ENVIRONMENTAL MICROBIOLOGY
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2015
·Vol. 17
·期 10
·3795-3806
·
IF 6.201
Zi-Hao Mi,Zi-Chao Yu,Hai-Nan Su,Lei Wang,Xiu-Lan Chen,Xiuhua Pang,Qi-Long Qin,Bin-Bin Xie,Xi-Ying Zhang,Bai-Cheng Zhou,Yu-Zhong Zhang
Summary Although bacteriobenthos play a major role in the degradation of particulate organic matter in marine sediment, knowledge of the sediment-adapted lifestyles of bacteriobenthos is still scarce. Here, the particle-associated, swimming and swarming lifestyles of the benthonic bacterium P seudoalteromonas sp. SM9913 (SM9913) were illustrated. SM9913 had a clay particle-associated lifestyle, and its exopolysaccharide played an important role in this lifestyle. SM9913 also had swimming and swarming motilities, indicating that it may have swimming and swarming lifestyles in the sediment. The lateral flagella were responsible for the swarming motility, and the polar flagella were responsible for the swimming motility. Iron limitation was an indispensable inductive signal of the swarming motility. An analysis of the motilities of SM9913 and its mutants in clay demonstrated that SM9913 moved in clay by both swimming and swarming motilities. Genomic analysis suggests that having two flagella systems is most likely a common adaptation of some bacteriobenthos to the sediment environment. Our results reveal the lifestyles of benthonic SM9913, providing a better understanding of the environmental adaptation of benthonic bacteria.
研究领域:
微生物学
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海洋生物学
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基因组学
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环境科学
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DOI
PubMed
高影响因子
MOLECULAR PLANT PATHOLOGY
·
2024
·Vol. 25
·期 9
·e70001
·
IF 4.8
Meilin Li,Liya Xiong,Wenhan Chen,YiSha Li,Abdullah Khan,Charles A. Powell,Baoshan Chen,Muqing Zhang
Xanthomonas albilineans (Xal) is a gram-negative bacterial pathogen responsible for developing sugarcane leaf scald disease, which engenders significant economic losses within the sugarcane industry. In the current study, homologous recombination exchange was carried out to induce mutations within the virB/D4 -like type IV secretion system (T4SS) genes of Xal. The results revealed that the virB11 -deletion mutant (Δ virB11 ) exhibited a loss in swimming and twitching motility. Application of transmission electron microscopy analysis further demonstrated that the Δ virB11 failed to develop flagella formation and type IV pilus morphology and exhibited reduced swarming behaviour and virulence. However, these alterations had no discernible impact on bacterial growth. Comparative transcriptome analysis between the wild-type Xal JG43 and the deletion-mutant Δ virB11 revealed 123 differentially expressed genes (DEGs), of which 28 and 10 DEGs were notably associated with flagellar assembly and chemotaxis, respectively. In light of these findings, we postulate that virB11 plays an indispensable role in regulating the processes related to motility and chemotaxis in Xal.
研究领域:
微生物学
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植物病理学
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分子生物学
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DOI
高影响因子
Frontiers in Microbiology
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2020
·
IF 4.236
Wang Feiying,Deng Le,Huang Fangfang,Wang Zefeng,Lu Qiujun,Xu Chenran
The food-borne pathogen Salmonella enterica serovar Typhimurium (S. Typhimurium) causes self-limiting gastroenteritis in humans and is not easily eradicated because it often attaches to suitable surfaces to form biofilms that have high resistance to disinfectants and antimicrobials. To develop an alternative strategy for the treatment of biofilms, it is necessary to further explore the effects of flagellar motility on the development process of Salmonella biofilms. Here, we constructed flagella mutants (ΔflgE and ΔfliC) to systematically study this process. By comparing them with wild-type strains, we found that these mutants lacking flagellar motility form fewer biofilms in the early stage, and the formed mature biofilms contain more cells and extracellular polymeric substances (EPS). In addition, fewer mutant cells adhered to glass plates compared with wild-type cells even after 6 h of incubation, suggesting that flagellar motility plays a significant role in preliminary cell-surface interactions. More importantly, the motility of wild-type strain was greatly decreased when they were treated with carbonyl cyanide m-chlorophenylhydrazone, which inhibited flagellar motility and reduced biofilm formation, as in the case of the ΔflgE mutant. Overall, these findings suggest that flagellar motility plays an important role in Salmonella biofilm initiation and maturation, which can help us to counteract the mechanisms involved in biofilm formation and to develop more rational control strategies.
