[P008] Poster

1:00 PM - 1:50 PM JST(4:00 AM - 4:50 AM UTC)

[P04-602] Establishment of a Pathogen-Identification System for Bloodstream Infections by Baculovirus Surface Display Technology

○Bing-Yan Li¹, Ching-Chi Li², Chih-Hsuan Tsai¹ (1. Department of Microbiology and Immunology, College of Medicine, National Cheng Kung University (Taiwan), 2. Department of Internal Medicine, National Cheng Kung University Hospital, College of Medicine, National Cheng Kung University (Taiwan))

Keywords:

Bloodstream infection,Pathogen identification,Baculovirus expression system,Rapid diagnostic tool

Bloodstream infection (BSI), caused by bacteria, fungi, or viruses, is a life-threatening systemic condition closely associated with sepsis and high mortality. Conventional diagnostic methods, such as blood culture, are time-consuming and may delay clinical decisions. Molecular diagnostic approaches, such as polymerase chain reaction (PCR), offer improved sensitivity and specificity. However, these methods are typically expensive and require a well-equipped laboratory, limiting their widespread clinical application. Therefore, rapid and accurate pathogen-identification systems are urgently needed in clinical practice. Single-chain variable fragments (scFvs) are the smallest functional units of antibodies responsible for antigen binding, consisting of variable regions of heavy (VH) and light (VL) chains linked by a flexible peptide. Due to their small size, high flexibility, and cost-effective production, scFvs are well-suited for high-density immobilization on biosensing platforms and have great potential in diagnostic applications. In this study, we aimed to establish an scFv-based pathogen-identification system for BSI. We developed scFvs targeting key Escherichia coli antigens and toxins, including outer membrane protein A (OmpA), O-antigen, Shiga toxin B (StxB), and heat-labile and heat-stable enterotoxins (LT and ST). These scFvs were expressed through the baculovirus-insect cell expression system. Instead of being secreted and purified, the scFv constructs were designed to be displayed on the surface of recombinant baculoviruses and infected insect cells. After virus infection, the expression and surface display of the scFvs were examined in the infected insect cells. Bacterium-capture ability was evaluated using a cell-based ELISA. In the future, this system could be integrated with electro-biosensing platforms, enabling the detection of BSI through electrical signal changes generated by antigen–antibody interactions. Overall, this study establishes a foundation for a rapid and specific pathogen-identification system for BSI and highlights the potential of scFv-based tools for future clinical diagnostic applications.