# Development of Monoclonal Antibody against PirB and Establishment of a Colloidal Gold Immunochromatographic Assay for the Rapid Detection of AHPND-Causing Vibrio

## TL;DR

This study develops a rapid test using a special antibody to detect harmful bacteria causing a deadly shrimp disease, which could improve disease control in aquaculture.

## Contribution

A monoclonal antibody and colloidal gold immunochromatographic assay were developed for rapid detection of AHPND-causing Vibrio.

## Key findings

- The test accurately distinguishes between AHPND-causing and non-AHPND-causing Vibrio species.
- The developed assay shows good specificity and potential for early diagnosis of AHPND.
- Further optimization is needed to improve the sensitivity of the test for practical use.

## Abstract

This research aims to develop rapid and user-friendly diagnostic approaches for the detection of acute hepatopancreatic necrosis disease (AHPND), a lethal disease threatening the shrimp industry worldwide. We have developed a special antibody to target a virulence protein in the bacteria that cause this disease. By using this antibody, we have created a rapid and accurate test using gold particles to detect these harmful bacteria. The test has shown promising results, accurately distinguishing between disease-causing and harmless bacteria. This innovative method could revolutionize the early detection and management of AHPND in shrimp farms, leading to healthier shrimp production and improved disease control. Ultimately, this advancement has the potential to benefit the aquaculture industry by safeguarding shrimp populations and ensuring sustainable farming practices.

Acute hepatopancreatic necrosis disease (AHPND) poses a significant threat to shrimp aquaculture worldwide, necessitating the accurate and rapid detection of the pathogens. However, the increasing number of Vibrio species that cause the disease makes diagnosis and control more difficult. This study focuses on developing a monoclonal antibody against the Photorhabdus insect-related (Pir) toxin B (PirB), a pivotal virulence factor in AHPND-causing Vibrio, and establishing a colloidal gold immunochromatographic assay for the enhanced early diagnosis and monitoring of AHPND. Monoclonal antibodies targeting PirB were developed and utilized in the preparation of colloidal-gold-labeled antibodies for the immunochromatographic assay. The specificity and sensitivity of the assay were evaluated through various tests, including antibody subclass detection, affinity detection, and optimal labeling efficiency assessment. The developed PirB immunochromatographic test strips exhibited a good specificity, as demonstrated by the positive detection of AHPND-causing Vibrio and negative results for non-AHPND-causing Vibrio. The study highlights the potential of the developed monoclonal antibody and immunochromatographic assay for the effective detection of AHPND-causing Vibrio. Further optimization is needed to enhance the sensitivity of the test strips for improved practical applications in disease prevention and control in shrimp aquaculture.