Concordance of next-generation sequencing and conventional microbiology for pathogen detection and antimicrobial resistance prediction in pneumonia

Abstract Delays in pathogen and antimicrobial resistance (AMR) profiling adversely affect patient outcomes. Next-generation sequencing (NGS) may complement conventional microbiology (CM), yet real-world value of NGS in pneumonia diagnosis remains unclear. We quantified concordance between a commercial NGS panel and CM for pathogen detection and genotypic AMR prediction in 48 pneumonia inpatients with culture-confirmed infections. Archived sputum was analysed using the Ion AmpliSeq Pan-Bacterial targeted panel with 16S rRNA profiling. CM comprised culture, matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) identification and disc-diffusion antibiotic susceptibility testing. NGS recovered 27/50 pathogens detected by CM (54.0%, 95% CI 40.4–67.0), with more organisms per sample than CM (mean 2.42 versus 1.04), including uncultured taxa, indicating broader detection. AMR sensitivity of NGS was low (41.2%, 105/255; 95% CI 35.3–47.3; ranging from 1.1% for fluoroquinolones to 100% for cephamycins/lincosamides/tetracyclines) and remained low (37.6–69.8%) across alternative read and abundance cut-offs. Overall, the commercial NGS panel expanded pathogen detection beyond culture but showed only moderate concordance with CM and limited sensitivity for AMR phenotypes; it is therefore best regarded as an adjunct to CM and phenotypic susceptibility testing in pneumonia, not a replacement.