Actinomyces bowdenii sp. nov., isolated from canine and feline clinical specimens

Four strains of a previously undescribed Actinomyces-like bacterium were isolated from canine and feline clinical specimens. Phenotypic studies indicated the strains were members of the genus Actinomyces, and most closely resembled Actinomyces viscosus serotype I and Actinomyces slackii. Comparative 16S rRNA gene sequencing studies demonstrated the unknown bacterium constitutes a new subline within a group of Actinomyces species, which includes Actinomyces bovis, the type species of the genus. Based on phylogenetic and phenotypic evidence it is proposed that the unknown bacterium be classified as Actinomyces bowdenii sp. nov. The type strain of Actinomyces bowdenii is CCUG 37421T.

Characterization of a novel Atopobium isolate from the human vagina: description of Atopobium vaginae sp. nov

Phenotypic and phylogenetic studies were performed on a hitherto undescribed micro-organism isolated from the human vagina. Comparative 16S rRNA gene sequencing studies demonstrated that the unknown strain constituted a new subline within the genus Atopobium. The unknown bacterium was readily distinguished from other Atopobium species by biochemical tests and electrophoretic analysis of whole-cell proteins. Based on phylogenetic and phenotypic evidence, it is proposed that the unknown bacterium be classified as Atopobium vaginae sp. nov. The type strain of Atopobium vaginae is CCUG 38953T.

Brevibacterium avium sp. nov., isolated from poultry

Two strains of a Brevibacterium-like bacterium originating from bumble-foot lesions of domestic fowls were subjected to a polyphasic taxonomic study. The phenotypic characteristics of the bacterium were consistent with its assignment to the genus Brevibacterium although comparative 16S rRNA gene sequencing showed that the organism represents a distinct subline within the genus. Chromosomal DNA-DNA pairing studies confirmed that the unidentified bacterium was genomically distinct and worthy of separate species status. Based on the phenotypic and genotypic distinctiveness of the bacterium from poultry, a new species, Brevibacterium avium, is proposed. The type strain of Brevibacterium avium is NCIMB 703055T.

Cloning and analysis of the L-lactate utilization genes from Streptococcus iniae

The presence of lactate oxidase was examined in eight Streptococcus species and some related species of bacteria. A clone (pGR002) was isolated from a genomic library of Streptococcus iniae generated in Escherichia coli, containing a DNA fragment spanning two genes designated lctO and lctP. We show that these genes are likely to be involved in the L-lactic acid aerobic metabolism of this organism. This DNA fragment has been sequenced and characterized. A comparison of the deduced amino acid sequence of LctP protein demonstrated that the protein had significant homology with the L-lactate permeases of other bacteria. The amino acid sequence of the LctO protein of S. iniae also showed a strong homology to L-lactate oxidase from Aerococcus viridans and some NAD-independent lactate dehydrogenases, all belonging to the family of flavin mononucleotide-dependent alpha-hydroxyacid-oxidizing enzymes. Biochemical assays of the gene products confirm the identity of the genes from the isolated DNA fragment and reveal a possible role for the lactate oxidase from S. iniae. This lactate oxidase is discussed in relation to the growth of the organism in response to carbon source availability.

Characterization of a Gemella-like organism from the oral cavity of a dog: description of Gemella palaticanis sp. nov

A hitherto unknown Gram-positive, catalase-negative, facultatively anaerobic coccus isolated from a vesicle on the gum of a dog was characterized by phenotypic and molecular taxonomic methods. Comparative 16S rRNA gene sequencing studies demonstrated that the isolate represents a new subline within the genus Gemella. The unknown bacterium was readily distinguished from all currently described members of this genus, Gemella haemolysans, Gemella bergeri, Gemella morbillorum and Gemella sanguinis, by biochemical tests and electrophoretic analysis of whole-cell proteins. On the basis of phylogenetic and phenotypic evidence, it is proposed that the unknown bacterium be classified as Gemella palaticanis sp. nov. The type strain of Gemella palaticanis is CCUG 39489T.

Helcococcus ovis sp. nov., a gram-positive organism from sheep

Two strains of a hitherto undescribed Gram-positive, catalase-negative, facultatively anaerobic coccus isolated from sheep were characterized by phenotypic and molecular taxonomic methods. Comparative 16S rRNA gene sequencing studies demonstrated that the unknown strains were genealogically highly related and constitute a new line close to, but distinct from, Helcococcus kunzii. The unknown bacterium was readily distinguished from H. kunzii by biochemical tests and electrophoretic analysis of whole-cell proteins. Based on phylogenetic and phenotypic evidence, it is proposed that the unknown bacterium be classified as Helcococcus ovis sp. nov. The type strain of Helcococcus ovis is CCUG 37441T.

