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Yang Y, Shi Y, Fang J, Chu H, Adams JM. Soil Microbial Network Complexity Varies With pH as a Continuum, Not a Threshold, Across the North China Plain. Front Microbiol 2022; 13:895687. [PMID: 35733957 PMCID: PMC9207804 DOI: 10.3389/fmicb.2022.895687] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2022] [Accepted: 04/27/2022] [Indexed: 11/22/2022] Open
Abstract
There has been little study on the biogeographical patterns of microbial co-occurrence, especially in agricultural soils. Here we investigated the biogeographical patterns and major drivers of co-occurrence network topological structure, and the relative abundance of keystone taxa for soil bacterial and fungal communities using high-throughput sequencing on a set of 90 samples across a 1,092 km transect in wheat fields of the North China Plain (NCP). We found that pH was the most important environmental factor driving network topology and relative abundance of keystone taxa. For the metacommunity composed of both bacteria and fungi, and for the bacterial community alone, lower soil pH was associated with a more complex microbial network. However, the network for fungi showed no strong trend with soil pH. In addition, keystone taxa abundance was positively correlated with ecosystem function and stability, and best explained by pH. Our results present new perspectives on impacts of pH on soil microbial network structure across large scales in agricultural environments. This improved knowledge of community processes provides a step toward understanding of functioning and stability of agricultural ecosystems.
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Affiliation(s)
- Ying Yang
- School of Geography and Ocean Science, Nanjing University, Nanjing, China
| | - Yu Shi
- State Key Laboratory of Crop Stress Adaptation and Improvement, School of Life Sciences, Henan University, Kaifeng, China
| | - Jie Fang
- School of Geography and Ocean Science, Nanjing University, Nanjing, China
| | - Haiyan Chu
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing, China
| | - Jonathan M. Adams
- School of Geography and Ocean Science, Nanjing University, Nanjing, China
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2
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Tian L, Yan Z, Wang C, Xu S, Jiang H. Habitat heterogeneity induces regional differences in sediment nitrogen fixation in eutrophic freshwater lake. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 772:145594. [PMID: 33770866 DOI: 10.1016/j.scitotenv.2021.145594] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/03/2020] [Revised: 01/25/2021] [Accepted: 01/29/2021] [Indexed: 06/12/2023]
Abstract
Biological nitrogen fixation (BNF) in sediments is an important source of bioavailable nitrogen in aquatic systems. However, the effect of habitat change caused by eutrophication on nitrogen fixation within sediments is still unclear. In this study, nitrogen fixation rates and diazotroph diversities in sediments with heterogeneous ecological status in one eutrophic lake were investigated by using an isotope tracer method and sequencing of nitrogen-fixing (nif) genes. The results showed that both nitrogenase activity (NA) and nifH abundance in sediments of blooms area were higher than those in vegetation-dominated habitats. Correlation analysis showed that NA was correlated closely to nifH abundance, dissolved sulfide, and iron. The diazotrophic assemblage contained mainly Proteobacterial sequences belonging to Cluster I and III, and the variations of diazotrophic community could be explained by total nitrogen content, total phosphorus content, organic matters, sulfides, ammonium and iron content. Moreover, the co-occurrence network analysis showed the Alphaproteobacteria shaped the major interactions in diazotrophic community, and sediment properties had stronger effect on diazotrophic community in cyanobacteria-dominated habitat. This study revealed that habitat heterogeneity in eutrophic lakes shaped different succession of BNF in sediments and cyanobacterial blooms significantly improved the nitrogen-fixing activity in sediments, which broadened our understanding of nitrogen cycle and nutrient management in eutrophic freshwater lakes.
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Affiliation(s)
- Linqi Tian
- State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Zaisheng Yan
- State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, China
| | - Changhui Wang
- State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, China
| | - Shengqi Xu
- State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, China
| | - Helong Jiang
- State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, China.
