Methods: Patients admitted to Northwestern Memorial Hospital between 10/2008 and 11/2014 that had a 16S rRNA PCR test performed on a sterile site (e.g. blood, cerebrospinal fluid), direct specimen (e.g. heart valve tissue) were considered for inclusion. All patients had a suspected active infection based on clinical presentation and/or consultation from the ID service. Patients with a 16S rRNA PCR (+) were matched 1:1 based on specimen site to patients with 16S rRNA PCR (-). Pertinent variables including site of suspected infection were collected.
Results: In total, 90 patients were included (n=45 16S rRNA PCR (+) and (-)). The most common suspected infection was endocarditis (n=38), followed by osteomyelitis (n=13). Baseline demographics including modified APACHE II score did not differ between groups. Patients with a 16S rRNA PCR (-) had a shorter median total LOT than patients with a 16S rRNA PCR (+) (33 days [IQR 8-46] vs. 43 days [IQR 29-51], p=0.02). Antibiotics post-PCR were discontinued more frequently in patients with 16S rRNA PCR (-) than 16S rRNA PCR (+) (38% vs 4%, p<0.01). In a subgroup analysis of endocarditis, patients with 16S rRNA PCR (-) had a numerically shorter median LOT (32.5 [IQR 12.5-46] vs 45 [IQR 31-52], p=0.08) and had more frequent discontinuation of antimicrobials (37% vs 5%, p=0.04) than patients with16S rRNA (+).
Conclusion: 16S rRNA PCR may be useful as a stewardship tool to decrease overall LOT and discontinue antibiotics in patients without detection of a microbial organism. Future studies are needed to further determine the potential use of 16S rRNA PCR as a diagnostic aid for difficult to culture microbes or sites.
D. Smith, None
J. Esterly, None
C. Qi, None
M. Malczynski, None
M. Postelnick, None
M. Mclaughlin, BioCryst Pharmaceuticals: Served on Advisory Board , Consulting fee