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| 2. |
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| 3. |
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| 4. |
- Backhans, Annette, et al.
(författare)
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Occurrence of pathogenic Yersinia enterocolitica and Yersinia pseudotuberculosis in small wild rodents
- 2011
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Ingår i: Epidemiology and Infection. - 0950-2688 .- 1469-4409. ; 139, s. 1230-1238
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Tidskriftsartikel (refereegranskat)abstract
- Rodents are a potential source of pathogenic Yersinia enterocolitica and Y. pseudotuberculosis. In order to study this, 190 rodents were captured and sampled on seven pig farms (n = 110), five chicken farms (n = 55) and six other locations (n = 25) in Sweden. Pigs from three of the pig farms were also sampled (n = 60). Pathogenic Y. enterocolitica was detected by TaqMan PCR in about 5% of rodent samples and 18% of pig samples. Only rodents caught on pig farms tested positive for the pathogen. Y. enterocolitica bioserotype 4/O:3 strains isolated from the rodent and pig samples were compared by pulsed-field gel electrophoresis and revealed a high degree of similarity, which was confirmed by random amplified polymorphic DNA. Y. pseudotuberculosis was only detected in one rodent sample. Thus, rodents may be vectors for the transmission of pathogenic Y. enterocolitica to pigs, acting as carriers rather than a reservoir, and should therefore remain an important issue in hygiene control measures on farms.
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| 5. |
- Backhans, Annette, et al.
(författare)
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Occurrence of pathogens in wild rodents caught on Swedish pig and chicken farms
- 2013
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Ingår i: Epidemiology and Infection. - 0950-2688 .- 1469-4409. ; 141, s. 1885-1891
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Tidskriftsartikel (refereegranskat)abstract
- A total of 207 wild rodents were caught on nine pig farms, five chicken farms and five non-farm locations in Sweden and surveyed for a selection of bacteria, parasites and viruses. Lawsonia intracellularia and pathogenic Yersinia enterocolitica were only detected in rodents on pig farms (9% and 8% prevalence, respectively) which indicate that these agents are more likely to be transmitted to rodents from pigs or the environment on infected farms. Brachyspira hyodysenteriae (1%), Brachyspira intermedia (2%), Campylobacter jejuni (4%), Campylobacter upsaliensis (2%), leptospires (7%) and encephalomyocarditis virus (9%) were also detected from rodents not in contact with farm animals. Giardia and Cryptosporidium spp. were common, although no zoonotic types were verified, and Salmonella enterica was isolated from 1/11 mice on one farm but not detected by PCR from any of the rodents. Trichinella spp. and Toxoplasma gondii were not detected.
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| 6. |
- Backhans, Annette, et al.
(författare)
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Phenotypic and molecular characterization of Brachyspira spp. isolated from wild rodents
- 2010
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Ingår i: Environmental Microbiology Reports. - : Wiley. - 1758-2229. ; 2, s. 720-727
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Tidskriftsartikel (refereegranskat)abstract
- P>The occurrence of intestinal spirochaetes of genus Brachyspira in wild rodents was studied by cultivating 209 caecal samples. Spirochaetal cultures were obtained from 83% of rats and 33% of house mice. Biochemical characterization and six different species-specific PCR methods were applied to 101 of 118 isolates and a selection of 34 brachyspiras were further studied by sequencing of the 16S rRNA gene. The results showed that isolates representing all the established biochemical phenotypes could be cultured from the rodents, including the porcine pathogens Brachyspira hyodysenteriae and Brachyspira pilosicoli. Phylogenetic studies indicated that rodents carry Brachyspira spp. that are closely related to porcine and avian isolates, as well as variants previously not described. One group of hippurate-negative rat isolates were shown to possess the 16S rRNA gene hexa(T) nucleotide segment, previously described only in B. pilosicoli and 'Brachyspira corvi', and phylogenetically they formed a sister lineage of the B. pilosicoli cluster. Furthermore, a large number of the rodents were colonized by slowly growing, non- or weakly haemolytic spirochaetes. Most of these brachyspiras were isolated at 37 degrees C and phylogenetically they formed two separate clusters. Sequence analysis of their 16S rRNA genes indicated that the new variants of Brachyspira spp. may constitute novel species of the genus Brachyspira.
