1
|
Viteri-Dávila C, Morales-Jadán D, Creel A, Jop Vidal AG, Boldo XM, Rivera-Olivero IA, Bautista-Muñoz C, Alibayov B, Garcia-Bereguiain MÁ, Vidal JE. The Crisis of Macrolide Resistance in Pneumococci in Latin America. Am J Trop Med Hyg 2024; 111:756-764. [PMID: 39084209 PMCID: PMC11448541 DOI: 10.4269/ajtmh.23-0913] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2023] [Accepted: 04/24/2024] [Indexed: 08/02/2024] Open
Abstract
Macrolide antibiotics are recommended for the treatment of pneumococcal pneumonia and invasive pneumococcal disease (IPD). Prior to 2000, ∼10% of Streptococcus pneumoniae strains isolated from IPD cases in Latin American countries were resistant to macrolides. The mechanism of resistance to macrolides was associated mainly with the efflux pump known as the macrolide efflux genetic assembly, since most pneumococcal strains carried the mef(A/E) gene, whereas <6% strains carried both the methylase gene ermB and mef(A/E). In the first decade of this century, a significant increase in the prevalence of macrolide resistance was observed in pneumococcal strains in both Mexico and Peru. Approximately 30% of S. pneumoniae strains in these countries were already resistant to erythromycin, while the prevalence in Colombia, Argentina, and Brazil remained below 10%. During the last decade, we have been experiencing a worrisome increase in pneumococcal strains carrying resistance to macrolides, with a prevalence of up to 80% for resistance to erythromycin. The mechanism for disseminating macrolide resistance has evolved. Currently, more than 55% of invasive S. pneumoniae macrolide-resistant strains carry both the ermB and the mef(A/E)/mel genes. Lessons learned from the current macrolide resistance crisis in Latin America can inform interventions in other regions.
Collapse
Affiliation(s)
| | | | - Aidan Creel
- Summer Undergraduate Research Experience Program, School of Graduate Studies in the Health Sciences, University of Mississippi Medical Center, Jackson, Mississippi
| | - Ana G. Jop Vidal
- Department of Cell and Molecular Biology, University of Mississippi Medical Center, Jackson, Mississippi
| | - Xavier M. Boldo
- Research Center, Health Sciences Academic Division, Juarez Autonomous University of Tabasco, Villahermosa, Mexico
| | | | | | - Babek Alibayov
- Department of Cell and Molecular Biology, University of Mississippi Medical Center, Jackson, Mississippi
| | | | - Jorge E. Vidal
- Department of Cell and Molecular Biology, University of Mississippi Medical Center, Jackson, Mississippi
- Center for Immunology and Microbial Research, University of Mississippi Medical Center, Jackson, Mississippi
| |
Collapse
|
2
|
Nor Amdan NA, Shahrulzamri NA, Hashim R, Mohamad Jamil N. Understanding the evolution of macrolides resistance: A mini review. J Glob Antimicrob Resist 2024; 38:368-375. [PMID: 39117142 DOI: 10.1016/j.jgar.2024.07.016] [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: 11/28/2023] [Revised: 05/31/2024] [Accepted: 07/29/2024] [Indexed: 08/10/2024] Open
Abstract
BACKGROUND Macrolides inhibit the growth of bacterial cells by preventing the elongation of polypeptides during protein biosynthesis and include natural, synthetic, and semi-synthetic products. Elongation prevention occurs by blocking the passage of the polypeptide chain as the macrolides bind at the nascent peptide exit tunnel. OBJECTIVE Recent data of ribosome profiling via ribo-seq further proves that, other than blocking the polypeptide chain, macrolides are also able to affect the synthesis of individual proteins. Thus, this shows that the mode of action of macrolides is more complex than we initially thought. Since the discovery of macrolides in the 1950s, they have been widely used in veterinary practice, agriculture, and medicine. Due to misuse and overuse of antibiotics, bacteria have acquired resistance against them. Hence, it is of utmost importance for us to fully understand the mode of action of macrolides as well as the mechanisms of resistance against macrolides in order to mitigate antibiotic-resistance issues. RESULTS Chemical modifications can be performed to improve macrolide potency if we have a better understanding of their mode of action. Furthermore, a complete and detailed understanding of the mode of action of macrolides has remained vague, as new findings have challenged theories that are already in existence-due to this obscurity, research into macrolide modes of action continues to this day. CONCLUSION In this review, we present an overview of macrolide antibiotics, with an emphasis on the latest knowledge regarding the mode of action of macrolides as well as the mechanisms of resistance employed by bacteria against macrolides.
Collapse
Affiliation(s)
- Nur Asyura Nor Amdan
- Bacteriology Unit, Infectious Disease Research Centre (IDRC), Institute for Medical Research (IMR), National Institutes of Health, Ministry of Health Malaysia, 40170, Shah Alam, Selangor, Malaysia
| | - Nur Atikah Shahrulzamri
- Faculty of Applied Sciences, Universiti Teknologi MARA (UiTM), 40450 Shah Alam, Selangor, Malaysia
| | - Rohaidah Hashim
- Bacteriology Unit, Infectious Disease Research Centre (IDRC), Institute for Medical Research (IMR), National Institutes of Health, Ministry of Health Malaysia, 40170, Shah Alam, Selangor, Malaysia
| | - Norashirene Mohamad Jamil
- Faculty of Applied Sciences, Universiti Teknologi MARA (UiTM), 40450 Shah Alam, Selangor, Malaysia; Molecular Microbial Pathogenicity Research Group, Pharmaceutical and Life Sciences Community of Research, Faculty of Applied Sciences, Universiti Teknologi MARA (UiTM), 40450 Shah Alam, Selangor, Malaysia.
| |
Collapse
|
3
|
Svetlov MS, Dunand CF, Nakamoto JA, Atkinson GC, Safdari HA, Wilson DN, Vázquez-Laslop N, Mankin AS. Peptidyl-tRNA hydrolase is the nascent chain release factor in bacterial ribosome-associated quality control. Mol Cell 2024; 84:715-726.e5. [PMID: 38183984 DOI: 10.1016/j.molcel.2023.12.002] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2023] [Revised: 11/08/2023] [Accepted: 12/01/2023] [Indexed: 01/08/2024]
Abstract
Rescuing stalled ribosomes often involves their splitting into subunits. In many bacteria, the resultant large subunits bearing peptidyl-tRNAs are processed by the ribosome-associated quality control (RQC) apparatus that extends the C termini of the incomplete nascent polypeptides with polyalanine tails to facilitate their degradation. Although the tailing mechanism is well established, it is unclear how the nascent polypeptides are cleaved off the tRNAs. We show that peptidyl-tRNA hydrolase (Pth), the known role of which has been to hydrolyze ribosome-free peptidyl-tRNA, acts in concert with RQC factors to release nascent polypeptides from large ribosomal subunits. Dislodging from the ribosomal catalytic center is required for peptidyl-tRNA hydrolysis by Pth. Nascent protein folding may prevent peptidyl-tRNA retraction and interfere with the peptide release. However, oligoalanine tailing makes the peptidyl-tRNA ester bond accessible for Pth-catalyzed hydrolysis. Therefore, the oligoalanine tail serves not only as a degron but also as a facilitator of Pth-catalyzed peptidyl-tRNA hydrolysis.
Collapse
Affiliation(s)
- Maxim S Svetlov
- Center for Biomolecular Sciences, University of Illinois at Chicago, Chicago, IL 60607, USA; Department of Pharmaceutical Sciences, University of Illinois at Chicago, Chicago, IL 60607, USA.
| | - Clémence F Dunand
- Center for Biomolecular Sciences, University of Illinois at Chicago, Chicago, IL 60607, USA; Department of Pharmaceutical Sciences, University of Illinois at Chicago, Chicago, IL 60607, USA
| | - Jose A Nakamoto
- Department of Experimental Medicine, University of Lund, 221 00 Lund, Sweden
| | - Gemma C Atkinson
- Department of Experimental Medicine, University of Lund, 221 00 Lund, Sweden
| | - Haaris A Safdari
- Institute for Biochemistry and Molecular Biology, University of Hamburg, 20146 Hamburg, Germany
| | - Daniel N Wilson
- Institute for Biochemistry and Molecular Biology, University of Hamburg, 20146 Hamburg, Germany
| | - Nora Vázquez-Laslop
- Center for Biomolecular Sciences, University of Illinois at Chicago, Chicago, IL 60607, USA; Department of Pharmaceutical Sciences, University of Illinois at Chicago, Chicago, IL 60607, USA
| | - Alexander S Mankin
- Center for Biomolecular Sciences, University of Illinois at Chicago, Chicago, IL 60607, USA; Department of Pharmaceutical Sciences, University of Illinois at Chicago, Chicago, IL 60607, USA.
| |
Collapse
|
4
|
Nagao A, Nakanishi Y, Yamaguchi Y, Mishina Y, Karoji M, Toya T, Fujita T, Iwasaki S, Miyauchi K, Sakaguchi Y, Suzuki T. Quality control of protein synthesis in the early elongation stage. Nat Commun 2023; 14:2704. [PMID: 37198183 PMCID: PMC10192219 DOI: 10.1038/s41467-023-38077-5] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2021] [Accepted: 04/14/2023] [Indexed: 05/19/2023] Open
Abstract
In the early stage of bacterial translation, peptidyl-tRNAs frequently dissociate from the ribosome (pep-tRNA drop-off) and are recycled by peptidyl-tRNA hydrolase. Here, we establish a highly sensitive method for profiling of pep-tRNAs using mass spectrometry, and successfully detect a large number of nascent peptides from pep-tRNAs accumulated in Escherichia coli pthts strain. Based on molecular mass analysis, we found about 20% of the peptides bear single amino-acid substitutions of the N-terminal sequences of E. coli ORFs. Detailed analysis of individual pep-tRNAs and reporter assay revealed that most of the substitutions take place at the C-terminal drop-off site and that the miscoded pep-tRNAs rarely participate in the next round of elongation but dissociate from the ribosome. These findings suggest that pep-tRNA drop-off is an active mechanism by which the ribosome rejects miscoded pep-tRNAs in the early elongation, thereby contributing to quality control of protein synthesis after peptide bond formation.
