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Vaz MSM, de Almeida de Souza GH, Dos Santos Radai JA, Fraga TL, de Oliveira GG, Wender H, da Silva KE, Simionatto S. Antimicrobial activity of cinnamaldehyde against multidrug-resistant Klebsiella pneumoniae: an in vitro and in vivo study. Braz J Microbiol 2023; 54:1655-1664. [PMID: 37392293 PMCID: PMC10485196 DOI: 10.1007/s42770-023-01040-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2023] [Accepted: 06/10/2023] [Indexed: 07/03/2023] Open
Abstract
The emergence and spread of multidrug-resistant (MDR) Klebsiella pneumoniae strains have increased worldwide, posing a significant health threat by limiting the therapeutic options. This study aimed to investigate the antimicrobial potential of cinnamaldehyde against MDR-K. pneumoniae strains in vitro and in vivo assays. The presence of resistant genes in MDR- K. pneumoniae strains were evaluated by Polymerase Chain Reaction (PCR) and DNA sequencing. Carbapenem-resistant K. pneumoniae strains show the blaKPC-2 gene, while polymyxin-resistant K. pneumoniae presented blaKPC-2 and alterations in the mgrB gene. Cinnamaldehyde exhibited an inhibitory effect against all MDR- K. pneumoniae evaluated. An infected mice model was used to determine the in vivo effects against two K. pneumoniae strains, one carbapenem-resistant and another polymyxin-resistant. After 24 h of cinnamaldehyde treatment, the bacterial load in blood and peritoneal fluids decreased. Cinnamaldehyde showed potential effectiveness as an antibacterial agent by inhibiting the growth of MDR-K. pneumoniae strains.
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Affiliation(s)
- Marcia Soares Mattos Vaz
- Laboratório de Pesquisa Em Ciências da Saúde, Universidade Federal da Grande Dourados-UFGD, Cidade Universitária, Itahum, Km 12, Dourados, Mato Grosso Do Sul, CEP: 79804970, Brazil
| | - Gleyce Hellen de Almeida de Souza
- Laboratório de Pesquisa Em Ciências da Saúde, Universidade Federal da Grande Dourados-UFGD, Cidade Universitária, Itahum, Km 12, Dourados, Mato Grosso Do Sul, CEP: 79804970, Brazil
| | - Joyce Alencar Dos Santos Radai
- Laboratório de Pesquisa Em Ciências da Saúde, Universidade Federal da Grande Dourados-UFGD, Cidade Universitária, Itahum, Km 12, Dourados, Mato Grosso Do Sul, CEP: 79804970, Brazil
| | - Thiago Leite Fraga
- Centro Universitário da Grande Dourados-UNIGRAN, Dourados, Mato Grosso Do Sul, Brazil
| | | | - Heberton Wender
- Grupo de Pesquisa Em Nano E Fótons, Instituto de Física, Universidade Federal de Mato Grosso Do Sul, Campo Grande, Brazil
| | - Kesia Esther da Silva
- Laboratório de Pesquisa Em Ciências da Saúde, Universidade Federal da Grande Dourados-UFGD, Cidade Universitária, Itahum, Km 12, Dourados, Mato Grosso Do Sul, CEP: 79804970, Brazil
- Division of Infectious Diseases and Geographic Medicine, Stanford University, Stanford, CA, 94304, USA
| | - Simone Simionatto
- Laboratório de Pesquisa Em Ciências da Saúde, Universidade Federal da Grande Dourados-UFGD, Cidade Universitária, Itahum, Km 12, Dourados, Mato Grosso Do Sul, CEP: 79804970, Brazil.
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2
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Serrano I, Verdial C, Tavares L, Oliveira M. The Virtuous Galleria mellonella Model for Scientific Experimentation. Antibiotics (Basel) 2023; 12:antibiotics12030505. [PMID: 36978373 PMCID: PMC10044286 DOI: 10.3390/antibiotics12030505] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2023] [Revised: 02/28/2023] [Accepted: 03/01/2023] [Indexed: 03/06/2023] Open
Abstract
The first research on the insect Galleria mellonella was published 85 years ago, and the larva is now widely used as a model to study infections caused by bacterial and fungal pathogens, for screening new antimicrobials, to study the adjacent immune response in co-infections or in host-pathogen interaction, as well as in a toxicity model. The immune system of the G. mellonella model shows remarkable similarities with mammals. Furthermore, results from G. mellonella correlate positively with mammalian models and with other invertebrate models. Unlike other invertebrate models, G. mellonella can withstand temperatures of 37 °C, and its handling and experimental procedures are simpler. Despite having some disadvantages, G. mellonella is a virtuous in vivo model to be used in preclinical studies, as an intermediate model between in vitro and mammalian in vivo studies, and is a great example on how to apply the bioethics principle of the 3Rs (Replacement, Reduction, and Refinement) in animal experimentation. This review aims to discuss the progress of the G. mellonella model, highlighting the key aspects of its use, including experimental design considerations and the necessity to standardize them. A different score in the “cocoon” category included in the G. mellonella Health Index Scoring System is also proposed.
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Affiliation(s)
- Isa Serrano
- CIISA—Center for Interdisciplinary Research in Animal Health, Faculty of Veterinary Medicine, University of Lisbon, Avenida da Universidade Técnica, 1300-477 Lisboa, Portugal
- Associate Laboratory for Animal and Veterinary Sciences (AL4AnimalS), 1300-477 Lisboa, Portugal
- Correspondence:
| | - Cláudia Verdial
- CIISA—Center for Interdisciplinary Research in Animal Health, Faculty of Veterinary Medicine, University of Lisbon, Avenida da Universidade Técnica, 1300-477 Lisboa, Portugal
- Associate Laboratory for Animal and Veterinary Sciences (AL4AnimalS), 1300-477 Lisboa, Portugal
| | - Luís Tavares
- CIISA—Center for Interdisciplinary Research in Animal Health, Faculty of Veterinary Medicine, University of Lisbon, Avenida da Universidade Técnica, 1300-477 Lisboa, Portugal
- Associate Laboratory for Animal and Veterinary Sciences (AL4AnimalS), 1300-477 Lisboa, Portugal
| | - Manuela Oliveira
- CIISA—Center for Interdisciplinary Research in Animal Health, Faculty of Veterinary Medicine, University of Lisbon, Avenida da Universidade Técnica, 1300-477 Lisboa, Portugal
- Associate Laboratory for Animal and Veterinary Sciences (AL4AnimalS), 1300-477 Lisboa, Portugal
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3
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Le D, Akiyama T, Weiss D, Kim M. Dissociation kinetics of small-molecule inhibitors in Escherichia coli is coupled to physiological state of cells. Commun Biol 2023; 6:223. [PMID: 36841892 PMCID: PMC9968327 DOI: 10.1038/s42003-023-04604-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2022] [Accepted: 02/16/2023] [Indexed: 02/27/2023] Open
Abstract
Bioactive small-molecule inhibitors represent a treasure chest for future drugs. In vitro high-throughput screening is a common approach to identify the small-molecule inhibitors that bind tightly to purified targets. Here, we investigate the inhibitor-target binding/unbinding kinetics in E. coli cells using a benzimidazole-derivative DNA inhibitor as a model system. We find that its unbinding rate is not constant but depends on cell growth rate. This dependence is mediated by the cellular activity, forming a feedback loop with the inhibitor's activity. In accordance with this feedback, we find cell-to-cell heterogeneity in inhibitor-target interaction, leading to co-existence of two distinct subpopulations: actively growing cells that dissociate the inhibitors from the targets and non-growing cells that do not. We find similar heterogeneity for other clinical DNA inhibitors. Our studies reveal a mechanism that couples inhibitor-target kinetics to cell physiology and demonstrate the significant effect of this coupling on drug efficacy.
