daptomycin. Diagnosis of BJI was based on clinical, laboratory and radiological findings according to IDSA guidelines.

Results

From 5107 articles, 12 articles were included. Only three studies described the outcomes of patients with BJI treated with daptomycin with comparator regimen (vancomycin, teicoplanin and oxacillin). Studies presented large heterogeneity regarding device related infections, surgical procedures, and daptomycin regimens (varied from 4 mg/kg to 10 mg/kg). A total of 299 patients have been included in all studies (184 infections associated with orthopedic disposal and 115 osteomyelitis/septic arthritis). Two hundred and thirty-three patients were treated with daptomycin. The clinical cure rates on device related and non-device related infections (i.e. osteomyelitis) were 70% and 78%, respectively. Compared to all regimens evaluated, daptomycin group outcomes were non-inferior.

Conclusion

Although a randomized clinical trial is needed, this systematic review tends to support daptomycin usage for bone and joint infections.

Multifunctional Pharmaceutical Effects of the Antibiotic Daptomycin

Daptomycin (DAP), a cyclic lipopeptide produced by Streptomyces roseosporus, is a novel antibiotic to clinically treat various Gram-positive pathogenic bacteria-induced infections. Although DAP has a strong broad-spectrum bactericidal effect, recently rare bacterial antibiotic resistance against DAP gradually arises. The review is to summarize the normal indications of DAP, its off-label usage against several clinical pathogen infections, the unique antibacterial mechanisms of DAP, and the combination of antibiotic therapies for highly DAP-resistant pathogens. More noticeably, rising evidences demonstrate that DAP has new potential activity of anticancer and immunomodulatory effects. So far the multifunctional pharmaceutical effects of DAP deserve to be further explored for future clinical applications.

msaABCR operon is involved in persister cell formation in Staphylococcus aureus

Background

Persister cells comprise a phenotypic variant that shows extreme antibiotic tolerance resulting in treatment failures of bacterial infections. While this phenomenon has posed a great threat in public health, mechanisms underlying their formation in Staphylococcus aureus remain largely unknown. Increasing evidences of the presence of persister cells in recalcitrant infections underscores the great urgency to unravel the mechanism by which these cells develop. Previously, we characterized msaABCR operon that plays roles in regulation of virulence, biofilm development and antibiotic resistance. We also characterized the function of MsaB protein and showed that MsaB is a putative transcription factor that binds target DNA in response to nutrients availability.

Results

In this study, we compared the number of persister cell in wild type, msaABCR deletion mutant and the complemented strain in two backgrounds USA300 LAC and Mu50. Herein, we report that msaABCR deletion mutant forms significantly less number of persister cells relative to wild type after challenge with various antibiotics in planktonic and biofilm growth conditions. Complementation of the msaABCR operon restored wild type phenotype. Combined antibiotic therapy along with msaABCR deletion significantly improves the killing kinetics of stationary phase and biofilm S. aureus cells. Transcriptomics analysis showed that msaABCR regulates several metabolic genes, transcription factors, transporters and enzymes that may play role in persister cells formation, which we seek to define in the future.

Conclusions

This study presented a new regulator, msaABCR operon, that is involved in the persister cells formation, which is a poorly understood in S. aureus. Indeed, we showed that msaABCR deletion significantly reduces the persister cells formation in all growth phases tested. Although, we have not yet defined the mechanism, we have shown that msaABCR regulates several metabolic, transporters, and extracellular proteases genes that have been previously linked with persister cells formation in other bacterial systems. Taken together, this study showed that inactivation of the msaABCR operon enhances the effectiveness of antibiotics for the treatment of S. aureus infections, especially in context of persister cells.

Electronic supplementary material

The online version of this article (10.1186/s12866-017-1129-9) contains supplementary material, which is available to authorized users.

Impact of Sequential Culture Results on Diagnosis and De-Escalation of the Antibiotic Regimen in Joint and Bone Infections

BACKGROUND

According to existing guidelines, orthopedic specimens collected in joint and bone infections (JBI) in our institution are cultured on several media sets and incubated for two, seven, and 14 days. The optimal timing for de-escalation of the first-line antibiotic combination according to the culture results needs to be defined.

METHODS

Single-center, retrospective analysis of all adult patients with a first documented episode of JBI between May 2012 and April 2013.

