60% of VAP is caused by which organisms?

• A. 30%
• B. 60%
• C. 70%
• D. 90%

Answer: (B)

In ventilator-associated pneumonia, the majority of infections come from Gram-negative bacteria. Studies in ICU patients show that about six in ten VAP cases are caused by Gram-negative bacilli such as Pseudomonas, Klebsiella, E. coli, Enterobacterales, and Acinetobacter. That’s why the correct answer aligns with the idea that roughly 60% of VAP etiologies are due to these organisms. The remaining cases are mainly Gram-positive cocci like Staphylococcus aureus (including MRSA) and some Streptococcus species, with fungal pathogens being relatively uncommon unless there are specific risk factors. So the 60% figure best matches the established distribution, which is why it’s the right choice.