Separation of Escherichia adecarboxylata from the "Erwinia herbicola-Enterobacter agglomerans" complex and from the other Enterobacteriaceae by nucleic acid and protein electrophoretic techniques

Abstract

The species Escherichia adecarboxylata was examined for DNA relatedness to the "Erwinia herbicola-Enterobacter agglomerans" complex and to other members of the family Enterobacteriaceae. DNA-DNA hybridizations (nitrocellulose filter method) showed that strains received as E. adecarboxylata were highly related to each other (73-100% homology). Three strains of E. agglomerans and one strain of E. herbicola showed, respectively, 77, 96, 97 and 92% relatedness with the labelled DNA of E. adecarboxylata. Two groups (E2 and E3) of "atypical coliforms" previously described by Gavini et al. (1983) showed high reassociation values (76-79% and 80-89%, respectively) with E. adecarboxylata. Most of these strains produced similar or nearly identical protein electrophoregrams. All these strains were therefore classified in E. adecarboxylata. This taxon yielded hybridization values lower than 53% with the previously described phenetic or genetic groups belonging to or related to the "herbicola-agglomerans" complex and values lower than 64% with 56 other species of the Enterobacteriaceae. It was concluded that E. adecarboxylata is a species different from E. agglomerans and the other species of the family Enterobacteriaceae. A new definition of the species E. adecarboxylata is presented.