Rapid detection and identification of viral and bacterial fish pathogens using a DNA array-based multiplex assay

Area of Science:

• Aquatic animal health
• Molecular diagnostics
• Fish pathology

Background:

• Fish diseases caused by diverse pathogens threaten aquaculture and the ornamental fish industry.
• Current diagnostic methods for fish pathogens lack speed, accuracy, and reliability.
• This limitation hinders effective fish disease management.

Purpose of the Study:

• To develop a novel diagnostic technique for simultaneous detection and identification of specific fish pathogens.
• To address the limitations of existing fish pathogen diagnostic methods.

Main Methods:

• Multiplex and broad-range PCR amplification combined with DNA array hybridization.
• Targeting DNA polymerase and helicase genes for cyprinid herpesviruses (CyHV-1, CyHV-2, CyHV-3).
• Utilizing the ribosomal RNA gene for identifying pathogenic Flavobacterium species (F. branchiophilum, F. columnare, F. psychrophilum).

Main Results:

• Achieved 100% specificity in identifying target viral and bacterial species.
• Demonstrated high sensitivity: detection of ≤10 viral genomes or <1 pg bacterial DNA.
• Successfully applied the array for pathogen detection in complex infected tissue samples.

Conclusions:

• The developed DNA array hybridization method offers a sensitive and specific tool for fish pathogen diagnosis.
• This technique can significantly improve fish disease management in aquaculture.
• The method facilitates simultaneous identification of multiple critical fish pathogens.