Karianne Wiger Gammelsrud

• Huncikova, Zuzana; Christensen, Martin; Wolden, Runa; Venter, Hermoine Jean; Gammelsrud, Karianne Wiger & Bjørnholt, Jørgen [Vis alle 15 forfattere av denne artikkelen] (2026). CoNS blood culture isolates from very preterm infants: antibiotic susceptibility, synergy testing and mecA gene expression. JAC-Antimicrobial Resistance (JAC-AMR). 8(2). doi: 10.1093/jacamr/dlag058. Fulltekst i vitenarkiv Vis sammendrag

  Objectives: Previous reports suggest that neonatal sepsis with methicillin-resistant (MR) CoNS can be treated with first-generation cephalosporins. We have evaluated the in vitro effect of cefazolin and other antibiotics, synergy between β-lactams and aminoglycosides, and mecA expression in MR-CoNS isolates. Patients and methods: Antimicrobial susceptibility testing was performed in 167 CoNS isolates from 135 very preterm infants (<32 weeks gestation) with late-onset sepsis. Microbroth dilution chequerboard assay explored antibiotic synergy. PCR detected mecA and three aminoglycoside-modifying enzyme genes. Induction experiments evaluated if exposure to cefazolin induces resistance. RT-PCR determined mecA expression in selected MR-CoNS isolates with different cefazolin/oxacillin MICs. Results: All CoNS isolates were susceptible to amikacin and vancomycin. Most were phenotypically resistant to gentamicin (92%) and cefoxitin (93%), and 89% carried the mecA gene. MIC90 values of cefazolin and oxacillin were 16 mg/L and >256 mg/L, respectively. At the cefazolin breakpoint of 8 mg/L, 83% of isolates were susceptible in vitro. No antibiotic combinations showed synergy using the FIC index, but cefazolin combined with aminoglycosides had favourable susceptibility breakpoint index values. In a simplified synergy screen of ‘highly resistant’ isolates, growth was inhibited with a combination of gentamicin and cefazolin at sub-MIC concentrations in 8/42 (19%) isolates. Exposure to cefazolin sub-MICs caused reduced susceptibility in 1/30 (3%) tested isolates. The highest mecA expression was observed in isolates with high oxacillin/cefazolin MICs. Conclusions: CoNS isolates had lower MICs for cefazolin than oxacillin, and 83% were in vitro susceptible to cefazolin. A clinical trial comparing cefazolin with vancomycin as empirical therapy for suspected neonatal sepsis is warranted.

• Helset, Elin; Cheng, Vesa; Sporsem, Hilde Margrete; Thorstensen, Christian; Nordøy, Ingvild & Gammelsrud, Karianne Wiger [Vis alle 10 forfattere av denne artikkelen] (2024). Meropenem pharmacokinetic/pharmacodynamic target attainment and clinical response in ICU patients: A prospective observational study. Acta Anaesthesiologica Scandinavica. ISSN 0001-5172. 68(4), s. 502–511. doi: 10.1111/aas.14376. Fulltekst i vitenarkiv Vis sammendrag

  Background Several studies report lack of meropenem pharmacokinetic/pharmacodynamic (PK/PD) target attainment (TA) and risk of therapeutic failure with intermittent bolus infusions in intensive care unit (ICU) patients. The aim of this study was to describe meropenem TA in an ICU population and the clinical response in the first 72 h after therapy initiation. Methods A prospective observational study of ICU patients ≥18 years was conducted from 2014 to 2017. Patients with normal renal clearance (NRC) and augmented renal clearance (ARC) and patients on continuous renal replacement therapy (CRRT) were included. Meropenem was administered as intermittent bolus infusions, mainly at a dose of 1 g q6h. Peak, mid, and trough levels were sampled at 24, 48, and 72 h after therapy initiation. TA was defined as 100% T > 4× MIC or trough concentration above 4× MIC. Meropenem PK was estimated using traditional calculation methods and population pharmacokinetic modeling (P-metrics®). Clinical response was evaluated by change in C-reactive protein (CRP), Sequential Organ Failure Assessment (SOFA) score, leukocyte count, and defervescence. Results Eighty-seven patients were included, with a median Simplified Acute Physiology (SAPS) II score 37 and 90 days mortality rate of 32%. Median TA was 100% for all groups except for the ARC group with 45.5%. Median CRP fell from 175 (interquartile range [IQR], 88–257) to 70 (IQR, 30–114) (p < .001) in the total population. A reduction in SOFA score was observed only in the non-CRRT groups (p < .001). Conclusion Intermittent meropenem bolus infusion q6h gives satisfactory TA in an ICU population with variable renal function and CRRT modality, except for ARC patients. No consistent relationship between TA and clinical endpoints were observed.