研究领域:
微生物学
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感染病学
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DOI
PubMed
高影响因子
Animal Diseases
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2022
·Vol. 2
·期 1
·1-9
·
IF 0
Lu Ying,Liu Zehui,Li Yingxiang,Deng Zhuofan,Fang Weihuan,He Fang
Porcine circovirus type 2 (PCV2) is the main causative agent of porcine circovirus-associated diseases, and it causes substantial economic losses in the swine industry each year. It is crucial to develop an effective vaccine against the circulating strain PCV2d, which is prone to substantial degrees of mutation. In this study, a truncated form of flagellin (tFlic: 85-111 aa) was inserted into the C-terminal sequence of 2dCap, and Western blotting results showed that recombinant Cap-tFlic VLPs were successfully expressed. Transmission electron microscopy (TEM) and dynamic light scattering (DLS) data indicated that purified recombinant Cap-tFlic fusion proteins existed in the form of polymers and that tFlic could not affect the formation and internalization of VLPs. Integrated Cap-tFlic VLPs induced the expression of antigen presentation-related factors (MHC-II and CD86) by bone marrow-derived dendritic cells (BM-DCs), and the expression of TLR5-related factors (TNF-α) was dramatically elevated. Mice intramuscularly immunized with Cap-tFlic VLPs exhibited significantly higher levels of Cap-specific antibodies and neutralizing antibodies than mice immunized with wild-type Cap VLPs. The data obtained in the current study indicate that Cap-tFlic may be a candidate for a subunit vaccine against PCV2 in the future.
研究领域:
兽医学
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免疫学
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病毒学
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DOI
JOURNAL OF BASIC MICROBIOLOGY
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2023
·
IF 3.1
Panmei Jiang,Yingxiang Ye,Jian Liu,Fangbin Wang
The antiglycemic drug metformin, which is widely prescribed as a first-line drug for the treatment of type 2 diabetes, has become a concern for emerging pollutants in natural ecosystems. However, its effects on bacterial swimming motility remain unclear. In this study, we showed that metformin promotes bacterial surface aggregation by tracking swimming and by measuring the density distribution of Escherichia coli cultured with metformin near a surface in a homogeneous environment. Flagella are essential for the promotion of bacterial surface aggregation by metformin. Swimming motility, which is mediated by flagella, determines bacterial surface aggregation. The promotion of bacterial surface aggregation by metformin is caused by a reduction in swimming motility, which is governed by a decrease in the proton motive force. Our results reveal that metformin has a pronounced effect on flagellated bacterial motility associated with surface sensing and aggregation.
