A new causative bacteria of infective endocarditis, Bergeyella cardium sp. nov.

• We report the first cases of infective endocarditis due to a new species of Bergeyella, Bergeyella cardium sp. nov., are reported.
• B. cardium sp. nov. isolates were susceptible to ampicillin/sulbactam, cefepime, ceftriaxone, penicillin, ciprofloxacin, and piperacillin/tazobactam.
• Our report of B. cardium sp. nov., isolated from patients, expands the range of known bacterial causes of infective endocarditis.

The first cases of infective endocarditis due to a new species of Bergeyella, Bergeyella cardium sp. nov., are reported. Two strains, 13-07T (= JCM 30115T = NCCP 15908T) and 13-16, were independently isolated from 2 patients in different hospitals in Korea. Initially, the isolates were identified as Brevundimonas spp.; however, their 16S rRNA gene sequences shared a similarity of 94.9% with Bergeyella zoohelcum, implying that they are a new species belonging to of the genus Bergeyella. The organisms might be susceptible to many commonly used antibiotics, including penicillin. The first case was successfully treated with ceftriaxone, and the second, with piperacillin/tazobactam plus amikacin.