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| 7. |
- Backhans, Annette, et al.
(författare)
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Rodents on pig and chicken farms - a potential threat to human and animal health
- 2012
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Ingår i: Infection Ecology & Epidemiology. - : Informa UK Limited. - 2000-8686. ; 2
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Forskningsöversikt (refereegranskat)abstract
- Rodents can cause major problems through spreading various diseases to animals and humans. The two main species of rodents most commonly found on farms around the world are the house mouse (Mus musculus) and the brown rat (Rattus norvegicus). Both species are omnivorous and can breed year-round under favourable conditions. This review describes the occurrence of pathogens in rodents on specialist pig and chicken farms, which are usually closed units with a high level of bio-security. However, wild rodents may be difficult to exclude completely, even from these sites, and can pose a risk of introducing and spreading pathogens. This article reviews current knowledge regarding rodents as a hazard for spreading disease on farms. Most literature available regards zoonotic pathogens, while the literature regarding pathogens that cause disease in farm animals is more limited.
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| 8. |
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| 9. |
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| 10. |
- 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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| 11. |
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| 12. |
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| 13. |
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| 14. |
- Eriksson, Helena, et al.
(författare)
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Erysipelas in laying hens is associated with housing system
- 2013
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Ingår i: Veterinary Record. - : Wiley. - 0042-4900 .- 2042-7670. ; 173, s. 18-
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Tidskriftsartikel (refereegranskat)abstract
- Following the change from conventional cages to non-cage housing systems and furnished cages, which in Sweden was finalised by 2005, problems caused by Erysipelothrix rhusiopathiae increased in laying hen flocks. This study aimed to investigate possible associations between housing systems for laying hens and outbreaks of erysipelas. Also, sera from 129 flocks in different housing systems, collected during 2005-2007, were analysed for the presence of antibodies to E rhusiopathiae using an indirect ELISA test. Antibodies were detected in all housing systems. The mean flock absorbance values from free-range flocks were significantly higher than corresponding values from other housing systems. Data on the Swedish laying hen population were compared with the recorded number of erysipelas outbreaks during 1998-2011. Outbreaks occurred on 15 farms with indoor litter-based systems (n=194 farms in 2011) and on 21 free-range farms (n=87 farms in 2011). No outbreak was diagnosed on farms with flocks in conventional or furnished cages. The results indicate that the risk for an outbreak was higher in free-range systems than in indoor litter-based systems, and lowest for flocks housed in cages. Absence of erysipelas in the majority of subsequent flocks on the affected farms suggested that proper measures, including vaccination, were undertaken.
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| 15. |
- Eriksson, Helena, et al.
(författare)
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Erysipelothrix rhusiopathiae contamination in the poultry house environment during erysipelas outbreaks in organic laying hen flocks
- 2014
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Ingår i: Avian Pathology. - : Informa UK Limited. - 0307-9457 .- 1465-3338. ; 43, s. 231-237
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Tidskriftsartikel (refereegranskat)abstract
- This study investigated organic laying hen farms for the presence of Erysipelothrix rhusiopathiae in the house environment and from potential carriers (i.e. insects and mice) during ongoing erysipelas outbreaks, and compared the obtained isolates with those from laying hens. The samples were investigated by selective culture followed by species-specific polymerase chain reaction on cultures. E. rhusiopathiae was isolated from the spleen, jejunal contents, manure, dust and swabs from water nipples. Three more samples from the house environment tested positive by polymerase chain reaction compared with selective culture alone. Selected isolates were investigated by pulsed-field gel electrophoresis (PFGE) and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). One farm was represented by isolates from laying hens only, and one of these isolates differed in one PFGE band from the others. Different banding patterns were observed for isolates from laying hens and manure on one farm. On the remaining two farms, the isolates from the house environment and laying hens were identical but differed between farms. Outbreaks reoccurred in the next flock on two of the farms, and different PFGE types were isolated from consecutive flocks. Our results suggest an external source of infection, which would explain the previously reported increased risk of outbreaks in free-range flocks. Contaminated manure and dust may represent sources of transmission. For the isolates, MALDI-TOF MS and biochemical typing results were in agreement but, since the type strain of Erysipelothrix tonsillarum was typed as E. rhusiopathiae using MALDI-TOF MS, further studies into this method are needed.
