APPLIED AND ENVIRONMENTAL MICROBIOLOGY
·
2024
·
IF 3.9
Xuemeng Ji,Dancai Fan,Jin Wang,Bowei Zhang,Yaozhong Hu,Huan Lv,Jing Wu,Yi Sun,Jingmin Liu,Yan Zhang,Shuo Wang
Cronobacter sakazakii poses a significant threat, particularly to neonates and infants. Despite its strong pathogenicity, understanding of C. sakazakii biofilms and their role in infections remains limited. This study investigates the roles of HmsP and c-di-GMP in biofilm formation and identifies key genetic and proteomic elements involved. Gene knockout experiments reveal that HmsP and c-di-GMP are linked to biofilm formation in C. sakazakii. Comparative proteomic profiling identifies the lysozyme inhibitor protein LprI, which is downregulated in hmsP knockouts and upregulated in c-di-GMP knockouts, as a potential biofilm formation factor. Further investigation of the lprI knockout strain shows significantly reduced biofilm formation and decreased virulence in a rat infection model. Additionally, LprI is demonstrated to bind extracellular DNA, suggesting a role in anchoring C. sakazakii within the biofilm matrix. These findings enhance our understanding of the molecular mechanisms underlying biofilm formation and virulence in C. sakazakii, offering potential targets for therapeutic intervention and food production settings.
研究领域:
微生物学
·
分子生物学
·
感染病学
✓ 已验证
DOI
PubMed
高影响因子
MICROBIOLOGICAL RESEARCH
·
2023
·
IF 6.7
Xiao-Yu Sun,Jie Deng,Chenhui Zhang,Sin-Yee Fung,Kam-Leung Siu,Ying-Ying Cheng,Liumei Ye,Jiaoxia Qin,Ke Wang,Jiu-Xin Qu,Wenying Gao,Fuxiang Wang,Dong-Yan Jin,Liang Yang
C-di-GMP is a bacterial second messenger implicated in the regulation of many key functions including antibiotic tolerance and biofilm formation. Our understanding of how c-di-GMP exerts its action via receptors to modulate different biological functions is still limited. Here we used a c-di-GMP affinity pull-down assay coupled to LC-MS/MS to identify c-di-GMP-binding proteins in the opportunistic pathogen Stenotrophomonas maltophilia. This analysis identified Smlt3238 (SodA), a protein of the superoxide dismutase family, as a c-di-GMP-binding protein. Microscale thermophoresis showed that purified SodA protein bound c-di-GMP with an estimated dissociation constant (Kd) value of 141.5 μM. Using various in vivo and in vitro experiments, we demonstrated that c-di-GMP modulates the enzyme activity of SodA directly. Circular dichroism experiments revealed that SodA protein gradually altered its basic structure with increasing levels of c-di-GMP. Phenotypic experiments conducted in the presence of a range of intracellular c-di-GMP levels showed that SodA function is modulated by c-di-GMP. The findings thus identify a novel c-di-GMP binding protein that governs oxidative stress tolerance in S. maltophilia .
研究领域:
微生物学
·
分子生物学
·
生物化学
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DOI
PubMed
高影响因子
FOOD MICROBIOLOGY
·
2024
·
IF 4.5
Mengyuan Qin,Shuo Han,Miaomiao Chen,Pengju Li,Yuqi Wang,Wenfang Niu,Chao Gao,Hailei Wang,Yi Li
Hafnia paralvei , a Gram-negative foodborne pathogen, is found ubiquitously in various aquatic animals and seafoods, which can form biofilm as a dominant virulence factor that contributes to its pathogenesis. However, the biofilm formation mechanism of H. paralvei and its effect on food spoilage has not been fully characterized. Here we show that biofilm formation, is regulated by c-di-GMP which mediated by bcsB , can increase the spoilage ability of H. paralvei . We found that GTP was added exogenously to enhance the synthesis of c-di-GMP, which further promoted biofilm formation. The gene dgcC , one of 11 genes encoding GGDEF domain-containing proteins in H. paralvei , was significantly upregulated with GTP as substrate. The upregulation of dgcC contributes to a significant increase of c-di-GMP and the formation of biofilm. In addition, the overexpression of dgcC induced upregulation of bcsB , a reported effector protein encoding gene, which was further demonstrated that overexpression of bcsB can encourage the synthesis of bacterial cellulose and biofilm formation. The effect of biofilm formation induced by c-di-GMP on spoilage of Yellow River carp ( Cyprinus carpio ) was evaluated by sensory evaluation , the total viable count , and the total volatile basic nitrogen, which showed that biofilm formation can significantly increase the spoilage ability of H. paralvei on C. carpio . Our findings provide the regulation of c-di-GMP on expression of bcsB , that can contribute to biofilm formation and spoilage ability of H. paralvei , which is favor to understanding the pathogenesis of Hafnia paralvei and its role in food spoilage.
