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Pereira AJ, Xing H, de Campos LJ, Seleem MA, de Oliveira KMP, Obaro SK, Conda-Sheridan M. Structure-Activity Relationship Study to Develop Peptide Amphiphiles as Species-Specific Antimicrobials. Chemistry 2024; 30:e202303986. [PMID: 38221408 PMCID: PMC10939825 DOI: 10.1002/chem.202303986] [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: 11/29/2023] [Revised: 01/05/2024] [Accepted: 01/09/2024] [Indexed: 01/16/2024]
Abstract
Antimicrobial peptide amphiphiles (PAs) are a promising class of molecules that can disrupt the bacterial membrane or act as drug nanocarriers. In this study, we prepared 33 PAs to establish supramolecular structure-activity relationships. We studied the morphology and activity of the nanostructures against different Gram-positive and Gram-negative bacterial strains (such as Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa and Acinetobacter baumannii). Next, we used principal component analysis (PCA) to determine the key contributors to activity. We found that for S. aureus, the zeta potential was the major contributor to the activity while Gram-negative bacteria were more influenced by the partition coefficient (LogP) with the following order P. aeruginosa>E. coli>A. baumannii. We also performed a study of the mechanism of action of selected PAs on the bacterial membrane assessing the membrane permeability and depolarization, changes in zeta potential and overall integrity. We studied the toxicity of the nanostructures against mammalian cells. Finally, we performed an in vivo study using the wax moth larvae to determine the therapeutic efficacy of the active PAs. This study shows cationic PA nanostructures can be an intriguing platform for the development of nanoantibacterials.
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Affiliation(s)
- Aramis J. Pereira
- A. J. Pereira, Dr. H. Xing, L. J. de Campos, Prof. Dr. M. Conda-Sheridan, Department of Pharmaceutical Sciences, University of Nebraska Medical Center (UNMC), Omaha, NE 68198 (USA)
| | - Huihua Xing
- A. J. Pereira, Dr. H. Xing, L. J. de Campos, Prof. Dr. M. Conda-Sheridan, Department of Pharmaceutical Sciences, University of Nebraska Medical Center (UNMC), Omaha, NE 68198 (USA)
| | - Luana J. de Campos
- A. J. Pereira, Dr. H. Xing, L. J. de Campos, Prof. Dr. M. Conda-Sheridan, Department of Pharmaceutical Sciences, University of Nebraska Medical Center (UNMC), Omaha, NE 68198 (USA)
| | - Mohamed A. Seleem
- Dr. M.A. Seleem, Department of Pharmaceutical Organic Chemistry, Al-Azhar University, Cairo, 4434003 (Egypt)
| | - Kelly M. P. de Oliveira
- Prof. Dr. K. M. P. de Oliveira, Department of Biological and Environmental Science, Federal University of Grande Dourados (UFGD), Dourados, MS 79804-970 (Brazil)
| | - Stephen K. Obaro
- Prof. Dr. S. K. Obaro, Division of Pediatric Infectious Diseases, University of Alabama at Birmingham (UAB), Birmingham, AL 35233 (USA), International Foundation against Infectious Diseases in Nigeria (IFAIN), Abuja, 900108 (Nigeria)
| | - Martin Conda-Sheridan
- A. J. Pereira, Dr. H. Xing, L. J. de Campos, Prof. Dr. M. Conda-Sheridan, Department of Pharmaceutical Sciences, University of Nebraska Medical Center (UNMC), Omaha, NE 68198 (USA)
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Inclán M, Torres Hernández N, Martínez Serra A, Torrijos Jabón G, Blasco S, Andreu C, del Olmo ML, Jávega B, O’Connor JE, García-España E. Antimicrobial Properties of New Polyamines Conjugated with Oxygen-Containing Aromatic Functional Groups. Molecules 2023; 28:7678. [PMID: 38005400 PMCID: PMC10675077 DOI: 10.3390/molecules28227678] [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: 10/10/2023] [Revised: 11/09/2023] [Accepted: 11/16/2023] [Indexed: 11/26/2023] Open
Abstract
Antibiotic resistance is now a first-order health problem, which makes the development of new families of antimicrobials imperative. These compounds should ideally be inexpensive, readily available, highly active, and non-toxic. Here, we present the results of our investigation regarding the antimicrobial activity of a series of natural and synthetic polyamines with different architectures (linear, tripodal, and macrocyclic) and their derivatives with the oxygen-containing aromatic functional groups 1,3-benzodioxol, ortho/para phenol, or 2,3-dihydrobenzofuran. The new compounds were prepared through an inexpensive process, and their activity was tested against selected strains of yeast, as well as Gram-positive and Gram-negative bacteria. In all cases, the conjugated derivatives showed antimicrobial activity higher than the unsubstituted polyamines. Several factors, such as the overall charge at physiological pH, lipophilicity, and the topology of the polyamine scaffold were relevant to their activity. The nature of the lipophilic moiety was also a determinant of human cell toxicity. The lead compounds were found to be bactericidal and fungistatic, and they were synergic with the commercial antifungals fluconazole, cycloheximide, and amphotericin B against the yeast strains tested.
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Affiliation(s)
- Mario Inclán
- Institute of Molecular Science, University of Valencia, 46980 Valencia, Spain; (N.T.H.); (A.M.S.); (S.B.); (E.G.-E.)
- Escuela Superior de Ingeniería, Ciencia y Tecnología, International University of Valencia—VIU, 46002 Valencia, Spain
| | - Neus Torres Hernández
- Institute of Molecular Science, University of Valencia, 46980 Valencia, Spain; (N.T.H.); (A.M.S.); (S.B.); (E.G.-E.)
| | - Alejandro Martínez Serra
- Institute of Molecular Science, University of Valencia, 46980 Valencia, Spain; (N.T.H.); (A.M.S.); (S.B.); (E.G.-E.)
| | - Gonzalo Torrijos Jabón
- Departament de Bioquímica i Biologia Molecular, Facultat de Biologia, University of Valencia, 46100 Valencia, Spain; (G.T.J.); (M.l.d.O.)
| | - Salvador Blasco
- Institute of Molecular Science, University of Valencia, 46980 Valencia, Spain; (N.T.H.); (A.M.S.); (S.B.); (E.G.-E.)
| | - Cecilia Andreu
- Departament de Química Orgànica, Facultat de Farmàcia, University of Valencia, 46100 Valencia, Spain
| | - Marcel lí del Olmo
- Departament de Bioquímica i Biologia Molecular, Facultat de Biologia, University of Valencia, 46100 Valencia, Spain; (G.T.J.); (M.l.d.O.)
| | - Beatriz Jávega
- Laboratory of Cytomics, Joint Research Unit CIPF-UVEG, Department of Biochemistry and Molecular Biology, Faculty of Medicine, University of Valencia, 46010 Valencia, Spain; (B.J.); (J.-E.O.)
| | - José-Enrique O’Connor
- Laboratory of Cytomics, Joint Research Unit CIPF-UVEG, Department of Biochemistry and Molecular Biology, Faculty of Medicine, University of Valencia, 46010 Valencia, Spain; (B.J.); (J.-E.O.)
| | - Enrique García-España
- Institute of Molecular Science, University of Valencia, 46980 Valencia, Spain; (N.T.H.); (A.M.S.); (S.B.); (E.G.-E.)
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3
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Chen D, Cadelis MM, Rouvier F, Troia T, Edmeades LR, Fraser K, Gill ES, Bourguet-Kondracki ML, Brunel JM, Copp BR. α,ω-Diacyl-Substituted Analogues of Natural and Unnatural Polyamines: Identification of Potent Bactericides That Selectively Target Bacterial Membranes. Int J Mol Sci 2023; 24:5882. [PMID: 36982955 PMCID: PMC10052977 DOI: 10.3390/ijms24065882] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2023] [Revised: 03/14/2023] [Accepted: 03/19/2023] [Indexed: 03/30/2023] Open
Abstract
In this study, α-ω-disubstituted polyamines exhibit a range of potentially useful biological activities, including antimicrobial and antibiotic potentiation properties. We have prepared an expanded set of diarylbis(thioureido)polyamines that vary in central polyamine core length, identifying analogues with potent methicillin-resistant Staphylococcus aureus (MRSA), Escherichia coli, Acinetobacter baumannii and Candida albicans growth inhibition properties, in addition to the ability to enhance action of doxycycline towards Gram-negative bacterium Pseudomonas aeruginosa. The observation of associated cytotoxicity/hemolytic properties prompted synthesis of an alternative series of diacylpolyamines that explored aromatic head groups of varying lipophilicity. Examples bearing terminal groups each containing two phenyl rings (15a-f, 16a-f) were found to have optimal intrinsic antimicrobial properties, with MRSA being the most susceptible organism. A lack of observed cytotoxicity or hemolytic properties for all but the longest polyamine chain variants identified these as non-toxic Gram-positive antimicrobials worthy of further study. Analogues bearing either one or three aromatic-ring-containing head groups were either generally devoid of antimicrobial properties (one ring) or cytotoxic/hemolytic (three rings), defining a rather narrow range of head group lipophilicity that affords selectivity for Gram-positive bacterial membranes versus mammalian. Analogue 15d is bactericidal and targets the Gram-positive bacterial membrane.