RESULTS

Ninety patients were included, 51 males (57%), median age 58 y (range 18-87 y), with prosthesis infection in 62 cases (69%). Rapidly growing pathogens (Staphylococcus aureus [n = 36] and Enterobacteriaceae [n = 12]) usually were diagnosed within two days, whereas coagulase-negative staphylococci (n = 25) and Propionibacterium acnes (n = 13) generally were identified after seven days (p < 10^-5). Positive culture results at day 2 fit with definitive microbiological diagnosis in 95% of cases, and prolonged incubation led to the identification of additional micro-organisms in only four of 76 patients (5%) with day-2-positive cultures. Conversely, for those with negative two-day culture (n = 14), the seven-day culture allowed identification of less virulent pathogens in eight cases (57%).

CONCLUSIONS

Our results suggest that, in JBI, de-escalation of the empirical antibiotic regimen can be based on micro-organisms identified on the two-day culture set. The impact of such a strategy on clinical outcomes, antibiotic consumption, and costs needs to be assessed in larger studies.

Randomized Controlled Trial to Determine the Efficacy of Early Switch From Vancomycin to Vancomycin Alternatives as a Strategy to Prevent Nephrotoxicity in Patients With Multiple Risk Factors for Adverse Renal Outcomes (STOP-NT)

BACKGROUND

Use of alternative antimicrobials to vancomycin is a potential strategy to reduce acute kidney injury (AKI) in high-risk patients, but current data do not support widespread adoption of this practice.

OBJECTIVE

To determine the efficacy of early switch to a nonnephrotoxic alternative for prevention of AKI in high-risk patients who receive vancomycin.

METHODS

This was an IRB-approved, prospective randomized controlled trial in a single, tertiary care academic medical center. Patients initially prescribed vancomycin between October 2011 to April 2013 with at least 2 risk factors for AKI were included. Treatment randomization was stratified by indication for therapy. Patients were randomized to continuation of dose-optimized vancomycin or early switch to an alternative antimicrobial agent. The primary end point was nephrotoxicity by consensus guideline definition adjudicated by blinded review; the secondary end point was AKI network-defined AKI.

RESULTS

A total of 103 patients were randomized; 100 were included in the modified intent-to-treat population, 51 in the vancomycin group and 49 in the alternative group. The incidence of nephrotoxicity was 6.1% in the alternative therapy arm and 9.8% in the vancomycin group ( P = 0.72). The incidence of AKI was 32.7% in the alternative therapy group and 31.4% in the vancomycin group ( P = 0.89).

CONCLUSIONS

No significant difference in nephrotoxicity or AKI was detected among patients treated with alternative antimicrobials compared with vancomycin. The use of alternative antimicrobial therapy instead of vancomycin solely for the purpose of preventing AKI in high-risk patients does not appear to be warranted.

Daptomycin: Physicochemical, Analytical, and Pharmacological Properties

Daptomycin is the first approved member of a new class of antimicrobials, the cyclic lipopeptides, and presents selective action against gram-positive bacteria, including methicillin- and vancomycin-resistant strains. Considering that resistance to daptomycin is rare, the drug has become very important for current clinical practice. This review covers daptomycin's physicochemical characteristics, antibacterial spectrum, mechanism of action, pharmacokinetics, clinical applications, side effects, drug interactions, and the analytical methods used to measure daptomycin in pharmaceutical products and biologic samples. Special attention has been given to therapeutic drug monitoring reports, as studies have shown its highly variable pharmacokinetics in specific circumstances, such as in patients suffering from critical illness, morbid obesity, severe sepsis, and kidney injury. For the same reason, methods described for therapeutic drug monitoring of daptomycin in the special patient population have been reviewed. In addition, the review presents a discussion of environmentally friendly analytical methods for daptomycin, which are necessary to reduce the impact of our activities on the environment. However, it was observed that there is a gap in the literature in this regard and further research involving the development of "green" methodologies for the analysis of daptomycin is necessary. The review will be useful to the clinical community in assisting with the responsible use of daptomycin, which is critical to prevent the emergence of resistant strains.

