Willem van Schaik

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UNLABELLED Enterococcus faecium has recently emerged as an important multiresistant nosocomial pathogen. Defining population structure in this species is required to provide insight into the existence, distribution, and dynamics of specific multiresistant or pathogenic lineages in particular environments, like the hospital. Here, we probe the population(More)
BACKGROUND Hospital strains of Enterococcus faecium could be characterized and typed by various molecular methods (MLST, AFLP, MLVA) and allocated to a distinct clonal complex known as MLST CC17. However, these techniques are laborious, time-consuming and cost-intensive. Our aim was to identify hospital E. faecium strains and differentiate them from(More)
Log-phase Listeria monocytogenes cells become tolerant to a variety of environmental stresses following acid adaptation at pH 5.5. We demonstrated that adapted cells also exhibit increased tolerance to nisin and, to a lesser extent, lacticin 3147. At nisin concentrations of 100 and 200 IU/ml the survival of acid-adapted cells was approximately 10-fold(More)
The Gram-positive bacterium Enterococcus faecium is an important cause of nosocomial infections in immunocompromized patients. We present a pyrosequencing-based comparative genome analysis of seven E. faecium strains that were isolated from various sources. In the genomes of clinical isolates several antibiotic resistance genes were identified, including(More)
Third-generation cephalosporins are a class of β-lactam antibiotics that are often used for the treatment of human infections caused by Gram-negative bacteria, especially Escherichia coli. Worryingly, the incidence of human infections caused by third-generation cephalosporin-resistant E. coli is increasing worldwide. Recent studies have suggested that these(More)
The Gram-positive species Enterococcus faecium has long been thought of as a harmless commensal of the mammalian GI tract. In the last two decades, however, E. faecium has become an important cause of nosocomial bacteremias. These infections are often difficult to treat owing to the resistance of E. faecium to a large number of antibiotics. In this article,(More)
The enterococci evolved over eons as highly adapted members of gastrointestinal consortia of a wide variety of hosts, but for reasons that are not entirely clear, emerged in the 1970s as leading causes of multidrug resistant hospital infection. Hospital-adapted pathogenic isolates are characterized by the presence of multiple mobile elements conferring(More)
UNLABELLED Enterococcus faecium, natively a gut commensal organism, emerged as a leading cause of multidrug-resistant hospital-acquired infection in the 1980s. As the living record of its adaptation to changes in habitat, we sequenced the genomes of 51 strains, isolated from various ecological environments, to understand how E. faecium emerged as a leading(More)
Enterococcus faecium is considered to be a nosocomial pathogen with increasing medical importance. The putative virulence factor, hyl(Efm), encoding a putative hyaluronidase, is enriched among the hospital-associated polyclonal subpopulation of E. faecium.. The hyl(Efm) gene is described to be part of a genomic island and was recently identified to be(More)
Comparative genome analysis of Enterococcus faecium recently revealed that a genomic island containing the esp gene, referred to as the esp-containing pathogenicity island (esp PAI), can be transferred by conjugation and contains a partial Tn916-like element and an integrase gene, intA. Here, we characterize the role of intA in the excision of the esp PAI.(More)