- Volume 31, Issue 4, 1981

We characterized the superoxide dismutases of Neisseria ovis, Neisseria caviae, and Branhamella catarrhalis after electrophoresis. Comparisons of the metal contents (as determined by sensitivity to hydrogen peroxide) and the relative mobilities of the dismutases showed that the dismutases of all six isolates of B. catarrhalis were identical to each other and to the dismutase of N. ovis strain T2B. The dismutase of N. caviae was similar to the dismutases of the B. catarrhalis strains in that it also contained manganese. However, the dismutase of N. ovis strain NRL 30014 was more similar to the dismutases of 17 other Neisseria strains previously tested in that it appeared to contain iron instead of manganese.

We characterized 13 cultures of the enteric bacterium causing enteric septicemia of catfish by studying their biochemical reactions, deoxyribonucleic hybridizations, and deoxyribonucleic acid guanine-plus-cytosine contents. We confirmed that this bacterium is a new species, which is most closely related to Edwardsiella tarda of the family Enterobacteriaceae. Five strains of the bacterium causing enteric septicemia of catfish were 80% or more related to the type strain, SECFDL GA 77-52 (= CDC 1976-78 = ATCC 33202), in 60°C deoxyribonucleic acid homology reactions. Species level relatedness among the 13 strains which we studied was demonstrated by the more than 80% relatedness in 75°C reactions. The bacterium causing enteric septicemia of catfish was most closely related to E. tarda (56 to 62%) in 60°C reactions. The guanine-plus-cytosine was 53 mol%, as determined by buoyant density centrifugation. We propose the name Edwardsiella ictaluri sp. nov. for the bacterium causing enteric septicemia of catfish.

We studied the taxonomic interrelationships of 332 Yersinia strains by using a numerical analysis that was based on 46 cultural and biochemical characters and involved both a hierarchical clustering procedure and a principal components analysis. Yersinia pseudotuberculosis and Yersinia kristensenii were recognized as relatively distinct phenotypic clusters. Y. kristensenii was further distinguishable from the remaining taxa by antigenic and enterotoxigenic parameters. These results supported the suggestion that Y. kristensenii deserves species status. On the other hand, Yersinia enterocolitica sensu stricto, Yersinia frederiksenii, and Yersinia intermedia constituted a phenotypic continuum. Each of these three taxa prevailed in different parts of a heterogeneous cluster of strains that were connected by intermediate phenotypes. This pattern of overlapping phenotypes was supported further by antigenic properties, habitat preferences, and pathogenic characteristics. Thus, we failed to find a basis for separating Y. enterocolitica sensu stricto, Y. frederiksenii, and Y. intermedia on phenetic, ecological, or pathogenic grounds. We suggest that the taxonomic relationships among these nomenspecies may require further evaluation. Two phenetic clusters contained strains not ascribable to any presently defined species. One of these clusters consisted mainly of rhamnose-positive, sucose-negative strains and the other contained strains negative for sucrose or ornithine decarboxylase or both.

We investigated the relatedness of 24 named species belonging to 18 sporeforming genera of the order Actinomycetales with respect to deoxyribonucleic acid-deoxyribonucleic acid homology and ribosomal ribonucleic acid cistron similarity. A total of 21 of these species grouped in three deoxyribonucleic acid homology clusters in which the homology values ranged between 20 and 45%. The first cluster contained Actinoplanes, Ampullariella, Amorphosporangium, Micromonospora, and Dactylosporangium; the second cluster contained Streptosporangium, Planomonospora, and Planobispora; and the third cluster included Streptomyces, Chainia, Kitasatoa, Streptoverticillium, Microellobosporia, Ely-trosporangium, and Actinosporangium. The close molecular genetic relationship of the organisms in each cluster was supported by several physiological and biochemical properties of taxonomic value. The ribosomal ribonucleic acid cistron similarity data did not indicate that any two of these clusters were specifically related to each other. Microtetraspora viridis DSM 43175, Spirillospora albida DSM 43034, and Actinomadura madurae DSM 43067 grouped separately from all of the the other organisms investigated.

