| 1. |
- Berndtson, Eva, et al.
(författare)
-
Experimental colonization of mice with Campylobacter jejuni
- 1994
-
Ingår i: Veterinary Microbiology. - : Elsevier. - 0378-1135 .- 1873-2542. ; 41:1-2, s. 183-188
-
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.
|
|
| 2. |
- Eld, Karin, et al.
(författare)
-
Comparison of a cold enrichment method and the IDF method for isolation of Listeria monocytogenes from autopsy material
- 1993
-
Ingår i: Veterinary Microbiology. - : Elsevier. - 0378-1135 .- 1873-2542. ; 36:1-2, s. 185-189
-
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.
|
|
| 3. |
- Abro, Shahid, hussain, et al.
(författare)
-
Emergence of novel strains of avian infectious bronchitis virus in Sweden
- 2012
-
Ingår i: Veterinary Microbiology. - : Elsevier BV. - 0378-1135 .- 1873-2542. ; 155, s. 237-246
-
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.
|
|
| 4. |
- Backhans, Annette, et al.
(författare)
-
Typing of Brachyspira spp. from rodents, pigs and chickens on Swedish farms
- 2011
-
Ingår i: Veterinary Microbiology. - : Elsevier BV. - 0378-1135 .- 1873-2542. ; 153, s. 156-162
-
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.
|
|
| 5. |
- Bálint, Adám, et al.
(författare)
-
Characterization of two low pathogenic avian influenza viruses isolated in Hungary in 2007
- 2010
-
Ingår i: Veterinary Microbiology. - : Elsevier BV. - 0378-1135 .- 1873-2542. ; 145, s. 142-147
-
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.
|
|
| 6. |
- Belak, Sandor
(författare)
-
Epizotiology and phylogeny of equine arteritis virus in hucul horses
- 2011
-
Ingår i: Veterinary Microbiology. - : Elsevier BV. - 0378-1135 .- 1873-2542. ; 148, s. 402-407
-
Tidskriftsartikel (refereegranskat)abstract
- The aim of the study was to determine the situation of equine arteritis virus (EAV) infections in hucul horses. A total of 176 horses (154 mares and 22 stallions) from the biggest hucul horse stud in Poland were tested. Antibodies against EAV were detected in 97 (55.1%) horses. The EAV seroprevalence among mares was 53.2% while in stallions - 68.2%. The percentage of positive mares increased with their age, thus amongst the mares of less than 2 years of age the percentage was 32.5%, while in the group of 3-5 years old increased to 59.4% and in the mares in the age of 6-10 years and older than 10 years 89.5% and 95% were seropositive, respectively. Among 11 seropositive stallions five were supposed to be shedders of EAV with their semen. It is likely that those persistently infected stallions were the reservoirs of the virus in the stud. Genetic studies using of ORF5 gene showed high homology between the viruses detected in the semen of those stallions what suggested lateral transmission between the stallions sharing the same stable. Persistent infection in an immature stallion, which has not yet been used for breeding, was established as a result of infection via respiratory route. Phylogenetic analysis confirmed that all hucul viruses shared the same ancestor and as most of EAV strains dominating in Polish horse population belonged to the European origin EAV subgroup (EU-1). (C) 2010 Elsevier B.V. All rights reserved.
|
|
| 7. |
- Belak, Sandor, et al.
(författare)
-
Four different sublineages of highly pathogenic avian influenza H5N1 introduced in Hungary in 2006–2007
- 2009
-
Ingår i: Veterinary Microbiology. - : Elsevier BV. - 0378-1135 .- 1873-2542. ; 139, s. 24-33
-
Tidskriftsartikel (refereegranskat)abstract
- Highly pathogenic avian influenza (HPAI) H5N1 viruses were introduced to Hungary during 2006–2007 in three separate waves. This study aimed at determining the full-length genomic coding regions of the index strains from these epizootics in order to: (i) understand the phylogenetic relationship to other European H5N1 isolates, (ii) elucidate the possible connection between the different outbreaks and (iii) determine the putative origin and way of introduction of the different virus variants. Molecular analysis of the HA gene of Hungarian HPAI isolates obtained from wild birds during the first introduction revealed two groups designated Hungarian1 (HUN1) and Hungarian2 (HUN2) within sublineage 2.2B and clade 2.2.1, respectively. Sequencing the whole coding region of the two index viruses A/mute swan/Hungary/3472/2006 and A/mute swan/4571/Hungary/2006 suggests the role of wild birds in the introduction of HUN1 and HUN2 viruses: the most similar isolates to HUN1 and HUN2 group were found in wild avian species in Croatia and Slovakia, respectively. The second introduction of HPAI H5N1 led to the largest epizootic in domestic waterfowl in Europe. The index strain of the epizootic A/goose/Hungary/14756/2006 clustered to sublineage 2.2.A1 forming the Hungarian3 (HUN3) group. A common ancestry of HUN3 isolates with Bavarian strains is suggested as the most likely scenario of origin. Hungarian4 (HUN4) viruses isolated from the third introduction clustered with isolate A/turkey/United Kingdom/750/2007 forming a sublineage 2.2.A2. The origin and way of introduction of HUN4 viruses is still obscure, thus further genetic, phylogenetic, ecological and epidemiological data are required in order to elucidate it
|
|
| 8. |
- Belak, Sandor, et al.
(författare)
-
New viruses in veterinary medicine, detected by metagenomic approaches
- 2013
-
Ingår i: Veterinary Microbiology. - : Elsevier BV. - 0378-1135 .- 1873-2542. ; 165, s. 95-101
-
Tidskriftsartikel (refereegranskat)abstract
- In our world, which is faced today with exceptional environmental changes and dramatically intensifying globalisation, we are encountering challenges due to many new factors, including the emergence or re-emergence of novel, so far “unknown” infectious diseases. Although a broad arsenal of diagnostic methods is at our disposal, the majority of the conventional diagnostic tests is highly virus-specific or is targeted entirely towards a limited group of infectious agents. This specificity complicates or even hinders the detection of new or unexpected pathogens, such as new, emerging or re-emerging viruses or novel viral variants. The recently developed approaches of viral metagenomics provide an effective novel way to screen samples and detect viruses without previous knowledge of the infectious agent, thereby enabling a better diagnosis and disease control, in line with the “One World, One Health” principles (www.oneworldonehealth.org). Using metagenomic approaches, we have recently identified a broad variety of new viruses, such as novel bocaviruses, Torque Teno viruses, astroviruses, rotaviruses and kobuviruses in porcine disease syndromes, new virus variants in honeybee populations, as well as a range of other infectious agents in further host species. These findings indicate that the metagenomic detection of viral pathogens is becoming now a powerful, cultivation-independent, and useful novel diagnostic tool in veterinary diagnostic virology.
|
|
| 9. |
- Bengtsson, Björn, et al.
(författare)
-
High occurrence of mecC-MRSA in wild hedgehogs (Erinaceus europaeus) in Sweden
- 2017
-
Ingår i: Veterinary Microbiology. - : Elsevier. - 0378-1135 .- 1873-2542. ; 207, s. 103-107
-
Tidskriftsartikel (refereegranskat)abstract
- We investigated the occurrence of mecC-MRSA in wild hedgehogs (Erinaceus europaeus) in Sweden and characterized the obtained isolates. Samples from 55 hedgehogs from five counties of Sweden were cultivated selectively for MRSA and putative isolates were confirmed by real-time PCR detecting mecA, mecC, nuc and PVL genes. mecC-MRSA was confirmed in 35 (64%) animals from three geographically separated counties. Confirmed isolates were spa-typed and tested for antimicrobial susceptibility by broth microdilution. Eight different spa-types were identified (t843, t978, t3391, t9111, t10751, t10893, t11015, t15312) of which t843 (49%) was the most common. The spa-types t843, t3391 and t978 were found in isolates from two counties. The study shows that mecC-MRSA is common in wild hedgehogs in two counties of Sweden but occurs in hedgehogs also in other parts of the country. Our findings suggest that hedgehogs could be a reservoir for mecC-MRSA. In addition, similar spa-types of isolates from hedgehogs and isolates previously described in domesticated animals and in humans indicates transfer between these populations.
|
|
| 10. |
- Bergström, Karin, et al.
