Alternative clinical indications for novel antibiotics licensed for skin and soft tissue infection?

Left ventricular assist device-associated driveline infections as a specific form of complicated skin and soft tissue infection/acute bacterial skin and skin structure infection - issues and therapeutic options

PURPOSE OF REVIEW

This review comments on the current guidelines for the treatment of wound infections under definition of acute bacterial skin and skin structure infections (ABSSSI). However, wound infections around a catheter, such as driveline infections of a left ventricular assist device (LVAD) are not specifically listed under this definition in any of the existing guidelines.

RECENT FINDINGS

Definitions and classification of LVAD infections may vary across countries, and the existing guidelines and recommendations may not be equally interpreted among physicians, making it unclear if these infections can be considered as ABSSSI. Consequently, the use of certain antibiotics that are approved for ABSSSI may be considered as 'off-label' for LVAD infections, leading to rejection of reimbursement applications in some countries, affecting treatment strategies, and hence, patients' outcomes. However, we believe driveline exit site infections related to LVAD can be included within the ABSSSI definition.

SUMMARY

We argue that driveline infections meet the criteria for ABSSSI which would enlarge the 'on-label' antibiotic armamentarium for treating these severe infections, thereby improving the patients' quality of life.

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.

Clinical Use and Adverse Drug Reactions of Linezolid: A Retrospective Study in Four Belgian Hospital Centers

In Belgium, linezolid is indicated for pneumonia and skin and soft tissue infections, but is more broadly used, due to its oral bioavailability and activity against multiresistant organisms. This could increase the risk of adverse drug reactions (ADR), notably hematological disorders (anemia, thrombocytopenia), neuropathy, or lactic acidosis. We analyzed linezolid clinical use in relationship with occurrence of ADR in Belgian hospitals and highlighted risk factors associated with the development of thrombocytopenia. A retrospective analysis of electronic medical records and laboratory tests of adult patients treated with linezolid in four Belgian hospitals in 2016 allowed the collection of ADR for 248 linezolid treatments. Only 19.7% of indications were in-label. ADR included 43 thrombocytopenia, 17 anemia, 4 neuropathies, and 4 increases in lactatemia. In a multi-variate analysis, risk factors of thrombocytopenia were a treatment duration > 10 days, a glomerular filtration rate < 60 mL/min, and a Charlson index ≥ 4. Off-label use of linezolid is frequent in Belgium, and ADR more frequent than reported in the summary of product characteristics, but not statistically associated with any indication. This high prevalence of ADR could be related to a high proportion of patients presenting risk factors in our population, highlighting the importance of detecting them prospectively.

Linezolid use in German acute care hospitals: results from two consecutive national point prevalence surveys

Background

Linezolid belongs to a reserve group of antibiotics. In recent years, reports on linezolid resistance in gram-positive cocci have become more frequent. Overuse of linezolid is a relevant factor for resistance development. The objective of this study was to describe current prescription practices of linezolid in German hospitals and identify targets for antimicrobial stewardship interventions.

Methods

We analyzed all linezolid prescriptions from the datasets of the consecutive national point prevalence surveys performed in German hospitals in 2011 and 2016. In both surveys, data on healthcare-associated infections and antimicrobial use were collected following the methodology of the European Centre for Disease Prevention and Control.

Results

Overall, the percentage of linezolid among all documented antimicrobials increased significantly from 2011 to 2016 (p < 0.01). In 2011, 0.3% (119 of 41,539) patients received linezolid, in 2016 this proportion was significantly higher (0.4%; 255 of 64,412 patients; p < 0.01). In 2016, intensive care units (ICUs) were the wards most frequently prescribing linezolid. The largest proportion of patients receiving linezolid were non-ICU patients. Roughly 38% of linezolid prescriptions were for treatment of skin/soft tissue and respiratory tract infections. In 2016, linezolid was administered parenterally in 70% (n = 179) of cases. Multivariable analysis showed that the ward specialty ICU posed an independent risk factor, while Northern and Southwestern regions in Germany were independent protective factors for a high rate of linezolid prescriptions.

Conclusions

In conclusion, we detected potentials for improving linezolid prescription practices in German hospitals. Given the emergence of linezolid resistance, optimization of linezolid use must be a target of future antimicrobial stewardship activities.

A sequence symmetry analysis of the interrelationships between statins, diabetes and skin infections

AIMS

To determine statins' impact on skin infection risk in view of conflicting literature: that statins may reduce infection risk, but are also associated with diabetes mellitus, a risk factor for skin and soft tissue infections (SSTIs).

