Biomedical subjects

Enevold Falsen

Publications and source records attributed to Enevold Falsen.

65 records · Page 4Linked to original sources

PubMed2003

Characterization of some actinomyces-like isolates from human clinical sources: description of Varibaculum cambriensis gen nov, sp nov.

Fifteen strains of an anaerobic, catalase-negative, gram-positive diphtheroid-shaped bacterium recovered from human sources were characterized by phenotypic and molecular chemical and molecular genetic methods. The unidentified bacterium showed some resemblance to Actinomyces species and related taxa, but biochemical testing, polyacrylamide gel electrophoresis analysis of whole-cell proteins, and amplified 16S ribosomal DNA restriction analysis indicated the strains were distinct from all currently named Actinomyces species and related taxa. Comparative 16S rRNA gene sequencing studies showed that the bacterium represents a hitherto-unknown phylogenetic line that is related to but distinct from Actinomyces, Actinobaculum, Arcanobacterium, and Mobiluncus: We propose, on the basis of phenotypic and phylogenetic evidence, that the unknown bacterium from human clinical specimens should be classified as a new genus and species, Varibaculum cambriensis gen. nov., sp. nov. The type strain of Varibaculum cambriensis sp. nov. is CCUG 44998(T) = CIP 107344(T).

Actinomycetaceae↗

PubMed2002

Dysgonomonas mossii sp. nov., from human sources.

Phenotypic and phylogenetic studies were performed on seven unidentified gram-negative, facultatively anaerobic, coccobacillus-shaped organisms isolated from human clinical specimens. Comparative 16S rRNA gene sequencing demonstrated that four of the strains corresponded to Dysgonomonas capnocytophagoides whereas the remaining three isolates represent a new sub-line within the genus Dysgonomonas, displaying greater than 5% sequence divergence with Dysgonomonas capnocytophagoides and Dysgonomonas gadei. The three novel isolates were readily distinguished from D.capnocytophagoides and D. gadei by biochemical tests. The DNA base composition of the novel species was consistent with its assignment to the genus Dysgonomonas. Based on phylogenetic and phenotypic evidence it is proposed that the unknown species, be classified as Dysgonomonas mossii sp. nov. The type strain of Dysgonomonas mossii is CCUG 43457T (= CIP 107079T).

Base Sequence↗

PubMed2002

Diversity of transconjugants that acquired plasmid pJP4 or pEMT1 after inoculation of a donor strain in the A- and B-horizon of an agricultural soil and description of Burkholderia hospita sp. nov. and Burkholderia terricola sp. nov.

We examined the diversity of transconjugants that acquired the catabolic plasmids pJP4 or pEMT1, which encode degradation of 2,4-dichlorophenoxyacetic acid (2,4-D), in microcosms with agricultural soil inoculated with a donor strain (Dejonghe, W., Goris, J., El Fantroussi, S., Höfte, M., De Vos, P., Verstraete, W., and Top, E. M. Appl. Environ. Microbiol. 2000, p. 3297-3304). Using repetitive element PCR fingerprinting, eight different rep-clusters and six separate isolates could be discriminated among 95 transconjugants tested. Representative isolates were identified using 16S rDNA sequencing, cellular fatty acid analysis, whole-cell protein analysis and/or DNA-DNA hybridisations. Plasmids pJP4 and pEMT1 appeared to have a similar transfer and expression range, and were preferably acquired and expressed in soil by indigenous representatives of Ralstonia and Burkholderia. Two rep-clusters were shown to represent novel Burkholderia species, for which the names Burkholderia hospita sp. nov. and Burkholderia terricola sp. nov. are proposed. When easily degradable carbon sources were added together with the plasmid-bearing donor strain, also a significant proportion of Stenotrophomonas maltophilia isolates were found. The transconjugant collections isolated from A- (0-30 cm depth) and B-horizon (30-60 cm depth) soil were similar, except for B. terricola transconjugants, which were only isolated from the B-horizon.

2,4-Dichlorophenoxyacetic Acid↗

PubMed2002

Isobaculum melis gen. nov., sp. nov., a Carnobacterium-like organism isolated from the intestine of a badger.