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Affiliation(s)
- Dan Chen
- School of Chemical Sciences, The University of Auckland, Private Bag 92019, Auckland 1142, New Zealand
| | - Melissa M. Cadelis
- School of Chemical Sciences, The University of Auckland, Private Bag 92019, Auckland 1142, New Zealand
| | - Florent Rouvier
- UMR MD1 “Membranes et Cibles Therapeutiques”, U1261 INSERM, Faculté de Pharmacie, Aix-Marseille Universite, 27 bd Jean Moulin, 13385 Marseille, France
| | - Thomas Troia
- UMR MD1 “Membranes et Cibles Therapeutiques”, U1261 INSERM, Faculté de Pharmacie, Aix-Marseille Universite, 27 bd Jean Moulin, 13385 Marseille, France
| | - Liam R. Edmeades
- School of Chemical Sciences, The University of Auckland, Private Bag 92019, Auckland 1142, New Zealand
| | - Kyle Fraser
- School of Chemical Sciences, The University of Auckland, Private Bag 92019, Auckland 1142, New Zealand
| | - Evangelene S. Gill
- School of Chemical Sciences, The University of Auckland, Private Bag 92019, Auckland 1142, New Zealand
| | - Marie-Lise Bourguet-Kondracki
- Laboratoire Molécules de Communication et Adaptation des Micro-Organismes, UMR 7245 CNRS, Muséum National d’Histoire Naturelle, 57 Rue Cuvier (C.P. 54), 75005 Paris, France
| | - Jean Michel Brunel
- UMR MD1 “Membranes et Cibles Therapeutiques”, U1261 INSERM, Faculté de Pharmacie, Aix-Marseille Universite, 27 bd Jean Moulin, 13385 Marseille, France
| | - Brent R. Copp
- School of Chemical Sciences, The University of Auckland, Private Bag 92019, Auckland 1142, New Zealand
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Wesseling CJ, Martin NI. Synergy by Perturbing the Gram-Negative Outer Membrane: Opening the Door for Gram-Positive Specific Antibiotics. ACS Infect Dis 2022; 8:1731-1757. [PMID: 35946799 PMCID: PMC9469101 DOI: 10.1021/acsinfecdis.2c00193] [Citation(s) in RCA: 24] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
New approaches to target antibacterial agents toward Gram-negative bacteria are key, given the rise of antibiotic resistance. Since the discovery of polymyxin B nonapeptide as a potent Gram-negative outer membrane (OM)-permeabilizing synergist in the early 1980s, a vast amount of literature on such synergists has been published. This Review addresses a range of peptide-based and small organic compounds that disrupt the OM to elicit a synergistic effect with antibiotics that are otherwise inactive toward Gram-negative bacteria, with synergy defined as a fractional inhibitory concentration index (FICI) of <0.5. Another requirement for the inclusion of the synergists here covered is their potentiation of a specific set of clinically used antibiotics: erythromycin, rifampicin, novobiocin, or vancomycin. In addition, we have focused on those synergists with reported activity against Gram-negative members of the ESKAPE family of pathogens namely, Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumoniae, and/or Acinetobacter baumannii. In cases where the FICI values were not directly reported in the primary literature but could be calculated from the published data, we have done so, allowing for more direct comparison of potency with other synergists. We also address the hemolytic activity of the various OM-disrupting synergists reported in the literature, an effect that is often downplayed but is of key importance in assessing the selectivity of such compounds for Gram-negative bacteria.
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5
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Li SA, Cadelis MM, Deed RC, Douafer H, Bourguet-Kondracki ML, Michel Brunel J, Copp BR. Valorisation of the diterpene podocarpic acid - Antibiotic and antibiotic enhancing activities of polyamine conjugates. Bioorg Med Chem 2022; 64:116762. [PMID: 35477062 DOI: 10.1016/j.bmc.2022.116762] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2022] [Revised: 04/05/2022] [Accepted: 04/18/2022] [Indexed: 11/02/2022]
Abstract
As part of our search for new antimicrobials and antibiotic adjuvants, a series of podocarpic acid-polyamine conjugates have been synthesized. The library of compounds made use of the phenolic and carboxylic acid moieties of the diterpene allowing attachment of polyamines (PA) of different lengths to afford a structurally-diverse set of analogues. Evaluation of the conjugates for intrinsic antimicrobial properties identified two derivatives of interest: a PA3-4-3 (spermine) amide-bonded variant 7a that was a non-cytotoxic, non-hemolytic potent growth inhibitor of Gram-positive Staphylococcus aureus (MRSA) and 9d, a PA3-8-3 carbamate derivative that was a non-toxic selective antifungal towards Cryptococcus neoformans. Of the compound set, only one example exhibited activity towards Gram-negative bacteria. However, in the presence of sub-therapeutic amounts of either doxycycline (4.5 µM) or erythromycin (2.7 μM) several analogues were observed to exhibit weak to modest antibiotic adjuvant properties against Pseudomonas aeruginosa and/or Escherichia coli. The observation of strong cytotoxicity and/or hemolytic properties for subsets of the library, in particular those analogues bearing methyl ester or n-pentylamide functionality, highlighted the fine balance of structural requirements and lipophilicity for antimicrobial activity as opposed to mammalian cell toxicity.
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Affiliation(s)
- Steven A Li
- School of Chemical Sciences, The University of Auckland, Waipapa Taumata Rau, Private Bag 92019, Auckland 1142, New Zealand
| | - Melissa M Cadelis
- School of Chemical Sciences, The University of Auckland, Waipapa Taumata Rau, Private Bag 92019, Auckland 1142, New Zealand
| | - Rebecca C Deed
- School of Chemical Sciences, The University of Auckland, Waipapa Taumata Rau, Private Bag 92019, Auckland 1142, New Zealand; School of Biological Sciences, The University of Auckland, Waipapa Taumata Rau, Private Bag 92019, Auckland 1142, New Zealand
| | - Hana Douafer
- Aix-Marseille Universite, INSERM, SSA, MCT, Faculté de Pharmacie, 27 bd Jean Moulin, 13385 Marseille, France
| | - Marie-Lise Bourguet-Kondracki
- Laboratoire Molécules de Communication et Adaptation des Micro-organismes, UMR 7245 CNRS, Muséum National d'Histoire Naturelle, 57 rue Cuvier (C.P. 54), 75005 Paris, France
| | - Jean Michel Brunel
- Aix-Marseille Universite, INSERM, SSA, MCT, Faculté de Pharmacie, 27 bd Jean Moulin, 13385 Marseille, France
| | - Brent R Copp
- School of Chemical Sciences, The University of Auckland, Waipapa Taumata Rau, Private Bag 92019, Auckland 1142, New Zealand.
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Pearce AN, Chen D, Edmeades LR, Cadelis MM, Troudi A, Brunel JM, Bourguet-Kondracki ML, Copp BR. Repurposing primaquine as a polyamine conjugate to become an antibiotic adjuvant. Bioorg Med Chem 2021; 38:116110. [PMID: 33831695 DOI: 10.1016/j.bmc.2021.116110] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2020] [Revised: 03/04/2021] [Accepted: 03/06/2021] [Indexed: 11/17/2022]
Abstract
In our search for new antibiotic adjuvants as a novel strategy to deal with the emergence of multi-drug resistant (MDR) bacteria, a series of succinylprimaquine-polyamine (SPQ-PA) conjugates and derivatives of a cationic amphiphilic nature have been prepared. Evaluation of these primaquine conjugates for intrinsic antimicrobial properties and the ability to restore the antibiotic activity of doxycycline identified two derivatives, SPQ-PA3-8-3 and SPQ-PA3-10-3 that exhibited intrinsic activity against the Gram-positive bacteria Staphylococcus aureus and the yeast Cryptococcus neoformans. None of the analogues were active against the Gram-negative bacterium Pseudomonas aeruginosa. However, in the presence of a sub-therapeutic amount of doxycycline (4.5 µM), both SPQ-PA3-4-3 and SPQ-PA3-10-3 compounds displayed potent antibiotic adjuvant properties against P. aeruginosa, with MIC's of 6.25 µM. A series of derivatives were prepared to investigate the structure-activity relationship that explored the influence of both a simplified aryl lipophilic substituent and variation of the length of the polyamine scaffold on observed intrinsic antimicrobial properties and the ability to potentiate the action of doxycycline against P. aeruginosa.
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Affiliation(s)
- A Norrie Pearce
- School of Chemical Sciences, The University of Auckland, Private Bag 92019, Auckland 1142, New Zealand
| | - Dan Chen
- School of Chemical Sciences, The University of Auckland, Private Bag 92019, Auckland 1142, New Zealand
| | - Liam R Edmeades
- School of Chemical Sciences, The University of Auckland, Private Bag 92019, Auckland 1142, New Zealand
| | - Melissa M Cadelis
- School of Chemical Sciences, The University of Auckland, Private Bag 92019, Auckland 1142, New Zealand
| | - Azza Troudi
- UMR_MD1, U-1261, Aix Marseille Universite, INSERM, SSA, MCT, 13385 Marseille, France
| | - Jean Michel Brunel
- UMR_MD1, U-1261, Aix Marseille Universite, INSERM, SSA, MCT, 13385 Marseille, France
| | - Marie-Lise Bourguet-Kondracki
- Laboratoire Molécules de Communication et Adaptation des Micro-organismes, UMR 7245 CNRS, Muséum National d'Histoire Naturelle, 57 rue Cuvier (C.P. 54), 75005 Paris, France
| | - Brent R Copp
- School of Chemical Sciences, The University of Auckland, Private Bag 92019, Auckland 1142, New Zealand.
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Gagic M, Kociova S, Smerkova K, Michalkova H, Setka M, Svec P, Pribyl J, Masilko J, Balkova R, Heger Z, Richtera L, Adam V, Milosavljevic V. One-pot synthesis of natural amine-modified biocompatible carbon quantum dots with antibacterial activity. J Colloid Interface Sci 2020; 580:30-48. [PMID: 32679365 DOI: 10.1016/j.jcis.2020.06.125] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2020] [Revised: 06/29/2020] [Accepted: 06/30/2020] [Indexed: 10/23/2022]
Abstract
In the present study, the thermal decomposition of citric acid in the presence of biogenic amine was used to synthesize four different functionalized carbon quantum dots (CQDs), namely, histamine-(HCQDs), putrescine-(PCQDs), cadaverine-(CCQDs) and spermine-(SCQDs). The thermal decomposition of the precursors resulted in a decrease in stability and the formation of surface amides via a cross-linking process between the carboxyl and amine groups. The deposition of biogenic amines was confirmed by a structural characterization of the synthesized CQDs. The resulting CQDs, with a net zero charge, exhibited excellent stability in environments with different pH values. Through a set of different cytotoxicity tests, the absence of gene mutations, apoptosis, necrosis or disruption in cell membranes revealed the high biocompatibility of the CQDs. The antimicrobial activity of the synthesized CQDs was investigated against different bacterial species (Staphylococcus aureus, Escherichia coli, and Klebsiella pneumonia). We determined the growth kinetics, production of reactive oxygen species (ROS), cell viability and changes in membrane integrity by scanning electron microscopy (SEM). The minimal inhibitory concentrations (MICs) for S. aureus ranged from 3.4 to 6.9 µg/mL. Regarding E.coli and K. pneumonia, all CQD formulations reduced growth, and the MICs were determined for CCQDs and HCQDs (6.9-19.4 µg/mL). The antibacterial activity mechanism was attributed to the oxidative stress generated after CQD treatment, which resulted in the destabilization of the bacterial membrane. The bacterial permeability to propidium iodide indicated a change in membrane integrity, and the effect of CQDs on the morphology of the bacterial cells was evidenced by SEM.
