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Staudacher M, Hotz JF, Kriz R, Schefberger K, Schneider L, Spettel K, Starzengruber P, Hagemann JB, Leutzendorff A, Burgmann H, Lagler H. Differences in oxazolidinone resistance mechanisms and small colony variants emergence of Staphylococcus aureus induced in an in vitro resistance development model. Emerg Microbes Infect 2024; 13:2292077. [PMID: 38055244 PMCID: PMC10849000 DOI: 10.1080/22221751.2023.2292077] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2022] [Accepted: 12/03/2023] [Indexed: 12/07/2023]
Abstract
Invasive Staphylococcus aureus infections are associated with a high burden of disease, case fatality rate and healthcare costs. Oxazolidinones such as linezolid and tedizolid are considered potential treatment choices for conditions involving methicillin resistance or penicillin allergies. Additionally, they are being investigated as potential inhibitors of toxins in toxin-mediated diseases. In this study, linezolid and tedizolid were evaluated in an in vitro resistance development model for induction of resistance in S. aureus. Whole genome sequencing was conducted to elucidate resistance mechanisms through the identification of causal mutations. After inducing resistance to both linezolid and tedizolid, several partially novel single nucleotide variants (SNVs) were detected in the rplC gene, which encodes the 50S ribosome protein L3 in S. aureus. These SNVs were found to decrease the binding affinity, potentially serving as the underlying cause for oxazolidinone resistance. Furthermore, in opposite to linezolid we were able to induce phenotypically small colony variants of S. aureus after induction of resistance with tedizolid for the first time in literature. In summary, even if different antibiotic concentrations were required and SNVs were detected, the principal capacity of S. aureus to develop resistance to oxazolidinones seems to differ between linezolid and tedizolid in-vivo but not in vitro. Stepwise induction of resistance seems to be a time and cost-effective tool for assessing resistance evolution. Inducted-resistant strains should be examined and documented for epidemiological reasons, if MICs start to rise or oxazolidinone-resistant S. aureus outbreaks become more frequent.
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Affiliation(s)
- Moritz Staudacher
- Department of Medicine I, Division of Infectious Diseases and Tropical Medicine, Medical University of Vienna, Vienna, Austria
- Department of Angiology, Medical University of Vienna, Vienna, Austria
| | - Julian Frederic Hotz
- Department of Medicine I, Division of Infectious Diseases and Tropical Medicine, Medical University of Vienna, Vienna, Austria
- Department of Neurology, Evangelic Hospital Vienna, Vienna, Austria
| | - Richard Kriz
- Department of Medicine I, Division of Infectious Diseases and Tropical Medicine, Medical University of Vienna, Vienna, Austria
| | - Katharina Schefberger
- Department of Medicine I, Division of Infectious Diseases and Tropical Medicine, Medical University of Vienna, Vienna, Austria
| | - Lisa Schneider
- Department of Medicine I, Division of Infectious Diseases and Tropical Medicine, Medical University of Vienna, Vienna, Austria
| | - Kathrin Spettel
- Department of Laboratory Medicine, Division of Clinical Microbiology, Medical University of Vienna, Vienna, Austria
| | - Peter Starzengruber
- Department of Laboratory Medicine, Division of Clinical Microbiology, Medical University of Vienna, Vienna, Austria
| | | | - Amelie Leutzendorff
- Department of Medicine I, Division of Infectious Diseases and Tropical Medicine, Medical University of Vienna, Vienna, Austria
- Department of Clinical Pharmacology, Medical University of Vienna, Vienna, Austria
| | - Heinz Burgmann
- Department of Medicine I, Division of Infectious Diseases and Tropical Medicine, Medical University of Vienna, Vienna, Austria
| | - Heimo Lagler
- Department of Medicine I, Division of Infectious Diseases and Tropical Medicine, Medical University of Vienna, Vienna, Austria
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Wang C, Ji Y, Huo X, Li X, Lu W, Zhang Z, Dong W, Wang X, Chen H, Tan C. Discovery of Salifungin as a Repurposed Antibiotic against Methicillin-Resistant Staphylococcus aureus with Limited Resistance Development. ACS Infect Dis 2024; 10:1576-1589. [PMID: 38581387 DOI: 10.1021/acsinfecdis.3c00611] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/08/2024]
Abstract
Exploring novel antimicrobial drugs and strategies has become essential to the fight MRSA-associated infections. Herein, we found that membrane-disrupted repurposed antibiotic salifungin had excellent bactericidal activity against MRSA, with limited development of drug resistance. Furthermore, adding salifungin effectively decreased the minimum inhibitory concentrations of clinical antibiotics against Staphylococcus aureus. Evaluations of the mechanism demonstrated that salifungin disrupted the level of H+ and K+ ions using hydrophilic and lipophilic groups to interact with bacterial membranes, causing the disruption of bacterial proton motive force followed by impacting on bacterial the function of the respiratory chain and adenosine 5'-triphosphate, thereby inhibiting phosphatidic acid biosynthesis. Moreover, salifungin also significantly inhibited the formation of bacterial biofilms and eliminated established bacterial biofilms by interfering with bacterial membrane potential and inhibiting biofilm-associated gene expression, which was even better than clinical antibiotics. Finally, salifungin exhibited efficacy comparable to or even better than that of vancomycin in the MRSA-infected animal models. In conclusion, these results indicate that salifungin can be a potential drug for treating MRSA-associated infections.
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Affiliation(s)
- Chenchen Wang
- National Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430000, Hubei, China
- Hubei Hongshan Laboratory, Wuhan 430000, Hubei, China
| | - Yueyue Ji
- National Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430000, Hubei, China
- Hubei Hongshan Laboratory, Wuhan 430000, Hubei, China
| | - Xingyu Huo
- National Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430000, Hubei, China
- Hubei Hongshan Laboratory, Wuhan 430000, Hubei, China
| | - Xiaodan Li
- National Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430000, Hubei, China
- Hubei Hongshan Laboratory, Wuhan 430000, Hubei, China
| | - Wenjia Lu
- National Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430000, Hubei, China
- Hubei Hongshan Laboratory, Wuhan 430000, Hubei, China
| | - Zhaoran Zhang
- National Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430000, Hubei, China
- Hubei Hongshan Laboratory, Wuhan 430000, Hubei, China
| | - Wenqi Dong
- National Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430000, Hubei, China
- Hubei Hongshan Laboratory, Wuhan 430000, Hubei, China
| | - Xiangru Wang
- National Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430000, Hubei, China
- Hubei Hongshan Laboratory, Wuhan 430000, Hubei, China
- Frontiers Science Center for Animal Breeding and Sustainable Production, Wuhan 430000, Hubei, China
- Key Laboratory of Preventive Veterinary Medicine in Hubei Province, Wuhan 430000, Hubei, China
- The Cooperative Innovation Center for Sustainable Pig Production, Wuhan 430000, Hubei, China
| | - Huanchun Chen
- National Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430000, Hubei, China
- Hubei Hongshan Laboratory, Wuhan 430000, Hubei, China
- Frontiers Science Center for Animal Breeding and Sustainable Production, Wuhan 430000, Hubei, China
- Key Laboratory of Preventive Veterinary Medicine in Hubei Province, Wuhan 430000, Hubei, China
- The Cooperative Innovation Center for Sustainable Pig Production, Wuhan 430000, Hubei, China
| | - Chen Tan
- National Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430000, Hubei, China
- Hubei Hongshan Laboratory, Wuhan 430000, Hubei, China
- Frontiers Science Center for Animal Breeding and Sustainable Production, Wuhan 430000, Hubei, China
- Key Laboratory of Preventive Veterinary Medicine in Hubei Province, Wuhan 430000, Hubei, China
- The Cooperative Innovation Center for Sustainable Pig Production, Wuhan 430000, Hubei, China
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3
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Lu H, Wang C, Lu W, Li X, Wang G, Dong W, Wang X, Chen H, Tan C. Antibacterial efficacy and mechanism of Cyprinus carpio chemokine-derived L-10 against multidrug-resistant Escherichia coli infections. Int J Antimicrob Agents 2024; 63:107104. [PMID: 38325720 DOI: 10.1016/j.ijantimicag.2024.107104] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2023] [Revised: 01/02/2024] [Accepted: 01/29/2024] [Indexed: 02/09/2024]
Abstract
OBJECTIVES Antimicrobial resistance has raised concerns regarding untreatable infections and poses a growing threat to public health. Rational design of new AMPs is an ideal solution to this threat. METHODS In this study, we designed, modified, and synthesised an excellent AMP, L-10, based on the original sequence of the Cyprinus carpio chemokine. All experimental data were presented as the mean ± standard deviation (SD), and the two-tailed unpaired T-test method was used to analyze all data. RESULTS L-10 exhibited excellent antibacterial activity with negligible toxicity and improved the efficacy of a broad class of antibiotics against MDR Gram-negative pathogens, including tetracycline, meropenem, levofloxacin, and rifampin. Mechanistic studies have suggested that L-10 targets the bacterial membrane components, LPS and PG, to disrupt bacterial membrane integrity, thereby exerting antibacterial effects and enhancing the efficacy of antibiotics. Moreover, in animal infection models, L-10 significantly increased the survival rate of infected animals and effectively reduced the tissue bacterial load and inflammatory factor levels. In addition to its direct antibacterial activity, L-10 dramatically reduced pulmonary pathological alterations in a mouse model of endotoxemia and suppressed LPS-induced proinflammatory cytokines in vitro and in vivo. Lastly, L-10 was successfully expressed in Pichia pastoris and maintained antimicrobial activity against MDR Gram-negative pathogens in vivo and in vitro. CONCLUSION Collectively, these results reveal the potential of L-10 as an ideal candidate against MDR bacterial infections and provide new insights into the design, development, and clinical application of AMPs.
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Affiliation(s)
- Hao Lu
- National Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, Hubei, China; Hubei Hongshan Laboratory, Wuhan, Hubei, China
| | - Chenchen Wang
- National Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, Hubei, China; Hubei Hongshan Laboratory, Wuhan, Hubei, China
| | - Wenjia Lu
- National Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, Hubei, China; Hubei Hongshan Laboratory, Wuhan, Hubei, China
| | - Xiaodan Li
- National Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, Hubei, China; Hubei Hongshan Laboratory, Wuhan, Hubei, China
| | - Gaoyan Wang
- National Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, Hubei, China; Hubei Hongshan Laboratory, Wuhan, Hubei, China
| | - Wenqi Dong
- National Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, Hubei, China; Hubei Hongshan Laboratory, Wuhan, Hubei, China
| | - Xiangru Wang
- National Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, Hubei, China; Hubei Hongshan Laboratory, Wuhan, Hubei, China; Frontiers Science Center for Animal Breeding and Sustainable Production, Wuhan, Hubei, China; Key Laboratory of Preventive Veterinary Medicine in Hubei Province, Wuhan, Hubei, China; The Cooperative Innovation Center for Sustainable Pig Production, Wuhan, Hubei, China
| | - Huanchun Chen
- National Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, Hubei, China; Hubei Hongshan Laboratory, Wuhan, Hubei, China; Frontiers Science Center for Animal Breeding and Sustainable Production, Wuhan, Hubei, China; Key Laboratory of Preventive Veterinary Medicine in Hubei Province, Wuhan, Hubei, China; The Cooperative Innovation Center for Sustainable Pig Production, Wuhan, Hubei, China
| | - Chen Tan
- National Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, Hubei, China; Hubei Hongshan Laboratory, Wuhan, Hubei, China; Frontiers Science Center for Animal Breeding and Sustainable Production, Wuhan, Hubei, China; Key Laboratory of Preventive Veterinary Medicine in Hubei Province, Wuhan, Hubei, China; The Cooperative Innovation Center for Sustainable Pig Production, Wuhan, Hubei, China.
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4
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Sordo M, Grilo T, Freire S, Rodrigues B, Bouvier M, Poirel L, Aires-de-Sousa M. Rapid culture-based LNZ test for detection of linezolid susceptibility/resistance in staphylococci and enterococci. Diagn Microbiol Infect Dis 2023; 107:116058. [PMID: 37657232 DOI: 10.1016/j.diagmicrobio.2023.116058] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2023] [Revised: 08/07/2023] [Accepted: 08/10/2023] [Indexed: 09/03/2023]
Abstract
A rapid, easy-to-handle, cost-effective and universal culture-based test was developed for the identification of linezolid resistance among the most clinically relevant enterococcal and staphylococcal species. Our technique was tested using linezolid-resistant (n = 50) and linezolid-susceptible (n = 67) Gram-positive isolates: 34 Enterococcus faecium, 20 Enterococcus faecalis, 20 Staphylococcus aureus, 38 Staphylococcus epidermidis, and 5 Staphylococcus capitis. The susceptibility/resistance phenotype of E. faecium, E. faecalis, S. aureus, and S. epidermidis to linezolid was detected within 4.5 hours, while an extended timeframe was actually required for S. capitis (6.5 hours). The Rapid LNZ test showed a full agreement with the standard broth microdilution method, independently of the molecular resistance mechanism and MIC values, with sensitivities and specificities of 100% for all species.
