| 1. |
- Berndtson, Eva, et al.
(författare)
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Experimental colonization of mice with Campylobacter jejuni
- 1994
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Ingår i: Veterinary Microbiology. - : Elsevier. - 0378-1135 .- 1873-2542. ; 41:1-2, s. 183-188
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Tidskriftsartikel (refereegranskat)abstract
- The ability of one human and two chicken strains of Campylobacter jejuni to colonise and survive in three different strains of laboratory mice (NMRI, CBA and C57-Black) was studied. Mice were inoculated orally with Campylobacter jejuni and faeces samples were cultured at regular intervals during the following months. The length of colonisation of mice differed between mouse strains but also between Campylobacter strains. The mouse strain C57-Black was not colonised with C. jejuni to the same degree as the other mouse strains. It is concluded that mice can become colonised for prolonged periods and that they may act as reservoirs of Campylobacter for other species.
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| 2. |
- Eld, Karin, et al.
(författare)
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Comparison of a cold enrichment method and the IDF method for isolation of Listeria monocytogenes from autopsy material
- 1993
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Ingår i: Veterinary Microbiology. - : Elsevier. - 0378-1135 .- 1873-2542. ; 36:1-2, s. 185-189
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Tidskriftsartikel (refereegranskat)abstract
- The method most often used in Sweden for isolation of Listeria monocytogenes from animal autopsy material is a cold enrichment method. This method is very slow. The International Dairy Federation (IDF) has recently presented a method for detection of L. monocytogenes in milk and milk products that is complete in one week. During a two year period 69 specimens from dead animals with suspected listeriosis were examined for L. monocytogenes in parallel analyses with both the cold enrichment method and the IDF method. Samples derived from different autopsy material representing a variety of animals. L. monocytogenes was isolated in 27.5% of the samples with the IDF method but only in 4.3% with the cold enrichment method. It is concluded that the IDF method was more sensitive than the cold enrichment method.
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| 3. |
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| 6. |
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| 7. |
- Abro, Shahid, hussain, et al.
(författare)
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Emergence of novel strains of avian infectious bronchitis virus in Sweden
- 2012
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Ingår i: Veterinary Microbiology. - : Elsevier BV. - 0378-1135 .- 1873-2542. ; 155, s. 237-246
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Tidskriftsartikel (refereegranskat)abstract
- Infectious bronchitis virus (IBV) causes avian infectious bronchitis, an important disease that produces severe economic losses in the poultry industry worldwide. Recent IBV infections in Sweden have been associated with poor growth in broilers, drop in egg production and thin egg shells in layers. The complete spike gene of selected isolates from IBV cases was amplified and sequenced using conventional RT-PCR. Nucleotide and amino acid sequence comparisons have shown that the recent isolates bear 98.97% genetic similarity with strains of the QX-like genotype. The phylogenetic analysis revealed that strains predominant in the nineties, which were of the Massachusetts type, have been replaced by D388/QX-Iike strains, however the evolutionary link could not be established. The homology between the two genotypes was 79 and 81%. Remarkably, a strong positive selection pressure was determined, mostly involving the S1 subunit of the S gene. This strong selective pressure resulted in recombination events, insertions and deletions in the S gene. Two new isolates generated from recombination were found with nucleotide sequence diverging 1.7-2.4% from the D388/QX-Iike branch, indicating the emergence of a new lineage. The study demonstrates a constant evolution of IBV that might be in relation to increased poultry farming, trade and vaccine pressure. The findings underscore the importance of continuous monitoring to control spread of infections, as well as to timely adjust diagnostic methods, molecular epidemiological studies, development and use of vaccines that are adapted to the changing disease scenario. (C) 2011 Elsevier B.V. All rights reserved.
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| 8. |
- Artursson, Karin, et al.
