VETERINARY MICROBIOLOGY
·
2022
·
IF 3.246
Hongyan Luo,Mengru Li,Zhishuang Yang,Dekang Zhu,Pei Li
A novel chromosomally-located β-lactamase gene, bla RASA-1 , was identified in Riemerella anatipestifer RA-CH-1. The RASA-1, encoded by bla RASA-1 , was a class A extended-spectrum β-lactamase (ESBL), which shared 42.7% and 40.5% identities with the RAA-1 and CGA-1 β-lactamase, respectively. Overexpression of RASA-1 in Escherichia coli confers broad resistance to β-lactams and the purified native RASA-1 revealed ESBL-like hydrolysis activity. Blasting in GenBank showed that bla RASA-1 was exclusively detected in Riemerella anatipestifer . Moreover, sequence analysis revealed that this gene was located within the multi-resistance region of Riemerella anatipestifer genome.
研究领域:
微生物学
·
抗药性研究
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DOI
高影响因子
Antibiotics-Basel
·
2025
·Vol. 14
·期 9
·915
·
IF 4.6
Ru Wang,Kun Mi,Aihua Lu,Chengyang Zhang,Lei Sun,Yuxiang Chen,Yuanhu Pan,Yanfei Tao,Lingli Huang
Background/Objectives: Extended-spectrum β-lactamase (ESBL)-producingEscherichia coliposes a significant global health challenge, as it leads to antimicrobial treatment failure and is associated with elevated mortality rates. The use of β-lactam/β-lactamase inhibitor combinations offers an alternative approach for combating ESBL-producing bacteria. Ceftriaxone (CRO) and sulbactam have been coadministered in the clinical settings; however, discrepancies in their pharmacokinetics raise concerns regarding the rationality of this combination.Methods: This study was designed to investigate the postβ-lactamase inhibitor effect (PLIE) under both static and dynamic conditions, with the aim of supporting the clinical application of this combination.Results: The minimum inhibitory concentration (MIC) of CRO/SBT (2:1 ratio) againstE. coliNCTC 13353 was determined to be 32/16 μg/mL. The PLIEs were determined to be −1.26, −0.57, and 0.37 h at CRO/SBT concentrations ranging from 1/2 MIC to 2 MIC, respectively. The results of CRO concentration, β-lactamase activity,blaCTX-M-15expression, and cell morphology collectively support that SBT exerts PLIEs and protects against the antibacterial activity of CRO. In the dynamic hollow-fiber infection model, CRO monotherapy showed no inhibitory effect onE. coli, whereas CRO/SBT combination therapy rapidly eliminated SBT, achieved comparable bactericidal effects, prolonged CRO exposure, and maintained low β-lactamase activity levels.Conclusions: In conclusion, CRO/SBT exerts an inhibitory effect on enzyme-producing strains by being able to produce PLIE to maintain the inhibition of β-lactamase.
研究领域:
微生物学
·
感染病学
·
药理学
·
临床药学
·
抗菌药物治疗
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分子生物学
·
转化医学
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产品关联
DOI
PubMed
高影响因子
Research
·
2025
·
IF 10.7
Lei Xu,Sangyu Hu,Yuzhu Pei,Yutong Zhou,Xiuli Zhang,Linlin Ding,Minhe Cui,Yonglin Zhou,Xuming Deng,Zihao Teng,Jianfeng Wang
The emergence and prevalence of methicillin-resistant Staphylococcus aureus (MRSA) severely compromises conventional β-lactam antibiotics efficacy and poses an extensive global health challenge. Given the close relationship between docosahexaenoic acid (DHA) and metabolic alterations, this study aimed to reveal the novel function of DHA to potentiate β-lactam antibiotics activity through a lipid peroxidation mechanism. Additionally, DHA exhibited significant inhibitory effects on the catalytic function of β-lactamase through interactions with active residues. Herein, the dual-faceted mechanisms of perturbation of lipid metabolism and β-lactamase catalytic inhibition achieved the potentiated antibacterial efficacy of β-lactam antibiotics in combination with DHA against MRSA. Furthermore, to enhance the pharmacodynamic performance and stability of DHA, amoxicillin and DHA co-loaded nanoemulsions (Amo/DHA-NEs) were prepared via high-energy emulsification. Intriguingly, we found that Amo/DHA-NEs effectively rescued MRSA-induced infections in the murine infection models, as evidenced by the superior bacterial clearance and mitigated inflammation. Collectively, this work reveals a potentially exploitable link between DHA-driven metabolic reprogramming and β-lactams resistance, and we propose combination therapies of DHA and β-lactams targeting the emerging threat of MRSA infections.
