Biomedical subjects

E Falsen

Publications and source records attributed to E Falsen.

At least 73 records · Page 4Linked to original sources

PubMed1998

Actinomyces naeslundii genospecies 1 and 2 express different binding specificities to N-acetyl-beta-D-galactosamine, whereas Actinomyces odontolyticus expresses a different binding specificity in colonizing the human mouth.

A total of 102 strains of Actinomyces were isolated from teeth, buccal mucosa and tongue in eight individuals. The isolates were characterized by multivariate statistical analyses of phenotypic characteristics, serotyping and binding to beta-linked galactosamine (N-acetyl-beta-D-galactosamine) and acidic proline-rich protein structures. Based on these characteristics, isolates were classified into three major groups: (i) Isolates of Actinomyces naeslundii genospecies 2 were the dominant species on teeth and buccal mucosa and bound commonly to N-acetyl-beta-D-galactosamine (63 of 63 isolates) and acidic proline-rich proteins (63 of 63 isolates), regardless of tissue origin. They all exhibited a N-acetyl-beta-D-galactosamine binding specificity signified by N-acetyl-beta-D-galactosamine-inhibitable coaggregation with the streptococcal strains LVG1, GVE1, 24892 and MPB1; (ii) Isolates of A. naeslundii genospecies 1 were prevalent on teeth in certain individuals and bound commonly to N-acetyl-beta-D-galactosamine (20 of 20 isolates), but less commonly to acidic proline-rich proteins (5 of 20 isolates). They all possessed another N-acetyl-beta-D-galactosamine specificity, i.e. N-acetyl-beta-D-galactosamine-inhibitable coaggregation with the same streptococcal strains except for strain MPB1; (iii) Isolates of Actinomyces odontolyticus, the dominant species on the tongue (17 of 19 isolates), bound commonly to unknown structures on streptococci (17 of 19 isolates) but rarely to N-acetyl-beta-D-galactosamine (2 of 19 isolates) or acidic proline-rich proteins (3 of 19 isolates). In conclusion, A. naeslundii genospecies 1 and 2 exhibit different patterns of N-acetyl-beta-D-galactosamine and acidic proline-rich protein specificities to colonize dental and buccal mucosa surfaces, whereas A. odontolyticus utilizes another specificity to colonize the tongue.

Acetylgalactosamine↗

PubMed1998

PCR for detection and identification of Abiotrophia spp.

Members of the genus Abiotrophia, formerly known as nutritionally variant streptococci, are important pathogens causing septicemia and endocarditis. Cultivation and biochemical differentiation of Abiotrophia spp. are often difficult. Based on 16S rRNA sequences, two PCR assays for detection and identification of Abiotrophia spp. were developed. The first PCR assay was positive for all Abiotrophia spp. Subsequently performed restriction fragment length polymorphism analysis allowed the verification of the PCR amplicons and the differentiation of the three species. The second PCR assay was positive only for A. elegans, the most fastidious species of Abiotrophia. Both PCR assays were shown to be specific and sensitive and should facilitate the identification of Abiotrophia spp.

Bacteremia↗

PubMed1998

Description of Gemella sanguinis sp. nov., isolated from human clinical specimens.

Six strains of a hitherto undescribed gram-positive, catalase-negative, facultatively anaerobic coccus isolated from human sources were characterized by phenotypic and molecular taxonomic methods. Comparative 16S rRNA gene sequencing studies demonstrated that the unknown strains were genealogically identical and constitute a new subline within the genus Gemella. The unknown bacterium was readily distinguished from Gemella haemolysans, Gemella bergeriae, and Gemella morbillorum 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 Gemella sanguinis sp. nov. The type strain is CCUG 37820(T).

DNA, Bacterial↗

PubMed1998

Gemella bergeriae sp. nov., isolated from human clinical specimens.

Six strains of a hitherto-undescribed gram-positive, catalase-negative, facultatively anaerobic coccus from human sources were characterized by phenotypic and molecular taxonomic methods. Comparative 16S rRNA gene sequencing studies demonstrated that the unknown strains are genealogically homogeneous and constitute a new subline within the genus Gemella. The unknown bacterium was readily distinguished from Gemella haemolysans, the type species of the genus Gemella, and from Gemella morbillorum 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 from clinical specimens be classified as Gemella bergeriae sp. nov. The type strain of G. bergeriae is CCUG 37817 (= strain 617-93).

DNA, Bacterial↗

PubMed1998

Characteristics of Arthrobacter cumminsii, the most frequently encountered Arthrobacter species in human clinical specimens.

