- Volume 33, Issue 1, 1983

A new species, Staphylococcus auricularis, was isolated from the human external ear (external auditory meatus) and is described here. This species can be distinguished from other staphylococci primarily on the basis of growth rate and colony morphology on agar, carbohydrate reaction pattern, cell wall composition, and deoxyribonucleic acid sequence relationships. The type strain of this species is ATCC 33753.

Deoxyribonucleic acid homology studies of 66 strains formerly classified as Bacteroides melaninogenicus subsp. intermedius showed two distinct groups with negligible intergroup homology. The larger group, with homology to the type strain of B. melaninogenicus subsp. intermedius, is designated Bacteroides intermedius, and the description of the taxon is emended. The other deoxyribonucleic acid homology group, which includes strains that differ from B. intermedius in not fermenting sucrose or producing indole, is designated Bacteroides corporis sp. nov.; ATCC 33547T (= VPI 9342) is the type strain. Strains of B. intermedius and B. corporis do not ferment lactose, as strains of B. melaninogenicus, Bacteroides loescheii, and Bacteroides denticola do. Strain ATCC 29147T is designated the type strain of Bacteroides levii sp. nov. This organism is a pigmenting bacteroides whose strains have been isolated from cattle and include the LEV strain (previously called B. melaninogenicus or “B. melaninogenicus subsp. levii”). Phenotypic characteristics useful in differentiating among nine species that formerly have been included in or identified as B. melaninogenicus are listed.

Isolates of Paracoccus denitrificans were obtained from various habitats by enrichment in a mineral medium, using molecular hydrogen as the hydrogen donor and nitrate as the hydrogen acceptor. A total of 11 strains were compared with the following three reference strains: P. denitrificans Stanier 381T (type strain) (= DSM 65T = ATCC 17741T), Morris (= DSM 413 = ATCC 19367), and Vogt (= DSM 415). A computer analysis based on 235 characters indicated that the strains clustered into subgroups. Deoxyribonucleic acid-deoxyribonucleic acid homology determinations confirmed this suggestion. A formal description of the species is presented, and the taxonomic position of P. denitrificans is discussed.

The taxonomy of the bacteria symbiotically associated with the insect-pathogenic nematodes Neoaplectana and Heterorhabditis was examined. The bacteria studied were isolated from 33 populations obtained from Australasia, Europe, and the United States. The symbionts of all species of Neoaplectana and Heterorhabditis examined were members of the genus Xenorhabdus, but they differed in several respects from the description of the genus Xenorhabdus, including the guanine-plus-cytosine content of the deoxyriboneucleic acid and the production of acid from carbohydrates. All bacteria isolated from Heterorhabditis spp. were identified as members of Xenorhabdus luminescens. The bacteria isolated from one Neoaplectana species were similar and were distinguishable from the bacteria isolated from other Neoaplectana species. The following three subspecies of Xenorhabdus nematophilus are proposed: Xenorhabdus nematophilus subsp. nematophilus (bacteria symbiotic with Neoaplectana feltiae [= Neoaplectana carpocapsae]; type strain ATCC 19061), Xenorhabdus nematophilus subsp. bovienii (bacteria symbiotic with Neoaplectana bibionis; type strain, UQM 2210T), and Xenorhabdus nematophilus subsp. poinarii (bacteria symbiotic with Neoaplectana glaseri; type strain, UQM 2216). These subspecies vary in host nematode, pigmentation, maximum temperature for growth, responses to tests for phenylalanine deaminase by secondary-form isolates and for lipase (Tween 80 test) and lecithinase by primary-form isolates, and coloration of primary-form isolates on MacConkey agar and media containing bromthymol blue.

The guanine-plus-cytosine (G+C) contents of 123 strains previously identified as Bacillus circulans Jordan 1890 were determined. Of the strains examined, only 18 had G+C contents of 37 to 41 mol%, a range that included the G+C content (38.1 mol%) of the type strain. A major portion of the strain (93 strains) had G+C contents in the range from 46 to 55 mol%. For seven strains the G+C contents ranged from 42 to 45 mol%, and for another small group of five strains the G+C contents ranged from 56 to 61 mol%. Deoxyribonucleic acid reassociation studies revealed that 10 of the 18 strains with G+C contents of 37 to 41 mol% were closedly related genetically to each other and to the type strain. This genetically related group was phenotypically quite homogeneous. Our results strongly suggested that most of the strains were misclassified as B. circulans. Consequently, the phenotypic heterogeneity of the species B. circulans Jordan 1890 was not due to inherent variability of genetically related strains, but to variability introduced by inclusion of genetically unrelated organisms.

