Which of the following best defines a superinfection in the context of antibiotic therapy?

• A. A secondary infection that becomes established during or after antimicrobial therapy because susceptible members of the normal microbial community were removed, allowing resistant organisms to colonize and proliferate.
• B. The initial primary infection occurring at the same anatomical site that is exacerbated by the use of broad-spectrum antibiotics, without involvement of a new organism or colonization event.
• C. An infection that occurs when the initial pathogen mutates into a more virulent strain during treatment, acquiring additional virulence factors that are unrelated to community disruption but directly caused by antibiotic-induced mutations in the original infecting organism.
• D. An infection caused by the same original pathogen that persists because the prescribed antibiotic concentration failed to reach the infected tissue and therefore allowed continued growth of the original organism despite therapy.

Answer: (A)