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


  • Disclaimer: Mention of trade names or commercial products in manuscript are provided for specific information only and does not imply endorsement or recommendation by the authors or their affiliations.

Anthony Pavic, Birling Avian Laboratories, PO Box 111, Bringelly, NSW 2556, Australia. E-mail:


Aims:  To evaluate a semi-automated repetitive extragenic palindromic sequence-based PCR (rep-PCR) system for the classification of Salmonella serotypes from Australian poultry.

Methods and Results:  Using a DNA fingerprint library within the DiversiLab® System, four separate databases were constructed (serogroup B, C, E and Other). These databases contained 483 serologically confirmed (reference laboratory) Salmonella isolates. A blinded set of Salmonella cultures (= 155) were typed by rep-PCR, matched against the internal library and compared with traditional serotyping. The predicted (Kullback–Leibler) serotype of 143 (92·3%) isolates matched traditional typing (< 0·05). Of the 12 (7·7%) remaining isolates, ten (6·5%) resulted in ‘No Match’, one (0·65%) was incorrectly matched to the library (Salm. subsp 1 ser 4,12:-:-), and the other (0·65%) was referenced as Salm. ser. Sofia, whereas rep-PCR and in-house serotyping concurred as Salmonella serovar Typhimurium. Financial analysis showed higher material cost (215%) and a lower labour component (47·5%) for rep-PCR compared with serotyping.

Conclusion:  The DiversiLab® System, with serogroup databases, was successfully implemented as an adjunct for reference serotyping of Salmonella enterica.

Significance and Impact of the Study:  The DiversiLab® System platform is a cost-effective and easy-to-use system, which can putatively determine Salmonella enterica serotypes within a few hours.