What is the most common etiologic organism causing spinal infection?

What is the most common etiologic organism causing spinal infection?

• A. Escherichia coli
• B. Staphylococcus aureus
• C. Pseudomonas aeruginosa
• D. Streptococcus pneumoniae

Answer: (B)

Staphylococcus aureus is the most common cause of spinal infection because these bacteria frequently enter the bloodstream from superficial or soft-tissue sites and readily seed the vertebral endplates and intervertebral discs. Its virulence and ability to form biofilms make vertebral osteomyelitis and discitis more likely than infections caused by other organisms. While Escherichia coli, Pseudomonas aeruginosa, and Streptococcus pneumoniae can cause spine infections in certain settings—E. coli more with urinary/GI sources, Pseudomonas often in intravenous drug users or hospital-acquired cases, and S. pneumoniae less commonly—the overall frequency is highest for Staphylococcus aureus. In high-risk groups like IV drug users, Pseudomonas may appear more often, but S. aureus remains the leading offender in spine infections.

Staphylococcus aureus is the most common cause of spinal infection because these bacteria frequently enter the bloodstream from superficial or soft-tissue sites and readily seed the vertebral endplates and intervertebral discs. Its virulence and ability to form biofilms make vertebral osteomyelitis and discitis more likely than infections caused by other organisms. While Escherichia coli, Pseudomonas aeruginosa, and Streptococcus pneumoniae can cause spine infections in certain settings—E. coli more with urinary/GI sources, Pseudomonas often in intravenous drug users or hospital-acquired cases, and S. pneumoniae less commonly—the overall frequency is highest for Staphylococcus aureus. In high-risk groups like IV drug users, Pseudomonas may appear more often, but S. aureus remains the leading offender in spine infections.