M2 Assessment : Biochemical Reactions I

Which of the following organisms is NOT Gram-positive?

• E.coli
• Staphylococcus aureus
• Staphylococcus saprophyticus
• Streptococcus pyogenes

Each of the following statements concerning the Gram stain is correct EXCEPT

• Escherichia coli stains red 
•  Streptococcus pyogens stains blue 
• Staphylococcus aureus stains red 
• Streptococcus pyogenes stains blue 

What is the most important test  that can distinguish Staphylococcus aureus from other staphylococci?

• Catalase
• Coagulase
• Motility
• Gram stain

 An incomplete hemolysis will show streaks of what color on blood agar?

• Clear
• No change
• Green
• Red

Which of the following tests would involve looking the formation of “bubbling” after application of the test agent?

• Catalase
• Coagulase
• Motility
• Oxidase

Which of the following tests would involve the formation of a clot?

• Catalase
• Coagulase
• Motility
• Oxidase