Dolosicoccus paucivorans gen. nov., sp. nov., isolated from human blood

Phenotypic and phylogenetic studies were performed on a hitherto undescribed Gram-positive, catalase-negative, chain-forming coccus isolated from human blood. Comparative 16S rRNA gene sequencing studies demonstrated that the unknown organism constitutes a new phylogenetic line, close to, but distinct from, Facklamia and Globicatella. The unknown bacterium was readily distinguished from currently recognized Facklamia species and Globicatella sanguinis by biochemical tests and electrophoretic analysis of whole-cell proteins. On the basis of phylogenetic and phenotypic evidence, it is proposed that the unknown bacterium be classified as Dolosicoccus paucivorans gen. nov., sp. nov. The type strain of Dolosicoccus paucivorans is CCUG 39307T.

Isolation of rifampin-resistant mutants of Listeria monocytogenes and their characterization by rpoB gene sequencing, temperature sensitivity for growth, and interaction with an epithelial cell line

The sequence of the rpoB gene from Listeria monocytogenes was determined. Rifampin-resistant (Rif(r)) mutants arising from L. monocytogenes cultures exposed to rifampin were isolated, and by partial sequencing of their rpoB genes, seven different point mutations affecting five different amino acids (473Asp-->Asn or Gly, 479Gly-->Asp, 483His-->Tyr or Leu, 528Ile-->Phe, and 530Ser-->Tyr), which led to MICs of 0.5 to 100 microg/ml for the organisms, were determined. These mutants showed various deficiencies for growth at 42 degrees C, with only one being comparable to the wild-type strain. The interaction of these Rif(r) mutants with human Caco-2 cells was examined by using an immunofluorescence technique. Three mutants failed to interact, while three showed a reduced interaction compared to that of the wild type. It is believed that these pleiotropic phenotypes have arisen as a result of mutations within the DNA-dependent RNA polymerase holoenzyme.

Teratogenic response to arsenite during neurulation: relative sensitivities of C57BL/6J and SWV/Fnn mice and impact of the splotch allele

Arsenic is an environmental contaminant that induces congenital malformations, primarily neural tube defects, in laboratory animals, and it may contribute to human birth defects. The acute doses of arsenicals required to elicit teratogenesis in outbred strains of mice, however, are orders of magnitude higher than those to which humans are exposed environmentally. In order to examine interactions between arsenite administration during neurulation and murine genotype, the present study compares two inbred mouse strains, establishes a teratogenic dose of arsenite, and evaluates the effect of the splotch mutation on arsenic-induced teratogenesis. SWV/Fnn or C57BL/6J females were injected intraperitoneally with sodium arsenite (10 mg/kg) on days 6.5, 7.0, 7.5, 8.0, 8.5, or 9.0 of gestation. A dose-response study was carried out in the C57BL/6J strain, and the effect of the splotch mutation, introduced via the male (C57BL/6J Sp/+), was assessed. Fetuses were examined for external, visceral, and skeletal malformations. Fetuses from crosses of C57BL/6J females with C57BL/6J Sp/+ males were genotyped by PCR. Ten-mg/kg sodium arsenite was teratogenic in nearly 50% of C57BL/6J fetuses, and the C57BL/6J strain was significantly more sensitive to arsenite-induced embryo-lethality and teratogenicity than the SWV/Fnn strain. The spectrum of malformations produced was dependent on the gestational time point of arsenite administration. Introduction of the splotch allele significantly increased neural tube defects and other specific malformations. This result demonstrates that a mutation in a single gene can increase sensitivity to arsenic-induced birth defects. This murine study examines the interaction between arsenite-induced teratogenicity and genotype.

Streptococcus pluranimalium sp. nov., from cattle and other animals

Strains from subclinical mastitis, from the genital tract and tonsils of cattle, from tonsils of a goat and a cat and from the crop and the respiratory tract of canaries were found to constitute a new streptococcal species, for which the name Streptococcus pluranimalium sp. nov. is proposed. Sequencing of 16S rRNA showed that Streptococcus thoraltensis and Streptococcus hyovaginalis were its closest known phylogenetic relatives. The new species showed some phenotypic resemblance to the poorly described species Streptococcus acidominimus, but whole-cell protein analysis and 16S rRNA sequencing revealed that the new species was only distantly related to the type strain of S. acidominimus. Identification of these bacteria, which showed heterogeneous biochemical reaction patterns, was most reliably made by whole-cell protein analysis. Nevertheless, a number of biochemical reactions can be used to differentiate S. pluranimalium from other animal streptococci. Strain LMG 14177T, isolated from mastitic milk of a dairy cow, was designated as the type strain of S. pluranimalium sp. nov.

