1
|
Bhawsar S, Pawar S, Deshpande P, Yeole R, Chavan R, Nandanwar M, Bhagwat S, Patel M. WCK 4034: A promising oxazolidinone for treating gram positive infections. Bioorg Med Chem Lett 2022; 71:128842. [PMID: 35680102 DOI: 10.1016/j.bmcl.2022.128842] [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: 03/24/2022] [Revised: 05/31/2022] [Accepted: 06/01/2022] [Indexed: 11/19/2022]
Abstract
Increased resistance to gram positive infections have highlighted the limitations of currently available drug treatments including penicillins, macrolides and glycopeptides. As an alternative to address these challenges; Linezolid, the first antibiotic from oxazolidinone class, have shown the promising activities against such infections, although associated toxicological issues limiting the use of linezolid for prolonged treatments. In order to circumvent disadvantages allied with the marketed drugs, we herein reporting the synthesis of WCK 4034, an oxazolidinone antibiotic through our structure activity relationship (SAR) program. Through this exercise, WCK 4034, has shown competitive MIC values against Methicillin Sensitive S. aureus (MSSA, Sta-001), Methicillin Resistant S. aureus (MRSA, Sta-032), S. pneumoniae ATCC 49619 and H. influenza ATCC 35054 species as like linezolid. Although with an additional advantage; WCK 4034 has been found superior during dog PK studies as compare to Linezolid. With the preliminary studies in our hand, we herein assuming these improved pharmacokinetic values would be helpful. Moreover, WCK 4034 has successfully completed pre-clinical studies and ready to enter the clinical space, and paved the way for in house development of other oxazolidinone NCEs.
Collapse
Affiliation(s)
- Satish Bhawsar
- Wockhardt Research Center, D-4, MIDC, Chikalthana, Aurangabad, MS 431006, India.
| | - Shivaji Pawar
- Wockhardt Research Center, D-4, MIDC, Chikalthana, Aurangabad, MS 431006, India
| | - Prasad Deshpande
- Wockhardt Research Center, D-4, MIDC, Chikalthana, Aurangabad, MS 431006, India
| | - Ravindra Yeole
- Wockhardt Research Center, D-4, MIDC, Chikalthana, Aurangabad, MS 431006, India
| | - Rajesh Chavan
- Wockhardt Research Center, D-4, MIDC, Chikalthana, Aurangabad, MS 431006, India
| | - Manohar Nandanwar
- Wockhardt Research Center, D-4, MIDC, Chikalthana, Aurangabad, MS 431006, India
| | - Sachin Bhagwat
- Wockhardt Research Center, D-4, MIDC, Chikalthana, Aurangabad, MS 431006, India
| | - Mahesh Patel
- Wockhardt Research Center, D-4, MIDC, Chikalthana, Aurangabad, MS 431006, India
| |
Collapse
|
2
|
Singh Dewhare S. Drug resistant tuberculosis: Current scenario and impending challenges. Indian J Tuberc 2022; 69:227-233. [PMID: 35379406 DOI: 10.1016/j.ijtb.2021.04.008] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2021] [Accepted: 04/05/2021] [Indexed: 06/14/2023]
Abstract
Tuberculosis is still one of the ten leading causes for death worldwide. In spite of the latest medical and health advance gained over a period of time, tuberculosis effectively evades the successful targeting by drugs. The persistence abilities demonstrated by the mycobacteria had surprised the global community, since its discovery and pathogenesis in humans. Emergence and detection of drug resistant mycobacteria (MDR-TB, XDR-TB) had further complicated the treatment regime. Under the aegis of WHO, there is a concerted understanding and effort by the global community to eradicate TB. Towards this goal, novel drug molecules, new vaccine and treatment regime are being developed. Here, our current understanding pertaining to mode of action, molecular mechanisms of novel as well as traditional drug molecules and possible drug resistance mechanism in M. Tuberculosis is reviewed. Recent advances on new vaccination regime are also reviewed as it demonstrated huge potential in containing TB. This knowledge is essential for the development of more effective drug molecules, vaccines and may help in devising new strategy for containing and eradicating TB.
Collapse
Affiliation(s)
- Shivendra Singh Dewhare
- School of Studies in Life Science, Pt. RavishankarShukla University, Raipur, 492010, Chhattisgarh, India.
| |
Collapse
|
3
|
Fernandes GFDS, Salgado HRN, Santos JLD. A critical review of HPLC-based analytical methods for quantification of Linezolid. Crit Rev Anal Chem 2019; 50:196-211. [PMID: 31017000 DOI: 10.1080/10408347.2019.1605876] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Linezolid is a synthetic antimicrobial agent belonging to the oxazolidinone class. Since its approval in the year 2000 until now, linezolid remains the main representative drug for the oxazolidinone class of drugs, which is used in therapy due to its unique mode of action, which involves inhibition of protein synthesis. As linezolid holds great importance in antimicrobial therapy, it is necessary to compile the various analytical methods that have been reported in the literature for its analysis. Analytical techniques used for pharmaceutical analyses and therapeutic drug monitoring play an important role in comprehending the aspects regarding bioavailability, bioequivalence, and therapeutic monitoring during patient follow-ups. Even though linezolid has had the approval for clinical use for more than 18 years now, most of the analytical methods for its determination reported in the scientific literature are the ones which utilize HPLC. Therefore, the present review provides a summary of the HPLC-based methods used in the determination and quantification of linezolid in different matrices since the time of its discovery.
