Pulmonary abscess caused by Streptococcus pseudopneumoniae in a child: A case report and review of literature.

Background: Lung abscess found on chest X-ray and computed tomography examinations is rare in infants and young children. Several pathogens can cause lung abscesses, with the most common pathogens being anaerobes, Streptococci and Staphylococcus aureus. Streptococcus pseudopneumoniae (S. pseudopneumoniae) is a member of the Streptococcaceae family, and is mainly isolated from respiratory tract specimens. There are currently no cases of lung abscess caused by S. pseudopneumoniae in the literature.

Case summary: A 2-year-old boy was admitted to hospital due to persistent cough and fever. Lung computed tomography examination suggested the formation of a lung abscess. His diagnosis was not confirmed by testing for serum respiratory pathogens (6 items), respiratory pathogen nucleic acid (27 items), and laboratory culture. Finally, metagenomic next-generation sequencing of bronchoalveolar lavage fluid revealed the presence of S. pseudopneumoniae, confirming its role in causing the lung abscess. After receiving antibiotic treatment, reexamination with lung computed tomography showed that the abscess was resorbed and the patient's outcome was good.

Conclusion: This is the first report of a lung abscess in a child caused by S. pseudopneumoniae infection. Metagenomic next-generation sequencing of bronchoalveolar lavage fluid is helpful in achieving rapid and accurate pathogen identification.