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Szymczak K, Szewczyk G, Rychłowski M, Sarna T, Zhang L, Grinholc M, Nakonieczna J. Photoactivated Gallium Porphyrin Reduces Staphylococcus aureus Colonization on the Skin and Suppresses Its Ability to Produce Enterotoxin C and TSST-1. Mol Pharm 2023; 20:5108-5124. [PMID: 37653709 PMCID: PMC10553792 DOI: 10.1021/acs.molpharmaceut.3c00399] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2023] [Revised: 08/21/2023] [Accepted: 08/22/2023] [Indexed: 09/02/2023]
Abstract
Staphylococcus aureus is a key pathogen in atopic dermatitis (AD) pathogenicity. Over half of AD patients are carriers of S. aureus. Clinical isolates derived from AD patients produce various staphylococcal enterotoxins, such as staphylococcal enterotoxin C or toxic shock syndrome toxin. The production of these virulence factors is correlated with more severe AD. In this study, we propose cationic heme-mimetic gallium porphyrin (Ga3+CHP), a novel gallium metalloporphyrin, as an anti-staphylococcal agent that functions through dual mechanisms: a light-dependent mechanism (antimicrobial photodynamic inactivation, aPDI) and a light-independent mechanism (suppressing iron metabolism). Ga3+CHP has two additive quaternary ammonium groups that increase its water solubility. Furthermore, Ga3+CHP is an efficient generator of singlet oxygen and can be recognized by heme-target systems such as Isd, which improves the intracellular accumulation of this compound. Ga3+CHP activated with green light effectively reduced the survival of clinical S. aureus isolates derived from AD patients (>5 log10 CFU/mL) and affected their enterotoxin gene expression. Additionally, there was a decrease in the biological functionality of studied toxins regarding their superantigenicity. In aPDI conditions, there was no pronounced toxicity in HaCaT keratinocytes with both normal and suppressed filaggrin gene expression, which occurs in ∼50% of AD patients. Additionally, no mutagenic activity was observed. Green light-activated gallium metalloporphyrins may be a promising chemotherapeutic to reduce S. aureus colonization on the skin of AD patients.
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Affiliation(s)
- Klaudia Szymczak
- Laboratory
of Photobiology and Molecular Diagnostics, Intercollegiate Faculty
of Biotechnology, University of Gdansk and
Medical University of Gdansk, Gdansk 80-307, Poland
| | - Grzegorz Szewczyk
- Department
of Biophysics, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Krakow 30-387, Poland
| | - Michał Rychłowski
- Laboratory
of Virus Molecular Biology, Intercollegiate Faculty of Biotechnology, University of Gdansk and Medical University of Gdansk, Gdansk 80-307, Poland
| | - Tadeusz Sarna
- Department
of Biophysics, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Krakow 30-387, Poland
| | - Lei Zhang
- Department
of Biochemical Engineering, School of Chemical Engineering and Technology,
Frontier Science Center for Synthetic Biology and Key Laboratory of
Systems Bioengineering (MOE), Tianjin University, Tianjin 300350, China
| | - Mariusz Grinholc
- Laboratory
of Photobiology and Molecular Diagnostics, Intercollegiate Faculty
of Biotechnology, University of Gdansk and
Medical University of Gdansk, Gdansk 80-307, Poland
| | - Joanna Nakonieczna
- Laboratory
of Photobiology and Molecular Diagnostics, Intercollegiate Faculty
of Biotechnology, University of Gdansk and
Medical University of Gdansk, Gdansk 80-307, Poland
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2
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Almeida MC, da Costa PM, Sousa E, Resende DISP. Emerging Target-Directed Approaches for the Treatment and Diagnosis of Microbial Infections. J Med Chem 2023; 66:32-70. [PMID: 36586133 DOI: 10.1021/acs.jmedchem.2c01212] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
With the rising levels of drug resistance, developing efficient antimicrobial therapies has become a priority. A promising strategy is the conjugation of antibiotics with relevant moieties that can potentiate their activity by target-directing. The conjugation of siderophores with antibiotics allows them to act as Trojan horses by hijacking the microorganisms' highly developed iron transport systems and using them to carry the antibiotic into the cell. Through the analysis of relevant examples of the past decade, this Perspective aims to reveal the potential of siderophore-antibiotic Trojan horses for the treatment of infections and the role of siderophores in diagnostic techniques. Other conjugated molecules will be the subject of discussion, namely those involving vitamin B12, carbohydrates, and amino acids, as well as conjugated compounds targeting protein degradation and β-lactamase activated prodrugs.
