A recently introduced Dichelobacter nodosus strain caused an outbreak of footrot in Norway

BACKGROUND: In 2008, an outbreak of ovine footrot occurred in Norway. Dichelobacter nodosus isolates collected between 2008 and 2011 have been characterised. Isolates defined as virulent by the gelatin gel test (GG-test) were only found in sheep in Rogaland County, where the severe cases of footrot were registered. The majority (96%) of the virulent isolates belonged to serogroup A. It is suspected that they represent a newly introduced strain, and the aim of the present study was to investigate whether they are genetically similar. Sixty-one virulent isolates from sheep and 116 benign isolates from sheep, cattle and goats were included. Four GG-test virulent isolates from Danish sheep were also included. All isolates were genotyped by pulsed-field gel electrophoresis (PFGE) and by PCR for pgr variant determination. RESULTS: The Norwegian virulent isolates were assigned to 8 pulsotypes (PTs), while the benign isolates were assigned to 66 PTs. Thirty-seven (68.5%) of the 54, virulent, serogroup A isolates belonged to the same PT, and included isolates from 2008 through 2011. Isolates belonging to this PT were defined as the outbreak strain. The remaining virulent serogroup A isolates belonged to 4 PTs differing by ≤3 bands from the outbreak strain. Two virulent, Danish, serogroup A isolates differed by 2 bands from the Norwegian outbreak strain. All but 3 (95%) of the virulent isolates had the pgrA variant while 85% of the benign isolates had the pgrB variant. CONCLUSION: This study provides evidence that the footrot outbreak in Norway in 2008 most likely was caused by new introduction and local spread of one virulent D. nodosus strain

Cross-infection of virulent Dichelobacter nodosus between sheep and co-grazing cattle

AbstractDichelobacter nodosus is the main aetiological agent of ovine footrot and the bacterium has also been associated with interdigital dermatitis is cattle. The aim of this study was to investigate possible cross-infection of virulent D. nodosus between sheep and co-grazing cattle. Five farms, where sheep previously diagnosed with virulent D. nodosus were co-grazing with cattle for different periods of time, were included. The study sample consisted of 200 cows and 50 sheep. All cows were examined for the presence of interdigital dermatitis, and ten ewes, preferably with symptoms of footrot, had the footrot scores recorded. On each farm, the same ten ewes and ten cows were chosen for bacterial analyses. Swabs were analysed for D. nodosus by PCR and culturing. D. nodosus isolates were virulence-tested and assigned to serogroups by fimA variant determination. Biopsies were evaluated histopathologically and analysed by fluorescent in situ hybridization for D. nodosus, Treponema spp. and Fusobacterium necrophorum. D. nodosus defined as virulent by the gelatin gel test were isolated from 16 sheep from four farms and from five cows from two of the same farms. All five cows had interdigital dermatitis. Two of the cows stayed infected for at least eight months. By pulsed-field gel electrophoresis (PFGE), the isolates from the five cows were found to be genetically indistinguishable or closely related to isolates from sheep from the same farm. This indicates that cross-infection between sheep and cows have occurred

Characterising an amplicon on chromosome 19q13 in ovarian cancer cell lines, by fluorescence in situ hybridisation (FISH)

Kull 1996

2. Anbefalinger for god dyrevelferd og trygg produksjon

Produksjonen av storfekjøtt i Norge kjennetegnes bl.a. av stor variasjon med hensyn til fjøsbygg, driftssystemer, driftsrutiner og beiteforhold. Vi har besøkt 30 gårdsbruk og spurt produsentene selv om hva som er de viktigste suksessfaktorene for god produksjon og dyrevelferd i storfekjøttproduksjonen. I en serie på tre NIBIO-POPer publiseres resultater fra prosjektene «Arktisk storfekjøttproduksjon » (Hansen & Jørgensen 2016) og «Storfekjøttproduksjon i fjellregionen» (Berge m.fl. 2017). Dette er den andre, hvor vi deler bøndenes anbefalinger for god dyrevelferd og trygg produksjon. Målgruppa er storfekjøttprodusenter, spesielt de som er i etableringsfasen