(författare)
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Genotyping of Staphylococcus aureus in bovine mastitis and correlation to phenotypic characteristics
- 2016
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Ingår i: Veterinary Microbiology. - : Elsevier BV. - 0378-1135. ; 193, s. 156-161
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Tidskriftsartikel (refereegranskat)abstract
- Reducing the prevalence of mastitis caused by Staphylococcus aureus (S. aureus) is essential to improve animal health and reduce economic losses for farmers. The clinical outcome of acute mastitis and risk of progression to persistent mastitis can, at least to some extent, be related to genetic variants of the strain causing the infection. In the present study we have used microarrays to investigate the presence of virulence genes in S. aureus isolates from dairy cows with acute clinical mastitis (n = 70) and correlated the findings to other genotypic and phenotypic characteristics. Among the most commonly found virulence factors were genes encoding several hemolysin types, leukocidins D and lukM/lukF-P83, clumping factors A and B, fibrinogen binding protein and fibronectin-binding protein A. Some virulence factors e.g. fibronectin-binding protein B and Staphylococcus aureus surface protein G were less common. Genes coding for several staphylococcal enterotoxins and toxic shock syndrome toxin-1 (TSST-1) were commonly found, especially in one major pulsotype. No beta-lactamase genes were found in any common pulsotype, while present in some rare pulsotypes, indicated to be of human origin. Production of TSST-1, enterotoxins, hemolysins and beta-lactamase could all be positively correlated to presence of the corresponding genes. This study reveals a number of genotypic differences and similarities among common and rare pulsotypes of S. aureus from cases of mastitis in Sweden. The results could help the design of diagnostic tools to guide on-farm interventions according to the expected impact on udder health from a specific S. aureus genotype.
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| 9. |
- Backhans, Annette, et al.
(författare)
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Typing of Brachyspira spp. from rodents, pigs and chickens on Swedish farms
- 2011
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Ingår i: Veterinary Microbiology. - : Elsevier BV. - 0378-1135 .- 1873-2542. ; 153, s. 156-162
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Tidskriftsartikel (refereegranskat)abstract
- The aim of the current study was to look for evidence of possible cross-species transmission of Brachyspira species between rodents and farm animals. To do this, previously collected and characterised Brachyspira isolates from rodents, pigs and chickens on the same farms were analysed by random amplified polymorphic DNA (RAPD). Isolates with similar RAPD banding patterns were further typed by pulsed-field gel electrophoresis (PFGE). Identical isolates of Brachyspira pilosicoli, Brachyspira intermedia, Brachyspira murdochii and Brachyspira innocens from pigs and rodents and of B. murdochii from laying hens and rodents were found, indicating cross-species transmission at farm level. PFGE data from rodent isolates of Brachyspira hyodysenteriae were compared with PFGE data from previously typed field isolates of B. hyodysenteriae from pigs with swine dysentery and isolates from mallards (Anas platyrhynchos). Three of four isolates of B. hyodysenteriae from rodents were similar to porcine field isolates by PFGE. PCR analyses of the plasmid-encoded and potential virulence determinants rib genes B, A, D and C showed that they were present in isolates of B. hyodysenteriae of porcine, mallard and rodent origin. (C) 2011 Elsevier B.V. All rights reserved.
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| 10. |
- Bálint, Adám, et al.
(författare)
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Characterization of two low pathogenic avian influenza viruses isolated in Hungary in 2007
- 2010
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Ingår i: Veterinary Microbiology. - : Elsevier BV. - 0378-1135 .- 1873-2542. ; 145, s. 142-147
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Tidskriftsartikel (refereegranskat)abstract
- Two low pathogenic (LP) avian influenza virus strains, A/mallard/Hungary/19616/07 (H3N8) and A/mute swan/Hungary/5973/07 (H7N7), isolated as part of the National Surveillance Program in Hungary, were fully sequenced and characterized. The two viruses showed the closest phylogenetic relationship regarding their acidic polymerase genes. The H7N7 Hungarian virus and some H5N2 influenza viruses isolated from Korean pigs appeared to have their basic polymerase gene 1 from a relatively recent common ancestor. The matrix gene nucleotide sequence of each Hungarian virus showed close relationship with contemporaneous Czech H3N8 mallard isolates, which belonged to distinct phylogenetic branches. The non-structural protein genes belonged to different alleles, rendering a peculiar characteristic to the H7N7 isolate compared to the so far analyzed Eurasian H7 viruses. The surface glycoprotein genes of the H3N8 isolate showed a close phylogenetic relationship and high nucleotide identities to H3N8 subtype isolates from Northern Europe collected in 2003-2006, and to an H3N2 isolate in Italy in 2006, extending the perceptions of this HA subtype across Northern and Southern Europe close to this period. These findings provide further data to the diversity of influenza viruses found in wild migratory birds and present useful information for large scale studies on influenza virus evolution. (c) 2010 Elsevier B.V. All rights reserved.
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