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: A 30 - year old Caucasian man reported with abdominal pain and jaundice after 3 - day administration of oral ciprofloxacin for a suspect of urinary tract infection .
### Output Text:
A 30 - year old Caucasian man reported with abdominal pain and jaundice after 3 - day administration of oral <span class="chemical">ciprofloxacin</span> for a suspect of urinary tract infection . 