Karina Frahm Kirk

Dr. Karina Frahm Kirk


Research Focus & Metrics

Academic Career Length

12Years (2015-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

View All Publications
1 June 2016 in Gut Pathogens
Verified
Journal Article
Open access
PDF file
KKKarina Frahm Kirk
Karina Frahm Kirk
HNHans Linde Nielsen
Hans Linde Nielsen
OTOle Thorlacius-Ussing
Ole Thorlacius-Ussing
HNHenrik Nielsen
Henrik Nielsen
Campylobacter concisus is a commensal of the human oral flora that has been linked to prolonged diarrhea and inflammatory bowel disease (IBD). It has been detected more often from intestinal biopsies in patients with IBD compared to healthy controls using PCR-based techniques, whereas the number of C. concisus culture-positive biopsies in previous studies has been very limited. Determining the rate of viable isolates present in the gut mucosa is of great importance when evaluating the role in different disease presentations. We therefore investigated a novel two-step cultivation procedure combining anaerobic and microaerobic incubation from several gut mucosal sites to improve isolate yield, and compared this to PCR results, from IBD patients and healthy controls. Cultivation with the novel two-step procedure yielded a higher rate of C. concisus isolates from mucosal biopsies than previously reported by other methods. From 52 IBD patients, 52/245 (21 %) biopsies were culture positive for C. concisus, while 121/245 (49 %) of biopsies were PCR positive. For 26 healthy controls, the numbers were 23/182 (13 %) and 66/182 (36 %), respectively (p < 0.001). The rate of cultivation and PCR detection was higher for IBD patients compared to healthy controls (p = 0.021, p = 0.008, respectively). Patients with IBD had a higher prevalence of C. concisus than healthy controls, by both cultivation and PCR detection. We found a higher rate of C. concisus isolates from gut mucosal biopsies in both IBD patients and healthy controls than in preceding studies, indicating that colonization of C. concisus in the gastrointestinal tract is more extensive than previously assumed.

30 January 2018 in Scientific Reports
Verified
Journal Article
Open access
PDF file
KKKarina Frahm Kirk
Karina Frahm Kirk
GMGuillaume Méric
Guillaume Méric
HNHans Linde Nielsen
Hans Linde Nielsen
Ben PascoeBen Pascoe
Ben Pascoe
SSSamuel K. Sheppard
Samuel K. Sheppard
HNHenrik Nielsen
Henrik Nielsen
Campylobacter concisus is an emerging pathogen associated with inflammatory bowel disease (IBD), yet little is known about the genetic diversity of C. concisus in relation to host niches and disease. We isolated 104 C. concisus isolates from saliva, mucosal biopsies and faecal samples from 41 individuals (26 IBD, 3 Gastroenteritis (GE), 12 Healthy controls (HC)). Whole genomes were sequenced and the dataset pan-genome examined, and genomic information was used for typing using multi-locus-sequence typing (MLST). C. concisus isolates clustered into two main groups/genomospecies (GS) with 71 distinct sequence types (STs) represented. Sampling site (p < 0.001), rather than disease phenotype (p = 1.00) was associated with particular GS. We identified 97 candidate genes associated with increase or decrease in prevalence during the anatomical descent from the oral cavity to mucosal biopsies to faeces. Genes related to cell wall/membrane biogenesis were more common in oral isolates, whereas genes involved in cell transport, metabolism and secretory pathways were more prevalent in enteric isolates. Furthermore, there was no correlation between individual genetic diversity and clinical phenotype. This study confirms the genetic heterogeneity of C. concisus and provides evidence that genomic variation is related to the source of isolation, but not clinical phenotype.

