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  • 1. Ahlm, Clas
    et al.
    Olsen, Björn
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Koskinen, Lars-Owe D
    Monsen, Tor
    Brain abscess caused by methicillin resistant Staphylococcus aureus (MRSA)2000In: Scandinavian Journal of Infectious Diseases, Vol. 32, p. 562-563Article in journal (Refereed)
  • 2.
    Ardiles-Villegas, Karen
    et al.
    Universidad de Concepción, Chile.
    González-Acuña, Daniel
    Universidad de Concepción, Chile.
    Waldenström, Jonas
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Olsen, Björn
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences. Uppsala University.
    Hernandez, Jorge
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences. Uppsala University.
    Antibiotic resistance patterns in fecal bacteria isolated from Christmas shearwater (Puffinus nativitatis) and masked booby (Sula dactylatra) at remote Easter Island2011In: Avian diseases, ISSN 0005-2086, E-ISSN 1938-4351, Vol. 55, no 3, p. 486-489Article in journal (Refereed)
    Abstract [en]

    Antibiotic use and its implications have been discussed extensively in the past decades. This situation has global consequences when antibiotic resistance becomes widespread in the intestinal bacterial flora of stationary and migratory birds. This study investigated the incidence of fecal bacteria and general antibiotic resistance, with special focus on extended spectrum beta-lactamase (ESBL) isolates, in two species of seabirds at remote Easter Island. We identified 11 species of bacteria from masked booby (Sula dactylatra) and Christmas shearwater (Puffinus nativitatis); five species of gram-negative bacilli, four species of Streptococcus (Enterococcus), and 2 species of Staphylococcus. In addition, 6 types of bacteria were determined barely to the genus level. General antibiotic susceptibility was measured in the 30 isolated Enterobacteriaceae to 11 antibiotics used in human and veterinary medicine. The 10 isolates that showed a phenotypic ESBL profile were verified by clavulanic acid inhibition in double mixture discs with cefpodoxime, and two ESBL strains were found, one strain in masked booby and one strain in Christmas shearwater. The two bacteria harboring the ESBL type were identified as Serratia odorifera biotype 1, which has zoonotic importance. Despite minimal human presence in the masked booby and Christmas shearwater habitats, and the extreme geographic isolation of Easter Island, we found several multiresistant bacteria and even two isolates with ESBL phenotypes. The finding of ESBLs has animal and public health significance and is of potential concern, especially because the investigation was limited in size and indicated that antibiotic-resistant bacteria now are distributed globally.

  • 3.
    Axelsson Olsson, Diana
    et al.
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Ellström, Patrik
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Waldenström, Jonas
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Haemig, Paul D
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Brudin, Lars
    Olsen, Björn
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Acanthamoeba-Campylobacter coculture as a novel method for enrichment of Campylobacter species2007In: Applied and Environmental Microbiology, Vol. 73, no 21, p. 6864-6869Article in journal (Refereed)
    Abstract [en]

    In this study, we present a novel method to isolate and enrich low concentrations of Campylobacter pathogens. This method, Acanthamoeba-Campylobacter coculture (ACC), is based on the intracellular survival and multiplication of Campylobacter species in the free-living protozoan Acanthamoeba polyphaga. Four of the Campylobacter species relevant to humans and livestock, Campylobacter jejuni, C. coli, C. lari, and C. hyointestinalis, were effectively enriched by the coculture method, with growth rates comparable to those observed in other Campylobacter enrichment media. Studying six strains of C. jejuni isolated from different sources, we found that all of the strains could be enriched from an inoculum of fewer than 10 bacteria. The sensitivity of the ACC method was not negatively affected by the use of Campylobacter-selective antibiotics in the culture medium, but these were effective in suppressing the growth of seven different bacterial species added at a concentration of 10(4) CFU/ml of each species as deliberate contamination. The ACC method has advantages over other enrichment methods as it is not dependent on a microaerobic milieu and does not require the use of blood or other oxygen-quenching agents. Our study found the ACC method to be a promising tool for the enrichment of Campylobacter species, particularly from water samples with low bacterial concentrations.

  • 4.
    Axelsson Olsson, Diana
    et al.
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Olofsson, Jenny
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Ellström, Patrik
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Waldenström, Jonas
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Olsen, Björn
    University of Kalmar, School of Pure and Applied Natural Sciences.
    A simple method for long-term storage Acanthamoeba species2009In: Parasitology Research, ISSN 0932-0113, E-ISSN 1432-1955, Vol. 104, no 4, p. 935-937Article in journal (Refereed)
    Abstract [en]

    We present a novel and simple technique for storing live Acanthamoeba for long periods of time. The amoebae are maintained at refrigerator temperatures in a peptone-yeast extract-glucose (PYG) medium normally used for cultivation. Using this method, we obtained survival rates of at least 4 years for Acanthamoeba polyphaga and 3 years for Acanthamoeba castellanii and Acanthamoeba rhysodes. Advantages of this storage method are: (1) it is quick and simple, (2) inexpensive, (3) does not require encystment before storage, (4) resuscitation of cysts can be achieved within a week of culture in PYG medium at 27A degrees C, and does not require co-culture with bacteria or any special equipment.

  • 5.
    Axelsson Olsson, Diana
    et al.
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Olofsson, Jenny
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Svensson, Lovisa
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Griekspoor, Petra
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Waldenström, Jonas
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Ellström, Patrik
    Clinical Bacteriology, Department of Medical Sciences, Uppsala University and Uppsala University Hospital, SE-751 85 Uppsala, Sweden.
    Olsen, Björn
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Amoebae and algae can prolong the survival of Campylobacter species in co-culture2010In: Experimental parasitology, ISSN 0014-4894, E-ISSN 1090-2449, Vol. 126, p. 59-64Article in journal (Refereed)
    Abstract [en]

    Several species of free-living amoebae can cause disease in humans. However, in addition to the direct pathogenicity of e.g. Acanthamoebae and Naegleria species, they are recognized as environmental hosts, indirectly involved in the epidemiology of many pathogenic bacteria. Although several studies have demonstrated intracellular survival of many different bacteria in these species, the extent of such interactions as well as the implications for the epidemiology of the bacterial species involved, are largely unknown and probably underestimated. In this study, we evaluated eight different unicellular eukaryotic organisms, for their potential to serve as environmental hosts for Campylobacter species. These organisms include four amoebozoas (Acanthamoeba polyphaga, Acanthamoeba castellanii, Acanthamoeba rhysodes and Hartmanella vermiformis), one alveolate (Tetrahymena pyriformis), one stramenopile (Dinobryon sertularia), one eugoenozoa (Euglena gracilis) and one heterolobosea (Naegleria americana). Campylobacter spp. including Campylobacter jejuni, Campylobacter coli and Campylobacter lari are the most common cause of gastroenteritis in the western world. Survival and replication of these three species as well as Campylobacter hyointestinalis were assessed in co-cultures with the eukaryotic organisms. Campylobacter spp. generally survived longer in co-cultures, compared to when incubated in the corresponding growth media. The eukaryotic species that best promoted bacterial survival was the golden algae D. sertularia. Three species of amoebozoas, of the genus Acanthamoeba promoted both prolonged survival and replication of Campylobacter spp. The high abundance in lakes, ponds and water distribution networks of these organisms indicate that they might have a role in the epidemiology of campylobacteriosis, possibly contributing to survival and dissemination of these intestinal pathogens to humans and other animals. The results suggest that not only C. jejuni, but a variety of Campylobacter spp. can interact with different eukaryotic unicellular organisms.

