Ozenoxacin: A Novel Drug Discovery for the Treatment of Impetigo

2019 ◽  
Vol 16 (3) ◽  
pp. 259-264 ◽  
Author(s):  
Jagdish K. Sahu ◽  
Arun K. Mishra
Keyword(s):  
Mechanism Of Action ◽  
Bacterial Infections ◽  
Dna Gyrase ◽  
The United States ◽  
Present Review ◽  
Topoisomerase Iv ◽  
Gyrase A ◽  
Chromosomal Condensation ◽  
Supercoil Relaxation ◽  
Novel Drug

Objective: Ozenoxacin is one of the potent quinolone antibiotics, recently approved by the United States Food and Drug Administration (USFDA) with reported pharmacology to treat the impetigo. The demand for better acting topical formulation is increasing day by day. The present review is an attempt to summarize the facts behind the chemistry and biological applications of Ozenoxacin. Mechanism of Action: This novel drug being a quinolone antibiotic compound, acts by inhibiting DNA gyrase A and topoisomerase IV and affects supercoiling, supercoil relaxation, chromosomal condensation, chromosomal decatenation and many others. Mechanism of Action: This novel drug being a quinolone antibiotic compound, acts by inhibiting DNA gyrase A and topoisomerase IV and affects supercoiling, supercoil relaxation, chromosomal condensation, chromosomal decatenation and many others. Pharmacology: Ozenoxacin has demonstrated to have a bactericidal activity against organisms, such as Staphylococcus aureus and Staphylococcus pyogenes. Ozenoxacin is non-fluorinated quinolone and being developed for the other dermatological bacterial infections as well. No sign of genotoxicity was observed when tested experimentally. Conclusion: The present review also covers the complete picture of pharmacokinetics, clinical trials, toxicity and future scope and possible avenues in this arena.

scholarly journals In Vitro Evaluation of CBR-2092, a Novel Rifamycin-Quinolone Hybrid Antibiotic: Studies of the Mode of Action in Staphylococcus aureus

2008 ◽  
Vol 52 (7) ◽  
pp. 2313-2323 ◽  
Author(s):  
Gregory T. Robertson ◽  
Eric J. Bonventre ◽  
Timothy B. Doyle ◽  
Qun Du ◽  
Leonard Duncan ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Rna Polymerase ◽  
Mode Of Action ◽  
Bacterial Infections ◽  
Dna Gyrase ◽  
Topoisomerase Iv ◽  
Dna Topoisomerase ◽  
Resistant Variant ◽  
Proven Efficacy

ABSTRACT Rifamycins have proven efficacy in the treatment of persistent bacterial infections. However, the frequency with which bacteria develop resistance to rifamycin agents restricts their clinical use to antibiotic combination regimens. In a program directed toward the synthesis of rifamycins with a lower propensity to elicit resistance development, a series of compounds were prepared that covalently combine rifamycin and quinolone pharmacophores to form stable hybrid antibacterial agents. We describe mode-of-action studies with Staphylococcus aureus of CBR-2092, a novel hybrid that combines the rifamycin SV and 4H-4-oxo-quinolizine pharmacophores. In biochemical studies, CBR-2092 exhibited rifampin-like potency as an inhibitor of RNA polymerase, was an equipotent (balanced) inhibitor of DNA gyrase and DNA topoisomerase IV, and retained activity against a prevalent quinolone-resistant variant. Macromolecular biosynthesis studies confirmed that CBR-2092 has rifampin-like effects on RNA synthesis in rifampin-susceptible strains and quinolone-like effects on DNA synthesis in rifampin-resistant strains. Studies of mutant strains that exhibited reduced susceptibility to CBR-2092 further substantiated RNA polymerase as the primary cellular target of CBR-2092, with DNA gyrase and DNA topoisomerase IV being secondary and tertiary targets, respectively, in strains exhibiting preexisting rifampin resistance. In contrast to quinolone comparator agents, no strains with altered susceptibility to CBR-2092 were found to exhibit changes consistent with altered efflux properties. The combined data indicate that CBR-2092 may have potential utility in monotherapy for the treatment of persistent S. aureus infections.