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Liang J, Wang H, Libera M. Biomaterial surfaces self-defensive against bacteria by contact transfer of antimicrobials. Biomaterials 2019; 204:25-35. [PMID: 30875516 PMCID: PMC10755758 DOI: 10.1016/j.biomaterials.2019.03.006] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2018] [Revised: 03/04/2019] [Accepted: 03/07/2019] [Indexed: 11/17/2022]
Abstract
Despite extensive engineering of tissue-contacting biomedical devices to control healing, these devices remain susceptible to bacterial colonization, biofilm formation, and chronic infection. The threat of selecting for resistance genes largely precludes sustained antimicrobial elution as a wide-spread clinical solution. In response, self-defensive surfaces have been developed where antimicrobial is released only when and where there is a bacterial challenge. We explore a new self-defensive approach using anionic microgels into which small-molecule cationic antimicrobials are loaded by complexation. We identify conditions where antimicrobial remains sequestered within the microgels for periods as long as weeks. However, bacterial contact triggers release and leads to local bacterial killing. We speculate that the close proximity of bacteria alters the local thermodynamic environment and interferes with the microgel-antimicrobial complexation. The contact-transfer approach does not require bacterial metabolism but instead appears to be driven by differences between the microgels and the bacterial cell envelope where there is a high concentration of negative charge and hydrophobicity. Contact with metabolizing macrophages or osteoblasts is, however, insufficient to trigger antimicrobial release, indicating that contact transfer can be specific to bacteria and suggesting an avenue to biomedical device surfaces that can simultaneously promote healing and resist infection.
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Affiliation(s)
- Jing Liang
- Department of Chemical Engineering and Materials Science, Stevens Institute of Technology, Hoboken, New Jersey, 07030, USA
| | - Hongjun Wang
- Department of Biomedical Engineering, Stevens Institute of Technology, Hoboken, NJ, 07030, USA
| | - Matthew Libera
- Department of Chemical Engineering and Materials Science, Stevens Institute of Technology, Hoboken, New Jersey, 07030, USA.
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Klimenko AI, Matushkin YG, Kolchanov NA, Lashin SA. Spatial heterogeneity promotes antagonistic evolutionary scenarios in microbial community explained by ecological stratification: a simulation study. Ecol Modell 2019. [DOI: 10.1016/j.ecolmodel.2019.02.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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5
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Cuevas-Yáñez K, Benítez M, Rocha M, Córdoba-Aguilar A. Large-scale human environmental intervention is related to a richness reduction in Mexican odonates. REV MEX BIODIVERS 2017. [DOI: 10.1016/j.rmb.2017.06.008] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
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Bi Y, Li C, Liu L, Zhou J, Li Z, Deng H, Wu C, Han Y, Song Y, Tan Y, Wang X, Du Z, Cui Y, Yan Y, Zhi F, Liu G, Qin N, Zhang H, Yang R. IL-17A-dependent gut microbiota is essential for regulating diet-induced disorders in mice. Sci Bull (Beijing) 2017; 62:1052-1063. [PMID: 36659332 DOI: 10.1016/j.scib.2017.07.011] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2017] [Revised: 06/16/2017] [Accepted: 06/19/2017] [Indexed: 01/21/2023]
Abstract
The gut microbiota plays a key role in obesity and related metabolic disorders, and multiple factors including diet, host genotype, and age regulate it. Many studies have examined the contribution of extrinsic factors to the regulation of the gut microbiota, but the importance of the host genetic constitution cannot be ignored. Interleukin 17A (IL-17A), a pro-inflammatory cytokine, is important in the defense against infection and diseases. Here, we investigated the association among IL-17, a high-fat diet (HFD), and the gut microbiota. Mice deficient in IL-17A were resistant to diet-induced obesity and related diseases. Compared with the Il-17a-/- mice, wild-type (WT) mice challenged with HFD showed obvious weight fluctuations, such as those seen in type 2 diabetes, and hematological changes similar to those associated with metabolic syndrome. However, housing WT mice and Il-17a-/- mice together significantly alleviated these symptoms in the WT mice. A metagenomic analysis of the mouse feces indicated that the microbial community compositions of these two groups differed before HFD feeding. The HFD mediated shifts in the gut microbial compositions, which were associated with the mouse phenotypes. We also identified potentially beneficial and harmful species present during this period, and drew networks of the most abundant species. A functional analysis indicated pathway changes in the WT and Il-17a-/- mice when fed the HFD. Collectively, these data underscore the importance of the host factor IL-17A in shaping and regulating the gut microbiota, which conversely, influences the host health.
