ANALYTICA CHIMICA ACTA
·
2017
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IF 4.95
Mengyao Wang,Yue Wu,Yong He,Xiaoxiao Su,Hui Ouyang,Zhifeng Fu
A bioluminescent method was proposed for rapid detection of viable Gram-positive bacteria based on a novel antibiotic-affinity strategy on a magnetic beads (MBs) platform. Daptomycin , a highly efficient lipopeptide antibiotic for Gram-positive bacteria, was used as a recognition agent to functionalize MBs. The daptomycin-functionalized MBs showed high capture and concentration efficiency for Gram-positive bacteria due to the strong binding between daptomycin and bacterial cell membrane in the presence of Ca 2+ ion. The captured bacteria were lysed by hexadecyl trimethyl ammonium bromide solution, followed by a bioluminescent detection of the released intracellular adenosine triphosphate. Four Gram-positive bacteria, including Staphylococcus aureus , Streptococcus mutans , Bacillus subtilis and Staphylococcus epidermidis , were detected as model bacteria by this method. Under the optimal conditions, the bacteria could be detected within a linear range of 1.0 × 10 2 –3.0 × 10 6 CFU mL −1 , with a detection limit of 33 CFU mL −1 . The whole detection procedure could be completed within 20 min. Gram-negative bacteria and dead Gram-positive bacteria showed negligible interference to the detection of viable Gram-positive bacteria. The proposed method was successfully applied to quantify the amount of viable Gram-positive bacteria in cheese, milk, lake water, human urine and physiological saline injection with acceptable recovery values ranging from 75.0% to 120.0%. The strategy possessed some advantages such as high sensitivity, short assay time and simple operation, thus showed great promise for food hygiene, environment monitoring, clinical diagnosis and drug safety.
研究领域:
微生物学
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分析化学
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食品科学
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产品关联
DOI
PubMed
高影响因子
Pharmaceuticals
·
2025
·Vol. 18
·期 8
·1169
·
IF 4.8
Yuqin Zhou,Shihan Du,Kailun He,Beilei Zhou,Zixuan Chen,Cheng Zheng,Minghao Zhou,Jue Li,Yue Chen,Hu Zhang,Hong Yuan,Yinghong Li,Yan Chen,Fuqiang Hu
Background/Objective: Staphylococcus aureus ( S. aureus ) is a clinically significant pathogenic bacterium. Daptomycin (DAP) is a cyclic lipopeptide antibiotic used to treat infections caused by multidrug-resistant Gram-positive bacteria, including S. aureus . However, DAP currently faces clinical limitations due to its short half-life, toxic side effects, and increasingly severe drug resistance issues. This study aimed to develop a biomimetic nano-drug delivery system to enhance targeting ability, prolong blood circulation, and mitigate resistance of DAP. Methods: DAP-loaded chitosan nanocomposite particles (DAP-CS) were prepared by electrostatic self-assembly. Macrophage membrane vesicles (MM) were prepared by fusion of M1-type macrophage membranes with 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC). A biomimetic nano-drug delivery system (DAP-CS@MM) was constructed by the coextrusion process of DAP-CS and MM. Key physicochemical parameters, including particle diameter, zeta potential, encapsulation efficiency, and membrane protein retention, were systematically characterized. In vitro immune escape studies and in vivo zebrafish infection models were employed to assess the ability of immune escape and antibacterial performance, respectively. Results: The particle size of DAP-CS@MM was 110.9 ± 13.72 nm, with zeta potential +11.90 ± 1.90 mV, and encapsulation efficiency 70.43 ± 1.29%. DAP-CS@MM retained macrophage membrane proteins, including functional TLR2 receptors. In vitro immune escape assays, DAP-CS@MM demonstrated significantly enhanced immune escape compared with DAP-CS ( p < 0.05). In the zebrafish infection model, DAP-CS@MM showed superior antibacterial efficacy over both DAP and DAP-CS ( p < 0.05). Conclusions: The DAP-CS@MM biomimetic nano-drug delivery system exhibits excellent immune evasion and antibacterial performance, offering a novel strategy to overcome the clinical limitations of DAP.
研究领域:
药剂学
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纳米技术
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微生物学
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药物递送
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免疫学
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生物医学工程
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产品关联
DOI
PubMed
高影响因子
Frontiers in Bioengineering and Biotechnology
·
2021
·
IF 5.89
Wu Jiequn,Chen Danqing,Wu Jinrong,Chu Xiaohe,Yang Yongmei,Fang Lina,Zhang Wei
Daptomycin, which is produced by Streptomyces roseosporus, has been characterized as a novel cyclic lipopeptide antibiotic that is effective against Gram-positive bacteria. The biosynthesis of daptomycin is regulated by various factors. In the present study, we demonstrated that the cyclic AMP receptor protein (Crp) plays an important role in producing daptomycin in the S. roseosporus industrial strain. We found that daptomycin production from the crp deletion strain decreased drastically, whereas production from the crp overexpression strain increased by 22.1%. Transcriptome and qPCR analyses showed that some genes related to the daptomycin biosynthetic gene cluster (dpt) and the pleiotropic regulator (adpA) were significantly upregulated. RNA-seq also shows Crp to be a multifunctional regulator that modulates primary metabolism and enhances precursor flux to secondary metabolite biosynthesis. These results provide guidance for the development and improvement of potential natural products.
研究领域:
微生物学
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分子生物学
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药学
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DOI
PubMed
高影响因子
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