  • 6.
    Axelsson Olsson, Diana
    et al.
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Svensson, Lovisa
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Olofsson, Jenny
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Salomon, Paulo
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Waldenström, Jonas
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Ellström, Patrik
    Olsen, Björn
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Increase in Acid Tolerance of Campylobacter jejuni through Coincubation with Amoebae2010In: Applied and Environmental Microbiology, ISSN 0099-2240, E-ISSN 1098-5336, Vol. 76, no 13, p. 4194-4200Article in journal (Refereed)
    Abstract [en]

    Campylobacter jejuni is a recognized and common gastrointestinal pathogen in most parts of the world. Human infections are often food borne, and the bacterium is frequent among poultry and other food animals. However, much less is known about the epidemiology of C. jejuni in the environment and what mechanisms the bacterium depends on to tolerate low pH. The sensitive nature of C. jejuni stands in contrast to the fact that it is difficult to eradicate from poultry production, and even more contradictory is the fact that the bacterium is able to survive the acidic passage through the human stomach. Here we expand the knowledge on C. jejuni acid tolerance by looking at protozoa as a potential epidemiological pathway of infection. Our results showed that when C. jejuni cells were coincubated with Acanthamoeba polyphaga in acidified phosphate-buffered saline (PBS) or tap water, the bacteria could tolerate pHs far below those in their normal range, even surviving at pH 4 for 20 h and at pH 2 for 5 h. Interestingly, moderately acidic conditions (pH 4 and 5) were shown to trigger C. jejuni motility as well as to increase adhesion/internalization of bacteria into A. polyphaga. Taken together, the results suggest that protozoa may act as protective hosts against harsh conditions and might be a potential risk factor for C. jejuni infections. These findings may be important for our understanding of C. jejuni passage through the gastrointestinal tract and for hygiene practices used in poultry settings.

  • 7.
    Axelsson Olsson, Diana
    et al.
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Waldenström, Jonas
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Broman, Tina
    Olsen, Björn
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Holmberg, M
    The protozoan Acanthamoeba polyphaga as a potential reservoir for Campylobacter jejuni2005In: Applied and environmental microbiology, Vol. 71 (2), p. 987-992Article in journal (Refereed)
  • 8.
    Bengtsson, Daniel
    et al.
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science.
    Avril, Alexis
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science.
    Gunnarsson, Gunnar
    Kristianstad University.
    Elmberg, Johan
    Kristianstad University.
    Söderquist, Pär
    Kristianstad University.
    Norevik, Gabriel
    Ottenby Bird Observatory.
    Tolf, Conny
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science.
    Safi, Kamran
    Max Planck Institute for Ornitholology, Germany ; University of Konstanz, Germany.
    Fiedler, Wolfgang
    Max Planck Institute for Ornitholology, Germany ; University of Konstanz, Germany.
    Wikelski, Martin
    Max Planck Institute for Ornitholology, Germany ; University of Konstanz, Germany.
    Olsen, Björn
    Uppsala University.
    Waldenström, Jonas
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science.
    Movements, Home-Range Size and Habitat Selection of Mallards during Autumn Migration2014In: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 9, no 6, article id e100764Article in journal (Refereed)
    Abstract [en]

    The mallard (Anas platyrhynchos) is a focal species in game management, epidemiology and ornithology, but comparably little research has focused on the ecology of the migration seasons. We studied habitat use, time-budgets, home-range sizes, habitat selection, and movements based on spatial data collected with GPS devices attached to wild mallards trapped at an autumn stopover site in the Northwest European flyway. Sixteen individuals (13 males, 3 females) were followed for 15-38 days in October to December 2010. Forty-nine percent (SD = 8.4%) of the ducks' total time, and 85% of the day-time (SD = 28.3%), was spent at sheltered reefs and bays on the coast. Two ducks used ponds, rather than coast, as day-roosts instead. Mallards spent most of the night (76% of total time, SD = 15.8%) on wetlands, mainly on alvar steppe, or in various flooded areas (e.g. coastal meadows). Crop fields with maize were also selectively utilized. Movements between roosting and foraging areas mainly took place at dawn and dusk, and the home-ranges observed in our study are among the largest ever documented for mallards (mean = 6,859 ha; SD = 5,872 ha). This study provides insights into relatively unknown aspects of mallard ecology. The fact that autumn-staging migratory mallards have a well-developed diel activity pattern tightly linked to the use of specific habitats has implications for wetland management, hunting and conservation, as well as for the epidemiology of diseases shared between wildlife and domestic animals.

  • 9. Bergström, Sven
    et al.
    Haemig, Paul D
    Olsen, Björn
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Distribution and abundance of the tick Ixodes uriae in a subantarctic seabird community1999In: Journal of Parasitology, Vol. 85, p. 25-27Article in journal (Refereed)
  • 10. Bergström, Sven
    et al.
    Haemig, Paul D
    Olsen, Björn
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Increased mortality of black-browed albatross chicks at a colony heavily-infested with the tick Ixodes uriae1999In: International Journal for Parasitology, Vol. 29, p. 1359-1361Article in journal (Refereed)
  • 11. Bergström, Sven
    et al.
    Olsen, Björn
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Burman, N
    Gothefors, L
    Jaenson, Thomas G T
    Jonsson, M
    Mejlon, H
    Molecular characterization of Borrelia burgdorferi isolated from Ixodes ricinus in northern Sweden1992In: Scandinavian journal of infectious diseases, Vol. 24, p. 181-188Article in journal (Refereed)
  • 12. Bjöersdorff, Anneli
    et al.
    Bergström, Sven
    Massung, Robert F
    Haemig, Paul D
    Olsen, Björn
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Ehrlichia-infected ticks on migrating birds2001In: Emerging Infectious Diseases, Vol. 7, p. 877-879Article in journal (Refereed)
  • 13.
    Blomqvist, Maria
    et al.
    Uppsala University.
    Christerson, Linus
    Uppsala University.
    Waldenström, Jonas
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Herrmann, Björn
    Uppsala University.
    Olsen, Björn
    Uppsala Univ, Dept Med Sci, Sect Infect Dis, S-75185 Uppsala, Sweden.
    Chlamydia psittaci in Swedish Wetland Birds: A Risk to Zoonotic Infection?2012In: Avian diseases, ISSN 0005-2086, E-ISSN 1938-4351, Vol. 56, no 4, p. 737-740Article in journal (Refereed)
    Abstract [en]

    Chlamydia psittaci in birds may be transmitted to humans and cause respiratory infections, sometimes as severe disease. Our study investigated the C. psittaci prevalence in migratory birds in Sweden by real-time PCR. Fecal specimens or cloacal swabs were collected from 497 birds from 22 different species, mainly mallards (Anas platyrhynchos), at two bird observatories in Sweden. DNA from C. psittaci was found in six (1.2%) birds from three different species. Five of the positive specimens were infected with four novel strains of C. psittaci, based on sequencing of partial 16S rRNA gene and ompA gene, and the sixth was indentified as a recently described Chlamydiaceae-like bacterium. Considering exposure to humans it is concluded that the risk of zoonotic infection is low.