scholarly journals Prevalence of Plasmid-Mediated Quinolone Resistance

2003 ◽  
Vol 47 (2) ◽  
pp. 559-562 ◽  
Author(s):  
George A. Jacoby ◽  
Nancy Chow ◽  
Ken B. Waites
Keyword(s):  
Medical Center ◽  
Dna Gyrase ◽  
The United States ◽  
Quinolone Resistance ◽  
Clinical Strain ◽  
University Of Alabama ◽  
Repeat Family ◽  
Gyrase A ◽  
The University ◽  
Microcin B17

ABSTRACT Quinolone resistance encoded by the qnr gene and mediated by plasmid pMG252 was discovered in a clinical strain of Klebsiella pneumoniae that was isolated in 1994 at the University of Alabama at Birmingham Medical Center. The gene codes for a protein that protects DNA gyrase from quinolone inhibition and that belongs to the pentapeptide repeat family of proteins. The prevalence of the gene has been investigated by using PCR with qnr-specific primers with a sample of more than 350 gram-negative strains that originated in 18 countries and 24 states in the United States and that included many strains with plasmid-mediated AmpC or extended spectrum β-lactamase enzymes. qnr was found in isolates from the University of Alabama at Birmingham only during 6 months in 1994, despite the persistence of the gene for FOX-5 β-lactamase, which is linked to qnr on pMG252. Isolates from other locations were negative for qnr. The prevalence of mcbG in the same sample was also examined. mcbG encodes another member of the pentapeptide repeat family and is involved in immunity to microcin B17, which, like quinolones, targets DNA gyrase. A single clinical isolate contained mcbG on a transmissible R plasmid. This plasmid and one carrying the complete microcin B17 operon slightly decreased sparfloxacin susceptibility but had a much less protective effect than pMG252. Plasmid-mediated quinolone resistance was thus rare in the sample examined.

scholarly journals Dual Targeting of Topoisomerase IV and Gyrase To Reduce Mutant Selection: Direct Testing of the Paradigm by Using WCK-1734, a New Fluoroquinolone, and Ciprofloxacin

2005 ◽  
Vol 49 (5) ◽  
pp. 1949-1956 ◽  
Author(s):  
Jacob Strahilevitz ◽  
David C. Hooper
Keyword(s):  
Dna Gyrase ◽  
Single Mutation ◽  
Topoisomerase Iv ◽  
Mutant Selection ◽  
Fourfold Increase ◽  
Development Of Resistance ◽  
Dual Targeting ◽  
Gyrase A ◽  
Resistant Strains ◽  
Selection Of

ABSTRACT Quinolones that act equally against DNA gyrase and topoisomerase IV are a desirable modality to decrease the selection of resistant strains. We first determined by genetic and biochemical studies in Staphylococcus aureus that the primary target enzyme of WCK-1734, a new quinolone, was DNA gyrase. A single mutation in gyrase, but not topoisomerase IV, caused a two- to fourfold increase in the MIC. Studies with purified topoisomerase IV and gyrase from S. aureus also showed that gyrase was more sensitive than topoisomerase IV to WCK-1734 (50% inhibitory concentration, 1.25 and 2.5 to 5.0 μg/ml, respectively; 50% stimulation of cleavage complex formation, 0.62 and 2.5 to 5.0 μg/ml, respectively). To test the effect of balanced activity of quinolones against the two target enzymes, we measured the frequency of selection of mutants with ciprofloxacin (which targets topoisomerase IV) and WCK-1734 alone and in combination. With the combination of ciprofloxacin and WCK-1734, each at its MIC, the ratio of frequency of mutants selected was significantly lower than that with each drug alone at two times their respective MICs. We further characterized resistant strains selected with the combination of ciprofloxacin and WCK-1734 and found evidence to suggest the existence of novel mutational mechanisms for low-level quinolone resistance. By use of a combination of differentially targeting quinolones, this study provides novel data in direct support of the paradigm for dual targeting of quinolone action and reduced development of resistance.

scholarly journals Hybrid Inhibitors of DNA Gyrase A and B: Design, Synthesis and Evaluation

Pharmaceutics ◽  
2020 ◽  
Vol 13 (1) ◽  
pp. 6
Author(s):  
Martina Durcik ◽  
Žiga Skok ◽  
Janez Ilaš ◽  
Nace Zidar ◽  
Anamarija Zega ◽  
...  
Keyword(s):  
Antibacterial Activity ◽  
Dna Gyrase ◽  
Topoisomerase Iv ◽  
Design Synthesis ◽  
Bacterial Dna ◽  
E Coli ◽  
Catalytic Inhibitor ◽  
Catalytic Sites ◽  
Competitive Inhibitors ◽  
Gyrase A

