Integrative model-based comparison of target site-specific antimicrobial effects: A case study with ceftaroline and lefamulin

OBJECTIVE

Predictions of antimicrobial effects typically rely on plasma-based pharmacokinetic-pharmacodynamic (PK-PD) targets, ignoring target-site concentrations and potential differences in tissue penetration between antibiotics. In this study, we applied PK-PD modelling to compare target site-specific effects of antibiotics by integrating clinical microdialysis data, in vitro time-kill curves, and antimicrobial susceptibility distributions. As a case study, we compared the effect of lefamulin and ceftaroline against methicillin-resistant Staphylococcus aureus (MRSA) at soft-tissue concentrations.

METHODS

A population PK model describing lefamulin concentrations in plasma, subcutaneous adipose and muscle tissue was developed. For ceftaroline, a similar previously reported PK model was adopted. In vitro time-kill experiments were performed with six MRSA isolates and a PD model was developed to describe bacterial growth and antimicrobial effects. The clinical PK and in vitro PD models were linked to compare antimicrobial effects of ceftaroline and lefamulin at the different target sites.

RESULTS

Considering minimum inhibitory concentration (MIC) distributions and standard dosages, ceftaroline showed superior anti-MRSA effects compared to lefamulin both at plasma and soft-tissue concentrations. Looking at the individual antibiotics, lefamulin effects were highest at soft-tissue concentrations, while ceftaroline effects were highest at plasma concentrations, emphasising the importance of considering target-site PK-PD in antibiotic treatment optimisation.

CONCLUSION

Given standard dosing regimens, ceftaroline appeared more effective than lefamulin against MRSA at soft-tissue concentrations. The PK-PD model-based approach applied in this study could be used to compare or explore the potential of antibiotics for specific indications or in populations with unique target-site PK.

The Etiology, Antibiotic Therapy and Outcomes of Bacteremic Skin and Soft-Tissue Infections in Onco-Hematological Patients

OBJECTIVES

to assess the current epidemiology, antibiotic therapy and outcomes of onco- hematological patients with bacteremic skin and soft-tissue infections (SSTIs), and to identify the risk factors for Gram-negative bacilli (GNB) infection and for early and overall mortality.

METHODS

episodes of bacteremic SSTIs occurring in cancer patients at two hospitals were prospectively recorded and retrospectively analyzed.

RESULTS

Of 164 episodes of bacteremic SSTIs, 53% occurred in patients with solid tumors and 47% with hematological malignancies. GNB represented 45.5% of all episodes, led by Pseudomonas aeruginosa (37.8%). Multidrug resistance rate was 16%. Inadequate empirical antibiotic therapy (IEAT) occurred in 17.7% of episodes, rising to 34.6% in those due to resistant bacteria. Independent risk factors for GNB infection were corticosteroid therapy and skin necrosis. Early and overall case-fatality rates were 12% and 21%, respectively. Risk factors for early mortality were older age, septic shock, and IEAT, and for overall mortality were older age, septic shock and resistant bacteria.

CONCLUSIONS

GNB bacteremic SSTI was common, particularly if corticosteroid therapy or skin necrosis. IEAT was frequent in resistant bacteria infections. Mortality occurred mainly in older patients with septic shock, resistant bacteria and IEAT. These results might guide empirical antibiotic therapy in this high-risk population.

In Vitro Activities of Ceftobiprole, Dalbavancin, Tedizolid and Comparators against Clinical Isolates of Methicillin-Resistant Staphylococcus aureus Associated with Skin and Soft Tissue Infections

Skin and soft tissue infections (SSTIs) are associated with significant morbidity and healthcare costs, especially when caused by methicillin-resistant Staphylococcus aureus (MRSA). Vancomycin is a preferred antimicrobial therapy for the management of complicated SSTIs (cSSTIs) caused by MRSA, with linezolid and daptomycin regarded as alternative therapeutic options. Due to the increased rates of antimicrobial resistance in MRSA, several new antibiotics with activity against MRSA have been recently introduced in clinical practice, including ceftobiprole, dalbavancin, and tedizolid. We evaluated the in vitro activities of the aforementioned antibiotics against 124 clinical isolates of MRSA obtained from consecutive patients with SSTIs during the study period (2020-2022). Minimum inhibitory concentrations (MICs) for vancomycin, daptomycin, ceftobiprole, dalbavancin, linezolid and tedizolid were evaluated by the MIC Test Strip using Liofilchem strips. We found that when compared to the in vitro activity of vancomycin (MIC₉₀ = 2 μg/mL), dalbavancin possessed the lowest MIC₉₀ (MIC₉₀ = 0.094 μg/mL), followed by tedizolid (MIC₉₀ = 0.38 μg/mL), linezolid, ceftobiprole, and daptomycin (MIC₉₀ = 1 μg/mL). Dalbavancin demonstrated significantly lower MIC₅₀ and MIC₉₀ values compared to vancomycin (0.064 vs. 1 and 0.094 vs. 2, respectively). Tedizolid exhibited an almost threefold greater level of in vitro activity than linezolid, and also had superior in vitro activity compared to ceftobiprole, daptomycin and vancomycin. Multidrug-resistant (MDR) phenotypes were detected among 71.8% of the isolates. In conclusion, ceftobiprole, dalbavancin and tedizolid exhibited potent activity against MRSA and are promising antimicrobials in the management of SSTIs caused by MRSA.

The Epidemiology of Antibiotic-Related Adverse Events in the Treatment of Diabetic Foot Infections: A Narrative Review of the Literature

The use of antibiotics for the treatment of diabetic foot infections (DFIs) over an extended period of time has been shown to be associated with adverse events (AEs), whereas interactions with concomitant patient medications must also be considered. The objective of this narrative review was to summarize the most frequent and most severe AEs reported in prospective trials and observational studies at the global level in DFI. Gastrointestinal intolerances were the most frequent AEs, from 5% to 22% among all therapies; this was more common when prolonged antibiotic administration was combined with oral beta-lactam or clindamycin or a higher dose of tetracyclines. The proportion of symptomatic colitis due to Clostridium difficile was variable depending on the antibiotic used (0.5% to 8%). Noteworthy serious AEs included hepatotoxicity due to beta-lactams (5% to 17%) or quinolones (3%); cytopenia's related to linezolid (5%) and beta-lactams (6%); nausea under rifampicin, and renal failure under cotrimoxazole. Skin rash was found to rarely occur and was commonly associated with the use of penicillins or cotrimoxazole. AEs from prolonged antibiotic use in patients with DFI are costly in terms of longer hospitalization or additional monitoring care and can trigger additional investigations. The best way to prevent AEs is to keep the duration of antibiotic treatment short and with the lowest dose clinically necessary.

Cost analysis of disease including treatment with dalbavancin in a Spanish hospital: ECODAL ANALYSIS

INTRODUCTION AND AIM

Dalbavancin is an antibiotic with activity against gram-positive bacteria that allows early discharge of patients requiring intravenous therapy. Outpatient treatment helps offset hospitalisation costs associated with standard intravenous treatment. Our objective was to assess the cost of disease management, including treatment with dalbavancin, in a Spanish hospital for 1 year, and the hypothetical costs associated with treatment with other therapeutic alternatives to dalbavancin.

METHODS

A single-centre, observational, retrospective post-hoc analysis was conducted based on electronic medical records analysing all patients who received dalbavancin treatment for 1 year; cost analysis was performed for the whole process. In addition, three scenarios designed on the basis of real clinical practice by clinical experts were hypothesised: (i) individual therapeutic alternative to dalbavancin, (ii) all patients treated with daptomycin, and (iii) all days of dalbavancin as outpatient treatment transformed into hospital stay. Costs were obtained from the hospital.

RESULTS

Thirty-four patients were treated with dalbavancin; their mean age was 57.9 years, and 70.6% were men. The main reasons for dalbavancin use were outpatient management (61.7%, n = 21) and ensuring treatment adherence (26.5%, n = 9). The main indications were: osteoarticular infection (32.4%) and infective endocarditis (29.4%). One-half (50%) of the infections were due to Staphylococcus aureus (23.5% were methicillin resistant). All patients achieved clinical resolution, and no costs associated with dalbavancin-associated adverse events or re-admissions were reported. The mean total cost of treatment was 22,738€per patient, with the greatest expenditures in interventions (8,413€) and hospital stay (6,885€). The mean cost of dalbavancin treatment was 3,936€; without dalbavancin, this cost could have been increased to 3,324-11,038€depending on the scenario, mainly due to hospital stays.