Advances in antibiotic therapy for infection after the surgical installation of implants to treat internal fractures

To summarize the advances in antibiotic therapy for infection after the surgical installation of implants to treat internal fractures. Recent studies on antibiotic therapy for infection after the surgical installation of implants to internal fractures were reviewed and analyzed. In general, systematic antibiotics are selected based on the results of bacterial culture. The duration of antibiotic treatment lasts for no more than 4 to 6 weeks. Orally administered and intravenously injected antibiotics have similar efficacies. Orally administered antibiotics exhibit a lower incidence of complications and are less costly than intravenously injected antibiotics. In addition, the efficacy of daptomycin in the treatment of bone infection is problematic. Rifampicin or fluoroquinolone antibiotics should be jointly administered when infection with bacterial biofilms is likely to occur. Calcium sulfate is a typical topically applied antibiotic delivery vehicle that can be completely degraded, with good biocompatibility, bone conduction, and drug release. The rational, systematic, and combined topical application of antibiotics can effectively decrease the recurrence rates of infection after the surgical installation of implants to treat internal fractures and can improve the quality of life of patients.

Daptomycin for the treatment of major gram-positive infections after cardiac surgery

Background

Infection is a main cause of morbidity and mortality after heart surgery, with multi-resistant pathogens increasingly representing a challenge. Daptomycin provides bactericidal activity against gram-positive organisms that are resistant to standard treatment including vancomycin.

Methods

A cohort of cardiac surgical patients, treated with daptomycin for major infection at two tertiary care centers, were retrospectively studied with a particular focus on the type of infection, causative pathogens and co-infections, daptomycin dosage, adverse events and outcome in order to provide evidence for the efficiency and safety of daptomycin in a distinct high-risk patient population.

Results

Sixty-five patients (87.7 % males, 60.4 ± 13.5 years) who had undergone aortic surgery (20.0 %), ventricular assist device (VAD) implantation (21.5 %), combined procedures (21.5 %), coronary artery bypass grafting (12.3 %), isolated valve surgery (15.4 %) and heart transplantation (7.7 %) were diagnosed with catheter-related infection (26.1 %), valve endocarditis (18.8 %), sternal wound (13.0 %), VAD-associated (11.6 %), cardiac implantable electrophysiological device (CIED)-associated (4.1 %), respiratory tract (4.3 %), bloodstream (4.3 %) and other infection (4.3 %). In 13.0 %, no focus of infection was identified though symptoms of severe infection were present. The most frequent pathogens were Staphylococcus epidermidis (30.4 %), Staphylococcus aureus (23.1 %) and Enterococcus species (10.1 %). Daptomycin doses ranging from 3 mg/kg every 48 h to 10 mg/kg every 24 h were administered for 15.4 ± 11.8 days. 87.0 % of the cases were classified as success, 7.2 % as treatment failure and 5.8 as non-evaluable. Adverse events were limited to one case of mild and one case of moderate neutropenia with recovery upon termination of treatment.

Conclusion

Daptomycin proved safe and effective in major infection in high-risk cardiac surgical patients.

A retrospective study of outcomes of device-associated osteomyelitis treated with daptomycin

Background

Daptomycin appears well tolerated and effective for osteomyelitis treatment. However, limited data exist regarding daptomycin use for treatment of device-associated osteomyelitis (DAO).

Methods

We used a retrospective, observational database (Cubicin® Outcomes Registry and Experience [CORE® 2007–2009]) that assessed patients treated with daptomycin to evaluate the characteristics of patients with DAO, outcomes after daptomycin treatment, and safety of daptomycin in this setting. Information from 54 institutions for patients with prosthetic joint infection (PJI) and other hardware-associated osteomyelitis (OHAO) who received daptomycin from January 2007 to December 2008 with follow-up data in 2009 was collected using a standardized data collection form.

Results

Eighty-two patients receiving daptomycin were identified in CORE 2007–2009; 48 patients (59 %) had follow-up data. Sixty-seven percent of patients had received a previous antibiotic. Surgical intervention was similar between the 2 groups: PJI, 22 of 27 (82 %) and OHAO, 17 of 21 (81 %). However, device removal or replacement was more frequent in the PJI patients (17 of 27, 63 %) than in the OHAO patients (8 of 21, 38 %). Clinical success was reported in 22 of 27 (82 %; 95 % confidence interval [CI], 62–94 %) patients with PJI and 18 of 21 (86 %; 95 % CI, 64–97 %) patients with OHAO at follow-up (13–402 days). Adverse events occurred in 8 of 50 (16 %) patients in the safety population and did not differ by daptomycin dose.