(författare)
-
Longitudinal study of horses for carriage of methicillin-resistant Staphylococcus aureus following wound infections
- 2013
-
Ingår i: Veterinary Microbiology. - : Elsevier BV. - 0378-1135 .- 1873-2542. ; 163, s. 388-391
-
Tidskriftsartikel (refereegranskat)abstract
- The most sensitive sampling site was the nostrils, with a sensitivity of 0.91 (95% CI: 0.59-1.00). The other test sites had a sensitivity of 0-0.09. Individual cases tested positive, but with time all tested negative. The observed carriage time ranged from 55 to 711 days (median = 143, IQR: 111-172 days), but these data should be interpreted with caution since only a small number of cases were studied. (C) 2013 Elsevier B.V. All rights reserved.
|
|
| 11. |
|
|
| 12. |
- Bröjer, Caroline, et al.
(författare)
-
Pathogenicity and tissue tropism of currently circulating highly pathogenic avian influenza A virus (H5N1; clade 2.3.2) in tufted ducks (Aythya fuligula)
- 2015
-
Ingår i: Veterinary Microbiology. - : Elsevier BV. - 0378-1135 .- 1873-2542. ; 180, s. 273-280
-
Tidskriftsartikel (refereegranskat)abstract
- Reports describing the isolation of highly pathogenic avian influenza (HPAI) virus (H5N1) clade 2.3.2 in feces from apparently healthy wild birds and the seemingly lower pathogenicity of this clade compared to clade 2.2 in several experimentally infected species, caused concern that the new clade might be maintained in the wild bird population. To investigate whether the pathogenicity of a clade 2.3.2 virus was lower than that of clades previously occurring in free-living wild birds in Europe, four tufted ducks were inoculated with influenza A/duck/HongKong/1091/2011 (H5N1) clade 2.3.2 virus. The ducks were monitored and sampled for virus excretion daily during 4 days, followed by pathologic, immunohistochemical, and virological investigations. The virus produced severe disease as evidenced by clinical signs, presence of marked lesions and abundant viral antigen in several tissues, especially the central nervous system. The study shows that HPAI-H5N1 virus clade 2.3.2 is highly pathogenic for tufted ducks and thus, they are unlikely to maintain this clade in the free-living population or serve as long-distance vectors. (C) 2015 Elsevier B.V. All rights reserved.
|
|
| 13. |
- Börjesson, Stefan, 1979-, et al.
(författare)
-
Introduction of quinolone resistant Escherichia coli to Swedish broiler population by imported breeding animals
- 2016
-
Ingår i: Veterinary Microbiology. - : Elsevier. - 0378-1135 .- 1873-2542. ; 194, s. 74-78
-
Tidskriftsartikel (refereegranskat)abstract
- During recent years a rapid increase of quinolone resistant Escherichia coli have been noted in the Swedish broiler population, despite the lack of a known selective pressure. The current study wanted to investigate if imported breeding birds could be a source for the quinolone resistant E. coli. The occurrence of quinolone resistant E. coli was investigated, using selective cultivation with nalidixic acid, in grand-parent birds on arrival to Sweden and their progeny. In addition, sampling in hatcheries and empty cleaned poultry houses was performed. Clonality of isolates was investigated using a 10-loci multiple-locus variable number tandem repeat analysis (MLVA). To identify the genetic basis for the resistance isolates were also analysed for occurrence of plasmid-mediated quinolone resistance (PMQR) determinants and characterization of chromosomal mutations. E. coli resistant to nalidixic acid occurred in grandparent birds imported to Sweden for breeding purposes. Four predominant MLVA types were identified in isolates from grandparent birds, parent birds and broilers. However, resistant E. coli with identical MLVA patterns were also present in hatcheries and poultry houses suggesting that the environment plays a role in the occurrence. Nalidixic acid resistance was due to a mutation in the gyrA gene and no PMQR could be identified. The occurrence of identical clones in all levels of the production pyramid points to that quinolone resistant E. coli can be introduced through imported breeding birds and spread by vertical transmission to all levels of the broiler production pyramid.
|
|
| 14. |
|
|
| 15. |
- Erfan, Ahmed M., et al.
(författare)
-
Chicken anaemia virus enhances and prolongs subsequent avian influenza (H9N2) and infectious bronchitis viral infections
- 2019
-
Ingår i: Veterinary Microbiology. - : ELSEVIER SCIENCE BV. - 0378-1135 .- 1873-2542. ; 230, s. 123-129
-
Tidskriftsartikel (refereegranskat)abstract
- Immunosuppressive viral diseases have a great economic importance in the poultry industry due to the increased susceptibility to secondary infections. Chicken anaemia virus (CAV) is one of the major immunosuppressive diseases in chickens. In addition, low pathogenic avian influenza (LPAI) of subtype H9N2 and infectious bronchitis (IB) viruses are among the most frequently reported respiratory viral diseases in poultry worldwide. In the present study, specific pathogen free chickens were used to understand the impact of CAV on secondary infection with LPAI-H9N2 or 1B viruses. Clinical outcomes, viral shedding dynamics, and cytokine levels wereassessed. The results exhibit that chickens previously infected with CAV produceconsiderablyhigher titresof LPAI-H9N2 or IB viruses in the oropharyngeal swabs (P < 0.05), tracheas and kidneys. In addition, the immunologic effect of CAV provokedthe development of clinical signs of LPAI-H9N2 and IB virus infections. Moreover, results suggested that pre-infection with CAV directly correlated with elevated levels of IL-6 and IFN gamma. These findings underline the importance of CAV pre-infection on LPAI-H9N2 or IB infection in chickens, and indicate that co-circulation of CAV can contribute to the spread and evolution of LPAI H9N2 and IB viruses.
|
|
| 16. |
- Fellström, Claes
(författare)
-
A review of methods used for studying the molecular epidemiology of Brachyspira hyodysenteriae
- 2017
-
Ingår i: Veterinary Microbiology. - : Elsevier BV. - 0378-1135 .- 1873-2542. ; 207, s. 181-194
-
Forskningsöversikt (refereegranskat)abstract
- Brachyspira (B.) spp. are intestinal spirochaetes isolated from pigs, other mammals, birds and humans. In pigs, seven Brachyspira spp. have been described, i.e. B. hyodysenteriae, B. pilosicoli, B. intermedia, B. murdochii, B. innocens, B. suanatina and B. hampsonii. Brachyspira hyodysenteriae is especially relevant in pigs as it causes swine dysentery and hence considerable economic losses to the pig industry. Furthermore, reduced susceptibility of B. hyodysenteriae to antimicrobials is of increasing concern. The epidemiology of B. hyodysenteriae infections is only partially understood, but different methods for detection, identification and typing have supported recent improvements in knowledge and understanding. In the last years, molecular methods have been increasingly used. Molecular epidemiology links molecular biology with epidemiology, offering unique opportunities to advance the study of diseases. This review is based on papers published in the field of epidemiology and molecular epidemiology of B. hyodysenteriae in pigs. Electronic databases were screened for potentially relevant papers using title and abstract and finally, Barcellos et al. papers were systemically selected and assessed. The review summarises briefly the current knowledge on B. hyodysenteriae epidemiology and elaborates on molecular typing techniques available.Results of the studies are compared and gaps in the knowledge are addressed. Finally, potential areas for future research are proposed.
|
|
| 17. |
- Frosth, Sara, et al.
(författare)
-
Characterisation of Dichelobacter nodosus and detection of Fusobacterium necrophorum and Treponema spp. in sheep with different clinical manifestations of footrot
- 2015
-
Ingår i: Veterinary Microbiology. - : Elsevier BV. - 0378-1135 .- 1873-2542. ; 179, s. 82-90
-
Tidskriftsartikel (refereegranskat)abstract
- The aim of this study was to determine the proportion of Dichelobacter nodosus, Fusobacterium necrophorum and Treponema spp. in sheep with different clinical manifestations of footrot compared to healthy sheep both at flock and individual level. The second aim was to characterise D. nodosus with respect to virulence, presence of intA gene and the serogroups.Swab samples (n = 1000) from footrot-affected (n = 10) and healthy flocks (n = 10) were analysed for the presence of D. nodosus, F. necrophorum and Treponema spp. by real-time PCR and culturing (D. nodosus only). Dichelobacter nodosus isolates (n = 78) and positive swabs (n = 474) were analysed by real-time PCR for the aprV2/B2 and the intA genes and by PCR for the fimA gene (isolates only).D. nodosus was more commonly found in flocks affected with footrot than in clinically healthy flocks. A significant association was found between feet with severe footrot lesions and the aprV2 gene and between feet with moderate or no lesions and the aprB2 gene, respectively. F. necrophorum was more commonly found in flocks with footrot lesions than in flocks without lesions. No significant association was found between sheep flocks affected with footrot and findings of Treponema spp. or the intA gene. Benign D. nodosus of six different serogroups was detected in twelve flocks and virulent D. nodosus of serogroup G in one.In conclusion, D. nodosus and F. necrophorum were more commonly found in feet with footrot than in healthy feet. The majority of D. nodosus detected was benign, while virulent D. nodosus was only detected in a single flock. (C) 2015 The Authors. Published by Elsevier B.V.
