BIOTECHNOLOGY AND BIOENGINEERING
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2020
·Vol. 117
·期 11
·3559-3571
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IF 4.002
Zhong Yu,Dongchen Shi,Wencong Liu,Yabing Meng,Fangang Meng
Enterococcus faecium is gaining increasing interest due to its virulence and tolerance to a range of stresses (e.g., acid shock and nitrite stress in human stomach). The chemical taxonomy and basic structural features of cellular metabolite can provide us a deeper understanding of bacterial tolerance at molecular level. Here, we used hierarchical classification and molecular composition analysis to investigate the metabolome responses of E. faecium to acid shock and nitrite stress. Our results showed that considerable high biodegradable compounds (e.g., dipeptides) were produced by E. faecium under acid shock, while nitrite stress induced the accumulations of some low biodegradable compounds (e.g., organoheterocyclic compounds and benzenoids). Complete genome analysis and metabolic pathway profiling suggested that E. faecium produced high biodegradable metabolites responsible for the proton-translocation and biofilm formation, which increase its tolerance to acid shock. Yet, the presence of low biodegradable metabolites due to the nitrite exposure could disturb the bacterial productions of surface proteins, and thus inhibiting biofilm formation. Our approach uncovered the hidden interactions between intracellular metabolites and exogenous stress, and will improve the understanding of host-microbe interactions.
研究领域:
微生物学
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分子生物学
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DOI
PubMed
高影响因子
Frontiers in Microbiology
·
2024
·
IF 4
Yuanyuan Li,Tao Jiang,Jianfeng Mao,Fangyi Xu,Rong Zhang,Jing Yan,Jiachang Cai,Yanjun Xie
Linezolid-resistant enterococci have increased in recent years due to the worldwide spread of acquired resistance genes (cfr, optrA, and poxtA) in clinical, animal, and environmental settings. This study investigated the carriage of optrA-positive enterococci among patients in the anorectal surgery ward in Hangzhou, China, and characterized the genetic context of optrA. A total of 173 wound secretion samples were obtained to screen optrA-positive enterococci. Of the 173 samples, 15 (8.67%) were positive for optrA, including 12 Enterococcus faecalis, two E. faecium, and one E. hirae. Multilocus sequence type analysis revealed that 12 optrA-positive E. faecalis isolates belonged to eight different sequence types (STs), of which ST16 was the main type. Eight optrA variants were identified, whose optrA flanking regions with a fexA gene downstream were bounded by different mobile genetic elements. Furthermore, the optrA gene in 8 out of 15 optrA-positive enterococci could be successfully transferred through conjugation. The findings revealed a high carriage rate of optrA in enterococci from one anorectal surgery ward in China. The dissemination of optrA-positive enterococci isolates in clinical settings should be continually monitored.
研究领域:
微生物学
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分子生物学
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临床医学
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遗传学
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PubMed
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ANTIMICROBIAL AGENTS AND CHEMOTHERAPY
·
2020
·Vol. 64
·期 3
·
IF 4.904
Zhiwei Lin,Zhangya Pu,Guangjian Xu,Bing Bai,Zhong Chen,Xiang Sun,Jinxin Zheng,Peiyu Li,Di Qu,Qiwen Deng,Zhijian Yu
This study aimed to evaluate the in vitro antimicrobial activity, heteroresistance emergence, and resistance mechanism of omadacycline (OMC) in clinical Enterococcus faecalis isolates from China. A total of 276 isolates were collected retrospectively in China from 2011 to 2015. The MICs of OMC, doxycycline (DOX), and minocycline (MIN) against E. faecalis were determined by broth microdilution. Tetracycline (TET)-specific resistance genes and multilocus sequence typing (MLST) of the isolates were investigated using PCR. The detection frequency of OMC heteroresistance in E. faecalis was evaluated with population analysis profiling (PAP). The mechanism of OMC heteroresistance and resistance in E. faecalis was examined by amplifying 30S ribosomal subunit genes, RNA sequencing (RNA-Seq), and in vitro recombination experiments. The OMC MICs of clinical E. faecalis isolates ranged from ≤0.06 to 1.0 mg/liter, and 42% of the E. faecalis isolates with an OMC MIC of 1.0 mg/liter were found to be sequence type 16 (ST16). Six OMC-heteroresistant isolates with MIC values of ≤0.5 mg/liter were detected among 238 E. faecalis isolates. The resistant subpopulations of heteroresistant isolates showed OMC MICs in the range of 2 to 4 mg/liter and were found without 30S ribosomal subunit gene mutations. Moreover, RNA sequencing and in vitro recombination experiments demonstrated that overexpression of a bone morphogenetic protein (BMP) family ATP-binding cassette (ABC) transporter substrate-binding protein, OG1RF_RS00630, facilitated OMC heteroresistance in E. faecalis. In conclusion, OMC exhibited better activity against clinical E. faecalis isolates from China than that of DOX or MIN, and overexpression of OG1RF_RS00630 in E. faecalis facilitated the development of OMC heteroresistance.