• Fostervold, Aasmund; Raffelsberger, Niclas Peter; Hetland, Marit; Bakksjø, Ragna-Johanne; Bernhoff, Eva & Samuelsen, Ørjan [Vis alle 22 forfattere av denne artikkelen] (2024). Risk of death in Klebsiella pneumoniae bloodstream infections is associated with specific phylogenetic lineages. Journal of Infection. ISSN 0163-4453. 88(5), s. 1–11. doi: 10.1016/j.jinf.2024.106155. Fulltekst i vitenarkiv Vis sammendrag

  Background: Klebsiella pneumoniae species complex (KpSC) bloodstream infections (BSIs) are associated with considerable morbidity and mortality, particularly in elderly and multimorbid patients. Multidrug-resistant (MDR) strains have been associated with poorer outcome. However, the clinical impact of KpSC phylogenetic lineages on BSI outcome is unclear. Methods: In an 18-month nationwide Norwegian prospective study of KpSC BSI episodes in adults, we used whole-genome sequencing to describe the molecular epidemiology of KpSC, and multivariable Cox regression analysis including clinical data to determine adjusted hazard ratios (aHR) for death associated with specific genomic lineages. Findings: We included 1078 BSI episodes and 1082 bacterial isolates from 1055 patients. The overall 30-day case-fatality rate (CFR) was 12.5%. Median patient age was 73.4, 61.7% of patients were male. Median Charlson comorbidity score was 3. Klebsiella pneumoniae sensu stricto (Kp) (79.3%, n = 858/1082) and K. variicola (15.7%, n = 170/1082) were the dominating phylogroups. Global MDR-associated Kp clonal groups (CGs) were prevalent (25.0%, n = 270/1082) but 78.9% (n = 213/270) were not MDR, and 53.7% (n = 145/270) were community acquired. The major findings were increased risk for death within 30 days in monomicrobial BSIs caused by K. variicola (CFR 16.9%, n = 21; aHR 1.86, CI 1.10-3.17, p = 0.02), and global MDR-associated Kp CGs (CFR 17.0%, n = 36; aHR 1.52, CI 0.98-2.38, p = 0.06) compared to Kp CGs not associated with MDR (CFR 10.1%, n = 46). Conclusion: Bacterial traits, beyond antimicrobial resistance, have a major impact on the clinical outcome of KpSC BSIs. The global spread of MDR-associated Kp CGs is driven by other mechanisms than antibiotic selection alone. Further insights into virulence determinants, and their association with phylogenetic lineages are needed to better understand the epidemiology of KpSC infection and clinical outcome.