Collapse
Affiliation(s)
- Asuteka Nagao
- Department of Chemistry and Biotechnology, Graduate School of Engineering, University of Tokyo, Bunkyo-ku, Tokyo, 113-8656, Japan.
| | - Yui Nakanishi
- Department of Chemistry and Biotechnology, Graduate School of Engineering, University of Tokyo, Bunkyo-ku, Tokyo, 113-8656, Japan
| | - Yutaro Yamaguchi
- Department of Chemistry and Biotechnology, Graduate School of Engineering, University of Tokyo, Bunkyo-ku, Tokyo, 113-8656, Japan
| | - Yoshifumi Mishina
- Department of Chemistry and Biotechnology, Graduate School of Engineering, University of Tokyo, Bunkyo-ku, Tokyo, 113-8656, Japan
| | - Minami Karoji
- Department of Chemistry and Biotechnology, Graduate School of Engineering, University of Tokyo, Bunkyo-ku, Tokyo, 113-8656, Japan
| | - Takafumi Toya
- Department of Chemistry and Biotechnology, Graduate School of Engineering, University of Tokyo, Bunkyo-ku, Tokyo, 113-8656, Japan
| | - Tomoya Fujita
- RNA Systems Biochemistry Laboratory, RIKEN Cluster for Pioneering Research, Wako, Saitama, 351-0198, Japan
| | - Shintaro Iwasaki
- RNA Systems Biochemistry Laboratory, RIKEN Cluster for Pioneering Research, Wako, Saitama, 351-0198, Japan
- Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, The University of Tokyo, Kashiwa, Chiba, 277-8561, Japan
| | - Kenjyo Miyauchi
- Department of Chemistry and Biotechnology, Graduate School of Engineering, University of Tokyo, Bunkyo-ku, Tokyo, 113-8656, Japan
| | - Yuriko Sakaguchi
- Department of Chemistry and Biotechnology, Graduate School of Engineering, University of Tokyo, Bunkyo-ku, Tokyo, 113-8656, Japan
| | - Tsutomu Suzuki
- Department of Chemistry and Biotechnology, Graduate School of Engineering, University of Tokyo, Bunkyo-ku, Tokyo, 113-8656, Japan.
| |
Collapse
|
5
|
Pharmacokinetics of Tildipirosin in Plasma, Milk, and Somatic Cells Following Intravenous, Intramuscular, and Subcutaneous Administration in Dairy Goats. Pharmaceutics 2022; 14:pharmaceutics14040860. [PMID: 35456694 PMCID: PMC9031826 DOI: 10.3390/pharmaceutics14040860] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2022] [Revised: 04/08/2022] [Accepted: 04/11/2022] [Indexed: 12/05/2022] Open
Abstract
Tildipirosin is a macrolide currently authorized for treating respiratory diseases in cattle and swine. The disposition kinetics of tildipirosin in plasma, milk, and somatic cells were investigated in dairy goats. Tildipirosin was administered at a single dose of 2 mg/kg by intravenous (IV) and 4 mg/kg by intramuscular (IM) and subcutaneous (SC) routes. Concentrations of tildipirosin were determined by an HPLC method with UV detection. Pharmacokinetic parameters were estimated by non-compartmental analysis. Muscle damage, cardiotoxicity, and inflammation were evaluated. After IV administration, the apparent volume of distribution in the steady state was 7.2 L/kg and clearance 0.64 L/h/kg. Plasma and milk half-lives were 6.2 and 58.3 h, respectively, indicating nine times longer persistence of tildipirosin in milk than in plasma. Moreover, if somatic cells are considered, persistence and exposure measured by the area under concentration–time curve (AUC) significantly exceeded those obtained in plasma. Similarly, longer half-lives in whole milk and somatic cells compared to plasma were observed after IM and SC administration. No adverse effects were observed. In brief, tildipirosin should be reserved for cases where other suitable antibiotics have been unsuccessful, discarding milk production of treated animals for at least 45 days or treating goats at the dry-off period.
Collapse
|
6
|
Kragol G, Steadman VA, Marušić Ištuk Z, Čikoš A, Bosnar M, Jelić D, Ergović G, Trzun M, Bošnjak B, Bokulić A, Padovan J, Glojnarić I, Eraković Haber V. Unprecedented Epimerization of an Azithromycin Analogue: Synthesis, Structure and Biological Activity of 2'-Dehydroxy-5″-Epi-Azithromycin. Molecules 2022; 27:1034. [PMID: 35164298 PMCID: PMC8838534 DOI: 10.3390/molecules27031034] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2021] [Revised: 01/19/2022] [Accepted: 01/28/2022] [Indexed: 11/30/2022] Open
Abstract
Certain macrolide antibiotics, azithromycin included, possess anti-inflammatory properties that are considered fundamental for their efficacy in the treatment of chronic inflammatory diseases, such as diffuse pan-bronchiolitis and cystic fibrosis. In this study, we disclose a novel azithromycin analog obtained via Barton-McCombie oxidation during which an unprecedented epimerization on the cladinose sugar occurs. Its structure was thoroughly investigated using NMR spectroscopy and compared to the natural epimer, revealing how the change in configuration of one single stereocenter (out of 16) profoundly diminished the antimicrobial activity through spatial manipulation of ribosome binding epitopes. At the same time, the anti-inflammatory properties of parent macrolide were retained, as demonstrated by inhibition of LPS- and cigarette-smoke-induced pulmonary inflammation. Not surprisingly, the compound has promising developable properties including good oral bioavailability and a half-life that supports once-daily dosing. This novel anti-inflammatory candidate has significant potential to fill the gap in existing anti-inflammatory agents and broaden treatment possibilities.
Collapse
Affiliation(s)
- Goran Kragol
- Fidelta Ltd., Prilaz baruna Filipovića 29, 10000 Zagreb, Croatia; (Z.M.I.); (A.Č.); (M.B.); (D.J.); (G.E.); (M.T.); (B.B.); (A.B.); (J.P.); (I.G.); (V.E.H.)
| | | | - Zorica Marušić Ištuk
- Fidelta Ltd., Prilaz baruna Filipovića 29, 10000 Zagreb, Croatia; (Z.M.I.); (A.Č.); (M.B.); (D.J.); (G.E.); (M.T.); (B.B.); (A.B.); (J.P.); (I.G.); (V.E.H.)
| | - Ana Čikoš
- Fidelta Ltd., Prilaz baruna Filipovića 29, 10000 Zagreb, Croatia; (Z.M.I.); (A.Č.); (M.B.); (D.J.); (G.E.); (M.T.); (B.B.); (A.B.); (J.P.); (I.G.); (V.E.H.)
| | - Martina Bosnar
- Fidelta Ltd., Prilaz baruna Filipovića 29, 10000 Zagreb, Croatia; (Z.M.I.); (A.Č.); (M.B.); (D.J.); (G.E.); (M.T.); (B.B.); (A.B.); (J.P.); (I.G.); (V.E.H.)
| | - Dubravko Jelić
- Fidelta Ltd., Prilaz baruna Filipovića 29, 10000 Zagreb, Croatia; (Z.M.I.); (A.Č.); (M.B.); (D.J.); (G.E.); (M.T.); (B.B.); (A.B.); (J.P.); (I.G.); (V.E.H.)
| | - Gabrijela Ergović
- Fidelta Ltd., Prilaz baruna Filipovića 29, 10000 Zagreb, Croatia; (Z.M.I.); (A.Č.); (M.B.); (D.J.); (G.E.); (M.T.); (B.B.); (A.B.); (J.P.); (I.G.); (V.E.H.)
| | - Marija Trzun
- Fidelta Ltd., Prilaz baruna Filipovića 29, 10000 Zagreb, Croatia; (Z.M.I.); (A.Č.); (M.B.); (D.J.); (G.E.); (M.T.); (B.B.); (A.B.); (J.P.); (I.G.); (V.E.H.)
| | - Berislav Bošnjak
- Fidelta Ltd., Prilaz baruna Filipovića 29, 10000 Zagreb, Croatia; (Z.M.I.); (A.Č.); (M.B.); (D.J.); (G.E.); (M.T.); (B.B.); (A.B.); (J.P.); (I.G.); (V.E.H.)
| | - Ana Bokulić
- Fidelta Ltd., Prilaz baruna Filipovića 29, 10000 Zagreb, Croatia; (Z.M.I.); (A.Č.); (M.B.); (D.J.); (G.E.); (M.T.); (B.B.); (A.B.); (J.P.); (I.G.); (V.E.H.)
| | - Jasna Padovan
- Fidelta Ltd., Prilaz baruna Filipovića 29, 10000 Zagreb, Croatia; (Z.M.I.); (A.Č.); (M.B.); (D.J.); (G.E.); (M.T.); (B.B.); (A.B.); (J.P.); (I.G.); (V.E.H.)
| | - Ines Glojnarić
- Fidelta Ltd., Prilaz baruna Filipovića 29, 10000 Zagreb, Croatia; (Z.M.I.); (A.Č.); (M.B.); (D.J.); (G.E.); (M.T.); (B.B.); (A.B.); (J.P.); (I.G.); (V.E.H.)
| | - Vesna Eraković Haber
- Fidelta Ltd., Prilaz baruna Filipovića 29, 10000 Zagreb, Croatia; (Z.M.I.); (A.Č.); (M.B.); (D.J.); (G.E.); (M.T.); (B.B.); (A.B.); (J.P.); (I.G.); (V.E.H.)
| |
Collapse
|
7
|
Tajima K, Katoh T, Suga H. OUP accepted manuscript. Nucleic Acids Res 2022; 50:2736-2753. [PMID: 35188576 PMCID: PMC8934632 DOI: 10.1093/nar/gkac068] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2021] [Revised: 01/13/2022] [Accepted: 02/07/2022] [Indexed: 11/13/2022] Open
Abstract
In ribosomal translation, peptidyl transfer occurs between P-site peptidyl-tRNA and A-site aminoacyl-tRNA, followed by translocation of the resulting P-site deacylated-tRNA and A-site peptidyl-tRNA to E and P site, respectively, mediated by EF-G. Here, we report that mistranslocation of P-site peptidyl-tRNA and A-site aminoacyl-tRNA toward E and A site occurs when high concentration of EF-G triggers the migration of two tRNAs prior to completion of peptidyl transfer. Consecutive incorporation of less reactive amino acids, such as Pro and d-Ala, makes peptidyl transfer inefficient and thus induces the mistranslocation event. Consequently, the E-site peptidyl-tRNA drops off from ribosome to give a truncated peptide lacking the C-terminal region. The P-site aminoacyl-tRNA allows for reinitiation of translation upon accommodation of a new aminoacyl-tRNA at A site, leading to synthesis of a truncated peptide lacking the N-terminal region, which we call the ‘reinitiated peptide’. We also revealed that such a drop-off-reinitiation event can be alleviated by EF-P that promotes peptidyl transfer of Pro. Moreover, this event takes place both in vitro and in cell, showing that reinitiated peptides during protein synthesis could be accumulated in this pathway in cells.
Collapse
Affiliation(s)
- Kenya Tajima
- Department of Chemistry, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | | | - Hiroaki Suga
- To whom correspondence should be addressed. Tel: +81 3 5841 8372; Fax: +81 3 5841 8372;
| |
Collapse
|
8
|
Hasan CM, Dutta D, Nguyen ANT. Revisiting Antibiotic Resistance: Mechanistic Foundations to Evolutionary Outlook. Antibiotics (Basel) 2021; 11:antibiotics11010040. [PMID: 35052917 PMCID: PMC8773413 DOI: 10.3390/antibiotics11010040] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Revised: 11/22/2021] [Accepted: 11/23/2021] [Indexed: 12/12/2022] Open
Abstract
Antibiotics are the pivotal pillar of contemporary healthcare and have contributed towards its advancement over the decades. Antibiotic resistance emerged as a critical warning to public wellbeing because of unsuccessful management efforts. Resistance is a natural adaptive tool that offers selection pressure to bacteria, and hence cannot be stopped entirely but rather be slowed down. Antibiotic resistance mutations mostly diminish bacterial reproductive fitness in an environment without antibiotics; however, a fraction of resistant populations 'accidentally' emerge as the fittest and thrive in a specific environmental condition, thus favouring the origin of a successful resistant clone. Therefore, despite the time-to-time amendment of treatment regimens, antibiotic resistance has evolved relentlessly. According to the World Health Organization (WHO), we are rapidly approaching a 'post-antibiotic' era. The knowledge gap about antibiotic resistance and room for progress is evident and unified combating strategies to mitigate the inadvertent trends of resistance seem to be lacking. Hence, a comprehensive understanding of the genetic and evolutionary foundations of antibiotic resistance will be efficacious to implement policies to force-stop the emergence of resistant bacteria and treat already emerged ones. Prediction of possible evolutionary lineages of resistant bacteria could offer an unswerving impact in precision medicine. In this review, we will discuss the key molecular mechanisms of resistance development in clinical settings and their spontaneous evolution.
