scholarly journals Second-generation 4,5,6,7-tetrahydrobenzo[d]thiazoles as novel DNA gyrase inhibitors

2020 ◽  
Vol 12 (4) ◽  
pp. 277-297 ◽  
Author(s):  
Andraž Lamut ◽  
Žiga Skok ◽  
Michaela Barančoková ◽  
Lucas J Gutierrez ◽  
Cristina D Cruz ◽  
...  
Keyword(s):  
First Generation ◽  
Bacterial Resistance ◽  
Dna Gyrase ◽  
Wild Type ◽  
Topoisomerase Iv ◽  
Starting Point ◽  
Good Starting Point ◽  
Resistant Strains ◽  
Gyrase Inhibitors ◽  
Nanomolar Range

Aim: DNA gyrase and topoisomerase IV are essential bacterial enzymes, and in the fight against bacterial resistance, they are important targets for the development of novel antibacterial drugs. Results: Building from our first generation of 4,5,6,7-tetrahydrobenzo[ d]thiazole-based DNA gyrase inhibitors, we designed and prepared an optimized series of analogs that show improved inhibition of DNA gyrase and topoisomerase IV from Staphylococcus aureus and Escherichia coli, with IC50 values in the nanomolar range. Importantly, these inhibitors also show improved antibacterial activity against Gram-positive strains. Conclusion: The most promising inhibitor, 29, is active against Enterococcus faecalis, Enterococcus faecium and S. aureus wild-type and resistant strains, with minimum inhibitory concentrations between 4 and 8 μg/ml, which represents good starting point for development of novel antibacterials.

scholarly journals In Vitro Characterization of the Antibacterial Spectrum of Novel Bacterial Type II Topoisomerase Inhibitors of the Aminobenzimidazole Class

2006 ◽  
Vol 50 (4) ◽  
pp. 1228-1237 ◽  
Author(s):  
Nagraj Mani ◽  
Christian H. Gross ◽  
Jonathan D. Parsons ◽  
Brian Hanzelka ◽  
Ute Müh ◽  
...  
Keyword(s):  
Bacterial Resistance ◽  
Wide Spectrum ◽  
Dna Gyrase ◽  
Antibacterial Activities ◽  
Mechanisms Of Action ◽  
Fluoroquinolone Resistance ◽  
Topoisomerase Iv ◽  
Low Frequencies

ABSTRACT Antibiotics with novel mechanisms of action are becoming increasingly important in the battle against bacterial resistance to all currently used classes of antibiotics. Bacterial DNA gyrase and topoisomerase IV (topoIV) are the familiar targets of fluoroquinolone and coumarin antibiotics. Here we present the characterization of two members of a new class of synthetic bacterial topoII ATPase inhibitors: VRT-125853 and VRT-752586. These aminobenzimidazole compounds were potent inhibitors of both DNA gyrase and topoIV and had excellent antibacterial activities against a wide spectrum of problematic pathogens responsible for both nosocomial and community-acquired infections, including staphylococci, streptococci, enterococci, and mycobacteria. Consistent with the novelty of their structures and mechanisms of action, antibacterial potency was unaffected by commonly encountered resistance phenotypes, including fluoroquinolone resistance. In time-kill assays, VRT-125853 and VRT-752586 were bactericidal against Staphylococcus aureus, Streptococcus pneumoniae, Enterococcus faecalis, and Haemophilus influenzae, causing 3-log reductions in viable cells within 24 h. Finally, similar to the fluoroquinolones, relatively low frequencies of spontaneous resistance to VRT-125853 and VRT-752586 were found, a property consistent with their in vitro dual-targeting activities.

scholarly journals Quinolone-resistant mutants of escherichia coli DNA topoisomerase IV parC gene.

