Bacteriological tests

gram positive cocci

• gram positive cocci cultured
  • catalase positive - staphylococci
    • coagulase test
      • coagulase positive - S. aureus
      • coagulase negative - other staphylococci
  • catalase negative - streptococci
    • check hemolysis
      • alpha hemolytic
        • S. pneumoniae
        • viridans streptococci group
          • Optochin test
            • optochin positive - S. pneumoniae
            • optochin negative - other streptococci
    • beta hemolytic
      • Lancefield antigen test
        • group A - S. pyogenes
        • group B - S. agalactiae
        • group C - S. dysgalactiae
        • group D - S. bovis, E. faecalis, E. faecium
        • group G - S. dysgalactiae

gram positive bacilli

• gram positive bacilli cultured
  • large and spore-forming
    • anaerobic - Clostridium spp.
    • aerobic - Bacillus spp.
  • large and non-spore-forming
    • catalase positive - Corynebacterium spp., Listeria spp.
    • catalase negative - Lactobacillus spp., Erysipelothrix spp.
  • small

gram negative bacilli

• gram negative bacilli cultured
  • grown in MacConkey agar
    • lactose-fermenting - E. coli, Klebsiella
    • non-lactose-fermenting
      • oxidase positive - Pseudomonal aeruginosa
      • oxidase negative - Shigella spp., Salmonella spp., Proteus spp.
  • not grown in MacConkey agar

• agar other than MacConkey
  • xylose lysine deoxycholate (XLD) agar
  • chromogenic agar