| 1. |
- Parihar, Vishal Singh, et al.
(författare)
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Characterization of human invasive isolates of Listeria monocytogenes in Sweden 1986-2007
- 2008
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Ingår i: Foodborne pathogens and disease. - : Mary Ann Liebert. - 1535-3141 .- 1556-7125. ; 5:6, s. 755-761
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Tidskriftsartikel (refereegranskat)abstract
- Since 1986, 68% of the Listeria monocytogenes isolates from human cases of invasive listeriosis in Sweden are available for retrospective studies. The aim of the present study was to characterize 601 human invasive isolates of L. monocytogenes in Sweden from 1986 to 2007 by using serotyping and pulsed-field gel electrophoresis. Since 1996, serovar 4b was permanently reduced to the second or third most common serovar in human cases in Sweden. During the latter period, 2000-2007, only 13% belonged to serovar 4b and 71% to 1/2a. The dendrogram, based on pulsovars, reveals two clusters with different serovars. Cluster 1 exhibits serovars 4b and 1/2b, whereas cluster 2 consists of serovar 1/2a. Serovar 1/2a seems to be more heterogeneous than serovar 4b.
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| 2. |
- Lopez-Valladares, Gloria, 1963-, et al.
(författare)
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Human isolates of Listeria monocytogenes in Sweden during half a century (1958-2010)
- 2014
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Ingår i: Epidemiology and Infection. - 0950-2688 .- 1469-4409. ; 142, s. 2251-2260
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Tidskriftsartikel (refereegranskat)abstract
- Isolates of Listeria monocytogenes (n=932) isolated in Sweden during 1958–2010 from human patients with invasive listeriosis were characterized by serotyping and pulsed-field gel electrophoresis (PFGE) (AscI). Of the 932 isolates, 183 different PFGE types were identified, of which 83 were each represented by only one isolate. In all, 483 serovar 1/2a isolates were distributed over 114 PFGE types; 90 serovar 1/2b isolates gave 32 PFGE types; 21 serovar 1/2c isolates gave nine PFGE types; three serovar 3b isolates gave one PFGE type; and, 335 serovar 4b isolates gave 31 PFGE types. During the 1980s in Sweden, several serovar 4b cases were associated with the consumption of European raw soft cheese. However, as cheese-production hygiene has improved, the number of 4b cases has decreased. Since 1996, serovar 1/2a has been the dominant L. monocytogenes serovar in human listeriosis in Sweden. Therefore, based on current serovars and PFGE types, an association between human cases of listeriosis and the consumption of vacuum-packed gravad and cold-smoked salmon is suggested.
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| 3. |
- Ericsson, Henrik, et al.
(författare)
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Subtyping of a frequent phagovar of Listeria monocytogenes in Sweden by use of restriction endonuclease analysis
- 1993
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Ingår i: APMIS. - : John Wiley & Sons. - 0903-465X .- 1600-5503 .- 0903-4641 .- 1600-0463. ; 101:7-12, s. 971-974
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Tidskriftsartikel (refereegranskat)abstract
- In Sweden, many Listeria monocytogenes strains belonging to serovar 4b and isolated during the last five years from different sources share the same phagovar - 2389:2425:3274:2671:47:108:340. The object of the present study was to investigate if 31 L. monocytogenes serovar 4b strains belonging to this particular phagovar could be differentiated by use of a simple restriction endonuclease analysis (REA). Among the enzymes tested, Xho I was found to be the most useful, since this enzyme could divide the 31 strains into five groups. The profiles of all human clinical isolates were indistinguishable from each other, which indicates that these strains may represent a single clone. The food isolates and the strains of human origin did not share the same profile. This further characterization may be of epidemiological importance as this phagovar of L. monocytogenes has been associated with at least two outbreaks of human listeriosis in Europe.
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| 4. |
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| 5. |
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| 6. |
- Unnerstad, Helle, et al.
(författare)
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Pyrosequencing as a method for grouping of Listeria monocytogenes strains on the basis of single-nucleotide polymorphisms in the inlB gene
- 2001
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Ingår i: Applied and Environmental Microbiology. - Washington, USA : American Society for Microbiology. - 0099-2240 .- 1098-5336. ; 67:11, s. 5339-5342
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Tidskriftsartikel (refereegranskat)abstract
- By using pyrosequencing (i.e., sequencing by synthesis) 106 strains of different serovars of Listeria monocytogenes were rapidly grouped into four categories based on nucleotide variations at positions 1575 and 1578 of the inlB gene. Strains of serovars 1/2a and 1/2c constituted one group, and strains of serovars 1/2b and 3b constituted another group, whereas serovar 4b strains were separated into two groups.
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| 7. |
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| 8. |
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| 9. |
- Broman, T., et al.
(författare)
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Campylobacter jejuni in black-headed gulls (Larus ridibundus) : prevalence, genotypes, and influence on C. jejuni epidemiology
- 2002
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Ingår i: Journal of Clinical Microbiology. - 0095-1137 .- 1098-660X. ; 40:12, s. 4594-4602
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Tidskriftsartikel (refereegranskat)abstract
- Campylobacteriosis is a zoonotic disease in which birds have been suggested to play an important role as a reservoir. We investigated the prevalence of Campylobacter jejuni subsp. jejuni in black-headed gulls (Larus ridibundus) in southern Sweden with the aim of examining the nature of C. jejuni infection in this bird species. Birds were sampled in four sampling series each year during 1999 (n = 419) and 2000 (n = 365). Longitudinally sampled C. jejuni isolates from individual gulls were subjected to macrorestriction profiling (MRP) by pulsed-field gel electrophoresis to investigate the genotypical stability during the natural course of infection. Furthermore, a subset (n = 76) of black-headed gull isolates was compared to isolates from broiler chickens (n = 38) and humans (n = 56) originating from the same geographic area. We found a pronounced seasonal variation in C. jejuni carriage, with the highest rates found in late autumn. MRP similarities were higher between isolates of human and broiler chicken origin, than between those of wild bird origin and either of the other two hosts. However, identical MRPs were found in two gull isolates and one human isolate after digestion with two restriction enzymes, strongly indicating that they may have been colonized by the same clone of C. jejuni. The MRPs most prevalent in gull isolates did not occur among isolates from humans and broiler chickens, suggesting the existence of a subpopulation of C. jejuni adapted to species-specific colonization or environmental survival.
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| 10. |
- Tham, Wilhelm, 1951-, et al.
(författare)
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Listeria och Erysipelothrix
- 2015. - 1
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Ingår i: Medicinsk mikrobiologi & immunologi. - Lund : Studentlitteratur AB. - 9789144038681 ; , s. 210-214
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Bokkapitel (refereegranskat)abstract
- Släktena Listeria och Erysipelothrix hör till gruppen grampositiva, icke-sporbildande regelbundet formade stavar. Gruppen är mycket heterogen och inkluderar både patogena och apatogena bakterier.
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