Highly specific and super-sensitive Dot-ELISA and colloidal gold immunochromatographic strips for the detection of Burkholderia glumae and Burkholderia plantarii of Rice bacterial panicle blight

Burkholderia glumae (B. glumae) and Burkholderia plantarii (B. plantarii) are primary causal agents of rice bacterial panicle blight (RBPB) and cause substantial yield losses in rice worldwide. Given their seed-borne transmission characteristics, quarantine status and destructive hazards, rapid, super-sensitive, highly specific on-site detection technologies are urgently needed. Here, using B. glumae Os48 and B. plantarii ZJ171 as immunogens, we prepared two highly specific and ultra-sensitive monoclonal antibodies (mAbs) against B. glumae (4A7 and 8C5) and two highly specific and ultra-sensitive mAbs against B. plantarii (12B5 and 14B3). We then developed dot-enzyme-linked immunosorbent assays (Dot-ELISA) and colloidal gold immunochromatographic strip (CGICS) assays for detecting B. glumae and B. plantarii with the prepared mAbs as the detection antibodies. These developed mAb-based serological techniques enabled the rapid, broad-spectrum, and specific detection of B. glumae and B. plantarii, respectively, and showed no cross-reaction with other control plant bacteria included in the analysis. Moreover, the detection limits of the Dot-ELISAs for B. glumae or B. plantarii were up to 1.96 × 10⁴ colony-forming units (CFU)/mL, and CGICSs could detect B. glumae and B. plantarii at concentrations as low as 9.78 × 10³ CFU/mL. Surprisingly, these two serological techniques are 2 ~ 8 times more sensitive than conventional polymerase chain reaction (PCR). Collectively, the two newly developed serological techniques in this work provide two simple, rapid, broad-spectrum, highly specific, ultra-sensitive and on-site means to detect B. glumae and B. plantarii in rice grains and leaves, thereby offering reliable and practical tools for the detection and quarantine of these two RBPB pathogens.