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| 3. |
- Bonnedahl, Jonas, 1970-, et al.
(författare)
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Antibiotic susceptibility of faecal bacteria in Antarctic penguins
- 2008
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Ingår i: Polar Biology. - : Springer. - 0722-4060 .- 1432-2056. ; 31:6, s. 759-763
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Tidskriftsartikel (refereegranskat)abstract
- Faecal bacteria from 49 Gentoo penguins on the Antarctic Peninsula were identified by biochemical methods and sequencing, and tested for antibiotic susceptibility using agar dilution. Of the 42 Enterobacteriaceae isolates found, 39 belonged to the genus Edwardsiella. All isolates were susceptible to the 17 antibiotics tested. This implies that antibiotic selection pressure is a prerequisite to a high prevalence of antibiotic resistance, and in the absence of contact with human activities, antibiotic resistance in Enterobacteriaceae remains undetectable.
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| 4. |
- Bonnedahl, Jonas, et al.
(författare)
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In search of human-associated bacterial pathogens in Antarctic wildlife : report from six penguin colonies regularly visited by tourists.
- 2005
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Ingår i: Ambio: A Journal of the Human Environment. - : Springer. - 0044-7447 .- 1654-7209. ; 34:6, s. 430-2
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Tidskriftsartikel (refereegranskat)abstract
- We investigated the potential role of Antarctic tourism in the introduction of human-associated pathogens into Antarctic wildlife. We collected and analyzed 233 fecal samples from eight bird species. The samples were collected at six localities on the Antarctic Peninsula, which often is visited by tourists. Every sample was investigated for pathogens of potential human origin: Campylobacter jejuni, Salmonella spp., and Yersina spp. None of these bacteria was found. Our data suggest that the tourism industry so far has achieved its goal of not introducing pathogens into the Antarctic region. There is, however, an urgent need to further investigate the situation in areas closer to permanent Antarctic settlements.
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| 10. |
- Debruyne, Lies, et al.
(författare)
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Campylobacter subantarcticus sp. nov., isolated from birds in the sub-Antarctic region
- 2010
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Ingår i: International Journal of Systematic and Evolutionary Microbiology. - : Microbiology Society. - 1466-5026 .- 1466-5034. ; 60:Pt 4, s. 815-819
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Tidskriftsartikel (refereegranskat)abstract
- Six Gram-stain-negative, spiral-shaped, microaerobic isolates were obtained during a sampling from wild birds in the sub-Antarctic region. Based on initial observations, these isolates were classified as Campylobacter lari-like. The isolates were further characterized by whole-cell protein and amplified fragment length polymorphism (AFLP) analysis, which revealed that they were distinct from C. lari and all other known species of the genus Campylobacter. Here, we present comprehensive phylogenetic, genomic and phenotypic evidence that these isolates represent a novel species within the genus Campylobacter, for which the name Campylobacter subantarcticus sp. nov. is proposed. The type strain is R-3023(T) (=LMG 24377(T) =CCUG 38513(T)).
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| 11. |
- Debruyne, Lies, et al.
(författare)
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Campylobacter volucris sp. nov., isolated from black-headed gulls (Larus ridibundus)
- 2010
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Ingår i: International Journal of Systematic and Evolutionary Microbiology. - : Microbiology Society. - 1466-5026 .- 1466-5034. ; 60:8, s. 1870-1875
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Tidskriftsartikel (refereegranskat)abstract
- During a study of the prevalence of Campylobacter jejuni in black-headed gulls (Larus ridibundus) in Sweden, three isolates were initially identified as Campylobacter lari. Further characterization by both AFLP and whole-cell protein SDS-PAGE analysis revealed that they formed a distinct group in the Campylobacter genus. This unique position was confirmed by phenotypic characterization, 16S rRNA and hsp60 gene sequence analysis, and DNA-DNA hybridisations. The combined data confirm that these isolates represent a novel species within the genus Campylobacter, for which the name Campylobacter volucris sp. nov. is proposed. The type strain is LMG 24380T (=CCUG 57498T).
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| 13. |
- Hansson, Magnus L., et al.
(författare)
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Artificial spider silk supports and guides neurite extension in vitro
- 2021
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Ingår i: The FASEB Journal. - : John Wiley & Sons. - 0892-6638 .- 1530-6860. ; 35:11
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Tidskriftsartikel (refereegranskat)abstract
- Surgical intervention with the use of autografts is considered the gold standard to treat peripheral nerve injuries. However, a biomaterial that supports and guides nerve growth would be an attractive alternative to overcome problems with limited availability, morbidity at the site of harvest, and nerve mismatches related to autografts. Native spider silk is a promising material for construction of nerve guidance conduit (NGC), as it enables regeneration of cm-long nerve injuries in sheep, but regulatory requirements for medical devices demand synthetic materials. Here, we use a recombinant spider silk protein (NT2RepCT) and a functionalized variant carrying a peptide derived from vitronectin (VN-NT2RepCT) as substrates for nerve growth support and neurite extension, using a dorsal root ganglion cell line, ND7/23. Two-dimensional coatings were benchmarked against poly-d-lysine and recombinant laminins. Both spider silk coatings performed as the control substrates with regards to proliferation, survival, and neurite growth. Furthermore, NT2RepCT and VN-NT2RepCT spun into continuous fibers in a biomimetic spinning set-up support cell survival, neurite growth, and guidance to an even larger extent than native spider silk. Thus, artificial spider silk is a promising biomaterial for development of NGCs.
