Legionella bozemanii lymphadenitis in an immunocompetent child and the role of sequencing in the diagnostic evaluation of culture-negative pediatric lymphadenitis: a case report

July 31, 2025
Case Report
Grace St Cyr, Robert F Potter, Katia C Halabi, Coralee Del Valle Mojica
Pathogen:Legionella bozemanii
Infection Type:Lymphadenitis
Pathogen Type:Bacteria

Summary

An immunocompetent child presented with culture-negative cervical lymphadenitis, initially treated with antibiotics without resolution. Diagnostic challenges were overcome through metagenomic next-generation sequencing (mNGS) of lymph node tissue, which identified Legionella bozemanii as the causative agent. This atypical pathogen, usually associated with pulmonary disease in immunocompromised individuals, caused localized lymphadenitis in a healthy pediatric patient. The case highlights the critical utility of advanced sequencing techniques for diagnosing fastidious or unusual pathogens in culture-negative infections, especially when conventional methods fail. Early and accurate identification enabled targeted treatment and successful patient recovery, emphasizing the evolving role of molecular diagnostics in clinical microbiology.

Key note: Metagenomic next-generation sequencing is invaluable for diagnosing culture-negative lymphadenitis caused by fastidious or unexpected pathogens in immunocompetent children.

DOI: 10.1128/asmcr.00071-24