Molecular characteristics of carbapenemase-producing Enterobacterales in the Netherlands; results of the 2014–2018 national laboratory surveillance

Objectives: Carbapenem resistance mediated by mobile genetic elements has emerged worldwide and has become a major public health threat. To gain insight into the molecular epidemiology of carbapenem resistance in The Netherlands, Dutch medical microbiology laboratories are requested to submit suspected carbapenemase-producing Enterobacterales (CPE) to the National Institute for Public Health and the Environment as part of a national surveillance system. Methods: Meropenem MICs and species identification were confirmed by E-test and MALDI-TOF and carbapenemase production was assessed by the Carbapenem Inactivation Method. Of all submitted CPE, one species/carbapenemase gene combination per person per year was subjected to next-generation sequencing (NGS). Results: In total, 1838 unique isolates were received between 2014 and 2018, of which 892 were unique CPE isolates with NGS data available. The predominant CPE species were Klebsiella pneumoniae (n = 388, 43%), Escherichia coli (n = 264, 30%) and Enterobacter cloacae complex (n = 116, 13%). Various carbapenemase alleles of the same carbapenemase gene resulted in different susceptibilities to meropenem and this effect varied between species. Analyses of NGS data showed variation of prevalence of carbapenemase alleles over time with blaOXA-48 being predominant (38%, 336/892), followed by blaNDM-1 (16%, 145/892). For the first time in the Netherlands, blaOXA-181, blaOXA-232 and blaVIM-4 were detected. The genetic background of K. pneumoniae and E. coli isolates was highly diverse. Conclusions: The CPE population in the Netherlands is diverse, suggesting multiple introductions. The predominant carbapenemase alleles are blaOXA-48 and blaNDM-1. There was a clear association between species, carbapenemase allele and susceptibility to meropenem

Quantification of abdominal aortic aneurysm wall enhancement with dynamic contrast-enhanced MRI: Feasibility, reproducibility, and initial experience.

Keywords: dynamic contrast-enhanced MRI; abdominal aortic aneurysm; microvascularization; vessel wall imaging Purpose : To investigate the feasibility and reproducibility of dynamic contrast-enhanced MRI (DCE-MRI) to quantify abdominal aortic aneurysm (AAA) vessel wall enhancement dynamics which may reflect the amount of wall microvasculature. AAA vessel wall microvasculature has been linked with aneurysm progression and rupture. Materials and Methods : Thirty patients with AAA underwent DCE-MRI at 1.5 Tesla. Enhancement dynamics of the aneurysm wall were quantified in regions-of-interest (ROIs) in the vessel wall by calculating the transfer constant (Ktrans) using pharmacokinetic modeling and the area-under-gadolinium-curve (AUC). To assess reproducibility, 10 patients were imaged twice on different occasions. ROIs were drawn by two independent observers. The intraclass correlation coefficients (ICC) and coefficients of variation (CV) were determined to investigate intra-, interobserver, and interscan variability. Results : Twenty-eight analyzable MR examinations were included for pharmacokinetic analysis after excluding two examinations due to severe motion artifacts. Intra-, interobserver, and interscan variability for Ktrans were small (all ICC > 0.90, CV <14%) as well as for AUC measurements (all ICC > 0.88, CV <23%). Conclusion: Quantitative analysis of AAA vessel wall enhancement dynamics with DCE-MRI is feasible and reproducible. J. Magn. Reson. Imaging 2014;39:1449–1456. © 2013 Wiley Periodicals, Inc

Third-generation cephalosporin and carbapenem resistance in Streptococcus mitis/oralis. Results from a nationwide registry in the Netherlands

Molecular basis of bacterial pathogenesis, virulence factors and antibiotic resistanc