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| 16. |
- Fellström, Claes
(författare)
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A review of methods used for studying the molecular epidemiology of Brachyspira hyodysenteriae
- 2017
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Ingår i: Veterinary Microbiology. - : Elsevier BV. - 0378-1135 .- 1873-2542. ; 207, s. 181-194
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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.
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| 17. |
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| 18. |
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| 19. |
- Fellström, Claes, et al.
(författare)
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Identification and genetic fingerprinting of Brachyspira species
- 2008
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Ingår i: Journal of Microbiological Methods. - : Elsevier BV. - 1872-8359 .- 0167-7012. ; 72:2, s. 133-140
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Tidskriftsartikel (refereegranskat)abstract
- Six Brachyspira type and reference strains, and 14 well characterized porcine field isolates representing all recognised porcine Brachyspira spp. were compared by different molecular methods. Sequence analysis of the 16S rRNA and the nox genes, pulsed-field gel electrophoresis (PFGE) and randomly amplified polymorphic DNA (RAPD) were used in the study. In addition the isolates were analysed by five species-specific PCR systems. The topologies of the dendrograms obtained from each of the four typing systems were different. The B. pilosicoli isolates formed monophyletic clusters in all dendrograms, but with different sister lines. All five porcine Brachyspira species formed monophyletic clusters in the nox gene-based dendrogram only. All five PCR systems accurately identified their targets, except for the nox gene-based B. intermedia-specific system, by which it was not possible to identify one of the presumed B. intermedia isolates, and the other B. intermedia-specific system, based on the 23S rRNA gene, gave a positive reaction for one B. innocens isolate. In an extended study, 46 additional isolates and the original eight isolates with the phenotypes of B. hyodysenteriae or B. intermedia were compared by PFGE and PCR. The PFGE results indicated a high genetic diversity of isolates with the phenotype of B. intermedia. Thirty-three of 34 tested isolates could be identified by one or both of the two B. intennedia-specific PCR systems used, however, only 19 of the 34 isolates were positive in both systems.
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| 20. |
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| 21. |
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| 22. |
- Ikwap, Kokas, et al.
(författare)
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Characterization of pig production in Gulu and Soroti districts in northern and eastern Uganda
- 2014
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Ingår i: Livestock Research For Rural Development. - 0121-3784. ; 26
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Tidskriftsartikel (refereegranskat)abstract
- Owing to loss of cattle and goats during the recent civil unrest, pig farming has become popular in northern and eastern Uganda as a quick mitigation to poverty. This study was carried out to describe the characteristics of pig production in these regions. Using a cross-sectional design, data were collected from 96 households (51 from Gulu district, northern Uganda and 45 from Soroti district, eastern Uganda) raising pigs with suckling and weaned piglets. The households were selected using the snowballing method. The households were predominantly headed by adult men, of which 97% had attended at least primary education. The mean numbers of suckling, weaned, growing and adult pigs per household in Gulu and Soroti were 8 and 7.3, 4.8 and 5.3, 2.3 and 2.6 and 3.1 and 3.1, respectively, with no significant difference (p > 0.05) between the districts. Overall, the majority of households (64%, n=96) kept local breeds of pigs. The most common management method was tethering, as practiced by 67% of the study households. Home-made feeds were the most common (88%, n=96) and the wives/women provided much of the labour (60%, n=96). However, in only 23% of the households, women owned and made decisions on the pigs. Male children also owned and made decisions on pigs in 8% of the households. Natural breeding of sows with a shared boar was the most common practice (88%, n=96). The litter size at birth was 6 to 10 piglets in 78% (n= 96) of the households. Based on the clinical signs reported by the households, 38% and 23% of the herds experienced problems with diarrhoea and respiratory diseases, respectively. In total, 39% of the households were receiving professional veterinary care, when pigs fall sick. In conclusion, pig production around regional urban centers in northern and eastern Uganda is largely smallholder, practiced by farmers who have attended at least primary education, tether their pigs, depend on labour provided largely by housewives and there is inadequate veterinary care. The findings of this study point at a need for increased involvement of women in decision making in pig farming, increased pig veterinary care and investigation of the causes of diseases such as diarrhoea in order to support this major livelihood resource for the poor in northern and eastern Uganda, especially women and children.