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| 14. |
- Holmberg, Carl Jacob, et al.
(författare)
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The efficacy of immune checkpoint blockade for melanoma in-transit with or without nodal metastases - A multicenter cohort study
- 2022
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Ingår i: EUROPEAN JOURNAL OF CANCER. - : Elsevier BV. - 0959-8049 .- 1879-0852. ; 40:16
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: Guidelines addressing melanoma in-transit metastasis (ITM) recommend immune checkpoint inhibitors (ICI) as a first-line treatment option, despite the fact that there are no efficacy data available from prospective trials for exclusively ITM disease. The study aims to analyze the outcome of patients with ITM treated with ICI based on data from a large cohort of patients treated at international referral clinics. Methods: A multicenter retrospective cohort study of patients treated between January 2015 and December 2020 from Australia, Europe, and the USA, evaluating treatment with ICI for ITM with or without nodal involvement (AJCC8 N1c, N2c, and N3c) and without distant disease (M0). Treatment was with PD-1 inhibitor (nivolumab or pembrolizumab) and/or CTLA-4 inhibitor (ipilimumab). The response was evaluated according to the RECIST criteria modified for cutaneous lesions. Results: A total of 287 patients from 21 institutions in eight countries were included. Immunotherapy was first-line treatment in 64 (22%) patients. PD-1 or CTLA-4 inhibitor monotherapy was given in 233 (81%) and 23 (8%) patients, respectively, while 31 (11%) received both in combination. The overall response rate was 56%, complete response (CR) rate was 36%, and progressive disease (PD) rate was 32%. Median PFS was ten months (95% CI 7.4-12.6 months) with a one-, two-, and five-year PFS rate of 48%, 33%, and 18%, respectively. Median MSS was not reached, and the one-, two-, and five-year MSS rates were 95%, 83%, and 71%, respectively. Conclusion: Systemic immunotherapy is an effective treatment for melanoma ITM. Future studies should evaluate the role of systemic immunotherapy in the context of multimodality therapy, including locoregional treatments such as surgery, intralesional therapy, and regional therapies.
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| 15. |
- Jansson, Desirée, et al.
(författare)
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Intestinal spirochaetes (genus Brachyspira) colonise wild birds in the southern Atlantic region and Antarctica
- 2015
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Ingår i: Infection Ecology & Epidemiology. - : Informa UK Limited. - 2000-8686. ; 5
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Tidskriftsartikel (refereegranskat)abstract
- INTRODUCTION: The genus Brachyspira contains well-known enteric pathogens of veterinary significance, suggested agents of colonic disease in humans, and one potentially zoonotic agent. There are recent studies showing that Brachyspira are more widespread in the wildlife community than previously thought. There are no records of this genus in wildlife from the southern Atlantic region and Antarctica. Our aim was therefore, to determine whether intestinal spirochaetes of genus Brachyspira colonise marine and coastal birds in this region.METHOD: Faecal samples were collected from marine and coastal birds in the southern Atlantic region, including sub-Antarctic islands and Antarctica, in 2002, 2009, and 2012, with the aim to isolate and characterise zoonotic agents. In total, 205 samples from 11 bird species were selectively cultured for intestinal spirochaetes of genus Brachyspira. To identify isolates to species level, they were subjected to phenotyping, species-specific polymerase chain reactions, sequencing of partial 16S rRNA, NADH oxidase (nox), and tlyA genes, and phylogenetic analysis. Antimicrobial susceptibility tests were performed.RESULTS: Fourteen unique strains were obtained from 10 birds of three species: four snowy sheathbills (Chionis albus), three kelp geese (Chloephaga hybrida subsp. malvinarum), and three brown skua (Stercorarius antarcticus subsp. lonnbergi) sampled on the Falkland Islands, Tierra del Fuego in Argentina, South Georgia, South Shetland Islands, and the Antarctic Peninsula. Five Brachyspira strains were closely related to potentially enteropathogenic Brachyspira sp. of chickens: B. intermedia (n=2, from snowy sheathbills), and B. alvinipulli (n=3, from a kelp goose and two snowy sheathbills). Three strains from kelp geese were most similar to the presumed non-pathogenic species 'B. pulli' and B. murdochii, whereas the remaining six strains could not be attributed to currently known species. No isolates related to human strains were found. None of the tested strains showed decreased susceptibility to tiamulin, valnemulin, doxycycline, tylvalosin, lincomycin, or tylosin.CONCLUSIONS: This is the first report of intestinal spirochaetes from this region. Despite limitations of current diagnostic methods, our results, together with earlier studies, show that Brachyspira spp., including potentially pathogenic strains, occur globally among free-living avian hosts, and that this genus encompasses a higher degree of biodiversity than previously recognised.
