Classification of Salmonella enterica serotypes from Australian poultry using repetitive sequence-based PCR.

Area of Science:

• Microbiology
• Molecular Biology
• Food Safety

Background:

• Salmonella enterica is a significant foodborne pathogen.
• Accurate serotyping is crucial for epidemiological surveillance and control.
• Traditional serotyping methods can be labor-intensive and time-consuming.

Purpose of the Study:

• To evaluate the DiversiLab(®) System, a semi-automated repetitive extragenic palindromic sequence-based PCR (rep-PCR) method.
• To assess its utility for classifying Salmonella serotypes from Australian poultry.
• To compare its performance and cost-effectiveness against traditional serotyping.

Main Methods:

• Construction of four Salmonella DNA fingerprint databases (serogroups B, C, E, and Other) within the DiversiLab(®) System.
• Typing of 155 blinded Salmonella isolates using rep-PCR and comparison against the established library.
• Validation against serologically confirmed reference laboratory results and traditional serotyping.

Main Results:

• The rep-PCR system correctly predicted the serotype for 92.3% of isolates (143/155) when compared to traditional typing (P < 0.05).
• Discrepancies were observed in 7.7% of cases, including 'No Match' results and one misclassification.
• Financial analysis indicated higher material costs but significantly lower labor costs for rep-PCR compared to traditional serotyping.

Conclusions:

• The DiversiLab(®) System, augmented with serogroup-specific databases, serves as a valuable adjunct for reference serotyping of Salmonella enterica.
• This platform offers a cost-effective, user-friendly, and rapid alternative for Salmonella serotype determination.
• The system demonstrates potential for efficient Salmonella surveillance in poultry.