Differentiation of the Oxytocum Group from Klebsiella by Deoxyribonucleic Acid-Deoxyribonucleic Acid Hybridization

Abstract

By deoxyribonucleic acid-deoxyribonucleic acid molecular hybridization, evidence was obtained that the bacteria of the Oxytocum group represent a distinct deoxyribonucleic acid homology group and are not indole-forming and gelatin-liquefying variants of Klebsiella aerogenes and Klebsiella pneumoniae (sensu lato), respectively, and not a subgroup within Klebsiella, as had been suggested previously. The establishment of a new, but presently unnamed, genus of Enterobacteriaceae, with one species, is proposed, represented by strain 497-2 of R. Hugh (ATCC 13182). Furthermore, none of a series of bacterial strains classified as Enterobacter, Hafnia, or Erwinia species was found to be related to Klebsiella or to the Oxytocum strains. The deoxyribonucleic acid reassociation values do not allow species differentiation within the true, indole-negative klebsiellae.