Collapse
Affiliation(s)
- Chowdhury M. Hasan
- School of Biological Sciences, University of Queensland, Brisbane 4072, Australia
- Department of Clinical Infection, Microbiology and Immunology, Institute of Infection, Veterinary & Ecological Sciences (IVES), University of Liverpool, Liverpool L7 3EA, UK;
- School of Biological Sciences, Monash University, Melbourne 3800, Australia;
- Correspondence:
| | - Debprasad Dutta
- Department of Clinical Infection, Microbiology and Immunology, Institute of Infection, Veterinary & Ecological Sciences (IVES), University of Liverpool, Liverpool L7 3EA, UK;
- Department of Human Genetics, National Institute of Mental Health & Neurosciences (NIMHANS), Bangalore 560029, India
| | - An N. T. Nguyen
- School of Biological Sciences, Monash University, Melbourne 3800, Australia;
| |
Collapse
|
9
|
da Silva PB, Araújo VHS, Fonseca-Santos B, Solcia MC, Ribeiro CM, da Silva IC, Alves RC, Pironi AM, Silva ACL, Victorelli FD, Fernandes MA, Ferreira PS, da Silva GH, Pavan FR, Chorilli M. Highlights Regarding the Use of Metallic Nanoparticles against Pathogens Considered a Priority by the World Health Organization. Curr Med Chem 2021; 28:1906-1956. [PMID: 32400324 DOI: 10.2174/0929867327666200513080719] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2020] [Revised: 02/11/2020] [Accepted: 03/20/2020] [Indexed: 11/22/2022]
Abstract
The indiscriminate use of antibiotics has facilitated the growing resistance of bacteria, and this has become a serious public health problem worldwide. Several microorganisms are still resistant to multiple antibiotics and are particularly dangerous in the hospital and nursing home environment, and to patients whose care requires devices, such as ventilators and intravenous catheters. A list of twelve pathogenic genera, which especially included bacteria that were not affected by different antibiotics, was released by the World Health Organization (WHO) in 2017, and the research and development of new antibiotics against these genera has been considered a priority. The nanotechnology is a tool that offers an effective platform for altering the physicalchemical properties of different materials, thereby enabling the development of several biomedical applications. Owing to their large surface area and high reactivity, metallic particles on the nanometric scale have remarkable physical, chemical, and biological properties. Nanoparticles with sizes between 1 and 100 nm have several applications, mainly as new antimicrobial agents for the control of microorganisms. In the present review, more than 200 reports of various metallic nanoparticles, especially those containing copper, gold, platinum, silver, titanium, and zinc were analyzed with regard to their anti-bacterial activity. However, of these 200 studies, only 42 reported about trials conducted against the resistant bacteria considered a priority by the WHO. All studies are in the initial stage, and none are in the clinical phase of research.
Collapse
Affiliation(s)
- Patricia Bento da Silva
- Sao Paulo State University (UNESP), School of Pharmaceutical Sciences, Araraquara-SP, Brazil
| | | | - Bruno Fonseca-Santos
- Sao Paulo State University (UNESP), School of Pharmaceutical Sciences, Araraquara-SP, Brazil
| | - Mariana Cristina Solcia
- Sao Paulo State University (UNESP), School of Pharmaceutical Sciences, Araraquara-SP, Brazil
| | | | | | - Renata Carolina Alves
- Sao Paulo State University (UNESP), School of Pharmaceutical Sciences, Araraquara-SP, Brazil
| | - Andressa Maria Pironi
- Sao Paulo State University (UNESP), School of Pharmaceutical Sciences, Araraquara-SP, Brazil
| | | | | | - Mariza Aires Fernandes
- Sao Paulo State University (UNESP), School of Pharmaceutical Sciences, Araraquara-SP, Brazil
| | - Paula Scanavez Ferreira
- Sao Paulo State University (UNESP), School of Pharmaceutical Sciences, Araraquara-SP, Brazil
| | - Gilmar Hanck da Silva
- Sao Paulo State University (UNESP), School of Pharmaceutical Sciences, Araraquara-SP, Brazil
| | - Fernando Rogério Pavan
- Sao Paulo State University (UNESP), School of Pharmaceutical Sciences, Araraquara-SP, Brazil
| | - Marlus Chorilli
- Sao Paulo State University (UNESP), School of Pharmaceutical Sciences, Araraquara-SP, Brazil
| |
Collapse
|
10
|
Lu ZY, Fu JJ, Ma YL, Jin RC, Fan NS. Response of anammox granules to the simultaneous exposure to macrolide and aminoglycoside antibiotics: Linking performance to mechanism. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2021; 286:112267. [PMID: 33667820 DOI: 10.1016/j.jenvman.2021.112267] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/15/2021] [Revised: 02/11/2021] [Accepted: 02/22/2021] [Indexed: 06/12/2023]
Abstract
Antibiotic pollution is becoming increasingly severe due to its extensive use. The potential application of the anaerobic ammonium oxidation (anammox) process in the treatment of wastewater containing antibiotics has attracted much attention. As common antibiotics, spiramycin (SPM) and streptomycin (STM) are widely used to treat human and animal diseases. However, their combined effects on the anammox process remain unknown. Therefore, this study systematically evaluated the response of the anammox process to both antibiotics. The half maximal inhibitory concentrations of SPM and STM were determined. The continuous-flow anammox system could adapt to SPM and STM at low concentrations, while antibiotics at high concentrations exhibited inhibitory effects. When the concentrations reached 5 mg L-1 SPM and 50 mg L-1 STM, the nitrogen removal efficiency dramatically decreased and then rapidly recovered within 8 days. Correspondingly, the abundances of dominant bacteria and genes also changed with antibiotic concentrations. In general, the anammox process showed a stable performance and a high resistance to SPM and STM, suggesting that acclimatization by elevating the concentrations was beneficial for the anammox process to obtain resistance to different antibiotics with high concentrations. This study provides guidance for the stable operation of anammox-based biological treatment of antibiotics containing wastewater.
Collapse
Affiliation(s)
- Zheng-Yang Lu
- Laboratory of Water Pollution Remediation, School of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou, 311121, China
| | - Jin-Jin Fu
- Laboratory of Water Pollution Remediation, School of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou, 311121, China
| | - Yuan-Long Ma
- Laboratory of Water Pollution Remediation, School of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou, 311121, China
| | - Ren-Cun Jin
- Laboratory of Water Pollution Remediation, School of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou, 311121, China
| | - Nian-Si Fan
- Laboratory of Water Pollution Remediation, School of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou, 311121, China.
| |
Collapse
|
11
|
Seefeldt AC, Aguirre Rivera J, Johansson M. Direct Measurements of Erythromycin's Effect on Protein Synthesis Kinetics in Living Bacterial Cells. J Mol Biol 2021; 433:166942. [PMID: 33744313 DOI: 10.1016/j.jmb.2021.166942] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2020] [Revised: 03/09/2021] [Accepted: 03/09/2021] [Indexed: 10/21/2022]
Abstract
Macrolide antibiotics, such as erythromycin, bind to the nascent peptide exit tunnel (NPET) of the bacterial ribosome and modulate protein synthesis depending on the nascent peptide sequence. Whereas in vitro biochemical and structural methods have been instrumental in dissecting and explaining the molecular details of macrolide-induced peptidyl-tRNA drop-off and ribosome stalling, the dynamic effects of the drugs on ongoing protein synthesis inside live bacterial cells are far less explored. In the present study, we used single-particle tracking of dye-labeled tRNAs to study the kinetics of mRNA translation in the presence of erythromycin, directly inside live Escherichia coli cells. In erythromycin-treated cells, we find that the dwells of elongator tRNAPhe on ribosomes extend significantly, but they occur much more seldom. In contrast, the drug barely affects the ribosome binding events of the initiator tRNAfMet. By overexpressing specific short peptides, we further find context-specific ribosome binding dynamics of tRNAPhe, underscoring the complexity of erythromycin's effect on protein synthesis in bacterial cells.
Collapse
Affiliation(s)
| | | | - Magnus Johansson
- Department of Cell and Molecular Biology, Uppsala University, Sweden.
| |
Collapse
|
12
|
Liu J, Chen F, Wang X, Peng H, Zhang H, Wang KJ. The Synergistic Effect of Mud Crab Antimicrobial Peptides Sphistin and Sph 12-38 With Antibiotics Azithromycin and Rifampicin Enhances Bactericidal Activity Against Pseudomonas Aeruginosa. Front Cell Infect Microbiol 2020; 10:572849. [PMID: 33194811 PMCID: PMC7645104 DOI: 10.3389/fcimb.2020.572849] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2020] [Accepted: 09/02/2020] [Indexed: 12/16/2022] Open
Abstract
Overuse or abuse of antibiotics has undoubtedly accelerated the increasing prevalence of global antibiotic resistance crisis, and thus, people have been trying to explore approaches to decrease dosage of antibiotics or find new antibacterial agents for many years. Antimicrobial peptides (AMPs) are the ideal candidates that could kill pathogens and multidrug-resistant bacteria either alone or in combination with conventional antibiotics. In the study, the antimicrobial efficacy of mud crab Scylla paramamosain AMPs Sphistin and Sph12−38 in combination with eight selected antibiotics was evaluated using a clinical pathogen, Pseudomonas aeruginosa. It was interesting to note that the in vitro combination of rifampicin and azithromycin with Sphistin and Sph12−38 showed significant synergistic activity against P. aeruginosa. Moreover, an in vivo study was carried out using a mouse model challenged with P. aeruginosa, and the result showed that the combination of Sph12−38 with either rifampicin or azithromycin could significantly promote the healing of wounds and had the healing time shortened to 4–5 days compared with 7–8 days in control. The underlying mechanism might be due to the binding of Sphistin and Sph12−38 with P. aeruginosa lipopolysaccharides (LPS) and subsequent promotion of the intracellular uptake of rifampicin and azithromycin. Taken together, the significant synergistic antibacterial effect on P. aeruginosa in vitro and in vivo conferred by the combination of low dose of Sphistin and Sph12−38 with low dose of rifampicin and azithromycin would be beneficial for the control of antibiotic resistance and effective treatment of P. aeruginosa-infected diseases in the future.
