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Olofsson, Jenny
Publications (10 of 10) Show all publications
Olofsson, J., Axelsson Olsson, D., Brudin, L., Olsen, B. & Ellström, P. (2013). Campylobacter jejuni Actively Invades the Amoeba Acanthamoeba polyphaga and Survives within Non Digestive Vacuoles. PLoS ONE, 8(11), Article ID e78873.
Open this publication in new window or tab >>Campylobacter jejuni Actively Invades the Amoeba Acanthamoeba polyphaga and Survives within Non Digestive Vacuoles
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2013 (English)In: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 8, no 11, article id e78873Article in journal (Refereed) Published
Abstract [en]

The Gram-negative bacterium Campylobacter jejuni is able to enter, survive and multiply within the free living amoeba Acanthamoeba polyphaga, but the molecular mechanisms behind these events are still unclear. We have studied the uptake and intracellular trafficking of viable and heat killed bacterial cells of the C. jejuni strain 81-176 in A. polyphaga. We found that viable bacteria associated with a substantially higher proportion of Acanthamoeba trophozoites than heat killed bacteria. Furthermore, the kinetics of internalization, the total number of internalized bacteria as well as the intracellular localization of internalized C. jejuni were dramatically influenced by bacterial viability. Viable bacteria were internalized at a high rate already after 1 h of co-incubation and were observed in small vacuoles tightly surrounding the bacteria. In contrast, internalization of heat killed C. jejuni was low at early time points and did not peak until 96 h. These cells were gathered in large spacious vacuoles that were part of the degradative pathway as determined by the uptake of fluorescently labeled dextran. The amount of heat killed bacteria internalized by A. polyphaga did never reach the maximal amount of internalized viable bacteria. These results suggest that the uptake and intracellular survival of C. jejuni in A. polyphaga is bacterially induced.

National Category
Microbiology
Research subject
Ecology, Zoonotic Ecology
Identifiers
urn:nbn:se:lnu:diva-30994 (URN)10.1371/journal.pone.0078873 (DOI)000326656200061 ()2-s2.0-84892404372 (Scopus ID)
Available from: 2013-12-06 Created: 2013-12-06 Last updated: 2017-12-06Bibliographically approved
Griekspoor, P., Olofsson, J., Axelsson Olsson, D., Waldenström, J. & Olsen, B. (2013). Multilocus Sequence Typing and FlaA Sequencing Reveal the Genetic Stability of Campylobacter jejuni Enrichment during Coculture with Acanthamoeba polyphaga. Applied and Environmental Microbiology, 79(7), 2477-2479
Open this publication in new window or tab >>Multilocus Sequence Typing and FlaA Sequencing Reveal the Genetic Stability of Campylobacter jejuni Enrichment during Coculture with Acanthamoeba polyphaga
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2013 (English)In: Applied and Environmental Microbiology, ISSN 0099-2240, E-ISSN 1098-5336, Vol. 79, no 7, p. 2477-2479Article in journal (Refereed) Published
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.

National Category
Microbiology
Research subject
Ecology, Microbiology
Identifiers
urn:nbn:se:lnu:diva-25338 (URN)10.1128/AEM.02918-12 (DOI)000316183500046 ()2-s2.0-84875513333 (Scopus ID)
Available from: 2013-04-18 Created: 2013-04-18 Last updated: 2017-12-06Bibliographically approved
Mohlin, C., Liljekvist-Soltic, I., Olofsson, J. & Johansson, K. (2011). Neuropathology of cultured retinas: degenerative events and rescue paradigms. In: William L. Thomsen (Ed.), Advances in Eye Research. Volume 2: (pp. 177-190). Nova Science Publishers, Inc. (2)
Open this publication in new window or tab >>Neuropathology of cultured retinas: degenerative events and rescue paradigms
2011 (English)In: Advances in Eye Research. Volume 2 / [ed] William L. Thomsen, Nova Science Publishers, Inc., 2011, no 2, p. 177-190Chapter in book (Refereed)
Place, publisher, year, edition, pages
Nova Science Publishers, Inc., 2011
National Category
Ophthalmology
Research subject
Chemistry, Medical Chemistry
Identifiers
urn:nbn:se:lnu:diva-67989 (URN)978-1-61324-605-4 (ISBN)978-1-62257-129-1 (ISBN)
Available from: 2017-09-15 Created: 2017-09-15 Last updated: 2018-02-26Bibliographically approved
Axelsson Olsson, D., Olofsson, J., Svensson, L., Griekspoor, P., Waldenström, J., Ellström, P. & Olsen, B. (2010). Amoebae and algae can prolong the survival of Campylobacter species in co-culture. Experimental parasitology, 126, 59-64
Open this publication in new window or tab >>Amoebae and algae can prolong the survival of Campylobacter species in co-culture
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2010 (English)In: Experimental parasitology, ISSN 0014-4894, E-ISSN 1090-2449, Vol. 126, p. 59-64Article in journal (Refereed) Published
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.