MAIN LIMITATION

Limited sample size obtained from a single centre.

CONCLUSION

The economic impact of the management of these infections is high. The cost of dalbavancin is offset by the decreased length of stay.

Acute Bacterial Skin and Skin-Structure Infections, efficacy of Dalbavancin: a systematic review and meta-analysis

OBJECTIVES

To know the efficacy of different doses of dalbavancin in acute bacterial skin and skin-structure infections (ABSSSIs) and versus other antibiotics.

METHODS

We performed a systematic review of dalbavancin efficacy for ABSSSIs. We selected 10 clinical trials from MEDLINE and Cochrane databases for qualitative review. Of these, five trials compared one or two doses of dalbavancin versus other antibiotics such as vancomycin or linezolid.

RESULTS

Treatment outcomes with other antibiotics were not significantly different versus two doses of dalbavancin (OR 1.13; 95% CI 0.75-1.71; p = 0.55) or single dose dalbavancin (OR 0.98; 95% CI 0.19-5.17; p = 0.98). One dose versus two doses of dalbavancin did not show significant differences in any of the treatment groups. In contrast, the global microbiological assessment results indicated a favorable outcome for two doses of dalbavancin compared to the single dose of dalbavancin (OR 2.96; 95% CI 1.19-7.39; p = 0.02) in both methicillin-resistant and methicillin-susceptible Staphylococcus aureus.

CONCLUSION

Either single dose or two dose dalbavancin treatment is as clinically effective as other antibiotics such as vancomycin and linezolid for the treatment of ABSSSIs.Abbreviations ABSSI: acute bacterial skin and skin-structure infection; AUC: area under the concentration-time curve; CE: clinical evaluable; CI: confidence interval; EOT: end of treatment; ITT: intention-to-treat; LOS: length of stay; MIC: minimum inhibitory concentration; MIC₉₀: minimum concentration to inhibit growth of 90% of isolates; MR: methicillin resistant; MRSA: methicillin-resistant Staphylococcus aureus; MS: methicillin susceptible; MSSA: methicillin-susceptible Staphylococcus aureus; OPAT: Outpatient Parenteral Antimicrobial Therapy; OR: odds ratio; PI: penicillin intermediate; PR: penicillin resistant; PS penicillin susceptible; SIRS: systemic inflammatory response syndrome; SSTI: skin and soft tissue infection; TOC: test of cure; VR: vancomycin resistant; VS: vancomycin susceptible.

Cost-minimisation analysis of oritavancin for the treatment of acute bacterial skin and skin structure infections from a United Kingdom perspective

BACKGROUND

Early discharge (ED) from hospital and outpatient parenteral antibiotic therapy (OPAT) are effective approaches for the management of a range of infections, including acute bacterial skin and skin structure infections (ABSSSI). Strategies that facilitate ED, thereby reducing complications such as healthcare-acquired infection whilst enhancing patient quality of life, are being increasingly adopted in line with good antimicrobial stewardship practice. This study presents a cost-minimisation analysis for the use of oritavancin at ED versus relevant comparators from a National Health Service (NHS) and personal and social services United Kingdom perspective.

METHODS

A cost-minimisation model considering adult patients with ABSSSI with suspected or confirmed methicillin-resistant Staphylococcus aureus (MRSA) infection, was developed based on publicly available NHS costs, practice guidelines for ABSSSI and clinical expert's opinion. Cost of treatment and treatment days were compared for oritavancin at ED to dalbavancin, teicoplanin, daptomycin and linezolid.

RESULTS

Following the empiric use of either flucloxacillin or vancomycin in the inpatient setting, oritavancin was compared to OPAT with dalbavancin, teicoplanin and daptomycin, and oral linezolid from day 4 of treatment. Oritavancin at ED reduced treatment duration by 0.8 days and led to cost savings of £281 in comparison to dalbavancin. In comparison to teicoplanin, daptomycin and linezolid, oritavancin reduced treatment duration by 5 days, with marginally higher costs (£446, £137, and £1,434, respectively).

CONCLUSION

Oritavancin, used to support ED, is associated with lower costs compared with dalbavancin and reduced treatment duration relative to all comparators. Its use would support an ED approach in MRSA ABSSSI management.

MRSA and Skin Infections in Psoriatic Patients: Therapeutic Options and New Perspectives

Psoriatic patients present various infectious risk factors, but there are few studies in the literature evaluating the actual impact of psoriasis in severe staphylococcal skin infections. Our narrative review of the literature suggests that psoriatic patients are at increased risk of both colonization and severe infection, during hospitalization, by S. aureus. The latter also appears to play a role in the pathogenesis of psoriasis through the production of exotoxins. Hospitalized psoriatic patients are also at increased risk of MRSA skin infections. For this reason, new molecules are needed that could both overcome bacterial resistance and inhibit exotoxin production. In our opinion, in the near future, topical quorum sensing inhibitors in combination with current anti-MRSA therapies will be able to overcome the increasing resistance and block exotoxin production. Supplementation with Vitamin E (VE) or derivatives could also enhance the effect of anti-MRSA antibiotics, considering that psoriatic patients with metabolic comorbidities show a low intake of VE and low serum levels, making VE supplementation an interesting new perspective.

Tackling Extended Hospital Stays in Patients with Acute Bacterial Skin and Skin Structure Infections

Hospitalisation rates for acute bacterial skin and skin structure infection (ABSSSI) are rising and represent a large pharmacoeconomic burden as treatment may involve an extended number of days of antibiotic therapy. This article first aims to provide a review of treatment challenges associated with ABSSSIs in both hospital and outpatient settings, and shows that while more traditionally treatment has been conducted in a hospital setting, for a number of patients, a variety of considerations, including pharmacoeconomics, infection control, and patient preference, has led to the development of recommendations to assess the eligibility of patients for early discharge from hospital to complete their antibiotic regimen in the outpatient setting. However, such patients require monitoring for drug adherence to oral regimens or complications associated with daily intravenous administration, such as injection site reactions and infection. This review also focuses on one of a number of new antibiotics for ABSSSI, dalbavancin, as the long-acting glycopeptide with the most clinical experience to date. This antibiotic has been shown to be as effective as a daily/twice daily regimen with similar safety profiles. Health economic analysis of dalbavancin is also presented. It has shown that in some, though not all, clinical settings a reduction in the overall treatment cost is evident as, despite a higher medication cost, the lower hospitalisation time can lead to greater cost savings. In conclusion, while the burden of ABSSSI is rising, new treatment options provide additional therapeutic choice, although pharmacoeconomic considerations might limit use in some cases.

Role of Daptomycin in Cutaneous Wound Healing: A Narrative Review

Daptomycin is active against Gram-positive bacteria, including methicillin-resistant Staphylococcus aureus (MRSA) and the on-label indications for its use include complicated skin and skin structure infections (cSSSI). We performed a narrative review of the literature with the aim to evaluate the role of daptomycin in the skin wound healing process, proposing our point of view on the possible association with other molecules that could improve the skin healing process. Daptomycin may improve wound healing in MRSA-infected burns, surgical wounds, and diabetic feet, but further studies in humans with histological examination are needed. In the future, the combination of daptomycin with other molecules with synergistic action, such as vitamin E and derivates, IB-367, RNA III-inhibiting peptide (RIP), and palladium nanoflowers, may help to improve wound healing and overcome forms of antibiotic resistance.

Skin infections in Europe: a retrospective study of incidence, patient characteristics and practice patterns

OBJECTIVE

Acute bacterial skin and skin structure infections (ABSSSIs) are associated with considerable morbidity and a heavy healthcare burden. The primary objectives of this two-phase study were to determine the incidence of skin infections and ABSSSIs in hospitalized patients (Phase A), and to describe the characteristics and treatment of hospitalized patients with ABSSSIs (Phase B).

METHODS

This non-interventional, retrospective study was based on data collected from adult patients hospitalized for skin infections in six European countries (Czech Republic, Greece, Italy, Portugal, Russia and Spain) between January 2014 and June 2016.

RESULTS

In Phase A, the total hospital incidence of skin infections and ABSSSIs was 2.4 and 1.8 per 1000 patient-days, respectively. Overall, 73.6% of 50,469 hospitalizations for skin infections were for ABSSSIs. Among the 750 patients with ABSSSIs included in Phase B, Gram-positive bacteria were isolated in 24.9%, most commonly methicillin-susceptible Staphylococcus aureus (11.5%). Empirical therapy was administered to 98.1% of patients, most often with a penicillin, with or without a β-lactamase inhibitor (42.1%). Complete cure was achieved in 46.5% and 34.5% of patients after initial treatment and treatment modification, respectively. Overall, 22.7% of patients had at least one additional ABSSSI-related hospitalization, 47.1% of patients visited the emergency room, 19.3% of patients visited primary care clinics, and 34.8% of patients visited a specialist.