|
|
| 18. |
- Frosth, Sara
(författare)
-
Potential transmission routes of Dichelobacter nodosus
- 2018
-
Ingår i: Veterinary Microbiology. - : Elsevier BV. - 0378-1135 .- 1873-2542. ; 218, s. 20-24
-
Tidskriftsartikel (refereegranskat)abstract
- Footrot caused by Dichelobacter nodosus is a highly contagious bacterial disease affecting the claw of sheep and the main cause of lameness in these animals. It is not only an economic burden but also a serious animal welfare issue. More information about the transmission of D. nodosus is needed for effective footrot control programs. We therefore determined the prevalence of D. nodosus in sheep presented at shows and markets where commingling of animals occurs. Furthermore, possible transmission vectors during foot trimming were investigated and trimming knife decontamination protocols evaluated. Sheep at six markets and four shows were sampled and tested for the presence of D. nodosus by real-time PCR. Different vectors, such as trimming knives were tested by real-time PCR and for viable D. nodosus by culture. The prevalence of virulent D. nodosus in sheep presented at shows and markets ranged from 1.7% to 100%. Regions with an ongoing control program showed significantly lower prevalence. After trimming, positive real-time PCR and culture results were obtained from the knives, the hands of the claw trimmers as well as removed claw horn material whereas boots were only positive by real-time PCR. In conclusion, markets and shows pose a risk for transmission of D. nodosus. The risk of transmission is particularly high during claw trimming and recommended measures to limit this risk include wiping the knife with a disinfection towel, wearing and changing gloves after every sheep, as well as proper disposal of trimmed and infectious horn.
|
|
| 19. |
- Gavier-Widén, Dolores
(författare)
-
Tularaemia in Norwegian dogs
- 2014
-
Ingår i: Veterinary Microbiology. - : Elsevier BV. - 0378-1135 .- 1873-2542. ; 173, s. 318-322
-
Tidskriftsartikel (refereegranskat)abstract
- We describe tularaemia in a Norwegian dog caused by Francisella tularensis subspecies holarctica. A Hamilton Hound and his owner developed tulaeremia after hunting an infected mountain hare (Lepus timidus). The dog showed signs of lethargy, anorexia and fever during a period two to four days after hunting and thereafter fully recovered. Its antibody titers increased 32-fold from one to three weeks post exposure. Thereafter, the titer declined and leveled off at moderate positive values up to one year after exposure (end of study). This is believed to be the first case report of clinical F. tularensis subspecies holarctica infection in a European dog.In 2011, enormous numbers of Norway lemmings (Lemmus lemmus) occurred in Finnmark, the northernmost county of Norway and many dogs caught and swallowed lemmings. Some of these dogs developed non-specific signs of disease and the owners consulted a veterinary surgeon, who suspected tularaemia. In order to investigate this hypothesis, serum samples from 33 dogs were examined for antibodies to F. tularensis. The dogs were allocated into three groups: Dogs from Finnmark that became sick (Group 1) or remained healthy following contact with lemmings (Group 2), and healthy control dogs from Oslo without known contact with lemmings (Group 3). All the serum samples were analyzed with a tube agglutination assay. Among dogs exposed to lemmings, 10/11 and 3/12 were antibody positive in Group 1 and Group 2, respectively, whereas none of the control dogs (n = 10) were positive for antibodies against F. tularensis. These results strongly indicate that the non-specific disease seen in the dogs in Finnmark was linked to F. tularensis infection acquired through contact with lemmings. (C) 2014 Elsevier B.V. All rights reserved.
|
|
| 20. |
- Griekspoor, Petra, et al.
(författare)
-
Genetic diversity and host associations in Campylobacter jejuni from human cases and broilers in 2000 and 2008
- 2015
-
Ingår i: Veterinary Microbiology. - : Elsevier BV. - 0378-1135 .- 1873-2542. ; 178:1-2, s. 94-98
-
Tidskriftsartikel (refereegranskat)abstract
- Campylobacter jejuni is an important food-borne pathogen, with a global distribution. It can colonize numerous host species, including both domestic and wild animals, but is particularly associated with birds (poultry and wild birds). For human campylobacteriosis, poultry products are deemed the most significant risk factor for acquiring infection. We conducted a genotyping and host attribution study of a large representative collection of C. jejuni isolated from humans and broilers in Sweden in the years 2000 and 2008. In total 673 broiler and human isolates from 10 different abattoirs and 6 different hospitals were genotyped with multilocus sequence typing. Source attribution analyses confirmed the strong linkage between broiler C. jejuni and domestic human cases, but also indicated a significant association to genotypes more commonly found in wild birds. Genotype distributions did not change dramatically between the two study years, suggesting a stable population of infecting bacteria.
|
|
| 21. |
- Griekspoor, Petra, et al.
(författare)
-
Multilocus sequence typing of Campylobacter jejuni from broilers
- 2010
-
Ingår i: Veterinary Microbiology. - : Elsevier BV. - 0378-1135 .- 1873-2542. ; 140, s. 180-185
-
Tidskriftsartikel (refereegranskat)abstract
- Campylobacter jejuni isolates from a national Swedish Campylobacter monitoring in broilers were characterized by multilocus sequencing typing (MLST) in order to study the genetic diversity of this bacterial population. Isolates were initially characterized by pulsed-field gel electrophoresis (PFGE). One hundred were chosen for MLST genotyping. PFGE identified 69 distinct types compared to 44 different sequence types (STs) identified with MLST. Eighteen STs had not been described previously, while the remaining 26 STs were assigned to previously known clonal complexes. The majority of isolates were of genotypes noted in broilers and in humans in earlier studies. However, three clonal complexes, ST-206 complex, ST-677 complex and ST-1034 complex, previously associated with wild bird and environmental samples, were among the genotypes found. This study shows that most of the Swedish broiler isolates were of genotypes noted as common in broilers. However, it also highlights the potential influence of environmental sources on the broiler C jejuni genotypes.
|
|
| 22. |
- Hasan, Badrul, et al.
(författare)
-
Fecal carriage of multi-drug resistant and extended spectrum beta-lactamases producing E. coli in household pigeons, Bangladesh
- 2014
-
Ingår i: Veterinary Microbiology. - : Elsevier BV. - 0378-1135 .- 1873-2542. ; 168:1, s. 221-224
-
Tidskriftsartikel (refereegranskat)abstract
- Antibiotic resistance and ESBL constitute a risk to human and animal health. Birds residing close to humans could mirror the spectrum of human associated antibiotic resistance. Household pigeons were screened in Bangladesh to shed light on human associated, as well as, environmental antibiotic resistance. Escherichia coil from pigeons (n = 150) were tested against 11 antibiotics. 89% E. coil isolates were resistant to one or more critically important human antibiotics like ampicillin, cefadroxil, mecillinam, ciprofloxacin, gentamicin and tigecycline. No carbapenamase-producers were detected and the lower ESBL prevalence (5%) in pigeons. ESBL-producing E. coil isolates had bla(CTX-M_15) genes. Pigeons shared some bacterial clones and had bird associated sequence types like E. coil ST1408. Fecal carriage of bacteria resistance of critically important human antibiotics, together with examples of shared genotypes among pigeons, indicate the human-birds and bird to bird transmissions are important in the epidemiology of antibiotic resistance.
|
|
| 23. |
- Höök, Helena, et al.
(författare)
-
Genotype dynamics of Campylobacter jejuni in a broiler flock
- 2005
-
Ingår i: Veterinary Microbiology. - Amsterdam, Netherlands : Elsevier. - 0378-1135 .- 1873-2542. ; 106, s. 109-117
-
Tidskriftsartikel (refereegranskat)abstract
- We investigated the genotype diversity and dynamics of Campylobacter in a commercial broiler flock during rearing and slaughter. In total, 220 Campylobacter jejuni isolates collected on four sampling occasions during rearing and from routine sampling during slaughter were subtyped by SmaI macrorestriction and pulsed-field gel electrophoresis, PFGE. Eight different SmaI types were found. During rearing, a subsequent addition of genotypes occurred, with two SmaI types found at 2 weeks of age and six types on the day before slaughter. All types that were detected in more than one isolate were also found on all succeeding sampling occasions, including the slaughter sampling. Two new types were found in the slaughter samples. In twothirds of the individual birds sampled the day before slaughter, more than one SmaI type were found, although there was a clear tendency for dominance of one type in individual birds. Our results show that multiple genotypes of C. jejuni may be present in a commercial broiler flock during rearing and even in gastrointestinal tracts of individual birds. Both recurring environmental exposure and genetic changes within the population may explain the genotype diversity. Although the distribution of genotypes varied between different sampling occasions, we found no indication that any subtype excluded another during the rearing of the broiler flock.
|
|
| 24. |
- Jacobson, Magdalena, et al.
