101
|
Hamed RB, Gomez-Castellanos JR, Henry L, Ducho C, McDonough MA, Schofield CJ. The enzymes of β-lactam biosynthesis. Nat Prod Rep 2013; 30:21-107. [DOI: 10.1039/c2np20065a] [Citation(s) in RCA: 146] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
|
102
|
Search for new tools to combat Gram-negative resistant bacteria among amine derivatives of 5-arylidenehydantoin. Bioorg Med Chem 2013; 21:135-45. [DOI: 10.1016/j.bmc.2012.10.053] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2012] [Revised: 10/30/2012] [Accepted: 10/31/2012] [Indexed: 11/23/2022]
|
103
|
Simčič M, Sosič I, Hodošček M, Barreteau H, Blanot D, Gobec S, Grdadolnik SG. The binding mode of second-generation sulfonamide inhibitors of MurD: clues for rational design of potent MurD inhibitors. PLoS One 2012; 7:e52817. [PMID: 23285193 PMCID: PMC3527612 DOI: 10.1371/journal.pone.0052817] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2012] [Accepted: 11/23/2012] [Indexed: 11/19/2022] Open
Abstract
A series of optimized sulfonamide derivatives was recently reported as novel inhibitors of UDP-N-acetylmuramoyl-L-alanine:D-glutamate ligase (MurD). These are based on naphthalene-N-sulfonyl-D-glutamic acid and have the D-glutamic acid replaced with rigidified mimetics. Here we have defined the binding site of these novel ligands to MurD using (1)H/(13)C heteronuclear single quantum correlation. The MurD protein was selectively (13)C-labeled on the methyl groups of Ile (δ1 only), Leu and Val, and was isolated and purified. Crucial Ile, Leu and Val methyl groups in the vicinity of the ligand binding site were identified by comparison of chemical shift perturbation patterns among the ligands with various structural elements and known binding modes. The conformational and dynamic properties of the bound ligands and their binding interactions were examined using the transferred nuclear Overhauser effect and saturation transfer difference. In addition, the binding mode of these novel inhibitors was thoroughly examined using unrestrained molecular dynamics simulations. Our results reveal the complex dynamic behavior of ligand-MurD complexes and its influence on ligand-enzyme contacts. We further present important findings for the rational design of potent Mur ligase inhibitors.
Collapse
Affiliation(s)
- Mihael Simčič
- EN-FIST Centre of Excellence, Ljubljana, Slovenia
- Laboratory of Biomolecular Structure, National Institute of Chemistry, Ljubljana, Slovenia
| | - Izidor Sosič
- Faculty of Pharmacy, University of Ljubljana, Ljubljana, Slovenia
| | - Milan Hodošček
- Laboratory of Molecular Modeling, National Institute of Chemistry, Ljubljana, Slovenia
| | - Hélène Barreteau
- Laboratoire des Enveloppes Bactériennes et Antibiotiques, Université Paris-Sud, Orsay, France
| | - Didier Blanot
- Laboratoire des Enveloppes Bactériennes et Antibiotiques, Université Paris-Sud, Orsay, France
- Centre National de la Recherche Scientifique, Orsay, France
| | - Stanislav Gobec
- Faculty of Pharmacy, University of Ljubljana, Ljubljana, Slovenia
| | - Simona Golič Grdadolnik
- EN-FIST Centre of Excellence, Ljubljana, Slovenia
- Laboratory of Biomolecular Structure, National Institute of Chemistry, Ljubljana, Slovenia
- * E-mail:
| |
Collapse
|
104
|
Collu F, Vargiu AV, Dreier J, Cascella M, Ruggerone P. Recognition of imipenem and meropenem by the RND-transporter MexB studied by computer simulations. J Am Chem Soc 2012; 134:19146-58. [PMID: 23146101 DOI: 10.1021/ja307803m] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Basic understanding of the means by which multidrug efflux systems can efficiently recognize and transport drugs constitutes a fundamental step toward development of compounds able to tackle the continuous outbreak of new bacterial strains resistant to traditional antibiotics. We applied a series of computational techniques, from molecular docking to molecular dynamics simulations and free energy estimate methods, to determine the differences in the binding properties of imipenem and meropenem, two potent antibiotics of the carbapenem family, to MexB, the RND transporter of the major efflux system of Pseudomonas aeruginosa. We identified and characterized two affinity sites in the periplasmic domain of the transporter, sharing strong similarities with the distal and proximal binding pockets identified in AcrB, the homologue of MexB in Escherichia coli. According to our results, meropenem has a higher affinity to the distal binding pocket than imipenem while both compounds are weakly bound to the proximal pocket. This different behavior is mainly due to the hydration properties of the nonpharmacophore part of the two compounds, being that of imipenem less bulky and hydrophobic. Our data provide for the first time a rationale at molecular level for the experimental evidence indicating meropenem as a compound strongly affected by MexB contrary to imipenem, which is apparently poorly transported by the same pump.
Collapse
Affiliation(s)
- Francesca Collu
- Departement für Chemie und Biochemie, Universität Bern, Freiestrasse 3, CH-3012 Bern, Switzerland
| | | | | | | | | |
Collapse
|
105
|
The target of daptomycin is absent from Escherichia coli and other gram-negative pathogens. Antimicrob Agents Chemother 2012; 57:637-9. [PMID: 23114759 DOI: 10.1128/aac.02005-12] [Citation(s) in RCA: 84] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Antistaphylococcal agents commonly lack activity against Gram-negative bacteria like Escherichia coli owing to the permeability barrier presented by the outer membrane and/or the action of efflux transporters. When these intrinsic resistance mechanisms are artificially compromised, such agents almost invariably demonstrate antibacterial activity against Gram negatives. Here we show that this is not the case for the antibiotic daptomycin, whose target appears to be absent from E. coli and other Gram-negative pathogens.
Collapse
|
106
|
Synthesis of new 3-aryl-4-(3-aryl-4,5-dihydro-1H-pyrazol-5-yl)-1-phenyl-1H-pyrazole derivatives as potential antimicrobial agents. Med Chem Res 2012. [DOI: 10.1007/s00044-012-0267-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
|
107
|
Sun D, Hurdle JG, Lee R, Lee R, Cushman M, Pezzuto JM. Evaluation of flavonoid and resveratrol chemical libraries reveals abyssinone II as a promising antibacterial lead. ChemMedChem 2012; 7:1541-5. [PMID: 22847956 PMCID: PMC3516920 DOI: 10.1002/cmdc.201200253] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2012] [Indexed: 11/12/2022]
Abstract
Lead on! In the course of screening flavonoid and resveratrol libraries, abyssinone II, a naturally occurring prenylated flavonoid, was found to exhibit relatively good antitubercular and antibacterial activity. Preliminary mechanistic studies revealed that abyssinone II hyperpolarizes the bacterial membrane potential and inhibits the biosynthesis of key cellular macromolecules (DNA, RNA, and protein).
