Scientists develop “rapid” salmonella detector

Scientists develop “rapid” salmonella detector

Researchers have developed a colorimetric sensor that they claim can “rapidly” detect food contaminated with salmonella using a nucleic acid probe.

A team of researchers have been working on a device that they claim can detect the presence of salmonella in food.

According to the team, the device is an “easy-to-use” colorimetric assay that is based on a novel nucleic acid probe, cleaved by an RNase enzyme specific to the salmonella species. The researchers have said that this specific enzymatic cleavage principle “made it possible to build a sensitive but simple and portable test system using colloidal gold”.

Noting that typically, food contaminated with salmonella is “usually only confirmed several days later when the bacteria are detected in microbiology laboratories by growing them in culture”, the scientists worked on developing a novel test system based on a hybrid DNA-RNA probe that specifically and rapidly detects salmonella, without the need for microbiological diagnostics or expensive analytical equipment.

The team at McMaster University in Hamilton, Canada used a multi-round selection process, and uncovered an artificial DNA-RNA hybrid probe that is a substrate for a salmonella-specific form of an RNase H enzyme.

Based on these findings, the team first developed a fluorescence-based assay on salmonella RNase H, and then extended the principle to a simple, portable salmonella assay based on a colloidal gold colorimetry.

“When the sample mixture contains salmonella, the upper layer is released thanks to the salmonella RNase H specifically cleaving the DNA-RNA linker probe,” explained the researchers.

“When the gold-containing solution is then drained onto an absorbent pad with a nylon membrane, a clear red spot indicates the presence of salmonella in the sample being tested.”

The team also tested the specificity of their system and have claimed that it did not falsely detect the presence of other bacteria containing RNAse H.

Stating that their testing system is “much less complex than other methods for detecting salmonella”, the team has also claimed that the method is much faster.

“In contrast to other methods, only one hour of incubation in a pipette tip is required for highly sensitive detection of salmonella, for example, in ground beef,” said the researchers.

Looking forward, the scientists have said that they envision developing more nucleic acid probes which can specifically detect other infectious pathogens such as E. coli.

Recent Posts

  • 7305

ISO/IEC 27001:2022 Transition Guidance

ISO/IEC 27001:2022 Transition Guidance for Clients ISO/IEC 27001:2022 “Information security, cybersecurity and privacy protection — Information security management systems — Requirements” was released in October 2022 and is replacing ISO 27001:2013 […]

  • 6999

ISO 22000 (FSMS) Auditor / Lead Auditor

FSMS (ISO 22000:2018) Auditor / Lead Auditor As a result of further growth of our Certification Division we are looking for 3rd party Auditors or qualified applicants for the following […]


Comments

Leave a Reply

Your email address will not be published. Required fields are marked *

Loading

0