Publikationsserver der RWTH Aachen University
Nachweis von parodontopathogenen Bakterien mit Hilfe von Genchips
Abstract
dc:descriptionThe focus of this dissertation is the detection of periodontal pathogens by Genechips. The experiments were done with the ParoCheck® Kit 20. It is the first commercial, semi-quantitative DNA-Chip for the detection of periodontitis associated bacteria. The following bacteria can be detected by the ParoCheck® Kit 20: Actinobacillus actinomycetem comitans A.a., Actinomyces odontolyticus A.o., Bacteroides forsythus B.f. (synonym: Tannerella forsythensis, T.f.), Campylobacter concisus C.c, Campylobacter gracilis C.g., Campylobacter rectus C.r., Capnocytophaga gingivalis Cap.g., Eikenella corrodens E.c., Eubacterium nodatum E.n., Fusobacterium nucleatum F.n., Peptostreptococcus micros P.m., Porphyromonas gingivalis P.g., Prevotella intermedia P.i., Prevotella nigrescens P.n., Streptococcus constellatus S.c., Streptococcus gordonii S.g., Streptococcus mitis S.m., Treponema denticola T.d., Veillonella parvula V.p.. Ten samples from ten different patients with a chronic periodontitis were taken. Each patient was examined for a detailed anamnesis and a periodontal status. After taking the samples the DNA was extracted, amplified by PCR and finally hybridised on the Chips. Each sample was analysed with the older ParoChip® (ParoChip1) and also with the more modern version of the Chip (ParoChip2). Both Chips have a different configuration. ParoChip1 is a glass microscope slide which can hold only one single sample. For each bacteria there are three measuring points on the Chip. In contrast, the ParoChip2 is a plexiglass microscope slide which can hold 12 samples and has five measuring points for each bacteria. Both Chips used fluorophor marked primer for the PCR (cy5 marked) and fluorophor marked probes for internal control systems (cy3 marked). The Chips were scanned with the wavelength 532nm (cy3 marked) and 635nm (cy5 marked) by the Axon Scanner 4100A and analysed by the GenePix4.x software. The results of both Chips matched in 75% of the tests. The discrepancy between the Chips is likely due to the different surface chemistry and therefore the different SNR- (Signal-to-Noise-Ratio) thresholds. In single cases a different probesequence (with better specificity) may also be an explanation. In comparison with other methods of bacteria detection the GeneChip had clear advantages: The detection of 20 bacteria in one test, quick results and also the robust and semi-quantitative character. Additional microbiological and clinical studies are required, particularly for specificity, sensitivity and practicality of the method, however initial testing suggest that the ParoChip® Genechips could find a place in routine diagnostics.
Degree
thesis:*- Grantor dc:publisher
- Publikationsserver der RWTH Aachen University
- Year dc:date
- 2007
Author and committee
dc:creator, dc:contributor.*- Author dc:creator
-
- Schulthoff, Wiebke
- Contributors dc:contributor
-
- Conrads, Georg
Subjects
dc:subject × 11Rights
dc:rights- Statement dc:rights
-
- info:eu-repo/semantics/openAccess
- Language dc:language
- ger