研究领域:
微生物学
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环境科学
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药理学
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产品关联
DOI
PubMed
高影响因子
Biology-Basel
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2024
·Vol. 13
·期 12
·960
·
IF 3.6
Kuo Yang,Jueyu Wang,Ying Zhang,Daizong Cui,Min Zhao
Simple SummaryThis study proposed a new method for extractingE. coliflagella, which served as a template for synthesizing palladium (Pd) nanowires. By improving the flagella extraction process, we successfully produced Pd nanowires with better structure and function, which could have important applications in technology and medicine. Traditional methods often led to impurities that interfered with nanomaterial synthesis, but our method provided a cleaner and more efficient way of producing high-quality nanowires. UsingE. coliflagella as a template offered environmental benefits, as it eliminated the need for toxic chemicals and reduced energy consumption. This eco-friendly approach was also safer and more reliable for practical applications. Our research also showed how the functional groups on the flagella surface helped form strong bonds with metals, improving the nanowire formation process. This study highlighted the potential of using biological templates for nanomaterial synthesis, contributing to the development of greener and more efficient technologies.In recent years, the use of bacterial flagella as biomimetic templates has gained increasing attention in nanomaterial synthesis due to their unique structural and functional properties. In this study, we optimized the flagella extraction method and achieved a high concentration of flagella solution. Flagella were isolated fromEscherichia coli. Surface characterization revealed that the flagella had abundant functional groups, such as amino and carboxyl groups, which can serve as nucleation sites for the controlled nucleation and growth of metal nanomaterials. Using bacterial flagella as a template, we synthesized one-dimensional palladium nanowires (Fla-Pd NWs). The results of morphological and phase analyses showed that the synthesized palladium nanoparticles were uniformly and densely distributed on the surface of the flagella. Moreover, the Fla-Pd nanowires exhibited superior electrocatalytic activity, which was applied to develop an electrochemical biosensor. This biosensor was used to detect the early breast cancer biomarker microRNA-21 and exhibited a linear range of 0.66–1.98 µmol/L and a detection limit of 0.78 µmol/L. The method demonstrated high selectivity and reusability, making it a promising strategy for early cancer diagnosis.
研究领域:
纳米材料
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生物医学工程
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癌症诊断
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DOI
PubMed
高影响因子
INTERNATIONAL JOURNAL OF FOOD MICROBIOLOGY
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2023
·
IF 5.4
Yang Wang,Na Ling,Yaping Wang,Dexin Ou,Zhao Liang,Guoqing Li,Hongyuan Zhao,Yingwang Ye
Cronobacter sakazakii ( C. sakazakii ) is a common food-borne pathogen that induces meningitis, sepsis, and necrotizing enterocolitis, primarily in newborns and infants. Iron plays a pivotal role in the growth of cells and biofilm formation. However, the effects of hemin (ferric ion donor) on C. sakazakii cells are scarcely known. Here, we explored the effect of ferric ions on the growth of planktonic C. sakazakii , biofilm formation, and swarming motility by crystal violet staining (CVS), scanning electron microscopy (SEM), confocal laser scanning microscopy (CLSM), and swarming assay. Our study demonstrated that ferric ions facilitated the growth of planktonic C. sakazakii , while hemin at concentrations ranging from 50 to 800 μmol/L promoted biofilm formation and at concentrations between 50 and 200 μmol/L enhanced the swarming motility of C. sakazakii . Furthermore, high hemin concentrations (400–800 μmol/L) were found to reduce flagellar length, as confirmed by transmission electron microscopy (TEM). These findings indicated that ferric ions mediated the swarming motility of C. sakazakii by regulating flagellar assembly. Finally, transcriptomic analysis of C. sakazakii was performed at hemin concentrations of 0, 50, and 200 μmol/L, which revealed that several genes associated with iron transport and metabolism, and flagellar assembly were essential for the survival of C. sakazakii under hemin treatment. Our findings revealed the molecular basis of ferric ions on C. sakazakii growth and biofilm formation, thus providing a novel perspective for its prevention and control.
研究领域:
微生物学
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食品安全
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分子生物学
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产品关联
DOI
PubMed
高影响因子
Molecular Medicine Reports
·
2020
·
IF 2.1
Rui Li,Yu Li,Xiaoyan Dong
Acute lung injury (ALI) is a complex condition frequently encountered in the clinical setting. The aim of the present study was to investigate the effect of conditioned media (CM) from human adipose‑derived mesenchymal stromal cells (MSCs) activated by flagellin (F‑CM), a Toll‑like receptor 5 ligand, on inflammation‑induced lung injury. In the in vitro study, RAW264.7 macrophages treated with F‑CM had a higher proportion of cells with the M2 phenotype, lower expression of pro‑inflammatory factors and stronger expression of anti‑inflammatory genes compared with the CM from normal adipose‑derived MSCs. Furthermore, in vivo experiments were performed in mice with ALI induced by intraperitoneal injection of lipopolysaccharide. F‑CM significantly alleviated the lung exudation, inhibited inflammatory cell recruitment in lung tissues and decreased the concentration of inflammatory factors in the bronchoalveolar lavage fluid. These findings indicated that F‑CM has superior anti‑inflammation ability compared with CM, and that it may represent a promising therapeutic approach to the treatment of inflammation‑induced ALI.
