Freie Universität Berlin
1.
Schlafer, Sebastian.
molecular epidemiology and spatial distribution in biofilms.
Degree: 2012, Freie Universität Berlin
URL: http://dx.doi.org/10.17169/refubium-12753 
Periodontitis is an inflammatory disease of bacterial aetiology that affects
all structures supporting and anchoring the tooth. In the adult population,
periodontitis represents the most frequent cause of tooth loss. The microflora
in periodontal lesions forms complex, structurally heterogeneous biofilms on
the root surface of affected teeth and comprises a multitude of fastidious and
as yet uncultured bacteria. Identification of these organisms was only made
possible by the advent of culture-independent DNA-based techniques. Filifactor
alocis is a fastidious, Gram-positive rod and was repeatedly detected in
patients suffering from chronic periodontitis (CP) and generalized aggressive
periodontitis (GAP) in recent years. For the first study of the present
dissertation, a species-specific oligonucleotide probe was designed, and dot
blot hybridizations were performed to determine the prevalence of F. alocis in
a total of 490 subgingival samples from GAP patients, CP patients and
periodontitis-resistant (PR) patients. Furthermore, fluorescence in situ
hybridization (FISH) and subsequent epifluorescence microscopy were used to
analyse the spatial distribution and structural arrangement of F. alocis in
subgingival biofilms from GAP patients. In the second study, identical methods
were employed to determine the prevalence of oral Selenomonas spp., regarded
as candidate periodontal pathogens by some authors, in 742 samples from GAP,
CP and PR patients. Moreover, the structural arrangement of these organisms in
GAP biofilms was studied. F. alocis proved to be an excellent marker organism
for periodontal disease. The species could be detected in the majority of CP
and GAP patients and had an extremely low prevalence in the PR group. The
microscopic analysis of subgingival biofilms from GAP patients suggested an
important role of F. alocis in the pathogenesis of periodontal disease. The
organism predominantly colonized the depth of periodontal pockets and
contributed to numerous bacterial formations that reflect a structural
organization of the biofilms. In contrast, the prevalence of Selenomonas spp.
was not correlated with periodontal disease. However, FISH and subsequent
microscopic analysis of GAP biofilms showed that, at least in some cases,
Selenomonas spp. appeared in large numbers and made a relevant contribution to
biofilm architecture. In the third study of the present work, biopsies from
digital dermatitis (DD) lesions, an ulcerative inflammatory bovine foot
disease, were analysed. With the help of FISH, Guggenheimella bovis, a Gram-
positive coccoid rod that is only seldom detected in DD-lesions, could be
visualized deep inside the tissue as a pioneer organism way ahead of the
advancing bacterial front. The present work clearly demonstrates the
advantages of a combined epidemiological and microscopic approach for the
study of polymicrobial biofilm diseases.
Advisors/Committee Members: [email protected] (contact), m (gender), PD Dr. med. Annette Moter (firstReferee), Prof. Dr. sc. med. Wolfgang Presber (furtherReferee), PD Dr. med. Dirk Theegarten (furtherReferee).Subjects/Keywords: Biofilm; digital dermatitis; dot blot hybridization; FISH; periodontitis; 600 Technik, Medizin, angewandte Wissenschaften::610 Medizin und Gesundheit
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APA (6th Edition):
Schlafer, S. (2012). molecular epidemiology and spatial distribution in biofilms. (Thesis). Freie Universität Berlin. Retrieved from http://dx.doi.org/10.17169/refubium-12753
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Schlafer, Sebastian. “molecular epidemiology and spatial distribution in biofilms.” 2012. Thesis, Freie Universität Berlin. Accessed December 06, 2019.
http://dx.doi.org/10.17169/refubium-12753.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Schlafer, Sebastian. “molecular epidemiology and spatial distribution in biofilms.” 2012. Web. 06 Dec 2019.
Vancouver:
Schlafer S. molecular epidemiology and spatial distribution in biofilms. [Internet] [Thesis]. Freie Universität Berlin; 2012. [cited 2019 Dec 06].