(författare)
-
Microarray and cytokine analyses of field cases of pigs with diarrhoea
- 2011
-
Ingår i: Veterinary Microbiology. - : Elsevier BV. - 0378-1135 .- 1873-2542. ; 153, s. 307-314
-
Tidskriftsartikel (refereegranskat)abstract
- This field study explored the cytokine expression in intestinal tissue and serum from 19 diarrhoeic and 9 healthy pigs in herds with a long-time history of Lawsonia intracellularis-infection. The disease, proliferative enteropathy (PE), is associated with diarrhoea and poor performance in growers and haemorrhagic diarrhoea and sudden death in finisher pigs, but the immunopathology is poorly understood. Histopathology, demonstration of L intracellularis and porcine circovirus type 2 (PCV2) in intestinal tissue by PCR, and detection of serum antibodies to L. intracellularis, were performed. The presence of IL-1 beta, IL-6, IL-10, IFN-alpha, IFN-gamma, TNF-alpha and TGF-beta in sera was determined by immunoassays, and intestinal mRNA expression of these cytokines plus IL-12p40 was determined by qPCR. Intestinal specimens from pigs with intestinal adenomatosis (n = 2), proliferative haemorrhagic enteropathy or swine dysentery (n = 2), and controls (n = 2) were analysed by a genome wide porcine microarray. The clinical signs of PE were not always supported by the subsequent analyses, and the presence of PCV2 may have contributed to an increased mRNA expression for IFN-gamma in intestinal specimens from some pigs. The limited gene expression in the microarray analyses and the limited expression of cytokines in both sera and intestines, indicate that the immune response is poorly activated in the initial course of an infection with L. intracellularis. However, the gene encoding for insulin-like growth factor binding protein 3 (IGFBP-3) was up-regulated in two pigs with prominent mucosal proliferation. (C) 2011 Elsevier B.V. All rights reserved.
|
|
| 25. |
- Jacobson, Magdalena, et al.
(författare)
-
Monitoring of Lawsonia intracellularis in breeding herd gilts
- 2010
-
Ingår i: Veterinary Microbiology. - : Elsevier BV. - 0378-1135 .- 1873-2542. ; 142, s. 317-322
-
Tidskriftsartikel (refereegranskat)abstract
- In modern pig production, proliferative enteropathy is a common cause of diarrhoea and poor growth in young animals. This study aimed to determine the possible spread of Lawsonia intracellularis through the sale of replacement gilts and the possibility to protect the herds by adequate biosecurity measures. This was achieved by repeated sampling of 50 gilts in an infected multiplying herd, from the last day in the farrowing pen and until sale. Further, 60 gilts sold from this herd were tested during their stay in quarantine in a recipient herd. To confirm freedom from infection, 100 growing pigs in the recipient herd were also tested. Individual faecal (n = 748) and blood (n = 728) samples were analysed by PCR and ELISA, respectively. Transmission of L intracellularis from the sows to their offspring was not demonstrated. However, the possible transmission between herds by replacement gilts was demonstrated. Peak shedding occurred at 12 and 15 weeks of age, and single animals were also PCR-positive at 24-36 weeks of age in the multiplying herd and in the quarantine in the recipient herd. Further, the possible occurrence of chronically infected carrier animals was suggested. Although L intracellularis is widely spread, it appears possible to avoid the transmission between herds by employing adequate biosecurity measures. Thus, it would be advisable to establish herd profiles in breeding herds to avoid the selling of infected animals as well as to establish the health status of the recipient herd. Further, the health status of the recipient herds should be known. (C) 2009 Elsevier B.V. All rights reserved.
|
|
| 26. |
- Jansson, Desirée
(författare)
-
Occurrence and spread of a reassortant very virulent genotype of infectious bursal disease virus with altered VP2 amino acid profile and pathogenicity in some European countries
- 2020
-
Ingår i: Veterinary Microbiology. - : Elsevier BV. - 0378-1135 .- 1873-2542. ; 245
-
Tidskriftsartikel (refereegranskat)abstract
- Reassortant strains of Infectious Bursal Disease Virus (IBDV) were detected in commercial broiler flocks in the Netherlands, Belgium, Denmark, Czech Republic and Germany and in layers and organic broilers in Sweden in the period of 2017 - 19. Genetic analysis, based on hypervariable region of VP2 gene showed grouping together with very virulent IBDV strains (vvIBDV, Genogroup 3), but these recent viruses formed a separate cluster, which was most closely related to Latvian IBDV strains from 2010 - 13. VP1 gene of these isolates was most closely related to D78 attenuated IBDV strain. The recently described reassortant IBDV strain (Bpop/03/PL) from Poland with similar genomic constellation (segment A from vvIBDV, segment B from attenuated strain) retained its pathogenicity (80 % mortality in SPF chickens). Infection with the North-West European reassortant IBDVs described in this study showed subclinical feature in the field (without complicating agents) and when tested under standardized pathogenicity test in SPF layer chickens (no mortality or clinical signs, but marked bursa atrophy was observed). Although these recent North-West European reassortant strains had all amino acid residues in their VP2 gene which are considered as markers of vvIBDV strains, they exhibited typical amino acid changes compared to vvIBDV reference strains that should contribute to the determination of pathogenicity. Diagnostic investigations indicated that co-infection with fowl adenovirus or chicken infectious anaemia virus exaggerated the outcome of the IBDV infection (10-20 % mortality). Widespread presence of this reassortant IBDV group in clinically healthy flocks draws attention to the importance of active surveillance.
|
|
| 27. |
- Johansson, Karl-Erik, et al.
(författare)
-
Characterization of Erysipelothrix rhusiopathiae isolates from poultry, pigs, emus, the poultry red mite and other animals
- 2009
-
Ingår i: Veterinary Microbiology. - : Elsevier BV. - 0378-1135 .- 1873-2542. ; 137, s. 98-104
-
Tidskriftsartikel (refereegranskat)abstract
- Erysipelothrix rhusiopathiae is the causative agent of erysipelas in mammals and birds, especially pigs and poultry. In order to investigate the suitability of different subtyping methods for genetic and phenotypic similarities among Swedish isolates of the organism, 45 isolates from poultry (n = 23), pigs (n = 17), emus (n = 2) and the poultry red mite Dermanyssus gallinae (n = 3) were investigated by serotyping, pulsed-field gel electrophoresis (PFGE) and antimicrobial susceptibility testing. Sequence analysis of the 16S rRNA gene was performed on eleven isolates from nine animal species. The results indicated a random scattering of serotypes throughout the dendrogram based on PFGE banding patterns following Smal digestion. In three cases, isolates with an identical PFGE pattern were of differing serotypes. No differentiation into subgroups by antimicrobial susceptibility testing by broth microdilution was possible as results were similar for all isolates. The Minimum Inhibitory Concentrations for most antimicrobials, including penicillin and oxytetracycline, were low. The 16S rRNA gene sequences (1443 nts) from eight of eleven selected isolates of Erysipelothrix spp. were identical to that of the type strain E. rhusiopathiae ATCC 19414(T). The other three isolates differed from the type strain by two or three nucleotides. While this method may be useful for identification of Erysipelothrix spp., it is unsuitable for epidemiological investigations. Similarities in PFGE banding patterns between isolates from chickens and mites supported the hypothesis that D. gallinae may act as a reservoir and vector for E. rhusiopathiae. Further PFGE studies on E. rhusiopathiae isolates are appropriate to investigate the epidemiology of poultry erysipelas. (C) 2008 Elsevier B.V. All rights reserved.
|
|
| 28. |
|
|
| 29. |
- Jonare, Liv, et al.