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Affiliation(s)
- Mariana C Almeida
- Laboratório de Química Orgânica e Farmacêutica, Departamento de Ciências Químicas, FFUP - Faculdade de Farmácia, Universidade do Porto, Rua de Jorge de Viterbo Ferreira 228, 4050-313 Porto, Portugal.,CIIMAR- Centro Interdisciplinar de Investigação Marinha e Ambiental, Terminal de Cruzeiros do Porto de Leixões, 4450-208 Matosinhos, Portugal
| | - Paulo M da Costa
- CIIMAR- Centro Interdisciplinar de Investigação Marinha e Ambiental, Terminal de Cruzeiros do Porto de Leixões, 4450-208 Matosinhos, Portugal.,ICBAS - Instituto de Ciências Biomédicas Abel Salazar, Universidade do Porto, Rua de Jorge Viterbo Ferreira 228, 4050-313 Porto, Portugal
| | - Emília Sousa
- Laboratório de Química Orgânica e Farmacêutica, Departamento de Ciências Químicas, FFUP - Faculdade de Farmácia, Universidade do Porto, Rua de Jorge de Viterbo Ferreira 228, 4050-313 Porto, Portugal.,CIIMAR- Centro Interdisciplinar de Investigação Marinha e Ambiental, Terminal de Cruzeiros do Porto de Leixões, 4450-208 Matosinhos, Portugal
| | - Diana I S P Resende
- Laboratório de Química Orgânica e Farmacêutica, Departamento de Ciências Químicas, FFUP - Faculdade de Farmácia, Universidade do Porto, Rua de Jorge de Viterbo Ferreira 228, 4050-313 Porto, Portugal.,CIIMAR- Centro Interdisciplinar de Investigação Marinha e Ambiental, Terminal de Cruzeiros do Porto de Leixões, 4450-208 Matosinhos, Portugal
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3
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Baker JM, Baba-Dikwa A, Shah R, Lea S, Singh D. Gallium protoporphyrin as an antimicrobial for non-typeable Haemophilus influenzae in COPD patients. Life Sci 2022; 305:120794. [PMID: 35835251 DOI: 10.1016/j.lfs.2022.120794] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2022] [Revised: 07/06/2022] [Accepted: 07/06/2022] [Indexed: 11/30/2022]
Abstract
AIMS Colonisation with non-typeable Haemophilus influenzae (NTHi) is common in COPD. Iron is required by bacteria for nutrition. Gallium is imported into bacteria using iron import proteins. Gallium cannot fulfill key metabolic functions, causing bactericidal effects. We tested the efficacy of gallium compounds as antimicrobials against NTHi in hemin rich conditions, and their ability to reduce NTHi induced pro-inflammatory responses in macrophages. MAIN METHODS NTHi was cultured with the free iron analogue gallium nitrate (GaN) and heme iron analogue gallium protoporphyrin (GaPP) (0.5-4 μM; 24 h). Growth of NTHi reference strain (NCTC 12699) and 6 clinical isolates from COPD patients (including antibiotic resistant isolates) was assessed by optical density, and viability by Miles Misra. Monocyte derived macrophages (MDMs) were treated with GaPP before/after NTHi exposure. Viable intracellular NTHi was assessed by gentamicin protection assay. GaN or GaPP was added to NTHi cultures prior to culture with MDMs. Cytokine gene expression (qPCR) and protein secretion (ELISA) were measured. KEY FINDINGS NTHi growth and viability were reduced by GaPP but not GaN. GaPP inhibited growth of COPD isolates (4 μM: 87 % reduction). GaPP reduced intracellular viability of NTHi in macrophage infection models. MDM cytokine gene expression and protein secretion (TNF-α, IL-6 and CXCL8) in response to NTHi was reduced (82, 66 and 86 % for gene expression) when cultured with GaPP 4 μM. SIGNIFICANCE GaPP is an effective antimicrobial for NTHi while GaN showed no effect on growth or viability. Culture of NTHi with GaPP also reduced the pro-inflammatory cytokine response in MDMs.
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Affiliation(s)
- James M Baker
- Division of Infection, Immunity and Respiratory Medicine, School of Biological Sciences, Faculty of Biology, Medicine and Health, Manchester Academic Health Science Centre, The University of Manchester, Manchester, UK.
| | - Aisha Baba-Dikwa
- Division of Infection, Immunity and Respiratory Medicine, School of Biological Sciences, Faculty of Biology, Medicine and Health, Manchester Academic Health Science Centre, The University of Manchester, Manchester, UK
| | - Rajesh Shah
- Department of Thoracic Surgery, Manchester University Hospital NHS Foundation Trust, Manchester, UK
| | - Simon Lea
- Division of Infection, Immunity and Respiratory Medicine, School of Biological Sciences, Faculty of Biology, Medicine and Health, Manchester Academic Health Science Centre, The University of Manchester, Manchester, UK
| | - Dave Singh
- Division of Infection, Immunity and Respiratory Medicine, School of Biological Sciences, Faculty of Biology, Medicine and Health, Manchester Academic Health Science Centre, The University of Manchester, Manchester, UK; Medicines Evaluation Unit, Manchester University NHS Foundation Trust, Manchester, UK
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4
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Oliveira F, Rohde H, Vilanova M, Cerca N. Fighting Staphylococcus epidermidis Biofilm-Associated Infections: Can Iron Be the Key to Success? Front Cell Infect Microbiol 2021; 11:798563. [PMID: 34917520 PMCID: PMC8670311 DOI: 10.3389/fcimb.2021.798563] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2021] [Accepted: 11/11/2021] [Indexed: 12/29/2022] Open
Abstract
Staphylococcus epidermidis is one of the most important commensal microorganisms of human skin and mucosae. However, this bacterial species is also the cause of severe infections in immunocompromised patients, specially associated with the utilization of indwelling medical devices, that often serve as a scaffold for biofilm formation. S. epidermidis strains are often multidrug resistant and its association with biofilm formation makes these infections hard to treat. Their remarkable ability to form biofilms is widely regarded as its major pathogenic determinant. Although a significant amount of knowledge on its biofilm formation mechanisms has been achieved, we still do not understand how the species survives when exposed to the host harsh environment during invasion. A previous RNA-seq study highlighted that iron-metabolism associated genes were the most up-regulated bacterial genes upon contact with human blood, which suggested that iron acquisition plays an important role in S. epidermidis biofilm development and escape from the host innate immune system. In this perspective article, we review the available literature on the role of iron metabolism on S. epidermidis pathogenesis and propose that exploiting its dependence on iron could be pursued as a viable therapeutic alternative.
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Affiliation(s)
- Fernando Oliveira
- Centre of Biological Engineering, Laboratory of Research in Biofilms Rosário Oliveira (LIBRO), University of Minho, Braga, Portugal
| | - Holger Rohde
- Institut für Medizinische Mikrobiologie, Virologie und Hygiene, Universitätsklinikum Hamburg-Eppendorf, Hamburg, Germany
| | - Manuel Vilanova
- Instituto de Investigação e Inovação em Saúde (i3S), Universidade do Porto, Porto, Portugal
- Instituto de Biologia Molecular e Celular (IBMC), Universidade do Porto, Porto, Portugal
- Instituto de Ciências Biomédicas de Abel Salazar, Universidade do Porto (ICBAS-UP), Porto, Portugal
| | - Nuno Cerca
- Centre of Biological Engineering, Laboratory of Research in Biofilms Rosário Oliveira (LIBRO), University of Minho, Braga, Portugal
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5
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Extracellular haem utilization by the opportunistic pathogen Pseudomonas aeruginosa and its role in virulence and pathogenesis. Adv Microb Physiol 2021; 79:89-132. [PMID: 34836613 DOI: 10.1016/bs.ampbs.2021.07.004] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Iron is an essential micronutrient for all bacteria but presents a significant challenge given its limited bioavailability. Furthermore, iron's toxicity combined with the need to maintain iron levels within a narrow physiological range requires integrated systems to sense, regulate and transport a variety of iron complexes. Most bacteria encode systems to chelate and transport ferric iron (Fe3+) via siderophore receptor mediated uptake or via cytoplasmic energy dependent transport systems. Pathogenic bacteria have further lowered the barrier to iron acquisition by employing systems to utilize haem as a source of iron. Haem, a lipophilic and toxic molecule, presents a significant challenge for transport into the cell. As such pathogenic bacteria have evolved sophisticated cell surface signaling (CSS) and transport systems to sense and obtain haem from the host. Once internalized haem is cleaved by both oxidative and non-oxidative mechanisms to release iron. Herein we summarize our current understanding of the mechanism of haem sensing, uptake and utilization in Pseudomonas aeruginosa, its role in pathogenesis and virulence, and the potential of these systems as antimicrobial targets.