Conclusion

Daptomycin appeared effective and well tolerated in patients with DAO, including PJI or OHAO.

Acute bacterial sternoclavicular osteomyelitis in a long-term renal transplant recipient

Kidney transplantation is the treatment of choice for a significant number of patients with end-stage renal disease. Although immunosuppression therapy improves graft and patient’s survival, it is a major risk factor for infection following kidney transplantation altering clinical manifestations of the infectious diseases and complicating both the diagnosis and management of renal transplant recipients (RTRs). Existing literature is very limited regarding osteomyelitis in RTRs. Sternoclavicular osteomyelitis is rare and has been mainly reported after contiguous spread of infection or direct traumatic seeding of the bacteria. We present an interesting case of acute, bacterial sternoclavicular osteomyelitis in a long-term RTR. Blood cultures were positive for Streptococcus mitis, while the portal entry site was not identified. Magnetic resonance imaging of the sternoclavicluar region and a three-phase bone scan were positive for sternoclavicular osteomyelitis. Eventually, the patient was successfully treated with Daptomycin as monotherapy. In the presence of immunosuppression, the transplant physician should always remain alert for opportunistic pathogens or unusual location of osteomyelitis.

Real-world daptomycin use across wide geographical regions: results from a pooled analysis of CORE and EU-CORE

Background

Pooled data from two large registries, Cubicin^® Outcomes Registry and Experience (CORE; USA) and European Cubicin^® Outcomes Registry and Experience (EU-CORE; Europe, Latin America, and Asia), were analyzed to determine the characteristics and clinical outcomes of daptomycin therapy in patients with Gram-positive infections across wide geographical regions.

Methods

Patients receiving at least one dose of daptomycin between 2004 and 2012 for the treatment of Gram-positive infections were included. Clinical success was defined as an outcome of ‘cured’ or ‘improved’. Post-treatment follow-up data were collected for a subset of patients (CORE: osteomyelitis and orthopedic foreign body device infection; EU-CORE: endocarditis, intracardiac/intravascular device infection, osteomyelitis, and orthopedic device infection). Safety was assessed for up to 30 days after daptomycin treatment.

Results

In 11,557 patients (CORE, 5482; EU-CORE, 6075) treated with daptomycin (median age, 62 [range, 1–103] years), the most frequent underlying conditions were cardiovascular disease (54.7 %) and diabetes mellitus (28.0 %). The most commonly treated primary infections were complicated skin and soft tissue infection (cSSTI; 31.2 %) and bacteremia (21.8 %). The overall clinical success rate was 77.2 % (uncomplicated SSTI, 88.3 %; cSSTI, 81.0 %; osteomyelitis, 77.7 %; foreign body/prosthetic infection (FBPI), 75.9 %; endocarditis, 75.4 %; and bacteremia, 69.5 %). The clinical success rate was 79.1 % in patients with Staphylococcus aureus infections (MRSA, 78.1 %). An increasing trend of high-dose daptomycin (>6 mg/kg/day) prescribing pattern was observed over time. Clinical success rates were higher with high-dose daptomycin treatment for endocarditis and FBPI. Adverse events (AEs) and serious AEs possibly related to daptomycin therapy were reported in 628 (5.4 %) and 133 (1.2 %) patients, respectively.

Conclusions

The real-world data showed that daptomycin was effective and safe in the treatment of various Gram-positive infections, including those caused by resistant pathogens, across wide geographical regions.

Daptomycin > 6 mg/kg/day as salvage therapy in patients with complex bone and joint infection: cohort study in a regional reference center

Background

Even if daptomycin does not have approval for the treatment of bone and joint infections (BJI), the Infectious Diseases Society of America guidelines propose this antibiotic as alternative therapy for prosthetic joint infection. The recommended dose is 6 mg/kg/d, whereas recent data support the use of higher doses in these patients.

Methods

We performed a cohort study including consecutive patients that have received daptomycin >6 mg/kg/d for complex BJI between 2011 and 2013 in a French regional reference center. Factors associated with treatment failure were determined on univariate Cox analysis and Kaplan-Meier curves.

