Cross‐Platform Concordance Between Metagenomic and Targeted DNA Sequencing for Diagnosing Polymicrobial Infections in an Immunosuppressed Patient: A Case Report

ABSTRACT Immunocompromised patients are highly susceptible to complex and rapidly progressive infections, for which early pathogen identification is critical. We report the case of an immunosuppressed patient aged 40 years with severe mixed pulmonary infections caused by Pneumocystis jirovecii and carbapenem‐resistant Klebsiella pneumoniae . During the disease course, metagenomic next‐generation sequencing and targeted next‐generation sequencing were repeatedly performed using three sequencing platforms. All platforms consistently identified the pathogens, guiding timely adjustment of antimicrobial therapy. Compared with conventional cultures (first positive result on hospital day 10), next‐generation sequencing detected Pneumocystis jirovecii 9 days earlier and rising Klebsiella pneumoniae 1 day before culture positivity and septic shock. This case highlights the clinical utility of metagenomic next‐generation sequencing and targeted next‐generation sequencing, providing real‐world evidence of cross‐platform concordance.