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Basrani ST, Kadam NS, Yadav DV, Patil SB, Mohan Karuppayil S, Jadhav AK. Antifungal Activity of Mefloquine Against Candida albicans Growth and Virulence Factors: Insights Into Mode of Action. Curr Microbiol 2024; 81:213. [PMID: 38847863 DOI: 10.1007/s00284-024-03739-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2023] [Accepted: 05/11/2024] [Indexed: 06/29/2024]
Abstract
The antimalarial drug Mefloquine has demonstrated antifungal activity against growth and virulence factors of Candida albicans. The current study focused on the identification of Mefloquine's mode of action in C. albicans by performing cell susceptibility assay, biofilm assay, live and dead assay, propidium iodide uptake assay, ergosterol quantification assay, cell cycle study, and gene expression studies by RT-PCR. Mefloquine inhibited the virulence factors in C. albicans, such as germ tube formation and biofilm formation at 0.125 and 1 mg/ml, respectively. Mefloquine-treated cells showed a decrease in the quantity of ergosterol content of cell membrane in a concentration-dependent manner. Mefloquine (0.25 mg/ml) arrested C. albicans cells at the G2/M phase and S phase of the cell cycle thereby preventing the progression of the normal yeast cell cycle. ROS level was measured to find out oxidative stress in C. albicans in the presence of mefloquine. The study revealed that, mefloquine was found to enhance the ROS level and subsequently oxidative stress. Gene expression studies revealed that mefloquine treatment upregulates the expressions of SOD1, SOD2, and CAT1 genes in C. albicans. In vivo, the antifungal efficacy of mefloquine was confirmed in mice for systemic candidiasis and it was found that there was a decrease in the pathogenesis of C. albicans after the treatment of mefloquine in mice. In conclusion, mefloquine can be used as a repurposed drug as an alternative drug against Candidiasis.
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Affiliation(s)
- Sargun T Basrani
- Department of Stem Cell and Regenerative Medicine & Medical Biotechnology, Centre for Interdisciplinary Research, DY Patil Education Society (Deemed to Be University), Kasaba Bawada, Kolhapur, Maharashtra, 416006, India
| | - Nandakumar S Kadam
- iSERA Biological Pvt Ltd. MIDC Shirala, Sangli, Maharashtra, 415408, India
| | | | - Shivani B Patil
- Department of Stem Cell and Regenerative Medicine & Medical Biotechnology, Centre for Interdisciplinary Research, DY Patil Education Society (Deemed to Be University), Kasaba Bawada, Kolhapur, Maharashtra, 416006, India
| | - S Mohan Karuppayil
- Department of Stem Cell and Regenerative Medicine & Medical Biotechnology, Centre for Interdisciplinary Research, DY Patil Education Society (Deemed to Be University), Kasaba Bawada, Kolhapur, Maharashtra, 416006, India.
| | - Ashwini K Jadhav
- Department of Stem Cell and Regenerative Medicine & Medical Biotechnology, Centre for Interdisciplinary Research, DY Patil Education Society (Deemed to Be University), Kasaba Bawada, Kolhapur, Maharashtra, 416006, India.
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Li R, Shen X, Li Z, Shen J, Tang H, Xu H, Shen J, Xu Y. Combination of AS101 and Mefloquine Inhibits Carbapenem-Resistant Pseudomonas aeruginosa in vitro and in vivo. Infect Drug Resist 2023; 16:7271-7288. [PMID: 38023412 PMCID: PMC10664714 DOI: 10.2147/idr.s427232] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2023] [Accepted: 10/27/2023] [Indexed: 12/01/2023] Open
Abstract
Background In recent years, carbapenem-resistant Pseudomonas aeruginosa (CRPA) has spread around the world, leading to a high mortality and close attention of medical community. In this study, we aim to find a new strategy of treatment for CRPA infections. Methods Eight strains of CRPA were collected, and PCR detected the multi-locus sequence typing (MLST). The antimicrobial susceptibility test was conducted using the VITEK@2 compact system. The minimum inhibitory concentration (MIC) for AS101 and mefloquine was determined using the broth dilution method. Antibacterial activity was tested in vitro and in vivo through the chessboard assay, time killing assay, and a mouse model. The mechanism of AS101 combined with mefloquine against CRPA was assessed through the biofilm formation inhibition assay, electron microscopy, and detection of reactive oxygen species (ROS). Results The results demonstrated that all tested CRPA strains exhibited multidrug resistance. Moreover, our investigation revealed a substantial synergistic antibacterial effect of AS101-mefloquine in vitro. The assay for inhibiting biofilm formation indicated that AS101-mefloquine effectively suppressed the biofilm formation of CRPA-5 and CRPA-6. Furthermore, AS101-mefloquine were observed to disrupt the bacterial cell wall and enhance the permeability of the cell membrane. This effect was achieved by stimulating the production of ROS, which in turn hindered the growth of CRPA-3. To evaluate the therapeutic potential, a murine model of CRPA-3 peritoneal infection was established. Notably, AS101-mefloquine administration resulted in a significant reduction in bacterial load within the liver, kidney, and spleen of mice after 72 hours of treatment. Conclusion The present study showed that the combination of AS101 and mefloquine yielded a notable synergistic bacteriostatic effect both in vitro and in vivo, suggesting a potential clinical application of this combination in the treatment of CRPA.
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Affiliation(s)
- Rongrong Li
- Department of Clinical Laboratory, The First Affiliated Hospital of Anhui Medical University, Hefei, People’s Republic of China
- Provincial Laboratories of Pathogen Biology and Zoonoses, Anhui Medical University, Hefei, People’s Republic of China
| | - Xuhang Shen
- Department of Gastroenterology, The First Affiliated Hospital of Anhui Medical University, Hefei, People’s Republic of China
| | - Zhengyuan Li
- Orthopedics, The First Affiliated Hospital of Anhui Medical University, Hefei, People’s Republic of China
| | - Jilong Shen
- Provincial Laboratories of Pathogen Biology and Zoonoses, Anhui Medical University, Hefei, People’s Republic of China
| | - Hao Tang
- Department of Clinical Laboratory, the Second Affiliated Hospital of Anhui Medical University, Hefei, People’s Republic of China
| | - Huaming Xu
- Department of Clinical Laboratory, the First Affiliated Hospital of Anhui University of Traditional Chinese Medicine, Hefei, People’s Republic of China
| | - Jilu Shen
- Department of Clinical Laboratory, The First Affiliated Hospital of Anhui Medical University, Hefei, People’s Republic of China
- Anhui Public Health Clinical Center, Hefei, People’s Republic of China
| | - Yuanhong Xu
- Department of Clinical Laboratory, The First Affiliated Hospital of Anhui Medical University, Hefei, People’s Republic of China
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Memedovski R, Preza M, Müller J, Kämpfer T, Rufener R, de Souza MVN, da Silva ET, de Andrade GF, Braga S, Uldry AC, Buchs N, Heller M, Lundström-Stadelmann B. Investigation of the mechanism of action of mefloquine and derivatives against the parasite Echinococcus multilocularis. Int J Parasitol Drugs Drug Resist 2023; 21:114-124. [PMID: 36921443 PMCID: PMC10025029 DOI: 10.1016/j.ijpddr.2023.03.002] [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: 12/14/2022] [Revised: 03/03/2023] [Accepted: 03/05/2023] [Indexed: 03/12/2023]
Abstract
Alveolar echinococcosis (AE) is caused by infection with the fox tapeworm E. multilocularis. The disease affects humans, dogs, captive monkeys, and other mammals, and it is caused by the metacestode stage of the parasite growing invasively in the liver. The current drug treatment is based on non-parasiticidal benzimidazoles. Thus, they are only limitedly curative and can cause severe side effects. Therefore, novel and improved treatment options for AE are needed. Mefloquine (MEF), an antimalarial agent, was previously shown to be effective against E. multilocularis in vitro and in experimentally infected mice. However, MEF is not parasiticidal and needs improvement for successful treatment of patients, and it can induce strong neuropsychiatric side-effects. In this study, the structure-activity relationship and mode of action of MEF was investigated by comparative analysis of 14 MEF derivatives. None of them showed higher activity against E. multilocularis metacestodes compared to MEF, but four compounds caused limited damage. In order to identify molecular targets of MEF and effective derivatives, differential affinity chromatography combined with mass spectrometry was performed with two effective compounds (MEF, MEF-3) and two ineffective compounds (MEF-13, MEF-22). 1'681 proteins were identified that bound specifically to MEF or derivatives. 216 proteins were identified as binding only to MEF and MEF-3. GO term enrichment analysis of these proteins and functional grouping of the 25 most abundant MEF and MEF-3 specific binding proteins revealed the key processes energy metabolism and cellular transport and structure, as well as stress responses and nucleic acid binding to be involved. The previously described ferritin was confirmed as an exclusively MEF-binding protein that could be relevant for its efficacy against E. multilocularis. The here identified potential targets of MEF will be further investigated in the future for a clear understanding of the pleiotropic effects of MEF, and improved therapeutic options against AE.