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Affiliation(s)
- Miguel Sordo
- Laboratory of Molecular Biology, Portuguese Red Cross, Lisboa, Portugal
| | - Teresa Grilo
- Laboratory of Molecular Biology, Portuguese Red Cross, Lisboa, Portugal
| | - Samanta Freire
- Laboratory of Molecular Biology, Portuguese Red Cross, Lisboa, Portugal; Medical and Molecular Microbiology Unit, Faculty of Science and Medicine, University of Fribourg, Fribourg, Switzerland
| | - Bruna Rodrigues
- Laboratory of Molecular Biology, Portuguese Red Cross, Lisboa, Portugal
| | - Maxime Bouvier
- Medical and Molecular Microbiology Unit, Faculty of Science and Medicine, University of Fribourg, Fribourg, Switzerland; Swiss National Reference Center for Emerging Antibiotic Resistance (NARA), Fribourg, Switzerland
| | - Laurent Poirel
- Medical and Molecular Microbiology Unit, Faculty of Science and Medicine, University of Fribourg, Fribourg, Switzerland; Swiss National Reference Center for Emerging Antibiotic Resistance (NARA), Fribourg, Switzerland
| | - Marta Aires-de-Sousa
- Escola Superior de Saúde da Cruz Vermelha Portuguesa-Lisboa (ESSCVP-Lisboa), Lisboa, Portugal; Laboratory of Molecular Genetics, Instituto de Tecnologia Química e Biológica António Xavier (ITQB), Universidade Nova de Lisboa (UNL), Oeiras, Portugal.
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5
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Youenou B, Martins Simoes P, Tristan A, Farfour E, Beauruelle C, Kolenda C, Ranc AG, Vandenesch F, Laurent F, Dupieux C. Linezolid resistance: detection of the cfr(B) gene in French clinical MRSA strains. J Antimicrob Chemother 2023; 78:445-449. [PMID: 36509546 DOI: 10.1093/jac/dkac411] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2022] [Accepted: 11/15/2022] [Indexed: 12/15/2022] Open
Abstract
OBJECTIVES To describe two linezolid-resistant MRSA strains carrying the cfr(B) gene detected in the French National Reference Centre for staphylococci. METHODS Two linezolid-resistant MRSA strains isolated from cystic fibrosis patients in two different French hospitals in 2017 and 2019 were examined to explore the mechanisms of linezolid resistance. Antimicrobial susceptibility was tested using broth microdilution and gradient strips. The genetic determinants of linezolid resistance were assessed by a multiplex PCR targeting cfr/cfr(B), optrA and poxtA genes, by amplification and sequencing of individual 23S rRNA genes and by WGS using both Illumina and Nanopore technologies. RESULTS The two MRSA strains were resistant to linezolid but susceptible to tedizolid, and PCR-positive for cfr/cfr(B). The WGS analysis indicated that they belonged to two different STs (ST8-MRSA-IV and ST5382-MRSA-IV) and that they both harboured the cfr(B) gene on the same 9.7 kb Tn6218-like chromosomal transposon, a finding only previously reported in Enterococcus sp. and Clostridioides difficile. CONCLUSIONS To the best of our knowledge, this is the first description of the presence of cfr(B) in staphylococci, more specifically in linezolid-resistant MRSA strains. This finding illustrates the risk of horizontal intergenus transfer of oxazolidinone resistance genes in Staphylococcus aureus and highlights the need to monitor such emergence in this species.
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Affiliation(s)
- Benjamin Youenou
- Hospices Civils de Lyon, Centre National de Référence des Staphylocoques, Institut des Agents Infectieux, Lyon F-69004, France
| | - Patricia Martins Simoes
- Hospices Civils de Lyon, Centre National de Référence des Staphylocoques, Institut des Agents Infectieux, Lyon F-69004, France.,Equipe Pathogénie des staphylocoques, CIRI, Centre International de Recherche en Infectiologie, Université de Lyon, Inserm U1111, Université Claude Bernard Lyon 1, CNRS UMR5308, ENS de Lyon, France
| | - Anne Tristan
- Hospices Civils de Lyon, Centre National de Référence des Staphylocoques, Institut des Agents Infectieux, Lyon F-69004, France.,Equipe Pathogénie des staphylocoques, CIRI, Centre International de Recherche en Infectiologie, Université de Lyon, Inserm U1111, Université Claude Bernard Lyon 1, CNRS UMR5308, ENS de Lyon, France
| | - Eric Farfour
- Hôpital Foch, Service de Biologie clinique, Suresnes F-92150, France
| | - Clémence Beauruelle
- University Brest, INSERM, EFS, UMR 1078, GGB, Brest F-29200, France.,Department of Bacteriology, Virology, Brest University Hospital, Hospital Hygiene, and Parasitology-Mycology, Brest F-29200, France
| | - Camille Kolenda
- Hospices Civils de Lyon, Centre National de Référence des Staphylocoques, Institut des Agents Infectieux, Lyon F-69004, France.,Equipe Pathogénie des staphylocoques, CIRI, Centre International de Recherche en Infectiologie, Université de Lyon, Inserm U1111, Université Claude Bernard Lyon 1, CNRS UMR5308, ENS de Lyon, France
| | - Anne-Gaëlle Ranc
- Hospices Civils de Lyon, Centre National de Référence des Staphylocoques, Institut des Agents Infectieux, Lyon F-69004, France.,Equipe Pathogénie des staphylocoques, CIRI, Centre International de Recherche en Infectiologie, Université de Lyon, Inserm U1111, Université Claude Bernard Lyon 1, CNRS UMR5308, ENS de Lyon, France
| | - François Vandenesch
- Hospices Civils de Lyon, Centre National de Référence des Staphylocoques, Institut des Agents Infectieux, Lyon F-69004, France.,Equipe Pathogénie des staphylocoques, CIRI, Centre International de Recherche en Infectiologie, Université de Lyon, Inserm U1111, Université Claude Bernard Lyon 1, CNRS UMR5308, ENS de Lyon, France
| | - Frédéric Laurent
- Hospices Civils de Lyon, Centre National de Référence des Staphylocoques, Institut des Agents Infectieux, Lyon F-69004, France.,Equipe Pathogénie des staphylocoques, CIRI, Centre International de Recherche en Infectiologie, Université de Lyon, Inserm U1111, Université Claude Bernard Lyon 1, CNRS UMR5308, ENS de Lyon, France
| | - Céline Dupieux
- Hospices Civils de Lyon, Centre National de Référence des Staphylocoques, Institut des Agents Infectieux, Lyon F-69004, France.,Equipe Pathogénie des staphylocoques, CIRI, Centre International de Recherche en Infectiologie, Université de Lyon, Inserm U1111, Université Claude Bernard Lyon 1, CNRS UMR5308, ENS de Lyon, France
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6
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Wang C, Lu H, Li X, Zhu Y, Ji Y, Lu W, Wang G, Dong W, Liu M, Wang X, Chen H, Tan C. Identification of an anti-virulence drug that reverses antibiotic resistance in multidrug resistant bacteria. Biomed Pharmacother 2022; 153:113334. [DOI: 10.1016/j.biopha.2022.113334] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2022] [Revised: 06/14/2022] [Accepted: 06/23/2022] [Indexed: 11/02/2022] Open
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7
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Perlaza-Jiménez L, Tan KS, Piper SJ, Johnson RM, Bamert RS, Stubenrauch CJ, Wright A, Lupton D, Lithgow T, Belousoff MJ. A Structurally Characterized Staphylococcus aureus Evolutionary Escape Route from Treatment with the Antibiotic Linezolid. Microbiol Spectr 2022; 10:e0058322. [PMID: 35736238 PMCID: PMC9431193 DOI: 10.1128/spectrum.00583-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2022] [Accepted: 06/03/2022] [Indexed: 11/30/2022] Open
Abstract
Methicillin-resistant Staphylococcus aureus (MRSA) is a bacterial pathogen that presents great health concerns. Treatment requires the use of last-line antibiotics, such as members of the oxazolidinone family, of which linezolid is the first member to see regular use in the clinic. Here, we report a short time scale selection experiment in which strains of MRSA were subjected to linezolid treatment. Clonal isolates which had evolved a linezolid-resistant phenotype were characterized by whole-genome sequencing. Linezolid-resistant mutants were identified which had accumulated mutations in the ribosomal protein uL3. Multiple clones which had two mutations in uL3 exhibited resistance to linezolid, 2-fold higher than the clinical breakpoint. Ribosomes from this strain were isolated and subjected to single-particle cryo-electron microscopic analysis and compared to the ribosomes from the parent strain. We found that the mutations in uL3 lead to a rearrangement of a loop that makes contact with Helix 90, propagating a structural change over 15 Å away. This distal change swings nucleotide U2504 into the binding site of the antibiotic, causing linezolid resistance. IMPORTANCE Antibiotic resistance poses a critical problem to human health and decreases the utility of these lifesaving drugs. Of particular concern is the "superbug" methicillin-resistant Staphylococcus aureus (MRSA), for which treatment of infection requires the use of last-line antibiotics, including linezolid. In this paper, we characterize the atomic rearrangements which the ribosome, the target of linezolid, undergoes during its evolutionary journey toward becoming drug resistant. Using cryo-electron microscopy, we describe a particular molecular mechanism which MRSA uses to become resistant to linezolid.
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Affiliation(s)
- Laura Perlaza-Jiménez
- Centre to Impact AMR, Monash University, Clayton, Victoria, Australia
- Infection Program, Biomedicine Discovery Institute and Department of Microbiology, Monash University, Clayton, Victoria, Australia
| | - Kher-Shing Tan
- Centre to Impact AMR, Monash University, Clayton, Victoria, Australia
- Infection Program, Biomedicine Discovery Institute and Department of Microbiology, Monash University, Clayton, Victoria, Australia
| | - Sarah J. Piper
- Drug Development Biology, Monash Institute of Pharmaceutical Sciences, Parkville, Victoria, Australia
- Centre for Cryo-electron Microscopy of Membrane Proteins, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria, Australia
| | - Rachel M. Johnson
- Drug Development Biology, Monash Institute of Pharmaceutical Sciences, Parkville, Victoria, Australia
- Centre for Cryo-electron Microscopy of Membrane Proteins, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria, Australia
| | - Rebecca S. Bamert
- Centre to Impact AMR, Monash University, Clayton, Victoria, Australia
- Infection Program, Biomedicine Discovery Institute and Department of Microbiology, Monash University, Clayton, Victoria, Australia
| | - Christopher J. Stubenrauch
- Centre to Impact AMR, Monash University, Clayton, Victoria, Australia
- Infection Program, Biomedicine Discovery Institute and Department of Microbiology, Monash University, Clayton, Victoria, Australia
| | - Alexander Wright
- School of Chemistry, Monash University, Clayton, Victoria, Australia
| | - David Lupton
- School of Chemistry, Monash University, Clayton, Victoria, Australia
| | - Trevor Lithgow
- Centre to Impact AMR, Monash University, Clayton, Victoria, Australia
- Infection Program, Biomedicine Discovery Institute and Department of Microbiology, Monash University, Clayton, Victoria, Australia
| | - Matthew J. Belousoff
- Infection Program, Biomedicine Discovery Institute and Department of Microbiology, Monash University, Clayton, Victoria, Australia
- Drug Development Biology, Monash Institute of Pharmaceutical Sciences, Parkville, Victoria, Australia
- Centre for Cryo-electron Microscopy of Membrane Proteins, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria, Australia
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8
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Tayal A, Singh NP, Rai S, Gupta K, Gupta A, Agarwal AN, Saha R, Kaur IR. First study on detection of cryptic resistance to linezolid among clinical isolates of methicillin resistant Staphylococcus aureus from India. Indian J Med Microbiol 2022; 40:384-388. [PMID: 35667921 DOI: 10.1016/j.ijmmb.2022.05.004] [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: 10/20/2020] [Revised: 04/20/2022] [Accepted: 05/13/2022] [Indexed: 11/05/2022]
Abstract
PURPOSE Linezolid is an oral antibiotic which is widely used for serious infections caused by Methicillin Resistant Staphylococcus aureus (MRSA). With emergence of vancomycin MIC creep among clinical strains of MRSA, it is essential to know the possible emergence of subclinical resistance against linezolid as well. With this background, we aimed to detect evident (phenotypic) and cryptic (hidden or genotypic) linezolid resistance among MRSA isolates. METHODS 250 clinical isolates of MRSA were collected and their susceptibility patterns were determined. Every third MRSA isolate was subjected to PCR for domain V of the 23S rRNA for the mutation hotspot in the 746bp segment which harbors the classical mutation for linezolid resistance. Restriction Fragment Length Polymorphism was done to confirm presence of the G2576U mutation. RESULTS Six isolates (2.4%) were phenotypically resistant to linezolid. Among these six LRSA isolates, 5 demonstrated the G2576U mutation by PCR - RFLP. Cryptic resistance to Linezolid was identified in two isolates among linezolid susceptible isolates. CONCLUSIONS In the present study, hidden resistance to linezolid was observed in linezolid susceptible clinical isolates. Emergence of resistance against over-the-counter drugs like linezolid is major challenge. Identification of cryptic resistance among patients implies impending resistance to linezolid. Judicious use of antimicrobials, application of strict infection control practices and prescription audit needs to be made mandatory to preserve such drugs.
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Affiliation(s)
- Ayushi Tayal
- Department of Clinical Microbiology, University College of Medical Sciences, Delhi, India.
| | - Narendra Pal Singh
- Department of Clinical Microbiology, University College of Medical Sciences, Delhi, India.
| | - Sumit Rai
- Department of Clinical Microbiology, University College of Medical Sciences, Delhi, India.
| | - Kavita Gupta
- Department of Clinical Microbiology, University College of Medical Sciences, Delhi, India.
| | - Arun Gupta
- Department of Clinical Microbiology, University College of Medical Sciences, Delhi, India.
| | - Aditya Nath Agarwal
- Department of Clinical Microbiology, University College of Medical Sciences, Delhi, India.
| | - Rituparna Saha
- Department of Clinical Microbiology, University College of Medical Sciences, Delhi, India.
| | - Iqbal Rajinder Kaur
- Department of Clinical Microbiology, University College of Medical Sciences, Delhi, India.
