Mermaid Chart

flowchart TD
    A[Unknown bacterial isolate] --> B{Gram stain}

    B -->|Gram-positive| C{Cell shape}
    B -->|Gram-negative| D{Oxidase test}

    C -->|Cocci| E{Catalase test}
    C -->|Rods| F{Spore-forming}

    E -->|Positive| G{Coagulase test}
    E -->|Negative| H{Hemolysis}

    G -->|Positive| I[Staphylococcus aureus]
    G -->|Negative| J{Novobiocin}

    J -->|Sensitive| K[Staphylococcus epidermidis]
    J -->|Resistant| L[Staphylococcus saprophyticus]

    H -->|Beta| M{Bacitracin}
    H -->|Alpha| N{Optochin}
    H -->|Gamma| O{Growth in 6.5 percent NaCl}

    M -->|Sensitive| P[Streptococcus pyogenes]
    M -->|Resistant and CAMP positive| Q[Streptococcus agalactiae]

    N -->|Sensitive| R[Streptococcus pneumoniae]
    N -->|Resistant| S[Viridans streptococci]

    O -->|Positive| T[Enterococcus species]
    O -->|Negative| U[Group D Streptococcus]

    F -->|Yes and aerobic| V[Bacillus species]
    F -->|Yes and anaerobic| W[Clostridium species]
    F -->|No| X{Morphology and motility}

    X -->|Tumbling motility| Y[Listeria monocytogenes]
    X -->|Club-shaped rods| Z[Corynebacterium species]
    X -->|Branching rods| AA[Actinomyces or Nocardia]

    D -->|Negative| AB{Lactose fermentation}
    D -->|Positive| AC{Special features}

    AB -->|Lactose fermenter| AD{Indole test}
    AB -->|Non-lactose fermenter| AE{Hydrogen sulfide on TSI}

    AD -->|Positive| AF[Escherichia coli]
    AD -->|Negative and mucoid| AG[Klebsiella species]
    AD -->|Negative and motile| AH[Enterobacter species]

    AE -->|Positive and urease negative| AI[Salmonella species]
    AE -->|Positive and urease positive| AJ[Proteus species]
    AE -->|Negative and nonmotile| AK[Shigella species]

    AC -->|Blue-green pigment and growth at 42 C| AL[Pseudomonas aeruginosa]
    AC -->|Kidney-shaped diplococci| AM[Neisseria species]
    AC -->|Curved rod| AN[Vibrio or Campylobacter species]