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Affiliation(s)
- Roman Memedovski
- Institute of Parasitology, Department of Infectious Diseases and Pathobiology, Vetsuisse Faculty, University of Bern, Bern, Switzerland
| | - Matías Preza
- Institute of Parasitology, Department of Infectious Diseases and Pathobiology, Vetsuisse Faculty, University of Bern, Bern, Switzerland
| | - Joachim Müller
- Institute of Parasitology, Department of Infectious Diseases and Pathobiology, Vetsuisse Faculty, University of Bern, Bern, Switzerland
| | - Tobias Kämpfer
- Institute of Parasitology, Department of Infectious Diseases and Pathobiology, Vetsuisse Faculty, University of Bern, Bern, Switzerland
| | - Reto Rufener
- Institute of Parasitology, Department of Infectious Diseases and Pathobiology, Vetsuisse Faculty, University of Bern, Bern, Switzerland
| | | | - Emerson Teixeira da Silva
- Fundação Oswaldo Cruz, Instituto de Tecnologia em Fármacos - Far Manguinhos, 21041-250, Rio de Janeiro, Brazil
| | | | - Sophie Braga
- Proteomics and Mass Spectrometry Core Facility, Department for BioMedical Research (DBMR), University of Bern, Bern, Switzerland
| | - Anne-Christine Uldry
- Proteomics and Mass Spectrometry Core Facility, Department for BioMedical Research (DBMR), University of Bern, Bern, Switzerland
| | - Natasha Buchs
- Proteomics and Mass Spectrometry Core Facility, Department for BioMedical Research (DBMR), University of Bern, Bern, Switzerland
| | - Manfred Heller
- Proteomics and Mass Spectrometry Core Facility, Department for BioMedical Research (DBMR), University of Bern, Bern, Switzerland
| | - Britta Lundström-Stadelmann
- Institute of Parasitology, Department of Infectious Diseases and Pathobiology, Vetsuisse Faculty, University of Bern, Bern, Switzerland; Multidisciplinary Center for Infectious Diseases, University of Bern, Bern, Switzerland.
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Demmer JK, Phillips BP, Uhrig OL, Filloux A, Allsopp LP, Bublitz M, Meier T. Structure of ATP synthase from ESKAPE pathogen Acinetobacter baumannii. SCIENCE ADVANCES 2022; 8:eabl5966. [PMID: 35171679 PMCID: PMC8849298 DOI: 10.1126/sciadv.abl5966] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/23/2021] [Accepted: 12/23/2021] [Indexed: 06/14/2023]
Abstract
The global spread of multidrug-resistant Acinetobacter baumannii infections urgently calls for the identification of novel drug targets. We solved the electron cryo-microscopy structure of the F1Fo-adenosine 5'-triphosphate (ATP) synthase from A. baumannii in three distinct conformational states. The nucleotide-converting F1 subcomplex reveals a specific self-inhibition mechanism, which supports a unidirectional ratchet mechanism to avoid wasteful ATP consumption. In the membrane-embedded Fo complex, the structure shows unique structural adaptations along both the entry and exit pathways of the proton-conducting a-subunit. These features, absent in mitochondrial ATP synthases, represent attractive targets for the development of next-generation therapeutics that can act directly at the culmination of bioenergetics in this clinically relevant pathogen.
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Affiliation(s)
- Julius K. Demmer
- Department of Life Sciences, Imperial College London, Exhibition Road, London SW7 2AZ, UK
| | - Ben P. Phillips
- Department of Life Sciences, Imperial College London, Exhibition Road, London SW7 2AZ, UK
| | - O. Lisa Uhrig
- Department of Life Sciences, Imperial College London, Exhibition Road, London SW7 2AZ, UK
| | - Alain Filloux
- MRC Centre for Molecular Bacteriology and Infection, Department of Life Sciences, Imperial College London, London SW7 2AZ, UK
| | - Luke P. Allsopp
- MRC Centre for Molecular Bacteriology and Infection, Department of Life Sciences, Imperial College London, London SW7 2AZ, UK
- National Heart and Lung Institute, Imperial College, London, UK
| | - Maike Bublitz
- Department of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, UK
| | - Thomas Meier
- Department of Life Sciences, Imperial College London, Exhibition Road, London SW7 2AZ, UK
- Private University in the Principality of Liechtenstein, Triesen, Liechtenstein
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Targeting the ATP synthase in bacterial and fungal pathogens – beyond Mycobacterium tuberculosis. J Glob Antimicrob Resist 2022; 29:29-41. [DOI: 10.1016/j.jgar.2022.01.026] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2021] [Revised: 01/24/2022] [Accepted: 01/30/2022] [Indexed: 11/23/2022] Open
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Rossi R, Ciofalo M. Palladium-Catalysed Intermolecular Direct C–H Bond Arylation of Heteroarenes with Reagents Alternative to Aryl Halides: Current State of the Art. CURR ORG CHEM 2022. [DOI: 10.2174/1385272826666220201124008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Abstract:
Abstract: This unprecedented review with 322 references provides a critical up-to-date picture of the Pd-catalysed intermolecular direct C–H bond arylation of heteroarenes with arylating reagents alternative to aryl halides that include aryl sulfonates (aryl triflates, tosylates, mesylates, and imidazole-1-sulfonates), diaryliodonium salts, [(diacetoxy)iodo]arenes, arenediazonium salts, 1-aryltriazenes, arylhydrazines and N’-arylhydrazides, arenesulfonyl chlorides, sodium arenesulfinates, arenesulfinic acids, and arenesulfonohydrazides. Particular attention has been paid to summarise the preparation of the various arylating reagents and to highlight the practicality, versatility, and limitations of the various developed arylation protocols, also comparing their results with those achieved in analogous Pd-catalysed arylation reactions involving the use of aryl halides as electrophiles. Mechanistic proposals have also been briefly summarised and discussed. However, data concerning Pd-catalysed direct C–H bond arylations involving the C–H bonds of aryl substituents of the examined heteroarene derivatives have not been taken into account.
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Affiliation(s)
- Renzo Rossi
- Dipartimento di Chimica e Chimica Industriale, University of Pisa, Via G. Moruzzi 3, I-56124 Pisa, Italy
| | - Maurizio Ciofalo
- Dipartimento di Scienze Agrarie, Alimentari e Forestali, University of Palermo, Viale delle Scienze, Edificio 4, I-90128, Palermo, Italy
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Overcoming the Prokaryote/Eukaryote Barrier in Tuberculosis Treatment: A Prospect for the Repurposing and Use of Antiparasitic Drugs. Microorganisms 2021; 9:microorganisms9112335. [PMID: 34835459 PMCID: PMC8622410 DOI: 10.3390/microorganisms9112335] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2021] [Revised: 11/07/2021] [Accepted: 11/09/2021] [Indexed: 11/17/2022] Open
Abstract
Antimicrobial resistance, the so-called silent pandemic, is pushing industry and academia to find novel antimicrobial agents with new mechanisms of action in order to be active against susceptible and drug-resistant microorganisms. In the case of tuberculosis, the need of novel anti-tuberculosis drugs is specially challenging because of the intricate biology of its causative agent, Mycobacterium tuberculosis. The repurposing of medicines has arisen in recent years as a fast, low-cost, and efficient strategy to identify novel biomedical applications for already approved drugs. This review is focused on anti-parasitic drugs that have additionally demonstrated certain levels of anti-tuberculosis activity; along with this, natural products with a dual activity against parasites and against M. tuberculosis are discussed. A few clinical trials have tested antiparasitic drugs in tuberculosis patients, and have revealed effective dose and toxicity issues, which is consistent with the natural differences between tuberculosis and parasitic infections. However, through medicinal chemistry approaches, derivatives of drugs with anti-parasitic activity have become successful drugs for use in tuberculosis therapy. In summary, even when the repurposing of anti-parasitic drugs for tuberculosis treatment does not seem to be an easy job, it deserves attention as a potential contributor to fuel the anti-tuberculosis drug pipeline.
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Cellular targets of mefloquine. Toxicology 2021; 464:152995. [PMID: 34678321 DOI: 10.1016/j.tox.2021.152995] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2021] [Revised: 10/14/2021] [Accepted: 10/15/2021] [Indexed: 11/24/2022]
Abstract
Mefloquine is a quinoline-based compound widely used as an antimalarial drug, particularly in chemoprophylaxis. Although decades of research have identified various aspects of mefloquine's anti-Plasmodium properties, toxic effects offset its robust use in humans. Mefloquine exerts harmful effects in several types of human cells by targeting many of the cellular lipids, proteins, and complexes, thereby blocking a number of downstream signaling cascades. In general, mefloquine modulates several cellular phenomena, such as alteration of membrane potential, induction of oxidative stress, imbalance of ion homeostasis, disruption of metabolism, failure of organelle function, etc., leading to cell cycle arrest and programmed cell death. This review aims to summarize the information on functional and mechanistic findings related to the cytotoxic effects of mefloquine.
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Description of optochin-resistant Streptococcus pneumoniae due to an uncommon mutation in the atpA gene and comparison with previously identified atpC mutants from Brazil. Sci Rep 2021; 11:7936. [PMID: 33846478 PMCID: PMC8041871 DOI: 10.1038/s41598-021-87071-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2020] [Accepted: 03/15/2021] [Indexed: 11/09/2022] Open
Abstract
Optochin susceptibility testing is a major assay used for presumptive identification of Streptococcus pneumoniae. Still, atypical optochin-resistant (Optr) pneumococci have been reported and this phenotype has been attributed to nucleotide substitutions in the genes coding for the F0F1ATPase. While substitutions in the atpC gene (c-subunit of ATPase) are more common and better characterized, data on mutations in the atpA (a-subunit) are still limited. We have characterized five Optr isolates presenting alterations in the atpA (Trp206Cys in four isolates and Trp206Ser in one isolate), constituting the first report of such mutations in Brazil. Most of the Optr isolates consisted of heterogeneous populations. Except for Opt MICs and the nucleotide changes in the atpA gene, Optr and Opts subpopulations originating from the same culture had identical characteristics. In addition, we compared phenotypic and genetic characteristics of these atpA mutants with those of atpC mutants previously identified in Brazil. No structural alterations were detected among predicted proteins, regardless of mutations in the coding gene, suggesting that, despite the occurrence of mutations, protein structures tend to be highly conserved, ensuring their functionalities. Phylogenetic analysis revealed that atypical Optr strains are true pneumococci and Opt resistance does not represent any apparent selective advantage for clinical isolates.
