Bacterial identification by 16S rRNA gene PCR-hybridization as a supplement to negative culture results

PCR-hybridization was compared to culture methods for evaluating suspected blood infections. A total of 231 clinical samples from blood culture bottles that were flagged positive by the BacT/Alert system or were negative 1 week after inoculation were tested. When the PCR-hybridization and culture method results were compared, the positive and negative concordance rates were 99.2% (122/123) and 89.5% (94/105), respectively. Of the negative blood cultures, 10.5% (11/105) were positive by PCR-hybridization. Supplemental testing of negative blood cultures may identify bacterial pathogens that are undetectable by culture methods.