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Affiliation(s)
- Yujing Bi
- State Key laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing 100071, China
| | - Chunxiao Li
- Key Laboratory of Cell Proliferation and Regulation Biology, Ministry of Education, Institute of Cell Biology, College of Life Science, Beijing Normal University, Beijing 100875, China
| | - Lin Liu
- State Key Laboratory for Diagnosis and Treatment of Infectious Disease, The First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou 310003, China; Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Zhejiang University, Hangzhou 310003, China
| | - Jiyuan Zhou
- State Key laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing 100071, China
| | - Zhengchao Li
- State Key laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing 100071, China; Guangdong Provincial Key Laboratory of Gastroenterology, Institute of Gastroenterology of Guangdong Province, Department of Gastroenterology, Nanfang Hospital, Southern Medical University, Guangzhou 510515, China
| | - Huimin Deng
- State Key laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing 100071, China; Guangdong Provincial Key Laboratory of Gastroenterology, Institute of Gastroenterology of Guangdong Province, Department of Gastroenterology, Nanfang Hospital, Southern Medical University, Guangzhou 510515, China
| | - Chunyan Wu
- Realbio Genomics Institute, Shanghai 200050, China
| | - Yanping Han
- State Key laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing 100071, China
| | - Yajun Song
- State Key laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing 100071, China
| | - Yafang Tan
- State Key laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing 100071, China
| | - Xiaoyi Wang
- State Key laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing 100071, China
| | - Zongmin Du
- State Key laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing 100071, China
| | - Yujun Cui
- State Key laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing 100071, China
| | - Yanfeng Yan
- State Key laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing 100071, China
| | - Fachao Zhi
- Guangdong Provincial Key Laboratory of Gastroenterology, Institute of Gastroenterology of Guangdong Province, Department of Gastroenterology, Nanfang Hospital, Southern Medical University, Guangzhou 510515, China
| | - Guangwei Liu
- Key Laboratory of Cell Proliferation and Regulation Biology, Ministry of Education, Institute of Cell Biology, College of Life Science, Beijing Normal University, Beijing 100875, China.
| | - Nan Qin
- State Key Laboratory for Diagnosis and Treatment of Infectious Disease, The First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou 310003, China; Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Zhejiang University, Hangzhou 310003, China.
| | - Heping Zhang
- Key Laboratory of Dairy Biotechnology and Engineering, Education Ministry of China, Inner Mongolia Agricultural University, Hohhot 010018, China.
| | - Ruifu Yang
- State Key laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing 100071, China.
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Kao WK, Gagnon PM, Vogel JP, Chole RA. Surface charge modification decreases Pseudomonas aeruginosa adherence in vitro and bacterial persistence in an in vivo implant model. Laryngoscope 2017; 127:1655-1661. [PMID: 28295372 PMCID: PMC5476480 DOI: 10.1002/lary.26499] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2016] [Revised: 11/30/2016] [Accepted: 12/23/2016] [Indexed: 12/16/2022]
Abstract
OBJECTIVE Chronic, persistent infections complicate otologic procedures utilizing implantable devices such as cochlear implants or tympanostomy tubes. These infections are thought to be due to the establishment of microbial biofilms on implant surfaces. To address this issue, we hypothesized that surface charge modification may inhibit the formation of Pseudomonas aeruginosa biofilms on implant surfaces in vitro and in vivo. STUDY DESIGN We evaluated the effect of surface charge modification on bacterial biofilm formation by assessing the effect of the surface charge on bacterial adhesion in vitro and bacterial persistence in vivo. METHODS To study the effect of surface charge in vitro, the surface wells in culture plates were modified using a layer-by-layer polyelectrolyte assembly method. Bacterial adherence was measured at 30-, 60-, and 120-minute intervals. To study the effect of surface charge modification in vivo, the surface of titanium microscrews was similarly modified and then surgically implanted into the dorsal calvaria of adult rats and inoculated with bacteria. Two weeks after implantation and inoculation, the number of bacteria remaining in vivo was evaluated. RESULTS Surface charge modification results in a significant decrease in adherence of bacteria in vitro. Surface charge modification of titanium microscrew implants also resulted in a significant decrease in P. aeruginosa recovered 2 weeks after surgical implantation. CONCLUSION Charge modification decreases the number of bacteria adherent to a surface in vitro and decreases the risk and severity of implant infection in an in vivo rat infection model. These results have promising biomedical applications. LEVEL OF EVIDENCE NA. Laryngoscope, 127:1655-1661, 2017.
