Nutrient and environmental growth factors for eight small‐sized oral spirochetes

Fiehn, Nils‐Erik; Westergaard, Jytte

doi:10.1111/j.1600-0722.1986.tb01755.x

Cited by 12 publications

(23 citation statements)

References 26 publications

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“…and reference strains of T. socranskii and T. denticola were examined in the present study. By use of electron microscopy, it was previously documented that the 1:2:1 and 2:4:2 cultures are pure, as they only contain cells with either 1:2:1 or 2:4:2 endoflagella arrangements (8,10). As the examined cultures originate from a single colony grown on an agar plate after the spreading of a diluted culture, it is reasonable to assume that the final cultures originate from one cell.…”

Section: Discussionmentioning

confidence: 99%

Ribotyping on small‐sized spirochetes isolated from subgingival plaque

Fiehn

Bangsborg

Colding

1995

Oral Microbiology and Immunology

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In the present study DNA restriction patterns and corresponding ribotypes of 17 subgingival small-sized spirochetes (1:2:1 and 2:4:2 isolates), 2 Treponema socranskii strains and two Treponema denticola strains were examined. Purified chromosomal DNA was digested by BamHI, HindIII, PstI and ClaI. The DNA fragments were separated in a horizontal slab of 0.7% agarose containing ethidium bromide and transferred by nylon membranes. Hybridization was carried out with digoxigenin-labelled copy DNA of 16S and 23S ribosomal RNA from Escherichia coli. Depending on the restriction endonuclease used, up to 4 distinct bands were observed for the 2:4:2 isolates and the T. denticola strains. For each of the endonucleases used, identical band patterns were always observed for this group of isolates, and these patterns differed persistently from the T. denticola strains. For the 1:2:1 strains, up to 11 distinct bands were observed after digestion with HindIII, whereas a maximum of 6 bands were observed when PstI or ClaI was used. By using ClaI, the examined 1:2:1 isolates were separated into 8 groups, whereas PstI and HindIII separated these isolates into 5 groups. The ribotyping showed that the tested 1:2:1 spirochetes were more heterogeneous than the 2:4:2 spirochetes examined.

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Section: Discussionmentioning

confidence: 99%

Ribotyping on small‐sized spirochetes isolated from subgingival plaque

Fiehn

Bangsborg

Colding

1995

Oral Microbiology and Immunology

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“…Neither the OppA peptide nor the gene encoding it were detected in T. pectinovorum or T. socranskii. Interestingly, metabolic requirements of T. pectinovorum and T. socranskii are somewhat distinct from those of T. denticola and T. vincentii (26,28,53,69) and neither possesses the high levels of cell surface peptidase activity characteristic of T. denticola and T. vincentii (53,64). This suggests that OppA may be important for survival of T. denticola in the subgingival environment, perhaps functioning in the acquisition of peptide nutrients.…”

Section: Discussionmentioning

confidence: 99%

“…denticola derives energy primarily from anaerobic degradation of peptides and amino acids (63). Nutrient requirements of this organism are complex (71), and the mechanisms of nutrient uptake are not well understood (12,27,28,61). Peptide uptake requires specific systems for the binding and transport of substrates across the bacterial cell envelope.…”

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confidence: 99%

Identification of a Treponema denticola OppA Homologue That Binds Host Proteins Present in the Subgingival Environment