Collapse
Affiliation(s)
- Jie Liu
- State Key Laboratory of Marine Environmental Science, College of Ocean & Earth Sciences, Xiamen University, Xiamen, China
| | - Fangyi Chen
- State Key Laboratory of Marine Environmental Science, College of Ocean & Earth Sciences, Xiamen University, Xiamen, China.,State-Province Joint Engineering Laboratory of Marine Bioproducts and Technology, College of Ocean & Earth Sciences, Xiamen University, Xiamen, China
| | - Xiaofei Wang
- State Key Laboratory of Marine Environmental Science, College of Ocean & Earth Sciences, Xiamen University, Xiamen, China
| | - Hui Peng
- State Key Laboratory of Marine Environmental Science, College of Ocean & Earth Sciences, Xiamen University, Xiamen, China.,State-Province Joint Engineering Laboratory of Marine Bioproducts and Technology, College of Ocean & Earth Sciences, Xiamen University, Xiamen, China
| | - Hua Zhang
- State Key Laboratory of Marine Environmental Science, College of Ocean & Earth Sciences, Xiamen University, Xiamen, China
| | - Ke-Jian Wang
- State Key Laboratory of Marine Environmental Science, College of Ocean & Earth Sciences, Xiamen University, Xiamen, China.,State-Province Joint Engineering Laboratory of Marine Bioproducts and Technology, College of Ocean & Earth Sciences, Xiamen University, Xiamen, China
| |
Collapse
|
13
|
Tracking of single tRNAs for translation kinetics measurements in chloramphenicol treated bacteria. Methods 2019; 162-163:23-30. [DOI: 10.1016/j.ymeth.2019.02.004] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2018] [Revised: 02/01/2019] [Accepted: 02/05/2019] [Indexed: 01/28/2023] Open
|
14
|
Vázquez-Laslop N, Mankin AS. How Macrolide Antibiotics Work. Trends Biochem Sci 2018; 43:668-684. [PMID: 30054232 PMCID: PMC6108949 DOI: 10.1016/j.tibs.2018.06.011] [Citation(s) in RCA: 177] [Impact Index Per Article: 29.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2018] [Revised: 06/17/2018] [Accepted: 06/29/2018] [Indexed: 01/24/2023]
Abstract
Macrolide antibiotics inhibit protein synthesis by targeting the bacterial ribosome. They bind at the nascent peptide exit tunnel and partially occlude it. Thus, macrolides have been viewed as 'tunnel plugs' that stop the synthesis of every protein. More recent evidence, however, demonstrates that macrolides selectively inhibit the translation of a subset of cellular proteins, and that their action crucially depends on the nascent protein sequence and on the antibiotic structure. Therefore, macrolides emerge as modulators of translation rather than as global inhibitors of protein synthesis. The context-specific action of macrolides is the basis for regulating the expression of resistance genes. Understanding the details of the mechanism of macrolide action may inform rational design of new drugs and unveil important principles of translation regulation.
Collapse
Affiliation(s)
- Nora Vázquez-Laslop
- Center for Biomolecular Sciences, University of Illinois at Chicago, Chicago, IL 60607, USA.
| | - Alexander S Mankin
- Center for Biomolecular Sciences, University of Illinois at Chicago, Chicago, IL 60607, USA.
| |
Collapse
|
15
|
Han D, Liu Y, Li J, Liu C, Gao Y, Feng J, Lu H, Yang G. Twenty-seven-nucleotide repeat insertion in the rplV gene confers specific resistance to macrolide antibiotics in Staphylococcus aureus. Oncotarget 2018; 9:26086-26095. [PMID: 29899844 PMCID: PMC5995244 DOI: 10.18632/oncotarget.25441] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2018] [Accepted: 04/28/2018] [Indexed: 11/29/2022] Open
Abstract
Macrolide antibiotics are used for treatment of soft-tissue infection caused by Staphylococcus aureus in humans. However, infections with S. aureus are increasingly difficult to treat owing to the emergence and rapid spread of multiple-drug resistant S. aureus. Resistance to macrolide in S. aureus is mostly due to the modification of 23 S rRNA by methylases encoded by erm genes. Here, we have identified that a 27-nucleotide repeat sequence insertion in the rplV gene induced a specific resistance to macrolide antibiotics. An erythromycin-resistant strain, 8325ER+, was screened by resistance to erythromycin from the macrolide-sensitive strain 8325-4. Comparative genome sequencing analysis showed that 8325ER+ contained a 27-nt repeat sequence insertion in the rplV gene that encodes the ribosomal protein L22, when compared to its parent strain. The 27-nt repeat sequence led to an insertion of 9 amino acids in L22, which had been identified to reduce the sensitivity to erythromycin and other macrolide antibiotics. Moreover, we show that the ectopic expression of the mutated rplV gene containing the 27-nt repeat sequence insertion in several susceptible strains specifically conferred resistance to macrolide antibiotics. Our findings present a potential mechanism of resistance to macrolide antibiotics in S. aureus.
Collapse
Affiliation(s)
- Dianpeng Han
- Beijing Institute of Basic Medical Sciences, Beijing, China.,State Key Laboratory of Toxicology and Medical Countermeasures, Beijing, China
| | - Yu Liu
- Beijing Institute of Basic Medical Sciences, Beijing, China.,State Key Laboratory of Toxicology and Medical Countermeasures, Beijing, China
| | - Jingjing Li
- Henan University School of Basic Medical Science, Kaifeng, China
| | - Chenghua Liu
- Beijing Institute of Basic Medical Sciences, Beijing, China.,State Key Laboratory of Toxicology and Medical Countermeasures, Beijing, China
| | - Yaping Gao
- Beijing Institute of Basic Medical Sciences, Beijing, China.,State Key Laboratory of Toxicology and Medical Countermeasures, Beijing, China
| | - Jiannan Feng
- Beijing Institute of Basic Medical Sciences, Beijing, China.,State Key Laboratory of Toxicology and Medical Countermeasures, Beijing, China
| | - Huizhe Lu
- Department of Applied Chemistry, College of Science, China Agricultural University, Beijing, China
| | - Guang Yang
- Beijing Institute of Basic Medical Sciences, Beijing, China.,State Key Laboratory of Toxicology and Medical Countermeasures, Beijing, China
| |
Collapse
|
16
|
El Zahed SS, Brown ED. Chemical-Chemical Combinations Map Uncharted Interactions in Escherichia coli under Nutrient Stress. iScience 2018; 2:168-181. [PMID: 30428373 PMCID: PMC6136904 DOI: 10.1016/j.isci.2018.03.018] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2017] [Revised: 02/28/2018] [Accepted: 03/07/2018] [Indexed: 11/16/2022] Open
Abstract
Of the ∼4,400 genes that constitute Escherichia coli's genome, ∼300 genes are indispensable for its growth in nutrient-rich conditions. These encode housekeeping functions, including cell wall, DNA, RNA, and protein syntheses. Under conditions in which nutrients are limited to a carbon source, nitrogen source, essential phosphates, and salts, more than 100 additional genes become essential. These largely code for the synthesis of amino acids, vitamins, and nucleobases. Although much is known about this collection of ∼400 genes, their interactions under nutrient stress are uncharted. Using a chemical biology approach, we focused on 45 chemical probes targeting encoded proteins in this collection and mapped their interactions under nutrient-limited conditions. Encompassing 990 unique pairwise chemical combinations, we revealed a highly connected network of 186 interactions, of which 81 were synergistic and 105 were antagonistic. The network revealed signature interactions for each probe and highlighted new connectivity between housekeeping functions and those essential in nutrient stress. Chemical probes map a complex interaction network in E. coli under nutrient stress A total of 990 unique chemical combinations reveal a dense network of 186 interactions New connections between housekeeping functions and those in nutrient stress
Collapse
Affiliation(s)
- Sara S El Zahed
- Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, ON L8N 3Z5, Canada; Michael G. DeGroote Institute of Infectious Disease Research, McMaster University, Hamilton, ON L8N 3Z5, Canada
| | - Eric D Brown
- Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, ON L8N 3Z5, Canada; Michael G. DeGroote Institute of Infectious Disease Research, McMaster University, Hamilton, ON L8N 3Z5, Canada.
| |
Collapse
|
17
|
Lu J, Xiong L, Zhang X, Liu Z, Wang S, Zhang C, Zheng J, Wang G, Zheng R, Simpson JL, Wang F. The Role of Lower Airway Dysbiosis in Asthma: Dysbiosis and Asthma. Mediators Inflamm 2017; 2017:3890601. [PMID: 29386750 PMCID: PMC5745728 DOI: 10.1155/2017/3890601] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2017] [Revised: 09/13/2017] [Accepted: 10/04/2017] [Indexed: 12/12/2022] Open
Abstract
With the development of culture-independent techniques, numerous studies have demonstrated that the lower airway is not sterile in health and harbors diverse microbial communities. Furthermore, new evidence suggests that there is a distinct lower airway microbiome in those with chronic respiratory disease. To understand the role of lower airway dysbiosis in the pathogenesis of asthma, in this article, we review the published reports about the lung microbiome of healthy controls, provide an outlook on the contribution of lower airway dysbiosis to asthma, especially steroid-resistant asthma, and discuss the potential therapies targeted for lower airway dysbiosis.
Collapse
Affiliation(s)
- Junying Lu
- Department of Pathogeny Biology, College of Basic Medical Sciences, Jilin University, Changchun 130021, China
- Department of Intensive Care Unit, First Hospital of Jilin University, Changchun 130021, China
| | - Lingxin Xiong
- Department of Pathogeny Biology, College of Basic Medical Sciences, Jilin University, Changchun 130021, China
- School of Pharmaceutical Sciences, Jilin University, Changchun 130021, China
| | - Xiaohao Zhang
- Department of Cardiology, Second Hospital of Jilin University, Changchun 130041, China
| | - Zhongmin Liu
- Department of Intensive Care Unit, First Hospital of Jilin University, Changchun 130021, China
| | - Shiji Wang
- Department of Intensive Care Unit, First Hospital of Jilin University, Changchun 130021, China
| | - Chao Zhang
- Department of Pathogeny Biology, College of Basic Medical Sciences, Jilin University, Changchun 130021, China
| | - Jingtong Zheng
- Department of Pathogeny Biology, College of Basic Medical Sciences, Jilin University, Changchun 130021, China
| | - Guoqiang Wang
- Department of Pathogeny Biology, College of Basic Medical Sciences, Jilin University, Changchun 130021, China
| | - Ruipeng Zheng
- Department of Pathogeny Biology, College of Basic Medical Sciences, Jilin University, Changchun 130021, China
- Department of Interventional Therapy, First Hospital of Jilin University, Changchun 130021, China
| | - Jodie L. Simpson
- Department of Pathogeny Biology, College of Basic Medical Sciences, Jilin University, Changchun 130021, China
- Department of Respiratory and Sleep Medicine, University of Newcastle, New Lambton, NSW, Australia
| | - Fang Wang
- Department of Pathogeny Biology, College of Basic Medical Sciences, Jilin University, Changchun 130021, China
| |
Collapse
|
18
|
Dinos GP. The macrolide antibiotic renaissance. Br J Pharmacol 2017; 174:2967-2983. [PMID: 28664582 DOI: 10.1111/bph.13936] [Citation(s) in RCA: 217] [Impact Index Per Article: 31.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2017] [Revised: 05/29/2017] [Accepted: 06/20/2017] [Indexed: 12/19/2022] Open
Abstract
Macrolides represent a large family of protein synthesis inhibitors of great clinical interest due to their applicability to human medicine. Macrolides are composed of a macrocyclic lactone of different ring sizes, to which one or more deoxy-sugar or amino sugar residues are attached. Macrolides act as antibiotics by binding to bacterial 50S ribosomal subunit and interfering with protein synthesis. The high affinity of macrolides for bacterial ribosomes, together with the highly conserved structure of ribosomes across virtually all of the bacterial species, is consistent with their broad-spectrum activity. Since the discovery of the progenitor macrolide, erythromycin, in 1950, many derivatives have been synthesised, leading to compounds with better bioavailability and acid stability and improved pharmacokinetics. These efforts led to the second generation of macrolides, including well-known members such as azithromycin and clarithromycin. Subsequently, in order to address increasing antibiotic resistance, a third generation of macrolides displaying improved activity against many macrolide resistant strains was developed. However, these improvements were accompanied with serious side effects, leading to disappointment and causing many researchers to stop working on macrolide derivatives, assuming that this procedure had reached the end. In contrast, a recent published breakthrough introduced a new chemical platform for synthesis and discovery of a wide range of diverse macrolide antibiotics. This chemical synthesis revolution, in combination with reduction in the side effects, namely, 'Ketek effects', has led to a macrolide renaissance, increasing the hope for novel and safe therapeutic agents to combat serious human infectious diseases.