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Affiliation(s)
- W Katherine Kao
- Department of Otolaryngology, Washington University in St. Louis School of Medicine, St. Louis, Missouri, U.S.A
| | - Patricia M Gagnon
- Department of Otolaryngology, Washington University in St. Louis School of Medicine, St. Louis, Missouri, U.S.A
| | - Joseph P Vogel
- Department of Molecular Microbiology, Washington University in St. Louis School of Medicine, St. Louis, Missouri, U.S.A
| | - Richard A Chole
- Department of Otolaryngology, Washington University in St. Louis School of Medicine, St. Louis, Missouri, U.S.A
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8
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Hartmann H, Krastev R. Biofunctionalization of surfaces using polyelectrolyte multilayers. ACTA ACUST UNITED AC 2017. [DOI: 10.1515/bnm-2016-0015] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
AbstractBiomaterials play a central role in modern strategies in regenerative medicine and tissue engineering to restore the structure and function of damaged or dysfunctional tissue and to direct cellular behavior. Both biologically derived and synthetic materials have been extensively explored in this context. However, most materials when implanted into living tissue initiate a host response. Modern implant design therefore aims to improve implant integration while avoiding chronic inflammation and foreign body reactions, and thus loss of the intended implant function. Directing these processes requires an in-depth understanding of the immunological processes that take place at the interface between biomaterials and the host tissue. The physicochemical properties of biomaterial surfaces (charge, charge density, hydrophilicity, functional molecular domains, etc.) are decisive, as are their stiffness, roughness and topography. This review outlines specific strategies, using polyelectrolyte multilayers to modulate the interactions between biomaterial surfaces and biological systems. The described coatings have the potential to control the adhesion of proteins, bacteria and mammalian cells. They can be used to decrease the risk of bacterial infections occurring after implantation and to achieve better contact between biological tissue and implants. In summary, these results are important for further development and modification of surfaces from different medical implants.
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9
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Azevedo AS, Almeida C, Melo LF, Azevedo NF. Impact of polymicrobial biofilms in catheter-associated urinary tract infections. Crit Rev Microbiol 2016; 43:423-439. [PMID: 28033847 DOI: 10.1080/1040841x.2016.1240656] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Recent reports have demonstrated that most biofilms involved in catheter-associated urinary tract infections are polymicrobial communities, with pathogenic microorganisms (e.g. Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumoniae) and uncommon microorganisms (e.g. Delftia tsuruhatensis, Achromobacter xylosoxidans) frequently co-inhabiting the same urinary catheter. However, little is known about the interactions that occur between different microorganisms and how they impact biofilm formation and infection outcome. This lack of knowledge affects CAUTIs management as uncommon bacteria action can, for instance, influence the rate at which pathogens adhere and grow, as well as affect the overall biofilm resistance to antibiotics. Another relevant aspect is the understanding of factors that drive a single pathogenic bacterium to become prevalent in a polymicrobial community and subsequently cause infection. In this review, a general overview about the IMDs-associated biofilm infections is provided, with an emphasis on the pathophysiology and the microbiome composition of CAUTIs. Based on the available literature, it is clear that more research about the microbiome interaction, mechanisms of biofilm formation and of antimicrobial tolerance of the polymicrobial consortium are required to better understand and treat these infections.
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Affiliation(s)
- Andreia S Azevedo
- a Department of Chemical Engineering, Faculty of Engineering , Laboratory for Process Engineering, Environment, and Energy and Biotechnology Engineering (LEPABE), University of Porto , Porto , Portugal
| | - Carina Almeida
- a Department of Chemical Engineering, Faculty of Engineering , Laboratory for Process Engineering, Environment, and Energy and Biotechnology Engineering (LEPABE), University of Porto , Porto , Portugal.,b Institute for Biotechnology and Bioengineering (IBB), Centre of Biological Engineering, Universidade do Minho , Braga , Portugal
| | - Luís F Melo
- a Department of Chemical Engineering, Faculty of Engineering , Laboratory for Process Engineering, Environment, and Energy and Biotechnology Engineering (LEPABE), University of Porto , Porto , Portugal
| | - Nuno F Azevedo
- a Department of Chemical Engineering, Faculty of Engineering , Laboratory for Process Engineering, Environment, and Energy and Biotechnology Engineering (LEPABE), University of Porto , Porto , Portugal
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10
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Tetz G, Vikina D, Tetz V. Antimicrobial activity of mul-1867, a novel antimicrobial compound, against multidrug-resistant Pseudomonas aeruginosa. Ann Clin Microbiol Antimicrob 2016; 15:19. [PMID: 27001074 PMCID: PMC4802586 DOI: 10.1186/s12941-016-0134-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2015] [Accepted: 03/14/2016] [Indexed: 02/07/2023] Open
Abstract
Background There is an urgent need for new antimicrobial compounds to treat various lung infections caused by multidrug-resistant Pseudomonas aeruginosa (MDR-PA). Methods We studied the potency of Mul-1867 against MDR-PA isolates from patients with cystic fibrosis, chronic obstructive pulmonary disease, and ventilator-associated pneumonia. The minimal inhibitory concentrations (MICs) and minimum biofilm eliminating concentrations (MBECs), defined as the concentrations of drug that kill 50 % (MBEC50), 90 % (MBEC90), and 100 % (MBEC100) of the bacteria in preformed biofilms, were determined by using the broth macrodilution method. Results Mul-1867 exhibited significant activity against MDR-PA and susceptible control strains, with MICs ranging from 1.0 to 8.0 µg/mL. Mul-1867 also possesses anti-biofilm activity against mucoid and non-mucoid 24-h-old MDR-PA biofilms. The MBEC50 value was equal to onefold the MIC. The MBEC90 value ranged from two to fourfold the MIC. Moreover, Mul-1867 completely eradicated mature biofilms at the concentrations tested, with MBEC100 values ranging between 16- and 32-fold the MIC. Mul-1867 was non-toxic to Madin-Darby canine kidney (MDCK) cells at concentrations up to 256 µg/mL. Conclusion Overall, these data indicate that Mul-1867 is a promising locally acting antimicrobial for the treatment and prevention of P. aeruginosa infections.
