What bacteria primarily causes microbial keratitis?

What bacteria primarily causes microbial keratitis?

• A. Staphylococcus aureus
• B. Streptococcus pneumoniae
• C. Pseudomonas aeruginosa
• D. Moraxella lacunata

Answer: (C)

This item centers on which bacterium most often causes microbial keratitis. Pseudomonas aeruginosa is the best answer because it is the leading cause of bacterial keratitis, especially in contact lens wearers. It’s a gram-negative, non-fermenting rod that thrives in moist environments and has virulence factors like proteases and toxins that rapidly damage corneal tissue, leading to quick ulceration if not treated promptly. While Staphylococcus aureus and Streptococcus pneumoniae can cause keratitis, they are less commonly the primary culprits overall. Moraxella lacunata is a less frequent cause and tends to show up in different clinical contexts. Understanding that Pseudomonas keratitis tends to be aggressive and fast-moving helps explain why it’s emphasized as the primary concern.

This item centers on which bacterium most often causes microbial keratitis. Pseudomonas aeruginosa is the best answer because it is the leading cause of bacterial keratitis, especially in contact lens wearers. It’s a gram-negative, non-fermenting rod that thrives in moist environments and has virulence factors like proteases and toxins that rapidly damage corneal tissue, leading to quick ulceration if not treated promptly. While Staphylococcus aureus and Streptococcus pneumoniae can cause keratitis, they are less commonly the primary culprits overall. Moraxella lacunata is a less frequent cause and tends to show up in different clinical contexts. Understanding that Pseudomonas keratitis tends to be aggressive and fast-moving helps explain why it’s emphasized as the primary concern.