Open AccessClassification of Citrobacteria by DNA Hybridization: Designation of Citrobacter farmeri sp. nov., Citrobacter youngae sp. nov., Citrobacter braakii sp. nov., Citrobacter werkmanii sp. nov., Citrobacter sedlakii sp. nov., and Three Unnamed Citrobacter Genomospecies
Author(s) -
Don J. Brenner,
Patrick A. D. Grimont,
Arnold G. Steigerwalt,
G R Fanning,
Elisabeth Ageron,
Conradine F. Riddle
Publication year - 1993
Publication title -
international journal of systematic bacteriology
Language(s) - English
Resource type - Journals
eISSN - 1070-6259
pISSN - 0020-7713
DOI - 10.1099/00207713-43-4-645
Subject(s) - citrobacter , citrobacter freundii , enterobacteriaceae , microbiology and biotechnology , biology , genetics , escherichia coli , gene
DNA relatedness studies (hydroxyapatite method) were done on 112 strains of citrobacteria. By using the recommended definition of a genomospecies 11 genomospecies were identified in the genus Citrobacter. These genomospecies were separable by their biochemical profiles. Citrobacter koseri (Citrobacter diversus) and Citrobacter amalonaticus proved to be homogeneous species, as previously described. C. amalonaticus biogroup 1, as described by Farmer et al. (J. Clin. Microbiol. 21:46-76, 1985), was shown to be a separate homogeneous species, which was named Citrobacter farmeri sp. nov. The Citrobacter freundii complex was quite heterogeneous. C. freundii sensu stricto, as represented by the type strain, contained only 9 of 66 strains in this complex. The remaining 57 strains were members of seven genomospecies. Genomospecies 5, containing 21 strains, was named Citrobacter youngae sp. nov. Genomospecies 6, containing 15 strains, was named Citrobacter braakii sp. nov. Genomospecies 7 and 8, each containing six strains, were named Citrobacter werkmanii sp. nov. and Citrobacter sedlakii sp. nov., respectively. Genomospecies 9, 10, and 11, each containing three strains, were not named.