Abstract
The microbiology of severe community acquired pneumonia (SCAP) has implications on
management, clinical outcomes and public health policy. Therefore, knowledge of the
etiologies of SCAP and methods to identify these microorganisms is key. Bacteria including
Streptococcus pneumoniae, Staphylococcus aureus and Enterobacteriaceae continue to
be important causes of SCAP. Viruses remain the most commonly identified etiology
of SCAP. Atypical organisms are also important etiologies of SCAP and are critical
to identify for public health. With the increased number of immunocompromised individuals,
less common pathogens may also be found as the causative agent of SCAP. Traditional
diagnostic tests, including semi-quantitative respiratory cultures, blood cultures
and urinary antigens continue to hold an important role in the evaluation of patients
with SCAP. Many of the limitations of the aforementioned tests are addressed by rapid,
molecular diagnostic tests. Molecular diagnostics utilize culture-independent technology
to identify species-specific genetic sequences. These tests are often semi-automated
and provide results within hours, which provides an opportunity for expedient antibiotic
stewardship. The existing literature suggests molecular diagnostic techniques may
improve antibiotic stewardship in CAP, and future research should investigate optimal
methods for implementation of these assays into clinical practice.
Keywords
pneumonia - community-acquired - molecular diagnostic - antibiotic - stewardship