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| 17. |
- Lundström, Jan O, et al.
(författare)
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The geographic distribution of mosquito species in Sweden
- 2013
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Ingår i: Journal of the European Mosquito Control Association. - 2054-930X .- 1460-6127. ; 31, s. 21-35
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Tidskriftsartikel (refereegranskat)abstract
- Surveillance of the actual distribution of mosquito species in Northern Europe is fundamental for evaluating risk for emerging pathogens, and for research on potential vectors. The Swedish mosquito fauna composition and geographic distribution, originally described by Professor Christine Dahl in the 1970´s, included 43 species. We have compiled the information published from 1978 to 2012, and our own surveillance data from 2001 to 2013, and compared this with the species list and geographic distribution provided in "Taxonomy and geographic distribution of Swedish Culicidae" by Dahl (1977). New species detected during these 36 years were Culiseta (Culicella) ochroptera (Peus, 1935) published 1984, Aedes (Aedes) rossicus Dolbeskin, Goritzkaja & Mitrofanova, 1930 published 1986, Anopheles (Anopheles) beklemishevi published 1986, Aedes (Ochlerotatus) euedes (Howard, Dyar & Knab, 1912) published 2001, Aedes (Ochlerotatus) nigrinus (Eckstein, 1918) first recorded in 2012, and Anopheles (Anopheles) algeriensis Theobald, 1903, first recorded in 2013. We provide maps with the distribution by province for each species, including historic information up until 1977, and new records from 1978 to 2013, showing the similarities and differences between the old and the new records. Important findings in recent years include the wide distribution of the Sindbis virus enzootic vector Culex (Culex) torrentium Martinii, 1925, and the more limited distribution of the potential West Nile virus vector Culex (Culex) pipiens Linnaeus, 1758. The updated list of mosquito species in Sweden now includes 49 species.
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| 21. |
- Palmgren, Helena, 1955-, et al.
(författare)
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Salmonella in Black-headed gulls ( Larus ridibundus); prevalence, genotypes and influence on Salmonella epidemiology.
- 2006
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Ingår i: Epidemiology and Infection. - 0950-2688 .- 1469-4409. ; 134:3, s. 635-644
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Tidskriftsartikel (refereegranskat)abstract
- During a period of 3 years, 1998-2000, 1047 faecal swabs from Black-headed gulls were sampled at one location in Southern Sweden. Salmonella spp. was found in 28 individuals (2.7%) and the dominating serotype found was S. Typhimurium (83%). Twenty-five per cent of the Salmonella-infected gulls were later recaptured and re-sampled. We found that Salmonella infection in Black-headed gulls was of short duration, and that infection in this bird species was predominantly expressed as carriage without disease manifestations. All S. Typhimurium isolates were subjected to antibiotic resistance profiling and molecular characterization by pulsed-field gel electrophoresis and IS200 polymerase chain reaction. The S. Typhimurium gull isolates were compared to human and domestic animal isolates of the same serotype and phage type. We found genetic relatedness of S. Typhimurium DT195 isolates from gulls, domestic animals and humans, indicating that Black-headed gulls might play a role in the spread of S. Typhimurium in Sweden.
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| 22. |
- Palmgren, Helena, 1955-, et al.
(författare)
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Salmonella in sub-Antarctica : low heterogeneity in salmonella serotypes in South Georgian seals and birds
- 2000
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Ingår i: Epidemiology and Infection. - : Cambridge University Press. - 0950-2688 .- 1469-4409. ; 125:2, s. 257-262
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Tidskriftsartikel (refereegranskat)abstract
- The number of human visitors to Antarctica is increasing rapidly, and with it a risk of introducing infectious organisms to native animals. To study the occurrence of salmonella serotypes in sub- Antarctic wildlife, faecal samples were collected from gentoo penguins, macaroni penguins, gray-headed albatrosses, black-browed albatrosses and Antarctic fur seals on Bird Island in the South Georgian archipelago during the austral summer of 1996 and 1998. In 1996, S. havana, S. typhimurium and S. enteritidis were isolated from 7% of gentoo penguins and 4% of fur seals. In 1998, however, 22% of fur seals were found to be infected with S. havana, S. enteritidis and S. newport. All isolates, except one, showed identical pulsed-field gel electrophoresis-patterns within each serotype, irrespective of sampling year and animal reservoir. No significant antibiotic resistance was found. The very low heterogeneity in the salmonella isolates found could either indicate a high genetic adaptation of the bacteria to the environment or a recent introduction of salmonella into the area.