CONCLUSION

Treatment of ABSSSIs in Europe is associated with a heavy healthcare burden, highlighting the need for optimized management strategies that may reduce healthcare utilization.

Antibiotic treatment of acute bacterial skin and skin structure infections

PURPOSE OF REVIEW

Acute bacterial skin and skin structure infections (ABSSSI) are a leading cause of morbidity, with a considerable variety of clinical presentation and a wide range of etiological pathogens. Of importance, the spread of multidrug-resistant (MDR) strains (i.e. methicillin-resistant Staphylococcus aureus or Gram-negative bacteria) is increasingly reported in some regions. in this review, we summarize the current clinical approach to patients with ABSSSI.

RECENT FINDINGS

Accurate diagnosis and identification of risk factors for MDR pathogens are key determinants for administering appropriate therapy in patients with ABSSSI. In daily clinical practice, this can be critical as there are many features defining the 'high risk patient' including both disease and host-associated risk factors.

SUMMARY

Antibiotic therapy should be based according to the different clinical spectrum of disease belonging to the ABSSSI, on the pathogens most likely to be involved and local resistance. Careful evaluation of antibiotic therapy after 48-72 h of initial therapy could help clinicians to early identify patients with treatment failure and to consider an alternative approach. Close monitoring of patients with multiple comorbidities, drug-drug interaction or adverse host factors are also necessary.

Kimyrsa, An Oritavancin-Containing Product: Clinical Study and Review of Properties

Background

There is a need for improved antibiotic formulations for the treatment of acute bacterial skin and soft structure infection (ABSSSI), especially with the rise of antimicrobial resistance among Gram-positive bacteria. A new formulation of oritavancin was developed to reduce intravenous infusion volume (from 1000 mL to 250 mL), shorten infusion time (from 3 hours to 1 hour), and provide pharmacies with flexibility in oritavancin preparation (from 5% dextrose in sterile water to either normal saline or 5% dextrose in sterile water) compared with the current formulation.

Methods

A total of 102 adult patients with a diagnosis of ABSSSI suspected or confirmed to be caused by a Gram-positive pathogen were randomized 1:1 to receive either the new formulation of oritavancin or the current formulation. After a single 1200-mg intravenous infusion of oritavancin, the relative area-under-the-curve exposure of the new formulation and current formulation groups were compared. Safety and tolerability of the new formulation were assessed for treatment-emergent adverse events, serious adverse events, and changes to laboratory parameters.

Results

The area under the curve for 0 hour to 72 hours postdose was very similar in the new formulation group compared with the current formulation group. No differences in treatment-emergent adverse events were observed between the current and new formulation groups, and all treatment-emergent adverse events were consistent with the known safety profile of the current formulation.

Conclusions

The new formulation of oritavancin with reduced volume and duration of intravenous infusion demonstrates a safety profile and pharmacokinetics similar to that of the original formulation.

Ceftaroline Fosamil for the Empiric Treatment of Hospitalized Adults with cSSTI: An Economic Analysis from the Perspective of the Spanish National Health System

Purpose

Complicated skin and soft tissue infections (cSSTI) are associated with high healthcare resource use and costs. The emergency nature of cSSTI hospitalizations requires starting immediate empiric intravenous (IV) antibiotic treatment, making the appropriate choice of initial antibiotic therapy crucial.

Patients and Methods

The use of ceftaroline fosamil (CFT) as an alternative to other IV antibiotic therapies for the empiric treatment of hospitalized adults with cSSTI (vancomycin, linezolid, daptomycin, cloxacillin, tedizolid) was evaluated through cost consequences analysis. The model structure was a decision tree accounting for four different pathways: patients demonstrating early response (ER) either discharged early (with oral antibiotic) or remaining in hospital to continue the initial therapy; non-responders either remaining on the initial IV therapy or switching to a second-line antibiotic. The model perspective was the Spanish National Health System.

Results

CFT resulted in average percentage of patients discharged early (PDE) of 24.6% (CI 19.49–30.2%) with average total cost per patient of €6763 (€6268–€7219). Vancomycin, linezolid, daptomycin and tedizolid resulted in average PDE of 22% (17.34–27.09%), 26.4% (20.5–32.32%), 28.6% (22.08–35.79%) and 26.5% (20.39–33.25%), respectively, for a total cost per patient of €6,619 (€5,902–€6,929), €6,394 (€5,881–€6,904), €6,855 (€5,800–€7,410) and €7,173 (€6,608–€7,763), respectively. Key model drivers were ER and antibiotic treatment duration, with hospital costs accounting for over 83% of the total expenditures.

Conclusion

Given its clinical and safety profile, CFT is an acceptable choice for cSSTI empiric therapy providing comparable ER and costs to other relevant antibiotic options.

Antimicrobial Management of Complicated Skin and Soft Tissue Infections in an Era of Emerging Multi-Drug Resistance: Perspectives from 5 Gulf Countries

The number of complicated skin and soft tissue infections (cSSTIs) in the Arabian Gulf region has risen in recent years, particularly those caused by multi-drug resistant (MDR) pathogens. The high prevalence of diabetes, obesity, and associated cardio-metabolic comorbidities in the region renders medical and surgical management of cSSTI patients with MDR infections challenging. An experienced panel of international and regional cSSTI experts (consensus group on cSSTIs) was convened to discuss clinical considerations for MDR infections from societal, antimicrobial stewardship, and cost perspectives, to develop best practice recommendations. This article discusses antibiotic therapies suitable for treating MDR cSSTIs in patients from the Gulf region and recommends that these should be tailored according to the local bacterial ecology by country and region. The article highlights the need for a comprehensive patient treatment pathway and defined roles of each of the multidisciplinary teams involved with managing patients with MDR cSSTIs. Aligned and inclusive definitions of cSSTIs for clinical and research purposes, thorough and updated epidemiological data on cSSTIs and methicillin-resistant <i>Staphylococcus aureus</i> in the region, clearcut indications of novel agents and comprehensive assessment of comparative data should be factored into decision-making are necessary.

Current and future options for treating complicated skin and soft tissue infections: focus on fluoroquinolones and long-acting lipoglycopeptide antibiotics

Bacterial skin and soft tissue infections are among the most common bacterial infections and constitute a major burden for patients and healthcare systems. Care is complicated by the variety of potential pathogens, some with resistance to previously effective antimicrobial agents, the wide spectrum of clinical presentations and the risk of progression to life-threatening forms. More-efficient care pathways are needed that can reduce hospital admissions and length of stay, while maintaining a high quality of care and adhering to antimicrobial stewardship principles. Several agents approved recently for treating acute bacterial skin and skin structure infections have characteristics that meet these requirements. We address the clinical and pharmacological characteristics of the fourth-generation fluoroquinolone delafloxacin, and the long-acting lipoglycopeptide agents dalbavancin and oritavancin.

Update on the epidemiology of healthcare-acquired bacterial infections: focus on complicated skin and skin structure infections

Healthcare-associated infections (HCAIs) are a threat to patient safety and cause substantial medical and economic burden in acute care and long-term care facilities. Risk factors for HCAIs include patient characteristics, the type of care and the setting. Local surveillance data and microbiological characterization are crucial tools for guiding antimicrobial treatment and informing efforts to reduce the incidence of HCAI. Skin and soft tissue infections, including superficial and deep incisional surgical site infections, are among the most frequent HCAIs. Other skin and soft tissue infections associated with healthcare settings include vascular access site infections, infected burns and traumas, and decubitus ulcer infections.

Impact of Underlying Comorbidities on Outcomes of Patients Treated with Ceftaroline Fosamil for Complicated Skin and Soft Tissue Infections: Pooled Results from Three Phase III Randomized Clinical Trials

Introduction

In three phase III randomized controlled trials, ceftaroline fosamil was shown to be non-inferior to vancomycin plus aztreonam for the treatment of complicated skin and soft tissue infections (cSSTIs). This exploratory analysis evaluated the impact of underlying comorbidities on clinical outcomes in patients with cSSTI pooled from these three studies.

