This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: All India exam, Subject name: Microbiology
Most common organism involved in nosocomial infection - 
Select and explain. 
A. Staph aureus, B. E. coli, C. Legionella, D. Strep pneumonia
A: Staph aureus
Answer: A: Staph aureus 
Explanation: UTI is the most common type of nosocomial infection. . Most common cause of UTI ---> E coli . Most common cause of UTI in ICU ----> Candida . Overall staph aureus is a leading cause of nosocomial infection. . Staph aureus is the most common cause of surgical wound infection - . Most common cause of primary bacteremia --> Coagulase negative staphylococcus. REF : ananthanarayana 10th ed