No abstract

was expected to contain information for at least partial phylogenetic characterization that was useful to subclassify clinically important bacterial species (13 ). The variability of this interprimer region was not revealed clearly in conventional PCR because of the low-resolution capability of agarose gel electrophoresis. However, the intrinsic variability of real-time PCR products could be disclosed by high-resolution melting curve analysis, where T m could serve as a measure of DNA length and nucleotide composition (Table 1).We identified four subgroups of bacteria each with distinct T m s in a limited range. Similar to any broad-range PCR detection of bacterial DNA, the assay could not determine the viability of the organism, particularly during the treatment with antibiotics, or identify the bacterial species. However, because it detects a broad range of bacteria usually present in clinical specimens, this assay may complement the time-consuming blood culture test and supply timely information needed by physicians to determine whether bacterial infection has occurred and to plan treatment regimens. The unique feature of the method presented in this study (the classification information disclosed by the melting peak profiles) could be used in the design of multiplex PCR to confirm the identity of infectious bacterial species in a clinical or laboratory setting.In summary, the decontamination procedure and the broad-range real-time PCR method allow rapid detection, quantification, and classification of several clinically important bacteria and may facilitate rapid detection of local and systemic infection. Our laboratory and others have demonstrated the presence of microchimeric cells in the peripheral blood of nonpregnant patients with systemic sclerosis (SSc) (1-4 ). In addition, we have demonstrated the presence of ma- Detection of Microchimeric Cells in the Peripheral