"Flexispira rappini" bacteremia in a child with pneumonia

Abstract

We describe a case of "Flexispira rappini" bacteremia from a 9-year-old girl who presented with a 5-day history of fever, productive cough, and malaise. A chest X-ray result was compatible with right middle lobe pneumonia. Blood culture grew a gram-negative spiral fusiform bacterium 2 days after the inoculation. Biochemical tests showed the organism to be catalase negative, oxidase positive, sodium hippurate hydrolysis negative, and urea hydrolysis negative. 16S rRNA gene sequencing identified this organism as "F. rappini," showing a six-base substitution from the type strain. This is the first report of "F. rappini" bacteremia in a human, suggesting that this organism has the potential of causing invasive infection, but its role in pneumonia is uncertain and could be unrelated to the bacteremia.

FIG. 1

Light microscopy photomicrograph of a Gram smear of a culture of the clinical isolate of “F. rappini” showing characteristic slightly curved fusiforms. Magnification, ×1,000.