Browsing by Author "Hegstad, Kristin"
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Alternative vanHAX promoters and increased vanA-plasmid copy number resurrect silenced glycopeptide resistance in Enterococcus faecium
Wagner, Theresa; Janice, Jessin; Sivertsen, Audun; Sjögren, Ingegerd; Sundsfjord, Arnfinn; Hegstad, Kristin (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-12-26)<i>Background</i> - Vancomycin variable enterococci (VVE) are <i>van</i>-positive isolates with a susceptible phenotype that can convert to a resistant phenotype during vancomycin selection.<p> <p><i>Objectives</i> - To describe a vancomycin-susceptible <i>vanA</i>-PCR positive ST203 VVE <i>Enterococcus faecium</i> isolate (VVE<i>Swe</i>-S) from a liver transplantation patient in Sweden which ... -
Bacterial genomic epidemiology with mixed samples
Mäklin, Tommi; Kallonen, Teemu; Alanko, Jarno; Samuelsen, Ørjan; Hegstad, Kristin; Mäkinen, Veli; Corander, Jukka; Heinz, Eva; Honkela, Antti (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-11-15)Genomic epidemiology is a tool for tracing transmission of pathogens based on whole-genome sequencing. We introduce the mGEMS pipeline for genomic epidemiology with plate sweeps representing mixed samples of a target pathogen, opening the possibility to sequence all colonies on selective plates with a single DNA extraction and sequencing step. The pipeline includes the novel mGEMS read binner for ... -
Bacterial membrane-derived vesicles attenuate vancomycin activity against methicillin-resistant staphylococcus aureus
Kumaraswamy, Monika; Wiull, Kamilla; Joshi, Bishnu; Sakoulas, George; Kousha, Armin; Vaaje-Kolstad, Gustav; Johannessen, Mona; Hegstad, Kristin; Nizet, Victor; Askarian, Fatemeh (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-09-29)Methicillin-resistant Staphylococcus aureus (MRSA) has evolved numerous antimicrobial resistance mechanisms and is identified as a serious public health threat by the World Health Organization and U.S. Centers for Disease Control and Prevention. The glycopeptide vancomycin (VAN) remains a cornerstone of therapy for severe MRSA infections despite increasing reports of therapeutic failure in hospitalized ... -
Characterization and Fitness Cost of Tn7100, a Novel Integrative and Conjugative Element Conferring Multidrug Resistance in Haemophilus influenzae
Johannessen, Helene; Anthonisen, Inger Lill; Zecic, Nermin; Hegstad, Kristin; Ranheim, Trond Egil; Skaare, Dagfinn (Journal article; Tidsskriftartikkel, 2022-07-22)A multidrug-resistant (MDR) strain of Haemophilus influenzae, Hi-228, with phenotypic resistance toward ampicillin, cefotaxime, chloramphenicol, gentamicin, and azithromycin, was isolated in Oslo, Norway. The strain was part of a clonal outbreak (2016–2017) comprising five ST143 strains with identical resistotypes. Hi-228 carries a novel integrative and conjugative element (ICE), Tn7100, contributing ... -
Chlorhexidine compounds in cosmetic products Risk assessment of antimicrobial and antibiotic resistance development in microorganisms
Lunestad, Bjørn Tore; Møretrø, Trond; Hegstad, Kristin; Langsrud, Solveig; Scheie, Anne Aamdal; Kapperud, Georg; Lassen, Jørgen Fr; Nygård, Karin Maria; Robertson, Lucy; Nesbakken, Truls; Olsvik, Ørjan; Tranulis, Michael A.; Tryland, Morten; Rimstad, Espen (Research report; Forskningsrapport, 2010-04-15)Chlorhexidine and its salts are reported as being used in cosmetics as an active ingredient to give the desired effect or as a preservative in concentrations of up to 0.3 %. Such products include mouthwashes, hair dying and bleaching formulations, shampoos, anti hair “aging” products and exfoliants, body lotions, eye creams, face cleansers, sun cream, after-sun lotions, ... -