The lipopolysaccharide (O-antigen) of the phototrophic bacterium Rhodocyclus purpureus Ames 6770T was isolated and chemically analyzed. Like the lipid A moiety of Rhodospirillum tenue lipopolysaccharide, the lipid A moiety of Rhodocyclus purpureus lipopolysaccharide contains arabinose, 4-amino-arabinose, glu-cosamine, glucosamine phosphate, and fatty acids. In addition, the fatty acid spectrum, which is comprised of β-C10OH, C14, and C16, is identical to the fatty acid spectrum of Rhodospirillum tenue lipid A. The polysaccharide moiety (degraded polysaccharide) of Rhodocyclus purpureus lipopolysaccharide contains rhamnose, mannose, glucose, galactosamine, and d-glycero-d-mannoheptose in addition to l-glycero-d-mannoheptose and 2-keto-3-deoxyoctonate. The data on lipopolysaccharide composition indicate that the taxonomic relationship between Rhodocyclus purpureus and Rhodospirillum tenue is closer than the relationship between Rhodocyclus purpureus and Rhodopseudomonas gelatinosa.

The genetic and phenotypic properties of 18 strains which were considered to be Bacteroides oralis or related organisms were examined. These strains were differentiated into several groups on the basis of deoxyribonucleic acid homology, physiological properties, guanine-plus-cytosine content of the deoxyribonucleic acid, and electrophoretic patterns of cell proteins. The groups were considered to constitute separate species. Strains of group I (strains VPI7570A, WAL 3030, and 1221) belonged to the newly described species Bacteroides denticola. Strain VPI 8906D (group II) has been designated a new species, Bacteroides buccalis, by Shah and Collins. Strain VPI D27B-24 (group III) is the type strain of B. oralis. However, the biological properties of none of the three groups described above fit the original description of B. oralis (Loesche et al. 1964). Strain VPI D22A-7T did not belong to any of the three groups but had phenotypic properties that matched the phenotypic properties given in the first description of B. oralis. We propose the name Bacteroides veroralis for this organism and have deposited strain VPI D22A-7 in the American Type Culture Collection (= ATCC 33779) as the type strain.

Ninety-eight Gluconobacter strains of various origins were examined by numerical analysis of 177 phenotypic features and by gel electrophoresis of soluble proteins. Gluconobacter was phenotypically quite different from Acetobacter and Frateuria. An extensive phenotypic description and a minimal description of the genus Gluconobacter are given. The genus Gluconobacter contained two groups, A and B, by both techniques. Phenons A and B could be differentiated only by the requirement for nicotinic acid and by their electrophoretic patterns. Protein electrophoresis showed clearly that Gluconobacter strains are genetically stable over several decades. The strains of all five subspecies of Gluconobacter oxydans cited in the Approved Lists of Bacterial Names (Skerman et al., Int. J. Syst. Bacteriol. 30:225–420, 1980) were distributed randomly over the phenotypic and electrophoretic clusters and subclusters, and the type strains of the subspecies all fell in phenon B. We conclude that the single species Gluconobacter oxydans should not be further divided into subspecies.

On the basis of increased fermentative ability when growth is stimulated by Tween 80, with the production of large amounts of lactic acid and only traces of acetic, succinic, or formic acid, it is proposed that Peptostreptococcus parvulus (Weinberg, Nativelle, and Prévot 1937) Smith 1957 be returned to the genus Streptococcus, where it was placed by the original authors. The description has been amended to reflect the increased biochemical activity of strains of this species when all media contain 0.02% Tween 80. The type strain of Streptococcus parvulus (Weinberg, Nativelle, and Prévot 1937) comb. nov., nom. rev. (VPI 0546) has been deposited in the American Type Culture Collection as ATCC 33793.

