(A) The unrooted three-domain tree derived by phylogenetic analysis of 16S rRNA and other information-processing genes. (B) The rooted three-domain tree. (C) The network of life. A: archaea ...

Blood specimens collected from 172 cases of suspected septicemia were cultured and then tested separately by PCR for the bacterial 16S rRNA. Of the 172 clinical cases, 17 cases tested positive by PCR.