Phenotypic and phylogenetic studies were performed on a hitherto undescribed facultatively anaerobic, catalase-negative, gram-positive rod-shaped organism, strain M577-94T, isolated from the small intestine of a dead badger. It resembled carnobacteria in terms of its long-chain cellular fatty acid composition, but differed markedly from the latter in possessing a cell-wall murein based on L-lysine (type L-Lys-L-Thr-Gly). Comparative 16S rRNA gene sequencing showed that the unknown bacterium represents a new line closely related to, albeit distinct from, the genera Carnobacterium and Desemzia. On the basis of phylogenetic and phenotypic evidence, it is proposed that strain M577-94T be classified as Isobaculum melis gen. nov., sp. nov. The type strain of Isobaculum melis is CCUG 37660T (= DSM 13760T).

Anaerobiosis↗

PubMed2002

Arthrobacter nasiphocae sp. nov., from the common seal (Phoca vitulina).

An unknown gram-positive, catalase-positive, strictly aerobic, rod-shaped bacterium was isolated from the nasal cavities of two common seals. Chemical analysis revealed the presence in the bacterium of a hitherto unknown cell-wall murein [type: L-Lys-L-Ala2-Gly(2-3)-L-Ala (Gly)]. Comparative 16S rRNA gene sequencing showed that the unidentified rod was related to the Arthrobacter group of organisms, although sequence divergence values of >3% from established members of this genus indicated that it represents a novel species. On the basis of phenotypic and phylogenetic considerations, it is proposed that the unknown bacterium from seals (Phoca vitulina) be classified as a novel species, Arthrobacter nasiphocae sp. nov. The type strain of Arthrobacter nasiphocae is CCUG 42953T.

Animals↗

PubMed2002

Arcanobacterium hippocoleae sp. nov., from the vagina of a horse.

A polyphasic taxonomic study was performed on a previously unidentified gram-positive, facultatively anaerobic, diphtheroid-shaped organism isolated from a vaginal discharge of a horse. Comparative 16S rRNA gene sequencing demonstrated that the strain was a member of the genus Arcanobacterium, but sequence divergence values of >4% with described species of this genus (viz: Arcanobacterium haemolyticum, Arcanobacterium bernardiae, Arcanobacterium phocae, Arcanobacterium pluranimalium and Arcanobacterium pyogenes) demonstrated that the isolate represented a novel species. The unknown bacterium was readily distinguished from other Arcanobacterium species by biochemical tests. Based on phylogenetic and phenotypic evidence, it is proposed that the unknown bacterium be classified as Arcanobacterium hippocoleae sp. nov. The type strain of A. hippocoleae is CCUG 44697T (= CIP 106850T).

Actinomycetaceae↗

PubMed2002

Bifidobacterium scardovii sp. nov., from human sources.

Five strains of an unusual catalase-negative Gram-positive asporogenous rod-shaped bacterium from human sources were subjected to a polyphasic taxonomic study. The presence of fructose-6-phosphate phosphoketolase, a key enzyme of bifidobacterial hexose metabolism, indicated the strains were members of the genus Bifidobacterium but they did not correspond to any of the recognized species of this genus on the basis of biochemical profiles and whole-cell protein analyses. Comparative 16S rRNA gene sequencing confirmed the placement of the isolates in the genus Bifidobacterium, and demonstrated they represent a hitherto unknown subline within the genus displaying > 5% sequence divergence with recognized species. Based on both phenotypic and phylogenetic criteria, it is proposed that the isolates recovered from human sources be classified as a new species, Bifidobacterium scardovii sp. nov.; the type strain is CCUG 13008T (= DSM 13734T).

Adult↗

PubMed2002

Streptococcus gallinaceus sp. nov., from chickens.