• Rubaye, Mushtaq al; Janice, Jessin; Bjørnholt, Jørgen Vildershøj; Kacelnik, Oliver; Haldorsen, Bjørg C. & Nygaard, Randi M. [Vis alle 26 forfattere av denne artikkelen] (2023). 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. Microbial Genomics. 9(12). doi: 10.1099/mgen.0.001160. Fulltekst i vitenarkiv Vis sammendrag

  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 system for antimicrobial resistance in microbes (2008 and 2014; n=261) for further analysis. Whole-genome sequences were collected for population structure, van gene cluster, mobile genetic element and virulome analysis, as well as antimicrobial susceptibility testing. Comparative genomic and phylogeographical analyses were performed with complete genomes of global E. faecium strains from the National Center for Biotechnology Information (NCBI) (1946–2022; n=272). All Norwegian VREfm and most of the VSEfm clustered with global hospital-associated sequence types (STs) in the phylogenetic subclade A1. The vanB2 subtype carried by chromosomal Tn1549 integrative conjugative elements was the dominant van type. The major Norwegian VREfm cluster types (CTs) were in accordance with concurrent European CTs. The dominant vanB-type VREfm CTs, ST192-CT3/26 and ST117-CT24, were mostly linked to a single hospital in Norway where the clones spread after independent chromosomal acquisition of Tn1549. The less prevalent vanA VRE were associated with more diverse CTs and vanA carrying Inc18 or RepA_N plasmids with toxin–antitoxin systems. Only 5 % of the Norwegian VRE were Enterococcus faecalis, all of which contained vanB. The Norwegian VREfm and VSEfm isolates harboured CT-specific virulence factor (VF) profiles supporting biofilm formation and colonization. The dominant VREfm CTs in general hosted more virulence determinants than VSEfm. The phylogenetic clade B VSEfm isolates (n=21), recently classified as Enterococcus lactis, harboured fewer VFs than E. faecium in general, and particularly subclade A1 isolates. In conclusion, the population structure of Norwegian E. faecium isolates mirrors the globally prevalent clones and particularly concurrent European VREfm/VSEfm CTs. Novel chromosomal acquisition of vanB2 on Tn1549 from the gut microbiota, however, formed a single major hospital VREfm outbreak. Dominant VREfm CTs contained more VFs than VSEfm.

• Ravn, Christen; Neyt, Jeroen; Benito, Natividad; Abreu, Miguel Araújo; Achermann, Yvonne & Bozhkova, Svetlana [Vis alle 27 forfattere av denne artikkelen] (2023). Guideline for management of septic arthritis in native joints (SANJO). Journal of Bone and Joint Infection (JBJI). 8(1), s. 29–37. doi: 10.5194/jbji-8-29-2023. Fulltekst i vitenarkiv
• Ljungquist, Oskar; Haldorsen, Bjørg; Pöntinen, Anna Kaarina; Janice, Jessin; Josefsen, Ellen Haldis & Elstrøm, Petter [Vis alle 28 forfattere av denne artikkelen] (2023). Nationwide, population-based observational study of the molecular epidemiology and temporal trend of carbapenemase-producing Enterobacterales in Norway, 2015 to 2021. Eurosurveillance. ISSN 1025-496X. 28(27), s. 1–11. doi: 10.2807/1560-7917.es.2023.28.27.2200774. Fulltekst i vitenarkiv Vis sammendrag

  Introduction National and regional carbapenemase-producing Enterobacterales (CPE) surveillance is essential to understand the burden of antimicrobial resistance, elucidate outbreaks, and develop infection-control or antimicrobial-treatment recommendations. Aim This study aimed to describe CPE and their epidemiology in Norway from 2015 to 2021. Methods A nationwide, population-based observational study of all verified clinical and carriage CPE isolates submitted to the national reference laboratory was conducted. Isolates were characterised by antimicrobial susceptibility testing, whole genome sequencing (WGS) and basic metadata. Annual CPE incidences were also estimated. Results A total of 389 CPE isolates were identified from 332 patients of 63 years median age (range: 0-98). These corresponded to 341 cases, 184 (54%) being male. Between 2015 and 2021, the annual incidence of CPE cases increased from 0.6 to 1.1 per 100,000 person-years. For CPE-isolates with available data on colonisation/infection, 58% (226/389) were associated with colonisation and 38% (149/389) with clinical infections. WGS revealed a predominance of OXA-48-like (51%; 198/389) and NDM (34%; 134/389) carbapenemases in a diversified population of Escherichia coli and Klebsiella pneumoniae, including high-risk clones also detected globally. Most CPE isolates were travel-related (63%; 245/389). Although local outbreaks and healthcare-associated transmission occurred, no interregional spread was detected. Nevertheless, 18% (70/389) of isolates not directly related to import points towards potentially unidentified transmission routes. A decline in travel-associated cases was observed during the COVID-19 pandemic. Conclusions The close-to-doubling of CPE case incidence between 2015 and 2021 was associated with foreign travel and genomic diversity. To limit further transmission and outbreaks, continued screening and monitoring is essential.

