SENSORS AND ACTUATORS B-CHEMICAL
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2015
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IF 4.097
Ting Wang,Zhang Zhang,Yiyan Li,Guoming Xie
Rapid detection of drug-resistant bacteria can facilitate the early diagnosis of various infections and provide essential guidance for appropriate usage of antibiotics. An ultrasensitive electrochemical DNA (E-DNA) sensor based on isothermal strand-displacement polymerization reaction (ISDPR) for detection of mecA gene in methicillin-resistant Staphylococcus aureus (MRSA) was proposed in this study. Methylene blue (MB)-labeled hairpin probes were self-assembled on a gold electrode to confine MB molecules close to the electrode surface for efficient electron transfer. The hairpin probes were then hybridized with complementary target DNA and undergone conformational changes, which led to a decreased electrochemical response. The primers annealed with the opened stems of hairpin probes were extended by DNA polymerase, which in turn released the target DNA to trigger the next polymerization cycle. Finally, each target DNA underwent through many rounds, resulting in a mass of MB molecules moved away from the electrode surface, which generated significant amplified current suppression for mecA gene detection. With this target recycling amplification strategy, the proposed DNA biosensor could offer excellent analytical performance for the detection of mecA gene and provide a new electrochemical method for the early diagnosis of drug-resistant bacteria.
研究领域:
微生物学
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分子生物学
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生物医学工程
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产品关联
DOI
高影响因子
MICROCHEMICAL JOURNAL
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2023
·
IF 4.8
Xianfeng Wang,Chengxiang Chu,Yuanyi Deng,Yi Ma,Mei Yang,Huibo Luo,Danqun Huo,Changjun Hou
Accurate identification of Staphylococcus aureus ( S. aureus ) is crucial for food safety and clinical diagnosis. Particularly, identifying drug-resistant strains guides effective treatment and prevention of infectious diseases. Herein, we presented a highly efficient programmable CRISPR/Cas12a system for identification of methicillin-resistant S. aureus (MRSA). Genus-specific gene (spec gene) and methicillin-resistant gene (mecA gene) of S. aureus were amplified by PCR. According to the sequences of spec gene and mecA gene, corresponding programmable crRNAs were designed and prepared to construct CRISPR/Cas12a system, which recognized and bound to the PCR products through complementary interactions to activate the trans -cleavage activity of Cas12a. This led to the indiscriminate digestion of surrounding FQ-reporter, releasing a distinct fluorescence signal for MRSA identification. In addition, we devised a pair of AuNPs-DNA probes for colorimetric recognition of S. aureus . Target-triggered trans -cleavage for linker probe led to an non-aggregation of AuNPs-DNA probes pair. This led to a noticeable appearance of red color, enabling naked-eye detection. Thus, MRSA identification was realized with remarkable sensitivity and exceptional selectivity. Successful identification of MRSA in clinical samples validated the practical applications of the proposed CRISPR/Cas12a assay, establishing it as a universal platform for diagnosing pathogenic microorganisms with versatility and compatibility.
研究领域:
分子生物学
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医学诊断
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食品安全
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产品关联
DOI
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
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2024
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IF 12.2
Yu-E Gao,Qing Huang,Yue Huang,Li-Xia Yan,Wen-Long Wang,WenFeng Zhao,Yong-Wei Feng,Xiao-Dong Huang,Yi Zhang
Antibiotic resistance genes (ARGs) are markers of drug-resistant pathogens, monitoring them contribute to prevent resistance to drugs. The detection methods for ARGs including PCR and isothermal amplification are sensitive and selective. However, it may take several hours or cannot be used on spot. Here, a detection method was developed based on a novel nanoparticle-mediated light-driven (LD) loop-mediated isothermal amplification (LAMP) combining with test strips, and a commonly found methicillin-resistant gene mecA was analyzed to verify the method. Under laser irradiation, gold nanoparticles produced localized surface plasmon resonance. Therefore, they provided both light-induced electrons and localized heat, the former acted as the catalyst of LD-LAMP and the latter as the energy supply. The mecA was amplified, producing numerous double-labeled amplicons. The LD-LAMP was three times as efficient as metal-bathed LAMP. A visual test strip (TS) was designed based on sandwich lateral flow chromatography, reading a LAMP result within 5~10 min. The method has a detection limit of 13.8 copies/μL, with a linear range of 13.8 copies/μL~1.38×10 7 copies/μL. The LD-LAMP TS was applied to the on-site detection of mecA in milk samples. The results were consistent with qPCR, and total detection time reduced from 1 h by qPCR to 20~25 min by LD-LAMP TS.
