Culture-negative bacterial endocarditis may be attributed to fastidious microorganisms, prior institution of antibiotic treatment, or both. We describe a case of culture-negative endocarditis in which a modified Steiner stain revealed bacterial structures in the resected heart valve material. Prompted by this finding, broad-range polymerase chain reaction (PCR) amplification of small-subunit ribosomal DNA (16S rDNA) was performed, and Cardiobacterium hominis sequences were detected. This case demonstrates the usefulness of both the Steiner stain and broad-range direct molecular amplification as supplemental diagnostic tools in identification of otherwise unexplained infections.
Aortic valve tissue specimen from a 48-year-old man with culture-negative endocarditis. Pleomorphic argyrophilic rods and filaments are seen in panel A and clusters of bacilli in panel B (modified Steiner stain, original magnification ×1000).
Agarose gel electrophoresis of polymerase chain reaction (PCR) products. Twenty-six thermal cycles with primers 516F and 806R were performed. The M lanes indicate molecular-weight markers; lane 1, 5-µL heart valve digestion product used as PCR template; lane 2, 0.5-µL heart valve digestion product; lane 3, sterile water processed in a manner similar to the heart valve specimen (digestion control); lane 4, sterile water as template (negative PCR control); lane 5, Escherichia coli DNA (equivalent to 500 recombinant ribsomal RNA gene copies, positive PCR control); and bp, base pairs.
Thank you for submitting a comment on this article. It will be reviewed by JAMA Internal Medicine editors. You will be notified when your comment has been published. Comments should not exceed 500 words of text and 10 references.
Do not submit personal medical questions or information that could identify a specific patient, questions about a particular case, or general inquiries to an author. Only content that has not been published, posted, or submitted elsewhere should be submitted. By submitting this Comment, you and any coauthors transfer copyright to the journal if your Comment is posted.
* = Required Field
Disclosure of Any Conflicts of Interest*
Indicate all relevant conflicts of interest of each author below, including all relevant financial interests, activities, and relationships within the past 3 years including, but not limited to, employment, affiliation, grants or funding, consultancies, honoraria or payment, speakers’ bureaus, stock ownership or options, expert testimony, royalties, donation of medical equipment, or patents planned, pending, or issued. If all authors have none, check "No potential conflicts or relevant financial interests" in the box below. Please also indicate any funding received in support of this work. The information will be posted with your response.
Some tools below are only available to our subscribers or users with an online account.
Download citation file:
Web of Science® Times Cited: 15
Customize your page view by dragging & repositioning the boxes below.
More Listings atJAMACareerCenter.com >
Enter your username and email address. We'll send you a link to reset your password.
Enter your username and email address. We'll send instructions on how to reset your password to the email address we have on record.
Athens and Shibboleth are access management services that provide single sign-on to protected resources. They replace the multiple user names and passwords necessary to access subscription-based content with a single user name and password that can be entered once per session. It operates independently of a user's location or IP address. If your institution uses Athens or Shibboleth authentication, please contact your site administrator to receive your user name and password.