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| 23. |
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| 24. |
- Ikwap, Kokas, et al.
(författare)
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Salmonella species in piglets and weaners from Uganda: Prevalence, antimicrobial resistance and herd-level risk factors
- 2014
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Ingår i: Preventive Veterinary Medicine. - : Elsevier BV. - 0167-5877 .- 1873-1716. ; 115, s. 39-47
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Tidskriftsartikel (refereegranskat)abstract
- Non-typhoidal salmonellosis is of concern in humans in sub-Saharan Africa, and this is partly due to the high number of immunocompromised persons. Pork and pork products could be among the sources of these non-typhi Salmonella spp. The aim of this study was to identify Salmonella spp. in piglets and weaners in northern and eastern Uganda, characterize their antimicrobial resistance patterns and determine herd-level risk factors. Fecal samples were collected from 465 piglets and weaners from 93 herds (49 and 44 from northern and eastern Uganda, respectively). In addition, information about the herd management and potential risk factors were collected. The fecal samples were cultured for the identification of Salmonella spp. The Salmonella spp. confirmed by serotyping were further characterized by determination of minimum inhibitory concentration (MIC) to 12 antimicrobials by broth microdilution. At individual level, the total prevalence of Salmonella spp. was 12% (12.2% in northern and 11.9% in eastern Uganda). At herd level, the total prevalence was 39% (43% in northern and 34% in eastern Uganda). From 56 samples with Salmonella spp., 20 serovars were identified including two serovars identified only by their antigenic formulae. The predominant serovars were S. Zanzibar, S. Heidelberg, S. Infantis, S. Typhimurium, S. Stanleyville, S. Aberdeen and S. Kampala. In total, 57% of the 53 Salmonella spp. analyzed, originating from 27% of the herds, were resistant to at least one antimicrobial agent. The majority of drug-resistant isolates (60%) were from northern Uganda. Eight multidrug-resistant (MDR) isolates were from northern Uganda and three MDR isolates were from eastern Uganda. Increased prevalence of Salmonella spp. was associated with feeding the young and adults separately as compared to feeding the young and adults together (p = 0.043, OR = 4.3; 95% CI 1.1, 17.38). Protective factors were "intensive" method of keeping the pigs versus "tethering and roaming" (p = 0.016, OR = 0.11; 95% CI 0.02, 0.64), "intensive" method versus "semi-intensive" method (p = 0.048, OR = 0.12; 95% CI 0.01, 0.96) and cleaning feeders after every two days versus daily (p = 0.017, OR = 0.18; 95% CI 0.05, 0.72). This study has revealed a high prevalence of infection of piglets and weaners with diverse non-typhi Salmonella serovars and highlights the potential role of pork and pork products as sources of these organisms for humans. In addition, this study has identified protective factors that could be promoted to control Salmonella spp. and in antimicrobial resistance reduction programs in rural pigs from Uganda. (C) 2014 Elsevier B.V. All rights reserved.
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| 25. |
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| 26. |
- Jacobson, Magdalena, et al.
(författare)
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Porcine proliferative enteropathy: An important disease with questions remaining to be solved
- 2010
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Ingår i: Veterinary Journal. - : Elsevier BV. - 1090-0233 .- 1532-2971. ; 184, s. 264-268
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Forskningsöversikt (refereegranskat)abstract
- Proliferative enteropathy caused by the intracellular bacterium Lawsonia intracellularis is an endemic disease with high herd prevalences reported worldwide. The infection has a considerable impact on pig production and herd economics and, with the development of new diagnostic techniques, L intracellularis is being identified in an increasing number of pig herds and a wider range of species. This paper reviews current knowledge of the disease, with a focus on the epidemiology in pigs. The prevalence of infection, transmission, predisposing factors, microbial features, pathogenesis, clinical signs, diagnosis, treatment and control are discussed. The disease is mainly controlled by antibiotic treatment and vaccination at herd level. In the development of effective measures to prevent the spread of the infection, increased knowledge of the transmission and persistence of the microorganism are crucial. (C) 2009 Elsevier Ltd. All rights reserved.