Cluster of linezolid-resistant Enterococcus faecium ST117 in Norwegian hospitals
Hegstad, Kristin; Longva, Jørn-Åge; Hide, Reidar; Aasnæs, Bettina; Lunde, Tracy Tamara Munthali; Simonsen, Gunnar Skov (Journal article; Tidsskriftartikkel; Peer reviewed, 2014-08-19)A linezolid-resistant, vancomycin-susceptible Enterococcus faecium strain was isolated from 3 patients who had not received linezolid. The first patient was hospitalized in the same hospitals and wards as the 2 following patients. The E. faecium isolates were resistant to linezolid (minimum inhibitory concentration 8–32 mg/l), ampicillin, and high levels of gentamicin. Resistance to linezolid was ... -
Emergence of vancomycin-resistant enterococci from vancomycin susceptible enterococci in hospitalized patients under antimicrobial therapy
Janice, Jessin; Wagner, Theresa Maria; Olsen, Karina; Hegstad, Joachim; Hegstad, Kristin (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-12-19)Objectives: Enterococci are opportunistic pathogens with plastic genomes that evolve, acquire, and transmit antimicrobial-resistant determinants such as vancomycin resistance clusters. While vancomycinresistant enterococci (VRE) have emerged as successful nosocomial pathogens, the mechanism by which vancomycin-susceptible enterococci (VSE) transform to VRE in hospitalized patients remains ... -
Enterococcal Membrane Vesicles as Vaccine Candidates
Wagner, Theresa Maria; Romero-Saavedra, Felipe; Laverde, Diana; Johannessen, Mona Susan; Hübner, Johannes; Hegstad, Kristin (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-11-07)Enterococcus faecium is a leading cause of nosocomial infections, particularly in immunocompromised patients. The rise of multidrug-resistant E. faecium, including Vancomycin-Resistant Enterococci (VRE), is a major concern. Vaccines are promising alternatives to antibiotics, but there is currently no vaccine available against enterococci. In a previous study, we identified six protein vaccine ... -
The enterococcus cassette chromosome, a genomic variation enabler in enterococci
Sivertsen, Audun; James Peter, Jessin Janice; Pedersen, Torunn Annie; Wagner, Theresa; Hegstad, Joachim; Hegstad, Kristin (Journal article; Tidsskriftartikkel; Peer reviewed, 2018-11-07)Enterococcus faecium has a highly variable genome prone to recombination and horizontal gene transfer. Here, we have identified a novel genetic island with an insertion locus and mobilization genes similar to those of staphylococcus cassette chromosome elements SCCmec. This novel element termed the enterococcus cassette chromosome (ECC) element was located in the 3′ region of rlmH and encoded large ... -
Enterococcus faecium produces membrane vesicles containing virulence factors and antimicrobial resistance related proteins
Wagner, Theresa; Joshi, Bishnu; James Peter, Jessin Janice; Askarian, Fatemeh; Skalko-Basnet, Natasa; Hagestad, Ole Christian; Mekhlif, Ahmed; Wai, Sun Nyunt; Hegstad, Kristin; Johannessen, Mona (Journal article; Tidsskriftartikkel; Peer reviewed, 2018-05-30)<i>Enterococcus faecium</i> is a commensal but also a bacteremia causing pathogen, which is inherently resistant to several antimicrobials and has a great ability to acquire new traits. Bacterial membrane vesicles (MVs) are increasingly recognized as a mode of cell-free communication and a way to deliver virulence factors and/or antimicrobial resistance determinants. These features make MVs interesting ... -
Enterococcus faecium TIR-Domain Genes Are Part of a Gene Cluster Which Promotes Bacterial Survival in Blood