• Gladstone, Rebecca Ashley; McNally, Alan; Pöntinen, Anna Kaarina; Tonkin-Hill, Gerry; Lees, John A. & Skytén, Kusti Onni [Vis alle 29 forfattere av denne artikkelen] (2021). Emergence and dissemination of antimicrobial resistance in Escherichia coli causing bloodstream infections in Norway in 2002–17: a nationwide, longitudinal, microbial population genomic study. Lancet Microbe. 2(7), s. e331–e341. doi: 10.1016/S2666-5247(21)00031-8. Fulltekst i vitenarkiv Vis sammendrag

  Background The clonal diversity underpinning trends in multidrug resistant Escherichia coli causing bloodstream infections remains uncertain. We aimed to determine the contribution of individual clones to resistance over time, using large-scale genomics-based molecular epidemiology. Methods This was a longitudinal, E coli population, genomic, cohort study that sampled isolates from 22 512 E coli bloodstream infections included in the Norwegian surveillance programme on resistant microbes (NORM) from 2002 to 2017. 15 of 22 laboratories were able to share their isolates, and the first 22·5% of isolates from each year were requested. We used whole genome sequencing to infer the population structure (PopPUNK), and we investigated the clade composition of the dominant multidrug resistant clonal complex (CC)131 using genetic markers previously reported for sequence type (ST)131, effective population size (BEAST), and presence of determinants of antimicrobial resistance (ARIBA, PointFinder, and ResFinder databases) over time. We compared these features between the 2002–10 and 2011–17 time periods. We also compared our results with those of a longitudinal study from the UK done between 2001 and 2011. Findings Of the 3500 isolates requested from the participating laboratories, 3397 (97·1%) were received, of which 3254 (95·8%) were successfully sequenced and included in the analysis. A significant increase in the number of multidrug resistant CC131 isolates from 71 (5·6%) of 1277 in 2002–10 to 207 (10·5%) of 1977 in 2011–17 (p<0·0001), was the largest clonal expansion. CC131 was the most common clone in extended-spectrum β-lactamase (ESBL)-positive isolates (75 [58·6%] of 128) and fluoroquinolone non-susceptible isolates (148 [39·2%] of 378). Within CC131, clade A increased in prevalence from 2002, whereas the global multidrug resistant clade C2 was not observed until 2007. Multiple de-novo acquisitions of both blaCTX-M ESBL-encoding genes in clades A and C1 and gain of phenotypic fluoroquinolone non-susceptibility across the clade A phylogeny were observed. We estimated that exponential increases in the effective population sizes of clades A, C1, and C2 occurred in the mid-2000s, and in clade B a decade earlier. The rate of increase in the estimated effective population size of clade A (Ne=3147) was nearly ten-times that of C2 (Ne=345), with clade A over-represented in Norwegian CC131 isolates (75 [27·0%] of 278) compared with the UK study (8 [5·4%] of 147 isolates). Interpretation The early and sustained establishment of predominantly antimicrobial susceptible CC131 clade A isolates, relative to multidrug resistant clade C2 isolates, suggests that resistance is not necessary for clonal success. However, even in the low antibiotic use setting of Norway, resistance to important antimicrobial classes has rapidly been selected for in CC131 clade A isolates. This study shows the importance of genomic surveillance in uncovering the complex ecology underlying multidrug resistance dissemination and competition, which have implications for the design of strategies and interventions to control the spread of high-risk multidrug resistant clones.

