Feasibility of high resolution melting curve analysis for rapid serotyping of Salmonella from hospitalised patients

Abstract

Backgrounds: Serum agglutination test is the gold standard phenotyping method widely used for Salmonella enterica characterisation.This conventional method is limited by its complicated and time-consuming procedures. High resolution melting curve (HRM) analysis is introduced as a rapid and labour-saving method. Objectives: To compare the results of conventional serum agglutination and quantitative PCR-HRM analysis to assess the feasibility of this alternative approach for Salmonella serotyping. Materials and methods: Salmonella strains from 38 human-originating samples were serotyped using the conventional serum agglutination method and HRM analysis. Results: The conventional serum agglutination assay detected 14 serotypes, while the HRM analysis identified 10 HRM profiles. There was a correlation between most of the serotyping results obtained by the two methods. Nine of the HRM profiles were unique to a single serotype, of each. One exception was HRM_3. Many of the indistinct curves that were grouped in this HRM pattern belonged to five Salmonella serotypes, including Weltevreden, Corvallis, Derby, Kedougou and Kentucky. Conclusion: It is difficult to determine all Salmonella serotypes by HRM analysis. However, this method can be used as an alternative to the conventional serum agglutination assay for rapid and labour-saving serotyping.

Keywords

• Salmonella
• Serotyping
• HRM-PCR