Three isolates of an unknown Gram-positive, catalase-negative, chain-forming, coccus-shaped organism isolated from an outbreak of septicaemia in a flock of adult broiler parents were characterized by phenotypic and molecular taxonomic methods. Comparative 16S rRNA gene sequencing studies demonstrated that the bacterium represents a new subline within the genus Streptococcus, related to, albeit distinct from, Streptococcus acidominimus, Streptococcus ovis, Streptococcus suis and close relatives. The unknown bacterium was readily distinguished from all recognized streptococcal species by biochemical tests. Based on phylogenetic and phenotypic evidence, it is proposed that the unknown bacterium from chickens be classified as Streptococcus gallinaceus sp. nov. The type strain is CCUG 42692T (= CIP 107087T).

Animals↗

PubMed2002

Actinomyces coleocanis sp. nov., from the vagina of a dog.

A hitherto undescribed Actinomyces-like bacterium was isolated from the vagina of a dog. Biochemical testing and PAGE analysis of whole-cell proteins indicated that the isolate was phenotypically different from previously described Actinomyces species and related taxa. Sequencing of 165 rRNA showed that the unknown bacterium was distinct from all currently known Actinomyces species. Phylogenetically, the unidentified organism displayed a specific association with Actinomyces europaeus, but a sequence divergence of > 5% demonstrated that it represents a distinct species. Based on both phenotypic and 165 rRNA sequence considerations, it is proposed that the unknown strain from a dog be classified as a novel species, Actinomyces coleocanis sp. nov. The type strain is CCUG 41708T (= CIP 106873T).

Actinomyces↗

PubMed2002

Actinomyces cardiffensis sp. nov. from human clinical sources.

Eight strains of a previously undescribed catalase-negative Actinomyces-like bacterium were recovered from human clinical specimens. The morphological and biochemical characteristics of the isolates were consistent with their assignment to the genus Actinomyces, but they did not appear to correspond to any recognized species. 16S rRNA gene sequence analysis showed the organisms represent a hitherto unknown species within the genus Actinomyces related to, albeit distinct from, a group of species which includes Actinomyces turicensis and close relatives. Based on biochemical and molecular genetic evidence, it is proposed that the unknown isolates from human clinical sources be classified as a new species, Actinomyces cardiffensis sp. nov. The type strain of Actinomyces cardiffensis is CCUG 44997(T).

Actinomyces↗

PubMed1998

Whole cell protein and partial 16S rRNA gene sequence analysis suggest the existence of a second Rothia species.

OBJECTIVE: To subject ten clinical isolates grouped together based on their biochemical and microbiological profile to further investigations aimed at correct species identification. METHODS: The 16S rRNA gene was partially sequenced using nested amplification. Whole cell protein analysis (SDS-PAGE) and cluster analysis were performed on the 10 strains and also for comparison on 31 reference strains. The API Coryne biochemical kit as well as API 20 Strep were used for analysis of the phenotypic diversity of the strains by use of computerized numerical identification procedures. Antibiotic susceptibility testing was performed using a standardized disk diffusion test. RESULTS: The 265--556-bp-long 16S rRNA gene sequences of all 10 strains showed highest similarity to Rothia dentocariosa. Three strains showed complete identity between the sequences obtained and the sequence of the type strain of Rothia dentocariosa 16S rRNA gene (M59055), and the other seven ranged between 99.7% and 98.3% similarity. Detailed analysis of the sequences revealed a clustering of the strains into two groups. One group consisted of four isolates with the highest degrees of similarity with the reference strain (type I), while the members of another group (type II) showed differences in their nucleotide sequence at four distinct positions in the variable V7 region. T was replaced by C at position 597, C by T at position 608, T by C at position 610, and G by A at position 684 (position numbers according to reference sequence M59055, EMBL/GenBank). Whole cell protein analysis (SDS-PAGE) and cluster analysis also segregated the 10 Rothia dentocariosa strains into two different clusters, with one cluster containing all four strains belonging to 16S rRNA gene type I, and a second cluster containing all six strains belonging to 16S rRNA gene type II. CONCLUSIONS: Partial sequence data of the 16S rRNA gene as well as whole cell protein analysis showed a subdivision of the Rothia species into two groups, genomovar I (Rothia dentocariosa sensu stricto) and genomovar II, a possible new Rothia species.

Journal Article↗