1996 ◽  
Vol 40 (3) ◽  
pp. 710-714 ◽  
Author(s):  
Y Kumagai ◽  
J I Kato ◽  
K Hoshino ◽  
T Akasaka ◽  
K Sato ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Dna Gyrase ◽  
Mutant Gene ◽  
Missense Mutations ◽  
Topoisomerase Iv ◽  
Dna Topoisomerase ◽  
E Coli ◽  
A Subunit ◽  
Resistant Strains ◽  
Mutant Genes

Escherichia coli quinolone-resistant strains with mutations of the parC gene, which codes for a subunit of topoisomerase IV, were isolated from a quinolone-resistant gyrA mutant of DNA gyrase. Quinolone-resistant parC mutants were also identified among the quinolone-resistant clinical strains. The parC mutants became susceptible to quinolones by introduction of a parC+ plasmid. Introduction of the multicopy plasmids carrying the quinolone-resistant parC mutant gene resulted in an increase in MICs of quinolones for the parC+ and quinolone-resistant gyrA strain. Nucleotide sequences of the quinolone-resistant parC mutant genes were determined, and missense mutations at position Gly-78, Ser-80, or Glu-84, corresponding to those in the quinolone-resistance-determining region of DNA gyrase, were identified. These results indicate that topoisomerase IV is a target of quinolones in E. coli and suggest that the susceptibility of E. coli cells to quinolones is determined by sensitivity of the targets, DNA gyrase and topoisomerase IV.

Topoisomerase Sequences of Coagulase-Negative Staphylococcal Isolates Resistant to Ciprofloxacin or Trovafloxacin

1999 ◽  
Vol 43 (7) ◽  
pp. 1631-1637 ◽  
Author(s):  
Donald T. Dubin ◽  
Joseph E. Fitzgibbon ◽  
Massoumeh D. Nahvi ◽  
Joseph F. John
Keyword(s):  
Dna Gyrase ◽  
Fluoroquinolone Resistance ◽  
Topoisomerase Iv ◽  
Dna Topoisomerase ◽  
Methicillin Resistant ◽  
Intraspecies Variation ◽  
Rrna Sequencing ◽  
Identification Of Species ◽  
Resistant Strains ◽  
Ciprofloxacin Resistance

ABSTRACT Coagulase-negative staphylococcal isolates (n = 188) were screened for susceptibility to oxacillin, ciprofloxacin, and trovafloxacin, a new fluoroquinolone. At an oxacillin concentration of ≥4 μg/ml, 43% were methicillin resistant; of these, 70% were ciprofloxacin resistant (MIC, ≥4 μg/ml). Of the methicillin-resistant, ciprofloxacin-resistant isolates, 46% were susceptible to ≤2 μg of trovafloxacin per ml and 32% were susceptible to ≤1 μg of trovafloxacin per ml. Sixteen isolates, including twelve that expressed fluoroquinolone resistance, were chosen for detailed analysis. Identification of species by rRNA sequencing revealed a preponderance of Staphylococcus haemolyticus andS. hominis among fluoroquinolone-resistant strains. Segments of genes (gyrA and grlA) encoding DNA gyrase and DNA topoisomerase IV were sequenced. Considerable interspecies variation was noted, mainly involving noncoding nucleotide changes. Intraspecies variation consisted of coding changes associated with fluoroquinolone resistance. As for S. aureus, ciprofloxacin resistance (MIC, ≥8 μg/ml) and increased trovafloxacin MICs (0.25 to 2 μg/ml) could be conferred by the combined presence of single mutations in each gyrA and grlA gene. Trovafloxacin MICs of ≥8 μg/ml also occurred, but these required an additional mutation in grlA.

scholarly journals Cloning, Expression, and Enzymatic Characterization of Pseudomonas aeruginosaTopoisomerase IV

1999 ◽  
Vol 43 (3) ◽  
pp. 530-536 ◽  
Author(s):  
Takaaki Akasaka ◽  
Yoshikuni Onodera ◽  
Mayumi Tanaka ◽  
Kenichi Sato
Keyword(s):  
Dna Gyrase ◽  
Fusion System ◽  
Enzymatic Characterization ◽  
Wild Type ◽  
Inhibitory Effects ◽  
Topoisomerase Iv ◽  
Upstream Gene ◽  
E Coli ◽  
New Quinolones