Methods

CANVAS 1 and 2 and COVERS evaluated ceftaroline fosamil (600 mg every 12 h [q12h]; 600 mg every 8 h [q8h; COVERS]) versus vancomycin plus aztreonam (1 g q12h each [CANVAS 1 and 2]; vancomycin 15 mg/kg q12h and aztreonam 1 g q8h [COVERS]) in hospitalized adults with cSSTI. The primary efficacy variable in each trial was clinical response at the test-of-cure (TOC) visit. Subgroup analyses were performed on the pooled clinically evaluable (CE) population, exploring the impact of age and various baseline comorbidities.

Results

Overall, 1808 patients were included in the CE population (1005 ceftaroline fosamil; 803 vancomycin plus aztreonam). Clinical cure rates at TOC were 89.7% (ceftaroline fosamil) and 90.8% (vancomycin plus aztreonam) (difference [95% confidence interval] − 1.13 [− 3.87, 1.67]). Clinical response rates were similar between treatment groups, regardless of age (≤ 65 years or > 65 years), and in subgroups of patients with and without diabetes mellitus, peripheral vascular disease, cancer/malignancy, renal impairment, and obesity; within these subgroups, efficacy and safety results were generally consistent with those of the overall cSSTI population.

Conclusions

This analysis provides supportive evidence of the efficacy of ceftaroline fosamil in patients with cSSTI and underlying comorbidities.

Trial Registration

CANVAS 1, NCT00424190 and CANVAS 2, NCT00423657 (both trials first posted on ClinicalTrials.gov 18/01/2007); COVERS, NCT01499277 (first posted on ClinicalTrials.gov 26/12/2011).

Supplementary Information

The online version contains supplementary material available at 10.1007/s40121-021-00557-w.

Impact of prior antibiotic therapy on severe necrotizing soft-tissue infections in ICU patients: results from a French retrospective and observational study

Necrotizing soft-tissue infection (NSTI) is a life-threatening pathology that often requires management in intensive care unit (ICU). Therapies consist of early diagnosis, adequate surgical source control, and antimicrobial therapy. Whereas guidelines underline the need for appropriate routine microbiological cultures before starting antimicrobial therapy in patients with suspected sepsis or septic shock, delaying adequate therapy also strongly increases mortality. The aim of the present study was to compare the characteristics and outcomes of patients hospitalized in ICU for NSTI according to their antimicrobial therapy exposure > 24 h before surgery (called the exposed group) or not (called the unexposed group) before surgical microbiological sampling. We retrospectively included 100 consecutive patients admitted for severe NSTI. The exposed group consisted of 23(23%) patients, while 77(77%) patients belonged to the unexposed group. The demographic and underlying disease conditions were similar between the two groups. Microbiological cultures of surgical samples were positive in 84 patients and negative in 16 patients, including 3/23 (13%) patients and 13/77 (17%) patients in the exposed and unexposed groups, respectively (p = 0.70). The distribution of microorganisms was comparable between the two groups. The main antimicrobial regimens for empiric therapy were also similar, and the proportions of adequacy were comparable (n = 60 (84.5%) in the unexposed group vs. n = 19 (86.4%) in the exposed group, p = 0.482). ICU and hospital lengths of stay and mortality rates were similar between the two groups. In conclusion, in a population of severe ICU NSTI patients, antibiotic exposure before sampling did not impact either culture sample positivity or microbiological findings.

[Acute Hand Infections - Survey of the Pathogen Spectrum and appropriate Antibiotics]

Acute infections of the hand can be a pathology with severe consequences. Alongside the surgical therapy, it is necessary to establish a systemic antiinfective therapy as well. The most frequent bacteria in acute hand infections are Staphylococcus aureus and, less frequently, different Streptococci. If the infection is the result of a bite wound, the most frequently found bacterium is Pasteurella multocida. Fortunately, the susceptibility to frequently used antibiotics in the (middle-)European area is quite good - according to the literature, resistances are rare. First line antibiotics are 1st and 2nd generation cephalosporins as well as aminopenicillins in combination with beta-lactamase inhibitors. Especially in multi-morbid patients or infections with unusual aetiology, a broader bacterial spectrum is to be expected. It is very effective to collect a tissue sample or swab for microbiological analysis before the establishment of the antiinfective therapy to gain valuable information about the prospective therapy. Ultimately, hand infections are a pathology to be treated with increased attention to avoid severe complications. A close cooperation with the involved specialties and physiotherapists should be sought to guarantee the best possible outcome.

Costo-utilità di dalbavancina versus standard of care (SoC) in pazienti con ABSSSI non severa in Italia

Introduction:

Acute Bacterial Skin and Skin Structure Infections (ABSSSIs) include all complicated skin and soft tissue infections. The aim of this study was to conduct a cost-utility analysis to compare dalbavancin with standard antibiotic therapies for the management of non-severe ABSSSIs from the National Health Service (NHS) perspective.

Methods:

A probabilistic decision tree model was developed considering a 30-days follow-up to simulate the therapeutic pathway of a patient treated with dalbavancin or Standard of Care (SoC). The model considered three mutually exclusive health states: a) discharge of patients from the emergency department, b) discharge of patients after one night from admission, c) discharge after 24 or 36 hours from admission. A one-way deterministic sensitivity analysis and a probabilistic sensitivity analysis were conducted.

Results:

The analysis showed that the use of dalbavancin in patients with non-severe ABSSSI compared to SoC could generate a reduction in costs (– € 291.6 per patient treated) and an increase in QALYs (+0.0018 per patient treated). In 99.7% of the simulations carried out, dalbavancin was dominant compared to the SoC. Considering a threshold for the willingness to pay of € 30,000 for QALY gained, the minimum level of efficacy of dalbavancin so that the treatment can be considered cost-effective compared to the SoC was equal to 69.4%.

Conclusions:

The analysis showed that dalbavancin may represent a cost-effective option compared to SoC for the treatment of patients with non-severe ABSSSI.

The clinical and economic burden of community-onset complicated skin and skin structure infections in Korea

BACKGROUND/AIMS

To investigate epidemiologic characteristics, clinical and economic burdens, and factors associated with mortality in complicated skin and skin structure infection (cSSSI) patients in Korea.

METHODS

A retrospective, observational, nationwide study was conducted between April to July 2012 at 14 tertiary-hospitals in Korea. Eligible patients were hospitalized adults with community acquired cSSSI, who underwent surgical intervention and completed treatment between November 2009 and October 2011. Data on demography, clinical characteristics, outcomes and medical resource utilization were collected through medical record review. Direct medical costs were calculated by multiplying quantities of resources utilized by each unit price in Korea.

RESULTS

Of 473 patients enrolled, 449 patients (except 24 patients with no record on surgical intervention) were eligible for analysis. Microbiological testing was performed on 66.1% of patients and 8.2% had multiple pathogens. Among culture confirmed pathogens (n = 297 patients, 340 episodes), 76.2% were gram-positive (Staphylococcus aureus; 41.2%) and 23.8% were gram-negative. The median duration of hospital stay was 16 days. Among treated patients, 3.3% experienced recurrence and 4.2% died in-hospital. The mean direct medical costs amounted to $4,195/ person, with the greatest expenses for hospitalization and antibiotics. The in-hospital mortality and total medical costs were higher in combined antibiotics therapy than monotherapy (p < 0.05). Charlson's comorbidity index ≥ 3, standardized early warning scoring ≥ 4, sub-fascia infections and combined initial therapy, were all found to be associated with higher mortality.

CONCLUSION

Korean patients with community-onset cSSSI suffer from considerable clinical and economic burden. Efforts should be made to reduce this burden through appropriate initial treatment.

Baseline Characteristics and Outcomes Among Patients with Complicated Skin and Soft Tissue Infections Admitted to the Intensive Care Unit: Analysis of the Phase 3 COVERS Randomized Trial of Ceftaroline Fosamil Versus Vancomycin Plus Aztreonam

Aim

Exploratory analyses evaluated patient characteristics and outcomes among patients with complicated skin and soft tissue infection (cSSTI) in the phase 3 COVERS study who were admitted to an intensive care unit (ICU).

Methods

Adults with cSSTI (surface area ≥ 75 cm²) and evidence of systemic inflammation and/or underlying comorbidities were randomized 2:1 to intravenous ceftaroline fosamil (600 mg every 8 h [q8h]) or vancomycin (15 mg/kg every 12 h) plus aztreonam (1 g q8h) for 5–14 days. Clinical response and ICU length of stay (LOS) within first hospitalization were evaluated in the modified intent-to-treat (MITT) and clinically evaluable (CE) populations; a Cox proportional hazards model identified factors associated with increased hospital LOS.