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Nagendran S, Balasubramaniyan S, Irfan N. Virtually screened novel sulfathiazole derivatives as a potential drug candidate for methicillin-resistant Staphylococcus aureus and multidrug-resistant tuberculosis. J Biomol Struct Dyn 2022:1-10. [DOI: 10.1080/07391102.2022.2079002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Affiliation(s)
- Saraswathy Nagendran
- Department of Botany, SVKM’s Mithibai College of Arts Chauhan Institute of Science and Amrutben Jivanlal College of Commerce and Economics, Mumbai, India
| | - Sakthivel Balasubramaniyan
- Drug Discovery and Development Research Group, Department of Pharmaceutical Technology, University College of Engineering, Anna University, Tiruchirapalli, Tamil Nadu, India
| | - Navabshan Irfan
- Crescent School of Pharmacy, B.S. Abdur Rahman Crescent Institute of Science & Technology, Chennai, Tamil Nadu, India
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10
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Tsai K, Stojković V, Noda-Garcia L, Young ID, Myasnikov AG, Kleinman J, Palla A, Floor SN, Frost A, Fraser JS, Tawfik DS, Fujimori DG. Directed evolution of the rRNA methylating enzyme Cfr reveals molecular basis of antibiotic resistance. eLife 2022; 11:e70017. [PMID: 35015630 PMCID: PMC8752094 DOI: 10.7554/elife.70017] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2021] [Accepted: 11/25/2021] [Indexed: 12/11/2022] Open
Abstract
Alteration of antibiotic binding sites through modification of ribosomal RNA (rRNA) is a common form of resistance to ribosome-targeting antibiotics. The rRNA-modifying enzyme Cfr methylates an adenosine nucleotide within the peptidyl transferase center, resulting in the C-8 methylation of A2503 (m8A2503). Acquisition of cfr results in resistance to eight classes of ribosome-targeting antibiotics. Despite the prevalence of this resistance mechanism, it is poorly understood whether and how bacteria modulate Cfr methylation to adapt to antibiotic pressure. Moreover, direct evidence for how m8A2503 alters antibiotic binding sites within the ribosome is lacking. In this study, we performed directed evolution of Cfr under antibiotic selection to generate Cfr variants that confer increased resistance by enhancing methylation of A2503 in cells. Increased rRNA methylation is achieved by improved expression and stability of Cfr through transcriptional and post-transcriptional mechanisms, which may be exploited by pathogens under antibiotic stress as suggested by natural isolates. Using a variant that achieves near-stoichiometric methylation of rRNA, we determined a 2.2 Å cryo-electron microscopy structure of the Cfr-modified ribosome. Our structure reveals the molecular basis for broad resistance to antibiotics and will inform the design of new antibiotics that overcome resistance mediated by Cfr.
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Affiliation(s)
- Kaitlyn Tsai
- Department of Cellular and Molecular Pharmacology, University of California San FranciscoSan FranciscoUnited States
| | - Vanja Stojković
- Department of Cellular and Molecular Pharmacology, University of California San FranciscoSan FranciscoUnited States
| | - Lianet Noda-Garcia
- Department of Biomolecular Sciences, Weizmann Institute of ScienceRehovotIsrael
| | - Iris D Young
- Department of Bioengineering and Therapeutic Sciences, University of California San FranciscoSan FranciscoUnited States
| | - Alexander G Myasnikov
- Department of Biochemistry and Biophysics, University of California San FranciscoSan FranciscoUnited States
| | - Jordan Kleinman
- Department of Cellular and Molecular Pharmacology, University of California San FranciscoSan FranciscoUnited States
| | - Ali Palla
- Department of Cellular and Molecular Pharmacology, University of California San FranciscoSan FranciscoUnited States
| | - Stephen N Floor
- Helen Diller Family Comprehensive Cancer Center, University of California San FranciscoSan FranciscoUnited States
- Department of Cell and Tissue Biology, University of California San FranciscoSan FranciscoUnited States
| | - Adam Frost
- Department of Biochemistry and Biophysics, University of California San FranciscoSan FranciscoUnited States
- Quantitative Biosciences Institute, University of California San FranciscoSan FranciscoUnited States
| | - James S Fraser
- Department of Bioengineering and Therapeutic Sciences, University of California San FranciscoSan FranciscoUnited States
- Quantitative Biosciences Institute, University of California San FranciscoSan FranciscoUnited States
| | - Dan S Tawfik
- Department of Biomolecular Sciences, Weizmann Institute of ScienceRehovotIsrael
| | - Danica Galonić Fujimori
- Department of Cellular and Molecular Pharmacology, University of California San FranciscoSan FranciscoUnited States
- Quantitative Biosciences Institute, University of California San FranciscoSan FranciscoUnited States
- Department of Pharmaceutical Chemistry, University of California San FranciscoSan FranciscoUnited States
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11
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Huber S, Knoll MA, Berktold M, Würzner R, Brindlmayer A, Weber V, Posch AE, Mrazek K, Lepuschitz S, Ante M, Beisken S, Orth-Höller D, Weinberger J. Genomic and Phenotypic Analysis of Linezolid-Resistant Staphylococcus epidermidis in a Tertiary Hospital in Innsbruck, Austria. Microorganisms 2021; 9:1023. [PMID: 34068744 PMCID: PMC8150687 DOI: 10.3390/microorganisms9051023] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2021] [Revised: 05/06/2021] [Accepted: 05/07/2021] [Indexed: 11/17/2022] Open
Abstract
Whole genome sequencing is a useful tool to monitor the spread of resistance mechanisms in bacteria. In this retrospective study, we investigated genetic resistance mechanisms, sequence types (ST) and respective phenotypes of linezolid-resistant Staphylococcus epidermidis (LRSE, n = 129) recovered from a cohort of patients receiving or not receiving linezolid within a tertiary hospital in Innsbruck, Austria. Hereby, the point mutation G2603U in the 23S rRNA (n = 91) was the major resistance mechanism followed by the presence of plasmid-derived cfr (n = 30). The majority of LRSE isolates were ST2 strains, followed by ST5. LRSE isolates expressed a high resistance level to linezolid with a minimal inhibitory concentration of ≥256 mg/L (n = 83) in most isolates, particularly in strains carrying the cfr gene (p < 0.001). Linezolid usage was the most prominent (but not the only) trigger for the development of linezolid resistance. However, administration of linezolid was not associated with a specific resistance mechanism. Restriction of linezolid usage and the monitoring of plasmid-derived cfr in LRSE are potential key steps to reduce linezolid resistance and its transmission to more pathogenic Gram-positive bacteria.
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Affiliation(s)
- Silke Huber
- Institute of Hygiene and Medical Microbiology, Medical University of Innsbruck, 6020 Innsbruck, Austria; (S.H.); (M.A.K.); (M.B.); (R.W.)
| | - Miriam A. Knoll
- Institute of Hygiene and Medical Microbiology, Medical University of Innsbruck, 6020 Innsbruck, Austria; (S.H.); (M.A.K.); (M.B.); (R.W.)
| | - Michael Berktold
- Institute of Hygiene and Medical Microbiology, Medical University of Innsbruck, 6020 Innsbruck, Austria; (S.H.); (M.A.K.); (M.B.); (R.W.)
| | - Reinhard Würzner
- Institute of Hygiene and Medical Microbiology, Medical University of Innsbruck, 6020 Innsbruck, Austria; (S.H.); (M.A.K.); (M.B.); (R.W.)
| | - Anita Brindlmayer
- Center for Biomedical Technology, Department for Biomedical Research, Danube University Krems, 3500 Krems, Austria; (A.B.); (V.W.)
| | - Viktoria Weber
- Center for Biomedical Technology, Department for Biomedical Research, Danube University Krems, 3500 Krems, Austria; (A.B.); (V.W.)
| | - Andreas E. Posch
- Ares Genetics GmbH, 1030 Vienna, Austria; (A.E.P.); (K.M.); (S.L.); (M.A.); (S.B.); (J.W.)
| | - Katharina Mrazek
- Ares Genetics GmbH, 1030 Vienna, Austria; (A.E.P.); (K.M.); (S.L.); (M.A.); (S.B.); (J.W.)
| | - Sarah Lepuschitz
- Ares Genetics GmbH, 1030 Vienna, Austria; (A.E.P.); (K.M.); (S.L.); (M.A.); (S.B.); (J.W.)
| | - Michael Ante
- Ares Genetics GmbH, 1030 Vienna, Austria; (A.E.P.); (K.M.); (S.L.); (M.A.); (S.B.); (J.W.)
| | - Stephan Beisken
- Ares Genetics GmbH, 1030 Vienna, Austria; (A.E.P.); (K.M.); (S.L.); (M.A.); (S.B.); (J.W.)
| | | | - Johannes Weinberger
- Ares Genetics GmbH, 1030 Vienna, Austria; (A.E.P.); (K.M.); (S.L.); (M.A.); (S.B.); (J.W.)
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12
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Liu WT, Chen EZ, Yang L, Peng C, Wang Q, Xu Z, Chen DQ. Emerging resistance mechanisms for 4 types of common anti-MRSA antibiotics in Staphylococcus aureus: A comprehensive review. Microb Pathog 2021; 156:104915. [PMID: 33930416 DOI: 10.1016/j.micpath.2021.104915] [Citation(s) in RCA: 50] [Impact Index Per Article: 16.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2021] [Revised: 04/02/2021] [Accepted: 04/06/2021] [Indexed: 01/10/2023]
Abstract
Staphylococcus aureus is one of the leading hospital-associated and community-associated pathogens, which has caused a global public health concern. The emergence of methicillin-resistant S. aureus (MRSA) along with the widespread use of different classes of antibiotics has become a significant therapeutic challenge. Antibiotic resistance is a disturbing problem that poses a threat to humans. Treatment options for S. aureus resistant to β-lactam antibiotics include glycopeptide antibiotic, cyclic lipopeptide antibiotic, cephalosporins and oxazolidinone antibiotic. The most representative types of these antibiotics are vancomycin, daptomycin, ceftaroline and linezolid. The frequent use of the first-line drug vancomycin for MRSA treatment has increased the number of resistant strains, namely vancomycin intermediate resistant S. aureus (VISA) and vancomycin resistant S. aureus (VRSA). A systematic literature review of relevant published studies in PubMed before 2020 was conducted. In recent years, there have been some reports on the relevant resistant mechanisms of vancomycin, daptomycin, ceftaroline and linezolid. In this review, we have summarized the antibiotic molecular modes of action and different gene mutants at the whole-genome level, which will aid in further development on new drugs for effective MRSA treatment based on describing different resistance mechanisms of classic antibiotics.
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Affiliation(s)
- Wan-Ting Liu
- Microbiome Medicine Center, Division of Laboratory Medicine, Zhujiang Hospital, Southern Medical University, Guangzhou, Guangdong, 510282, China
| | - En-Zhong Chen
- Microbiome Medicine Center, Division of Laboratory Medicine, Zhujiang Hospital, Southern Medical University, Guangzhou, Guangdong, 510282, China
| | - Ling Yang
- Department of Laboratory Medicine, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou, Guangdong, 510120, China
| | - Chen Peng
- Department of Laboratory Medicine, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou, Guangdong, 510120, China
| | - Qun Wang
- Department of Laboratory Medicine, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou, Guangdong, 510120, China
| | - Zhenbo Xu
- School of Food Science and Engineering, Guangdong Province Key Laboratory for Green Processing of Natural Products and Product Safety, South China University of Technology, Guangzhou 510640, China; College of Pharmacy, University of Tennessee Health Science Center, Memphis, TN38163, USA; Research Institute for Food Nutrition and Human Health, Guangzhou, 510640, China; Home Economics Technology, Rajamangala University of Technology Phra Nakhon, Bangkok, Thailand.
| | - Ding-Qiang Chen
- Microbiome Medicine Center, Division of Laboratory Medicine, Zhujiang Hospital, Southern Medical University, Guangzhou, Guangdong, 510282, China.
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13
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Turner AM, Lee JYH, Gorrie CL, Howden BP, Carter GP. Genomic Insights Into Last-Line Antimicrobial Resistance in Multidrug-Resistant Staphylococcus and Vancomycin-Resistant Enterococcus. Front Microbiol 2021; 12:637656. [PMID: 33796088 PMCID: PMC8007764 DOI: 10.3389/fmicb.2021.637656] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2020] [Accepted: 02/25/2021] [Indexed: 12/17/2022] Open
Abstract
Multidrug-resistant Staphylococcus and vancomycin-resistant Enterococcus (VRE) are important human pathogens that are resistant to most clinical antibiotics. Treatment options are limited and often require the use of 'last-line' antimicrobials such as linezolid, daptomycin, and in the case of Staphylococcus, also vancomycin. The emergence of resistance to these last-line antimicrobial agents is therefore of considerable clinical concern. This mini-review provides an overview of resistance to last-line antimicrobial agents in Staphylococcus and VRE, with a particular focus on how genomics has provided critical insights into the emergence of resistant clones, the molecular mechanisms of resistance, and the importance of mobile genetic elements in the global spread of resistance to linezolid.