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6
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D'Agostino A, Tana F, Ettorre A, Pavarini M, Serafini A, Cochis A, Scalia AC, Rimondini L, De Giglio E, Cometa S, Chiesa R, De Nardo L. Mesoporous zirconia surfaces with anti-biofilm properties for dental implants. Biomed Mater 2021; 16. [PMID: 33857927 DOI: 10.1088/1748-605x/abf88d] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2021] [Accepted: 04/15/2021] [Indexed: 01/30/2023]
Abstract
Cytocompatible bioactive surface treatments conferring antibacterial properties to osseointegrated dental implants are highly requested to prevent bacteria-related peri-implantitis. Here we focus on a newly designed family of mesoporous coatings based on zirconia (ZrO2) microstructure doped with gallium (Ga), exploiting its antibacterial and pro-osseo-integrative properties. The ZrO2films were obtained via sol-gel synthesis route using Pluronic F127 as templating agent, while Ga doping was gained by introducing gallium nitrate hydrate. Chemical characterization by means of x-ray photoelectron spectroscopy and glow discharge optical emission spectroscopy confirmed the effective incorporation of Ga. Then, coatings morphological and structural analysis were carried out by transmission electron microscopy and selected area electron diffraction unveiling an effective stabilization of both the mesoporous structure and the tetragonal ZrO2phase. Specimens' cytocompatibility was confirmed towards gingival fibroblast and osteoblasts progenitors cultivated directly onto the coatings showing comparable metabolic activity and morphology in respect to controls cultivated on polystyrene. The presence of Ga significantly reduced the metabolic activity of the adhered oral pathogensPorphyromonas gingivalisandAggregatibacter actinomycetemcomitansin comparison to untreated bulk zirconia (p< 0.05); on the opposite, Ga ions did not significantly reduce the metabolism of the oral commensalStreptococcus salivarius(p> 0.05) thus suggesting for a selective anti-pathogens activity. Finally, the coatings' ability to preserve cells from bacterial infection was proved in a co-culture method where cells and bacteria were cultivated in the same environment: the presence of Ga determined a significant reduction of the bacteria viability while allowing at the same time for cells proliferation. In conclusion, the here developed coatings not only demonstrated to satisfy the requested antibacterial and cytocompatibility properties, but also being promising candidates for the improvement of implantable devices in the field of implant dentistry.
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Affiliation(s)
- Agnese D'Agostino
- Department of Chemistry, Materials and Chemical Engineering 'G. Natta', Politecnico di Milano, Milan, Italy
| | - Francesca Tana
- Department of Chemistry, Materials and Chemical Engineering 'G. Natta', Politecnico di Milano, Milan, Italy.,National Interuniversity Consortium of Materials Science and Technology (INSTM), Local Unit Politecnico di Milano, Florence, Italy
| | - Alessandro Ettorre
- Department of Chemistry, Materials and Chemical Engineering 'G. Natta', Politecnico di Milano, Milan, Italy
| | - Matteo Pavarini
- Department of Chemistry, Materials and Chemical Engineering 'G. Natta', Politecnico di Milano, Milan, Italy
| | - Andrea Serafini
- National Interuniversity Consortium of Materials Science and Technology (INSTM), Local Unit Politecnico di Milano, Florence, Italy
| | - Andrea Cochis
- Department of Health Sciences, Center for Translational Research on Autoimmune and Allergic Diseases CAAD, Università del Piemonte Orientale UPO, Novara, Italy
| | - Alessandro Calogero Scalia
- Department of Health Sciences, Center for Translational Research on Autoimmune and Allergic Diseases CAAD, Università del Piemonte Orientale UPO, Novara, Italy
| | - Lia Rimondini
- Department of Health Sciences, Center for Translational Research on Autoimmune and Allergic Diseases CAAD, Università del Piemonte Orientale UPO, Novara, Italy
| | - Elvira De Giglio
- Department of Chemistry, Università di Bari Aldo Moro, Bari, Italy
| | | | - Roberto Chiesa
- Department of Chemistry, Materials and Chemical Engineering 'G. Natta', Politecnico di Milano, Milan, Italy.,National Interuniversity Consortium of Materials Science and Technology (INSTM), Local Unit Politecnico di Milano, Florence, Italy
| | - Luigi De Nardo
- Department of Chemistry, Materials and Chemical Engineering 'G. Natta', Politecnico di Milano, Milan, Italy.,National Interuniversity Consortium of Materials Science and Technology (INSTM), Local Unit Politecnico di Milano, Florence, Italy
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7
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Bamunuarachchi NI, Khan F, Kim YM. Inhibition of Virulence Factors and Biofilm Formation of Acinetobacter Baumannii by Naturally-derived and Synthetic Drugs. Curr Drug Targets 2021; 22:734-759. [PMID: 33100201 DOI: 10.2174/1389450121666201023122355] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2020] [Revised: 09/17/2020] [Accepted: 09/22/2020] [Indexed: 11/22/2022]
Abstract
Acinetobacter baumannii is a gram-negative, aerobic, non-motile, and pleomorphic bacillus. A. baumannii is also a highly-infectious pathogen causing high mortality and morbidity rates in intensive care units. The discovery of novel agents against A. baumannii infections is urgently needed due to the emergence of drug-resistant A. baumannii strains and the limited number of efficacious antibiotics available for treatment. In addition to the production of several virulence factors, A. baumannii forms biofilms on the host cell surface as well. Formation of biofilms occurs through initial surface attachment, microcolony formation, biofilm maturation, and detachment stages, and is one of the major drug resistance mechanisms employed by A. baumannii. Several studies have previously reported the efficacy of naturally-derived and synthetic compounds as anti- biofilm and anti-virulence agents against A. baumannii. Here, inhibition of biofilm formation and virulence factors of A. baumannii using naturally-derived and synthetic compounds are reviewed.
