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Ellström, Patrik
Publications (10 of 17) Show all publications
Waldenström, J., Axelsson Olsson, D., Olsen, B., Hasselquist, D., Griekspoor, P., Jansson, L., . . . Ellström, P. (2010). Campylobacter jejuni colonization in wild birds: Results from an infection experiment. PLoS ONE, 5(2), Article ID e9082.
Open this publication in new window or tab >>Campylobacter jejuni colonization in wild birds: Results from an infection experiment
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2010 (English)In: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 5, no 2, article id e9082Article in journal (Refereed) Published
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.

National Category
Microbiology
Research subject
Ecology, Zoonotic Ecology
Identifiers
urn:nbn:se:lnu:diva-7083 (URN)10.1371/journal.pone.0009082 (DOI)2-s2.0-77949373747 (Scopus ID)
Available from: 2010-08-10 Created: 2010-08-10 Last updated: 2017-12-12Bibliographically approved
Axelsson Olsson, D., Svensson, L., Olofsson, J., Salomon, P., Waldenström, J., Ellström, P. & Olsen, B. (2010). Increase in Acid Tolerance of Campylobacter jejuni through Coincubation with Amoebae. Applied and Environmental Microbiology, 76(13), 4194-4200
Open this publication in new window or tab >>Increase in Acid Tolerance of Campylobacter jejuni through Coincubation with Amoebae
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2010 (English)In: Applied and Environmental Microbiology, ISSN 0099-2240, E-ISSN 1098-5336, Vol. 76, no 13, p. 4194-4200Article in journal (Refereed) Published
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.

National Category
Microbiology
Research subject
Ecology, Microbiology
Identifiers
urn:nbn:se:lnu:diva-7087 (URN)10.1128/AEM.01219-09 (DOI)2-s2.0-77954258414 (Scopus ID)
Available from: 2010-08-10 Created: 2010-08-10 Last updated: 2017-12-12Bibliographically approved
Axelsson Olsson, D., Olofsson, J., Ellström, P., Waldenström, J. & Olsen, B. (2009). A simple method for long-term storage Acanthamoeba species. Parasitology Research, 104(4), 935-937
Open this publication in new window or tab >>A simple method for long-term storage Acanthamoeba species
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2009 (English)In: Parasitology Research, ISSN 0932-0113, E-ISSN 1432-1955, Vol. 104, no 4, p. 935-937Article in journal (Refereed) Published
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.

National Category
Microbiology
Research subject
Ecology, Zoonotic Ecology; Ecology, Microbiology; Biomedical Sciences, Virology
Identifiers
urn:nbn:se:lnu:diva-1912 (URN)10.1007/s00436-008-1304-x (DOI)
Available from: 2010-04-06 Created: 2010-04-06 Last updated: 2017-12-12Bibliographically approved
Axelsson Olsson, D., Olofsson, J., Svensson, L., Ellström, P., Waldenström, J. & Olsen, B. (2009). Campylobacter jejuni acid tolerance increases when co-incubated with amoebae. In: : . Paper presented at CHRO 2009, 15th International Workshop on Campylobacter, Helicobacter and Related Organisms, Niigata, Japan, September 2-5th 2009.
Open this publication in new window or tab >>Campylobacter jejuni acid tolerance increases when co-incubated with amoebae
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2009 (English)Conference paper, Oral presentation with published abstract (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.