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Dos Santos MC, Scaini JLR, Lopes MVC, Rodrigues BG, Silva NO, Borges CRL, Dos Santos SC, Dos Santos Machado K, Werhli AV, da Silva PEA, Lourenço MCS, da Silva ET, de Souza MVN, de Lima VR, Gonçalves RSB. Mefloquine synergism with anti-tuberculosis drugs and correlation to membrane effects: Biologic, spectroscopic and molecular dynamics simulations studies. Bioorg Chem 2021; 110:104786. [PMID: 33740676 DOI: 10.1016/j.bioorg.2021.104786] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2020] [Revised: 12/07/2020] [Accepted: 02/26/2021] [Indexed: 12/26/2022]
Abstract
Studies displaying the combination of mefloquine (MFL) with anti-tuberculosis (TB) substances are limited in the literature. In this work, the effect of MFL-association with two first-line anti-TB drugs and six fluoroquinolones was evaluated against Mycobacterium tuberculosis drug resistant strains. MFL showed synergistic interaction with isoniazid, pyrazinamide, and several fluoroquinolones, reaching fractional inhibitory concentration indexes (FICIs) ranging from 0.03 to 0.5. In order to better understand the observed results, two approaches have been explored: (i) spectroscopic responses attributed to the effect of MFL on physicochemical properties related to a liposomal membrane model composed by soybean asolectin; (ii) molecular dynamics (MD) simulation data regarding MFL interaction with a membrane model based on PIM2, a lipid constituent of the mycobacterial cell wall. FTIR and NMR data showed that MFL affects expressively the region between the phosphate and the first methylene groups of soybean asolectin membranes, disordering these regions. MD simulations results detected high MFL density in the glycolipid interface and showed that the drug increases the membrane lateral diffusion, enhancing its permeability. The obtained results suggest that synergistic activities related to MFL are attributed to its effect of lipid disorder and membrane permeability enhancement.
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Affiliation(s)
- Marinalva Cardoso Dos Santos
- Grupo de Investigação de Interações Moleculares em Membranas, Escola de Química e Alimentos, Programa de Pós-Graduação em Química Tecnológica e Ambiental, Universidade Federal do Rio Grande - FURG, Av. Itália, km 8, Campus Carreiros, 96203-900, Rio Grande, RS, Brazil
| | - João Luís Rheingantz Scaini
- COMBI-Lab, Grupo de Biologia Computacional, Centro de Ciências Computacionais, Universidade Federal do Rio Grande - FURG, Av. Itália, km 8, Campus Carreiros, 96203-900, Rio Grande, RS, Brazil; Faculdade de Medicina, Universidade Federal do Rio Grande - FURG, Av. Itália, km 8, Campus Carreiros, 96203-900, Rio Grande, RS, Brazil
| | - Márcio Vinicius Costa Lopes
- Instituto de Química, Universidade Federal do Rio de Janeiro, Av. Athos da Silveira Ramos, 149 - Cidade Universitária, Rio de Janeiro, RJ 21941-909, Brazil
| | - Beatriz Gonçalves Rodrigues
- Grupo de Investigação de Interações Moleculares em Membranas, Escola de Química e Alimentos, Programa de Pós-Graduação em Química Tecnológica e Ambiental, Universidade Federal do Rio Grande - FURG, Av. Itália, km 8, Campus Carreiros, 96203-900, Rio Grande, RS, Brazil
| | - Nichole Osti Silva
- Grupo de Investigação de Interações Moleculares em Membranas, Escola de Química e Alimentos, Programa de Pós-Graduação em Química Tecnológica e Ambiental, Universidade Federal do Rio Grande - FURG, Av. Itália, km 8, Campus Carreiros, 96203-900, Rio Grande, RS, Brazil
| | - Carla Roberta Lopes Borges
- Grupo de Investigação de Interações Moleculares em Membranas, Escola de Química e Alimentos, Programa de Pós-Graduação em Química Tecnológica e Ambiental, Universidade Federal do Rio Grande - FURG, Av. Itália, km 8, Campus Carreiros, 96203-900, Rio Grande, RS, Brazil
| | - Sandra Cruz Dos Santos
- Grupo de Investigação de Interações Moleculares em Membranas, Escola de Química e Alimentos, Programa de Pós-Graduação em Química Tecnológica e Ambiental, Universidade Federal do Rio Grande - FURG, Av. Itália, km 8, Campus Carreiros, 96203-900, Rio Grande, RS, Brazil
| | - Karina Dos Santos Machado
- COMBI-Lab, Grupo de Biologia Computacional, Centro de Ciências Computacionais, Universidade Federal do Rio Grande - FURG, Av. Itália, km 8, Campus Carreiros, 96203-900, Rio Grande, RS, Brazil
| | - Adriano Velasque Werhli
- COMBI-Lab, Grupo de Biologia Computacional, Centro de Ciências Computacionais, Universidade Federal do Rio Grande - FURG, Av. Itália, km 8, Campus Carreiros, 96203-900, Rio Grande, RS, Brazil
| | - Pedro Eduardo Almeida da Silva
- Faculdade de Medicina, Universidade Federal do Rio Grande - FURG, Av. Itália, km 8, Campus Carreiros, 96203-900, Rio Grande, RS, Brazil
| | - Maria C S Lourenço
- Instituto de Pesquisas Clínica Evandro Chagas-IPEC, Av. Brasil, 4365 Manguinhos, Rio de Janeiro, Brazil
| | - Emerson T da Silva
- FioCruz-Fundação Oswaldo Cruz, Instituto de Tecnologia em Fármacos-Far-Manguinhos, Rua Sizenando Nabuco, 100, Manguinhos, 21041-250 Rio de Janeiro, RJ, Brazil
| | - Marcus V N de Souza
- FioCruz-Fundação Oswaldo Cruz, Instituto de Tecnologia em Fármacos-Far-Manguinhos, Rua Sizenando Nabuco, 100, Manguinhos, 21041-250 Rio de Janeiro, RJ, Brazil
| | - Vânia Rodrigues de Lima
- Grupo de Investigação de Interações Moleculares em Membranas, Escola de Química e Alimentos, Programa de Pós-Graduação em Química Tecnológica e Ambiental, Universidade Federal do Rio Grande - FURG, Av. Itália, km 8, Campus Carreiros, 96203-900, Rio Grande, RS, Brazil.
| | - Raoni Schroeder B Gonçalves
- Instituto de Química, Universidade Federal do Rio de Janeiro, Av. Athos da Silveira Ramos, 149 - Cidade Universitária, Rio de Janeiro, RJ 21941-909, Brazil.
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Derivatives of the Antimalarial Drug Mefloquine Are Broad-Spectrum Antifungal Molecules with Activity against Drug-Resistant Clinical Isolates. Antimicrob Agents Chemother 2020; 64:AAC.02331-19. [PMID: 31907188 DOI: 10.1128/aac.02331-19] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2019] [Accepted: 12/20/2019] [Indexed: 12/21/2022] Open
Abstract
The antifungal pharmacopeia is critically small, particularly in light of the recent emergence of multidrug-resistant pathogens, such as Candida auris Here, we report that derivatives of the antimalarial drug mefloquine have broad-spectrum antifungal activity against pathogenic yeasts and molds. In addition, the mefloquine derivatives have activity against clinical isolates that are resistant to one or more of the three classes of antifungal drugs currently used to treat invasive fungal infections, indicating that they have a novel mechanism of action. Importantly, the in vitro toxicity profiles obtained using human cell lines indicated that the toxicity profiles of the mefloquine derivatives are very similar to those of the parent mefloquine, despite being up to 64-fold more active against fungal cells. In addition to direct antifungal activity, subinhibitory concentrations of the mefloquine derivatives inhibited the expression of virulence traits, including filamentation in Candida albicans and capsule formation/melanization in Cryptococcus neoformans Mode/mechanism-of-action experiments indicated that the mefloquine derivatives interfere with both mitochondrial and vacuolar function as part of a multitarget mechanism of action. The broad-spectrum scope of activity, blood-brain barrier penetration, and large number of previously synthesized analogs available combine to support the further optimization and development of the antifungal activity of this general class of drug-like molecules.
