Tim dependent killing and prolonged post antibiotic effect is seen with
**Core Concept**
The question is testing the understanding of the bactericidal effects of antibiotics, specifically the distinction between time-dependent killing and concentration-dependent killing. Time-dependent killing refers to the ability of an antibiotic to kill bacteria based on the duration of exposure, whereas concentration-dependent killing relies on the peak concentration of the antibiotic.
**Why the Correct Answer is Right**
The correct answer is **C. Aminoglycosides**. Aminoglycosides, such as gentamicin and tobramycin, exhibit time-dependent killing and prolonged post-antibiotic effects. This is because these antibiotics inhibit protein synthesis by binding to the 30S subunit of the bacterial ribosome, and their bactericidal effects are more dependent on the duration of exposure rather than the peak concentration. The prolonged post-antibiotic effect of aminoglycosides means that even after the antibiotic is cleared from the system, bacterial growth is delayed for an extended period.
**Why Each Wrong Option is Incorrect**
* **Option A:** Beta-lactam antibiotics, such as penicillins and cephalosporins, exhibit concentration-dependent killing and a shorter post-antibiotic effect.
* **Option B:** Macrolides, such as erythromycin and azithromycin, also exhibit concentration-dependent killing and a shorter post-antibiotic effect.
* **Option D:** Fluoroquinolones, such as ciprofloxacin and levofloxacin, exhibit concentration-dependent killing and a shorter post-antibiotic effect.
**Clinical Pearl / High-Yield Fact**
When choosing an antibiotic for a patient with a severe infection, it's essential to consider the pharmacodynamics of the antibiotic, particularly its mechanism of action and the duration of exposure required to achieve bactericidal effects.
**Correct Answer:** C. Aminoglycosides