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Wu HY, Niu TX, Bi JR, Hou HM, Hao HS, Zhang GL. Exploration of the antimicrobial activity of benzyl isothiocyanate against Salmonella enterica serovar Typhimurium. JOURNAL OF FOOD MEASUREMENT AND CHARACTERIZATION 2021. [DOI: 10.1007/s11694-021-01175-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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52
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Han Q, Yan X, Zhang R, Wang G, Zhang Y. Juglone Inactivates Pseudomonas aeruginosa through Cell Membrane Damage, Biofilm Blockage, and Inhibition of Gene Expression. Molecules 2021; 26:molecules26195854. [PMID: 34641398 PMCID: PMC8510502 DOI: 10.3390/molecules26195854] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2021] [Revised: 09/23/2021] [Accepted: 09/23/2021] [Indexed: 11/16/2022] Open
Abstract
Due to the strong drug resistance of Pseudomonas aeruginosa (P. aeruginosa), the inhibition effects of conventional disinfectants and antibiotics are not obvious. Juglone extracted from discarded walnut husk, as a kind of plant-derived antimicrobial agent, has the advantages of naturalness, high efficiency, and low residue, with a potential role in the inhibition of P. aeruginosa. This study elucidated the inhibitory effect of juglone on the growth of plankton and the formation of P. aeruginosa biofilm. The results showed that juglone (35 μg/mL) had an irreversible inhibitory effect on P. aeruginosa colony formation (about 107 CFU/mL). The integrity and permeability of the cell membrane were effectively destroyed, accompanied by disorder of the membrane permeability, mass leakage of the cytoplasm, and ATP consumption. Further studies manifested that juglone could induce the abnormal accumulation of ROS in cells and block the formation of the cell membrane. In addition, RT-qPCR showed that juglone could effectively block the expression of five virulence genes and two genes involved in the production of extracellular polymers, thereby reducing the toxicity and infection of P. aeruginosa and preventing the production of extracellular polymers. This study can provide support for the innovation of antibacterial technology toward P. aeruginosa in food.
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Affiliation(s)
| | | | | | - Guoliang Wang
- Correspondence: (G.W.); (Y.Z.); Tel.: +86-138-1830-0608 (Y.Z.)
| | - Youlin Zhang
- Correspondence: (G.W.); (Y.Z.); Tel.: +86-138-1830-0608 (Y.Z.)
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53
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Wei X, Wang YL, Wen BT, Liu SJ, Wang L, Sun L, Gu TY, Li Z, Bao Y, Fan SL, Zhou H, Wang F, Xin F. The α-Helical Cap Domain of a Novel Esterase from Gut Alistipes shahii Shaping the Substrate-Binding Pocket. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2021; 69:6064-6072. [PMID: 33979121 DOI: 10.1021/acs.jafc.1c00940] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
The human gut microbiota regulates nutritional metabolism, especially by encoding specific ferulic acid esterases (FAEs) to release functional ferulic acid (FA) from dietary fiber. In our previous study, we observed seven upregulated FAE genes during in vitro fecal slurry fermentation using wheat bran. Here, a 29 kDa FAE (AsFAE) from Alistipes shahii of Bacteroides was characterized and identified as the type-A FAE. The X-ray structure of AsFAE has been determined, revealing a unique α-helical domain comprising five α-helices, which was first characterized in FAEs from the gut microbiota. Further molecular docking analysis and biochemical studies revealed that Tyr100, Thr122, Tyr219, and Ile220 are essential for substrate binding and catalytic efficiency. Additionally, Glu129 and Lys130 in the cap domain shaped the substrate-binding pocket and affected the substrate preference. This is the first report on A. shahii FAE, providing a theoretical basis for the dietary metabolism in the human gut.