Collapse
Affiliation(s)
- George P Dinos
- Department of Biochemistry, School of Medicine, University of Patras, Patras, Greece
| |
Collapse
|
19
|
Auckloo BN, Pan C, Akhter N, Wu B, Wu X, He S. Stress-Driven Discovery of Novel Cryptic Antibiotics from a Marine Fungus Penicillium sp. BB1122. Front Microbiol 2017; 8:1450. [PMID: 28824581 PMCID: PMC5540946 DOI: 10.3389/fmicb.2017.01450] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2017] [Accepted: 07/17/2017] [Indexed: 11/13/2022] Open
Abstract
Standard laboratory cultures have long been known to hinder activation of specific gene clusters which in turn hamper production of secondary metabolites with unique properties due to lack of innovation or the inability to trigger cryptic gene clusters’ expression. Due to challenges related to the avoidance of the isolation of replicated metabolites, resistance-developing pathogens are to be addressed by the scientific community worldwide in order to progress with novel and potent compounds which could further be developed in the future for pharmaceutical usage. This study reports the isolation of novel cryptic antibiotics from a marine fungus Penicillium sp. BB1122 collected from Zhoushan coast by applying the “metal-stress” strategy, here referring to the heavy metal cobalt (6 mM). High-performance liquid chromatography-guided isolation of four novel and four known compounds belonging to the polyketide class has been carried out where their relative as well as absolute configurations have been determined using spectroscopic analysis techniques as well as by the comparison of theoretically calculated ECD spectrum and the experimental ECD spectrum, respectively. The structures of novel compounds 7 and 8 represent the first example of 2,5-dioxabicyclo[2.2.1]heptane pyrone backbone bearing a migrated polyene chain. The novel compounds 7, 8, and 5 exhibited impressive antibiotic properties against methicillin resistant Staphylococcus aureus (MRSA) with MIC value of around 0.5 and 1 μg/mL, respectively. Moreover, the new compounds 1, 7, and 8 displayed potent antibiotic activities with MIC values of around 4 μg/mL against the pathogenic Pseudomonas aeruginosa. Moreover, the MBC of the different potent compounds ranged from 1 to 128 μg/mL against MRSA, P. aeruginosa, and Klebsiella pneumoniae. In addition, the cytotoxic activities were also evaluated where new antibiotics 7 and 8 were not obviously harmful toward normal liver cell lines LO2, showing IC50 values above 100 μg/mL. As a consequence, the results from this study unveiled that cobalt stress is an effective strategy to discover novel antibiotics from microorganisms.
Collapse
Affiliation(s)
| | | | | | - Bin Wu
- Ocean College, Zhejiang UniversityHangzhou, China
| | - Xiaodan Wu
- Center of Analysis and Measurement, Zhejiang UniversityHangzhou, China
| | - Shan He
- Laboratory of Marine Natural Products, School of Marine Sciences, Ningbo UniversityNingbo, China
| |
Collapse
|
20
|
Pavlova A, Parks JM, Oyelere AK, Gumbart JC. Toward the rational design of macrolide antibiotics to combat resistance. Chem Biol Drug Des 2017; 90:641-652. [DOI: 10.1111/cbdd.13004] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2017] [Revised: 04/03/2017] [Accepted: 04/08/2017] [Indexed: 12/14/2022]
Affiliation(s)
- Anna Pavlova
- School of Physics Georgia Institute of Technology Atlanta GA USA
| | - Jerry M. Parks
- Biosciences Division Oak Ridge National Laboratory Oak Ridge TN USA
| | - Adegboyega K. Oyelere
- School of Chemistry and Biochemistry Parker H. Petit Institute for Bioengineering and Bioscience Georgia Institute of Technology Atlanta GA USA
| | - James C. Gumbart
- School of Physics Georgia Institute of Technology Atlanta GA USA
- School of Chemistry and Biochemistry Parker H. Petit Institute for Bioengineering and Bioscience Georgia Institute of Technology Atlanta GA USA
| |
Collapse
|
21
|
Identification of two regulatory genes involved in carbomycin biosynthesis in Streptomyces thermotolerans. Arch Microbiol 2017; 199:1023-1033. [PMID: 28389815 DOI: 10.1007/s00203-017-1376-z] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2017] [Revised: 03/28/2017] [Accepted: 03/30/2017] [Indexed: 10/19/2022]
Abstract
Carbomycins are 16-membered macrolide antibiotics produced by Streptomyces thermotolerans ATCC 11416T. To characterize gene cluster responsible for carbomycin biosynthesis, the draft genome sequences for strain ATCC 11416T were obtained, from which the partial carbomycin biosynthetic gene cluster was identified. This gene cluster was approximately 40 kb in length, and encoding 30 ORFs. Two putative transcriptional regulatory genes, acyB2 and cbmR, were inactivated by insertion of the apramycin resistance gene, and the resulting mutants were unable to produce carbomycin, thus confirming the involvement of two regulatory genes in carbomycin biosynthesis. Overexpression of acyB2 greatly improved the yield of carbomycin; however, overexpression of cbmR blocked carbomycin production. The qPCR analysis of the carbomycin biosynthetic genes in various mutants indicated that most genes were highly expressed in acyB2-overexpressing strains, but few expressed in cbmR-overexpressing strains. Furthermore, acyB2 co-expression with 4″-isovaleryltransferase gene (ist), resulted in efficient biotransformation of spiramycin into bitespiramycin in S. lividans TK24, whereas ist gene regulated by acyB2 and cbmR would cause the lower efficiency of spiramycin biotransformation. These results indicated that AcyB2 was a pathway-specific positive regulator of carbomycin biosynthesis. However, CbmR played a dual role in the carbomycin biosynthesis by acting as a positive regulator, and as a repressor at cbmR high expression levels.
Collapse
|
22
|
Pierattini EC, Francini A, Raffaelli A, Sebastiani L. Morpho-physiological response of Populus alba to erythromycin: A timeline of the health status of the plant. THE SCIENCE OF THE TOTAL ENVIRONMENT 2016; 569-570:540-547. [PMID: 27366984 DOI: 10.1016/j.scitotenv.2016.06.152] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/28/2016] [Revised: 06/17/2016] [Accepted: 06/19/2016] [Indexed: 06/06/2023]
Abstract
Populus alba Villafranca clone was chosen for a proof of concept study to determine the potential uptake and accumulation of antibiotics by trees. Plants were grown hydroponically and irrigated with a recirculating Hoagland's nutrient solution (control) and Hoagland's nutrient solution fortified with erythromycin at 0.01, 0.1 and 1mgL(-1). After 3 and 28days of treatment, poplar plants were separated into roots, stem, and leaves. Plants showed good health all over the period of treatment, and no differences in poplar growth for all the concentrations of erythromycin tested were observed. Quantification of erythromycin was performed using liquid chromatography electrospray ionization tandem mass spectrometry (LC-MS/MS) in positive ion mode using multiple reaction ion monitoring. Erythromycin was detected in all organs analyzed. Roots showed an erythromycin concentration tenfold higher than leaves. The photochemical efficiency of photosystem II did not show a dose-dependant trend. From the quenching analysis of chlorophyll fluorescence, low nonphotochemical quenching (NPQ) and high photochemical quenching (qP) for the first week of erythromycin exposure was observed, depending on leaves position along the stem. Results suggest a short term adaptation of the photosynthetic apparatus of Populus alba in response to environmental realistic erythromycin concentrations.
Collapse
Affiliation(s)
- Erika Carla Pierattini
- Institute of Life Sciences, Scuola Superiore Sant'Anna, Piazza Martiri della Libertà 33, I-56127 Pisa, Italy
| | - Alessandra Francini
- Institute of Life Sciences, Scuola Superiore Sant'Anna, Piazza Martiri della Libertà 33, I-56127 Pisa, Italy.
| | - Andrea Raffaelli
- CNR - Istituto di Fisiologia Clinica, Via Moruzzi 1, I-56124 Pisa, Italy
| | - Luca Sebastiani
- Institute of Life Sciences, Scuola Superiore Sant'Anna, Piazza Martiri della Libertà 33, I-56127 Pisa, Italy
| |
Collapse
|
23
|
Bartram DJ, Moyaert H, Vanimisetti BH, Ramage CP, Reddick D, Stegemann MR. Comparative efficacy of tulathromycin and tildipirosin for the treatment of experimental Mycoplasma bovis infection in calves. Vet Med Sci 2016; 2:170-178. [PMID: 29067192 PMCID: PMC5645867 DOI: 10.1002/vms3.31] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2015] [Revised: 01/04/2016] [Accepted: 02/14/2016] [Indexed: 11/24/2022] Open
Abstract
The objective of this negative controlled, blinded, randomised, parallel group study was to compare the efficacy of two injectable macrolide antimicrobials, tulathromycin and tildipirosin, administered by single subcutaneous injection at dose rates of 2.5 and 4.0 mg kg−1 bodyweight, respectively, in the treatment of an experimentally induced Mycoplasma bovis infection in calves. A total of 238 M. bovis‐negative calves were challenged on three consecutive days with M. bovis by endobronchial deposition. Post‐challenge, a total of 126 animals fulfilled the inclusion criteria and were randomly allocated to three treatment groups: tulathromycin, tildipirosin and saline. Clinical observations for signs of respiratory disease and injection site assessments were conducted daily for 14 days post‐treatment. The animals were then killed, the lungs were examined for evidence of lesions, and samples collected for bacterial isolation. Calves treated with tulathromycin had a lower percentage of lung with lesions (P = 0.0079), lower mortality (P = 0.0477), fewer days with depressed demeanour (P = 0.0486) and higher body weight (P = 0.0112) than calves administered tildipirosin.
Collapse
Affiliation(s)
| | | | | | - Clifford P Ramage
- Moredun ScientificPentlands Science ParkBush LoanPenicuikEH26 0PZUnited Kingdom
| | - David Reddick
- Moredun ScientificPentlands Science ParkBush LoanPenicuikEH26 0PZUnited Kingdom
| | | |
Collapse
|
24
|
Probing the Translation Dynamics of Ribosomes Using Zero-Mode Waveguides. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2015; 139:1-43. [PMID: 26970189 DOI: 10.1016/bs.pmbts.2015.10.006] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
In order to coordinate the complex biochemical and structural feat of converting triple-nucleotide codons into their corresponding amino acids, the ribosome must physically manipulate numerous macromolecules including the mRNA, tRNAs, and numerous translation factors. The ribosome choreographs binding, dissociation, physical movements, and structural rearrangements so that they synergistically harness the energy from biochemical processes, including numerous GTP hydrolysis steps and peptide bond formation. Due to the dynamic and complex nature of translation, the large cast of ligands involved, and the large number of possible configurations, tracking the global time evolution or dynamics of the ribosome complex in translation has proven to be challenging for bulk methods. Conventional single-molecule fluorescence experiments on the other hand require low concentrations of fluorescent ligands to reduce background noise. The significantly reduced bimolecular association rates under those conditions limit the number of steps that can be observed within the time window available to a fluorophore. The advent of zero-mode waveguide (ZMW) technology has allowed the study of translation at near-physiological concentrations of labeled ligands, moving single-molecule fluorescence microscopy beyond focused model systems into studying the global dynamics of translation in realistic setups. This chapter reviews the recent works using the ZMW technology to dissect the mechanism of translation initiation and elongation in prokaryotes, including complex processes such as translational stalling and frameshifting. Given the success of the technology, similarly complex biological processes could be studied in near-physiological conditions with the controllability of conventional in vitro experiments.
