What Does 16S rRNA Gene-Targeted Next Generation Sequencing Contribute to the Study of Infective Endocarditis in Heart-Valve Tissue?

Area of Science:

• Microbiology
• Infectious Diseases
• Genomics

Background:

• Infective endocarditis (IE) is a severe infection requiring accurate etiological diagnosis for effective treatment and reduced mortality.
• Conventional methods, including blood cultures, may fail to identify the causative agent in a significant number of IE cases.
• Metataxonomics offers a potential alternative for comprehensive microbiological diagnosis.

Purpose of the Study:

• To evaluate the utility of metataxonomics, specifically 16S rRNA gene sequencing, for improving the microbiological diagnosis of IE.
• To compare the diagnostic performance of metataxonomics with conventional techniques in IE patients.
• To explore the potential of metataxonomics in identifying coinfections or previously undiagnosed cases.

Main Methods:

• Next-generation sequencing (NGS) of the V3-V4 region of the 16S rRNA gene was performed on heart valve tissues from 27 IE patients.
• Samples included native valves, intravascular devices, and prosthetic valves.
• Results were compared with conventional microbiological diagnostic techniques.

Main Results:

• Metataxonomics achieved diagnostic concordance with conventional methods in 88.9% of cases (24/27).
• It successfully identified the etiological agent in one patient with previously negative blood cultures.
• NGS also suggested coinfections in one patient and identified mixed infections in three cases, with causative agents detected at high percentages (>99% reads in 22 cases).

Conclusions:

• 16S rRNA gene-targeted metataxonomics is a valuable tool for identifying causative agents in infective endocarditis.
• This NGS-based approach can enhance microbiological diagnosis, particularly in cases with negative conventional cultures.
• Further research is warranted to establish 16S rRNA gene-targeted NGS as a routine diagnostic method for IE.