M10 - gram -ve Flashcards
what are the 4 main groups in gram-ve bacteria?
- cocci
- strict anaerobes
- facultative anaerobes
- curved rods
give a general description of Neisseria
- gram -ve, facultative/aerobic
- non-motile
- pathogens:
neisseria gonorrhoeae and N meningitidis
not considered to be normal oral flora
which oral neisseria in dental plaque saccharolytic produces polysaccharide and a yellow green pigment?
neisseria subflava - most commonly isolated
which oral neisseria is saccharolytic and polysaccheride producing but does not produce a pigment?
neisseria sicca
which gram - bacteria has a facultative intracellular lifecycle that allows it to infect tonsillar B cells?
moraxella catarrhalis
How does moraxella catarrhalis complicates antibiotic therapy?
most strains produce a Beta-lactamase
which gram -ve anaerobic cocci makes up to 20% of plaque flora ?
veillonella- do not ferment carbohydrates
how does veillonella parvula raise pH?
catabolises lactic acid (anaerobe) to weaker organic acids
what is the general link between Veillonella parvula and caries?
High number of V. parvula raise pH but reduce cariogenecity of plaque
list 3 motile GNABs
- selenomonas
- centipeda
- helicobacter
List 6 non motile GNABs
Bacteriodes porphyromonas prevotella Tannerella fusobacterium leptotrichia
selenomonas (non-motile) are cresent shaped bacteria with many flagellae, what are they reportedly associated with?
aggressive forms of periodontitis
where has helicobacter been found?
-reported in dental plaque (Motile)
which type of anaerobic Gram-ve bacilli are a large proportion of oral bacteria?
non-motile
which bacteriode is found in the mouth and GI tract?
bacteroides fragilis