Collapse
|
25
|
Pavlova A, Gumbart JC. Parametrization of macrolide antibiotics using the force field toolkit. J Comput Chem 2015; 36:2052-63. [PMID: 26280362 DOI: 10.1002/jcc.24043] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2015] [Revised: 06/25/2015] [Accepted: 07/03/2015] [Indexed: 01/09/2023]
Abstract
Macrolides are an important class of antibiotics that target the bacterial ribosome. Computer simulations of macrolides are limited as specific force field parameters have not been previously developed for them. Here, we determine CHARMM-compatible force field parameters for erythromycin, azithromycin, and telithromycin, using the force field toolkit (ffTK) plugin in VMD. Because of their large size, novel approaches for parametrizing them had to be developed. Two methods for determining partial atomic charges, from interactions with TIP3P water and from the electrostatic potential, as well as several approaches for fitting the dihedral parameters were tested. The performance of the different parameter sets was evaluated by molecular dynamics simulations of the macrolides in ribosome, with a distinct improvement in maintenance of key interactions observed after refinement of the initial parameters. Based on the results of the macrolide tests, recommended procedures for parametrizing very large molecules using ffTK are given.
Collapse
Affiliation(s)
- Anna Pavlova
- School of Physics and School of Chemistry, Georgia Institute of Technology, Atlanta, 30332, Georgia
| | - James C Gumbart
- School of Physics and School of Chemistry, Georgia Institute of Technology, Atlanta, 30332, Georgia
| |
Collapse
|
26
|
Krokidis M, Bougas A, Stavropoulou M, Kalpaxis D, Dinos GP. The slow dissociation rate of K-1602 contributes to the enhanced inhibitory activity of this novel alkyl-aryl-bearing fluoroketolide. J Enzyme Inhib Med Chem 2015; 31:276-82. [PMID: 25807301 DOI: 10.3109/14756366.2015.1018246] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Ketolides belong to the latest generation of macrolides and are not only effective against macrolide susceptible bacterial strains but also against some macrolide resistant strains. Here we present data providing insights into the mechanism of action of K-1602, a novel alkyl-aryl-bearing fluoroketolide. According to our data, the K-1602 interacts with the ribosome as a one-step slow binding inhibitor, displaying an association rate constant equal to 0.28 × 10(4) M(-1) s(-1) and a dissociation rate constant equal to 0.0025 min(-1). Both constants contribute to produce an overall inhibition constant Ki equal to 1.49 × 10(-8) M, which correlates very well with the superior activity of this compound when compared with many other ketolides or fluoroketolides.
Collapse
Affiliation(s)
- Marios Krokidis
- a Department of Pharmacology , Medical School, University of Athens , Athens , Greece
| | - Anthony Bougas
- b Laboratory of Biochemistry , School of Medicine, University of Patras , Patras , Greece , and
| | - Maria Stavropoulou
- c Department of Chemistry , Technical University of Munich , Munich , Germany
| | - Dimitrios Kalpaxis
- b Laboratory of Biochemistry , School of Medicine, University of Patras , Patras , Greece , and
| | - George P Dinos
- b Laboratory of Biochemistry , School of Medicine, University of Patras , Patras , Greece , and
| |
Collapse
|
27
|
Wong EHC, Porter JD, Edwards MR, Johnston SL. The role of macrolides in asthma: current evidence and future directions. THE LANCET RESPIRATORY MEDICINE 2014; 2:657-70. [PMID: 24948430 DOI: 10.1016/s2213-2600(14)70107-9] [Citation(s) in RCA: 70] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
Macrolides, such as clarithromycin and azithromycin, possess antimicrobial, immunomodulatory, and potential antiviral properties. They represent a potential therapeutic option for asthma, a chronic inflammatory disorder characterised by airway hyper-responsiveness that leads to recurrent episodes of wheezing, breathlessness, chest tightness, and coughing. Results from clinical trials, however, have been contentious. The findings could be confounded by many factors, including the heterogeneity of asthma, treatment duration, dose, and differing outcome measures. Recent evidence suggests improved effectiveness of macrolides in patients with sub-optimally controlled severe neutrophilic asthma and in asthma exacerbations. We examine the evidence from clinical trials and discuss macrolide properties and their relevance to the pathophysiology of asthma. At present, the use of macrolides in chronic asthma or acute exacerbations is not justified. Further work, including proteomic, genomic, and microbiome studies, will advance our knowledge of asthma phenotypes, and help to identify a macrolide-responsive subgroup. Future clinical trials should target this subgroup and place emphasis on clinically relevant outcomes such as asthma exacerbations.
Collapse
Affiliation(s)
- Ernie H C Wong
- Airway Disease Infection Section, National Heart and Lung Institute, Imperial College London, London, UK; MRC and Asthma UK Centre in Allergic Mechanisms of Asthma, London, UK; Centre for Respiratory Infection, London, UK; Imperial College Healthcare NHS Trust, London, UK
| | - James D Porter
- Airway Disease Infection Section, National Heart and Lung Institute, Imperial College London, London, UK; MRC and Asthma UK Centre in Allergic Mechanisms of Asthma, London, UK; Centre for Respiratory Infection, London, UK
| | - Michael R Edwards
- Airway Disease Infection Section, National Heart and Lung Institute, Imperial College London, London, UK; MRC and Asthma UK Centre in Allergic Mechanisms of Asthma, London, UK; Centre for Respiratory Infection, London, UK
| | - Sebastian L Johnston
- Airway Disease Infection Section, National Heart and Lung Institute, Imperial College London, London, UK; MRC and Asthma UK Centre in Allergic Mechanisms of Asthma, London, UK; Centre for Respiratory Infection, London, UK; Imperial College Healthcare NHS Trust, London, UK.
| |
Collapse
|
28
|
Johansson M, Chen J, Tsai A, Kornberg G, Puglisi JD. Sequence-dependent elongation dynamics on macrolide-bound ribosomes. Cell Rep 2014; 7:1534-1546. [PMID: 24836000 DOI: 10.1016/j.celrep.2014.04.034] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2014] [Revised: 03/27/2014] [Accepted: 04/17/2014] [Indexed: 01/27/2023] Open
Abstract
The traditional view of macrolide antibiotics as plugs inside the ribosomal nascent peptide exit tunnel (NPET) has lately been challenged in favor of a more complex, heterogeneous mechanism, where drug-peptide interactions determine the fate of a translating ribosome. To investigate these highly dynamic processes, we applied single-molecule tracking of elongating ribosomes during inhibition of elongation by erythromycin of several nascent chains, including ErmCL and H-NS, which were shown to be, respectively, sensitive and resistant to erythromycin. Peptide sequence-specific changes were observed in translation elongation dynamics in the presence of a macrolide-obstructed NPET. Elongation rates were not severely inhibited in general by the presence of the drug; instead, stalls or pauses were observed as abrupt events. The dynamic pathways of nascent-chain-dependent elongation pausing in the presence of macrolides determine the fate of the translating ribosome stalling or readthrough.
Collapse
Affiliation(s)
- Magnus Johansson
- Department of Structural Biology, Stanford University School of Medicine, Stanford, CA 94305-5126, USA
| | - Jin Chen
- Department of Structural Biology, Stanford University School of Medicine, Stanford, CA 94305-5126, USA; Department of Applied Physics, Stanford University, Stanford, CA 94305-4090, USA
| | - Albert Tsai
- Department of Structural Biology, Stanford University School of Medicine, Stanford, CA 94305-5126, USA; Department of Applied Physics, Stanford University, Stanford, CA 94305-4090, USA
| | - Guy Kornberg
- Department of Structural Biology, Stanford University School of Medicine, Stanford, CA 94305-5126, USA
| | - Joseph D Puglisi
- Department of Structural Biology, Stanford University School of Medicine, Stanford, CA 94305-5126, USA; Stanford Magnetic Resonance Laboratory, Stanford University School of Medicine, Stanford, CA 94305-5126, USA.
| |
Collapse
|
29
|
Gupta P, Kannan K, Mankin AS, Vázquez-Laslop N. Regulation of gene expression by macrolide-induced ribosomal frameshifting. Mol Cell 2013; 52:629-42. [PMID: 24239289 DOI: 10.1016/j.molcel.2013.10.013] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2013] [Revised: 09/11/2013] [Accepted: 10/09/2013] [Indexed: 11/29/2022]
Abstract
The expression of many genes is controlled by upstream ORFs (uORFs). Typically, the progression of the ribosome through a regulatory uORF, which depends on the physiological state of the cell, influences the expression of the downstream gene. In the classic mechanism of induction of macrolide resistance genes, antibiotics promote translation arrest within the uORF, and the static ribosome induces a conformational change in mRNA, resulting in the activation of translation of the resistance cistron. We show that ketolide antibiotics, which do not induce ribosome stalling at the uORF of the ermC resistance gene, trigger its expression via a unique mechanism. Ketolides promote frameshifting at the uORF, allowing the translating ribosome to invade the intergenic spacer. The dynamic unfolding of the mRNA structure leads to the activation of resistance. Conceptually similar mechanisms may control other cellular genes. The identified property of ketolides to reduce the fidelity of reading frame maintenance may have medical implications.
Collapse
Affiliation(s)
- Pulkit Gupta
- Center for Pharmaceutical Biotechnology, University of Illinois at Chicago, 900 South Ashland Avenue, Chicago, IL 60607, USA
| | - Krishna Kannan
- Center for Pharmaceutical Biotechnology, University of Illinois at Chicago, 900 South Ashland Avenue, Chicago, IL 60607, USA
| | - Alexander S Mankin
- Center for Pharmaceutical Biotechnology, University of Illinois at Chicago, 900 South Ashland Avenue, Chicago, IL 60607, USA.
| | - Nora Vázquez-Laslop
- Center for Pharmaceutical Biotechnology, University of Illinois at Chicago, 900 South Ashland Avenue, Chicago, IL 60607, USA.
| |
Collapse
|
30
|
Insights into the mode of action of novel fluoroketolides, potent inhibitors of bacterial protein synthesis. Antimicrob Agents Chemother 2013; 58:472-80. [PMID: 24189263 DOI: 10.1128/aac.01994-13] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Ketolides, the third generation of expanded-spectrum macrolides, have in the last years become a successful weapon in the endless war against macrolide-resistant pathogens. Ketolides are semisynthetic derivatives of the naturally produced macrolide erythromycin, displaying not only improved activity against some erythromycin-resistant strains but also increased bactericidal activity as well as inhibitory effects at lower drug concentrations. In this study, we present a series of novel ketolides carrying alkyl-aryl side chains at the C-6 position of the lactone ring and, additionally, one or two fluorine atoms attached either directly to the lactone ring at the C-2 position or indirectly via the C-13 position. According to our genetic and biochemical studies, these novel ketolides occupy the known macrolide binding site at the entrance of the ribosomal tunnel and exhibit lower MIC values against wild-type or mutant strains than erythromycin. In most cases, the ketolides display activities comparable to or better than the clinically used ketolide telithromycin. Chemical protection experiments using Escherichia coli ribosomes bearing U2609C or U754A mutations in 23S rRNA suggest that the alkyl-aryl side chain establishes an interaction with the U2609-A752 base pair, analogous to that observed with telithromycin but unlike the interactions formed by cethromycin. These findings reemphasize the versatility of the alkyl-aryl side chains with respect to species specificity, which will be important for future design of improved antimicrobial agents.
