Which antibiotic provides Gram-positive coverage for ocular infections?

• A. Cefazolin
• B. Gentamicin
• C. Ofloxacin
• D. Tobramycin

Answer: (A)

For ocular infections, targeting Gram-positive bacteria requires an antibiotic with strong Gram-positive activity. Cefazolin is a first-generation cephalosporin that provides robust coverage against common Gram-positive pathogens such as Staphylococcus and Streptococcus species, which are frequent culprits in conjunctivitis and keratitis. Its excellent activity against these organisms, along with good ocular penetration, makes it the preferred option when Gram-positive coverage is the priority. In contrast, gentamicin and tobramycin are primarily valued for Gram-negative coverage, with less reliable Gram-positive activity, and ofloxacin offers broad-spectrum activity but is not as targeted for Gram-positive pathogens. Therefore, cefazolin best satisfies the need for Gram-positive coverage in ocular infections.