Collapse
Affiliation(s)
- Dianqing Sun
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Hawai'i at Hilo, 34 Rainbow Drive, Hilo, HI 96720, USA.
| | | | | | | | | | | |
Collapse
|
108
|
Hong MK, Lee JJ, Wu X, Kim JK, Jeong BC, Pham TV, Kim SH, Lee SH, Kang LW. Crystallization and preliminary diffraction studies of SFC-1, a carbapenemase conferring antibiotic resistance. Acta Crystallogr Sect F Struct Biol Cryst Commun 2012; 68:1124-7. [PMID: 22949211 DOI: 10.1107/s1744309112033702] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2012] [Accepted: 07/26/2012] [Indexed: 11/10/2022]
Abstract
SFC-1, a class A carbapenemase that confers antibiotic resistance, hydrolyzes the β-lactam rings of β-lactam antibiotics (carbapenems, cephalosporins, penicillins and aztreonam). SFC-1 presents an enormous challenge to infection control, particularly in the eradication of Gram-negative pathogens. As SFC-1 exhibits a remarkably broad substrate range, including β-lactams of all classes, the enzyme is a potential target for the development of antimicrobial agents against pathogens producing carbapenemases. In this study, SFC-1 was cloned, overexpressed, purified and crystallized. The SFC-1 crystal diffracted to 1.6 Å resolution and belonged to the orthorhombic space group P2(1)2(1)2(1), with unit-cell parameters a = 65.8, b = 68.3, c = 88.8 Å. Two molecules are present in the asymmetric unit, with a corresponding V(M) of 1.99 Å(3) Da(-1) and a solvent content of 38.1%.
Collapse
Affiliation(s)
- Myoung-Ki Hong
- Department of Advanced Technology Fusion, Konkuk University, Hwayang-dong, Gwangjin-gu, Seoul 143-701, Republic of Korea
| | | | | | | | | | | | | | | | | |
Collapse
|
109
|
Shen Z, Lei H. Expression of hBD-2 induced by 23-valent pneumococcal polysaccharide vaccine, Haemophilus influenzae type b vaccine and split influenza virus vaccine. Mol Med Rep 2012; 6:733-8. [PMID: 22842707 DOI: 10.3892/mmr.2012.1005] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2012] [Accepted: 07/18/2012] [Indexed: 11/05/2022] Open
Abstract
Human β-defensin-2 (hBD-2) is an antimicrobial peptide with high activity and broad spectrum activity. hBD-2 expression may be highly elevated by microorganisms and inflammation. We reported that the majority of common vaccines used, including 23-valent pneumococcal polysaccharide vaccine, Haemophilus influenzae type b vaccine and split influenza virus vaccine, could induce the expression of hBD-2 in epithelial cells. Among them, the 23-valent pneumococcal polysaccharide vaccine was effective at a lower concentration (0.5 µg/ml), while Haemophilus influenzae type b vaccine and split influenza virus vaccine were effective at the concentration of 1 µg/ml. However, bacteriostatic experiments revealed that the split influenza virus vaccine was capable of inducing the highest antimicrobial activity. The medium of the 23-valent pneumococcal polysaccharide vaccine treatment group had a higher antimicrobial activity than the medium of the Haemophilus influenzae type b vaccine treatment group. The transcriptional regulator of hBD-2, that is, the NF-κB subunit, had a high level of activity, while the normal epithelial cells showed barely detectable activity, indicating that these vaccines have potential for clinical application.
Collapse
Affiliation(s)
- Zhenwei Shen
- Department of Intensive Care Unit, Eastern Hospital, Tongji University, Shanghai 200120, PR China
| | | |
Collapse
|
110
|
Luo Y, Zhang LR, Hu Y, Zhang S, Fu J, Wang XM, Zhu HL. Synthesis and Antimicrobial Activities of Oximes Derived from O-Benzylhydroxylamine as FabH Inhibitors. ChemMedChem 2012; 7:1587-93. [DOI: 10.1002/cmdc.201200225] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2012] [Revised: 06/12/2012] [Indexed: 11/07/2022]
|
111
|
McConnell MJ, Actis L, Pachón J. Acinetobacter baumannii: human infections, factors contributing to pathogenesis and animal models. FEMS Microbiol Rev 2012; 37:130-55. [PMID: 22568581 DOI: 10.1111/j.1574-6976.2012.00344.x] [Citation(s) in RCA: 358] [Impact Index Per Article: 29.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2011] [Revised: 04/30/2012] [Accepted: 05/03/2012] [Indexed: 11/30/2022] Open
Abstract
Acinetobacter baumannii has emerged as a medically important pathogen because of the increasing number of infections produced by this organism over the preceding three decades and the global spread of strains with resistance to multiple antibiotic classes. In spite of its clinical relevance, until recently, there have been few studies addressing the factors that contribute to the pathogenesis of this organism. The availability of complete genome sequences, molecular tools for manipulating the bacterial genome, and animal models of infection have begun to facilitate the identification of factors that play a role in A. baumannii persistence and infection. This review summarizes the characteristics of A. baumannii that contribute to its pathogenesis, with a focus on motility, adherence, biofilm formation, and iron acquisition. In addition, the virulence factors that have been identified to date, which include the outer membrane protein OmpA, phospholipases, membrane polysaccharide components, penicillin-binding proteins, and outer membrane vesicles, are discussed. Animal models systems that have been developed during the last 15 years for the study of A. baumannii infection are overviewed, and the recent use of these models to identify factors involved in virulence and pathogenesis is highlighted.
Collapse
Affiliation(s)
- Michael J McConnell
- Unit of Infectious Disease, Microbiology, and Preventive Medicine, Institute of Biomedicine of Sevilla (IBiS), University Hospital Virgen del Rocío/CSIC/University of Sevilla, Sevilla, Spain.
| | | | | |
Collapse
|
112
|
Antibacterial and antifungal activity of lawsone and novel naphthoquinone derivatives. Med Mal Infect 2012; 42:270-5. [PMID: 22682997 DOI: 10.1016/j.medmal.2012.05.002] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2011] [Revised: 01/03/2012] [Accepted: 05/01/2012] [Indexed: 10/25/2022]
Abstract
INTRODUCTION Naphthoquinone derivatives are under investigation as potential therapeutic agents. The antibacterial and antifungal activity of lawsone and of some novel naphthoquinone derivatives was assessed in vitro. METHODS The antimicrobial activity was determined using diffusion disk and the broth microdilution methods against seven bacteria and three Candida species, according to recommendations of the Clinical and Laboratory Standards Institute. RESULTS Two compounds (P05 et P06) presented a good antibacterial effectiveness against two gram-positive bacteria. No antifungal potency was observed against the three Candida albicans strains used in the test. CONCLUSION Our results prove that the introduction of substituents on ketone function position 4 decreased the antimicrobial properties of the synthetized compounds.
Collapse
|
113
|
Mingeot-Leclercq MP, Tulkens PM, Denamur S, Vaara T, Vaara M. Novel polymyxin derivatives are less cytotoxic than polymyxin B to renal proximal tubular cells. Peptides 2012; 35:248-52. [PMID: 22504013 DOI: 10.1016/j.peptides.2012.03.033] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/13/2012] [Revised: 03/29/2012] [Accepted: 03/30/2012] [Indexed: 11/25/2022]
Abstract
The emergence of very multiresistant Gram-negative bacterial strains has reinstated polymyxins (polymyxin B, colistin), pentacationic lipopeptides, in the therapy, in spite of their nephrotoxicity. Extensive tubular reabsorption concentrates polymyxin in proximal tubular cells. The novel polymyxin derivatives NAB739, NAB7061 and NAB741 have their cyclic part identical to that of polymyxin B, but their side chain consists of uncharged octanoyl-threonyl-d-serinyl, octanoyl-threonyl-aminobutyryl, and acetyl-threonyl-D-serinyl respectively. In this study, we compared the toxicities of NAB739, NAB7061 and NAB741 with that of polymyxin B by using the porcine renal proximal tubular cell line LLC-PK1 electroporated or incubated with the selected compound. Both the ability to cause cell necrosis (quantified as the leakage of lactate dehydrogenase) and the ability to cause apoptosis (as quantified by counting apoptotic nuclei) were assessed. In electroporated cells, polymyxin B induced total (>85%) necrosis of the cells at 0.016 mM, whereas an approx. 8-fold concentration of NAB739 and NAB7961 and an approx. 32-fold concentration of NAB741 was required for the same effect. In cells treated without electroporation (incubated), polymyxin B elicited a marked degree (approx. 50%) of necrosis at 0.5mM, whereas the NAB compounds were inert even at 1mM. Neither polymyxin B nor the NAB compounds induced apoptosis.