Collapse
|
31
|
Inhibition of protein synthesis on the ribosome by tildipirosin compared with other veterinary macrolides. Antimicrob Agents Chemother 2012; 56:6033-6. [PMID: 22926570 DOI: 10.1128/aac.01250-12] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Tildipirosin is a 16-membered-ring macrolide developed to treat bacterial pathogens, including Mannheimia haemolytica and Pasteurella multocida, that cause respiratory tract infections in cattle and swine. Here we evaluated the efficacy of tildipirosin at inhibiting protein synthesis on the ribosome (50% inhibitory concentration [IC(50)], 0.23 ± 0.01 μM) and compared it with the established veterinary macrolides tylosin, tilmicosin, and tulathromycin. Mutation and methylation at key rRNA nucleotides revealed differences in the interactions of these macrolides within their common ribosomal binding site.
Collapse
|
32
|
|
33
|
Kannan K, Mankin AS. Macrolide antibiotics in the ribosome exit tunnel: species-specific binding and action. Ann N Y Acad Sci 2012; 1241:33-47. [PMID: 22191525 DOI: 10.1111/j.1749-6632.2011.06315.x] [Citation(s) in RCA: 86] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Macrolide antibiotics bind in the nascent peptide exit tunnel of the ribosome and inhibit protein synthesis. The majority of information on the principles of binding and action of these antibiotics comes from studies that employed model organisms. However, there is a growing understanding that the binding of macrolides to their target, as well as the mode of inhibition of translation, can be strongly influenced by variations in ribosome structure between bacterial species. Awareness of the existence of species-specific differences in drug action and appreciation of the extent of these differences can stimulate future work on developing better macrolide drugs. In this review, representative cases illustrating the organism-specific binding and action of macrolide antibiotics, as well as species-specific mechanisms of resistance are analyzed.
Collapse
Affiliation(s)
- Krishna Kannan
- Center for Pharmaceutical Biotechnology, University of Illinois at Chicago, 60607, USA
| | | |
Collapse
|
34
|
Abstract
The peptidyltransferase center of the large ribosomal subunit is responsible for catalyzing peptide bonds. This active site is the target of a variety of diverse antibiotics, many of which are used clinically. The past decade has seen a plethora of structures of antibiotics in complex with the large ribosomal subunit, providing unprecedented insight into the mechanism of action of these inhibitors. Ten distinct antibiotics (chloramphenicol, clindamycin, linezolid, tiamulin, sparsomycin, and five macrolides) have been crystallized in complex with four distinct ribosomal species, three bacterial, and one archaeal. This review aims to compare these structures in order to provide insight into the conserved and species-specific modes of interaction for particular members of each class of antibiotics. Coupled with the wealth of biochemical data, a picture is emerging defining the specific functional states of the ribosome that antibiotics preferentially target. Such mechanistic insight into antibiotic inhibition will be important for the development of the next generation of antimicrobial agents.
Collapse
|
35
|
Sadreddini S, Noshad H, Molaeefard M, Moloudi R, Ardalan MR, Ghojazadeh M. A double blind, randomized, placebo controlled study to evaluate the efficacy of erythromycin in patients with knee effusion due to osteoarthritis. Int J Rheum Dis 2010; 12:44-51. [PMID: 20374316 DOI: 10.1111/j.1756-185x.2009.01379.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
OBJECTIVE The efficacy of erythromycin in treatment of knee effusion due to osteoarthritis was evaluated. METHOD We assessed efficacy and safety of erythromycin during 16 weeks in patients enrolled in a randomized double-blind study. One hundred and eight patients with knee effusion due to osteoarthritis (OA) received 12-week courses of erythromycin or placebo allocated randomly, and were followed for 4 months. Acetaminophen 650 mg/day was used in both groups, while they received no other anti-inflammatory drugs (such as corticosteroid or nonsteroidal anti-inflammatory drugs) during the course of the study. Our patients were divided in two groups, erythromycin in doses of 200 mg four times per day was given to the first group (51 patients) over the first 3 months of the study and in the second group we used placebo with the same dosage and schedule (53 patients). Outcomes improvement for the erythromycin-treated group was assessed by a significantly higher mean score from baseline to the end of the trial, compared with placebo group. Patients were examined monthly during the treatment period. Measurement values included recording of Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) questionnaire subscales (pain, stiffness and function), range of motion and knee circumference. RESULTS Erythromycin produced a higher response rate than placebo in treatment of knee effusion due to OA. Significant reduction in knee circumference (P < 0.0005) and pain (P < 0.001) with functional improvement (P < 0.0005) were seen. At the first month after treatment, 11.8% (6 patients) in erythromycin and 9.4% (5 patients) in placebo groups had 50% pain reduction, which was not significant (P = 0.75). At the fourth month, 50% reduction of pain was seen in 45.1% (23 patients) of the erythromycin and 11.3% (6 patients) of the placebo group. This was statistically significant (P < 0.0005). Erythromycin treatment was well tolerated and mild adverse events caused no discontinuation during the study. CONCLUSION This is a placebo-controlled study of macrolid efficacy on knee effusion due to OA in a short period. Results of this research showed the better efficacy of erythromycin in controlling effusion and pain with functional improvement in patients with knee effusion due to OA.
Collapse
|
36
|
Abstract
Antibiotic drug-target interactions, and their respective direct effects, are generally well characterized. By contrast, the bacterial responses to antibiotic drug treatments that contribute to cell death are not as well understood and have proven to be complex as they involve many genetic and biochemical pathways. In this Review, we discuss the multilayered effects of drug-target interactions, including the essential cellular processes that are inhibited by bactericidal antibiotics and the associated cellular response mechanisms that contribute to killing. We also discuss new insights into these mechanisms that have been revealed through the study of biological networks, and describe how these insights, together with related developments in synthetic biology, could be exploited to create new antibacterial therapies.
Collapse
|
37
|
Abstract
Protein synthesis is one of the major targets in the cell for antibiotics. This review endeavors to provide a comprehensive "post-ribosome structure" A-Z of the huge diversity of antibiotics that target the bacterial translation apparatus, with an emphasis on correlating the vast wealth of biochemical data with more recently available ribosome structures, in order to understand function. The binding site, mechanism of action, and modes of resistance for 26 different classes of protein synthesis inhibitors are presented, ranging from ABT-773 to Zyvox. In addition to improving our understanding of the process of translation, insight into the mechanism of action of antibiotics is essential to the development of novel and more effective antimicrobial agents to combat emerging bacterial resistance to many clinically-relevant drugs.
Collapse
Affiliation(s)
- Daniel N Wilson
- Gene Center and Department of Chemistry and Biochemistry, University of Munich, LMU, Munich, Germany.
| |
Collapse
|
38
|
Distinct mode of interaction of a novel ketolide antibiotic that displays enhanced antimicrobial activity. Antimicrob Agents Chemother 2009; 53:1411-9. [PMID: 19164155 DOI: 10.1128/aac.01425-08] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Ketolides represent the latest generation of macrolide antibiotics, displaying improved activities against some erythromycin-resistant strains, while maintaining their activity against erythromycin-susceptible ones. In this study, we present a new ketolide, K-1325, that carries an alkyl-aryl side chain at C-13 of the lactone ring. According to our genetic and biochemical studies, K-1325 binds within the nascent polypeptide exit tunnel, at a site previously described as the primary attachment site of all macrolide antibiotics. Compared with telithromycin, K-1325 displays enhanced antimicrobial activity against wild-type Escherichia coli strains, as well as against strains bearing the U2609C mutation in 23S rRNA. Chemical protection experiments showed that the alkyl-aryl side chain of K-1325 interacts specifically with helix 35 of 23S rRNA, a fact leading to an increased affinity of U2609C mutant ribosomes for the drug and rationalizing the enhanced effectiveness of this new ketolide.
Collapse
|
39
|
Vourekas A, Stamatopoulou V, Toumpeki C, Tsitlaidou M, Drainas D. Insights into functional modulation of catalytic RNA activity. IUBMB Life 2008; 60:669-83. [PMID: 18636557 DOI: 10.1002/iub.105] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
RNA molecules play critical roles in cell biology, and novel findings continuously broaden their functional repertoires. Apart from their well-documented participation in protein synthesis, it is now apparent that several noncoding RNAs (i.e., micro-RNAs and riboswitches) also participate in the regulation of gene expression. The discovery of catalytic RNAs had profound implications on our views concerning the evolution of life on our planet at a molecular level. A characteristic attribute of RNA, probably traced back to its ancestral origin, is the ability to interact with and be modulated by several ions and molecules of different sizes. The inhibition of ribosome activity by antibiotics has been extensively used as a therapeutical approach, while activation and substrate-specificity alteration have the potential to enhance the versatility of ribozyme-based tools in translational research. In this review, we will describe some representative examples of such modulators to illustrate the potential of catalytic RNAs as tools and targets in research and clinical approaches.
Collapse
Affiliation(s)
- Anastassios Vourekas
- Department of Biological Chemistry, School of Medicine, University of Patras, Rio-Patras, Greece
| | | | | | | | | |
Collapse
|
40
|
Abstract
The ribosome has the intrinsic capacity to monitor the sequence and structure of the nascent peptide. This fundamental property of the ribosome is often exploited in regulation of gene expression, in particular, for activation of expression of genes conferring resistance to ribosome-targeting antibiotics. Induction of expression of these genes is controlled by the programmed stalling of the ribosome at a regulatory open reading frame located upstream of the resistance cistron. Formation of the stalled translation complex depends on the presence of an antibiotic in the ribosome exit tunnel and the sequence of the nascent peptide. In this review, we summarize our current understanding of the molecular mechanisms of drug- and nascent peptide-dependent ribosome stalling.
Collapse
Affiliation(s)
- Haripriya Ramu
- Center for Pharmaceutical Biotechnology, University of Illinois, 900 S. Ashland Ave., Chicago, IL 60607, USA
| | | | | |
Collapse
|
41
|
Mankin AS. Macrolide myths. Curr Opin Microbiol 2008; 11:414-21. [PMID: 18804176 DOI: 10.1016/j.mib.2008.08.003] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2008] [Revised: 08/11/2008] [Accepted: 08/22/2008] [Indexed: 10/21/2022]
Abstract
In spite of decades of research, our knowledge of the mode of interaction of macrolide antibiotics with their ribosomal target and of the mechanism of action of these drugs remain fragmentary. Experimental facts obtained over the past several years question some of the concepts that were viewed as a 'common knowledge'. This review focuses on certain aspects of binding and action of macrolides that may need re-evaluation in view of the new findings.