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12
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Laumaillé P, Dassonville-Klimpt A, Peltier F, Mullié C, Andréjak C, Da-Nascimento S, Castelain S, Sonnet P. Synthesis and Study of New Quinolineaminoethanols as Anti-Bacterial Drugs. Pharmaceuticals (Basel) 2019; 12:E91. [PMID: 31216783 PMCID: PMC6630482 DOI: 10.3390/ph12020091] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2019] [Revised: 06/12/2019] [Accepted: 06/14/2019] [Indexed: 11/22/2022] Open
Abstract
The lack of antibiotics with a novel mode of action associated with the spread of drug resistant bacteria make the fight against infectious diseases particularly challenging. A quinoline core is found in several anti-infectious drugs, such as mefloquine and bedaquiline. Two main objectives were set in this work. Firstly, we evaluated the anti-mycobacterial properties of the previous quinolines 3, which have been identified as good candidates against ESKAPEE (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, Enterobacter spp. and Escherichia coli) bacteria. Secondly, a new series 4 was designed and assessed against the same bacteria strains, taking the pair of enantiomers 3m/3n as the lead. More than twenty compounds 4 were prepared through a five-step asymmetric synthesis with good enantiomeric excesses (>90%). Interestingly, all compounds of series 3 were efficient on M. avium with MIC = 2-16 µg/mL, while series 4 was less active. Both series 3 and 4 were generally more active than mefloquine against the ESKAPEE bacteria. The quinolines 4 were either active against Gram-positive bacteria (MIC ≤ 4 µg/mL for 4c-4h and 4k/4l) or E. coli (MIC = 32-64 µg/mL for 4q-4v) according to the global lipophilicity of these compounds.
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Affiliation(s)
- Pierre Laumaillé
- AGIR, EA 4294, UFR of Pharmacy, Jules Verne University of Picardie, 80037 Amiens, France.
| | | | - François Peltier
- AGIR, EA 4294, UFR of Pharmacy, Jules Verne University of Picardie, 80037 Amiens, France.
- Department of Bacteriology, Amiens University Hospital, 80054 Amiens, France.
| | - Catherine Mullié
- AGIR, EA 4294, UFR of Pharmacy, Jules Verne University of Picardie, 80037 Amiens, France.
| | - Claire Andréjak
- AGIR, EA 4294, UFR of Pharmacy, Jules Verne University of Picardie, 80037 Amiens, France.
- Respiratory and Intensive Care Unit, University Hospital Amiens, 80054 Amiens, France.
| | - Sophie Da-Nascimento
- AGIR, EA 4294, UFR of Pharmacy, Jules Verne University of Picardie, 80037 Amiens, France.
| | - Sandrine Castelain
- AGIR, EA 4294, UFR of Pharmacy, Jules Verne University of Picardie, 80037 Amiens, France.
- Department of Bacteriology, Amiens University Hospital, 80054 Amiens, France.
| | - Pascal Sonnet
- AGIR, EA 4294, UFR of Pharmacy, Jules Verne University of Picardie, 80037 Amiens, France.
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13
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Wang X, Zeng Y, Sheng L, Larson P, Liu X, Zou X, Wang S, Guo K, Ma C, Zhang G, Cui H, Ferguson DM, Li Y, Zhang J, Aldrich CC. A Cinchona Alkaloid Antibiotic That Appears To Target ATP Synthase in Streptococcus pneumoniae. J Med Chem 2019; 62:2305-2332. [PMID: 30779564 DOI: 10.1021/acs.jmedchem.8b01353] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Optochin, a cinchona alkaloid derivative discovered over 100 years ago, possesses highly selective antibacterial activity toward Streptococcus pneumoniae. Pneumococcal disease remains the leading source of bacterial pneumonia and meningitis worldwide. The structure-activity relationships of optochin were examined through modification to both the quinoline and quinuclidine subunits, which led to the identification of analogue 48 with substantially improved activity. Resistance and molecular modeling studies indicate that 48 likely binds to the c-ring of ATP synthase near the conserved glutamate 52 ion-binding site, while mechanistic studies demonstrated that 48 causes cytoplasmic acidification. Initial pharmacokinetic and drug metabolism analyses of optochin and 48 revealed limitations of these quinine analogues, which were rapidly cleared, resulting in poor in vivo exposure through hydroxylation pendants to the quinuclidine and O-dealkylation of the quinoline. Collectively, the results provide a foundation to advance 48 and highlight ATP synthase as a promising target for antibiotic development.
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Affiliation(s)
| | - Yuna Zeng
- Center for Infectious Disease Research, School of Medicine , Tsinghua University , Beijing 100084 , People's Republic of China
| | | | - Peter Larson
- Department of Medicinal Chemistry , University of Minnesota , Minneapolis , Minnesota 55455 , United States
| | - Xue Liu
- Center for Infectious Disease Research, School of Medicine , Tsinghua University , Beijing 100084 , People's Republic of China
| | | | | | | | | | | | | | - David M Ferguson
- Department of Medicinal Chemistry , University of Minnesota , Minneapolis , Minnesota 55455 , United States
| | | | - Jingren Zhang
- Center for Infectious Disease Research, School of Medicine , Tsinghua University , Beijing 100084 , People's Republic of China
| | - Courtney C Aldrich
- Department of Medicinal Chemistry , University of Minnesota , Minneapolis , Minnesota 55455 , United States
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14
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Veale CGL. Unpacking the Pathogen Box-An Open Source Tool for Fighting Neglected Tropical Disease. ChemMedChem 2019; 14:386-453. [PMID: 30614200 DOI: 10.1002/cmdc.201800755] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2018] [Indexed: 12/13/2022]
Abstract
The Pathogen Box is a 400-strong collection of drug-like compounds, selected for their potential against several of the world's most important neglected tropical diseases, including trypanosomiasis, leishmaniasis, cryptosporidiosis, toxoplasmosis, filariasis, schistosomiasis, dengue virus and trichuriasis, in addition to malaria and tuberculosis. This library represents an ensemble of numerous successful drug discovery programmes from around the globe, aimed at providing a powerful resource to stimulate open source drug discovery for diseases threatening the most vulnerable communities in the world. This review seeks to provide an in-depth analysis of the literature pertaining to the compounds in the Pathogen Box, including structure-activity relationship highlights, mechanisms of action, related compounds with reported activity against different diseases, and, where appropriate, discussion on the known and putative targets of compounds, thereby providing context and increasing the accessibility of the Pathogen Box to the drug discovery community.
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Affiliation(s)
- Clinton G L Veale
- School of Chemistry and Physics, Pietermaritzburg Campus, University of KwaZulu-Natal, Private Bag X01, Scottsville, 3209, South Africa
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15
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Gold B, Nathan C. Targeting Phenotypically Tolerant Mycobacterium tuberculosis. Microbiol Spectr 2017; 5:10.1128/microbiolspec.TBTB2-0031-2016. [PMID: 28233509 PMCID: PMC5367488 DOI: 10.1128/microbiolspec.tbtb2-0031-2016] [Citation(s) in RCA: 80] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2016] [Indexed: 01/08/2023] Open
Abstract
While the immune system is credited with averting tuberculosis in billions of individuals exposed to Mycobacterium tuberculosis, the immune system is also culpable for tempering the ability of antibiotics to deliver swift and durable cure of disease. In individuals afflicted with tuberculosis, host immunity produces diverse microenvironmental niches that support suboptimal growth, or complete growth arrest, of M. tuberculosis. The physiological state of nonreplication in bacteria is associated with phenotypic drug tolerance. Many of these host microenvironments, when modeled in vitro by carbon starvation, complete nutrient starvation, stationary phase, acidic pH, reactive nitrogen intermediates, hypoxia, biofilms, and withholding streptomycin from the streptomycin-addicted strain SS18b, render M. tuberculosis profoundly tolerant to many of the antibiotics that are given to tuberculosis patients in clinical settings. Targeting nonreplicating persisters is anticipated to reduce the duration of antibiotic treatment and rate of posttreatment relapse. Some promising drugs to treat tuberculosis, such as rifampin and bedaquiline, only kill nonreplicating M. tuberculosisin vitro at concentrations far greater than their minimal inhibitory concentrations against replicating bacilli. There is an urgent demand to identify which of the currently used antibiotics, and which of the molecules in academic and corporate screening collections, have potent bactericidal action on nonreplicating M. tuberculosis. With this goal, we review methods of high-throughput screening to target nonreplicating M. tuberculosis and methods to progress candidate molecules. A classification based on structures and putative targets of molecules that have been reported to kill nonreplicating M. tuberculosis revealed a rich diversity in pharmacophores.
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Affiliation(s)
- Ben Gold
- Department of Microbiology & Immunology, Weill Cornell Medical College, New York, NY, 10065
| | - Carl Nathan
- Department of Microbiology & Immunology, Weill Cornell Medical College, New York, NY, 10065
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16
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Rossi R, Lessi M, Manzini C, Marianetti G, Bellina F. Achievement of regioselectivity in transition metal-catalyzed direct C–H (hetero)arylation reactions of heteroarenes with one heteroatom through the use of removable protecting/blocking substituents or traceless directing groups. Tetrahedron 2016. [DOI: 10.1016/j.tet.2016.02.037] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
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17
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Ikryannikova LN, Ischenko DS, Lominadze GG, Kanygina AV, Karpova IY, Kostryukova ES, Mayansky NA, Skvortsov VS, Ilina EN, Govorun VM. The mystery of the fourth clone: comparative genomic analysis of four non-typeable Streptococcus pneumoniae strains with different susceptibilities to optochin. Eur J Clin Microbiol Infect Dis 2015; 35:119-30. [PMID: 26563895 DOI: 10.1007/s10096-015-2516-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2015] [Accepted: 10/26/2015] [Indexed: 11/25/2022]
Abstract
Optochin-resistant pneumococci can be rarely caught in clinical microbiology laboratories because of the routine identification of all such strains as viridans group non-pneumococci. We were lucky to find four non-typeable Streptococcus pneumoniae clones demonstrating the different susceptibilities to optochin: one of them (Spn_13856) was resistant to optochin, while the other three (Spn_1719, Spn_27, and Spn_2298) were susceptible. Whole genome nucleotide sequences of these strains were compared to reveal the differences between the optochin-resistant and optochin-susceptible strains. Two adjacent genes coding maltose O-acetyltransferase and uridine phosphorylase which were presented in the genomes of all optochin-susceptible strains and missed in the optochin-resistant strain were revealed. Non-synonymous substitutions in 14 protein-coding genes were discovered, including the Ala49Ser mutation in the C-subunit of the F0 part of the ATP synthase rotor usually associated with pneumococcal optochin resistance. Modeling of a process of optochin interaction with the F0 part of the ATP synthase rotor indicates that the complex of optochin with "domain C" composed by wild-type C-subunits is more stable than the same complex composed of Ala49Ser mutant C-subunits.