Results

Overall, 42 of 761 randomized patients were admitted to the ICU (ceftaroline fosamil, n = 32; vancomycin plus aztreonam, n = 10) prior to, or at start of, study treatment. Baseline differences between the ICU and non-ICU populations were indicative of more severe disease in ICU patients; within this subset, there were also some notable imbalances between treatment groups. Clinical cure rates at test-of-cure (ceftaroline fosamil vs. vancomycin plus aztreonam) were generally similar in the non-ICU and ICU subsets (MITT population 79% vs. 79% and 69% vs. 90.0%, respectively; CE population 87% vs. 85% and 80% vs. 89%, respectively). Median ICU LOS was 8 vs. 13 days, respectively. ICU admission was a risk factor predicting increased hospital LOS (P < 0.001).

Conclusions

Clinical outcomes for patients admitted to the ICU were generally similar to non-ICU patients, despite more severe baseline disease, with shorter median treatment duration in the ceftaroline fosamil group. ICU admission was associated with longer hospital LOS. Given the small sample size and unbalanced patient and disease characteristics within the ICU subgroup, differences between treatment groups should be interpreted with caution.

Trial registration

ClinicalTrials.gov identifier, NCT01499277.

Electronic supplementary material

The online version of this article (10.1007/s40121-020-00297-3) contains supplementary material, which is available to authorized users.

Dalbavancin for the Treatment of Complicated Gram-Positive Skin and Soft Tissue Infections

New antimicrobial agents have been developed to treat infections caused by methicillin-resistant Staphylococcus aureus and other multidrug-resistant pathogens. Dalbavancin is a novel semisynthetic lipoglycopeptide antibiotic, particularly active against methicillin-resistant Staphylococcus aureus. Due to its unique pharmacological characteristics and longer half-life, it can be administered once-weekly or every 15 days and in outpatient setting. Currently, it is indicated for complicated skin and soft tissue infections, but accumulating evidence points to its off-label efficacy in osteomyelitis and endocarditis. Further experience is still needed to increase our knowledge on the role of dalbavancin in a wider range of Gram-positive infections requiring prolonged antimicrobial treatment.

Innovative therapies for acute bacterial skin and skin-structure infections (ABSSSI) caused by methicillin-resistant Staphylococcus aureus: advances in phase I and II trials

INTRODUCTION

Methicillin-resistant Staphylococcus aureus (MRSA) is among the most frequent causative agents of acute bacterial skin and skin-structure infections (ABSSSI) and has been associated with increased risks of invasive disease and of treatment failure.

AREAS COVERED

In this review, we focus on those novel anti-MRSA agents currently in phase I or II of clinical development that may enrich the armamentarium against ABSSSI caused by MRSA in the future.

EXPERT OPINION

Promising agents belonging to either old or novel antibiotic classes are currently in early phases of clinical development and may become available in the future for the effective treatment of ABSSSI caused by MRSA. In particular, the future availability of agents belonging to novel classes will be important for guaranteeing an effective treatment and for allowing outpatient treatment/early discharge, with a consequent reduced impact on healthcare resources. However, this does not mean that we can relax our efforts directed toward improving the responsible use of already available agents. Indeed, preserving their activity in the long term is crucial for optimizing the use of healthcare resources.

In Vitro Activity and Microbiological Efficacy of Gepotidacin from a Phase 2, Randomized, Multicenter, Dose-Ranging Study in Patients with Acute Bacterial Skin and Skin Structure Infections

A phase 2 study of gepotidacin demonstrated the safety and efficacy of 3 gepotidacin doses (750 mg every 12 h [q12h], 1,000 mg q12h, and 1,000 mg every 8 h [q8h]) in hospitalized patients with suspected/confirmed Gram-positive acute bacterial skin and skin structure infections (ABSSSIs). Evaluating microbiology outcomes and responses were secondary endpoints. Pretreatment isolates recovered from infected lesions underwent susceptibility testing per Clinical and Laboratory Standards Institute guidelines. Staphylococcus aureus accounted for 78/102 (76%) of Gram-positive isolates; 54/78 (69%) were methicillin-resistant S. aureus (MRSA), and 24/78 (31%) were methicillin-susceptible S. aureus (MSSA). Posttherapy microbiological success (culture-confirmed eradication of the pretreatment pathogen or presumed eradication based on a clinical outcome of success) for S. aureus was 90% for the gepotidacin 750-mg q12h group, 89% for the 1,000-mg q12h, and 73% in the 1000-mg q8h group. For 78 S. aureus isolates obtained from pretreatment lesions, gepotidacin MIC50/MIC90 values were 0.25/0.5 μg/ml against both MRSA and MSSA. Isolates recovered from the few patients with posttreatment cultures showed no significant reduction in gepotidacin susceptibility (≥4-fold MIC increase) between pretreatment and posttreatment isolates. Two of the 78 S. aureus isolates from pretreatment lesions had elevated gepotidacin MICs and had mutations known to occur in quinolone-resistant S. aureus (GyrA S84L, ParC S80Y, and ParE D422E) or to confer elevated MICs to novel bacterial topoisomerase inhibitors (GyrA D83N, both isolates; ParC V67A, one isolate). This first report of microbiological outcomes and responses of gepotidacin in patients with ABSSSIs supports further evaluation of gepotidacin as a novel first-in-class antibacterial agent. (This study has been registered at ClinicalTrials.gov under identifier NCT02045797.).

Inpatient Management of Uncomplicated Skin and Soft Tissue Infections in 34 Veterans Affairs Medical Centers: A Medication Use Evaluation

BACKGROUND

Skin and soft tissue infections (SSTIs) are a key antimicrobial stewardship target because they are a common infection in hospitalized patients, and non-guideline-concordant antibiotic use is frequent. To inform antimicrobial stewardship interventions, we evaluated the proportion of veterans hospitalized with SSTIs who received guideline-concordant empiric antibiotics or an appropriate total duration of antibiotics.

METHODS

A retrospective medication use evaluation was performed in 34 Veterans Affairs Medical Centers between 2016 and 2017. Hospitalized patients who received antibiotics for uncomplicated SSTI were included. Exclusion criteria were complicated SSTI, severe immunosuppression, and antibiotics for any non-SSTI indication. Data were collected by manual chart review. The primary outcome was the proportion of patients receiving both guideline-concordant empiric antibiotics and appropriate treatment duration, defined as 5-10 days of antibiotics. Data were analyzed and reported using descriptive statistics.

RESULTS

Of the 3890 patients manually evaluated for inclusion, 1828 patients met inclusion criteria. There were 1299 nonpurulent (71%) and 529 purulent SSTIs (29%). Overall, 250 patients (14%) received guideline-concordant empiric therapy and an appropriate duration. The most common reason for non-guideline-concordance was receipt of antibiotics targeting methicillin-resistant Staphylococcus aureus (MRSA) in 906 patients (70%) with a nonpurulent SSTI. Additionally, 819 patients (45%) received broad-spectrum Gram-negative coverage, and 860 patients (48%) received an antibiotic duration >10 days.

CONCLUSIONS

We identified 3 common opportunities to improve antibiotic use for patients hospitalized with uncomplicated SSTIs: use of anti-MRSA antibiotics in patients with nonpurulent SSTIs, use of broad-spectrum Gram-negative antibiotics, and prolonged durations of therapy.

Tedizolid Versus Linezolid for the Treatment of Acute Bacterial Skin and Skin Structure Infection: A Systematic Review and Meta-Analysis

This meta-analysis aims to assess the efficacy and safety of tedizolid, compared to linezolid, in the treatment of acute bacterial skin and skin structure infection (ABSSSI). PubMed, Web of Science, EBSCO (Elton B. Stephens Co.), Cochrane Library, Ovid Medline and Embase databases were accessed until 18 July 2019. Only randomized controlled trials (RCTs) comparing the efficacy of tedizolid with linezolid for adult patients with ABSSSIs were included. The outcomes included the clinical response, microbiological response, and risk of adverse events (AEs). A total of four RCTs involving 2056 adult patients with ABSSSI were enrolled. The early clinical response rate was 79.6% and 80.5% for patients receiving tedizolid and linezolid, respectively. The pooled analysis showed that tedizolid had a non-inferior early clinical response rate to linezolid (odds ratio (OR) = 0.96, 95% confidence interval (CI) = 0.77-1.19, I² = 0%). The early response rate was similar between tedizolid and linezolid among patients with cellulitis/erysipelas (75.1% vs. 77.1%; OR = 0.90, 95% CI = 0.64-1.27, I² = 25%), major cutaneous abscess (85.1% vs. 86.8%; OR = 0.93, 95% CI = 0.42-2.03, I² = 37%) and wound infection (85.9% vs. 82.6%; OR = 1.29, 95% CI = 0.66-2.51, I² = 45%). For methicillin-resistant Staphylococcus aureus patients, tedizolid had a favorable microbiological response rate of 95.2% which was comparable to linezolid (94%) (OR = 1.19, 95% CI = 0.49-2.90, I² = 0%). In addition to the similar risk of treatment-emergent AEs (a serious event, the discontinuation of the study drug due to AEs and mortality between tedizolid and linezolid), tedizolid was associated with a lower risk of nausea, vomiting and abnormal neutrophil count than linezolid. In conclusion, once-daily tedizolid (200 mg for six days) compared to linezolid (600 mg twice-daily for 10 days) was non-inferior in efficacy in the treatment of ABSSSI. Besides, tedizolid was generally as well tolerated as linezolid, and had a lower incidence of gastrointestinal AEs and bone marrow suppression than linezolid.

