Journal of Global Antimicrobial Resistance
·
2024
·
IF 3.7
Xiaoqian Long,Feng Lin,Biao Tang,Fengcheng Miao,Zhiyu Li,Yao Shen,Hua Yang,Jiangang Ma
Objectives Acinetobacter indicus is an important pathogen of nosocomial infection. The purpose of this study was to analyze the resistance and transmission of A. indicus strain AIBD14 isolated from slaughterhouse environment. Methods A total of 96 environmental samples were collected from slaughterhouse. The antimicrobial susceptibility test was carried out by microbroth dilution method and E -test. Whole genome sequencing and bioinformatics analysis of the AIBD14 were performed, then S1-PFGE and southern blot verified the location of bla NDM-1 and tet (X6). Results The AIBD14 is resistant to meropenem but susceptibility to tigecycline, and coharboring bla NDM-1 and tet (X6). The bla NDM-1 is located on the pAIBD14-NDM-1 that cannot be transferred by conjugation. Specifically, bla NDM-1 is located on the transposon Tn 125 , and bla NDM-1 can be transferred to other species with the help of transposon. The genetic background of bla NDM-1 is "IS Aba125 - bla NDM-1 - ble MEL - dsbD - cutA - groES - groEL -insE-IS Aba125 ". pAIBD14-NDM-1 is classified into the GR31 plasmid based on the homology of the repB . Meanwhile, there are two XerC/D-like binding sites on the plasmid, which can mediate the transfer of resistance genes. The tet (X6) gene is located on the chromosome of AIBD14, its downstream is accompanied by the neglected macrolide resistance gene estT , and there is a single copy of the insertion element IS CR2 around tet (X6) as the genetic background "IS Aba4 -IS 3 -hp-hp- tet (X6)- estT - guaA -IS CR2 ". Conclusions This is the first report of the coexistence of tet (X6) and bla NDM-1 in the A. indicus , and it has the risk of horizontal transfer across multiple species. So strict monitoring the multiple-resistant bacteria in the industrial chain is necessary based on the "One Heath".
研究领域:
微生物学
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传染病学
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基因组学
✓ 已验证
DOI
高影响因子
VETERINARY RESEARCH
·
2024
·Vol. 55
·期 1
·1-9
·
IF 3.7
Yang Jia,Li Li,Xu Fuqiang,Jia Fan
Feline herpesvirus type 1 (FHV-1), a member of the Herpesviridae family, is one of the most important pathogens that causes upper respiratory tract disease in felines. Following infection, FHV-1 can spread retrogradely to the trigeminal ganglia, establishing a life-long latency. Although vaccines are available for routine feline vaccination, FHV-1 is still an agent that poses a serious threat to feline health. There are currently no specific drugs for the treatment of FHV-1. To facilitate the screening of antiviral drugs, we constructed a reporter FHV-1 virus, which expresses a secreted Gaussia luciferase (GLuc) and a bright green fluorescent protein, mNeonGreen. The reporter virus shows slower growth than does the wild-type FHV-1. The expression of the two reporter genes, Gluc and mNeonGreen, was consistent with viral propagation and remained stable during continuous passage in CRFK cells, even after twenty rounds. In addition, the known inhibitor ganciclovir was used to confirm the characteristics of the reporter virus for drug screening. We found that the reporter FHV-1 is suitable for antiviral screening assays. Overall, our work provides a useful tool for screening drugs to combat FHV-1.