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Affiliation(s)
- Xue Wei
- Laboratory of Biomanufacturing and Food Engineering, Institute of Food Science and Technology, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Yu-Lu Wang
- Laboratory of Biomanufacturing and Food Engineering, Institute of Food Science and Technology, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Bo-Ting Wen
- Laboratory of Biomanufacturing and Food Engineering, Institute of Food Science and Technology, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Shu-Jun Liu
- Laboratory of Biomanufacturing and Food Engineering, Institute of Food Science and Technology, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Luyao Wang
- Laboratory of Biomanufacturing and Food Engineering, Institute of Food Science and Technology, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Lichao Sun
- Laboratory of Biomanufacturing and Food Engineering, Institute of Food Science and Technology, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Tian-Yi Gu
- Laboratory of Biomanufacturing and Food Engineering, Institute of Food Science and Technology, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Zhen Li
- Laboratory of Biomanufacturing and Food Engineering, Institute of Food Science and Technology, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Yuming Bao
- Laboratory of Biomanufacturing and Food Engineering, Institute of Food Science and Technology, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Shi-Long Fan
- Key Laboratory of Ministry of Education for Protein Science, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Huan Zhou
- Shanghai Synchrotron Radiation Facility, Shanghai Advanced Research Institute, Chinese Academy of Sciences, Shanghai 201204, China
| | - Fengzhong Wang
- Laboratory of Biomanufacturing and Food Engineering, Institute of Food Science and Technology, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Fengjiao Xin
- Laboratory of Biomanufacturing and Food Engineering, Institute of Food Science and Technology, Chinese Academy of Agricultural Sciences, Beijing 100193, China
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54
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Fan Q, Yuan Y, Jia H, Zeng X, Wang Z, Hu Z, Gao Z, Yue T. Antimicrobial and anti-biofilm activity of thymoquinone against Shigella flexneri. Appl Microbiol Biotechnol 2021; 105:4709-4718. [PMID: 34014346 DOI: 10.1007/s00253-021-11295-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2021] [Revised: 04/03/2021] [Accepted: 04/12/2021] [Indexed: 10/21/2022]
Abstract
Shigella flexneri (Sh. flexneri), a common foodborne pathogen, has become one of the main threats to food safety and human health due to its high pathogenicity and persistent infection. The objective of this study was to explore the antimicrobial and anti-biofilm activities and the possible mechanism of thymoquinone (TQ) against Sh. flexneri. The minimum inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) of TQ against Sh. flexneri were 0.4 and 0.5 mg/mL, respectively. TQ showed bactericidal activity against Sh. flexneri in culture medium and milk system. Scanning electron microscopy (SEM) and confocal laser scanning microscopy (CLSM) observations demonstrated that TQ could induce abnormal cell morphology and destroy cell membrane. Sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) analysis suggested that TQ could inhibit protein synthesis in Sh. flexneri. Also, at sub-inhibitory concentrations (SICs), TQ exhibited an inhibitory effect on Sh. flexneri biofilm formation, which was confirmed by crystal violet quantitative analysis and SEM observation. Real-time quantitative PCR (RT-qPCR) analyses revealed that TQ downregulated the expression of genes involved in Sh. flexneri biofilm formation. Thus, TQ has potential as a natural antimicrobial and anti-biofilm agent to address the contamination and infection caused by Sh. flexneri. KEY POINTS: • Antimicrobial and anti-biofilm activity of TQ on Shigella flexneri were investigated. • TQ inhibited biofilm formation by Shigella flexneri. • TQ provided a new strategy for Shigella flexneri control.
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Affiliation(s)
- Qiuxia Fan
- College of Food Science and Engineering, Northwest A&F University, 22 Xinong Road, Yangling, 712100, Shaanxi, China.,Laboratory of Quality & Safety Risk Assessment for Agro-products (Yangling), Ministry of Agriculture, Yangling, 712100, China
| | - Yahong Yuan
- College of Food Science and Engineering, Northwest A&F University, 22 Xinong Road, Yangling, 712100, Shaanxi, China.,Laboratory of Quality & Safety Risk Assessment for Agro-products (Yangling), Ministry of Agriculture, Yangling, 712100, China
| | - Hang Jia
- College of Food Science and Engineering, Northwest A&F University, 22 Xinong Road, Yangling, 712100, Shaanxi, China.,Laboratory of Quality & Safety Risk Assessment for Agro-products (Yangling), Ministry of Agriculture, Yangling, 712100, China
| | - Xuejun Zeng
- College of Food Science and Engineering, Northwest A&F University, 22 Xinong Road, Yangling, 712100, Shaanxi, China.,Laboratory of Quality & Safety Risk Assessment for Agro-products (Yangling), Ministry of Agriculture, Yangling, 712100, China
| | - Zhouli Wang
- College of Food Science and Engineering, Northwest A&F University, 22 Xinong Road, Yangling, 712100, Shaanxi, China.,Laboratory of Quality & Safety Risk Assessment for Agro-products (Yangling), Ministry of Agriculture, Yangling, 712100, China
| | - Zhongqiu Hu
- College of Food Science and Engineering, Northwest A&F University, 22 Xinong Road, Yangling, 712100, Shaanxi, China.,Laboratory of Quality & Safety Risk Assessment for Agro-products (Yangling), Ministry of Agriculture, Yangling, 712100, China
| | - Zhenpeng Gao
- College of Food Science and Engineering, Northwest A&F University, 22 Xinong Road, Yangling, 712100, Shaanxi, China.,Laboratory of Quality & Safety Risk Assessment for Agro-products (Yangling), Ministry of Agriculture, Yangling, 712100, China
| | - Tianli Yue
- College of Food Science and Engineering, Northwest A&F University, 22 Xinong Road, Yangling, 712100, Shaanxi, China. .,Laboratory of Quality & Safety Risk Assessment for Agro-products (Yangling), Ministry of Agriculture, Yangling, 712100, China. .,College of Food Science and Technology, Northwest University, Xi'an, 710069, China.