“Alcaligenes denitrificans” Leifson and Hugh 1954 was not included in the Approved Lists of Bacterial Names and hence has no standing in bacteriological nomenclature. However, Alcaligenes faecalis DSM 30026 (“A. denitrificans” Leifson and Hugh 1954, type strain) has a DNA base composition of 69.1 ± 0.3 mol% G+C, whereas A. faecalis DSM 30030 (type strain) and A. faecalis DSM 30033 (“A. odorans” type strain) have 57.6 ± 0.5 and 55.3 ± 0.8 mol% G+C, respectively. DNA hybridization revealed homologies of 27% between A. faecalis DSM 30026T and strain DSM 30030T, 26% between A. faecalis DSM 30026T and strain DSM 30033T, but 71% between strains DSM 30030T and DSM 30033T. A yellow fluorescent pigment in King medium B was produced by A. faecalis strains DSM 30030T and DSM 30033T but not by strain DSM 30026T. Only A. faecalis DSM 30026T was able to grow with nitrate or nitrite as sole source of nitrogen and to reduce nitrate to nitrite and gas. All three strains reduced nitrite to gas, but an additional nitrogen source, e.g., ammonium ion, was necessary for the growth of strains DSM 30030T and DSM 30033T. In mineral media, the nitrate reduction to nitrite and gas has been shown to be reproducible. Based on the differences among A. faecalis DSM 30026 and both A. faecalis DSM 30030T and DSM 30033T, the revival of the name Alcaligenes denitrificans is herein proposed.

During studies to serotype tick-borne rickettsiae from various areas in the United States, particularly those areas associated with the vectors of Rickettsia rickettsii, we obtained 263 isolates of a rickettsia whose prototype is referred to as strain 369-C. Although rickettsiae of the strain 369-C serotype are distinct from rickettsiae of other serotypes, as determined by cross-micro-immunofluorescence tests of mouse antisera, they do possess one or more antigens that react with convalescent sera from Rocky Mountain spotted fever, epidemic typhus, and murine typhus patients. Because strain 369-C-like isolates have been recovered from eight species of argasid and ixodid ticks from widely separated areas of the United States, we set out to characterize these organisms more precisely, particularly with regard to their relationships to rickettsiae of the spotted fever and typhus groups. The characteristics which we used included morphology as determined by light microscopy and electron microscopy; cytopathogenicity in Vero cell cultures; pathogenicity for embryonated chicken eggs, laboratory mice, guinea pigs, and voles; protein composition as determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis; and deoxyribonucleic acid base composition. Our results indicated that strain 369-C-like rickettsiae are significantly different phenotypically from rickettsiae of both the spotted fever and typhus groups. Furthermore, the guanine-plus-cytosine content of the deoxyribonucleic acid of strain 369-C (30 mol%) was not different from the guanine-plus-cytosine content of rickettsiae of the typhus group, but it was lower than the guanine-plus-cytosine content recorded by other workers for rickettsiae of the spotted fever group. We propose that this species be named Rickettsia beliti sp. nov., with strain RML 369-C as the type strain; all serologically related rickettsiae should henceforth be referred to as the R. beliti serogroup.

A new species of bacteria is described, for which we propose the name Micromonospora olivasterospora. This organism produces new aminoglycoside antibiotics (the fortimicin complex) and is characterized by its olive black spore layer, spores with blunt spiny surfaces, an olive green soluble pigment, and its carbon utilization pattern. The type strain of M. olivasterospora is MK70 (= ATCC 21819).

Mycoplasmas were isolated from the conjunctivas and nasopharynges of Chinese hamsters. Four clones obtained from three separate colonies were examined in detail. These clones were indistinguishable from each other and were serologically distinct from 67 recognized Mycoplasma spp. Strain CH (NCTC 10190) is designated the type strain of a new species, M. cricetuli. This is the only Mycoplasma species recorded from Chinese hamsters.

Leuconostoc mesenteroides (Tsenkovskii) van Tieghem 1878, Leuconostoc dextranicum (Beijerinck) Hucker and Pederson 1930, and Leuconostoc cremoris (Knudsen and Sørensen) Garvie 1960 belong to a single deoxyribonucleic acid homology group. These three organisms have similar lactate dehydrogenases and glucose-6-phosphate dehydrogenases. Because of these common properties, these organisms are here regarded as subspecies within a single species, Leuconostoc mesenteroides. The names of the subspecies are Leuconostoc mesenteroides subsp. mesenteroides, Leuconostoc mesenteroides subsp. dextranicum (Beijerinck) comb. nov., and Leuconostoc mesenteroides subsp. cremoris (Knudsen and Sørensen) comb. nov. The type strains of these subspecies are ATCC 8293, NCDO 529, and NCDO 543, respectively.

The guanine-plus-cytosine contents of Bacteroides putredinis and Bacteroides splanchnicus deoxyribonucleic acids were determined after the deoxyribonucleic acids were purified by gel chromatography. In addition, both species were tested for the production of phenylacetic acid. The guanine-plus-cytosine content of B. putredinis deoxyribonucleic acid was 50 to 52 mol%, and that of B. splanchnicus deoxyribonucleic acid was 38 to 40 mol%. Both species produced phenylacetic acid.