研究领域:
微生物学
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感染病学
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药理学
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PubMed
高影响因子
BRAZILIAN JOURNAL OF MICROBIOLOGY
·
2021
·Vol. 53
·期 1
·161-169
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IF 2.476
Duan Mengting,Sun Qing,Fan Wei,Fan Bing
Enterococcus faecalis ( E. faecalis ) is commonly considered to be one of chief culprits of secondary and persistent root canal infections. As antibiotic resistance has become a global issue, in order to reduce the use of antibiotics, metal ions have recently been widely used as an alternative. Silver ions (Ag + ) have been proved to be a strong bactericide but with high cytotoxicity and discoloration property. Triton X-100 (TX-100) and Ag + were co-used for the first time as a clinical intracanal medication to obtain both enhanced antibacterial effect and low cytotoxicity. The synergistic antibacterial effect of TX-100 + Ag + was tested on both planktonic and biofilm-resident E. faecalis on dentine. And the cytotoxicity was tested on MC3T3-E1 cells. Results confirmed the antibacterial activity against both planktonic and biofilm-resident E. faecalis was dramatically improved after TX-100 incorporation. TX-100 and Ag + mixture demonstrated a similar inhibitory effect as the 2% chlorhexidine (CHX), while the cytotoxicity was much lower than 2% CHX ( p < 0.05). In conclusion, TX-100 + Ag + mixture might be developed into a new effective intracanal medication as the 2% CHX.
研究领域:
口腔医学
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微生物学
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PubMed
高影响因子
Virology Journal
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2025
·Vol. 22
·期 1
·1-11
·
IF 3.8
Zeng Huiran,Wang Yuan,Tian Yachen,Yao Xiaoting,Li Yixuan,Xu Linan,Yang Xiangpeng,Zhang Xinglin,Ma Junfei
The high-level colonization of vancomycin-resistant Enterococci (VRE) in the gastrointestinal tract could lead to systemic infections such as bacteremia, endocarditis, and urinary tract infections, particularly in hospitalized patients. Given the potent bactericidal activity and host specificity of bacteriophages, phage therapy represents a promising alternative strategy for controlling VRE infections. In this study, we isolated and characterized phage A155, which targets vancomycin-resistant Enterococcus faecalis (VR-Efs) V583. Genomic analyses revealed that it is a member of the Kochikohdavirus genus, while functional characterization defined its optimal multiplicity of infection (MOI), one-step growth kinetics, and stability under varying thermal (20–50 °C) and pH (3.0–11.0) conditions. The phage demonstrated a broad lytic spectrum and effective in vitro antibacterial activity. Furthermore, phage A155 could significantly reduce the VRE intestinal colonization loads by 1.13 orders of magnitude in a mouse model. These findings exhibit the characterization and genome analysis of a novel VR-Efs phage A155, highlighting its therapeutic potential against E. faecalis colonization.