et al. 2000

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Proteins secreted or exported by Treponema denticola have been implicated as mediators of specific interactions between the spirochete and subgingival tissues in periodontal diseases. However, limited information is available on the ability of this peptidolytic organism to bind or transport soluble peptides present in the subgingival environment. A prominent 70-kDa protein was isolated from surface extracts of T. denticola ATCC 35405. A clone expressing a portion of the protein was identified in an Escherichia coli expression library of T. denticola DNA. DNA sequence analysis showed that the cloned gene encoded a peptide homologous to OppA, the solute binding protein of an ATP-binding cassette-type peptide transporter involved in peptide uptake and environmental signaling in a wide range of bacteria. Genes encoding OppB, -C, -D, and -F were identified directly downstream of oppA in T. denticola. OppA was present in representative strains of T. denticola and in Treponema vincentii but was not detected in Treponema pectinovorum or Treponema socranskii. Immunogold electron microscopy suggested that OppA was accessible to proteins at the surface of the spirochete. Native OppA bound soluble plasminogen and fibronectin but did not bind to immobilized substrates or epithelial cells. A T. denticola oppA mutant bound reduced amounts of soluble plasminogen, and plasminogen binding to the parent strain was inhibited by the lysine analog -aminocaproic acid. Binding of soluble host proteins by OppA may be important both for spirochete-host interactions in the subgingival environment and for uptake of peptide nutrients.Treponema denticola is recognized as one of several potential pathogens in acute and chronic forms of human periodontal disease (50,55,62), and closely related spirochetes have been identified in bovine digital dermatitis lesions (10). Likely virulence factors of oral spirochetes include the ability to attach to host tissue and other microorganisms, motility and chemotaxis, immunomodulation, production of toxic metabolic byproducts, and direct cytopathogenicity (reviewed in reference 22). In the case of periodontal diseases, bacterial factors that contribute to the overgrowth of subgingival microflora must also be considered as potential virulence factors. These could include, for instance, uptake systems for peptide nutrients present in a high concentration in the inflamed gingival sulcus. Characterization of these processes will aid in understanding the biology of this organism and may suggest targets for treatment or prophylaxis.T. denticola derives energy primarily from anaerobic degradation of peptides and amino acids (63). Nutrient requirements of this organism are complex (71), and the mechanisms of nutrient uptake are not well understood (12,27,28,61). Peptide uptake requires specific systems for the binding and transport of substrates across the bacterial cell envelope. Oligopeptide uptake systems, members of a superfamily of highly conserved ATP-binding cassette (ABC) transporters, have been described...

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“…nucleatum (Walker et al, 1979). The spirochetes were grown in enriched brain heart in-fusion (Difco) (Fiehn 1987, Fiehn & Westergaard 1986). The plates were incubated anaerobically (70% N2, 20% H2, 10"/, CO2) for 7 days, except the A. actinofnycetemcomitans-medmm which was incubated aerobically with 7.5%* CO2.…”

Section: Methodsmentioning

confidence: 99%

“…fluorescence in long-wave ultraviolet light and analyses by Api-Zym (Laughon et al 1982, Slots & Reynolds 1982. The spirochetes were characterized as previousiy described (Fiehn 1987, Fiehn & Westergaard 1986).…”

Section: Methodsmentioning

confidence: 99%

Development of resistance to metronidazole and minocycline in vitro

Larsen

Fiehn

1997

J Clinic Periodontology

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By local delivery of antibiotics to periodontal pockets, very high initial concentrations are often quickly succeeded by subinhibitory concentrations, which may facilitate development of bacterial resistance. The purpose of the present study was to investigate possible development of resistance in suspected periodontal pathogens after exposure to subinhibitory concentrations of metronidazole and minocycline. The minimal inhibitory concentration (MIC) of 18 reference strains and 12 clinical isolates was determined by a broth dilution method. Subsequently, all strains with MIC < 8 micrograms/ml were exposed to serial passage on plates containing subinhibitory and gradually increasing concentrations of antibiotics, until growth was inhibited. Initially, most strains were inhibited at < or = 0.250 microgram/ml of minocycline and < or = 0.5 microgram/ml of metronidazole, though A. actinomycetemcomitans was resistant to metronidazole. After growth at subinhibitory concentrations, 8 strains survived 1-2 x and 11 stains survived 8-32 x their initial MIC of metronidazole, growing at up to 8 micrograms/ml. All A. actinomycetemcomitans survived 8-64 x their initial MIC of minocycline, growing at > or = 2 micrograms/ml, while all other strains were inhibited at < or = 0.250 microgram/ml, corresponding to a 1-8 x increase in their initial MIC. Thus, development of resistance was observed for periodontal bacteria growing at up to 64 x their initial MIC, but the final level of resistance was moderate.

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Nutrient and environmental growth factors for eight small‐sized oral spirochetes

Cited by 12 publications

References 26 publications

Ribotyping on small‐sized spirochetes isolated from subgingival plaque

Ribotyping on small‐sized spirochetes isolated from subgingival plaque

Identification of a Treponema denticola OppA Homologue That Binds Host Proteins Present in the Subgingival Environment

Development of resistance to metronidazole and minocycline in vitro

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