Microiology- Systemic Microbiology Flashcards
Which organisms don’t stain well with gram stain
Mycobacterium tuberculosis
Treponema pallium
Why doe M. TB not stain well on gram stain?
It has a lipid rich/ waxy cell wall
Obligate aerobes
Require air
Obligate anaerobes
Killed by oxygen
Facultative anaerobes
Tolerate oxygen
Aerobic
Grow in oxygen
Capnophillic
Prefer high CO2 levels
Which type of organism is haemolysis used on?
Streptococcus
Endogenous
Microorganisms
Exogenous
Not normal flora
Virulence
The capacity of a microbe to cause damage to it’s host
Commensal/mutualism/ symbiosis
Part of the normal flora
Fugal infection
Candida spp.
Yeast. Aspergillus
Moulds in immunocompromised
Protozoan disease
Malaria
Toxoplasma
GI infection eg cryptosporidiosis
Gram positive prokaryotic pathogens
Streptococcus
Staphylococcus
Enertococcus
Gram negative prokaryotic pathogens
Neisseria spp
Escherichia spp
Klebsiella
Gram negative cocci
Aerobic
Diplococci on gram film
Eg neisseria meningitidis, neisseria gonorrhoeae
Coliforms
Gram negative bacilli
Look like E. coli
Targeted with gentamicin
Why do patients with coliform sepsis become very unwell very quickly?
Endotoxin released from cell wall when bacteria dies
Alpha haemolysis
Partial haemolysis
Green colony-> enzymes denature the Hb
Beta haemolysis
Complete haemolysis
Enzymes breaks down/ lyse the RBC-> clears around the colony
The most pathogenic strep are beta haemolytic
Group a strep
Gamma haemolysis
No haemolysis
Most important group-> enterococci
Strep. Pneumoniae
Gm +ve, alpha haemolytic cocci
Commonest cause of pneumonia
Part of normal URT flora
C diff
Antibiotic associated diarrhoea
Produces exotoxins
