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

Abstract

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.

Detection and diversity of a putative novel heterogeneous polymorphic proline-glycine repeat (Pgr) protein in the footrot pathogen Dichelobacter nodosus

“…Western Australia isolated from the feet of sheep at an abattoir (Buller et al, 2010 The complete pgr gene was amplified in 8 isolates ( primers. Fifty isolates were tested against each set of primers for the pgrA and pgrB genes.…”

The Applied Development of a Tiered Multilocus Sequence Typing (MLST) Scheme for Dichelobacter nodosus

“…Genetic epidemiology has long been used to track and infer relatedness within and between species of bacteria. Various tools have been applied to D. nodosus ; RFLP (Ghimire and Egerton, 1999 ), infrequent restriction site PCR (Zakaria et al, 1998 ) and the traditional “Gold Standard” epidemiological tool PGFE (Buller et al, 2010 ), to try and understand the diversity and inform approaches to combat footrot. However, these often suffer with poor reproducibility between laboratories and are time consuming and expensive.…”

“…However, both are time consuming and require a large amount of input DNA and suffer from inter-lab biases. Infrequent restriction site PCR has also been implemented but was shown to be less robust than the RFLP (Buller et al, 2010 ). More recently Multiple Locus Variable Number Tandem repeat (VNTR) analysis has proven to be a reproducible and high discriminatory method (Russell et al, 2014 ), however further analysis is limited due to VNTR only using PCR and gel electrophoresis visualization to draw conclusions.…”

Draft Genome Sequence of Dichelobacter nodosus ATCC 25549, Strain VPI 2340 [11342], a Bacterium Causing Footrot in Sheep

“…Dichelobacter nodosus , a Gram-negative, non-spore-forming obligate anaerobe, is the primary causative organism of footrot in ungulates (mammals with hooves, including cattle, sheep, deer, and goats) ( 1 ). The most well-known disease caused by D. nodosus is ovine footrot, a highly contagious necrotic disease of sheep hooves ( 2 ).…”