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New tracing technology to help identify Salmonella outbreaks

Australian researchers from the University of New South Wales Sydney have developed a technique to identify Salmonella strains in order to more effectively trace outbreaks. The multilevel genome typing (MGT) method, which took two years to develop, identifies unique strains of the bacterium and associates it with a unique nine-digit 'barcode.'

The genome of Salmonella has more than four million DNA bases (A-T-C-G) and conventional tracing methods can take days to analyze the full genome and accurately identify the strain under analysis. In this new approach, the bases are converted into nine unique numbers - which make up the nine-digit 'barcodes' assigned to each strain - so that analysis can be instantly conducted.

When the nine digits are organized into a unique 'barcode' for the individual bacteria strains, an isolated bacterium can be analyzed and its genome sequenced and compared against public health databases to determine the type of Salmonella. There are currently 26,000 strains in databases worldwide, according to Food Navigator.

The research was led by Professor Ruiting Lan who earlier this year developed a testing technique to detect Salmonella DNA in as little as eight minutes. This rapid testing technology is able to identify the most common variations of Salmonella found in Australia that account for 85% of the country’s Salmonella infections. These strains are: Typhimurium, Enteritidis, Virchow, Saintpaul, and Infantis. The testing technique was originally announced in a published article in The Journal of Molecular Diagnostics.

Having the capability to accurately and rapidly test for Salmonella strains could be a boon for the FMCG industry. In Australia, Food Navigator reported that there has been a 30% increase in Salmonella cases over the previous 10-year average. In the United States, The Centers for Disease Control and Prevention cited data from 2019 showing that cases of Salmonella are also on the rise.

Foodborne illnesses plague the food industry and result in costly product recalls that financially impact sales and brand perception by consumers. If manufacturers and governments have access to fast, traceable testing, it could go a long way toward mitigating Salmonella outbreaks or at least quickly halting the spread in its tracks.