We compared 46 strains of gram-negative, asaccharolytic, rod-shaped bacteria which were isolated from humans with gingivitis, periodontal pockets, and lesions in alveolar bone with 10 reference strains of Eikenella corrodens, Vibrio succinogenes, Bacteroides ureolyticus, and species of Campylobacter. We divided these 56 strains into seven groups based on the guanine-plus-cytosine contents of their deoxyribonucleic acids, their deoxyribonucleic acid homologies, and cluster analyses of their phenotypic features. A total of 23 of the fresh isolates showed more than 90% similarity (Jaccard coefficient) with E. corrodens. Growth of the remaining 23 isolates was enhanced in. broth cultures by formate and fumarate. These isolates were not members of B. ureolyticus, V. succinogenes, or previously described species of Campylobacter, they constituted three distinct new species. We propose Bacteroides gracilis sp. nov. (type strain, ATCC 33236) as the name for seven isolates of slender, gram-negative, nonmotile, anaerobic, rod-shaped bacteria that corroded agar and had deoxyribonucleic acid guanine-plus-cytosine contents of 44 to 46 mol%. All of the remaining isolates were motile by means of a single polar flagellum. Ten anaerobic strains were similar to V. succinogenes in phenotypic characteristics and guanine-plus-cytosine contents. However, these strains were distinct from V. succinogenes on the basis of deoxyribonucleic acid homology results. We propose Wolinella as the name of a new genus to include anaerobic, asaccharolytic, rod-shaped bacteria with single polar flagella and deoxyribonucleic acid guanine-plus-cytosine contents of 42 to 49 mol%. Wolinella succinogenes (Wolin et al.) comb. nov. is designated the type species of the genus, and ATCC 29543 is the type strain of W. succinogenes. We propose Wolinella recta sp. nov. (type strain, ATCC 33238) as the name for nine of the strains that formed a related but distinct group. We propose Campylobacter concisus sp. nov. (type strain, ATCC 33237) as the name for the six isolates of noncorroding, microaerophilic, gram-negative, rod-shaped bacteria that have predominantly curved cells and deoxyribonucleic acid guanine-plus-cytosine contents of 34 to 38 mol%. The description of the genus Campylobacter is amended to include species with deoxyribonucleic acid guanine-plus-cytosine contents of 30 to 38 mol%.

Gram-negative, asaccharolytic, agar-corroding organisms were isolated from lesions of advanced destructive periodontal disease. We grouped 78 oral isolates and reference strains of Eikenella corrodens, Bacteroides ureolyticus, Wolinella succinogenes (Vibrio succinogenes), and Campylobacter spp. serologically by using the microagglutination technique. The four species of oral organisms (E. corrodens, Bacteroides gracilis, Wolinella recta, and Campylobacter concisus) were clearly differentiated from each other on the basis of agglutination with rabbit antisera produced against representative live organisms. Agglutination patterns showed both a lack of intergroup relatedness among the oral isolates and a lack of serological identity with the biochemically similar organisms W. succinogenes, B. ureolyticus, and Campylobacter species.

We studied the taxonomically relevant characteristics of a microaerophilic, chemoheterotrophic, magnetotactic, freshwater spirillum. Our results indicated that this organism represents a new bacterial species, which is most appropriately placed in the genus Aquaspirillum despite its microaerophilic nature and its lack of detectable catalase and oxidase activities. The name proposed for this new species is Aquaspirillum magnetotacticum, which reflects the remarkable magnetic responsiveness of this organism. The type strain is MS-1 (= ATCC 31632).