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| 27. |
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| 28. |
- Jansson, Desirée, et al.
(författare)
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Experimental Challenge of Mallards (Anas platyrhynchos) with Brachyspira hyodysentetiae and "Brachyspira suanatina" Isolated from Pigs and Mallards
- 2009
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Ingår i: Journal of Comparative Pathology. - : Elsevier BV. - 0021-9975 .- 1532-3129. ; 141, s. 211-222
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Tidskriftsartikel (refereegranskat)abstract
- Brachyspira hyodysenteriae, the aetiological agent of swine dysentery, and a recently proposed and closely related enteropathogenic spirochaete "Brachyspira suanatina", originally isolated from pigs or mallards (Anas platyrhynchos), were used to inoculate week-old mallard ducklings orally or cloacally. The colonization rate, clinical outcome, faecal dry matter content, blood leucocyte counts and gross, microscopical and electron microscopical features 14-16 days post-inoculation were investigated at necropsy examination. Strains of "B. suanatina" of pig and mallard origin and B. hyodysenteriae of mallard origin colonized the ducklings by oral inoculation, and colonization was also established by cloacal inoculation with a "B. suanatina" strain of mallard origin. The porcine reference strain of B. hyodysenteriae (13204 R) failed to colonize the birds. Unchallenged contact birds in one of the challenge groups were readily colonized by a strain of "B. suanatina" of mallard origin. The proportion of colonized birds differed significantly between the challenge groups (P < 0.0001). For each challenge group, the inoculum and a randomly selected subset of recovered isolates had an identical biochemical profile and banding pattern by randomly amplified polymorphic DNA (RAPD) analysis. None of the birds developed clinical signs of gastrointestinal disease during the trial. The faecal dry weight contents, body weights and total leucocyte and heterophal counts did not differ between the various groups of birds. At the microscopical and electron microscopical levels, the caecal mucosa in some of the Brachyspira culture-positive birds had sharply demarcated epithelial cell changes and there were features of irreversible cell damage in crypt necks coinciding with spirochaetal infiltration of the mucosa. The crypts in Brachyspira culture-positive birds were deeper than in culture-negative birds (median: 237 mu m and 218 mu m, respectively, P = 0.019). This challenge model was well suited for use in mallards and consistent with previous findings that strongly haemolytic Brachyspira spp. may cross the species barrier between pigs and birds. (C) 2009 Elsevier Ltd. All rights reserved.
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| 29. |
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| 30. |
- Karlsson, Frida, et al.
(författare)
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Occurrence of Treponema spp. in porcine skin ulcers and gingiva
- 2013
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Ingår i: Veterinary Microbiology. - : Elsevier BV. - 0378-1135 .- 1873-2542. ; 165, s. 402-409
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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.
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| 31. |
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| 32. |
- Pringle, Märit, et al.
(författare)
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Characterization and epidemiological relationships of Spanish Brachyspira hyodysenteriae field isolates
- 2010
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Ingår i: Epidemiology and Infection. - 0950-2688 .- 1469-4409. ; 138, s. 76-85
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Tidskriftsartikel (refereegranskat)abstract
- This research aimed to describe the genetic and phenotypic diversity of 74 Spanish Brachyspira hyodysenteriae field isolates, to establish epidemiological relationships between the isolates and to confirm the presence of tiamulin-resistant isolates in Spain. For these purposes, we performed biochemical tests in combination with diagnostic PCR analysis for the identification of Brachyspira spp. and for detection of the smpA/smpB gene. We also used antimicrobial susceptibility tests, random amplified polymorphic DNA (RAPD) and a new pulsed-field gel electrophoresis (PFGE) protocol. The combination of RAPD and PFGE allowed the study of epidemiological relationships. Both indole-negative and tiamulin-resistant isolates of B. hyodysenteriae are reported in Spain for the first time. The genetic analyses indicated a relationship between these Spanish isolates and indole-negative isolates previously obtained from Germany and Belgium.
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| 33. |
- Pringle, Märit, et al.
