Don J. Brenner

Characterization ofYersinia enterocolitica sensu stricto

The speciesYersinia enterocolitica is definedsensu stricto on the bases of biochemical and other phenotypic characteristics. Biochemically,Y. enterocolitica contains five major biotypes: 1 through 4 of Niléhn and of Wauters, and the trehalose-negative, metabolically inactive, socalled hare strains in biotype 5 of Niléhn and of Wauters, and biochemically atypical strains, including urease-negative, Simmons citrate-positive, and lactose-and raffinose-positive strains.Y. enterocolitica sensu stricto was distinguishable from the newly described speciesYersinia kristensenii by sucrose and Voges-Proskauer reactions (negative inY. kristensenii). These species were previously separated by DNA relatedness.Y. enterocolitica was also separable biochemically and by DNA relatedness from the two newly proposed rhamnose-positive species,Yersinia intermedia andYersinia frederiksenii. Strain 161(=CIP 80-27=ATCC 9610) is proposed as the neotype forY. enterocolitica.

Intra- and interspecies relatedness ofYersinia pestis by DNA hybridization and its relationship toYersinia pseudotuberculosis

The biochemical characteristics ofYersinia pestis are presented and compared with those ofY. pseudotuberculosis. Motility at 28°C, urease, fermentation of rhamnose, and growth rate on nutrient agar are the best means of separating these organisms. DNA hybridization studies demonstrated thatY. pestis strains are 90% or more interrelated and thatY. pestis andY. pseudotuberculosis are indistinguishable by DNA relatedness. On the basis of DNA data and biochemical and antigenic similarity, these organisms should be treated as two separate subspecies of the same species.Y. pseudotuberculosis was described beforeY. pestis and therefore has priority.Y. pseudotuberculosis subsp.pseudotuberculosis andY. pseudotuberculosis subsp.pestis are recommended as new designations forY. pseudotuberculosis andY. pestis. For medical purposes,Y. pestis andY. pseudotuberculosis can and should continue to be used.

Yersinia intermedia: A new species of enterobacteriaceae composed of rhamnose-positive, melibiose-positive, raffinose-positive strains (formerly calledYersinia enterocolitica orYersinia enterocolitica-like)

Yersinia intermedia sp. nov. is defined biochemically and genetically.Y. intermedia strains belong to a single DNA relatedness group that is separable fromY. enterocolitica, Y. frederiksenii, Y. kristensenii, andY. pseudotuberculosis. Y. intermedia is positive in reactions for melibiose, raffinose, α-methyl-d-glucoside, rhamnose, and usually Simmons citrate. It is metabolically more active at 22–28°C than at 35–37°C. These positive reactions serve to distinguishY. intermedia fromY. enterocolitica andY. kristensenii. Positive melibiose, raffinose, and α-methyl-d-glucoside reactions differentiateY. intermedia from the other new rhamnose-positive species,Y. frederiksenii. Y. intermedia is separated fromY. pseudotuberculosis by its positive reactions for sucrose, indole, cellobiose,i-inositol,d-sorbitol, α-methyl-d-glucoside, and ornithine decarboxylase.Yersinia biotype X2, an additional rhamnose-positive, sucrose-negative group, as yet not identified to a species, and X1, a sucrose- and ornithine decarboxylase-negativeYersinia biotype, do not belong toY. intermedia. Strain 3953 (=CIP 80-28=ATCC 29909=Bottone 48=Chester 48) is proposed as the type strain forY. intermedia.

Klebsiella planticola sp. nov.: A new species of enterobacteriaceae found primarily in nonclinical environments

The nameKlebsiella planticola sp. nov. is proposed for a group of organisms isolated primarily from botanical and daquatic environments. Both numerical and molecular taxonomy techniques show that the species belongs within the genusKlebsiella and that it is distinct from other described species of the genus. The new species has 3 biogroups.K. planticolla is phenotypically identical toK. pneumoniae in classical biochemical tests, but it is distinguishable fromK. pneumoniae based on its ability to grow at 10°C and its inability to produce gas from lactose at 44.5°C. Additional reactions that can be used in combination with the temperature criteria includel-sorbose fermentation and ability to utilize hydroxy-l-proline as a sole carbon source. Strain V-236 (ATCC 33531; CDC 4245-72) is the type strain of the new species.

Legionella bozemanii sp. nov. andLegionella dumoffii sp. nov.: Classification of two additional species ofLegionella associated with human pneumonia

Deoxyribonucleic acid (DNA) relatedness was used to distinguish strains ofLegionella-like organisms (LLO) fromLegionella pneumophila. Two of these LLO strains, WIGA and MI 15, showed sufficient DNA relatedness to one another to be classified in the same species. The nameLegionella bozemanii species nova is proposed for this new species. The type strain ofL. bozemanii is WIGA (=ATCC 33217) Two other LLO strains, NY 23 and Tex-KL, were shown to represent a new species. The nameLegionella dumoffii species nova is proposed for this species. The type strain ofL. dumoffii is NY 23 (=ATCC 33279). These two species joinL. pneumophila andL. micdadei in the genusLegionella.

Deoxyribonucleic acid relatedness inYersinia enterocolitica andYersinia enterocolitica-like organisms

Yersinia enterocolitica andY. enterocolitica-like strains were characterized by DNA relatedness. These strains formed four distinct DNA relatedness groups: (i) the 5 classical biotypes ofY. enterocolitica sensu stricto as designated by Wauters; (ii) strains that are rhamnose positive and also positive in tests for melibiose, α-methyl-d-glucoside, raffinose, and Simmons citrate; (iii) strains that are rhamnose positive but negative in tests for melibiose, α-methyl-d-glucoside, and raffinose; (iv) sucrose-negative, Voges-Proskauer-negative, trehalose-positive strains.

Lack of genetic relatedness betweenYersinia philomiragia (the “philomiragia” bacterium) andYersinia species

Four strains ofYersinia philomiragia were studied biochemically and genetically. They showed a high degree of phenotypic similarity and formed a homogenous DNA relatedness group. We could not demonstrate any significant DNA relatedness between this group and otherYersinia species, other Enterobacteriaceae, orPasteurella multocida. Y. philomiragia is phenotypically quite different from other yersiniae and Enterobacteriaceae. These DNA and phenotypic data indicate thatY. philomiragia is not a member of the genusYersinia or a member of the family Enterobacteriaceae. It is suggested that, pending further study, this organism be referred to as the “Philomiragia” bacterium.