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Affiliation(s)
- Adrianna M Turner
- Department of Microbiology and Immunology, Doherty Institute, The University of Melbourne, Melbourne, VIC, Australia
| | - Jean Y H Lee
- Department of Microbiology and Immunology, Doherty Institute, The University of Melbourne, Melbourne, VIC, Australia.,Department of Infectious Diseases, Monash Health, Melbourne, VIC, Australia
| | - Claire L Gorrie
- Department of Microbiology and Immunology, Doherty Institute, The University of Melbourne, Melbourne, VIC, Australia.,Antimicrobial Reference and Research Unit, Microbiological Diagnostic Unit Public Health Laboratory, Department of Microbiology and Immunology, Doherty Institute, The University of Melbourne, Melbourne, VIC, Australia
| | - Benjamin P Howden
- Department of Microbiology and Immunology, Doherty Institute, The University of Melbourne, Melbourne, VIC, Australia.,Antimicrobial Reference and Research Unit, Microbiological Diagnostic Unit Public Health Laboratory, Department of Microbiology and Immunology, Doherty Institute, The University of Melbourne, Melbourne, VIC, Australia.,Department of Infectious Diseases, Austin Health, Melbourne, VIC, Australia
| | - Glen P Carter
- Department of Microbiology and Immunology, Doherty Institute, The University of Melbourne, Melbourne, VIC, Australia.,Antimicrobial Reference and Research Unit, Microbiological Diagnostic Unit Public Health Laboratory, Department of Microbiology and Immunology, Doherty Institute, The University of Melbourne, Melbourne, VIC, Australia
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14
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De Oliveira DMP, Forde BM, Kidd TJ, Harris PNA, Schembri MA, Beatson SA, Paterson DL, Walker MJ. Antimicrobial Resistance in ESKAPE Pathogens. Clin Microbiol Rev 2020; 23:788-99. [PMID: 32404435 DOI: 10.1111/imb.12124] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/23/2023] Open
Abstract
Antimicrobial-resistant ESKAPE ( Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter species) pathogens represent a global threat to human health. The acquisition of antimicrobial resistance genes by ESKAPE pathogens has reduced the treatment options for serious infections, increased the burden of disease, and increased death rates due to treatment failure and requires a coordinated global response for antimicrobial resistance surveillance. This looming health threat has restimulated interest in the development of new antimicrobial therapies, has demanded the need for better patient care, and has facilitated heightened governance over stewardship practices.
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Affiliation(s)
- David M P De Oliveira
- School of Chemistry and Molecular Biosciences, The University of Queensland, QLD, Australia
- Australian Infectious Diseases Research Centre, The University of Queensland, QLD, Australia
| | - Brian M Forde
- School of Chemistry and Molecular Biosciences, The University of Queensland, QLD, Australia
- Australian Infectious Diseases Research Centre, The University of Queensland, QLD, Australia
| | - Timothy J Kidd
- School of Chemistry and Molecular Biosciences, The University of Queensland, QLD, Australia
- Australian Infectious Diseases Research Centre, The University of Queensland, QLD, Australia
| | - Patrick N A Harris
- Australian Infectious Diseases Research Centre, The University of Queensland, QLD, Australia
- UQ Centre for Clinical Research, The University of Queensland, QLD, Australia
| | - Mark A Schembri
- School of Chemistry and Molecular Biosciences, The University of Queensland, QLD, Australia
- Australian Infectious Diseases Research Centre, The University of Queensland, QLD, Australia
| | - Scott A Beatson
- School of Chemistry and Molecular Biosciences, The University of Queensland, QLD, Australia
- Australian Infectious Diseases Research Centre, The University of Queensland, QLD, Australia
| | - David L Paterson
- Australian Infectious Diseases Research Centre, The University of Queensland, QLD, Australia
- UQ Centre for Clinical Research, The University of Queensland, QLD, Australia
| | - Mark J Walker
- School of Chemistry and Molecular Biosciences, The University of Queensland, QLD, Australia
- Australian Infectious Diseases Research Centre, The University of Queensland, QLD, Australia
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15
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Abstract
Antimicrobial-resistant ESKAPE ( Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter species) pathogens represent a global threat to human health. The acquisition of antimicrobial resistance genes by ESKAPE pathogens has reduced the treatment options for serious infections, increased the burden of disease, and increased death rates due to treatment failure and requires a coordinated global response for antimicrobial resistance surveillance. This looming health threat has restimulated interest in the development of new antimicrobial therapies, has demanded the need for better patient care, and has facilitated heightened governance over stewardship practices.
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16
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Hammad A, Abutaleb NS, Elsebaei MM, Norvil AB, Alswah M, Ali AO, Abdel-Aleem JA, Alattar A, Bayoumi SA, Gowher H, Seleem MN, Mayhoub AS. From Phenylthiazoles to Phenylpyrazoles: Broadening the Antibacterial Spectrum toward Carbapenem-Resistant Bacteria. J Med Chem 2019; 62:7998-8010. [PMID: 31369262 DOI: 10.1021/acs.jmedchem.9b00720] [Citation(s) in RCA: 41] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
The narrow antibacterial spectrum of phenylthiazole antibiotics was expanded by replacing central thiazole with a pyrazole ring while maintaining its other pharmacophoric features. The most promising derivative, compound 23, was more potent than vancomycin against multidrug-resistant Gram-positive clinical isolates, including vancomycin- and linezolid-resistant methicillin-resistant Staphylococcus aureus (MRSA), with a minimum inhibitory concentration (MIC) value as low as 0.5 μg/mL. Moreover, compound 23 was superior to imipenem and meropenem against highly pathogenic carbapenem-resistant strains, such as Acinetobacter baumannii, Klebsiella pneumoniae, and Escherichia coli. In addition to the notable biofilm inhibition activity, compound 23 outperformed both vancomycin and kanamycin in reducing the intracellular burden of both Gram-positive and Gram-negative pathogenic bacteria. Compound 23 cleared 90% of intracellular MRSA and 98% of Salmonella enteritidis at 2× the MIC. Moreover, preliminary pharmacokinetic investigations indicated that this class of novel antibacterial compounds is highly metabolically stable with a biological half-life of 10.5 h, suggesting a once-daily dosing regimen.
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Affiliation(s)
- Ali Hammad
- Department of Pharmaceutical Organic Chemistry, College of Pharmacy , Al-Azhar University , Cairo 11884 , Egypt
| | | | - Mohamed M Elsebaei
- Department of Pharmaceutical Organic Chemistry, College of Pharmacy , Al-Azhar University , Cairo 11884 , Egypt
| | | | - Mohamed Alswah
- Department of Pharmaceutical Organic Chemistry, College of Pharmacy , Al-Azhar University , Cairo 11884 , Egypt
| | - Alsagher O Ali
- Division of Infectious Diseases, Animal Medicine Department, Faculty of Veterinary Medicine , South Valley University , Qena , 83523 , Egypt
| | - Jelan A Abdel-Aleem
- Department of Industrial Pharmacy, Faculty of Pharmacy , Assiut University , Assiut , 71515 , Egypt
| | - Abdelaziz Alattar
- Department of Analytical Chemistry, College of Pharmacy , Al-Azhar University , Cairo 11884 , Egypt
| | - Sammar A Bayoumi
- Department of Pharmaceutics, College of Pharmacy , Heliopolis University , Cairo , 11777 , Egypt
| | | | - Mohamed N Seleem
- Purdue Institute for Inflammation, Immunology, and Infectious Diseases , West Lafayette , Indiana 47907 , United States
| | - Abdelrahman S Mayhoub
- Department of Pharmaceutical Organic Chemistry, College of Pharmacy , Al-Azhar University , Cairo 11884 , Egypt.,University of Science and Technology, Nanoscience Program , Zewail City of Science and Technology , October Gardens, 6th of October , Giza 12578 , Egypt
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17
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Roger C, Roberts JA, Muller L. Clinical Pharmacokinetics and Pharmacodynamics of Oxazolidinones. Clin Pharmacokinet 2019; 57:559-575. [PMID: 29063519 DOI: 10.1007/s40262-017-0601-x] [Citation(s) in RCA: 68] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Oxazolidinones are a class of synthetic antimicrobial agents with potent activity against a wide range of multidrug-resistant Gram-positive pathogens including methicillin-resistant Staphylococcus aureus and vancomycin-resistant enterococci. Oxazolidinones exhibit their antibacterial effects by inhibiting protein synthesis acting on the ribosomal 50S subunit of the bacteria and thus preventing formation of a functional 70S initiation complex. Currently, two oxazolidinones have been approved by the US Food and Drug Administration: linezolid and more recently tedizolid. Other oxazolidinones are currently under investigation in clinical trials. These antimicrobial agents exhibit a favourable pharmacokinetic profile with an excellent bioavailability and a good tissue and organ penetration. In-vitro susceptibility studies have shown that oxazolidinones are bacteriostatic against enterococci and staphylococci, and bactericidal for the majority of strains of streptococci. In the context of emergence of resistance to glycopeptides, oxazolidinones have become an effective alternative to vancomycin treatment frequently associated with nephrotoxicity. However, oxazolidinones, and linezolid in particular, are associated with significant adverse events, myelosuppression representing the main unfavourable side effect. More recently, tedizolid has been shown to effectively treat acute bacterial skin and skin structure infections. This newer oxazolidinone offers the advantages of once-daily dosing and a better safety profile in healthy volunteer studies (fewer gastrointestinal and haematological side effects). The potential use of tedizolid for other infections that could require longer therapy warrants further studies for positioning this new oxazolidinone in the available antimicrobial armamentarium. Moreover, other oxazolidinones are currently under active investigation.
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Affiliation(s)
- Claire Roger
- Department of Anesthesiology, Intensive Care, Pain and Emergency Medicine, Nîmes University Hospital, Place du Professeur Robert Debré, 30 029, Nîmes cedex 9, France.
- EA 2992, Faculty of Medicine, Montpellier-Nimes University, Nîmes, France.
- Burns Trauma and Critical Care Research Centre, The University of Queensland, Brisbane, QLD, Australia.
| | - Jason A Roberts
- Burns Trauma and Critical Care Research Centre, The University of Queensland, Brisbane, QLD, Australia
- School of Pharmacy, The University of Queensland, Brisbane, QLD, Australia
- Department of Intensive Care Medicine, Royal Brisbane and Womens' Hospital, Brisbane, QLD, Australia
| | - Laurent Muller
- Department of Anesthesiology, Intensive Care, Pain and Emergency Medicine, Nîmes University Hospital, Place du Professeur Robert Debré, 30 029, Nîmes cedex 9, France
- EA 2992, Faculty of Medicine, Montpellier-Nimes University, Nîmes, France
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18
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Design, synthesis, and antibacterial evaluation of novel derivatives of NPS-2143 for the treatment of methicillin-resistant S. aureus (MRSA) infection. J Antibiot (Tokyo) 2019; 72:545-554. [PMID: 30940910 DOI: 10.1038/s41429-019-0177-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2018] [Revised: 02/19/2019] [Accepted: 03/04/2019] [Indexed: 02/05/2023]
Abstract
Methicillin-resistant Staphylococcus aureus (MRSA) infections are a significant global health challenge due to the emergence of strains exhibiting resistance to nearly all classes of antibiotics. This necessitates the rapid development of novel antimicrobials to circumvent this critical problem. Screening of compounds based on phenotypes is one of the major strategies for finding new antibiotics at present. Hence, we here performed a phenotypic screening against MRSA and identified NPS-2143 exhibiting activity against MRSA with an MIC value of 16 μg ml-1. In order to discover more potent anti-MRSA agents, a series of derivatives of NPS-2143 were designed and synthesized. The most promising compounds 48 and 49 exhibited favorable antimicrobial activity with an MIC value of 2 μg ml-1.
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19
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Corey R, Moran G, Goering R, Bensaci M, Sandison T, De Anda C, Prokocimer P. Comparison of the microbiological efficacy of tedizolid and linezolid in acute bacterial skin and skin structure infections: pooled data from phase 3 clinical trials. Diagn Microbiol Infect Dis 2019; 94:277-286. [PMID: 30940414 DOI: 10.1016/j.diagmicrobio.2019.01.017] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2017] [Revised: 09/24/2018] [Accepted: 01/23/2019] [Indexed: 11/27/2022]
Abstract
We evaluated the microbiological efficacy of tedizolid compared with that of linezolid against common and emerging pathogens using pooled data from 2 phase 3 trials (NCT01170221 and NCT01421511) in patients with acute bacterial skin and skin structure infections. Patients received tedizolid 200 mg once daily for 6 days (n = 664) or linezolid 600 mg twice daily for 10 days (n = 669). Favorable microbiological outcome in both treatment groups, defined as eradication or presumed eradication at the end of treatment and at the posttherapy evaluation, exceeded 85% for most pathogens, including methicillin-resistant Staphylococcus aureus. Favorable microbiological response was observed for staphylococci and streptococci at tedizolid minimal inhibitory concentration values ≤0.5 mg/L and 0.25 mg/L, respectively. The studies demonstrated positive microbiological outcomes against common pathogens with a 6-day, once-daily regimen of tedizolid phosphate in patients with acute bacterial skin and skin structure infections.
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Affiliation(s)
- Ralph Corey
- Division of Infectious Diseases, Duke University Medical Center, 2301 Erwin Road, Durham, NC 27710, USA
| | - Gregory Moran
- Department of Emergency Medicine and Division of Infectious Diseases, Olive View-UCLA Medical Center, 14445 Olive View Drive, Sylmar, CA 91342, USA
| | - Richard Goering
- Department of Medical Microbiology and Immunology, Creighton University Medical Center, School of Medicine, 2500 California Plaza, Omaha, NE 68178, USA
| | - Mekki Bensaci
- Merck & Co, Inc., 2000 Galloping Hill Road, Kenilworth, NJ 07033, USA
| | - Taylor Sandison
- Merck & Co., Inc., 4747 Executive Drive, San Diego, CA 92121, USA
| | - Carisa De Anda
- Merck & Co., Inc., 4747 Executive Drive, San Diego, CA 92121, USA.
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20
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Molecular Analysis of Linezolid-Resistant Clinical Isolates of Mycobacterium abscessus. Antimicrob Agents Chemother 2019; 63:AAC.01842-18. [PMID: 30478161 PMCID: PMC6355594 DOI: 10.1128/aac.01842-18] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2018] [Accepted: 11/16/2018] [Indexed: 11/25/2022] Open
Abstract
A total of 194 Mycobacterium abscessus isolates were collected from patients, and the whole genomes were sequenced. Eighty-five (43.8%) isolates showed linezolid (LZD) resistance. A total of 194 Mycobacterium abscessus isolates were collected from patients, and the whole genomes were sequenced. Eighty-five (43.8%) isolates showed linezolid (LZD) resistance. Only 8.2% of resistant isolates harbored 23S rRNA mutations. Quantitative real-time PCR (qRT-PCR) revealed higher transcriptional levels of efflux pumps lmrS and mmpL9 in LZD-resistant isolates. Genome comparative analysis identified several new LZD resistance-associated genes. This study highlights the role of efflux pumps in LZD-resistant M. abscessus and proposes potential target genes for further studies.
