Withering syndrome is a fatal disease of wild and cultured abalone, Haliotis spp., that inhabit the west coast of North America. The aetiological agent of withering syndrome has recently been identified as a member of the family Rickettsiaceae in the order Rickettsiales. Using a combination of morphological, serological, life history and genomic (16S rDNA) characterization, we have identified this bacterium as a unique taxon and propose the provisional status of 'Candidatus Xenohaliotis californiensis'. The Gram-negative, obligate intracellular pleomorphic bacterium is found within membrane-bound vacuoles in the cytoplasm of abalone gastrointestinal epithelial cells. The bacterium is not cultivable on synthetic media or in fish cell lines (e.g. CHSE-214) and may be controlled by tetracyclines (oxytetracycline) but not by chloramphenicol, clarithromycin or sarafloxicin. Phylogenetic analysis based on the 16S rDNA of 'Candidatus Xenohaliotis californiensis' places it in the α-subclass of the class Proteobacteria but not to the four recognized subtaxa of the α-Proteobacteria (α-1, α-2, α-3 and α-4). The bacterium can be detected in tissue squashes stained with propidium iodide, microscopic examination of stained tissue sections, PCR or in situ hybridization. 'Candidatus Xenohaliotis californiensis' can be differentiated from other closely related α-Proteobacteria by its unique 16S rDNA sequence.
|Original language||English (US)|
|Number of pages||9|
|Journal||International Journal of Systematic and Evolutionary Microbiology|
|State||Published - Jan 1 2000|
- 'Candidatus Xenohaliotis californiensis'
- New taxon
ASJC Scopus subject areas
- Ecology, Evolution, Behavior and Systematics