The discovery of multi-targeting ligands of bacterial enzymes is an important strategy to combat rapidly spreading antimicrobial resistance. Bacterial DNA gyrase and topoisomerase IV are validated targets for the development of antibiotics. They can be inhibited at their catalytic sites or at their ATP binding sites. Here we present the design of new hybrids between the catalytic inhibitor ciprofloxacin and ATP-competitive inhibitors that show low nanomolar inhibition of DNA gyrase and antibacterial activity against Gram-negative pathogens. The most potent hybrid 3a has MICs of 0.5 µg/mL against Klebsiella pneumoniae, 4 µg/mL against Enterobacter cloacae, and 2 µg/mL against Escherichia coli. In addition, inhibition of mutant E. coli strains shows that these hybrid inhibitors interact with both subunits of DNA gyrase (GyrA, GyrB), and that binding to both of these sites contributes to their antibacterial activity.

scholarly journals Prevalence of Single Mutations in Topoisomerase Type II Genes among Levofloxacin-Susceptible Clinical Strains of Streptococcus pneumoniae Isolated in the United States in 1992 to 1996 and 1999 to 2000

2002 ◽  
Vol 46 (1) ◽  
pp. 119-124 ◽  
Author(s):  
Todd A. Davies ◽  
Alan Evangelista ◽  
Sharon Pfleger ◽  
Karen Bush ◽  
Daniel F. Sahm ◽  
...  
Keyword(s):  
United States ◽  
Streptococcus Pneumoniae ◽  
Oligonucleotide Probe ◽  
Dna Gyrase ◽  
The United States ◽  
Single Step ◽  
Type Ii ◽  
Topoisomerase Iv ◽  
Resistant Strains ◽  
Probe Assay

ABSTRACT Levofloxacin resistance in Streptococcus pneumoniae is rare, requiring at least two mutations in the quinolone resistance-determining region (QRDR) of topoisomerase IV and DNA gyrase. The prevalence of single QRDR mutations in these genes is unknown. Of 9,438 levofloxacin-susceptible pneumococci from the TRUST 4 surveillance study (1999–2000), 528 strains (MICs of 0.5 to 2.0 μg/ml) were selected for analysis. For comparison, 214 levofloxacin-susceptible strains (MICs of 0.5 to 1 μg/ml) isolated between 1992 and 1996 were analyzed. Oligonucleotide probe assay and DNA sequencing were used to detect QRDR mutations leading to changes at Ser79 and Asp83 in ParC, Ser81 in GyrA, and Asp435 in ParE, the most frequently found substitutions among levofloxacin-resistant strains. Among the 1992 to 1996 isolates only one strain (levofloxacin MIC, 1 μg/ml) had a mutation (Ser79 to Phe in ParC). No single mutations were found among 270 TRUST 4 strains with levofloxacin MICs of 0.5 μg/ml. Among 244 strains for which levofloxacin MICs were 1 μg/ml, 15 strains (6.1%) had a parC mutation and 3 strains (1.2%) had a parE mutation. Of 14 strains for which levofloxacin MICs were 2 μg/ml, 10 strains (71%) had a parC mutation; no parE mutations were found. No gyrA mutations were detected. It was estimated that 4.5% of the 9,438 levofloxacin-susceptible TRUST 4 isolates (MICs, ≤0.06 to 2 μg/ml) had a single parC or parE QRDR mutation. Although there has been an increase in the prevalence of single-step mutants, the increase may have been overestimated due in part to differences in geographical distribution for the two sets of isolates.

scholarly journals Delafloxacin, Finafloxacin, and Zabofloxacin: Novel Fluoroquinolones in the Antibiotic Pipeline

Antibiotics ◽  
2021 ◽  
Vol 10 (12) ◽  
pp. 1506
Author(s):  
Béla Kocsis ◽  
Dániel Gulyás ◽  
Dóra Szabó
Keyword(s):  
Broad Spectrum ◽  
Bacterial Infections ◽  
Chemical Structure ◽  
Antimicrobial Agents ◽  
Treatment Options ◽  
Dna Gyrase ◽  
Daily Practice ◽  
Molecular Surface ◽  
Chronic Obstructive ◽  
Topoisomerase Iv