Collapse
Affiliation(s)
- Guilherme Felipe Dos Santos Fernandes
- Institute of Chemistry, São Paulo State University, Araraquara, Brazil.,School of Pharmaceutical Sciences, São Paulo State University, Araraquara, Brazil
| | | | - Jean Leandro Dos Santos
- Institute of Chemistry, São Paulo State University, Araraquara, Brazil.,School of Pharmaceutical Sciences, São Paulo State University, Araraquara, Brazil
| |
Collapse
|
4
|
Zhou M, Zheng X, Wang Y, Yuan D, Yao Y. A Multicomponent Approach to Oxazolidinone Synthesis Catalyzed by Rare‐Earth Metal Amides. ChemCatChem 2019. [DOI: 10.1002/cctc.201900221] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Affiliation(s)
- Meixia Zhou
- Laboratory of Organic Synthesis of Jiangsu Province College of Chemistry, Chemical Engineering and Materials Science Dushu Lake CampusSoochow University Suzhou 215123 P.R. China
| | - Xizhou Zheng
- Laboratory of Organic Synthesis of Jiangsu Province College of Chemistry, Chemical Engineering and Materials Science Dushu Lake CampusSoochow University Suzhou 215123 P.R. China
| | - Yaorong Wang
- Laboratory of Organic Synthesis of Jiangsu Province College of Chemistry, Chemical Engineering and Materials Science Dushu Lake CampusSoochow University Suzhou 215123 P.R. China
| | - Dan Yuan
- Laboratory of Organic Synthesis of Jiangsu Province College of Chemistry, Chemical Engineering and Materials Science Dushu Lake CampusSoochow University Suzhou 215123 P.R. China
| | - Yingming Yao
- Laboratory of Organic Synthesis of Jiangsu Province College of Chemistry, Chemical Engineering and Materials Science Dushu Lake CampusSoochow University Suzhou 215123 P.R. China
| |
Collapse
|
5
|
McPherson CG, Cooper AK, Bubliauskas A, Mulrainey P, Jamieson C, Watson AJB. A Multicomponent Route to Functionalized Amides and Oxazolidinones. Org Lett 2017; 19:6736-6739. [PMID: 29193973 DOI: 10.1021/acs.orglett.7b03470] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
An organobase-mediated multicomponent reaction of unactivated esters, epoxides, and amines is reported, furnishing functionalized amide derivatives. A wide range of substrates are tolerated under the reaction conditions, including chiral epoxides, which react with no erosion of enantiopurity. Facile modification of the method through replacing the ester derivative with dimethyl carbonate enables access to the corresponding oxazolidinone derivatives.
Collapse
Affiliation(s)
- Christopher G McPherson
- Department of Pure & Applied Chemistry, University of Strathclyde , 295 Cathedral Street, Glasgow G1 1XL, U.K
| | - Alasdair K Cooper
- Department of Pure & Applied Chemistry, University of Strathclyde , 295 Cathedral Street, Glasgow G1 1XL, U.K
| | - Andrius Bubliauskas
- Department of Pure & Applied Chemistry, University of Strathclyde , 295 Cathedral Street, Glasgow G1 1XL, U.K
| | - Paul Mulrainey
- Department of Pure & Applied Chemistry, University of Strathclyde , 295 Cathedral Street, Glasgow G1 1XL, U.K
| | - Craig Jamieson
- Department of Pure & Applied Chemistry, University of Strathclyde , 295 Cathedral Street, Glasgow G1 1XL, U.K
| | - Allan J B Watson
- Department of Pure & Applied Chemistry, University of Strathclyde , 295 Cathedral Street, Glasgow G1 1XL, U.K
| |
Collapse
|
6
|
Bassetti M, Righi E. Safety profiles of old and new antimicrobials for the treatment of MRSA infections. Expert Opin Drug Saf 2016; 15:467-81. [PMID: 26764972 DOI: 10.1517/14740338.2016.1142528] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
INTRODUCTION Methicillin-resistant Staphylococcus aureus (MRSA) is a frequent cause of severe nosocomial and community-acquired infections. Various adverse effects have been associated with compounds that are commonly used in the treatment of MRSA. AREAS COVERED Prolonged use of high-dose vancomycin has been linked with nephrotoxicity. Linezolid use has been associated with lactic acidosis in regimens longer than 14 days and occurrence of thrombocytopenia in patients with renal impairment. Daptomycin use correlates with reversible and often asymptomatic myopathy. Among new compounds, telavancin has shown increased toxicity compared to vancomycin, especially in patients with severe renal impairment, while a low rate of adverse effects was reported others glycolipopeptides such as dalbavancin and oritavancin and for new cephalosporins. Recently studied oxazolidinones (tedizolid and radezolid) also showed mild adverse effects in Phase 2 and 3 clinical trials. EXPERT OPINION Due to the constant increase in antimicrobial resistance, the use of higher doses and prolonged regimens of antibiotics employed in the treatment of Gram-positive infections has become more common and linked to increased toxicity. Furthermore, new compounds with MRSA activity have been recently approved and will be regularly employed in clinical practice. The knowledge of the adverse effects and risk factors for the development of toxicity associated with anti-MRSA antimicrobials is paramount for the correct use of old and new compounds, especially in the treatment of severe infections.
Collapse
Affiliation(s)
- Matteo Bassetti
- a Infectious Diseases Division , Santa Maria Misericordia Hospital , Udine , Italy
| | - Elda Righi
- a Infectious Diseases Division , Santa Maria Misericordia Hospital , Udine , Italy
| |
Collapse
|
7
|
|
8
|
Sangshetti JN, Khan FAK, Patil RH, Marathe SD, Gade WN, Shinde DB. Biofilm inhibition of linezolid-like Schiff bases: Synthesis, biological activity, molecular docking and in silico ADME prediction. Bioorg Med Chem Lett 2015; 25:874-80. [DOI: 10.1016/j.bmcl.2014.12.063] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2014] [Revised: 12/05/2014] [Accepted: 12/19/2014] [Indexed: 02/02/2023]
|
9
|
Sanapala SR, Kulkarni SS. One-pot synthesis of bicyclic sugar oxazolidinone from d-glucosamine. RSC Adv 2015. [DOI: 10.1039/c5ra02270c] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022] Open
Abstract
Herein we report a one-pot and efficient method for the synthesis of a 1,2-cis fused furanoside bicyclic oxazolidinone derivative of d-glucosamine via pyranose to furanose conversion and concomitant cyclization involving the N-Troc group.