研究领域:
病毒学
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兽医学
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分子生物学
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药理学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
GEOMICROBIOLOGY JOURNAL
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2015
·
IF 1.44
Hongliang Liu,Jun Huang,Shengzhe Zhang,Biao Xu,Gejiao Wang
This study was conducted to determine the microbe-chromate [Cr(VI)] interaction and the effect of quinoid analogue anthraquinone-2-sulfonate (AQS) on aerobic Cr(VI) reduction by Intrasporangium chromatireducens Q5-1. The addition of redox mediator AQS, which might expedite the electron transfer, promoted Cr(VI) bioreduction. Addition of carbon sources, such as maltose, acetate, sucrose and lactose stimulated the AQS-promoted Cr(VI) reduction of strain Q5-1. Induction experiment clarified that the enzyme involves in the Cr(VI) reduction is constitutive. Energy-dispersive spectroscopy (EDS) spectra showed the existence of trace Cr distributed on the cell surface. X-ray photoelectron spectroscopy (XPS) analysis revealed that the Cr(III) complex was bound to the cell surface (0.87%, atomic percent). The spectra shifts detected by Fourier transform infrared (FTIR) spectroscopy indicated that Cr(III) was bound to the carbonyl and amide groups. In addition, Cr(VI) reduction by different cell fractions showed that Cr(VI) reduction was occurred extracellularly rather than intracellularly. The results disclosed that Cr(VI) detoxification of strain Q5-1 was mainly associated with extracellular Cr(VI) reduction process in combination with trace Cr(III) adsorption on the cell surface. A schematic figure depicting the interactions between strain Q5-1 and Cr(VI) was presented. This study enhanced the understanding of the microbe-Cr(VI) interaction mechanism and revealed the AQS-promoted aerobic Cr(VI) reduction of strain Q5-1. Such strain and quinoid analogue-mediated bacterial Cr(VI) reduction may facilitate the bioremediation for Cr(VI)-polluted environment.
研究领域:
微生物学
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环境科学
✓ 已验证
DOI
高影响因子
FOOD HYDROCOLLOIDS
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2014
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IF 4.28
Xiuting Hu,Hongyan Li,Benxi Wei,Xueming Xu,Zhengyu Jin,Yaoqi Tian
The aim of this study was to examine 1-buatnol–hydrochloric acid (1-butanol–HCl) hydrolysis process of starch . Normal rice starch was hydrolyzed by 0.36% HCl in anhydrous 1-butanol at 40 °C from 4 h to 7 days. The changes in starch granule, crystalline, and molecular weight during the 1-butanol–HCl hydrolysis were determined using SEM, particle size analyzer, XRD, HPSEC–MALLS–RI, and iodine staining. SEM and particle size analyzer analysis showed that the granule morphology significantly changed and the granule size decreased from 5.47 μm to 5.07 μm after the hydrolysis by 1-butanol–HCl for 7 days. XRD results indicated that amorphous areas of normal rice starch were firstly hydrolyzed followed by the ordered areas during 1-butanol–HCl hydrolysis. The peak (2 θ ) of V-type crystallinity was detected at around 20° in the XRD curves of 1-butanol–HCl-hydrolyzed starches. This peak confirmed the formation of amylose–1-butanol complex. HPSEC–MALLS–RI and iodine staining analysis demonstrated that the weight-average molecular weight of normal rice starch sharply decreased from 2.4 × 10 7 Da to 4.9 × 10 5 Da after 1-butanol–HCl hydrolysis for 4 h, then gradually decreased, and finally stabilized at about 2.6 × 10 4 Da after hydrolysis for 4 days. These results suggest that the attack of 1-butanol–HCl on normal rice starch preferentially occurred in the amylopectin molecules of amorphous areas.
研究领域:
食品科学
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生物化学
✓ 已验证
产品关联
DOI
高影响因子
Nano Research
·
2023
·Vol. 16
·期 5
·6278-6289
·
IF 9.9
Xu Jialun,Zhang Zhihua,Yu Daiyi,Du Wei,Song Nan,Duan Xuezhi,Zhou Xinggui
The catalytic performances over propylene epoxidation with H 2 and O 2 (HOPO process) are significantly affected by the properties (e.g., surface properties, Ti coordination, and morphology) of titanosilicate zeolite. Introducing urea into zeolite synthesis is a simple and convenient method to modify these properties of titanosilicate zeolite. Uncalcined pore-blocked titanium silicalite-1 (TS-1, i.e., TS-1-B) with the lower urea dosage possesses more defective structure and unsaturated coordinated Ti sites verified by 29 Si nuclear magnetic resonance (NMR) and X-ray photoelectron spectroscopy (XPS) analysis, which results in a high initial activity and hydrogen efficiency; while the high surface acidity generated by these Ti species leads to a continuous decrease in the activity and the propylene oxide (PO) selectivity during the reaction. As the amount of urea gradually increases, the TS-1-B samples present the reduced surface defects and defective and unsaturated Ti species. Specially, TS-1-B-0.30U presents the weaker PO adsorption on PO-diffusion reflectance infrared Fourier transform spectra (DRIFTS), and thus results in the high stable PO formation rate and selectivity over its Au catalyst. Furthermore, a flat-plate-like shape with a shorter thickness of 100 nm along the b-axis direction is observed on the urea-modified TS-1. Compared with the conventional ellipsoidal TS-1 with crystal sizes of 200 and 500 nm, the flat-plate-like TS-1-0.30U displays the less surface defects, unsaturated Ti species, and the weaker Lewis acid, which is favorable for the desorption and intracrystalline diffusion of PO, thus reduces the occurrence of side reactions for the improved selectivity and stability. This work may provide a reference for developing titanium-containing materials with high activity and stability over HOPO reaction.
