is the causative agent of ovine footrot. The regions of the genome may have arisen by the integration of a genetic element and may have a role in virulence. The virulent strain A198 has multiple copies of the regions. In the present study, sequences to the left and right of regions 1, 2 and 3 of strain A198 were analysed by Southern blotting and DMA sequencing. The results suggest that regions 1 and 2 arose by independent integration events into different tRNA genes. The discovery of a second integrase gene (), a gene with similarity to bacteriophage repressor proteins (), and a gene similar to an ORF from a conjugative transposon (), suggests that a second genetic element, either a bacteriophage or a conjugative transposon, is integrated next to region 3 in the genome. The arrangement of and the regions in three other virulent strains and one benign strain was determined using using Southern blotting and PCR. One strain, H1215, contained and not and thus resembles region 3, suggesting that region 3 also may have arisen by an independent integration event. In all strains, a copy of was found next to the regions. The regions contain two genes, and with similarity to the genes of the killer plasmid Rts1. Evidence is presented that and have a similar function in


Article metrics loading...

Loading full text...

Full text loading...


Most cited this month Most Cited RSS feed

This is a required field
Please enter a valid email address
Approval was a Success
Invalid data
An Error Occurred
Approval was partially successful, following selected items could not be processed due to error