Novel antimicrobial agents, approved for clinical use in past years, represent potential treatment options for various infections. In this review, we summarize the most important medical and microbiological features of three recently approved fluoroquinolones, namely delafloxacin, finafloxacin, and zabofloxacin. Delafloxacin possesses an anionic chemical structure, and represents broad-spectrum activity, as it targets both bacterial DNA gyrase and topoisomerase IV enzymes of gram-positive and gram-negative bacteria with equal affinity. Its molecular surface is larger than that of other fluoroquinolones, and it has enhanced antibacterial efficacy in acidic environments. Delafloxacin has been approved to treat acute bacterial skin and skin-structure infections, as well as community-acquired bacterial pneumonia. Finafloxacin has a zwitterionic chemical structure, and targets both DNA gyrase and topoisomerase IV enzymes. This enables a broad antibacterial spectrum; however, finafloxacin has so far only been approved in ear-drops to treat bacterial otitis externa. Zabofloxacin is also a broad-spectrum fluoroquinolone agent, and was first approved in South Korea to treat acute bacterial exacerbation of chronic obstructive pulmonary disease. The introduction of these novel fluoroquinolones into daily practice extends the possible indications of antibiotics into different bacterial infections, and provides treatment options in difficult-to-treat infections. However, some reports of delafloxacin resistance have already appeared, thus underlining the importance of the prudent use of antibiotics.

scholarly journals Design, Synthesis and Antimicrobial Evaluation of New Norfloxacin-Naphthoquinone Hybrid Molecules

Proceedings ◽  
2019 ◽  
Vol 41 (1) ◽  
pp. 9 ◽  
Author(s):  
Andrea Defant ◽  
Alessandro Vozza ◽  
Ines Mancini
Keyword(s):  
Bacterial Infections ◽  
Antimicrobial Agents ◽  
Biological Activities ◽  
Dna Gyrase ◽  
Structural Features ◽  
Therapeutic Agents ◽  
Topoisomerase Iv ◽  
Design Synthesis ◽  
Biological Targets ◽  
Hybrid Molecules

Although the wide arsenal of drugs available to treat bacterial infections, emerging drug-resistant bacterial pathogens have recently highlighted an urgent need to find new more effective and less toxic therapeutic agents. Fluoroquinolones, including norfloxacin, are antibiotics showing a concentration-dependent bactericidal capacity due to the activity inhibition of DNA-gyrase and topoisomerase IV, which are enzymes essential for bacterial DNA replication. Naphthoquinones are secondary metabolites showing different biological activities, including cytotoxic, antibacterial and antifungal effects. In particular, the efficacy of natural and synthetic 1,4-naphthoquinone derivatives is likely due to their oxidizing/reducing capability, through which they destroy cellular targets as nucleic acids. Hybrid molecules are produced combining structural features of two or more bioactive compounds, in order to obtain new therapeutic agents able, not only to reduce undesirable side effects of the parent drugs, but also to inhibit more biological targets, hopefully with a better therapeutic property than the administration of combined single-target drugs. With the aim to apply this strategy in the study of new potential antimicrobial agents, we have synthesized four hybrid molecules by the reaction of norfloxacin with suitable quinones and their activities have been evaluated against both bacteria and fungi, in comparison with synthetic precursors. The experimental data are supported by docking calculations on S. aureus DNA-gyrase, discussing the interactions involved for each hybrid molecule, in comparison with norfloxacin and the original ligand moxifloxacin.

scholarly journals Role of the Extended α4 Domain of Staphylococcus aureus Gyrase A Protein in Determining Low Sensitivity to Quinolones

2006 ◽  
Vol 50 (2) ◽  
pp. 600-606 ◽  
Author(s):  
Jacob Strahilevitz ◽  
Ari Robicsek ◽  
David C. Hooper
Keyword(s):  
Staphylococcus Aureus ◽  
Acquired Resistance ◽  
Dna Gyrase ◽  
Wild Type ◽  
Topoisomerase Iv ◽  
E Coli ◽  
Gyrase A ◽  
Low Sensitivity ◽  
Emergence Of Resistance