  • 14. Bonnedahl, Jonas
    et al.
    Broman, Tina
    Waldenström, Jonas
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Palmgren, Helena
    Niskanen, Taina
    Olsen, Björn
    University of Kalmar, School of Pure and Applied Natural Sciences.
    In search of human-associated bacterial pathogens in Antarctic wildlife: report from six penguin colonies regularly visited by tourists2005In: Ambio, Vol. 34, p. 424-426Article in journal (Refereed)
  • 15.
    Bonnedahl, Jonas
    et al.
    Uppsala University ; Kalmar County Hospital.
    Drobni, M
    Gauthier-Clerc, M
    Hernandez, Jorge
    Kalmar County Hospital.
    Granholm, S
    Kayser, Y
    Melhus, Å
    Kahlmeter, G
    Waldenström, Jonas
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Johansson, A
    Olsen, Björn
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Dissemination of Escherichia coli with CTX-M Type ESBL between Humans and Yellow-Legged Gulls in the South of France2009In: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 4, no Article number: e5958Article in journal (Refereed)
    Abstract [en]

     Extended Spectrum beta-Lactamase (ESBL) producing Enterobacteriaceae started to appear in the 1980s, and have since emerged as some of the most significant hospital-acquired infections with Escherichia coli and Klebsiella being main players. More than 100 different ESBL types have been described, the most widespread being the CTX-M beta-lactamase enzymes (bla(CTX-M) genes). This study focuses on the zoonotic dissemination of ESBL bacteria, mainly CTX-M type, in the southern coastal region of France. We found that the level of general antibiotic resistance in single randomly selected E. coli isolates from wild Yellow-legged Gulls in France was high. Nearly half the isolates (47,1%) carried resistance to one or more antibiotics (in a panel of six antibiotics), and resistance to tetracycline, ampicillin and streptomycin was most widespread. In an ESBL selective screen, 9,4% of the gulls carried ESBL producing bacteria and notably, 6% of the gulls carried bacteria harboring CTX-M-1 group of ESBL enzymes, a recently introduced and yet the most common clinical CTX-M group in France. Multi locus sequence type and phylogenetic group designations were established for the ESBL isolates, revealing that birds and humans share E. coli populations. Several ESBL producing E. coli isolated from birds were identical to or clustered with isolates with human origin. Hence, wild birds pick up E. coli of human origin, and with human resistance traits, and may accordingly also act as an environmental reservoir and melting pot of bacterial resistance with a potential to re-infect human populations.

  • 16.
    Bonnedahl, Jonas
    et al.
    Uppsala University ; Kalmar County Hospital.
    Drobni, P.
    Cent Hosp Växjö.
    Johansson, A.
    Umeå University.
    Hernandez, Jorge
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences. Uppsala University.
    Melhus, A.
    Uppsala University.
    Stedt, Johan
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Olsen, Björn
    Uppsala University.
    Drobni, M.
    Uppsala University.
    Characterization, and comparison, of human clinical and black-headed gull (Larus ridibundus) extended-spectrum beta-lactamase-producing bacterial isolates from Kalmar, on the southeast coast of Sweden2010In: Journal of Antimicrobial Chemotherapy, ISSN 0305-7453, E-ISSN 1460-2091, Vol. 65, no 9, p. 1939-1944Article in journal (Refereed)
    Abstract [en]

    Antibiotic resistance is one of the great challenges for modern healthcare. In Gram-negative bacteria, CTX-M-type extended-spectrum beta-lactamases (ESBLs) have been rapidly spreading through Europe since the early 2000s. In Sweden, ESBL-producing Escherichia coli are still rare, but a 3-fold increase has been seen from 2004 to 2007. Enterobacteria and normal flora of wild animals, with or without antibiotic resistance traits, constitute a potential source of human infection and colonization. We studied wild birds with the aim to understand the environmental dissemination of antibiotic resistance and, focusing on clinically relevant resistance types, we made comparisons with human clinical samples. In this study, ESBL-producing human clinical isolates and isolates from juvenile black-headed gulls from Kalmar County hospital and the city of Kalmar, respectively, on the southeast coast of Sweden, were characterized and compared. Despite a low frequency of antibiotic resistance among the isolates from gulls, ESBL-producing E. coli isolates were found, two with bla(CTX-M-14) and one with bla(CTX-M-15). The same CTX-M types were dominant among human ESBL isolates. In addition, gull isolates were dispersed among the human samples in the PhenePlate (TM) clustering system, indicating that they neither differ from the human isolates nor form any separate clonal clustering. The finding of CTX-M-type ESBLs in E. coli isolated from black-headed gulls in Sweden, where 'background resistance' is low, is consistent with an ongoing environmental spread of these plasmid-borne resistance genes. The results indicate that a potential for transfer between the human population and environment exists even in countries with a low level of antibiotic resistance.

  • 17. Bonnedahl, Jonas
    et al.
    Olsen, Björn
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Waldenström, Jonas
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Broman, Tina
    Jalava, J
    Huovinen, P
    Österblad, Monika
    Antibiotic susceptibility of faecal bacteria in Antarctic penguins2008In: Polar Biology, ISSN 0722-4060, E-ISSN 1432-2056, Vol. 31, p. 759-763Article in journal (Refereed)
  • 18.
    Bonnedahl, Jonas
    et al.
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science. Kalmar County Hospital.
    Stedt, Johan
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science.
    Waldenström, Jonas
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science.
    Svensson, Lovisa
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science.
    Drobni, Mirva
    Uppsala University.
    Olsen, Björn
    Uppsala University.
    Comparison of Extended-Spectrum beta-Lactamase (ESBL) CTX-M Genotypes in Franklin Gulls from Canada and Chile2015In: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 10, no 10, article id e0141315Article in journal (Refereed)
    Abstract [en]

    Migratory birds have been suggested to contribute to long-distance dispersal of antimicrobial resistant bacteria, but tests of this hypothesis are lacking. In this study we determined resistance profiles and genotypes of ESBL-producing bacteria in randomly selected Escherichia coli from Franklin's gulls (Leucophaeus pipixcan) at breeding sites in Canada and compared with similar data from the gulls' wintering grounds in Chile. Resistant E. coli phenotypes were common, most notably to ampicillin (30.1%) and cefadroxil (15.1%). Furthermore, 17.0% of the gulls in Canada carried ESBL producing bacteria, which is higher than reported from human datasets from the same country. However, compared to gulls sampled in Chile (30.1%) the prevalence of ESBL was much lower. The dominant ESBL variants in Canada were bla(CTX-M-14) and bla(CTX-M-15) and differed in proportions to the data from Chile. We hypothesize that the observed differences in ESBL variants are more likely linked to recent exposure to bacteria from anthropogenic sources, suggesting high local dissemination of resistant bacteria both at breeding and non-breeding times rather than a significant trans-hemispheric exchange through migrating birds.

