Staphylococcus aureus (S. aureus) has proven to be a major pathogen with the emergence of methicillin-resistant S. aureus (MRSA) infections and recently with heteroresistant vancomycin-intermediate S. aureus (hVISA) and vancomycin-intermediate S. aureus (VISA) infections. Although vancomycin is traditionally a first-line and relatively effective antibiotic, its continued use is under question b...

We assessed all episodes of methicillin-resistant Staphylococcus aureus (MRSA) bacteremia at our hospital during a 12-month period (n=53) and compared those due to heterogeneous vancomycin-intermediate S. aureus (hVISA; n = 5, 9.4%) with those due to vancomycin-susceptible MRSA (n=48). Patients with hVISA bacteremia were more likely to have high bacterial load infections (P=.001), vancomycin tr...

The prevalence of heterogeneous vancomycin-intermediate Staphylococcus aureus (hVISA) infections varies in the literature, a problem complicated by the lack of routine screening procedures; however, limited data suggest that hVISA has been associated with persistent bloodstream infections (BSI) and vancomycin failure, yet these studies have been confounded by design issues. We conducted this st...

To investigate the prevalence of Staphylococcus aureus with reduced susceptibility to vancomycin among methicillin-resistant S. aureus (MRSA) strains in Asian countries, a total of 1,357 clinical isolates of MRSA collected from 12 Asian countries were screened by using brain heart infusion agar plates containing 4 mg of vancomycin per liter. The presence of strains that were heterointermediatel...

INTRODUCTION Continued pressure from glycopeptide use has led to non-susceptible strains of Staphylococcus aureus including heterogeneously vancomycin-intermediate S. aureus (hVISA). Infections with hVISA are associated with poor patient outcomes, thus incentivizing novel treatments. Evidence suggests that vancomycin and anti-staphylococcal penicillin susceptibility are inversely related which ...

OBJECTIVES We compared the clinical characteristics and outcomes of, and the bacterial genotypes in, patients with bacteraemia due to heteroresistant vancomycin-intermediate Staphylococcus aureus (hVISA) and vancomycin-susceptible S. aureus (VSSA). METHODS A total of 268 consecutive patients with methicillin-resistant S. aureus (MRSA) bacteraemia were prospectively enrolled. All isolates were...

Vancomycin remains the mainstay treatment for methicillin-resistant Staphylococcus aureus (MRSA) infections, including pneumonia. There is concern regarding the emergence of vancomycin tolerance, caused by heterogeneous vancomycin-intermediate S. aureus (hVISA), and subsequent vancomycin treatment failure. Pneumonia is associated with high morbidity and mortality, especially with delays in appr...

Questions regarding the prevalence and clinical significance of both vancomycin-intermediate Staphylococcus aureus (VISA) and, more importantly, heterogeneous VISA (hVISA) are difficult to address, mainly due to the lack of accurate methods and guidelines for the identification of hVISA. VISA strains have been isolated from many areas of the world but are few in number ( 30); however, hVISA str...

BACKGROUND In vitro data suggests that suboptimal initial vancomycin exposure may select for heterogeneous vancomycin-intermediate Staphylococcus aureus (hVISA) infections. However, no clinical studies have evaluated the relationship between initial vancomycin exposure and emergence of hVISA. This pilot study seeks to assess the relationship between day 1 and day 2 vancomycin area under the cur...

Low-level vancomycin-resistant Staphylococcus aureus (vancomycin-intermediate S. aureus [VISA] and heterogenous VISA [hVISA]) is increasingly reported and leads to glycopeptide treatment failure. Various phenotypic features have been reported for these isolates, but the genetic changes leading to hVISA and VISA have yet to be clearly determined. We assessed phenotypic, antibiotic resistance, an...