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: An improvement in renal function that followed the discontinuation of the offending antibiotic supports the presumptive diagnosis of ciprofloxacin - induced acute renal failure .
### Output Text:
An improvement in renal function that followed the discontinuation of the offending antibiotic supports the presumptive diagnosis of <span class="chemical">ciprofloxacin</span> - induced acute renal failure . 