In an effort to improve timeliness of Salmonella serotyping, the Iowa State University Veterinary Diagnostic Laboratory (ISU VDL) has implemented the Check&Trace Salmonella assay through the molecular diagnostics section. The test is a commercial assay that employs highly specific DNA markers to allow accurate identification of the Salmonella serotype when present.
Serotyping (serological typing) is based on the long standing observation that microorganisms from the same species can differ in the antigenic determinants expressed on the cell surface. Serotyping is one of the classic tools for epidemiological study and is applied to numerous species that express different serotypes such as Salmonella spp.
The technology of the Check&Trace Salmonella system is based on specific molecular recognition of DNA target sequences and subsequent amplification with universal primers based on a microarray platform. Each position on the microarray represents a specific DNA marker associated with a unique Salmonella target sequence.
This innovative method can discriminate over 300 serotypes due to the differences in their DNA sequences. This enables the test to confirm Salmonella presence and the serotype with a single test and allows the Check & Trace Salmonella assay to significantly decrease serotyping lead times. This is in contrast to previous processes that required submitting Salmonella isolates to NVSL and approximately 6 weeks to receive serotyping results.
The Check&Trace Salmonella test is only conducted on pure cultures of Salmonella spp. that are isolated through routine bacterial culture not clinical samples. The test is conducted one time per week on Tuesdays with results reported the following day at a cost of $75 per test. Please call the ISU VDL with questions regarding this new assay.