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Zhao L, Duan F, Gong M, Tian X, Guo Y, Jia L, Deng S. (+)-Terpinen-4-ol Inhibits Bacillus cereus Biofilm Formation by Upregulating the Interspecies Quorum Sensing Signals Diketopiperazines and Diffusing Signaling Factors. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2021; 69:3496-3510. [PMID: 33724028 DOI: 10.1021/acs.jafc.0c07826] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Bacillus cereus is a Gram-positive endospore-forming foodborne pathogen that causes lethal food poisoning and significant economic losses, usually through biofilm- and endospore-induced recurrent cross- and postprocessing contamination. Due to the lack of critical inhibitory targets and control strategies, B. cereus biofilm contamination is a problem that urgently needs a solution. In this study, the antibacterial and antibiofilm activities of several natural potential bacterial quorum sensing (QS) interferers, a group of spice-originated monoterpenoids, were screened, and terpinen-4-ol effectively inhibited B. cereus growth and biofilm and spore germination with minimum growth inhibition and 50% biofilm inhibitory concentrations of 8 and 2 μmol/mL, respectively. FESEM/CLSM and phenotypic research illustrated that in addition to a decrease in the number of attached B. cereus cells, (+)-terpinen-4-ol also obviously reduced extracellular matrix synthesis, especially exopolysaccharides, and inhibited the swarming motility and protease activity of B. cereus. (+)-Terpinen-4-ol did not exert a significant effect on AI-2 signals in B. cereus. Accordingly, the B. cereus-produced interspecies QS signals diffusing signal factors (DSFs, C8-C15) and diketopiperazines (DKPs) were detected and identified here, which suppressed B. cereus biofilm formation in a concentration-dependent manner. (+)-Terpinen-4-ol significantly increased the levels of specific DSF and DKP signals in B. cereus and down-regulated the gene expression of some rpfB homologues in transcription level. Moreover, both DKPs and DSFs inhibited swarming motility and protease activity in B. cereus, while just the DSF signals 2-dodecenoic acid and 11-methyl-2-dodecenoic acid inhibited exopolysaccharide synthesis like (+)-terpinen-4-ol. In summary, B. cereus strains were found to produce nine DSF- and six DKP-type QS signaling molecules, which repressed B. cereus biofilm formation. (+)-Terpinen-4-ol was confirmed to be a promising antibacterial and antibiofilm agent against B. cereus upregulating DSFs and DKPs levels, and it could target the critical genes rpfB for DSFs turnover.