研究领域:
免疫学
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肺病学
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细胞生物学
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DOI
PubMed
高影响因子
INTERNATIONAL IMMUNOPHARMACOLOGY
·
2018
·
IF 3.118
Shuang Luo,Xiangliang Deng,Qi Liu,Zengfeng Pan,Zhongxiang Zhao,Lian Zhou,Xia Luo
Emodin is an anthraquinone compound derived from Rheum officinale Baill . Several reports showed that emodin had efficacy on acute pancreatitis , keratitis , myocarditis , and rheumatoid arthritis . However, the potency of emodin on ulcerative colitis(UC) remains unclear. In this study, we investigated the effect of emodin on dextran sodium sulfate (DSS)-induced ulcerative colitis in mice. Our results showed that emodin significantly alleviated the symptoms of DSS-induced UC in mice, involving prevented the loss of body weight and colon shortening, decreased the disease activity index (DAI), intestinal damages and the count of white blood cells (WBC) in peripheral blood. In addition, emodin treatment decreased the level of anti-flagellin antibody in serum and significantly down-regulated the expression of TLR5 and NF-κB p65 in colon of the UC mice. Further study in vitro showed that emodin down-regulated the expression of TLR5 and MyD88 , up-regulated the expression of IκB, inhibited the nuclear translocation of NF-κB p65 and decreased the release of IL-8 in flagellin-stimulated HT-29 cells. These results, for the first time, demonstrated that emodin had the therapeutic potential to ameliorate UC symptoms possibly via regulating the flagellin-TLR5 signaling pathway . Emodin may be a potential candidate ingredient for ulcerative colitis.
研究领域:
药理学
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免疫学
·
胃肠病学
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产品关联
DOI
PubMed
高影响因子
FOOD CONTROL
·
2024
·
IF 5.6
Ling Jiang,Yuxi Yue,Kai Zhong,Yanping Wu,Hong Gao
Listeria monocytogenes is a foodborne pathogen that forms biofilms on various surfaces in food processing environments, leading to significant safety issues. Pyrrole-2-carboxylic acid (PCA), a natural organic acid produced by a Bacillus cereus strain, has been reported to exhibit prominent antibacterial and antibiofilm activities against L. monocytogenes in our previous study. This study aimed to explore the underlying antibiofilm mechanism of PCA at the gene level, and assess its efficacy in controlling L. monocytogenes in cheese. The results showed that PCA specifically inhibited the early stage of biofilm development in L. monocytogenes , and remarkably reduced the cell surface hydrophobicity and auto-aggregation. Transcriptomic analysis revealed that PCA significantly altered the gene expression levels of L. monocytogenes , with 159 up-regulated and 360 down-regulated genes. The most representative dysregulated genes were enriched in flagellar assembly and bacterial chemotaxis pathways, which are associated with cell motility. Meanwhile, the inhibitory effects of PCA on the swimming and swarming motility of L. monocytogenes were verified. Transmission electron microscopic observation confirmed the impaired flagellar assembly of L. monocytogenes following PCA treatment. Additionally, PCA effectively inhibited the attachment of L. monocytogenes on eggshells and suppressed its proliferation in cheese without affecting the color and texture. These findings suggest that PCA inhibits L. monocytogenes biofilm formation by interfering with flagella-mediated motility and is a potential natural antimicrobial agent applied in the food industry.