研究领域:
微生物学
·
食品安全
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产品关联
DOI
PubMed
高影响因子
APPLIED MICROBIOLOGY AND BIOTECHNOLOGY
·
2020
·Vol. 104
·期 5
·2205-2216
·
IF 3.53
Wang Feifei,Wang Yongzheng,Cen Congnan,Fu Linglin,Wang Yanbo
Cyclic diguanylate (c-di-GMP) is a second messenger involved in the regulation of various physiological processes in bacteria. However, its function in spoilage bacteria has not yet been addressed. Here, we studied the function of a tandem GGDEF-EAL domain protein, Sbal_3235, in the spoilage bacterium Shewanella baltica OS155. The deletion of sbal_3235 significantly reduced the c-di-GMP level, biofilm formation, and exopolysaccharide, trimethylamine (TMA), and putrescine production; sbal_3235 deletion also downregulated the expression of the torS and speF genes and affected membrane fatty acid composition. Site-directed mutagenesis in conserved GGDEF and EAL motifs abolished diguanylate cyclase (DGC) and phosphodiesterase (PDE) activity, respectively. These data indicate that Sbal_3235 is an essential contributor to the c-di-GMP pool with bifunctional DGC and PDE activity, which is involved in the biofilm formation and spoilage activity of S. baltica OS155. Our findings expand the biochemical role of c-di-GMP and uncover its link to spoilage activities, providing novel targets for food quality and safety controlling.
研究领域:
微生物学
·
食品科学
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DOI
PubMed
高影响因子
COLLOIDS AND SURFACES B-BIOINTERFACES
·
2020
·
IF 4.389
Shanshan Yang,Yichao Wu,Chenchen Qu,Jeremy B. Fein,Yizhuang He,Qiaoyun Huang,Peng Cai
Cyclic diguanylate monophosphate (c-di-GMP) is a ubiquitous intracellular secondary messenger which governs the transition from a bacterial cell’s planktonic state to biofilm formation by stimulating the production of a variety of exopolysaccharide material by the bacterial cell. A range of genes involved in c-di-GMP signaling in the Gram-negative species Comamonas testosteroni have been identified previously, yet the physical-chemical properties of the produced extracellular polymeric substances (EPS) and the bacterial adhesion characteristics regulated by c-di-GMP are not well understood. Here, we modulated the in vivo c-di-GMP levels of Comamonas testosteroni WDL7 through diguanylate cyclase (YedQ) and phosphodiesterase (YhjH) gene editing. The strains and their adhesion properties were characterized by Fourier-transform infrared and two-dimensional correlation spectroscopy analysis (FTIR-2D CoS), contact angle and zeta potential measurements, atomic force microscopy (AFM) and extended-Derjaguin-Landau-Verwey-Overbeek (ExDLVO) analysis. Our results show that high c-di-GMP levels promoted the secretion of long-chain hydrophobic and electroneutral extracellular polysaccharides and proteins. The protein molecules on WDL7/pYedQ2 promoted the bacterial self-aggregation and adhesion onto negatively charged surfaces. In contrast, the reduction of intracellular c-di-GMP concentrations resulted in a nearly 80 % decrease in the adhesion of bacterial cells, although little change in the surface hydrophobicity or surface charge properties were observed for these cells relative to the wild type. These results indicate that the reduced adsorption of WDL7/YhjH that we observed may be caused by the flagellum-accelerated mobility at low c-di-GMP concentrations. Taken together, these results improve our mechanistic understanding of the effects of c-di-GMP in controlling bacterial physical-chemical properties and initial biofilm development.
