Gram positive bacteria Flashcards
What colour do Gram positive bacteria stain?
Purple (crystal violet/iodine complex)
What are the two main classes of Gram positive bacteria?
Cocci (round)
Bacilli (rod)
What are the two main classes of Gram positive cocci?
Staphylococci (clusters)
Streptococci (chains)
How are staphylococci further distinguished?
Coagulase test; positive or negative
Name a type of coagulase positive bacteria and give its symptoms
Staph. aureus;
- commensal in nose/groin
- boils/blood and food poisoning
- methicillin resistant = MRSA
Name a type of coagulase negative bacteria and give its symptoms
Staph epidermidis;
- skin commemsal
- pathogenic in presence of prosthetics/foreign bodies
How are streptococci further distinguished?
Haemolysis; alpha (partial)/beta (full)/non-haemolytic
What action does alpha-haemolytic bacteria have on blood agar?
Turns it green
What action does beta-haemolytic bacteria have on blood agar?
Turns it clear
Name a type of alpha-haemolytic bacteria and give its symptoms
Strep. pneumonia;
- pneumonia
- meningitis
- blood poisoning
Name a type of beta-haemolytic bacteria and give its symptoms
Strep. pyogenes - Lancefield group A
- sore throat
- cellulitis
- necrotising fasciitis
Name a type of non-haemolytic bacteria and give its symptoms
Enterococcus
- gut commensal
- causes UTI
What are the two main classes of Gram positive bacilli?
aerobic/anaerobic
large/small
Give the main class of anaerobic Gram positive bacilli
Clostridium species
Name the three main type of clostridium
Difficile
Perfringens
Tetani
