- Volume 31, Issue 1, 1981

Thirty-two gram-negative bacterial strains, most of which were yellow-pigmen ted and isolated from clinical sources, were compared with 17 culture collection strains representing 13 named strains of four Flavobacterium species and 4 unnamed strains of Flavobacterium species. Twenty-nine of the strains were originally received as or subsequently assigned to group IIk, biotype 2. All 49 strains were examined for 127 characteristics, including reactions to 58 enzyme tests (API ZYM system), and the data were analyzed by numerical taxonomic methods involving estimation of Gower’s general similarity coefficient and clustering by unweighted pair-group average linkage and single-linkage analyses. Twenty-eight of the group IIk, biotype 2, strains formed a single, well-defined cluster (92.0% similarity level). These 28 strains were aerobic, gram-negative, nonmotile, oxidative rods; the mean base composition of the deoxyribonucleic acids of 11 strains was 39.6 ±0.5 mol% guanine plus cytosine. Distinctive features of the 28 strains were the ability to produce acid from a range of carbohydrates and their resistance to antimicrobial agents. The 28 strains were classified in the genus Flavobacterium, but they could not be assigned to any previously defined species. Therefore a new species, with the name Flavobacterium multivorum, is proposed for these 28 strains; the type strain is B5533 (= NCTC 11343).

A deoxyribonucleic acid (DNA)-DNA hybridization study was carried out to determine the taxonomic position of a new group of enterobacters (group H3, Gavini et al. [Ann. Microbiol. (Inst. Pasteur) 127B:317-335, 1976]) previously studied by numerical taxonomy. The reassociation binding ratios with the group H3 strain ATCC 33072 ranged from 61 to 97%. With respect to DNA hybridization, this group, which represents a new species in the genus Enterobacter, Enterobacter amnigenus, is closely related (49 to 66%) to Enterobacter cloacae. A difference in genome size between E. amnigenus ATCC 33072 and E. cloacae Collection de l’Unité d’Écotoxicologie Microbienne (CUETM) 77-120 was observed after reciprocal binding: The genome of ATCC 33072 was 24% larger. E. amnigenus was defined from phenotypic and genetic data. The type strain of E. amnigenus is CUETM 77-118 (ATCC 33072).

Cultures of four species of Pseudomonas grown in a complex medium were shifted down to a minimal medium for assaying aminopeptidases and metabolic end products. Cultural conditions were further modified to include both agitation and stationary conditions. Growth rates were determined for each condition to obtain maximal cell yield. Cells were then harvested for intracellular aminopeptidase assay by fluorometric analysis of enzyme activity, and a gas-liquid chromatography analysis was made for extracellular metabolic end products. A high reproducibility was obtained from the aminopeptidase profiles of strains of Pseudomonas fluorescens, P. putida, P. stutzeri, and P. pickettii, including a control consisting of a blind test of previous isolates. The shift down to the minimal medium increased enzyme activity in each case and induced characteristic new peaks in most instances. Gas-liquid chromatography analysis was concentrated on short-chain volatile fatty acids no longer than seven carbons. Butyl ester derivatives were prepared to enhance separation and increase percent recovery of these volatile components. The resulting change in profiles under different physiological conditions indicates a new method for the possible identification of Pseudomonas species.

Several starch-hydrolyzing strains of Lactobacillus Beijerinck 1901 were isolated from cattle waste-corn fermentations. The isolates were facultatively anaerobic, gram-positive, nonmotile, nonsporeforming, rod-shaped organisms that grew singly and in short chains, produced lactic acid and small amounts of acetic acid but no gas from glucose, and did not exhibit oxidase-, catalase-, or nitrate-reducing activities. Growth occurred at 45°C but not at 15°C. dl-Lactic acid was synthesized from glucose. An extracellular amylolytic enzyme was formed. The organisms fermented amygdalin, cellobiose, esculin, fructose, galactose, glucose, maltose, mannose, salicin, starch, sucrose, and trehalose. Some strains fermented mannitol and lactose. Arabinose, gluconate, melezitose, melibiose, raffinose, rham-nose, ribose, and xylose were not fermented. The average guanine-plus-cytosine content of the deoxyribonucleic acid was 40.4 mol%. Reassociation values of 15% or less were obtained with the deoxyribonucleic acids of the starch hydrolyzers and those of the type strains of Lactobacillus acidophilus (Moro) Hansen and Mocquot 1970; Lactobacillus jensenii Gasser, Mandel, and Rogosa 1970; and Lactobacillus leichmanii (Henneberg) Bergey et al. 1923. The new species was differentiated from the three recognized species on the basis of starch fermentation, vitamin requirements, guanine-plus-cytosine contents, and stereoisomerism of lactic acid produced. It was concluded that these organisms represent strains of a hitherto unrecognized species for which the name Lactobacillus amylovorus is proposed. The type strain of L. amylovorus is NRRL B-4540.