During a 2-year period, 10 strains of Arthrobacter cumminsii were isolated in or received by a Swiss routine clinical bacteriology laboratory, and 5 further isolates were referred to a Swedish bacteriology reference center over a 5-year period, making A. cumminsii the most frequently encountered Arthrobacter species in these two laboratories. The present report outlines the clinical features of the 15 A. cumminsii strains and presents an extended biochemical characterization of this microorganism. A. cumminsii exhibits a unique cellular fatty acid pattern with the consistent presence of C14:0i and C14:0 fatty acids as well as relatively large amounts of C16:0i and C16:0 fatty acids usually not seen in other Arthrobacter spp. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis was found to be a useful tool for confirmation of the identification of A. cumminsii. The MICs of 39 antimicrobial agents were determined, and it was demonstrated that aminoglycosides and quinolones had only weak activities against A. cumminsii strains, in contrast to their activities against most other coryneform bacteria. As a result of the extended characterization of A. cumminsii, an emended description of this species is presented. Due to the lack of A. cumminsii in established identification systems, it is most likely that this species is underdiagnosed in many routine clinical bacteriology laboratories.

Actinomycetales Infections↗

PubMed1998

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

Two strains of a hitherto-undescribed gram-positive, catalase-negative coccus isolated from human sources were characterized by phenotypic and molecular taxonomic methods. Comparative 16S rRNA gene sequencing studies demonstrated that the unknown strains are genealogically identical and constitute a new line close to, but distinct from, Facklamia hominis. The unknown bacterium was readily distinguished from F. hominis 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 ignava sp. nov. The type strain of Facklamia ignava is CCUG 37419.

Aged↗

PubMed1997

Relationships among strains classified with the ruminant Pasteurella haemolytica-complex using quantitative evaluation of phenotypic data.

The phenotypic relationships among 246 trehalose-negative strains classified under the [Pasteurella] haemolytica-complex in ruminants were investigated by clustering and multidimensional ordinations based upon 79 phenotypic characters. A quantitative evaluation of phenotypic data using a 5-level scoring system is presented permitting a comprehensive utilization of the recorded phenotypic variation among the strains in the analyses. Clustering and ordination analyses display complementary aspects of data which has been clearly demonstrated in this investigation. The main clusters revealed by the numerical techniques could be related to distinctive phenotypic differences and showed an extensive correlation with the recognized biogroups. This classification was based only upon 4 characters (fermentation of L-arabinose, D-sorbitol, glucosides and ornithine decarboxylase). In contrast, there was no obvious interpretation of the clusters formed by using binary scores. Phenotypic subgroups within the recognized biogroups have been described as well as a new, related group of bacteria, tentatively named Bisgaard taxon 36. Quantitative interpretation of phenotypic data seems to represent a promising method for finding relations among affiliated strains of bacteria and to assist in forming hypotheses for subsequent genotypic investigations.

Animals↗

PubMed1997

Actinomyces europaeus sp. nov., isolated from human clinical specimens.

Ten strains of a hitherto undescribed catalase-negative, facultatively anaerobic, coryneform bacterium were isolated or collected by workers at three European clinical bacteriology laboratories or reference centers. These strains were isolated from humans, and most came from abscess material. Biochemical and chemotaxonomic characterization revealed that the strains belonged to the genus Actinomyces. The phenotypic features of the 10 strains were incompatible with the descriptions of the previously established Actinomyces species. A comparative 16S rRNA gene sequence analysis demonstrated that the previously undescribed strains constitute a new line in the genus Actinomyces. The name Actinomyces europaeus sp. nov. is proposed for these clinical isolates. The type strain is CCUG 32789A.

Actinomyces↗

PubMed1997

Phenotypic and phylogenetic characterization of some Globicatella-like organisms from human sources: description of Facklamia hominis gen. nov., sp. nov.

Six strains of a hitherto undescribed gram-positive, catalase-negative, facultatively anaerobic coccus from human sources were characterized by phenotypic and molecular taxonomic methods. Comparative 16S rRNA gene sequencing studies demonstrated that the unknown strains were genealogically homogeneous and constitute a new line closely related to, but distinct from, the genus Globicatella. The unknown bacterium was readily distinguished from Globicatella sanguis, the type species of the genus Globicatella, by the results of biochemical tests and an electrophoretic analysis of whole-cell proteins. Based on phylogenetic and phenotypic evidence, we propose that the unknown bacterium be classified as Facklamia hominis gen. nov., sp. nov. The type strain of Facklamia hominis is CCUG 36813.

Bacteria, Anaerobic↗

PubMed1997

Actinomyces graevenitzii sp. nov., isolated from human clinical specimens.

