Which of the following best defines a broad-spectrum antibacterial drug?

A clinician must choose empiric therapy for severe sepsis of unknown bacterial source. Which of the following is the best reason to start a broad-spectrum agent rather than a narrow-spectrum agent?

A new antibiotic irreversibly inhibits transpeptidase enzymes that crosslink peptidoglycan and cannot cross intact lipid membranes efficiently. For which bacteria would you predict the drug to be most effective and why?

Design a set of three desirable chemical or pharmacologic properties you would prioritize when synthesizing a new broad-spectrum antibiotic intended to penetrate both Gram-positive and Gram-negative bacteria; which combination below best supports broad spectrum activity?