16S Ribosomal RNA Gene PCR and Sequencing for Pediatric Infection Diagnosis, United States, 2020-2023.

Gene PCR and sequencing using 16S ribosomal RNA (rRNA) can help diagnose challenging bacterial infections. Data on the optimal clinical settings for this type of testing are limited. We performed a retrospective study at Mayo Clinic, Rochester, Minnesota, USA, with typically sterile specimens from children that underwent 16S rRNA PCR testing during September 2020-December 2023. Of 162 tests performed on 124 patients, 20% were positive; 58% of positive samples were from culture-negative specimens. Fluid specimens were >3 times as likely to test positive as tissue specimens (odds ratio 3.07 [95% CI 1.32-7.11]; p = 0.007), and pleural fluid demonstrated the highest positivity rate (50%). Of 33 positive results, 4 (12%) specimens qualified for reporting to the state health department for communicable diseases. Those single-laboratory findings demonstrate that the highest positivity rate of 16S rRNA PCR and sequencing is pleural fluid, although many specimen types tested positive.