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Affiliation(s)
- Dai Le
- Department of Physics, Emory University, Atlanta, GA, 30322, USA
- Graduate Division of Biological and Biomedical Sciences, Emory University, Atlanta, GA, 30322, USA
| | - Tatsuya Akiyama
- Department of Physics, Emory University, Atlanta, GA, 30322, USA
- Graduate Division of Biological and Biomedical Sciences, Emory University, Atlanta, GA, 30322, USA
| | - David Weiss
- Graduate Division of Biological and Biomedical Sciences, Emory University, Atlanta, GA, 30322, USA
- Division of Infectious Diseases, Department of Medicine, Emory University, Atlanta, GA, 30322, USA
- Antibiotic Research Center, Emory University, Atlanta, GA, 30322, USA
| | - Minsu Kim
- Department of Physics, Emory University, Atlanta, GA, 30322, USA.
- Graduate Division of Biological and Biomedical Sciences, Emory University, Atlanta, GA, 30322, USA.
- Antibiotic Research Center, Emory University, Atlanta, GA, 30322, USA.
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4
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Disruption of nucleosomes by DNA groove binders of clinical significance and implications for chromatin remodeling. Proc Natl Acad Sci U S A 2023; 120:e2216611120. [PMID: 36574674 PMCID: PMC9910476 DOI: 10.1073/pnas.2216611120] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Small molecules that bind in the minor groove of DNA are in clinical use as antibiotics and antitumor drugs. Two members of this class of molecules, netropsin and chromomycin, are shown here to displace DNA from the nucleosome and promote transfer of the histone octamer to an acceptor protein. The effects of these groove-binding molecules are exploited to address an outstanding problem in the mechanism of the RSC chromatin remodeling complex. RSC and other remodeling complexes are DNA translocases, acting near the center of the nucleosomal DNA, but translocation is apparently impossible because DNA cannot slide across the histone surface in the nucleosome. Netropsin and chromomycin promote the release of DNA from the histone surface, enhance the formation of a RSC-nucleosome complex, and synergize with RSC in chromatin remodeling. These findings are in keeping with an involvement of bulge translocation in chromatin remodeling.
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Synergistic Effects of Capric Acid and Colistin against Colistin-Susceptible and Colistin-Resistant Enterobacterales. Antibiotics (Basel) 2022; 12:antibiotics12010036. [PMID: 36671237 PMCID: PMC9854470 DOI: 10.3390/antibiotics12010036] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2022] [Revised: 12/20/2022] [Accepted: 12/23/2022] [Indexed: 12/29/2022] Open
Abstract
Colistin is a last-line antibiotic against Gram-negative pathogens. However, the emergence of colistin resistance has substantially reduced the clinical effectiveness of colistin. In this study, synergy between colistin and capric acid was examined against twenty-one Gram-negative bacterial isolates (four colistin-susceptible and seventeen colistin-resistant). Checkerboard assays showed a synergistic effect against all colistin-resistant strains [(FICI, fractional inhibitory concentration index) = 0.02-0.38] and two colistin-susceptible strains. Time-kill assays confirmed the combination was synergistic. We suggest that the combination of colistin and capric acid is a promising therapeutic strategy against Gram-negative colistin-resistant strains.
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Kang M, Kim W, Lee J, Jung HS, Jeon CO, Park W. 6-Bromo-2-naphthol from Silene armeria extract sensitizes Acinetobacter baumannii strains to polymyxin. Sci Rep 2022; 12:8546. [PMID: 35595766 PMCID: PMC9123208 DOI: 10.1038/s41598-022-11995-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2022] [Accepted: 05/04/2022] [Indexed: 12/02/2022] Open
Abstract
The overuse of antibiotics has led to the emergence of multidrug-resistant bacteria, which are resistant to various antibiotics. Combination therapies using natural compounds with antibiotics have been found to have synergistic effects against several pathogens. Synergistic natural compounds can potentiate the effects of polymyxins for the treatment of Acinetobacter baumannii infection. Out of 120 types of plant extracts, only Silene armeria extract (SAE) showed a synergistic effect with polymyxin B (PMB) in our fractional inhibitory concentration and time-kill analyses. The survival rate of G. mellonella infected with A. baumannii ATCC 17978 increased following the synergistic treatment. Interestingly, the addition of osmolytes, such as trehalose, canceled the synergistic effect of SAE with PMB; however, the underlying mechanism remains unclear. Quadrupole time-of-flight liquid chromatography-mass spectrometry revealed 6-bromo-2-naphthol (6B2N) to be a major active compound that exhibited synergistic effects with PMB. Pretreatment with 6B2N made A. baumannii cells more susceptible to PMB exposure in a time- and concentration-dependent manner, indicating that 6B2N exhibits consequential synergistic action with PMB. Moreover, the exposure of 6B2N-treated cells to PMB led to higher membrane leakage and permeability. The present findings provide a promising approach for utilizing plant extracts as adjuvants to reduce the toxicity of PMB in A. baumannii infection.
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Affiliation(s)
- Mingyeong Kang
- Laboratory of Molecular Environmental Microbiology, Department of Environmental Science and Ecological Engineering, Korea University, Seoul, 02841, Republic of Korea
| | - Wonjae Kim
- Laboratory of Molecular Environmental Microbiology, Department of Environmental Science and Ecological Engineering, Korea University, Seoul, 02841, Republic of Korea
| | - Jaebok Lee
- Laboratory of Molecular Environmental Microbiology, Department of Environmental Science and Ecological Engineering, Korea University, Seoul, 02841, Republic of Korea
| | - Hye Su Jung
- Department of Life Science, Chung-Ang University, Seoul, 06974, Republic of Korea
| | - Che Ok Jeon
- Department of Life Science, Chung-Ang University, Seoul, 06974, Republic of Korea
| | - Woojun Park
- Laboratory of Molecular Environmental Microbiology, Department of Environmental Science and Ecological Engineering, Korea University, Seoul, 02841, Republic of Korea.
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Tao Y, Duma L, Rossez Y. Galleria mellonella as a Good Model to Study Acinetobacter baumannii Pathogenesis. Pathogens 2021; 10:1483. [PMID: 34832638 PMCID: PMC8623143 DOI: 10.3390/pathogens10111483] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2021] [Revised: 11/08/2021] [Accepted: 11/10/2021] [Indexed: 12/29/2022] Open
Abstract
The invertebrate model, Galleria mellonella, has been widely used to study host-pathogen interactions due to its cheapness, ease of handling, and similar mammalian innate immune system. G. mellonella larvae have been proven to be useful and a reliable model for analyzing pathogenesis mechanisms of multidrug resistant Acinetobacter baumannii, an opportunistic pathogen difficult to kill. This review describes the detailed experimental design of G. mellonella/A. baumannii models, and provides a comprehensive comparison of various virulence factors and therapy strategies using the G. mellonella host. These investigations highlight the importance of this host-pathogen model for in vivo pathogen virulence studies. On the long term, further development of the G. mellonella/A. baumannii model will offer promising insights for clinical treatments of A. baumannii infection.