Results

Forty-three patients (age, 61 ± 17 years) received a mean dose of 8 ± 0.9 mg/kg/d daptomycin, for a mean 81 ± 59 days (range, 6–303 days). Most had chronic (n = 37, 86 %) implant-associated (n = 37, 86 %) BJI caused by coagulase-negative staphylococci (n = 32, 74 %). A severe adverse event (SAE) occurred in 6 patients (14 %), including 2 cases of eosinophilic pneumonia, concomitant with daptomycin C_min >24 mg/L. Outcome was favorable in 30 (77 %) of the 39 clinically assessable patients. Predictors for treatment failure were age, non-optimal surgery and daptomycin withdrawal for SAE.

Conclusions

Prolonged high-dose daptomycin therapy was effective in patients with complex BJI. However, optimal surgery remains the cornerstone of medico-surgical strategy; and a higher incidence of eosinophilic pneumonia than expected was recorded.

Towards a definition of daptomycin optimal dose: Lessons learned from experimental and clinical data

Daptomycin exhibits excellent antibacterial activity against a wide range of Gram-positive bacteria. The on-label standard daily doses for daptomycin are 4 mg/kg for skin infections and 6 mg/kg for bacteraemia or right-sided endocarditis. Daptomycin bactericidal activity is predominantly concentration-dependent and by considering the values of pharmacokinetic targets established by several authors as well as the peak and trough concentrations of daptomycin obtained at various daily dosages, it appears that these targets can easily be reached with a dose of 6 mg/kg but only for a minimum inhibitory concentration (MIC) at 0.1 mg/L, and that for increasing MICs (e.g. 0.5 mg/L or 1 mg/L) these targets may only be attained with higher dosages (i.e. ≥10 mg/kg). High-dose (HD) daptomycin therapy has also been proven to be effective for reducing the risk of selection of daptomycin-resistant strains. Given the concentration-dependent bactericidal activity of daptomycin, the absence of a dose-toxicity relationship and the need to prevent the selection of resistant strains, we propose to consider for staphylococcal (i) skin and soft-tissue infections, daily doses of daptomycin of 6 mg/kg (new standard dose) and (ii) endocarditis or bacteraemia including those associated with intravascular catheter and implant-related infections, ≥10 mg/kg (HD) when the MIC is unknown or >0.25 mg/L, and 6-10 mg/kg (intermediate doses) when the MIC is ≤0.25 mg/L. For severe and deep-seated enterococcal infections, we propose high (≥10 mg/kg) daily doses of daptomycin in combination with another active agent, especially a β-lactam.

Daptomycin for the treatment of osteomyelitis and orthopaedic device infections: real-world clinical experience from a European registry

Osteomyelitis is a serious infection predominantly caused by Gram-positive bacteria, including methicillin-resistant Staphylococcus aureus (MRSA). Orthopaedic device-related infections are complex and require a careful combination of surgical intervention and antimicrobial therapy. Daptomycin, a cyclic lipopeptide, effectively penetrates soft tissue and bone and demonstrates rapid concentration-dependent bactericidal activity against Gram-positive pathogens. This retrospective, non-interventional study evaluated clinical outcomes in patients with osteomyelitis or orthopaedic device infections treated with daptomycin from the European Cubicin® Outcomes Registry and Experience (EU-CORE^SM) study. Patients were treated between January 2006 and April 2012, with follow-up to 2014. Clinical outcomes were assessed as success (cured or improved), failure or non-evaluable. Of 6,075 patients enrolled, 638 (median age, 63.5 years) had primary infections of osteomyelitis or orthopaedic device infections, 224 had non-prosthetic osteomyelitis, 208 had osteomyelitis related to a permanent or temporary prosthetic device, and 206 had orthopaedic device infections. The most commonly isolated pathogen was S. aureus (214 [49.1 %]; 24.8 % were MRSA). Overall, 455 (71.3 %) patients had received previous antibiotic therapy. Patients underwent surgical interventions, including tissue (225 [35.3 %]) and bone (196 [30.7 %]) debridement, as part of their treatment. Clinical success rates were 82.7 % and 81.7 % in S. aureus and coagulase-negative staphylococcal infections. Adverse events (AEs) and serious AEs assessed as possibly related to daptomycin were observed in 6.7 % and 1.9 % of patients, respectively. Daptomycin was discontinued by 5.5 % of patients due to AEs and 10 (1.6 %) deaths were reported. In conclusion, daptomycin was effective and safe in patients with osteomyelitis or orthopaedic device infections.

