27233
The antibacterial activity was determined against four standard strains ( Staphylococcus aureus , Staphylococcus epidermidis , Escherichia coli , Pseudomonas aeruginosa ) and 21 clinical isolates of methicillin - resistant Staphylococcus aureus .
 Chemical: methicillin
Given options, please tell me the categories of all the listed entity words.Output format is "type1: word1; type2: word2". 
Option: Chemical 
Text: {0} 
 Entities: methicillin 
Answer:
 Chemical: methicillin