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Affiliation(s)
- Milica Gagic
- Department of Chemistry and Biochemistry, Mendel University in Brno, Zemedelska 1, 613 00 Brno, Czech Republic
| | - Silvia Kociova
- Department of Chemistry and Biochemistry, Mendel University in Brno, Zemedelska 1, 613 00 Brno, Czech Republic
| | - Kristyna Smerkova
- Department of Chemistry and Biochemistry, Mendel University in Brno, Zemedelska 1, 613 00 Brno, Czech Republic; Central European Institute of Technology, Purkyňova 123, 61 200 Brno, Czech Republic
| | - Hana Michalkova
- Department of Chemistry and Biochemistry, Mendel University in Brno, Zemedelska 1, 613 00 Brno, Czech Republic
| | - Milena Setka
- Central European Institute of Technology, Purkyňova 123, 61 200 Brno, Czech Republic
| | - Pavel Svec
- Department of Chemistry and Biochemistry, Mendel University in Brno, Zemedelska 1, 613 00 Brno, Czech Republic
| | - Jan Pribyl
- CEITEC MU, Masaryk University, Kamenice 5/A35, 62 500 Brno, Czech Republic
| | - Jiri Masilko
- Brno University of Technology, Institute of Materials Chemistry, Purkyňova 464/118, 612 00 Brno, Czech Republic
| | - Radka Balkova
- Brno University of Technology, Institute of Materials Chemistry, Purkyňova 464/118, 612 00 Brno, Czech Republic
| | - Zbynek Heger
- Department of Chemistry and Biochemistry, Mendel University in Brno, Zemedelska 1, 613 00 Brno, Czech Republic; Central European Institute of Technology, Purkyňova 123, 61 200 Brno, Czech Republic
| | - Lukas Richtera
- Department of Chemistry and Biochemistry, Mendel University in Brno, Zemedelska 1, 613 00 Brno, Czech Republic; Central European Institute of Technology, Purkyňova 123, 61 200 Brno, Czech Republic
| | - Vojtech Adam
- Department of Chemistry and Biochemistry, Mendel University in Brno, Zemedelska 1, 613 00 Brno, Czech Republic; Central European Institute of Technology, Purkyňova 123, 61 200 Brno, Czech Republic
| | - Vedran Milosavljevic
- Department of Chemistry and Biochemistry, Mendel University in Brno, Zemedelska 1, 613 00 Brno, Czech Republic; Central European Institute of Technology, Purkyňova 123, 61 200 Brno, Czech Republic.
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Liu J, Chen F, Wang X, Peng H, Zhang H, Wang KJ. The Synergistic Effect of Mud Crab Antimicrobial Peptides Sphistin and Sph 12-38 With Antibiotics Azithromycin and Rifampicin Enhances Bactericidal Activity Against Pseudomonas Aeruginosa. Front Cell Infect Microbiol 2020; 10:572849. [PMID: 33194811 PMCID: PMC7645104 DOI: 10.3389/fcimb.2020.572849] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2020] [Accepted: 09/02/2020] [Indexed: 12/16/2022] Open
Abstract
Overuse or abuse of antibiotics has undoubtedly accelerated the increasing prevalence of global antibiotic resistance crisis, and thus, people have been trying to explore approaches to decrease dosage of antibiotics or find new antibacterial agents for many years. Antimicrobial peptides (AMPs) are the ideal candidates that could kill pathogens and multidrug-resistant bacteria either alone or in combination with conventional antibiotics. In the study, the antimicrobial efficacy of mud crab Scylla paramamosain AMPs Sphistin and Sph12−38 in combination with eight selected antibiotics was evaluated using a clinical pathogen, Pseudomonas aeruginosa. It was interesting to note that the in vitro combination of rifampicin and azithromycin with Sphistin and Sph12−38 showed significant synergistic activity against P. aeruginosa. Moreover, an in vivo study was carried out using a mouse model challenged with P. aeruginosa, and the result showed that the combination of Sph12−38 with either rifampicin or azithromycin could significantly promote the healing of wounds and had the healing time shortened to 4–5 days compared with 7–8 days in control. The underlying mechanism might be due to the binding of Sphistin and Sph12−38 with P. aeruginosa lipopolysaccharides (LPS) and subsequent promotion of the intracellular uptake of rifampicin and azithromycin. Taken together, the significant synergistic antibacterial effect on P. aeruginosa in vitro and in vivo conferred by the combination of low dose of Sphistin and Sph12−38 with low dose of rifampicin and azithromycin would be beneficial for the control of antibiotic resistance and effective treatment of P. aeruginosa-infected diseases in the future.
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Affiliation(s)
- Jie Liu
- State Key Laboratory of Marine Environmental Science, College of Ocean & Earth Sciences, Xiamen University, Xiamen, China
| | - Fangyi Chen
- State Key Laboratory of Marine Environmental Science, College of Ocean & Earth Sciences, Xiamen University, Xiamen, China.,State-Province Joint Engineering Laboratory of Marine Bioproducts and Technology, College of Ocean & Earth Sciences, Xiamen University, Xiamen, China
| | - Xiaofei Wang
- State Key Laboratory of Marine Environmental Science, College of Ocean & Earth Sciences, Xiamen University, Xiamen, China
| | - Hui Peng
- State Key Laboratory of Marine Environmental Science, College of Ocean & Earth Sciences, Xiamen University, Xiamen, China.,State-Province Joint Engineering Laboratory of Marine Bioproducts and Technology, College of Ocean & Earth Sciences, Xiamen University, Xiamen, China
| | - Hua Zhang
- State Key Laboratory of Marine Environmental Science, College of Ocean & Earth Sciences, Xiamen University, Xiamen, China
| | - Ke-Jian Wang
- State Key Laboratory of Marine Environmental Science, College of Ocean & Earth Sciences, Xiamen University, Xiamen, China.,State-Province Joint Engineering Laboratory of Marine Bioproducts and Technology, College of Ocean & Earth Sciences, Xiamen University, Xiamen, China
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9
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Espinoza-Culupú A, Mendes E, Vitorino HA, da Silva PI, Borges MM. Mygalin: An Acylpolyamine With Bactericidal Activity. Front Microbiol 2020; 10:2928. [PMID: 31998255 PMCID: PMC6965172 DOI: 10.3389/fmicb.2019.02928] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2019] [Accepted: 12/05/2019] [Indexed: 01/15/2023] Open
Abstract
Inappropriate use of antibiotics favors the selection and spread of resistant bacteria. To reduce the spread of these bacteria, finding new molecules with activity is urgent and necessary. Several polyamine analogs have been constructed and used to control microorganisms and tumor cells. Mygalin is a synthetic acylpolyamine, which are analogs of spermidine, derived from the hemolymph of the spider Acanthoscurria gomesiana. The effective activity of polyamines and their analogs has been associated with their structure. The presence of two acyl groups in the Mygalin structure may give this molecule a specific antibacterial activity. The aim of this study was to identify the mechanisms involved in the interaction of Mygalin with Escherichia coli to clarify its antimicrobial action. The results indicated that Mygalin exhibits intense dose and time-dependent bactericidal activity. Treatment of E. coli with this molecule caused membrane rupture, inhibition of DNA synthesis, DNA damage, and morphological changes. The esterase activity increased along with the intracellular production of reactive oxygen species (ROS) after treatment of the bacteria with Mygalin. In addition, this molecule was able to sequester iron and bind to LPS. We have shown that Mygalin has bactericidal activity with underlying mechanisms involving ROS generation and chelation of iron ions that are necessary for bacterial metabolism, which may contribute to its microbicidal activity. Taken together, our data suggest that Mygalin can be explored as a new alternative drug with antimicrobial potential against Gram-negative bacteria or other infectious agents.
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Affiliation(s)
- Abraham Espinoza-Culupú
- Ph.D. Program in Biotechnology, University of São Paulo, São Paulo, Brazil.,Bacteriology Laboratory, Butantan Institute, São Paulo, Brazil
| | | | - Hector Aguilar Vitorino
- Institute of Marine and Environmental Technology, University of Maryland Center for Environmental Science, Columbus Center, Baltimore, MD, United States
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10
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HAMLET, a protein complex from human milk has bactericidal activity and enhances the activity of antibiotics against pathogenic Streptococci. Antimicrob Agents Chemother 2019:AAC.01193-19. [PMID: 31591115 DOI: 10.1128/aac.01193-19] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
HAMLET is a protein-lipid complex derived from human milk that was first described for its tumoricidal activity. Later studies showed that HAMLET also has direct bactericidal activity against select species of bacteria, with highest activity against Streptococcus pneumoniae Additionally, HAMLET in combination with various antimicrobial agents can make a broader range of antibiotic-resistant bacterial species sensitive to antibiotics. Here, we show that HAMLET has direct antibacterial activity not only against pneumococci, but also against Streptococcus pyogenes (GAS) and Streptococcus agalactiae (GBS). Analogous to pneumococci, HAMLET-treatment of GAS and GBS resulted in depolarization of the bacterial membrane followed by membrane permeabilization and death that could be inhibited by calcium and sodium transport inhibitors. Treatment of clinical antibiotic-resistant isolates of S. pneumoniae, GAS, and GBS with sublethal concentrations of HAMLET in combination with antibiotics decreased the minimal inhibitory concentrations of the respective antibiotic into the sensitive range. This effect could also be blocked by ion transport inhibitors, suggesting that HAMLET's bactericidal and combination treatment effects used similar mechanisms. Finally, we show that HAMLET potentiated the effects of erythromycin against erythromycin-resistant bacteria more effectively than it potentiated killing by penicillin G of bacteria resistant to penicillin G. These results show for the first time that HAMLET effectively kills three different species of pathogenic Streptococci using similar mechanisms and also potentiate the activity of macrolides and lincosamides more effectively than combination treatment with beta-lactams. These findings suggest a potential therapeutic role for HAMLET in repurposing antibiotics currently causing treatment failures in patients.
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Sim JY, Kim S, Lee J, Lim H, Kim HH, Park ZY, Kim JI. A significantly enhanced antibacterial spectrum of D-enantiomeric lipopeptide bactenecin. Biochem Biophys Res Commun 2019; 514:497-502. [PMID: 31056261 DOI: 10.1016/j.bbrc.2019.04.153] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2019] [Accepted: 04/22/2019] [Indexed: 10/26/2022]
Abstract
Cationic antimicrobial peptides (CAMPs) are important antibiotics because they possess a broad spectrum of activity against both Gram-positive and Gram-negative bacteria, including those resistant to traditional antibiotics. The cyclic peptide bactenecin is a 12-amino acid CAMP that contains one intramolecular disulfide bond. To improve the antibacterial activity of bactenecin, we designed and synthesized several bactenecin analogs by applying multiple approaches, including amino acid substitution, use of the d-enantiomeric form, and lipidation. Among the synthetic analogs, d-enantiomeric bactenecin conjugated to capric acid, which we named dBacK-(cap), exhibited a significantly enhanced antibacterial spectrum with MIC values ranging from 1 to 8 μM against both Gram-positive and Gram-negative bacteria, including some drug-resistant bacteria. Upon exposure to dBacK-(cap), S. aureus cells were killed within 1 h at the MIC value, but full inactivation of E. coli required over 2 h. These results indicate that covalent addition of a d-amino acid and a fatty acid to bactenecin is the most effective approach for enhancing its antibacterial activity.
