Which of the following statement(s) regarding the function of antimicrobial drugs are correct:
A. Beta-lactams such as penicillin impairs bacterial cell wall synthesis
B. Antimicrobial drugs that target DNA synthesis have a narrow spectrum, thus they are considered bacteriostatic
C. Narrow spectrum drugs are best because they can be used to treat a wide range of serious infections
D. An antibiotic that disrupts the normal flora can cause a superinfection
E. Tetracyclines are usually considered bacteriostatic rather than bactericidal