Virulence
·
2025
·
IF 5.4
Hao-Jie Shen,Jun-Feng Wang,Zheng-Jie Xue,Jia-Qi Shi,Bing Chen,Dong-Min Chen,Ni-Pi Chen,Yu-Dong Li,Chao-Dong Qian
Antimicrobial resistance is one of the greatest threats to global health. A thorough comprehension of the underlying processes through which bacteria evolve the ability to withstand diverse stressors is vital for the development of efficacious strategies to address this challenge. This study aimed to elucidate the mechanisms underlying the adaptation of an acrB-deficient strain of Escherichia coli ATCC 35218 (35218m) to sanguinarine (SAN), the main component of phytobiotic derived from Macleaya cordata. Analysis of the in vitro-selected SAN-resistant clones of strain 35218m led to the identification of a functionally uncharacterized TetR regulator, EefR. The regulator represses its own expression and that of four neighboring genes forming the eefRABCD operon, encoding components of a tripartite RND-efflux pump (EefABC) and a putative MFS-type exporter (EefD). Overexpression of these pumps reduces the susceptibility of acrB-deficient E. coli to SAN and structurally diverse antibiotics. The eefR-eefABC-eefD cluster, widely distributed across Enterobacteriaceae genomes, is also found on plasmids in several E. coli isolates, indicating a significant risk for the rapid spread of this multidrug resistance mechanism.
研究领域:
微生物学
·
分子生物学
·
耐药机制
·
细菌遗传学
·
抗生素耐药性
✓ 已验证
DOI
PubMed
高影响因子
Frontiers in Veterinary Science
·
2025
·
IF 2.9
Qiuru Chen,Yulei Liang,Yanbin Dong,Junling Cui,Kun He,Xiaoyuan Ma,Jinfeng Zhao,Yajun Zhai,Li Yuan
H-NS is a histone-like nucleoid-structuring protein that regulates gene expressions, particularly acquired foreign genes, however, little is known about whether H-NS can modulate bacterial susceptibility by regulating its intrinsic genes. The hns-deleted mutant EΔhns, the hns-complemented strain EΔhns/phns and the hns-overexpressed strain E/phns were derivatives of Escherichia coli ATCC 25922, the susceptibility of which were assessed by the broth microdilution method and time-kill curves assays. We found that the MICs for strain EΔhns against gentamicin and amikacin were significantly decreased by 8–16 folds in contrast to E. coli ATCC 25922. Further studies displayed that the absence of hns caused damage to the bacterial outer membrane and increased the expression levels of porin-related genes, such as ompC, ompF, ompG, and ompN, thus obviously enhancing aminoglycosides uptake of strain EΔhns. Meanwhile, hns deletion also led to remarkable inhibition of the efflux pumps activity and decreased expressions of efflux-related genes clbM, acrA, acrB, acrD, and emrE, which reduced the efflux of aminoglycosides. In addition, the activation of glycolysis and electron transport chain, as well as the reduction of Δψ dissipation, could lead to a remarkable increase in proton motive force (PMF), thus further inducing more aminoglycosides uptake by strain EΔhns. Our findings reveal that H-NS regulates the resistance of E. coli to aminoglycosides by influencing its uptake and efflux, which will enrich our understanding of the mechanism by which H-NS modulates bacterial resistance.