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Affiliation(s)
- L N Ikryannikova
- Research Institute of Physical-Chemical Medicine, Ministry of Public Health of Russian Federation, 119992, Malaya Pirogovskaya str., 1a, Moscow, Russia.
| | - D S Ischenko
- Research Institute of Physical-Chemical Medicine, Ministry of Public Health of Russian Federation, 119992, Malaya Pirogovskaya str., 1a, Moscow, Russia
| | - G G Lominadze
- Federal State Budgetary Institute "Scientific Center of Children Health" of RAMS, Moscow, Russia
| | - A V Kanygina
- Research Institute of Physical-Chemical Medicine, Ministry of Public Health of Russian Federation, 119992, Malaya Pirogovskaya str., 1a, Moscow, Russia
| | - I Y Karpova
- Research Institute of Physical-Chemical Medicine, Ministry of Public Health of Russian Federation, 119992, Malaya Pirogovskaya str., 1a, Moscow, Russia
| | - E S Kostryukova
- Research Institute of Physical-Chemical Medicine, Ministry of Public Health of Russian Federation, 119992, Malaya Pirogovskaya str., 1a, Moscow, Russia
| | - N A Mayansky
- Federal State Budgetary Institute "Scientific Center of Children Health" of RAMS, Moscow, Russia
| | - V S Skvortsov
- Institute of Biomedical Chemistry, 10 Pogodinskaya str., Moscow, 119121, Russia
| | - E N Ilina
- Research Institute of Physical-Chemical Medicine, Ministry of Public Health of Russian Federation, 119992, Malaya Pirogovskaya str., 1a, Moscow, Russia
| | - V M Govorun
- Research Institute of Physical-Chemical Medicine, Ministry of Public Health of Russian Federation, 119992, Malaya Pirogovskaya str., 1a, Moscow, Russia
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18
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Gerlini A, Colomba L, Furi L, Braccini T, Manso AS, Pammolli A, Wang B, Vivi A, Tassini M, van Rooijen N, Pozzi G, Ricci S, Andrew PW, Koedel U, Moxon ER, Oggioni MR. The role of host and microbial factors in the pathogenesis of pneumococcal bacteraemia arising from a single bacterial cell bottleneck. PLoS Pathog 2014; 10:e1004026. [PMID: 24651834 PMCID: PMC3961388 DOI: 10.1371/journal.ppat.1004026] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2013] [Accepted: 02/10/2014] [Indexed: 01/27/2023] Open
Abstract
The pathogenesis of bacteraemia after challenge with one million pneumococci of three isogenic variants was investigated. Sequential analyses of blood samples indicated that most episodes of bacteraemia were monoclonal events providing compelling evidence for a single bacterial cell bottleneck at the origin of invasive disease. With respect to host determinants, results identified novel properties of splenic macrophages and a role for neutrophils in early clearance of pneumococci. Concerning microbial factors, whole genome sequencing provided genetic evidence for the clonal origin of the bacteraemia and identified SNPs in distinct sub-units of F0/F1 ATPase in the majority of the ex vivo isolates. When compared to parental organisms of the inoculum, ex-vivo pneumococci with mutant alleles of the F0/F1 ATPase had acquired the capacity to grow at low pH at the cost of the capacity to grow at high pH. Although founded by a single cell, the genotypes of pneumococci in septicaemic mice indicate strong selective pressure for fitness, emphasising the within-host complexity of the pathogenesis of invasive disease.
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Affiliation(s)
- Alice Gerlini
- LAMMB, Department of Biotechnology, University of Siena, Siena, Italy
| | - Leonarda Colomba
- LAMMB, Department of Biotechnology, University of Siena, Siena, Italy
| | - Leonardo Furi
- LAMMB, Department of Biotechnology, University of Siena, Siena, Italy
| | - Tiziana Braccini
- LAMMB, Department of Biotechnology, University of Siena, Siena, Italy
| | - Ana Sousa Manso
- LAMMB, Department of Biotechnology, University of Siena, Siena, Italy
| | - Andrea Pammolli
- Department of Pathophysiology, Experimental Medicine and Public Health, University of Siena, Siena, Italy
| | - Bo Wang
- Department of Mathematics, University of Leicester, Leicester, United Kingdom
| | | | | | - Nico van Rooijen
- Department of Molecular Cell Biology, Vrije Universiteit Medical Center, Amsterdam, The Netherlands
| | - Gianni Pozzi
- LAMMB, Department of Biotechnology, University of Siena, Siena, Italy
- UOC Batteriologia, Azienda Ospedaliera Universitaria Senese, Siena, Italy
| | - Susanna Ricci
- LAMMB, Department of Biotechnology, University of Siena, Siena, Italy
| | - Peter W. Andrew
- Department of Infection, Immunity and Inflammation, University of Leicester, Leicester, United Kingdom
| | - Uwe Koedel
- Department of Neurology, Ludwig-Maximilians University of Munich, München, Germany
| | - E. Richard Moxon
- Division of Medical Sciences, John Radcliffe Hospital, University of Oxford, Oxford, United Kingdom
| | - Marco R. Oggioni
- LAMMB, Department of Biotechnology, University of Siena, Siena, Italy
- UOC Batteriologia, Azienda Ospedaliera Universitaria Senese, Siena, Italy
- Department of Genetics, University of Leicester, Leicester, United Kingdom
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19
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Rossi R, Bellina F, Lessi M, Manzini C. Cross-Coupling of Heteroarenes by CH Functionalization: Recent Progress towards Direct Arylation and Heteroarylation Reactions Involving Heteroarenes Containing One Heteroatom. Adv Synth Catal 2014. [DOI: 10.1002/adsc.201300922] [Citation(s) in RCA: 366] [Impact Index Per Article: 36.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
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20
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Phenotypic and molecular characterization of optochin-resistant Streptococcus pneumoniae isolates from Brazil, with description of five novel mutations in the ATPC gene. J Clin Microbiol 2013; 51:3242-9. [PMID: 23884994 DOI: 10.1128/jcm.01168-13] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Optochin (Opt) susceptibility is used largely for the identification of Streptococcus pneumoniae in diagnostic laboratories. Opt-resistant (Opt(r)) S. pneumoniae isolates have been reported, however, indicating the potential for misidentification of this important pathogen. Point mutations in the atpC gene have been associated with the emergence of Opt(r) S. pneumoniae, but data on the characterization of such atypical variants of S. pneumoniae are still limited. The present report describes the results of a polyphasic approach to identifying and characterizing 26 Opt(r) S. pneumoniae isolates recovered from patients or carriers living in Brazil. Sixteen isolates consisted of heterogeneous populations, and 10 isolates were homogeneously Opt(r). The isolates had different serotypes and antimicrobial susceptibility profiles. They also presented diverse genetic characteristics, as indicated by pulsed-field gel electrophoresis (PFGE), multilocus variable-number tandem-repeat analysis (MLVA), and pspA gene typing. Except for Opt MICs (4- to 64-fold higher among Opt(r) variants), Opt(r) and Opt-susceptible (Opt(s)) subpopulations originating from the same culture had identical characteristics. Sequencing of the atpC gene of the Opt(r) variants revealed 13 different nucleotide changes distributed among eight different codons. Changes in codon 49 were the most frequent, suggesting that this might be a hot spot for optochin resistance-conferring mutations. On the other hand, five novel types of mutations in the atpC gene (Met13Ile, Gly18Ser, Gly20Ala, Ala31Val, and Ala49Gly) were identified. In silico prediction modeling indicated that the atpC gene mutations corresponded to alterations in the transmembrane region of the ATPase, leading to a higher hydrophobicity profile in α-helix 1 and to a lower hydrophobicity profile in α-helix 2.