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Affiliation(s)
- George Tetz
- TGV-Laboratories LLC, 303 5th avenue, # 2012, New York, NY, 10016, USA.
| | - Daria Vikina
- Institute of Human Microbiology, New York, NY, 10016, USA
| | - Victor Tetz
- Institute of Human Microbiology, New York, NY, 10016, USA
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11
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Bionda N, Fleeman RM, de la Fuente-Núñez C, Rodriguez MC, Reffuveille F, Shaw LN, Pastar I, Davis SC, Hancock REW, Cudic P. Identification of novel cyclic lipopeptides from a positional scanning combinatorial library with enhanced antibacterial and antibiofilm activities. Eur J Med Chem 2016; 108:354-363. [PMID: 26703794 PMCID: PMC4724249 DOI: 10.1016/j.ejmech.2015.11.032] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2015] [Revised: 11/12/2015] [Accepted: 11/17/2015] [Indexed: 12/25/2022]
Abstract
Treating bacterial infections can be difficult due to innate or acquired resistance mechanisms, and the formation of biofilms. Cyclic lipopeptides derived from fusaricidin/LI-F natural products represent particularly attractive candidates for the development of new antibacterial and antibiofilm agents, with the potential to meet the challenge of bacterial resistance to antibiotics. A positional-scanning combinatorial approach was used to identify the amino acid residues responsible for driving antibacterial activity, and increase the potency of these cyclic lipopeptides. Screening against the antibiotic resistant ESKAPE pathogens revealed the importance of hydrophobic as well as positively charged amino acid residues for activity of this class of peptides. The improvement in potency was especially evident against bacterial biofilms, since the lead cyclic lipopeptide showed promising in vitro and in vivo anti-biofilm activity at the concentration far below its respective MICs. Importantly, structural changes resulting in a more hydrophobic and positively charged analog did not lead to an increase in toxicity toward human cells.
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Affiliation(s)
- Nina Bionda
- Torrey Pines Institute for Molecular Studies, 11350 SW Village Parkway, Port St. Lucie 34987-2352, FLA, USA
| | - Renee M Fleeman
- Department of Cell Biology, Microbiology and Molecular Biology, University of South Florida, 4202 East Fowler Avenue, ISA2015, Tampa 33620-5150, FLA, USA
| | - César de la Fuente-Núñez
- Department of Microbiology and Immunology, Centre for Microbial Diseases and Immunity Research, 232-2259 Lower Mall Research Station, University of British Columbia, Vancouver V6T 1Z4, BC, Canada
| | - Maria C Rodriguez
- Torrey Pines Institute for Molecular Studies, 11350 SW Village Parkway, Port St. Lucie 34987-2352, FLA, USA
| | - Fany Reffuveille
- Department of Microbiology and Immunology, Centre for Microbial Diseases and Immunity Research, 232-2259 Lower Mall Research Station, University of British Columbia, Vancouver V6T 1Z4, BC, Canada
| | - Lindsey N Shaw
- Department of Cell Biology, Microbiology and Molecular Biology, University of South Florida, 4202 East Fowler Avenue, ISA2015, Tampa 33620-5150, FLA, USA
| | - Irena Pastar
- Department of Dermatology and Cutaneous Surgery, University of Miami Miller School of Medicine, Miami, FLA, USA
| | - Stephen C Davis
- Department of Dermatology and Cutaneous Surgery, University of Miami Miller School of Medicine, Miami, FLA, USA
| | - Robert E W Hancock
- Department of Microbiology and Immunology, Centre for Microbial Diseases and Immunity Research, 232-2259 Lower Mall Research Station, University of British Columbia, Vancouver V6T 1Z4, BC, Canada
| | - Predrag Cudic
- Torrey Pines Institute for Molecular Studies, 11350 SW Village Parkway, Port St. Lucie 34987-2352, FLA, USA.
