通讯机构:
[Lu, Fangguo] U;[Hu, J; Lu, FG] H;Hunan Univ Chinese Med, Dept Microbiol, Sch Med, Changsha 410208, Hunan, Peoples R China.;Univ Innovat Team Hunan Prov, Key Discipline Pathogen Biol, Changsha 410208, Hunan, Peoples R China.
关键词:
*16S rRNA;*Carboxyfluorescein;*DNA probe;*DNA/RNA hybrids;*Drug-resistant bacteria;*Enzymatic reaction;*Fluorescence resonance energy transfer;*Fluorometry;*Quenching
摘要:
The authors describe a method for the fluorometric determination of methicillin-resistant Staphylococcus aureus (MRSA) by exploiting target-triggered chain reactions and deoxyribonuclease I (DNase I)-aided target recycling. It is making use of a carboxy-fluorescein (FAM)-labeled single-stranded probe containing two sections. One is complementary to the 5' terminus of the target, while the 3' terminus of the other target is adsorbed on the surface of graphene oxide (GO) via pi-stacking interactions without the target (16S rRNA). This adsorption results in quenching of the fluorescence of the label and protects it from being cleaved by DNase I. However, upon addition of the target, DNA/RNA hybrids are repelled by GO. This leads to fluorescence recovery as measured at excitation/emission wavelengths of 480/514 nm due to a chain reaction that is triggered by the target. The signal is strongly amplified by using DNase I-mediated target recycling. The 16S rRNA of MRSA can be detected by this method in the 1 to 30 nM concentration range, and the detection limit is 0.02 nM. The method was applied to analyze bacterial samples, and the detection limit is as low as 30 CFU . mL(-1). The assay is highly sensitive and selective and in our percpetion has a large potential in diagnosis of drug-resistant bacteria. Graphical abstract Schematic of the graphene oxide-based fluorescent bioassay for Methicillin-resistant Staphylococcus aureus detection by using target-triggered chain reaction and deoxyribonuclease I-aided signal amplification.
作者机构:
[Fang, Fang; Zhang, Fenghua; Peng, Bo; Fang, F; Chen, Ze; Chang, Haiyan] Hunan Normal Univ, Coll Life Sci, Changsha, Hunan, Peoples R China.;[Zhang, Ran] Hunan Normal Univ, Sch Med, Changsha, Hunan, Peoples R China.;[Lu, Fangguo] Hunan Univ Chinese Med, Sch Med, Changsha, Hunan, Peoples R China.;[Wang, Fuyan] Cent S Univ, Dept Immunol, Coll Basic Med Sci, Changsha, Hunan, Peoples R China.;[Chen, Ze] Shanghai Inst Biol Prod, Shanghai, Peoples R China.
通讯机构:
[Fang, F; Chen, Z] H;[Chen, Ze] S;Hunan Normal Univ, Coll Life Sci, Changsha, Hunan, Peoples R China.;Shanghai Inst Biol Prod, Shanghai, Peoples R China.
关键词:
Vaccines;Influenza;Enzyme-linked immunoassays;Immune response;H5N1;Viral vaccines;Vaccination and immunization;Influenza viruses
摘要:
Maternally-derived antibodies (MDAs) can protect offspring against influenza virus infection but may also inhibit active immune responses. To overcome MDA- mediated inhibition, active immunization of offspring with an inactivated H5N1 whole-virion vaccine under the influence of MDAs was explored in mice. Female mice were vaccinated twice via the intraperitoneal (IP) or intranasal (IN) route with the vaccine prior to mating. One week after birth, the offspring were immunized twice via the IP or IN route with the same vaccine and then challenged with a lethal dose of a highly homologous virus strain. The results showed that, no matter which immunization route (IP or IN) was used for mothers, the presence of MDAs severely interfered with the active immune response of the offspring when the offspring were immunized via the IP route. Only via the IN immunization route did the offspring overcome the MDA interference. These results suggest that intranasal immunization could be a suitable inoculation route for offspring to overcome MDA interference in the defense against highly pathogenic H5N1 virus infection. This study may provide references for human and animal vaccination to overcome MDA-induced inhibition.
作者机构:
[张波] School of Medicine, Hunan University of Chinese Medicine, Changsha 410208;[张波; 张健] Key Laboratory of Protein Chemistry and Developmental Biology, Ministry of Education, School of Life Sciences, Hunan Normal University, Changsha 410081, China;[周芳亮; 严杰; 卢芳国] School of Medicine, Hunan University of Chinese Medicine, Changsha 410208, China
作者机构:
[卢芳国] Department of Microbiology and Immunology, Preclinical Medicine College of Hunan University of Traditional Chinese Medicine, Changsha 410208
作者机构:
[李玲] Department of Microbiology, Hunan University of Traditional Chinese Medicine, Changsha 410208, Hunan Province, China;College of Integrated Traditional Chinese and Western Medicine, Hunan University of Traditional Chinese Medicine, Changsha 410208, Hunan Province, China
通讯机构:
Department of Microbiology, Hunan University of Traditional Chinese Medicine, China