Use of the novel phylogenetic marker dnaJ and DNA-DNA hybridization to clarify interrelationships within the genus Aeromonas.
The interrelationships of 27 Aeromonas strains were investigated using dnaJ sequences and DNA-DNA hybridization. dnaJ sequence similarities showed a stronger relationship with DNA-DNA relatedness values than did 16S rRNA gene sequence similarities. Additionally, dnaJ sequence analysis, with interspecies divergence over 5.2 % in most cases, gave better resolution than 16S rRNA gene sequences for the differentiation of strains at the species level. Relationships among Aeromonas species were therefore elucidated on the basis of dnaJ sequences and DNA-DNA reassociation. Strains of Aeromonas encheleia and Aeromonas sp. HG11 were unquestionably grouped in the same genetic species, since they shared 98.7 % dnaJ sequence similarity and 82-85 % genomic relatedness. The phylogenetically close relationships obtained from dnaJ sequence analysis (1.7-3.3 % genetic distance) were corroborated by high DNA-DNA relatedness (73-97 %) to support the previous suggestion that Aeromonas culicicola and Aeromonas allosaccharophila are later heterotypic synonyms of Aeromonas veronii. Our findings will contribute to the clarification of controversial relationships in the genus Aeromonas and also demonstrate that analysis of dnaJ sequences can be a powerful tool for interspecies study of the genus.
Nhung
Pham Hong
PH
Department of Microbiology, Regeneration and Advanced Medical Science, Gifu University Graduate School of Medicine, 1-1 Yanagido, Gifu 501-1194, Japan.
Hata
Hiroyuki
H
Department of Microbiology, Regeneration and Advanced Medical Science, Gifu University Graduate School of Medicine, 1-1 Yanagido, Gifu 501-1194, Japan.
Ohkusu
Kiyofumi
K
Department of Microbiology, Regeneration and Advanced Medical Science, Gifu University Graduate School of Medicine, 1-1 Yanagido, Gifu 501-1194, Japan.
Noda
Makiko
M
Department of Microbiology, Regeneration and Advanced Medical Science, Gifu University Graduate School of Medicine, 1-1 Yanagido, Gifu 501-1194, Japan.
Shah
Mohammad Monir
MM
Department of Microbiology, Regeneration and Advanced Medical Science, Gifu University Graduate School of Medicine, 1-1 Yanagido, Gifu 501-1194, Japan.
Goto
Keiichi
K
Food Research Laboratories, Mitsui Norin Co. Ltd, 223-1 Miyahara, Fujieda, Shizuoka 426-0133, Japan.
Ezaki
Takayuki
T
Department of Microbiology, Regeneration and Advanced Medical Science, Gifu University Graduate School of Medicine, 1-1 Yanagido, Gifu 501-1194, Japan.
D000333:Aeromonas / Q000145:classification* / Q000235:genetics*; D001426:Bacterial Proteins / Q000235:genetics*; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D050956:HSP40 Heat-Shock Proteins / Q000235:genetics*; D008969:Molecular Sequence Data; D009693:Nucleic Acid Hybridization; D010802:Phylogeny; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid
D001426:Bacterial Proteins; D004269:DNA, Bacterial; D050956:HSP40 Heat-Shock Proteins