This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Microbiology
Which is false regarding Gram positive cocci ? 
Select and explain. 
A. Staph. saprophyticus causes UTI in females, B. Micrococci are oxidase positive, C. Most enterococci are sensitive to penicillin, D. Pneumococci are capsulated
C: Most enterococci are sensitive to penicillin
Answer: C: Most enterococci are sensitive to penicillin 
Explanation: Unlike streptococci enterococci are not reliably killed by penicillin or ampicillin alone at concentration acheived clinically in the blood or tissues.

Antimicrobial susceptibility testing should be performed routinely on enterococcal isolates.

Other options
Option ‘a’ • Staph. saprophyiticus specially causes UTI in sexually active young women.
Option ‘b’ • Micrococci are catalase and oxidase positive Gr (+ve) cocci. They are strict aerobes and are non pathogenic.

Micrococci are differentiated from Staphylococci by Hugh and deifson oxidation fermentation test in which micrococci shows oxidative pattern while staphylococci show fermentive pattern.