研究领域:
微生物学
·
分子生物学
·
生物物理化学
✓ 已验证
DOI
高影响因子
Cell Reports
·
2025
·
IF 6.9
Mingfang Wang,Jia Zeng,Binbin Cui,Guangliang Wu,Xiayu Chen,Yikai Fu,Bing Gu,Yinyue Deng
It was previously demonstrated that intestinal pathogens have evolved different mechanisms to enhance their infection and colonization in the intestines of hosts. However, it is unclear how Shigella effectively survives in the presence of bile salts. Here, we report that the biofilm formation and pathogenicity of S . sonnei are induced by primary bile salts through the two-component system EvgS/EvgA. The response regulator EvgA controls the transcription of the cyclic AMP synthase-encoding gene. Furthermore, the effector protein CRP of the cyclic AMP (cAMP) signal not only positively controls the transcription of ydeH , a gene encoding cyclic di-GMP (c-di-GMP) synthase, but also forms a complex with YdeH to improve its catalytic production of c-di-GMP. Additionally, interacting with YdeH enhances the ability of CRP to bind to the promoter of ydeH . Our work provides insights into how S . sonnei utilizes cascade amplification of c-di-GMP to promote fitness and pathogenicity in response to primary bile salts.
研究领域:
微生物学
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分子生物学
·
感染与免疫
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信号转导
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病原生物学
·
环境应答
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产品关联
DOI
PubMed
高影响因子
BIOTECHNOLOGY LETTERS
·
2021
·Vol. 43
·期 3
·677-690
·
IF 2.461
Zhang Chaolei,Wang Chao,Zhao Shan,Xiu Zhilong
Objectives Probiotics ( Bacillus subtilis 04178) were entrapped in alginate-chitosan microcapsules by high-voltage electrostatic process. The encapsulation pattern was established as entrapped low density cells with culture (ELDC wc ). The performance of ELDC wc cells was investigated against stress environments of simulated digestive fluids. Results After incubation in simulated gastric (pH 2.5) and intestinal fluids (4% bile salt) for 2 h, the survival rate of ELDC wc cells (18.19% and 27.54%) was significantly higher than that of the free cells (0.0000009% and 0.0005%). The reason why B. subtilis embedded in microcapsules can resist the stress environments was that the mass production of extracellular proteins and polysaccharides prompted B. subtilis to form cell aggregates. The production of extracellular proteins and polysaccharides were regulated by the concentration of c-di-GMP and the expression of ydaJKLMN operon, abbA , sinI , slrA , slrB , abrR and sinR . Conclusions c-di-GMP is important for the production of extracellular polymer substance to enhance probiotic viability in stress environments.
研究领域:
微生物学
·
生物技术
·
食品科学
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产品关联
DOI
PubMed
高影响因子
Biotechnology Journal
·
2024
·Vol. 19
·期 2
·2300542
·
IF 3.2
Yongshuai Yang,Siyu Guo,Can-Jian Hong,Zhao-Xun Liang,Chun Loong Ho
Bacterial second messenger c-di-GMP upregulation is associated with the transition from planktonic to sessile microbial lifestyle, inhibiting cellular motility, and virulence. However, in-depth elucidation of the cellular processes resulting from c-di-GMP upregulation has not been fully explored. Here, we report the role of upregulated cellular c-di-GMP in promoting planktonic cell growth of Escherichia coli K12 and Pseudomonas aeruginosa PAO1. We found a rapid expansion of cellular growth during initial cellular c-di-GMP upregulation, resulting in a larger planktonic bacterial population. The initial increase in c-di-GMP levels promotes bacterial swarming motility during the growth phase, which is subsequently inhibited by the continuous increase of c-di-GMP, and ultimately facilitates the formation of biofilms. We demonstrated that c-di-GMP upregulation triggers key bacterial genes linked to bacterial growth, swarming motility, and biofilm formation. These genes are mainly controlled by the master regulatory genes csgD and csrA . This study provides us a glimpse of the bacterial behavior of evading potential threats through adapting lifestyle changes via c-di-GMP regulation.