Four strains of a previously unknown, catalase-negative, facultatively anaerobic, gram-positive, rod-shaped organism originating from humans were characterized by biochemical, chemical, and molecular taxonomic methods. The four strains phenotypically closely resembled one another, and although they possessed characteristics consistent with membership in the genus Actinomyces, they differed from all previously recognized species of this genus. The results of comparative 16S rRNA gene sequencing studies demonstrated that the unknown human bacterium was phylogenetically a member of the genus Actinomyces. Within the genus Actinomyces, the unidentified bacterium formed a loose, but statistically significant, association with a subgroup which included Actinomyces bovis, the type species of the genus. 16S rRNA sequence divergence values of > 6%, however, unequivocally demonstrated that the unidentified bacterium represents a new subline of the genus Actinomyces. A new species, Actinomyces graevenitzii, is proposed for the four new isolates. The type strain of A. graevenitzii is CCUG 27294.

Actinomyces↗

PubMed1997

Characterization of some Actinomyces-like isolates from human clinical specimens: reclassification of Actinomyces suis (Soltys and Spratling) as Actinobaculum suis comb. nov. and description of Actinobaculum schaalii sp. nov.

Five strains of a hitherto unknown Actinomyces-like bacterium were isolated from human clinical sources, including blood cultures. Biochemical and chemotaxonomic characterization indicated that the strains were distinct from previously described Actinomyces and Arcanobacterium species. A comparative 16S rRNA gene sequence analysis demonstrated that the undescribed strains constitute a new subline within the Actinomyces-Arcanobacterium species complex. The closest known relative of the isolates was found to be Actinomyces suis, although a 16S rRNA sequence divergence value of approximately 6% clearly demonstrated that the unknown bacterium represents a distinct species. Based on the results of the present and earlier phylogenetic investigations, it is proposed that Actinomyces suis should be reclassified in a new genus, the genus Actinobaculum, as Actinobaculum suis comb. nov. In addition, a new species, Actinobaculum schaalii, is proposed for the Actinomyces-like bacterium from human sources. The type strain of Actinobaculum schaalii is CCUG 27420.

Actinomyces↗

PubMed1996

Polyphasic approach to the classification and identification of Gardnerella vaginalis and unidentified Gardnerella vaginalis-like coryneforms present in bacterial vaginosis.

A taxonomic study of Gardnerella vaginalis and G. vaginalis-like coryneforms was performed in order to clarify the phylogenetic affiliation of these organisms and to improve future identification. We examined 50 strains by performing whole-cell protein and fatty acid analyses, a 16S rRNA sequence analysis, and an extensive phenotypic characterization analysis. The results of both chemotaxonomic techniques which we used divided the organisms into two main clusters, and the 16S rRNA sequence analysis revealed that the clusters represent different genera, which were easily distinguished by the results of classical phenotypic tests. The cluster I strains were identified as G. vaginalis, which was shown to be a close relative of the genus Bifidobacterium. An improved description of G. vaginalis is presented. The cluster II strains belong to or are closely related to Actinomyces turicensis.

Bacterial Proteins↗

PubMed1996

Taxonomic study of lancefield streptococcal groups C, G, and L (Streptococcus dysgalactiae) and proposal of S. dysgalactiae subsp. equisimilis subsp. nov.

Streptococcus dysgalactiae consists of at least five distinct subgroups on the basis of serogroups, biotypes, and hosts. A chemotaxonomic and phenotypic examination of 80 S. dysgalactiae strains representing the known diversity within this species and 49 reference strains representing all members of the streptococcal pyogenic species group revealed two subpopulations of strains within S. dysgalactiae. The name S. dysgalactiae subsp. dysgalactiae is proposed for strains of animal origin. These strains belong to Lancefield serogroups C and L, are alpha-, beta-, or nonhemolytic, and do not exhibit streptokinase activity on human plasminogen or proteolytic activity on human fibrin. The name S. dysgalactiae subsp. equisimilis is proposed for human isolates. These strains belong to Lancefield serogroups C and G, are beta-hemolytic, and exhibit streptokinase activity on human plasminogen and proteolytic activity on human fibrin.

Animals↗

PubMed1996

Emended description of Herbaspirillum; inclusion of [Pseudomonas] rubrisubalbicans, a milk plant pathogen, as Herbaspirillum rubrisubalbicans comb. nov.; and classification of a group of clinical isolates (EF group 1) as Herbaspirillum species 3.

