Blar i forfatter "Hegstad, Kristin"

Viser treff 21-30 av 30

    • Performance of the EUCAST disk diffusion method, the CLSI agar screen method, and the Vitek 2 automated antimicrobial susceptibility testing system for detection of clinical isolates of enterococci with low- and medium-level VanB-type vancomycin resistance: A multicenter study 

      Hegstad, Kristin; Giske, Christian G.; Haldorsen, Bjørg; Matuschek, Erika; Schønning, Kristian; Leegaard, Truls Michael; Kahlmeter, Gunnar; Sundsfjord, Arnfinn (Journal article; Tidsskriftartikkel; Peer reviewed, 2014)

    • The population structure of vancomycin-resistant and -susceptible Enterococcus faecium in a low-prevalence antimicrobial resistance setting is highly influenced by circulating global hospital-associated clones 

      al Rubaye, Mushtaq Talib Shawi; Janice, Jessin; Bjørnholt, Jørgen; Kacelnik, Oliver; Haldorsen, Bjørg C; Nygaard, Randi Monsen; Hegstad, Joachim; Sundsfjord, Arnfinn Ståle; Hegstad, Kristin (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-09-19)
      Between 2010 and 2015 the incidence of vancomycin-resistant Enterococcus faecium (VREfm) in Norway increased dramatically. Hence, we selected (1) a random subset of vancomycin-resistant enterococci (VRE) from the Norwegian Surveillance System for Communicable Diseases (2010–15; n=239) and (2) Norwegian vancomycin-susceptible E. faecium (VSEfm) bacteraemia isolates from the national surveillance ...

    • Reversible vancomycin susceptibility within emerging ST1421 Enterococcus faecium strains is associated with rearranged vanA-gene clusters and increased vanA plasmid copy number 

      Wagner, Theresa; Janice, Jessin; Schluz, Marc; Ballard, Susan; da Silva, Anders; Coombs, Geoffrey W; Daley, Denise; Pang, Stanley; Mowlaboccus, Shakeel; Stinear, Tim; Hegstad, Kristin; Howden, Benjamin P; Sundsfjord, Arnfinn (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-05-13)
      Vancomycin variable enterococci (VVE) are van-positive enterococci with a vancomycin-susceptible phenotype (VVE-S) that can convert to a resistant phenotype (VVE-R) and be selected for during vancomycin exposure. VVE-R outbreaks have been reported in Canada and Scandinavian countries. The aim of this study was to examine the presence of VVE in whole genome sequenced (WGS) Australian bacteremia ...

    • Role of Horizontal Gene Transfer in the Development of Multidrug Resistance in Haemophilus influenzae 

      Hegstad, Kristin; Mylvaganam, Haima; Janice, Jessin; Josefsen, Ellen H.; Sivertsen, Audun; Skaare, Dagfinn (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-01-29)
      <i>Haemophilus influenzae</i> colonizes the respiratory tract in humans and causes both invasive and noninvasive infections. Resistance to extended-spectrum cephalosporins in <i>H. influenzae</i> is rare in Europe. In this study, we defined acquired resistance gene loci and <i>ftsI</i> mutations in multidrug-resistant (MDR) and/or PBP3-mediated beta-lactam-resistant (rPBP3) <i>H. influenzae</i> ...

    • Silenced vanA gene cluster on a transferable plasmid cause outbreak of vancomycin variable enterococci 

      Sivertsen, Audun; Pedersen, Torunn Annie; Larssen, Kjersti Wik; Bergh, Kåre; Rønning, Torunn Gresdal; Radtke, Andreas; Hegstad, Kristin (Journal article; Tidsskriftartikkel; Peer reviewed, 2016-05-02)
      We report an outbreak of vancomycin-variable vanA+ enterococci (VVE) able to escape phenotypic detection by current guide- lines and demonstrate the molecular mechanisms for in vivo switching into vancomycin resistance and horizontal spread of the vanA cluster. Forty-eight vanA+ Enterococcus faecium isolates and one Enterococcus faecalis isolate were analyzed for clonality with pulsed-field ...