Wagner, Theresa; James Peter, Jessin Janice; Paganelli, Fernanda; Willems, Rob J.L.; Askarian, Fatemeh; Pedersen, Torunn Annie; Top, Janetta; de Haas, Carla; van strijp, Jos A. G.; Johannessen, Mona; Hegstad, Kristin (Journal article; Tidsskriftartikkel; Peer reviewed, 2018-12-03)<i>Enterococcus faecium</i> has undergone a transition to a multidrug-resistant nosocomial pathogen. The population structure of <i>E. faecium</i> is characterized by a sharp distinction of clades, where the hospital-adapted lineage is primarily responsible for bacteremia. So far, factors that were identified in hospital-adapted strains and that promoted pathogenesis of nosocomial <i>E. faecium</i> ... -
The fight to keep resistance at bay, epidemiology of carbapenemase producing organisms (CPOs), vancomycin resistant enterococci (VRE) and methicillin resistant Staphylococcus aureus (MRSA) in Norway, 2006-2017
Elstrøm, Petter; Astrup, Elisabeth; Hegstad, Kristin; Samuelsen, Ørjan; Enger, Hege; Kacelnik, Oliver (Journal article; Tidsskriftartikkel; Peer reviewed, 2019-02-04)<p><i>Introduction - </i>Scandinavian countries have traditionally had a low prevalence of resistant organisms, but have in recent years experienced a change in their epidemiology. We aim to describe the epidemiology of carbapenemase-producing organisms (CPOs), vancomycin-resistant enterococci (VRE) and methicillin-resistant <i>S. aureus</i> (MRSA) in Norway, measure the importance of infections ... -
The first tigecycline resistant Enterococcus faecium in Norway was related to tigecycline exposure
Hegstad, Kristin; Pöntinen, Anna Kaarina; Bjørnholt, Jørgen; Paulsen, Else Quist; Sundsfjord, Arnfinn Ståle (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-12-19)Objectives - We describe the first tigecycline resistant enterococcal isolate in Norway and the mechanisms involved.<p> <p>Material and methods - The Norwegian National Advisory Unit on Detection of Antimicrobial Resistance (K-res). received in 2022 an Enterococcus faecium blood culture isolate with decreased susceptibility to tigecycline from a hospitalized patient in the South-Eastern Norway ... -
The first vanE-type vancomycin resistant Enterococcus faecalis isolates in Norway – phenotypic and molecular characteristics
al Rubaye, Mushtaq Talib Shawi; Janice, Jessin; Bjørnholt, Jørgen; Löhr, Iren Høyland; Sundsfjord, Arnfinn Ståle; Hegstad, Kristin (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-12-27)Objectives - We aimed to characterize the vanE cluster and its genetic support in the first Norwegian vanE-type isolates and assess genetic relatedness to other vanE isolates.<p> <p>Methods - Two vanE-type vancomycin resistant Enterococcus faecalis (vanE-VREfs) isolates (E1 and E2) recovered from the same patient 30 months apart were examined for antimicrobial susceptibility, genome sequence, ... -
Genomic insights into Enterococcus faecium isolates from marine bivalves highlight One Health concerns and healthcare linkages
von Barner Tvedegaard Heim, Amalie; Janice, Jessin; Bjørnholt, Jørgen; Lunestad, Bjørn Tore; Hegstad, Kristin; Svanevik, Cecilie Smith (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-12-12)Enterococci, especially Enterococcus faecium, are one of today’s leading causes of multidrug-resistant infections in hospital settings. The marine environment may harbour enterococci, but its role as an evolutionary niche and as a vector for the spread of enterococci is sparsely investigated. Hence, by applying enterococci in bivalves as a sentinel tool, this study aimed to describe the prevalence ... -
The global dissemination of hospital clones of Enterococcus faecium