Collapse
|
10
|
Tekin A, Dal T, Deveci Ö, Tekin R, Özcan N, Atmaca S, Dayan S. In vitro susceptibility to methicillin, vancomycin and linezolid of staphylococci isolated from bloodstream infections in eastern Turkey. Braz J Microbiol 2014; 45:829-33. [PMID: 25477914 PMCID: PMC4204965 DOI: 10.1590/s1517-83822014000300010] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2012] [Accepted: 12/13/2013] [Indexed: 12/02/2022] Open
Abstract
Staphylococcus species are one of the major causes of bacterial bloodstream infections. Multi-resistant staphylococci infections are major therapeutic problems. This study was aimed to detect methicillin, linezolid and vancomycin susceptibilities of Staphylococcus isolates. A total of 870 Staphylococcus strains isolated from blood cultures of hospitalized patients with BSI. Antimicrobial susceptibilities of methicillin, linezolid and vancomycin were detected according to the Clinical and Laboratory Standards Institute (CLSI). A total of 771 (88.6%) isolates were coagulase-negative staphylococci (CoNS). 700 (80.5%) isolates were methicillin-resistant (MR) and 170 (19.5%) were methicillin-susceptible (MS). All the MS isolates were also susceptible to linezolid. However 15 (1.7%) of MR strains were resistant to linezolid. The minimum inhibitory concentration range for the linezolid-resistant isolates by Etest was 6–32 μg/mL. The difference between linezolid susceptibilities for MS and MR staphylococci was not quite statistically significant (p = 0.052). There was no statistically significant difference between S. aureus and CoNS isolates for linezolid susceptibility. All of the isolates were susceptible to vancomycin. In conclusion, linezolid is currently an efficient option for the treatment of methicillin-resistant staphylococci infections.
Collapse
Affiliation(s)
- Alicem Tekin
- Department of Microbiology and Clinical Microbiology Medical Faculty Dicle University Diyarbakir Turkey Department of Microbiology and Clinical Microbiology, Medical Faculty, Dicle University, Diyarbakir, Turkey
| | - Tuba Dal
- Department of Microbiology and Clinical Microbiology Medical Faculty Dicle University Diyarbakir Turkey Department of Microbiology and Clinical Microbiology, Medical Faculty, Dicle University, Diyarbakir, Turkey
| | - Özcan Deveci
- Department of Clinical Microbiology and Infectious Diseases Medical Faculty Dicle University Diyarbakir Turkey Department of Clinical Microbiology and Infectious Diseases, Medical Faculty, Dicle University, Diyarbakir, Turkey
| | - Recep Tekin
- Department of Clinical Microbiology and Infectious Diseases Medical Faculty Dicle University Diyarbakir Turkey Department of Clinical Microbiology and Infectious Diseases, Medical Faculty, Dicle University, Diyarbakir, Turkey
| | - Nida Özcan
- Department of Microbiology and Clinical Microbiology Medical Faculty Dicle University Diyarbakir Turkey Department of Microbiology and Clinical Microbiology, Medical Faculty, Dicle University, Diyarbakir, Turkey
| | - Selahattin Atmaca
- Department of Microbiology and Clinical Microbiology Medical Faculty Dicle University Diyarbakir Turkey Department of Microbiology and Clinical Microbiology, Medical Faculty, Dicle University, Diyarbakir, Turkey
| | - Saim Dayan
- Department of Clinical Microbiology and Infectious Diseases Medical Faculty Dicle University Diyarbakir Turkey Department of Clinical Microbiology and Infectious Diseases, Medical Faculty, Dicle University, Diyarbakir, Turkey
| |
Collapse
|
11
|
Tan TQ, Yogev R. Clinical pharmacology of linezolid: an oxazolidinone antimicrobial agent. Expert Rev Clin Pharmacol 2014; 1:479-89. [DOI: 10.1586/17512433.1.4.479] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
|
12
|
Moellering RC. Tedizolid: A Novel Oxazolidinone for Gram-Positive Infections. Clin Infect Dis 2014; 58 Suppl 1:S1-3. [DOI: 10.1093/cid/cit658] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
|
13
|
Synthesis and evaluation of some novel precursors of oxazolidinone analogues of chloroquinoline for their antimicrobial and cytotoxic potential. J CHEM SCI 2013. [DOI: 10.1007/s12039-013-0492-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
|
14
|
An assessment of linezolid utilization in selected canadian provinces. CANADIAN JOURNAL OF INFECTIOUS DISEASES & MEDICAL MICROBIOLOGY 2011; 17:177-82. [PMID: 18418496 DOI: 10.1155/2006/818535] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/11/2005] [Accepted: 04/06/2006] [Indexed: 11/17/2022]
Abstract
BACKGROUND Linezolid is approved for the treatment of designated infections caused by methicillin-resistant and -susceptible Staphylococcus aureus and vancomycin-resistant Enterococcus faecium. OBJECTIVE To characterize linezolid utilization since its launch in Canada in 2001. METHODS Demographics, antimicrobial regimens, and clinical and resource utilization data for linezolid-treated patients were collected retrospectively by hospital pharmacists at nine tertiary care hospitals in four provinces. Statistics describing linezolid utilization were calculated and the appropriateness of use was assessed according to a treatment algorithm based on recommendations of the Infectious Diseases Pharmacy Specialty Network in 2001. RESULTS Ninety-nine linezolid courses were prescribed for 103 infections in 95 patients (mean age 57.8 years, 52.6% male) with an average length of hospital stay of 40.6 days. Fifty-three per cent of patients had an allergy to at least one antibiotic other than linezolid. The major use of linezolid was for treatment of skin and soft tissue infections (32.0%), followed by bacteremia (15.5%). The most prevalent pathogen was methicillin-resistant S aureus, identified in 44.7% of infections. Linezolid was primarily prescribed as the oral form following other intravenous anti-infectives (55.6% of courses) for an average duration of 14.4 days. The rate of appropriate utilization was 53% (range 25% to 75% by site). In 93.5% of courses deemed inappropriate, recommended first-line therapies were not attempted before linezolid. CONCLUSIONS Linezolid was prescribed appropriately in approximately one-half of cases reviewed. The rate of appropriate utilization is similar to those rates reported in other Canadian antibiotic reviews.