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Affiliation(s)
- Ye Tao
- Université de Technologie de Compiègne, UPJV, UMR CNRS 7025, Enzyme and Cell Engineering, Centre de Recherche Royallieu–CS 60 319 , 60203 Compiègne, France; (Y.T.); (L.D.)
| | - Luminita Duma
- Université de Technologie de Compiègne, UPJV, UMR CNRS 7025, Enzyme and Cell Engineering, Centre de Recherche Royallieu–CS 60 319 , 60203 Compiègne, France; (Y.T.); (L.D.)
- Université de Reims Champagne-Ardenne, CNRS, ICMR UMR 7312, 51097 Reims, France
| | - Yannick Rossez
- Université Lille, CNRS, UMR 8576-UGSF-Unité de Glycobiologie Structurale et Fonctionnelle, F-59000 Lille, France
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8
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Pereira MF, Rossi CC, da Silva GC, Rosa JN, Bazzolli DMS. Galleria mellonella as an infection model: an in-depth look at why it works and practical considerations for successful application. Pathog Dis 2021; 78:5909969. [PMID: 32960263 DOI: 10.1093/femspd/ftaa056] [Citation(s) in RCA: 41] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2020] [Accepted: 09/18/2020] [Indexed: 12/14/2022] Open
Abstract
The larva of the greater wax moth Galleria mellonella is an increasingly popular model for assessing the virulence of bacterial pathogens and the effectiveness of antimicrobial agents. In this review, we discuss details of the components of the G. mellonella larval immune system that underpin its use as an alternative infection model, and provide an updated overview of the state of the art of research with G. mellonella infection models to study bacterial virulence, and in the evaluation of antimicrobial efficacy. Emphasis is given to virulence studies with relevant human and veterinary pathogens, especially Escherichia coli and bacteria of the ESKAPE group. In addition, we make practical recommendations for larval rearing and testing, and overcoming potential limitations of the use of the model, which facilitate intra- and interlaboratory reproducibility.
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Affiliation(s)
- Monalessa Fábia Pereira
- Laboratório de Bioquímica e Microbiologia, Departamento de Ciências Biológicas, Universidade do Estado de Minas Gerais, 36800-000, Carangola, MG, Brazil
| | - Ciro César Rossi
- Laboratório de Microbiologia Molecular, Departamento de Microbiologia Médica, Instituto de Microbiologia Paulo de Góes, Universidade Federal do Rio de Janeiro, 21941-901, Rio de Janeiro, RJ, Brazil
| | - Giarlã Cunha da Silva
- Laboratório de Genética Molecular de Bactérias, Instituto de Biotecnologia Aplicada à Agropecuária-BIOAGRO, Departamento de Microbiologia, Universidade Federal de Viçosa, 36570-900, Viçosa, MG, Brazil
| | - Jéssica Nogueira Rosa
- Laboratório de Genética Molecular de Bactérias, Instituto de Biotecnologia Aplicada à Agropecuária-BIOAGRO, Departamento de Microbiologia, Universidade Federal de Viçosa, 36570-900, Viçosa, MG, Brazil
| | - Denise Mara Soares Bazzolli
- Laboratório de Genética Molecular de Bactérias, Instituto de Biotecnologia Aplicada à Agropecuária-BIOAGRO, Departamento de Microbiologia, Universidade Federal de Viçosa, 36570-900, Viçosa, MG, Brazil
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Zhou L, Alcalde RE, Deng J, Zuniga B, Sanford RA, Fouke BW, Werth CJ. Impact of antibiotic concentration gradients on nitrate reduction and antibiotic resistance in a microfluidic gradient chamber. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 779:146503. [PMID: 34030234 DOI: 10.1016/j.scitotenv.2021.146503] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/18/2020] [Revised: 03/05/2021] [Accepted: 03/11/2021] [Indexed: 06/12/2023]
Abstract
In order to explore the impact of antibiotics on the bacterial metabolic cycling of nitrate within contaminated soil and groundwater environments, we compared the effects of polymyxin B (PMB) and ciprofloxacin (CIP) concentration gradients on the distribution and activity of a wild type (WT) and a flagella deficient mutant (Δflag) of Shewanella oneidensis MR-1 in a microfluidic gradient chamber (MGC). Complementary batch experiments were performed to measure bacteriostatic versus bactericidal concentrations of the two antibiotics, as well as their effect on nitrate reduction. Prior work demonstrated that PMB disrupts cell membranes while CIP inhibits DNA synthesis. Consistent with these modes of action, batch results from this work show that PMB is bactericidal at lower concentrations than CIP relative to their respective minimum inhibitory concentrations (MICs) (≥5× MICPMB vs. ≥20× MICCIP). Concentration gradients from 0 to 50× the MIC of both antibiotics were established in the MGC across a 2-cm interconnected pore network, with nutrients injected at both concentration boundaries. The WT cells could only access and reduce nitrate in regions of the MGC with PMB at <18× MICPMB, whereas this occurred with CIP up to 50× MICCIP; and cells extracted from these MGCs showed no antibiotic resistance. The distribution of Δflag cells was further limited to lower antibiotic concentrations (≤1× MICPMB, ≤43× MICCIP) due to inability of movement. These results indicate that S. oneidensis access and reduce nitrate in bactericidal regions via chemotactic migration without development of antibiotic resistance, and that this migration is inhibited by acutely lethal bactericidal levels of antibiotics.
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Affiliation(s)
- Lang Zhou
- Department of Civil, Architectural and Environmental Engineering, University of Texas at Austin, Austin, TX 78712, USA
| | - Reinaldo E Alcalde
- Department of Civil, Architectural and Environmental Engineering, University of Texas at Austin, Austin, TX 78712, USA
| | - Jinzi Deng
- Carl R. Woese Institute of Genomic Biology, University of Illinois Urbana-Champaign, Urbana, IL 61801, USA
| | - Baltazar Zuniga
- College of Natural Sciences, University of Texas at Austin, Austin, TX 78712, USA
| | - Robert A Sanford
- Department of Geology, University of Illinois Urbana-Champaign, Urbana, IL 61801, USA
| | - Bruce W Fouke
- Carl R. Woese Institute of Genomic Biology, University of Illinois Urbana-Champaign, Urbana, IL 61801, USA; Department of Geology, University of Illinois Urbana-Champaign, Urbana, IL 61801, USA; Department of Microbiology, University of Illinois Urbana-Champaign, Urbana, IL 61801, USA
| | - Charles J Werth
- Department of Civil, Architectural and Environmental Engineering, University of Texas at Austin, Austin, TX 78712, USA.