(författare)
-
Core genome multilocus sequence typing (cgMLST) confirms systemic spread of avian pathogenic Escherichia coli (APEC) in broilers with cellulitis
- 2023
-
Ingår i: Veterinary Microbiology. - 0378-1135 .- 1873-2542. ; 282
-
Tidskriftsartikel (refereegranskat)abstract
- Broiler cellulitis has emerged as an important cause of economic losses for farmers and slaughter plants from carcass condemnation at processing. Avian pathogenic Escherichia coli (APEC) has been identified as the main causative agent. The aim was to characterize E. coli isolated from cellulitis and organs in broilers at slaughter by whole genome sequencing analysis to study if systemic spread could be confirmed. Isolates were collected postmortem from 101 carcasses condemned due to dermatitis/cellulitis from five commercial farms and six flocks. Forty-six isolates were characterised to determine serotypes, sequence types and virulence-associated genes. Analysis by cgMLST was performed to study the genetic similarity between isolates from the same broiler, among birds from the same flock and between flocks. Escherichia coli was isolated from 90% of birds from subcutaneous samples. In 20 broilers, E. coli was isolated from organs in pure culture or mixed with sparse growth of other bacteria. In eight of these, there were post-mortem findings suggestive of systemic bacterial spread. The majority of the isolates from the same bird and flock belonged to the same serotype and sequence type and were genetically indistinguishable, but differed when compared between flocks. Common APEC virulence genes, i.e. chuA, fyuA, hlyF, iroN, irp2, iss, ompT, sitA, TerC, TraT, were present in > 87% of the isolates. We conclude that evidence of systemic spread of E. coli from cellulitis was present in some birds at time of slaughter but cannot be reliably detected at meat inspection.
|
|
| 30. |
- Kaden, Rene, et al.
(författare)
-
Brucellosis outbreak in a Swedish kennel in 2013 : Determination of genetic markers for source tracing
- 2014
-
Ingår i: Veterinary Microbiology. - : Elsevier BV. - 0378-1135 .- 1873-2542. ; 174:3–4, s. 523-530
-
Tidskriftsartikel (refereegranskat)abstract
- Brucellosis is a highly infectious zoonotic disease but rare in Sweden. Nonetheless, an outbreak of canine brucellosis caused by an infected dog imported to Sweden was verified in 2013. In total 25 dogs were tested at least duplicated by the following approaches: real-time PCR for the detection of Brucella canis, a Brucella genus-specific real-time PCR, selective cultivation, and microscopic examination. The whole genome of B. canis strain SVA13 was analysed regarding genetic markers for epidemiological examination. The genome of an intact prophage of Roseobacter was detected in B. canis strain SVA13 with whole genome sequence prophage analysis (WGS-PA). It was shown that the prophage gene content in the American, African and European isolates differs remarkably from the Asian strains. The prophage sequences in Brucella may therefore serve of use as genetic markers in epidemiological investigations. Phage DNA fragments were also detected in clustered, regularly interspaced short palindromic repeats (CRISPR) in the genome of strain SVA13. In addition to the recommendations for genetic markers in Brucella outbreak tracing, our paper reports a validated two-step stand-alone real-time PCR for the detection of B. canis and its first successful use in an outbreak investigation.
|
|
| 31. |
- Karlsson, Frida
(författare)
-
Identification of Treponema pedis as the predominant Treponema species in porcine skin ulcers by fluorescence in situ hybridization and high-throughput sequencing
- 2014
-
Ingår i: Veterinary Microbiology. - : Elsevier BV. - 0378-1135 .- 1873-2542. ; 171, s. 122-131
-
Tidskriftsartikel (refereegranskat)abstract
- Skin lesions often seen in pig production are of great animal welfare concern. To study the potential role of Treponema bacteria in porcine skin ulcers, we investigated the presence and distribution of these organisms in decubital shoulder ulcers (n = 51) and ear necroses (n = 54) by fluorescence in situ hybridization (FISH) and high-throughput sequencing. In addition, two cases of facial ulcers and five cases of other skin ulcers were included in the study. Samples from all 112 skin lesions and intact skin from pigs without skin ulcers (n = 14) were screened by FISH. Three different oligonucleotide probes targeting 16S rRNA were used, specific for domain bacterium, Treponema spp. and species T. pedis. Screening showed that two cases each of facial and other ulcers, 35 (69%) of shoulder ulcers and 32 (59%) of ear necroses were positive for Treponema spp. T. pedis was the unequivocally, predominant species typically constituting more than 90% of the treponemes in a lesion, assessed visually by microscopy. Altogether, T. pedis was demonstrated in 69 of the 71 Treponema spp. positive lesions. We conclude that Treponema spp. are frequently present and abundant in various skin ulcers of pigs. The results from this study point toward an important role of T. pedis as a secondary bacterial infection in porcine skin ulcers, especially in severe and chronic lesions. (C) 2014 Elsevier B.V. All rights reserved.
|
|
| 32. |
- Karlsson, Frida, et al.
(författare)
-
Occurrence of Treponema spp. in porcine skin ulcers and gingiva
- 2013
-
Ingår i: Veterinary Microbiology. - : Elsevier BV. - 0378-1135 .- 1873-2542. ; 165, s. 402-409
-
Tidskriftsartikel (refereegranskat)abstract
- Porcine shoulder ulcers and ear necrosis are a significant animal welfare concern and impair efficient livestock production. Although spirochetes have been detected in both types of lesions the potential role of these bacteria in lesion propagation has received little attention. The objective of this study was to investigate the occurrence of spirochetes of the genus Treponema in shoulder ulcers or ear necrosis in pigs and compare these with treponemes from porcine gingiva. Samples were collected from gingiva and necrotic ulcers in 169 pigs. Presence of spirochetes was observed in silver stained histological sections and by phase contrast microscopy in scrapings from the necrotic lesions. Additionally, PCR of the 16SrRNA-tRNA(Ile) intergenic spacer region (ISR2) was used to detect Treponema spp. in all samples. Combined analysis showed that 73% of the shoulder ulcers and 53% of the ear necroses were positive for spirochetes. Treponema spp. were detected in 9.7% of the gingival samples. Comparative DNA sequence analysis of the ISR2 sequences revealed the presence of three distinct genetic phylotypes of Treponema spp. corresponding to Treponema pedis, and as yet two unnamed phylotypes represented by GenBank sequences C1UD1 (Acc. No. AY342041) and C1BT2-8 (Acc. No. AY342046). Detection of identical ISR2 sequences from gingiva and ulcer samples indicates that oral Treponema spp. are spread from mouth to ulcer. We conclude that Treponema spp. frequently occur in shoulder ulcers and ear necrosis in pigs, and suggest a possible infection route through biting and licking. (c) 2013 Elsevier B.V. All rights reserved.
|
|
| 33. |
- Kautto, Arja H, et al.
(författare)
-
Pestivirus and alphaherpesvirus infections in Swedish reindeer (Rangifer tarandus tarandus L.)
- 2012
-
Ingår i: Veterinary Microbiology. - : Elsevier. - 0378-1135 .- 1873-2542. ; 156:1-2, s. 64-71
-
Tidskriftsartikel (refereegranskat)abstract
- Herding semi-domesticated reindeer has economic and social value for Sami people in the northern territories of Fennoscandia. However, with the intensification of reindeer husbandry, interspecies transmission of pathogens between reindeer and domestic animals may become a problem, especially for countries such as Sweden, Norway, and Finland where pestivirus and alphaherpesvirus have been eradicated in domestic ruminants. This study, which included 1158 Swedish reindeer, showed relatively high prevalence of antibodies against bovine viral diarrhoea virus (BVDV) (32%) and bovine herpesvirus-1 (BoHV-1) (53%). Adult animals were more often seropositive for BVDV and BoHV-1 (50% and 78%, respectively) than were calves (18 and 11%, respectively). While the seroprevalence of alphaherpesvirus was similar in different herding districts, pestivirus seropositivity was highest in the South and diminished towards the North of the Swedish reindeer herding area. High correlation of the seropositivity against both pathogens at both individual and herd levels may indicate possible mutual synergetic effects and may be explained by the immunosuppressive nature of the viruses. While alphaherpesvirus seroprevalence was probably related to putative cervid herpesvirus 2 (CvHV-2), the pestivirus infecting reindeer remains undefined. The virus neutralisation test of reindeer sera using different pestivirus strains, revealed higher titres against Border disease virus strains like 137/4 (BDV-1) and Reindeer-1 (BDV-2) than against BVDV-1. However, the virus was not identified by real time RT-PCR in any of the samples (n=276) from seronegative reindeers. The study showed that pestivirus and alphaherpesvirus infections are endemic in the Swedish reindeer population.
|
|
| 34. |
- LeBlanc, Neil, et al.
