Background Bloodstream infection (BSI) is a life-threatening condition with high morbidity and mortality rates worldwide. Early diagnosis of BSI is critical to avoid the unnecessary application of antimicrobial agents and for proper treatment. However, the current standard methods based on blood culture are time-consuming, thus failing to provide a timely etiological diagnosis of BSI, and common PCR-based detection might be inhibited by matrix components. Methods The current study explored an integrated pre-analytical treatment protocol for whole blood samples, wherein pathogens are enriched and purified by incubation and concentration, and inhibitors are inactivated and removed. Further, this study developed and evaluated a novel high-throughput multiplex genetic detection system (HMGS) to detect 24 of the most clinically prevalent BSI pathogens in blood culture samples and pre-treated whole blood samples. The specificity and sensitivity were evaluated using related reference strains and quantified bacterial/fungal suspensions. The clinical utility of BSI-HMGS combined with the pre-analytical treatment protocol was verified using blood cultures and whole blood samples. Results The combined pre-treatment protocol and BSI-HMGS was highly specific for target pathogens and possessed a low detection limit for clinical whole blood samples. The pre-treatment protocol could deplete the PCR inhibitors effectively. For blood culture samples, the current method showed 100.0% negative percent agreements and > 87.5% positive percent agreements compared to the reference results based on blood culture findings. For whole blood samples, the current method showed 100.0% negative percent agreements and > 80.0% positive percent agreements compared to the reference results for most pathogens. The turnaround time was ≤ 8 h, and all the procedures could be conducted in a general clinical laboratory. Conclusion The BSI-HMGS combined with the pre-treatment protocol was a practical and promising method for early and precise detection of BSIs, especially for areas without access to advanced medical facilities.

Background In recent years, the incidence of bloodstream infections (BSI) has increased, the composition of pathogenic bacteria has changed, and drug resistance among bacteria has gradually increased due to the widespread use of interventional techniques, broad‐spectrum antibacterial drugs, hormones, and immunosuppressive agents. Here, we have developed a multiplex PCR assay kit for the detection of pathogens (14 Gram‐negative bacteria, 15 Gram‐positive bacteria, and 4 fungi) in whole blood from patients with BSI using five‐color fluorescent multiplex PCR followed by capillary electrophoresis. Our assay exhibits a diagnosis of higher quality and an improved detection rate for common pathogens. Methods A local genome DNA database of 33 pathogenic bacteria was constructed. Next, “Exhaustive” primer search of the full coding sequence of the reference genomes of these bacteria was performed. Panels with minimal interactions between primers and amplicons were selected by random sampling and testing by a recursive algorithm. Primers and Mg2+ concentrations and PCR reaction procedures were optimized to maximize the detection efficacy. Results The LOD of the kit was determined as 100 copies/μl. Using clinical samples, results generated by this kit and regular blood culture method were found to be 95.08% consistent. Additionally, six pathogens which were unidentifiable by blood culture were successfully detected by this kit. Conclusion Our study provided a bioinformatics approach to the challenge of primer design in multiplex PCR, and combined with optimized wet lab practice, a multiplex PCR‐based assay kit for BSI with higher sensitivity and accuracy than blood culture was produced.