16S rRNA gene sequence analysis of Photobacterium damselae and nested PCR method for rapid detection of the causative agent of fish pasteurellosis

The causative agent of fish pasteurellosis, the organism formerly known as Pasteurella piscicida, has been reclassified as Photobacterium damselae subsp. piscicida on the basis of 16S rRNA gene sequence comparisons and chromosomal DNA-DNA hybridization data; thus, this organism belongs to the same species as Photobacterium damselae subsp. damselae (formerly Vibrio damselae). Since reassignment of P. damselae subsp. piscicida was based on only two strains, one objective of the present work was to confirm the taxonomic position of this fish pathogen by sequencing the 16S rRNA genes of 26 strains having different geographic and host origins. In addition, a nested PCR protocol for detection of P. damselae based on 16S rRNA was developed. This PCR protocol was validated by testing 35 target and 24 nontarget pure cultures, and the detection limits obtained ranged from 1 pg to 10 fg of DNA (200 to 20 cells). A similar level of sensitivity was observed when the PCR protocol was applied to fish tissues spiked with bacteria. The PCR approach described in this paper allows detection of the pathogen in mixed plate cultures obtained from asymptomatic fish suspected to be carriers of P. damselae subsp. piscicida, in which growth of this bacterium cannot be visualized. Our results indicate that the selective primers which we designed represent a powerful tool for sensitive and specific detection of fish pasteurellosis.

An indigo-reducing moderate thermophile from a woad vat, Clostridium isatidis sp. nov

A Gram-positive, anaerobic, moderate thermophile, strain Wv6T, capable of reducing indigo dye, was isolated from a fermenting woad vat prepared essentially as in medieval Europe. Strain Wv6T formed rod-shaped cells, which occurred singly, in pairs or in chains and produced terminal oval endospores. Strain Wv6T was saccharolytic. Growth occurred at pH 5.9-9.9 (initial pH) with an optimum at 50 degrees C of pH 7.2 +/- 0.2 (constant pH). At pH 7.8, the temperature range for growth was 30-55 degrees C with the optimum at 49-52 degrees C. Comparative 16S rRNA gene sequence analysis demonstrated that the bacterium represents a hitherto unknown subline within rRNA cluster I Clostridium. Based on the results of the phylogenetic analysis and phenotypic criteria, it is proposed that the unknown moderate thermophile should be classified as Clostridium isatidis sp. nov., a new species of the genus Clostridium. The type strain of Clostridium isatidis is strain Wv6T (= NCFB 3071T).

Aerococcus christensenii sp. nov., from the human vagina

Phenotypic and phylogenetic studies were performed on two strains of a hitherto undescribed Aerococcus-like organism isolated from the human vagina. Comparative 16S rRNA gene sequencing studies demonstrated that the unknown strains constitute a new subline within the genus Aerococcus. The unknown bacterium was readily distinguished from the two currently recognized Aerococcus species, Aerococcus viridans and Aerococcus urinae, by biochemical tests and electrophoretic analysis of whole-cell proteins. On the basis of phylogenetic and phenotypic evidence, it is proposed that the unknown bacterium be classified as Aerococcus christensenii sp. nov. The type strain of A. christensenii is CCUG 28831T.

Arthrobacter rhombi sp. nov., isolated from Greenland halibut (Reinhardtius hippoglossoides)

Two strains of a hitherto undescribed Gram-positive coryneform bacterium isolated from Greenland halibut (Reinhardtius hippoglossoides) were characterized by phenotypic and molecular taxonomic methods. Comparative 16S rRNA gene sequencing studies demonstrated that the unknown strains constitute a new line within the genus Arthrobacter. The nearest relatives of the bacterium from fish were members of the Arthrobacter nicotianael Arthrobacter sulfureus group. The unknown bacterium was readily distinguished from these species by phenotypic methods. Based on phylogenetic and phenotypic evidence, it is proposed that the unknown bacterium be classified as Arthrobacter rhombi sp. nov. The type strain of Arthrobacter rhombi is CCUG 38813T.

