First Korean Case of Helcococcus kunzii Bacteremia in a Patient with Diabetes

Dear Editor Members of the Helcococcus genus are non-motile, catalasenegative, facultatively anaerobic gram-positive cocci. To date, a total of 5 species have been assigned to Helcococcus, including H. kunzii, H. ovis, H. pyogenes, H. seattlensis, and H. sueciensis; however, H. pyogenes has not yet received official taxonomic classification [1, 2]. H. kunzii has been identified as a causative pathogen of abscess, bacteremia, cellulitis, empyema, implantable cardiac device infection, osteomyelitis, prosthetic joint infection, and sebaceous cyst infection; however, H. kunziiassociated bacteremia is not common [3-7]. We report a case of H. kunzii bacteremia in a patient with diabetes. A 58-yr-old man complained of redness in his left foot with abrasions on the third and fourth toes and pain 8 days prior to admission to the emergency room. His diabetes was diagnosed 20 yr ago and he was receiving hemodialysis for treatment of end-stage renal disease. Physical examination revealed an ulcerative lesion on the dorsum and sole of his left foot. The patient had temperature of 38.0°C, blood pressure of 195/86 mm Hg, pulse of 62/min, and respiratory rate of 20 breaths/min. Laboratory investigation showed Hb of 9.1 g/dL, leukocyte count of 7.6×10/L, platelet count of 267×10/L, C-reactive protein level of 7.42 mg/dL, erythrocyte sedimentation rate of 112 mm/ hr, glucose level of 251 mg/dL, Hb A1c level of 7.1%, blood urea nitrogen/creatinine of 18/4.4 mg/dL, and total protein/albumin level of 7.4/3.2 g/dL. Magnetic resonance imaging of the left foot revealed a soft tissue abscess in the third webspace and infectious arthritis at the third and fourth metatarsophalangeal joints. A wound swab sample and 2 sets of blood samples were collected, and the patient received empirical antibiotic therapy with intravenous piperacillin/tazobactam. Cultured swab samples were positive for Proteus mirabilis. After 48 hr of incubation, gram-positive cocci grew in 2 anaerobic blood culture bottles. The positive culture broth was streaked onto a blood agar plate (BAP) and incubated for 24 hr at 35°C in a 5% CO2 atmosphere, but few colonies were observed. The positive culture broth was also streaked onto a BAP and cultured anaerobically for 48 hr. Tiny gray-colored, non-hemolytic colonies were observed on the BAP cultured anaerobically; Gram staining of this microorganism revealed gram-positive cocci (Fig. 1). The isolate was positive for pyrrolidonyl arylamidase production, but was negative for leucine aminopeptidase production. The isolate was identified as H. kunzii by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-