Jonas Waldenström | Linnaeus University (original) (raw)

Uploads

Papers by Jonas Waldenström

Proceedings of the Royal Society B: Biological Sciences, 2014

The Journal of general virology, Jan 22, 2015

Low pathogenic avian influenza A viruses have a natural host reservoir in wild waterbirds and the... more Low pathogenic avian influenza A viruses have a natural host reservoir in wild waterbirds and the potential to spread to other host species. Here we investigate the evolutionary, spatial and temporal dynamics of avian influenza A viruses in Eurasian wild birds. We use whole genome sequences collected as part of an intensive long-term Eurasian wild bird surveillance study and combine this genetic data with temporal and spatial information to explore the virus evolutionary dynamics. Frequent reassortment and co-circulating lineages were observed for all eight genomic RNA segments over time. There was no apparent species-specific effect on the diversity of the avian influenza A viruses. There was a spatial and temporal relationship between the Eurasian sequences and significant viral migration of avian influenza A viruses from West towards Central Asia. The observed viral migration patterns differed between segments. Further we discuss the challenges faced when analysing these surveill...

Applied and environmental microbiology, 2003

A polyphasic identification approach was used to investigate the taxonomic position of Campylobac... more A polyphasic identification approach was used to investigate the taxonomic position of Campylobacter-like isolates recovered from barnacle geese (Branta leucopsis) and Canada geese (Branta candensis). Seven strains were selected from a collection of 21 isolates and analyzed by extensive phenotypic testing; four strains were characterized by 16S rRNA gene sequence analysis. The results clearly identified the bird isolates as Helicobacter canadensis, recently described as an emerging human pathogen. This is the first report of an animal reservoir for this organism and of its presence in Europe and confirms the zoonotic potential of H. canadensis.

Applied and environmental microbiology, 2005

In order to determine the occurrence and frequency of resistant strains of the bacterium Campylob... more In order to determine the occurrence and frequency of resistant strains of the bacterium Campylobacter jejuni and to establish baseline MICs in isolates from an environmental reservoir, the resistance profiles of 10 antimicrobial substances were determined for 137 C. jejuni isolates from wild birds in Sweden. Observed MICs were generally low, with only low to moderate incidence of resistance to the tested compounds. One isolate, however, was resistant to nalidixic acid and ciprofloxacin, indicating that quinolone-resistant genotypes of C. jejuni have the potential to spread to wild bird hosts.

Applied and environmental microbiology, 2002

A total of 1,794 migrating birds trapped at a coastal site in southern Sweden were sampled for de... more A total of 1,794 migrating birds trapped at a coastal site in southern Sweden were sampled for detection of Campylobacter spp. All isolates phenotypically identified as Campylobacter jejuni and a subset of those identified as non-C. jejuni were identified to the species level by PCR-based techniques. C. jejuni was found in 5.0% of the birds, Campylobacter lari was found in 5.6%, and Campylobacter coli was found in 0.9%. An additional 10.7% of the tested birds were infected with hippurate hydrolysis-negative Campylobacter spp. that were not identified to the species level. The prevalence of Campylobacter spp. differed significantly between ecological guilds of birds. Shoreline-foraging birds feeding on invertebrates and opportunistic feeders were most commonly infected (76.8 and 50.0%, respectively). High prevalence was also shown in other ground-foraging guilds, i.e., ground-foraging invertebrate feeders (11.0%), ground-foraging insectivores (20.3%), and plant-eating species (18.8%)...

