# Dual-Channel Colloidal Gold-Based Immunochromatographic Test Strip for Rapidly Differentiating Between Two Major Groups of Paracidovorax citrulli

## TL;DR

A new test strip was developed to quickly identify two types of bacteria causing a plant disease, helping farmers manage outbreaks more effectively.

## Contribution

A dual-channel colloidal gold immunochromatographic test strip was developed to differentiate two genetic groups of Paracidovorax citrulli.

## Key findings

- The test strip can distinguish between group I and group II P. citrulli strains with high sensitivity.
- The test strip showed no cross-reactions with related bacterial species.
- The device is stable and suitable for field use in managing bacterial fruit blotch.

## Abstract

Bacterial fruit blotch (BFB) caused by Paracidovorax citrulli is a severe threat to melon, watermelon, and other cucurbit crop production worldwide. The long-term adaptation of the pathogen to environmental conditions has resulted in substantial genetic diversity. In this study, we used P. citrulli strains from two groups as immunogens to obtain antibodies that were used to generate A.C1 and A.C2 colloidal gold immunochromatographic single test strips, which specifically identified group I and group II P. citrulli strains, respectively. We combined the A.C1 and A.C2 single test strips in a dual-channel plastic cartridge to construct a dual-channel colloidal gold immunochromatographic test strip able to distinguish between P. citrulli strains from two distinct groups. Test strip sensitivity reached 106 CFU/mL under ideal conditions. Moreover, it was relatively stable, with no cross-reactions with strains of closely related genera. The dual-channel test strip developed in this study may provide farmers with a useful tool for managing BFB through the prompt implementation of quarantine procedures in the field.