Collapse
|
15
|
Darehkordi A, Javanmiri M, Ghazi S, Assar S. Synthesis of N-aryl-2,2,2-trifluoroacetimidoyl piperazinylquinolone derivatives and their antibacterial evaluations. J Fluor Chem 2011. [DOI: 10.1016/j.jfluchem.2011.02.002] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
|
16
|
Abstract
The elucidation of the precise molecular structure and dynamics of biological processes is the great work of biochemistry. From this, insights into the changes leading to process dysfunction or disease are derived, as well as the possible approaches to restore healthy function. Translating this information into effective and safe treatments for disease requires a coordinated interdisciplinary effort, a fusion of creativity and practicality, and a healthy dose of luck. Using several reviews in this volume as springboards, I discuss the broader issues of drug development, highlighting some recent successes and future directions. Such occurrences inspire awe but remain too rare for comfort.
Collapse
|
17
|
Brickner SJ, Barbachyn MR, Hutchinson DK, Manninen PR. Linezolid (ZYVOX), the first member of a completely new class of antibacterial agents for treatment of serious gram-positive infections. J Med Chem 2008; 51:1981-90. [PMID: 18338841 DOI: 10.1021/jm800038g] [Citation(s) in RCA: 141] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Steven J Brickner
- Pfizer Global Research and Development, Groton, Connecticut 06340, USA.
| | | | | | | |
Collapse
|
18
|
Burchard GD, Einsele H, Hebart H, Heinz WJ, Herrmann M, Hörauf A, Mertens T, von Müller L, Zimmerli W. Antimikrobielle Therapie. KLINISCHE INFEKTIOLOGIE 2008. [PMCID: PMC7158361 DOI: 10.1016/b978-343721741-8.50008-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
|
19
|
Cipolla L, Fernandes MR, Gregori M, Airoldi C, Nicotra F. Synthesis and biological evaluation of a small library of nojirimycin-derived bicyclic iminosugars. Carbohydr Res 2007; 342:1813-30. [PMID: 17477911 DOI: 10.1016/j.carres.2007.04.002] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2007] [Revised: 04/04/2007] [Accepted: 04/09/2007] [Indexed: 10/23/2022]
Abstract
Novel nojirimycin-derived bicyclic structures, containing cyclic carbamate, urea and guanidine moieties have been synthesised starting from suitably protected alpha-C-vinylnojirimycin and alpha-C-allylnojirimycin, respectively, and their biological activity against different glycosidases and as antibacterial agents tested.
Collapse
Affiliation(s)
- Laura Cipolla
- Department of Biotechnology and Biosciences, University of Milano-Bicocca, P.za della Scienza 2, 20126 Milano, Italy.
| | | | | | | | | |
Collapse
|
20
|
Abstract
The emergence of mutations in nucleic acids is one of the major factors underlying evolution, providing the working material for natural selection. Most bacteria are haploid for the vast majority of their genes and, coupled with typically short generation times, this allows mutations to emerge and accumulate rapidly, and to effect significant phenotypic changes in what is perceived to be real-time. Not least among these phenotypic changes are those associated with antibiotic resistance. Mechanisms of horizontal gene spread among bacterial strains or species are often considered to be the main mediators of antibiotic resistance. However, mutational resistance has been invaluable in studies of bacterial genetics, and also has primary clinical importance in certain bacterial species, such as Mycobacterium tuberculosis and Helicobacter pylori, or when considering resistance to particular antibiotics, especially to synthetic agents such as fluoroquinolones and oxazolidinones. In addition, mutation is essential for the continued evolution of acquired resistance genes and has, e.g., given rise to over 100 variants of the TEM family of beta-lactamases. Hypermutator strains of bacteria, which have mutations in genes affecting DNA repair and replication fidelity, have elevated mutation rates. Mutational resistance emerges de novo more readily in these hypermutable strains, and they also provide a suitable host background for the evolution of acquired resistance genes in vitro. In the clinical setting, hypermutator strains of Pseudomonas aeruginosa have been isolated from the lungs of cystic fibrosis patients, but a more general role for hypermutators in the emergence of clinically relevant antibiotic resistance in a wider variety of bacterial pathogens has not yet been proven.
Collapse
Affiliation(s)
- N Woodford
- Antibiotic Resistance Monitoring and Reference Laboratory, Centre for Infections, Health Protection Agency, London, UK.
| | | |
Collapse
|
21
|
Sriharsha SN, Satish S, Shashikanth S, Raveesha KA. Design, synthesis and antibacterial activity of novel 1,3-thiazolidine pyrimidine nucleoside analogues. Bioorg Med Chem 2006; 14:7476-81. [PMID: 16890445 DOI: 10.1016/j.bmc.2006.07.014] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2006] [Revised: 07/03/2006] [Accepted: 07/07/2006] [Indexed: 10/24/2022]
Abstract
The synthesis of a new class of 1,3-thiazolidine nucleoside analogues in which furanose oxygen atom was replaced with nitrogen atom and 2'-carbon atom with sulfur atom is described. N-tert-butoxycarbonyl-2-acyloxy-4-trityloxymethyl-1,3-thiazolidine was coupled with the pyrimidine bases like uracil, thymine, etc. in the presence of lewis acids stannic chloride or trimethyl silyl triflate following Vorbruggen procedure. The antibacterial activity of the novel 1,3-thiazolidine pyrimidine nucleoside analogues is highlighted. All compounds (7a-e) with free NH group in the pyrimidine moiety showed significant biological activity against all the standard strains used and in that compounds 7d and 7e showed significant activity against 14 human pathogens tested.
Collapse
|
22
|
Naruganahalli KS, Shirumalla RK, Bansal V, Gupta JB, Das B, Ray A. Ranbezolid, a novel oxazolidinone antibacterial: In vivo characterisation of monoamine oxidase inhibitory potential in conscious rats. Eur J Pharmacol 2006; 545:167-72. [PMID: 16899241 DOI: 10.1016/j.ejphar.2006.06.065] [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] [Received: 02/15/2006] [Revised: 06/20/2006] [Accepted: 06/27/2006] [Indexed: 11/22/2022]
Abstract
Ranbezolid, a novel oxazolidinone antibacterial, competitively inhibits monoamine oxidase-A (MAO-A), in vitro. The consequences of MAO-A inhibition was evaluated in vivo, by testing interaction of Ranbezolid with tyramine (in solution or mixed with feed), and amine containing cold remedies on pressor response in conscious rats. Single and repeat doses of Ranbezolid (50 mg/kg, p.o.) did not affect pressor response to tyramine (5 or 15 mg/kg), but potentiated the same after a single dose of 100 mg/kg. Co-administration of Ranbezolid with tyramine in feed or with cold remedies also did not potentiate the respective pressor responses. These results suggest that Ranbezolid exhibits minimal cardiovascular liability associated with MAO-A inhibition.