Collapse
Affiliation(s)
- Marie-Paule Mingeot-Leclercq
- Louvain Drug Research Institute, Pharmacologie Cellulaire et Moléculaire, Université Catholique de Louvain, Brussels, Belgium
| | | | | | | | | |
Collapse
|
114
|
Singh K, Kumar Y, Puri P, Kumar M, Sharma C. Cobalt, nickel, copper and zinc complexes with 1,3-diphenyl-1H-pyrazole-4-carboxaldehyde Schiff bases: Antimicrobial, spectroscopic, thermal and fluorescence studies. Eur J Med Chem 2012; 52:313-21. [DOI: 10.1016/j.ejmech.2012.02.053] [Citation(s) in RCA: 116] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2011] [Revised: 02/22/2012] [Accepted: 02/27/2012] [Indexed: 11/30/2022]
|
115
|
Synthesis and antimicrobial activity of coumarin pyrazole pyrimidine 2,4,6(1H,3H,5H)triones and thioxopyrimidine4,6(1H,5H)diones. Med Chem Res 2012. [DOI: 10.1007/s00044-012-0078-y] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
|
116
|
Ribosome clearance by FusB-type proteins mediates resistance to the antibiotic fusidic acid. Proc Natl Acad Sci U S A 2012; 109:2102-7. [PMID: 22308410 DOI: 10.1073/pnas.1117275109] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Resistance to the antibiotic fusidic acid (FA) in the human pathogen Staphylococcus aureus usually results from expression of FusB-type proteins (FusB or FusC). These proteins bind to elongation factor G (EF-G), the target of FA, and rescue translation from FA-mediated inhibition by an unknown mechanism. Here we show that the FusB family are two-domain metalloproteins, the C-terminal domain of which contains a four-cysteine zinc finger with a unique structural fold. This domain mediates a high-affinity interaction with the C-terminal domains of EF-G. By binding to EF-G on the ribosome, FusB-type proteins promote the dissociation of stalled ribosome⋅EF-G⋅GDP complexes that form in the presence of FA, thereby allowing the ribosomes to resume translation. Ribosome clearance by these proteins represents a highly unusual antibiotic resistance mechanism, which appears to be fine-tuned by the relative abundance of FusB-type protein, ribosomes, and EF-G.
Collapse
|
117
|
Medell M, Medell M, Martínez A, Valdés R. Characterization and sensitivity to antibiotics of bacteria isolated from the lower respiratory tract of ventilated patients hospitalized in intensive care units. Braz J Infect Dis 2012. [DOI: 10.1016/s1413-8670(12)70273-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022] Open
|
118
|
Piddock LJV. The crisis of no new antibiotics--what is the way forward? THE LANCET. INFECTIOUS DISEASES 2011; 12:249-53. [PMID: 22101066 DOI: 10.1016/s1473-3099(11)70316-4] [Citation(s) in RCA: 258] [Impact Index Per Article: 19.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Antibiotic use not only underpins modern medicine, but has brought huge changes to the world, especially in expectations of survival of children into adulthood. The theme of World Health Day, 2011, was "antimicrobial resistance: no action today and no cure tomorrow". The demise of antibacterial drug discovery brings the spectre of untreatable infections. To prevent this crisis immediate action is needed and a new initiative, Antibiotic Action, has been launched. By bringing together communities who need these drugs with academia, health-care professionals, and pharmaceutical companies, this initiative aims to strengthen and enhance academic-industrial partnerships, bring about revision of costly and laborious processes of licensing and regulation of new antibiotics, and address the economics of antimicrobial drugs (cost of use vs profit). A global alliance for antibiotic drug discovery and development would provide a platform for these initiatives.
Collapse
Affiliation(s)
- Laura J V Piddock
- Antimicrobial Agents Research Group, School of Immunity and Infection, College of Medical and Dental Sciences, University of Birmingham, Edgbaston, Birmingham, UK. aeron.hurt@infl uenzacentre.org
| |
Collapse
|
119
|
Synthesis, characterization and antimicrobial activity evaluation of new 2,4-Thiazolidinediones bearing imidazo[2,1-b][1,3,4]thiadiazole moiety. ARAB J CHEM 2011. [DOI: 10.1016/j.arabjc.2010.07.012] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
|
120
|
Handzlik J, Szymańska E, Chevalier J, Otrębska E, Kieć-Kononowicz K, Pagès JM, Alibert S. Amine-alkyl derivatives of hydantoin: new tool to combat resistant bacteria. Eur J Med Chem 2011; 46:5807-16. [PMID: 22000919 DOI: 10.1016/j.ejmech.2011.09.032] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2011] [Revised: 09/20/2011] [Accepted: 09/20/2011] [Indexed: 02/04/2023]
Abstract
A series of new 5,5-diphenylhydantoin derivatives with various amine-alkyl terminal fragments at N1-position were synthesized. Then a series of twenty-eight compounds with the same hydantoin scaffold were evaluated for their potency to combat bacterial MultiDrug Resistance (MDR). Intrinsic antibacterial activities were first evaluated. As these compounds showed no direct activity on bacteria, their influence on minimal inhibitory concentration (MIC) of nalidixic acid was tested in two strains of Enterobacter aerogenes: the reference-strain ATCC-13048 and the CM-64 strain which over-produces AcrAB-TolC efflux pump. The compounds showed moderate- or low- anti-MDR properties. According to SAR-studies, hit compounds containing 2-methoxyphenylpiperazine at N1-terminal fragment and methylcarboxyl acid one at N3-position of hydantoin have been identified for further microbiological studies and pharmacomodulations to develop efflux pump inhibitors.
Collapse
Affiliation(s)
- Jadwiga Handzlik
- Department of Technology and Biotechnology of Drugs, Jagiellonian University-Medical College, Medyczna 9, PL 30-688 Kraków, Poland
| | | | | | | | | | | | | |
Collapse
|
121
|
Zheng CJ, Jiang SM, Chen ZH, Ye BJ, Piao HR. Synthesis and Anti-Bacterial Activity of Some Heterocyclic Chalcone Derivatives Bearing Thiofuran, Furan, and Quinoline Moieties. Arch Pharm (Weinheim) 2011; 344:689-95. [DOI: 10.1002/ardp.201100005] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2011] [Revised: 03/10/2011] [Accepted: 04/06/2011] [Indexed: 11/05/2022]
|
122
|
Tomašić T, Kovač A, Simčič M, Blanot D, Grdadolnik SG, Gobec S, Kikelj D, Peterlin Mašič L. Novel 2-thioxothiazolidin-4-one inhibitors of bacterial MurD ligase targeting d-Glu- and diphosphate-binding sites. Eur J Med Chem 2011; 46:3964-75. [DOI: 10.1016/j.ejmech.2011.05.070] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2011] [Revised: 05/11/2011] [Accepted: 05/28/2011] [Indexed: 12/27/2022]
|
123
|
Kenneley IL. Stopping HAIs at their source. Nurse Pract 2011; 36:47-51. [PMID: 21857217 DOI: 10.1097/01.npr.0000403293.97339.64] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Healthcare-associated infections caused by multidrug-resistant organisms are a serious threat to public health. Changes in healthcare delivery have caused these infections to affect the community. NPs should be aware of the most prevalent multidrug-resistant organisms and effective methods to prevent the spread of infection.