• Helset, Elin; Nordøy, Ingvild; Sporsem, Hilde Margrete; Bakke, Victoria Desiree; Bugge, Jan F & Gammelsrud, Karianne Wiger [Vis alle 8 forfattere av denne artikkelen] (2020). Factors increasing the risk of inappropriate vancomycin therapy in ICU patients: A prospective observational study. Acta Anaesthesiologica Scandinavica. ISSN 0001-5172. 64(9), s. 1295–1304. doi: 10.1111/aas.13658. Fulltekst i vitenarkiv
• Åkerlund, Anna; Jonasson, Emma; Matuschek, Erika; Serrander, Lena; Sundqvist, Martin & Kahlmeter, Gunnar [Vis alle 49 forfattere av denne artikkelen] (2020). EUCAST rapid antimicrobial susceptibility testing (RAST) in blood cultures: validation in 55 European laboratories. Journal of Antimicrobial Chemotherapy. ISSN 0305-7453. 75(11), s. 3230–3238. doi: 10.1093/jac/dkaa333. Fulltekst i vitenarkiv Vis sammendrag

  Objectives: When bloodstream infections are caused by resistant bacteria, rapid antimicrobial susceptibility testing (RAST) is important for adjustment of therapy. The EUCAST RAST method, directly from positive blood cultures, was validated in a multi-laboratory study in Europe. Methods: RAST was performed in 40 laboratories in northern Europe (NE) and 15 in southern Europe (SE) from clinical blood cultures positive for Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Staphylococcus aureus or Streptococcus pneumoniae. Categorical results at 4, 6 and 8 h of incubation were compared with results for EUCAST standard 16-20 h disc diffusion. The method, preliminary breakpoints and the performance of the laboratories were evaluated. Results: The total number of isolates was 833/318 in NE/SE. The number of zone diameters that could be read (88%, 96% and 99%) and interpreted (70%, 81% and 85%) increased with incubation time (4, 6 and 8 h). The categorical agreement was acceptable, with total error rates in NE/SE of 2.4%/4.9% at 4 h, 1.1%/3.5% at 6 h and 1.1%/3.3% at 8 h. False susceptibility at 4, 6 and 8 h of incubation was below 0.3% and 1.1% in NE and SE, respectively, and the corresponding percentages for false resistance were below 1.9% and 2.8%. After fine-tuning breakpoints, more zones could be interpreted (73%, 89% and 93%), with only marginally affected error rates. Conclusions: The EUCAST RAST method can be implemented in routine laboratories without major investments. It provides reliable antimicrobial susceptibility testing results for relevant bloodstream infection pathogens after 4-6 h of incubation. © The Author(s) 2020. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy.

• Rojahn, Astrid Elisabeth; Gammelsrud, Karianne Wiger; Brunvand, Leif Inge; HANCHE-OLSEN, TERJE PEDER; Schistad, Ole & Æter, Christine Bendixens [Vis alle 7 forfattere av denne artikkelen] (2020). Multiorgan inflammatorisk syndrom assosiert med sars-CoV-2 hos et barn. Tidsskrift for Den norske legeforening (Tidsskriftet). ISSN 0029-2001. 140(11), s. 1–9. doi: 10.4045/tidsskr.20.0485. Fulltekst i vitenarkiv
• Knudsen, Per Kristian; Gammelsrud, Karianne Wiger; Alfsnes, Kristian; Steinbakk, Martin; Abrahamsen, Tore G & Müller, Fredrik [Vis alle 7 forfattere av denne artikkelen] (2018). Transfer of a bla CTX-M-1-carrying plasmid between different Escherichia coli strains within the human gut explored by whole genome sequencing analyses. Scientific Reports. 8(1). doi: 10.1038/s41598-017-18659-2. Fulltekst i vitenarkiv Vis sammendrag

