Gram positives

Gram positive cocci

Staphylococci

• Staph. aureus - flucloxacillin IV in sepsis, vancomycin IV in allergy or MRSA sepsis
  • Other active drugs if not sepsis - oral doxycycline, cotrimoxazole, clindamycin
• Staphylocossus epidermidis and other coagulase negative e.g. Staphlococci - many are flucloxacillin resistant

Streptococci

• Occur in pairs or chains
• Catalase positive, need particular nutrients
• Facultative anaerobes - grow aerobically and anaerobically
• Further classified by action on agar (haemolysis)
  • Beta haemolytic strep: complete lysis next to growth, clear zone
  • Alpha hamolytic strep: partial haemolysis, greenish colour to the blood agar
  • Gamma haemolytic strep: non-haemolytic
• Can also be classified using Lancefield antigen

Enterococci

• E. faecalis and E. faecium
• Amoxicillin is the drug of choice, vancomycin is used if amoxicillin resistant
• VRE - vancomycin resistant enterococcus
  • Linezolid, daptomycin, tigecycline, quinupristine/dalfopristin

Gram positive bacilli

• Listeria monocytogenes
• Cutibacteria (Propionibacteria)
• Clostridia
  • Clostridioides difficile
  • Clostridium perfringes
  • Clostridium tetani