研究领域:
微生物学
·
分子生物学
✓ 已验证
DOI
PubMed
高影响因子
INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
·
2024
·Vol. 25
·期 2
·1051
·
IF 4.9
Jiaqi Zhang,Yingying Liu,Junxing Hu,Guangxian Leng,Xining Liu,Zailin Cui,Wenzhen Wang,Yufang Ma,Shanshan Sha
Biofilm dispersal contributes to bacterial spread and disease transmission. However, its exact mechanism, especially that in the pathogenMycobacterium tuberculosis, is unclear. In this study, the cellulase activity of theM. tuberculosisRv0062 protein was characterized, and its effect on mycobacterial biofilm dispersal was analyzed by observation of the structure and components of Rv0062-treated biofilm in vitro. Meanwhile, the metabolite factors that induced cellulase-related biofilm dispersal were also explored with metabolome analysis and further validations. The results showed that Rv0062 protein had a cellulase activity with a similar optimum pH (6.0) and lower optimum temperature (30 °C) compared to the cellulases from other bacteria. It promoted mycobacterial biofilm dispersal by hydrolyzing cellulose, the main component of extracellular polymeric substrates of mycobacterial biofilm. A metabolome analysis revealed that 107 metabolites were significantly altered at different stages ofM. smegmatisbiofilm development. Among them, a decrease in gamma-aminobutyric acid (GABA) promoted cellulase-related biofilm dispersal, and this effect was realized with the down-regulation of the bacterial signal molecule c-di-GMP. All these findings suggested that cellulase promotes mycobacterial biofilm dispersal and that this process is closely associated with biofilm metabolite alterations.Keywords:biofilm;biofilm dispersal;Mycobacterium tuberculosis;cellulase;GABA;c-di-GMP
研究领域:
微生物学
·
生物化学
·
传染病
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DOI
PubMed
高影响因子
CURRENT BIOLOGY
·
2026
·
IF 7.5
Fugui Xu,Zeyu Zhang,Fengzhi Yuan,Limin Wang,Qing Yan,Mingming Yang,Xiaolong Shao,Yongxing He,Fengquan Liu,Mengcen Wang,Bingxin Wang,Guoliang Qian
Microbial competition serves as a fundamental driver for the evolution of offensive and defensive mechanisms among microorganisms. While it is well established that bacteria utilize specialized secretion systems to deliver both toxic and non-toxic effector proteins into competing cells, thereby directly killing them or modulating cellular events, it remains largely unclear whether bacteria can hijack effector proteins derived from competitors to resolve interspecies conflicts. Here, we demonstrate that Pseudomonas protegens employs a sophisticated defense strategy, hijacking LtaE, a non-cytotoxic effector delivered via the type IV secretion system (T4SS) of non-flagellated Lysobacter enzymogenes , to resolve interbacterial conflict through transcriptional reprogramming. Translocated LtaE neutralizes an uncharacterized antibacterial toxin in P. protegens . Surprisingly, as a countermeasure, P. protegens hijacks LtaE to rewire its host signaling hierarchy, converting it into a motility activation switch. Mechanistically, LtaE directly binds to FleQ, the σ54-dependent master regulator of flagellar biosynthesis, shielding it from inhibitory c-di-guanosine monophosphate (GMP) binding—a universal second messenger whose elevated concentration typically inhibits bacterial motility and promotes biofilm formation. Remarkably, the LtaE-FleQ complex remains stable under high c-di-GMP conditions, overriding sessility signals to derepress flagellar gene expression and trigger escape motility. Biochemical analyses reveal that LtaE broadly targets FleQ homologs across pseudomonads through competitive inhibition of c-di-GMP binding, linking competitor detection to motility activation. Our findings establish a novel bacterial conflict-resolution paradigm, demonstrating how non-cytotoxic effectors act as molecular switches to dynamically reprogram transcriptional networks and enhance phenotypic plasticity.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Theranostics