  Horizontal transfer of antibiotic resistance determinants contributes to dissemination of antibiotic resistance. Such transfer of resistance genes within the human gut has been documented in some in vivo studies. The present study investigated seven bla CTX-M-1-carrying Escherichia coli isolates from three consecutive faecal samples collected from one cystic fibrosis patient in a nine-months period, by analysing whole genome sequencing data. The analyses showed that the seven E. coli isolates represented three genetically diverse strains. All isolates contained bla CTX-M-1-carrying Incl1 plasmids that shared a common 101 kb backbone differing by only four SNPs. The plasmids harboured by the three different E. coli strains varied within limited regions suggestive of recombination events, according to the phylogenetic topology of the genomes of the isolates harbouring them. The findings strongly suggest that horizontal transfer of a bla CTX-M-1-carrying plasmid had occurred within the patient´s gut. The study illustrates the within-host diversity of faecally carried resistant E. coli isolates and highlights the value of collecting multiple bacterial colonies from longitudinally collected samples to assess faecal carriage of resistant enterobacteria. The clustering of the plasmids with the corresponding E. coli strains carrying them indicates that the plasmids appear to have adapted to their respective E. coli hosts.

• Knudsen, Per Kristian; Brandtzæg, Petter; Høiby, Ernst Arne; Bohlin, Jon; Samuelsen, Ørjan & Steinbakk, Martin [Vis alle 9 forfattere av denne artikkelen] (2017). Impact of extensive antibiotic treatment on faecal carriage of antibiotic-resistant enterobacteria in children in a low resistance prevalence setting. PLOS ONE. 12(11). doi: 10.1371/journal.pone.0187618. Fulltekst i vitenarkiv Vis sammendrag

  We prospectively studied the consequences of extensive antibiotic treatment on faecal carriage of antibiotic-resistant enterobacteria in a cohort of children with cystic fibrosis (CF) and a cohort of children with cancer compared to healthy children with no or low antibiotic exposure. The study was conducted in Norway in a low resistance prevalence setting. Sixty longitudinally collected faecal samples from children with CF (n = 32), 88 samples from children with cancer (n = 45) and 127 samples from healthy children (n = 70) were examined. A direct MIC-gradient strip method was used to detect resistant Enterobacteriaceae by applying Etest strips directly onto agar-plates swabbed with faecal samples. Whole genome sequencing (WGS) data were analysed to identify resistance mechanisms in 28 multidrug-resistant Escherichia coli isolates. The prevalence of resistance to third-generation cephalosporins, gentamicin and ciprofloxacin was low in all the study groups. At inclusion the prevalence of ampicillin-resistant E. coli and trimethoprim-sulfamethoxazole-resistant E. coli in the CF group compared to healthy controls was 58.6% vs. 28.4% (p = 0.005) and 48.3% vs. 14.9% (p = 0.001), respectively, with a similar prevalence at the end of the study. The prevalence of resistant enterobacteria was not significantly different in the children with cancer compared to the healthy children, not even at the end of the study when the children with cancer had been treated with repeated courses of broad-spectrum antibiotics. Children with cancer were mainly treated with intravenous antibiotics, while the CF group mainly received peroral treatment. Our observations indicate that the mode of administration of antibiotics and the general level of antimicrobial resistance in the community may have an impact on emergence of resistance in intestinal enterobacteria during antibiotic treatment. The WGS analyses detected acquired resistance genes and/or chromosomal mutations that explained the observed phenotypic resistance in all 28 multidrug-resistant E. coli isolates examined.