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Affiliation(s)
| | - Fazlurrahman Khan
- Institute of Food Science, Pukyong National University, Busan 48513, South Korea
| | - Young-Mog Kim
- Department of Food Science and Technology, Pukyong National University, Busan 48513, South Korea
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8
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Müller A, Fessele C, Zuber F, Rottmar M, Maniura-Weber K, Ren Q, Guex AG. Gallium Complex-Functionalized P4HB Fibers: A Trojan Horse to Fight Bacterial Infection. ACS APPLIED BIO MATERIALS 2021. [DOI: 10.1021/acsabm.0c01221] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Affiliation(s)
- Adrienne Müller
- Laboratory for Biointerfaces, Empa, Swiss Federal Laboratories for Materials Science and Technology, Lerchenfeldstrasse 5, 9014 St. Gallen, Switzerland
| | - Claudia Fessele
- Laboratory for Biointerfaces, Empa, Swiss Federal Laboratories for Materials Science and Technology, Lerchenfeldstrasse 5, 9014 St. Gallen, Switzerland
| | - Flavia Zuber
- Laboratory for Biointerfaces, Empa, Swiss Federal Laboratories for Materials Science and Technology, Lerchenfeldstrasse 5, 9014 St. Gallen, Switzerland
| | - Markus Rottmar
- Laboratory for Biointerfaces, Empa, Swiss Federal Laboratories for Materials Science and Technology, Lerchenfeldstrasse 5, 9014 St. Gallen, Switzerland
| | - Katharina Maniura-Weber
- Laboratory for Biointerfaces, Empa, Swiss Federal Laboratories for Materials Science and Technology, Lerchenfeldstrasse 5, 9014 St. Gallen, Switzerland
| | - Qun Ren
- Laboratory for Biointerfaces, Empa, Swiss Federal Laboratories for Materials Science and Technology, Lerchenfeldstrasse 5, 9014 St. Gallen, Switzerland
| | - Anne Géraldine Guex
- Laboratory for Biointerfaces, Empa, Swiss Federal Laboratories for Materials Science and Technology, Lerchenfeldstrasse 5, 9014 St. Gallen, Switzerland
- Laboratory for Biomimetic Membranes and Textiles, Empa, Swiss Federal Laboratories for Materials Science and Technology, Lerchenfeldstrasse 5, 9014 St. Gallen, Switzerland
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9
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Abstract
Drug-resistant infections pose a significant risk to global health as pathogenic bacteria become increasingly difficult to treat. The rapid selection of resistant strains through poor antibiotic stewardship has reduced the number of viable treatments and increased morbidity of infections, especially among the immunocompromised. To circumvent such challenges, new strategies are required to stay ahead of emerging resistance trends, yet research and funding for antibiotic development lags other classes of therapeutics. Though the use of metals in therapeutics has been around for centuries, recent strategies have devoted a great deal of effort into the pathways through which bacteria acquire and utilize iron, which is critical for the establishment of infection. To target iron uptake systems, siderophore-drug conjugates have been developed that hijack siderophore-based iron uptake for delivery of antibiotics. While this strategy has produced several potential leads, the use of siderophores in infection is diminished over time when bacteria adapt to utilize heme as an iron source, leading to a need for the development of porphyrin mimetics as therapeutics. The use of such strategies as well as the inclusion of gallium, a redox-inert iron mimic, are herein reviewed.
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Affiliation(s)
- Garrick Centola
- Department of Pharmaceutical Sciences, University of Maryland School of Pharmacy, Baltimore, MD 21201, USA.
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10
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Abstract
Traditional organic antimicrobials mainly act on specific biochemical processes such as replication, transcription and translation. However, the emergence and wide spread of microbial resistance is a growing threat for human beings. Therefore, it is highly necessary to design strategies for the development of new drugs in order to target multiple cellular processes that should improve their efficiency against several microorganisms, including bacteria, viruses or fungi. The present review is focused on recent advances and findings of new antimicrobial strategies based on metal complexes. Recent studies indicate that some metal ions cause different types of damages to microbial cells as a result of membrane degradation, protein dysfunction and oxidative stress. These unique modes of action, combined with the wide range of three-dimensional geometries that metal complexes can adopt, make them suitable for the development of new antimicrobial drugs.
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11
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Choi SR, Switzer B, Britigan BE, Narayanasamy P. Gallium Porphyrin and Gallium Nitrate Synergistically Inhibit Mycobacterial Species by Targeting Different Aspects of Iron/Heme Metabolism. ACS Infect Dis 2020; 6:2582-2591. [PMID: 32845117 DOI: 10.1021/acsinfecdis.0c00113] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
There is an urgent need for new effective and safe antibiotics active against pathogenic mycobacterial species. Gallium (Ga) nitrate (Ga(NO3)3) and Ga porphyrin (GaPP) have each been shown to inhibit the growth of a variety of mycobacterial species. The Ga(III) ion derived from Ga(NO3)3 has the potential to disrupt the mycobacterial Fe(III) uptake mechanisms and utilization, including replacing iron (Fe) in the active site of enzymes, resulting in the disruption of function. Similarly, noniron metalloporphyrins such as heme mimetics, which can be transported across the bacterial membrane via heme-uptake pathways, would potentially block the acquisition of iron-containing heme and bind to heme-utilizing proteins, making them nonfunctional. Given that they likely act on different aspects of mycobacterial Fe metabolism, the efficacy of combining Ga(NO3)3 and GaPP was studied in vitro against Mycobacterium avium, Mycobacterium abscessus, and Mycobacterium tuberculosis (M. tb). The combination was then assessed in vivo in a murine pulmonary infection model of M. abscessus. We observed that Ga(NO3)3 in combination with GaPP exhibited synergistic inhibitory activity against the growth of M. avium, M. tb, and M. abscessus, being most active against M. abscessus. Activity assays indicated that Ga(NO3)3 and GaPP inhibited both catalase and aconitase at high concentrations. However, the combination showed a synergistic effect on the aconitase activity of M. abscessus. The Ga(NO3)3/GaPP combination via intranasal administration showed significant antimicrobial activity in mice infected with M. abscessus. M. abscessus CFU from the lungs of the Ga(NO3)3/GaPP-treated mice was significantly less compared to that of nontreated or single Ga(III)-treated mice. These findings suggest that combinations of different Ga(III) compounds can synergistically target multiple iron/heme-utilizing mycobacterial enzymes. The results support the potential of combination Ga therapy for development against mycobacterial pathogens.