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21
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Wang L, Zhao Q, Zhang Z, Lu Z, Zhao Y, Tang Y. Fluorescent Conjugated Polymer/Quarternary Ammonium Salt Co-assembly Nanoparticles: Applications in Highly Effective Antibacteria and Bioimaging. ACS APPLIED BIO MATERIALS 2018; 1:1478-1486. [DOI: 10.1021/acsabm.8b00422] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Affiliation(s)
- Lianqi Wang
- Key Laboratory of Applied Surface and Colloid Chemistry, Ministry of Education, Key Laboratory of Analytical Chemistry for Life Science of Shaanxi Province, School of Chemistry and Chemical Engineering, Shaanxi Normal University, Xi’ an 710062, P. R. China
| | - Qi Zhao
- Key Laboratory of Applied Surface and Colloid Chemistry, Ministry of Education, Key Laboratory of Analytical Chemistry for Life Science of Shaanxi Province, School of Chemistry and Chemical Engineering, Shaanxi Normal University, Xi’ an 710062, P. R. China
| | - Ziqi Zhang
- Key Laboratory of Applied Surface and Colloid Chemistry, Ministry of Education, Key Laboratory of Analytical Chemistry for Life Science of Shaanxi Province, School of Chemistry and Chemical Engineering, Shaanxi Normal University, Xi’ an 710062, P. R. China
| | - Zhuanning Lu
- Key Laboratory of Applied Surface and Colloid Chemistry, Ministry of Education, Key Laboratory of Analytical Chemistry for Life Science of Shaanxi Province, School of Chemistry and Chemical Engineering, Shaanxi Normal University, Xi’ an 710062, P. R. China
| | - Yantao Zhao
- Key Laboratory of Applied Surface and Colloid Chemistry, Ministry of Education, Key Laboratory of Analytical Chemistry for Life Science of Shaanxi Province, School of Chemistry and Chemical Engineering, Shaanxi Normal University, Xi’ an 710062, P. R. China
| | - Yanli Tang
- Key Laboratory of Applied Surface and Colloid Chemistry, Ministry of Education, Key Laboratory of Analytical Chemistry for Life Science of Shaanxi Province, School of Chemistry and Chemical Engineering, Shaanxi Normal University, Xi’ an 710062, P. R. China
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Karash S, Kwon YM. Iron-dependent essential genes in Salmonella Typhimurium. BMC Genomics 2018; 19:610. [PMID: 30107784 PMCID: PMC6092869 DOI: 10.1186/s12864-018-4986-1] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2018] [Accepted: 07/31/2018] [Indexed: 12/17/2022] Open
Abstract
Background The molecular mechanisms underlying bacterial cell death due to stresses or bactericidal antibiotics are complex and remain puzzling. Due to the current crisis of antibiotic resistance, development of effective antibiotics is urgently required. Previously, it has been shown that iron is required for effective killing of bacterial cells by numerous bactericidal antibiotics. Results We investigated the death or growth inhibition of S. Typhimurium under iron-restricted conditions, following disruption of essential genes, by transposon mutagenesis using transposon sequencing (Tn-seq). Our high-resolution Tn-seq analysis revealed that transposon mutants of S. Typhimurium with insertions in essential genes escaped immediate killing or growth inhibition under iron-restricted conditions for approximately one-third of all previously known essential genes. Based on this result, we classified all essential genes into two categories, iron-dependent essential genes, for which the insertion mutants can grow slowly if iron is restricted, and iron-independent essential genes, for which the mutants become nonviable regardless of iron concentration. The iron-dependency of the iron-dependent essential genes was further validated by the fact that the relative abundance of these essential gene mutants increased further with more severe iron restrictions. Our unexpected observation can be explained well by the common killing mechanisms of bactericidal antibiotics via production of reactive oxygen species (ROS). In this model, iron restriction would inhibit production of ROS, leading to reduced killing activity following blocking of essential gene functions. Interestingly, the targets of most antibiotics currently in use clinically are iron-dependent essential genes. Conclusions Our result suggests that targeting iron-independent essential genes may be a better strategy for future antibiotic development, because blocking their essential gene functions would lead to immediate cell death regardless of the iron concentration. This work expands our knowledge on the role of iron to a broad range of essential functions and pathways, providing novel insights for development of more effective antibiotics. Electronic supplementary material The online version of this article (10.1186/s12864-018-4986-1) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Sardar Karash
- Cell and Molecular Biology Program, University of Arkansas, Fayetteville, AR, USA.,Department of Biology, College of Education, Salahaddin University, Erbil, Kurdistan, Iraq
| | - Young Min Kwon
- Cell and Molecular Biology Program, University of Arkansas, Fayetteville, AR, USA. .,Department of Poultry Science, University of Arkansas, Fayetteville, AR, 72701, USA.
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Karlowsky JA, Hackel MA, Bouchillon SK, Alder J, Sahm DF. In Vitro activities of Tedizolid and comparator antimicrobial agents against clinical isolates of Staphylococcus aureus collected in 12 countries from 2014 to 2016. Diagn Microbiol Infect Dis 2017; 89:151-157. [DOI: 10.1016/j.diagmicrobio.2017.07.001] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2016] [Revised: 06/26/2017] [Accepted: 07/03/2017] [Indexed: 11/29/2022]
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Different Resistance Mechanisms for Cadazolid and Linezolid in Clostridium difficile Found by Whole-Genome Sequencing Analysis. Antimicrob Agents Chemother 2017; 61:AAC.00384-17. [PMID: 28584149 DOI: 10.1128/aac.00384-17] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2017] [Accepted: 05/27/2017] [Indexed: 12/16/2022] Open
Abstract
Cadazolid (CDZ) is a new antibiotic currently in clinical development for the treatment of Clostridium difficile infections. CDZ interferes with the bacterial protein synthesis machinery. The aim of the present study was to identify resistance mechanisms for CDZ and compare the results to those obtained for linezolid (LZD) in C. difficile by whole-genome sequencing (WGS) of strains generated by in vitro passages and to those obtained for LZD-resistant clinical isolates. Clones of C. difficile 630 selected with CDZ during 46 passages had a maximally 4-fold increase in CDZ MIC, while the LZD MIC for clones selected with LZD increased up to 16-fold. CDZ cross-resistance with LZD was maximally 4-fold, and no cross-resistance with other antibiotics tested was observed. Our data suggest that there are different resistance mechanisms for CDZ and LZD in C. difficile Mutations after passages with CDZ were found in rplD (ribosomal protein L4) as well as in tra and rmt, whereas similar experiments with LZD showed mutations in rplC (ribosomal protein L3), reg, and tpr, indicating different resistance mechanisms. Although high degrees of variation between the sequenced genomes of the clinical isolates were observed, the same mutation in rplC was found in two clinical isolates with high LZD MICs. No mutations were found in the 23S rRNA genes, and attempts to isolate the cfr gene from resistant clinical isolates were unsuccessful. Analysis of 50% inhibitory concentrations (IC50s) determined in in vitro transcription/translation assays performed with C. difficile cell extracts from passaged clones correlated well with the MIC values for all antibiotics tested, indicating that the ribosomal mutations are causing the resistant phenotype.
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Dai X, Chen X, Zhao J, Zhao Y, Guo Q, Zhang T, Chu C, Zhang X, Li C. Structure-Activity Relationship of Membrane-Targeting Cationic Ligands on a Silver Nanoparticle Surface in an Antibiotic-Resistant Antibacterial and Antibiofilm Activity Assay. ACS APPLIED MATERIALS & INTERFACES 2017; 9:13837-13848. [PMID: 28383253 DOI: 10.1021/acsami.6b15821] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
To explore the structure-activity relationship of membrane-targeting cationic ligands on a silver nanoparticle surface in an antibiotic-resistant antibacterial and antibiofilm activity assay, a series of functionalized silver nanocomposites were synthesized. Tuning the structural configuration, molecular weight, and side-chain length of the cationic ligands on the nanoparticle surface provided silver nanocomposites with effective antibacterial activity against both antibiotic-resistant Gram-negative and Gram-positive bacteria, including bacterial biofilms. These silver nanocomposites did not trigger hemolytic activity. Significantly, the bacteria did not develop resistance to the obtained nanocomposites even after 30 generations. A study of the antibacterial mechanism confirmed that these nanocomposites could irreversibly disrupt the membrane structure of bacteria and effectively inhibit intracellular enzyme activity, ultimately leading to bacterial death. The silver nanocomposites (64 μg/mL) could eradicate 80% of an established antibiotic-resistant bacterial biofilm. The strong structure-activity relationship toward antibacterial and antibiofilm activity suggests that variations in the conformational property of the functional ligand could be valuable in the discovery of new nano-antibacterial agents for treating pathogenic bacterial infections.
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Affiliation(s)
- Xiaomei Dai
- Key Laboratory of Functional Polymer Materials of Ministry of Education, Institute of Polymer Chemistry, Nankai University , Tianjin 300071, China
| | - Xuelei Chen
- Key Laboratory of Functional Polymer Materials of Ministry of Education, Institute of Polymer Chemistry, Nankai University , Tianjin 300071, China
| | - Jing Zhao
- Key Laboratory of Functional Polymer Materials of Ministry of Education, Institute of Polymer Chemistry, Nankai University , Tianjin 300071, China
| | - Yu Zhao
- Key Laboratory of Functional Polymer Materials of Ministry of Education, Institute of Polymer Chemistry, Nankai University , Tianjin 300071, China
| | - Qianqian Guo
- Key Laboratory of Functional Polymer Materials of Ministry of Education, Institute of Polymer Chemistry, Nankai University , Tianjin 300071, China
| | - Tianqi Zhang
- Key Laboratory of Functional Polymer Materials of Ministry of Education, Institute of Polymer Chemistry, Nankai University , Tianjin 300071, China
| | - Chunli Chu
- College of Environmental Science and Engineering, Nankai University , Tianjin 300350, China
| | - Xinge Zhang
- Key Laboratory of Functional Polymer Materials of Ministry of Education, Institute of Polymer Chemistry, Nankai University , Tianjin 300071, China
| | - Chaoxing Li
- Key Laboratory of Functional Polymer Materials of Ministry of Education, Institute of Polymer Chemistry, Nankai University , Tianjin 300071, China
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Surveillance of tedizolid activity and resistance: In vitro susceptibility of Gram-positive pathogens collected over 5 years from the United States and Europe. Diagn Microbiol Infect Dis 2017; 87:133-138. [DOI: 10.1016/j.diagmicrobio.2016.10.009] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2016] [Revised: 09/08/2016] [Accepted: 10/03/2016] [Indexed: 11/19/2022]
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Rapid Acquisition of Linezolid Resistance in Methicillin-Resistant Staphylococcus aureus: Role of Hypermutation and Homologous Recombination. PLoS One 2016; 11:e0155512. [PMID: 27182700 PMCID: PMC4868352 DOI: 10.1371/journal.pone.0155512] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2015] [Accepted: 04/30/2016] [Indexed: 01/01/2023] Open
Abstract
Background We previously reported the case of a 64-year-old man with mediastinitis caused by Staphylococcus aureus in which the infecting bacterium acquired linezolid resistance after only 14 days treatment with linezolid. We therefore investigated relevant clinical isolates for possible mechanisms of this rapid acquisition of linezolid resistance. Methods Using clinical S. aureus isolates, we assessed the in vitro mutation rate and performed stepwise selection for linezolid resistance. To investigate homologous recombination, sequences were determined for each of the 23S ribosomal RNA (23S rRNA) loci; analyzed sequences spanned the entirety of each 23S rRNA gene, including domain V, as well as the 16S-23S intergenic spacer regions. We additionally performed next-generation sequencing on clinical strains to identify single-nucleotide polymorphisms compared to the N315 genome. Results Strains isolated from the patient prior to linezolid exposure (M5-M7) showed higher-level linezolid resistance than N315, and the pre-exposure strain (M2) exhibited more rapid acquisition of linezolid resistance than did N315. However, the mutation rates of these and contemporaneous clinical isolates were similar to those of N315, and the isolates did not exhibit any mutations in hypermutation-related genes. Sequences of the 23S rRNA genes and 16S-23S intergenic spacer regions were identical among the pre- and post-exposure clinical strains. Notably, all of the pre-exposure isolates harbored a recQ missense mutation (Glu69Asp) with respect to N315; such a lesion may have affected short sequence recombination (facilitating, for example, recombination among rrn loci). We hypothesize that this mechanism contributed to rapid acquisition of linezolid resistance. Conclusions Hypermutation and homologous recombination of the ribosomal RNA genes, including 23S rRNA genes, appear not to have been sources of the accelerated acquisition of linezolid resistance observed in our clinical case. Increased frequency of short sequence recombination may have resulted from a recQ variant in the infecting organism.