Collapse
Affiliation(s)
- Krishna S Naruganahalli
- Department of Pharmacology, Ranbaxy Research Laboratories, Plot-20, Sector-18, Gurgaon 122001, India
| | | | | | | | | | | |
Collapse
|
23
|
|
24
|
Chopra I. Protein synthesis as a target for antibacterial drugs: current status and future opportunities. Expert Opin Investig Drugs 2005; 7:1237-44. [PMID: 15992027 DOI: 10.1517/13543784.7.8.1237] [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
The discovery and development of clinically useful antibiotic classes, such as the aminoglycosides, macrolides and tetracyclines, have clearly demonstrated that bacterial protein synthesis is a suitable target for drug intervention. New information on the binding of classical protein synthesis inhibitors to ribosomal RNA provides a rational explanation for their selective action against bacteria and also explains why chromosomal point mutations conferring resistance by structural changes at the target site are relatively rare in the majority of bacteria. These principles will be helpful when considering strategies for the screening or design of novel protein synthesis inhibitors that could be developed as new antibiotics. Recent progress in the discovery and development of bacterial protein synthesis inhibitors is illustrated by consideration of the glycylcyclines, ketolides, oxazolidinones and streptogramins.
Collapse
Affiliation(s)
- I Chopra
- Antimicrobial Research Centre and Department of Microbiology, University of Leeds, Leeds, LS2 9JT, UK
| |
Collapse
|
25
|
Ammazzalorso A, Amoroso R, Bettoni G, Fantacuzzi M, De Filippis B, Giampietro L, Maccallini C, Paludi D, Tricca ML. Synthesis and antibacterial evaluation of oxazolidin-2-ones structurally related to linezolid. ACTA ACUST UNITED AC 2004; 59:685-90. [PMID: 15337433 DOI: 10.1016/j.farmac.2004.05.002] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2004] [Accepted: 05/07/2004] [Indexed: 11/16/2022]
Abstract
Compounds structurally related to the known antimicrobial drug linezolid were selected in order to evaluate the influence of electron-withdrawing properties and altered geometric features as a result of the N-substituent modification. After a preliminary study of molecular modeling, cinnamoyl-, pyridin- and pyrimidinoxazolidin-2-ones were synthesized. None of the new compounds showed antibacterial activity.
Collapse
|
26
|
Rosner AJ, Becker DL, Wong AH, Miller E, Conly JM. The costs and consequences of methicillin-resistant Staphylococcus aureus infection treatments in Canada. THE CANADIAN JOURNAL OF INFECTIOUS DISEASES & MEDICAL MICROBIOLOGY = JOURNAL CANADIEN DES MALADIES INFECTIEUSES ET DE LA MICROBIOLOGIE MEDICALE 2004; 15:213-20. [PMID: 18159495 PMCID: PMC2094976 DOI: 10.1155/2004/383461] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/30/2003] [Accepted: 06/12/2004] [Indexed: 11/17/2022]
Abstract
BACKGROUND A multinational randomized controlled trial has shown a trend toward early discharge of patients taking oral linezolid versus intravenous vancomycin (IV) in the treatment of methicillinresistant Staphylococcus aureus (MRSA) infections. Infection treatments resulting in shorter hospitalization durations are associated with cost savings from the hospital perspective. OBJECTIVE To determine whether similar economic advantages are associated with oral linezolid, the costs and consequences of linezolid use following vancomycin IV versus the existing practice in the treatment of infections caused by MRSA were compared. METHODS The charts of all patients admitted to one of three tertiary care teaching hospitals between January 1, 1997 and August 31, 2000 and treated with vancomycin IV for an active MRSA infection (skin and soft tissue only) were reviewed. Based on the vancomycin IV chart review data set and a simulated linezolid data set, the clinical consequences and the associated costs of MRSA treatment with vancomycin IV, and oral and IV forms of linezolid were quantified and compared within the framework of a cost-consequence analysis. RESULTS Patients treated with oral and IV forms of linezolid compared with the existing practice had a shorter length of stay and required fewer home IV care services, which resulted in a cost savings of $750 (2001 values) to the Canadian health care perspective. CONCLUSIONS The estimated cost savings associated with linezolid use not only offset the higher acquisition cost of the anti-infective, but may be substantial to health care systems across Canada, especially as the incidence of MRSA continues to rise.
Collapse
Affiliation(s)
- Andrew J Rosner
- Health Economics and Outcomes Research, Innovus Research Inc, Burlington
| | | | | | | | | |
Collapse
|
27
|
Muller-Serieys C, Drugeon HB, Etienne J, Lascols C, Leclercq R, Nguyen J, Soussy CJ. Activity of linezolid against Gram-positive cocci isolated in French hospitals as determined by three in-vitro susceptibility testing methods. Clin Microbiol Infect 2004; 10:242-6. [PMID: 15008946 DOI: 10.1111/j.1198-743x.2004.00751.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
In total, 844 strains of Gram-positive cocci were collected from six university hospitals in France between September 1999 and January 2000. MICs of linezolid were determined: (i) for all strains by agar dilution (method A); (ii) by broth microdilution (method B) for staphylococci and enterococci; (iii) by Etest (method E) for beta-haemolytic streptococci and Streptococcus pneumoniae. Susceptibility to other antibiotics was determined by the disk diffusion method. MIC50 and MIC90 values were identical (2 mg/L) for methicillin-susceptible Staphylococcus aureus (n = 179) by methods A and B. Linezolid was active against methicillin-resistant S. aureus (n = 117), with an MIC90 of 2 mg/L (methods A and B), but with a lower MIC50 of 1 mg/L by method A. Of the 200 coagulase-negative staphylococci, 56.5% were methicillin-resistant and 43.5% were methicillin-susceptible. Linezolid had similar in-vitro activity by methods A and B (MIC50 and MIC90 values of 1-2 mg/L), irrespective of methicillin susceptibility. The MIC90 of linezolid for all enterococci (150 Enterococcus faecalis and 50 Enterococcus faecium) was 2 mg/L by both methods. MICs of linezolid for beta-haemolytic streptococci had a narrow range of 0.5-2 mg/L (method A) and 0.125-2 mg/L (method E). Pneumococci (n = 118), including 67 penicillin G-intermediate and -resistant strains, were all inhibited by linezolid 2 mg/L (MIC90 of 2 mg/L by methods A and E). No strain had an MIC of > 2 mg/L by agar dilution or Etest, or of > 4 mg/L by broth microdilution. Overall, the study confirmed the good in-vitro activity of linezolid and the very narrow range of MICs for Gram-positive cocci susceptible or resistant to other antibiotics, irrespective of the method used.