Spiroplasma strains 23-6 and 27-31 from flowers of Liriodendron tulipifera L. (tulip tree) were indistinguishable from one another but were distinct from Spiroplasma citri and from members of serogroups other than the serogroup which contains S. citri. These two strains shared close to 100% deoxyribonucleic acid homology with one another, but only low homology (< 5%) with S. citri and other Spiroplasma strains. The acrylamide gel electrophoretic patterns of the cellular proteins of strains 23-6 and 27-31 appeared to be identical to each other, but they were distinct from the patterns of S. citri and various other strains. On the basis of serological and biochemical characteristics, we propose that strains 23-6 and 27-31 belong to a new species, Spiroplasma floricola, with strain 23-6 (= ATCC 29989) as the type strain. This new species grew well at 30 and 37°C, in contrast to S. citri, which grows poorly if at all at 37°C. During log-phase growth in broth medium, S. floricola cells occurred as motile, helical, cell wallless filaments 0.15 to 0.2µm in diameter and 2 to about 5µm long. Classical “friedegg”Mycoplasma-type colonies were not observed on 1% agar medium. Instead, colonies had granular centers and diffuse borders and contained abundant, motile, helical cells. Growth was stimulated by cholesterol and inhibited by digitonin. Tests for catabolism of glucose, fructose, mannose, and arginine were positive. Tests for phosphatase activity were negative. The guanine-plus-cytosine contents of the deoxyribonucleic acids of strains 23-6 and 27-31 were close to 25 mol%.

Using transmission electron microscopy, we examined the ultrastructures of 13 isolates and 2 reference strains of Eikenella corrodens, 6 isolates of Bacteroides gracilis, 6 isolates of Wolinella recta, 5 isolates of Campylobacter concisus, 2 reference strains of Bacteroides ureolyticus, 2 reference strains of Campylobacter fetus, 2 reference strains of Campylobacter sputorum, and 1 reference strain (VPI 9584) that was originally identified as Vibrio succinogenes. All E. corrodens strains were nonflagellated rods that were ultrastructurally distinct from another group of nonflagellated rod-shaped bacteria (B. gracilis and B. ureolyticus). The cells of W. recta strains were short rods, each having a single polar flagellum and a characteristic outer membrane covered with a distinctive array of hexagonally packed macromolecular subunits. C. concisus, C. fetus, C. sputorum, and strain VPI 9584 formed a heterogeneous group of monoflagellated rod-shaped bacteria. All of the strains which we examined had cell wall structures compatible with the structures of gram-negative microorganisms. The morphological distinctions among species appeared to be helpful in the identification of similar isolates.

The name Clostridium aceticum Wieringa 1940 was omitted from the Approved Lists of Bacterial Names. The name is here revived and validly published as Clostridium aceticum sp. nov., nom. rev. in accordance with Rules 27 and 28a and Provisional Rules B2 and B3 of the International Code of Nomenclature of Bacteria. The type strain is DSM 1496.

The names Achromobacter Bergey et al. 1923 and Achromobacter xylosoxidans Yabuuchi and Ohyama 1971 were not included on the Approved Lists of Bacterial Names. The name Achromobacter xylosoxidans is here revived for the same organism to which the name was originally applied, and the new name Achromobacter is proposed for the genus in which this species is placed. A. xylosoxidans is the type species of Achromobacter, and ATCC 27061 is the type strain of A. xylosoxidans. The correct author citations for these names are Achromobacter Yabuuchi and Yano 1981 and A. xylosoxidans (ex Yabuuchi and Ohyama 1971) Yabuuchi and Yano 1981, or simply A. xylosoxidans Yabuuchi and Yano 1981.

The name Pseudomonas cepacia Burkholder was omitted from the Approved Lists of Bacterial Names and therefore lost standing in bacterial nomenclature. In this paper we revive this name; it is used for the same taxon to which it was originally applied by Burkholder. A description of the species and a comparison with other species of Pseudomonas ribonucleic acid homology group II are included. Since no type strain was chosen by Burkholder, strain ATCC 25416 is designated the type, following the suggestion of Ballard et al.