(författare)
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Isolation of spirochetes of genus Treponema from pigs with ear necrosis
- 2009
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Ingår i: Veterinary Microbiology. - : Elsevier BV. - 0378-1135 .- 1873-2542. ; 139, s. 279-283
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Tidskriftsartikel (refereegranskat)abstract
- Various ear lesions, often caused by ear biting, are common in pigs. Some herds have a high frequency of ear necrosis, a syndrome characterized by necrotic lesions along the rim of the pinna, often bilateral and sometimes resulting in loss of the entire ear. In samples from such lesions spirochetes have been observed microscopically but never isolated or identified. In this study two herds with periodic outbreaks of ear necrosis among weaners were investigated. Samples were collected from ear lesions and from the gingiva of the pigs. Spirochetes were observed in silver stained histological sections and by phase contrast microscope in scrapings from the necrotic lesions. From an ear lesion a pure spirochete isolate was obtained and identified as a yet unnamed species of genus Treponema, closely related to spirochetes found in digital dermatitis in cattle. From the oral samples two pure isolates were obtained. One of these isolates was identified as the same species as in the ear lesion and one as Treponema socranskii. Species identification was based on 165 rRNA gene sequences. (C) 2009 Elsevier B.V. All rights reserved.
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| 34. |
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| 35. |
- Rosander, Anna, et al.
(författare)
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Experimental inoculation of Treponema pedis T A4 failed to induce ear necrosis in pigs
- 2017
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Ingår i: Porcine Health Management. - : Springer Science and Business Media LLC. - 2055-5660. ; 3
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Tidskriftsartikel (refereegranskat)abstract
- Ear necrosis is a syndrome affecting pigs shortly after weaning and is regarded as an animal welfare issue. The etiology is unknown but Treponema spp., predominantly Treponema pedis, are commonly detected in the lesions. Oral treponemes have been suggested as source of infection, transferred by biting and licking behavior. In this study, five pigs were intradermally inoculated with Treponema pedis strain T A4 with the aim of investigating if this strain would induce ear lesions. Three pigs served as controls. The inoculation was repeated after 29 days, and the study continued for 56 days. Serum samples were collected throughout the study and analyzed by ELISA for IgG antibodies towards T. pedis T A4 lysate. Skin biopsies were taken from the inoculation area at the end of the study. Gingival samples were collected and cultivated for treponemes, for comparison to the inoculation strain and to follow colonisation. The challenged pigs did not develop any clinical signs of infection and no spirochetes were detected in sections from skin biopsies. The number of Treponema-positive gingival samples increased during the study. In the challenge group, IgG towards the bacterial lysate peaked 7 days after each inoculation and decreased rapidly hereafter. In the control group a weak IgG response was observed after the second inoculation, possibly caused by the oral treponemes.
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| 36. |
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| 37. |
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| 38. |
- Sternberg Lewerin, Susanna, et al.
(författare)
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Risk assessment as a tool for improving external biosecurity farm level
- 2015
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Ingår i: BMC Veterinary Research. - : Springer Science and Business Media LLC. - 1746-6148. ; 11, s. 1-10
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Tidskriftsartikel (refereegranskat)abstract
- Background: Biosecurity routines at herd level may reduce the probability of introduction of disease into the herd, but some measures may be regarded as expensive and cumbersome for the farmers. Custom-made measures based on individual farm characteristics may aid in improving the actual application of on-farm biosecurity. The aim of the study was to provide a tool for calculating the effects of different biosecurity measures and strategies on the individual farm level.A simple model was developed to assess the risk of disease introduction and the need for biosecurity measures in individual farms. To illustrate the general applicability of the tool, it was applied to theoretical examples of Swedish cattle and pig farms and diseases endemic in those animal species in the EU, in two scenarios with different between-farm contact patterns.Results: The model illustrated that the most important factors affecting the risk, and the effect of biosecurity measures such as quarantine routines and protective clothing, were the frequency of between- farm contacts and prevalence of the disease. The risk of introduction as well as the effect of biosecurity measures differed between farm types and disease transmission routes. Adapting contact patterns to mitigate a specific disease risk was as important as biosecurity measures for some farm types, but the largest effect was seen when combining biosecurity measures with more planned contact patterns.Conclusions: The risk assessment model proved useful for illustrating the risk of introduction of endemic diseases and the mitigating effect of different biosecurity measures on farm level. Model outputs could be used to justify prioritisation of measures or adapting contact patterns. The theoretic exercise of adjusting model inputs and comparing outputs may help veterinary advisors to understand farm-specific risks and motivate farmers to improve biosecurity in their individual farm, as it can be tailored to each farmer's needs and preferences.