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Chung ES, Ko KS. Eradication of persister cells of Acinetobacter baumannii through combination of colistin and amikacin antibiotics. J Antimicrob Chemother 2021; 74:1277-1283. [PMID: 30759206 DOI: 10.1093/jac/dkz034] [Citation(s) in RCA: 32] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2018] [Revised: 01/09/2019] [Accepted: 01/10/2019] [Indexed: 12/12/2022] Open
Abstract
OBJECTIVES Persister cells following antibiotic exposure may cause failure of antibiotic treatment. The synergistic effects of antibiotic combinations with respect to eliminating persister cells were investigated based on their characteristics. METHODS For Acinetobacter baumannii clinical isolates, persister assays were performed using colistin, amikacin, imipenem and ciprofloxacin in various ways, including exposure to antibiotics in combination and sequentially. Persister phenotypes were observed through analysis of ATP concentration, membrane potential and transmission electron microscopy. RESULTS Each A. baumannii isolate showed a specific survival rate of persister cells against each antibiotic. The persister cells were eradicated effectively by exposure to the combination of colistin and amikacin, especially in the sequential order of colistin then amikacin. While the persister cells were not identified after 6 h when exposed to the antibiotics in the order colistin then amikacin, they remained at 0.016% when antibiotic exposure was done in the order amikacin then colistin. Although membrane potential was low in both colistin and amikacin persisters, depletion of the intracellular ATP concentration was only observed in colistin persisters. In addition, transmission electron microscopy analysis showed that colistin persisters have a unique morphology with a rough and rippled membrane and many outer membrane vesicles. Empty pore-like structures surrounded by cracks were also observed. CONCLUSIONS In A. baumannii, the combination of colistin and amikacin was most effective for eradication of persister cells, probably due to different mechanisms of persister cell formation between antibiotics. It was also identified that the sequential order of colistin followed by amikacin was important to eradicate the persister cells.
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Affiliation(s)
- Eun Seon Chung
- Department of Molecular Cell Biology and Samsung Medical Center, Sungkyunkwan University School of Medicine, Suwon, South Korea
| | - Kwan Soo Ko
- Department of Molecular Cell Biology and Samsung Medical Center, Sungkyunkwan University School of Medicine, Suwon, South Korea
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11
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Nikolaev YA, Tutel’yan AV, Loiko NG, Buck J, Sidorenko SV, Lazareva I, Gostev V, Manzen’yuk OY, Shemyakin IG, Abramovich RA, Huwyler J, El’-Registan GI. The use of 4-Hexylresorcinol as antibiotic adjuvant. PLoS One 2020; 15:e0239147. [PMID: 32960928 PMCID: PMC7508414 DOI: 10.1371/journal.pone.0239147] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2020] [Accepted: 08/31/2020] [Indexed: 12/24/2022] Open
Abstract
Ever decreasing efficiency of antibiotic treatment due to growing antibiotic resistance of pathogenic bacteria is a critical issue in clinical practice. The two generally accepted major approaches to this problem are the search for new antibiotics and the development of antibiotic adjuvants to enhance the antimicrobial activity of known compounds. It was therefore the aim of the present study to test whether alkylresorcinols, a class of phenolic lipids, can be used as adjuvants to potentiate the effect of various classes of antibiotics. Alkylresorcinols were combined with 12 clinically used antibiotics. Growth-inhibiting activity against a broad range of pro- and eukaryotic microorganisms was determined. Test organisms did comprise 10 bacterial and 2 fungal collection strains, including E. coli and S. aureus, and clinical isolates of K. pneumoniae. The highest adjuvant activity was observed in the case of 4-hexylresorcinol (4-HR), a natural compound found in plants with antimicrobial activity. 50% of the minimal inhibitory concentration (MIC) of 4-HR caused an up to 50-fold decrease in the MIC of antibiotics of various classes. Application of 4-HR as an adjuvant revealed its efficiency against germination of bacterial dormant forms (spores) and prevented formation of antibiotic-tolerant persister cells. Using an in vivo mouse model of K. pneumoniae-induced sepsis, we could demonstrate that the combination of 4-HR and polymyxin was highly effective. 75% of animals were free of infection after treatment as compared to none of the animals receiving the antibiotic alone. We conclude that alkylresorcinols such as 4-HR can be used as an adjuvant to increase the efficiency of several known antibiotics. We suggest that by this approach the risk for development of genetically determined antibiotic resistance can be minimized due to the multimodal mode of action of 4-HR.
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Affiliation(s)
- Y. A. Nikolaev
- Federal Research Centre “Fundamentals of Biotechnology”, Russian Academy of Sciences, Moscow, Russia
| | - A. V. Tutel’yan
- Central Research Institute of Epidemiology of Russian Federal Service for Surveillance on Consumer Rights Protection and Human Wellbeing (Rospotrebnadzor) and I.M. Sechenov First Moscow State Medical University of the Ministry of Health of the Russian Federation (Sechenov University), Moscow, Russia
| | - N. G. Loiko
- Federal Research Centre “Fundamentals of Biotechnology”, Russian Academy of Sciences, Moscow, Russia
| | - J. Buck
- Department of Pharmaceutical Sciences, University of Basel, Basel, Switzerland
| | - S. V. Sidorenko
- Pediatric Research and Clinical Center for Infectious Diseases, Saint Petersburg, Russia
- I.I. Mechnikov North Western State Medical University, St Petersburg, Russia
| | - I. Lazareva
- Pediatric Research and Clinical Center for Infectious Diseases, Saint Petersburg, Russia
- I.I. Mechnikov North Western State Medical University, St Petersburg, Russia
| | - V. Gostev
- Pediatric Research and Clinical Center for Infectious Diseases, Saint Petersburg, Russia
- I.I. Mechnikov North Western State Medical University, St Petersburg, Russia
| | - O. Y. Manzen’yuk
- State Research Center for Applied Microbiology and Biotechnology of Russian Federal Service for Surveillance on Consumer Rights Protection and Human Welfare (Rospotrebnadzor), Obolensk, Russia
| | - I. G. Shemyakin
- State Research Center for Applied Microbiology and Biotechnology of Russian Federal Service for Surveillance on Consumer Rights Protection and Human Welfare (Rospotrebnadzor), Obolensk, Russia
| | - R. A. Abramovich
- Peoples’ Friendship University of Russia (RUDN University), Moscow, Russia
| | - J. Huwyler
- Department of Pharmaceutical Sciences, University of Basel, Basel, Switzerland
| | - G. I. El’-Registan
- Federal Research Centre “Fundamentals of Biotechnology”, Russian Academy of Sciences, Moscow, Russia
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12
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Yarlagadda V, Medina R, Wright GD. Venturicidin A, A Membrane-active Natural Product Inhibitor of ATP synthase Potentiates Aminoglycoside Antibiotics. Sci Rep 2020; 10:8134. [PMID: 32424122 PMCID: PMC7235042 DOI: 10.1038/s41598-020-64756-0] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2019] [Accepted: 04/16/2020] [Indexed: 12/12/2022] Open
Abstract
Despite the remarkable advances due to the discovery and development of antimicrobials agents, infectious diseases remain the second leading cause of death worldwide. This fact underlines the importance of developing new therapeutic strategies to address the widespread antibiotic resistance, which is the major contributing factor for clinical failures of the current therapeutics. In a screen for antibiotic adjuvants, we identified a natural product from actinomycetes, venturicidin A (VentA), that potentiates the aminoglycoside antibiotic gentamicin against multidrug-resistant clinical isolates of Staphylococcus, Enterococcus, and Pseudomonas aeruginosa. Furthermore, the combination of gentamicin and VentA was bactericidal and rapidly eradicated methicillin-resistant S. aureus (MRSA). The molecular mechanism of gentamicin potentiation activity is attributed to uncoupling of ATP synthesis by VentA from electron transport presumably by blocking the proton flow through ATP synthase, which results in an elevated concentration of extracellular protons and subsequent anticipated raise in gentamicin uptake. The disruption of the proton flux was characterized by perturbed membrane potential in MRSA. These results demonstrate that inhibition of ATP synthase along with the subsequent membrane dysregulation, as shown here with VentA, complements aminoglycoside antibiotics against MDR bacteria, and that this approach may be employed to combat bacterial resistance.