Collapse
Affiliation(s)
- C Muller-Serieys
- Laboratoire de Bactériologie, Groupe Hospitalier Bichat-Claide Bernard, Paris, France.
| | | | | | | | | | | | | |
Collapse
|
28
|
Gordeev MF, Hackbarth C, Barbachyn MR, Banitt LS, Gage JR, Luehr GW, Gomez M, Trias J, Morin SE, Zurenko GE, Parker CN, Evans JM, White RJ, Patel DV. Novel oxazolidinone–quinolone hybrid antimicrobials. Bioorg Med Chem Lett 2003; 13:4213-6. [PMID: 14623004 DOI: 10.1016/j.bmcl.2003.07.021] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Antimicrobial compounds incorporating oxazolidinone and quinolone pharmacophore substructures have been synthesized and evaluated. Representative analogues 2, 5, and 6 display an improved potency versus linezolid against gram-positive and fastidious gram-negative pathogens. The compounds are also active against linezolid- and ciprofloxacin-resistant Staphylococcus aureus and Enterococcus faecium strains. The MOA for these new antimicrobials is consistent with a combination of protein synthesis and gyrase A/topoisomerase IV inhibition, with a structure-dependent degree of the contribution from each inhibitory mechanism.
Collapse
Affiliation(s)
- Mikhail F Gordeev
- Vicuron Pharmaceuticals Inc., 34790 Ardentech Ct., Fremont, CA 94555, USA.
| | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
29
|
Johnson PD, Aristoff PA, Zurenko GE, Schaadt RD, Yagi BH, Ford CW, Hamel JC, Stapert D, Moerman JK. Synthesis and biological evaluation of benzazepine oxazolidinone antibacterials. Bioorg Med Chem Lett 2003; 13:4197-200. [PMID: 14623000 DOI: 10.1016/j.bmcl.2003.07.017] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Novel benzazepine oxazolidinone antibacterials were synthesized and evaluated against clinically relevant susceptible and resistant organisms. The effect of ring nitrogen position and N-substitution on antibacterial activity is examined.
Collapse
Affiliation(s)
- Paul D Johnson
- Discovery-Chemistry, Pharmacia Corporation, 7000 Portage Road, Kalamazoo, MI 49001, USA.
| | | | | | | | | | | | | | | | | |
Collapse
|
30
|
Abstract
Many common gram-positive pathogens (eg, Staphylococcus aureus, Enterococcus spp, and Streptococcus pneumoniae) have become increasingly resistant to antimicrobial agents, and new drugs with activity against gram-positive bacteria are urgently needed. The oxazolidinones, a new chemical class of synthetic antimicrobial agent, have a unique mechanism of inhibiting bacterial protein synthesis. Linezolid, the first oxazolidinone to be approved for clinical use, displays in-vitro activity (generally bacteriostatic) against many important resistant pathogens, including meticillin-resistant Staph aureus, vancomycin-resistant enterococci, and penicillin-resistant Strep pneumoniae. Linezolid is a parenteral agent that also possesses near-complete oral bioavailability plus favourable pharmacokinetic and toxic effect profiles. Clinical trials confirm the activity of linezolid in the setting of pneumonia, skin and soft-tissue infections, and infections due to vancomycin-resistant enterococci. Linezolid shows promise as an alternative to glycopeptides and streptogramins to treat serious infections due to resistant gram-positive organisms. New agents with greater potency and new spectra of activity could arise from further modification of the oxazolidinone nucleus.
Collapse
Affiliation(s)
- D J Diekema
- Division of Infectious Diseases, Department of Internal Medicine, University of Iowa College of Medicine, Iowa City, Iowa 52242, USA.
| | | |
Collapse
|
31
|
Humphrey SJ, Curry JT, Turman CN, Stryd RP. Cardiovascular sympathomimetic amine interactions in rats treated with monoamine oxidase inhibitors and the novel oxazolidinone antibiotic linezolid. J Cardiovasc Pharmacol 2001; 37:548-63. [PMID: 11336106 DOI: 10.1097/00005344-200105000-00007] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Linezolid (PNU-100766) is a new gram-positive oxazolidinone antibiotic that is effective at in vitro concentrations < or =4 microg/ml and in vivo doses < or =10 mg/kg. Because linezolid also competitively inhibits human monoamine oxidase-A (MAO-A; Ki = 55 microM), we monitored its effects on the cardiovascular responses to tyramine and amine cold remedies in comparison with standard MAO inhibitors. In anesthetized rats, the pressor response to 16 microg i.v. tyramine was potentiated by the MAO-A inhibitors clorgyline (0.1-1.0 mg/kg i.v.) and moclobemide (5.0-50 mg/kg p.o.), but not by the MAO-B inhibitor selegiline (0.15-15 mg/kg p.o.). Fifteen milligrams per kilogram intravenous linezolid weakly potentiated i.v. tyramine independent of changes in alpha-adrenoceptor reactivity, but this effect was not enhanced chronically (90-100 mg/kg/day). In conscious rats, 30 mg/kg/day oral linezolid (8 microg/ml plasma concentration) minimally affected the pressor response to 20 mg/kg oral tyramine, whereas 100 mg/kg/day linezolid (20 microg/ml plasma concentration) moderately potentiated this response similar to 3 mg/kg per day moclobemide. Linezolid's tyramine potentiation was reversible, attenuated by food, and independent of pseudoephedrine, phenylpropanolamine, and dextromethorphan interactions. These studies demonstrate that high-dose linezolid only moderately potentiates the cardiovascular effects of tyramine and validate these models for evaluating such MAO inhibitory interactions.
