|Trott, Darren - MURDOCH UNIV, AUSTRALIA|
|Hampson, David - MURDOCH UNIV, AUSTRALIA|
Submitted to: Australian Society for Microbiology
Publication Type: Abstract Only
Publication Acceptance Date: August 1, 1996
Publication Date: N/A
Technical Abstract: Intestinal spirochaetosis (IS) is a condition of humans and pigs in which large numbers of spirochaetes are found attached by one end to the colonic epithelium. IS has been experimentally reproduced in day-old SPF chicks infected with both human and porcine spirochaetes, and these have been shown to be genetically similar. Although they were originally thought to belong to a new genus and species, recent analysis of 16S ribosomal rRNA sequences has revealed that they are more likely to belong within the genus Serpulina, which already contains two species; Serpulina hyodysenteriae, the cause of swine dysentery, and Serpulina innocens, a nonpathogenic commensal organism. The phenotypic and genetic traits of three human and three porcine intestinal spirochaete strains recovered from cases of IS were examined and compared with the type strains of S. hyodysenteriae and S. innocens. Phenotypic traits that distinguished IS-associated strains included their ultrastructural appearance, faster growth rate and higher maximum cell density, fermentation of D-ribose, hydrolysis of hippurate and increased sensitivity to rifampicin and spiramycin. Intestinal spirochaetes associated with IS in both humans and swine apparently belong to a new species within the genus Serpulina.