INTERNATIONAL JOURNAL OF SYSTEMATIC BACTERIOLOGY, Jan. 1994, p. 2437 Copyright zyxwvutsrqpo 0 1994, International Union of Microbiological Societies 0020-7713/94/$04.00+0 Vol. 44, No. 1 z Ornithobacterium zyxwv rhinotracheale gen. nov., sp. nov. Isolated from the Avian Respiratory Tract P. VANDAMME,l* P. SEGERS,l M. VANCANNEYT,l K. VAN HOVE,l R. MUTTERS,2 J. HOMMEZ,3 F. DEWHIRST,4 B. PASTER,4 K. KERSTERS,l E. FALSEN,’ L. A. DEVRIESE,6 M. BISGAARD,7 K.-H. zyxwvu HINZ,8 AND W. MA”HEIM2 La boratorium voor Microbiologie, Faculteit Wetenschappen, and Laboratorium voor Bacteriologie, Faculteit Diergeneeskunde, University of Ghent, B-9000 Ghent, Belgium; Klinikum der Philipps- Universitat Marburg, Marbuv, Germany,; Provinciaal Verbond voor Dierenziektenbestnyding, Torhout, Belgium3;Department of Molecular Genetics, Forsyth Dental Center, Boston, Massachusetts 021 1 zyxw j4; Culture Collection, Department zy of Clinical Bacteriology, University of Gotebolg, S-413 46 Goteborg, Sweden’; Royal Veterinary and Agncultural University and National VeterinaryLaboratory, Frederiksberg, Denmark7; and Klinik fur Geflugel der Tierantlichen Hochschule, Hannover, Germany’ The phylogenetic position and various genotypic, chemotaxonomic, and classical phenotypic characteristics of zyxwvutsr 21 gram-negative avian isolates were studied. These strains constitute a genotypically homogeneous taxon in rRNA superfamily V, as shown by DNA-rRNA hybridization data. Determination of the 16s rRNA sequence of this taxon revealed its detailed position within the “flavobacter” subgroup of the “flavobacter-bacteroides” phylum as described by Gherna and Woese (R. Gherna and C. R. Woese, Syst. Apple Microbiol. 15513-521, 1992). This new taxon is only distantly related to other members of the “flavobacter-bacteroides” phylum and is therefore given separate generic status. The DNA-DNA binding values for members of this taxon, for which we propose the name Ornithobacterium rhinotracheale, confirmed that all of the strains are highly interrelated (DNA-DNA binding values greater than 90% were measured). The G+C contents of members of this taxon are between 37 and 39 mol%, An analysis of the cellular proteins and fatty acids and classical phenotypic characteristics allowed us to distinguish 0. rhinotracheafe from phenotypically similar taxa, such as Riemrelliz anatipestiyer and Capnocytophaga species. The respiratory quinone content (menaquinone 7) and carbohydrate pattern of 0. rhinotracheale conform with the respiratory quinone contents and carbohydrate patterns of other members of rRNA superfamily V. In the past decade, we determined the protein and fatty acid profiles of a large number of avian isolates which could not be classified after primary identification tests were performed in veterinary laboratories. A total of 21 of these isolates had very similar profiles and differed clearly from all of the other strains investigated, including reference strains of well-known fowl pathogens. These 21 strains were iso- lated from the respiratory tracts of turkeys (10 strains), chickens (7 strains), rooks, (3 strains), and a partridge (1 strain). Clinical data were not available for all of these strains. However, most of the strains were associated with various respiratory tract infections, including tracheitis, pericarditis, sinusitis, airsacculitis, and pneumonia. Prelim- inary data on some of the chemotaxonomic characteristics of four strains have been described previously (36). We studied a wide range of taxonomic parameters, includ- ing genotypic, chemotaxonomic, and classical phenotypic parameters, in order to establish the phylogenetic affiliation and to comprehensively describe the new taxon, for which we propose the name Omithobacterium rhinotracheale. Special emphasis was given to the differentiation of 0. rhinotracheale, Riemerella anatipestifer, and Capnocytoph- aga species as these taxa share a number of phenotypic characteristics. zyxwvutsrq * Corresponding author. Mailing address: Laboratorium voor Microbiologie, Universiteit Gent, K. L. Ledeganckstraat 35, B-9000 Gent, Belgium. Phone: 32-9-2645114. Fax: 32-9-2645346. MATERIALS AND METHODS Isolation of 0. rhinotracheale strains. Samples were inocu- lated onto media routinely used in veterinary laboratories, such as blood agar (e.g., Columbia agar base [catalog no. CM331; Oxoid] supplemented with 5 or 7% defibrinated sheep blood) or chocolate agar. The inoculated plates were incubated at different temperatures under various atmo- spheric conditions. Bacterial strains and growth conditions. 0. rhinotracheale strains and Riemerella and Capnocytophaga reference strains were grown on Trypticase soy agar (catalog no. 11768; BBL, Becton Dickinson Microbiology Systems, Cockeysville, Md.) and were incubated at 36 to 37°C in a microaerobic atmosphere containing approximately 5% O , 3.5% CO,, 7.5% H,, and 84% N, unless indicated otherwise. The strains used and their sources are shown in Table 1. BacteriologicaI purity was checked by plating and exam- ining living cells, using phase-contrast microscopy and Gram-stained cells. For mass cultures, cells were grown in Roux flasks. PAGE of whole-cell proteins. 0. rhinotracheale, Riemer- ella, and Capnocytophaga strains were grown for 48 h on one to three petri dishes. Whole-cell protein extracts were prepared, and sodium dodecyl sulfate (SDS)-polyacrylamide gel electrophoresis (PAGE) was performed as described previously (54). Numerical analysis of the protein gel electropherograms. A densitometric analysis, normalization and interpolation of the protein profiles, and a numerical analysis were per- formed by using the GelCompar software package (Applied Maths, Kortrijk, Belgium) as described previously (45). 24