Successful Daptomycin Use in a Pediatric Patient With Acute, Bilateral Osteomyelitis Caused by Methicillin-Resistant Staphylococcus aureus

Staphylococcus aureus is the most common bacteria associated with the development of osteomyelitis in pediatric patients. Osteomyelitis caused by methicillin-resistant Staphylococcus aureus (MRSA) can be difficult to safely and effectively treat. Vancomycin, linezolid, and clindamycin are commonly used to treat osteomyelitis caused by MRSA. While adult studies suggest intravenous (IV) daptomycin may by beneficial for the treatment of MRSA osteomyelitis, it is not Food and Drug Administration approved for use in pediatrics, and minimal data are available related to its use in this population. This case report describes the successful use of daptomycin (8 mg/kg/dose IV daily) combined with rifampin for 5 weeks, followed by 5 weeks of oral sulfamethoxazole/trimethoprim, for treatment of acute bilateral osteomyelitis caused by MRSA in an 8-year-old male. The patient did not initially respond to the combination of vancomycin plus rifampin and gentamicin, nor did he respond to ceftaroline treatment. After initiation of daptomycin, his fevers quickly subsided, his pain rapidly improved, and his inflammatory markers significantly decreased. While daptomycin was effective in this patient, additional research is needed to determine the true safety and efficacy of this drug for treatment of osteomyelitis caused by MRSA in pediatric patients.

Daptomycin for the Treatment of Infective Endocarditis: Results from European Cubicin(®) Outcomes Registry and Experience (EU-CORE)

INTRODUCTION

The European Cubicin(®) Outcomes Registry and Experience (EU-CORE(SM)) was a retrospective, non-interventional, multicenter study which evaluated the safety and effectiveness of daptomycin therapy in patients with Gram-positive infections including infective endocarditis (IE).

METHODS

Data from the EU-CORE registry were collected for patients with IE who had received at least one dose of daptomycin between January 2006 and April 2012, across 18 countries in Europe (12), Latin America (5) and Asia (1). Clinical outcomes were assessed as success (cured or improved), failure or non-evaluable. Adverse events (AEs) were recorded during treatment and for up to 30 days post-treatment; follow-up data were collected for 2 years.

RESULTS

Of 6075 patients included in the EU-CORE registry, 610 were diagnosed with IE as primary infection; 149 (24.4%) right-sided IE (RIE), 414 (67.9%) left-sided IE (LIE), and 47 (7.7%) with both right- and left-sided IE (BRLIE). Overall clinical success was achieved in 80.0% of patients (RIE 88.6%, LIE 76.6% and BRLIE 82.9%). Success rates for methicillin-resistant Staphylococcus aureus (MRSA) infections were 90.9%, 71.7% and 66.6% in patients with RIE, LIE and BRLIE, respectively. The overall sustained clinical success rate in patients followed for up to 2 years was 86.7% (RIE 93.5%, LIE 88.3% and BRLIE 77.8%). AEs deemed possibly related to daptomycin in the investigator's opinion were reported in 2 (1.3%) RIE, 18 (4.3%) LIE and 1 (2.1%) BRLIE patients. There were 11 (1.8%) patients (2 with RIE, 8 with LIE and 1 with BRLIE) with AEs of creatine phosphokinase elevation reported as possibly related to daptomycin.

CONCLUSION

Data from this real-world clinical setting showed that daptomycin was well tolerated and effective for the treatment of LIE and BRLIE in addition to RIE caused by Gram-positive bacteria, including MRSA. Two-year follow-up data showed that a high proportion of patients had a sustained response.

Approach to chronic wound infections

Infection is the likeliest single cause of delayed healing in healing of chronic open wounds by secondary intention. If neglected it can progress from contamination to colonization and local infection through to systemic infection, sepsis and multiple organ dysfunction syndrome, and it can be life-threatening. Infection in chronic wounds is not as easy to define as in acute wounds, and is complicated by the presence of biofilms. There is, as yet, no diagnostic for biofilm presence, but it contributes to excessive inflammation - through excessive and prolonged stimulation of nitric oxide, inflammatory cytokines and free radicals - and activation of immune complexes and complement, leading to a delay in healing. Control of biofilm is a key part of chronic wound management. Maintenance debridement and use of topical antimicrobials (antiseptics) are more effective than antibiotics, which should be reserved for treating spreading local and systemic infection. The continuing rise of antimicrobial resistance to antibiotics should lead us to reserve their use for these indications, as no new effective antibiotics are in the research pipeline. Antiseptics are effective through many mechanisms of action, unlike antibiotics, which makes the development of resistance to them unlikely. There is little evidence to support the theoretical risk that antiseptics select resistant pathogens. However, the use of antiseptic dressings for preventing and managing biofilm and infection progression needs further research involving well-designed, randomized controlled trials.