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Affiliation(s)
| | | | - Bradley E. Britigan
- Department of Internal Medicine and Research Service, Veterans Affairs Medical Center−Nebraska Western Iowa, Omaha, Nebraska 68105, United States
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12
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Centola G, Deredge DJ, Hom K, Ai Y, Dent AT, Xue F, Wilks A. Gallium(III)-Salophen as a Dual Inhibitor of Pseudomonas aeruginosa Heme Sensing and Iron Acquisition. ACS Infect Dis 2020; 6:2073-2085. [PMID: 32551497 DOI: 10.1021/acsinfecdis.0c00138] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Pseudomonas aeruginosa is an opportunistic bacterium that causes life-threatening infections in immunocompromised patients. In infection, it uses heme as a primary iron source and senses the availability of exogenous heme through the heme assimilation system (Has), an extra cytoplasmic function σ-factor system. A secreted hemophore HasAp scavenges heme and, upon interaction with the outer-membrane receptor HasR, activates a signaling cascade, which in turn creates a positive feedback loop critical for sensing and adaptation within the host. The ability to sense and respond to heme as an iron source contributes to virulence. Consequently, the inhibition of this system will lead to a disruption in iron homeostasis, decreasing virulence. We have identified a salophen scaffold that successfully inhibits the activation of the Has signaling system while simultaneously targeting iron uptake via xenosiderophore receptors. We propose this dual mechanism wherein free Ga3+-salophen reduces growth through uptake and iron mimicry. A dual mechanism targeting extracellular heme signaling and uptake together with Ga3+-induced toxicity following active Ga3+salophen uptake provides a significant therapeutic advantage while reducing the propensity to develop resistance.
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Affiliation(s)
- Garrick Centola
- Department of Pharmaceutical Sciences, University of Maryland School of Pharmacy, Baltimore, Maryland 21201, United States
| | - Daniel J. Deredge
- Department of Pharmaceutical Sciences, University of Maryland School of Pharmacy, Baltimore, Maryland 21201, United States
| | - Kellie Hom
- Department of Pharmaceutical Sciences, University of Maryland School of Pharmacy, Baltimore, Maryland 21201, United States
| | - Yong Ai
- Department of Pharmaceutical Sciences, University of Maryland School of Pharmacy, Baltimore, Maryland 21201, United States
| | - Alecia T. Dent
- Department of Pharmaceutical Sciences, University of Maryland School of Pharmacy, Baltimore, Maryland 21201, United States
| | - Fengtian Xue
- Department of Pharmaceutical Sciences, University of Maryland School of Pharmacy, Baltimore, Maryland 21201, United States
| | - Angela Wilks
- Department of Pharmaceutical Sciences, University of Maryland School of Pharmacy, Baltimore, Maryland 21201, United States
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13
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Anane YA, Apalata T, Vasaikar S, Okuthe GE, Songca SP. In vitro antimicrobial photodynamic inactivation of multidrug-resistant Acinetobacter baumannii biofilm using Protoporphyrin IX and Methylene blue. Photodiagnosis Photodyn Ther 2020; 30:101752. [PMID: 32289462 DOI: 10.1016/j.pdpdt.2020.101752] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2020] [Revised: 03/19/2020] [Accepted: 03/27/2020] [Indexed: 12/11/2022]
Abstract
BACKGROUND Acinetobacter baumannii is a challenging pathogen due to the rapid development of antimicrobial resistance and biofilm formation. The objective of this study was to evaluate the effect of antimicrobial photodynamic inactivation against biofilms of multidrug-resistant A. baumannii isolated from clinical, abattoir and aquatic sources. METHODS The isolates were tested for susceptibility to imipenem, meropenem, tigecycline and colistin using autoSCAN-4 automated system and rechecked by the E-test. Methylene blue, Protoporphyrin IX, and a halogen lamp were used in the in vitro assay against biofilms of the isolates. The antimicrobial photodynamic inactivation was assessed by counting colony-forming units (CFU). RESULTS The isolates from abattoir and aquatic sources were resistant to carbapenems (>64 μg/mL) but susceptible to tigecycline (2 μg/mL) and colistin (Abattoir, 0.35 μg/mL and Aquatic, 0.24 μg/mL), whereas the clinical isolate was susceptible to only colistin (0.5 μg/mL) using the E-test. The log survival percentages of the control group at a concentration of 20 μM were 5 × 10-6 % for Protoporphyrin IX and 2 × 10-6 % for Methylene blue. Therefore, Methylene blue showed higher bacterial reduction of 7.0 log10 colony forming units than 6.0 log10 for Protoporphyrin IX. No significant difference was observed with respect to the origin of isolates and the minimum inhibitory concentrations. CONCLUSION The results indicate that antimicrobial photodynamic inactivation could be an alternative strategy for the control of infections caused by multi-drug resistant A. baumannii by significantly reducing biofilm growth at a sub-lethal concentrations.
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Affiliation(s)
- Yaw Adjei Anane
- Division of Medical Microbiology, Department of Laboratory Medicine and Pathology, Faculty of Health Sciences, Walter Sisulu University, Private Bag: X1, Mthatha, 5117 Eastern Cape Province, South Africa.
| | - Teke Apalata
- Division of Medical Microbiology, Department of Laboratory Medicine and Pathology, Faculty of Health Sciences, Walter Sisulu University, Private Bag: X1, Mthatha, 5117 Eastern Cape Province, South Africa; Division of Medical Microbiology, National Health Laboratory Services (NHLS), Nelson Mandela Central Hospital, Mthatha 5100, South Africa.
| | - Sandeep Vasaikar
- Division of Medical Microbiology, Department of Laboratory Medicine and Pathology, Faculty of Health Sciences, Walter Sisulu University, Private Bag: X1, Mthatha, 5117 Eastern Cape Province, South Africa; Division of Medical Microbiology, National Health Laboratory Services (NHLS), Nelson Mandela Central Hospital, Mthatha 5100, South Africa
| | - Grace Emily Okuthe
- Department of Biological & Environmental Sciences, Walter Sisulu University, Private Bag: X1, Mthatha, 5117 Eastern Cape Province, South Africa.
| | - Sandile Phinda Songca
- School of Chemistry and Physics, College of Agriculture Engineering and Science, University of KwaZulu-Natal, 2nd Floor, Francis Stock Building, Howard College Campus, UKZN, Durban, 4041, South Africa.
