Biochemical identification of Citrobacter species defined by DNA hybridization and description of Citrobacter gillenii sp nov (formerly Citrobacter genomospecies 10) and Citrobacter murliniae sp nov (formerly Citrobacter genomospecies 11)

Recent work describing six named species and two unnamed genomospecies with in Citrobacter has enlarged the genus to II species. DNA relatedness and ph enotypic tests were used to determine how well these species can be identif ied. One hundred thirty-six strains were identified to species level by DNA relatedness and then identified phenotypically in a blinded fashion. By us ing conventional tests, 119 of the 136 strains (88%) were correctly identif ied to species level. Three additional strains (2%) were identified as citr obacteria but were not identified to species level, and 14 strains (10%) we re misidentified as other Citrobacter species, Carbon source utilization te sts were used to identify 86 of the strains. Eighty-four strains (98%) were correctly identified, and two strains (2%) were misidentified as other Cit robacter species, Additional strains of Citrobacter genomospecies 10 and Ci trobacter genomospecies 11 were identified, allowing these species to be fo rmally named as Citrobacter gillenii sp, nov. and Citrobacter murliniae sp. nov., respectively.