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Antibacterial activity and mechanism of action of auranofin against multi-drug resistant bacterial pathogens. Sci Rep 2016; 6:22571. [PMID: 26936660 PMCID: PMC4776257 DOI: 10.1038/srep22571] [Citation(s) in RCA: 125] [Impact Index Per Article: 15.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2015] [Accepted: 02/17/2016] [Indexed: 11/18/2022] Open
Abstract
Traditional methods employed to discover new antibiotics are both a time-consuming and financially-taxing venture. This has led researchers to mine existing libraries of clinical molecules in order to repurpose old drugs for new applications (as antimicrobials). Such an effort led to the discovery of auranofin, a drug initially approved as an anti-rheumatic agent, which also possesses potent antibacterial activity in a clinically achievable range. The present study demonstrates auranofin’s antibacterial activity is a complex process that involves inhibition of multiple biosynthetic pathways including cell wall, DNA, and bacterial protein synthesis. We also confirmed that the lack of activity of auranofin observed against Gram-negative bacteria is due to the permeability barrier conferred by the outer membrane. Auranofin’s ability to suppress bacterial protein synthesis leads to significant reduction in the production of key methicillin-resistant Staphylococcus aureus (MRSA) toxins. Additionally, auranofin is capable of eradicating intracellular MRSA present inside infected macrophage cells. Furthermore, auranofin is efficacious in a mouse model of MRSA systemic infection and significantly reduces the bacterial load in murine organs including the spleen and liver. Collectively, this study provides valuable evidence that auranofin has significant promise to be repurposed as a novel antibacterial for treatment of invasive bacterial infections.
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Global analysis of the impact of linezolid onto virulence factor production in S. aureus USA300. Int J Med Microbiol 2016; 306:131-40. [PMID: 26996810 DOI: 10.1016/j.ijmm.2016.02.004] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2015] [Revised: 02/10/2016] [Accepted: 02/15/2016] [Indexed: 12/20/2022] Open
Abstract
The translation inhibitor linezolid is an antibiotic of last resort against Gram-positive pathogens including methicillin resistant strains of the nosocomial pathogen Staphylococcus aureus. Linezolid is reported to inhibit production of extracellular virulence factors, but the molecular cause is unknown. To elucidate the physiological response of S. aureus to linezolid in general and the inhibition of virulence factor synthesis in particular a holistic study was performed. Linezolid was added to exponentially growing S. aureus cells and the linezolid stress response was analyzed with transcriptomics and quantitative proteomics methods. In addition, scanning and transmission electron microscopy experiments as well as fluorescence microscopy analyses of the cellular DNA and membrane were performed. As previously observed in studies on other translation inhibitors, S. aureus adapts its protein biosynthesis machinery to the reduced translation efficiency. For example the synthesis of ribosomal proteins was induced. Also unexpected results like a decline in the amount of extracellular and membrane proteins were obtained. In addition, cell shape and size changed after linezolid stress and cell division was diminished. Finally, the chromosome was condensed after linezolid stress and lost contact to the membrane. These morphological changes cannot be explained by established theories. A new hypothesis is discussed, which suggests that the reduced amount of membrane and extracellular proteins and observed defects in cell division are due to the disintegration of transertion complexes by linezolid.
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Zhanel GG, Love R, Adam H, Golden A, Zelenitsky S, Schweizer F, Gorityala B, Lagacé-Wiens PRS, Rubinstein E, Walkty A, Gin AS, Gilmour M, Hoban DJ, Lynch JP, Karlowsky JA. Tedizolid: a novel oxazolidinone with potent activity against multidrug-resistant gram-positive pathogens. Drugs 2015; 75:253-70. [PMID: 25673021 DOI: 10.1007/s40265-015-0352-7] [Citation(s) in RCA: 116] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Tedizolid phosphate is a novel oxazolidinone prodrug (converted to the active form tedizolid by phosphatases in vivo) that has been developed and recently approved (June 2014) by the United States FDA for the treatment of acute bacterial skin and skin structure infections (ABSSSIs) caused by susceptible Gram-positive pathogens, including methicillin-resistant Staphylococcus aureus (MRSA). Tedizolid is an oxazolidinone, but differs from other oxazolidinones by possessing a modified side chain at the C-5 position of the oxazolidinone nucleus which confers activity against certain linezolid-resistant pathogens and has an optimized C- and D-ring system that improves potency through additional binding site interactions. The mechanism of action of tedizolid is similar to other oxazolidinones and occurs through inhibition of bacterial protein synthesis by binding to 23S ribosomal RNA (rRNA) of the 50S subunit of the ribosome. As with other oxazolidinones, the spontaneous frequency of resistance development to tedizolid is low. Tedizolid is four- to eightfold more potent in vivo than linezolid against all species of staphylococci, enterococci, and streptococci, including drug-resistant phenotypes such as MRSA and vancomycin-resistant enterococci (VRE) and linezolid-resistant phenotypes. Importantly, tedizolid demonstrates activity against linezolid-resistant bacterial strains harboring the horizontally transmissible cfr gene, in the absence of certain ribosomal mutations conferring reduced oxazolidinone susceptibility. With its half-life of approximately 12 h, tedizolid is dosed once daily. It demonstrates linear pharmacokinetics, has a high oral bioavailability of approximately 90 %, and is primarily excreted by the liver as an inactive, non-circulating sulphate conjugate. Tedizolid does not require dosage adjustment in patients with any degree of renal dysfunction or hepatic dysfunction. Studies in animals have demonstrated that the pharmacodynamic parameter most closely associated with the efficacy of tedizolid is fAUC(0-24h)/MIC. In non-neutropenic animals, a dose-response enhancement was observed with tedizolid and lower exposures were required compared to neutropenic cohorts. Two Phase III clinical trials have demonstrated non-inferiority of a once-daily tedizolid 200 mg dose for 6-10 days versus twice-daily 600 mg linezolid for the treatment of ABSSSIs. Both trials used the primary endpoint of early clinical response at 48-72 h; however, one trial compared oral formulations while the other initiated therapy with the parenteral formulation and allowed oral sequential therapy following initial clinical response. Throughout its development, tedizolid has demonstrated that it is well tolerated and animal studies have shown a lower propensity for neuropathies with long-term use than its predecessor linezolid. Data from the two completed Phase III clinical trials demonstrated that the studied tedizolid regimen (200 mg once daily for 6 days) had significantly less impact on hematologic parameters as well as significantly less gastrointestinal treatment-emergent adverse effects (TEAEs) than its comparator linezolid. As with linezolid, tedizolid is a weak, reversible MAO inhibitor; however, a murine head twitch model validated to assess serotonergic activity reported no increase in the number of head twitches with tedizolid even at doses that exceeded the C max in humans by up to 25-fold. Tyramine and pseudoephedrine challenge studies in humans have also reported no meaningful MAO-related interactions with tedizolid. With its enhanced in vitro activity against a broad-spectrum of Gram-positive aerobic bacteria, convenient once-daily dosing, a short 6-day course of therapy, availability of both oral and intravenous routes of administration, and an adverse effect profile that appears to be more favorable than linezolid, tedizolid is an attractive agent for use in both the hospital and community settings. Tedizolid is currently undergoing additional Phase III clinical trials for the treatment of hospital-acquired bacterial pneumonia (HABP) and ventilated nosocomial pneumonia (VNP).
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Affiliation(s)
- George G Zhanel
- Department of Medical Microbiology, Faculty of Medicine, University of Manitoba, Winnipeg, MB, Canada,
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Exploring simvastatin, an antihyperlipidemic drug, as a potential topical antibacterial agent. Sci Rep 2015; 5:16407. [PMID: 26553420 PMCID: PMC4639749 DOI: 10.1038/srep16407] [Citation(s) in RCA: 79] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2015] [Accepted: 10/13/2015] [Indexed: 12/17/2022] Open
Abstract
The rapid rise of bacterial resistance to traditional antibiotics combined with the decline in discovery of novel antibacterial agents has created a global public health crisis. Repurposing existing drugs presents an alternative strategy to potentially expedite the discovery of new antimicrobial drugs. The present study demonstrates that simvastatin, an antihyperlipidemic drug exhibited broad-spectrum antibacterial activity against important Gram-positive (including methicillin-resistant Staphylococcus aureus (MRSA)) and Gram-negative pathogens (once the barrier imposed by the outer membrane was permeabilized). Proteomics and macromolecular synthesis analyses revealed that simvastatin inhibits multiple biosynthetic pathways and cellular processes in bacteria, including selective interference of bacterial protein synthesis. This property appears to assist in simvastatin's ability to suppress production of key MRSA toxins (α-hemolysin and Panton-Valentine leucocidin) that impair healing of infected skin wounds. A murine MRSA skin infection experiment confirmed that simvastatin significantly reduces the bacterial burden and inflammatory cytokines in the infected wounds. Additionally, simvastatin exhibits excellent anti-biofilm activity against established staphylococcal biofilms and demonstrates the ability to be combined with topical antimicrobials currently used to treat MRSA skin infections. Collectively the present study lays the foundation for further investigation of repurposing simvastatin as a topical antibacterial agent to treat skin infections.
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Mutations in the bacterial ribosomal protein l3 and their association with antibiotic resistance. Antimicrob Agents Chemother 2015; 59:3518-28. [PMID: 25845869 DOI: 10.1128/aac.00179-15] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2015] [Accepted: 03/31/2015] [Indexed: 11/20/2022] Open
Abstract
Different groups of antibiotics bind to the peptidyl transferase center (PTC) in the large subunit of the bacterial ribosome. Resistance to these groups of antibiotics has often been linked with mutations or methylations of the 23S rRNA. In recent years, there has been a rise in the number of studies where mutations have been found in the ribosomal protein L3 in bacterial strains resistant to PTC-targeting antibiotics but there is often no evidence that these mutations actually confer antibiotic resistance. In this study, a plasmid exchange system was used to replace plasmid-carried wild-type genes with mutated L3 genes in a chromosomal L3 deletion strain. In this way, the essential L3 gene is available for the bacteria while allowing replacement of the wild type with mutated L3 genes. This enables investigation of the effect of single mutations in Escherichia coli without a wild-type L3 background. Ten plasmid-carried mutated L3 genes were constructed, and their effect on growth and antibiotic susceptibility was investigated. Additionally, computational modeling of the impact of L3 mutations in E. coli was used to assess changes in 50S structure and antibiotic binding. All mutations are placed in the loops of L3 near the PTC. Growth data show that 9 of the 10 mutations were well accepted in E. coli, although some of them came with a fitness cost. Only one of the mutants exhibited reduced susceptibility to linezolid, while five exhibited reduced susceptibility to tiamulin.
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Mohammad H, Reddy PVN, Monteleone D, Mayhoub AS, Cushman M, Seleem MN. Synthesis and antibacterial evaluation of a novel series of synthetic phenylthiazole compounds against methicillin-resistant Staphylococcus aureus (MRSA). Eur J Med Chem 2015; 94:306-16. [PMID: 25771109 DOI: 10.1016/j.ejmech.2015.03.015] [Citation(s) in RCA: 61] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2015] [Revised: 03/04/2015] [Accepted: 03/06/2015] [Indexed: 01/26/2023]
Abstract
Methicillin-resistant Staphylococcus aureus infections are a significant global health challenge in part due to the emergence of strains exhibiting resistance to nearly all classes of antibiotics. This underscores the urgent need for the rapid development of novel antimicrobials to circumvent this burgeoning problem. Previously, whole-cell screening of a library of 2,5-disubstituted thiazole compounds revealed a lead compound exhibiting potent antimicrobial activity against MRSA. The present study, conducting a more rigorous analysis of the structure-activity relationship of this compound, reveals a nonpolar, hydrophobic functional group is favored at thiazole-C2 and an ethylidenehydrazine-1-carboximidamide moiety is necessary at C5 for the compound to possess activity against MRSA. Furthermore, the MTS assay confirmed analogs 5, 22d, and 25 exhibited an improved toxicity profile (not toxic up to 40 μg/mL to mammalian cells) over the lead 1. Analysis with human liver microsomes revealed compound 5 was more metabolically stable compared to the lead compound (greater than eight-fold improvement in the half-life in human liver microsomes). Collectively the results presented demonstrate the novel thiazole derivatives synthesized warrant further exploration for potential use as future antimicrobial agents for the treatment of multidrug-resistant S. aureus infections.
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Affiliation(s)
- Haroon Mohammad
- Department of Comparative Pathobiology, Purdue University College of Veterinary Medicine, West Lafayette, IN 47907, USA
| | - P V Narasimha Reddy
- Department of Medicinal Chemistry and Molecular Pharmacology, Purdue University College of Pharmacy, and the Purdue Center for Cancer Research, West Lafayette, IN 47907, USA
| | - Dennis Monteleone
- Department of Medicinal Chemistry and Molecular Pharmacology, Purdue University College of Pharmacy, and the Purdue Center for Cancer Research, West Lafayette, IN 47907, USA
| | | | - Mark Cushman
- Department of Medicinal Chemistry and Molecular Pharmacology, Purdue University College of Pharmacy, and the Purdue Center for Cancer Research, West Lafayette, IN 47907, USA
| | - Mohamed N Seleem
- Department of Comparative Pathobiology, Purdue University College of Veterinary Medicine, West Lafayette, IN 47907, USA.
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Ribosomal protein L3 mutations are associated with cfr-mediated linezolid resistance in clinical isolates of Staphylococcus cohnii. Curr Microbiol 2015; 70:840-5. [PMID: 25726423 DOI: 10.1007/s00284-015-0793-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2014] [Accepted: 01/16/2015] [Indexed: 10/23/2022]
Abstract
From June, 2012 to November, 2013 five linezolid-resistant Staphylococcus cohnii isolates were identified in our hospital in Beijing, China. The investigation of the resistance mechanisms confirmed that the cfr-carrying plasmids were the main cause of linezolid resistance in those clinical isolates. Moreover, all the five isolates had ribosomal protein L3 mutations, which had different coordinate effect on cfr-mediated linezolid resistance directly through the substitution of serine 158 by phenylalanine or tyrosine in L3 protein. In this study, two types of plasmids (p432, p438) (Accession No. KM114207) were found, which share high sequence identity with previously reported cfr-carrying pRM01 and pMHZ plasmids originated from northern and southern China, showing wide regional dissemination in China. The stability of linezolid resistance was studied by passaging single colonies serially on antibiotic-free blood medium, which showed that the susceptible derivatives emerged until the passages 39-42 with the elimination of cfr-carrying plasmid. Thus the high stability of this plasmid may pose a risk for the transmission among patients or even cause an outbreak in clinical settings.