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21
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Biuković G, Basak S, Manimekalai MSS, Rishikesan S, Roessle M, Dick T, Rao SPS, Hunke C, Grüber G. Variations of subunit {varepsilon} of the Mycobacterium tuberculosis F1Fo ATP synthase and a novel model for mechanism of action of the tuberculosis drug TMC207. Antimicrob Agents Chemother 2013; 57:168-76. [PMID: 23089752 PMCID: PMC3535943 DOI: 10.1128/aac.01039-12] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2012] [Accepted: 10/11/2012] [Indexed: 11/20/2022] Open
Abstract
The subunit ε of bacterial F(1)F(O) ATP synthases plays an important regulatory role in coupling and catalysis via conformational transitions of its C-terminal domain. Here we present the first low-resolution solution structure of ε of Mycobacterium tuberculosis (Mtε) F(1)F(O) ATP synthase and the nuclear magnetic resonance (NMR) structure of its C-terminal segment (Mtε(103-120)). Mtε is significantly shorter (61.6 Å) than forms of the subunit in other bacteria, reflecting a shorter C-terminal sequence, proposed to be important in coupling processes via the catalytic β subunit. The C-terminal segment displays an α-helical structure and a highly positive surface charge due to the presence of arginine residues. Using NMR spectroscopy, fluorescence spectroscopy, and mutagenesis, we demonstrate that the new tuberculosis (TB) drug candidate TMC207, proposed to bind to the proton translocating c-ring, also binds to Mtε. A model for the interaction of TMC207 with both ε and the c-ring is presented, suggesting that TMC207 forms a wedge between the two rotating subunits by interacting with the residues W15 and F50 of ε and the c-ring, respectively. T19 and R37 of ε provide the necessary polar interactions with the drug molecule. This new model of the mechanism of TMC207 provides the basis for the design of new drugs targeting the F(1)F(O) ATP synthase in M. tuberculosis.
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Affiliation(s)
- Goran Biuković
- School of Biological Sciences, Nanyang Technological University, Singapore, Republic of Singapore
| | - Sandip Basak
- School of Biological Sciences, Nanyang Technological University, Singapore, Republic of Singapore
| | | | | | - Manfred Roessle
- European Molecular Biology Laboratory, Hamburg Outstation, EMBL c/o DESY, Hamburg, Germany
| | - Thomas Dick
- National University of Singapore, Yong Loo Lin School of Medicine, Department of Microbiology, Singapore, Republic of Singapore
| | - Srinivasa P. S. Rao
- Novartis Institute for Tropical Diseases Pte. Ltd., Singapore, Republic of Singapore
| | - Cornelia Hunke
- School of Biological Sciences, Nanyang Technological University, Singapore, Republic of Singapore
| | - Gerhard Grüber
- School of Biological Sciences, Nanyang Technological University, Singapore, Republic of Singapore
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22
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Characterization of recombinant fluoroquinolone-resistant pneumococcus-like isolates. Antimicrob Agents Chemother 2012; 57:254-60. [PMID: 23114769 DOI: 10.1128/aac.01357-12] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Fourteen fluoroquinolone-resistant streptococcal isolates with recombinant DNA topoisomerase genes, preliminarily identified as pneumococci, were further characterized using phenotypic and genotypic approaches. Phenotypic tests classified them as atypical pneumococci. Phylogenetic relationships were analyzed by using the sequences of seven housekeeping alleles from these isolates and from isolates of Streptococcus pneumoniae, Streptococcus mitis, Streptococcus oralis, and Streptococcus pseudopneumoniae. Four isolates grouped with S. pneumoniae, seven grouped with S. pseudopneumoniae, and three grouped with S. mitis. These results generally agreed with those obtained with an optochin susceptibility test and with the organization of the atp operon chromosomal region, encoding the F(o)F(1) H(+)-ATPase (the target of optochin). All seven isolates grouping with S. pseudopneumoniae share the same spr1368-atpC-atpA gene order; all four grouping with S. pneumoniae share the spr1368-IS1239-atpC-atpA order, and two out of the three grouping with S. mitis share the spr1284-atpC-atpA order. In addition, evidence for recombination within the seven housekeeping alleles of the S. pseudopneumoniae population was provided by several methods: the index of association (0.4598, P < 0.001), the pairwise homoplasy index, and the split-decomposition method. This study confirms the existence of pneumococci among the alpha-hemolytic streptococci with DNA topoisomerase genes showing a mosaic structure and reveals a close relationship between atypical pneumococci and S. pseudopneumoniae.
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23
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Palomino JC, Martin A. Is repositioning of drugs a viable alternative in the treatment of tuberculosis? J Antimicrob Chemother 2012; 68:275-83. [DOI: 10.1093/jac/dks405] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
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24
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Gonçalves RS, Kaiser CR, Lourenço MC, Bezerra FA, de Souza MV, Wardell JL, Wardell SM, Henriques MDGMO, Costa T. Mefloquine–oxazolidine derivatives, derived from mefloquine and arenecarbaldehydes: In vitro activity including against the multidrug-resistant tuberculosis strain T113. Bioorg Med Chem 2012; 20:243-8. [DOI: 10.1016/j.bmc.2011.11.006] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2011] [Revised: 10/30/2011] [Accepted: 11/05/2011] [Indexed: 11/28/2022]
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25
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Gonçalves RS, Kaiser CR, Lourenço MC, de Souza MV, Wardell JL, Wardell SM, da Silva AD. Synthesis and antitubercular activity of new mefloquine-oxazolidine derivatives. Eur J Med Chem 2010; 45:6095-100. [PMID: 20932608 DOI: 10.1016/j.ejmech.2010.09.024] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2010] [Revised: 09/02/2010] [Accepted: 09/08/2010] [Indexed: 10/19/2022]
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26
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MAEDA M. H +-transporting ATP Synthases: Insights into How Their Electrochemically Driven Motor Might Serve as a Drug Target. YAKUGAKU ZASSHI 2010; 130:191-7. [DOI: 10.1248/yakushi.130.191] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Affiliation(s)
- Masatomo MAEDA
- Department of Molecular Biology, School of Pharmacy, Iwate Medical University
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27
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Novel quinoline and naphthalene derivatives as potent antimycobacterial agents. Eur J Med Chem 2010; 45:1854-67. [PMID: 20137835 DOI: 10.1016/j.ejmech.2010.01.024] [Citation(s) in RCA: 84] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2009] [Revised: 01/08/2010] [Accepted: 01/12/2010] [Indexed: 11/21/2022]
Abstract
We have designed and synthesized both the quinoline and naphthalene based molecules influenced by the unique structural make-up of mefloquine and TMC207, respectively. These compounds were evaluated for their anti-mycobacterial activity against drug sensitive Mycobacterium tuberculosis H37Rv in vitro at single-dose concentration (6.25 microg/mL). The compounds 22, 23, 26 and 27 inhibited the growth of M. tuberculosis H37Rv 99%, 90%, 98% and 91% respectively. Minimum inhibitory concentration of compounds 22, 23, 26 and 27 was found to be 6.25 microg/mL. Our molecular modeling and docking studies of designed compounds showed hydrogen bonding with Glu-61, Tyr-64 and Asn-190 amino acid residues at the putative binding site of ATP synthase, these interactions were coherent as shown by Mefloquine and TMC207, where hydrogen bonding was found with Tyr-64 and Glu-61 respectively. SAR analysis indicates importance of hydroxyl group and nature of substituents on piperazinyl-phenyl ring was critical in dictating the biological activity of newly synthesized compounds.
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28
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Schipper DJ, El-Salfiti M, Whipp CJ, Fagnou K. Direct arylation of azine N-oxides with aryl triflates. Tetrahedron 2009. [DOI: 10.1016/j.tet.2009.03.077] [Citation(s) in RCA: 91] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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29
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Lilienkampf A, Mao J, Wan B, Wang Y, Franzblau SG, Kozikowski AP. Structure−Activity Relationships for a Series of Quinoline-Based Compounds Active against Replicating and Nonreplicating Mycobacterium tuberculosis. J Med Chem 2009; 52:2109-18. [DOI: 10.1021/jm900003c] [Citation(s) in RCA: 233] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Annamaria Lilienkampf
- Drug Discovery Program, Department of Medicinal Chemistry and Pharmacognosy, College of Pharmacy, University of Illinois at Chicago, 833 South Wood Street, Chicago, Illinois 60612, Institute for Tuberculosis Research, College of Pharmacy, University of Illinois at Chicago, 833 South Wood Street, Chicago, Illinois 60612
| | - Jialin Mao
- Drug Discovery Program, Department of Medicinal Chemistry and Pharmacognosy, College of Pharmacy, University of Illinois at Chicago, 833 South Wood Street, Chicago, Illinois 60612, Institute for Tuberculosis Research, College of Pharmacy, University of Illinois at Chicago, 833 South Wood Street, Chicago, Illinois 60612
| | - Baojie Wan
- Drug Discovery Program, Department of Medicinal Chemistry and Pharmacognosy, College of Pharmacy, University of Illinois at Chicago, 833 South Wood Street, Chicago, Illinois 60612, Institute for Tuberculosis Research, College of Pharmacy, University of Illinois at Chicago, 833 South Wood Street, Chicago, Illinois 60612
| | - Yuehong Wang
- Drug Discovery Program, Department of Medicinal Chemistry and Pharmacognosy, College of Pharmacy, University of Illinois at Chicago, 833 South Wood Street, Chicago, Illinois 60612, Institute for Tuberculosis Research, College of Pharmacy, University of Illinois at Chicago, 833 South Wood Street, Chicago, Illinois 60612
| | - Scott G. Franzblau
- Drug Discovery Program, Department of Medicinal Chemistry and Pharmacognosy, College of Pharmacy, University of Illinois at Chicago, 833 South Wood Street, Chicago, Illinois 60612, Institute for Tuberculosis Research, College of Pharmacy, University of Illinois at Chicago, 833 South Wood Street, Chicago, Illinois 60612
| | - Alan P. Kozikowski
- Drug Discovery Program, Department of Medicinal Chemistry and Pharmacognosy, College of Pharmacy, University of Illinois at Chicago, 833 South Wood Street, Chicago, Illinois 60612, Institute for Tuberculosis Research, College of Pharmacy, University of Illinois at Chicago, 833 South Wood Street, Chicago, Illinois 60612
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30
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Mao J, Wang Y, Wan B, Kozikowski AP, Franzblau SG. Design, synthesis, and pharmacological evaluation of mefloquine-based ligands as novel antituberculosis agents. ChemMedChem 2008; 2:1624-30. [PMID: 17680579 DOI: 10.1002/cmdc.200700112] [Citation(s) in RCA: 66] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Tuberculosis (TB) is presently regarded as one of the most dangerous infective diseases worldwide and one of the major AIDS-associated infections. To shorten the current treatment regimen, there is an urgent need to identify new anti-TB agents which are active against both replicating TB (R-TB) and nonreplicating TB (NRP-TB). Mefloquine, a well-known antimalarial drug was found to possess reasonable activity against NRP-TB, and accordingly, 30 new analogues were synthesized and evaluated for their anti-TB activity against Mycobacterium tuberculosis H(37)Rv. As the target of mefloquine in Mycobacterium tuberculosis remains unknown, we resorted to modifying mefloquine in a variety of chemically convenient ways, which led us in turn to the active hydrazone 10 a. Further modifications of 10 a led to compound 7 f, with an improved anti-TB activity/selectivity profile with both less cytotoxicity and less predicted CNS side effects compared with mefloquine. The clear structure-activity relationships (SARs) derived from this study should facilitate our ultimate goal of identifying improved anti-TB agents.