van Hal, Sebastiaan J.; Willems, Rob J.L.; Gouliouris, Theodore; Ballard, Susan A.; Coque, Teresa M.; Hammerum, Anette M.; Hegstad, Kristin; Westh, Henrik; Howden, Benjamin P.; Malhotra-Kumar, Surbhi; Werner, Guido; Yanagihara, Katsunori; Earl, Ashlee M.; Raven, Katherine E.; Corander, Jukka; Bowden, Rory (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-03-30)<i>Background</i> - The hospital-adapted A1 group of <i>Enterococcus faecium</i> remains an organism of significant concern in the context of drug-resistant hospital-associated infections. How this pathogen evolves and disseminates remains poorly understood.<br><br> <i>Methods</i> - A large, globally representative collection of short-read genomic data from the hospital-associated A1 group of ... -
ICESluvan, a 94-Kilobase Mosaic Integrative Conjugative Element Conferring Interspecies Transfer of VanB-Type Glycopeptide Resistance, a Novel Bacitracin Resistance Locus, and a Toxin- Antitoxin Stabilization System
Bjørkeng, Eva katrin; Hjerde, Erik; Pedersen, Torunn; Sundsfjord, Arnfinn; Hegstad, Kristin (Journal article; Tidsskriftartikkel; Peer reviewed, 2013)A 94-kb integrative conjugative element (ICESluvan) transferable to Enterococcus faecium and Enterococcus faecalis from an animal isolate of Streptococcus lutetiensis consists of a mosaic of genetic fragments from different Gram-positive bacteria. A variant of ICESluvan was confirmed in S. lutetiensis from a patient. A complete Tn5382/Tn1549 with a vanB2 operon is integrated into a streptococcal ... -
Investigating the mobilome in clinically important lineages of Enterococcus faecium and Enterococcus faecalis
Mikalsen, Theresa; Pedersen, Torunn Annie; Willems, Rob J; Coque, Teresa M.; Werner, Guido; Sadowy, Eva; van Schaik, Willem; Jensen, Lars Bogø; Sundsfjord, Arnfinn; Hegstad, Kristin (Journal article; Tidsskriftartikkel; Peer reviewed, 2015-04-10)Background: The success of Enterococcus faecium and E. faecalis evolving as multi-resistant nosocomial pathogens is associated with their ability to acquire and share adaptive traits, including antimicrobial resistance genes encoded by mobile genetic elements (MGE). Here, we investigate this mobilome in successful hospital associated genetic lineages, E. faecium sequence type (ST)17 (n=10) and ... -
A multicentre hospital outbreak in Sweden caused by introduction of a vanB2 transposon into a stably maintained pRUM-plasmid in an Enterococcus faecium ST192 clone.
Sivertsen, Audun; Billström, Hanna; Melefors, Öjar; Liljequist, Barbro Olsson; Wisell, Karin Tegmark; Ullberg, Måns; Özenci, Volkan; Sundsfjord, Arnfinn; Hegstad, Kristin (Journal article; Tidsskriftartikkel; Peer reviewed, 2014)The clonal dissemination of VanB-type vancomycin-resistant Enterococcus faecium (VREfm) strains in three Swedish hospitals between 2007 and 2011 prompted further analysis to reveal the possible origin and molecular characteristics of the outbreak strain. A representative subset of VREfm isolates (n = 18) and vancomycin-susceptible E. faecium (VSEfm, n = 2) reflecting the spread in time and location ... -
Novel genomic islands and a new vanDsubtype in the first sporadic VanD-type vancomycin resistant enterococci in Norway
AL-Rubaye, Mushtaq Talib Shawi; Janice, Jessin; Bjørnholt, Jørgen Vildershøj; Jakovljev, Aleksandra; Hultström, Maria Elisabeth; Sundsfjord, Arnfinn; Hegstad, Kristin (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-07-23)Background - Vancomycin-resistant enterococci (VRE) represent several types of transferable vancomycin resistance gene clusters. The vanD type, associated with moderate to high level vancomycin resistance, has only sporadically been described in clinical isolates. The aim of this study was to perform a genetic characterization of the first VanD-type VRE strains detected in Norway.<p> <p>Methods ...