研究领域:
催化化学
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
BRITISH JOURNAL OF PHARMACOLOGY
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2015
·Vol. 172
·期 16
·4052-4065
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IF 4.842
Lin Guo,Yanke Chen,Rui Zhao,Guanghui Wang,Eitan Friedman,Ao Zhang,Xuechu Zhen
Background and Purpose Application of orthosteric sigma-1 receptor agonists as anti-seizure drugs has been hindered by questionable efficacy and potential adverse effects. Here, we have investigated the anti-seizure effects of the novel and potent allosteric modulator of sigma-1 receptors, SKF83959 and its derivative SOMCL-668 (3-methyl-phenyl-2,3,4,5-tetrahydro-1H-benzo[d]azepin-7-ol). Experimental Approach The anti-seizure effects of SKF83959 were investigated in three mouse models, maximal electroshock seizures, pentylenetetrazole-induced convulsions and kainic acid-induced ‘status epilepticus’. Also, in rats, the cortical epileptiform activity induced by topical application of picrotoxin was recorded in electrocorticograms. In rat hippocampal brain slices, effects of the drugs on the high potassium-evoked epileptiform local field potentials were studied. Anti-seizure activities of SOMCL-668, a newly developed sigma-1 receptor selective allosteric modulator, were also investigated. Key Results SKF83959 (20, 40 mg·kg −1 ) exhibited anti –seizure actitity in the three mouse models and reduced the cortical epileptiform activity without alteration of spontaneous motor activity and motor coordination. These effects were blocked by the sigma-1 receptor antagonist BD1047, but not the dopamine D 1 receptor antagonist SCH23390. SKF83959 alone did not directly inhibit the epileptiform firing of CA3 neurons induced by high potassium in hippocampal slices, but did potentiate inhibition by the orthosteric sigma-1 receptor agonist SKF10047. Lastly, a selective sigma-1 receptor allosteric modulator SOMCL-668, which does not bind to dopamine receptors, exerted similar anti-seizure activities. Conclusions and Implications SKF83959 and SOMCL-668 displayed anti-seizure activities, indicating that allosteric modulation of sigma-1 receptors may provide a novel approach for discovering new anti-seizure drugs.
研究领域:
药理学
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神经科学
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分子生物学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF VOICE
·
2024
·
IF 2.5
Zhe Chen,Ke-Da Li,Min Gao,Shui-Hong Zhou,Hong-Tian Yao,Jiang-Tao Zhong,Yang-Yang Bao,Zi-Ming Fu,Zai-Zai Cao
Summary Objective We assessed the expression of glucose transporter (GLUT)-1 and hexokinase (HK)-Ⅱ in vocal cord leukoplakia (VCL) and investigated its clinical significance. Methods We collected 127 archival pathological specimens from patients with VCL, 29 from vocal cord polyps, and 31 with laryngeal carcinoma at our hospital between December 2018 and December 2022. GLUT-1 and HK-II expression was detected using immunohistochemistry. Results Significant differences were observed between the VCL and vocal cord polyp groups according to sex ( P < 0.0001), smoking status ( P = 0.001), and alcohol consumption ( P = 0.007). GLUT-1 expression was observed in 36.2%, 20.7%, and 90.3% of patients with VCL, vocal cord polyps, and laryngeal carcinoma, respectively. GLUT-1 was highly expressed in severe dysplasia or carcinoma in situ (CIS) compared with vocal cord polyps ( P < 0.001). GLUT-1 expression was lower in the VCL group than in the laryngeal carcinoma group ( P < 0.001). HK-II expression was observed in 42.5%, 34.5%, and 80.6% of patients with VCL, vocal cord polyps, and laryngeal carcinoma, respectively. HK-II expression was significantly higher in severe dysplasia or CIS compared with vocal cord polyps ( P = 0.004). HK-II expression was lower in the VCL group than in the laryngeal carcinoma group ( P < 0.001). Both GLUT-1 expression ( P < 0.001) and HK-II expression ( P = 0.03) increased significantly with the degree of dysplasia. A significant correlation was observed between GLUT-1 and HK-II expression (r = 0.313, P < 0.001). Conclusion GLUT-1 and HK-II are significantly overexpressed in VCL patients. In VCL patients, GLUT-1 and HK-II expression levels increase proportionally with the degree of dysplasia.