Collapse
Affiliation(s)
- Alexander S Mankin
- Center for Pharmaceutical Biotechnology-m/c 870, University of Illinois at Chicago, 900 S. Ashland Avenue, Room 3052, Chicago, IL 60607, USA.
| |
Collapse
|
42
|
Yao S, Blaustein JB, Bechhofer DH. Erythromycin-induced ribosome stalling and RNase J1-mediated mRNA processing in Bacillus subtilis. Mol Microbiol 2008; 69:1439-49. [PMID: 18647167 DOI: 10.1111/j.1365-2958.2008.06370.x] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
SUMMARY Addition of erythromycin (Em) to a Bacillus subtilis strain carrying the ermC gene results in ribosome stalling in the ermC leader peptide coding sequence. Using DeltaermC, a deletion derivative of ermC that specifies the 254 nucleotide DeltaermC mRNA, we showed previously that ribosome stalling is concomitant with processing of DeltaermC mRNA, generating a 209 nucleotide RNA whose 5' end maps to codon 5 of the DeltaermC coding sequence. Here we probed for peptidyl-tRNA to show that ribosome stalling occurs after incorporation of the amino acid specified by codon 9. Thus, cleavage upstream of codon 5 is not an example of 'A-site cleavage' that has been reported for Escherichia coli. Analysis of DeltaermC mRNA processing in endoribonuclease mutant strains showed that this processing is RNase J1-dependent. DeltaermC mRNA processing was inhibited by the presence of stable secondary structure at the 5' end, demonstrating 5'-end dependence, and was shown to be a result of RNase J1 endonuclease activity, rather than 5'-to-3' exonuclease activity. Examination of processing in derivatives of DeltaermC that had codons inserted upstream of the ribosome stalling site revealed that Em-induced ribosome stalling can occur considerably further from the start codon than would be expected based on previous studies.
Collapse
Affiliation(s)
- Shiyi Yao
- Department of Pharmacology and Systems Therapeutics, Mount Sinai School of Medicine of New York University, New York, NY 10029, USA
| | | | | |
Collapse
|
43
|
Pulavarti S, Jain A, Prakash Pathak P, Mahmood A, Arora A. Solution Structure and Dynamics of Peptidyl-tRNA Hydrolase from Mycobacterium tuberculosis H37Rv. J Mol Biol 2008; 378:165-77. [DOI: 10.1016/j.jmb.2008.02.027] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2007] [Revised: 01/15/2008] [Accepted: 02/14/2008] [Indexed: 11/28/2022]
|
44
|
Zaman S, Fitzpatrick M, Lindahl L, Zengel J. Novel mutations in ribosomal proteins L4 and L22 that confer erythromycin resistance in Escherichia coli. Mol Microbiol 2007; 66:1039-50. [PMID: 17956547 PMCID: PMC2229831 DOI: 10.1111/j.1365-2958.2007.05975.x] [Citation(s) in RCA: 79] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
L4 and L22, proteins of the large ribosomal subunit, contain globular surface domains and elongated ‘tentacles’ that reach into the core of the large subunit to form part of the lining of the peptide exit tunnel. Mutations in the tentacles of L4 and L22 confer macrolide resistance in a variety of pathogenic and non-pathogenic bacteria. In Escherichia coli, a Lys-to-Glu mutation in L4 and a three-amino-acid deletion in the L22 had been reported. To learn more about the roles of the tentacles in ribosome assembly and function, we isolated additional erythromycin-resistant E. coli mutants. Eight new mutations mapped in L4, all within the tentacle. Two new mutations were identified in L22; one mapped outside the tentacle. Insertion mutations were found in both genes. All of the mutants grew slower than the parent, and they all showed reduced in vivo rates of peptide-chain elongation and increased levels of precursor 23S rRNA. Large insertions in L4 and L22 resulted in very slow growth and accumulation of abnormal ribosomal subunits. Our results highlight the important role of L4 and L22 in ribosome function and assembly, and indicate that a variety of changes in these proteins can mediate macrolide resistance.
Collapse
Affiliation(s)
- Sephorah Zaman
- Department of Biological Sciences, University of Maryland Baltimore County, 1000 Hilltop Circle, Baltimore, MD 21250, USA
| | | | | | | |
Collapse
|
45
|
Transient erythromycin resistance phenotype associated with peptidyl-tRNA drop-off on early UGG and GGG codons. J Bacteriol 2007; 189:8993-9000. [PMID: 17951392 DOI: 10.1128/jb.01004-07] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Expression of minigenes encoding tetra- or pentapeptides MXLX or MXLXV (E peptides), where X is a nonpolar amino acid, renders cells erythromycin resistant whereas expression of minigenes encoding tripeptide MXL does not. By using a 3A' reporter gene system beginning with an E-peptide-encoding sequence, we asked whether the codons UGG and GGG, which are known to promote peptidyl-tRNA drop-off at early positions in mRNA, would result in a phenotype of erythromycin resistance if located after this sequence. We find that UGG or GGG, at either position +4 or +5, without a following stop codon, is associated with an erythromycin resistance phenotype upon gene induction. Our results suggest that, while a stop codon at +4 gives a tripeptide product (MIL) and erythromycin sensitivity, UGG or GGG codons at the same position give a tetrapeptide product (MILW or MILG) and phenotype of erythromycin resistance. Thus, the drop-off event on GGG or UGG codons occurs after incorporation of the corresponding amino acid into the growing peptide chain. Drop-off gives rise to a peptidyl-tRNA where the peptide moiety functionally mimics a minigene peptide product of the type previously associated with erythromycin resistance. Several genes in Escherichia coli fulfill the requirements of high mRNA expression and an E-peptide sequence followed by UGG or GGG at position +4 or +5 and should potentially be able to give an erythromycin resistance phenotype.
Collapse
|
46
|
Akashi T. [Macrolide and macrolide-related antibacterial agents]. Nihon Yakurigaku Zasshi 2007; 130:294-8. [PMID: 17938515 DOI: 10.1254/fpj.130.294] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
|
47
|
Abstract
The macrolides have evolved through four chemical generations since erythromycin became available for clinical use in 1952. The first generation, the 14-membered ring macrolide erythromycin, induced resistance and was replaced by the second generation 16-membered ring macrolides which did not. The inability to induce came at the price of mutation, in the pathogenic target strain, to constitutive expression of resistance. A third generation of macrolides improved the acid-stability, and therefore the pharmacokinetics of erythromycin, extending the clinical use of macrolides to Helicobacter pylori and Mycobacterium tuberculosis. Improved pharmacokinetics resulted in the selection of intrinsically resistant mutant strains with rRNA structural alterations. Expression of resistance in these strains was unexpected, explainable by low rRNA gene copy number which made resistance dominant. A fourth generation of macrolides, the 14-membered ring ketolides are the most recent development. Members of this generation are reported to be effective against inducibly resistant strains, and ketolide resistant strains have not yet been reported. In this review we discuss details of the ways in which bacteria have become resistant to the first three generations of macrolides, both with respect to their biochemistry, and the genetic mechanisms by which their expression is regulated.
Collapse
Affiliation(s)
- B Weisblum
- Department of Pharmacology, University of Wisconsin Medical School, Madison, Wisconsin 53706, USA.
| |
Collapse
|
48
|
Bal NC, Agrawal H, Meher AK, Arora A. Characterization of peptidyl-tRNA hydrolase encoded by open reading frame Rv1014c of Mycobacterium tuberculosis H37Rv. Biol Chem 2007; 388:467-79. [PMID: 17516842 DOI: 10.1515/bc.2007.057] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
The enzyme peptidyl-tRNA hydrolase (Pth, EC 3.1.1.29) is essential for the viability of bacteria. The ORF Rv1014c of Mycobacterium tuberculosis H37Rv, designated as the mtpth gene, was cloned and over-expressed and the product was purified. Generation of polyclonal antibodies against the purified recombinant protein, termed MtPth, facilitated detection of endogenously expressed MtPth in M. tuberculosis H37Rv cell lysate. MtPth could release diacetyl-[(3)H]-lysine from diacetyl-[(3)H]-lysyl-tRNA(Lys) with Michaelis-Menten kinetic parameters of K (m)=0.7+/-0.2 microM and k (cat)=1.22+/-0.2 s(-1). Transformation of a pTrc99c/mtpth vector allowed the growth of E. coli thermosensitive Pth(ts) mutant strain AA7852 at the non-permissive temperature of 42 degrees C, demonstrating the in vivo activity of MtPth. In addition, at 39 degrees C, over-expression of MtPth in AA7852 cells allowed the cells to remain viable in the presence of up to 200 microg/ml erythromycin. A 3D fold based on NMR and a structural model based on the E. coli Pth crystal structure were generated for MtPth. The essential nature of conserved active-site residues N12, H22 and D95 of MtPth for catalysis was demonstrated by mutagenesis and complementation in E. coli mutant strain AA7852. Thermal and urea/guanidinium chloride (GdmCl)-induced unfolding curves for MtPth indicate a simple two-state unfolding process without any intermediates.
Collapse
Affiliation(s)
- Naresh C Bal
- Molecular and Structural Biology, Central Drug Research Institute, Lucknow, India
| | | | | | | |
Collapse
|
49
|
Abstract
The ribosome is one of the main antibiotic targets in the cell. Recent years brought important insights into the mode of interaction of antibiotics with the ribosome and mechanisms of antibiotic action. Ribosome crystallography provided a detailed view of the interactions between antibiotics and rRNA. Advances in biochemical techniques let us better understand how the binding of small organic molecules can interfere with functions of an enzyme four orders of magnitude larger than the inhibitor. These and other achievements paved the way for the development of new ribosome-targeting antibiotics, some of which have already entered medical practice. The recent progress, problems and new directions of research of ribosome-targeting antibiotics are discussed in this review.
Collapse
Affiliation(s)
- Tanel Tenson
- Institute of Technology, University of Tartu, Estonia.
| | | |
Collapse
|
50
|
Abstract
Antibiotics target ribosomes at distinct locations within functionally relevant sites. They exert their inhibitory action by diverse modes, including competing with substrate binding, interfering with ribosomal dynamics, minimizing ribosomal mobility, facilitating miscoding, hampering the progression of the mRNA chain, and blocking the nascent protein exit tunnel. Although the ribosomes are highly conserved organelles, they possess subtle sequence and/or conformational variations. These enable drug selectivity, thus facilitating clinical usage. The structural implications of these differences were deciphered by comparisons of high-resolution structures of complexes of antibiotics with ribosomal particles from eubacteria resembling pathogens and from an archaeon that shares properties with eukaryotes. The various antibiotic-binding modes detected in these structures demonstrate that members of antibiotic families possessing common chemical elements with minute differences might bind to ribosomal pockets in significantly different modes, governed by their chemical properties. Similarly, the nature of seemingly identical mechanisms of drug resistance is dominated, directly or via cellular effects, by the antibiotics' chemical properties. The observed variability in antibiotic binding and inhibitory modes justifies expectations for structurally based improved properties of existing compounds as well as for the discovery of novel drug classes.
Collapse
Affiliation(s)
- Ada Yonath
- Department of Structural Biology, Weizmann Institute, Rehovot, Israel.
| |
Collapse
|