研究领域:
微生物学
·
药理学
·
感染病学
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产品关联
DOI
PubMed
高影响因子
ACS Applied Optical Materials
·
2023
·
IF 0
Jie Zhu,Yang Sun,Meng-Xin Duan,Zheng-Wu Wang,Xin Tan,Zhen Yu,He-Fang Wang
The fast and accurate detection of β-lactamase is a prerequisite of customized treatments and food safety. We present a pretreatment-free dual-excitation three-mode detection of β-lactamase by using ZnAl2O4:Cr3+ etched by ethylenediaminetetraacetic acid disodium (ZAO-EDTA) as a phosphorescent probe and nitrocefin as the signal mediator. The changes in the wavelength overlaps of UV–vis absorbance of nitrocefin upon interactions with β-lactamase and the dual excitation of ZAO-EDTA enable the design of three detection modes: i.e., the enhanced emission when excited at 393 nm, the quenched emission when excited at 533 nm, and the ratio of enhanced excitation of 393 nm and decreased excitation of 533 nm to determine β-lactamase. All three modes have a wide linear range, high sensitivity and selectivity, and fine anti-interference capability. The lowest limit of detection is observed in the ratiometric excitation mode (0.2 U·L–1), and the proposed method can directly detect β-lactamase in bacteria and milk samples without any pretreatments, with the spiked recoveries of 95.3–113% and relative standard deviation < 3.1%. Therefore, the proposed method would be attractive for the detection of β-lactamase in a complex sample, and the ZAO-EDTA probe can be widely used to establish other excitation ratiometric optosensings by changing other signal mediators.
研究领域:
分析化学
·
生物传感
·
食品安全
·
微生物学
✓ 已验证
DOI
Catalysis Science & Technology
·
2016
·Vol. 6
·期 16
·6305-6310
·
IF 5.287
Jin-Gang Yin,Yi Gong,Xiao-Yan Zhang,Gao-Wei Zheng,Jian-He Xu
A novel non-heme chloroperoxidase (SvGL) with promiscuous (−)-γ-lactamase activity towards Vince lactam was identified from Streptomyces viridochromogenes by genome data-mining. SvGL possesses high activity and excellent thermal stability and enantioselectivity. Furthermore, it is able to tolerate extremely high substrate concentrations (4.0 M, 436.5 g L−1). Using the newly discovered (−)-γ-lactamase as a biocatalyst, an efficient and environmentally benign process for the production of (+)-γ-lactam was developed. The process allowed an enantioselective resolution of 436.5 g L−1 racemic γ-lactam with only 0.2 g L−1 lyophilized cell-free extract, affording an extremely high substrate/catalyst ratio of 2183 (g g−1), a space-time yield of 458 g L−1 d−1, and a very low E factor (environmental factor) of 5.7 (kg waste per kg product) even when the process water is included.
研究领域:
生物催化
·
酶学
·
绿色化学
·
微生物学
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产品关联
DOI
高影响因子
BIORESOURCE TECHNOLOGY
·
2025
·
IF 9
Yang Li,Changyang Yang,Mingxiong Liu,Hongxin Fu,Jufang Wang
Biomanufacturing offers a promising alternative for the production of the building block of nylons, of which butyrolactam is an important platform chemical. To date, there is few studies on butyrolactam biosynthesis, and static control characterized by orientation, irreversibility and ineffectiveness often impedes synthesis efficiency. Here, the chassis Escherichia coli was systematically engineered for butyrolactam synthesis by stepwise optimization strategies. In particular, inadequate α-ketoglutarate pool was identified as the main bottleneck, and then the CRISPRa and CRISPRi served as ON- and OFF-switch for establishing the temperature-powered bioswitch (thereafter renamed AITB circuit), achieving simultaneous transcriptional down- and up-regulation of the multi-genes. In the fed-batch culture, the highest titer of 59.87 g/L butyrolactam was produced by redirecting α-ketoglutarate catabolism. Further, with cassava starch as the substrate, a total of 14.96 g/L butyrolactam was generated, providing the possibility for bioproduct synthesis from renewable feedstock. This study provides efficient tool for developing high-performance biorefineries for bio-based compounds production of interest.