研究领域:
微生物学
·
分子生物学
·
抗菌素耐药性
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ACS Synthetic Biology
·
2024
·
IF 3.7
Chenghu Chen,Cong Gao,Guipeng Hu,Wanqing Wei,Xiaoge Wang,Jian Wen,Xiulai Chen,Liming Liu,Wei Song,Jing Wu
Salicylate plays a pivotal role as a pharmaceutical intermediate in drugs, such as aspirin and lamivudine. The low catalytic efficiency of key enzymes and the inherent toxicity of salicylates to cells pose significant challenges to large-scale microbial production. In this study, we introduced the salicylate synthase Irp9 into an l-phenylalanine-producing Escherichia coli, constructing the shortest salicylate biosynthetic pathway. Subsequent protein engineering increased the catalytic efficiency of Irp9 by 33.5%. Furthermore, by integrating adaptive evolution with transcriptome analysis, we elucidated the crucial mechanism of efflux proteins in salicylate tolerance. The elucidation of this mechanism guided us in the targeted modification of these transport proteins, achieving a reported maximum level of 3.72 g/L of salicylate in a shake flask. This study highlights the importance of efflux proteins for enhancing the productivity of microbial cell factories in salicylate production, which also holds potential for application in the green synthesis of other phenolic acids.
研究领域:
合成生物学
·
代谢工程
·
生物化学
✓ 已验证
DOI
PubMed
高影响因子
Experimental and Therapeutic Medicine
·
2019
·Vol. 18
·期 5
·3715-3722
·
IF 1.448
Haiming Yu,Yuefei Wang,Xiaoqing Wang,Junjie Guo,Hui Wang,Hao Zhang,Fengxia Du
Bacterial resistance to antimicrobial agents, including multidrug resistance, is an increasing problem in the treatment of infectious diseases. The development of resistance‑modifying agents represents a potential strategy to alleviate the spread of bacterial resistance to antibiotics. A checkerboard microdilution assay was used to determine the synergy of jatrorrhizine and the antibiotic, norfloxacin (NFX). A bacterial ethidium bromide efflux assay, reverse transcription semi‑quantitative polymerase chain reaction analysis and molecular docking study were performed. The three‑dimensional structure of NorA multidrug efflux pump (NorA) was generated using a multiple threading approach. A murine thigh infection model was used to evaluate the in vivo synergistic effect. As a natural product, jatrorrhizine exhibited little antibacterial activity against methicillin‑resistant Staphylococcus aureus (MRSA) SA1199B with a minimum inhibitory concentration (MIC) of 64 mg/l. According to the investigations of the mechanism, jatrorrhizine significantly inhibited bacterial drug efflux and the expression of NorA in the mRNA level as it can bind to NorA by hydrogen‑bonds, hydrophobic and electrostatic interactions. The in vivo synergistical bactericidal activity of jatrorrhizine and NFX against MRSA was confirmed in a murine thigh infection model. As a novel resistance‑modifying agent, jatrorrhizine exhibited in vitro and in vivo synergistic activities against MRSA, and inhibited bacterial drug efflux. The effects were mediated by the suppression of NorA mRNA expression and/or interactions with NorA efflux pump. These data support the hypothesis that jatrorrhizine is a potential agent for therapeutic use in infections caused by MRSA.
研究领域:
微生物学
·
药理学
·
传染病学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
BIOMEDICINE & PHARMACOTHERAPY
·
2018
·
IF 3.457
Yi-jin Wu,Ming-yi Zhao,Jian Wang,Hao Tang,Bin Wang,Feng Xiao,Li-hua Liu,Yun-fang Zhang,Ai-wu Zhou,Chun Wang,Wei Wei
Paeoniflorin-6′- O -benzene sulfonate (code: CP-25), is an active monomer obtained by modifying the structure of paeoniflorin (Pae). CP-25 can alleviate the course of adjuvant arthritis (AA) rats by regulating immune inflammatory response and reducing bone damage. In addition, our research has found that immune cells are important target cells for its anti-inflammatory and immunomodulatory effects. Therefore, it is of great significance to study the pharmacokinetics of CP-25 in immune cells. The aim of this study was to investigate the absorption and efflux of CP-25 in plasma and peripheral blood mononuclear cells (PBMCs) of rats. We established a sensitive ultra-high performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) to rapidly determine CP-25 in plasma and PBMC of rat. We found that the transport amount of CP-25 in PBMC gradually decreased with the increase of time, and reached equilibrium after 1 h. Moreover, there is a certain correlation between the concentration of CP-25 in plasma and the concentration of CP-25 in PBMC. In addition, we used several transporter inhibitors to study their effects on the efflux of CP-25 in PBMC. The efflux of CP-25 in PBMC increased with the increase of time in the first 30 min, and the efflux of CP-25 decreased gradually after 30 min. Furthermore, after multiple administration of 50 mg/kg in rats, concentration of CP-25 in PBMC is similar to the change of concentration of CP-25 in plasma. Our results suggest that CP-25 may enter PBMC by passive transport, and P-glycoprotein (P-gp), multidrug resistance-associated protein 2 (MRP2) and breast cancer resistance protein (BCRP) may be involved in the efflux of CP-25 in PBMC. This research provides a basis and guidance for further study of the clinical application of CP-25.