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Affiliation(s)
- Ji-Yeong Sim
- School of Life Sciences, Gwangju Institute of Science and Technology, 123, Cheomdan-gwagiro (Oryong-dong), Buk-gu, Gwangju, 61005, Republic of Korea
| | - Shanghyeon Kim
- School of Life Sciences, Gwangju Institute of Science and Technology, 123, Cheomdan-gwagiro (Oryong-dong), Buk-gu, Gwangju, 61005, Republic of Korea
| | - Jaeho Lee
- School of Life Sciences, Gwangju Institute of Science and Technology, 123, Cheomdan-gwagiro (Oryong-dong), Buk-gu, Gwangju, 61005, Republic of Korea
| | - Hyunjung Lim
- School of Life Sciences, Gwangju Institute of Science and Technology, 123, Cheomdan-gwagiro (Oryong-dong), Buk-gu, Gwangju, 61005, Republic of Korea
| | - Ha Hyung Kim
- Biotherapeutics and Glycomics Laboratory, College of Pharmacy, Chung-Ang University, 84 Heukseok-ro, Dongjak-gu, Seoul, 06944, South Korea
| | - Zee-Yong Park
- School of Life Sciences, Gwangju Institute of Science and Technology, 123, Cheomdan-gwagiro (Oryong-dong), Buk-gu, Gwangju, 61005, Republic of Korea
| | - Jae Il Kim
- School of Life Sciences, Gwangju Institute of Science and Technology, 123, Cheomdan-gwagiro (Oryong-dong), Buk-gu, Gwangju, 61005, Republic of Korea.
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Rodrigues de Almeida N, Han Y, Perez J, Kirkpatrick S, Wang Y, Sheridan MC. Design, Synthesis, and Nanostructure-Dependent Antibacterial Activity of Cationic Peptide Amphiphiles. ACS APPLIED MATERIALS & INTERFACES 2019; 11:2790-2801. [PMID: 30588791 PMCID: PMC7199185 DOI: 10.1021/acsami.8b17808] [Citation(s) in RCA: 80] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
The development of bacterial resistant strains is a global health concern. Designing antibiotics that limit the rise of pathogenic resistance is essential to efficiently treat pathogenic infections. Self-assembling amphiphilic molecules are an intriguing platform for the treatment of pathogens because of their ability to disrupt bacterial membranes and function as drug nanocarriers. We have designed cationic peptide amphiphiles (PAs) that can form micelles, nanofibers, and twisted ribbons with the aim of understanding antimicrobial activity at the supramolecular level. We have found that micelle-forming PAs possess excellent antimicrobial activity against various Gram-positive and Gram-negative pathogens, such as methicillin-resistant Staphylococcus aureus (MRSA) and multidrug-resistant Klebsiella pneumoniae with minimal inhibitory concentrations (MICs) ranging between 1 and 8 μg/mL, when compared to nanofibers with MICs >32 μg/mL. The data suggest that the antimicrobial activity of the PAs depends on their morphology, amino acid sequence, the length of the alkyl tail, and the overall hydrophobicity of the PA. Scanning electron microscopy, confocal microscopy, and flow cytometry studies using MRSA and Escherichia coli K12 strains showed that PAs increase cell membrane permeability and disrupt the integrity of pathogen's membrane, leading to cell lysis and death. PAs are a promising platform to develop new antimicrobials that could work as nanocarriers to develop synergistic antibacterial therapies.
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Affiliation(s)
- Nathalia Rodrigues de Almeida
- Department of Pharmaceutical Sciences , College of Pharmacy, University of Nebraska Medical Center , Omaha , Nebraska 68198 , United States
| | - Yuchun Han
- Key Laboratory of Colloid and Interface Science, Beijing National Laboratory for Molecular Sciences (BNLMS) , Institute of Chemistry, Chinese Academy of Sciences , Beijing 100190 , People's Republic of China
| | | | | | - Yilin Wang
- Key Laboratory of Colloid and Interface Science, Beijing National Laboratory for Molecular Sciences (BNLMS) , Institute of Chemistry, Chinese Academy of Sciences , Beijing 100190 , People's Republic of China
| | - Martin Conda Sheridan
- Department of Pharmaceutical Sciences , College of Pharmacy, University of Nebraska Medical Center , Omaha , Nebraska 68198 , United States
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Abstract
This review summarizes evidence that the impact of protein binding of the activity of antibiotics is multifaceted and more complex than indicated by the numerical value of protein binding alone. A plethora of studies has proven that protein binding of antibiotics matters, as the free fraction only is antibacterially active and governs pharmacokinetics. Several studies have indicated that independent from protein binding of immunoglobulin G, albumin, α1-acid-glycoprotein, and pulmonary surfactant acted synergistically with antibacterial agents, thus suggesting that some intrinsic properties of serum proteins may have mediated serum-antibiotic synergisms. It has been demonstrated that IgG and albumin permeabilized Gram-negative and Gram-positive bacteria and facilitated the uptake of poorly penetrating antibiotics. Alpha-1-acid-glycoprotein and pulmonary surfactant also exerted a permeabilizing activity, but proof that this property results in a sensitizing effect is missing. The permeabilizing effect of serum proteins may explain why serum-antibiotic synergisms do not represent a general phenomenon but are limited to specific drug-bug associations only. Although evidence has been generated to support the hypothesis that native serum proteins interact synergistically with antibiotics, systematic and well-controlled studies have to be performed to substantiate this phenomenon. The interactions between serum proteins and bacterial surfaces are driven by physicochemical forces. However, preparative techniques, storage conditions, and incubation methods have a significant impact on the intrinsic activities of these serum proteins affecting serum-antibiotic synergisms, so these techniques have to be standardized; otherwise, contradictory data or even artifacts will be generated.
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Affiliation(s)
- Axel Dalhoff
- Christian-Albrechts-University of Kiel, Institute for Infection Medicine, Kiel, Germany
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Konai MM, Adhikary U, Haldar J. Design and Solution-Phase Synthesis of Membrane-Targeting Lipopeptides with Selective Antibacterial Activity. Chemistry 2017; 23:12853-12860. [PMID: 28718982 DOI: 10.1002/chem.201702227] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2017] [Indexed: 02/06/2023]
Abstract
Designing selective antibacterial molecules remains an unmet goal in the field of membrane-targeting agents. Herein, we report the rational design and synthesis of a new class of lipopeptides, which possess highly selective bacterial killing over mammalian cells. The selective interaction with bacterial over mammalian membranes was established through various spectroscopic, as well as microscopic experiments, including biophysical studies with the model membranes. A detailed antibacterial structure-activity relationship was delineated after preparing a series of molecules consisting of the peptide moieties with varied sequence of amino acids, such as d-phenylalanine, d-leucine, and d-lysine. Antibacterial activity was found to vary with the nature and positioning of hydrophobicity in the molecules, as well as number of positive charges. Optimized lipopeptide 9 did not show any hemolytic activity even at 1000 μg mL-1 and displayed >200-fold and >100-fold selectivity towards S. aureus and E. coli, respectively. More importantly, compound 9 was found to display good antibacterial activity (MIC 6.3-12.5 μg mL-1 ) against the five top most critical bacteria according to World Health Organization (WHO) priority pathogens list. Therefore, the results suggested that this new class of lipopeptides bear real promises for the development as future antibacterial agents.
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Affiliation(s)
- Mohini M Konai
- Antimicrobial Research Laboratory, New Chemistry Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur, Bengaluru, 560064, Karnataka, India
| | - Utsarga Adhikary
- Antimicrobial Research Laboratory, New Chemistry Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur, Bengaluru, 560064, Karnataka, India
| | - Jayanta Haldar
- Antimicrobial Research Laboratory, New Chemistry Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur, Bengaluru, 560064, Karnataka, India
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A High-Throughput Approach To Identify Compounds That Impair Envelope Integrity in Escherichia coli. Antimicrob Agents Chemother 2016; 60:5995-6002. [PMID: 27458225 DOI: 10.1128/aac.00537-16] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2016] [Accepted: 07/17/2016] [Indexed: 12/24/2022] Open
Abstract
The envelope of Gram-negative bacteria constitutes an impenetrable barrier to numerous classes of antimicrobials. This intrinsic resistance, coupled with acquired multidrug resistance, has drastically limited the treatment options against Gram-negative pathogens. The aim of the present study was to develop and validate an assay for identifying compounds that increase envelope permeability, thereby conferring antimicrobial susceptibility by weakening of the cell envelope barrier in Gram-negative bacteria. A high-throughput whole-cell screening platform was developed to measure Escherichia coli envelope permeability to a β-galactosidase chromogenic substrate. The signal produced by cytoplasmic β-galactosidase-dependent cleavage of the chromogenic substrate was used to determine the degree of envelope permeabilization. The assay was optimized by using known envelope-permeabilizing compounds and E. coli gene deletion mutants with impaired envelope integrity. As a proof of concept, a compound library comprising 36 peptides and 45 peptidomimetics was screened, leading to identification of two peptides that substantially increased envelope permeability. Compound 79 reduced significantly (from 8- to 125-fold) the MICs of erythromycin, fusidic acid, novobiocin and rifampin and displayed synergy (fractional inhibitory concentration index, <0.2) with these antibiotics by checkerboard assays in two genetically distinct E. coli strains, including the high-risk multidrug-resistant, CTX-M-15-producing sequence type 131 clone. Notably, in the presence of 0.25 μM of this peptide, both strains were susceptible to rifampin according to the resistance breakpoints (R > 0.5 μg/ml) for Gram-positive bacterial pathogens. The high-throughput screening platform developed in this study can be applied to accelerate the discovery of antimicrobial helper drug candidates and targets that enhance the delivery of existing antibiotics by impairing envelope integrity in Gram-negative bacteria.
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16
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Polyamine derivatives: a revival of an old neglected scaffold to fight resistant Gram-negative bacteria? Future Med Chem 2016; 8:963-73. [DOI: 10.4155/fmc-2016-0011] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Emergence of multidrug-resistant pathogens was responsible for microbial infections and inefficacy of numerous antimicrobial therapies has induced a need for the research of new classes of antibiotics. In this review, we will focus our interest toward the biological properties of polyamino antimicrobial agents.