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14
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Marchetti M, De Bei O, Bettati S, Campanini B, Kovachka S, Gianquinto E, Spyrakis F, Ronda L. Iron Metabolism at the Interface between Host and Pathogen: From Nutritional Immunity to Antibacterial Development. Int J Mol Sci 2020; 21:E2145. [PMID: 32245010 PMCID: PMC7139808 DOI: 10.3390/ijms21062145] [Citation(s) in RCA: 40] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2020] [Revised: 03/16/2020] [Accepted: 03/17/2020] [Indexed: 02/08/2023] Open
Abstract
Nutritional immunity is a form of innate immunity widespread in both vertebrates and invertebrates. The term refers to a rich repertoire of mechanisms set up by the host to inhibit bacterial proliferation by sequestering trace minerals (mainly iron, but also zinc and manganese). This strategy, selected by evolution, represents an effective front-line defense against pathogens and has thus inspired the exploitation of iron restriction in the development of innovative antimicrobials or enhancers of antimicrobial therapy. This review focuses on the mechanisms of nutritional immunity, the strategies adopted by opportunistic human pathogen Staphylococcus aureus to circumvent it, and the impact of deletion mutants on the fitness, infectivity, and persistence inside the host. This information finally converges in an overview of the current development of inhibitors targeting the different stages of iron uptake, an as-yet unexploited target in the field of antistaphylococcal drug discovery.
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Affiliation(s)
- Marialaura Marchetti
- Interdepartmental Center Biopharmanet-TEC, University of Parma, 43124 Parma, Italy; (M.M.); (S.B.)
| | - Omar De Bei
- Department of Food and Drug, University of Parma, 43124 Parma, Italy; (O.D.B.); (B.C.)
| | - Stefano Bettati
- Interdepartmental Center Biopharmanet-TEC, University of Parma, 43124 Parma, Italy; (M.M.); (S.B.)
- Department of Medicine and Surgery, University of Parma, 43126 Parma, Italy
- Institute of Biophysics, National Research Council, 56124 Pisa, Italy
- National Institute of Biostructures and Biosystems, 00136 Rome, Italy
| | - Barbara Campanini
- Department of Food and Drug, University of Parma, 43124 Parma, Italy; (O.D.B.); (B.C.)
| | - Sandra Kovachka
- Department of Drug Science and Technology, University of Turin, 10125 Turin, Italy; (S.K.); (E.G.); (F.S.)
| | - Eleonora Gianquinto
- Department of Drug Science and Technology, University of Turin, 10125 Turin, Italy; (S.K.); (E.G.); (F.S.)
| | - Francesca Spyrakis
- Department of Drug Science and Technology, University of Turin, 10125 Turin, Italy; (S.K.); (E.G.); (F.S.)
| | - Luca Ronda
- Interdepartmental Center Biopharmanet-TEC, University of Parma, 43124 Parma, Italy; (M.M.); (S.B.)
- Department of Medicine and Surgery, University of Parma, 43126 Parma, Italy
- Institute of Biophysics, National Research Council, 56124 Pisa, Italy
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15
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Choi SR, Britigan BE, Narayanasamy P. Dual Inhibition of Klebsiella pneumoniae and Pseudomonas aeruginosa Iron Metabolism Using Gallium Porphyrin and Gallium Nitrate. ACS Infect Dis 2019; 5:1559-1569. [PMID: 31264851 DOI: 10.1021/acsinfecdis.9b00100] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Iron- and heme-uptake pathways and metabolism are promising targets for the development of new antimicrobial agents, as their disruption would lead to nutritional iron starvation and inhibition of bacterial growth. Salts of gallium(III) (Ga), an iron mimetic metal, disrupt iron-dependent biological processes by binding iron-utilizing proteins and competing with iron for uptake by bacterial siderophore-mediated iron uptake systems. Ga porphyrins, heme mimetic complexes, disrupt heme-utilizing hemoproteins. Because Ga(NO3)3 and Ga porphyrin disrupt different pathways of bacterial ion acquisition and utilization, we hypothesized that if used in combination, they would result in enhanced antimicrobial activity. Antimicrobial activity of Ga porphyrins (Ga protoporphyrin, GaPP, or Ga mesoporphyrin, GaMP) alone and in combination with Ga(NO3)3 were evaluated against Pseudomonas aeruginosa, Klebsiella pneumoniae, Acinetobacter baumannii, and methicillin-resistant Staphylococcus aureus (MRSA) under iron-limited conditions. The Ga porphyrin/Ga(NO3)3 combination demonstrated substantial synergism against K. pneumoniae, P. aeruginosa, and MRSA. Time-kill assays revealed that the synergistic combination of GaPP/Ga(NO3)3 was bacteriostatic against K. pneumoniae and MRSA and bactericidal against P. aeruginosa. The GaPP/Ga(NO3)3 combination significantly disrupted K. pneumoniae and P. aeruginosa biofilms on plasma-coated surfaces and increased the survival of Caenorhabditis elegans infected with K. pneumoniae or P. aeruginosa. When assessing the antibacterial activity of the Ga(III)/antibiotic combinations, GaPP/colistin and Ga(NO3)3/colistin combinations also showed synergistic activity against K. pneumoniae and P. aeruginosa. Our results demonstrate that GaPP and Ga(NO3)3 have significant synergistic effects against several important human bacterial pathogens through dual inhibition of iron and heme metabolism.