Collapse
Affiliation(s)
- Irena L Kenneley
- Case Western Reserve University, Frances Payne Bolton School of Nursing, Cleveland, Ohio, USA
| |
Collapse
|
124
|
Nikaido H, Pagès JM. Broad-specificity efflux pumps and their role in multidrug resistance of Gram-negative bacteria. FEMS Microbiol Rev 2011; 36:340-63. [PMID: 21707670 DOI: 10.1111/j.1574-6976.2011.00290.x] [Citation(s) in RCA: 489] [Impact Index Per Article: 37.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Antibiotic resistance mechanisms reported in Gram-negative bacteria are causing a worldwide health problem. The continuous dissemination of 'multidrug-resistant' (MDR) bacteria drastically reduces the efficacy of our antibiotic 'arsenal' and consequently increases the frequency of therapeutic failure. In MDR bacteria, the overexpression of efflux pumps that expel structurally unrelated drugs contributes to the reduced susceptibility by decreasing the intracellular concentration of antibiotics. During the last decade, several clinical data have indicated an increasing involvement of efflux pumps in the emergence and dissemination of resistant Gram-negative bacteria. It is necessary to clearly define the molecular, functional and genetic bases of the efflux pump in order to understand the translocation of antibiotic molecules through the efflux transporter. The recent investigation on the efflux pump AcrB at its structural and physiological levels, including the identification of drug affinity sites and kinetic parameters for various antibiotics, may pave the way towards the rational development of an improved new generation of antibacterial agents as well as efflux inhibitors in order to efficiently combat efflux-based resistance mechanisms.
Collapse
Affiliation(s)
- Hiroshi Nikaido
- Department of Molecular and Cell Biology, University of California, Berkeley, CA, USA
| | | |
Collapse
|
125
|
Wu XW, Wu ZP, Wang LX, Zhang HB, Chen JW, Zhang W, Gu LQ, Huang ZS, An LK. Synthesis, antimicrobial activity and possible mechanism of action of 9-bromo-substituted indolizinoquinoline-5,12-dione derivatives. Eur J Med Chem 2011; 46:4625-33. [PMID: 21839550 DOI: 10.1016/j.ejmech.2011.07.042] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2011] [Revised: 07/22/2011] [Accepted: 07/22/2011] [Indexed: 01/02/2023]
Abstract
A series of 9-bromo-substituted indolizinoquinoline-5,12-dione derivatives was synthesized. Antimicrobial activity assessment indicates that compounds 1, 26, 27 and 28 exhibit strong activity against gram-positive bacterial strains, including Beta-hemolytic streptococcus CMCC32210, Staphylococcus aureus ATCC25923, Staphylococcus epidermidis ATCC12228, Enterococcus faecalis ATCC29212 and methicillin-resistant S. aureus ATCC43300 (MRSA). Compound 27 shows the best anti-MRSA activity with an MIC value of 0.031 μg/ml. To assess the mechanism of action, the inhibitory activities of compound 1 against DNA gyrase and DNA topoisomerase IV were also measured. The results indicate that compound 1 has strong inhibitory effects on the Escherichia coli DNA gyrase supercoiling activity and S. aureus Topo IV relaxing activity.
Collapse
Affiliation(s)
- Xi-Wei Wu
- School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou 510006, China
| | | | | | | | | | | | | | | | | |
Collapse
|
126
|
Fadli M, Chevalier J, Saad A, Mezrioui NE, Hassani L, Pages JM. Essential oils from Moroccan plants as potential chemosensitisers restoring antibiotic activity in resistant Gram-negative bacteria. Int J Antimicrob Agents 2011; 38:325-30. [PMID: 21752605 DOI: 10.1016/j.ijantimicag.2011.05.005] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2011] [Revised: 04/29/2011] [Accepted: 05/03/2011] [Indexed: 11/16/2022]
Abstract
Bacterial drug resistance is a worrying public health problem. Antibiotic efflux is a major non-specific resistance mechanism used by bacteria, and efflux pumps are involved in the low-level susceptibility of various important Gram-negative pathogens. Use of molecules that can block bacterial pumps is an attractive strategy, but several studies report only partial efficacy owing to limits of these molecules (stability, selectivity, bioavailability, toxicity, etc.). The objective of this study was to search for natural sources of molecules able to inhibit efflux pump systems of resistant Gram-negative bacteria (Escherichia coli, Enterobacter aerogenes, Klebsiella pneumoniae, Salmonella enterica serotype Typhimurium and Pseudomonas aeruginosa). The results indicate that the studied essential oils exhibit interesting activity against the tested bacteria. This activity was significantly enhanced in the presence of an efflux pump inhibitor such as phenylalanine arginyl β-naphthylamide (PAβN). The role of lipopolysaccharide (LPS) structure in the effect of essential oils was also reported in Salmonella LPS deep-rough mutants. In addition, essential oils of Thymus maroccanus and Thymus broussonetii, used at a low concentration (a fraction of the minimum inhibitory concentration), are able to significantly increase chloramphenicol susceptibility of several resistant isolates. These results demonstrate that these essential oils can alter efflux pump activity and may be attractive candidates to develop new drugs for chemosensitising multidrug-resistant strains to clinically used antibiotics.
Collapse
Affiliation(s)
- Mariam Fadli
- UMR-MD1, Facultés de Médecine et de Pharmacie, Université de la Méditerranée, Marseille, France
| | | | | | | | | | | |
Collapse
|
127
|
Synthesis, characterization and biological activity of some new carbostyril bearing 1H-pyrazole moiety. Med Chem Res 2011. [DOI: 10.1007/s00044-011-9693-2] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
|
128
|
Tomašić T, Zidar N, Šink R, Kovač A, Blanot D, Contreras-Martel C, Dessen A, Müller-Premru M, Zega A, Gobec S, Kikelj D, Peterlin Mašič L. Structure-Based Design of a New Series of d-Glutamic Acid Based Inhibitors of Bacterial UDP-N-acetylmuramoyl-l-alanine:d-glutamate Ligase (MurD). J Med Chem 2011; 54:4600-10. [DOI: 10.1021/jm2002525] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Affiliation(s)
- Tihomir Tomašić
- Faculty of Pharmacy, University of Ljubljana, 1000 Ljubljana, Slovenia
| | - Nace Zidar
- Faculty of Pharmacy, University of Ljubljana, 1000 Ljubljana, Slovenia
| | - Roman Šink
- Faculty of Pharmacy, University of Ljubljana, 1000 Ljubljana, Slovenia
| | - Andreja Kovač
- Faculty of Pharmacy, University of Ljubljana, 1000 Ljubljana, Slovenia
| | - Didier Blanot
- Enveloppes Bactériennes et Antibiotiques, IBBMC, UMR 8619 CNRS, Université Paris-Sud, 91405 Orsay, France
| | | | | | - Manica Müller-Premru
- Medical Faculty, Institute of Microbiology and Immunology, University of Ljubljana, 1105 Ljubljana, Slovenia
| | - Anamarija Zega
- Faculty of Pharmacy, University of Ljubljana, 1000 Ljubljana, Slovenia
| | - Stanislav Gobec
- Faculty of Pharmacy, University of Ljubljana, 1000 Ljubljana, Slovenia
| | - Danijel Kikelj
- Faculty of Pharmacy, University of Ljubljana, 1000 Ljubljana, Slovenia
| | | |
Collapse
|
129
|
Bolla JM, Alibert-Franco S, Handzlik J, Chevalier J, Mahamoud A, Boyer G, Kieć-Kononowicz K, Pagès JM. Strategies for bypassing the membrane barrier in multidrug resistant Gram-negative bacteria. FEBS Lett 2011; 585:1682-90. [DOI: 10.1016/j.febslet.2011.04.054] [Citation(s) in RCA: 141] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2011] [Revised: 04/20/2011] [Accepted: 04/21/2011] [Indexed: 10/18/2022]
|
130
|
Second-generation sulfonamide inhibitors of D-glutamic acid-adding enzyme: activity optimisation with conformationally rigid analogues of D-glutamic acid. Eur J Med Chem 2011; 46:2880-94. [PMID: 21524830 DOI: 10.1016/j.ejmech.2011.04.011] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2011] [Revised: 03/24/2011] [Accepted: 04/03/2011] [Indexed: 01/06/2023]
Abstract
D-Glutamic acid-adding enzyme (MurD) catalyses the essential addition of d-glutamic acid to the cytoplasmic peptidoglycan precursor UDP-N-acetylmuramoyl-l-alanine, and as such it represents an important antibacterial drug-discovery target enzyme. Based on a series of naphthalene-N-sulfonyl-d-Glu derivatives synthesised recently, we synthesised two series of new, optimised sulfonamide inhibitors of MurD that incorporate rigidified mimetics of d-Glu. The compounds that contained either constrained d-Glu or related rigid d-Glu mimetics showed significantly better inhibitory activities than the parent compounds, thereby confirming the advantage of molecular rigidisation in the design of MurD inhibitors. The binding modes of the best inhibitors were examined with high-resolution NMR spectroscopy and X-ray crystallography. We have solved a new crystal structure of the complex of MurD with an inhibitor bearing a 4-aminocyclohexane-1,3-dicarboxyl moiety. These data provide an additional step towards the development of sulfonamide inhibitors with potential antibacterial activities.