    • Structural basis for PoxtA-mediated resistance to phenicol and oxazolidinone antibiotics 

      Crowe-McAuliffe, Caillan; Murina, Victoriia; Turnbull, Kathryn Jane; Huch, Susanne; Kasari, Marje; Takada, Hiraku; Nersisyan, Lilit; Sundsfjord, Arnfinn; Hegstad, Kristin; Atkinson, Gemma C.; Pelechano, Vicent; Wilson, Daniel N.; Hauryliuk, Vasili (Journal article; Tidsskriftartikkel; Peer reviewed, 2022-04-06)
      PoxtA and OptrA are ATP binding cassette (ABC) proteins of the F subtype (ABCF). They confer resistance to oxazolidinone and phenicol antibiotics, such as linezolid and chloramphenicol, which stall translating ribosomes when certain amino acids are present at a defined position in the nascent polypeptide chain. These proteins are often encoded on mobile genetic elements, facilitating their rapid ...

    • Taking hospital pathogen surveillance to the next level 

      Werner, Guido; Couto, Natacha; Feil, Edward J.; Novais, Angela; Hegstad, Kristin; Howden, Benjamin P.; Friedrich, Alexander W.; Reuter, Sandra (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-04-26)
      High-throughput bacterial genomic sequencing and subsequent analyses can produce large volumes of high-quality data rapidly. Advances in sequencing technology, with commensurate developments in bioinformatics, have increased the speed and efficiency with which it is possible to apply genomics to outbreak analysis and broader public health surveillance. This approach has been focused on targeted ...

    • Transcriptome profiling of staphylococcus aureus associated extracellular vesicles reveals presence of small RNA-cargo 

      Joshi, Bishnu; Singh, Bhupender; Nadeem, Aftab; Askarian, Fatemeh; Wai, Sun Nyunt; Johannessen, Mona; Hegstad, Kristin (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-01-13)
      Bacterial extracellular vesicles (EVs) have a vital role in bacterial pathogenesis. However, to date, the small RNA-cargo of EVs released by the opportunistic pathogen Staphylococcus aureus has not been characterized. Here, we shed light on the association of small RNAs with EVs secreted by S. aureus MSSA476 cultured in iron-depleted bacteriologic media supplemented with a subinhibitory dosage of ...

    • Transiently silent acquired antimicrobial resistance: an emerging challenge in susceptibility testing 

      Wagner, Theresa; Howden, Benjamin P; Sundsfjord, Arnfinn; Hegstad, Kristin (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-01-31)
      Acquisition and expression of antimicrobial resistance (AMR) mechanisms in bacteria are often associated with a fitness cost. Thus, evolutionary adaptation and fitness cost compensation may support the advance of subpopulations with a silent resistance phenotype when the antibiotic selection pressure is absent. However, reports are emerging on the transient nature of silent acquired AMR, describing ...

    • Update on prevalence and mechanisms of resistance to linezolid, tigecycline and daptomycin in enterococci in Europe: towards a common nomenclature 

      Bender, Jennifer; Cattoir, Vincent; Hegstad, Kristin; Sadowy, Eva; Coque, Teresa M.; Westh, Henrik; Hammerum, Anette M.; Schaffer, Kirsten; Burns, Karen; Murchan, Stephen; Novais, Carla; Freitas, Ana R.; Peixe, Luísa; Del Grosso, Maria; Pantosti, Annalisa; Werner, Guido (Journal article; Tidsskriftartikkel; Peer reviewed, 2018-11-02)
      Vancomycin-resistant enterococci (VRE) are important nosocomial pathogens. Invasive VRE infections are difficult to treat since common therapeutic options including ampicillin and glycopeptides often fail. In vitro, most VRE remain susceptible to last-resort antibiotics such as linezolid, tigecycline and daptomycin. However, neither tigecycline nor linezolid act in a bactericidal manner, and ...