ABSTRACT The topoisomerase IV subunit A gene, parC homolog, has been cloned and sequenced from Pseudomonas aeruginosa PAO1, with cDNA encoding the N-terminal region of Escherichia coli parC used as a probe. The homolog and its upstream gene were presumed to be parC and parE through sequence homology with the parC and parE genes of other organisms. The deduced amino acid sequence of ParC and ParE showed 33 and 32% identity with that of the P. aeruginosa DNA gyrase subunits, GyrA and GyrB, respectively, and 69 and 75% identity with that of E. coli ParC and ParE, respectively. The putative ParC and ParE proteins were overexpressed and separately purified by use of a fusion system with a maltose-binding protein, and their enzymatic properties were examined. The reconstituted enzyme had ATP-dependent decatenation activity, which is the main catalytic activity of bacterial topoisomerase IV, and relaxing activities but had no supercoiling activity. So, the cloned genes were identified asP. aeruginosa topoisomerase IV genes. The inhibitory effects of quinolones on the activities of topoisomerase IV and DNA gyrase were compared. The 50% inhibitory concentrations of quinolones for the decatenation activity of topoisomerase IV were from five to eight times higher than those for the supercoiling activities ofP. aeruginosa DNA gyrase. These results confirmed that topoisomerase IV is less sensitive to fluoroquinolones than is DNA gyrase and may be a secondary target of new quinolones in wild-typeP. aeruginosa.

scholarly journals Topoisomerase Mutations in Fluoroquinolone-Resistant and Methicillin-Susceptible and -Resistant Clinical Isolates of Staphylococcus aureus

1998 ◽  
Vol 42 (1) ◽  
pp. 197-198 ◽  
Author(s):  
Glenn W. Kaatz ◽  
Susan M. Seo
Keyword(s):  
Staphylococcus Aureus ◽  
Restriction Fragment Length Polymorphism ◽  
Fragment Length Polymorphism ◽  
Dna Gyrase ◽  
Clinical Isolates ◽  
Polymorphism Analysis ◽  
Topoisomerase Iv ◽  
Genes Encoding ◽  
Resistant Strains ◽  
Restriction Fragment Length

ABSTRACT The incidence of the various mutations in the genes encoding topoisomerase IV and DNA gyrase in fluoroquinolone-resistant clinical isolates of Staphylococcus aureus is not known. Using restriction fragment length polymorphism analysis and DNA sequencing, we found that in fluoroquinolone- and methicillin-resistant strains, mutations in grlA and gyrA are quite likely to be present together. For fluoroquinolone-resistant but methicillin-susceptible strains, mutations in grlA alone are more common.

scholarly journals Discovery of Novel DNA Gyrase Inhibitors by High-Throughput Virtual Screening

2007 ◽  
Vol 51 (10) ◽  
pp. 3688-3698 ◽  
Author(s):  
David A. Ostrov ◽  
José A. Hernández Prada ◽  
Patrick E. Corsino ◽  
Kathryn A. Finton ◽  
Nhan Le ◽  
...  
Keyword(s):  
Small Molecules ◽  
Dna Gyrase ◽  
Binding Pocket ◽  
Small Region ◽  
Dna Supercoiling ◽  
Resistant Bacteria ◽  
Topoisomerase Iv ◽  
Antimicrobial Drugs ◽  
Drug Resistant Bacteria ◽  
Gyrase Inhibitors

ABSTRACT The bacterial type II topoisomerases DNA gyrase and topoisomerase IV are validated targets for clinically useful quinolone antimicrobial drugs. A significant limitation to widely utilized quinolone inhibitors is the emergence of drug-resistant bacteria due to an altered DNA gyrase. To address this problem, we have used structure-based molecular docking to identify novel drug-like small molecules that target sites distinct from those targeted by quinolone inhibitors. A chemical ligand database containing approximately 140,000 small molecules (molecular weight, <500) was molecularly docked onto two sites of Escherichia coli DNA gyrase targeting (i) a previously unexplored structural pocket formed at the dimer interface of subunit A and (ii) a small region of the ATP binding pocket on subunit B overlapping the site targeted by coumarin and cyclothialidine drugs. This approach identified several small-molecule compounds that inhibited the DNA supercoiling activity of purified E. coli DNA gyrase. These compounds are structurally unrelated to previously identified gyrase inhibitors and represent potential scaffolds for the optimization of novel antibacterial agents that act on fluoroquinolone-resistant strains.

scholarly journals Nybomycin Inhibits both Fluoroquinolone-Sensitive and Fluoroquinolone-Resistant Escherichia coli DNA Gyrase

2021 ◽  
Vol 65 (5) ◽  
Author(s):  
Dmitrii I. Shiriaev ◽  
Alina A. Sofronova ◽  
Ekaterina A. Berdnikovich ◽  
Dmitrii A. Lukianov ◽  
Ekaterina S. Komarova ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Bacterial Species ◽  
Dna Gyrase ◽  
Resistant Bacteria ◽  
Mutant Form ◽  
Wild Type ◽  
Topoisomerase Iv ◽  
Gram Positive ◽  
Gram Negative ◽  
Content Type

