To determine the pathogenesis of empyema caused by Streptococcus anginosus group (SAG) bacteria in both pure cultures (no other organisms present) and mixed cultures.
Key Findings:
37 patients with SAG empyema identified: 14 with polymicrobial cultures (pSAG) and 23 with pure cultures.
Patients were primarily middle-aged men with comorbidities predisposing to aspiration.
SAG empyema is often misdiagnosed as atelectasis; pneumonia was the source in all cases with suitable CT scans.
Streptococcus intermedius was the most common species isolated, highlighting its significance.
Interpretation:
Community-acquired SAG empyema is a complication of unrecognized SAG pneumonia, with S. intermedius being a significant pathogen, underscoring the need for awareness in clinical settings.
Limitations:
Retrospective analysis with potential biases.
Not all patients had contrast-enhanced CT scans.
Lack of molecular methods for speciation of SAG isolates.
Small sample size may limit the generalizability of findings.
Conclusion:
SAG organisms should be considered as potential causes of community-acquired pneumonia, particularly in cases presenting as empyema.