  • 19. Brojer, Caroline
    et al.
    Jarhult, Josef D.
    Muradrasoli, Shaman
    Soderstrom, Hanna
    Olsen, Björn
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science.
    Gavier-Widen, Dolores
    Pathobiology and virus shedding of low-pathogenic avian influenza virus (A/H1N1) infection in mallards exposed to oseltamivir2013In: Journal of Wildlife Diseases, ISSN 0090-3558, E-ISSN 1943-3700, Vol. 49, no 1, p. 103-113Article in journal (Refereed)
    Abstract [en]

    Low-pathogenic avian influenza (LPAI) viruses in wild birds are important as they can constitute the basis for the development of highly pathogenic avian influenza viruses or form part of human-adapted strains with pandemic potential. However, the pathogenesis of LPAI viruses is not well characterized in dabbling ducks, one of the natural reservoirs of LPAI viruses. Between 21 September 2009 and 21 December 2009, we used real-time reverse transcriptase polymerase chain reaction (q-PCR), histopathology, and immunohistochemistry (IHC) to study Mallards (Anas platyrhynchos) infected with an influenza A/H1N1 virus isolated from a wild Mallard in Sweden. The ducks were either inoculated intraesophageally ("artificial infection") or infected by virus shed by other ducks in the experiment ("contact infection"). The ducks were subjected to three low concentrations (80 ng/L, 1 mu g/L, and 80 mu g/L) of the active metabolite of oseltamivir (Tamiflu (R)), oseltamivir carboxylate (OC), which resulted in the development of the viral resistance mutation H274Y at 1 and 80 mu g/L. The LPAI virus infection was localized to the intestinal tract and cloacal bursa except in one Mallard. The exception was a duck euthanized 1 day postinoculation, whose infection was located solely in the lung, possibly due to intratracheal deposition of virus. The intestinal infection was characterized by occasional degenerating cells in the lamina propria and presence of viral antigen as detected by IHC, as well as positive q-PCR performed on samples from feces and intestinal contents. Histopathologic changes, IHC positivity, and viral shedding all indicated that the infection peaked early, around 2 days postinfection. Furthermore, more viral antigen and viral RNA were detected with IHC and q-PCR in the proximal parts early in the infection. There was no obvious difference in the course of the infection in artificial versus contact infection, when the level of OC was increased from 80 ng/L to 1 mu g/L (based on IHC and q-PCR), when the level of OC was increased to 80 mu/L, or when the resistance mutation H274Y developed (based on q-PCR).

  • 20. Broman, Tina
    et al.
    Bergström, Sven
    On, S L W
    Palmgren, Helena
    McCafferty, D J
    Sellin, Mats
    Olsen, Björn
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Isolation and characterization of Campylobacter jejuni subsp. jejuni from Macaroni penguins (Eudyptes chrysolophus) in the subantarctic region2000In: Applied and Environmental Microbiology, Vol. 66, p. 449-452Article in journal (Refereed)
  • 21. Broman, Tina
    et al.
    Palmgren, Helena
    Bergström, Sven
    Sellin, Mats
    Waldenström, Jonas
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Danielsson-Tham, Marie-Louise
    Olsen, Björn
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Campylobacter jejuni in Black-Headed Gulls (Larus ridibundus): prevalence, genotypes, and influence on C. jejuni epidemiology2002In: Journal of Clinical Microbiology, Vol. 40, p. 4594-4602Article in journal (Refereed)
  • 22. Broman, Tina
    et al.
    Waldenström, Jonas
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Dahlgren, Daniel
    Carlsson, Inger
    Eliasson, Ingvar
    Olsen, Björn
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Diversities and Similarities in PFGE profiles of Campylobacter jejuni isolated from Migrating Birds and Humans2004In: Journal of Applied Microbiology, Vol. 96, p. 834-843Article in journal (Refereed)
  • 23. Bunikis, J
    et al.
    Olsen, Björn
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Fingerle, V
    Bonnedahl, Jonas
    Wilske, B
    Bergström, Sven
    Molecular polymorphism of the Lyme disease agent Borrelia garinii in northern Europe is influenced by a novel enzootic Borrelia focus in the North Atlantic1996In: Journal of Clinical Microbiology, Vol. 34, p. 364-368Article in journal (Refereed)
  • 24. Bunikis, J
    et al.
    Olsen, Björn
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Westman, G
    Bergström, Sven
    Variable serum immunoglobulin responses against different Borrelia burgdorferi sensu lato species in a population at risk for and patients with Lyme disease1995In: Journal of Clinical Microbiology, Vol. 33, p. 1473-1478Article in journal (Refereed)
  • 25. Christersson, Linus
    et al.
    Blomqvist, Maria
    Grannas, Karin
    Thollesson, Mikael
    Laroucau, Karine
    Waldenström, Jonas
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Eliasson, Ingvar
    Olsen, Björn
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Herrmann, Björn
    A novel Chlamydiaceae-like bacterium found in fecal specimens from sea birds from the Bering Sea.2010In: Environmental Microbiology Reports, ISSN 1758-2229, E-ISSN 1758-2229, Vol. 2, no 4, p. 605-610Article in journal (Refereed)
    Abstract [en]

    The family Chlamydiaceae contains several bacterial pathogens of important human and veterinary medical concern, such as Chlamydia trachomatis and Chlamydophila psittaci. Within the order Chlamydiales there are also an increasing number of chlamydia-like bacteria whose biodiversity, host range and environmental spread seem to have been largely underestimated, and which are currently being investigated for their potential medical relevance. In this study we present 16S rRNA, rnpB and ompA gene sequence data congruently indicating a novel chlamydia-like bacterium found in faecal specimens from opportunistic fish-eating sea birds, belonging to the Laridae and Alcidae families, from the Bering Sea. This novel bacterium appears to be closer to the Chlamydiaceae than other chlamydia-like bacteria and is most likely a novel genus within the Chlamydiaceae family.