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Affiliation(s)
- Seoung-ryoung Choi
- Department of Pathology and Microbiology, College of Medicine, University of Nebraska Medical Center, 985900 Nebraska Medical Center, Omaha, Nebraska 68198, United States
| | - Bradley E. Britigan
- Department of Pathology and Microbiology, College of Medicine, University of Nebraska Medical Center, 985900 Nebraska Medical Center, Omaha, Nebraska 68198, United States
- Department of Internal Medicine, College of Medicine, University of Nebraska Medical Center, Omaha, Nebraska 68198, United States
- Department of Internal Medicine and Research Service, Veterans Affairs Medical Center—Nebraska Western Iowa, Omaha, Nebraska 68105, United States
| | - Prabagaran Narayanasamy
- Department of Pathology and Microbiology, College of Medicine, University of Nebraska Medical Center, 985900 Nebraska Medical Center, Omaha, Nebraska 68198, United States
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16
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Targeting Quorum Sensing: High-Throughput Screening to Identify Novel LsrK Inhibitors. Int J Mol Sci 2019; 20:ijms20123112. [PMID: 31242708 PMCID: PMC6627609 DOI: 10.3390/ijms20123112] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2019] [Revised: 06/11/2019] [Accepted: 06/19/2019] [Indexed: 12/22/2022] Open
Abstract
Since quorum sensing (QS) is linked to the establishment of bacterial infection, its inactivation represents one of the newest strategies to fight bacterial pathogens. LsrK is a kinase playing a key role in the processing of autoinducer-2 (AI-2), a quorum-sensing mediator in gut enteric bacteria. Inhibition of LsrK might thus impair the quorum-sensing cascade and consequently reduce bacterial pathogenicity. Aiming for the development of a target-based assay for the discovery of LsrK inhibitors, we evaluated different assay set-ups based on ATP detection and optimized an automation-compatible method for the high-throughput screening of chemical libraries. The assay was then used to perform the screening of a 2000-compound library, which provided 12 active compounds with an IC50 ≤ 10 µM confirming the effectiveness and sensitivity of our assay. Follow-up studies on the positive hits led to the identification of two compounds, harpagoside and rosolic acid, active in a cell-based AI-2 QS interference assay, which are at the moment the most promising candidates for the development of a new class of antivirulence agents based on LsrK inhibition.
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17
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Iron/Heme Metabolism-Targeted Gallium(III) Nanoparticles Are Active against Extracellular and Intracellular Pseudomonas aeruginosa and Acinetobacter baumannii. Antimicrob Agents Chemother 2019; 63:AAC.02643-18. [PMID: 30782994 DOI: 10.1128/aac.02643-18] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2018] [Accepted: 02/06/2019] [Indexed: 12/24/2022] Open
Abstract
Iron/heme acquisition systems are critical for microorganisms to acquire iron from the human host, where iron sources are limited due to the nutritional immune system and insolubility of the ferric form of iron. Prior work has shown that a variety of gallium compounds can interfere with bacterial iron acquisition. This study explored the intra- and extracellular antimicrobial activities of gallium protoporphyrin (GaPP), gallium mesoporphyrin (GaMP), and nanoparticles encapsulating GaPP or GaMP against the Gram-negative pathogens Pseudomonas aeruginosa and Acinetobacter baumannii, including clinical isolates. All P. aeruginosa and A. baumannii isolates were susceptible to GaPP and GaMP, with MICs ranging from 0.5 to ∼32 μg/ml in iron-depleted medium. Significant intra- and extracellular growth inhibition was observed against P. aeruginosa cultured in macrophages at a gallium concentration of 3.3 μg/ml (5 μM) of all Ga(III) compounds, including nanoparticles. Nanoparticle formulations showed prolonged activity against both P. aeruginosa and A. baumannii in previously infected macrophages. When the macrophages were loaded with the nanoparticles 3 days prior to infection, there was a 5-fold decrease in growth of P. aeruginosa in the presence of single emulsion F127 copolymer nanoparticles encapsulating GaMP (eFGaMP). In addition, all Ga(III) porphyrins and nanoparticles showed significant intracellular and antibiofilm activity against both pathogens, with the nanoparticles exhibiting intracellular activity for 3 days. Ga nanoparticles also increased the survival rate of Caenorhabditis elegans nematodes infected by P. aeruginosa and A. baumannii Our results demonstrate that Ga nanoparticles have prolonged in vitro and in vivo activities against both P. aeruginosa and A. baumannii, including disruption of their biofilms.
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18
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Abstract
Staphylococcus aureus is one of the most important human pathogens that is responsible for a variety of diseases ranging from skin and soft tissue infections to endocarditis and sepsis. In recent decades, the treatment of staphylococcal infections has become increasingly difficult as the prevalence of multi-drug resistant strains continues to rise. With increasing mortality rates and medical costs associated with drug resistant strains, there is an urgent need for alternative therapeutic options. Many innovative strategies for alternative drug development are being pursued, including disruption of biofilms, inhibition of virulence factor production, bacteriophage-derived antimicrobials, anti-staphylococcal vaccines, and light-based therapies. While many compounds and methods still need further study to determine their feasibility, some are quickly approaching clinical application and may be available in the near future.
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19
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Hijazi S, Visaggio D, Pirolo M, Frangipani E, Bernstein L, Visca P. Antimicrobial Activity of Gallium Compounds on ESKAPE Pathogens. Front Cell Infect Microbiol 2018; 8:316. [PMID: 30250828 PMCID: PMC6139391 DOI: 10.3389/fcimb.2018.00316] [Citation(s) in RCA: 82] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2018] [Accepted: 08/20/2018] [Indexed: 12/22/2022] Open
Abstract
ESKAPE bacteria are a major cause of multidrug-resistant infections, and new drugs are urgently needed to combat these pathogens. Given the importance of iron in bacterial physiology and pathogenicity, iron uptake and metabolism have become attractive targets for the development of new antibacterial drugs. In this scenario, the FDA-approved iron mimetic metal Gallium [Ga(III)] has been successfully repurposed as an antimicrobial drug. Ga(III) disrupts ferric iron-dependent metabolic pathways, thereby inhibiting microbial growth. This work provides the first comparative assessment of the antibacterial activity of Ga(NO3)3 (GaN), Ga(III)-maltolate (GaM), and Ga(III)-protoporphyrin IX (GaPPIX), belonging to the first-, second- and third-generation of Ga(III) formulations, respectively, on ESKAPE species, including reference strains and multidrug-resistant (MDR) clinical isolates. In addition to the standard culture medium Mueller Hinton broth (MHB), iron-depleted MHB (DMHB) and RPMI-1640 supplemented with 10% human serum (HS) (RPMI-HS) were also included in Ga(III)-susceptibility tests, because of their different nutrient and iron contents. All ESKAPE species were resistant to all Ga(III) compounds in MHB and DMHB (MIC > 32 μM), except Staphylococcus aureus and Acinetobacter baumannii, which were susceptible to GaPPIX. Conversely, the antibacterial activity of GaN and GaM was very evident in RPMI-HS, in which the low iron content and the presence of HS better mimic the in vivo environment. In RPMI-HS about 50% of the strains were sensitive (MIC < 32) to GaN and GaM, both compounds showing a similar spectrum of activity, although GaM was more effective than GaN. In contrast, GaPPIX lost its antibacterial activity in RPMI-HS likely due to the presence of albumin, which binds GaPPIX and counteracts its inhibitory effect. We also demonstrated that the presence of multiple heme-uptake systems strongly influences GaPPIX susceptibility in A. baumannii. Interestingly, GaN and GaM showed only a bacteriostatic effect, whereas GaPPIX exerted a bactericidal activity on susceptible strains. Altogether, our findings raise hope for the future development of Ga(III)-based compounds in the treatment of infections caused by multidrug-resistant ESKAPE pathogens.
