Genomic characterization of a liberibacter present in an ornamental rutaceous tree, Calodendrum capense, in the Western Cape province of South Africa. Proposal of 'Candidatus Liberibacter africanus subsp capensis'

In 1994, the uncultured phloem-restricted bacteria of citrus huanglongbing (ex-greening) disease in Asia and Africa were characterized as 'Candidatus Liberobacter asiaticum' and 'Candidatus Liberobacter africanum', respective ly. Following the rules of the International Code of Nomenclature of Bacter ia, the two bacterial species have now been renamed 'Candidatus Liberibacte r asiaticus' and 'Candidatus Liberibacter africanus'. A third liberibacter was detected by PCR in an ornamental rutaceous tree, Cape chestnut (Caloden drum capense), in South Africa. The new liberibacter was characterized by s erology and from the sequences of its 16S rDNA, intergenic 16S/23S rDNA and ribosomal protein genes of the beta operon. Phylogenetic analysis showed t hat the liberibacter present in C capense differed from the two previously described liberibacter species from citrus and that it was more closely rel ated to 'Candidatus Liberibacter africanus' than to 'Candidatus Liberibacte r asiaticus'. It is proposed that the liberibacter from C. capense be assig ned a subspecies status, 'Candidatus Liberibacter africanus subsp. capensis '.