研究领域:
微生物学
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病毒学
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传染病学
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基因组学
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抗菌治疗
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DOI
PubMed
高影响因子
Microbiology Spectrum
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2024
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IF 3.7
Yanjun Xie,Fangyi Xu,Huali Dong,Jianfeng Mao,Chuanling Zhang
The colonization of Enterococcus in the female vagina leads to neonatal and pediatric enterococcal septicemia. Linezolid (LZD) is a kind of mainstream drug for treating multidrug-resistant Gram-positive infections. OptrA is the main LZD-resistance gene at Enterococci in human isolates. It is essential to explore the prevalence of optrA-carrying Enterococcus in vaginal secretions of late pregnant women and the drug resistance of optrA. From May to June 2023, this study recruited 340 volunteers in late pregnancy (35–40 weeks of pregnancy) to provide non-repetitive vaginal discharge samples. Luria-Bertani broth and florfenicol (10 µg/mL) were used to enrich bacteria. Enterococci was identified through time-of-flight mass spectrometry. Additionally, antimicrobial susceptibility, polymerase chain reaction, and next-generation sequencing assays were applied to this study. Fifty-four optrA-carrying Enterococcus strains were obtained, the proportion of the whole vagina of late pregnant women was 15.88% (54 out of 340), and Enterococcus faecalis account the highest proportion. All optrA-carrying Enterococcus were resistant to at least three drugs. Tetracycline, chloramphenicol, erythromycin, and LZD have higher bacterial resistance rates. Genetic environment analysis revealed that IS1216E, fexA, and erm(A) may synergistically exert multidrug resistance with optrA. It is necessary to strengthen the surveillance of optrA-carrying Enterococcus in pregnant women. This study provides scientific support for controlling hospital infections and managing antibiotic-resistant bacteria, and provides a scientific basis for rational clinical medication.
研究领域:
微生物学
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妇产科学
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感染病学
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PubMed
高影响因子
JOURNAL OF NANOBIOTECHNOLOGY
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2018
·Vol. 16
·期 1
·1-16
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IF 5.294
Fan Wei,Sun Qing,Li Yanyun,Tay Franklin R.,Fan Bing
Background Ag + and Zn 2+ have already been used in combinations to obtain both enhanced antibacterial effect and low cytotoxicity. Despite this, it is still unclear how the Zn 2+ co-works with Ag + in the synergistic antibacterial activity. The main purposes of this study were to investigate the co-work pattern and optimum ratio between Ag + and Zn 2+ in their synergistic antibacterial activity against E. faecalis , the possible mechanisms behind this synergy and the primary application of optimum Ag + –Zn 2+ co-work pattern against the E. faecalis biofilm on dentin. A serial of Ag + –Zn 2+ atomic combination ratios were tested on both planktonic and biofilm-resident E. faecalis on dentin, their antibacterial efficiency was calculated and optimum ratio determined. And the cytotoxicity of various Ag + –Zn 2+ atomic ratios was tested on MC3T3-E1 Cells. The role of Zn 2+ in Ag + –Zn 2+ co-work was evaluated using a Zn 2+ pretreatment study and membrane potential—permeability measurement. Results The results showed that the synergistically promoted antibacterial effect of Ag + –Zn 2+ combinations was Zn 2+ amount-dependent with the 1:9 and 1:12 Ag + –Zn 2+ atomic ratios showing the most powerful ability against both planktonic and biofilm-resident E. faecalis. This co-work could likely be attributed to the depolarization of E. faecalis cell membrane by the addition of Zn 2+ . The cytotoxicity of the Ag + –Zn 2+ atomic ratios of 1:9 and 1:12 was much lower than 2% chlorhexidine. Conclusions The Ag + –Zn 2+ atomic ratios of 1:9 and 1:12 demonstrated similar strong ability against E. faecalis biofilm on dentin but much lower cytotoxicity than 2% chlorhexidine. New medications containing optimum Ag + –Zn 2+ atomic ratios higher than 1:6, such as 1:9 or 1:12, could be developed against E. faecalis infection in root canals of teeth or any other parts of human body.
