Aim:  To develop antibody–aptamer functionalized fibre‐optic biosensor for specific detection of Listeria monocytogenes from food products. Methods and Results:  Aptamer, a single‐stranded oligonucleotide ligand that displays affinity for the target molecule, was used in the assay to provide sensor specificity. Aptamer‐A8, specific for internalin A, an invasin protein of L. monocytogenes, was used in the fibre‐optic sensor together with antibody in a sandwich format for detection of L. monocytogenes from food. Biotinylated polyclonal anti‐Listeria antibody, P66, was immobilized on streptavidin‐coated optical waveguide surface for capturing bacteria, and Alexa Fluor 647‐conjugated A8 was used as a reporter. The biosensor was able to selectively detect pathogenic Listeria in pure culture and in mixture with other bacteria at a concentration of approx. 103 CFU ml−1. This sensor also successfully detected L. monocytogenes cells from artificially contaminated (initial inoculation of 102 CFU 25 g−1) ready‐to‐eat meat products such as sliced beef, chicken and turkey after 18 h of enrichment. Conclusion:  Based on the data presented in this study, the antibody–aptamer functionalized fibre‐optic biosensor could be used as a detection tool for sensitive and specific detection of L. monocytogenes from foods. Significance and Impact of the Study:  The study demonstrates feasibility and novel application of aptamer on fibre‐optic biosensor platform for the sensitive detection of L. monocytogenes from food products.

The surface modification of orthodontic wires with photocatalytic TiO(2) can be used to prevent the development of dental plaque during orthodontic treatment.

No abstract

Erythritol is one of the most widely used low calorie sugar substitutes and has known inhibitory effects on the growth of Streptococcus mutans. However, the mechanism underlying this inhibition is poorly understood. Expression profiles of the glucosyltransferase (GTF) and fructosyltransferase (FTF) genes in S. mutans were evaluated in the presence of erythritol and other sweeteners. Adhesion of S. mutans to different carbohydrates was also determined across a range of concentrations. Erythritol significantly (p<0.05) inhibited adherence of S. mutans under multiple conditions, compared with sucrose. Erythritol significantly (p<0.05) inhibited expressions of gtfB, gtfC, gtfD, and ftf in the presence of various carbohydrates compared with sucrose. These findings were consistent with an anti-cariogenic effect of erythritol on S. mutans, and suggested mechanisms by which erythritol inhibits formation of dental caries.

These findings suggest that T. lecithinolyticum induces osteoclast differentiation by a prostaglandin E2-dependent mechanism and that heat-labile components may be involved in this process.