title: Detection of Staphylococcus aureus carrying the gene for toxic shock syndrome toxin 1 by quantum-dot-probe complexes.
abstract: In this study, a high-sensitive and high-specific method to detect the toxic shock syndrome toxin-1 (TSST-1)-producing Staphylococcus aureus was developed based on quantum dot (QD) and oligonucleotide probe complexes. S. aureus carrying tst gene which is responsible for the production of TSST-1 were detected based on fluorescence resonance energy transfer (FRET) occurring between CdSe/ZnS QD donors and black hole quencher (BHQ) acceptors. QD-DNA probe was prepared by conjugating the carboxyl-modified QD and the amino-modified DNA with the EDC. Photoluminescence (PL) quenching was achieved through FRET after the addition of BHQ-DNA which was attached to tst gene probe by match sequence hybridization. The PL recovery was detected in the presence of target DNA by BHQ-DNA detached from QD-DNA probe because of the different affinities. In contrast, mismatch oligonucleotides and DNAs of other bacteria did not contribute to fluorescence intensity recovery, which exhibits the higher selectivity of the biosensor. The experimental results showed clearly that the intensity of recovered QD PL is linear to the concentration of target DNA within the range of 0.2-1.2 μM and the detection limit was 0.2 μM.
authors.affiliation: The Co-construction Laboratory of Microbial Molecular Biology of Province Department and Ministry of Science and Technology, College of Life Science, Hunan Normal University, Changsha, Hunan 410081, People's Republic of China.
authors.forename: Dan
authors.initials: D
authors.lastname: Wang
authors.forename: Hui
authors.initials: H
authors.lastname: Chen
authors.forename: Hua
authors.initials: H
authors.lastname: Li
authors.forename: QiZhi
authors.initials: Q
authors.lastname: He
authors.forename: XingHua
authors.initials: X
authors.lastname: Ding
authors.forename: Le
authors.initials: L
authors.lastname: Deng
mesh_terms: D001427:Bacterial Toxins / Q000032:analysis*; D019187:Cadmium Compounds / Q000737:chemistry*; D004768:Enterotoxins / Q000032:analysis*; D031541:Fluorescence Resonance Energy Transfer; D049449:Luminescence; D015345:Oligonucleotide Probes / Q000737:chemistry*; D045663:Quantum Dots; D018036:Selenium Compounds / Q000737:chemistry*; D013050:Spectrometry, Fluorescence; D013211:Staphylococcus aureus / Q000235:genetics*; D013440:Sulfides / Q000737:chemistry*; D018089:Superantigens / Q000032:analysis*; D017967:Zinc Compounds / Q000737:chemistry*
chemical_list: D001427:Bacterial Toxins; D019187:Cadmium Compounds; D004768:Enterotoxins; D015345:Oligonucleotide Probes; D018036:Selenium Compounds; D013440:Sulfides; D018089:Superantigens; D017967:Zinc Compounds; C030107:enterotoxin F, Staphylococcal; C058667:cadmium selenide; C031238:zinc sulfide