ABSTRACT Fluoroquinolones target two bacterial type II topoisomerases, DNA gyrase and topoisomerase IV. Acquired resistance to quinolones occurs stepwise, with the first mutation occurring in the more sensitive target enzyme. To limit the emergence of resistance, quinolones should ideally possess dual activities against the two enzymes. For reasons that are as yet unclear, Staphylococcus aureus gyrase is less sensitive to quinolones than topoisomerase IV, counter to its greater sensitivity in Escherichia coli, thereby limiting the use of quinolones for the treatment of staphylococcal infections. Mutations in the α4-helix domain of the GyrA subunit of gyrase are important in determining quinolone resistance. We replaced an extended region encompassing the α4 domain in the E. coli GyrA protein with its homolog in S. aureus and tested for its ability to complement a thermosensitive gyrase and its catalytic and noncatalytic properties. Purified gyrase reconstituted with chimeric GyrA was more resistant to ciprofloxacin than wild-type gyrase at both inhibition of catalytic activity and stimulation of cleavage complexes, and this difference was more apparent in the presence of K+-glutamate. The chimeric GyrA subunit was able to complement thermosensitive gyrase, similar to wild-type GyrA. Without supplemental K+-glutamate the MICs of ciprofloxacin for thermosensitive E. coli complemented with chimeric DNA gyrase were equal to those for E. coli complemented with wild-type gyrase but were twofold higher in the presence of K+-glutamate. Our findings suggest that the extended α4 domain of S. aureus GyrA is responsible, at least in part, for the increased resistance of S. aureus gyrase to quinolones and that this effect is modulated by K+-glutamate.

scholarly journals Mechanism of Action of the Des-F(6) Quinolone BMS-284756 Measured by Supercoiling Inhibition and Cleavable Complex Assays

2001 ◽  
Vol 45 (12) ◽  
pp. 3660-3662 ◽  
Author(s):  
Ping Wu ◽  
Laura E. Lawrence ◽  
Kenneth L. Denbleyker ◽  
John F. Barrett
Keyword(s):  
Escherichia Coli ◽  
Mechanism Of Action ◽  
Dna Gyrase ◽  
Gyrase A ◽  
Cleavable Complex

ABSTRACT BMS-284756 (T-3811ME), a novel des-F(6) quinolone, was tested in the supercoiling inhibition and cleavable complex assays against Escherichia coli DNA gyrase, a target of quinolones. The results suggest that BMS-284756 has the same mechanism of action against DNA gyrase as other quinolones and a similar level of potency.

DNA gyrase, topoisomerase IV, and the 4-quinolones

1997 ◽  
Vol 61 (3) ◽  
pp. 377-392
Author(s):  
K Drlica ◽  
X Zhao
Keyword(s):  
Dna Gyrase ◽  
Lethal Gene ◽  
Dna Breaks ◽  
Topoisomerase Iv ◽  
Primary Resistance ◽  
Double Strand Dna Breaks ◽  
Drug Concentrations ◽  
Gyrase A ◽  
Inhibition Of Dna Synthesis ◽  
Host Parasite

For many years, DNA gyrase was thought to be responsible both for unlinking replicated daughter chromosomes and for controlling negative superhelical tension in bacterial DNA. However, in 1990 a homolog of gyrase, topoisomerase IV, that had a potent decatenating activity was discovered. It is now clear that topoisomerase IV, rather than gyrase, is responsible for decatenation of interlinked chromosomes. Moreover, topoisomerase IV is a target of the 4-quinolones, antibacterial agents that had previously been thought to target only gyrase. The key event in quinolone action is reversible trapping of gyrase-DNA and topoisomerase IV-DNA complexes. Complex formation with gyrase is followed by a rapid, reversible inhibition of DNA synthesis, cessation of growth, and induction of the SOS response. At higher drug concentrations, cell death occurs as double-strand DNA breaks are released from trapped gyrase and/or topoisomerase IV complexes. Repair of quinolone-induced DNA damage occurs largely via recombination pathways. In many gram-negative bacteria, resistance to moderate levels of quinolone arises from mutation of the gyrase A protein and resistance to high levels of quinolone arises from mutation of a second gyrase and/or topoisomerase IV site. For some gram-positive bacteria, the situation is reversed: primary resistance occurs through changes in topoisomerase IV while gyrase changes give additional resistance. Gyrase is also trapped on DNA by lethal gene products of certain large, low-copy-number plasmids. Thus, quinolone-topoisomerase biology is providing a model for understanding aspects of host-parasite interactions and providing ways to investigate manipulation of the bacterial chromosome by topoisomerases.

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