METHODS

Sequence symmetry analysis was performed on prescription claims (2001-2011) from the Australian Department of Veterans' Affairs to determine the interrelationships between: (i) statins and SSTIs; (ii) statins and diabetes; and (iii) diabetes and SSTIs; as well as whether statins increased the risk of SSTIs, independent of diabetes status. Chi-square tests were performed to detect differences in Index of Relative Socio-economic Advantage and Disadvantage scores of patients within each interrelationship. Prescriptions for statins, antidiabetic medication, and antistaphylococcal antibiotics were evaluated using nonidentifiable client numbers, prescription dates filled, residential electorates, and pharmaceutical codes. Adjusted sequence ratio and confidence interval were calculated at intervals of 91, 182 and 365 days for sequence symmetry analysis studies.

RESULTS

Statins were associated with: (i) significant SSTI risk (adjusted sequence ratio > 1; confidence interval >1), (ii) significant diabetes risk, and (iii) diabetic patients had increased risk of SSTIs. Diabetic and nondiabetic statin users had significantly increased risks of SSTIs, while the influence from socioeconomic status was not significant for each of the 3 relationships.

CONCLUSIONS

Statins are associated with increased risk of SSTIs via direct and indirect mechanisms, probably independent of diabetes or socioeconomic statuses. We believe that clinicians should be aware of the association between statins and SSTIs, and, where appropriate, monitor blood glucose levels of statin users.

Antimicrobial and antibiofilm activity of polyurethane/Hypericum perforatum extract (PHPE) composite

Microbial accumulation in materials used in sectors such as medical, textile and food can lead to serious diseases, infections and uncontrollable problems. Many of the materials used in the above-mentioned industries have highly sensitive surfaces for microorganisms and cause colonization and biofilm formation. Colonization and biofilm formation threaten human health and they cause many diseases that result in death every year. Antimicrobial materials have an important role in combating pathogens. This article is about a new material with antibiofilm and antimicrobial properties combining polyurethane and Hypericum perforatum extract (PHPE) together. Antimicrobial effect of H. perforatum extract was determined against three clinical pathogens; C. albicans, E. coli and S. aureus. The highest antimicrobial activity of H. perforatum extract was found against S. aureus strain. Antibiofilm analysis results revealed that H. perforatum was also inhibited by the biofilm formation of S. aureus by 56.85%. The combination of polyurethane material and H. perforatum extract (PHPE) resulted in 92.85% decrease in S. aureus biofilm compared to control group. The reduction of S. aureus after H. perforatum incorporation was revealed by Scanning Electron Microscopy (SEM) study. The results show that the polyurethane material combined with H. perforatum extract inhibits the formation of S. aureus biofilm.

Risk factors for amendment in type, duration and setting of prescribed outpatient parenteral antimicrobial therapy (OPAT) for adult patients with cellulitis: a retrospective cohort study and CART analysis

PURPOSE OF THE STUDY

To measure the percentage rate and risk factors for amendment in the type, duration and setting of outpatient parenteral antimicrobial therapy (OPAT) for the treatment of cellulitis.

STUDY DESIGN

A retrospective cohort study of adult patients receiving OPAT for cellulitis was performed. Treatment amendment (TA) was defined as hospital admission or change in antibiotic therapy in order to achieve clinical response. Multivariable logistic regression (MVLR) and classification and regression tree (CART) analysis were performed.

RESULTS

There were 307 patients enrolled. TA occurred in 36 patients (11.7%). Significant risk factors for TA on MVLR were increased age, increased Numerical Pain Scale Score (NPSS) and immunocompromise. The median OPAT duration was 7 days. Increased age, heart rate and C reactive protein were associated with treatment prolongation. CART analysis selected age <64.5 years, female gender and NPSS <2.5 in the final model, generating a low-sensitivity (27.8%), high-specificity (97.1%) decision tree.

CONCLUSIONS

Increased age, NPSS and immunocompromise were associated with OPAT amendment. These identified risk factors can be used to support an evidence-based approach to patient selection for OPAT in cellulitis. The CART algorithm has good specificity but lacks sensitivity and is shown to be inferior in this study to logistic regression modelling.

New agents approved for treatment of acute staphylococcal skin infections

Vancomycin has been a predominant treatment for methicillin-resistant Staphylococcus aureus (MRSA) infections for decades. However, growing reservations about its efficacy led to an urgent need for new antibiotics effective against MRSA and other drug-resistant Staphylococcus aureus strains. This review covers three new anti-MRSA antibiotics that have been recently approved by the FDA: dalbavancin, oritavancin, and tedizolid. The mechanism of action, indications, antibacterial activity profile, microbial resistance, pharmacokinetics, clinical efficacy, adverse effects, interactions as well as available formulations and administration of each of these new antibiotics are described. Dalbavancin is a once-a-week, two-dose, long-acting intravenous bactericidal lipoglycopeptide antibiotic. Oritavancin, a lipoglycopeptide with bactericidal activity, was developed as a single-dose intravenous treatment for acute bacterial skin and skin-structure infections (ABSSSI), which offers simplifying treatment of infections. Tedizolid is an oxazolidinone-class bacteriostatic once-daily agent, available for intravenous as well as oral use. Increased ability to overcome bacterial resistance is the main therapeutic advantage of the novel agents over existing antibiotics.

