NeoSeek-ing pathogenic serotypes of Salmonella

NeoSeek pathogen DNA identification method can provide genomic-based serotypes (e.g., Salmonella enterica Enteritidis and Salmonella enterica Heidelberg) in 72 hours from suspected positive isolates.

The detection and identification technology provides DNA-specific test results for pathogenic serotypes of Salmonella.

Serotypes include all the “top 30” Salmonella ones the Centers for Disease Control and Prevention (CDC) identified as being the leading causes of human Salmonella infections since the agency started its national surveillance program in 1962.

The assay uses targeted amplicon sequencing with bioinformatics analysis to identify the serotypes and a report is generated and given to the client.

Current method challenges​

Kristen J. Antonellis, product manager, pathogens, said the current standard is traditional serology which relies on antisera and the expression of surface proteins.

“This can be challenging as it can be difficult to obtain all of the required antisera,” ​she told FoodQualityNews.

“Traditional methods that utilize antisera leave a lot of room for interpretation as well as considerations of the supply and reproducibility of the antisera. ​

“There are also instances of non-motile Salmonella in which serology will miss the appropriate serotype – a genomic-based assay like Neogen’s NeoSeek isn’t limited by expression of surface proteins or variability of antisera. ​

“That means using genomic-based tools provides a more accurate result, more consistently.”​

Rapid detection and identification of specific strains, or serotypes, can be critical to preventing foodborne illness, or responding to an existing outbreak, said the firm.

Collaboration with USDA-ARS​

The NeoSeek service was developed with Dr Jean Guard of the USDA’s Agricultural Research Service​.

It enables identification of Salmonella serotypes from Next Generation DNA sequencing data generated by Neogen’s GeneSeek genomics laboratory in Lincoln, Nebraska.

The firm said it collaborated with Dr Guard and incorporated her data which became one piece of the puzzle used to develop the database and the bioinformatics.

Antonellis said anyone who is using traditional serology can take advantage of the accuracy and speed of a genetic based assay.

“Commercial and independent labs can use this service because the labor, expertise, and time needed to complete the serology is greatly reduced using Neogen’s NeoSeek,” ​she said.

“This laboratory service adds to Neogen’s existing NeoSeek STEC confirmation service, which detects and identifies seven Shiga toxin-producing E. coli strains — O26, O45, O103, O111, O121, O145, and O157. ​

“This could be just the beginning as technology advances and the capabilities of our Lincoln, Nebraska facility allow us to develop assays beyond these two. There is a drive for more genetic based data and we can utilize the capabilities we have to expand our offerings.”​

The USDA issued a letter of no objection for the NeoSeek confirmatory method, and said the NeoSeek service is comparable to the reference method, FSIS MLG 5B.02.