研究领域:
微生物学
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口腔医学
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生物材料学
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DOI
PubMed
高影响因子
JOURNAL OF APPLIED MICROBIOLOGY
·
2017
·Vol. 123
·期 5
·1274-1285
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IF 2.099
Cui J.,Xiao M.,Liu M.,Wang Z.,Liu F.,Guo L.,Meng H.,Zhang H.,Yang J.,Deng D.,Huang S.,Ma Y.,Liu C.
AimsTo demonstrate a nonempirical workflow to select host‐specific probiotics for aquaculture industry.Methods and ResultsUsing both culture‐dependent and culture‐independent methods, we have systematically investigated, for the first time, the gut microbiota of twelve subtropical aquatic animal species. We found that the diversity, abundance and distribution of gut micro‐organisms of these animals were host‐specific and that lactic acid bacteria (LAB) were predominant among the indigenous probiotic microbes. Using culturing method, we isolated and characterized ninety‐eight LAB strains; however, only a few strains was representative of the dominant LAB OTUs recovered by culture‐independent analysis.ConclusionsTwo cultured LAB strains, Enterococcus faecalis LS1‐2 and Enterococcus faecium Z1‐2, capturing the major LAB OTUs in the sequencing data set of the most animal samples and showing significant antimicrobial activities against shrimp pathogens, were suggested to be the candidates of shrimp probiotics.Significance and Impact of StudyDisease outbreak and the consequential abuse of antibiotics have been the constraints to the aquaculture industry. However, the selection of probiotic bacteria is currently still an empirical process due to our limited knowledge on the gastrointestinal microbiota of aquatic organisms. Our study points to a nonempirical selection process by which host‐specific probiotics can be developed.
研究领域:
水产养殖
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微生物学
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分子生物学
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生物技术
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PubMed
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CELLULAR AND MOLECULAR BIOLOGY
·
2022
·Vol. 68
·期 1
·
IF 1.206
Yuwei Li,Tingting Yan,Lijun Yin,Yongqiang Cheng,Xin Jia
The Chinese traditional soybean product, sufu, is getting increasingly popular in Asia for its special taste and rich nutrition. In this paper, physicochemical properties of sufu during fermentation, isolation and characterization of BA-producing bacteria, as well as their decarboxylase activities were thoroughly investigated. Tyramine, putrescine, phenylethylamine and cadaverine were the main BA in sufu fermentation. Tyramine level increased drastically to reach 513.72 mg/kg during sufu ripening, posing potential health risks. During sufu fermentation, there was a positive correlation between amino nitrogen and BA, yet no significant correlation was found between BAs with pH and total acidity. Additionally, 23 strains of tyramine- and phenylethylamine-producing bacteria harboring the TDC gene, including Enterococcus faecalis 45, Enterococcus faecium 36, Pediococcus acidilactici 310 and Pediococcus pentosaceus 27 that were responsible for tyramine production in sufu have been characterized. The current study provides insights into understanding the production of tyramine in sufu by microorganisms, which laid the groundwork for controlling biogenic amine production in fermented soybean products.
研究领域:
食品科学
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微生物学
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生物技术
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DOI
PubMed
高影响因子
AIP Advances
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2024
·Vol. 14
·期 11
·
IF 1.4
Liu Xiao-Bin,Dai Xiao-Hua,Li Li,Shen Jing,Li Wei,Li Chang-Yi
Enterococcus faecalis ( E. faecalis ) is one of the dominant bacteria in infected root canals, and it is tolerant to commonly used root canal disinfectants. Ag + has a certain antibacterial effect on E. faecalis , but the instability and potential toxicity of Ag + limit its application. Metal azolate framework-7 (MAF-7) is a typical metal–organic framework that has been used for drug delivery due to its high encapsulation efficiency, tunable release profile, and low cytotoxicity. In this study, we used a simple method for the synthesis of Ag + /MAF-7 nanocomposites. After characterization via several techniques, the antibacterial activity of this nanocomposite against E. faecalis was investigated. Ag + was found to be uniformly bound to MAF-7, and the resulting Ag + /MAF-7 nanocomposite showed significant antibacterial activity against E. faecalis . This study demonstrates the potential application of nanocomposite antibacterial materials in treating infected root canals.
