Multilocus variable number tandem repeat analysis for Salmonella enterica subspecies.

Area of Science:

• Microbiology
• Genomics
• Epidemiology

Background:

• Salmonella enterica possesses variable number tandem repeats (VNTRs) at multiple genomic loci.
• Reference strains of S. enterica (e.g., Typhi, Typhimurium, Enteritidis) were utilized to identify potential genotyping markers.

Purpose of the Study:

• To analyze the characteristics and specifications of 58 Salmonella markers developed between 2003 and 2009.
• To evaluate the utility of these markers for discriminating S. enterica isolates from diverse sources and geographical locations.

Main Methods:

• Genomic analysis of Salmonella enterica to identify VNTR loci.
• Development and application of multiple-locus VNTR analysis (MLVA) using selected VNTR markers.
• Analysis of marker diversity index (DI) to assess polymorphism.

Main Results:

• Fifty-eight Salmonella markers were analyzed, with eight VNTR loci exhibiting a high diversity index (>0.80).
• The selected markers effectively discriminated S. enterica isolates from human, food, and environmental sources.
• A panel of markers proved powerful for surveillance and outbreak source identification, applicable to macro- or microepidemiology.

Conclusions:

• Multiple-locus VNTR analysis (MLVA) is a valuable tool for Salmonella enterica surveillance and outbreak investigations.
• The selection of appropriate VNTR markers allows for discrimination at different epidemiological scales.
• Standardization of the MLVA technique remains a key challenge for future implementation.