Stem-loop Structured Probes Designed by Sequence Comparisons for Detection of Staphylococcus aureus

Abstract:

Based on Staphylococcus aureus 16S rRNA gene sequences, sequence comparisons have been applied to design a kind of stem-loop structured oligonucleotide probes whose loop sequence mismatched other bacterial strains 16S rRNA gene sequences in more than two positions with high specificity and sensitivity. According to the principle of molecular beacon technology and enzyme linked immunosorbent assay, a method has been evaluated using immobilized stem-loop structured oligonucleotides probe as the conformation switch which is applied to enzymatic detection of nucleic acid targets. As its specificity has been strengthened, the system is able to successfully eliminate false-positive result that is mismatch in an oligonucleotide. Employing a microtiter assay format, 4ng of S. aureus 16S rRNA could be detected at least. This approach is more sensitive than other conventional method at least one order of magnitude.

Key words:Sequence comparisons, Stem-loop structured probe, 16S rRNA, Detection