Vertebral Aggregatibacter Aphrophilus Osteomyelitis Identi ied Using 16S Ribosomal RNA Sequencing Method

Aggregatibacter aphrophilus is a fastidious gram-negative coccobacillus, known to be dif icult to identify. Recent studies have shown that extended blood culture incubation is unnecessary. We present a case of thoracic vertebral osteomyelitis and spinal epidural abscess caused by A. aphrophilus in a 62-year old who presented with acute fever, back pain, and urinary incontinence. MRI con irmed osteomyelitis and epidural abscess. Emergent laminectomy was performed due to nerve compression and the abscess was cultured. The blood culture became positive on day seven of cultivation, while the abscess culture became positive on day three. A. aphrophilus was identi ied by 16S ribosomal RNA sequencing method. The routine ive-day blood culture incubation period might not be suf icient for A. aphrophilus to grow. The 16S rRNA sequencing method can be helpful when conventional phenotypic method cannot identify fastidious organisms.