The application of multiplex fluorescent PCR in the diagnosis of clinical bloodstream infection

Objective To observe the application of multiple fluorescent PCR (Polymerase Chain Reaction) in the diagnosis and clinical detection of bloodstream infection. Methods 256 blood cultures were collected by the Laboratory Department of Yinzhou People′s Hospital from January 2018 to May 2018, and were detected by multiplex fluorescent PCR. The results of the PCR were compared with the traditional blood culture bacteria identification instrument (traditional blood culture method). The number of positive and negative samples and the number of corresponding samples of the two methods were counted. Then, they analyzed the specificity and sensitivity of multiplex fluorescence PCR in the diagnosis of bloodstream flow infections. Results A total of 18 pathogenic microbes are detected through blood culture and PCR. Multiple fluorescent PCR detects 142 positive samples and 114 negative samples. Among them, 132 samples also show positive through blood culture, and 111 samples show negative. The consistency rate between multiple PCR and traditional blood cultures is 91.8% (235/256). The negative prediction rate of PCR is 97.4% (111/114), sensitivity rate 97.8% (132/135), specificity rate 91.7% (111/121). 10 samples show positive through multiple fluorescence PCR but negative for blood culture, 3 samples show positive through blood culture but negative for PCR. Besides, there are 3 types of pathogens that exceed the detection range of PCR. Conclusions Multiplex PCR method can detect 17 pathogens in blood culture specimens of patients, which can not only optimize the traditional blood culture process, but also greatly shorten the reporting time and improve the detection rate of blood culture methods. Especially for patients treated with antibiotics, it can reduce missed detection and improve the diagnostic rate of bloodstream infections. Key words: Bacteremia; Fungemia; Polymerase chain reaction; Blood culture