Molecular analysis of Dichelobacter nodosus isolated from footrot in sheep in Malaysia

Zunita, Z.; Radu, Son; Sheikh-Omar, A. R.; Mutalib, Abdul; Joseph, P. G.; Rusul, Gulam

doi:10.1016/s0378-1135(98)00219-3

Cited by 11 publications

(7 citation statements)

References 18 publications

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“…Results of PFGE from the current study are consistent with work done in Malaysia, where 12 isolates of D. nodosus from three epidemiologically unrelated farms had eight different molecular types (24), indicating a high genetic diversity in that D. nodosus population. A study in New Zealand investigated the genetic diversity of D. nodosus using PCR to amplify regions of the fimbrial gene (fimA) and found considerable genetic diversity, with 11 of 15 strains showing differences in fimbria sequences (25).…”

Section: Discussionsupporting

confidence: 88%

Understanding the Molecular Epidemiology of the Footrot Pathogen Dichelobacter nodosus To Support Control and Eradication Programs

et al. 2010

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Despite the high genetic diversity, three common clonal groups predominated in WA and were found in other Australian states. On some farms, molecular type was stable over a number of years, whereas on other farms genetically diverse isolates occurred within a flock of sheep or within a hoof. This study provides a large database from which to appropriately interpret molecular types found in epidemiological investigations and to identify common and unknown types that may compromise footrot eradication or control programs.

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Section: Discussionsupporting

confidence: 88%

Understanding the Molecular Epidemiology of the Footrot Pathogen Dichelobacter nodosus To Support Control and Eradication Programs

et al. 2010

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“…Several strain types of D. nodosus have been detected within and between sheep, flocks (7, 9, 13, 14, 16–18), and geographic regions (9, 13, 14). It has also been reported that clonal groups persist within farms and regions for decades (9); however, there is little information on the persistence of individual strains within sheep or feet.…”

Section: Introductionmentioning

confidence: 99%

Within-Flock Population Dynamics of Dichelobacter nodosus

et al. 2017

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Footrot causes 70–90% of lameness in sheep in Great Britain. With approximately 5% of 18 million adult sheep lame at any one time, it costs the UK sheep industry £24–84 million per year. The Gram-negative anaerobe Dichelobacter nodosus is the causative agent, with disease severity influenced by bacterial load, virulence, and climate. The aim of the current study was to characterize strains of D. nodosus isolated by culture of swabs from healthy and diseased feet of 99 ewes kept as a closed flock over a 10-month period and investigate persistence and transmission of strains within feet, sheep, and the flock. Overall 268 isolates were characterized into strains by serogroup, proline–glycine repeat (pgr) status, and multi-locus variable number tandem repeat analysis (MLVA). The culture collection contained 87 unique MLVA profiles and two major MLVA complexes that persisted over time. A subset of 189 isolates tested for the virulence marker aprV2 were all positive. The two MLVA complexes (76 and 114) comprised 62 and 22 MLVA types and 237 and 28 isolates, respectively. Serogroups B, and I, and pgrB were associated with MLVA complex 76, whereas serogroups D and H were associated with MLVA complex 114. We conclude that within-flock D. nodosus evolution appeared to be driven by clonal diversification. There was no association (P > 0.05) between serogroup, pgr, or MLVA type and disease state of feet. Strains of D. nodosus clustered within sheep and were transmitted between ewes over time. D. nodosus was isolated at more than one time point from 21 feet, including 5 feet where the same strain was isolated on two occasions at an interval of 1–33 weeks. Collectively, our results indicate that D. nodosus strains persisted in the flock, spread between sheep, and possibly persisted on feet over time.

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“…A few studies have used genotyping for molecular epidemiological investigations of D. nodosus [10-13]. Pulsed field gel electrophoresis (PFGE) is discriminatory and reproducible, and has been used for typing D. nodosus [10,13].…”

Section: Introductionmentioning

confidence: 99%

“…Pulsed field gel electrophoresis (PFGE) is discriminatory and reproducible, and has been used for typing D. nodosus [10,13]. Typing based on the proline-glycine repeat ( pgr ) gene in D. nodosus was described by Calvo-Bado et al .…”

Section: Introductionmentioning

confidence: 99%

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

et al. 2014

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BackgroundIn 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.ResultsThe 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.ConclusionThis 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.

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Molecular analysis of Dichelobacter nodosus isolated from footrot in sheep in Malaysia

Cited by 11 publications

References 18 publications

Understanding the Molecular Epidemiology of the Footrot Pathogen Dichelobacter nodosus To Support Control and Eradication Programs

Understanding the Molecular Epidemiology of the Footrot Pathogen Dichelobacter nodosus To Support Control and Eradication Programs

Within-Flock Population Dynamics of Dichelobacter nodosus

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

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