In VitroActivity of AZD0914, a Novel Bacterial DNA Gyrase/Topoisomerase IV Inhibitor, against Clinically Relevant Gram-Positive and Fastidious Gram-Negative Pathogens

ABSTRACTAZD0914, a new spiropyrimidinetrione bacterial DNA gyrase inhibitor with a novel mode of inhibition, has activity against bacterial species commonly cultured from patient infection specimens, including fluoroquinolone-resistant isolates. This study assessed thein vitroactivity of AZD0914 against key Gram-positive and fastidious Gram-negative clinical isolates collected globally in 2013. AZD0914 demonstrated potent activity, with MIC90s for AZD0914 of 0.25 mg/liter againstStaphylococcus aureus(n= 11,680), coagulase-negative staphylococci (n= 1,923), streptococci (n= 4,380), andMoraxella catarrhalis(n= 145), 0.5 mg/liter againstStaphylococcus lugdunensis(n= 120) andHaemophilus influenzae(n= 352), 1 mg/liter againstEnterococcus faecalis(n= 1,241), and 2 mg/liter againstHaemophilus parainfluenzae(n= 70). The activity againstEnterococcus faeciumwas more limited (MIC90, 8 mg/liter). The spectrum and potency of AZD0914 included fluoroquinolone-resistant isolates in each species group, including methicillin-resistant staphylococci, penicillin-resistant streptococci, vancomycin-resistant enterococci, β-lactamase-producingHaemophilusspp., andM. catarrhalis. Based on thesein vitrofindings, AZD0914 warrants further investigation for its utility against a variety of Gram-positive and fastidious Gram-negative bacterial species.

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In VitroAntibacterial Activity of AZD0914, a New Spiropyrimidinetrione DNA Gyrase/Topoisomerase Inhibitor with Potent Activity against Gram-Positive, Fastidious Gram-Negative, and Atypical Bacteria

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.04124-14 ◽

2014 ◽

Vol 59 (1) ◽

pp. 467-474 ◽

Cited By ~ 44

Author(s):

Michael D. Huband ◽

Patricia A. Bradford ◽

Linda G. Otterson ◽

Gregory S. Basarab ◽

Amy C. Kutschke ◽

...

Keyword(s):

Antibacterial Activity ◽

Legionella Pneumophila ◽

Bacterial Species ◽

Dna Gyrase ◽

Cross Resistance ◽

Gram Positive ◽

Gram Negative ◽

Content Type ◽

Topoisomerase Inhibitor

ABSTRACTAZD0914 is a new spiropyrimidinetrione bacterial DNA gyrase/topoisomerase inhibitor with potentin vitroantibacterial activity against key Gram-positive (Staphylococcus aureus,Staphylococcus epidermidis,Streptococcus pneumoniae,Streptococcus pyogenes, andStreptococcus agalactiae), fastidious Gram-negative (Haemophilus influenzaeandNeisseria gonorrhoeae), atypical (Legionella pneumophila), and anaerobic (Clostridium difficile) bacterial species, including isolates with known resistance to fluoroquinolones. AZD0914 works via inhibition of DNA biosynthesis and accumulation of double-strand cleavages; this mechanism of inhibition differs from those of other marketed antibacterial compounds. AZD0914 stabilizes and arrests the cleaved covalent complex of gyrase with double-strand broken DNA under permissive conditions and thus blocks religation of the double-strand cleaved DNA to form fused circular DNA. Whereas this mechanism is similar to that seen with fluoroquinolones, it is mechanistically distinct. AZD0914 exhibited low frequencies of spontaneous resistance inS. aureus, and if mutants were obtained, the mutations mapped togyrB. Additionally, no cross-resistance was observed for AZD0914 against recent bacterial clinical isolates demonstrating resistance to fluoroquinolones or other drug classes, including macrolides, β-lactams, glycopeptides, and oxazolidinones. AZD0914 was bactericidal in both minimum bactericidal concentration andin vitrotime-kill studies. Inin vitrocheckerboard/synergy testing with 17 comparator antibacterials, only additivity/indifference was observed. The potentin vitroantibacterial activity (including activity against fluoroquinolone-resistant isolates), low frequency of resistance, lack of cross-resistance, and bactericidal activity of AZD0914 support its continued development.