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12
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Tetz G, Tetz V. In vitro antimicrobial activity of a novel compound, Mul-1867, against clinically important bacteria. Antimicrob Resist Infect Control 2015; 4:45. [PMID: 26550474 PMCID: PMC4636785 DOI: 10.1186/s13756-015-0088-x] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2015] [Accepted: 10/27/2015] [Indexed: 11/21/2022] Open
Abstract
Background The antimicrobial activity of Mul-1867, a novel synthetic compound, was tested against 18 bacterial strains, including clinical isolates and reference strains from culture collections. Methods The minimal inhibitory concentration (MICs) and minimal bactericidal concentration (MBCs) were determined by using the broth macrodilution method. The kinetics of the inhibitory effects of Mul-1867 against biofilm-growing microorganisms was assessed at time-kill test in vitro against 48-h-old biofilms of Staphylococcus aureus and Escherichia coli. Transmission electron microscopy analyses was conducted to examine cell disruption. Results A comparative assessment of the antimicrobial activities of Mul-1867 and chlorhexidine digluconate (CHG), used as a control antimicrobial, indicated that Mul-1867 was significantly more effective as a disinfectant than CHG. Mul-1867 showed potent antimicrobial activities against all the tested bacteria (MIC: 0.03–0.5 μg/mL). Furthermore, MBC/MIC ratio of Mul-1867 for all tested strains was less than or equal to 4. Time-kill studies showed that treatment with Mul-1867 (0.05–2 %) reduced bacterial numbers by 2.8–4.8 log10 colony forming units (CFU)/mL within 15–60 s. Bactericidal activity of Mul-1867 was confirmed by morphological changes revealed by TEM suggested that the killing of bacteria was the result of membrane disruption. Conclusion Overall, these data indicated that Mul-1867 may be a promising antimicrobial for the treatment and prevention of human infections.
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Affiliation(s)
- George Tetz
- TGV-Therapeutics, Institute of Human Microbiology, LLC, 303 5th avenue, suite 2012, New York, NY 10016 USA
| | - Victor Tetz
- Department of Microbiology, Virology, and Immunology, Pavlov First St. Petersburg State Medical University, St. Petersburg, Russia
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13
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Mathematical Modeling of Microbial Community Dynamics: A Methodological Review. Processes (Basel) 2014. [DOI: 10.3390/pr2040711] [Citation(s) in RCA: 91] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
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14
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Photocatalytic and antimicrobial properties of surgical implant coatings of titanium dioxide deposited though cathodic arc evaporation. Biotechnol Lett 2012; 34:2299-305. [PMID: 22941372 DOI: 10.1007/s10529-012-1040-2] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2012] [Accepted: 08/14/2012] [Indexed: 10/27/2022]
Abstract
UNLABELLED Nanostructured crystalline titanium dioxide coatings deposited by cathodic arc evaporated on titanium grade five medical implant substrates were demonstrated to exhibit UV-induced photocatalytic activity that can be utilized to provide bactericidal effects against Staphylococcus epidermidis. The photocatalytic activity of the coatings was confirmed via degradation of Rhodamine B under UV illumination. A 90 % reduction of viable bacteria was achieved in a clinically suitable time of only 2 min with a UV dose of 2.4 J delivered at 365 nm. These results are encouraging for the development of antimicrobial surfaces in orthopedics and dentistry in order to prevent or treat post-surgical infections. PURPOSE OF WORK To assess the possibility of employing photocatalysis for elimination of S. epidermidis, known to cause medical device related infections, under short enough times to be clinically useful on an implant surface produced with a technique that is suitable for mass production.
