Erysipelothrix rhusiopathiae bacteremia: a challenging diagnosis!

Erysipelothrix rhusiopathiae, a Gram-positive bacillus, is reported to cause for cutaneous infections and endocarditis. We report a case of E. rhusiopathiae bacteremia without severe clinical illness. The patient, a 74-year-old man, is suffering from a chronic lymphoid leukemia (LLC). Following a trauma, the patient developed a bruise on the left inch. Because the site of shock seemed clinically infected, oral amoxicilline-acid clavulanic (AAC) treatment was started after withdrawn 1 set of blood cultures. These blood culture specimens yielded a Gram-positive bacillus identified as E. rhusiopathiae by mass spectrometry MALDI-TOF (Microflex Brüker). The strain was sensitive to beta-lactam, fluoroquinolones and macrolides, resistant to vancomycin (natural resistance), and amikacin but sensitive to gentamicin. After 5 days of treatment by AAC, the patient became apyretic. One year after this episode, we reported no further symptoms of infection, or endocarditis. The natural resistance of E. rhusiopathiae in glycopeptides underlines the importance of a microbiological diagnosis. Indeed, vancomycine can be the treatment of first intention in Gram-positive bacillus bacteremia. The identification of bacteria using mass spectrometry is available the same day of the blood culture positivity and allows to prescribe the most adapted antibiotic treatment for the patient.