Susceptibility of microorganisms causing acute hand infections

Hand infections are a common presentation at the emergency departments. Without knowing the source of infection clinicians are dependent on systematic reports on the bacterial spectrum and susceptibility tests of the specific infection in their patient community. This study was based on a retrospective chart review of patients presenting to our outpatient clinic with acute hand infections. We documented patient demographics, the etiology, location, culture tests of the infection and analyzed if certain bacteria could be cultured significantly more often in certain etiologies or in specific sites of the hand infection. Susceptibility tests were added. Bacterial swabs of 204 patients were analyzed. Overall S. aureus was found in 53% of all cases, in only one case revealed methicillin-resistant S. aureus (MRSA). There was no significant difference in the bacterial spectrum according to the etiology of the hand infections, except for animal bites where Pasteurella multocida was the dominating bacteria in 63% of all cases. Amoxicillin-clavulanic acid, fluoroquinolones, and piperacillin were effective against the main bacteria. Our study confirms the previously published antibiotic resistance reports and reinforces the current antibiotic treatment guidelines also in this western European population.

Risk factors associated with methicillin-resistant Staphylococcus aureus skin and soft tissue infections in hospitalized patients in Colombia

OBJECTIVES

Methicillin-resistant Staphylococcus aureus (MRSA) skin and soft tissue infections (SSTIs) represent a major clinical problem in Colombia. The aim of this study was to evaluate the risk factors associated with MRSA SSTI in Colombia.

METHODS

A multicenter cohort study with nested case-control design was performed. Patients with an SSTI with at least 48h of inpatient care were included. Patients with an MRSA SSTI were considered the case group and patients with either a non-MRSA SSTI or with an Methicillin-susceptible S. aureus (MSSA) SSTI were the control groups. A multivariate logistic regression approach was used to evaluate risk factors associated with MRSA SSTI with two different statistical models.

RESULTS

A total 1134 patients were included. Cultures were positive for 498 patients, of which 52% (n=259) were Staphylococcus aureus. MRSA was confirmed in 68.3% of the S. aureus cultures. In the first model, independent risk factors for MRSA SSTI were identified as the presence of abscess (P<0.0001), cellulitis (P=0.0007), age 18-44 years (P=0.001), and previous outpatient treatment in the previous index visit (P=0.003); surgical site infection was a protective factor (P=0.008). In the second model, the main risk factor found was previous outpatient treatment in the previous index visit (P=0.013).

CONCLUSIONS

Community-acquired SSTIs in Colombia are commonly caused by MRSA. Therefore, clinicians should consider MRSA when designing the initial empirical treatment for purulent SSTI in Colombia, although there seems to be low awareness of this fact.

Tedizolid phosphate for the treatment of acute bacterial skin and skin-structure infections: an evidence-based review of its place in therapy

Introduction

Tedizolid phosphate is an oxazolidinone approved for the treatment of acute bacterial skin and skin-structure infections (ABSSSIs) and active against methicillin-resistant Staphylococcus aureus.

Aims

The objective of this article was to review the evidence for the efficacy and safety of tedizolid phosphate for the treatment of ABSSSI.

Evidence review

Approval of tedizolid phosphate for the treatment of ABSSSI was based on the results of two phase III randomized controlled trials, ESTABLISH-1 (NCT01170221) and ESTABLISH-2 (NCT01421511), comparing 6-day once-daily tedizolid vs 10-day twice-daily linezolid. In ESTABLISH-1, noninferiority was met with early clinical response rates of 79.5% and 79.4% in tedizolid and linezolid groups, respectively (difference 0.1%, 95% CI –6.1% to 6.2%, with a 10% noninferiority margin). In ESTABLISH-2, noninferiority was met with 85% and 83% rates of early clinical response in tedizolid and linezolid groups, respectively (difference 2.6%, 95% CI –3.0% to 8.2%). Pooled data from ESTABLISH-1 and ESTABLISH-2 indicated a lower frequency of thrombocytopenia in tedizolid-treated than in linezolid-treated patients.

Conclusion

Tedizolid offers the option of an intravenous to oral switch, allows once-daily administration, and presents lower risk of myelotoxicity when a 6-day course is used for the treatment of ABSSSI. Greater economic cost associated with this antibiotic could be offset by its shorter treatment duration and possibility of oral administration in routine clinical practice, although either sponsored or nonsponsored postmarketing observational experience remains essential for ultimately confirming the effectiveness and tolerability of tedizolid outside clinical trials.

Efficacy and Safety of Tedizolid Phosphate versus Linezolid in a Randomized Phase 3 Trial in Patients with Acute Bacterial Skin and Skin Structure Infection

Tedizolid phosphate is approved for the treatment of acute bacterial skin and skin structure infection (ABSSSI) caused by Gram-positive bacteria in the United States, Europe, and other countries. In this multicenter, double-blind, phase 3 study, 598 adult ABSSSI patients in China, Taiwan, the Philippines, and the United States were randomized to receive 200 mg of tedizolid, intravenously (i.v.)/orally (p.o.), once daily for 6 days or 600 mg of linezolid, i.v./p.o.

Tedizolid phosphate is approved for the treatment of acute bacterial skin and skin structure infection (ABSSSI) caused by Gram-positive bacteria in the United States, Europe, and other countries. In this multicenter, double-blind, phase 3 study, 598 adult ABSSSI patients in China, Taiwan, the Philippines, and the United States were randomized to receive 200 mg of tedizolid, intravenously (i.v.)/orally (p.o.), once daily for 6 days or 600 mg of linezolid, i.v./p.o. twice daily for 10 days. The primary endpoint was early clinical response rate at 48 to 72 h. Secondary endpoints included programmatic and investigator-assessed outcomes at end-of-therapy (EOT) and posttherapy evaluation (PTE) visits. Safety was also evaluated. In the intent-to-treat (ITT) population, 75.3% of tedizolid-treated patients and 79.9% of linezolid-treated patients were early responders (treatment difference, –4.6%; 95% confidence interval [CI], –11.2, 2.2). After exclusion of patients who never received the study drug (tedizolid, n = 8; linezolid, n = 1; modified ITT), comparable early response rates were observed (tedizolid, 77.4%; linezolid, 80.1%; treatment difference, –2.7%; 95% CI, –9.4, 3.9). Secondary endpoints showed high and similar clinical success rates in the ITT and clinically evaluable (CE) populations at EOT and PTE visits (e.g., CE-PTE for tedizolid, 90.4%; for linezolid, 93.5%). Both drugs were well tolerated, and no death occurred. Eight patients experienced phlebitis with tedizolid while none did with linezolid; hence, drug-related treatment-emergent adverse events were reported in a slightly higher proportion in the tedizolid (20.9%) arm than in the linezolid arm (15.8%). The study demonstrated that tedizolid in a primarily Asian population was an efficacious and well-tolerated treatment option for ABSSSI patients. (This study has been registered at ClinicalTrials.gov under registration no. NCT02066402.)

The safety of treatment options for acute bacterial skin and skin structure infections

INTRODUCTION

Acute bacterial skin and skin-structure infections (ABSSSI) may develop in both in-patients and out-patients, possibly with a severe clinical presentation. Since most phase 3 randomized clinical trials have shown non-inferiority in efficacy across different agents, considerations regarding their different safety profiles inevitably play a crucial role in the everyday choice about which of them should be employed for the treatment of ABSSSI.

AREAS COVERED

In this review, the authors discuss the safety profile of different treatment options for ABSSSI.

