Related Experiment Video
Updated: Apr 17, 2026
An Allelotyping PCR for Identifying Salmonella enterica serovars Enteritidis, Hadar, Heidelberg, and Typhimurium
Published on: July 22, 2011
Multi locus variable-number tandem repeat (MLVA) typing tools improved the surveillance of Salmonella enteritidis: a
Sophie Bertrand1, Guillaume De Lamine de Bex1, Christa Wildemauwe1
1National Reference Centre for Salmonellas, Bacterial Diseases Division, Communicable and Infectious Diseases, Scientific Institute of Public Health, Brussels, Belgium.
Abstract:
Surveillance of Salmonella enterica subsp. enterica serovar Enteritidis is generally considered to benefit from molecular techniques like multiple-locus variable-number of tandem repeats analysis (MLVA), which allow early detection and confinement of outbreaks. Here, a surveillance study, including phage typing, antimicrobial susceptibility testing and MLVA on 1,535 S. Enteritidis isolates collected between 2007 and 2012, was used to evaluate the added value of MLVA for public health surveillance in Belgium. Phage types PT4, PT8, PT21, PT1, PT6, PT14b, PT28 and PT13 dominate the Belgian S. Enteritidis population. The isolates of S. Enteritidis were most frequently susceptible to all antibiotics tested. 172 different MLVA profiles were detected, of which 9 frequent profiles included 67.2% of the S. Enteritidis population. During a serial passage experiment on selected isolates to investigate the in vitro stability of the 5 MLVA loci, no variations over time were observed indicating that the MLVA profiles were stable. The MLVA profile of isolates originating from different outbreaks in the Democratic Republic of the Congo (DRC) between 2010 and 2011 were distinct from any of the MLVA profiles found in Belgian isolates throughout the six year observational period and demonstrates that MLVA improves public health surveillance of S. Enteritidis. However, MLVA should be complemented with other subtyping methods when investigating outbreaks is caused by the most common MLVA profile.
Insights
Multiple-locus variable-number tandem repeat analysis (MLVA) enhances Salmonella Enteritidis surveillance in Belgium. This molecular technique aids in early outbreak detection and confinement, improving public health strategies.
Area of Science:
- Foodborne Pathogen Surveillance
- Molecular Epidemiology
- Public Health Microbiology
Background:
- Salmonella Enteritidis surveillance benefits from molecular subtyping for outbreak detection.
- Multiple-locus variable-number tandem repeats analysis (MLVA) is a key molecular technique for pathogen surveillance.
Purpose of the Study:
- To evaluate the added value of MLVA for public health surveillance of Salmonella Enteritidis in Belgium.
- To assess the discriminatory power and stability of MLVA for S. Enteritidis isolates.
Main Methods:
- Analysis of 1,535 S. Enteritidis isolates collected between 2007 and 2012.
- Inclusion of phage typing, antimicrobial susceptibility testing, and MLVA.
- In vitro stability assessment of MLVA loci through serial passage.
Main Results:
- Seventeen prevalent phage types were identified in the Belgian S. Enteritidis population.
- Most isolates were susceptible to all tested antibiotics.
- 172 distinct MLVA profiles were detected, with 9 profiles covering 67.2% of isolates.
- MLVA profiles from the Democratic Republic of the Congo were distinct from Belgian isolates.
- MLVA loci demonstrated in vitro stability.
Conclusions:
- MLVA significantly improves public health surveillance of Salmonella Enteritidis in Belgium.
- MLVA provides valuable discriminatory power for tracking S. Enteritidis.
- Complementary subtyping methods are recommended for outbreaks involving common MLVA profiles.