[Pseudomonas] rubrisubalbicans, a mild plant pathogen. Herbaspirillum seropedicae, and EF group 1 strains (clustered by an immunological method) were investigated by a polyphasic approach with DNA-rRNA and DNA-DNA hybridizations and auxanography on 147 substrates. Our results show that they all belong to the genus Herbaspirillum. In addition to H. seropedicae, two other species are described: Herbaspirillum rubrisubalbicans and a new unnamed species, Herbaspirillum species 3, containing mainly strains of clinical origin. The three species can be differentiated on the basis of their auxanographic features and DNA-DNA similarities. The type strain of H. rubrisubalbicans is NCPPB 1027 (=LMG 2286); representative strains of the third Herbaspirillum species are strains CCUG 189 (=LMG 5523), CCUG 10263 (=LMG 5934), and CCUG 11060 (=LMG 5321). It has been confirmed that H. rubrisubalbicans is an endophytic diazotroph. It colonizes the roots, the stems, and predominantly the leaves of sugarcane (Saccharum spp.), while Herbaspirillum seropedicae colonizes in large numbers many different species of the Gramineae. Both diazotrophic Herbaspirillum species could be differentiated with meso-erythritol and N-acetylglucosamine. Oligonucleotide probes based on partial sequences of the 23S rRNA of H. seropedicae and H. rubrisubalbicans (HS and HR probes, respectively), were constructed and used as diagnostic probes.

Base Sequence↗

PubMed1996

Bordetella trematum sp. nov., isolated from wounds and ear infections in humans, and reassessment of Alcaligenes denitrificans Rüger and Tan 1983.

Ten strains recognized on the basis of a computer-assisted numerical comparison of whole-cell protein patterns as members of a novel species belonging to the family Alcaligenaceae were examined by using an integrated phenotypic and genotypic approach. This species, for which we propose the name Bordetella trematum sp. nov., was more closely related to the type species of the genus Bordetella (Bordetella pertussis) than to the type species of the genus Alcaligenes (Alcaligenes faecalis) and had the general characteristics of members of this family (i.e., a DNA base ratio in the range from 57 to 70 mol%, a fatty acid profile characterized by high percentages of 16:0, 17:0 cyclo, and 14:0 3OH, nonsaccharolytic metabolism, and several classical biochemical characteristics, including aerobic and microaerobic growth, catalase activity, assimilation of citrate, an absence of anaerobic growth, and an absence of acetylmethylcarbinol and indole production, gelatin liquefaction, and esculin hydrolysis). A reevaluation of the criteria used to classify Alcaligenes denitrificans Rüger and Tan 1983 and Achromobacter xylosoxidans Yabuuchi and Ohyama 1971 as subspecies of Alcaligenes xylosoxidans and additional evidence provided in recent studies revealed that, consistent with present standards, it is appropriate to consider these two taxa distinct species of the genus Alcaligenes.

Alcaligenes↗

PubMed1996

Bacteria Are Omnipresent on Phanerochaete chrysosporium Burdsall.

Bacteria have been isolated from 10 different strains of Phanerochaete chrysosporium, a white rot fungus which degrades lignocellulosic materials. The investigations showed that one or more bacterial species were always associated with the fungus. Various attempts to eliminate the bacteria on the fungus were unsuccessful. Three different bacterial species were isolated and identified. One of these was Agrobacterium radiobacter, while another may represent a new taxon close to the genus Burkholderia. A third strain remains unidentified but is most probably a member of rRNA superfamily IV or the Woese (alpha) group. Besides P. chrysosporium, 23 other white rot fungi and 9 brown rot fungi were also investigated. None of these was associated with bacteria. The physiological significance of the association between the fungus and the bacteria remains to be elucidated.

Journal Article↗

PubMed1996

"Corynebacterium aquaticum" wound infection after high-pressure water injection into the foot.

The organisms presently named "Corynebacterium aquaticum" have their natural habitat in water and are increasingly often isolated in clinical specimens, but are very seldom the proven cause of infection. A case of a 24-year-old man with a "C aquaticum" wound infection secondary to a high-pressure water injection injury in the foot is described. Cefadroxil and cefuroxime were used for treatment.

Adult↗

PubMed1995

Cytotoxin production in 100 strains of Haemophilus ducreyi from different geographic locations.

One-hundred strains of Haemophilus ducreyi, representing isolates from different parts of the world, including the reference strains, were obtained from different collections and characterized with special reference to cytotoxin production in vitro. The cytotoxic activity on cultured epithelial cells (HEp-2) was examined with two methods. The activity in bacterial sonicates was tested on freshly trypsinated cells and strains manifesting little or no cytotoxic activity in sonicates were investigated using attached living bacteria on HEp-2 cell-monolayers. Sonicates from the majority of the H. ducreyi strains (89%) produced significant cytotoxic effects on HEp-2 cells. The reciprocal cytotoxic titers of the sonicates ranged from 2.4 x 10(2) to 5.3 x 10(5). Sonicates of 11 strains had low cytotoxic titers (< or = 1:3 to 1:81), eight of those originating from Asia and three from Africa. These 11 strains caused no damage to the cell monolayer, indicating that the 11 strains produce little or no cytotoxic activity in vitro. In summary, the majority of H. ducreyi isolates produce cytotoxic activity, which support the hypothesis that the cytotoxin may be an important virulence factor of this species.

Africa↗