Transmission of ovine footrot : a dissertation submitted in partial fulfilment of the requirements for the degree of Bachelor of Science with Honours at Lincoln University

Abstract

Ovine footrot is a contagious bacterial disease caused by Dichelobacter nodosus. It is endemic to New Zealand and other sheep producing regions of the world and results in significant economic losses. Transmission of this bacterium is not well understood. It is thought to spread from host to host via contaminated soil. It has been suggested that other vectors may move the contaminated soil about on their feet, promoting transmission. To address the possibility of other vectors spreading the disease, primers specific to the fimA gene of D. nodosus were used to detect its presence in DNA derived from soil collected off paddocks containing footrot infected sheep, and soil and lesion material collected from the hooves of infected animals. D. nodosus was detected in lesion material, but not from DNA derived from the soil. The sensitivity of the fimA PCR was assessed and further extraction procedures were attempted to improve the purity of the DNA. It was concluded that the PCR was highly specific to D. nodosus, but the sensitivity of the reaction may have been a limitation to the analysis of the soil collected.