Building on their work with whole genome sequencing and eggs – because there’s a lot of outbreaks of Salmonella in eggs — a group of Australian researchers have reported on seven outbreaks of Salmonella Typhimurium multilocus variable-number tandem-repeat analysis (MLVA) 03-26-13-08-523 (European convention 2-24-12-7-0212) in three Australian states and territories investigated between November 2015 and March 2016.

We identified a common egg grading facility in five of the outbreaks. While no Salmonella Typhimurium was detected at the grading facility and eggs could not be traced back to a particular farm, whole genome sequencing (WGS) of isolates from cases from all seven outbreaks indicated a common source. WGS was able to provide higher discriminatory power than MLVA and will likely link more Salmonella Typhimurium cases between states and territories in the future. National harmonization of Salmonella surveillance is important for effective implementation of WGS for Salmonella outbreak investigations.

Seven Salmonella Typhimurium outbreaks in Australia linked by trace-back and whole genome sequencing

Foodborne Pathogens and Disease, March, 2018, 10.1089/fpd.2017.2353

Laura Ford Qinning Wang Russell Stafford,Kelly-Anne Ressler, Sophie Norton, Craig Shadbolt, Kirsty Hope, Neil Franklin, Radomir Krsteski, Adrienne Carswell,Glen P. Carter, Torsten Seemann,Peter Howard, Mary Valcanis,10 Cristina Fabiola Sotomayor Castillo, John Bates, Kathryn Glass,Deborah A. Williamson, Vitali Sintchenko, Benjamin P. Howden and Martyn D. Kirk1