The Microbial Etiology of Community-Acquired Pneumonia in Adults : from Classical Bacteriology to Host Transcriptional Signatures

All modern advances notwithstanding, pneumonia remains a common infection with substantial morbidity and mortality. Understanding of the etiology of pneumonia continues to evolve as new techniques enable identification of already known organisms and as new organisms emerge. We now review the etiology of pneumonia (at present often called "community-acquired pneumonia") beginning with classic bacteriologic techniques, which identified Streptococcus pneumoniae as the overwhelmingly common cause, to more modern bacteriologic studies, which emphasize Haemophilus influenzae, Staphylococcus aureus, Moraxella catarrhalis, Enterobacteriaceae, Pseudomonas, and normal respiratory flora. Urine antigen detection is useful in identifying Legionella and pneumococcus. The low yield of bacteria in recent studies is due to the failure to obtain valid sputum samples before antibiotics are administered. The use of high-quality sputum specimens enables identification of recognized ("typical") bacterial pathogens as well as a role for commensal bacteria ("normal respiratory flora"). Nucleic acid amplification technology for viruses has revolutionized diagnosis, showing the importance of viral pneumonia leading to hospitalization with or without coinfecting bacterial organisms. Quantitative PCR study of sputum is in its early stages of application, but regular detection of high counts of bacterial DNA from organisms that are not seen on Gram stain or grown in quantitative culture presents a therapeutic dilemma. This finding may reflect the host microbiome of the respiratory tract, in which case treatment may not need to be given for them. Finally, host transcriptional signatures might enable clinicians to distinguish between viral and bacterial pneumonia, an important practical consideration.

Medienart:

E-Artikel

Erscheinungsjahr:

2022

Erschienen:

2022

Enthalten in:

Zur Gesamtaufnahme - volume:35

Enthalten in:

Clinical microbiology reviews - 35(2022), 4 vom: 21. Dez., Seite e0001522

Sprache:

Englisch

Beteiligte Personen:

Gadsby, Naomi J [VerfasserIn]
Musher, Daniel M [VerfasserIn]

Links:

Volltext

Themen:

Atypical organisms
Bacterial
Coinfection
Community-acquired pneumonia
Etiology
Haemophilus
Host transcriptional signatures
Journal Article
Normal respiratory flora
Pneumococcus
Pneumonia
Quantitative molecular analysis
Respiratory viruses
Review
Viral

Anmerkungen:

Date Completed 23.12.2022

Date Revised 28.09.2023

published: Print-Electronic

Citation Status MEDLINE

doi:

10.1128/cmr.00015-22

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM34681426X