A reconsideration of the taxonomic position of two bacterial strains isolated from flacherie-diseased silkworms in 1965.

Recent advances in bacterial characterization methodologies have made taxonomic categorization significantly more accurate. Here, we re-evaluated the position of bacterial strains (532 and 652) belonging to the genus Hafnia, isolated from flacherie-diseased silkworms in 1965. Phylogenetic analysis based on the 16S rRNA gene sequences of these strains suggests that they belong to genus Enterobacter. Using multilocus sequence analysis (MLSA), these strains were further classified to MLSA group A, which is a "core" group of Enterobacter containing E. cloacae (the type species of the genus). Although these strains were closely related to E. mori, E. tabaci, and E. asburiae, they also had other MLSA characteristics that distinguished them from these neighboring bacterial species. These data were supported by further biochemical analysis. Thus, it appears that the 532 and 652 strains isolated almost half a century ago belong to genus Enterobacter, and their unique characteristics strongly suggest that they are a novel bacterial species. [ABSTRACT FROM AUTHOR]