  • 26.
    Chryssanthou, E.
    et al.
    Karolinska Univ Hosp.
    Wennberg, H.
    Karolinska Univ Hosp.
    Bonnedahl, Jonas
    Kalmar County Hospital ; Uppsala University.
    Olsen, Björn
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences. Uppsala University.
    Occurrence of yeasts in faecal samples from Antarctic and South American seabirds2011In: Mycoses (Berlin), ISSN 0933-7407, E-ISSN 1439-0507, Vol. 54, no 6, p. E811-E815Article in journal (Refereed)
    Abstract [en]

    During an expedition to the Southern Argentinean town of Ushuaia, the Antarctic Peninsula, Antarctic Islands and the Falkland Islands, we collected 94 faecal specimens from wild birds to screen for yeast within the different bird species. The yeast species were identified by morphological features and commercial characterisation kits. From 54% of the specimens, we isolated 122 strains representing 29 yeast species. Debaryomyces hansenii, Candida lambica and Candida krusei were the most frequently isolated species. We found a plethora of yeasts in birds living in proximity to humans, whereas birds living in more remote areas were colonised with a lower number of fungal species.

  • 27. Comstedt, Pär
    et al.
    Bergström, Sven
    Olsen, Björn
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Garpmo, Ulf
    Marjavaara, L
    Mejlon, H
    Barbour, A G
    Bunikis, J
    Migratory passerine birds as reservoirs of lyme borreliosis in Europe2006In: Emerging infectious diseases, Vol. 12, no 7, p. 1087-1095Article in journal (Refereed)
  • 28.
    Elfving, Karin
    et al.
    Uppsala University Hospital ; Falu Hospital.
    Olsen, Björn
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences. Uppsala University Hospital.
    Bergström, Sven
    Umeå University.
    Waldenström, Jonas
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences. Uppsala University Hospital.
    Lundkvist, Åke
    Swedish Institute for Infectious Disease Control.
    Sjöstedt, Anders
    Umeå University Hospital.
    Mejlon, Hans
    Uppsala University.
    Nilsson, Kenneth
    Uppsala University Hospital ; Falu Hospital ; Uppsala University.
    Dissemination of Spotted Fever Rickettsia Agents in Europe by Migrating Birds2010In: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 5, no 1, article id e8572Article in journal (Refereed)
    Abstract [en]

    Migratory birds are known to play a role as long-distance vectors for many microorganisms. To investigate whether this is true of rickettsial agents as well, we characterized tick infestation and gathered ticks from 13,260 migratory passerine birds in Sweden. A total of 1127 Ixodes spp. ticks were removed from these birds and the extracted DNA from 957 of them was available for analyses. The DNA was assayed for detection of Rickettsia spp. using real-time PCR, followed by DNA sequencing for species identification. Rickettsia spp. organisms were detected in 108 (11.3%) of the ticks. Rickettsia helvetica, a spotted fever rickettsia associated with human infections, was predominant among the PCR-positive samples. In 9 (0.8%) of the ticks, the partial sequences of 17kDa and ompB genes showed the greatest similarity to Rickettsia monacensis, an etiologic agent of Mediterranean spotted fever-like illness, previously described in southern Europe as well as to the Rickettsia sp. IrITA3 strain. For 15 (1.4%) of the ticks, the 17kDa, ompB, gltA and ompA genes showed the greatest similarity to Rickettsia sp. strain Davousti, Rickettsia japonica and Rickettsia heilongjiangensis, all closely phylogenetically related, the former previously found in Amblyomma tholloni ticks in Africa and previously not detected in Ixodes spp. ticks. The infestation prevalence of ticks infected with rickettsial organisms was four times higher among ground foraging birds than among other bird species, but the two groups were equally competent in transmitting Rickettsia species. The birds did not seem to serve as reservoir hosts for Rickettsia spp., but in one case it seems likely that the bird was rickettsiemic and that the ticks had acquired the bacteria from the blood of the bird. In conclusion, migratory passerine birds host epidemiologically important vector ticks and Rickettsia species and contribute to the geographic distribution of spotted fever rickettsial agents and their diseases.

  • 29.
    Ellström, Patrik
    et al.
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Jourdain, Elsa
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Gunnarsson, Oskar
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Waldenström, Jonas
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Olsen, Björn
    University of Kalmar, School of Pure and Applied Natural Sciences.
    The ”human influenza receptor” Neu5Ac alpha 2,6Gal is expressed among different taxa of wild birds2009In: Archives of Virology, ISSN 0304-8608, E-ISSN 1432-8798, Vol. 154, no 9, p. 1533-1537Article in journal (Refereed)
  • 30.
    Ellström, Patrik
    et al.
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Latorre-Margalef, Neus
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Griekspoor, Petra
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Waldenström, Jonas
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Olofsson, Jenny
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Wahlgren, John
    Ctr Microbiol Preparedness KCB, Swedish Inst Infect Dis Control SMI, SE-17182 Solna, Sweden.
    Olsen, Björn
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Sampling for low-pathogenic avian influenza A virus in wild Mallard ducks: Oropharyngeal versus cloacal swabbing2008In: Vaccine, ISSN 0264-410X, E-ISSN 1873-2518, Vol. 26, no 35, p. 4414-4416Article in journal (Refereed)
  • 31. Fouchier, R A M
    et al.
    Munster, V
    Wallensten, Anders
    Bestebroer, T M
    Herfst, S
    Smith, D
    Rimmelzwaan, G F
    Olsen, Björn
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Osterhaus, A D M E
    Characterization of a novel influenza a virus hemagglutinin subtype (H16) obtained from black-headed gulls2005In: Journal of virology, Vol. 79 (5), p. 2814-2822Article in journal (Refereed)
  • 32. Fouchier, R A M
    et al.
    Olsen, Björn
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Bestebroer, T M
    Herfst, S
    van der Kemp, L
    Rimmelzwaan, G F
    Osterhaus, A D M E
    Influenza A Virus Surveillance in Wild Birds in Northern Europe in 1999 and 20002003In: Avian Diseases, Vol. 47Article in journal (Refereed)
  • 33. Frick, Jerker
    et al.
    Lindberg, Richard
    Tysklind, Mats
    Haemig, Paul
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Waldenström, Jonas
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Wallensten, Anders
    Olsen, Björn
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Anitiviral Oseltamivir is not removed or degraded in normal sewage ater treatment: implications for the develoment of resitance by influenza A virus2007In: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 2, no 10Article in journal (Refereed)
  • 34.
    Gillman, Anna
    et al.
    Uppsala University.
    Muradrasoli, Shaman
    Swedish University of Agricultural Sciences.
    Söderstrom, Hanna
    Umeå University.
    Nordh, Johan
    Uppsala University.
    Bröjer, Caroline
    Swedish University of Agricultural Sciences.
    Lindberg, Richard H.
    Umeå University.
    Latorre-Margalef, Neus
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science.
    Waldenström, Jonas
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science.
    Olsen, Björn
    Uppsala University.
    Järhult, Josef D.
    Uppsala University.
    Resistance Mutation R292K Is Induced in Influenza A(H6N2) Virus by Exposure of Infected Mallards to Low Levels of Oseltamivir2013In: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 8, no 8, article id e71230Article in journal (Refereed)
    Abstract [en]