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| 40. |
- Svartström, Olov, et al.
(författare)
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Characterization of Treponema spp. isolates from pigs with ear necrosis and shoulder ulcers
- 2013
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Ingår i: Veterinary Microbiology. - : Elsevier BV. - 0378-1135 .- 1873-2542. ; 166, s. 617-623
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Tidskriftsartikel (refereegranskat)abstract
- Ear necrosis and shoulder ulcers in pigs are animal welfare problems and ethical issues that can cause economic losses for producers. Spirochetes have been observed microscopically in scrapings from pig ulcers since the early 1900s, but have until recently not been cultured and therefore not characterized. In this study, 12 Treponema spp. isolates were acquired from porcine ear necrosis, shoulder ulcers and gingiva. DNA analysis of the 16S rRNA-tRNA(Ile) intergenic spacer region (ISR2) or the 16S rRNA gene revealed relatedness to oral treponemes found in dogs and humans. All isolates except one aligned into two clusters, Treponema pedis and Treponema sp. OMZ 840-like. The 16S rRNA gene of the remaining isolate shared 99% nucleotide identity with Treponema parvum. Genetic fingerprinting of the isolates was performed through random amplification of polymorphic DNA (RAPD). In addition, the isolates were characterized by biochemical tests, including api (R) ZYM, tryptophanase and hippuricase activity, and by testing the antimicrobial susceptibility to tiamulin, valnemulin, tylosin, tylvalosin, lincomycin and doxycycline using broth dilution. All isolates except two showed unique RAPD fingerprints, whereas metabolic activity tests could not differentiate between the isolates. The MICs of all antimicrobial agents tested were low. (C) 2013 Elsevier B.V. All rights reserved.
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| 41. |
- Wu, Ping-Hsun, et al.
(författare)
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The association between Single Nucleotide Polymorphisms of Klotho Gene and Mortality in Elderly Men: The MrOS Sweden Study
- 2020
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Ingår i: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 10:1
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Tidskriftsartikel (refereegranskat)abstract
- The Klotho (KL) gene is involved in phosphate homeostasis. Polymorphisms in this gene have been reported to be associated with the risk of cardiovascular disease. Here we used computational tools to predict the damage-associated single nucleotide polymorphisms (SNPs) in the human KL gene. We further investigated the association of SNPs in the KL gene and mortality in the Swedish multicenter prospective Osteoporotic Fractures in Men (MrOS) cohort. This study included 2921 men (aged 69-81 years) with mean 4.49 +/- 1.03 years follow-up. 18 SNPs in the KL gene were genotyped using Sequenom. These SNPs were identified by in silico tools for the coding and noncoding genome to predict the damaging SNPs. After quality analyses, SNPs were analyzed for mortality risk using two steps approach on logistic regression model screening and then Cox regression model confirmation. Two non-synonymous SNPs rs9536314 and rs9527025 were found to be potentially damaging SNPs that affect KL protein stability and expression. However, these two SNPs were not statistically significantly associated with all-cause mortality (crude Hazard ratio [HR] 1.72, 95% confidence interval [CI] 0.96-3.07 in rs9536314; crude HR 1.82, 95% CI 0.998-3.33 in rs9527025) or cardiovascular mortality (crude HR 1.52, 95% CI 0.56-4.14 in rs9536314; crude HR 1.54, 95% CI 0.55-4.33 in rs9527025) in additive model using Cox regression analysis. In conclusion, these two potentially damaging SNPs (rs9536314 and rs9527025) in the KL gene were not associated with all-cause mortality or cardiovascular mortality in MrOs cohort. Larger scales studies and meta-analysis are needed to confirm the correlation between polymorphisms of the KL gene and mortality.
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