Facklamia tabacinasalis sp. nov., from powdered tobacco

An unknown Gram-positive, catalase-negative, facultatively anaerobic, coccus-shaped organism originating as a contaminant of snuff was characterized by phenotypic and molecular taxonomic methods. Comparative 16S rRNA gene sequencing studies demonstrated that the bacterium represents a new subline within the genus Facklamia. The unknown bacterium was readily distinguished from Facklamis hominis and Facklamia ignava by biochemical tests and electrophoretic analysis of whole-cell proteins. On the basis of phylogenetic and phenotypic evidence, it is proposed that the unknown bacterium be classified as Facklamia tabacinasalis sp. nov., the type strain of which is CCUG 30090T.

Vagococcus lutrae sp. nov., isolated from the common otter (Lutra lutra)

Phenotypic and phylogenetic studies were performed on an unknown Gram-positive catalase-negative coccus isolated from a common otter (Lutra lutra). Comparative 16S rRNA gene sequencing demonstrated that the unknown bacterium represents a new subline within the genus Vagococcus, close to, but distinct from, Vagococcus fluvialis and Vagococcus salmoninarum. The unknown bacterium was readily distinguished from the two currently recognized Vagococcus species by biochemical tests and electrophoretic analysis of whole-cell proteins. Based on phylogenetic and phenotypic evidence it is proposed that the unknown bacterium be classified as a new species, Vagococcus lutrae, the type strain of which is CCUG 39187T.

Differential sensitivity of the SWV and C57BL/6 mouse strains to the teratogenic action of single administrations of cadmium given throughout the period of anterior neuropore closure

When administered to mice during gestation, the heavy metal, cadmium, is known to induce malformations of the neural tube, craniofacial region, limbs, trunk, viscera, and axial skeleton that vary in scope and severity among inbred strains of mice. Two strains, C57BL/6 and SWV, were previously shown to differ in their susceptibility to exencephaly induced by many teratogenic treatments, including sodium 2-ethylhexanoate, hyperthermia, valproic acid, and carbon dioxide, with the SWV strain being consistently more sensitive than the C57BL/6 strain. These findings support the observation of Finnell et al. ([1988] Teratology 38:313-320) of shared hierarchies of relative susceptibility to exencephaly induced by biochemically distinct teratogens, and suggest that the SWV strain would also be more sensitive to exencephaly induced by cadmium. In the present study, pregnant mice from the two strains were exposed to single i.p. injections of cadmium chloride at 4 mg/kg-BW on day 6.5, 7.0, 7.5, 8.0, 8.5, or 9.0 of gestation. Fetuses were removed by cesarean section on day 18 of gestation and scored for malformations. The C57BL/6 strain was observed to be more sensitive than the SWV strain to the induction of exencephaly by cadmium on days 6.5, 7.0, and 8.0, with mean litter percentages of 3.6%, 88.3%, and 62.2%, respectively, compared to 0.0%, 4.1%, and 27.7% for the SWV strain. This finding provides evidence in contrast to the hypothesis of shared hierarchies of sensitivity to teratogen-induced exencephaly. Data on a number of other cadmium-induced malformations are also presented.

Teratology of retinoids

Either an excess or a deficiency of vitamin A and related compounds (retinoids) causes abnormal morphological development (teratogenesis). Potential retinoid sources come from dietary intake, nutritional supplements, and some therapeutic drugs. Therefore, understanding the mechanisms of retinoid teratogenesis is important. This review first gives an overview of the principles of teratology as they apply to retinoid-induced malformations. It then describes relevant aspects of the biochemical pathway and signal transduction of retinoids. The teratogenic activity of various retinoid compounds, the role of the retinoid receptors, and important toxicokinetic parameters in teratogenesis are reviewed.

Probiotics, prebiotics, and synbiotics: approaches for modulating the microbial ecology of the gut

The microbiota of the human large intestine influences health and well-being. Whereas it has long been accepted that gut bacteria play a role in host pathogenesis, current opinion is that certain microflora components can have beneficial effects on gastroenteritis resistance, blood lipids, antitumor properties, lactose tolerance, and gastrointestinal immunity. It is postulated that in the infant gut an elevated bifidobacterial count may be associated with health advantages that breast-fed infants may have over formula-fed infants. Whereas beneficial aspects of the human gut flora still need definitive confirmation and mechanistic explanations, there is now interest in modulating the composition of gut flora such that a potentially more remedial community exists. This may be achieved through the targeted use of dietary supplementation. This article provides an overview of how probiotics, prebiotics, and synbiotics may contribute toward nutritional modulation of the gut microecology, with emphasis on the neonatal intestine where appropriate. The use of modern molecular methods, as an essential step forward for assessing the validity and accuracy of the modulatory approach, is also discussed.