National Category
Microbiology
Research subject
Ecology, Microbiology
Identifiers
urn:nbn:se:lnu:diva-55450 (URN)
Conference
CHRO 2009, 15th International Workshop on Campylobacter, Helicobacter and Related Organisms, Niigata, Japan, September 2-5th 2009
Available from: 2016-08-15 Created: 2016-08-15 Last updated: 2018-05-22Bibliographically approved
Ellström, P., Jourdain, E., Gunnarsson, O., Waldenström, J. & Olsen, B. (2009). The ”human influenza receptor” Neu5Ac alpha 2,6Gal is expressed among different taxa of wild birds. Archives of Virology, 154(9), 1533-1537
Open this publication in new window or tab >>The ”human influenza receptor” Neu5Ac alpha 2,6Gal is expressed among different taxa of wild birds
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2009 (English)In: Archives of Virology, ISSN 0304-8608, E-ISSN 1432-8798, Vol. 154, no 9, p. 1533-1537Article in journal (Refereed) Published
National Category
Microbiology
Research subject
Natural Science, Zoonotic Ecology; Natural Science, Microbiology; Biomedical Sciences, Virology
Identifiers
urn:nbn:se:lnu:diva-2047 (URN)10.1007/s00705-009-0476-8 (DOI)
Available from: 2010-04-06 Created: 2010-04-06 Last updated: 2017-12-12Bibliographically approved
Ellström, P., Latorre-Margalef, N., Griekspoor, P., Waldenström, J., Olofsson, J., Wahlgren, J. & Olsen, B. (2008). Sampling for low-pathogenic avian influenza A virus in wild Mallard ducks: Oropharyngeal versus cloacal swabbing [Letter to the editor]. Vaccine, 26(35), 4414-4416
Open this publication in new window or tab >>Sampling for low-pathogenic avian influenza A virus in wild Mallard ducks: Oropharyngeal versus cloacal swabbing
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2008 (English)In: Vaccine, ISSN 0264-410X, E-ISSN 1873-2518, Vol. 26, no 35, p. 4414-4416Article in journal, Letter (Refereed) Published
National Category
Microbiology
Research subject
Ecology, Zoonotic Ecology; Ecology, Microbiology; Biomedical Sciences, Virology
Identifiers
urn:nbn:se:lnu:diva-1917 (URN)10.1016/j.vaccine.2008.06.027 (DOI)000258971800003 ()
Available from: 2010-04-06 Created: 2010-04-06 Last updated: 2017-05-15Bibliographically approved
Axelsson Olsson, D., Ellström, P., Waldenström, J., Haemig, P. D., Brudin, L. & Olsen, B. (2007). Acanthamoeba-Campylobacter coculture as a novel method for enrichment of Campylobacter species. Applied and Environmental Microbiology, 73(21), 6864-6869
Open this publication in new window or tab >>Acanthamoeba-Campylobacter coculture as a novel method for enrichment of Campylobacter species
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2007 (English)In: Applied and Environmental Microbiology, Vol. 73, no 21, p. 6864-6869Article in journal (Refereed) Published
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.

National Category
Microbiology
Research subject
Natural Science, Zoonotic Ecology; Natural Science, Microbiology; Biomedical Sciences, Virology
Identifiers
urn:nbn:se:lnu:diva-2343 (URN)10.1128/AEM.01305-07 (DOI)
Available from: 2010-04-07 Created: 2010-04-07 Last updated: 2015-12-04Bibliographically approved
Fischer, H., Ellström, P., Ekström, K., Gustafsson, L., Gustafsson, M. & Svanborg, C. (2007). Ceramide as a TLR4 agonist; a putative signalling intermediate between sphingolipid receptors for microbial ligands and TLR4. Cellular Microbiology, 9(5 May), 1239-51
Open this publication in new window or tab >>Ceramide as a TLR4 agonist; a putative signalling intermediate between sphingolipid receptors for microbial ligands and TLR4
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2007 (English)In: Cellular Microbiology, ISSN 1462-5814, E-ISSN 1462-5822, Vol. 9, no 5 May, p. 1239-51Article in journal (Refereed) Published
National Category
Natural Sciences
Research subject
Natural Science, Microbiology
Identifiers
urn:nbn:se:lnu:diva-2357 (URN)
Available from: 2010-04-07 Created: 2010-04-07 Last updated: 2017-12-12Bibliographically approved
Ellström, P. (2004). Role of TLR4 in Escherichia coli Urinary Tract Infection. (Doctoral dissertation).
Open this publication in new window or tab >>Role of TLR4 in Escherichia coli Urinary Tract Infection
2004 (English)Doctoral thesis, monograph (Other academic)
Research subject
Natural Science, Zoonotic Ecology; Natural Science, Microbiology; Biomedical Sciences, Virology
Identifiers
urn:nbn:se:lnu:diva-3018 (URN)
Public defence
(English)
Note
Nummer: Available from: 2007-01-25 Created: 2010-04-23 Last updated: 2010-04-23
Ellström, P., Hang, L., Wullt, B., Irjala, H. & Svanborg, C. (2004). Toll like Receptor 4 Expression and Cytokine Responses in the Human Urinary Tract Mucosa. Infection and immunity, 72(6), 3179-86
Open this publication in new window or tab >>Toll like Receptor 4 Expression and Cytokine Responses in the Human Urinary Tract Mucosa
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2004 (English)In: Infection and immunity, Vol. 72(6), p. 3179-86Article in journal (Refereed) Published
Research subject
Natural Science, Zoonotic Ecology; Natural Science, Microbiology; Biomedical Sciences, Virology
Identifiers
urn:nbn:se:lnu:diva-877 (URN)
Available from: 2010-04-01 Created: 2010-04-01 Last updated: 2011-09-29Bibliographically approved

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