11712
During antibacterial evaluation , compound 13 stood out as the most active of the series , showing a selective activity against the gram positive pathogenic methicillin - resistant S . aureus ( MRSA , MIC = 6 mu Mu ) , with a bacteriostatic effect .
 methicillin
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: Chemical 
Text: {0} 
Answer:
 methicillin