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Affiliation(s)
- Jialin Mao
- Drug Discovery Program, Department of Medicinal Chemistry and Pharmacognosy, University of Illinois at Chicago, 833 South Wood Street, Chicago, IL 60612, USA
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31
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Maeda M. ATP synthases: bioinformatic based insights into how their electrochemically driven motor comprised of subunits a and c might serve as a drug target. J Bioenerg Biomembr 2008; 40:117-21. [DOI: 10.1007/s10863-008-9135-0] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2007] [Accepted: 02/21/2008] [Indexed: 11/24/2022]
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Characterization of in vitro-generated and clinical optochin-resistant strains of Streptococcus pneumoniae isolated from Argentina. J Clin Microbiol 2008; 46:1930-4. [PMID: 18417665 PMCID: PMC2446823 DOI: 10.1128/jcm.02318-07] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Optochin susceptibility is a key test used for pneumococcal diagnosis, but optochin-resistant (Opt(r)) pneumococci have been reported in the last 2 decades. In this work, we characterized eight Opt(r) clinical strains which presented a new mutation, G47V, a predominant A49S mutation (recently reported in Brazil) and A49T. These mutations were found in the c subunit of the F(0)F(1) ATPase encoded by the atpC gene, and W206C was found in the a subunit encoded by the atpA gene. The Opt(r) clinical isolates were analyzed by BOX PCR, multilocus sequence typing, and serotype and antimicrobial resistance profiles, and they showed no epidemiological relationship. To characterize the Opt(r) mutations that could emerge among clinical strains, we studied a pool of spontaneous Opt(r) colonies obtained in vitro from the virulent D39 strain. We compared the atpAC mutations of these Opt(r) pneumococci (with or without passage through C57BL/6 mice) with those described in the clinical isolates. This analysis revealed three new mutations, G47V and L26M in the c subunit and L184S in the a subunit. Most of the mutations identified in the laboratory-generated Opt(r) strains were also found in clinical strains, with the exception of the L26M and L184S mutations, and we suppose that both mutations could emerge among invasive strains in the future. Considering that atpAC are essential genes, we propose that all spontaneous mutations that confer in vitro optochin resistance would not present severe physiological alterations in S. pneumoniae and may be carried by circulating pneumococcal strains.
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Jiang X, Kong W, Chen J, Ma S. Intermolecular sequential [4 + 2]-cycloaddition–aromatization reaction of aryl-substituted allenes with DMAD affording phenanthrene and naphthalene derivatives. Org Biomol Chem 2008; 6:3606-10. [DOI: 10.1039/b808767a] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Janin YL. Antituberculosis drugs: ten years of research. Bioorg Med Chem 2007; 15:2479-513. [PMID: 17291770 DOI: 10.1016/j.bmc.2007.01.030] [Citation(s) in RCA: 360] [Impact Index Per Article: 21.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2006] [Revised: 12/26/2006] [Accepted: 01/17/2007] [Indexed: 02/03/2023]
Abstract
Tuberculosis is today amongst the worldwide health threats. As resistant strains of Mycobacterium tuberculosis have slowly emerged, treatment failure is too often a fact, especially in countries lacking the necessary health care organisation to provide the long and costly treatment adapted to patients. Because of lack of treatment or lack of adapted treatment, at least two million people will die of tuberculosis this year. Due to this concern, this infectious disease was the focus of renewed scientific interest in the last decade. Regimens were optimized and much was learnt on the mechanisms of action of the antituberculosis drugs used. Moreover, the quest for original drugs overcoming some of the problems of current regimens also became the focus of research programmes and many new series of M. tuberculosis growth inhibitors were reported. This review presents the drugs currently used in antituberculosis treatments and the most advanced compounds undergoing clinical trials. We then provide a description of their mechanism of action along with other series of inhibitors known to act on related biochemical targets. This is followed by other inhibitors of M. tuberculosis growth, including recently reported compounds devoid of a reported mechanism of action.
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Affiliation(s)
- Yves L Janin
- URA 2128 CNRS-Institut Pasteur, 28 rue du Dr. Roux, 75724 Paris Cedex 15, France.
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Balsalobre L, Hernández-Madrid A, Llull D, Martín-Galiano AJ, García E, Fenoll A, de la Campa AG. Molecular characterization of disease-associated streptococci of the mitis group that are optochin susceptible. J Clin Microbiol 2006; 44:4163-71. [PMID: 16971639 PMCID: PMC1698351 DOI: 10.1128/jcm.01137-06] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2006] [Revised: 08/16/2006] [Accepted: 09/06/2006] [Indexed: 11/20/2022] Open
Abstract
Eight optochin-susceptible (Opt(s)) alpha-hemolytic (viridans) streptococcus isolates were characterized at the molecular level. These isolates showed phenotypic characteristics typical of both viridans streptococci and Streptococcus pneumoniae. Comparison of the sequence of housekeeping genes from these isolates with those of S. pneumoniae, Streptococcus mitis, Streptococcus oralis, and Streptococcus pseudopneumoniae suggested that the Opt(s) isolates corresponded to streptococci of the mitis group. Besides, the Opt(s) streptococci were negative by a Gen-Probe AccuProbe pneumococcus test and hybridized with specific pneumococcal probes (lytA and ply) but also with ant, a gene not present in most S. pneumoniae strains. Moreover, the isolates were insoluble in 1% sodium deoxycholate but completely dissolved in 0.1% deoxycholate. Sequence analysis of the lytA gene revealed that the Opt(s) streptococci carried lytA alleles characteristic of those present in nonpneumococcal streptococci of the mitis group. The determination of the partial nucleotide sequence embracing the atp operon encoding the F(o)F(1) H(+)-ATPase indicated that the optochin susceptibility of the isolates was due to the acquisition of atpC, atpA, and part of atpB from S. pneumoniae by horizontal gene transfer.
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Affiliation(s)
- Luz Balsalobre
- Unidad de Genética Bacteriana, Centro Nacional de Microbiología, Instituto de Salud Carlos III, 28220 Majadahonda, Madrid, Spain
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Jayaprakash S, Iso Y, Wan B, Franzblau SG, Kozikowski AP. Design, Synthesis, and SAR Studies of Mefloquine-Based Ligands as Potential Antituberculosis Agents. ChemMedChem 2006; 1:593-7. [PMID: 16892398 DOI: 10.1002/cmdc.200600010] [Citation(s) in RCA: 83] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Sarva Jayaprakash
- Drug Discovery Program, Department of Medicinal Chemistry and Pharmacognosy, University of Illinois at Chicago, 833 South Wood Street, Chicago, IL 60612, USA
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McArdle JJ, Sellin LC, Coakley KM, Potian JG, Hognason K. Mefloquine selectively increases asynchronous acetylcholine release from motor nerve terminals. Neuropharmacology 2005; 50:345-53. [PMID: 16288931 DOI: 10.1016/j.neuropharm.2005.09.011] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2005] [Revised: 08/26/2005] [Accepted: 09/23/2005] [Indexed: 11/16/2022]
Abstract
Effectiveness against chloroquine-resistant Plasmodia makes mefloquine a widely used antimalarial drug. However, mefloquine's neurologic effects offset this therapeutic advantage. Cellular actions which might contribute to the neurologic effects of mefloquine are not understood. Structural similarity to tacrine suggested that mefloquine might alter cholinergic synaptic transmission. Therefore, we examined mefloquine's effects at a model cholinergic synapse. Triangularis sterni nerve-muscle preparations were isolated from adult mice and examined with sharp electrode current clamp technique. Within 30 min of exposure to 10 microM mefloquine, miniature endplate potentials (mepps) occurred in summating bursts and their mean frequency increased 10-fold. The threshold concentration for the increase of mean mepp frequency was 0.6 microM mefloquine. Mefloquine continued to increase mean mepp frequency for preparations bathed in extracellular solution lacking Ca2+. In contrast, mefloquine no longer increased mean mepp frequency for preparations pre-treated with the intracellular Ca2+ buffer BAPTA-AM. Although mefloquine disrupts a thapsigargin-sensitive neuronal Ca2+ store, pre-treatment with thapsigargin did not alter the mefloquine-induced alterations of mepps. Since mefloquine, like oligomycin, inhibits mitochondrial FOF1H+ ATP synthase we tested the interaction between these two chemicals. Like mefloquine, oligomycin induced bursts and increased mean frequency of mepps. Furthermore, pre-treatment with oligomycin precluded the mefloquine-induced alterations of asynchronous transmsitter release. These data suggest that mefloquine inhibits ATP production which increases the concentration of Ca2+ within the cytosol of nerve terminals. This elevation of Ca2+ concentration selectively increases asynchronous transmitter release since 10 microM mefloquine did not alter stimulus-evoked transmsitter release.