Available from: http://dx.doi.org/10.17169/refubium-12753.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Schlafer S. molecular epidemiology and spatial distribution in biofilms. [Thesis]. Freie Universität Berlin; 2012. Available from: http://dx.doi.org/10.17169/refubium-12753
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Freie Universität Berlin
2.
Pauli, Daniela.
Molecular characterization of glucosamine-6-phosphate deaminase (NAG1) from
Candida albicans.
Degree: 2006, Freie Universität Berlin
URL: http://dx.doi.org/10.17169/refubium-7051
The conversion of glucosamine-6-phosphate into fructose-6-phosphate catalyzed
by the enzyme glucosamine-6-phosphate deaminase (GNPDA) is an important step
in the N-acetyl-glucosamine (GlcNAc) and glucosamine (GlcN) catabolic pathway.
Normally, C. albicans strains are able to utilize these two aminosugars as the
sole carbone source. The work group of Tietz described morphologically
atypical C. albicans strains from Africa which seemed to be less virulent than
typical C. albicans strains from the same geographical area [Tietz et al.,
1995]. The objective of this study was to search for mutations in the NAG1
gene, which the GNPDA encodes, or for changes in the gene regulation that may
explain the inability of GlcNAc- and GlcN-negative strains to assimilate the
two amino sugars. The ability to induce GNPDA through GlcNAc is reduced in the
atypical strains. However, in all uninduced strains, typical and atypical, an
activity of GNPDA was detectable. Specific PCR primers, based on sequences of
the NAG1 gene published by Natarajan and Datta (1993), were designed for the
amplification of the NAG1 gene DNA and mRNA in various typical and atypical C.
albicans strains. The analysis of the gene-expression showed no significant
differences in the concentrations of mRNA in both populations (GlcNAc induced
and not induced). To test for sequence polymorphisms, the amplification
products were subjected to an sscp analysis. All GlcNAc- and GlcN-negative
strains with the exception of two strains had an identical but unique sscp
pattern, whereas all typical strains tested showed varying, almost individual
sscp patterns. Sequencing of the amplified NAG1 genes of GlcNAc- and GlcN-
negative strains did reveal three mutations in the amino acid sequence
compared to the gene amplified from typical strains, which could provoke a
change of conformation in the enzyme and therefore a reduced induction may be
the consequence.
Advisors/Committee Members: n (gender), Prof. Dr. sc. med. Wolfgang Presber (firstReferee), Prof. Dr. med. Reinhard Rüchel (furtherReferee), Prof. Dr. med. Michael Seyfarth (furtherReferee).Subjects/Keywords: <; i>; C. albicans<; /i>;
Record Details
Similar Records
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Record Details
Similar Records
Cite
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❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Pauli, D. (2006). Molecular characterization of glucosamine-6-phosphate deaminase (NAG1) from
Candida albicans. (Thesis). Freie Universität Berlin. Retrieved from http://dx.doi.org/10.17169/refubium-7051
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Pauli, Daniela. “Molecular characterization of glucosamine-6-phosphate deaminase (NAG1) from
Candida albicans.” 2006. Thesis, Freie Universität Berlin. Accessed December 06, 2019.
http://dx.doi.org/10.17169/refubium-7051.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Pauli, Daniela. “Molecular characterization of glucosamine-6-phosphate deaminase (NAG1) from
Candida albicans.” 2006. Web. 06 Dec 2019.
Vancouver:
Pauli D. Molecular characterization of glucosamine-6-phosphate deaminase (NAG1) from
Candida albicans. [Internet] [Thesis]. Freie Universität Berlin; 2006. [cited 2019 Dec 06].
Available from: http://dx.doi.org/10.17169/refubium-7051.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Pauli D. Molecular characterization of glucosamine-6-phosphate deaminase (NAG1) from
Candida albicans. [Thesis]. Freie Universität Berlin; 2006. Available from: http://dx.doi.org/10.17169/refubium-7051
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
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