Prof. Dr. Henning Sørum

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Academic Career Length

28Years (1999-Present)

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

Representative Publications

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1 March 2019 in Science Advances

Journal Article

Antibiotic resistance in European wastewater treatment plants mirrors the pattern of clinical antibiotic resistance prevalence

Katariina M. M. Pärnänen

Carlos Narciso-Da-Rocha

+20

The antibiotic resistome in European UWTPs mirrors the gradient of north-to-south clinical antibiotic resistance prevalence.

24 February 2014 in Environmental Microbiology

Journal Article

Antimicrobial resistance and antimicrobial resistance genes in marine bacteria from salmon aquaculture and non‐aquaculture sites

Syed Q. A. Shah

Felipe C. Cabello

Trine M. L'ABée‐Lund

Alexandra Tomova

Henry Godfrey

Henning Sørum

Summary: Antimicrobial resistance ( AR ) detected by disc diffusion and antimicrobial resistance genes detected by DNA hybridization and polymerase chain reaction with amplicon sequencing were studied in 124 marine bacterial isolates from a C hilean salmon aquaculture site and 76 from a site without aquaculture 8 km distant. Resistance to one or more antimicrobials was present in 81% of the isolates regardless of site. Resistance to tetracycline was most commonly encoded by tetA and tetG ; to trimethoprim, by dfrA1, dfrA5 and dfrA12 ; to sulfamethizole, by sul1 and sul2 ; to amoxicillin, by bla _TEM ; and to streptomycin, by strA‐strB . Integron integrase intl1 was detected in 14 sul1 ‐positive isolates, associated with aad9 gene cassettes in two from the aquaculture site. intl2 Integrase was only detected in three dfrA1 ‐positive isolates from the aquaculture site and was not associated with gene cassettes in any. Of nine isolates tested for conjugation, two from the aquaculture site transferred AR determinants to E scherichia coli . High levels of AR in marine sediments from aquaculture and non‐aquaculture sites suggest that dispersion of the large amounts of antimicrobials used in Chilean salmon aquaculture has created selective pressure in areas of the marine environment far removed from the initial site of use of these agents.

1 September 2001 in Microbial Drug Resistance

Journal Article

Class 1 Integrons Mediate Antibiotic Resistance in the Fish Pathogen Aeromonas salmonicida Worldwide

T M L'Abée-Lund

Henning Sørum

The presence of class 1 integrons was investigated in 38 sulfonamide-resistant strains of Aeromonas salmonicida subsp. salmonicida , atypical A. salmonicida and Escherichia coli conjugants with R plasmids originating from A. salmonicida . The strains originated from Finland, France, Japan, Norway, Scotland, Switzerland, and the United States. Additional resistance determinants in strains with class 1 integrons were also determined. Of 21 strains containing a class 1 integron, 19 had a single gene cassette, 1 strain had two cassettes, and 1 strain was found to lack an integrated gene cassette. In the integrons with single cassettes, aadA2 was present in eight strains, dfr16 in five strains, and aadA1 and dfrIIc in three strains each. In the integron with two cassettes, qacG and orfD were present. Tetracycline resistance was observed in 20 of the integron-positive strains, caused by the determinants Tet A and Tet E, in which Tet A frequently was associated with Tn 1721 . Class 1 integrons seem to be important in mediating antibiotic resistance also in the marine environment. The gene cassettes reported in this study are all described in bacteria associated with humans, and this demonstrates once more how the common gene pool is shared between organisms belonging to different environments.

10 June 2015 in BMC Genomics

Journal Article

Co-cultivation and transcriptome sequencing of two co-existing fish pathogens Moritella viscosa and Aliivibrio wodanis

Aliivibrio wodanis and Moritella viscosa have often been isolated concurrently from fish with winter-ulcer disease. Little is known about the interaction between the two bacterial species and how the presence of one bacterial species affects the behaviour of the other. The impact on bacterial growth in co-culture was investigated in vitro, and the presence of A. wodanis has an inhibitorial effect on M. viscosa. Further, we have sequenced the complete genomes of these two marine Gram-negative species, and have performed transcriptome analysis of the bacterial gene expression levels from in vivo samples. Using bacterial implants in the fish abdomen, we demonstrate that the presence of A. wodanis is altering the gene expression levels of M. viscosa compared to when the bacteria are implanted separately. From expression profiling of the transcriptomes, it is evident that the presence of A. wodanis is altering the global gene expression of M. viscosa. Co-cultivation studies showed that A. wodanis is impeding the growth of M. viscosa, and that the inhibitorial effect is not contact-dependent.

31 October 2008 in Microbial Pathogenesis

Journal Article

Motility and flagellin gene expression in the fish pathogen Vibrio salmonicida: Effects of salinity and temperature

Simone Krinner

1 December 2017 in Proteomes

Journal Article

Isolation and Characterization of Serum Extracellular Vesicles (EVs) from Atlantic Salmon Infected with Piscirickettsia Salmonis

Leidy Lagos

Julia Tandberg

Alexander Kashulin-Bekkelund

Duncan Colquhoun

Henning Sørum

Hanne C. Winther-Larsen

Secretion of extracellular vesicles (EVs) is a common feature of both eukaryotic and prokaryotic cells. Isolated EVs have been shown to contain different types of molecules, including proteins and nucleic acids, and are reported to be key players in intercellular communication. Little is known, however, of EV secretion in fish, or the effect of infection on EV release and content. In the present study, EVs were isolated from the serum of healthy and Piscirickettsia salmonis infected Atlantic salmon in order to evaluate the effect of infection on EV secretion. P. salmonis is facultative intracellular bacterium that causes a systemic infection disease in farmed salmonids. EVs isolated from both infected and non-infected fish had an average diameter of 230–300 nm, as confirmed by transmission electron microscopy, nanoparticle tracking, and flow cytometry. Mass spectrometry identified 180 proteins in serum EVs from both groups of fish. Interestingly, 35 unique proteins were identified in serum EVs isolated from the fish infected with P. salmonis. These unique proteins included proteasomes subunits, granulins, and major histocompatibility class I and II. Our results suggest that EV release could be part of a mechanism in which host stimulatory molecules are released from infected cells to promote an immune response.

About Me

Name: Henning Sørum; Current position: Professor in Bacteriology; Education: 1978–83 Cand. med. vet, School of Veterinary Science, Oslo, Norway; 1984–86 Research work as a Ph.D. student with a degree of Doctor Scientiarum in 1986. Work experience: Ph.D. students supervised: 45 finished; 5 under supervision. Lecturing and coursing Veterinary students at the Norwegian School of Veterinary Medicine since January 1984 and full responsibility for teaching Bacteriology and Mycology to Veterinary students and Animal nurses since 1995. Supervised 6 Master's students and 11 Bachelor's students from various Norwegian universities and 19 veterinary student research tasks. Practitioner as an acute call surgeon on the weekends since 1984. Current and previous research interests: Antibiotic resistance in husbandry animals and farmed salmonids involving bacterial pathogens and normal gut microbiota. Effects of organic acids in the feed and antibiotic treatment of bacterial infections on the gut microbiota. Studies of bacteria in marine sediments of fish farms and human sewage. Investigating novel bacterial infections in the Norwegian salmon farming industry, including characterization of novel fish pathogenic bacterial agents and genetic analysis of the development of antibiotic resistance in bacteria of fish farms related to antibiotic use in controlling infections. Member of EAFP (European Association of Fish Pathologists), American Society of Microbiology.

Prof. Dr. Henning Sørum

Prof. Dr. Henning Sørum

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