研究领域:
牙科学
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微生物学
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纳米医学
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DOI
高影响因子
ACS Omega
·
2024
·
IF 3.7
Chengchun Chen,Duoyun Li,Yongpeng Shang,Zhiwei Lin,Zewen Wen,Peiyu Li,Zhijian Yu,Zhong Chen,Xiaoju Liu
Enterococcus faecalis infections pose a significant clinical challenge due to their multidrug resistance and propensity for biofilm formation. Exploring alternative treatment options, such as repurposing existing drugs, is crucial in addressing this issue. This study investigates the antibacterial activity of candesartan cilexetil against E. faecalis and elucidates its mechanism of action. Candesartan cilexetil exhibited notable antibacterial activity against both E. faecalis and Enterococcus faecium, with minimum inhibitory concentration (MIC) of ≤25 μM. Time-kill curves demonstrated concentration-dependent bactericidal effects. Candesartan cilexetil could significantly inhibited biofilm formation at the concentration of 1/4× MIC and induced alterations in biofilm structure. Permeability assays revealed compromised bacterial membranes, accompanied by the dissipation of membrane potential in E. faecalis cells after treatment with candesartan cilexetil. Checkerboard analysis showed that bacterial membrane phospholipids phosphatidylglycerol and cardiolipin could neutralize the antibacterial activity of candesartan cilexetil in a dose-dependent manner. Biolayer interferometry (BLI) assay indicated specific interactions between candesartan cilexetil and phosphatidylglycerol or cardiolipin. This study demonstrates the promising antibacterial and antibiofilm activities of candesartan cilexetil against multidrug-resistant E. faecalis. The mechanism of action involves disruption of bacterial membranes, possibly by interacting with membrane phospholipids. These findings underscore the potential utility of candesartan cilexetil as an effective therapeutic agent for combating E. faecalis infections, offering a valuable strategy in the battle against antibiotic-resistant pathogens.
研究领域:
微生物学
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药理学
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DOI
PubMed
高影响因子
Current Research in Microbial Sciences
·
2025
·
IF 5.8
Nan Chen,Zexu Yu,Xuan Ji,Siyi Zhang,Chongwei Yu,Teresa G. Valencak,Fushan Shi,Daxi Ren
Old age raises the susceptibility of age-related disease in domestic dogs. Discovering effective anti-aging interventions is key for mitigating age-related disease and conserving “healthspan” in pet dogs. In this study, 2 bacterial strains were isolated from canine feces. After screening and identifying the strains, Weissella confusa ZJUIDS-D034 and Enterococcus faecalis ZJUIDS-D016 were chosen to intervene during D- galactose-induced senescence in mice. We found that administering Weissella confusa ZJUIDS-D034 and Enterococcus faecalis ZJUIDS-D016 improved the aging phenotype of mice, including an increase in antioxidant activity, a decrease in pro-inflammatory cytokines, and the restoration of intestinal and liver tissue damage. In addition, Weissella confusa ZJUIDS-D034 and Enterococcus faecalis ZJUIDS-D016 lead to changes in the structure of intestinal microbiota in aging mice. Specifically, there was a decrease in the abundance of the Cyanobacteria and an increase in the abundance of Akkermansia and Lactobacillus . More importantly, there was a significant increase in acetic acid, a short-chain fatty acid, due to intervention with the 2 strains. This increase might be attributed to higher Akkermansia . We show that the modulation of gut microbiota and metabolism in aging mice may be a promising strategy through which Weissella confusa ZJUIDS-D034 and Enterococcus faecalis ZJUIDS-D016 might exert their anti-aging effects.
研究领域:
微生物学
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老年医学
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动物健康
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DOI
PubMed
高影响因子
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