title: Characterization of a novel clade of Xanthomonas isolated from rice leaves in Mali and proposal of Xanthomonas maliensis sp. nov.
abstract: Four bacterial strains, designated M89, M92, M97(T), and M106, were isolated in a previous study from surface-sterilized leaves of rice (Oryza sativa) or murainagrass (Ischaemum rugosum) at three sites in Mali, Africa. Here they were examined by a polyphasic taxonomic approach and analysis of a whole-genome sequence. Phylogenetic analyses based on 16S rRNA sequence and multilocus sequence analysis of seven genes showed that these four strains formed a distinct lineage representing a novel species within the genus Xanthomonas. This was supported by whole-genome average nucleotide identity values calculated from comparisons of strain M97(T) with established Xanthomonas species. The strains can be differentiated from the known Xanthomonas species on the basis of their fatty acid and carbohydrate utilization profiles. Population growth studies on rice confirmed that these bacteria multiply in rice leaves without causing symptoms. Identification of this novel species can be accomplished by using diagnostic primer sets or by gyrB gene sequence analysis. We propose to classify these rice- and grass-associated bacteria as Xanthomonas maliensis sp. nov. with strain M97(T) = CFBP7942(T) = LMG27592(T) as the type strain.
authors.affiliation: Department of Bioagricultural Sciences and Pest Management, Colorado State University, Fort Collins, CO, 80523-1177, USA, lindsay.triplett@ct.gov.
authors.forename: Lindsay R
authors.initials: LR
authors.lastname: Triplett
authors.forename: Valérie
authors.initials: V
authors.lastname: Verdier
authors.forename: Tony
authors.initials: T
authors.lastname: Campillo
authors.forename: Cinzia
authors.initials: C
authors.lastname: Van Malderghem
authors.forename: Ilse
authors.initials: I
authors.lastname: Cleenwerck
authors.forename: Martine
authors.initials: M
authors.lastname: Maes
authors.forename: Loïc
authors.initials: L
authors.lastname: Deblais
authors.forename: Rene
authors.initials: R
authors.lastname: Corral
authors.forename: Ousmane
authors.initials: O
authors.lastname: Koita
authors.forename: Bart
authors.initials: B
authors.lastname: Cottyn
authors.forename: Jan E
authors.initials: JE
authors.lastname: Leach
mesh_terms: D015373:Bacterial Typing Techniques; D016000:Cluster Analysis; D003600:Cytosol / Q000737:chemistry; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D004275:DNA, Ribosomal / Q000737:chemistry / Q000235:genetics; D005227:Fatty Acids / Q000032:analysis; D016680:Genome, Bacterial; D008302:Mali; D058885:Multilocus Sequence Typing; D012275:Oryza / Q000382:microbiology*; D010802:Phylogeny; D018515:Plant Leaves / Q000382:microbiology*; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D014974:Xanthomonas / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification*
chemical_list: D004269:DNA, Bacterial; D004275:DNA, Ribosomal; D005227:Fatty Acids; D012336:RNA, Ribosomal, 16S