Flashcards in GRAM -VE Deck (46)
Name 3 gram negative cocci
What type of bacteria is Neisseria?
Gram-negative cocci that is facultative aerobic
Appearance of Neisseria on gram stain?
Cocci - found in pairs, tetrads, short chains & clusters
List 2 species of Neisseria that are pathogens
1. Neisseria gonorrhoeae
2. Neisseria meningitidis
List 2 species of Neisseria that can be found in the oral cavity
1. Neisseria subflava
2. Neisseria sicca
Are the Neisseria species early or late colonizers of tooth?
Name a similarity and a difference between Neisseria subflava and Neisseria sicca
S: N. subflava and N. sicca are saccharolytics and polysaccharide producing bacteria found in the mouth
D: N. subflava produces a yellow-green pigment but N. sicca does not produce pigment.
State a difference between Neisseria and Moraxella
Neisseria is saccharolytic (i.e. produces polysaccharide) but Moraxella is asaccharolytic (i.e. does not produce polysaccharide)
Name a species of Moraxella
What do most strains of Moraxella produce? Why is that a danger?
Most strains produce B-lactamase --> complicates antibiotic therapy
Where can Moraxella catarrhalis be found?
Commensal of the mouth and upper respiratory tract
What is Moraxella catarrhalis a significant pathogen of?
Meningitis, endocarditis, otitis media, maxillary sinusitis
Similarity between Moraxella and Veillonella
Both are asaccharolytics (both do not ferment carbohydrates)
Where can Veillonella be found?
Mouth and dental plaque
Function of Veillonella
Catabolises lactic acid to weaker organic acids (acetate and propionate); hence raising pH of the oral cavity
Name the most common species of Veillonella
Where can veillonella parvula be found?
Oral cavity and intestines
Name 3 species of Veillonella
1. Veillonella Parvula
2. Veillonella Dispar
3. Veillonella Atypica
GNAB = Gram negative anaerobic bacteria - They are a large proportion of oral bacteria found especially in the gingival sulcus and periodontal pocket that is difficult and fastidious to study.
Name 3 motile GNAB
Name 6 non-motile GNAB
What are selenomonas associated with?
Periodontitis / Periodontal disease
Describe the appearance of Selenomonas
Cresent (moon-shaped) with many flagellae
Name 3 species of Selenomonas
1. Selenomonas Sputigena
2. Selenomonas Flueggei
3. Selenomonas Noxia
Name a species of Centipeda
Describe the appearance of Centipeda
flagellae arising from all around the cell
Name a species of Helicobacter
What does helicobacter pylori cause?
gastritis, gastric cancer, peptic ulcers
Describe the appearance of bacteroides on a CBA
Produces a dark pigment