What is the most common organism causing septic shock?

What is the most common organism causing septic shock?

• A. Gram negative rods
• B. Gram positive cocci
• C. Anaerobic bacteria
• D. Fungi

Answer: (A)

Gram-negative bacteria are the most common cause of septic shock. These organisms, especially Gram-negative rods such as E. coli, Klebsiella, and Pseudomonas, have lipopolysaccharide (endotoxin) in their outer membrane. When endotoxin is released, it triggers a strong inflammatory response with widespread cytokine release, leading to vasodilation, capillary leak, and depressed myocardial function that manifest as persistent hypotension despite fluids. While Gram-positive cocci, anaerobes, and fungi can cause sepsis and shock in specific situations, Gram-negative bacteria remain the leading culprits overall, particularly in urinary tract, intra-abdominal, and pneumonia sources.

Gram-negative bacteria are the most common cause of septic shock. These organisms, especially Gram-negative rods such as E. coli, Klebsiella, and Pseudomonas, have lipopolysaccharide (endotoxin) in their outer membrane. When endotoxin is released, it triggers a strong inflammatory response with widespread cytokine release, leading to vasodilation, capillary leak, and depressed myocardial function that manifest as persistent hypotension despite fluids. While Gram-positive cocci, anaerobes, and fungi can cause sepsis and shock in specific situations, Gram-negative bacteria remain the leading culprits overall, particularly in urinary tract, intra-abdominal, and pneumonia sources.