Collapse
Affiliation(s)
- S J Humphrey
- Pharmacology and Drug Metabolism Research, Pharmacia Corporation, Kalamazoo, Michigan 49007-4940, USA.
| | | | | | | |
Collapse
|
32
|
Li Z, Willke RJ, Pinto LA, Rittenhouse BE, Rybak MJ, Pleil AM, Crouch CW, Hafkin B, Glick HA. Comparison of length of hospital stay for patients with known or suspected methicillin-resistant Staphylococcus species infections treated with linezolid or vancomycin: a randomized, multicenter trial. Pharmacotherapy 2001; 21:263-74. [PMID: 11256381 DOI: 10.1592/phco.21.3.263.34198] [Citation(s) in RCA: 99] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
STUDY OBJECTIVE To compare hospital length of stay (LOS), weekly discharges, and days of antibiotic treatment with linezolid (intravenous with oral follow-up) and vancomycin (intravenous only). DESIGN Multinational, randomized, phase III trial. SETTINGS Hospitals in North America, Latin America, and Europe. PATIENTS Four hundred sixty hospitalized patients with infections of known or suspected methicillin-resistant Staphylococcus species. INTERVENTION Administration of linezolid or vancomycin. MEASUREMENTS AND MAIN RESULTS For linezolid recipients, median LOS was 5 and 8 days shorter (p=0.05 and 0.003) in the complicated skin and soft tissue infection intent-to-treat (230 patients) and clinically evaluable (144) samples, and slightly but not significantly shorter in the overall intent-to-treat (460) and clinically evaluable (254) samples. In all samples, linezolid recipients had more discharges in the first week of treatment and fewer days of intravenous therapy than vancomycin recipients. CONCLUSION Our results support linezolid's ability to reduce medical resource use.
Collapse
Affiliation(s)
- Z Li
- Global Outcomes Research, Pharmacia Corporation, Peapack, New Jersey, USA
| | | | | | | | | | | | | | | | | |
Collapse
|
33
|
Abstract
Many attempts have been made to prepare analogs of 4-quinolone antibacterial agents bearing novel ring systems, which might retain the favorable properties of these widely used antibacterial agents and at the same time increase activity against multidrug-resistant bacteria, streptococci, and anaerobic microorganisms. One such attempt involved bioisosteric exchange of the 1-N atom and 4a-C atom of naphthyridones, quinolones, and benzoxazines to produce a family of highly active pyridopyrimidines, quinolizines, and ofloxacin bioisosteres. These new antibacterial agents have been named collectively as the 2-pyridones. Many hundreds of 2-pyridones have been synthesized and evaluated in vitro and in vivo, and selected members are advancing toward human clinical trials. Preparation of these bioisosteres required the development of enabling chemistry, as previous methods were unsuccessful in producing the needed core structures. This review compares the structure-activity relationships of these agents with known trends among 4-quinolones, from which it is seen that there are many parallels, but also some significant departures as well. Generally, 2-pyridones are more highly active in vitro and in vivo and more water soluble than comparable 4-quinolones. These properties are posited to arise from electronic and conformational alternations in these new substances. Selected members show excellent pharmacodynamic properties, justifying the view that this is a very promising new class of totally synthetic antibacterial agents.
Collapse
Affiliation(s)
- Q Li
- Pharmaceutical Products Division, Abbott Laboratories, 100 Abbott Park Road, Abbott Park, IL 60064-6101, USA.
| | | | | |
Collapse
|
34
|
Johnson AP, Warner M, Livermore DM. Activity of linezolid against multi-resistant gram-positive bacteria from diverse hospitals in the United Kingdom. J Antimicrob Chemother 2000; 45:225-30. [PMID: 10660506 DOI: 10.1093/jac/45.2.225] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
The in vitro activity of linezolid, an oxazolidinone, was assessed against 374 gram-positive cocci, with an emphasis on testing multi-resistant, epidemiologically unrelated isolates. MICs of linezolid for staphylococci, pneumococci and streptococci had a narrow range, from 0.5 to 2 mg/L, whereas MICs for enterococci were uniformly 4 mg/L. For all the species tested, the MICs of linezolid were unrelated to those of other antimicrobials. Linezolid appears to be a potentially useful drug for infections caused by gram-positive cocci.
Collapse
Affiliation(s)
- A P Johnson
- Antibiotic Resistance Monitoring and Reference Laboratory, Central Public Health Laboratory, Colindale, London NW9 5HT, UK.
| | | | | |
Collapse
|
35
|
Abstract
The oxazolidinones represent a novel chemical class of synthetic antimicrobial agents. They exhibit an unique mechanism of protein synthesis inhibition and generally display bacteriostatic activity against many important human pathogens, including methicillin-resistant Staphylococcus aureus, vancomycin-resistant enterococci, and penicillin- and cephalosporin-resistant Streptococcus pneumoniae. Linezolid, the oxazolidinone which has been selected for clinical development, has near complete oral bioavailability plus favourable pharmacokinetic and toxicity profiles. Results from experimental models of infection and phase II trials reveal linezolid to be highly active in vivo against infections due to many common gram-positive pathogens. The role of linezolid remains to be determined in phase III clinical trials, but it shows great promise as an alternative to glycopeptides and streptogramins to treat serious infections due to resistant gram-positive organisms. Further modification of the oxazolidinone nucleus may yield agents with even greater potency and with novel spectra of activity.
