Developing a novel TaqMan qPCR assay for optimizing Salmonella Pullorum detection in chickens

Area of Science:

• Veterinary Microbiology
• Molecular Diagnostics
• Poultry Health

Background:

• Pullorum disease, caused by *Salmonella* Pullorum, significantly impacts global poultry production.
• Current detection methods for *Salmonella* Pullorum lack efficiency and accuracy.
• Accurate identification of *Salmonella* Pullorum is crucial for disease control in poultry.

Purpose of the Study:

• To develop a highly sensitive and specific molecular assay for *Salmonella* Pullorum identification.
• To compare the performance of the novel assay against traditional diagnostic methods.
• To enhance the overall detection rate of pullorum disease in chicken populations.

Main Methods:

• Development of a genomic deletion-targeted TaqMan quantitative polymerase chain reaction (qPCR) assay.
• Evaluation of assay sensitivity and specificity using plasmid and bacterial DNA.
• Comparison of the TaqMan qPCR assay with bacterial culturing and antibody detection using 676 chicken samples.
• Implementation of a T7 exonuclease-based anti-contamination system.

Main Results:

• The TaqMan qPCR assay demonstrated a low detection limit (5 copies/μL plasmid, 4 CFU/μL bacterial DNA).
• The assay identified over 80% of positive chickens, outperforming conventional methods in sensitivity and specificity.
• A combined framework of TaqMan qPCR and antibody detection achieved a 92% positive detection rate.
• The T7 exonuclease system effectively mitigated aerosol contamination.

Conclusions:

• The developed genomic deletion-targeted TaqMan qPCR assay offers a precise and efficient method for *Salmonella* Pullorum detection.
• Combining molecular and serological methods significantly enhances pullorum disease surveillance.
• The T7 exonuclease system provides a practical solution for preventing contamination in qPCR assays.
• Targeting genomic deletions is a viable strategy for pathogen detection assays.