BACKGROUND This study assessed the pharmacodynamics of ceftaroline against methicillin-resistant Staphylococcus aureus (MRSA), heteroresistant (h) vancomycin-intermediate S. aureus (hVISA), VISA and vancomycin-resistant S. aureus (VRSA) using an in vitro model. METHODS Two methicillin-susceptible S. aureus (MSSA), one community-associated (CA)-MRSA, one healthcare-associated (HA)-MRSA, one hV...

This study analyzed clinical and microbiological characteristics of heteroresistant (hVISA) and vancomycin-intermediate Staphylococcus aureus (VISA) from bloodstream infections (BSI) in a Brazilian teaching hospital, between 2011 and 2013. Minimum inhibitory concentrations (MIC) of antimicrobials were determined by broth microdilution method and SCCmec was detected by PCR. Isolates with a vanco...

BACKGROUND Staphylococcus aureus is one of most common pathogens in humans. Methicillin-resistant S. aureus (MRSA) accounts for 64 % of S. aureus bacteremia isolated in intensive care units (ICUs), and heteroresistant vancomycin-intermediates S. aureus (hVISA) is a phenotype of MRSA. However, studies focusing on the hVISA impact on critically ill patients are scarce. METHODS This was a retros...

Heterogeneous vancomycin-intermediate Staphylococcus aureus (hVISA) clinical strain Mu3 spontaneously generates VISA strains at an extremely high frequency (≥1×10(-6)). The generated VISA strains usually grow more slowly than does the parent hVISA strain, but they form colonies on vancomycin-containing agar plates before 48 h of incubation. However, we noticed a curious group of VISA strains, d...

The emergence of vancomycin intermediate Staphylococcus aureus (VISA) and heterogeneous VISA (hVISA) is of major concern worldwide. Our objective was to investigate the prevalence, phenotypic and molecular features of hVISA strains isolated from bacteremic patients and to determine the clinical significance of the hVISA phenotype in patients with bacteremia. A total of 104 S. aureus blood isola...

OBJECTIVES We investigated vancomycin-intermediate Staphylococcus aureus (VISA) and heterogeneously vancomycin-intermediate S. aureus (hetero-VISA) isolates from clinical specimens of hospitalized patients at Hacettepe University over a 4 year period. METHODS Strains were screened for VISA and hetero-VISA by using brain heart infusion agar containing 4 mg/L vancomycin (BHI-V4) and macro Etest...

Although methicillin (meticillin)-resistant Staphylococcus aureus (MRSA) strains with reduced susceptibility to vancomycin (RVS-MRSA; including vancomycin-intermediate S. aureus [VISA] and heterogeneous VISA [hVISA]) have been linked with vancomycin treatment failure, it is unclear whether they are more pathogenic than vancomycin-susceptible MRSA (VS-MRSA). We prospectively assessed patients wi...

There have been conflicting data about the interactions between vancomycin and beta-lactam agents against Staphylococcus aureus strains with heterogeneous resistance to vancomycin. We evaluated the efficacy of these combinations against Mu 3 and heterogeneously vancomycin-resistant S. aureus (hetero-VRSA) strains which were isolated from Korean patients using a population analysis method. Antag...

The first heterogeneously vancomycin-intermediate Staphylococcus aureus (hVISA) isolates to be identified in Poland were characterized. They were recovered in two Warsaw hospitals and, although in one of these the identification coincided with unsuccessful glycopeptide therapy, the selection conditions and clinical significance of the organisms remain unclear. Molecular typing revealed that the...

Beta-lactams enhance the killing activity of vancomycin. Due to structural and mechanistic similarities between vancomycin and telavancin, we investigated the activity of telavancin combined with nafcillin and imipenem compared to the known synergistic combination of telavancin and gentamicin. Thirty strains of Staphylococcus aureus, 10 methicillin-susceptible S. aureus (MSSA), 10 methicillin-r...