    Resistance to neuraminidase inhibitors (NAIs) is problematic as these drugs constitute the major treatment option for severe influenza. Extensive use of the NAI oseltamivir (Tamiflu(R)) results in up to 865 ng/L of its active metabolite oseltamivir carboxylate (OC) in river water. There one of the natural reservoirs of influenza A, dabbling ducks, can be exposed. We previously demonstrated that an influenza A(H1N1) virus in mallards (Anas platyrhynchos) exposed to 1 mu g/L of OC developed oseltamivir resistance through the mutation H274Y (N2-numbering). In this study, we assessed the resistance development in an A(H6N2) virus, which belongs to the phylogenetic N2 group of neuraminidases with distinct functional and resistance characteristics. Mallards were infected with A(H6N2) while exposed to 120 ng/L, 1.2 mu g/L or 12 mu g/L of OC in their sole water source. After 4 days with 12 mu g/L of OC exposure, the resistance mutation R292K emerged and then persisted. Drug sensitivity was decreased approximate to 13,000-fold for OC and approximate to 7.8-fold for zanamivir. Viral shedding was similar when comparing R292K and wild-type virus indicating sustained replication and transmission. Reduced neuraminidase activity and decrease in recovered virus after propagation in embryonated hen eggs was observed in R292K viruses. The initial, but not the later R292K isolates reverted to wild-type during egg-propagation, suggesting a stabilization of the mutation, possibly through additional mutations in the neuraminidase (D113N or D141N) or hemagglutinin (E216K). Our results indicate a risk for OC resistance development also in a N2 group influenza virus and that exposure to one NAI can result in a decreased sensitivity to other NAIs as well. If established in influenza viruses circulating among wild birds, the resistance could spread to humans via re-assortment or direct transmission. This could potentially cause an oseltamivir-resistant pandemic; a serious health concern as preparedness plans rely heavily on oseltamivir before vaccines can be mass-produced.

  • 35.
    Gillman, Anna
    et al.
    Uppsala University.
    Muradrasoli, Shaman
    Uppsala University ; Swedish University of Agricultural Sciences.
    Söderström, Hanna
    Umeå University.
    Holmberg, Fredrik
    Uppsala University.
    Latorre-Margalef, Neus
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science.
    Tolf, Conny
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science.
    Waldenström, Jonas
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science.
    Gunnarsson, Gunnar
    Kristianstad University.
    Olsen, Björn
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science. Uppsala University.
    Jarhult, Josef D.
    Uppsala University.
    Oseltamivir-Resistant Influenza A (H1N1) Virus Strain with an H274Y Mutation in Neuraminidase Persists without Drug Pressure in Infected Mallards2015In: Applied and Environmental Microbiology, ISSN 0099-2240, E-ISSN 1098-5336, Vol. 81, no 7, p. 2378-2383Article in journal (Refereed)
    Abstract [en]

    Influenza A virus (IAV) has its natural reservoir in wild waterfowl, and emerging human IAVs often contain gene segments from avian viruses. The active drug metabolite of oseltamivir (oseltamivir carboxylate [OC]), stockpiled as Tamiflu for influenza pandemic preparedness, is not removed by conventional sewage treatment and has been detected in river water. There, it may exert evolutionary pressure on avian IAV in waterfowl, resulting in the development of resistant viral variants. A resistant avian IAV can circulate among wild birds only if resistance does not restrict viral fitness and if the resistant virus can persist without continuous drug pressure. In this in vivo mallard (Anas platyrhynchos) study, we tested whether an OC-resistant avian IAV (H1N1) strain with an H274Y mutation in the neuraminidase (NA-H274Y) could retain resistance while drug pressure was gradually removed. Successively infected mallards were exposed to decreasing levels of OC, and fecal samples were analyzed for the neuraminidase sequence and phenotypic resistance. No reversion to wild-type virus was observed during the experiment, which included 17 days of viral transmission among 10 ducks exposed to OC concentrations below resistance induction levels. We conclude that resistance in avian IAV that is induced by exposure of the natural host to OC can persist in the absence of the drug. Thus, there is a risk that human-pathogenic IAVs that evolve from IAVs circulating among wild birds may contain resistance mutations. An oseltamivir-resistant pandemic IAV would pose a substantial public health threat. Therefore, our observations underscore the need for prudent oseltamivir use, upgraded sewage treatment, and surveillance for resistant IAVs in wild birds.

  • 36.
    Gillman, Anna
    et al.
    Uppsala University.
    Nykvist, Marie
    Uppsala University.
    Muradrasoli, Shaman
    Uppsala University;Swedish University of Agricultural Sciences.
    Söderström, Hanna
    Umeå University.
    Wille, Michelle
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science.
    Daggfeldt, Annika
    National Veterinary Institute, Uppsala.
    Brojer, Caroline
    National Veterinary Institute, Uppsala.
    Waldenström, Jonas
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science.
    Olsen, Björn
    Uppsala University.
    Jarhult, Josef D.
    Uppsala University.
    Influenza A(H7N9) Virus Acquires Resistance-Related Neuraminidase I222T Substitution When Infected Mallards Are Exposed to Low Levels of Oseltamivir in Water2015In: Antimicrobial Agents and Chemotherapy, ISSN 0066-4804, E-ISSN 1098-6596, Vol. 59, no 9, p. 5196-5202Article in journal (Refereed)
    Abstract [en]

    Influenza A virus (IAV) has its natural reservoir in wild waterfowl, and new human IAVs often contain gene segments originating from avian IAVs. Treatment options for severe human influenza are principally restricted to neuraminidase inhibitors (NAIs), among which oseltamivir is stockpiled in preparedness for influenza pandemics. There is evolutionary pressure in the environment for resistance development to oseltamivir in avian IAVs, as the active metabolite oseltamivir carboxylate (OC) passes largely undegraded through sewage treatment to river water where waterfowl reside. In an in vivo mallard (Anas platyrhynchos) model, we tested if low-pathogenic avian influenza A(H7N9) virus might become resistant if the host was exposed to low levels of OC. Ducks were experimentally infected, and OC was added to their water, after which infection and transmission were maintained by successive introductions of uninfected birds. Daily fecal samples were tested for IAV excretion, genotype, and phenotype. Following mallard exposure to 2.5 mu g/liter OC, the resistance-related neuraminidase (NA) I222T substitution, was detected within 2 days during the first passage and was found in all viruses sequenced from subsequently introduced ducks. The substitution generated 8-fold and 2.4-fold increases in the 50% inhibitory concentration (IC50) for OC (P < 0.001) and zanamivir (P = 0.016), respectively. We conclude that OC exposure of IAV hosts, in the same concentration magnitude as found in the environment, may result in amino acid substitutions, leading to changed antiviral sensitivity in an IAV subtype that can be highly pathogenic to humans. Prudent use of oseltamivir and resistance surveillance of IAVs in wild birds are warranted.

