This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Cell Wall Synthesis Inhibitors, Subject name: Pharmacology
All of the following drugs are bactericidal except 
Select and explain. 
A. Isoniazid, B. Tigecycline, C. Daptomycin, D. Ciprofloxacin
B: Tigecycline
Answer: B: Tigecycline 
Explanation: Tigecycline is a newer drug in the class 'Glycylcyclines.' Its mechanism of action and most propeies are similar to tetracyclines. However, it is resistant to efflux pump (major mechanism of resistance against tetracyclines). Most protein synthesis inhibiting drugs (including tetracyclines and tigecycline) are bacteriostatic except aminoglycosides. Isoniazid, ciprofloxacin and daptomycin are bactericidal.