Facklamia sourekii sp. nov., isolated from human sources

Two strains of a Gram-positive catalase-negative, facultatively anaerobic coccus originating from human sources were characterized by phenotypic and molecular taxonomic methods. The strains were found to be identical to each other based on 16S rRNA gene sequencing and constitute a new subline within the genus Facklamia. The unknown bacterium was readily distinguished from Facklamis hominis and Facklamia ignava by biochemical tests and electrophoretic analysis of whole-cell proteins. Based on phylogenetic and phenotypic evidence it is proposed that the unknown bacterium be classified as Facklamia sourekii sp. nov., the type strain of which is CCUG 28783AT.

Corynebacterium sundsvallense sp. nov., from human clinical specimens

Three strains of a previously undescribed catalase-positive non-lipophilic coryneform bacterium isolated from human clinical specimens were characterized by phenotypic and molecular taxonomic methods. Morphologically the unknown bacterium consisted of pleomorphic rods, some of which displayed bulges/knobs at their ends. All three strains were similar in that they produced acid from fructose, glucose, maltose and sucrose and were urease-positive. Chemotaxonomic investigations revealed the presence of meso-diaminopimelic acid and short-chain mycolic acids consistent with the genus Corynebacterium sensu stricto. Comparative 16S rRNA gene sequencing showed that the three strains are genealogically highly related and constitute a new subline within the genus Corynebacterium, displaying > 3% sequence divergence with recognized species. The unknown bacterium was distinguished from currently validly published Corynebacterium species by phenotypic tests, including electrophoretic analysis of whole-cell proteins. Based on phylogenetic and phenotypic evidence, it is proposed that the unknown bacterium from clinical specimens be classified as Corynebacterium sundsvallense sp. nov. The type strain is CCUG 36622T.

Abiotrophia balaenopterae sp. nov., isolated from the minke whale (Balaenoptera acutorostrata)

Phenotypic and phylogenetic studies were performed on a hitherto undescribed micro-organism isolated from a minke whale (Balaenoptera acutorostrata). Comparative 16S rRNA gene sequencing studies demonstrated that the unknown strain constituted a new subline close to, but distinct from, Abiotrophia adiacens and Abiotrophia elegans. The unknown bacterium was readily distinguished from these two Abiotrophia species by biochemical tests and electrophoretic analysis of whole-cell proteins. On the basis of phylogenetic and phenotypic evidence, it is proposed that the unknown bacterium be classified as Abiotrophia balaenopterae sp. nov., the type strain of which is M1975/96/1T (= CCUG 37380T).

Facklamia languida sp. nov., isolated from human clinical specimens

Three strains of a gram-positive catalase-negative, facultatively anaerobic coccus-shaped organism originating from human clinical samples were characterized by phenotypic and molecular taxonomic methods. Sequencing of genes encoding 16S rRNA showed that the strains are phylogenetically closely related (99.9 to 100% sequence similarity) and represent a new subline within the genus Facklamia. The unknown bacterium was readily distinguished from all currently described species of the genus Facklamia (viz., Facklamia hominis, Facklamia ignava, and Facklamia sourekii) by biochemical tests and electrophoretic analysis of whole-cell proteins. Based on phylogenetic and phenotypic evidence, it is proposed that the unknown bacterium be classified as Facklamia languida sp. nov. The type strain of F. languida is CCUG 37842.

Phenotypic and phylogenetic characterization of a novel Lactobacillus species from human sources: description of Lactobacillus iners sp. nov

Eleven strains of a hitherto undescribed Gram-positive, catalase-negative, facultatively anaerobic rod-shaped bacterium from human sources and medical care products were characterized by phenotypic and molecular taxonomic methods. The phenotypic properties of the bacterium were consistent with its assignment to the genus Lactobacillus but it was readily distinguished from all currently described species of this genus by its biochemical characteristics and by SDS-PAGE analysis of its cellular proteins. Comparative 16S rRNA gene sequence analysis demonstrated that the unknown bacterium was a member of rRNA group I Lactobacillus which includes Lactobacillus delbrueckii, the type species of the genus, and close relatives. Lactobacillus gasseri and Lactobacillus johnsonii were the nearest phylogenetic relatives of the unknown bacterium, but 16S rRNA sequence divergence values of > 4% clearly showed that it represents a distinct species. Based on both phylogenetic and phenotypic evidence, it is proposed that the unknown bacterium should be classified in the genus Lactobacillus, as Lactobacillus iners sp. nov. The type strain of Lactobacillus iners is CCUG 28746T.