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Affiliation(s)
- Venkateswarlu Yarlagadda
- David Braley Centre for Antibiotic Discovery, M.G. DeGroote Institute for Infectious Disease Research, Department of Biochemistry and Biomedical Sciences, DeGroote School of Medicine, McMaster University, 1280 Main Street West, Hamilton, Ontario, L8S 4K1, Canada
| | - Ricardo Medina
- Department of Microbiology, Central University of Las Villas, Santa Clara, Villa Clara, Cuba
| | - Gerard D Wright
- David Braley Centre for Antibiotic Discovery, M.G. DeGroote Institute for Infectious Disease Research, Department of Biochemistry and Biomedical Sciences, DeGroote School of Medicine, McMaster University, 1280 Main Street West, Hamilton, Ontario, L8S 4K1, Canada.
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13
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Cutuli MA, Petronio Petronio G, Vergalito F, Magnifico I, Pietrangelo L, Venditti N, Di Marco R. Galleria mellonella as a consolidated in vivo model hosts: New developments in antibacterial strategies and novel drug testing. Virulence 2019; 10:527-541. [PMID: 31142220 PMCID: PMC6550544 DOI: 10.1080/21505594.2019.1621649] [Citation(s) in RCA: 102] [Impact Index Per Article: 20.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2019] [Revised: 05/13/2019] [Accepted: 05/14/2019] [Indexed: 12/20/2022] Open
Abstract
A greater ethical conscience, new global rules and a modified perception of ethical consciousness entail a more rigorous control on utilizations of vertebrates for in vivo studies. To cope with this new scenario, numerous alternatives to rodents have been proposed. Among these, the greater wax moth Galleria mellonella had a preponderant role, especially in the microbiological field, as demonstrated by the growing number of recent scientific publications. The reasons for its success must be sought in its peculiar characteristics such as the innate immune response mechanisms and the ability to grow at a temperature of 37°C. This review aims to describe the most relevant features of G. mellonella in microbiology, highlighting the most recent and relevant research on antibacterial strategies, novel drug tests and toxicological studies. Although solutions for some limitations are required, G. mellonella has all the necessary host features to be a consolidated in vivo model host.
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Affiliation(s)
- Marco Alfio Cutuli
- Department of Medicine and Health Sciences “Vincenzo Tiberio”, Università degli Studi del Molise Italy - III Ed Polifunzionale, Campobasso, Italy
| | - Giulio Petronio Petronio
- Department of Medicine and Health Sciences “Vincenzo Tiberio”, Università degli Studi del Molise Italy - III Ed Polifunzionale, Campobasso, Italy
| | - Franca Vergalito
- Department of Medicine and Health Sciences “Vincenzo Tiberio”, Università degli Studi del Molise Italy - III Ed Polifunzionale, Campobasso, Italy
| | - Irene Magnifico
- Department of Medicine and Health Sciences “Vincenzo Tiberio”, Università degli Studi del Molise Italy - III Ed Polifunzionale, Campobasso, Italy
| | - Laura Pietrangelo
- Department of Medicine and Health Sciences “Vincenzo Tiberio”, Università degli Studi del Molise Italy - III Ed Polifunzionale, Campobasso, Italy
| | - Noemi Venditti
- Department of Medicine and Health Sciences “Vincenzo Tiberio”, Università degli Studi del Molise Italy - III Ed Polifunzionale, Campobasso, Italy
| | - Roberto Di Marco
- Department of Medicine and Health Sciences “Vincenzo Tiberio”, Università degli Studi del Molise Italy - III Ed Polifunzionale, Campobasso, Italy
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14
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Li Z, Cao Y, Yi L, Liu JH, Yang Q. Emergent Polymyxin Resistance: End of an Era? Open Forum Infect Dis 2019; 6:5550895. [PMID: 31420655 PMCID: PMC6767968 DOI: 10.1093/ofid/ofz368] [Citation(s) in RCA: 53] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2019] [Indexed: 12/03/2022] Open
Abstract
Until recently, the polymyxin antibiotics were used sparingly due to dose limiting toxicities. However, the lack of therapeutic alternatives for infections caused by highly resistant Gram-negative bacteria has led to the increased use of the polymyxins. Unfortunately, the world has witnessed increased rates of polymyxin resistance in the last decade, which is likely in part due to its irrational use in human and veterinary medicine. The spread of polymyxin resistance has been aided by the dissemination of the transferable polymyxin-resistance gene, mcr, in humans and the environment. The mortality of colistin-resistant bacteria (CoRB) infections varies in different reports. However, poor clinical outcome was associated with prior colistin treatment, illness severity, complications, and multidrug resistance. Detection of polymyxin resistance in the clinic is possible through multiple robust and practical tests, including broth microdilution susceptibility testing, chromogenic agar testing, and molecular biology assays. There are multiple risk factors that increase a person’s risk for infection with a polymyxin-resistant bacteria, including age, prior colistin treatment, hospitalization, and ventilator support. For patients that are determined to be infected by polymyxin-resistant bacteria, various antibiotic treatment options currently exist. The rising trend of polymyxin resistance threatens patient care and warrants effective control.
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Affiliation(s)
- Zekun Li
- Department of Clinical Laboratory, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, China.,Beijing Key Laboratory for Mechanisms Research and Precision Diagnosis of Invasive Fungal Diseases, Beijing, China.,Department of Laboratory Medicine, Xiangya School of Medicine, Central South University, Changsha, China
| | - Yuping Cao
- College of Veterinary Medicine, South China Agricultural University, Guangzhou, China
| | - Lingxian Yi
- College of Veterinary Medicine, South China Agricultural University, Guangzhou, China
| | - Jian-Hua Liu
- College of Veterinary Medicine, South China Agricultural University, Guangzhou, China
| | - Qiwen Yang
- Department of Clinical Laboratory, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, China.,Beijing Key Laboratory for Mechanisms Research and Precision Diagnosis of Invasive Fungal Diseases, Beijing, China
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15
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Mao T, Zhai H, Duan G, Yang H. Patterns of Drug-Resistant Bacteria in a General Hospital, China, 2011-2016. Pol J Microbiol 2019; 68:225-232. [PMID: 31250593 PMCID: PMC7256857 DOI: 10.33073/pjm-2019-024] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2018] [Revised: 02/19/2019] [Accepted: 03/06/2019] [Indexed: 12/23/2022] Open
Abstract
Drug-resistant bacteria has been a threat to public life and property. We described the trends and changes in antibiotic resistance of important pathogens in a general hospital in Zhengzhou, China from 2011 to 2016, to control antimicrobial-resistant bacteria in hospital and provide support to clinicians and decision-making departments. Five dominant bacteria were enrolled based on the data from the general hospital during 6 years. The results of antimicrobial susceptibility testing were interpreted according to Clinical and Laboratory Standards Institute (CLSI). From 2011 to 2016, a total of 19,260 strains of bacteria were isolated, of which Klebsiella pneumoniae, Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa and Acinetobacter baumannii accounted for 51.98%. The resistance rate of K. pneumoniae and E. coli to carbapenem was less than 15%, but resistance of K. pneumoniae to carbapenems increased with time and resistance of E. coli to meropenem increased. The rate of extended-spectrum beta-lactamase (ESBL) production among K. pneumoniae and E. coli was decreasing. For most antibiotics, the resistance rate of ESBL-positive isolates was higher than that of ESBL-negative isolates, excluding carbapenems and cefoxitin. For S. aureus, the rate of methicillin-resistant S. aureus (MRSA) was stable. Resistance of S. aureus to mostly antibiotics decreased with time. Besides polymyxin B, P. aeruginosa and A. baumannii showed high resistance to other antibiotics. For A. baumannii, the resistance rate to mostly antibiotics was increasing. The bacteria showed high levels of resistance and multiple drug resistance. Continuous surveillance and optimizing the use of antibiotics are essential. Drug-resistant bacteria has been a threat to public life and property. We described the trends and changes in antibiotic resistance of important pathogens in a general hospital in Zhengzhou, China from 2011 to 2016, to control antimicrobial-resistant bacteria in hospital and provide support to clinicians and decision-making departments. Five dominant bacteria were enrolled based on the data from the general hospital during 6 years. The results of antimicrobial susceptibility testing were interpreted according to Clinical and Laboratory Standards Institute (CLSI). From 2011 to 2016, a total of 19,260 strains of bacteria were isolated, of which Klebsiella pneumoniae, Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa and Acinetobacter baumannii accounted for 51.98%. The resistance rate of K. pneumoniae and E. coli to carbapenem was less than 15%, but resistance of K. pneumoniae to carbapenems increased with time and resistance of E. coli to meropenem increased. The rate of extended-spectrum beta-lactamase (ESBL) production among K. pneumoniae and E. coli was decreasing. For most antibiotics, the resistance rate of ESBL-positive isolates was higher than that of ESBL-negative isolates, excluding carbapenems and cefoxitin. For S. aureus, the rate of methicillin-resistant S. aureus (MRSA) was stable. Resistance of S. aureus to mostly antibiotics decreased with time. Besides polymyxin B, P. aeruginosa and A. baumannii showed high resistance to other antibiotics. For A. baumannii, the resistance rate to mostly antibiotics was increasing. The bacteria showed high levels of resistance and multiple drug resistance. Continuous surveillance and optimizing the use of antibiotics are essential.