  • 37. Gonzalez-Acuna, Daniel
    et al.
    Hernandez, Jorge
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science.
    Moreno, Lucila
    Herrmann, Bjorn
    Palma, Ricardo
    Latorre, Alejandra
    Medina-Vogel, Gonzalo
    Kinsella, Mike J.
    Martin, Nicolas
    Araya, Karolina
    Torres, Ivan
    Fernandez, Nicolas
    Olsen, Björn
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science. Uppsala Universitet.
    Health evaluation of wild gentoo penguins (Pygoscelis papua) in the Antarctic Peninsula2013In: Polar Biology, ISSN 0722-4060, E-ISSN 1432-2056, Vol. 36, no 12, p. 1749-1760Article in journal (Refereed)
    Abstract [en]

    Historically wildlife conservation was based on habitat protection and exploitation control. Only recently have diseases been considered an important issue. However, pathogens are usually described during or after disease outbreaks, but to determine which pathogens may be emerging, surveys of wildlife health are critical in a given time. This study deals with the health status of gentoo penguins Pygoscelis papua in two localities at the Antarctica Peninsula and one at Ardley Island off the South Shetland Islands. Cloacal swaps, fresh fecal samples, ectoparasites, and blood smears were collected. We examined and dissected 14 penguin corpses found dead. Fecal samples were positive for Campylobacter, Escherichia coli and in the carcasses four endoparasitic species were found: Diphyllobothrium sp. and Parorchites zederi, Corynosoma shackletoni and Stegophorus adeliae. The tick Ixodes uriae occurred in five of the examined penguins, and the louse Austrogoniodes gressitti on six birds. From the colony grounds, we collected 1,184 I. uriae. We recorded antibiotic-resistant bacteria, such as E. coli, in ecosystems where gentoo penguins breed. Cloacal samples (300) were negative for Chlamydia, as well as for Salmonella, Campylobacter, E. coli, Newcastle and Influenza viruses.

  • 38. Grenmyr, U
    et al.
    Olsen, Björn
    University of Kalmar, School of Pure and Applied Natural Sciences.
    The Goldcrest Regulus regulus migration over the Baltic Sea1995In: Ornis Svecica, Vol. 5, p. 15-22Article in journal (Refereed)
  • 39.
    Griekspoor, Petra
    et al.
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science.
    Colles, Frances M.
    Mccarthy, Noel D.
    Hansbro, Philip M.
    Ashhurst-Smith, Chris
    Olsen, Björn
    Department of Medical Sciences, Uppsala University.
    Hasselquist, Dennis
    Maiden, Martin C. J.
    Waldenström, Jonas
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science.
    Marked host specificity and lack of phylogeographic population structure of Campylobacter jejuni in wild birds2013In: Molecular Ecology, ISSN 0962-1083, E-ISSN 1365-294X, Vol. 22, no 5, p. 1463-1472Article in journal (Refereed)
    Abstract [en]

    Zoonotic pathogens often infect several animal species, and gene flow among populations infecting different host species may affect the biological traits of the pathogen including host specificity, transmissibility and virulence. The bacterium Campylobacter jejuni is a widespread zoonotic multihost pathogen, which frequently causes gastroenteritis in humans. Poultry products are important transmission vehicles to humans, but the bacterium is common in other domestic and wild animals, particularly birds, which are a potential infection source. Population genetic studies of C. jejuni have mainly investigated isolates from humans and domestic animals, so to assess C. jejuni population structure more broadly and investigate host adaptation, 928 wild bird isolates from Europe and Australia were genotyped by multilocus sequencing and compared to the genotypes recovered from 1366 domestic animal and human isolates. Campylobacter jejuni populations from different wild bird species were distinct from each other and from those from domestic animals and humans, and the host species of wild bird was the major determinant of C. jejuni genotype, while geographic origin was of little importance. By comparison, C. jejuni differentiation was restricted between more phylogenetically diverse farm animals, indicating that domesticated animals may represent a novel niche for C. jejuni and thereby driving the evolution of those bacteria as they exploit this niche. Human disease is dominated by isolates from this novel domesticated animal niche.

  • 40.
    Griekspoor, Petra
    et al.
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Engvall, Eva
    Olsen, Björn
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Waldenström, Jonas
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Multilocus sequence typing of Campylobacter jejuni from broilers2010In: Veterinary Microbiology, ISSN 0378-1135, E-ISSN 1873-2542, Vol. 140, p. 180-185Article in journal (Refereed)
    Abstract [en]

    Campylobacter jejuni isolates from a national Swedish Campylobacter monitoring in broilers were characterized by multilocus sequencing typing (MLST) in order to study the genetic diversity of this bacterial population. Isolates were initially characterized by pulsed-field gel electrophoresis (PFGE). One hundred were chosen for MLST genotyping. PFGE identified 69 distinct types compared to 44 different sequence types (STs) identified with MLST. Eighteen STs had not been described previously, while the remaining 26 STs were assigned to previously known clonal complexes. The majority of isolates were of genotypes noted in broilers and in humans in earlier studies. However, three clonal complexes, ST-206 complex, ST-677 complex and ST-1034 complex, previously associated with wild bird and environmental samples, were among the genotypes found. This study shows that most of the Swedish broiler isolates were of genotypes noted as common in broilers. However, it also highlights the potential influence of environmental sources on the broiler C jejuni genotypes.

  • 41.
    Griekspoor, Petra
    et al.
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science.
    Olofsson, Jenny
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science.
    Axelsson Olsson, Diana
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science.
    Waldenström, Jonas
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science.
    Olsen, Björn
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science.
    Multilocus Sequence Typing and FlaA Sequencing Reveal the Genetic Stability of Campylobacter jejuni Enrichment during Coculture with Acanthamoeba polyphaga2013In: Applied and Environmental Microbiology, ISSN 0099-2240, E-ISSN 1098-5336, Vol. 79, no 7, p. 2477-2479Article in journal (Refereed)
    Abstract [en]

    Low concentrations of Campylobacter jejuni cells in environmental samples make them difficult to study with conventional culture methods. Here, we show that enrichment by amoeba cocultures works well with low-concentration samples and that this method can be combined with molecular techniques without loss of genetic specificity.

