Sequencing: The answer to a safer food supply worldwide

August 13, 2019

Sequencing, a useful DNA technology for organism characterization, has received additional recognition as an effective method to identify and subtype food pathogens.

Last month, a peer-reviewed article about the different methods for Salmonella characterization highlighted sequencing as a solid approach to identifying the pathogen.

Implementation of molecular-based Salmonella characterization methods provides improvement of source tracking and root cause elimination, stated the article published in the journal Frontiers in Microbiology and co-authored by researchers from Cornell University and the Mars Global Food Safety Center in Japan.

The remarks are based on comparisons made among molecular subtyping methods and other methods for traditional serology subtyping of Salmonella that have slower turnarounds, higher cost, and potentially less accurate results.

“It isn’t a surprise that sequencing is becoming the food industry’s method of choice for the detection and subtyping of Salmonella,” said Neogen’s Director of Food Genomics, Dr. Edan Hosking. “Molecular-based Salmonella subtyping provides very valuable advantages that make the implementation of sequencing-based methods a crucial aspect in order to obtain an accurate and reliable identification of the pathogen.”

Sequencing analyzes the DNA structure of an organism or specific DNA targets by identifying the different nucleotides that make up each bacterial sequence.

“Sequencing plays a critical role in the improvement of our ability for further analysis of Salmonella,” Dr. Hosking said. “This technology provides data that makes it possible to identify some strains of Salmonella and trace where the bacteria came from by seeking the particular variant in other foods or food production sites.”

The article also showcases effective sequencing applications like whole-genome sequencing (WGS). WGS reveals the entire DNA structure of an organism.

WGS has been utilized by public health authorities for regular-basis surveillance of food contamination. The Centers for Disease Control and Prevention (CDC), for example, has been using WGS for outbreak investigations since 2013.

There are other applications, like targeted amplicon sequencing (TAS). This approach targets exact genes of interest to be amplified, developing a genetic profile for the samples. TAS allows the diagnostics to be pointed at the most informative section of the genome, without sequencing unnecessary areas.

Salmonella is known to be the pathogen with the biggest economic and health impact. This foodborne pathogen is responsible for at least 1.2 million illnesses and 450 deaths in the U.S. every year. One million of these illnesses and 380 of those deaths are linked to food as the source of the infection, according to the CDC.

“The future of the world’s food supply looks very promising if consistent and accurate methods for the characterization of Salmonella like sequencing get implemented globally,” Dr. Hosking said. “There is no doubt that this technology will help the food industry to approach Salmonella in more effective ways.”

Neogen’s line of services for the detection and identification of pathogens offers solutions that provide DNA-specific test results for pathogenic serotypes of Salmonella.


Category: Food Safety, Food & Beverage, Pathogens, Bacterial Sequencing