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Affiliation(s)
- Tingting Mao
- Department of Epidemiology, College of Public Health of Zhengzhou University , Zhengzhou, Henan , China
| | - Huijuan Zhai
- Department of Epidemiology, College of Public Health of Zhengzhou University , Zhengzhou, Henan , China
| | - Guangcai Duan
- Department of Epidemiology, College of Public Health of Zhengzhou University , Zhengzhou, Henan , China
| | - Haiyan Yang
- Department of Epidemiology, College of Public Health of Zhengzhou University , Zhengzhou, Henan , China
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Efficacy of netropsin dihydrochloride against the viability, cytopathogenicity and hemolytic activity of Trichomonas vaginalis clinical isolates. J Infect Chemother 2019; 25:955-964. [PMID: 31189504 DOI: 10.1016/j.jiac.2019.05.015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2019] [Revised: 04/12/2019] [Accepted: 05/16/2019] [Indexed: 11/22/2022]
Abstract
Trichomonas vaginalis (T. vaginalis) is a common sexually transmitted infection, affecting the urogenital tract. Trichomoniasis is customarily treated with metronidazole (MTZ). MTZ is known to cause undesirable side effects and there is several reports on MTZ resistant T. vaginalis. Thus, the present study aimed to in-vitro evaluate the activity of DNA minor groove binder drug ''Netropsin dihydrochloride'' against metronidazole-sensitive T. vaginalis isolates (G and U isolates) and resistant T. vaginalis isolate (ATCC50138) (R isolate). Netropsin was tested at concentrations ranging from 3.5 to 200 μg/ml. It showed effectiveness against all isolates with MLC of 12.5 μg/ml for G and U isolates and of 25 μg/ml for R isolate. Cytotoxicity assay of isolates exposed to the respective MLC of netropsin for 42 h showed a highly significant reduction in the death percentage of MCDK cell line as compared to the effect elicited by drug free controls. The hemolytic activity was evaluated by hemolytic assay and by monitoring the interaction of T. vaginalis isolates with human erythrocytes by inverted microscopy and scanning electron microscopy. The hemolytic assay showed (0%) hemolysis of RBCs incubated with T. vaginalis isolates treated with the corresponding MLC of netropsin for 24 h. Scanning electron microscopy revealed cytoskeletal deformities of netropsin treated isolates. Taken together, these observations suggest that netropsin is a promising therapy for T. vaginalis infection affecting its viability, virulence, cytopathogenic and hemolytic activity with a mechanism of action that might overcome T. vaginalis resistance to metronidazole.
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Jeong H, Choi SK, Ryu CM, Park SH. Chronicle of a Soil Bacterium: Paenibacillus polymyxa E681 as a Tiny Guardian of Plant and Human Health. Front Microbiol 2019; 10:467. [PMID: 30930873 PMCID: PMC6429003 DOI: 10.3389/fmicb.2019.00467] [Citation(s) in RCA: 53] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2018] [Accepted: 02/21/2019] [Indexed: 01/25/2023] Open
Abstract
The Gram-positive rhizosphere bacterium Paenibacillus polymyxa promotes plant growth and produces various antibiotics. Herein, we review research on this species over the past two and a half decades, and focus on the mechanisms of P. polymyxa strain E681, isolated from barley roots in the South Korea in 1995. Strain E681 has outstanding growth-promoting effects on barley, cucumber, pepper, sesame, and Arabidopsis thaliana and produces antimicrobial compounds that protect plants against pathogenic fungi, oomycetes, and bacteria. Induced systemic resistance elicited by treating seeds or roots with strain E681 is a possible mechanism for protecting systemic plant tissues from biotic and other environmental stresses. Genome sequencing has broadened our horizons for antibiotic development and other industrial applications beyond agricultural use. At least six gene clusters for the biosynthesis of antibiotics have been discovered, including polymyxin (pmx), which was recently re-instated as an antibiotic of last resort against Gram-negative drug-resistant bacteria. Three groups of antibiotic synthetases include the gene clusters that encode one for the non-ribosomal peptide polymyxin, fusaricidin, and tridecaptin, another for the lantibiotic paenilan, and the third for a polyketide. We successfully introduced the pmx gene cluster into the surrogate host Bacillus subtilis and created polymyxin derivatives by domain swapping. Furthermore, various E681 derivatives, including a high fusaricidin producer and strains lacking multi-antibiotics production, have been constructed by random mutagenesis and genome engineering. Thus, E681 is an important bacterium that contributes to both plant and human health.