研究领域:
药理学
·
免疫学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
NanoImpact
·
2025
·
IF 5.5
Yuan-Yuan Liu,Jie Liu,Yuan Guo,Qiangqiang Zhang,Aoneng Cao,Haifang Wang
Nanoplastics enter the human body mainly by ingestion through the gastrointestinal tract and thus the uptake and release of nanoplastics in intestinal cells have been studied. However, the fate of nanoplastics in intestinal cells remains poorly understood, particularly how they are exocytosed. Herein, we investigated the uptake, distribution, and exocytosis of nanoplastics in Caco-2 cells using 70 nm red fluorescent polystyrene (R70PS) as a nanoplastic model. The results show that R70PS readily enters Caco-2 cells and the content per cell peaks at around 24 h, but the total intracellular content in all cells increases continuously over 72 h. In addition, the uptake mechanisms change over incubation time, i.e. R70PS entered Caco-2 cells via both the energy-independent pathway and the energy-dependent caveolae-mediated endocytosis and macropinocytosis at 4 h incubation, but almost all R70PS entered cells in an energy-dependent manner via caveolae-mediated endocytosis, macropinocytosis, and clathrin-mediated endocytosis at 12 h incubation. Most of the intracellular R70PS accumulated in lysosomes, but R70PS also entered the mitochondria and its level increased over time. Approximately 45 % of the intracellular R70PS could be cleared from the cells within 12 h, mainly via the lysosomal pathway. Exocytosis was also associated with autophagy and was facilitated by the increase in the number of mitochondria and lysosomes, but inhibited by serum in the medium. Our findings deepen the understanding of the interaction between nanoplastics and intestinal cells, which is helpful for the risk assessment of nanoplastics.
研究领域:
生物学
·
医学
·
毒理学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Emerging Microbes & Infections
·
2018
·
IF 6.032
Jin-xin Zheng,Zhi-wei Lin,Xiang Sun,Wei-hong Lin,Zhong Chen,Yang Wu,Guo-bin Qi,Qi-wen Deng,Di Qu,Zhi-jian Yu
This study investigated the characteristics and mechanisms of eravacycline resistance and heteroresistance in clinical Klebsiella pneumoniae isolates. A total of 393 clinical K. pneumoniae isolates were collected and subjected to eravacycline and tigecycline MIC determinations using the agar dilution method. Eravacycline heteroresistance was assessed by a population analysis profile (PAP). The expression levels of efflux pumps and their regulators were determined by quantitative reverse-transcription PCR (qRT-PCR). This study identified 67 eravacycline-nonsusceptible isolates; among the extended-spectrum β-lactamase (ESBL)-positive isolates, eravacycline-nonsusceptible isolates were detected more frequently than tigecycline-nonsusceptible isolates (21.7% vs. 9.4%, p = 0.001). The study sample was observed to include 20 K. pneumoniae isolates with eravacycline heteroresistance. Compared to the reference strain, oqxA or oqxB overexpression was observed in nine eravacycline-nonsusceptible isolates (range, 35.64–309.02-fold) and 13 eravacycline-heteroresistant isolates (8.42–296.34-fold). The overexpression of macA or macB was detected in 12 eravacycline-heteroresistant isolates (3.23–28.35-fold). Overexpression of the efflux pump regulator gene ramA was observed in 11 eravacycline-nonsusceptible isolates (3.33–94.05-fold) and 18 eravacycline-heteroresistant isolates (3.89–571.70-fold). The eravacycline MICs were increased by one–fourfold by overexpression of oqxAB or macAB in three eravacycline-sensitive isolates. In conclusion, the overexpression of OqxAB and MacAB efflux pumps and the transcriptional regulator RamA were suggested to be involved in K. pneumoniae eravacycline resistance and heteroresistance.