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Abstract
Metagenomics and 16S pyrosequencing have enabled the study of ecosystem structure and dynamics to great depth and accuracy. Co-occurrence and correlation patterns found in these data sets are increasingly used for the prediction of species interactions in environments ranging from the oceans to the human microbiome. In addition, parallelized co-culture assays and combinatorial labelling experiments allow high-throughput discovery of cooperative and competitive relationships between species. In this Review, we describe how these techniques are opening the way towards global ecosystem network prediction and the development of ecosystem-wide dynamic models.
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Busscher HJ, van der Mei HC. How do bacteria know they are on a surface and regulate their response to an adhering state? PLoS Pathog 2012; 8:e1002440. [PMID: 22291589 PMCID: PMC3266930 DOI: 10.1371/journal.ppat.1002440] [Citation(s) in RCA: 126] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Affiliation(s)
- Henk J. Busscher
- Department of Biomedical Engineering, W.J. Kolff Institute, University Medical Center and University of Groningen, Groningen, The Netherlands
| | - Henny C. van der Mei
- Department of Biomedical Engineering, W.J. Kolff Institute, University Medical Center and University of Groningen, Groningen, The Netherlands
- * E-mail:
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18
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Pavlukhina S, Lu Y, Patimetha A, Libera M, Sukhishvili S. Polymer Multilayers with pH-Triggered Release of Antibacterial Agents. Biomacromolecules 2010; 11:3448-56. [DOI: 10.1021/bm100975w] [Citation(s) in RCA: 127] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Affiliation(s)
- Svetlana Pavlukhina
- Department of Chemistry, Chemical Biology and Biomedical Engineering and Department of Chemical Engineering and Materials Science, Stevens Institute of Technology, Hoboken, New Jersey 07030, United States
| | - Yiming Lu
- Department of Chemistry, Chemical Biology and Biomedical Engineering and Department of Chemical Engineering and Materials Science, Stevens Institute of Technology, Hoboken, New Jersey 07030, United States
| | - Altida Patimetha
- Department of Chemistry, Chemical Biology and Biomedical Engineering and Department of Chemical Engineering and Materials Science, Stevens Institute of Technology, Hoboken, New Jersey 07030, United States
| | - Matthew Libera
- Department of Chemistry, Chemical Biology and Biomedical Engineering and Department of Chemical Engineering and Materials Science, Stevens Institute of Technology, Hoboken, New Jersey 07030, United States
| | - Svetlana Sukhishvili
- Department of Chemistry, Chemical Biology and Biomedical Engineering and Department of Chemical Engineering and Materials Science, Stevens Institute of Technology, Hoboken, New Jersey 07030, United States
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Welch K, Cai Y, Engqvist H, Strømme M. Dental adhesives with bioactive and on-demand bactericidal properties. Dent Mater 2010; 26:491-9. [PMID: 20189237 DOI: 10.1016/j.dental.2010.01.008] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2009] [Revised: 12/22/2009] [Accepted: 01/08/2010] [Indexed: 11/19/2022]
Abstract
OBJECTIVES The aim of the present work was to perform the first in vitro evaluation of a new interfacial bond-promoting material-and-method concept for on-demand long term bacteria inhibition in dental restoration procedures. METHODS The bioactivity, mechanical bonding strength and photocatalytic bactericidal properties, induced by low dose ultraviolet-A (UV-A) irradiation of dental adhesives containing crystalline titania nanoparticles (NPs), were analyzed. RESULTS Dental adhesives with a NP content of 20wt% were shown to be bioactive in terms of spontaneous hydroxylapatite formation upon storage in simulated body fluid and the bioactivity was found to be promoted by chemical etching of the adhesives. The mechanical bonding strength between the adhesives and a HA tooth model was shown to be unaffected by the NPs up to a NP content of 30wt%. Elimination of Staphylococcus epidermidis in contact with the adhesives was found to depend both on UV photocatalytic irradiation intensity and time. Efficient elimination of the bacteria could be achieved using a UV-A dose of 4.5J/cm(2) which is about 6 times below the safe maximum UV dose according to industry guidelines, and 20 times below the average UV-A dose received during an ordinary sun bed session. SIGNIFICANCE The combined features of bioactivity and on-demand bactericidal effect should open up the potential to create dental adhesives that reduce the incidence of secondary caries and promote closure of gaps forming at the interface towards the tooth via remineralization of adjacent tooth substance, as well as prevention of bacterial infections via on-demand UV-A irradiation.