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Affiliation(s)
- Haeyoung Jeong
- Infectious Disease Research Center, KRIBB, Daejeon, South Korea
- Department of Biosystems and Bioengineering, KRIBB School of Biotechnology, Korea University of Science and Technology, Daejeon, South Korea
| | - Soo-Keun Choi
- Infectious Disease Research Center, KRIBB, Daejeon, South Korea
- Department of Biosystems and Bioengineering, KRIBB School of Biotechnology, Korea University of Science and Technology, Daejeon, South Korea
| | - Choong-Min Ryu
- Infectious Disease Research Center, KRIBB, Daejeon, South Korea
- Department of Biosystems and Bioengineering, KRIBB School of Biotechnology, Korea University of Science and Technology, Daejeon, South Korea
| | - Seung-Hwan Park
- Infectious Disease Research Center, KRIBB, Daejeon, South Korea
- Department of Biosystems and Bioengineering, KRIBB School of Biotechnology, Korea University of Science and Technology, Daejeon, South Korea
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18
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Zurawski DV, Black CC, Alamneh YA, Biggemann L, Banerjee J, Thompson MG, Wise MC, Honnold CL, Kim RK, Paranavitana C, Shearer JP, Tyner SD, Demons ST. A Porcine Wound Model of Acinetobacter baumannii Infection. Adv Wound Care (New Rochelle) 2019; 8:14-27. [PMID: 30705786 PMCID: PMC6350066 DOI: 10.1089/wound.2018.0786] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2018] [Accepted: 06/24/2018] [Indexed: 01/25/2023] Open
Abstract
Objective: To better understand Acinetobacter baumannii pathogenesis and to advance drug discovery against this pathogen, we developed a porcine, full-thickness, excisional, monospecies infection wound model. Approach: The research was facilitated with AB5075, a previously characterized, extensively drug-resistant A. baumannii isolate. The model requires cyclophosphamide-induced neutropenia to establish a skin and soft tissue infection (SSTI) that persists beyond 7 days. Multiple, 12-mm-diameter full-thickness wounds were created in the skin overlying the cervical and thoracic dorsum. Wound beds were inoculated with 5.0 × 104 colony-forming units (CFU) and covered with dressing. Results:A. baumannii was observed in the wound bed and on the dressing in what appeared to be biofilm. When bacterial burdens were measured, proliferation to at least 106 CFU/g (log106) wound tissue was observed. Infection was further characterized by scanning electron microscopy (SEM) and peptide nucleic acid fluorescence in situ hybridization (PNA-FISH) staining. To validate as a treatment model, polymyxin B was applied topically to a subset of infected wounds every 2 days. Then, the treated and untreated wounds were compared using multiple quantitative and qualitative techniques to include gross pathology, CFU burden, histopathology, PNA-FISH, and SEM. Innovation: This is the first study to use A. baumannii in a porcine model as the sole infectious agent. Conclusion: The porcine model allows for an additional preclinical assessment of antibacterial candidates that show promise against A. baumannii in rodent models, further evaluating safety and efficacy, and serve as a large animal in preclinical assessment for the treatment of SSTI.
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Affiliation(s)
- Daniel V. Zurawski
- Wound Infections Department, Bacterial Diseases Branch, Walter Reed Army Institute of Research, Silver Spring, Maryland
| | - Chad C. Black
- Experimental Therapeutics Branch, Walter Reed Army Institute of Research, Silver Spring, Maryland
| | - Yonas A. Alamneh
- Wound Infections Department, Bacterial Diseases Branch, Walter Reed Army Institute of Research, Silver Spring, Maryland
| | - Lionel Biggemann
- Wound Infections Department, Bacterial Diseases Branch, Walter Reed Army Institute of Research, Silver Spring, Maryland
| | - Jaideep Banerjee
- Wound Infections Department, Bacterial Diseases Branch, Walter Reed Army Institute of Research, Silver Spring, Maryland
| | - Mitchell G. Thompson
- Wound Infections Department, Bacterial Diseases Branch, Walter Reed Army Institute of Research, Silver Spring, Maryland
| | - Matthew C. Wise
- Veterinary Services Program, Department of Pathology, Walter Reed Army Institute of Research, Silver Spring, Maryland
| | - Cary L. Honnold
- Veterinary Services Program, Department of Pathology, Walter Reed Army Institute of Research, Silver Spring, Maryland
| | - Robert K. Kim
- Wound Infections Department, Bacterial Diseases Branch, Walter Reed Army Institute of Research, Silver Spring, Maryland
| | - Chrysanthi Paranavitana
- Wound Infections Department, Bacterial Diseases Branch, Walter Reed Army Institute of Research, Silver Spring, Maryland
| | - Jonathan P. Shearer
- Wound Infections Department, Bacterial Diseases Branch, Walter Reed Army Institute of Research, Silver Spring, Maryland
| | - Stuart D. Tyner
- Wound Infections Department, Bacterial Diseases Branch, Walter Reed Army Institute of Research, Silver Spring, Maryland
| | - Samandra T. Demons
- Wound Infections Department, Bacterial Diseases Branch, Walter Reed Army Institute of Research, Silver Spring, Maryland
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Chemotherapeutic efficacies of a clofazimine and diminazene aceturate combination against piroplasm parasites and their AT-rich DNA-binding activity on Babesia bovis. Sci Rep 2017; 7:13888. [PMID: 29066849 PMCID: PMC5654833 DOI: 10.1038/s41598-017-14304-0] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2017] [Accepted: 10/09/2017] [Indexed: 01/31/2023] Open
Abstract
Recently, we reported that clofazimine (CF) has an anti-piroplasm activity, but it could not completely eliminate parasites in the host. The currently available anti-piroplasm drug, diminazene aceturate (DA), has sometimes been reported to have toxic side effects. In the present study, we evaluated the combination treatment with CF and DA against piroplasms both in vitro and in vivo. Additionally, mRNA level and DNA amounts were analyzed in CF‒ and DA‒treated Babesia bovis by a qPCR. The CF-DA combination had additive effects on Babesia bovis, B. bigemina, and B. caballi and synergistic effects on Theileria equi. The CF-DA combination chemotherapies against B. microti in mice were more potent than their monotherapies. In the CF‒ and DA‒treated B. bovis, CF dose-dependently down-regulated mRNA level and DNA amounts of extranuclear genes (AT-rich featured), whereas DA down-regulated only DNA amounts of extranuclear genes, but those of nuclear genes were slightly down- or up-regulated by CF and DA. In conclusion, the CF-DA combination has a higher efficiency against piroplasms than CF or DA monotherapies. CF and DA might have an AT-rich DNA-binding activity. All results suggest that the CF-DA combination chemotherapy will be a better choice to treat piroplasmosis instead of DA monotherapy.
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Emergence and clonal spread of colistin resistance due to multiple mutational mechanisms in carbapenemase-producing Klebsiella pneumoniae in London. Sci Rep 2017; 7:12711. [PMID: 28983088 PMCID: PMC5629223 DOI: 10.1038/s41598-017-12637-4] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2017] [Accepted: 09/13/2017] [Indexed: 11/09/2022] Open
Abstract
Carbapenemase-producing Enterobacteriaceae (CPE) are emerging worldwide, limiting therapeutic options. Mutational and plasmid-mediated mechanisms of colistin resistance have both been reported. The emergence and clonal spread of colistin resistance was analysed in 40 epidemiologically-related NDM-1 carbapenemase producing Klebsiella pneumoniae isolates identified during an outbreak in a group of London hospitals. Isolates from July 2014 to October 2015 were tested for colistin susceptibility using agar dilution, and characterised by whole genome sequencing (WGS). Colistin resistance was detected in 25/38 (65.8%) cases for which colistin susceptibility was tested. WGS found that three potential mechanisms of colistin resistance had emerged separately, two due to different mutations in mgrB, and one due to a mutation in phoQ, with onward transmission of two distinct colistin-resistant variants, resulting in two sub-clones associated with transmission at separate hospitals. A high rate of colistin resistance (66%) emerged over a 10 month period. WGS demonstrated that mutational colistin resistance emerged three times during the outbreak, with transmission of two colistin-resistant variants.