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17
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Wang B, Pachaiyappan B, Gruber JD, Schmidt MG, Zhang YM, Woster PM. Antibacterial Diamines Targeting Bacterial Membranes. J Med Chem 2016; 59:3140-51. [PMID: 26964758 PMCID: PMC5927580 DOI: 10.1021/acs.jmedchem.5b01912] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Antibiotic resistance is a growing threat to human health exacerbated by a lack of new antibiotics. We now describe a series of substituted diamines that produce rapid bactericidal activity against both Gram-positive and Gram-negative bacteria, including methicillin-resistant Staphylococcus aureus and stationary-phase bacteria. These compounds reduce biofilm formation and promote biofilm dispersal in Pseudomonas aeruginosa. The most potent analogue, 3 (1,13-bis{[(2,2-diphenyl)-1-ethyl]thioureido}-4,10-diazatridecane), primarily acts by depolarization of the cytoplasmic membrane and permeabilization of the bacterial outer membrane. Transmission electron microscopy confirmed that 3 disrupts membrane integrity rapidly. Compound 3 is also synergistic with kanamycin, demonstrated by the checkerboard method and by time-kill kinetic experiments. In human cell toxicity assays, 3 showed limited adverse effects against the HEK293T human kidney embryonic cells and A549 human adenocarcinoma cells. In addition, 3 produced no adverse effects on Caenorhabditis elegans development, survival, and reproduction. Collectively, diamines related to 3 represent a new class of broad-spectrum antibacterials against drug-resistant pathogens.
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Affiliation(s)
- Bo Wang
- Department of Biochemistry and Molecular Biology, Medical University of South Carolina, Charleston, South Carolina 29425, United States
- Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, PR China
| | - Boobalan Pachaiyappan
- Department of Drug Discovery and Biomedical Sciences, Medical University of South Carolina, Charleston, South Carolina 29425, United States
| | - Jordon D. Gruber
- Department of Biochemistry and Molecular Biology, Medical University of South Carolina, Charleston, South Carolina 29425, United States
| | - Michael G. Schmidt
- Department of Microbiology & Immunology, Medical University of South Carolina, Charleston, South Carolina 29425, United States
| | - Yong-Mei Zhang
- Department of Biochemistry and Molecular Biology, Medical University of South Carolina, Charleston, South Carolina 29425, United States
| | - Patrick M. Woster
- Department of Drug Discovery and Biomedical Sciences, Medical University of South Carolina, Charleston, South Carolina 29425, United States
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18
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Konai MM, Adhikary U, Samaddar S, Ghosh C, Haldar J. Structure–Activity Relationship of Amino Acid Tunable Lipidated Norspermidine Conjugates: Disrupting Biofilms with Potent Activity against Bacterial Persisters. Bioconjug Chem 2015; 26:2442-53. [DOI: 10.1021/acs.bioconjchem.5b00494] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Affiliation(s)
- Mohini M. Konai
- Chemical Biology and Medicinal
Chemistry Laboratory, New Chemistry Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur, Bengaluru 560064, Karnataka, India
| | - Utsarga Adhikary
- Chemical Biology and Medicinal
Chemistry Laboratory, New Chemistry Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur, Bengaluru 560064, Karnataka, India
| | - Sandip Samaddar
- Chemical Biology and Medicinal
Chemistry Laboratory, New Chemistry Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur, Bengaluru 560064, Karnataka, India
| | - Chandradhish Ghosh
- Chemical Biology and Medicinal
Chemistry Laboratory, New Chemistry Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur, Bengaluru 560064, Karnataka, India
| | - Jayanta Haldar
- Chemical Biology and Medicinal
Chemistry Laboratory, New Chemistry Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur, Bengaluru 560064, Karnataka, India
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19
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Konai MM, Haldar J. Lysine-Based Small Molecules That Disrupt Biofilms and Kill both Actively Growing Planktonic and Nondividing Stationary Phase Bacteria. ACS Infect Dis 2015; 1:469-78. [PMID: 27623313 DOI: 10.1021/acsinfecdis.5b00056] [Citation(s) in RCA: 58] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
The emergence of bacterial resistance is a major threat to global health. Alongside this issue, formation of bacterial biofilms is another cause of concern because most antibiotics are ineffective against these recalcitrant microbial communities. Ideal future antibacterial therapeutics should possess both antibacterial and anti-biofilm activities. In this study we engineered lysine-based small molecules, which showed not only commendable broad-spectrum antibacterial activity but also potent biofilm-disrupting properties. Synthesis of these lipophilic lysine-norspermidine conjugates was achieved in three simple reaction steps, and the resultant molecules displayed potent antibacterial activity against various Gram-positive (Staphylococcus aureus, Enterococcus faecium) and Gram-negative bacteria (Escherichia coli) including drug-resistant superbugs MRSA (methicillin-resistant S. aureus), VRE (vancomycin-resistant E. faecium), and β-lactam-resistant Klebsiella pneumoniae. An optimized compound in the series showed activity against planktonic bacteria in the concentration range of 3-10 μg/mL, and bactericidal activity against stationary phase S. aureus was observed within an hour. The compound also displayed about 120-fold selectivity toward both classes of bacteria (S. aureus and E. coli) over human erythrocytes. This rapidly bactericidal compound primarily acts on bacteria by causing significant membrane depolarization and K(+) leakage. Most importantly, the compound disrupted preformed biofilms of S. aureus and did not trigger bacterial resistance. Therefore, this class of compounds has high potential to be developed as future antibacterial drugs for treating infections caused by planktonic bacteria as well as bacterial biofilms.
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Affiliation(s)
- Mohini M. Konai
- Chemical Biology and Medicinal
Chemistry Laboratory, New Chemistry Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur, Bengaluru 560064, Karnataka, India
| | - Jayanta Haldar
- Chemical Biology and Medicinal
Chemistry Laboratory, New Chemistry Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur, Bengaluru 560064, Karnataka, India
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20
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Bactericidal Effects and Mechanism of Action of Olanexidine Gluconate, a New Antiseptic. Antimicrob Agents Chemother 2015; 59:4551-9. [PMID: 25987609 DOI: 10.1128/aac.05048-14] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2014] [Accepted: 05/11/2015] [Indexed: 01/02/2023] Open
Abstract
Olanexidine gluconate [1-(3,4-dichlorobenzyl)-5-octylbiguanide gluconate] (development code OPB-2045G) is a new monobiguanide compound with bactericidal activity. In this study, we assessed its spectrum of bactericidal activity and mechanism of action. The minimal bactericidal concentrations of the compound for 30-, 60-, and 180-s exposures were determined with the microdilution method using a neutralizer against 320 bacterial strains from culture collections and clinical isolates. Based on the results, the estimated bactericidal olanexidine concentrations with 180-s exposures were 869 μg/ml for Gram-positive cocci (155 strains), 109 μg/ml for Gram-positive bacilli (29 strains), and 434 μg/ml for Gram-negative bacteria (136 strains). Olanexidine was active against a wide range of bacteria, especially Gram-positive cocci, including methicillin-resistant Staphylococcus aureus and vancomycin-resistant enterococci, and had a spectrum of bactericidal activity comparable to that of commercial antiseptics, such as chlorhexidine and povidone-iodine. In vitro experiments exploring its mechanism of action indicated that olanexidine (i) interacts with the bacterial surface molecules, such as lipopolysaccharide and lipoteichoic acid, (ii) disrupts the cell membranes of liposomes, which are artificial bacterial membrane models, (iii) enhances the membrane permeability of Escherichia coli, (iv) disrupts the membrane integrity of S. aureus, and (v) denatures proteins at relatively high concentrations (≥160 μg/ml). These results indicate that olanexidine probably binds to the cell membrane, disrupts membrane integrity, and its bacteriostatic and bactericidal effects are caused by irreversible leakage of intracellular components. At relatively high concentrations, olanexidine aggregates cells by denaturing proteins. This mechanism differs slightly from that of a similar biguanide compound, chlorhexidine.
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21
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Konai MM, Ghosh C, Yarlagadda V, Samaddar S, Haldar J. Membrane Active Phenylalanine Conjugated Lipophilic Norspermidine Derivatives with Selective Antibacterial Activity. J Med Chem 2014; 57:9409-23. [DOI: 10.1021/jm5013566] [Citation(s) in RCA: 96] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Mohini M. Konai
- Chemical Biology and Medicinal
Chemistry Laboratory, New
Chemistry Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur, Bengaluru 560064, Karnataka, India
| | - Chandradhish Ghosh
- Chemical Biology and Medicinal
Chemistry Laboratory, New
Chemistry Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur, Bengaluru 560064, Karnataka, India
| | - Venkateswarlu Yarlagadda
- Chemical Biology and Medicinal
Chemistry Laboratory, New
Chemistry Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur, Bengaluru 560064, Karnataka, India
| | - Sandip Samaddar
- Chemical Biology and Medicinal
Chemistry Laboratory, New
Chemistry Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur, Bengaluru 560064, Karnataka, India
| | - Jayanta Haldar
- Chemical Biology and Medicinal
Chemistry Laboratory, New
Chemistry Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur, Bengaluru 560064, Karnataka, India
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22
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N-terminally modified linear and branched spermine backbone dipeptidomimetics against planktonic and sessile methicillin-resistant Staphylococcus aureus. Antimicrob Agents Chemother 2014; 58:5435-47. [PMID: 24982082 DOI: 10.1128/aac.03391-14] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
Toward the discovery of useful therapeutic molecules, we report the design and synthesis of a focused library of new ultrashort N-terminally modified dipeptidomimetics, with or without modifications in the spermine backbone leading to linear (series 1) or branched (series 2) tryptophans, as antimicrobial agents. Eight peptidomimetics in the library showed good antibacterial activity (MICs of 1.77 to 14.2 μg/ml) against methicillin-resistant Staphylococcus aureus (MRSA) and methicillin-resistant Staphylococcus epidermidis bacterial strains. Tryptophan fluorescence measurements on artificial bacterial or mammalian mimic membranes and assessment of the MRSA potential depolarization ability of the designed compounds revealed membrane interactions dependent on tryptophan positioning and N-terminal tagging. Among active peptidomimetics, compounds 1c and 1d were found to be nonhemolytic, displaying rapid bactericidal activity (at 4× MIC) against exponentially growing MRSA. Further, scanning electron microscopy of peptidomimetic 1c- and 1d-treated MRSA showed morphological changes with damage to cell walls, defining a membrane-active mode of action. Moreover, peptidomimetics 1c and 1d did not induce significant drug resistance in MRSA even after 17 passages. We also investigated the activity of these molecules against MRSA biofilms. At sub-MIC levels (∼2 to 4 μg/ml), both peptidomimetics inhibited biofilm formation. At concentrations higher than the MIC (35 to 140 μg/ml), peptidomimetics 1c and 1d significantly reduced the metabolic activity and biomass of mature (24-h) MRSA biofilms. These results were corroborated by confocal laser scanning microscopy (live/dead assay). The in vitro protease stability and lower cytotoxicity of peptidomimetics against peripheral blood mononuclear cells (PBMCs) support them being novel staphylocidal peptidomimetics. In conclusion, this study provides two peptidomimetics as potential leads for treatment of staphylococcal infections under planktonic and sessile conditions.