  • 42.
    Griekspoor, Petra
    et al.
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Olsen, Björn
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Waldenström, Jonas
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Campylobacter jejuni in penguins, Antarctica2009In: Emerging Infectious Diseases, ISSN 1080-6040, E-ISSN 1080-6059, Vol. 15, no 5, p. 847-849Article in journal (Refereed)
  • 43.
    Gunnarsson, Gunnar
    et al.
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Jourdain, Elsa
    Waldenström, Jonas
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Helander, Björn
    Lindberg, Peter
    Elmberg, Johan
    Latorre-Margalef, Neus
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Olsen, Björn
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Zero prevalence of influenza A virus two raptor species by standard screeing.2009In: Vector Borne and Zoonotic Diseases, ISSN 1530-3667, E-ISSN 1557-7759, Vol. 10, no 4, p. 387-390Article in journal (Refereed)
    Abstract [en]

    Disease can have severe impact on animal populations, especially in rare species. Baseline data for atypical host species are missing for a range of infectious diseases, although such hosts are potentially more affected than the normal vectors and reservoir species. If highly pathogenic avian influenza strikes rare birds of prey, this may have crucial impact on the predator species itself, but also on the food web in which it interacts. Here we present the first large-scale screening of raptors that regularly consume birds belonging to the natural reservoir of influenza A viruses. Influenza A virus prevalence was studied in two rare raptors, the white-tailed sea eagle (Haliaeetus albicilla) and the peregrine falcon (Falco peregrinus). Nestlings were screened for active (181 white-tailed sea eagles and 168 peregrine falcons) and past (123 white-tailed sea eagles and 6 peregrine falcons) infection in 2006–2007, and an additional 20 succumbed adult white-tailed sea eagles were sampled in 2003–2006. Neither high- nor low-pathogenic influenza infections were found in our sample, but this does not rule out that the former may have major impact on rare raptors and their food webs.

  • 44. Gylfe, Åsa
    et al.
    Bergström, Sven
    Lundström, Jan
    Olsen, Björn
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Reactivation of Borrelia infection in birds2000In: Nature, Vol. 403, p. 724-725Article in journal (Refereed)
  • 45. Gylfe, Åsa
    et al.
    Olsen, Björn
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Strasevicius, Darius
    Marti Ras, Nuria
    Weihe, Pál
    Noppa, Laila
    Östberg, Yngve
    Baranton, Guy
    Bergström, Sven
    Isolation of Lyme disease Borrelia from Puffins (Fratercula arctica) and seabird ticks (Ixodes uriae) on Faeroe Islands1999In: Journal of Clinical Microbiology, Vol. 37, p. 890-896Article in journal (Refereed)
  • 46. Gylfe, Åsa
    et al.
    Yabuki, M
    Drotz, M
    Bergström, Sven
    Fukunaga, M
    Olsen, Björn
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Phylogenetic relationship of Ixodes uriae (Acari: Ixodidae) and their significance to transequatorial dispersal of Borrelia garinii2001In: Heriditas, Vol. 134, p. 195-199Article in journal (Refereed)
  • 47. Haemig, Paul D
    et al.
    Bergström, Sven
    Olsen, Björn
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Survival and mortality of Grey-headed Albatross chicks in relation to infestation by the tick Ixodes uriae1999In: Colonial Waterbirds, Vol. 21(3), p. 452-453Article in journal (Refereed)
  • 48.
    Haemig, Paul D.
    et al.
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Sjöstedt de Luna, S
    Grafström, A
    Lithner, Stefan
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Lundkvist, Åke
    Waldenström, Jonas
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Kindberg, Jonas
    Stedt, Johan
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Olsen, Björn
    Forecasting risk of tick-borne encephalitis (TBE): using data from wildlife and climate to predict next year's number of human victims.2011In: Scandinavian Journal of Infectious Diseases, ISSN 0036-5548, E-ISSN 1651-1980, Vol. 43, no 5, p. 366-372Article in journal (Refereed)
    Abstract [en]

    BACKGROUND: Over the past quarter century, the incidence of tick-borne encephalitis (TBE) has increased in most European nations. However, the number of humans stricken by the disease varies from year to year. A method for predicting major increases and decreases is needed.

    METHODS: We assembled a 25-y database (1984-2008) of the number of human TBE victims and wildlife and climate data for the Stockholm region of Sweden, and used it to create easy-to-use mathematical models that predict increases and decreases in the number of humans stricken by TBE.

    RESULTS: Our best model, which uses December precipitation and mink (Neovison vison, formerly Mustela vison) bagging figures, successfully predicted every major increase or decrease in TBE during the past quarter century, with a minimum of false alarms. However, this model was not efficient in predicting small increases and decreases.

    CONCLUSIONS: Predictions from our models can be used to determine when preventive and adaptive programmes should be implemented. For example, in years when the frequency of TBE in humans is predicted to be high, vector control could be intensified where infested ticks have a higher probability of encountering humans, such as at playgrounds, bathing lakes, barbecue areas and camping facilities. Because our models use only wildlife and climate data, they can be used even when the human population is vaccinated. Another advantage is that because our models employ data from previously-established databases, no additional funding for surveillance is required.

  • 49.
    Haemig, Paul
    et al.
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Hernandez, Jorge
    Waldenström, Jonas
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Bonnedahl, Jonas
    Olsen, Björn
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Barn Swallows (Hirundo rustica) Test Negative for Salmonella2008In: Vector Borne and Zoonotic Diseases, ISSN 1530-3667, E-ISSN 1557-7759, Vol. 8, p. 1-3Article in journal (Refereed)
  • 50.
    Haemig, Paul
    et al.
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Stefan, Lithner
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Sjöstedt de Luna, Sara
    Lundkvist, Åke
    Waldenström, Jonas
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Hansson, Lennart
    Arneborn, Malin
    Olsen, Björn
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Red fox and tick-borne encephalitis (TBE) in humans: Can predators influence public health?2008In: Scandinavian Journal of Infectious Diseases, ISSN 0036-5548, E-ISSN 1651-1980, Vol. 40, no 6-7, p. 527-532Article in journal (Refereed)
    Abstract [en]

    Analysing datasets from hunting statistics and human cases of tick-borne encephalitis (TBE), we found a positive correlation between the number of human TBE cases and the number of red fox (Vulpes vulpes). Time lags were also present, indicating that high numbers of red fox in 1 y translated into high numbers of human TBE cases the following y. Results for smaller predators were mixed and inconsistent. Hares and grouse showed negative correlations with human TBE cases, suggesting that they might function as dilution hosts. Combining our findings with food web dynamics, we hypothesize a diversity of possible interactions between predators and human disease – some predators suppressing a given disease, others enhancing its spread, and still others having no effect at all. Larger-sized predators that suppress red fox numbers and activity (i.e. wolf, Canis lupus; European lynx, Lynx lynx) were once abundant in our study area but have been reduced or extirpated from most parts of it by humans. We ask what would happen to red foxes and TBE rates in humans if these larger predators were restored to their former abundances.Read More: http://informahealthcare.com/doi/abs/10.1080/00365540701805446

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