Comparative healthcare-associated costs of methicillin-resistant Staphylococcus aureus bacteraemia-infective endocarditis treated with either daptomycin or vancomycin

In silico exploration of 4(α-l-rhamnosyloxy)-benzyl isothiocyanate: A promising phytochemical-based drug discovery approach for combating multi-drug resistant Staphylococcus aureus

Multidrug-resistant (MDR) Staphylococcus aureus infections significantly threaten global health. With rising resistance to current antibiotics and limited solutions, the urgent discovery of new, effective, and affordable antibacterials with low toxicity is imperative to combat diverse MDR S. aureus strains. Hence, in this study, we introduce an in silico phytochemical-based approach for discovering novel antibacterial agents, underscoring the potential of computational approaches in therapeutic discovery. Glucomoringin Isothiocyanate (GMG-ITC) from Moringa oleifera Lam. is one of the phytochemical compounds with several biological activities, including antimicrobial, anti-inflammatory, and antioxidant activities, and is also effective against S. aureus. This study focuses on screening GMG-ITC as a potential drug candidate to combat MDR S. aureus infections through a molecular docking approach. Moreover, interaction amino acid analysis, in silico pharmacokinetics, compound target prediction, pathway enrichment analysis and molecular dynamics (MD) simulations were conducted for further investigation. Molecular docking and interaction analysis showed strong binding affinity towards S. aureus lipase, dihydrofolate reductase, and other MDR S. aureus proteins, including penicillin-binding protein 2a, MepR, D-Ala:D-Ala ligase, and RPP TetM, through hydrophilic and hydrophobic interactions. GMG-ITC also showed a strong binding affinity to cyclooxygenase-2 and FAD-dependent NAD(P)H oxidase, suggesting that it is a potential anti-inflammatory and antioxidant candidate that may eliminate inflammation and oxidative stress associated with S. aureus infections. MD simulations validated the stability of the GMG-ITC molecular interactions determined by molecular docking. In silico pharmacokinetic analysis highlights its potency as a drug candidate, showing strong absorption, distribution, and excretion properties in combination with low toxicity. It acts as an active protease and enzyme inhibitor with moderate activity against GPCR ligands, ion channels, nuclear receptor ligands, and kinases. Enrichment analysis further elucidated its involvement in important biological, molecular, and cellular functions with potential therapeutic applications in diseases like cancer, hepatitis B, and influenza. Results suggest that GMG-ITC is an effective antibacterial agent that could treat MDR S. aureus-associated infections.

Phytochemicals with activity against methicillin-resistant Staphylococcus aureus

BACKGROUND

The evolution of resistance to antimicrobials is a ubiquitous phenomenon. The evolution of antibiotic resistance in Staphylococcus aureus suggests that there is no remedy with sustaining effectiveness against this pathogen. The limited number of antibacterial drug classes and the common occurrence of cross-resistant bacteria reinforce the urgent need to discover new compounds targeting novel cellular functions. Natural products are a potential source of novel antibacterial agents. Anti-MRSA (methicillin-resistant S. aureus) bioactive compounds from Streptomyces and the anti-MRSA activity of a series of plant extracts have been reviewed respectively. However, there has been no detailed review of the precise bioactive components from plants.

PURPOSE

The present review aimed to summarize the phytochemicals that have been reported with anti-MRSA activities, analyze their structure-activity relationship and novel anti-MRSA mechanisms.

METHODS

Data contained in this review article are compiled from the authoritative databases PubMed, Web of Science, Google Scholar, and so on.

RESULTS

This review summarizes 100 phytochemicals (27 flavonoids, 23 alkaloids, 17 terpenes and 33 others) that have been tested for their anti-MRSA activity. Among these phytochemicals, 39 compounds showed remarkable anti-MRSA activity with MIC values less than 10 μg/ml, 14 compounds with MIC ranges including values < 10 μg/ml, 5 compounds with MIC values less than 5 μM; 11 phytochemicals show synergism anti-MRSA effects in combination with antibiotics. Phytochemicals exerted anti-MRSA activities mainly by destroying the membrane structure and inhibiting the efflux pump.

CONCLUSIONS

The 58 compounds with excellent anti-MRSA activity the 11 compounds with synergistic anti-MRSA effect, especially cannabinoids, xanthones and fatty acids should be further studied in vitro. Novel targets, such as cell membrane and efflux pump could be promising alternatives to develop antibacterial drugs in the future in order to prevent drug resistance.

Exploratory Cost-Effectiveness Analysis for Treatment of Methicillin-Resistant Staphylococcus aureus Bloodstream Infections: Is Linezolid or Daptomycin Favored Over Vancomycin?

BACKGROUND AND OBJECTIVE

Methicillin-resistant Staphylococcus aureus bloodstream infections (MRSAB) cause significant mortality, and often require extended antibiotic therapy. Vancomycin, the most common initial MRSAB treatment, carries significant monitoring burden and nephrotoxicity risks. Our objective was to compare the cost-effectiveness of vancomycin and other antibiotic regimens against MRSAB.

METHODS

We estimated the cost-effectiveness of intravenous antibiotics (vancomycin, daptomycin, linezolid, ceftaroline/daptomycin) for Veterans Health Administration patients with MRSAB using an exploratory decision-tree model. Primary effectiveness outcome was composite of microbiological failure at 7 days and adverse drug event (ADE)-related discontinuation after at least 7 days.