Examination of three groups of catalase-positive campylobacters by phase-contrast microscopy showed significant differences in cell size between the groups. These differences were most striking when the spiral forms of the organisms were observed. Campylobacter jejuni consistently produced small, tightly coiled spirals with a mean wavelength and amplitude of 1.12 and 0.48 µm, respectively. Campylobacter fetus subsp. fetus produced intermediate-sized spirals (mean wavelength and amplitude of 1.80 and 0.55 µm, respectively); C. fetus subsp. venerealis produced the largest spirals (mean wavelength and amplitude of 2.43 and 0.73 µm, respectively). Organisms belonging to the different groups could be distinguished by a trained observer on the basis of size alone, without actual measurement. Two additional features which distinguish C. jejuni from C. fetus subsp. fetus and C. fetus subsp. venerealis are the tendencies of C. jejuni to swarm on moist agar plates and to undergo rapid coccal transformation in normal atmospheric air. These findings should help in clarifying the subdivision of catalase-positive campylobacters and in making a rapid presumptive species or subspecies identification.

Eight strains isolated from the hemolymph of moribund lobsters were classified in a new subspecies of Alcaligenes faecalis on the basis of a study of their phenotypic characteristics. The name Alcaligenes faecalis subsp. homari is proposed for this new subspecies, of which the type strain is L1 (= NCMB 2116 = ATCC 33127).

A study was made of the morphology, cell wall chemotype, and phage susceptibility of Actinoplanes armeniacus ATCC 15676, the type strain of the species (Kalakoutskii and Kusnetsov, Mikrobiologiya 33:553-560, 1964). The spore chains produced by A. armeniacus on its aerial mycelium are similar to those typical of streptomycetes. No spore vesicles (“sporangia” were observed. Whole-cell hydrolysates contained ll-diaminopimelic acid. Phage activity spectra showed extensive cross-reactions between streptomycetes and A. armeniacus ATCC 15676, whereas a phage propagated on this strain lysed a range of Streptomyces species. On the basis of these characteristics, the transfer of A. armeniacus Kalakoutskii and Kusnetsov to the genus Streptomyces is proposed as Streptomyces armeniacus (Kalakoutskii and Kusnetsov) comb. nov. The type strain of this taxon is ATCC 15676. An amended description of this species is given.

Recent evidence from both archaeology and biology suggests that the taxonomy of the human pathogenic treponemes may be more complex than previously thought. An alternative evolutionary tree for the treponematoses is suggested.

The elimination of the terms "gram positive, negative, and variable" and their replacement by the terms "Gram reaction positive, negative, and variable" and "Gram type positive, negative, and zero" are proposed. This action would permit a distinction between the reporting of the results of the Gram staining reaction and the placing of the bacteria into general taxonomic groups.

Deoxyribonucleic acid from Legionella pneumophila showed little or no relatedness to deoxyribonucleic acids from members of the families Cytophagaceae and "Pasteurellaceae" (not on Approved Lists of Bacterial Names [Skerman et al., ed., Int. J. Syst. Bacteriol 30:225"420, 1980]) or from Kingella kingae. These data support the recent recognition of L. pneumophila as a new species.

Deoxyribonucleic acid (DNA) was extracted and purified from three isolates of Filobasidiella neoformans, representing serotypes A and D, and from two isolates of Filobasidiella bacillispora, representing serotypes B and C. Portions of each DNA pool were labeled in vitro by nick translation. Thermal elution profiles were determined and were used to calculate the thermal elution midpoint temperature and moles percent guanine-plus-cytosine content for each DNA. The thermal elution midpoint temperatures of the five DNAs ranged from 91.3 to 92.9°C, and the corresponding estimated contents ranged from 53.4 to 57.2 mol%. Hybridizations were performed with all possible pairs of homologous and heterologous DNAs. The DNAs of serotypes A and D of F. neoformans demonstrated relatedness values of 87.7 to 93.5%. DNAs of serotypes B and C of F. bacillispora showed 88.5% relatedness. Hybridizations of DNAs of F. neoformans with those of F. bacillispora, however, yielded relatedness values of only 55.2 to 63%, indicating that these DNAs are significantly different. Moreover, thermal elution studies revealed substantial base mismatching in heteroduplexes formed between DNAs of F. neoformans and F. bacillispora. These data support previous conclusions suggesting that F. neoformans and F. bacillispora are closely related but different species.

It is proposed that Spirochaeta stenostrepta Zuelzer replace Spirochaeta plicatilis Ehrenberg as the type species of the genus Spirochaeta Ehrenberg.