• Gammelsrud, Karianne Wiger; Knudsen, Per Kristian & Høiby, Ernst Arne (2016). A novel Direct MIC-gradient Strip Method to screen for antibiotic-resistant faecal Enterobacteriaceae. Journal of Microbiological Methods. ISSN 0167-7012. 129, s. 94–97. doi: 10.1016/j.mimet.2016.08.007. Fulltekst i vitenarkiv Vis sammendrag

  A novel method to detect resistant faecal Enterobacteriaceae was developed by applying MIC-gradient strips directly onto agar plates inoculated with faeces. The method provided the susceptibility pattern (MICs) of the dominant bacterial population directly on the plates and also detected smaller resistant subpopulations with a sensitivity of 1/105.

• Kvakkestad, Kristin Marie; Gammelsrud, Karianne Wiger; Brandtzæg, Petter & Høiby, Ernst Arne (2012). Unchanged Antibiotic Susceptibility in Escherichia coli and Pseudomonas aeruginosa after Long-Term in vitro Exposure to Antineoplastic Drugs. Chemotherapy. ISSN 0009-3157. 58(2), s. 118–122. doi: 10.1159/000337058. Fulltekst i vitenarkiv
• Gammelsrud, Karianne Wiger; Langnes, Belinda; Gaustad, Peter; Ingebretsen, André; Høiby, Ernst Arne & Brandtzaeg, Petter [Vis alle 7 forfattere av denne artikkelen] (2012). Multilocus sequence typing of serial Candida albicans isolates from children with cancer, children with cystic fibrosis and healthy controls. Medical Mycology. ISSN 1369-3786. 50(6), s. 619–626. doi: 10.3109/13693786.2012.675088. Fulltekst i vitenarkiv
• Gammelsrud, Karianne Wiger; Sandven, Per; Høiby, Ernst Arne; Sandvik, Leiv; Brandtzæg, Petter & Gaustad, Peter (2011). Colonization by Candida in children with cancer, children with cystic fibrosis, and healthy controls. Clinical Microbiology and Infection (CMI). ISSN 1198-743X. 17(12), s. 1875–1881. doi: 10.1111/j.1469-0691.2011.03528.x. Fulltekst i vitenarkiv
• Høiby, Ernst Arne; Vestrheim, Didrik Frimann; Caugant, Dominique A & Gammelsrud, Karianne Wiger (2008). Bakteriell resistens mot antibiotika. Tidsskrift for Den norske legeforening (Tidsskriftet). ISSN 0029-2001. 128(21), s. 2452–2456. Fulltekst i vitenarkiv

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• Knudsen, Caroline Vestby; Akselsen, Per Espen; Fostervold, Aasmund; Gammelsrud, Karianne Wiger; Haugan, Ingvild & Husby, Alexander [Vis alle 11 forfattere av denne artikkelen] (2025). Bruk-Spar-Reserve. Tidsskrift for Den norske legeforening (Tidsskriftet). ISSN 0029-2001. 145(7). doi: 10.4045/tidsskr.25.0062. Fulltekst i vitenarkiv
• Skåland, Mari Ims; Tonby, Kristian; Ingebretsen, André; Gammelsrud, Karianne Wiger; Garborg, Kjetil Kjeldstad & Juul, Frederik Emil (2025). Clostridioides difficile-infeksjon. Tidsskrift for Den norske legeforening (Tidsskriftet). ISSN 0029-2001. 145(7). doi: 10.4045/tidsskr.24.0233. Fulltekst i vitenarkiv
• Rolfsen, Mads Peder; Gammelsrud, Karianne Wiger; Espeland, Ansgar; Bråten, Lars Christian Haugli; Mjønes, Sverre Markussen & Austevoll, Ivar Magne [Vis alle 15 forfattere av denne artikkelen] (2024). Bacterial growth in patients with low back pain and Modic changes: protocol of a multicentre, case-control biopsy study. BMJ Open. 14(5), s. 1–7. doi: 10.1136/bmjopen-2023-082244. Fulltekst i vitenarkiv Vis sammendrag