Efficacy and safety of daptomycin for skin and soft tissue infections: a systematic review with trial sequential analysis

Background

Skin and soft tissue infections (SSTIs) are significant indications for antibiotic treatment. Daptomycin, a novel antibiotic, has been registered and licensed to be used in the treatment of these infections. However, its efficacy and safety remain controversial.

Objective

The objective of this study was to conduct a systematic review with trial sequential analysis (TSA) to evaluate the efficacy and safety of daptomycin for the treatment of SSTIs and to analyze whether the available sample size has been large enough and is conclusive.

Methods

PubMed, the Cochrane Library, and EMBASE were searched for published randomized controlled trials (RCTs) that compared daptomycin with other antibiotics in adult patients with SSTIs up to February 2016.

Results

This meta-analysis included eight randomized controlled trials (n=2,002). There was no difference in either the clinical success rate (intention-to-treat population: relative risk [RR] =1.04, 95% confidence interval [CI] =0.99–1.10, P=0.12; clinically evaluable population: RR =1.00, 95% CI =0.97–1.04, P=0.82) or the microbiological success rate (RR =1.00, 95% CI =0.95–1.06, P=0.92) between the daptomycin and comparator groups for treating SSTIs, which was confirmed by TSA. Compared with vancomycin, daptomycin exhibited no advantage in increasing the clinical success rate (RR =1.03, 95% CI =0.95–1.13, P=0.47), and this was also confirmed by TSA. All-cause mortality, overall treatment-related adverse events, and creatine phosphokinase events were similar between these two groups.

Conclusion

Daptomycin and comparator drugs are equally efficacious with regard to clinical and microbiological success for patients with SSTIs, and TSA showed that no additional randomized controlled trials are required. Although daptomycin is a good alternative when other antibiotics are contraindicated for patients with SSTIs and it can serve as a first-line treatment for SSTIs, clinicians should be aware of potential adverse events, such as daptomycin-induced acute eosinophilic pneumonia and creatine phosphokinase, when treating patients with daptomycin.

Recent Advances in Antimicrobial Polymers: A Mini-Review

Human safety and well-being is threatened by microbes causing numerous infectious diseases resulting in a large number of deaths every year. Despite substantial progress in antimicrobial drugs, many infectious diseases remain difficult to treat. Antimicrobial polymers offer a promising antimicrobial strategy for fighting pathogens and have received considerable attention in both academic and industrial research. This mini-review presents the advances made in antimicrobial polymers since 2013. Antimicrobial mechanisms exhibiting either passive or active action and polymer material types containing bound or leaching antimicrobials are introduced. This article also addresses the applications of these antimicrobial polymers in the medical, food, and textile industries.

Hot topics in the diagnosis and management of skin and soft-tissue infections

Eighteen hot topics regarding the diagnosis and management of skin and soft-tissue infections (SSTIs) were selected and reviewed by members of the SSTI Working Group of the International Society of Chemotherapy (ISC). Despite the large amount of literature available on the issue selected, there are still many unknowns with regard to many of them and further studies are required to answer these challenging issues that face clinicians on a daily basis.

Linezolid susceptibility in Helicobacter pylori, including strains with multidrug resistance

Only a few studies have evaluated Helicobacter pylori susceptibility to linezolid. The aim of the present study was to assess linezolid susceptibility in H. pylori, including strains with double/multidrug resistance. The susceptibility of 53 H. pylori strains was evaluated by Etest and a breakpoint susceptibility testing method. Helicobacter pylori resistance rates were as follows: amoxicillin, 1.9%; metronidazole, 37.7%; clarithromycin, 17.0%; tetracycline, 1.9%; levofloxacin, 24.5%; and linezolid (>4 mg/L), 39.6%. The linezolid MIC50 value was 31.2-fold higher than that of clarithromycin and 10.5-fold higher than that of levofloxacin; however, 4 of 11 strains with double/multidrug resistance were linezolid-susceptible. The MIC range of the oxazolidinone agent was larger (0.125-64 mg/L) compared with those in the previous two reports. The linezolid resistance rate was 2.2-fold higher in metronidazole-resistant strains and in strains resistant to at least one antibiotic compared with the remaining strains. Briefly, linezolid was less active against H. pylori compared with clarithromycin and levofloxacin, and linezolid resistance was linked to resistance to metronidazole as well as to resistance to at least one antibiotic. However, linezolid activity against some strains with double/multidrug resistance may render the agent appropriate to treat some associated H. pylori infections following in vitro susceptibility testing of the strains. Clinical trials are required to confirm this suggestion.