研究领域:
微生物学
·
医学
·
药理学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CYTOTECHNOLOGY
·
2019
·Vol. 71
·期 4
·785-795
·
IF 1.672
Zhou Leilei,Weng Qi,Zheng Yixin,Zhou Yuqin,Li Qingyong,Li Fengzhi
Drug uptake and efflux are two of the critical factors required in order to be able to define drug efficacy. This study aims to investigate cytotoxicity and uptake mechanisms of two FL118 analogues (7-Q20 and val-FL118) in parallel with FL118 in three-dimensional multi-cellular spheroids model. The influence of compound concentration, time, temperature, cell lines, and the inhibitors of P-gp, BCRP and LAT1 on drug uptake and efflux were investigated. In vitro cytotoxicity studies revealed that FL118, 7-Q20 and val-FL118 exhibited sensitive cytotoxicity to the HCT-116 cell line and the water-soluble compound 7-Q20 showed the lowest IC 50 . Cellular uptake and efflux of FL118 was independent of efflux pump proteins. Uptake and efflux of 7-Q20 were affected by P-gp, which was one of reasons that caused a lower uptake at 37 °C than at 4 °C. The carrier protein LAT1 played a role in the cellular intakes of val-FL118. These findings provided basic information for FL118 and the two novel FL118 derivatives for further development.
研究领域:
药理学
·
肿瘤学
·
细胞生物学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
iScience
·
2021
·
IF 5.458
Wei Shi,Baoyue Zhang,Yanan Jiang,Chang Liu,Wei Zhou,Ming Chen,Yang Yang,Yangbo Hu,Bin Liu
The copper efflux regulator (CueR), a representative member of mercury resistance regulator (MerR) family metalloregulators, controls expression of copper homeostasis-regulating genes in bacteria. The mechanism of transcription activation by CueR and other MerR family regulators is bending the spacer domain of promoter DNA. Here, we report the cryo-EM structures of the intact CueR-dependent transcription activation complexes. The structures show that CueR dimer bends the 19-bp promoter spacer to realign the −35 and −10 elements for recognition by σ 70 -RNA polymerase holoenzyme and reveal a previously unreported interaction between the DNA-binding domain (DBD) from one CueR subunit and the σ 70 nonconserved region (σNCR). Functional studies have shown that the CueR-σNCR interaction plays an auxiliary role in CueR-dependent transcription, assisting the activation mechanism of bending promoter DNA by CueR dimer. Because DBDs are highly conserved in sequence and structure, this transcription-activating mechanism could be generally used by MerR family regulators.