EXPERT OPINION

The spread of methicillin-resistant Staphylococcus aureus (MRSA) in the last decades has inevitably influenced the therapeutic approach to ABSSSI. Adequate knowledge of the peculiar toxicity profile of each drug active against MRSA is essential for guiding, monitoring and managing adverse events, in turn reducing any unfavorable impact of toxicity on patients' outcomes. In the next five years, potential toxicity will play a critical role in establishing the best available therapy for each specific patient, together with consideration regarding the possibility of avoiding hospitalization or allowing a switch from intravenous to oral therapy and early discharge.

Factors associated with blood culture positivity in patients with complicated skin and skin structure infection-a population-based study

Skin and skin structure infection (SSSI) is classified as complicated (cSSSI) if it involves deep subcutaneous tissue or requires surgery. Factors associated with blood culture sampling and bacteremia have not been established in patients with cSSSI. Moreover, the benefit of information acquired from positive blood culture is unknown. The aim of this study was to address these important issues. In this retrospective population-based study from two Nordic cities, a total of 460 patients with cSSSI were included. Blood cultures were drawn from 258 (56.1%) patients and they were positive in 61 (23.6%) of them. Factors found to be associated with more blood culture sampling in multivariate analysis were diabetes, duration of symptoms shorter than 2 days and higher C-reactive protein (CRP) level. Whereas factors associated with less frequent blood culture sampling were peripheral vascular disease and a surgical wound infection. In patients from whom blood cultures were taken, alcohol abuse was the only factor associated with culture positivity, as CRP level was not. Patients with a positive blood culture had antibiotic streamlining more often than non-bacteremic patients. A high rate of blood culture positivity in patients with cSSSI was observed. Factors related to more frequent blood culture sampling were different from those associated with a positive culture.

Influence of age on the clinical efficacy of tigecycline in severely ill patients

OBJECTIVES

The aim of this study was to define the relationship between age and response to tigecycline among patients treated for complicated skin and soft-tissue infections (cSSTIs) and complicated intra-abdominal infections (cIAIs).

METHODS

Pooled data derived from five European observational studies on the use of tigecycline (July 2006-October 2011), either as monotherapy or in combination with other antibiotics, for the treatment of cSSTI or cIAI were used in the analysis.

RESULTS

The total population (N=1782 patients) was divided into three age categories: <65 years (804 patients); 65-80 years (836 patients) and >80 years (139 patients) (data unknown/missing for 3 patients). The overall mean Acute Physiology and Chronic Health Evaluation (APACHE) II score for patients with cSSTI and cIAI was 15.0±7.9 and 16.9±7.6, respectively, and the overall mean Sequential Organ Failure Assessment (SOFA) score was 5.8±3.9 and 7.0±4.2, respectively. Overall, patients with cSSTI and cIAI in the three age groups showed a good response to tigecycline treatment (76.2-80.0% and 69.2-81.1%, respectively) with patients aged ≤80 years showing higher response rates. Patients with cIAI appeared to be at greater risk for all types of adverse events compared with those with cSSTI, particularly in the older age groups.

CONCLUSION

In these real-life studies, tigecycline, either alone or in combination, achieved favourable clinical response rates in all age categories of patients with cSSTIs and cIAIs with a high severity of illness.

Skin and soft tissue infections after breast surgery

PURPOSE OF REVIEW

Breast surgery is considered a clean surgical procedure; nevertheless, infection rates are often higher than those reported after other similarly considered clean surgeries (e.g., thyroid, hernia). Acute bacterial skin and soft tissue infections, mostly surgical site infections and implant-associated infections are commonest events that could complicate postoperative care.

RECENT FINDINGS

Risk of infection is closely related to surgery procedure itself and patients host factors. Gram-positive bacteria with pattern of antimicrobial resistance are increasingly isolated and before today less frequent causes such as gram negative and mycobacteria infections. Impact of postoperative complications is underestimated and lacking an appropriate care and education for local and systemic management.

SUMMARY

We report the current evidence on the management of infections after breast surgery. New drugs options for methicillin-resistant Staphylococcus aureus and other gram positive should have a place in this setting. Stewardship activities aiming at reducing infections risks with the correct considerations of host, microbiological and surgical risk factors.

Management of bacterial skin and skin structure infections with polymicrobial etiology

INTRODUCTION

Skin and Soft Tissue Infections (SSTIs) are some of the most commonly occurring bacterial infections, with a wide range of possible etiological pathogens and a considerable variety of clinical presentations and severity; from mild to severe life-threatening infections. Several classifications have been proposed based on a specific variable, such as anatomical localization, skin extension, progression rate, clinical presentation, severity, and etiological agent. Areas covered: The last criteria allows the differentiation of SSTIs as monomicrobial and polymicrobial. Among them, especially those infections with a long lasting or chronic course can be sustained by multiple microbial etiology. Most polymicrobial SSTIs can be included in the following: diabetes foot infections (DFIs), pressure ulcers infection, burn infection, and infected chronic ulcers. Expert commentary: The medical management of these infections comprises the administration of wide a spectrum antibiotic, taking into consideration the frequent occurrence of multidrug resistant microorganisms as responsible agents. An appropriate deep tissue specimen for microbiological examination is a very important issue, especially for polymicrobial infections, sometimes permitting the distinction between real pathogens and contaminants avoiding more complex antibiotic treatments. This aspect must be strongly emphasized, as frequently superficial swabs remain the specimen of choice because they are easy to obtain.

[Bacterial skin and soft tissue infections]

Bacterial skin and soft tissue infections are frequent and represent one of the most important differential diagnoses in patients presenting with reddened and swollen skin and soft tissue. Among these infections, cellulitis (phlegmon), erysipelas and abscesses are the most frequent. Whereas erysipelas is almost exclusively caused by streptococci and can be successfully treated with penicillin, an effective antibiotic therapy targeted at Staphylococcus aureus should be empirically considered for abscesses and phlegmon; other pathogens, such as gram negative and anaerobic bacteria can be found in patients with the corresponding underlying disease and certain risk factors. Severe necrotizing soft tissue infections are acutely life-threatening and require rapid and broad antibiotic therapy followed by immediate surgery. Depending on the medical history or exposure (including bite wounds), other pathogens may have to be considered in special situations including the increasing prevalence of community-acquired methicillin-resistant Staphylococcus aureus (MRSA) outside hospitals.

Fast track SSTI management program based on a rapid molecular test (GeneXpert® MRSA/SA SSTI) and antimicrobial stewardship

PURPOSE

This study examines the impacts of a skin and soft tissue infection (SSTI) management program involving a rapid diagnostic algorithm (Gram stain plus real-time PCR, GeneXpert® MRSA/SA SSTI) performed directly on clinical samples plus antimicrobial stewardship (AMS) counseling of the responsible physician.

METHODS

Participants were 155 consecutive adult inpatients with SSTI and good quality clinical samples submitted to the microbiology laboratory from April 2016 to January 2017. Results of the rapid test and AMS recommendations were phoned through to the responsible physician. The comparison group was a historical cohort.

RESULTS

Most SSTI were surgical wound infections (41.3% vs 38.1% for the intervention and comparison groups respectively) followed by diabetic foot (14.2% and 18.1%), abscesses (13.5% both) and cellulitis (12.9% both). Isolated microorganisms were mostly Gram-negative bacilli (two-thirds), followed by Staphylococcus aureus (SA). The ratio methicillin-susceptible SA (MSSA) to methicillin-resistant SA (MRSA) was 4:1. Improvements in the intervention cohort were: DOT (22.0 vs. 24.3 days, p = 0.007), treatment duration per SSTI episode (14.1 vs. 15.0 days, p = 0.072), treatment cost (433.1 vs. 533.3 €, p = 0.039), length of stay (18.6 vs 20.7 days, p = 0.031), related mortality (1 vs. 4 patients, p = 0.022) and Clostridium difficile infection (CDI) (4 vs. 8 patients, p = 0.050). In 48 cases (31.4%) in the intervention group, advice was given to improve empiric antibiotic treatment.

CONCLUSION

This type of program could help adjust antibiotic treatment when inappropriate, reducing antibiotic use and costs, length of stay, CDI and related mortality.

