Gram + vs - Flashcards
What is the difference between gram + and - in terms of structure?
gram +: THICK peptidoglycan wall, stain purple
gram -: very thin peptidoglycan cell wall. Turn pink with safranin stain
What dye turns gram + bacteria violet?
crystal violet
What stain turns gram - pink?
safranin
What are the three key Gram POSITIVE COCCI
Staphylococcus
Streptococcus
Enterococcus
What are Gram POSITIVE RODS
“Mike’s list of basic cars”:
Mike’s – Mycobacteria
List of – Listeria
Basic – Bacillus
Cars – Nocardia
What are gram POSITIVE anaerobes?
“CLAP”:
C – Clostridium
L – Lactobacillus
A – Actinomyces
P – Propionibacterium
What are gram negatives
Neisseria meningitis Neisseria gonorrhoea Haemophilia influenza E. coli Klebsiella Pseudomonas aeruginosa Moraxella catarrhalis
What does atypical bacteria mean
That they cannot be cultured as normal on a gram stain
What are examples of atypical bacteria
Legions – Legionella pneumophila Psittaci – Chlamydia psittaci M – Mycoplasma pneumoniae C – Chlamydydophila pneumoniae Qs – Q fever (coxiella burneti)
Why do atypical bacteria not show up on gram stain
Because they have NO CELL WALL
What is the consequence of atypical bacteria not having a cell wall
They cannot be targeted by penicillins
Thereby give antibiotics that work on protein synthesis instead
What are antibiotics that work on protein synthesis
Macrolide (clarythromycin, erythromycin)
Tetracycline (doxycycline)