研究领域:
微生物学
·
结构生物学
·
分子生物学
✓ 已验证
DOI
PubMed
高影响因子
SCIENCE OF THE TOTAL ENVIRONMENT
·
2022
·
IF 10.753
Ruixuan Wang,Xiaozhi Lin,Guangcai Zha,Juan Wang,Wei Huang,Jiangyong Wang,Yuee Hou,Hongli Mou,Ting Zhang,Hui Zhu,Jun Wang
Vibrio harveyi infection had caused severe economic losses in aquaculture. A pathogenic V. harveyi strain had been successfully induced to be a multiple-resistant strain by enrofloxacin (EFX), then the mechanism of multidrug resistance was analyzed. It suggested that the minimum inhibitory concentration of EFX increased by 32-folds. Results of the Kirby-Bauer test showed that the inhibitory zone diameter was 25.3 mm for the sensitive strain (labeled as HL-S) and 8.5 mm for the resistant strain (labeled as HL-R). After 20 serial passages, even when the stress of EFX was removed, the resistance persisted. After induction of EFX, HL-R resisted to other fluoroquinolones, it even resisted to furazolidone and streptomycin, although it was sensitive to these antibiotics initially. Its sensitivity to rifampicin and doxycycline also decreased obviously. Results showed that 3522 differentially expressed genes were identified. Expression of the multidrugs efflux resistance-nodulation-cell division was significantly upregulated (164.61-folds) in HL-R. Other key genes connected with drug efflux were also upregulated significantly ( p < 0.05 ) . Notably, recA encoded for recombination protein was upregulated significantly, lexA was downregulated significantly in HL-R. Research results showed that the efflux system and the save our souls system have played crucial roles during the development of multidrug resistance of V. harveyi.
研究领域:
微生物学
·
水产养殖
·
药理学
✓ 已验证
DOI
PubMed
高影响因子
FOOD CHEMISTRY
·
2025
·
IF 9.8
Yan Zhu,Jiahui Yue,Ruyu Yan,Wenxin Xia,Tingting Li,Xueyan Fu
Ginseng, a widely used functional food and herbal medicine, contains ginsenosides as its primary active component. However, the low oral bioavailability of ginsenosides limits their therapeutic applications. Recent studies show that ginsenoside polysaccharides (GPSs) promote metabolism and biotransformation. Therefore, the objectives of this study are to investigate whether GPSs could effectively improve the oral absorption of ginsenoside components and to explore the underlying mechanisms of this effect. A GPS–ginsenoside Re complex was prepared and characterized. In vivo and in vitro experiments verified its absorption-enhancing effect. Results showed that the GPS–ginsenoside Re complex enhanced absorption through hydrogen bonding and protected ginsenoside Re from degradation. Mechanistic studies revealed that the GPS–ginsenoside Re complex promoted the absorption of ginsenoside Re by regulating the expression of four efflux proteins and two tight junction proteins. Therefore, GPSs can enhance the bioavailability and efficacy of ginsenosides, particularly for liver-related diseases.
研究领域:
药理学
·
中药学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
STRUCTURE
·
2025
·
IF 4.3
Zhenlin Ouyang,Wenbo He,Di Wu,Hao An,Lei Duan,Min Jiao,Xiaoyu He,Qinyue Yu,Jiaxin Zhang,Qian Qin,Ruochen Wang,Fang Zheng,Peter M. Hwang,Xiaoting Hua,Li Zhu,Yurong Wen
Multidrug-resistant Acinetobacter baumannii has emerged as one of the most antibiotic-resistant bacterial pathogens associated with nosocomial infection, with its resistance highly depending on multiple multidrug efflux pumps. Here, we report the cryoelectron microscopy (cryo-EM) structure of Acinetobacter drug efflux G (AdeG), the inner membrane component of one of three important resistance-nodulation-cell division (RND) pump family members in A. baumannii , which is involved in drug resistance to chloramphenicol, trimethoprim, ciprofloxacin, and clindamycin. We systematically compare the structures and substrate binding specificities of AdeG, AdeB, and AdeJ multidrug efflux pumps via molecular docking, revealing potential determinants for drug binding. Knockout experiments demonstrate a functional complementarity between AdeABC, AdeFGH, and AdeIJK. Our study provides a structural understanding of A. baumannii multidrug efflux pump AdeG and reveals complementary drug efflux activity between AdeG and other RND efflux pumps, which may promote further rational drug discovery efforts targeting multidrug efflux pumps.
研究领域:
微生物学
·
结构生物学
·
药理学
✓ 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）