  Introduction Bacterial infection and Modic changes (MCs) as causes of low back pain (LBP) are debated. Results diverged between two randomised controlled trials examining the effect of amoxicillin with and without clavulanic acid versus placebo on patients with chronic LBP (cLBP) and MCs. Previous biopsy studies have been criticised with regard to methods, few patients and controls, and insufficient measures to minimise perioperative contamination. In this study, we minimise contamination risk, include a control group and optimise statistical power. The main aim is to compare bacterial growth between patients with and without MCs. Methods and analysis This multicentre, case–control study examines disc and vertebral body biopsies of patients with cLBP. Cases have MCs at the level of tissue sampling, controls do not. Previously operated patients are included as a subgroup. Tissue is sampled before antibiotic prophylaxis with separate instruments. We will apply microbiological methods and histology on biopsies, and predefine criteria for significant bacterial growth, possible contamination and no growth. Microbiologists, surgeons and pathologist are blinded to allocation of case or control. Primary analysis assesses significant growth in MC1 versus controls and MC2 versus controls separately. Bacterial disc growth in previously operated patients, patients with large MCs and growth from the vertebral body in the fusion group are all considered exploratory analyses. Ethics and dissemination The Regional Committees for Medical and Health Research Ethics in Norway (REC South East, reference number 2015/697) has approved the study. Study participation requires written informed consent. The study is registered at ClinicalTrials.gov (NCT03406624). Results will be disseminated in peer-reviewed journals, scientific conferences and patient fora.

• Lindemann, Paul Christoffer; Gammelsrud, Karianne Wiger; Löhr, Iren Høyland; Akselsen, Per Espen; Lindbæk, Morten & Sundsfjord, Arnfinn (2019). Valg av antibiotika - viktig endring i prøvesvar fra mikrobiologen. 139(12). doi: 10.4045/tidsskr.19.0339. Fulltekst i vitenarkiv
• Larssen, Kjersti Wik; Skutlaberg, Dag Harald; Johansen, Therese; Gammelsrud, Karianne Wiger & Mengshoel, Anne Torunn (2023). Mikrobiologisk diagnostikk av ortopediske infeksjoner: Strategimøte nr. 34, 2021 27. oktober 2021, kl. 09.30 – 16.00 FHI, Marcus Thranes gt 6. Folkehelseinstituttet. Fulltekst i vitenarkiv Vis sammendrag

  Hovedbudskap Det 34. strategimøte i regi av Referansegruppen for eksterne kvalitetsvurderinger i bakteriologi, mykologi og parasittologi omhandlet ortopediske infeksjoner og ble avholdt 27.10.2021 i FHIs lokaler i Marcus Thranes gt 6 i Oslo. På møtet deltok 34 personer fra landets medisinsk-mikrobiologiske laboratorier. I tillegg var 24 personer fra landets laboratorier påmeldt som digitale observatører. Ansvarlig programkomité, som også har ferdigstilt denne avsluttende rapporten, var Dag Harald Skutlaberg, Karianne Wiger Gammelsrud, Therese Johansen og Kjersti Wik Larssen (leder). Rapporten inneholder sammendrag med anbefalinger samt bakgrunnsinformasjon med innleggene som ble holdt på møtet. I tillegg er resultat av quest-back utsendt før møtet vedlagt rapporten. Sammendrag med anbefalinger er ført i pennen av program-komiteen i forståelse med de ansvarlige for innleggene i etterkant av møtet. Bakgrunnsinformasjonen er ført i pennen av de ansvarlige for innleggene i forståelse med programkomiteen, og ble sendt ut til deltakerne i forkant av møtet. Programkomiteen arbeidet på oppdrag fra Referansegruppen for ringtester og strategimøter i bakteriologi, mykologi og parasittologi. Bak sistnevnte står Nasjonalt forum for medisinsk mikrobiologi, som er et kollegialt forum for mikrobiologer med medisinsk ansvar ved landets laboratorier, forankret i avtaler om nasjonalt samarbeid mellom Folkehelseinstituttet og de enkelte mikrobiologiske laboratoriene i Norge.

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