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Affiliation(s)
- Joseph J McArdle
- Department of Pharmacology and Physiology, New Jersey Medical School and Graduate School of Biomedical Sciences, UMDNJ, 185 South Orange Avenue, Newark, NJ 07101-1709, USA.
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Hayward R, Saliba KJ, Kirk K. Mutations in pfmdr1 modulate the sensitivity of Plasmodium falciparum to the intrinsic antiplasmodial activity of verapamil. Antimicrob Agents Chemother 2005; 49:840-2. [PMID: 15673784 PMCID: PMC547358 DOI: 10.1128/aac.49.2.840-842.2005] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
As well as having the ability to reverse chloroquine resistance in the human malaria parasite Plasmodium falciparum, verapamil has itself an innate antiplasmodial activity. We show here that mutations in Pgh1, the product of the malaria parasite's pfmdr1 gene, influence the parasite's susceptibility to the toxic effects of verapamil.
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Affiliation(s)
- Rhys Hayward
- School of Biochemistry and Molecular Biology, Faculty of Science, The Australian National University, Canberra A.C.T. 0200, Australia
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Martín-Galiano AJ, Balsalobre L, Fenoll A, de la Campa AG. Genetic characterization of optochin-susceptible viridans group streptococci. Antimicrob Agents Chemother 2003; 47:3187-94. [PMID: 14506029 PMCID: PMC201122 DOI: 10.1128/aac.47.10.3187-3194.2003] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2003] [Revised: 04/07/2003] [Accepted: 06/20/2003] [Indexed: 11/20/2022] Open
Abstract
Two clinical isolates of viridans group streptococci (VS) with different degrees of susceptibility to optochin (OPT), i.e., fully OPT-susceptible (Opt(s)) VS strain 1162/99 (for which the MIC was equal to that for Streptococcus pneumoniae, 0.75 micro g/ml) and intermediate Opt(s) VS strain 1174/97 (MIC, 6 micro g/ml) were studied. Besides being OPT susceptible, they showed characteristics typical of VS, such as bile insolubility; lack of reaction with pneumococcal capsular antibodies; and lack of hybridization with rRNA (AccuProbe)-, lytA-, and pnl-specific pneumococcal probes. However, these VS Opt(s) strains and VS type strains hybridized with ant, a gene not present in S. pneumoniae. A detailed characterization of the genes encoding the 16S rRNA and SodA classified isolates 1162/99 and 1174/97 as Streptococcus mitis. Analysis of the atpCAB region, which encodes the c, a, and b subunits of the F(0)F(1) H(+)-ATPase, the target of optochin, revealed high degrees of similarity between S. mitis 1162/99 and S. pneumoniae in atpC, atpA, and the N terminus of atpB. Moreover, amino acid identity between S. mitis 1174/97 and S. pneumoniae was found in alpha helix 5 of the a subunit. The organization of the chromosomal region containing the atp operon of the two Opt(s) VS and VS type strains was spr1284-atpC, with spr1284 being located 296 to 556 bp from atpC, whereas in S. pneumoniae this distance was longer than 68 kb. In addition, the gene order in S. pneumoniae was IS1239-74 bp-atpC. The results suggest that the full OPT susceptibility of S. mitis 1162/99 is due to the acquisition of atpC, atpA, and part of atpB from S. pneumoniae and that the intermediate OPT susceptibility of S. mitis 1174/97 correlates with the amino acid composition of its a subunit.
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Affiliation(s)
- Antonio J Martín-Galiano
- Unidad de Genética Bacteriana (Consejo Superior de Investigaciones Científicas), Centro Nacional de Microbiología, Instituto de Salud Carlos III, Majadahonda, Madrid, Spain
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Balsalobre L, Ferrándiz MJ, Liñares J, Tubau F, de la Campa AG. Viridans group streptococci are donors in horizontal transfer of topoisomerase IV genes to Streptococcus pneumoniae. Antimicrob Agents Chemother 2003; 47:2072-81. [PMID: 12821449 PMCID: PMC161831 DOI: 10.1128/aac.47.7.2072-2081.2003] [Citation(s) in RCA: 77] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
A total of 46 ciprofloxacin-resistant (Cip(r)) Streptococcus pneumoniae strains were isolated from 1991 to 2001 at the Hospital of Bellvitge. Five of these strains showed unexpectedly high rates of nucleotide variations in the quinolone resistance-determining regions (QRDRs) of their parC, parE, and gyrA genes. The nucleotide sequence of the full-length parC, parE, and gyrA genes of one of these isolates revealed a mosaic structure compatible with an interspecific recombination origin. Southern blot analysis and nucleotide sequence determinations showed the presence of an ant-like gene in the intergenic parE-parC regions of the S. pneumoniae Cip(r) isolates with high rates of variations in their parE and parC QRDRs. The ant-like gene was absent from typical S. pneumoniae strains, whereas it was present in the intergenic parE-parC regions of the viridans group streptococci (Streptococcus mitis and Streptococcus oralis). These results suggest that the viridans group streptococci are acting as donors in the horizontal transfer of fluoroquinolone resistance genes to S. pneumoniae.
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Affiliation(s)
- Luz Balsalobre
- Unidad de Genética Bacteriana (Consejo Superior de Investigaciones Científicas), Centro Nacional de Microbiología, Instituto de Salud Carlos III, 28220 Majadahonda, Madrid, Spain
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Martín-Galiano AJ, de la Campa AG. High-efficiency generation of antibiotic-resistant strains of Streptococcus pneumoniae by PCR and transformation. Antimicrob Agents Chemother 2003; 47:1257-61. [PMID: 12654655 PMCID: PMC152537 DOI: 10.1128/aac.47.4.1257-1261.2003] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
We designed a method by which to generate antibiotic-resistant strains of Streptococcus pneumoniae at frequencies 4 orders of magnitude greater than the spontaneous mutation rate. The method is based on the natural ability of this organism to be genetically transformed with PCR products carrying sequences homologous to its chromosome. The genes encoding the targets of ciprofloxacin (parC, encoding the ParC subunit of DNA topoisomerase IV), rifampin (rpoB, encoding the beta subunit of RNA polymerase), and streptomycin (rpsL, encoding the S12 ribosomal protein) from susceptible laboratory strain R6 were amplified by PCR and used to transform the same strain. Resistant mutants were obtained with a frequency of 10(-4) to 10(-5), depending on the fidelity of the DNA polymerase used for PCR amplifications. Ciprofloxacin-resistant mutants, for which the MICs were four-to eightfold higher than that for R6, carried a single mutation of a residue in the quinolone resistance-determining region: S79 (change to A, F, or Y) or D83 (change to N or V). Rifampin-resistant strains, for which the MICs were at least 133-fold higher than that for R6, contained a single mutation within cluster I of rpoB: S482 (change to P), Q486 (change to L), D489 (change to V), or H499 (change to L or Y). Streptomycin-resistant mutants, for which the MICs were at least 64-fold higher than that for R6, carried a mutation at either K56 (change to I, R, or T) or K101 (change to E). PCR products obtained from the mutants were able to transform R6 to resistance with high efficiency (>10(4)). This method could be used to efficiently obtain resistant mutants for any drug whose target is known.
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Affiliation(s)
- Antonio J Martín-Galiano
- Unidad de Genética Bacteriana (Consejo Superior de Investigaciones Científicas), Centro Nacional de Microbiología, Instituto de Salud Carlos III, 28220 Majadahonda, Madrid, Spain
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Ferrándiz MJ, de la Campa AG. The membrane-associated F(0)F(1) ATPase is essential for the viability of Streptococcus pneumoniae. FEMS Microbiol Lett 2002; 212:133-8. [PMID: 12076799 DOI: 10.1111/j.1574-6968.2002.tb11256.x] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
Genetic studies aimed at eliminating expression of the atp operon (F(0)F(1) H(+)-ATPase) of Streptococcus pneumoniae by genetic disruption of atpC, the first gene of the operon, with a chloramphenicol-resistance cassette were performed. Resistant transformants were obtained only when the recipient strain had a duplication of atpC, recombination occurring in such a way that transcription of the operon from its own promoter was allowed. These results imply that the atp operon is essential for the viability of the cells.
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Affiliation(s)
- María José Ferrándiz
- Unidad de Genética Bacteriana (Consejo Superior de Investigaciones Científicas), Centro Nacional de Microbiología, Instituto de Salud Carlos III, 28220 Majadahonda, Madrid, Spain
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