研究领域:
合成生物学
·
代谢工程
·
生物技术
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DOI
PubMed
高影响因子
REACTIVE & FUNCTIONAL POLYMERS
·
2021
·
IF 3.975
Fada Li,Bo Chen,Yu Han,Yiwen Cao,Xiaoxue Hong,Mancai Xu
Phenol, catechol , and pyrogallol were employed as the hydrogen-bond donors to chemically modify the commercial adsorbent Amberlite XAD16 via Friedel-Crafts reaction, and three phenols-modified XAD16 were named as, XAD16-Ph(OH), XAD16-Ph(OH) 2 , and XAD16-Ph(OH) 3 respectively. The resulting polymers had porous parameters including Brunauer-Emmett-Teller (BET) surface area ( S BET ) and total pore volume ( V total ) similar to Amberlite XAD16, however the oxygen (O) content was remarkably increased after the Friedel-Crafts reaction in the presence of anhydrous FeCl 3 as catalyst. The synthesized polymers had larger equilibrium adsorption capacities toward ε-caprolactam ( q max = 69.2 mg/g) than Amberlite XAD16 due to the enhanced adsorption contributed by hydrogen bonding between the phenolic hydroxyl groups uploaded on the polymers and the carbonyl of ε-caprolactam (CPL). Experimental data indicated that the removal percentage of CPL reached 93.2% at a concentration of 0.2840 g/25 mL for XAD16-Ph(OH) 2 while the equilibrium data were fitted by the Freundlich and Langmuir models, and the kinetic data were described by the pseudo-second-order rate equation and characterized by the micropore diffusion model.
研究领域:
化学工程
·
材料科学
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DOI
高影响因子
RSC Advances
·
2015
·Vol. 5
·期 32
·25365-25371
·
IF 3.84
Yang Li,Kai Wang,Kang Qin,Tao Wang
As an important green synthesis technology of caprolactam, the Beckmann rearrangement reaction of cyclohexanone oxime using high temperature and pressure water as the reaction media was carefully studied with a microreactor. An important byproduct – acetamide was confirmed with a selectivity higher than 40% in the subcritical water, which was more serious than the reported cyclohexanone. The effects of phase state and operating conditions, such as reaction temperature, pressure, flow rate ratio and reactant residence time, on the cyclohexanone oxime conversion and caprolactam selectivity were carefully analyzed, and the results showed that keeping the reaction close to the supercritical state was critical for the preparation of caprolactam.
研究领域:
化学工程
·
绿色化学
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DOI
高影响因子
International Journal of Environmental Research and Public Health
·
2013
·Vol. 10
·期 7
·2688-2698
·
IF 1.998
Wenbin Wang,Liqiang Liu,Liguang Xu,Wei Ma,Hua Kuang,Chuanlai Xu
β-Lactamase residues in milk represent a public health risk. The cylinder plate detection method, which is based on bacterial growth, is laborious and time consuming. In this study, 15 monoclonal antibodies (mAbs) were selected against Temoneira (TEM) 1 β-lactamase. A sandwich enzyme-linked immunosorbent assay (ELISA) based on an optimum mAb pair was developed and validated for the detection of β-lactamase. The limit of detection and linear dynamic range of the method were 4.17 ng/mL and 5.5–100 ng/mL, respectively. β-Lactamase recovery in pure milk was 96.82–103.13%. The intra- and inter-assay coefficients of variation were 6.21–7.38% and 12.96–13.74%, respectively. Our developed sandwich ELISA can be used as a rapid detection method of β-lactamase in milk.
