In the sentence extracted from biomedical literature, identify all the chemical entities. The required answer format is the same sentence with HTML <span> tags to mark up specific entities. 
### Entity Markup Guides:
Use <span class="chemical"> to denote a chemical.

### Input Text: Cerebrospinal fluid penetration of high - dose daptomycin in suspected Staphylococcus aureus meningitis .
### Output Text:
Cerebrospinal fluid penetration of high - dose <span class="chemical">daptomycin</span> in suspected Staphylococcus aureus meningitis . 