Evaluation and Optimization of Microdrop Digital PCR for Detection of Serotype A and B Clostridium botulinum

Abstract

Clostridium botulinum is the causative pathogen of botulism. Laboratory detection of C. botulinum is essential for clinical therapy treatment of botulism due to the difficulty in diagnosis, especially in infant botulism. The extreme toxicity of botulinum neurotoxin (BoNT) requires a sensitive detection method. Due to the detection limit of real-time quantitative PCR (q-PCR), a more sensitive detection method, micro-drop digital PCR (ddPCR) was applied in C. botulinum main serotypes A and B. The following performance criteria were evaluated by ddPCR: analytical sensitivity; repeatability; and diagnostic specificity. The limit of detection (LOD) was 0.84 and 0.88 copies/μl for BoNT A and B genes, respectively, by ddPCR with high specificity, compared to 5.04×102 and 6.91×102 copies/μl by q-PCR. It was increased 10 times compared with q-PCR in spiked stool samples. This improvement in sensitivity was especially important in clinical samples as more positive samples were detected by digital PCR compared with q-PCR. Meanwhile, enrichment time for low bacteria content samples was shortened by four hours both in serotypes A and B C. botulinum by ddPCR compared with q-PCR, which are important for laboratory diagnosis and epidemiology work.

Advances in droplet digital polymerase chain reaction on microfluidic chips

“…The advantage is valuable for laboratory analysis and clinical diagnosis as well as epidemiological studies. 30,139 5.3.2. Virus detection.…”

Development and clinical validation of a dual ddPCR assay for detecting carbapenem-resistant Acinetobacter baumannii in bloodstream infections

“…Droplet digital PCR (ddPCR) is one of the emerging nucleic acid detection and quantitation technologies. It separates the template DNA into tens of thousands of independent reaction units for amplification, so it can detect the target gene without being interfered by the complex environment in the blood ( Váňová et al, 2021 ; Zheng et al, 2021 ; Del Arco et al, 2022 ; Gao et al, 2022 ). Unlike real-time quantitative PCR (qPCR), ddPCR does not rely on the amplification curve cycle thresholds (Ct values) and standard curves.…”