研究领域:
食品科学
·
免疫学
·
公共卫生
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DOI
高影响因子
POLYMERS FOR ADVANCED TECHNOLOGIES
·
2022
·Vol. 33
·期 12
·4120-4130
·
IF 3.348
Xue Meng,Da Zhang,Meng Wang,Ronghui Zhao,Pengfei Zhang,Jingyuan Zhao,Kuilin Deng
For the nontraditional aggregation-induced emission (AIE) active polymers, the heterocyclic structure on the macromolecular backbone and side chains play a crucial role in its fluorescence generation. In this paper, we facilely prepared a series of poly(β-lactam) derivatives (PLTM) by Staudinger polymerization. As expected, PLTMs with four-membered heterocycles along the main-chain shows a remarkable AIE performance with the fluorescence emission at 520 nm, while no fluorescence was observed for both β-lactam (repeating unit) and a model polymer for PLTM. The fluorescence properties of PLTMs greatly depend on the intramolecular aggregation of β-lactam structures, the size of the substituents, and appropriate length of CH 2 spacer. In addition, PLTMs can specifically detect Fe 3+ ions with a limit of detection (LOD) of 7.2 μM even in the presence of other 13 metal ions. Similar to the biological activity of β-lactam, AIE-active PLTMs shows a bactericidal effect on Staphylococcus aureus and Escherichia coli with the minimum inhibitory concentration of about 8 and 4 mg/mL. In brief, the preparation and versatility of PLTMs with β-lactam structure provide useful references for designing other nontraditional AIE-active polymers as well as for ion detection and antibacterial processes.
研究领域:
高分子化学
·
分析化学
·
生物化学
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DOI
高影响因子
POLYMER ENGINEERING AND SCIENCE
·
2017
·Vol. 58
·期 9
·1523-1529
·
IF 1.449
Yusheng Dong,Jizong Chen,Fredrick Nzioka Mutua,Yuanbo Gao,Tingting Yang,Yong He
To modify the properties of poly(hexamethylene oxamide) (PA62), amine-terminated polyoxypropylene glycols (PGs) were introduced into the polyoxamide main chain as soft segments. A series of PA62/PG2 copolymers were synthesized successfully by a two-step method. Fourier transform infrared spectroscopy, solution proton nuclear magnetic resonance spectroscopy ( 1 H-NMR), differential scanning calorimetry, thermogravimetric analysis, and wide-angle X-ray diffraction were used to analyze the structures and to investigate the properties of these copolymers. The saturated water absorption was also evaluated by gravimetric analysis for PA62/PG2 copolymers. The results revealed the incorporation of PG2 effectively modified the properties of PA62 and the copolymers with PG2 content of 10–20 mol% possessed high melting point (293°C–314°C), good thermal stability and low saturated water absorption. POLYM. ENG. SCI., 58:1523–1529, 2018. © 2017 Society of Plastics Engineers
研究领域:
高分子化学
·
材料科学
✓ 已验证
DOI
高影响因子
Forests
·
2023
·Vol. 14
·期 6
·1242
·
IF 2.9
Ziheng Wang,Sheng He,Jiangtao Shi,Xuefeng Zhang,Weiqi Leng
Furfurylated wood has many advantages, such as decay resistance, dimensional stability, hardness, etc. However, furfurylation increases the brittleness and decreases the flexural resistance of wood, which greatly limits its application. Therefore, caprolactam (CPL) is incorporated with furfuryl alcohol (FA) to improve the performance of furfurylated wood. In this study, an FA and CPL combinational modifier was used to treat masson pine (Pinus massonianaLamb.) earlywood and latewood. The synergistic interaction of both components with the wood cell walls was systematically evaluated via microstructural, chemical, and thermal analysis using scanning electron microscopy (SEM), infrared spectroscopy (ATR-FTIR), X-ray photoelectron spectrometry (XPS), and differential scanning calorimetry (DSC). The SEM images showed that polymerized modifiers were distributed in tracheids, ray cells, and pits, with a higher degree of distribution in latewood tissues. The FA-CPL co-treatment led to the highest degree of distribution in cell cavities as well as of cell wall swelling. The results of the weight percentage gain (WPG) of modified wood agreed with the SEM findings that the FA-CPL co-treatment could more effectively increase the WPG than individual modification. The results of FTIR and XPS revealed that FA and CPL might chemically bind with each other as well as react with lignin and hemicellulose in the cell walls during the curing process. In addition, the interactions between modifiers and cell walls were slightly different for earlywood and latewood. DSC analysis indicated that the wood hygroscopicity decreased and the thermal stability improved after modification.Keywords:furfuryl alcohol;caprolactam;vacuum impregnation;synergistic interaction;earlywood;latewood
研究领域:
材料科学
·
木材化学
·
林业
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）