This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Bacteria, Subject name: Microbiology
Difference between staphylococcus aureus and staphylococcus saprophyticus - 
Select and explain. 
A. Catalase positivity, B. Coagulase positivity, C. Novobiocin susceptibility, D. Oxidase positivity
B: Coagulase positivity
Answer: B: Coagulase positivity 
Explanation: Ans. is 'b' i.e., Coagulase positivity * Coagulase test used to differentiate betweeni) Coagulase positive staphylococci - Staph aureusii) Coagulase negative staphylococci - Staph epidermidis, staph hemolyticus, staph saprophyticus.* Novobiocin sensitivity is used to differentiate coagulase negative staphylococci:i) Novobiocin susceptible : Staph epidermidis, staph hemolyticusii) Novobiocin resistant: Staph saprophyticus* Coagulase test is used to differentiate the different species of staphylococci (staph aureus, staph, epidermidis).* Catalase test is used to differentiate staphylococci from streptococci.