National Category
Infectious Medicine
Research subject
Natural Science, Biomedical Sciences
Identifiers
urn:nbn:se:lnu:diva-7086 (URN)10.1016/j.exppara.2009.12.016 (DOI)000278917000012 ()
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
Axelsson Olsson, D., Olofsson, J., Svensson, L., Griekspoor, P., Ellström, P., Waldenström, J. & Olsen, B. (2009). Protozoa as hosts for Campylobacter spp. In: : . Paper presented at XIIIth International Meeting on the Biology and Pathogenicity of Free-Living Amoebae, Puerto de la Cruz, Tenerife, Spain, 17-21th May, 2009.
Open this publication in new window or tab >>Protozoa as hosts for Campylobacter spp
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2009 (English)Conference paper, Oral presentation only (Refereed)
National Category
Microbiology
Research subject
Ecology, Microbiology
Identifiers
urn:nbn:se:lnu:diva-55452 (URN)
External cooperation:
Conference
XIIIth International Meeting on the Biology and Pathogenicity of Free-Living Amoebae, Puerto de la Cruz, Tenerife, Spain, 17-21th May, 2009
Available from: 2016-08-15 Created: 2016-08-15 Last updated: 2017-04-19Bibliographically approved
Liljekvist-Soltic, I., Olofsson, J. & Johansson, K. (2008). Progenitor cell-derived factors enhance photorecepto survival in rat retinal explants.. Brain Research, 1227, 226-233
Open this publication in new window or tab >>Progenitor cell-derived factors enhance photorecepto survival in rat retinal explants.
2008 (English)In: Brain Research, ISSN 0006-8993, E-ISSN 1872-6240, Vol. 1227, p. 226-233Article in journal (Refereed) Published
Abstract [en]

Explantation of postnatal rat retinas is associated with degenerative events that show morphological similarities to human retinal degenerative disorders. The most evident morphological features are photoreceptor apoptosis involving caspase-3 and Müller cell activation. The purpose of the present study was to determine the content of protective factors in rat retinal progenitor cells and analyze the influence of the identified factors on the survival of photoreceptor cells and retinal gliosis. Tissue inhibitors of matrix metalloproteinase-1 (TIMP-1) and vascular endothelial growth factor (VEGF) were identified as putative beneficial factors, and their combined effect was examined in rat retinal explant cultures. Photoreceptor apoptosis was estimated by cell counts of cleaved caspase-3 and caspase-12 immunolabeled as well as TUNEL labeled cells. TIMP-1 and VEGF in combination significantly suppressed photoreceptor apoptosis involving caspase-3 activation. Cell counts of caspase-12 and TUNEL labeled photoreceptors showed no significant difference between the experiment and control retinas. TIMP-1 and VEGF appeared to have no effect on Müller cell activation as measured by GFAP and Ki-67 immunohistochemistry. Our data suggest that TIMP-1 and VEGF in combination promote the survival of photoreceptor cells in rat retinal explants, possibly by affecting a caspase-3 signaling pathway.

National Category
Natural Sciences
Research subject
Natural Science, Biomedical Sciences
Identifiers
urn:nbn:se:lnu:diva-1815 (URN)10.1016/j.brainres.2008.06.077 (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
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