Diagnostic and Typing Methods Flashcards
what bacteria are associated with periodontal disease
porphyromonas gingivalis
prevotella intermedia
what bacteria is associated with dental caries
streptococcus mutans
what bacteria is associated with root canal infections
porphyromonas endodontalis
fusobacterium nucleatum
how would you do a microbial culture
culture on suitable agar medium
isolate bacteria
identify by characterisation of enzyme activities, sugar fermentation
what molecular biological methods are available for bacterial detection
DNA probes
PCR
what are the advantages of using culture methods
yields bacterial isolates for future testing and study
what are the disadvantages of culture methods
requires viable cells
insensitive
only small numbers of samples can be analysed at once
inconclusive results
labour intensive
what are the types of DNA probe
whole genomic
cloned gene
what is PCR used for
directly identifying bacteria in clinical specimens
what gene do PCR primers target
16S rRNA gene
what are the advantages of PCR and DNA probes
less time consuming than culture methods
very sensitive
directly detect bacterial DNA within clinical samples
does not require viable cells
what are the disadvantages of PCR and DNA probes
may detect dead cells
detects only pre-selected species
why is it important to subtype bacteria
track routes of transmission during disease outbreaks
study pathogenicity of specific strains
what are the molecular typing methods
restriction enzyme analysis
gene probe typing
ribotyping
16S-23S intergenic spacer region
DNA sequencing