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Gademann K, Kobylinska J, Wach JY, Woods TM. Surface modifications based on the cyanobacterial siderophore anachelin: from structure to functional biomaterials design. Biometals 2009; 22:595-604. [PMID: 19350397 DOI: 10.1007/s10534-009-9234-3] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2008] [Accepted: 03/23/2009] [Indexed: 11/25/2022]
Abstract
This review describes the design, synthesis and evaluation of novel catechol based anchors for surface modification. The anachelin chromophore, the catecholate fragment of the siderophore anachelin from the cyanobacterium Anabaena cylindrica, allows for the immobilization of polyethylene glycol (PEG) on titania and glass surfaces thus rendering them protein resistant and antifouling. It is proposed that catecholate siderophores constitute a class of natural products useful for surface modification similar to dihydroxyphenylalanine and dopamine derived compounds found in mussel adhesive proteins. Second-generation dopamine derivatives featuring a quaternary ammonium group were found to be equally efficient in generating antifouling surfaces. The anachelin chromophore, merged via a PEG linker to the glycopeptide antibiotic vancomycin, allowed for the generation of antimicrobial surfaces through an operationally simple dip-and-rinse procedure. This approach offers an option for the prevention of nosocomial infections through antimicrobial implants, catheters and stents. Consequences for the mild generation of functional biomaterials are discussed and novel strategies for the immobilization of complex natural products, proteins and DNA on surfaces are presented.
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Affiliation(s)
- Karl Gademann
- SB-ISIC-LSYNC, Swiss Federal Institute of Technology, Lausanne, Switzerland.
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A study on the interactions of Aurein 2.5 with bacterial membranes. Colloids Surf B Biointerfaces 2008; 68:225-30. [PMID: 19056250 DOI: 10.1016/j.colsurfb.2008.10.007] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2008] [Revised: 10/09/2008] [Accepted: 10/15/2008] [Indexed: 12/23/2022]
Abstract
Aurein 2.5 (GLFDIVKKVVGAFGSL-NH(2)) is an uncharacterised antimicrobial peptide. At an air/water interface, it exhibited strong surface activity (maximal surface pressure 25mNm(-1)) and molecular areas consistent with the adoption of alpha-helical structure orientated either perpendicular (1.72nm(2)molecule(-1)) or parallel (3.6nm(2)molecule(-1)) to the interface. Aurein 2.5 was strongly antibacterial, exhibiting a minimum inhibitory concentration (MIC) of 30microM against Bacillus subtilis and Escherichia coli. The peptide induced maximal surface pressure changes of 9mNm(-1) and 5mNm(-1), respectively, in monolayers mimicking membranes of these organisms whilst compression isotherm analysis of these monolayers showed DeltaG(Mix)>0, indicating destabilisation by Aurein 2.5. These combined data suggested that toxicity of the peptide to these organisms may involve membrane invasion via the use of oblique orientated alpha-helical structure. The peptide induced strong, comparable maximal surface changes in monolayers of DOPG (7.5mNm(-1)) and DOPE monolayers (6mNm(-1)) suggesting that the membrane interactions of Aurein 2.5 were driven by amphiphilicity rather than electrostatic interaction. Based on these data, it was suggested that the differing ability of Aurein 2.5 to insert into membranes of B. subtilis and E. coli was probably related to membrane-based factors such as differences in lipid packing characteristics. The peptide was active against both sessile E. coli and Staphylococcus aureus with an MIC of 125microM. The broad-spectrum antibacterial activity and non-specific modes of membrane action used by Aurein 2.5 suggested use as an anti-biofilm agent such as in the decontamination of medical devices.
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Wach JY, Bonazzi S, Gademann K. Antimikrobielle Oberflächen durch Naturstoffhybride. Angew Chem Int Ed Engl 2008. [DOI: 10.1002/ange.200801570] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Wach JY, Bonazzi S, Gademann K. Antimicrobial Surfaces through Natural Product Hybrids. Angew Chem Int Ed Engl 2008; 47:7123-6. [DOI: 10.1002/anie.200801570] [Citation(s) in RCA: 77] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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Dennison SR, Morton LH, Harris F, Phoenix DA. The impact of membrane lipid composition on antimicrobial function of an α-helical peptide. Chem Phys Lipids 2008; 151:92-102. [DOI: 10.1016/j.chemphyslip.2007.10.007] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2007] [Revised: 10/16/2007] [Accepted: 10/26/2007] [Indexed: 01/02/2023]
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Manuel Rodríguez-Martínez J, Pascual Á. Actividad de los antimicrobianos en biocapas bacterianas. Enferm Infecc Microbiol Clin 2008; 26:107-14. [DOI: 10.1157/13115546] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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