42002. The first case of infective endocarditis caused by Helicobacter cinaedi identified by 16S rRNA gene sequencing and H. cinaedi specific-PCR
Session: Poster Abstract Session: Medical Student Poster Session
Friday, October 4, 2013
Room: Yerba Buena Ballrooms
  • poster IDSA.pdf (4.8 MB)
  • Background: Identification of the causative pathogen is challenging in culture negative infective endocarditis (IE).  Helicobacter cinaedi (H. cinaedi) is a rare pathogen in humans, associated with bacteremia, cellulitis, and perirectal abscess.  It has never been reported to cause IE in the literature.  We report the first case of an IE due to H. cinaedi, which was identified by 16S rRNA gene sequencing and H. cinaedi-specific PCR.

    Methods: A 49-year-old Japanese man with a history of diabetes mellitus was admitted for fever and progressive dyspnea on exertion for one week.  The chest X-ray showed pulmonary edema.  The transthoracic echocardiogram showed severe aortic regurgitation (AR) and a vegetation on the aortic valve.  He was diagnosed with acute heart failure secondary to AR due to IE.  Four sets of blood culture were obtained before antibiotics were initiated.  The emergent aortic valve replacement was performed on the day of admission.

    Results: The surgical and histopathological findings of the aortic valve confirmed the diagnosis of IE.  All the blood cultures on admission were negative.  Culture of the surgical specimen was negative aerobically, microaerobically, with 5% CO2, or anaerobically, but 16S rRNA gene sequencing and PCR for H. cinaedi-specific cytolethal distending toxin gene (cdt) confirmed the microbiological diagnosis of H. cinaedi.  The patient was given six weeks of antibiotics including ceftriaxone followed by levofloxacin.  The patient has no evidence of recurrence at six months post operation. 

    Conclusion: This is the first report of IE caused by H. cinaedi.  H. cinaedi is an indolent pathogen which is often difficult to grow on culture.  16S rRNA gene sequencing can be a useful method to confirm the causative pathogen of culture negative IE, especially for an organism like H. cinaedi.

    Osamu Hamada, MD1, Hidetaka Kitazono, MD1, Shigeki Fujitani, M.D., Ph.D.1, Eiji Hiraoka, MD1, Hiroyuki Watanabe, MD2, Nobuhiro Ariyoshi, MD1, Yoshikazu Kawazuma, MD1, Toshihiko Suzuki, MD1, Shuichiro Takanashi3 and Ken Kikuchi, MD4, (1)Tokyo Bay Urayasu Ichikawa Medical Center / Noguchi Hideyo Memorial International Hospital, Urayasu, Japan, (2)Cardiology, Tokyo Bay Urayasu Ichikawa Medical Center / Noguchi Hideyo Memorial International Hospital, Urayasu, Japan, (3)Cardiovascular Surgery, Sakakibara Heart Institute, Fuchu-shi. Tokyo, Japan, (4)Department of Infectious Control Science, Juntendo University Faculty of Medicine, Tokyo, Japan


    O. Hamada, None

    H. Kitazono, None

    S. Fujitani, None

    E. Hiraoka, None

    H. Watanabe, None

    N. Ariyoshi, None

    Y. Kawazuma, None

    T. Suzuki, None

    S. Takanashi, None

    K. Kikuchi, None

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