Collapse
|
131
|
Alegaon SG, Alagawadi KR. Synthesis, characterization and antimicrobial activity evaluation of new imidazo [2,1-b][1,3,4]thiadiazole derivatives. ACTA ACUST UNITED AC 2011. [DOI: 10.5155/eurjchem.2.1.94-99.161] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
|
132
|
Antimicrobial peptoids are effective against Pseudomonas aeruginosa biofilms. Antimicrob Agents Chemother 2011; 55:3054-7. [PMID: 21422218 DOI: 10.1128/aac.01516-10] [Citation(s) in RCA: 94] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
The resistance of biofilms to conventional antibiotics complicates the treatment of chronic cystic fibrosis (CF). We investigated the effects of peptoids, peptides, and conventional antibiotics on the biomass and cell viability within Pseudomonas aeruginosa biofilms. At their MICs, peptoids 1 and 1-C13(4mer) caused maximum reductions in biomass and cell viability, respectively. These results suggest that peptoids of this class could be worth exploring for the treatment of pulmonary infections occurring in CF patients.
Collapse
|
133
|
Simmons KJ, Chopra I, Fishwick CWG. Structure-based discovery of antibacterial drugs. Nat Rev Microbiol 2011; 8:501-10. [PMID: 20551974 DOI: 10.1038/nrmicro2349] [Citation(s) in RCA: 108] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The modern era of antibacterial chemotherapy began in the 1930s, and the next four decades saw the discovery of almost all the major classes of antibacterial agents that are currently in use. However, bacterial resistance to many of these drugs is becoming an increasing problem. As such, the discovery of drugs with novel modes of action will be vital to meet the threats created by the emergence of resistance. Success in discovering inhibitors using high-throughput screening of chemical libraries is rare. In this Review we explore the exciting opportunities for antibacterial-drug discovery arising from structure-based drug design.
Collapse
Affiliation(s)
- Katie J Simmons
- Antimicrobial Research Centre, University of Leeds, Leeds, UK
| | | | | |
Collapse
|
134
|
Antibacterial activity of some natural products against bacteria expressing a multidrug-resistant phenotype. Int J Antimicrob Agents 2011; 37:156-61. [DOI: 10.1016/j.ijantimicag.2010.10.020] [Citation(s) in RCA: 115] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2010] [Revised: 10/13/2010] [Accepted: 10/14/2010] [Indexed: 11/24/2022]
|
135
|
Chen ZH, Zheng CJ, Sun LP, Piao HR. Synthesis of new chalcone derivatives containing a rhodanine-3-acetic acid moiety with potential anti-bacterial activity. Eur J Med Chem 2010; 45:5739-43. [DOI: 10.1016/j.ejmech.2010.09.031] [Citation(s) in RCA: 83] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2010] [Revised: 09/04/2010] [Accepted: 09/09/2010] [Indexed: 11/17/2022]
|
136
|
Mahamoud A, Chevalier J, Baitiche M, Adam E, Pagès JM. An alkylaminoquinazoline restores antibiotic activity in Gram-negative resistant isolates. MICROBIOLOGY-SGM 2010; 157:566-571. [PMID: 21071494 DOI: 10.1099/mic.0.045716-0] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
To date, various bacterial drug efflux pump inhibitors (EPIs) have been described. They exhibit variability in their activity spectrum with respect to antibiotic structural class and bacterial species. Among the various 4-alkylaminoquinazoline derivatives synthesized and studied in this work, one molecule, 1167, increased the susceptibility of important human-pathogenic, resistant, Gram-negative bacteria towards different antibiotic classes. This 4-(3-morpholinopropylamino)-quinazoline induced an increase in the activity of chloramphenicol, nalidixic acid, norfloxacin and sparfloxacin, which are substrates of the AcrAB-TolC and MexAB-OprM efflux pumps that act in these multidrug-resistant isolates. In addition, 1167 increased the intracellular concentration of chloramphenicol in efflux pump-overproducing strains. The rate of restoration depended on the structure of the antibiotic, suggesting that different sites in the efflux pumps may be involved. A molecule exhibiting a morpholine functional group and a propyl extension of the side chain was more active.
Collapse
Affiliation(s)
- Abdallah Mahamoud
- UMR-MD-1, Facultés de Médecine et de Pharmacie, Université de la Méditerranée, Marseille, France
| | - Jacqueline Chevalier
- UMR-MD-1, Facultés de Médecine et de Pharmacie, Université de la Méditerranée, Marseille, France
| | - Milad Baitiche
- UMR-MD-1, Facultés de Médecine et de Pharmacie, Université de la Méditerranée, Marseille, France
| | - Elissavet Adam
- UMR-MD-1, Facultés de Médecine et de Pharmacie, Université de la Méditerranée, Marseille, France
| | - Jean-Marie Pagès
- UMR-MD-1, Facultés de Médecine et de Pharmacie, Université de la Méditerranée, Marseille, France
| |
Collapse
|
137
|
Keen EF, Murray CK, Robinson BJ, Hospenthal DR, Co EMA, Aldous WK. Changes in the incidences of multidrug-resistant and extensively drug-resistant organisms isolated in a military medical center. Infect Control Hosp Epidemiol 2010; 31:728-32. [PMID: 20500036 DOI: 10.1086/653617] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
BACKGROUND Multidrug-resistant (MDR) Acinetobacter baumannii and Pseudomonas aeruginosa have emerged as the causes of nosocomial infections in critically ill patients. OBJECTIVE To characterize the incidence of these MDR bacteria over time in the military healthcare system, comparing isolates recovered from overseas combat casualties with isolates recovered from local military and civilian patients. METHODS Retrospective electronic records review of culture and/or susceptibility testing results of patients admitted to a military level I trauma center in San Antonio, Texas, during the period from January 2001 through December 2008. Multidrug resistance was defined as the first isolated organism resistant to 3 or more classes of antimicrobial agents. RESULTS Over time, the percentage of MDR A. baumannii isolates increased from 4% to 55%, whereas the percentage of MDR P. aeruginosa isolates increased from 2% to 8%. Respiratory tract specimens had a higher percentage of MDR A. baumannii isolates (49%), compared with specimens obtained from blood (30%), wound sites (24%), or urine (19%). No difference in the percentages of MDR P. aeruginosa isolates was observed with regard to source of specimen. The percentage of MDR A. baumannii isolates recovered was higher among patients who had been deployed overseas (52%) than among local patients (20%). When isolates recovered from patients in the burn intensive care unit (53% of MDR A. baumannii isolates) were removed from analysis, the percentage of MDR A. baumannii isolates decreased from 38% to 30% while the percentage of MDR P. aeruginosa isolates remained unaffected. CONCLUSION The percentage of MDR A. baumannii isolates increased in this facility among combat casualties and among local patients, which indicates nosocomial transmission; however, there was no significant increase in the percentage of MDR P. aeruginosa isolates. Isolated changes in the MDR pathogens within a facility can occur. Possible interventions to limit the spread of these organisms could include implementing aggressive infection control practices, controlling antibiotic use, and using active culture surveillance.