(författare)
-
A novel combination of TaqMan RT-PCR and a suspension microarray assay for the detection and species identification of pestiviruses
- 2010
-
Ingår i: Veterinary Microbiology. - : Elsevier BV. - 0378-1135 .- 1873-2542. ; 142:1-2, s. 81-86
-
Tidskriftsartikel (refereegranskat)abstract
- The genus pestivirus contains four recognized species: classical swine fever virus, border disease virus, bovine viral diarrhoea virus types 1 and 2. All are economically important and globally distributed but classical swine fever is the most serious, concerning losses and control measures. It affects both domestic pigs and wild boars. Outbreaks of this disease in domestic pigs call for the most serious measures of disease control, including a stamping out policy in Europe. Since all the members of the pestivirus genus can infect swine, differential diagnosis using traditional methods poses some problems. Antibody tests may lack specificity due to cross-reactions, antigen capture ELISAs may have low sensitivity, and virus isolation may take several days or even longer time to complete. PCR-based tests overcome these problems for the most part, but in general lack the multiplexing capability to detect and differentiate all the pestiviruses simultaneously. The assay platform described here addresses all of these issues by combining the advantages of real-time PCR with the multiplexing capability of microarray technology. The platform includes a TaqMan real-time PCR designed for the universal detection of pestiviruses and a microarray assay that can use the amplicons produced in the real-time PCR to identify the specific pestivirus.
|
|
| 35. |
- Lindahl, Susanne, et al.
(författare)
-
Outbreak of upper respiratory disease in horses caused by Streptococcus equi subsp zooepidemicus ST-24
- 2013
-
Ingår i: Veterinary Microbiology. - : Elsevier BV. - 0378-1135 .- 1873-2542. ; 166, s. 281-285
-
Tidskriftsartikel (refereegranskat)abstract
- Streptococcus equi subsp. zooepidemicus (S. zooepidemicus) is generally considered a commensal and an opportunistic pathogen of the upper airways in horses. Establishing whether certain strains of S. zooepidemicus can cause upper respiratory disease as a host-specific pathogen of horses, and if there are certain genogroups of S. zooepidemicus that are more virulent than others is of major clinical importance. In this study, we describe an outbreak of upper respiratory disease in horses that was associated with S. zooepidemicus. Upper respiratory samples were cultured, analyzed by real-time PCR for S. zooepidemicus and S. equi, and genetically differentiated by sequencing of the SzP protein gene and multilocus sequence typing (MLST). Serum samples were analyzed for antibodies against S. equi and common viral respiratory pathogens. The ST-24 strain of S. zooepidemicus was isolated from all horses with clinical signs of disease, while the healthy horses carried other strains of S. zooepidemicus. Bacteriological, molecular and serological analyses strongly suggest that a single strain (ST-24) was responsible for the disease outbreak, and that certain strains of this presumed commensal may be more virulent than others. (C) 2013 Elsevier B.V. All rights reserved.
|
|
| 36. |
- Lindahl, Susanne, et al.
(författare)
-
Tracing outbreaks of Streptococcus equi infection (strangles) in horses using sequence variation in the seM gene and pulsed-field gel electrophoresis
- 2011
-
Ingår i: Veterinary Microbiology. - : Elsevier BV. - 0378-1135 .- 1873-2542. ; 153, s. 144-149
-
Tidskriftsartikel (refereegranskat)abstract
- Strangles is a serious respiratory disease in horses caused by Streptococcus equi subspecies equi (S. equi). Transmission of the disease occurs by direct contact with an infected horse or contaminated equipment. Genetically, S. equi strains are highly homogenous and differentiation of strains has proven difficult. However, the S. equi M-protein SeM contains a variable N-terminal region and has been proposed as a target gene to distinguish between different strains of S. equi and determine the source of an outbreak. In this study, strains of S. equi (n = 60) from 32 strangles outbreaks in Sweden during 1998-2003 and 2008-2009 were genetically characterized by sequencing the SeM protein gene (seM), and by pulsed-field gel electrophoresis (PFGE). Swedish strains belonged to 10 different seM types, of which five have not previously been described. Most were identical or highly similar to allele types from strangles outbreaks in the UK. Outbreaks in 2008/2009 sharing the same seM type were associated by geographic location and/or type of usage of the horses (racing stables). Sequencing of the seM gene generally agreed with pulsed-field gel electrophoresis profiles. Our data suggest that seM sequencing as a epidemiological tool is supported by the agreement between seM and PFGE and that sequencing of the SeM protein gene is more sensitive than PFGE in discriminating strains of S. equi. (C) 2011 Elsevier B.V. All rights reserved.
|
|
| 37. |
- Liu, Lihong, et al.
(författare)
-
Virus recovery and full-length sequence analysis of atypical bovine pestivirus Th/04_KhonKaen
- 2009
-
Ingår i: Veterinary Microbiology. - : Elsevier BV. - 0378-1135 .- 1873-2542. ; 138, s. 62-68
-
Tidskriftsartikel (refereegranskat)abstract
- Phylogenetic analysis of recently identified "atypical" bovine pestiviruses, performed based on different gene regions, has revealed unclear relationships with other established species, therefore, their phylogenetic position could not be determined so far. In this study, the atypical pestivirus Th/04_KhonKaen was recovered from serum of a naturally infected calf and the complete genome sequence was determined and analysed, as means to define its position. The viral genome is 12,337 nucleotides (nt) long, and comprises a 5'-UTR of 383 nt, a 3'-UTR of 254 nt and an open reading frame of 11,700 nt, without duplication of viral sequences or insertions of cellular sequences. The phylogenetic analyses of the full-length sequence, performed by Neighbor-joining, Maximum likelihood, and the Bayesian approach, unanimously placed Th/04_KhonKaen in a single lineage, distinct from the established pestivirus species, and close to bovine viral diarrhea virus types 1 and 2. Furthermore, Th/04_KhonKaen and two previously reported atypical pestiviruses D32/00_'HoBi' and CH-KaHo/cont formed a well-supported monophyletic clade in trees based on the complete N(pro) and E2 gene regions. The finding provides conclusive classification of the Th/04_KhonKaen virus and confirms the standing of the "atypical" bovine pestiviruses as a novel pestivirus species. (C) 2009 Elsevier B.V. All rights reserved.
|
|
| 38. |
|
|
| 39. |
- Löfström, Charlotta, et al.
(författare)
-
Improvement and validation of RAPD in combination with PFGE analysis of Salmonella enterica ssp enterica serovar Senftenberg strains isolated from feed mills
- 2006
-
Ingår i: Veterinary Microbiology. - : Elsevier BV. - 0378-1135 .- 1873-2542. ; 114:3-4, s. 345-351
-
Tidskriftsartikel (refereegranskat)abstract
- In 1995 and 1996 a Swedish feed mill had problems due to a persistent contamination of Salmonella enterica spp. enterica serovar Senftenberg that was difficult to eliminate. Forty-eight strains isolated from the feed mill, together with unrelated strains included to evaluate the discriminatory power and reproducibility, were analysed by pulsed-field gel electrophoresis (PFGE). The source of contamination in the feed mill was identified and preventative measures were taken, that led to a resolution of the problem. A previously developed randomly amplified polymorphic DNA (RAPD) protocol was used, to evaluate a rapid and low-cost alternative to PFGE typing. The use of the alternative thermostable DNA polymerase Tth was shown to increase the reproducibility of the RAPD analysis. The reproducibility, in terms of Pearson's and Dice's similarity coefficients for duplicate runs, increased from 72.0 +/- 16.9% and 72.3 +/- 12.9% for Taq to 91.6 +/- 7.5% and 90.9 +/- 5.3% for the fingerprints obtained for the RAPD method employing Tth DNA polymerase. Simpson's index of diversity was calculated and found to be 0.580 for RAPD and 0.896 for PFGE. All of the seven RAPD, types could be subdivided into one or more PFGE types, whereas none of the 22 PFGE types was divided into more than one RAPD type. RAPD provides a simple, rapid and powerful screening method that can be used to initially select isolates for further analysis by PFGE
|
|
| 40. |
- Löfström, Charlotta, et al.