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Affiliation(s)
- Sarah Hijazi
- Department of Science, Roma Tre University, Rome, Italy
| | | | - Mattia Pirolo
- Department of Science, Roma Tre University, Rome, Italy
| | | | | | - Paolo Visca
- Department of Science, Roma Tre University, Rome, Italy
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20
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Infectious Complications After Battlefield Injuries: Epidemiology, Prevention, and Treatment. CURRENT TRAUMA REPORTS 2017. [DOI: 10.1007/s40719-017-0102-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
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21
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Innovative approaches to treat Staphylococcus aureus biofilm-related infections. Essays Biochem 2017; 61:61-70. [DOI: 10.1042/ebc20160056] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2016] [Revised: 11/22/2016] [Accepted: 11/24/2016] [Indexed: 01/04/2023]
Abstract
Many bacterial infections in humans and animals are caused by bacteria residing in biofilms, complex communities of attached organisms embedded in an extracellular matrix. One of the key properties of microorganisms residing in a biofilm is decreased susceptibility towards antimicrobial agents. This decreased susceptibility, together with conventional mechanisms leading to antimicrobial resistance, makes biofilm-related infections increasingly difficult to treat and alternative antibiofilm strategies are urgently required. In this review, we present three such strategies to combat biofilm-related infections with the important human pathogen Staphylococcus aureus: (i) targeting the bacterial communication system with quorum sensing (QS) inhibitors, (ii) a ‘Trojan Horse’ strategy to disturb iron metabolism by using gallium-based therapeutics and (iii) the use of ‘non-antibiotics’ with antibiofilm activity identified through screening of repurposing libraries.
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22
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Hijazi S, Visca P, Frangipani E. Gallium-Protoporphyrin IX Inhibits Pseudomonas aeruginosa Growth by Targeting Cytochromes. Front Cell Infect Microbiol 2017; 7:12. [PMID: 28184354 PMCID: PMC5266731 DOI: 10.3389/fcimb.2017.00012] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2016] [Accepted: 01/10/2017] [Indexed: 01/08/2023] Open
Abstract
Pseudomonas aeruginosa is a challenging pathogen due to both innate and acquired resistance to antibiotics. It is capable of causing a variety of infections, including chronic lung infection in cystic fibrosis (CF) patients. Given the importance of iron in bacterial physiology and pathogenicity, iron-uptake and metabolism have become attractive targets for the development of new antibacterial compounds. P. aeruginosa can acquire iron from a variety of sources to fulfill its nutritional requirements both in the environment and in the infected host. The adaptation of P. aeruginosa to heme iron acquisition in the CF lung makes heme utilization pathways a promising target for the development of new anti-Pseudomonas drugs. Gallium [Ga(III)] is an iron mimetic metal which inhibits P. aeruginosa growth by interfering with iron-dependent metabolism. The Ga(III) complex of the heme precursor protoporphyrin IX (GaPPIX) showed enhanced antibacterial activity against several bacterial species, although no inhibitory effect has been reported on P. aeruginosa. Here, we demonstrate that GaPPIX is indeed capable of inhibiting the growth of clinical P. aeruginosa strains under iron-deplete conditions, as those encountered by bacteria during infection, and that GaPPIX inhibition is reversed by iron. Using P. aeruginosa PAO1 as model organism, we show that GaPPIX enters cells through both the heme-uptake systems has and phu, primarily via the PhuR receptor which plays a crucial role in P. aeruginosa adaptation to the CF lung. We also demonstrate that intracellular GaPPIX inhibits the aerobic growth of P. aeruginosa by targeting cytochromes, thus interfering with cellular respiration.
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Affiliation(s)
- Sarah Hijazi
- Department of Science, Roma Tre University Rome, Italy
| | - Paolo Visca
- Department of Science, Roma Tre University Rome, Italy
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23
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Fowler LH, Lee S. Antibiotic Trends Amid Multidrug-Resistant Gram-Negative Infections in Intensive Care Units. Crit Care Nurs Clin North Am 2016; 29:111-118. [PMID: 28160952 DOI: 10.1016/j.cnc.2016.09.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
Isolates from ICUs most commonly find multidrug-resistant (MDR) gram-negative bacteria. The purpose of this article is to discuss the significant impact MDR gram-negative infections are having on ICUs, the threat on health and mortality, and effective and new approaches aimed to combat MDR gram-negative infections in critically ill populations. Inappropriate antibiotic therapies for suspected or documented infections are the leading cause of the emergence of bacterial resistance. A variety of strategies are aimed at combatting this international burden via antibiotic stewardship programs. Studies are demonstrating promise against the virulence MDR gram-negative infections have posed.
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Affiliation(s)
- Leanne H Fowler
- School of Nursing, Louisiana State University Health Sciences Center, 1900 Gravier Street, New Orleans, LA 70112, USA.
| | - Susan Lee
- School of Nursing, Louisiana State University Health Sciences Center, 1900 Gravier Street, New Orleans, LA 70112, USA
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