Community-acquired Staphylococcus aureus bacteriuria: a warning microbiological marker for infective endocarditis?

Area of Science:

• Infectious Diseases
• Cardiology
• Emergency Medicine

Background:

• Urinary tract infections (UTIs) are common in emergency departments (EDs).
• Staphylococcus aureus (SA) in urine cultures is rare (0.5-6%) without urinary tract colonization risk factors.
• SA bacteriuria may indicate deeper SA infections, such as infective endocarditis.

Purpose of the Study:

• To investigate if SA bacteriuria serves as a warning marker for unsuspected infective endocarditis in ED patients.
• To identify the association between SA bacteriuria and left-sided infective endocarditis in patients without UT colonization risk factors.

Main Methods:

• Retrospective chart review of adult patients from December 2005 to February 2018.
• Included patients with SA bacteriuria (≥10^4 CFU/ml) and SA bacteremia, lacking UT colonization risk factors.
• Infective endocarditis diagnosis based on Duke criteria.

Main Results:

• 27 patients diagnosed with community-acquired SA bacteriuria, bacteremia, and infective endocarditis.
• Only 18% presented with UTI symptoms; SA bacteriuria was identified significantly earlier than endocarditis diagnosis (1.4 vs. 4.3 days).
• Mitral and aortic valves were most affected (93%); 60-day mortality was 56%.

Conclusions:

• Community-acquired SA bacteriuria should alert emergency physicians to potential left-sided infective endocarditis in at-risk ED patients.
• SA bacteriuria can be a critical microbiological indicator for deep-seated SA infections.
• Timely recognition of SA bacteriuria may improve outcomes for patients with infective endocarditis.