Diagnostic Challenges in Aspiration Pneumonia With Repeated Isolation of Rothia aeria: A Case Report

Area of Science:

• Microbiology
• Infectious Diseases
• Pulmonology

Background:

• Rothia aeria is a rare, facultatively aerobic Gram-positive bacillus.
• While typically part of oral flora, R. aeria is increasingly recognized as an opportunistic pathogen, especially in immunocompromised individuals.
• Respiratory infections caused by R. aeria are exceptionally uncommon.

Observation:

• A case of an elderly woman with aspiration pneumonia is presented.
• R. aeria was repeatedly isolated from sputum cultures, with branching Gram-positive bacilli observed on Gram stain.
• The organism was not found within neutrophils, indicating a lack of active phagocytosis.

Findings:

• The patient experienced rapid clinical and radiological improvement after meropenem treatment.
• Post-treatment bronchoalveolar lavage fluid cultures were negative.
• Minimal inflammation and lack of tissue destruction suggested transient colonization or mild infection.

Implications:

• This case underscores the necessity of integrating clinical judgment with culture results when assessing rare organisms in non-sterile specimens.
• Repeated isolation of R. aeria from respiratory samples warrants consideration of its pathogenic potential, even in relatively immunocompetent hosts.
• Clinical context, radiological findings, and treatment response are crucial for evaluating R. aeria's role in respiratory illness.