LAB BACTERIAS

Gram-Positive

Staphylococcus aureus

Lab differentiation:

• Gram stain: Gram-positive cocci in clusters

• Catalase: Positive

• Coagulase: Positive

• Mannitol Growth: Positive

• Mannitol Fermentation: Positive

• Novobiocin Sensitivity: Sensitive

Staphylococcus epidermidis

🧪 Lab differentiation:

• Gram stain: Gram-positive cocci in clusters

• Catalase: Positive

• Coagulase: Negative

• Mannitol Growth: Positive

• Mannitol Fermentation: Negative

• Novobiocin Sensitivity: Sensitive

Staphylococcus saprophyticus

🧪 Lab differentiation:

• Gram stain: Gram-positive cocci in clusters

• Catalase: Positive

• Coagulase: Negative

• Mannitol Growth: Positive

• Mannitol Fermentation: Negative

• Novobiocin Sensitivity: Resistant

Gram-Positive Streptococci 🦠

Streptococcus pyogenes

• Gram stain: Gram-positive cocci in chains

• Catalase: Negative

• Hemolysis: Beta-hemolytic

• Bacitracin: Sensitive

• Optochin: Resistant

• Bile Esculin: Negative

• High Salt: Negative

Streptococcus agalactiae

🧪 Lab differentiation:

• Gram stain: Gram-positive cocci in chains

• Catalase: Negative

• Hemolysis: Beta-hemolytic

• Bacitracin: Resistant

• Optochin: Resistant

• TTC/Translucent: N/A

• Bile Esculin: Negative

• High Salt: Negative

Streptococcus pneumoniae

🧪 Lab differentiation:

• Gram stain: Gram-positive cocci in chains/pairs

• Catalase: Negative

• Hemolysis: Alpha-hemolytic

• Bacitracin: N/A

• Optochin: Sensitive

• TTC/Translucent: N/A

• Bile Esculin: Negative

• High Salt: Negative

Enterococcus faecalis

🧪 Lab differentiation:

• Gram stain: Gram-positive cocci in chains

• Catalase: Negative

• Hemolysis: Gamma-hemolytic (non-hemolytic)

• Bacitracin: Resistant

• Optochin: Resistant

• TTC/Translucent: N/A

• Bile Esculin: Positive

• High Salt: Positive

Streptococcus bovis

• Gram stain: Gram-positive cocci in chains

• Catalase: Negative

• Hemolysis: Gamma-hemolytic

• Bacitracin: Resistant

• Optochin: Resistant

• TTC/Translucent: N/A

• Bile Esculin: Positive

• High Salt: Negative

Gram-Negative Bacilli 🦠

E. coli

• Gram stain: Gram-negative bacillus.

• Urease: Negative

• Indole: Positive

• Methyl-red: Positive

• Voges-Proskauer: Negative

• Citrate: Negative

Salmonella enteritis

🧪 Lab differentiation:

• Gram stain: Gram-negative bacillus

• Urease: Negative

• Indole: Negative

• Methyl-red: Positive

• Voges-Proskauer: Negative

• Citrate: Positive

Enterobacter aerogenes

🧪 Lab differentiation:

• Gram stain: Gram-negative bacillus

• Urease: Negative

• Indole: Negative

• Methyl-red: Negative

• Voges-Proskauer: Positive

• Citrate: Positive

Proteus mirabilis

🧪 Lab differentiation:

• Gram stain: Gram-negative bacillus

• Urease: Positive

• Indole: Negative

• Methyl-red: Positive

• Voges-Proskauer: Negative

• Citrate: Positive