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  • 1.
    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.

  • 2.
    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.

  • 3.
    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.
    Svensson, Lovisa
    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
    Uppsala University Hospital.
    Campylobacter jejuni acid tolerance increases when co-incubated with amoebae2009Conference paper (Refereed)
    Abstract [en]

    Background: Although Campylobacter jejuni is a frequent cause of bacterial gastroenteritis, one of the enigmas is how thisfragile organism can survive the transit through the acid milieu of the stomach. C. jejuni is very sensitive to low pH, but cansurvive in moderately acid environment for short periods of time. We have previously shown that C. jejuni can colonize andeven replicate in different species of amoebas, thereby gaining protection from adverse environments.

    Objectives: We evaluated the effects of hydrochloric acid (HCl) on C. jejuni at various pH and time intervals, to study whetherco-cultivation with amoeba influenced C.jejuni acid tolerance. The setup was chosen to mimic the acidified milieu of the humangastrointestinal tract.

    Methods: Cultures of C. jejuni (CCUG 11284) were co-cultured with Acanthamoeba polyphaga in either PBS or tap wateracidified with HCl to pH 1, 2, 3 and 4. We also evaluated different treatments effect on campylobacter survival, by exposingsome bacterial samples to an acid shock and some to a slower acidification process.

    Results and conclusions: We show that C. jejuni can withstand pH below the normal range of survival, when co-cultured withA. polyphaga. C. jejuni co-cultured with amoebae survived acidified conditions at pH 3 for 20 hours and pH 2 for approximately5 hours. We also found a pH increase during the experiment, which correlated with campylobacter survival. These results pointto an unknown mechanism for C.jejuni to survive at low pH levels. This could be in the form of excretion of pH-increasingsubstances and simultaneous chemotaxic orientation towards a protective host. Our results could give one possible explanationto C. jejuni survival through the low pH of the gastrointestinal tract.

  • 4.
    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.

  • 5. Björkman, J
    et al.
    Ellström, Patrik
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Andersson, D I
    Hughes, D
    Novel ribosomal mutations affecting translational accuracy, antibiotic resistance and virulence of Salmonella typhimurium1999In: Molecular microbiology, Vol. 31, p. 53-58Article in journal (Refereed)
  • 6.
    Ellström, Patrik
    Lunds Universitet.
    Role of TLR4 in Escherichia coli Urinary Tract Infection2004Doctoral thesis, monograph (Other academic)
  • 7.
    Ellström, Patrik
    et al.
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Hang, L
    Wullt, B
    Irjala, H
    Svanborg, C
    Toll like Receptor 4 Expression and Cytokine Responses in the Human Urinary Tract Mucosa2004In: Infection and immunity, Vol. 72(6), p. 3179-86Article in journal (Refereed)
  • 8.
    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)
  • 9.
    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)
  • 10. Fischer, Hans
    et al.
    Ellström, Patrik
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Ekström, Kristina
    Gustafsson, Lotta
    Gustafsson, Matthias
    Svanborg, Catharina
    Ceramide as a TLR4 agonist; a putative signalling intermediate between sphingolipid receptors for microbial ligands and TLR42007In: Cellular Microbiology, ISSN 1462-5814, E-ISSN 1462-5822, Vol. 9, no 5 May, p. 1239-51Article in journal (Refereed)
  • 11. Frendeus, B
    et al.
    Wachtler, C
    Hedlund, M
    Fischer, H
    Ellström, Patrik
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Svensson, M
    Svanborg, C
    Escherichia coli P fimbriae utilize the TLR4 receptor pathway for cell activation2001In: Molecular microbiology, Vol. 40, p. 37-51Article in journal (Refereed)
  • 12. Godaly, G
    et al.
    Bergsten, G
    Frendéus, B
    Hang, L
    Hedlund, M
    Karpman, D
    Ellström, Patrik
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Svensson, M
    Otto, G
    Wullt, B
    Svanborg, C
    Innate defenses and resistance to gram negative mucosal infection2000In: Advances in experimental medicine and biology, Vol. 485, p. 9-24Article in journal (Refereed)
  • 13. Godaly, G
    et al.
    Bergsten, G
    Hang, L
    Fischer, H
    Frendéus, B
    Lundstedt, A-C
    Samuelsson, M
    Ellström, Patrik
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Svanborg, C
    Neutrophil recruitment, chemokine receptors and resistance to mucosal infection2001In: Journal of leukocyte biology, Vol. 69, p. 899-906Article in journal (Refereed)
  • 14. Svanborg, C
    et al.
    Bergsten, G
    Fischer, H
    Frendeus, B
    Godaly, G
    Gustafsson, G
    Hang, L
    Hedlund, M
    Lundstedt, A-C
    Samuelsson, M
    Ellström, Patrik
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Svensson, M
    Wullt, B
    Adhesion, signal transduction and mucosal inflammation2002In: Bacterial Adhesion to Host Tissues: Mechanisms and Consequences / [ed] Wilson, Michael, Cambridge: Cambridge University Press , 2002, p. 223-246Chapter in book (Other academic)
  • 15. Svanborg, C
    et al.
    Bergsten, G
    Fischer, H
    Frendéus, B
    Godaly, G
    Gustafsson, E
    Hang, L
    Hedlund, M
    Karpman, D
    Lundstedt, A-C
    Samuelsson, M
    Ellström, Patrik
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Svensson, M
    Wullt, B
    The 'innate' host response protects and damages the infected urinary tract2001In: Annals of medicine, Vol. 33, p. 563-570Article in journal (Refereed)
  • 16. Svanborg, C
    et al.
    Frendéus, B
    Godaly, G
    Hang, L
    Hedlund, M
    Ellström, Patrik
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Svensson, M
    Otto, G
    Wullt, B
    Innate defences and recistance to gram negative mucosal infection1999In: Bacterial Adherence, Vol. 13, p. 1-11Article in journal (Refereed)
  • 17.
    Waldenström, Jonas
    et al.
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences. Lund University.
    Axelsson Olsson, Diana
    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.
    Hasselquist, Dennis
    Lund University.
    Griekspoor, Petra
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Jansson, Lena
    University of Gothenburg.
    Teneberg, Susanne
    University of Gothenburg.
    Svensson, Lovisa
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Ellström, Patrik
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences. Uppsala University.
    Campylobacter jejuni colonization in wild birds: Results from an infection experiment2010In: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 5, no 2, article id e9082Article in journal (Refereed)
    Abstract [en]

    Campylobacter jejuni is a common cause of bacterial gastroenteritis in most parts of the world. The bacterium has a broad host range and has been isolated from many animals and environments. To investigate shedding patterns and putative effects on an avian host, we developed a colonization model in which a wild bird species, the European Robin Erithacus rubecula, was inoculated orally with C. jejuni from either a human patient or from another wild bird species, the Song Thrush Turdus philomelos. These two isolates were genetically distinct from each other and provoked very different host responses. The Song Thrush isolate colonized all challenged birds and colonization lasted 6.8 days on average. Birds infected with this isolate also showed a transient but significant decrease in body mass. The human isolate did not colonize the birds and could be detected only in the feces of the birds shortly after inoculation. European Robins infected with the wild bird isolate generated a specific antibody response to C. jejuni membrane proteins from the avian isolate, which also was cross-reactive to membrane proteins of the human isolate. In contrast, European Robins infected with the human isolate did not mount a significant response to bacterial membrane proteins from either of the two isolates. The difference in colonization ability could indicate host adaptations.

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