Clinical and microbiological aspects of biofilm-associated surgical site infections

While microbial biofilms have been recognized as being ubiquitous in nature for the past 40 years, it has only been within the past 20 years that clinical practitioners have realized that biofilm play a significant role in both device-related and tissue-based infections. The global impact of surgical site infections (SSIs) is monumental and as many as 80 % of these infections may involve a microbial biofilm. Recent studies suggest that biofilm- producing organisms play a significant role in persistent skin and soft tissue wound infections in the postoperative surgical patient population. Biofilm, on an organizational level, allows bacteria to survive intrinsic and extrinsic defenses that would inactivate the dispersed (planktonic) bacteria. SSIs associated with biomedical implants are notoriously difficult to eradicate using antibiotic regimens that would typically be effective against the same bacteria growing under planktonic conditions. This biofilm-mediated phenomenon is characterized as antimicrobial recalcitrance, which is associated with the survival of a subset of cells including "persister" cells. The ideal method to manage a biofilm-mediated surgical site wound infection is to prevent it from occurring through rational use of antibiotic prophylaxis, adequate skin antisepsis prior to surgery and use of innovative in-situ irrigation procedures; together with antimicrobial suture technology in an effort to promote wound hygiene at the time of closure; once established, biofilm removal remains a significant clinical problem.

Daptomycin plus fosfomycin, a synergistic combination in experimental implant-associated osteomyelitis due to methicillin-resistant Staphylococcus aureus in rats

The aim of this study was to evaluate the combination of daptomycin and fosfomycin in experimental chronic implant-associated osteomyelitis due to methicillin-resistant Staphylococcus aureus (MRSA). Infection was induced in the tibiae of rats by the insertion of a bacterial inoculum (1 to 5×10(8) CFU/ml) of a clinical MRSA isolate and a titanium wire. Four weeks after infection, each animal was assigned to a treatment group: daptomycin monotherapy at 60 mg/kg of body weight once daily (n=10), fosfomycin monotherapy at 40 mg/kg once daily (n=10), or daptomycin and fosfomycin combined at 60 mg/kg and 40 mg/kg, respectively, once daily (n=9). Ten animals were left untreated. After a 3-week treatment period, the animals were euthanized, and the infected tibiae and implants were processed for quantitative bacterial cultures. The bacterial cultures from bones were positive for MRSA in all animals in the untreated group, the daptomycin group, and the fosfomycin group, with median bacterial counts of 2.34×10(6) CFU/g bone, 1.57×10(6) CFU/g bone, and 3.48×10(2) CFU/g bone, respectively. In the daptomycin-fosfomycin group, 6 out of 9 animals were positive for MRSA, with a median count of 7.92 CFU/g bone. Bacterial cultures derived from the titanium wires were negative in the fosfomycin- and daptomycin-fosfomycin-treated groups. Based on bacterial counts in bones, treatment with daptomycin-fosfomycin was statistically significantly superior to all that of the other groups (P≤0.003). Fosfomycin was superior to daptomycin and no treatment (P<0.0001). No development of resistance was observed in any treatment arm. The combination of daptomycin and fosfomycin demonstrated synergism against MRSA in experimental implant-associated osteomyelitis.

Comparison of the antibiotic activities of Daptomycin, Vancomycin, and the investigational Fluoroquinolone Delafloxacin against biofilms from Staphylococcus aureus clinical isolates