Single Intravenous Dose of Oritavancin for Treatment of Acute Skin and Skin Structure Infections Caused by Gram-Positive Bacteria: Summary of Safety Analysis from the Phase 3 SOLO Studies

Oritavancin is a lipoglycopeptide with bactericidal activity against Gram-positive organisms. Its rapid concentration-dependent bactericidal activity and long elimination half-life allow single-dose treatment of acute bacterial skin and skin structure infections (ABSSSI). SOLO I and SOLO II were randomized, double-blind studies evaluating the efficacy and safety of a single 1,200-mg intravenous (i.v.) dose of oritavancin versus twice-daily i.v. vancomycin for 7 to 10 days in ABSSSI patients. Safety data from both studies were pooled for safety analysis. The database comprised pooled safety data for 976 oritavancin-treated patients and 983 vancomycin-treated patients. The incidences of adverse events, serious adverse events, and discontinuations due to adverse events were similar for oritavancin (55.3, 5.8, and 3.7%, respectively) and vancomycin (56.9, 5.9, and 4.2%, respectively). The median time to onset (3.8 days versus 3.1 days, respectively) and the duration (3.0 days for both groups) of adverse events were also similar between the two groups. The most frequently reported events were nausea, headache, and vomiting. Greater than 90% of all events were mild or moderate in severity. There were slightly more infections and infestations, abscesses or cellulitis, and hepatic and cardiac adverse events in the oritavancin group; however, more than 80% of these events were mild or moderate. Subgroup analyses did not identify clinically meaningful differences in the incidence of adverse events attributed to oritavancin. A single 1,200-mg dose of oritavancin was well tolerated and had a safety profile similar to that of twice-daily vancomycin. The long elimination half-life of oritavancin compared to that of vancomycin did not result in a clinically meaningful delay to the onset or prolongation of adverse events. (This study has been registered at ClinicalTrials.gov under registration no. NCT01252719 and NCT01252732.).

The role of methicillin-resistant Staphylococcus aureus in skin and soft tissue infections

PURPOSE OF REVIEW

Methicillin-resistant Staphylococcus aureus (MRSA) has become a major public health issue worldwide over the last years. MRSA is frequently implicated in the development of skin and soft tissue infections, leading to significant increases in morbidity, mortality and overall healthcare costs.

RECENT FINDINGS

In order to face the threat of MRSA, major changes in clinical management of skin and soft tissue infections are required. The identification of populations at risk for the acquisition of infections due to MRSA, together with the improvement of the diagnostic techniques, is paramount. Moreover, a number of new antimicrobials with activity against MRSA have been recently developed and approved for the treatment of skin and soft tissue infections, however, the use of the new drugs in the wide clinical practice remains limited.

SUMMARY

We reviewed the current epidemiology of MRSA in skin and soft tissue infections, with particular focus on implications for clinical management. The potential role of new antibiotic options against MRSA infections is also discussed.

2018 WSES/SIS-E consensus conference: recommendations for the management of skin and soft-tissue infections

Skin and soft-tissue infections (SSTIs) encompass a variety of pathological conditions that involve the skin and underlying subcutaneous tissue, fascia, or muscle, ranging from simple superficial infections to severe necrotizing infections. SSTIs are a frequent clinical problem in surgical departments. In order to clarify key issues in the management of SSTIs, a task force of experts met in Bertinoro, Italy, on June 28, 2018, for a specialist multidisciplinary consensus conference under the auspices of the World Society of Emergency Surgery (WSES) and the Surgical Infection Society Europe (SIS-E). The multifaceted nature of these infections has led to a collaboration among general and emergency surgeons, intensivists, and infectious disease specialists, who have shared these clinical practice recommendations.

Management of acute bacterial skin and skin structure infections with a focus on patients at high risk of treatment failure

Over the last 25 years, the terminology of skin and soft tissue infections, as well as their classification for optimal management of patients, has changed. The so-called and recently introduced term 'acute bacterial skin and skin structure infections' (ABSSSIs), a cluster of fairly common types of infection, including abscesses, cellulitis, and wound infections, require an immediate effective antibacterial treatment as part of a timely and cautious management. The extreme level of resistance globally to many antibiotic drugs in the prevalent causative pathogens, the presence of risk factors of treatment failure, and the high epidemic of comorbidities (e.g. diabetes and obesity) make the appropriate selection of the antibiotic for physicians highly challenging. The selection of antibiotics is primarily empirical for ABSSSI patients which subsequently can be adjusted based on culture results, although rarely available in outpatient management. There is substantial evidence suggesting that inappropriate antibiotic treatment is given to approximately 20-25% of patients, potentially prolonging their hospital stay and increasing the risk of morbidity and mortality. The current review paper discusses the concerns related to the management of ABSSSI and the patient types who are most vulnerable to poor outcomes. It also highlights the key management time-points that treating physicians and surgeons must be aware of in order to achieve clinical success and to discharge patients from the hospital as early as possible.

A potential benefit from infectious disease specialist and stationary ward in rational antibiotic therapy of complicated skin and skin structure infections

BACKGROUND

Management practices of complicated skin and skin structure infections (cSSSI) were compared between two areas with similar healthcare structure and low prevalence of antimicrobial resistance.

METHODS

The high affinity to public health-care in the Nordic countries enabled population-based approach used in this retrospective study. The study population (n = 460) consisted of all adult residents from Helsinki (Finland) and Gothenburg (Sweden) treated in hospital due to cSSSI during 2008-2011.

RESULTS

The majority of patients in Helsinki (57%) visited more than one ward during their hospital stay while in Gothenburg the majority of patients (85%) were treated in one ward only. Background and disease characteristics were largely similar in both cities but patients in Helsinki were younger [mean(SD) 59(18) versus 63(19) years, p = .0117], and greater proportions had diabetes (50% versus 32%, p < .0001) and polymicrobial infections (34% versus 13%, p < .0001). Patients in Helsinki received antimicrobials with Gram-negative coverage (in initial therapy 96%) more frequently than in Gothenburg (47%, p < .0001), had more treatment modifications (mean 4.3 versus 2.7 antibiotic agents used per patient, p < .0001), and longer median duration of antimicrobial therapy (29 versus 12 days, p < .0001) and median length of hospital stay (17 versus 11 days, p < .0001).

CONCLUSIONS

This real-life study revealed remarkable differences in the management of cSSSI between the two Nordic cities. Compared to mainly Infectious Disease Specialist guided treatment in Gothenburg, the more frequent transfer from one ward to another in Helsinki was linked to longer antimicrobial therapy and hospital stay and to more frequent changes in antimicrobial treatment.

Future trends in the treatment of methicillin-resistant Staphylococcus aureus (MRSA) infection: An in-depth review of newer antibiotics active against an enduring pathogen

Methicillin-resistant Staphylococcus aureus (MRSA) continues to be a major public health problem. Vancomycin and teicoplanin have been in clinical use for several decades but their drawbacks are well described. In the last 10 years, several antibiotics have been made available for clinical use. Daptomycin and linezolid have been extensively used during this period. Other agents such as ceftaroline, ceftobiprole, dalbavancin, oritavancin, tedizolid and telavancin have been approved by regulatory agencies since 2009. Many others, such as the newer tetracyclines, fluoroquinolones, oxazolidinones and pleuromutilins, are in various stages of development. In addition, an ongoing multicentre trial is investigating the role of combination of vancomycin or daptomycin with β-lactam antibiotics. This review discusses the role of the newer antibiotics, reflecting the views of the 6th MRSA Consensus Conference meeting of the International Society of Chemotherapy MRSA Working Group that took place in 2016.

Clinical efficacy of piperacillin/tazobactam in the treatment of complicated skin and soft tissue infections

INTRODUCTION

Complicated skin and soft tissue infections (cSSTIs) are skin and soft tissue infections (SSTIs) that involve deep soft tissue. cSSTIs often require surgical intervention and/or hospitalization. cSSTIs are associated with significant mortality and morbidity, and carry a significant burden on health care systems. Piperacillin/tazobactam has been regarded as a standard treatment for cSSTIs because of its antibiotic spectrum, safety and clinical efficacy. Several antibiotics, as compared to piperacillin/tazobactam, have been evaluated in the treatment of cSSTIs. Areas covered: This review summarizes randomized controlled trials (RCTs) evaluating the clinical efficacy of piperacillin/tazobactam for the treatment of cSSTIs. Expert opinion: Piperacillin/tazobactam, which covers most causative organisms in cSSTIs, is the drug of choice for the treatment of cSSTIs. Other options such as ertapenem and moxifloxacin may be reasonable where multiple daily dosing or intravenous administration is inappropriate. But in general, they should be avoided as an empirical treatment because of their highly association with resistant bacteria, which are becoming a global threat. Therefore, piperacilin/tazobactam is appropriate as an empirical therapy for the treatment of SSTIs and should be de-escalated as soon as causative organisms are identified, their drug-sensitivity results are available, and clinical condition becomes stable.