(författare)
-
Outbreak of Salmonella enterica serovar Typhimurium phage type DT41 in Danish poultry production
- 2015
-
Ingår i: Veterinary Microbiology. - : Elsevier BV. - 0378-1135 .- 1873-2542. ; 178:1-2, s. 167-172
-
Tidskriftsartikel (refereegranskat)abstract
- Salmonella enterica subspecies enterica serovar Typhimurium (S. Typhimurium) is one of the most prevalent serovars in Europe - where both poultry and poultry related products are common sources of human salmonellosis. Due to efficient control programs, the prevalence of S. Typhimurium in Danish poultry production is very low. Despite this, during the past decades there has been a reoccurring problem with infections with S. Typhimurium phage type DT41 in the Danish poultry production without identifying a clear source. In the end of 2013 and beginning of 2014 an increased isolation of S. Typhimurium DT41 was noted mainly in this production, but also in other samples. To investigate this is in more detail, 47 isolates from egg layers (n=. 5, 1 flock), broilers (n=. 33, 13 flocks), broiler breeding flocks and hatches (n=. 5; 2 flocks and 1 environmental hatchery sample), feed (n=. 1), poultry slaughter house (n=. 3, environmental sample and meat) were typed with multi locus variable number of tandem repeat analysis (MLVA) and pulsed-field gel electrophoresis (PFGE) to investigate the epidemiology of the outbreak. Based on PFGE results isolates were divided into four groups (Simpson's index of diversity (DI). =. 0.24. ±. 0.15). Due to the low DI, PFGE was not sufficient to provide information to unravel the outbreak. Based on MLVA typing the DT41 (42/47 isolates) and the RDNC isolates (5/47) were split into nine groups (DI. =. 0.65. ±. 0.14). When a maximum divergence at one locus was permitted these could be gathered into four groups. Using this criterion, combined with epidemiological information, a spread of one type from broiler breeders to broilers and further to the poultry slaughter house was plausible. In conclusion, although it could be concluded that a spread within the broiler production pyramid had taken place the source of the sudden increase of S. Typhimurium DT41 remains unclear. To investigate this in more detail, further studies using whole genome sequencing to obtain a higher discriminatory strength and including isolates from a longer period of time and from various sources are in progress.
|
|
| 41. |
- Löfström, Charlotta, et al.
(författare)
-
Validation of a 20-h real-time PCR method for screening of Salmonella in poultry faecal samples
- 2010
-
Ingår i: Veterinary Microbiology. - : Elsevier BV. - 0378-1135 .- 1873-2542. ; 144:3-4, s. 511-514
-
Tidskriftsartikel (refereegranskat)abstract
- Efficient and rapid monitoring of Salmonella in the poultry production chain is necessary to assure safe food. The objective was to validate an open-formula real-time PCR method for screening of Salmonella in poultry faeces (sock samples). The method consists of incubation in buffered peptone water for 18 ± 2 h, centrifugation of a 1-ml subsample, DNA extraction on the pellet and PCR. The total analysis time is 20 h. The validation study included comparative and collaborative trials, based on the recommendations from the Nordic organization for validation of alternative microbiological methods (NordVal). The comparative trial was performed against a reference method from the Nordic Committee on Food Analysis (NMKL187, 2007) using 132 artificially and naturally contaminated samples. The limit of detection (LOD50) was found to be 24 and 33. CFU/sample for the PCR and NMKL187 methods, respectively. The relative accuracy, relative sensitivity and relative specificity were all 100%, when including naturally contaminated samples and samples artificially contaminated with 10-100. CFU/sample. The collaborative trial included six laboratories and valid results were obtained from five of them. Apart from one of the samples that was artificially contaminated with 1-10. CFU/sample being a false negative with PCR for one of the laboratories, no false-positive or false-negative results were reported. This test supplies the growing demand for validated diagnostic PCR methods for screening of samples in the meat production chain to assure safe food. © 2010 Elsevier B.V.
|
|
| 42. |
- Löfström, Charlotta, et al.
(författare)
-
Validation of an open-formula, diagnostic real-time PCR method for 20-h detection of Salmonella in animal feeds
- 2012
-
Ingår i: Veterinary Microbiology. - : Elsevier BV. - 0378-1135 .- 1873-2542. ; 158:3-4, s. 431-435
-
Tidskriftsartikel (refereegranskat)abstract
- A comparative study of a 20-h, non-commercial, open-formula PCR method and the standard culture-based method NMKL 187, for detection of Salmonella, was performed according to the validation protocol from the Nordic organisation for validation of alternative microbiological methods (NordVal) on 81 artificially or naturally contaminated animal feed samples. The PCR method is based on culture enrichment in buffered peptone water for 16 ± 2. h followed by a magnetic beads based semi automated DNA extraction and real-time PCR analysis, including an internal amplification control. The limit of detection (LOD50) was found to be 7.19 and 7.24. CFU/sample for the PCR method and NMKL187, respectively. A very good correlation between results obtained by the two methods was found (Cohen's kappa = 0.92). The relative accuracy, relative sensitivity and relative specificity were found to be 97.5%, 102.0% and 96.6%, respectively. This method is the fastest open PCR based analysis protocol for detection of Salmonella in feed samples. Implementing rapid methods such as the one validated in this study can speed up Salmonella testing of feed for food-producing animals. © 2012 Elsevier B.V.
|
|
| 43. |
- Miles, K., et al.
(författare)
-
Insertion sequence profiling of UK Mycoplasma bovis field isolates
- 2005
-
Ingår i: Veterinary Microbiology. - : Elsevier BV. - 0378-1135 .- 1873-2542. ; 107:04-mar, s. 301-306
-
Tidskriftsartikel (refereegranskat)abstract
- The presence and distribution of insertion sequences ISMbov2 and ISMbov3 within Mycoplasma bovis were investigated. Analysis was carried out by Southern blotting using specific probes of 221 bp and 185 bp, to detect ISMbov2 and ISMbov3, respectively, amplified from the homologous sequences ISMmyl and ISI634 within Mycoplasma mycoides subspecies mycoides small colony type. We present data obtained from 49 field isolates of M. bovis, originating from pneumonic lungs, collected within the United Kingdom between 1996 and 2002. Hybridisation profiles show considerable variation between strains. ISMbov2 sequences are present between 2 and 17 copies while there are between 3 and 14 copies of the ISI634 homologue ISMbov3. These data also provide support for previous analysis by random amplified polymorphic DNA (RAPD) and amplified fragment length polymorphism (AFLP). Crown
|
|
| 44. |
- Mushtaq, Mamoona, et al.
(författare)
-
Genetic analysis of a Treponema phagedenis locus encoding antigenic lipoproteins with potential for antigenic variation
- 2016
-
Ingår i: Veterinary Microbiology. - : Elsevier BV. - 0378-1135 .- 1873-2542. ; 189, s. 91-98
-
Tidskriftsartikel (refereegranskat)abstract
- Digital dermatitis (DD) is a painful and debilitating claw disease in cattle. Spirochetes of the genus Treponema are found in high numbers in the lesions and are likely to be involved in the pathogenesis. The occurrence of Treponema phagedenis in DD lesions, especially near the interface of healthy and diseased tissue, suggests that this species contributes to the development and/or progression of the lesions. In this study we characterized a genetic locus in T. phagedenis that contains coding regions for three antigenic proteins, PrrA, VpsA, and VpsB. Comparative analysis of homologous loci from fifteen strains suggests that prrA may be transposed into or out of this locus. Alterations in the copy number of TA repeats within the putative promoter region may regulate VpsA/B expression. The vpsA and prrA genes occur in allelic variants in different T. phagedenis isolates and may provide one explanation for the antigenic variation observed in T. phagedenis DD isolates.
|
|
| 45. |
- Myrenås, Mattias, et al.
(författare)
-
Clonal spread of Escherichia coli resistant to cephalosporins and quinolones in the Nordic broiler production
- 2018
-
Ingår i: Veterinary Microbiology. - : Elsevier. - 0378-1135 .- 1873-2542. ; 213, s. 123-128
-
Tidskriftsartikel (refereegranskat)abstract
- The intestinal flora of healthy broilers can contain Escherichia coli resistant to extended spectrum cephalosporins (ESC) and fluoroquinolones (FQ), representing a possible public health problem. We investigated the clonal epidemiology of E. coli with reduced susceptibility to ESC or FQ in broilers in three Nordic countries interconnected by a common source of breeding animals. Isolates (n = 319 and n = 132 non-wild type for ESC and FQ, respectively) from Norwegian, Swedish and Icelandic production originated mainly from the intestinal flora of broilers at the age of 20-35 days. Genetic relationships were investigated by ten loci multilocus variable number tandem repeat analyses (MLVA) and representative isolates of inter-Nordic clusters were subjected to multilocus sequence typing (MLST). Antimicrobial susceptibility data based on minimum inhibitory concentrations was compiled. Approximately one third of the ESC non-wild type isolates, including isolates from all three countries, clustered together. These isolates belonged to sequence type (ST) 38 and contained blaCMY-2. The FQ non-wild type isolates were more genetically diverse, but related isolates occurred in more than one country. MLST typing showed clusters belonging to ST10, ST355, ST349, ST665 and ST93. Our study demonstrated inter-Nordic distribution of E. coli ST38 with blaCMY-2, suggesting clonal proliferation as a contributing factor for spread of ESC resistance in the broiler production. The international trade in breeding material may explain introduction of resistant E. coli. The reason for their success and the success of certain clonal lineages in broiler production not exposed to antimicrobial selection pressure is currently unknown.
|
|
| 46. |
- Namburi, Ramesh Babu, 1981-, et al.
