Biology subjects

Urdahl, A. M.

Publications and source records attributed to Urdahl, A. M..

3 recordsLinked to original sources

bioRxiv2024

A genome-wide One Health study of Klebsiella pneumoniae in Norway reveals overlapping populations but few recent transmission events across reservoirs

Members of the Klebsiella pneumoniae species complex (KpSC) are opportunistic pathogens that cause severe and difficult-to-treat infections. KpSC are common in non-human niches, but the clinical relevance of these populations is disputed. Utilising 3,255 whole-genome sequenced isolates from human, animal and marine sources collected during 2001-2020 in Norway, we showed the KpSC populations in different niches were distinct but overlapping. Notably, human infection isolates showed greatest connectivity with each other, followed by isolates from human carriage, pigs, and bivalves. Nearly 5% of human infection isolates had close relatives ([≤]22 substitutions) amongst animal and marine isolates, despite temporally and geographically distant sampling of these sources. Infection prevention measures are essential to limit transmission within human clinical settings and reduce disease burden. However, as colonisation often precedes infection, preventing transmission that leads to colonisation, e.g. transmission between animals and humans in the community, and in the food chain, could also be beneficial.

microbiology↗

bioRxiv2021

Defining the scope of the European Antimicrobial Resistance Surveillance network in Veterinary medicine (EARS-Vet): a bottom-up and One Health approach

BackgroundBuilding the European Antimicrobial Resistance Surveillance network in Veterinary medicine (EARS-Vet) was proposed to strengthen the European One Health antimicrobial resistance (AMR) surveillance approach. ObjectivesThe objectives were to (i) define the combinations of animal species, production types, age categories, bacterial species, specimens and antimicrobials to be monitored in EARS-Vet and to (ii) determine antimicrobial test panels able to cover most combinations. MethodsThe EARS-Vet scope was defined by consensus between 26 European experts. Decisions were guided by a survey of the combinations that are relevant and feasible to monitor in diseased animals in 13 European countries (bottom-up approach). Experts also considered the One Health approach and the need for EARS-Vet to complement existing European AMR monitoring systems coordinated by the European Centre for Disease Prevention and Control (ECDC) and the European Food Safety Authority (EFSA). ResultsEARS-Vet would monitor AMR in six animal species (cattle, swine, chicken (broiler and laying hen), turkey, cat and dog), for 11 bacterial species (Escherichia coli, Klebsiella pneumoniae, Mannheimia haemolytica, Pasteurella multocida, Actinobacillus pleuropneumoniae, Staphylococcus aureus, Staphylococcus pseudintermedius, Staphylococcus hyicus, Streptococcus uberis, Streptococcus dysgalactiae and Streptococcus suis). Relevant antimicrobials for their treatment were selected (e.g. tetracyclines) and complemented with antimicrobials of more specific public health interest (e.g. carbapenems). Three test panels of antimicrobials were proposed covering most EARS-Vet combinations of relevance for veterinary antimicrobial stewardship. ConclusionsWith this scope, EARS-Vet would enable to better address animal health in the strategy to mitigate AMR and better understand the multi-sectoral AMR epidemiology in Europe.

microbiology↗

bioRxiv2020

The prevalence and genomic context of Shiga toxin 2a genes in E. coli found in cattle

Shiga toxin-producing Escherichia coli (STEC) that cause severe disease predominantly carry the toxin gene variant stx2a. However, the role of Shiga toxin in the ruminant reservoirs of this zoonotic pathogen is poorly understood and strains that cause severe disease in humans (HUSEC) likely constitute a small and atypical subset of the overall STEC flora. The aim of this study was to investigate the presence of stx2a in samples from cattle and to isolate and characterize stx2a-positive E. coli. In nationwide surveys in Sweden and Norway samples were collected from individual cattle or from cattle herds, respectively. Samples were tested for Shiga toxin genes by real-time PCR and amplicon sequencing and stx2a-positive isolates were whole genome sequenced. Among faecal samples from Sweden, stx1 was detected in 37%, stx2 in 53% and stx2a in 5% and in skin samples in 64%, 79% and 2% respectively. In Norway, 79% of the herds were positive for stx1, 93% for stx2 and 17% for stx2a. Based on amplicon sequencing the most common stx2 types in samples from Swedish cattle were stx2a and stx2d. Multilocus sequence typing (MLST) of 39 stx2a-positive isolates collected from both countries revealed substantial diversity with 19 different sequence types. Only a few classical LEE-positive HUSEC were found among the stx2a-positive isolates, notably a single O121:H19 and an O26:H11. Known LEE-negative HUSEC lineages were also recovered including O113:H21 (ST-223), O130:H11 (ST-297), and O101:H33 (ST-330). We conclude that E. coli encoding stx2a in cattle are ranging from well-known HUSEC to unknown STEC variants. Comparison of isolates from human HUS cases to related STEC from the ruminant reservoirs can help identify combinations of virulence attributes necessary to cause HUS, as well as provide a better understanding of the routes of infection for rare and emerging pathogenic STEC.

microbiology↗