·
2022
·
IF 11.6
Xiaotong Yu,Jing Yu,Hong Dai,Chenyun Deng,Xudong Sun,Sijie Long,Zhujun Jiang,Hongyan Jin,Zhu Guan,Zhenjun Yang
Rationale: Cyclic dinucleotides (cDNs) are a promising class of immunotherapeutic agent targeting stimulator of interferon genes (STING). However, enzymatic instability and transmembrane barriers limit the extensive clinical application of cDNs. Thus, a novel delivery system, composed of a neutral cytidinyl lipid DNCA and a cationic lipid CLD (Mix) that interacts with cDNs via H-bonding, pi-stacking and electrostatic interaction, is developed and optimized to overcome the above issues. Methods: The optimal composition of Mix for cDNs encapsulation was explored with RAW-Lucia ISG cells. The physicochemical properties of resulted nanoparticles were characterized. To validate the anti-tumor immunity of cDNs/Mix both in vitro and in vivo , immunogenic cell death (ICD) related markers and tumor inhibition efficacy were evaluated in cancer cells and tumor models, respectively. The mechanism by which cdG/Mix exerted the antitumor effects was explored by flow cytometric analysis and in vivo depletion. Results: Based on our developed and optimized delivery system, neutral cytidinyl lipid DNCA/cationic lipid CLD (Mix), cdG (500 nM in vitro , 1-10 μg in vivo )/Mix not only more potently stimulated production of IFNβ and related cytokines including CXCL9 and CXCL10, promoted ICD, led to NK and CD8 + T cell activation, inhibited tumor growth in both EO771 and B16F10 models and increased their survival rate (~43%), but also obviously reversed the T cell exhaustion (Tex) in tumor, meanwhile down regulated the mRNA expression of Tox and Nr4a , which are key regulators of Tex. Conclusion: cdG/Mix triggered ICD in various cancer cells and reversed the Tex systemically in tumor-burden mice, which would be a promising alternative strategy for cancer immunotherapy.
研究领域:
免疫学
·
肿瘤学
·
药学
·
癌症治疗
✓ 已验证
DOI
PubMed
高影响因子
iScience
·
2022
·
IF 6.107
Shixun Liu,Anming Xu,Bin Xie,Fengxue Xin,Weiliang Dong,Jie Zhou,Min Jiang
Summary The synthesis of biofilm exopolysaccharides and rhamnolipids (RLs) are two interrelated processes in Pseudomonas aeruginosa , but how bacteria coordinate these two processes remains unclear. We collected a P. aeruginosa KT1115 with rugose small colony variant (RSCV) phenotype from soil, and used it to study the dynamic regulation mechanism of biofilm polysaccharide and RLs synthesis. The results showed that the overproduction of biofilm exopolysaccharides at biofilm stage ultimately contributed the surge of RLs production at RLs stage. This phenomenon was further verified by comparing PAO1 with its engineered RSCV mutant, PAO1Δ wspF . Further genomic, transcriptomic analyses and gene deletion revealed that downregulation of c-di-GMP level was the key to switch biofilm exopolysaccharides accumulation to RLs surge, by transcriptionally upregulating a c-di-GMP phosphodiesterase NbdA. Overall, this study demonstrates the importance of c-di-GMP in coordinating biofilm exopolysaccharides and RLs synthesis, and provides an inspiration for enhancing RLs production through regulating c-di-GMP level.
研究领域:
微生物学
·
分子生物学
·
细菌生理学
✓ 已验证
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）