(författare)
-
Chondroitinase AC : a host-associated genetic feature of Helicobacter bizzozeronii
- 2016
-
Ingår i: Veterinary Microbiology. - : Elsevier BV. - 0378-1135 .- 1873-2542. ; 186, s. 21-27
-
Tidskriftsartikel (refereegranskat)abstract
- Investigating mechanisms involved in host adaptation is crucial to understand pathogen evolution. Helicobacter species appear to have a host species-specific tropism, coevolving with their natural hosts, and to develop several strategies allowing the colonization of the stomach throughout lifetime of their hosts. However, little is known about genetic features associated with the adaptation to a specific animal host. In this study we discovered a polysaccharide lyase that is expressed by the canine-associated species H. bizzozeronii and acts as chondroitinase AC-type lyase of broad specificity. Except for its low pH optimum between pH 4.0 and pH 5.5, the properties of the H. bizzozeronii chondroitin lyase AC resemble the ones from Arthrobacter aurescens. However, homologues of this gene have been detected only in Helicobacter species colonizing the canine and feline gastric mucosa. Since a unique feature of the canine stomach is the secretion of chondroitin-4-sulphate in the gastric juice of the fundus mucosa by chief cells, the expression of chondroitinase AC by H. bizzozeronii is likely the consequence of adaptation of this bacterium to its host and a potential link to gastric disorders in dogs.
|
|
| 47. |
- Nordengrahn, Ann, et al.
(författare)
-
Evaluation of a novel proximity ligation assay for the sensitive and rapid detection of foot-and-mouth disease virus
- 2008
-
Ingår i: Veterinary Microbiology. - : Elsevier BV. - 0378-1135 .- 1873-2542. ; 127:3-4, s. 227-236
-
Tidskriftsartikel (refereegranskat)abstract
- A novel proximity ligation assay (PLA) using a pan-serotype reactive monoclonal antibody was developed and evaluated for the detection of foot-and-mouth disease virus (FMDV) in clinical samples collected from field cases of disease. The FMDV-specific PLA was found to be 100 times more sensitive for virus detection than the commonly used antigen capture-ELISA (AgELISA). As few as five TCID50 were detected in individual assays, which was comparable with the analytical sensitivity of real-time RT-PCR. Although this assay was capable of detecting diverse isolates from all seven FMDV serotypes, the diagnostic sensitivity of the PLA assay was lower than real-time RT-PCR mainly due to a failure to detect some SAT 1, SAT 2 and SAT 3 FMDV strains. In conclusion, this new PLA format has high analytical sensitivity for the detection of FMDV in clinical samples and may prove valuable as a rapid and simple tool for use in FMD diagnosis.
|
|
| 48. |
- Oidtmann, B, et al.
(författare)
-
Detection of genomic DNA of the crayfish plague fungus Aphanomyces astaci (Oomycete) in clinical samples by PCR.
- 2004
-
Ingår i: Veterinary Microbiology. - : Elsevier BV. - 0378-1135 .- 1873-2542. ; 100:3-4, s. 269-82
-
Tidskriftsartikel (refereegranskat)abstract
- A diagnostic procedure, based on a polymerase chain reaction method (PCR) was developed to detect infection of crayfish with the Oomycete Aphanomyces astaci. A set of oligonucleotide primers was designed to specifically amplify A. astaci DNA in the ITS region surrounding the 5.8S rDNA gene. The PCR amplifies a 115 bp amplicon. The specificity of the primers was demonstrated by testing on 27 A. astaci strains and against 20 non-A. astaci Oomycetes and 5 fungal species. Most of the non-A. astaci Oomycete or fungal species included in the study are either known parasites of freshwater crayfish cuticle or can be found in their natural environment. Specificity was also tested against crayfish tissue and some known parasites and bacteria infecting crayfish.A protocol for the extraction of A. astaci DNA from infected crayfish tissue was developed. The optimised method allows the detection of two genome equivalents of purified A. astaci genomic DNA.The method was tested on noble crayfish (Astacus astacus), artificially infected with A. astaci. Detection of A. astaci was possible at the very first time of sampling, which was 2 days after the beginning of spore exposure
|
|
| 49. |
- Pedersen, Karl, et al.
(författare)
-
Reappearance of Salmonella serovar Choleraesuis var. Kunzendorf in Danish pig herds
- 2015
-
Ingår i: Veterinary Microbiology. - : Elsevier. - 0378-1135 .- 1873-2542. ; 176:3-4, s. 282-291
-
Tidskriftsartikel (refereegranskat)abstract
- Salmonella enterica serovar Choleraesuis is a porcine adapted serovar which may cause serious outbreaks in pigs. Here we describe outbreaks of salmonellosis due to S. Choleraesuis in four Danish pig farms in 2012-2013 by clinic, serology, and microbiology and compare the isolates to those of a previous outbreak in 1999-2000. The infection was in some herds associated with high mortality and a moderate to high sero-prevalence was found. In 2012-2013 the disease contributed to increased mortality but occurred concomitant with other disease problems in the herds, which likely delayed the diagnosis by up to several months. Nine isolates from the four farms in 2012-2013 and 14 isolates obtained from the outbreak in Denmark in 1999-2000 were subjected to typing using pulsed-field gel electrophoresis (PFGE). Seven isolates were selected for whole genome sequencing (WGS). The PFGE results of 23 isolates displayed five different profiles. The isolates from 2012 to 2013 revealed two distinct profiles, both different from the isolates recovered in 1999-2000. Two of the 2012-2013 farms shared PFGE profiles and had also transported pigs between them. The profile found in the two other 2012-2013 farms was indistinguishable but no epidemiological connection between these farms was found. Analysis of the number of single nucleotide polymorphisms (SNPs) from the WGS data indicated that the isolates from the farms in 2012-2013 were more closely related to each other than to isolates from the outbreak in 1999. It was therefore concluded that the infection was a new introduction and not a persistent infection since the outbreak in 1999. It may further be suggested that there were two or three independent rather than a single introduction. The re-introduction of S. Choleraesuis in Denmark emphasizes the importance of strict hygiene measures in the herds. Further investigations using WGS are now in progress on a larger collection of isolates to study clonality at European level and trace the origin of the infections.
|
|
| 50. |
- Persson Waller, Karin, et al.
(författare)
-
CNS species and antimicrobial resistance in clinical and subclinical bovine mastitis
- 2011
-
Ingår i: Veterinary Microbiology. - : Elsevier BV. - 0378-1135 .- 1873-2542. ; 152, s. 112-116
-
Tidskriftsartikel (refereegranskat)abstract
- Coagulase-negative staphylococci (CNS) are often associated with bovine mastitis. Knowledge about the relative importance of specific CNS species in different types of mastitis, and differences in antimicrobial resistance among CNS species is, however, scarce. Therefore, the aims of this study were to compare prevalence and antimicrobial susceptibility of CNS species in clinical and subclinical mastitis using material from two national surveys. Overall, Staphylococcus chromogenes and Staphylococcus epidermidis were the most common CNS species found followed by Staphylococcus simulans and Staphylococcus haemolyticus. S. epidermidis was significantly more prevalent in subclinical than in clinical mastitis, and a similar trend was observed for Staphylococcus saprophyticus, while Staphylococcus hyicus was significantly more common in clinical mastitis. The prevalence of beta-lactamase producing isolates varied markedly between CNS species, and was significantly higher in S. epidermidis and S. haemolyticus (similar to 40%), than in S. simulans and S. chromogenes where none or a few of the isolates produced beta-lactamase. Resistance to more than one antimicrobial substance occurred in 9% and 7% of the clinical and subclinical isolates, respectively. In conclusion, the distribution of CNS species differed between clinical and subclinical mastitis indicating inter-species variation of pathogenicity and epidemiology. Overall, the prevalence of antimicrobial resistance was low, but some variation between CNS species was observed. (C) 2011 Elsevier B.V. All rights reserved.
|
|
