Disputas: Silje Bakken Jørgensen - Clinical microbiology

Cand.med. Silje Bakken Jørgensen at Institute of Clinical Medicine will be defending the thesis Extended-spectrum β-lactamases – aspects on human carriage and distribution in aquatic environments for the degree of PhD.

Foto: Kjetil Telle

Trial lecture - time and Place

See trial lecture.

Adjudication committee

  • 1st  opponent: Professor Åsa Melhus, Uppsala universitet
  • 2nd opponent: Professor Jan Egil Afset, Norges teknisk-naturvitenskaplige universitet (NTNU)
  • Committee chair: Dr. Karianne Wiger Gammelsrud, University of Oslo

Chair of the defence

Professor Olav Dalgard,

Principal Supervisor

 Pål A. Jenum,


Antimicrobial drug resistance has become one of the major global health challenges of the 21st century. The problem is linked to global movement of people, food and goods, veterinary medicine, food production, water, hygiene and sanitation challenges. Consequently, a One Health perspective is needed to understand and combat the increasing threat. This thesis within the field of clinical microbiology explores different aspects of extended-spectrum β-lactamases (ESBLs), which are enzymes that confer resistance to our most frequently used antimicrobial drugs. The overarching aim of the thesis was to increase our knowledge regarding the occurrence, dissemination and persistence of ESBL-producing bacteria in different ecological compartments in Norway. These questions were addressed through studies of two different patient cohorts and sampling from water at popular beaches and a wastewater plant in Oslo and Akershus counties. We found that previous travel to Asia was an important risk factor for ESBL carriage in patients with gastroenteritis. In patients who had had a urinary tract infection with ESBL-bacteria, the median fecal carriage duration was 12 months. The bacteria were also frequently found in aquatic environments, where all the wastewater samples and 40 % of the recreational samples were positive for ESBL-bacteria. Some of the bacterial strains from recreational water and wastewater had the same genetic fingerprint as strains from urinary tract infections. Hence, our studies confirm that ESBL-bacteria, including strains that are able to cause infection in humans, are present in recreational water where there is potential for subsequent colonisation and infection in humans. Our findings can contribute to improved antibiotic surveillance strategies and infection control recommendations.

Additional information

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Publisert 30. okt. 2018 15:50 - Sist endret 5. nov. 2018 15:20