ABSTRACT
The presence of tick-borne pathogens and their possible coinfections were evaluated among host-seeking ticks in seven cities from Jiaodong peninsula, Shandong Province, with specific PCR or reverse transcription-PCR tests. Among 2107 ticks collected, four species of three genera were identified with Haemaphysalis longicornis as predominant species, and total of 63 H. longicornis and 10 Rhicephalus microplus were confirmed infected with tick-borne pathogens. These pathogens were consequently identified as severe febrile and thrombocytopenic syndrome virus (SFTSV), Anaplasma capra, Anaplasma phygocytophilum, and Babesia microti, respectively, with high phylogenetic scores on some fragments of species-specific genes. The infection rates of the pathogens in H. longicornis were presented as 1.03%, 0.84%, 0.58%, and 1.66%, respectively, close related to its field density and clump distribution pattern. Furthermore, coinfection of A. capra and SFTSV was also discovered from two female H. longicornis in Pingdu city. These results indicated that the potential human pathogens other than severe febrile and thrombocytopenic syndrome might be transmitted by hard ticks separately or in combination, and more reliable differential diagnosis, proper administrations, rational prevention, and control measures should be developed with the support of precision laboratory tests.
Subject(s)
Anaplasma/isolation & purification , Babesia microti/isolation & purification , Ixodidae/microbiology , Phlebovirus/isolation & purification , Anaplasma/genetics , Animals , Babesia microti/genetics , China , Female , Male , Phlebovirus/genetics , Phylogeny , PrevalenceABSTRACT
In this research, a novel method for relative fluorescent quantification of DNA based on Fe3O4@SiO2@Au gold-coated magnetic nanocomposites (GMNPs) and multiplex ligation- dependent probe amplification (MLPA) has been developed. With the help of self-assembly, seed-mediated growth and chemical reduction method, core-shell Fe3O4@SiO2@Au GMNPs were synthesized. Through modified streptavidin on the GMNPs surface, we obtained a bead chip which can capture the biotinylated probes. Then we designed MLPA probes which were tagged with biotin or Cy3 and target DNA on the basis of human APP gene sequence. The products from the thermostable DNA ligase induced ligation reactions and PCR amplifications were incubated with SA-GMNPs. After washing, magnetic separation, spotting, the fluorescent scanning results showed our method can be used for the relative quantitative analysis of the target DNA in the concentration range of 03004~0.5 µM.
Subject(s)
DNA/analysis , DNA/genetics , Metal Nanoparticles/chemistry , Microscopy, Fluorescence/instrumentation , Multiplex Polymerase Chain Reaction/instrumentation , Nanocomposites/ultrastructure , Base Sequence , Biosensing Techniques/instrumentation , Biosensing Techniques/methods , Equipment Design , Equipment Failure Analysis , Gold/chemistry , Metal Nanoparticles/ultrastructure , Microscopy, Fluorescence/methods , Molecular Sequence Data , Multiplex Polymerase Chain Reaction/methods , Nanocomposites/chemistry , Sequence Analysis, DNA/instrumentation , Sequence Analysis, DNA/methods , Silicon Dioxide/chemistryABSTRACT
Gold-coated magnetic nanocomposites with unique physical and chemical properties have recently been subjected to extensive researches since the gold shells could improve their biocompatibility, functionality and stability further, which endue them with great application potentials in various fields. Several main approaches have been studied for the synthesis of gold-coated magnetic nanocomposites, including microemulsion, sonochemical synthesis, self assembly, seed-mediated growth method, and laser irradiation. This review is focused on describing various strategies for the preparation of gold-coated magnetic nanocomposites. Furthermore, we also introduce main applications of gold-coated magnetic nanocomposites in biomedical fields and point out some challenges in the synthesis of high-quality gold-coated magnetic nanocomposites.
Subject(s)
Gold , Magnetics , Nanocomposites , Therapeutics , HumansABSTRACT
In present study, we put forward an approach to prepare three-layer core-shell Fe3O4@SiO2@Au magnetic nanocomposites via the combination of self-assembling, seed-mediated growing and multi-step chemical reduction. The Fe3O4@SiO2@Au magnetic nanocomposites were analyzed and characterized by transmission electron microscope (TEM), scanning electronic microscope (SEM), energy dispersive spectrometer analysis (EDS), Fourier transform infrared spectroscopy (FT-IR), vibrating sample magnetometer (VSM), and ultraviolet and visible spectrophotometer (UV-Vis). TEM and SEM characterizations showed that the FeO4@SiO2@Au nanocomposites were obtained successfully with three-layer structures, especially a layer of thin, smooth and continuous gold shell. The average diameter of Fe3O4@SiO2@Au nanocomposites was about 600 nm and an excellent dispersity was observed for the as-prepared nanoparticles. EDS characterizations demonstrated that the nanocomposites contained three elements of the precursors, Fe, Si, and Au. Furthermore, FT-IR showed that the silica and gold shell were coated successfully. UV-Vis and VSM characterizations showed that the Fe3O4@SiO2@Au nanocomposites exhibited good optical and magnetic property, and the saturation magnetization was 25.76 emu/g. In conclusion, the Fe3O4@SiO2@Au magnetic nanocomposites with three-layer core-shell structures were prepared. Furthermore, Fe3O4@SiO2@Au magnetic nanocomposites were modified with streptavidin (SA) successfully, and it was validated that they performed low fluorescence background, suggesting that they should have good applications especially in bioassay based on fluorescence detection through bonding the biotinylated fluorescent probes.
