Annals of Clinical Microbiology (Ann Clin Microbiol) 2006 April Volume 9, Issue 1, pages 64-70.
https://doi.org/10.5145/ACM.2006.09.1.64
Evaluation of a 16S rDNA PCR Assay for Detection of Bacterial Pathogens in Blood Culture Broth
Sook-Jin Jang1,2, Jin Hee Kim1, Young Sook Kim3, Jong Hee Shin4, Geon Park1, Bidur Prasad Chaulagain1,2, Dae Soo Moon1, and Young Jin Park1
Department of Laboratory Medicine1, Research Center for Resistant Cells2, and Department of Diagnostic Radiology3, Chosun University Medical School; and Department of Laboratory Medicine4, Chonnam University Medical School, Gwangju, Korea
Abstract
Background: Rapid detection of pathogens in blood is important in patient management, because the mortality rate associated with bloodstream infections is very high. We evaluated the efficiency of a 16S rDNA PCR assay for the detection of various pathogens in blood culture broth in a clinical laboratory.
Methods: 16S rDNA PCR was performed on 221 blood culture bottles consisting of 99 culturepositive and 122 culture-negative samples. The results were compared with conventional culture methods. We also compared the efficiency of three DNA extraction and purification methods using proteinase K, triton X-100, and benzyl alcohol-guanidine DNA extraction of blood culture broths.
Results: The 16S rDNA PCR method detected 95 (12 Staphylococcus aureus, 27 coagulase negative staphylococci, 10 enterococci, 5 streptococci, 37 gram negative bacilli, 4 corynebacteria) of 99 positive culture bottles. Four false-negative results were obtained for bottles containing 2 Corynebacterium, 1 Escherichia coli, and 1 S. aureus species. All 122 bottles that showed no blood culture growth were negative by 16S rDNA PCR. Overall, the sensitivity, specificity, positive predictive values and negative predictive values of 16S rDNA PCR relative to the culture results were 96.0%, 100%, 100%, and 96.8%, respectively. Among the three DNA extraction methods, the benzyl alcohol-guanidine method was most effective.
Conclusion: The 16S rDNA PCR assay is a rapid and efficient means of detecting various pathogens in the blood and has great potential for use in the clinical microbiology laboratory. (Korean J Clin Microbiol 2006;9(1):64-70)