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de Haan, A.

Publications and source records attributed to de Haan, A..

2 recordsLinked to original sources

Plasmid diversity among genetically related Klebsiella pneumoniae blaKPC-2 and blaKPC-3 isolates collected in the Dutch national surveillance

Carbapenemase-producing Klebsiella pneumoniae emerged over the past decades as an important pathogen causing morbidity and mortality in hospitalized patients. For infection prevention and control, it is important to track the spread of bacterial strains in humans including the plasmids they contain. However, little is known concerning the plasmid repertoire among K. pneumoniae strains. Therefore, the major aim was to recapitulate the size, contents and diversity of the plasmids of genetically related K. pneumoniae strains harboring the beta-lactamase gene blaKPC-2 or blaKPC-3 to determine their dissemination in the Netherlands and the former Dutch Caribbean islands from 2014-2019. Next-generation sequencing was combined with long-read third-generation sequencing to reconstruct 18 plasmids of K. pneumoniae. wgMLST revealed five genetic clusters (termed KpnClusters) comprised of K. pneumoniae blaKPC-2 isolates and four clusters consisted of blaKPC-3 isolates. Each cluster was characterized by a distinct resistome and plasmidome. KpnCluster-019 blaKPC-2 isolates were found both in the Netherlands and the Caribbean islands. K. pneumoniae blaKPC-3 isolates were found in the collection of the Netherlands. The 18 plasmids were mostly unrelated and varied between K. pneumoniae blaKPC-2 and blaKPC-3 clusters. However, the large and medium sized plasmids contained a variety of antibiotic resistance genes, transposons, insertion sequence elements, conjugal transfer systems, cation transport systems, toxin/antitoxin systems, and prophage-related sequence elements. The small plasmids carried genes implicated in virulence. Thus, implementing long-read plasmid sequencing analysis for K. pneumoniae surveillance provided important insights in the success and understanding of transmission of a KpnCluster-019 blaKPC-2 strain between the Netherlands and the Caribbean. ImportanceCarbapenemase-producing Klebsiella pneumoniae has spread globally and is of great concern for debilitated patients. K. pneumoniae is notorious for spreading antimicrobial resistance genes by plasmids among Enterobacterales. Combining short and long read sequencing enables reconstruction of plasmids containing antibiotic resistance genes, conjugation machinery, transposons, toxins and/or virulence determinants and thereby enhancing international pathogen surveillance.

microbiology

DLC1 is a direct target of activated YAP/TAZ that drives collective migration and sprouting angiogenesis

YAP/TAZ signaling is crucial for sprouting angiogenesis and vascular homeostasis through the regulation of endothelial remodeling. Thus far the underlying molecular mechanisms that explain how YAP/TAZ control the vasculature remain unclear. We here identify Deleted-in-Liver-Cancer-1 (DLC1) as a direct transcriptional target of the activated YAP/TAZ-TEAD complex in the endothelium. Substrate stiffening and VEGF stimuli promote the endothelial expression of DLC1. DLC1 expression is dependent on the presence of YAP and TAZ, and constitutive activation of YAP efficiently promotes expression of DLC1. We show that DLC1 limits F-actin fiber formation, integrin-based focal adhesion lifetime and integrin-mediated traction forces. Depletion of endothelial DLC1 strongly perturbs cell polarization in directed collective migration and inhibits the formation of angiogenic sprouts. Importantly, the inability of YAP-depleted endothelial cells to collectively migrate and form angiogenic sprouts can be rescued by ectopic expression of DLC1. Together, these findings reveal that DLC1 fills a hitherto missing link between YAP/TAZ signaling and endothelial dynamics during angiogenesis.

cell biology