2 April 2020 in Scandinavian Journal of Gastroenterology
Verified
Journal Article
Closed access
SKSabrina Just Kousgaard
Sabrina Just Kousgaard
TMThomas Yssing Michaelsen
Thomas Yssing Michaelsen
HNHans Linde Nielsen
Hans Linde Nielsen
KKKarina Frahm Kirk
Karina Frahm Kirk
JBJakob Brandt
Jakob Brandt
OTOle Thorlacius-Ussing
Ole Thorlacius-Ussing
Objectives: Research evidence suggests that chronic pouchitis is associated with intestinal dysbiosis. Faecal microbiota transplantation (FMT) has been proposed as a possible treatment. We performed a 6-month prospective, open-label, single-centre cohort pilot-study (NCT03538366) to investigate if FMT could improve clinical outcome and alter gut microbiota in patients with chronic pouchitis. Materials and methods: Nine adult patients with chronic pouchitis were included and allocated to 14 days FMT by enemas from five faecal donors, with a 6-month follow-up. Pouchitis severity was assessed using pouchitis disease activity index (PDAI) before and after FMT. Changes in gut microbiota, and engraftment of donor’s microbiota were assessed in faecal samples. Results: All patients were treated with FMT for 14 continuous days. Overall, four of nine patients receiving FMT were in clinical remission at 30-day follow-up, and three patients remained in remission until 6-month follow-up. Clinical symptoms of pouchitis improved significantly between inclusion and 14-day follow-up (p = .02), but there was no improvement in PDAI between inclusion (mean 8.6) and 30-day follow-up (mean 5.2). Treatment with FMT caused a substantial shift in microbiota and increased microbial diversity in six patients, resembling that of the donors, with a high engraftment of specific donor microbiota. Conclusions: Symptomatic benefit in FMT treatment was found for four of nine patients with chronic pouchitis with increased microbial diversity and high engraftment of donor’s microbiota. A larger, randomised controlled study is required to fully evaluate the potential role of FMT in treating chronic pouchitis.

31 May 2021 in Digestive Diseases and Sciences
Verified
Journal Article
Closed access
PDF file
SHSandra Hertz
Sandra Hertz
JDJuliana Durack
Juliana Durack
KKKarina Frahm Kirk
Karina Frahm Kirk
HNHans Linde Nielsen
Hans Linde Nielsen
DLDin L. Lin
Din L. Lin
SLSusan V. Lynch
Susan V. Lynch

15 July 2020 in Scandinavian Journal of Gastroenterology
Verified
Journal Article
Closed access
MAMarta Emilie Yde Aagaard
Marta Emilie Yde Aagaard
KKKarina Frahm Kirk
Karina Frahm Kirk
HNHans Linde Nielsen
Hans Linde Nielsen
ITIrene Harder Tarpgaard
Irene Harder Tarpgaard
JHJesper Bach Hansen
Jesper Bach Hansen
HNHenrik Nielsen
Henrik Nielsen
Microscopic colitis (MC) is potentially induced by an inflammatory reaction to a luminal gut factor. The emerging pathogen Campylobacter concisus is associated with prolonged diarrhoea and subseque...

20 October 2020 in Microorganisms
Verified
Journal Article
Open access
PDF file
SKSabrina Just Kousgaard
Sabrina Just Kousgaard
TMThomas Yssing Michaelsen
Thomas Yssing Michaelsen
HNHans Linde Nielsen
Hans Linde Nielsen
KKKarina Frahm Kirk
Karina Frahm Kirk
MAMads Albertsen
Mads Albertsen
OTOle Thorlacius-Ussing
Ole Thorlacius-Ussing
The objective was to determine the bacterial composition in inflamed and non-inflamed pouches for comparison to the microbiota of healthy individuals. Pouch patients and healthy individuals were included between November 2017 and June 2019 at the Department of Gastrointestinal Surgery, Aalborg University Hospital, Denmark. A faecal sample was collected from all participants for microbiota analysis using 16S rRNA amplicon sequencing. Overall, 38 participants were included in the study. Eleven patients with a normally functioning pouch, 9 patients with chronic pouchitis, 6 patients with familial adenomatous polyposis, and 12 healthy individuals. Patients with chronic pouchitis had overall lower microbial diversity and richness compared to patients with a normal pouch function (p < 0.001 and p = 0.009) and healthy individuals (p < 0.001 and p < 0.001). No significant difference was found between patients with familial adenomatous polyposis and chronic pouchitis (microbial diversity p = 0.39 and richness p = 0.78). Several taxa from the family Enterobacteriaceae, especially genus Escherichia, were associated primarily with patients with chronic pouchitis, while taxa from the genus Bacteroides primarily were associated with healthy individuals and patients with a normally functioning pouch. Finally, a microbial composition gradient could be established from healthy individuals through patients with normal pouch function and familial adenomatous polyposis to patients with chronic pouchitis.