RESULTS

In base-case analyses, intravenous linezolid was the least expensive regimen at 4 and 6 weeks. Daptomycin was more expensive and more effective than linezolid, with an incremental cost-effectiveness ratio (ICER) of ~$13,000 (4 weeks) per composite failure avoided. With 6 weeks of treatment, daptomycin was more expensive and more effective than vancomycin (ICER ~$21,000 per composite failure avoided). Vancomycin and ceftaroline/daptomycin were dominated strategies at both 4 and 6 weeks. In one-way sensitivity analyses, vancomycin was favored when its microbiological failure risk was less than 20.1% (base-case: 27.2%), assuming a willingness to pay (WTP) threshold of $40,000/composite treatment failure avoided. In two-way sensitivity analyses, intravenous linezolid was favored if linezolid microbiological failure and ADE-related discontinuation rates were < 22.5% and < 17.3%, respectively. Daptomycin, vancomycin, and linezolid were favored in 50%, 31%, and 17% of 4-week probabilistic iterations, respectively, at $40,000 WTP.

CONCLUSION

Daptomycin is likely less expensive and more effective than vancomycin or other initial regimens for MRSAB. More data are needed on the safety of linezolid against MRSAB.

High-Dose Daptomycin and Clinical Applications

OBJECTIVE

To evaluate evidence for high-dose daptomycin (doses ≥ 8 mg/kg/d).

DATA SOURCES

A PubMed/MEDLINE literature search was performed (January 2000 to December 2020) using the search terms daptomycin, high dose, and dosing. Review article references and society guidelines were reviewed.

STUDY SELECTION AND DATA EXTRACTION

Clinical trials, observational studies, retrospective studies, meta-analyses, and systematic reviews reporting on high-dose daptomycin were included.

DATA SYNTHESIS

Experimentally, daptomycin outperforms other antimicrobials for high inoculum and biofilm-associated infections. Clinically, high-dose daptomycin is supported as salvage and first-line therapy for endocarditis and bacteremia, primarily when caused by methicillin-resistant Staphylococcus aureus (when vancomycin minimum inhibitory concentration is >1 mg/L) and Enterococcus. High-dose daptomycin appears effective for osteomyelitis and central nervous system infections, although comparative studies are lacking. High dosing in renal replacement therapy requires considering clearance modality to achieve exposures like normal renal function. Weight-based dosing in obesity draws concern for elevated exposures, although high doses have not been evaluated kinetically in obesity. Some data show benefits of high doses in overweight populations. Burn patients clear daptomycin more rapidly, and high doses may only achieve drug exposures similar to standard doses (6 mg/kg).

RELEVANCE TO PATIENT CARE AND CLINICAL PRACTICE

This review analyzes the efficacy and safety of high-dose daptomycin in serious gram-positive infections. Discussion of specific infectious etiologies and patient populations should encourage clinicians to evaluate their daptomycin dosing standards.

CONCLUSIONS

The efficacy of high-dose daptomycin and limited safety concerns encourage clinicians to consider high-dose daptomycin more liberally in severe gram-positive infections.

Assessing the Role of Daptomycin as Antibiotic Therapy for Staphylococcal Prosthetic Joint Infection

Background: The role of daptomycin, a potent, safe, convenient anti-staphylococcal antibiotic, in treatment of prosthetic joint infection (PJI) is unclear. We evaluated our experience with the largest cohort of patients with staphylococcal PJI managed with daptomycin. Methods: A cohort of staphylococcal hip and knee PJI treated with daptomycin was identified by hospital records from 2009 to 2016. All cases met Musculoskeletal Infection Society International Consensus criteria for PJI. The primary endpoint was 2 year prosthesis retention. Univariate analyses and regression statistics were calculated. Results: 341 patients with staphylococcal PJI were analyzed. 154 two-stages (77%) and 74 DAIR procedures (52%) met criteria for treatment success at 2 years. 77 patients were treated with daptomycin, of which 34 two-stages (68%) and 15 DAIRs (56%) achieved treatment success. Pairwise and regression analysis found no association between treatment success and daptomycin use. Organism (DAIR only) and Charlson Comorbidity Index scores (DAIR and two-stage) were significantly associated with treatment outcome. Six daptomycin patients (7.8%) had adverse side effects. Discussion: Daptomycin fared no better or worse than comparable antibiotics in a retrospective cohort of staphylococcal hip and knee PJI patients, regardless of surgical strategy. Conclusion: The convenient dosing, safety, and potency of daptomycin make it an attractive antibiotic for staphylococcal PJI. However, these advantages must be weighed against higher costs and rare, but serious side effects.

Economic evaluation of the treatment of Acute Bacterial Skin and Skin Structure Infections (ABSSSIs) from the national payer perspective: introduction of a new treatment to the patient journey. A simulation of three European countries

Background: The aim of this study was to develop a spending predictor model to evaluate the direct costs associated with the management of ABSSSIs from the National health-care provider's perspective of Italy, Romania, and Spain. Methodology: A decision-analytic model was developed to evaluate the diagnostic and clinical pathways of hospitalized ABSSSI patients based on scientific guidelines and real-world data. A Standard of Care (SoC) scenario was compared with a dalbavancin scenario in which the patients could be discharged early. The epidemiological and cost parameters were extrapolated from national administrative databases (i.e., hospital information system). A probabilistic sensitivity analysis (PSA) and one-way sensitivity analysis (OWA) were performed. Results: Overall, the model estimated an average annual number of patients with ABSSSIs of approximately 50,000 in Italy, Spain, and Romania. On average, the introduction of dalbavancin reduced the length of stay by 3.3 days per ABSSSI patient. From an economic perspective, dalbavancin did not incur any additional cost from the National Healthcare perspective, and the results were consistent among the countries. The PSA and OWA demonstrated the robustness of these results. Conclusion: This model represents a useful tool for policymakers by providing information regarding the economic and organizational consequences of an early discharge approach in ABSSSI management.