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| 25. |
- Sjodin, Andreas, et al.
(författare)
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The Need for High-Quality Whole-Genome Sequence Databases in Microbial Forensics
- 2013
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Ingår i: Biosecurity and Bioterrorism. - : Mary Ann Liebert Inc. - 1557-850X .- 1538-7135. ; 11, s. 78-86
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Tidskriftsartikel (refereegranskat)abstract
- Microbial forensics is an important part of a strengthened capability to respond to biocrime and bioterrorism incidents to aid in the complex task of distinguishing between natural outbreaks and deliberate acts. The goal of a microbial forensic investigation is to identify and criminally prosecute those responsible for a biological attack, and it involves a detailed analysis of the weapon-that is, the pathogen. The recent development of next-generation sequencing (NGS) technologies has greatly increased the resolution that can be achieved in microbial forensic analyses. It is now possible to identify, quickly and in an unbiased manner, previously undetectable genome differences between closely related isolates. This development is particularly relevant for the most deadly bacterial diseases that are caused by bacterial lineages with extremely low levels of genetic diversity. Whole-genome analysis of pathogens is envisaged to be increasingly essential for this purpose. In a microbial forensic context, whole-genome sequence analysis is the ultimate method for strain comparisons as it is informative during identification, characterization, and attribution-all 3 major stages of the investigation-and at all levels of microbial strain identity resolution (ie, it resolves the full spectrum from family to isolate). Given these capabilities, one bottleneck in microbial forensics investigations is the availability of high-quality reference databases of bacterial whole-genome sequences. To be of high quality, databases need to be curated and accurate in terms of sequences, metadata, and genetic diversity coverage. The development of whole-genome sequence databases will be instrumental in successfully tracing pathogens in the future.
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| 27. |
- Waldenström, Jonas, et al.
(författare)
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Antimicrobial resistance profiles of Campylobacter jejuni isolates from wild birds in Sweden.
- 2005
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Ingår i: Applied and Environmental Microbiology. - 0099-2240. ; 71:5, s. 2438-41
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Tidskriftsartikel (refereegranskat)abstract
- 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.
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| 29. |
- Waldenström, Jonas, et al.
(författare)
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Prevalence of Campylobacter jejuni, Campylobacter lari, and Campylobacter coli in different ecological guilds and taxa of migrating birds
- 2002
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Ingår i: Applied and Environmental Microbiology. - 0099-2240. ; 68:12, s. 5911-5917
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Tidskriftsartikel (refereegranskat)abstract
- 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%). Almost no Campylobacter spp. were found in ground-foraging granivores (2.3%), arboreal insectivores (0.6%), aerial insectivores (0%), or reed- and herbaceous plant-foraging insectivores (3.5%). During the autumn migration, a high proportion of samples from juveniles were positive (7.1% in passerines, 55.0% in shorebirds), indicating transmission on the breeding grounds or during the early part of migration. Prevalence of Campylobacter spp. was associated with increasing body mass among passerine bird species. Furthermore, prevalence was higher in short-distance migrants wintering in Europe than in long-distance migrants wintering in Africa, the Middle East, or Asia. Among ground-foraging birds of the Muscicapidae, those of the subfamily Turdinae (i.e., Turdus spp.) showed a high prevalence of Campylobacter spp., while the organism was not isolated in any member of the subfamily Muscicapinae (i.e., Erithacus and Luscinia). The prevalence of Campylobacter infection in wild birds thus seems to be linked to various ecological and phylogenetic factors, with great variations in carriership between different taxa and guilds.
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| 31. |
- Wallensten, Anders, 1974-, et al.
(författare)
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Mounting evidence for the presence of influenza A virus in the avifauna of the Antarctic region
- 2006
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Ingår i: Antarctic Science. - New York : Cambridge University Press. - 0954-1020 .- 1365-2079. ; 18:3, s. 353-356
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Tidskriftsartikel (refereegranskat)abstract
- Penguin blood samples collected at Bird Island, sub-Antarctic South Georgia, and faecal samples taken from penguins at several localities along the Antarctic Peninsula were analysed in order to investigate if influenza A virus is present in penguin populations in the South Atlantic Antarctic region. Serology was performed on the blood samples while the faecal samples were screened by a RT-PCR method directed at the matrix protein gene for determining the presence of influenza A virus. All faecal samples were negative by PCR, but the blood samples gave serologic indications that influenza A virus is present amongst these penguin species, confirming previous studies, although the virus has still not been isolated from any bird in the Antarctic region.
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