Arktisk storfekjøttproduksjon

Produksjonen av storfekjøtt i Norge kjennetegnes bl.a. av stor variasjon med hensyn til fjøsbygg, driftssystemer, driftsrutiner og beiteforhold. Vi har besøkt 30 gårdsbruk og spurt produsentene selv om hva som er de viktigste suksessfaktorene for god produksjon og dyrevelferd i storfekjøttproduksjonen. I en serie på tre NIBIO-POPer publiseres resultater fra prosjektene «Arktisk storfekjøttproduksjon » (Hansen & Jørgensen 2016) og «Storfekjøttproduksjon i fjellregionen» (Berge m.fl. 2017). Dette er den andre, hvor vi deler bøndenes anbefalinger for god dyrevelferd og trygg produksjon. Målgruppa er storfekjøttprodusenter, spesielt de som er i etableringsfasen

Arktisk storfekjøttproduksjon

Produksjonen av storfekjøtt i Norge kjennetegnes bl.a. av stor variasjon med hensyn til fjøsbygg, driftssystemer, driftsrutiner og beiteforhold. Vi har besøkt 30 gårdsbruk og spurt produsentene selv om hva de mener er de viktigste suksessfaktorene for god produksjon og dyrevelferd i storfekjøttproduksjonen. I en serie på tre NIBIO-POPer publiseres resultater fra prosjektene «Arktisk storfekjøttproduksjon» (Hansen & Jørgensen 2016) og «Storfekjøttproduksjon i fjellregionen» (Berge m.fl. 2017). Dette er den første, hvor vi deler bøndenes anbefalinger for gode driftsløsninger og bygninger som de selv har erfart fungerer. Målgruppa er storfekjøttprodusenter, spesielt de som er i etableringsfasen

Genomic evidence for a globally distributed, bimodal population in the ovine footrot pathogen Dichelobacter nodosus

UNLABELLED: Footrot is a contagious, debilitating disease of sheep, causing major economic losses in most sheep-producing countries. The causative agent is the Gram-negative anaerobe Dichelobacter nodosus. Depending on the virulence of the infective bacterial strain, clinical signs vary from a mild interdigital dermatitis (benign footrot) to severe underrunning of the horn of the hoof (virulent footrot). The aim of this study was to investigate the genetic relationship between D. nodosus strains of different phenotypic virulences and between isolates from different geographic regions. Genome sequencing was performed on 103 D. nodosus isolates from eight different countries. Comparison of these genome sequences revealed that they were highly conserved, with >95% sequence identity. However, single nucleotide polymorphism analysis of the 31,627 nucleotides that were found to differ in one or more of the 103 sequenced isolates divided them into two distinct clades. Remarkably, this division correlated with known virulent and benign phenotypes, as well as with the single amino acid difference between the AprV2 and AprB2 proteases, which are produced by virulent and benign strains, respectively. This division was irrespective of the geographic origin of the isolates. However, within one of these clades, isolates from different geographic regions generally belonged to separate clusters. In summary, we have shown that D. nodosus has a bimodal population structure that is globally conserved and provide evidence that virulent and benign isolates represent two distinct forms of D. nodosus strains. These data have the potential to improve the diagnosis and targeted control of this economically significant disease. IMPORTANCE: The Gram-negative anaerobic bacterium Dichelobacter nodosus is the causative agent of ovine footrot, a disease of major importance to the worldwide sheep industry. The known D. nodosus virulence factors are its type IV fimbriae and extracellular serine proteases. D. nodosus strains are designated virulent or benign based on the type of disease caused under optimal climatic conditions. These isolates have similar fimbriae but distinct extracellular proteases. To determine the relationship between virulent and benign isolates and the relationship of isolates from different geographical regions, a genomic study that involved the sequencing and subsequent analysis of 103 D. nodosus isolates was undertaken. The results showed that D. nodosus isolates are highly conserved at the genomic level but that they can be divided into two distinct clades that correlate with their disease phenotypes and with a single amino acid substitution in one of the extracellular proteases

1. Anbefalinger for driftsløsninger og bygninger

Produksjonen av storfekjøtt i Norge kjennetegnes bl.a. av stor variasjon med hensyn til fjøsbygg, driftssystemer, driftsrutiner og beiteforhold. Vi har besøkt 30 gårdsbruk og spurt produsentene selv om hva de mener er de viktigste suksessfaktorene for god produksjon og dyrevelferd i storfekjøttproduksjonen. I en serie på tre NIBIO-POPer publiseres resultater fra prosjektene «Arktisk storfekjøttproduksjon» (Hansen & Jørgensen 2016) og «Storfekjøttproduksjon i fjellregionen» (Berge m.fl. 2017). Dette er den første, hvor vi deler bøndenes anbefalinger for gode driftsløsninger og bygninger som de selv har erfart fungerer. Målgruppa er storfekjøttprodusenter, spesielt de som er i etableringsfasen