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Abstract
Treatment of multidrug-resistant Gram-positive infections continues to challenge clinicians as the emergence of new resistance mechanisms outpaces introduction of novel antimicrobial agents. Tedizolid phosphate is a next-generation oxazolidinone with activity against both methicillin-resistant Staphylococcus aureus and vancomycin-resistant Enterococcus spp. Tedizolid has consistently shown potency advantages over linezolid against Gram-positive microorganisms including those with reduced susceptibility to linezolid. Of particular significance, minimum inhibitory concentrations of tedizolid appear to be largely unaffected by the chloramphenicol-florfenicol resistance (cfr) gene, which has been implicated in a number of published linezolid-resistant organism outbreaks. Tedizolid phosphate also has been found to have a favorable pharmacokinetic profile allowing for once-daily dosing in both oral and intravenous forms. Potency and pharmacokinetic advantages have allowed for lower total daily doses of tedizolid, compared to linezolid, being needed for clinical efficacy in the treatment of acute bacterial skin and skin structure infections (ABSSSI). The decreased total drug exposure produced may in part be responsible for a decrease in the observed adverse effects including thrombocytopenia. Tedizolid phosphate is currently indicated for the treatment of ABSSSI and under investigation for the treatment of nosocomial pneumonia. Although much of the role of tedizolid remains to be defined by expanding clinical experience, tedizolid is likely a welcomed addition to the mere handful of agents available for the treatment of multidrug-resistant Gram-positive infections.
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Affiliation(s)
- Jeffrey M Rybak
- Department of Clinical Pharmacy, University of Tennessee Health Science Center, Memphis, TN, USA,
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Flanagan S, McKee EE, Das D, Tulkens PM, Hosako H, Fiedler-Kelly J, Passarell J, Radovsky A, Prokocimer P. Nonclinical and pharmacokinetic assessments to evaluate the potential of tedizolid and linezolid to affect mitochondrial function. Antimicrob Agents Chemother 2015; 59:178-85. [PMID: 25331703 PMCID: PMC4291347 DOI: 10.1128/aac.03684-14] [Citation(s) in RCA: 67] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2014] [Accepted: 10/14/2014] [Indexed: 11/20/2022] Open
Abstract
Prolonged treatment with the oxazolidinone linezolid is associated with myelosuppression, lactic acidosis, and neuropathies, toxicities likely caused by impairment of mitochondrial protein synthesis (MPS). To evaluate the potential of the novel oxazolidinone tedizolid to cause similar side effects, nonclinical and pharmacokinetic assessments were conducted. In isolated rat heart mitochondria, tedizolid inhibited MPS more potently than did linezolid (average [± standard error of the mean] 50% inhibitory concentration [IC50] for MPS of 0.31 ± 0.02 μM versus 6.4 ± 1.2 μM). However, a rigorous 9-month rat study comparing placebo and high-dose tedizolid (resulting in steady-state area under the plasma concentration-time curve values about 8-fold greater than those with the standard therapeutic dose in humans) showed no evidence of neuropathy. Additional studies explored why prolonged, high-dose tedizolid did not cause these mitochondriopathic side effects despite potent MPS inhibition by tedizolid. Murine macrophage (J774) cell fractionation studies found no evidence of a stable association of tedizolid with eukaryotic mitochondria. Monte Carlo simulations based on population pharmacokinetic models showed that over the course of a dosing interval using standard therapeutic doses, free plasma concentrations fell below the respective MPS IC50 in 84% of tedizolid-treated patients (for a median duration of 7.94 h) and 38% of linezolid-treated patients (for a median duration of 0 h). Therapeutic doses of tedizolid, but not linezolid, may therefore allow for mitochondrial recovery during antibacterial therapy. The overall results suggest that tedizolid has less potential to cause myelosuppression and neuropathy than that of linezolid during prolonged treatment courses. This, however, remains a hypothesis that must be confirmed in clinical studies.
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Affiliation(s)
| | - Edward E McKee
- College of Medicine, Central Michigan University, Mount Pleasant, Michigan, USA
| | - Debaditya Das
- Louvain Drug Research Institute, Université Catholique de Louvain, Brussels, Belgium
| | - Paul M Tulkens
- Louvain Drug Research Institute, Université Catholique de Louvain, Brussels, Belgium
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Rybak JM, Marx K, Martin CA. Early Experience with Tedizolid: Clinical Efficacy, Pharmacodynamics, and Resistance. Pharmacotherapy 2014; 34:1198-208. [DOI: 10.1002/phar.1491] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Jeffrey M. Rybak
- Department of Pharmacy; University of Kentucky HealthCare; Lexington Kentucky
| | - Kayleigh Marx
- Department of Pharmacy; University of Kentucky HealthCare; Lexington Kentucky
| | - Craig A. Martin
- Department of Pharmacy; University of Kentucky HealthCare; Lexington Kentucky
- Pharmacy Practice and Science Department; University of Kentucky College of Pharmacy; Lexington Kentucky
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Linezolid-resistant Staphylococcus aureus strain 1128105, the first known clinical isolate possessing the cfr multidrug resistance gene. Antimicrob Agents Chemother 2014; 58:6592-8. [PMID: 25155597 DOI: 10.1128/aac.03493-14] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
The Cfr methyltransferase confers resistance to six classes of drugs which target the peptidyl transferase center of the 50S ribosomal subunit, including some oxazolidinones, such as linezolid (LZD). The mobile cfr gene was identified in European veterinary isolates from the late 1990s, although the earliest report of a clinical cfr-positive strain was the 2005 Colombian methicillin-resistant Staphylococcus aureus (MRSA) isolate CM05. Here, through retrospective analysis of LZD(r) clinical strains from a U.S. surveillance program, we identified a cfr-positive MRSA isolate, 1128105, from January 2005, predating CM05 by 5 months. Molecular typing of 1128105 revealed a unique pulsed-field gel electrophoresis (PFGE) profile most similar to that of USA100, spa type t002, and multilocus sequence type 5 (ST5). In addition to cfr, LZD resistance in 1128105 is partially attributed to the presence of a single copy of the 23S rRNA gene mutation T2500A. Transformation of the ∼37-kb conjugative p1128105 cfr-bearing plasmid from 1128105 into S. aureus ATCC 29213 background strains was successful in recapitulating the Cfr antibiogram, as well as resistance to aminoglycosides and trimethoprim. A 7-kb cfr-containing region of p1128105 possessed sequence nearly identical to that found in the Chinese veterinary Proteus vulgaris isolate PV-01 and in U.S. clinical S. aureus isolate 1900, although the presence of IS431-like sequences is unique to p1128105. The cfr gene environment in this early clinical cfr-positive isolate has now been identified in Gram-positive and Gram-negative strains of clinical and veterinary origin and has been associated with multiple mobile elements, highlighting the versatility of this multidrug resistance gene and its potential for further dissemination.
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Identification and characterization of linezolid-resistant cfr-positive Staphylococcus aureus USA300 isolates from a New York City medical center. Antimicrob Agents Chemother 2014; 58:6949-52. [PMID: 25136008 DOI: 10.1128/aac.03380-14] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
The cfr gene was identified in three linezolid-resistant USA300 methicillin-resistant Staphylococcus aureus (MRSA) isolates collected over a 3-day period at a New York City medical center in 2011 as part of a routine surveillance program. Each isolate possessed a plasmid containing a pSCFS3-like cfr gene environment. Transformation of the cfr-bearing plasmids into the S. aureus ATCC 29213 background recapitulated the expected Cfr antibiogram, including resistance to linezolid, tiamulin, clindamycin, and florfenicol and susceptibility to tedizolid.
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Locke JB, Zurenko GE, Shaw KJ, Bartizal K. Tedizolid for the management of human infections: in vitro characteristics. Clin Infect Dis 2014; 58 Suppl 1:S35-42. [PMID: 24343830 DOI: 10.1093/cid/cit616] [Citation(s) in RCA: 81] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
The emerging antibiotic resistance of Gram-positive pathogens represents a significant challenge to the management of human infections. The novel oxazolidinone tedizolid demonstrates antimicrobial activity across a broad range of Gram-positive pathogens and greater potency than linezolid against wild-type and drug-resistant pathogens, including linezolid-resistant Staphylococcus aureus strains possessing mutations in chromosomal genes encoding 23S rRNA or ribosomal proteins L3 or L4. Strains harboring such mutations are also selected for much less frequently with tedizolid than with linezolid. In addition, tedizolid has a significant potency advantage over linezolid-resistant strains carrying the horizontally transferable cfr gene. Methylation of A2503 of 23S rRNA by the Cfr methyltransferase confers resistance to linezolid (and a variety of other 50S ribosomal subunit-targeted antibiotics) but not to tedizolid because of structural differences in A-ring C5 substituents between the 2 drugs. The greater potency and improved resistance profile of tedizolid provides the microbiologic basis for considering this molecule as an alternative to linezolid for the treatment of serious infections caused by Gram-positive pathogens.
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Zeng ZL, Wei HK, Wang J, Lin DC, Liu XQ, Liu JH. High prevalence of Cfr-producing Staphylococcus species in retail meat in Guangzhou, China. BMC Microbiol 2014; 14:151. [PMID: 24913069 PMCID: PMC4059476 DOI: 10.1186/1471-2180-14-151] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2014] [Accepted: 05/30/2014] [Indexed: 11/13/2022] Open
Abstract
Background The emergence and wide distribution of the transferable gene for linezolid resistance, cfr, in staphylococci of human and animal origins is of great concern as it poses a serious threat to the public health. In the present study, we investigated the emergence and presence of the multiresistance gene, cfr, in retail meat sourced from supermarkets and free markets of Guangzhou, China. Results A total of 118 pork and chicken samples, collected from Guangzhou markets, were screened by PCR for cfr. Twenty-two Staphylococcus isolates obtained from 12 pork and 10 chicken samples harbored cfr. The 22 cfr-positive staphylococci isolates, including Staphylococcus equorum (n = 8), Staphylococcus simulans (n = 7), Staphylococcus cohnii (n = 4), and Staphylococcus sciuri (n = 3), exhibited 17 major SmaI pulsed-field gel electrophoresis (PFGE) patterns. In 14 isolates, cfr was located on the plasmids. Sequence analysis revealed that the genetic structures (including ΔtnpA of Tn558, IS21-558, ΔtnpB, and tnpC of Tn558, orf138, fexA) of cfr in plasmid pHNTLD18 of a S. sciuri strain and in the plasmid pHNLKJC2 (including rep, Δpre/mob, cfr, pre/mob and partial ermC) of a S. equorum strain were identical or similar to the corresponding regions of some plasmids in staphylococcal species of animal and human origins. Conclusions To the best of our knowledge, this is the first study to report the presence of the multiresistance gene, cfr, in animal meat. A high occurrence of cfr was observed in the tested retail meat samples. Thus, it is important to monitor the presence of cfr in animal foods in China.
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Affiliation(s)
| | | | | | | | | | - Jian-Hua Liu
- College of Veterinary Medicine, National Reference Laboratory of Veterinary Drug Residues (SCAU), South China Agricultural University, Guangzhou, China.
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Mendes RE, Deshpande LM, Jones RN. Linezolid update: stable in vitro activity following more than a decade of clinical use and summary of associated resistance mechanisms. Drug Resist Updat 2014; 17:1-12. [PMID: 24880801 DOI: 10.1016/j.drup.2014.04.002] [Citation(s) in RCA: 155] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Linezolid, approved for clinical use since 2000, has become an important addition to the anti-Gram-positive infection armamentarium. This oxazolidinone drug has in vitro and in vivo activity against essentially all Gram-positive organisms, including methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant enterococci (VRE). The in vitro activity of linezolid was well documented prior to its clinical application, and several ongoing surveillance studies demonstrated consistent and potent results during the subsequent years of clinical use. Emergence of resistance has been limited and associated with invasive procedures, deep organ involvement, presence of foreign material and mainly prolonged therapy. Non-susceptible organisms usually demonstrate alterations in the 23S rRNA target, which remain the main resistance mechanism observed in enterococci; although a few reports have described the detection of cfr-mediated resistance in Enterococcus faecalis. S. aureus isolates non-susceptible to linezolid remain rare in large surveillance studies. Most isolates harbour 23S rRNA mutations; however, cfr-carrying MRSA isolates have been observed in the United States and elsewhere. It is still uncertain whether the occurrences of such isolates are becoming more prevalent. Coagulase-negative isolates (CoNS) resistant to linezolid were uncommon following clinical approval. Surveillance data have indicated that CoNS isolates, mainly Staphylococcus epidermidis, currently account for the majority of Gram-positive organisms displaying elevated MIC results to linezolid. In addition, these isolates frequently demonstrate complex and numerous resistance mechanisms, such as alterations in the ribosomal proteins L3 and/or L4 and/or presence of cfr and/or modifications in 23S rRNA. The knowledge acquired during the past decades on this initially used oxazolidinone has been utilized for developing new candidate agents, such as tedizolid and radezolid, and as linezolid patents soon begin to expire, generic brands will certainly become available. These events will likely establish a new chapter for this successful class of antimicrobial agents.