研究领域:
分子生物学
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病原微生物学
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分析化学
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产品关联
DOI
PubMed
高影响因子
MICROCHEMICAL JOURNAL
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2021
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IF 4.821
Zhengzheng Wang,Guoyang Xie,Guanhua Chen,Xingcai Gao,Jiaxin Li,Zongliang Xie,Hengyi Xu
Due to the massive use of antibiotics, clinical highly pathogenic bacteria methicillin-resistant Staphylococcus aureus (MRSA) have emerged. Given its non-uniform drug resistance, it brings numerous difficulties for clinical diagnostic tests. This study aimed to establish a fast and accurate method to detect MRSA in hospital samples. In order to shorten the detection time and eliminate the influence of matrix on the detection results, so as to improve the detection sensitivity. In this study, magnetic separation (MS) technology was used for pre-treatment of samples, and triplex PCR was established using mecA , nuc and flic genes to realize the detection of MRSA. The results showed that the lowest detection limit of MRSA in blood samples and cerebrospinal fluid could reach 10 2 CFU/mL and 10 3 CFU/mL. Therefore, the MS technology combined with triplex PCR assay established in this study is expected to provide a strong basis for the detection of MRSA in hospital samples.
研究领域:
医学检验
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微生物学
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临床诊断
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产品关联
DOI
高影响因子
Nature Communications
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2023
·Vol. 14
·期 1
·1-19
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IF 16.6
Lu Yunfu,Chen Feifei,Zhao Qingmin,Cao Qiao,Chen Rongrong,Pan Huiwen,Wang Yanhui,Huang Haixin,Huang Ruimin,Liu Qian,Li Min,Bae Taeok,Liang Haihua,Lan Lefu
Phenol-soluble modulins (PSMs) and Staphylococcal protein A (SpA) are key virulence determinants for community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA), an important human pathogen that causes a wide range of diseases. Here, using chemical and genetic approaches, we show that inhibition of TarO, the first enzyme in the wall teichoic acid (WTA) biosynthetic pathway, decreases the expression of genes encoding PSMs and SpA in the prototypical CA-MRSA strain USA300 LAC. Mechanistically, these effects are linked to the activation of VraRS two-component system that directly represses the expression of accessory gene regulator ( agr ) locus and spa . The activation of VraRS was due in part to the loss of the functional integrity of penicillin-binding protein 2 (PBP2) in a PBP2a-dependent manner. TarO inhibition can also activate VraRS in a manner independent of PBP2a. We provide multiple lines of evidence that accumulation of lipid-linked peptidoglycan precursors is a trigger for the activation of VraRS. In sum, our results reveal that WTA biosynthesis plays an important role in the regulation of virulence gene expression in CA-MRSA, underlining TarO as an attractive target for anti-virulence therapy. Our data also suggest that acquisition of PBP2a-encoding mecA gene can impart an additional regulatory layer for the modulation of key signaling pathways in S. aureus .
研究领域:
微生物学
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分子生物学
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传染病学
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药理学
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产品关联
DOI
PubMed
高影响因子
ACS Applied Materials & Interfaces
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2023
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IF 9.5
Ling Cai,Li Zhang,Jing Yang,Xinyi Zhu,Wei Wei,Minghui Ji,Huijun Jiang,Jin Chen
With the increasing prevalence of microbial infections, which results in prolonged inflammation and delayed wound healing, the development of effective and safe antimicrobial wound dressings of multiple properties remains challenging for public health. Despite their various formats, the available developed dressings with limited functions may not fulfill the diverse demands involved in the complex wound healing process. In this study, multifunctional sandwich-structured electrospinning nanofiber membranes (ENMs) were fabricated. According to the structural composition, the obtained ENMs included a hydrophilic inner layer loaded with curcumin and gentamicin sulfate, an antibacterial middle layer consisting of bovine serum albumin stabilized silver oxide nanoparticles, and a hydrophobic outer layer. The prepared sandwich-structured ENMs (SNM) exhibited good biocompatibility and killing efficacy on Escherichia coli, Staphylococcus aureus, and Methicillin-resistant S. aureus (MRSA). In particular, transcriptomic analysis revealed that SNM inactivated MRSA by inhibiting its carbohydrate and energy metabolism and reduced the bacterial resistance by downregulating mecA. In the animal experiment, SNM showed improved wound healing efficiency by reducing the bacterial load and inflammation. Moreover, 16S rDNA sequencing results indicated that SNM treatment may accelerate wound healing without observed influence on the normal skin flora. Therefore, the constructed sandwich-structured ENMs exhibited promising potential as dressings to deal with the infected wound management.
研究领域:
材料科学
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纳米技术
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生物医学工程
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药学
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微生物学
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产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）