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Suriyarak S, Gibis M, Schmidt H, Villeneuve P, Weiss J. Antimicrobial mechanism and activity of dodecyl rosmarinate against Staphylococcus carnosus LTH1502 as influenced by addition of salt and change in pH. J Food Prot 2014; 77:444-52. [PMID: 24674436 DOI: 10.4315/0362-028x.jfp-13-239] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Antimicrobial activity and mechanism of action of rosmarinic acid (RA) and dodecyl rosmarinate (RE12) against Staphylococcus carnosus LTH1502 were studied as a function of pH (5.8 to 7.2) and in the presence of salts (KCl and MgCl2, 0 to 500 mM). Microbial cultures were exposed to unesterified RA and to esterified RE12, and cell number was determined by plate counting. Cells exposed to RA and RE12 at the minimum bactericidal concentration (200 and 0.05 mM, respectively) were examined using scanning electron microscopy to observe potential morphological changes. Activity of RA was found to be strongly dependent on pH, salt type, and concentration, whereas RE12 led to the compound's activity becoming independent of pH, salt concentration, and type. Scanning electron microscopy images showed that morphology of cells treated with RE12 after incubation of 1 h was irrevocably altered. Our results suggest that esterification (i) altered the mechanism of action by increasing the compound's affinity for cell membranes and (ii) decreased the compound's susceptibility to changes in environmental conditions that alter its charge. Highly specific changes in structure-activity relationships can be observed when esterifying a naturally active phenol such as RA with an alkyl chain that has a carbon chain length of 12.
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Affiliation(s)
- Sarisa Suriyarak
- Department of Food Physics and Meat Science, Institute of Food Science and Biotechnology, University of Hohenheim, Garbenstrasse 21/25, 70599 Stuttgart, Germany
| | - Monika Gibis
- Department of Food Physics and Meat Science, Institute of Food Science and Biotechnology, University of Hohenheim, Garbenstrasse 21/25, 70599 Stuttgart, Germany
| | - Herbert Schmidt
- Centre de Coopération Internationale en Recherche Agronomique pour le Développement (CIRAD), Unité Mixte de Recherche (UMR), Ingénierie des Agropolymères et Technologies Émergentes (IATE), Montpellier, 34060 France
| | - Pierre Villeneuve
- Department of Food Microbiology, Institute of Food Science and Biotechnology, University of Hohenheim, Garbenstrasse 28, 70599 Stuttgart, Germany
| | - Jochen Weiss
- Department of Food Physics and Meat Science, Institute of Food Science and Biotechnology, University of Hohenheim, Garbenstrasse 21/25, 70599 Stuttgart, Germany.
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Martínez de Tejada G, Sánchez-Gómez S, Rázquin-Olazaran I, Kowalski I, Kaconis Y, Heinbockel L, Andrä J, Schürholz T, Hornef M, Dupont A, Garidel P, Lohner K, Gutsmann T, David SA, Brandenburg K. Bacterial cell wall compounds as promising targets of antimicrobial agents I. Antimicrobial peptides and lipopolyamines. Curr Drug Targets 2012; 13:1121-30. [PMID: 22664072 DOI: 10.2174/138945012802002410] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2011] [Revised: 09/30/2011] [Accepted: 05/18/2012] [Indexed: 11/22/2022]
Abstract
The first barrier that an antimicrobial agent must overcome when interacting with its target is the microbial cell wall. In the case of Gram-negative bacteria, additional to the cytoplasmic membrane and the peptidoglycan layer, an outer membrane (OM) is the outermost barrier. The OM has an asymmetric distribution of the lipids with phospholipids and lipopolysaccharide (LPS) located in the inner and outer leaflets, respectively. In contrast, Gram-positive bacteria lack OM and possess a much thicker peptidoglycan layer compared to their Gram-negative counterparts. An additional class of amphiphiles exists in Gram-positives, the lipoteichoic acids (LTA), which may represent important structural components. These long molecules cross-bridge the entire cell envelope with their lipid component inserting into the outer leaflet of the cytoplasmic membrane and the teichoic acid portion penetrating into the peptidoglycan layer. Furthermore, both classes of bacteria have other important amphiphiles, such as lipoproteins, whose importance has become evident only recently. It is not known yet whether any of these amphiphilic components are able to stimulate the immune system under physiological conditions as constituents of intact bacteria. However, all of them have a very high pro-inflammatory activity when released from the cell. Such a release may take place through the interaction with the immune system, or with antibiotics (particularly with those targeting cell wall components), or simply by the bacterial division. Therefore, a given antimicrobial agent must ideally have a double character, namely, it must overcome the bacterial cell wall barrier, without inducing the liberation of the pro-inflammatory amphiphiles. Here, new data are presented which describe the development and use of membrane-active antimicrobial agents, in particular antimicrobial peptides (AMPs) and lipopolyamines. In this way, essential progress was achieved, in particular with respect to the inhibition of deleterious consequences of bacterial infections such as severe sepsis and septic shock.
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Shukla NM, Salunke DB, Yoo E, Mutz CA, Balakrishna R, David SA. Antibacterial activities of Groebke-Blackburn-Bienaymé-derived imidazo[1,2-a]pyridin-3-amines. Bioorg Med Chem 2012; 20:5850-63. [PMID: 22925449 PMCID: PMC3448811 DOI: 10.1016/j.bmc.2012.07.052] [Citation(s) in RCA: 76] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2012] [Revised: 07/26/2012] [Accepted: 07/31/2012] [Indexed: 10/28/2022]
Abstract
We sought to explore the imidazo[1,2-a]pyridin-3-amines for TLR7 (or 8)-modulatory activities. This chemotype, readily accessed via the Groebke-Blackburn-Bienaymé multi-component reaction, resulted in compounds that were TLR7/8-inactive, but exhibited bacteriostatic activity against Gram-positive bacteria, including methicillin-resistant Staphylococcus aureus (MRSA). To investigate the mechanism of antibacterial activity of this new chemotype, a resistant strain of S. aureus was generated by serially passaging the organism in escalating doses of the most active analogue. A comparison of minimum inhibitory concentrations (MICs) of known bacteriostatic agents in wild-type and resistant strains indicates a novel mechanism of action. Structure-activity relationship studies have led to the identification of positions on the scaffold for additional structural modifications that should allow for the introduction of probes designed to examine cognate binding partners and molecular targets, while not significantly compromising antibacterial potency.
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Affiliation(s)
| | | | - Euna Yoo
- Department of Medicinal Chemistry, University of Kansas
| | - Cole A. Mutz
- Department of Medicinal Chemistry, University of Kansas
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Extensive in vitro activity of guanidine hydrochloride polymer analogs against antibiotics-resistant clinically isolated strains. MATERIALS SCIENCE & ENGINEERING. C, MATERIALS FOR BIOLOGICAL APPLICATIONS 2011. [DOI: 10.1016/j.msec.2011.08.015] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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Day TP, Sil D, Shukla NM, Anbanandam A, Day VW, David SA. Imbuing aqueous solubility to amphotericin B and nystatin with a vitamin. Mol Pharm 2011; 8:297-301. [PMID: 21141891 PMCID: PMC3034802 DOI: 10.1021/mp100363f] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Aqueous solubilities of many drugs in current clinical use are very low, necessitating formulations that often present problems for parenteral administration, including toxicities due to the excipients used. Recognizing that pharmacologically active compounds frequently possess amines, we asked whether pyridoxal phosphate (PLP), an inoccuous, water-soluble vitamin, could be utilized to form prodrug-like complexes via the formation of imine or iminium adducts and whether the vitamin would impart solubilizing properties to such complexes. Direct spectroscopic and crystallographic data obtained using model primary and secondary amines showed that PLP forms stable imine adducts with primary amines under entirely aqueous conditions and at physiologic pH, while no reaction was observed for secondary amines; the basis of the exceptional stability appears to be a consequence of favorable H-bond interactions of the imine nitrogen with the 5-OH group of PLP. Amphotericin B and nystatin in their native forms display marked aqueous insolubility and possess lone primary amines. We were able to utilize PLP in achieving excellent solubilization of both of these antifungal agents, surpassing aqueous solubilities of 100 mg/mL. In in vitro bioassays, both polyenes in their PLP-adducted form display attenuated antifungal potencies which are attributable to "prodrug-like" complexes. These results point to the utility of excipient-free, entirely aqueous formulations of amphotericin B for parenteral use, and may also be extended to other primary amine-bearing compounds exhibiting poor aqueous solubility.
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Affiliation(s)
| | - Diptesh Sil
- Department of Medicinal Chemistry, University of Kansas
| | | | | | - Victor W. Day
- The Small-Molecule X-Ray Crystallography Laboratory, University of Kansas
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Structural features governing the activity of lactoferricin-derived peptides that act in synergy with antibiotics against Pseudomonas aeruginosa in vitro and in vivo. Antimicrob Agents Chemother 2010; 55:218-28. [PMID: 20956602 DOI: 10.1128/aac.00904-10] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Pseudomonas aeruginosa is naturally resistant to many antibiotics, and infections caused by this organism are a serious threat, especially to hospitalized patients. The intrinsic low permeability of P. aeruginosa to antibiotics results from the coordinated action of several mechanisms, such as the presence of restrictive porins and the expression of multidrug efflux pump systems. Our goal was to develop antimicrobial peptides with an improved bacterial membrane-permeabilizing ability, so that they enhance the antibacterial activity of antibiotics. We carried out a structure activity relationship analysis to investigate the parameters that govern the permeabilizing activity of short (8- to 12-amino-acid) lactoferricin-derived peptides. We used a new class of constitutional and sequence-dependent descriptors called PEDES (peptide descriptors from sequence) that allowed us to predict (Spearman's ρ = 0.74; P < 0.001) the permeabilizing activity of a new peptide generation. To study if peptide-mediated permeabilization could neutralize antibiotic resistance mechanisms, the most potent peptides were combined with antibiotics, and the antimicrobial activities of the combinations were determined on P. aeruginosa strains whose mechanisms of resistance to those antibiotics had been previously characterized. A subinhibitory concentration of compound P2-15 or P2-27 sensitized P. aeruginosa to most classes of antibiotics tested and counteracted several mechanisms of antibiotic resistance, including loss of the OprD porin and overexpression of several multidrug efflux pump systems. Using a mouse model of lethal infection, we demonstrated that whereas P2-15 and erythromycin were unable to protect mice when administered separately, concomitant administration of the compounds afforded long-lasting protection to one-third of the animals.
