TABLE 1.
Criteria used to define the microbiological cause of infective endocarditisa
| Result | Criterion |
|---|---|
| Considered causal for endocarditis | Same pathogen in blood culture, valve culture, and 16S rRNA PCR |
| Same pathogen in at least one culture-based and 16S rRNA PCR, with a clinical presentation consistent with the pathogen identified | |
| A pathogen identified by any one modality—blood culture, valve culture, or 16S rRNA PCR—would only be considered if the same pathogen is identified in more than one specimen and if the clinical, operative, and histopathologic findings are consistent with endocarditis caused by that microorganism. | |
| A pathogen identified by any one modality—blood culture, valve culture, or 16S rRNA PCR —in only one specimen would only be considered if endocarditis caused by the pathogen has been well described and if the clinical, operative, and histopathologic findings are consistent with endocarditis caused by that microorganism. | |
| Excluded as the cause of endocarditis | Single colony or rare growth of coagulase-negative staphylococci, viridans streptococci, Propionibacterium acnes, corynebacteria, or Bacillus spp. on a single valve culture, unless the same pathogen is also identified by a different modality |
| Growth of coagulase-negative staphylococci, viridans streptococci, Propionibacterium acnes, corynebacteria, or Bacillus spp. on a single valve culture if there is another identified pathogen that could explain the endocarditis | |
| Positive 16S rRNA PCR results for coagulase-negative staphylococci, viridans streptococci, Propionibacterium acnes, corynebacteria, or Bacillus spp. on a single specimen if there is another identified pathogen that could explain the endocarditis | |
| Growth of any pathogen that is clearly inconsistent with endocarditis when interpreted in the context of clinical presentation, operative findings, histopathologic findings, and other microbiological findings |