Journal of Animal Ecology, 2007

Journal of Parasitology, 2004

Journal of Ornithology, 2005

The pattern of phenotypic and molecular variation within the polytypic olivaceous warbler H. pall... more The pattern of phenotypic and molecular variation within the polytypic olivaceous warbler H. pallida was examined. This species is distributed in the southern parts of the western Palaearctic, central Asia and in the arid parts of northern Africa, and also in parts of the sub-Saharan Sahel zone. Based on morphology, five subspecies, at times assigned to three groups, have been

Applied and Environmental Microbiology, 2015

Proceedings of the Royal Society B: Biological Sciences, 2014

The Journal of general virology, Jan 22, 2015

Low pathogenic avian influenza A viruses have a natural host reservoir in wild waterbirds and the... more Low pathogenic avian influenza A viruses have a natural host reservoir in wild waterbirds and the potential to spread to other host species. Here we investigate the evolutionary, spatial and temporal dynamics of avian influenza A viruses in Eurasian wild birds. We use whole genome sequences collected as part of an intensive long-term Eurasian wild bird surveillance study and combine this genetic data with temporal and spatial information to explore the virus evolutionary dynamics. Frequent reassortment and co-circulating lineages were observed for all eight genomic RNA segments over time. There was no apparent species-specific effect on the diversity of the avian influenza A viruses. There was a spatial and temporal relationship between the Eurasian sequences and significant viral migration of avian influenza A viruses from West towards Central Asia. The observed viral migration patterns differed between segments. Further we discuss the challenges faced when analysing these surveill...

Applied and environmental microbiology, 2003

A polyphasic identification approach was used to investigate the taxonomic position of Campylobac... more A polyphasic identification approach was used to investigate the taxonomic position of Campylobacter-like isolates recovered from barnacle geese (Branta leucopsis) and Canada geese (Branta candensis). Seven strains were selected from a collection of 21 isolates and analyzed by extensive phenotypic testing; four strains were characterized by 16S rRNA gene sequence analysis. The results clearly identified the bird isolates as Helicobacter canadensis, recently described as an emerging human pathogen. This is the first report of an animal reservoir for this organism and of its presence in Europe and confirms the zoonotic potential of H. canadensis.

Applied and environmental microbiology, 2005

In order to determine the occurrence and frequency of resistant strains of the bacterium Campylob... more In order to determine the occurrence and frequency of resistant strains of the bacterium Campylobacter jejuni and to establish baseline MICs in isolates from an environmental reservoir, the resistance profiles of 10 antimicrobial substances were determined for 137 C. jejuni isolates from wild birds in Sweden. Observed MICs were generally low, with only low to moderate incidence of resistance to the tested compounds. One isolate, however, was resistant to nalidixic acid and ciprofloxacin, indicating that quinolone-resistant genotypes of C. jejuni have the potential to spread to wild bird hosts.

Applied and environmental microbiology, 2002

A total of 1,794 migrating birds trapped at a coastal site in southern Sweden were sampled for de... more A total of 1,794 migrating birds trapped at a coastal site in southern Sweden were sampled for detection of Campylobacter spp. All isolates phenotypically identified as Campylobacter jejuni and a subset of those identified as non-C. jejuni were identified to the species level by PCR-based techniques. C. jejuni was found in 5.0% of the birds, Campylobacter lari was found in 5.6%, and Campylobacter coli was found in 0.9%. An additional 10.7% of the tested birds were infected with hippurate hydrolysis-negative Campylobacter spp. that were not identified to the species level. The prevalence of Campylobacter spp. differed significantly between ecological guilds of birds. Shoreline-foraging birds feeding on invertebrates and opportunistic feeders were most commonly infected (76.8 and 50.0%, respectively). High prevalence was also shown in other ground-foraging guilds, i.e., ground-foraging invertebrate feeders (11.0%), ground-foraging insectivores (20.3%), and plant-eating species (18.8%)...

Journal of Animal Ecology, 2007

Journal of Parasitology, 2004

Journal of Ornithology, 2005

The pattern of phenotypic and molecular variation within the polytypic olivaceous warbler H. pall... more The pattern of phenotypic and molecular variation within the polytypic olivaceous warbler H. pallida was examined. This species is distributed in the southern parts of the western Palaearctic, central Asia and in the arid parts of northern Africa, and also in parts of the sub-Saharan Sahel zone. Based on morphology, five subspecies, at times assigned to three groups, have been

Applied and Environmental Microbiology, 2015

Log In