A novel pathogen from Asian pears (Pyrus pyrifolia Nakai) was analysed by sequencing the 16S rDNA and the adjacent intergenic region, and the data were compared to related Enterobacteriaceae. The 16S rDNA of the Asian pear pathogen was almost identical with the sequence of Erwinia amylovora, in contrast to the 16S–23S rRNA intergenic transcribed spacer region of both species. A dendrogram was deduced from determined sequences of the spacer regions including those of several related species such as Erwinia amylovora, Enterobacter pyrinus, Pantoea stewartii subsp. stewartii and Escherichia coli. Dendrograms derived from 121 biochemical characteristics including Biotype 100 data placed the Asian pear pathogen close to Erwinia amylovora and more distantly to other members of the species Erwinia and to the species Pantoea and Enterobacter. Another DNA relatedness study was performed by DNA hybridizations and estimation of ΔTm values. The Asian pear strains constituted a tight DNA hybridization group (89–100%) and were barely related to strains of Erwinia amylovora (40–50%) with a ΔTm in the range of 5·2–6·8. The G+C content of DNA from the novel pathogen is 52 mol %. Therefore, it is proposed that strains isolated from Asian pears constitute a new species and the name Erwinia pyrifoliae is suggested; the type strain is strain Ep16/96T (= CFBP 4172T = DSM 12163T).
BereswillS.,
PahlA.,
BellemannP.,
ZellerW.,
GeiderK.1992; Sensitive and species-specific detection of Erwinia amylovora by polymerase chain reaction-analysis. Appl Environ Microbiol 58:3522–3526
BereswillS.,
BugertP.,
BruchmullerI.,
GeiderK.1995; Identification of Erwinia amylovora by PCR with chromosomal DNA. Appl Environ Microbiol 61:2636–2642
BereswillS.,
JockS.,
BellemannP.,
GeiderK.1997; Identification of Erwinia amylovora by growth in the presence of copper sulfate and by capsule staining with lectin. Plant Dis 82:158–164
BrennerD. J.,
McWorterA. C.,
Leete KnutsonJ. K.,
SteigerwaltA. G.1982; Escherichia vulneris: a new species of Enterobacteriaceae associated with human wounds. J Clin Microbiol 15:1133–1140
CrosaJ. M.,
BrennerD. J.,
FalkowS.1973; Use of a single-strand-specific nuclease for analysis of bacterial and plasmid deoxyribonucleic acid homo- and heteroduplexes. J Bacteriol 115:904–911
FalkensteinH.,
BellemannP.,
WalterS.,
ZellerW.,
GeiderK.1988; Identification of Erwinia amylovora, the fireblight pathogen, by colony hybridization with DNA from plasmid pEA29. Appl Environ Microbiol 54:2798–2802
KwonS.-W.,
GoS.-J.,
KangH.-W.,
RyuJ.-C.,
JoJ.-K.1997; Phylogenetic analysis of Erwinia species based on 16S rRNA gene sequences. Int J Syst Bacteriol 47:1061–1067