ABSTRACT Bacterial type II topoisomerases, DNA gyrase and topoisomerase IV, are targets of many antibiotics, including fluoroquinolones (FQs). Unfortunately, a number of bacterial species easily acquire resistance to FQs by mutations in either DNA gyrase or topoisomerase IV genes. The emergence of resistant pathogenic strains is a global problem in health care; therefore, identifying alternative pathways to thwart their persistence is the current frontier in drug discovery. Nybomycins are an attractive class of compounds, reported to be “reverse antibiotics” that selectively inhibit growth of some Gram-positive FQ-resistant bacteria by targeting the mutant form of DNA gyrase while being inactive against wild-type strains with FQ-sensitive gyrases. The strong “reverse” effect was demonstrated only for a few Gram-positive organisms resistant to FQs due to the S83L/I mutation in the GyrA subunit of DNA gyrase. However, the activity of nybomycins has not been extensively explored among Gram-negative species. Here, we observed that in a ΔtolC strain of the Gram-negative Escherichia coli with enhanced permeability, wild-type gyrase and a GyrA S83L mutant, resistant to fluoroquinolones, are similarly sensitive to nybomycin.

scholarly journals Alterations in the DNA topoisomerase IV grlA gene responsible for quinolone resistance in Staphylococcus aureus.

1996 ◽  
Vol 40 (5) ◽  
pp. 1157-1163 ◽  
Author(s):  
J Yamagishi ◽  
T Kojima ◽  
Y Oyamada ◽  
K Fujimoto ◽  
H Hattori ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Gene Dosage ◽  
Dna Gyrase ◽  
Quinolone Resistance ◽  
Wild Type Allele ◽  
Wild Type ◽  
Topoisomerase Iv ◽  
Dna Topoisomerase ◽  
Transformation Experiment ◽  
Dna Fragment

A 4.2-kb DNA fragment conferring quinolone resistance was cloned from a quinolone-resistant clinical isolate of Staphylococcus aureus and was shown to possess a part of the grlB gene and a mutated grlA gene. S-80-->F and E-84-->K mutations in the grlA gene product were responsible for the quinolone resistance. The mutated grlA genes responsible for quinolone resistance were dominant over the wild-type allele, irrespective of gene dosage in a transformation experiment with the grlA gene alone. However, dominance by mutated grlA genes depended on gene dosage when bacteria were transformed with the grlA and grlB genes in combination. Quinolone-resistant gyrA mutants were easily isolated from a strain, S. aureus RN4220, carrying a plasmid with the mutated grlA gene, though this was not the case for other S. aureus strains lacking the plasmid. The elimination of this plasmid from such quinolone-resistant gyrA mutants resulted in marked increases in quinolone susceptibility. These results suggest that both DNA gyrase and DNA topoisomerase IV may be targets of quinolones and that the quinolone susceptibility of organisms may be determined by which of these enzymes is most quinolone sensitive.

scholarly journals Contributions of the 8-Methoxy Group of Gatifloxacin to Resistance Selectivity, Target Preference, and Antibacterial Activity against Streptococcus pneumoniae

2001 ◽  
Vol 45 (6) ◽  
pp. 1649-1653 ◽  
Author(s):  
Hideyuki Fukuda ◽  
Ryuta Kishii ◽  
Masaya Takei ◽  
Masaki Hosaka
Keyword(s):  
Antibacterial Activity ◽  
Streptococcus Pneumoniae ◽  
Type Strain ◽  
Methoxy Group ◽  
Wild Type Strain ◽  
Dna Gyrase ◽  
Wild Type ◽  
Topoisomerase Iv ◽  
Mutant Strains

