Final answer:
Gentamicin, an aminoglycoside that binds the 30S subunit of bacterial ribosomes, can be administered rectally for treating enterococcal infections.
Step-by-step explanation:
The question pertains to the administration route of aminoglycosides for treating an enterococcal infection. Aminoglycosides, which act as protein synthesis inhibitors that bind the 30S subunit of bacterial ribosomes, include drugs like gentamicin, streptomycin, amikacin, and tobramycin. Among these, gentamicin is known to be available in formulations that can be administered via the rectal route to treat intestinal infections, making it the correct answer to the student's question. Gentamicin, which is produced by the microbe Micromonospora purpurea, has broad-spectrum antibacterial properties but also carries risks of nephrotoxicity, neurotoxicity, and ototoxicity. While other antibiotics such as MACROLIDES (azithromycin, clarithromycin, and erythromycin) and TETRACYCLINES also target bacterial protein synthesis, they act differently from aminoglycosides and are not mentioned as options for rectal administration in this context.