研究领域:
耳鼻喉科学
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病理学
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肿瘤学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
·
2022
·Vol. 29
·期 32
·48638-48647
·
IF 5.19
Li Qian,Tang Zeqin,Zhang Jiahui,Hu Jingtao,Chen Jianmeng,Chen Dongzhi
Simultaneous biodegradation of malodorous 1-propanethiol (PT) and dimethyl sulfide (DMS) by Pseudomonas putida S-1 and Alcaligenes sp. SY1 was investigated and the interactions implicated were explored. Results showed that PT was completely degraded in 33 h, while a lag of 10 h was observed for DMS degradation alone, and the lag was even extended to 81 h in the binary mixture. Mechanism analysis found that the lag was mainly attributed to the exposure of DMS degrader ( Alcaligenes sp. SY1), rather than PT metabolites and PT degrader. The exposure time and PT concentration also influenced the lag duration much. Citric acid could effectively reduce the lag. Pseudo-first-order model was proved suitable for the description of PT degradation, revealing that PT degradation could be enhanced in presence of DMS with a concentration of < 50 mg L −1 . A modified Gompertz model, incorporated the lag phase, was developed for the description of DMS degradation in the mixture, revealing that DMS degradation depended on the initial PT concentration, and when the lag was not considered, PT with low-concentration could promote DMS biodegradation, while a higher concentration (> 20 mg L −1 ) cast negative effect.
研究领域:
环境生物学
·
微生物学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
eLife
·
2024
·
IF 6.4
Shu-Ting Zhang,Shi-Kai Deng,Tao Li,Megan E Maloney,De-Feng Li,Jim C Spain,Ning-Yi Zhou
1-Naphthylamine (1NA), which is harmful to human and aquatic animals, has been used widely in the manufacturing of dyes, pesticides, and rubber antioxidants. Nevertheless, little is known about its environmental behavior and no bacteria have been reported to use it as the growth substrate. Herein, we describe a pathway for 1NA degradation in the isolate Pseudomonas sp. strain JS3066, determine the structure and mechanism of the enzyme NpaA1 that catalyzes the initial reaction, and reveal how the pathway evolved. From genetic and enzymatic analysis, a five gene-cluster encoding a dioxygenase system was determined to be responsible for the initial steps in 1NA degradation through glutamylation of 1NA. The γ-glutamylated 1NA was subsequently oxidized to 1,2-dihydroxynaphthalene which was further degraded by the well-established pathway of naphthalene degradation via catechol. A glutamine synthetase-like (GS-like) enzyme (NpaA1) initiates 1NA glutamylation, and this enzyme exhibits a broad substrate selectivity toward a variety of anilines and naphthylamine derivatives. Structural analysis revealed that the aromatic residues in the 1NA entry tunnel and the V201 site in the large substrate-binding pocket significantly influence NpaA1’s substrate preferences. The findings enhance understanding of degrading polycyclic aromatic amines, and will also enable the application of bioremediation at naphthylamine contaminated sites.