Biofilm-related infections remain a scourge. In an in vitro model of biofilms using Staphylococcus aureus reference strains, delafloxacin and daptomycin were found to be the most active among the antibiotics from 8 different pharmacological classes (J. Bauer, W. Siala, P. M. Tulkens, and F. Van Bambeke, Antimicrob. Agents Chemother. 57:2726-2737, 2013, doi:10.1128/AAC.00181-13). In this study, we compared delafloxacin to daptomycin and vancomycin using biofilms produced by 7 clinical strains (S. aureus epidemic clones CC5 and CC8) in order to rationalize the differences observed between the antibiotics and strains. The effects of the antibiotics on bacterial viability (resazurin reduction assay) and biomass (crystal violet staining) were measured and correlated with the proportion of polysaccharides in the matrix, the local microenvironmental pH (micro-pH), and the antibiotic penetration in the biofilm. At clinically meaningful concentrations, delafloxacin, daptomycin, and vancomycin caused a ≥25% reduction in viability against the biofilms formed by 5, 4, and 3 strains, respectively. The antibiotic penetration within the biofilms ranged from 0.6 to 52% for delafloxacin, 0.2 to 10% for daptomycin, and 0.2 to 1% for vancomycin; for delafloxacin, this was inversely related to the polysaccharide proportion in the matrix. Six biofilms were acidic, explaining the high potency of delafloxacin (lower MICs at acidic pH). Norspermidine and norspermine (disassembling the biofilm matrix) drastically increased delafloxacin potency and efficacy (50% reduction in viability for 6 biofilms at clinically meaningful concentrations) in direct correlation with its increased penetration within the biofilm, while they only modestly improved daptomycin efficacy (50% reduction in viability for 2 biofilms) and penetration, and they showed marginal effects with vancomycin. Delafloxacin potency and efficacy against biofilms are benefited by its penetration into the matrix and the local acidic micro-pH.

Penetration of daptomycin into bone and synovial fluid in joint replacement

Daptomycin exhibits clinical activity in the treatment of infections with Gram-positive organisms, including infections due to methicillin-resistant Staphylococcus aureus. However, little is known about its penetration into bone and synovial fluid. The aim of our study was to assess the penetration of daptomycin into bone and synovial fluid after a single intravenous administration. This study was conducted in 16 patients who underwent knee or hip replacement and received a single intravenous dose of 8 mg of daptomycin per kg of body weight prior to surgery. Plasma daptomycin concentrations were measured 1 h after the end of daptomycin infusion and when bone fragments were removed. Daptomycin concentrations were also measured on bone fragments and synovial fluid collected at the same time during surgery. All samples were analyzed with a diode array-high-performance liquid chromatography (HPLC) method. After a single-dose intravenous infusion, bone daptomycin concentrations were above the MIC of daptomycin for Staphylococcus aureus in all subjects, and the median bone penetration percentage was 9.0% (interquartile range [IQR], 4.4 to 11.4). These results support the use of daptomycin in the treatment of Staphylococcus aureus bone and joint infections.

Periprosthetic joint infections: clinical and bench research

Prosthetic joint infection is a devastating complication with high morbidity and substantial cost. The incidence is low but probably underestimated. Despite a significant basic and clinical research in this field, many questions concerning the definition of prosthetic infection as well the diagnosis and the management of these infections remained unanswered. We review the current literature about the new diagnostic methods, the management and the prevention of prosthetic joint infections.

Daptomycin: the role of high-dose and combination therapy for Gram-positive infections

Daptomycin, a cyclic lipopeptide with rapid bactericidal activity, is approved at doses of 4 mg/kg and 6 mg/kg for the treatment of its respective indications [i.e. complicated skin and soft-tissue infections (cSSTIs) caused by Gram-positive bacteria; and Staphylococcus aureus bacteraemia associated with right-sided infective endocarditis (RIE) or cSSTIs, or RIE due to S. aureus]. Higher doses and combination therapy strategies have been investigated in some difficult-to-treat infections in order to: enhance clinical success rates; treat pathogens that may be non-susceptible to standard doses; and minimise the risk of resistance development in patients, particularly those who may need an extended treatment duration, who may have had suboptimal surgical management and/or who may have not responded to prior antibiotic therapy. Although clinical trial data of daptomycin doses >6 mg/kg and of daptomycin in combination with other antibiotics are limited, clinical experience reported to date suggests that daptomycin is effective and well tolerated at higher doses and in combination. In this review, the rationale both for high-dose and combination therapy strategies with daptomycin is explored and the available evidence is presented by indication and evaluated from a clinical perspective. Safety and efficacy are discussed from prospective and retrospective clinical studies, together with case reports for a variety of infections, including bacteraemia, endocarditis, cSSTIs and osteomyelitis, and expert recommendations are provided in summary of the evidence. The use of high-dose daptomycin, alone or in combination, may be useful for difficult-to-treat Gram-positive infections and further evaluation of these strategies is warranted.