ABSTRACT
This review is the result of discussions that took place at the 5th MRSA Working Group Consensus Meeting and explores the possible treatment options available for different types of infections due to methicillin-resistant Staphylococcus aureus (MRSA), focusing on those antibiotics that could represent a valid alternative to vancomycin. In fact, whilst vancomycin remains a viable option, its therapy is moving towards individualised dosing. Other drugs, such as the new lipoglycopeptides (oritavancin, dalbavancin and telavancin) and fifth-generation cephalosporins (ceftaroline and ceftobiprole), are showing good in vitro potency and in vivo efficacy, especially for patients infected with micro-organisms with higher vancomycin minimum inhibitory concentrations (MICs). Tedizolid is an attractive agent for use both in hospital and community settings, but the post-marketing data will better clarify its potential. Daptomycin and linezolid have shown non-inferiority to vancomycin in the treatment of MRSA bacteraemia and non-inferiority/superiority to vancomycin in the treatment of hospital-acquired pneumonia. Thus, several options are available, but more data from clinical practice, especially for invasive infections, are needed to assign specific roles to each antibiotic and to definitely include them in the new antibacterial armamentarium.
Subject(s)
Anti-Bacterial Agents/therapeutic use , Methicillin-Resistant Staphylococcus aureus/drug effects , Staphylococcal Infections/drug therapy , Daptomycin/therapeutic use , Humans , Linezolid/therapeutic use , Vancomycin/therapeutic useABSTRACT
Successful meticillin-resistant Staphylococcus aureus (MRSA) clones have evolved to adapt to healthcare, community and livestock environments. This review will bring together recent studies into clone adaptation and the importance of genes acquired during horizontal gene transfer to survival in specific environments. It will also discuss the role of global regulators controlling virulence gene expression and resistance to antibiotics, such as the agr and vraRS systems. Understanding these processes in successful clones could reveal novel targets for therapeutic agents, which are urgently required to reduce the infection burden and improve treatment options.
ABSTRACT
Central venous catheters are indispensable for the long-term treatment of seriously and chronically ill patients, but their use is often associated with a variety of complications; indeed, 90% of primary bloodstream infections are related to patients having a catheter. In studies performed in France, Germany and Italy, meticillin-resistant Staphylococcus aureus (MRSA) accounted for >50% of all S. aureus isolates obtained in catheter-related bloodstream infections (CRBSIs). These infections have a serious impact on long-term disability of the patient, a substantial additional financial burden for health systems, and high costs for patients. Decreasing the rate of CRBSIs requires a multidisciplinary approach, including behavioural and educational interventions and the insertion of the correct type of catheter. Although vancomycin remains the cornerstone of empirical therapy for CRBSIs caused by MRSA, combination of different antimicrobials and new approaches are indispensable to enhance the eradication of S. aureus biofilms and to manage the patient appropriately.
ABSTRACT
We assessed a new screening method, based on δ-hemolysin production in the presence of 6 mg/liter vancomycin, to distinguish heteroresistant vancomycin-intermediate Staphylococcus aureus (hVISA) and vancomycin-intermediate S. aureus (VISA) from vancomycin-susceptible S. aureus (VSSA). On 37 clinical methicillin-resistant S. aureus (MRSA) isolates, hVISA and VISA displayed no δ-hemolysis whereas VSSA displayed strong δ-hemolysis, showing 91.6% sensitivity. These data, supported by real-time reverse transcription PCR (real-time RT-PCR) highlighting an hld downregulation, i.e., VSSA>hVISA>VISA, define this new assay as a valid screening method.