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Epigenetic Mechanisms Regulate Innate Immunity against Uropathogenic and Commensal-Like Escherichia coli in the Surrogate Insect Model Galleria mellonella. Infect Immun 2017; 85:IAI.00336-17. [PMID: 28739824 DOI: 10.1128/iai.00336-17] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2017] [Accepted: 07/12/2017] [Indexed: 11/20/2022] Open
Abstract
Innate-immunity-related genes in humans are activated during urinary tract infections (UTIs) caused by pathogenic strains of Escherichia coli but are suppressed by commensals. Epigenetic mechanisms play a pivotal role in the regulation of gene expression in response to environmental stimuli. To determine whether epigenetic mechanisms can explain the different behaviors of pathogenic and commensal bacteria, we infected larvae of the greater wax moth, Galleria mellonella, a widely used model insect host, with a uropathogenic E. coli (UPEC) strain that causes symptomatic UTIs in humans or a commensal-like strain that causes asymptomatic bacteriuria (ABU). Infection with the UPEC strain (CFT073) was more lethal to larvae than infection with the attenuated ABU strain (83972) due to the recognition of each strain by different Toll-like receptors, ultimately leading to differential DNA/RNA methylation and histone acetylation. We used next-generation sequencing and reverse transcription (RT)-PCR to correlate epigenetic changes with the induction of innate-immunity-related genes. Transcriptomic analysis of G. mellonella larvae infected with E. coli strains CFT073 and 83972 revealed strain-specific variations in the class and expression levels of genes encoding antimicrobial peptides, cytokines, and enzymes controlling DNA methylation and histone acetylation. Our results provide evidence for the differential epigenetic regulation of transcriptional reprogramming by UPEC and ABU strains of E. coli in G. mellonella larvae, which may be relevant to understanding the different behaviors of these bacterial strains in the human urinary tract.
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22
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Lee CR, Lee JH, Park M, Park KS, Bae IK, Kim YB, Cha CJ, Jeong BC, Lee SH. Biology of Acinetobacter baumannii: Pathogenesis, Antibiotic Resistance Mechanisms, and Prospective Treatment Options. Front Cell Infect Microbiol 2017; 7:55. [PMID: 28348979 PMCID: PMC5346588 DOI: 10.3389/fcimb.2017.00055] [Citation(s) in RCA: 487] [Impact Index Per Article: 69.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2016] [Accepted: 02/13/2017] [Indexed: 12/27/2022] Open
Abstract
Acinetobacter baumannii is undoubtedly one of the most successful pathogens responsible for hospital-acquired nosocomial infections in the modern healthcare system. Due to the prevalence of infections and outbreaks caused by multi-drug resistant A. baumannii, few antibiotics are effective for treating infections caused by this pathogen. To overcome this problem, knowledge of the pathogenesis and antibiotic resistance mechanisms of A. baumannii is important. In this review, we summarize current studies on the virulence factors that contribute to A. baumannii pathogenesis, including porins, capsular polysaccharides, lipopolysaccharides, phospholipases, outer membrane vesicles, metal acquisition systems, and protein secretion systems. Mechanisms of antibiotic resistance of this organism, including acquirement of β-lactamases, up-regulation of multidrug efflux pumps, modification of aminoglycosides, permeability defects, and alteration of target sites, are also discussed. Lastly, novel prospective treatment options for infections caused by multi-drug resistant A. baumannii are summarized.
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Affiliation(s)
- Chang-Ro Lee
- National Leading Research Laboratory of Drug Resistance Proteomics, Department of Biological Sciences, Myongji University Yongin, South Korea
| | - Jung Hun Lee
- National Leading Research Laboratory of Drug Resistance Proteomics, Department of Biological Sciences, Myongji University Yongin, South Korea
| | - Moonhee Park
- National Leading Research Laboratory of Drug Resistance Proteomics, Department of Biological Sciences, Myongji UniversityYongin, South Korea; DNA Analysis Division, Seoul Institute, National Forensic ServiceSeoul, South Korea
| | - Kwang Seung Park
- National Leading Research Laboratory of Drug Resistance Proteomics, Department of Biological Sciences, Myongji University Yongin, South Korea
| | - Il Kwon Bae
- Department of Dental Hygiene, College of Health and Welfare, Silla University Busan, South Korea
| | - Young Bae Kim
- Biotechnology Program, North Shore Community College Danvers, MA, USA
| | - Chang-Jun Cha
- Department of Systems Biotechnology, College of Biotechnology and Natural Resources, Chung-Ang University Anseong, South Korea
| | - Byeong Chul Jeong
- National Leading Research Laboratory of Drug Resistance Proteomics, Department of Biological Sciences, Myongji University Yongin, South Korea
| | - Sang Hee Lee
- National Leading Research Laboratory of Drug Resistance Proteomics, Department of Biological Sciences, Myongji University Yongin, South Korea
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Kong HG, Kim BK, Song GC, Lee S, Ryu CM. Aboveground Whitefly Infestation-Mediated Reshaping of the Root Microbiota. Front Microbiol 2016; 7:1314. [PMID: 27656163 PMCID: PMC5013075 DOI: 10.3389/fmicb.2016.01314] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2016] [Accepted: 08/09/2016] [Indexed: 11/13/2022] Open
Abstract
Plants respond to various types of herbivore and pathogen attack using well-developed defensive machinery designed for self-protection. Infestation from phloem-sucking insects such as whitefly and aphid on plant leaves was previously shown to influence both the saprophytic and pathogenic bacterial community in the plant rhizosphere. However, the modulation of the root microbial community by plants following insect infestation has been largely unexplored. Only limited studies of culture-dependent bacterial diversity caused by whitefly and aphid have been conducted. In this study, to obtain a complete picture of the belowground microbiome community, we performed high-speed and high-throughput next-generation sequencing. We sampled the rhizosphere soils of pepper seedlings at 0, 1, and 2 weeks after whitefly infestation versus the water control. We amplified a partial 16S ribosomal RNA gene (V1-V3 region) by polymerase chain reaction with specific primers. Our analysis revealed that whitefly infestation reshaped the overall microbiota structure compared to that of the control rhizosphere, even after 1 week of infestation. Examination of the relative abundance distributions of microbes demonstrated that whitefly infestation shifted the proteobacterial groups at week 2. Intriguingly, the population of Pseudomonadales of the class Gammaproteobacteria significantly increased after 2 weeks of whitefly infestation, and the fluorescent Pseudomonas spp. recruited to the rhizosphere were confirmed to exhibit insect-killing capacity. Additionally, three taxa, including Caulobacteraceae, Enterobacteriaceae, and Flavobacteriaceae, and three genera, including Achromobacter, Janthinobacterium, and Stenotrophomonas, were the most abundant bacterial groups in the whitefly infested plant rhizosphere. Our results indicate that whitefly infestation leads to the recruitment of specific groups of rhizosphere bacteria by the plant, which confer beneficial traits to the host plant. This study provides a new framework for investigating how aboveground insect feeding modulates the belowground microbiome.
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Affiliation(s)
- Hyun G. Kong
- Molecular Phytobacteriology Laboratory, Super-Bacteria Research Center, Korea Research Institute of Bioscience and BiotechnologyDaejeon, South Korea
| | | | - Geun C. Song
- Molecular Phytobacteriology Laboratory, Super-Bacteria Research Center, Korea Research Institute of Bioscience and BiotechnologyDaejeon, South Korea
| | - Soohyun Lee
- Molecular Phytobacteriology Laboratory, Super-Bacteria Research Center, Korea Research Institute of Bioscience and BiotechnologyDaejeon, South Korea
| | - Choong-Min Ryu
- Molecular Phytobacteriology Laboratory, Super-Bacteria Research Center, Korea Research Institute of Bioscience and BiotechnologyDaejeon, South Korea
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