Blood Culture Negative Endocarditis: A Review of Laboratory Diagnostic Approaches

Abstract

Infective endocarditis is a potentially fatal condition, and identifying the pathogen is crucial to optimizing antibiotic treatment. While a blood culture takes time and may yield negative results, it remains the gold standard for diagnosis, blood culture-negative endocarditis, which accounts for up to 20% of infective endocarditis cases, poses a clinical challenge with increasing mortality. To better understand the etiology of blood culture-negative infective endocarditis, we reviewed non-culture-based strategies and compared the results. Serology tests work best in limited pathogens, such as Coxiella burnetii and Bartonella infections. Most of the pathogens identified by broad-range PCR tests are Streptococcus spp , Staphylococcus spp and Propionibacterium spp . adding specific real-time PCR assays to the systematic PCR testing of patients with blood culture-negative endocarditis will increase the efficiency of diagnosis. Recently, metagenomic next-generation sequencing has also shown promising results.

Culture-Negative Endocarditis in an Immunocompromised Patient: A Case of Suspected Bartonella and Coxiella Co-Infection

“…Serology tests work best in limited pathogens, such as Coxiella burnetii and Bartonella infections. 28 This patient had an intrinsically accentuated risk of IE due to his BAV, and this “perfect storm” scenario may have precipitated his CNE-related sepsis and concomitant heart failure. It is also integral to consider his outpatient antibiotic stewardship, renal transplant, and immunosuppressive regimen as significant drug-drug interactions (hydroxychloroquine and tacrolimus) can lead to serious adverse events.…”

Endocarditis in critically ill patients: a review

“…In patients with negative blood cultures after 5 days of incubation and subculturing using standard methods, blood culture-negative IE should be suspected. Culture-negative IE may be caused by previous antibiotic therapy, fungi, or fastidious intracellular bacteria that require specialized culture media and grow relatively slowly [36].…”

Mitral Valve Culture Negative Endocarditis Complicated by Severe Mitral Regurgitation and Chordae Tendinea Rupture

“…The diagnosis of infective endocarditis is based on Duke's Criteria, the major criteria of which is a positive blood culture [1] . However, approximately 20% of cases of infective endocarditis have a negative blood culture (blood culture negative endocarditis [BCNE]) [2] , which presents clinicians with a challenge of proper diagnosis and treatment. The most common causes of culture-negative endocarditis are previous administration of antimicrobials and the presence of unculturable organisms [3] .…”