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Combined antibacterial and anti-inflammatory activity of a cationic disubstituted dexamethasone-spermine conjugate. Antimicrob Agents Chemother 2010; 54:2525-33. [PMID: 20308375 DOI: 10.1128/aac.01682-09] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
The rising number of antibiotic-resistant bacterial strains represents an emerging health problem that has motivated efforts to develop new antibacterial agents. Endogenous cationic antibacterial peptides (CAPs) that are produced in tissues exposed to the external environment are one model for the design of novel antibacterial compounds. Here, we report evidence that disubstituted dexamethasone-spermine (D2S), a cationic corticosteroid derivative initially identified as a by-product of synthesis of dexamethasone-spermine (DS) for the purpose of improving cellular gene delivery, functions as an antibacterial peptide-mimicking molecule. This moiety exhibits bacterial killing activity against clinical isolates of Staphylococcus aureus, Pseudomonas aeruginosa present in cystic fibrosis (CF) sputa, and Pseudomonas aeruginosa biofilm. Although compromised in the presence of plasma, D2S antibacterial activity resists the proteolytic activity of pepsin and is maintained in ascites, cerebrospinal fluid, saliva, and bronchoalveolar lavage (BAL) fluid. D2S also enhances S. aureus susceptibility to antibiotics, such as amoxicillin (AMC), tetracycline (T), and amikacin (AN). Inhibition of interleukin-6 (IL-6) and IL-8 release from lipopolysaccharide (LPS)- or lipoteichoic acid (LTA)-treated neutrophils in the presence of D2S suggests that this molecule might also prevent systemic inflammation caused by bacterial wall products. D2S-mediated translocation of green fluorescent protein (GFP)-labeled glucocorticoid receptor (GR) in bovine aorta endothelial cells (BAECs) suggests that some of its anti-inflammatory activities involve engagement of glucocorticoid receptors. The combined antibacterial and anti-inflammatory activities of D2S suggest its potential as an alternative to natural CAPs in the prevention and treatment of some bacterial infections.
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Abstract
Sepsis, otherwise referred to as "blood poisoning" is a serious clinical problem, the incidence of which continues to rise in the US and worldwide despite advances in antimicrobial chemotherapy. The primary trigger in Gram-negative sepsis is endotoxin, a lipopolysaccharide (LPS) constituent of the outer membrane of all Gram-negative bacteria. The structurally highly conserved glycolipid called lipid A is the active moiety of LPS. Lipid A is composed of a hydrophilic, bis-phosphorylated di-glucosamine backbone, and a hydrophobic polyacyl domain. The bis-anionic, amphiphilic nature of lipid A enables it to interact with a variety of cationic hydrophobic ligands, including polymyxin B, a toxic peptide antibiotic which binds to lipid A and neutralizes endotoxicity. Having determined the structural basis of the interaction of polymyxin B with lipid A, our long-term goal has been to rationally design non-peptidic, nontoxic, small-molecule LPS-sequestrants. Our efforts began with defining the central pharmacophore that determined LPS-recognition and -neutralization properties in small molecules, which led to the discovery of a novel lipopolyamine lead, DS-96. DS-96 is an effective LPS-neutralizer, rivaling polymyxin B in a panel of vitro assays, as well as in protecting animals against endotoxicosis. Structure-activity relationships in our effort to rationally design endotoxin sequestering agents, preclinical assessment of hits and leads, and approaches to overcoming issues with toxicity are described in this chapter.
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Affiliation(s)
- Sunil A David
- Department of Medicinal Chemistry, University of Kansas, Multidisciplinary Research Building, Room 320D, 2030 Becker Drive, Lawrence, KS 66047, USA.
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Adediran SA, Day TP, Sil D, Kimbrell MR, Warshakoon HJ, Malladi SS, David SA. Synthesis of a highly water-soluble derivative of amphotericin B with attenuated proinflammatory activity. Mol Pharm 2009; 6:1582-90. [PMID: 19663403 PMCID: PMC3709255 DOI: 10.1021/mp9001602] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Amphotericin B (AmB), a well-known polyene antifungal agent, displays a marked tendency to self-associate and, as a consequence, exhibits very poor solubility in water. The therapeutic index of AmB is low and is associated with significant dose-related nephrotoxicity, as well as acute, infusion-related febrile reactions. Reports in the literature indicate that the toxicity of AmB may be related to the physical state of the drug. Reaction of AmB in dimethylformamide with bis(dimethylaminopropyl)carbodiimide yielded an unexpected N-alkylguanidine/N-acylurea bis-adduct of AmB which was highly water-soluble. The absorption spectrum of the AmB derivative in water indicated excellent monomerization, and the antifungal activities of reference AmB and its water-soluble derivative against Candida albicans were found to be virtually identical. Furthermore, the water-soluble adduct is significantly less active in engaging TLR4, which would suggest that the adduct may be less proinflammatory.
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Affiliation(s)
| | | | - Diptesh Sil
- Department of Medicinal Chemistry, University of Kansas
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Zhou ZX, Wei DF, Guan Y, Zheng AN, Zhong JJ. Damage of Escherichia coli membrane by bactericidal agent polyhexamethylene guanidine hydrochloride: micrographic evidences. J Appl Microbiol 2009; 108:898-907. [PMID: 19709338 DOI: 10.1111/j.1365-2672.2009.04482.x] [Citation(s) in RCA: 88] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
AIMS The purpose of this study was to provide micrographic evidences for the damaged membrane structure and intracellular structure change of Escherichia coli strain 8099, induced by polyhexamethylene guanidine hydrochloride (PHMG). METHODS AND RESULTS The bactericidal effect of PHMG on E. coli was investigated based on beta-galactosidase activity assay, fluorescein-5-isothiocyanate confocal laser scanning microscopy, field emission scanning electron microscopy and transmission electron microscopy. The results revealed that a low dose (13 microg ml(-1)) of PHMG slightly damaged the outer membrane structure of the treated bacteria and increased the permeability of the cytoplasmic membrane, while no significant damage was observed to the morphological structure of the cells. A high dose (23 microg ml(-1)) of PHMG collapsed the outer membrane structure, led to the formation of a local membrane pore across the membrane and badly damaged the internal structure of the cells. Subsequently, intracellular components were leaked followed by cell inactivation. CONCLUSIONS Dose-dependent membrane disruption was the main bactericidal mechanism of PHMG. The formation of the local membrane pores was probable after exposure to a high dose (23 microg ml(-1)) of PHMG. Micrographic evidences were provided about the damaged membrane structure and intracellular structure change of E. coli. SIGNIFICANCE AND IMPACT OF THE STUDY The presented information helps understand the bactericidal mechanism of PHMG by membrane damage.
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Affiliation(s)
- Z X Zhou
- State Key Laboratory of Bioreactor Engineering, School of Biotechnology, East China University of Science and Technology, Shanghai, China
| | - D F Wei
- Key Laboratory for Ultrafine Materials, Ministry of Education, School of Materials Science and Engineering, East China University of Science and Technology, Shanghai, China
| | - Y Guan
- Key Laboratory for Ultrafine Materials, Ministry of Education, School of Materials Science and Engineering, East China University of Science and Technology, Shanghai, China
| | - A N Zheng
- Key Laboratory for Ultrafine Materials, Ministry of Education, School of Materials Science and Engineering, East China University of Science and Technology, Shanghai, China
| | - J J Zhong
- State Key Laboratory of Bioreactor Engineering, School of Biotechnology, East China University of Science and Technology, Shanghai, China., Key Laboratory of Microbial Metabolism, Ministry of Education, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, China
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Shrestha A, Li R, Sil D, Pardeshi NN, Schwarting N, Schorno KS, Rajewski RA, Datta A, David SA. Pharmacokinetics of DS-96, an alkylpolyamine lipopolysaccharide sequestrant, in rodents. J Pharm Sci 2009; 97:5376-85. [PMID: 18383338 DOI: 10.1002/jps.21361] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The pharmacokinetics of DS-96, an N-alkylhomospermine analog designed to sequester bacterial lipopolysaccharides, has been determined in rodent species. The elimination half-life in mice and rats are about 400 and 500 min, respectively, with other PK parameters being quite similar in the two rodent species. Interestingly, the mouse intravenous plasma concentration time curves exhibit an apparent absorption phase. While the rat intravenous data did not exhibit a pronounced apparent absorption phase immediately following injection, plasma levels did increase between 10 and 30 min following an expected drop from time 0 to 5 min. The data are consistent with first-pass uptake, possibly by the lung, with back diffusion as a function of time. The observed C(max) values of 1.36 microg/mL in the mouse intraperitoneal model suggest that a plasma concentration of 0.5-1 microg/mL corresponds to complete protection for a 200 ng/animal dose of intraperitoneally administered LPS in the D-galactosamine-primed model of endotoxin-induced lethality.
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Affiliation(s)
- Anurupa Shrestha
- Department of Medicinal Chemistry, University of Kansas, Lawrence, Kansas, USA
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Structure-activity relationships of antimicrobial and lipoteichoic acid-sequestering properties in polyamine sulfonamides. Antimicrob Agents Chemother 2008; 53:57-62. [PMID: 18955537 DOI: 10.1128/aac.00812-08] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
We have recently confirmed that lipoteichoic acid (LTA), a major constituent of the gram-positive bacterial surface, is the endotoxin of gram-positive bacteria that induces proinflammatory molecules in a Toll-like receptor 2 (TLR2)-dependent manner. LTA is an anionic amphipath whose physicochemical properties are similar to those of lipopolysaccharide (LPS), which is found on the outer leaflet of the outer membranes of gram-negative organisms. Hypothesizing that compounds that sequester LPS could also bind to and inhibit LTA-induced cellular activation, we screened congeneric series of polyamine sulfonamides which we had previously shown effectively neutralized LPS both in vitro and in animal models of endotoxemia. We observed that these compounds do bind to and neutralize LTA, as reflected by the inhibition of TLR2-mediated NF-kappaB induction in reporter gene assays. Structure-activity studies showed a clear dependence of the acyl chain length on activity against LTA in compounds with spermine and homospermine scaffolds. We then sought to examine possible correlations between the neutralizing potency toward LTA and antimicrobial activity in Staphylococcus aureus. A linear relationship between LTA sequestration activity and antimicrobial activity for compounds with a spermine backbone was observed, while all compounds with a homospermine backbone were equally active against S. aureus, regardless of their neutralizing potency toward LTA. These results suggest that the number of protonatable charges is a key determinant of the activity toward the membranes of gram-positive bacteria. The development of resistance to membrane-active antibiotics has been relatively slower than that to conventional antibiotics, and it is possible that compounds such as the acylpolyamines may be useful clinically, provided that they have an acceptable safety profile and margin of safety. A more detailed understanding of the mechanisms of interactions of these compounds with LPS and LTA, as well as the gram-negative and -positive bacterial cell surfaces, will be instructive and should allow the rational design of analogues which combine antisepsis and antibacterial properties.
