Takahashi Yoshinori, Nakade Junya, Zaimoku Yoshitaka, Watanabe Naoki, Watari Tomohisa, Otsuka Yoshihito, Iwata Yasunori, Kanamori Hajime
Department of General Medicine and Infectious Diseases, JA Toyama Koseiren Takaoka Hospital, Takaoka, Toyama, Japan.
Department of Infection Control and Prevention, University Hospital, Kanazawa University, Kanazawa, Ishikawa, Japan; Department of Hospital Pharmacy, University Hospital, Kanazawa University, Kanazawa, Ishikawa, Japan.
J Infect Chemother. 2025 Feb;31(2):102502. doi: 10.1016/j.jiac.2024.08.017. Epub 2024 Aug 28.
Blood culture-negative infective endocarditis (BCNE) has a poorer prognosis than culture-positive cases. Thus, it is crucial to determine the pathogenic microorganism using molecular diagnostic techniques, in addition to conventional techniques, including cultures of blood and/or resected valve tissue. Herein, we report a case of culture-negative infective endocarditis (IE) caused by Neisseria bacilliformis, as identified by 16S rRNA analysis of valve tissue. N. bacilliformis a non-gonococcal and non-meningococcal Neisseria species that partially comprises the oropharyngeal microbiome, and reports of invasive infections have increased recently. We conducted a literature review of IE caused by N. bacilliformis and found that beta-lactam antibiotics were effective with a relatively favorable prognosis. To the best of our knowledge, this is the first case of culture-negative IE in which N. bacilliformis was identified via 16S rRNA analysis.