研究领域:
微生物学
·
食品科学
·
分子生物学
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产品关联
DOI
高影响因子
INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
·
2024
·Vol. 25
·期 16
·8843
·
IF 4.9
Xia Xiao,Can Ma,Han Zhang,Wei Liu,Yanhu Huang,Chuang Meng,Zhiqiang Wang
The rise of antibiotic tolerance in bacteria harboring genetic elements conferring resistance to antibiotics poses an increasing threat to public health. However, the primary factors responsible for the emergence of antibiotic tolerance and the fundamental molecular mechanisms involved remain poorly comprehended. Here, we demonstrate that the commonly utilized food additive Benzaldehyde (BZH) possesses the capacity to induce a significant level of fluoroquinolone tolerance in vitro among resistantEscherichia coli. Our findings from animal models reveal that the pre-administration of BZH results in an ineffective eradication of bacteria through ciprofloxacin treatment, leading to similar survival rates and bacterial loads as observed in the control group. These results strongly indicate that BZH elicits in vivo tolerance. Mechanistic investigations reveal several key factors: BZH inhibits the formation of bacterial flagella and releases proton motive force (PMF), which aids in expelling antibiotics from within cells to reducing their accumulation inside. In addition, BZH suppresses bacterial respiration and inhibits the production of reactive oxygen species (ROS). Moreover, exogenous pyruvate successfully reverses BZH-induced tolerance and restores the effectiveness of antibiotics, highlighting how crucial the pyruvate cycle is in combating antibiotic tolerance. The present findings elucidate the underlying mechanisms of BZH-induced tolerance and highlight potential hazards associated with the utilization of BZH.
研究领域:
微生物学
·
药理学
·
分子生物学
·
传染病学
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产品关联
DOI
PubMed
高影响因子
JOURNAL OF APPLIED MICROBIOLOGY
·
2017
·Vol. 124
·期 2
·469-479
·
IF 2.099
T. Cheng,X. Xu,W. Zhang,L. Chen,T. Liu
Aims To establish a proper protoplast-preparation route from enriched motile flagellates and nonmotile resting cells of Haematococcus pluvialis . Methods and Results Through cultivations in two mixotrophic media, enriched Haematococcus flagellates and resting cells were respectively produced and applied in enzymatic protoplast preparations. Great differences of enzymatic sensitivity and osmotic-lability were identified between them. Flagellates showed the same osmotic-lability as protoplasts and the extracellular matrix-removing rate was applied for an evaluation of protoplast-releasing. During the treatment of flagellates, an addition of more than 0·2 mmol l −1 Ca 2+ was found to be essential for maintenance of high cellular viability. More than 80% cellular viability and a 90% protoplast-releasing rate were obtained simultaneously after 2–3 h treatment of 0·06% proteinase K in 0·05 mol l −1 Tris-HCl (pH7·8) buffer with 0·2 mmol l −1 CaCl 2 and 0·2 mol l −1 sorbitol/mannitol. For resting cells, a treatment of both 0·12% proteinase K and a combination of 2% cellulase + 1% snailase could function similarly in order to degrade the cellulosic cell wall, while the protoplast yield was limited to about 40%, due to the existence of an undegradable secondary wall in the mature resting cell. Conclusion Proteinase K was efficient for protoplast-releasing from either flagellates or resting cells. Due to the great difference of enzymatic sensitivity and osmotic-lability between flagellates and resting cells, it was necessary to select a different enzymatic treating process based upon the main cell type in the culture. A better protoplast-preparing efficiency was obtained from Haematococcus cells when flagellates were in the majority. Significance and Impact of the Study The protoplast preparation of H. pluvialis was firstly established based on two main cell types of H. pluvialis , motile flagellates and nonmotile resting cells. Increase of flagellate stability and viable protoplast-preparing efficiency through addition of Ca 2+ in enzymatic solution was firstly reported.
研究领域:
微生物学
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生物技术
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植物科学
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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）