Collapse
Affiliation(s)
- Edward F Keen
- San Antonio Military Medical Center, Brooke Army Medical Center, Fort Sam Houston, Texas 78234, USA
| | | | | | | | | | | |
Collapse
|
138
|
Vaara M. Polymyxins and their novel derivatives. Curr Opin Microbiol 2010; 13:574-81. [PMID: 20869908 DOI: 10.1016/j.mib.2010.09.002] [Citation(s) in RCA: 77] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2010] [Revised: 08/31/2010] [Accepted: 09/02/2010] [Indexed: 11/18/2022]
Abstract
The emerging very multiresistant Gram-negative bacteria cause remarkable therapeutic challenges. There are no novel classes of agents in clinical development for the treatment of Gram-negative infections. Polymyxins (polymyxin B and colistin) were abandoned in the seventies but are now back in the therapy as the last resort. Their nephrotoxicity may complicate the therapy or even necessitate its discontinuation. Less toxic polymyxin derivatives would be highly welcome. Novel derivatives lack in strategic positions two of the five cationic charges of polymyxins, differ from polymyxins in their renal handling and affinity to kidney brush-border membrane, and are in preclinical studies. Less characterized other recent derivatives, also reviewed here, have increased the collective knowledge on the structure-function relationships in polymyxins. Acquired resistance to polymyxins has been encountered. However, the resistance mechanism compromises the function of the bacterial outer membrane as a permeability barrier to other noxious agents.
Collapse
Affiliation(s)
- Martti Vaara
- Northern Antibiotics Ltd., Eskolantie 1, POB 72, FI-00720 Helsinki, Finland; Division of Clinical Microbiology, Helsinki University Hospital, Haartmaninkatu 3, POB 30, FI-00029 HUSLAB, Helsinki, Finland.
| |
Collapse
|
139
|
Al Johani SM, Akhter J, Balkhy H, El-Saed A, Younan M, Memish Z. Prevalence of antimicrobial resistance among gram-negative isolates in an adult intensive care unit at a tertiary care center in Saudi Arabia. Ann Saudi Med 2010; 30:364-9. [PMID: 20697174 PMCID: PMC2941248 DOI: 10.4103/0256-4947.67073] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
BACKGROUND AND OBJECTIVES Patients in the ICU have encountered an increasing emergence and spread of antibiotic-resistant pathogens. We examined patterns of antimicrobial susceptibility in gram-negative isolates to commonly used drugs in an adult ICU at a tertiary care hospital in Riyadh, Saudi Arabia. METHODS A retrospective study was carried out of gram-negative isolates from the adult ICU of King Fahad National Guard Hospital (KFNGH) between 2004 and 2009. Organisms were identified and tested by an automated identification and susceptibility system, and the antibiotic susceptibility testing was confirmed by the disk diffusion method. RESULTS The most frequently isolated organism was Acinetobacter baumannii, followed by Pseudomonas aeruginosa, Escherichia coli, Klebsiella pnemoniae, Stenotrophomonas maltophilia, and Enterobacter. Antibiotic susceptibility patterns significantly declined in many organisms, especially A baumannii, E coli, S marcescens, and Enterobacter. A baumannii susceptibility was significantly decreased to imipenem (55% to 10%), meropenem (33% to 10%), ciprofloxacin (22% to 10%), and amikacin (12% to 6%). E coli susceptibility was markedly decreased (from 75% to 50% or less) to cefuroxime, ceftazidime, cefotaxime, and cefepime. S marcescens susceptibility was markedly decreased to cefotaxime (100% to 32%), ceftazidime (100% to 35%), and cefepime (100% to 66%). Enterobacter susceptibility was markedly decreased to ceftazidime (34% to 5%), cefotaxime (34% to 6%), and pipracillin-tazobactam (51% to 35%). Respiratory samples were the most frequently indicative of multidrug-resistant pathogens (63%), followed by urinary samples (57%). CONCLUSION Antimicrobial resistance is an emerging problem in the KFNGH ICU, justifying new more stringent antibiotic prescription guidelines. Continuous monitoring of antimicrobial susceptibility and strict adherence to infection prevention guidelines are essential to eliminate major outbreaks in the future.
Collapse
|
140
|
|
141
|
Lee JH, Bae IK, Lee SH. New definitions of extended-spectrum β-lactamase conferring worldwide emerging antibiotic resistance. Med Res Rev 2010; 32:216-32. [PMID: 20577973 DOI: 10.1002/med.20210] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Although there is no consensus of the precise definition of ESBL, three kinds of ESBL definitions have been proposed. First, the classical definition includes variants derived from TEM-1, TEM-2, or SHV-1; K1 (KOXY) of Klebsiella oxytoca. Second, the broadened definition has stretched the classical definition of ESBL to include: (1) β-lactamases (CTX-M-ESBLs, GES-ESBLs, and VEB-ESBLs), with spectra similar to those of TEM and SHV variants (designated as TEM- and SHV-ESBLs, respectively) but derived from other sources; (2) TEM and SHV variants with borderline ESBL activity; e.g., TEM-12; and (3) various β-lactamases conferring wider resistance than their parent types but not meeting the definition for group 2be; e.g., OXA-types (OXA-ESBLs) and mutant AmpC-types (AmpC-ESBLs), with increased activity against oxyimino-cephalosporins and with resistance to clavulanic acid. Third, the all-inclusive definition includes: (1) ESBL(A) (named for class A ESBLs); (2) ESBL(M) (miscellaneous ESBLs), which has been subdivided into ESBL(M-C) (class C; plasmid-mediated AmpC) and ESBL(M-D) (class D); and (3) ESBL(CARBA) (ESBLs with hydrolytic activity against carbapenems), which has been subdivided into ESBL(CARBA-A) (class A carbapenemases), ESBL(CARBA-B) (class B carbapenemases), and ESBL(CARBA-D) (class D carbapenemases). The consensus view about the ESBL definition is that the classical ESBL definition must be expanded to class A non-TEM- and non-SHV-ESBLs (CTX-M-, GES-, VEB-ESBLs, etc.). However, these three definitions evoke rational debate on the question "Which would be included in the category of ESBLs among AmpC-ESBLs, OXA-ESBLs, and/or carbapenemases?" Therefore, there is a great need for consensus in the precise definition of ESBL.
