Molecular Test Rapidly Diagnoses Sepsis
By Labmedica International staff writers
Posted on 01 Jun 2017
Image: The TaqMan Multiplex Master Mix for real-time polymerase chain reactions (Photo courtesy of Thermo Fisher Scientific).
Rapid diagnosis of sepsis in hospitalized patients is crucial because in severe cases, there is an average 7.6% decrease in survival rate per hour from the onset of low blood pressure without effective antimicrobial treatment.
Early identification of a pathogen increases the chance of targeting the correct agent and may avoid misuse of antibiotics. A molecular test has been developed that can rapidly and reliably diagnose sepsis, a potentially life-threatening complication of bacterial infections.
Scientists at the Tongde Hospital of Zhejiang Province designed primers and TaqMan probes that were to be complementary to conserved regions in the 16S rDNA gene of different kinds of bacteria. To evaluate accurately, sensitively, and specifically, the known bacteria samples (Standard strains, whole blood samples) are determined by TaqMan-Based Multiplex real-time polymerase chain reaction (PCR). In addition, 30 blood samples taken from patients with clinical symptoms of sepsis were tested by TaqMan-Based Multiplex real-time PCR and blood culture.
The investigators found that the mean frequency of positive for Multiplex real-time PCR was 96% at a concentration of 100 colony-forming units (CFU)/mL, and it was 100% at a concentration greater than 1,000 CFU/mL. All the known blood samples and standard strains were detected positively by TaqMan-Based Multiplex PCR; no PCR products were detected when DNAs from other bacterium were used in the multiplex assay. Among the 30 patients with clinical symptoms of sepsis, 18 patients were confirmed positive by Multiplex real-time PCR and seven patients were confirmed positive by blood culture.
The authors concluded that TaqMan-Based Multiplex real-time PCR assay with highly sensitivity, specificity and broad detection range was a rapid and accurate method in the detection of bacterial pathogens of sepsis and should have a promising usage in the diagnosis of sepsis. The study was published on May 17, 2017, in the Journal of Clinical Laboratory Analysis.