A polymerase chain reaction assay for improved determination of virulence of Dichelobacter nodosus, the specific causative pathogen for ovine footrot

Improved diagnosis of virulent ovine footrot using the intA gene

“…DNA probes have been developed previously for the differentiation of virulent and benign footrot. These include the vap and vrl probes (Katz et al, 1991;Rood et al, 1996) and benign-specific and virulent-specific probes developed by Liu and Webber, (1995). The vap and vrl probes are not currently used for routine diagnosis of footrot in Australia, possibly because they were not more specific than the gelatin gel test.…”

“…This may explain the greater specificity of the intA probe compared with vap probes for the diagnosis of virulent footrot. The benign-specific probe (Liu and Webber, 1995)…”

Occurrence of different strains of Dichelobacter nodosus in new clinical lesions in sheep exposed to footrot associated with multi‐strain infections

“…Laboratory tests included culture of D nodosus, 3 classification of isolates according to protease characteristics 4 (gelatin gel and protease isoenzyme) and PCR to detect gene sequences homologous to pJIR314B, 5 pJIR318L 5 and pB645-335. 6 The latter test was performed on whole cell extracts from 2-to 4-day-old, TASH agar plate cultures of D nodosus.…”

Comparative study of the commonly used virulence tests for laboratory diagnosis of ovine footrot caused by Dichelobacter nodosus in Australia

“…An assessment of these probes in dot-blot hybridization assays using a collection of 96 D. nodosus isolates showed general agreement with elastase and gelatin gel test results and correlation with clinical manifestations of footrot (Liu 1994). PCR assays were developed based on the nucleotide sequence of the gene probes developed for dot-blot hybridization tests (Liu and Webber 1995). However, there were discrepancies between the phenotypic and genotypic classification of the isolates by this method.…”