Collapse
Affiliation(s)
- D I Diekema
- Department of Pathology, University of Iowa College of Medicine, Iowa City 52242, USA.
| | | |
Collapse
|
36
|
Chapter 12. Progress in the oxazolidinone antibacterials. ANNUAL REPORTS IN MEDICINAL CHEMISTRY 2000. [DOI: 10.1016/s0065-7743(00)35013-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register]
|
37
|
Embil JM, Nicolle LE. Antimicrobial Agents. Phys Med Rehabil Clin N Am 1999. [DOI: 10.1016/s1047-9651(18)30203-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
|
38
|
Edlund C, Oh H, Nord CE. In vitro activity of linezolid and eperezolid against anaerobic bacteria. Clin Microbiol Infect 1999; 5:51-53. [PMID: 11856214 DOI: 10.1111/j.1469-0691.1999.tb00099.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Affiliation(s)
- Charlotta Edlund
- Department of Immunology, Microbiology, Pathology and Infectious Diseases, Huddinge University Hospital, S-141 86 Huddinge
| | | | | |
Collapse
|
39
|
Abstract
Several new antibacterial agents are currently being developed in response to the emergence of bacterial resistance to existing drugs. The new agents include compounds that inhibit macromolecular synthesis or interfere with bacterial membrane function. Apart from the oxazolidinones and cationic peptides, the remainder of these new compounds are analogues of earlier antibiotic classes; therefore, it is probable that existing resistance mechanisms will adapt to accommodate the new derivatives. To minimise the potential for emergence of resistance to new agents, research strategies should be chosen that not only enhance the discovery of structurally novel drugs, but also direct these to new molecular targets that may themselves have decreased potential to give rise to drug-resistant variants.
Collapse
Affiliation(s)
- I Chopra
- Antimicrobial Research Centre Department of Microbiology, University of Leeds, Leeds LS2 9JT UK.
| |
Collapse
|
40
|
Abstract
The resistance of bacteria to antibiotics, particularly those used for first-line therapy, is an increasing cause for concern. In the UK, the prevalence of resistance to methicillin and mupirocin in Staphylococcus aureus, and to penicillin and macrolides in Streptococcus pneumoniae, appear to be increasing. There has also been an increase in the number of hospitals where glycopeptide-resistant enterococci are known to have been isolated. The increases in methicillin-resistant S. aureus and glycopeptide-resistant enterococci are due, in part, to the inter-hospital spread of epidemic strains. Although new quinolones and streptogramins with activity against Gram-positive bacteria (including strains resistant to currently available agents) are under development, there is no reason to believe that resistance to these agents will not emerge. The control of resistance in Gram-positive bacteria will require a multi-faceted approach, including continued and improved surveillance, a reduction in the unnecessary use of antibiotics, and the application of other strategies such as vaccination.
Collapse
Affiliation(s)
- A P Johnson
- Antibiotic Reference Laboratory, Central Public Health Laboratory, Colindale, London, UK
| |
Collapse
|
41
|
Abstract
With the completion of numerous bacterial genome sequences, the discovery of antibacterial drugs has fully entered the genomic era. The strategies for effectively using genomic information for target identification, target characterization, screen development and compound evaluation are emerging, and have greatly increased the number of antibacterial targets available for screening. Fortunately, simultaneous efforts in improving miniaturization, robotics and database tools are underway so that the potential of genomics can be realized.
Collapse
Affiliation(s)
- M B Schmid
- Microcide Pharmaceuticals Inc, Mountain View, CA 94043, USA.
| |
Collapse
|
42
|
Burghardt H, Schimz KL, Müller M. On the target of a novel class of antibiotics, oxazolidinones, active against multidrug-resistant Gram-positive bacteria. FEBS Lett 1998; 425:40-4. [PMID: 9541003 DOI: 10.1016/s0014-5793(98)00194-x] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Oxazolidinones are a promising new class of synthetic antibiotics active against multidrug-resistant Gram-positive bacteria. To elucidate their mode of action, the effect of DuP 721 on individual steps of protein translation was studied. The drug does not interfere with translation initiation at the stage of mRNA binding or formation of 30S pre-initiation complexes. However, it inhibits the puromycin-mediated release of [35S]formyl-methionine from 70S initiation complexes in a dose-dependent manner. Inhibition involves binding of the oxazolidinone to the large ribosomal subunit and is twice as high with 50S subunits from Gram-positive as with those from Gram-negative bacteria.
Collapse
Affiliation(s)
- H Burghardt
- Adolf Butenandt Institut für Physikalische Biochemie, Ludwig-Maximilians-Universität München, Munich, Germany
| | | | | |
Collapse
|
43
|
Chambers HF. Methicillin resistance in staphylococci: molecular and biochemical basis and clinical implications. Clin Microbiol Rev 1997; 10:781-91. [PMID: 9336672 PMCID: PMC172944 DOI: 10.1128/cmr.10.4.781] [Citation(s) in RCA: 607] [Impact Index Per Article: 22.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Methicillin resistance in staphylococci is determined by mec, composed of 50 kb or more of DNA found only in methicillin-resistant strains. mec contains mecA, the gene for penicillin-binding protein 2a (PBP 2a); mecI and mecR1, regulatory genes controlling mecA expression; and numerous other elements and resistance determinants. A distinctive feature of methicillin resistance is its heterogeneous expression. Borderline resistance, a low-level type of resistance to methicillin exhibited by strains lacking mecA, is associated with modifications in native PBPs, beta-lactamase hyperproduction, or possibly a methicillinase. The resistance phenotype is influenced by numerous factors, including mec and beta-lactamase (bla) regulatory elements, fem factors, and yet to be identified chromosomal loci. The heterogeneous nature of methicillin resistance confounds susceptibility testing. Methodologies based on the detection of mecA are the most accurate. Vancomycin is the drug of choice for treatment of infection caused by methicillin-resistant strains. PBP 2a confers cross-resistance to most currently available beta-lactam antibiotics. Investigational agents that bind PBP 2a at low concentrations appear promising but have not been tested in humans. Alternatives to vancomycin are few due to the multiple drug resistances typical of methicillin-resistant staphylococci.
Collapse
Affiliation(s)
- H F Chambers
- Medical Service, San Francisco General Hospital 94143, USA.
| |
Collapse
|
44
|
|