A 16S rRNA-based DNA probe and PCR method specific for Listeria ivanovii

Area of Science:

• Microbiology
• Molecular Biology
• Food Safety

Background:

• Listeria ivanovii is a bacterial species that can cause disease in animals and potentially humans.
• Accurate and rapid detection methods are crucial for controlling Listeria outbreaks.
• Existing detection methods can be time-consuming and require extensive sample preparation.

Purpose of the Study:

• To develop a specific and sensitive DNA probe and polymerase chain reaction (PCR) method for the rapid identification and detection of Listeria ivanovii.
• To evaluate the specificity and sensitivity of the developed method against other Listeria species and related bacteria.
• To assess the applicability of the method for detecting Listeria ivanovii in various sample types.

Main Methods:

• Development of a 16S rRNA-based DNA probe (R-1) specific to Listeria ivanovii.
• Design and implementation of a polymerase chain reaction (PCR) assay using the R-1 probe and a reverse primer (R-2).
• Testing the specificity of the probe and PCR assay against multiple Listeria species and other bacterial strains.
• Assessing the sensitivity of the PCR method in pure cultures and spiked biological samples (feed, blood, feces).

Main Results:

• The R-1 DNA probe demonstrated high specificity, reacting only with Listeria ivanovii and not with other tested Listeria species or bacteria.
• The PCR method using R-1 and R-2 primers successfully identified all tested Listeria ivanovii strains while remaining negative for other Listeria species, including Listeria monocytogenes.
• The entire PCR assay, from whole bacterial cells to electrophoresis, required only 4 hours, eliminating the need for DNA isolation and hybridization steps.
• The PCR method achieved high sensitivity, detecting as few as 4 cells of Listeria ivanovii in pure cultures and 4-40 cells in spiked animal feed, blood, and feces samples.

Conclusions:

• A novel and highly specific 16S rRNA-based DNA probe and PCR method for Listeria ivanovii detection has been successfully developed.
• This method offers a rapid, sensitive, and specific alternative to conventional techniques for identifying Listeria ivanovii.
• The developed assay has significant potential for application in food safety and clinical diagnostics, enabling swift identification of Listeria ivanovii in various matrices.