RT Journal Article SR Electronic(1) A1 Washio, Yohei A1 Sakamoto, Shun-ichiro A1 Saito, Ryoichi A1 Nei, Takahito A1 Morishima, Masayo A1 Shinoyama, Akihiro A1 Tashiro, Ayaka A1 Sugimoto, RyojiYR 2019 T1 Infective endocarditis caused by Cardiobacterium valvarum JF Access Microbiology, VO 1 IS 8 OP SP e000040 DO https://doi.org/10.1099/acmi.0.000040 PB Microbiology Society, SN 2516-8290, AB We report a case with infective endocarditis (IE) due to Cardiobacterium valvarum . The patient was a 57-year-old male, who was referred to our hospital based on suspected IE detected by transthoracic echocardiography at a neighbourhood clinic. Three sets of blood cultures obtained on admission yielded positive results, and revealed rather slender and linear Gram-negative bacilli with a rosette formation that dyed minimally, with a pale white appearance. Although no isolates were identified by conventional methods, C. valvarum was ultimately identified by 16 S ribosomal RNA genotyping. HACEK group strains are difficult to identify by conventional methods. Therefore, if Gram-negative bacilli are isolated from IE patients, 16 S ribosomal RNA genotyping will be necessary. Furthermore, IE due to C. valvarum is very rare. We thus discuss our case in comparison with previous reports., UL https://www.microbiologyresearch.org/content/journal/acmi/10.1099/acmi.0.000040