Collapse
Affiliation(s)
- Jung Hun Lee
- Drug Resistance Proteomics Laboratory, Department of Biological Sciences, Myongji University, San 38-2 Namdong, Yongin, Gyeonggido 449-728, Republic of Korea
| | | | | |
Collapse
|
142
|
Pranting M, Loov C, Burman R, Goransson U, Andersson DI. The cyclotide cycloviolacin O2 from Viola odorata has potent bactericidal activity against Gram-negative bacteria. J Antimicrob Chemother 2010; 65:1964-71. [DOI: 10.1093/jac/dkq220] [Citation(s) in RCA: 148] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
|
143
|
A novel polymyxin derivative that lacks the fatty acid tail and carries only three positive charges has strong synergism with agents excluded by the intact outer membrane. Antimicrob Agents Chemother 2010; 54:3341-6. [PMID: 20479195 DOI: 10.1128/aac.01439-09] [Citation(s) in RCA: 95] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Polymyxins are cationic lipopeptides (five cationic charges) and the last resort for the treatment of serious Gram-negative infections caused by multiresistant strains. NAB741 has a cyclic peptide portion identical to that of polymyxin B but carries in the linear peptide portion a threonyl-D-serinyl residue (no cationic charges) instead of the diaminobutyryl-threonyl-diaminobutyryl residue (two cationic charges). At the N terminus of the peptide, NAB741 carries an acetyl group instead of a mixture of methyl octanoyl and methyl heptanoyl residues. NAB741 sensitized Escherichia coli, Klebsiella pneumoniae, Enterobacter cloacae, and Acinetobacter baumannii to antibiotics against which the intact outer membrane is an effective permeability barrier. When tested by using Etest strips on plates containing increasing concentrations of NAB741, the fractional inhibition concentration index (FICI) of the combination of NAB741 with rifampin ranged from <or=0.111 to 0.158 and that with clarithromycin from <or=0.094 to 0.292. When tested by the checkerboard method, the corresponding FICI values against E. coli ATCC 25922 were <or=0.141 to <or=0.155 with rifampin and 0.094 with clarithromycin. In addition, at 4 microg/ml, NAB741 decreased the MICs of azithromycin, mupirocin, fusidic acid, and vancomycin for E. coli strains and E. cloacae by factors ranging from 8 to 200. A sister peptide, NAB752, carrying a threonyl-aminobutyryl residue as the linear peptide portion, was inactive. Furthermore, NAB741 sensitized E. coli to the bactericidal activity of fresh guinea pig serum. The renal clearance of NAB741 was approximately 400-fold, 16-fold, and 8-fold higher than those measured for colistin, NAB7061, and NAB739, respectively.
Collapse
|
144
|
In silico identification of common putative drug targets in Leptospira interrogans. J Chem Biol 2010; 3:165-73. [PMID: 21572503 DOI: 10.1007/s12154-010-0039-1] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2009] [Accepted: 04/22/2010] [Indexed: 10/19/2022] Open
Abstract
Infectious diseases are the leading causes of death worldwide. Hence, there is a need to develop new antimicrobial agents. Traditional method of drug discovery is time consuming and yields a few drug targets with little intracellular information for guiding target selection. Thus, focus in drug development has been shifted to computational comparative genomics for identifying novel drug targets. Leptospirosis is a worldwide zoonosis of global concern caused by Leptospira interrogans. Availability of L. interrogans serovars and human genome sequences facilitated to search for novel drug targets using bioinformatics tools. The genome sequence of L. interrogans serovar Copenhageni has 5,124 genes while that of serovar Lai has 4,727 genes. Through subtractive genomic approach 218 genes in serovar Copenhageni and 158 genes in serovar Lai have been identified as putative drug targets. Comparative genomic approach had revealed that 88 drug targets were common to both the serovars. Pathway analysis using the Kyoto Encyclopaedia of Genes and Genomes revealed that 66 targets are enzymes and 22 are non-enzymes. Sixty two common drug targets were predicted to be localized in cytoplasm and 16 were surface proteins. The identified potential drug targets form a platform for further investigation in discovery of novel therapeutic compounds against Leptospira.
Collapse
|
145
|
Affiliation(s)
- Anton Y Peleg
- Division of Infectious Diseases, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA.
| | | |
Collapse
|
146
|
Virtual screening for potential inhibitors of homology modeled Leptospira interrogans MurD ligase. J Chem Biol 2010; 3:175-87. [PMID: 21566738 DOI: 10.1007/s12154-010-0040-8] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2010] [Accepted: 04/22/2010] [Indexed: 10/19/2022] Open
Abstract
The life-threatening infections caused by Leptospira serovars remain a global challenge since long time. Prevention of infection by controlling environmental factors being difficult to practice in developing countries, there is a need for designing potent anti-leptospirosis drugs. ATP-dependent MurD involved in biosynthesis of peptidoglycan was identified as common drug target among pathogenic Leptospira serovars through subtractive genomic approach. Peptidoglycan biosynthesis pathway being unique to bacteria and absent in host represents promising target for antimicrobial drug discovery. Thus, MurD 3D models were generated using crystal structures of 1EEH and 2JFF as templates in Modeller9v7. Structural refinement and energy minimization of the model was carried out in Maestro 9.0 applying OPLS-AA 2001 force field and was evaluated through Procheck, ProSA, PROQ, and Profile 3D. The active site residues were confirmed from the models in complex with substrate and inhibitor. Four published MurD inhibitors (two phosphinics, one sulfonamide, and one benzene 1,3-dicarbixylic acid derivative) were queried against more than one million entries of Ligand.Info Meta-Database to generate in-house library of 1,496 MurD inhibitor analogs. Our approach of virtual screening of the best-ranked compounds with pharmacokinetics property prediction has provided 17 novel MurD inhibitors for developing anti-leptospirosis drug targeting peptidoglycan biosynthesis pathway.
Collapse
|
147
|
Tomasić T, Zidar N, Kovac A, Turk S, Simcic M, Blanot D, Müller-Premru M, Filipic M, Grdadolnik SG, Zega A, Anderluh M, Gobec S, Kikelj D, Peterlin Masic L. 5-Benzylidenethiazolidin-4-ones as multitarget inhibitors of bacterial Mur ligases. ChemMedChem 2010; 5:286-95. [PMID: 20024979 DOI: 10.1002/cmdc.200900449] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Mur ligases participate in the intracellular path of bacterial peptidoglycan biosynthesis and constitute attractive, although so far underexploited, targets for antibacterial drug discovery. A series of hydroxy-substituted 5-benzylidenethiazolidin-4-ones were synthesized and tested as inhibitors of Mur ligases. The most potent compound 5 a was active against MurD-F with IC(50) values between 2 and 6 microm, making it a promising multitarget inhibitor of Mur ligases. Antibacterial activity against different strains, inhibitory activity against protein kinases, mutagenicity and genotoxicity of 5 a were also investigated, and kinetic and NMR studies were conducted.