研究领域:
环境微生物学
·
生物化学
·
生物修复
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Catalysts
·
2022
·Vol. 12
·期 7
·685
·
IF 4.501
Hao Dong,Cheng-Hua Xu,Fang-Lu Yang,Lei Du,Chen-Long Liu,Wen-Jing Chen,Lin Wang
Ca–Zr–Sn composite oxides catalysts for 1,4-butanediol (BDO) selective dehydration to 3-butene-1-ol (BTO) are synthesized by impregnation and co-precipitation in the present work. The results show that Ca–Zr–Sn catalysts prepared from co-precipitation by using NaOH-Na2CO3mixing alkali solution as precipitant exhibit an excellent catalytic property for BDO dehydration to BTO. For instance, Ca–Zr–Sn oxide with Ca/Zr and Sn/Zr molar ratio of 0.68 and 0.28 calcined at 650 °C gives a BDO conversion and BTO selectivity of about 97% and 82%, respectively, and exhibits no deactivation during 1000 h scale-up experimental testing. X-ray diffraction results indicate that catalytic active centers for BDO dehydration to BTO are from Ca0.15Zr0.85O crystal phase. NH3- and CO2-temperature programmed desorption prove that the surface of obtained catalysts can provide a large amount of acid and base sites simultaneously. FT-IR spectra of pyridine-adsorbed samples show that acid sites on the surface of Ca–Zr–Sn oxide catalyst mainly exist in a state of Lewis acid, which activates terminal -OH groups of BDO molecule through complexing. The activated -OH interacts with β-H activated on base sites O2−anions relative to Ca species, thereby the CH2=CH- bonds are produced through dehydration to form BTO.
研究领域:
化学工程
·
催化材料科学
✓ 已验证
DOI
高影响因子
MICROPOROUS AND MESOPOROUS MATERIALS
·
2022
·
IF 5.876
Yongkui Liu,Fumin Wang,Xubin Zhang,Qing Zhang,Yi Zhai,Guojun Lv,Mengyao Li,Mengyue Li
Development of economic routes for synthesis of hollow titanium silicalite-1 (TS-1) zeolite is of great importance in industry. However, there are still challenges to synthesize hollow TS-1 zeolite without anatase TiO 2 . In this work, a one-step strategy without mesoporogen by the solid-phase conversion method was successfully developed to synthesize anatase-free hollow TS-1. The appropriate low amount of TPAOH (TPA/SiO 2 = 0.13) and the suitable crystallization temperature (170 °C) can not merely induce the formation of hollow structures, but also enable more titanium to enter the framework. Moreover, the transformation mechanism based on crystallization rate and dissolution rate was proposed according to the investigation of the transformation process. The hollow TS-1 with large cavities exhibits high catalytic activity and recycle stability in 1-hexene epoxidation. The efficient strategy reported in this paper will provide new opportunities for further promoting the industrial application of hollow TS-1.
研究领域:
材料科学
·
催化
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
Frontiers in Bioengineering and Biotechnology
·
2020
·
IF 3.644
Peng Fei,Su Hui-Hui,Ou Xiao-Yang,Ni Zi-Fu,Zong Min-Hua,Lou Wen-Yong
(R)-1-phenyl-1,2-ethanediol is an important synthon for the preparation of β-adrenergic blocking agents. This study identified a (2R,3R)-butanediol dehydrogenase (KgBDH) from Kurthia gibsonii SC0312, which showed high enantioselectivity for production of (R)-1-phenyl-1,2-ethanediol by reduction of 2-hydroxyacetophenone. KgBDH was expressed in a recombinant engineered strain, purified, and characterized. It showed good catalytic activity at pH 6–8 and better stability in alkaline (pH 7.5–8) than an acidic environment (pH 6.0–7.0), providing approximately 73 and 88% of residual activity after 96 h at pH 7.5 and 8.0, respectively. The maximum catalytic activity was obtained at 45°C; nevertheless, poor thermal stability was observed at >30°C. Additionally, the examined metal ions did not activate the catalytic activity of KgBDH. A recombinant Escherichia coli strain coexpressing KgBDH and glucose dehydrogenase (GHD) was constructed and immobilized via entrapment with a mixture of activated carbon and calcium alginate via entrapment. The immobilized cells had 1.8-fold higher catalytic activity than that of cells immobilized by calcium alginate alone. The maximum catalytic activity of the immobilized cells was achieved at pH 7.5, and favorable pH stability was observed at pH 6.0–9.0. Moreover, the immobilized cells showed favorable thermal stability at 25–30°C and better operational stability than free cells, retaining approximately 55% of the initial catalytic activity after four cycles. Finally, 81% yields (195 mM product) and >99% enantiomeric excess (ee) of (R)-1-phenyl-1,2-ethanediol were produced within 12 h through a fed-batch strategy with the immobilized cells (25 mg/ml wet cells) at 35°C and 180 rpm, with a productivity of approximately 54 g/L per day.
研究领域:
生物化学
·
酶工程
·
合成生物学
✓ 已验证
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）