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Affiliation(s)
| | | | - Ronald N Jones
- JMI Laboratories, North Liberty, IA 52317, USA; Tufts University School of Medicine, Boston, MA 02111, USA
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Rincón S, Panesso D, Díaz L, Carvajal LP, Reyes J, Munita JM, Arias CA. [Resistance to "last resort" antibiotics in Gram-positive cocci: The post-vancomycin era]. BIOMEDICA : REVISTA DEL INSTITUTO NACIONAL DE SALUD 2014; 34 Suppl 1:191-208. [PMID: 24968051 PMCID: PMC4435674 DOI: 10.1590/s0120-41572014000500022] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Received: 11/27/2013] [Accepted: 01/31/2014] [Indexed: 06/03/2023]
Abstract
New therapeutic alternatives have been developed in the last years for the treatment of multidrug-resistant Gram-positive infections. Infections caused by methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant enterococci (VRE) are considered a therapeutic challenge due to failures and lack of reliable antimicrobial options. Despite concerns related to the use of vancomycin in the treatment of severe MRSA infections in specific clinical scenarios, there is a paucity of solid clinical evidence that support the use of alternative agents (when compared to vancomycin). Linezolid, daptomycin and tigecycline are antibiotics approved in the last decade and newer cephalosporins (such as ceftaroline and ceftobiprole) and novel glycopeptides (dalvavancin, telavancin and oritavancin) have reached clinical approval or are in the late stages of clinical development. This review focuses on discussing these newer antibiotics used in the "post-vancomycin" era with emphasis on relevant chemical characteristics, spectrum of antimicrobial activity, mechanisms of action and resistance, as well as their clinical utility.
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Affiliation(s)
- Sandra Rincón
- Unidad de Genética y Resistencia Antimicrobiana (UGRA), Universidad El Bosque, Bogotá, D.C., Colombia
| | - Diana Panesso
- Unidad de Genética y Resistencia Antimicrobiana (UGRA), Universidad El Bosque, Bogotá, D.C., Colombia
- University of Texas Medical School at Houston, Houston, TX, USA
| | - Lorena Díaz
- Unidad de Genética y Resistencia Antimicrobiana (UGRA), Universidad El Bosque, Bogotá, D.C., Colombia
| | - Lina P. Carvajal
- Unidad de Genética y Resistencia Antimicrobiana (UGRA), Universidad El Bosque, Bogotá, D.C., Colombia
| | - Jinnethe Reyes
- Unidad de Genética y Resistencia Antimicrobiana (UGRA), Universidad El Bosque, Bogotá, D.C., Colombia
- University of Texas Medical School at Houston, Houston, TX, USA
| | - José M. Munita
- University of Texas Medical School at Houston, Houston, TX, USA
- Clínica Alemana de Santiago, Universidad del Desarrollo, Santiago de Chile, Chile
| | - César A. Arias
- Unidad de Genética y Resistencia Antimicrobiana (UGRA), Universidad El Bosque, Bogotá, D.C., Colombia
- University of Texas Medical School at Houston, Houston, TX, USA
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Epidemiological and genetic diversity of Staphylococcus aureus causing bloodstream infection in Shanghai, 2009-2011. PLoS One 2013; 8:e72811. [PMID: 24039803 PMCID: PMC3767693 DOI: 10.1371/journal.pone.0072811] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2013] [Accepted: 07/17/2013] [Indexed: 01/20/2023] Open
Abstract
OBJECTIVES Staphylococcus aureus or methicillin-resistant Staphylococcus aureus (MRSA) has been an important pathogen causing bloodstream infections. Our study aimed to investigate the epidemiological and genetic diversity of clinical S. aureus isolates from patients with bloodstream infection in four hospitals of Shanghai from 2009 to 2011. METHODS A collection of S. aureus isolates causing bloodstream infection from four hospitals in the central part of Shanghai was carried out. Antimicrobial susceptibility testings of collected isolates were performed according to the Clinical and Laboratory Standards Institute (CLSI) guidelines, and spa-type, multi-locus sequence typing, agr type and toxin gene profiling were performed to explore the molecular diversity. Moreover, MRSA strains were also characterized by Staphylococcal cassette chromosome mec (SCCmec) typing. RESULTS The drugs such as linezolid, teicoplanin and vancomycin were efficacious for treating S. aureus including MRSA bloodstream infection. Methicillin-sensitive Staphylococcus aureus (MSSA) strains displayed distinct diversity in molecular characterization and toxin genes, and three virulent MSSA strains encoding at least five toxins were detected. Five community-associated MRSA (CA-MRSA) strains were found, but the majority (88.7%) of MRSA strains belonged to two epidemic clones (ST239-MRSA- III and ST5-MRSA- II) with different toxin gene profiles among patients with bloodstream infection. CONCLUSIONS Healthcare-associated MRSA (HA-MRSA) strains were still the main pathogen causing bloodstream infections in spite of the emergence of CA-MRSA strains in hospital setting.
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Characterization and monitoring of linezolid-resistant clinical isolates of Staphylococcus epidermidis in an intensive care unit 4 years after an outbreak of infection by cfr-mediated linezolid-resistant Staphylococcus aureus. Diagn Microbiol Infect Dis 2013; 76:325-9. [DOI: 10.1016/j.diagmicrobio.2013.04.002] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2012] [Revised: 03/28/2013] [Accepted: 04/09/2013] [Indexed: 11/24/2022]
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Urbina O, Ferrández O, Espona M, Salas E, Ferrández I, Grau S. Potential role of tedizolid phosphate in the treatment of acute bacterial skin infections. DRUG DESIGN DEVELOPMENT AND THERAPY 2013; 7:243-65. [PMID: 23589680 PMCID: PMC3622392 DOI: 10.2147/dddt.s30728] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Tedizolid phosphate (TR-701), a prodrug of tedizolid (TR-700), is a next-generation oxazolidinone that has shown favorable results in the treatment of acute bacterial skin and skin-structure infections in its first Phase III clinical trial. Tedizolid has high bioavailability, penetration, and tissue distribution when administered orally or intravenously. The activity of tedizolid was greater than linezolid against strains of Staphylococcus spp., Streptococcus spp., and Enterococcus spp. in vitro studies, including strains resistant to linezolid and those not susceptible to vancomycin or daptomycin. Its pharmacokinetic characteristics allow for a once-daily administration that leads to a more predictable efficacy and safety profile than those of linezolid. No hematological adverse effects have been reported associated with tedizolid when used at the therapeutic dose of 200 mg in Phase I, II, or III clinical trials of up to 3 weeks of tedizolid administration. Given that the clinical and microbiological efficacy are similar for the 200, 300, and 400 mg doses, the lowest effective dose of 200 mg once daily for 6 days was selected for Phase III studies in acute bacterial skin and skin-structure infections, providing a safe dosing regimen with low potential for development of myelosuppression. Unlike linezolid, tedizolid does not inhibit monoamine oxidase in vivo, therefore interactions with adrenergic, dopaminergic, and serotonergic drugs are not to be expected. In conclusion, tedizolid is a novel antibiotic with potent activity against Gram-positive microorganisms responsible for skin and soft tissue infections, including strains resistant to vancomycin, linezolid, and daptomycin, thus answers a growing therapeutic need.
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Affiliation(s)
- Olatz Urbina
- Services of Hospital Pharmacy, Hospital Universitari del Mar, Universitat Autònoma de Barcelona
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The genetic environment of the cfr gene and the presence of other mechanisms account for the very high linezolid resistance of Staphylococcus epidermidis isolate 426-3147L. Antimicrob Agents Chemother 2012; 57:1173-9. [PMID: 23254434 DOI: 10.1128/aac.02047-12] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
The clinical Staphylococcus epidermidis isolate 426-3147L exhibits an unusually high resistance to linezolid that exceeds 256 μg/ml. The presence of the cfr gene, encoding the RNA methyltransferase targeting an rRNA nucleotide located in the linezolid binding site, accounts for a significant fraction of resistance. The association of cfr with a multicopy plasmid is one of the factors that contribute to its elevated expression. Mapping of the cfr transcription start sites identified the native cfr promoter. Furthermore, analysis of the cfr transcripts in Staphylococcus epidermidis 426-3147L showed that some of them originate from the upstream plasmid-derived promoters whose activity contributes to efficient cfr transcription. The genetic environment of the cfr gene and its idiosyncratic transcription pattern result in increased activity of Cfr methyltransferase, leading to a high fraction of the ribosomes being methylated at A2503 of the 23S rRNA. Curing of the Staphylococcus epidermidis 426-3147L isolate from the cfr-containing plasmid reduced the linezolid MIC to 64 μg/ml, indicating that other determinants contribute to resistance. Nucleotide sequence analysis revealed the presence of the C2534T mutation in two of the six 23S rRNA gene alleles as well as the presence of mutations in the genes of ribosomal proteins L3 and L4, which were previously implicated in linezolid resistance. Thus, the combination of resistance mechanisms operating through alteration of the drug target site appears to cause an unusually high level of linezolid resistance in the isolate.
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Diaz L, Kiratisin P, Mendes RE, Panesso D, Singh KV, Arias CA. Transferable plasmid-mediated resistance to linezolid due to cfr in a human clinical isolate of Enterococcus faecalis. Antimicrob Agents Chemother 2012; 56:3917-22. [PMID: 22491691 PMCID: PMC3393385 DOI: 10.1128/aac.00419-12] [Citation(s) in RCA: 126] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2012] [Accepted: 04/01/2012] [Indexed: 12/26/2022] Open
Abstract
Nonmutational resistance to linezolid is due to the presence of cfr, which encodes a methyltransferase responsible for methylation of A2503 in the 23S rRNA. The cfr gene was first described in animal isolates of staphylococci, and more recently, it has been identified in Staphylococcus aureus from human clinical infections, including in an outbreak of methicillin-resistant S. aureus. In enterococci, cfr has been described in an animal isolate of Enterococcus faecalis from China. Here, we report an isolate of linezolid-resistant E. faecalis (603-50427X) recovered from a patient in Thailand who received prolonged therapy with the antibiotic for the treatment of atypical mycobacterial disease. The isolate lacked mutations in the genes coding for 23S rRNA and L3 and L4 ribosomal proteins and belonged to the multilocus sequence type (MLST) 16 (ST16), which is commonly found in enterococcal isolates from animal sources. Resistance to linezolid was associated with the presence of cfr on an ~97-kb transferable plasmid. The cfr gene environment exhibited DNA sequences similar to those of other cfr-carrying plasmids previously identified in staphylococci (nucleotide identity, 99 to 100%). The cfr-carrying plasmid was transferable by conjugation to a laboratory strain of E. faecalis (OG1RF) but not to Enterococcus faecium or S. aureus. The cfr gene was flanked by IS256-like sequences both upstream and downstream. This is the first characterization of the potential horizontal transferability of the cfr gene from a human linezolid-resistant isolate of E. faecalis.
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Affiliation(s)
- Lorena Diaz
- Division of Infectious Diseases, Department of Internal Medicine, University of Texas Medical School at Houston, Houston, Texas
- Molecular Genetics and Antimicrobial Resistance Unit, Universidad El Bosque, Bogota, Colombia
| | - Pattarachai Kiratisin
- Department of Microbiology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand
| | | | - Diana Panesso
- Division of Infectious Diseases, Department of Internal Medicine, University of Texas Medical School at Houston, Houston, Texas
- Molecular Genetics and Antimicrobial Resistance Unit, Universidad El Bosque, Bogota, Colombia
| | - Kavindra V. Singh
- Division of Infectious Diseases, Department of Internal Medicine, University of Texas Medical School at Houston, Houston, Texas
| | - Cesar A. Arias
- Division of Infectious Diseases, Department of Internal Medicine, University of Texas Medical School at Houston, Houston, Texas
- Molecular Genetics and Antimicrobial Resistance Unit, Universidad El Bosque, Bogota, Colombia
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Brown-Elliott BA, Nash KA, Wallace RJ. Antimicrobial susceptibility testing, drug resistance mechanisms, and therapy of infections with nontuberculous mycobacteria. Clin Microbiol Rev 2012; 25:545-82. [PMID: 22763637 PMCID: PMC3416486 DOI: 10.1128/cmr.05030-11] [Citation(s) in RCA: 335] [Impact Index Per Article: 27.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
Within the past 10 years, treatment and diagnostic guidelines for nontuberculous mycobacteria have been recommended by the American Thoracic Society (ATS) and the Infectious Diseases Society of America (IDSA). Moreover, the Clinical and Laboratory Standards Institute (CLSI) has published and recently (in 2011) updated recommendations including suggested antimicrobial and susceptibility breakpoints. The CLSI has also recommended the broth microdilution method as the gold standard for laboratories performing antimicrobial susceptibility testing of nontuberculous mycobacteria. This article reviews the laboratory, diagnostic, and treatment guidelines together with established and probable drug resistance mechanisms of the nontuberculous mycobacteria.
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Pandit N, Singla RK, Shrivastava B. Current updates on oxazolidinone and its significance. INTERNATIONAL JOURNAL OF MEDICINAL CHEMISTRY 2012; 2012:159285. [PMID: 25954524 PMCID: PMC4412212 DOI: 10.1155/2012/159285] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/22/2011] [Revised: 10/16/2011] [Accepted: 10/20/2011] [Indexed: 11/17/2022]
Abstract
Oxazolidinone is a five-member heterocyclic ring exhibiting potential medicinal properties with preferential antibacterial activity. Scientists reported various synthetic procedures for this heterocyclic structure. Current review articles tried to cover each and every potential aspect of oxazolidinone like synthetic routes, pharmacological mechanism of action, medicinal properties, and current research activities.
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Affiliation(s)
- Neha Pandit
- Department of Pharmaceutical Chemistry, School of Pharmaceutical Sciences, Jaipur National University, Jagatpura-Jaipur, Rajasthan 302025, India
| | - Rajeev K. Singla
- Sadbhavna College of Management & Technology, Jalaldiwal, Ludhiana-Barnala State Highway-13, Raikot (Ludhiana), Punjab, India
| | - Birendra Shrivastava
- Department of Pharmaceutical Chemistry, School of Pharmaceutical Sciences, Jaipur National University, Jagatpura-Jaipur, Rajasthan 302025, India
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