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Affiliation(s)
- Lijun Zhao
- Department of Food Engineering, College of Biomass Science and Engineering, Sichuan University, Chengdu 610065, P. R. China
| | - Feixia Duan
- Department of Food Engineering, College of Biomass Science and Engineering, Sichuan University, Chengdu 610065, P. R. China
| | - Meng Gong
- Frontiers Science Center for Disease-related Molecular Network, Institutes for Systems Genetics, West China Hospital, Sichuan University, 88 Keyuan South Road, Hi-Tech Zone, Chengdu 610041, P. R. China
| | - Xue Tian
- Department of Food Engineering, College of Biomass Science and Engineering, Sichuan University, Chengdu 610065, P. R. China
| | - Yan Guo
- Sichuan Center for Disease Control and Prevention, Chengdu 610041, P. R. China
| | - Lirong Jia
- Department of Food Engineering, College of Biomass Science and Engineering, Sichuan University, Chengdu 610065, P. R. China
| | - Sha Deng
- Department of Food Engineering, College of Biomass Science and Engineering, Sichuan University, Chengdu 610065, P. R. China
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In Vitro Effects of Lactobacillus plantarum LN66 and Antibiotics Used Alone or in Combination on Helicobacter pylori Mature Biofilm. Microorganisms 2021; 9:microorganisms9020424. [PMID: 33670726 PMCID: PMC7923053 DOI: 10.3390/microorganisms9020424] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2021] [Revised: 01/29/2021] [Accepted: 01/30/2021] [Indexed: 12/16/2022] Open
Abstract
Helicobacter pylori is a gastrointestinal pathogen with high prevalence that harms human health. Studies have shown that H. pylori can form antibiotic-tolerant biofilms, which may interfere with the efficacy of clinical antibiotic therapy. Probiotics can antagonize planktonic and biofilm pathogen cells and thus may play an auxiliary role in H. pylori antibiotic therapy. However, the effects of different probiotic strains and antibiotic combinations on H. pylori biofilms need to be further investigated. We determined the cell viability of H. pylori mature biofilms after treatment with Lactobacillus plantarum LN66 cell-free supernatant (CFS), clarithromycin (CLR), and levofloxacin (LVX) alone or in combination by the XTT method. Biofilm cells were observed by scanning electron microscopy (SEM) and confocal laser scanning microscopy (CLSM). Subsequently, protein and polysaccharide concentrations in biofilm extracellular polymeric substances (EPSs) were quantitatively detected by the Bradford method and the phenol-sulfate method. The results showed that LN66 CFS had an eradication effect on mature H. pylori biofilm. When used in combination with CLR, LN66 CFS significantly attenuated the eradication effect of CLR on biofilms; in contrast, when used in combination with LVX, LN66 CFS enhanced the disrupting effect of LVX. We speculate that the different effects of CFS and antibiotic combinations on biofilms may be related to changes in the content of proteins and polysaccharides in EPS and that the combination of CFS and CLR might promote the secretion of EPS, while the combination of CFS and LVX might have the opposite effect. Accordingly, we suggest that supplementation with L. plantarum LN66 may provide additional help when therapy involving LVX is used for clinical H. pylori biofilm eradication, whereas it may impair CLR efficacy when therapy involving CLR is used.
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57
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Antibacterial Effects and Mechanism of Mandarin ( Citrus reticulata L.) Essential Oil against Staphylococcus aureus. Molecules 2020; 25:molecules25214956. [PMID: 33114746 PMCID: PMC7663016 DOI: 10.3390/molecules25214956] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2020] [Revised: 10/22/2020] [Accepted: 10/22/2020] [Indexed: 01/10/2023] Open
Abstract
Staphylococcus aureus (S. aureus) creates an array of challenges for the food industry and causes foodborne diseases in people, largely due to its strong antibiotic resistance. Mandarin (Citrus reticulata L.) essential oil (MEO) is recognized as a natural and safe preservative; however, the antibacterial effects and mechanism of MEO to combat S. aureus are not yet clearly understood. This study will examine the inhibitory effects of MEO against S. aureus and explore the antibacterial mechanism thereof from the perspective of membrane destruction. The antibacterial activity of MEO on planktonic S. aureus was examined to determine the minimal inhibitory concentration (MIC). Scanning electron microscope (SEM) images revealed the direct impacts of MEO treatment on the cell structure of S. aureus. The cell membrane was observed to be depolarized, the determination of extracellular nucleic acids, proteins and intracellular adenosine triphosphate (ATP) confirmed the increased permeability of the cell membrane, its integrity was destroyed and the cellular constituents had leaked. These results, thus, provided conclusive evidence that MEO constrains the growth of planktonic S. aureus by affecting the permeability and integrity of its cell membrane. Our study provides a basis for the further development and utilization of MEO as a natural antibacterial agent in the food industry.
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