ABSTRACT Gatifloxacin (8-methoxy, 7-piperazinyl-3′-methyl) at the MIC selected mutant strains that possessed gyrA mutations at a low frequency (3.7 × 10−9) from wild-type strainStreptococcus pneumoniae IID553. AM-1147 (8-methoxy, 7-piperazinyl-3′-H) at the MIC or higher concentrations selected no mutant strains. On the other hand, the respective 8-H counterparts of these two compounds, AM-1121 (8-H, 7-piperazinyl-3′-methyl) and ciprofloxacin (8-H, 7-piperazinyl-3′-H), at one and two times the MIC selected mutant strains that possessed parC mutations at a high frequency (>2.4 × 10−6). The MIC of AM-1147 increased for the gyrA mutant strains but not for theparC mutant strains compared with that for the wild-type strain. These results suggest that fluoroquinolones that harbor 8-methoxy groups select mutant strains less frequently and prefer DNA gyrase, as distinct from their 8-H counterparts. The in vitro activities of gatifloxacin and AM-1147 are twofold higher against the wild-type strain, eight- and twofold higher against the first-stepparC and gyrA mutant strains, respectively, and two- to eightfold higher against the second-step gyrA andparC double mutant strains than those of their 8-H counterparts. These results indicate that the 8-methoxy group contributes to enhancement of antibacterial activity against target-altered mutant strains as well as the wild-type strain. It is hypothesized that the 8-methoxy group of gatifloxacin increases the level of target inhibition, especially against DNA gyrase, so that it is nearly the same as that for topoisomerase IV inhibition in the bacterial cell, leading to potent antibacterial activity and a low level of resistance selectivity.

scholarly journals In Vitro Activities of Novel Nonfluorinated Quinolones PGE 9262932 and PGE 9509924 against Clinical Isolates of Staphylococcus aureus and Streptococcus pneumoniae with Defined Mutations in DNA Gyrase and Topoisomerase IV

2002 ◽  
Vol 46 (6) ◽  
pp. 1651-1657 ◽  
Author(s):  
Mark E. Jones ◽  
Ian A. Critchley ◽  
James A. Karlowsky ◽  
Renée S. Blosser-Middleton ◽  
Franz-Josef Schmitz ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Streptococcus Pneumoniae ◽  
Dna Gyrase ◽  
Quinolone Resistance ◽  
Clinical Isolates ◽  
Wild Type ◽  
Topoisomerase Iv ◽  
Selection Of

ABSTRACT Two 8-methoxy nonfluorinated quinolones (NFQs), PGE 9262932 and PGE 9509924, were tested against contemporary clinical isolates of Staphylococcus aureus (n = 122) and Streptococcus pneumoniae (n = 69) with genetically defined quinolone resistance-determining regions (QRDRs). For S. aureus isolates with wild-type (WT) sequences at the QRDRs, the NFQs demonstrated activities 4- to 32-fold more potent (MICs at which 90% of isolates are inhibited [MIC90s], 0.03 μg/ml) than those of moxifloxacin (MIC90, 0.12 μg/ml), gatifloxacin (MIC90, 0.25 μg/ml), levofloxacin (MIC90, 0.25 μg/ml), and ciprofloxacin (MIC90, 1 μg/ml). Against S. pneumoniae isolates with WT sequences at gyrA and parC, the NFQs PGE 9262932 (MIC90, 0.03 μg/ml) and PGE 9509924 (MIC90, 0.12 μg/ml) were 8- to 64-fold and 2- to 16-fold more potent, respectively, than moxifloxacin (MIC90, 0.25 μg/ml), gatifloxacin (MIC90, 0.5 μg/ml), levofloxacin (MIC90, 2 μg/ml), and ciprofloxacin (MIC90, 2 μg/ml). The MICs of all agents were elevated for S. aureus isolates with alterations in GyrA (Glu88Lys or Ser84Leu) and GrlA (Ser80Phe) and S. pneumoniae isolates with alterations in GyrA (Ser81Phe or Ser81Tyr) and ParC (Ser79Phe or Lys137Asn). Fluoroquinolone MICs for S. aureus strains with double alterations in GyrA combined with double alterations in GrlA were ≥32 μg/ml, whereas the MICs of the NFQs for strains with these double alterations were 4 to 8 μg/ml. The PGE 9262932 and PGE 9509924 MICs for the S. pneumoniae isolates did not exceed 0.5 and 1 μg/ml, respectively, even for isolates with GyrA (Ser81Phe) and ParC (Ser79Phe) alterations, for which levofloxacin MICs were >16 μg/ml. No difference in the frequency of selection of mutations (<10−8 at four times the MIC) in wild-type or first-step mutant isolates of S. aureus or S. pneumoniae was detected for the two NFQs. On the basis of their in vitro activities, these NFQ agents show potential for the treatment of infections caused by isolates resistant to currently available fluoroquinolones.

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