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Cirioni O, Silvestri C, Ghiselli R, Orlando F, Riva A, Mocchegiani F, Chiodi L, Castelletti S, Gabrielli E, Saba V, Scalise G, Giacometti A. Protective effects of the combination of alpha-helical antimicrobial peptides and rifampicin in three rat models of Pseudomonas aeruginosa infection. J Antimicrob Chemother 2008; 62:1332-8. [PMID: 18799470 DOI: 10.1093/jac/dkn393] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
INTRODUCTION An experimental study has been performed to compare the in vitro activity and the in vivo efficacy of magainin II and cecropin A with or without rifampicin against control and multidrug-resistant Pseudomonas aeruginosa strains. METHODS In vitro experiments included MIC determinations and synergy studies. For in vivo studies, animals were given an intraperitoneal injection of P. aeruginosa lipopolysaccharide, P. aeruginosa ATCC 27853 and one clinical multiresistant P. aeruginosa strain. Groups of animals received intravenously isotonic sodium chloride solution, 10 mg/kg rifampicin, 1 mg/kg magainin II or 1 mg/kg cecropin A. Two groups of animals received a combined treatment with magainin II + rifampicin or cecropin A + rifampicin at the same dosages as the singly treated groups. In addition, a further group was treated with tazobactam/piperacillin (120 mg/kg). Lethality, bacterial growth in blood and peritoneum, and endotoxin and TNF-alpha concentrations in plasma were evaluated. RESULTS Combinations of alpha-helical antimicrobial peptides showed in vitro synergistic interaction. Magainin II and cecropin A exerted strong antimicrobial activity and achieved a significant reduction in plasma endotoxin and TNF-alpha concentrations when compared with control and rifampicin-treated groups. Rifampicin exhibited no anti-P. aeruginosa activity and good substantial impact on endotoxin and TNF-alpha plasma concentrations. Combined treatment groups had significant reductions in bacterial count, positive blood cultures and mortality rates when compared with singly treated and control groups. CONCLUSIONS Our results highlight the potential usefulness of these combinations that provide future therapeutic alternatives in P. aeruginosa infections.
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Affiliation(s)
- Oscar Cirioni
- Institute of Infectious Diseases and Public Health, Università Politecnica delle Marche, Ancona, Italy.
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Efficacy of the combination of tachyplesin III and clarithromycin in rat models of Escherichia coli sepsis. Antimicrob Agents Chemother 2008; 52:4351-5. [PMID: 18779356 DOI: 10.1128/aac.00086-08] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
We investigated the efficacy of tachyplesin III and clarithromycin in two experimental rat models of severe gram-negative bacterial infections. Adult male Wistar rats were given either (i) an intraperitoneal injection of 1 mg/kg Escherichia coli 0111:B4 lipopolysaccharide or (ii) 2 x 10(10) CFU of E. coli ATCC 25922. For each model, the animals received isotonic sodium chloride solution, 1 mg/kg tachyplesin III, 50 mg/kg clarithromycin, or 1 mg/kg tachyplesin III combined with 50 mg/kg clarithromycin intraperitoneally. Lethality, bacterial growth in the blood and peritoneum, and the concentrations of endotoxin and tumor necrosis factor alpha (TNF-alpha) in plasma were evaluated. All the compounds reduced the lethality of the infections compared to that for the controls. Tachyplesin III exerted a strong antimicrobial activity and achieved a significant reduction of endotoxin and TNF-alpha concentrations in plasma compared to those of the control and clarithromycin-treated groups. Clarithromycin exhibited no antimicrobial activity but had a good impact on endotoxin and TNF-alpha plasma concentrations. A combination of tachyplesin III and clarithromycin resulted in significant reductions in bacterial counts and proved to be the most-effective treatment in reducing all variables measured.
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Efficacy of the bovine antimicrobial peptide indolicidin combined with piperacillin/tazobactam in experimental rat models of polymicrobial peritonitis. Crit Care Med 2008; 36:240-5. [PMID: 18090372 DOI: 10.1097/01.ccm.0000292157.60632.89] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Abstract
Lipopeptide daptomycin is one of the few recently approved antibiotics based on the novel mechanism of action. Recent advances in synthetic lipopeptides, driven by the biochemical and biophysical research, expanded their spectrum of antimicrobial activity and reduced their size to achieve economically viable production. Lipopeptides, consisting of a short peptide chain conjugated with an acyl chain, form a structurally defined conformation, which inserts into the bacterial membrane and dissipates its transmembrane potential. In addition to antimicrobial activity, synthetic lipopeptides also suppress inflammation through the neutralization of bacterial agonists of the innate immune response, synergize with conventional antibiotics and have improved proteolytic stability. Activities in animal models indicate that synthetic lipopeptides may surpass the natural lipopeptides as the perspective class of anti-infective agents.
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Affiliation(s)
- Roman Jerala
- National Institute of Chemistry, Department of Biotechnology, Hajdrihova 19, Ljubljana, Slovenia.
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Nguyen TB, Adisechan AK, Suresh Kumar EVK, Balakrishna R, Kimbrell MR, Miller KA, Datta A, David SA. Protection from endotoxic shock by EVK-203, a novel alkylpolyamine sequestrant of lipopolysaccharide. Bioorg Med Chem 2007; 15:5694-709. [PMID: 17583517 PMCID: PMC2039869 DOI: 10.1016/j.bmc.2007.06.015] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2007] [Revised: 06/01/2007] [Accepted: 06/05/2007] [Indexed: 11/20/2022]
Abstract
Lipopolysaccharides (LPS) play a key role in the pathogenesis of septic shock, a major cause of mortality in the critically ill patient. The only therapeutic option aimed at limiting downstream systemic inflammatory processes by targeting lipopolysaccharide is Toraymyxin, an extracorporeal hemoperfusion device using solid phase-immobilized polymyxin B (PMB). While PMB is known to effectively sequester LPS, its severe systemic toxicity proscribes its parenteral use, and hemoperfusion may not be feasible in patients in shock. In our continuing efforts to develop small-molecule mimics which display the LPS-sequestering properties, but not the toxicity of PMB, a series of mono- and bis-substituted dialkylpolyamines were synthesized and evaluated. We show that EVK-203, an alkylpolyamine compound, specifically binds to and neutralizes the activity of LPS, and affords complete protection in a murine model of endotoxic shock. EVK-203 is without any apparent toxicity when administered to mice at multiples of therapeutic doses for several days. The specific endotoxin-sequestering property along with a very favorable therapeutic index renders this compound an ideal candidate for preclinical development.
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Affiliation(s)
- Thuan B Nguyen
- Department of Medicinal Chemistry, University of Kansas, Multidisciplinary Research Building, Lawrence, KS 66047, USA
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Cirioni O, Ghiselli R, Orlando F, Silvestri C, Mocchegiani F, Rocchi M, Chiodi L, Abbruzzetti A, Saba V, Scalise G, Giacometti A. Efficacy of colistin/rifampin combination in experimental rat models of sepsis due to a multiresistant Pseudomonas aeruginosa strain*. Crit Care Med 2007; 35:1717-23. [PMID: 17452938 DOI: 10.1097/01.ccm.0000266685.25436.03] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
OBJECTIVE To investigate the efficacy of rifampin and colistin in three experimental rat models of Pseudomonas aeruginosa sepsis. DESIGN Prospective, randomized, controlled animal study. SETTING Research laboratory in a university hospital. SUBJECTS Adult male Wistar rats. INTERVENTIONS Adult male Wistar rats were given a) an intraperitoneal injection of 1 mg of P. aeruginosa 10 lipopolysaccharide; b) 2 x 10(10) colony-forming units of P. aeruginosa ATCC 27853; and c) 2 x 10(10) colony-forming units of one clinically multiresistant strain of P. aeruginosa. For each model, all animals were randomized to receive intravenously isotonic sodium chloride solution, 10 mg/kg rifampin, 1 mg/kg colistin, and 10 mg/kg rifampin plus 1 mg/kg colistin. MEASUREMENTS AND MAIN RESULTS Lethality, bacterial growth in blood and peritoneum, and endotoxin and tumor necrosis factor-alpha concentrations in plasma were measured. Colistin exerted a strong antimicrobial activity and achieved a significant reduction of plasma endotoxin and tumor necrosis factor-alpha concentration compared with control and rifampin-treated groups. Rifampin exhibited no antimicrobial activity with no substantial impact on endotoxin and tumor necrosis factor-alpha plasma concentrations. The combination of colistin and rifampin resulted in a significant reduction in bacterial count compared with colistin monotherapy, whereas no significant difference was found in positive hem cultures and mortality rates between the two groups. CONCLUSIONS Colistin and rifampin might have a role in the therapy of multiresistant P. aeruginosa infection.
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Affiliation(s)
- Oscar Cirioni
- Institute of Infectious Diseases and Public Health, Università Politecnica delle Marche, Ancona, Italy
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Burns MR, Jenkins SA, Kimbrell MR, Balakrishna R, Nguyen TB, Abbo BG, David SA. Polycationic Sulfonamides for the Sequestration of Endotoxin. J Med Chem 2007; 50:877-88. [PMID: 17256835 DOI: 10.1021/jm061198m] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Lipopolysaccharides (LPS) play a key role in the pathogenesis of septic shock, a major cause of mortality in the critically ill patient. We had previously shown that monoacylated polyamine compounds specifically bind to and neutralize the activity of LPS with high in vitro potency and afford complete protection in a murine model of endotoxic shock. Fatty acid amides of polyamines may be rapidly cleared from systemic circulation due to their susceptibility to nonspecific serum amidases and, thus, would be predicted to have a short duration of action. In a systematic effort to increase the likelihood of better bioavailability properties together with structural modifications that may result in gains in activity, we now report structure-activity relationships pertaining to endotoxin-binding and -neutralizing activities of homologated polyamine sulfonamides.
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Affiliation(s)
- Mark R Burns
- MediQuest Therapeutics, Inc., 22322 20th Avenue SE, Bothell, Washington 98021, USA.
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