Collapse
Affiliation(s)
- Tihomir Tomasić
- University of Ljubljana, Faculty of Pharmacy, Askerceva 7, 1000 Ljubljana, Slovenia
| | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
148
|
Mamelli L, Petit S, Chevalier J, Giglione C, Lieutaud A, Meinnel T, Artaud I, Pagès JM. New antibiotic molecules: bypassing the membrane barrier of gram negative bacteria increases the activity of peptide deformylase inhibitors. PLoS One 2009; 4:e6443. [PMID: 19649280 PMCID: PMC2713832 DOI: 10.1371/journal.pone.0006443] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2009] [Accepted: 06/14/2009] [Indexed: 02/04/2023] Open
Abstract
Background Multi-drug resistant (MDR) bacteria have become a major concern in hospitals worldwide and urgently require the development of new antibacterial molecules. Peptide deformylase is an intracellular target now well-recognized for the design of new antibiotics. The bacterial susceptibility to such a cytoplasmic target primarily depends on the capacity of the compound to reach and accumulate in the cytosol. Methodology/Principal Findings To determine the respective involvement of penetration (influx) and pumping out (efflux) mechanisms to peptide deformylase inhibitors (PDF-I) activity, the potency of various series was determined using various genetic contexts (efflux overproducers or efflux-deleted strains) and membrane permeabilizers. Depending on the structure of the tested molecules, two behaviors could be observed: (i) for actinonin the first PDF-I characterized, the AcrAB efflux system was the main parameter involved in the bacterial susceptibility, and (ii), for the lastest PDF-Is such as the derivatives of 2-(5-bromo-1H-indol-3-yl)-N-hydroxyacetamide, the penetration through the membrane was a important limiting step. Conclusions/Significance Our results clearly show that the bacterial membrane plays a key role in modulating the antibacterial activity of PDF-Is. The bacterial susceptibility for these new antibacterial molecules can be improved by two unrelated ways in MDR strains: by collapsing the Acr efflux activity or by increasing the uptake rate through the bacterial membrane. The efficiency of the second method is associated with the nature of the compound.
Collapse
Affiliation(s)
- Laurent Mamelli
- UMR-MD1, Transporteurs Membranaires, Chimiorésistance et Drug-Design, Facultés de Médecine et de Pharmacie, IFR 88, Université de la Méditerranée, Marseille, France
| | - Sylvain Petit
- UMR8601-CNRS, Université Paris Descartes, Laboratoire de Chimie et Biochimie, Pharmacologiques et Toxicologiques, Paris, France
- UPR2355-CNRS, Institut des Sciences du Végétal, Centre National de Recherche Scientifique, Gif sur Yvette, France
| | - Jacqueline Chevalier
- UMR-MD1, Transporteurs Membranaires, Chimiorésistance et Drug-Design, Facultés de Médecine et de Pharmacie, IFR 88, Université de la Méditerranée, Marseille, France
| | - Carmela Giglione
- UPR2355-CNRS, Institut des Sciences du Végétal, Centre National de Recherche Scientifique, Gif sur Yvette, France
| | - Aurélie Lieutaud
- UMR-MD1, Transporteurs Membranaires, Chimiorésistance et Drug-Design, Facultés de Médecine et de Pharmacie, IFR 88, Université de la Méditerranée, Marseille, France
| | - Thierry Meinnel
- UPR2355-CNRS, Institut des Sciences du Végétal, Centre National de Recherche Scientifique, Gif sur Yvette, France
| | - Isabelle Artaud
- UMR8601-CNRS, Université Paris Descartes, Laboratoire de Chimie et Biochimie, Pharmacologiques et Toxicologiques, Paris, France
| | - Jean-Marie Pagès
- UMR-MD1, Transporteurs Membranaires, Chimiorésistance et Drug-Design, Facultés de Médecine et de Pharmacie, IFR 88, Université de la Méditerranée, Marseille, France
- * E-mail:
| |
Collapse
|
149
|
Nicolau DP. Management of complicated infections in the era of antimicrobial resistance: the role of tigecycline. Expert Opin Pharmacother 2009; 10:1213-22. [PMID: 19405794 DOI: 10.1517/14656560902900853] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
BACKGROUND Increasing antimicrobial resistance and infection complications pose challenges to optimal antibiotic therapy. Paucity of new antibiotics (and the eventual bacterial resistance they face) highlights the critical need for more appropriate use of broadly effective agents, which may help to thwart the dramatic rise in global resistance. Single agents that can be combined effectively with others, if needed, promise the simplest overall utility. Approved in 2005 to treat complicated skin and intra-abdominal infections, tigecycline is a novel extended-spectrum minocycline derivative that circumvents bacterial resistance, as it is unaffected by efflux pumps and ribosomal protection. However, tigecycline should not be used as empiric monotherapy for treatment of health-care associated infections known or suspected to be owing to Pseudomonas aeruginosa or Proteus spp. OBJECTIVE This article summarizes the demonstrated clinical utility of tigecycline so far. METHODS A MEDLINE search examined authoritative published clinical studies, reviews and case reports detailing the clinical record of tigecycline since 2004. RESULTS/CONCLUSION Tigecycline continues to maintain satisfactory profiles of safety, efficacy and antimicrobial resistance avoidance. Regardless, continued surveillance is needed to detect reduced susceptibility and resistance against both community and nosocomial pathogens. Judicious use of agents reserved for multidrug resistant pathogens is vital to preserve their effectiveness.
Collapse
Affiliation(s)
- David P Nicolau
- Center for Anti-Infective Research & Development, Hartford Hospital, 80 Seymour Street, Hartford, CT 06102-5037, USA.
| |
Collapse
|
150
|
James CE, Mahendran KR, Molitor A, Bolla JM, Bessonov AN, Winterhalter M, Pagès JM. How beta-lactam antibiotics enter bacteria: a dialogue with the porins. PLoS One 2009; 4:e5453. [PMID: 19434239 PMCID: PMC2677626 DOI: 10.1371/journal.pone.0005453] [Citation(s) in RCA: 71] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2008] [Accepted: 04/02/2009] [Indexed: 01/26/2023] Open
Abstract
Background Multi-drug resistant (MDR) infections have become a major concern in hospitals worldwide. This study investigates membrane translocation, which is the first step required for drug action on internal bacterial targets. β-lactams, a major antibiotic class, use porins to pass through the outer membrane barrier of Gram-negative bacteria. Clinical reports have linked the MDR phenotype to altered membrane permeability including porin modification and efflux pump expression. Methodology/Principal Findings Here influx of β-lactams through the major Enterobacter aerogenes porin Omp36 is characterized. Conductance measurements through a single Omp36 trimer reconstituted into a planar lipid bilayer allowed us to count the passage of single β-lactam molecules. Statistical analysis of each transport event yielded the kinetic parameters of antibiotic travel through Omp36 and distinguishable translocation properties of β-lactams were quantified for ertapenem and cefepime. Expression of Omp36 in an otherwise porin-null bacterial strain is shown to confer increases in the killing rate of these antibiotics and in the corresponding bacterial susceptibility. Conclusions/Significance We propose the idea of a molecular “passport” that allows rapid transport of substrates through porins. Deciphering antibiotic translocation provides new insights for the design of novel drugs that may be highly effective at passing through the porin constriction zone. Such data may hold the key for the next generation of antibiotics capable of rapid intracellular accumulation to circumvent the further development MDR infections.
Collapse
Affiliation(s)
- Chloë E. James
- UMR-MD-1, Transporteurs membranaires, Chimiorésistance et Drug Design, Faculté de Médecine, IFR 88, Université de la Méditerranée, Marseille, France
| | | | - Alexander Molitor
- UMR-MD-1, Transporteurs membranaires, Chimiorésistance et Drug Design, Faculté de Médecine, IFR 88, Université de la Méditerranée, Marseille, France
| | - Jean-Michel Bolla
- UMR-MD-1, Transporteurs membranaires, Chimiorésistance et Drug Design, Faculté de Médecine, IFR 88, Université de la Méditerranée, Marseille, France
| | - Andrey N. Bessonov
- School of Engineering and Science, Jacobs University Bremen, Bremen, Germany
| | | | - Jean-Marie Pagès
- UMR-MD-1, Transporteurs membranaires, Chimiorésistance et Drug Design, Faculté de Médecine, IFR 88, Université de la Méditerranée, Marseille, France
- * E-mail:
| |
Collapse
|