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

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.00777-20 ◽

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.

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Inhibition of Neisseria gonorrhoeae Type II Topoisomerases by the Novel Spiropyrimidinetrione AZD0914

Journal of Biological Chemistry ◽

10.1074/jbc.m115.663534 ◽

2015 ◽

Vol 290 (34) ◽

pp. 20984-20994 ◽

Cited By ~ 21

Author(s):

Gunther Kern ◽

Tiffany Palmer ◽

David E. Ehmann ◽

Adam B. Shapiro ◽

Beth Andrews ◽

...

Keyword(s):

Neisseria Gonorrhoeae ◽

Bacterial Species ◽

Dna Gyrase ◽

Resistant Mutant ◽

Multidrug Resistant ◽

Type Ii ◽

Topoisomerase Iv ◽

Gram Positive ◽

Gram Negative

We characterized the inhibition of Neisseria gonorrhoeae type II topoisomerases gyrase and topoisomerase IV by AZD0914 (AZD0914 will be henceforth known as ETX0914 (Entasis Therapeutics)), a novel spiropyrimidinetrione antibacterial compound that is currently in clinical trials for treatment of drug-resistant gonorrhea. AZD0914 has potent bactericidal activity against N. gonorrhoeae, including multidrug-resistant strains and key Gram-positive, fastidious Gram-negative, atypical, and anaerobic bacterial species (Huband, M. D., Bradford, P. A., Otterson, L. G., Basrab, G. S., Giacobe, R. A., Patey, S. A., Kutschke, A. C., Johnstone, M. R., Potter, M. E., Miller, P. F., and Mueller, J. P. (2014) In Vitro Antibacterial Activity of AZD0914: A New Spiropyrimidinetrione DNA Gyrase/Topoisomerase Inhibitor with Potent Activity against Gram-positive, Fastidious Gram-negative, and Atypical Bacteria. Antimicrob. Agents Chemother. 59, 467–474). AZD0914 inhibited DNA biosynthesis preferentially to other macromolecules in Escherichia coli and induced the SOS response to DNA damage in E. coli. AZD0914 stabilized the enzyme-DNA cleaved complex for N. gonorrhoeae gyrase and topoisomerase IV. The potency of AZD0914 for inhibition of supercoiling and the stabilization of cleaved complex by N. gonorrhoeae gyrase increased in a fluoroquinolone-resistant mutant enzyme. When a mutation, conferring mild resistance to AZD0914, was present in the fluoroquinolone-resistant mutant, the potency of ciprofloxacin for inhibition of supercoiling and stabilization of cleaved complex was increased greater than 20-fold. In contrast to ciprofloxacin, religation of the cleaved DNA did not occur in the presence of AZD0914 upon removal of magnesium from the DNA-gyrase-inhibitor complex. AZD0914 had relatively low potency for inhibition of human type II topoisomerases α and β.

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In VitroandIn VivoCharacterization of the Novel Oxabicyclooctane-Linked Bacterial Topoisomerase Inhibitor AM-8722, a Selective, Potent Inhibitor of Bacterial DNA Gyrase

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.00619-16 ◽

2016 ◽

Vol 60 (8) ◽

pp. 4830-4839 ◽

Cited By ~ 12

Author(s):

Christopher M. Tan ◽

Charles J. Gill ◽

Jin Wu ◽

Nathalie Toussaint ◽

Jingjun Yin ◽

...

Keyword(s):

Broad Spectrum ◽

Antibacterial Agents ◽

Cell Activity ◽

Dna Gyrase ◽

Topoisomerase Iv ◽

Bacterial Dna ◽

Whole Cell ◽

Content Type

ABSTRACTOxabicyclooctane-linked novel bacterial topoisomerase inhibitors (NBTIs) represent a new class of recently described antibacterial agents with broad-spectrum activity. NBTIs dually inhibit the clinically validated bacterial targets DNA gyrase and topoisomerase IV and have been shown to bind distinctly from known classes of antibacterial agents directed against these targets. Herein we report the molecular, cellular, andin vivocharacterization of AM-8722 as a representative N-alkylated-1,5-naphthyridone left-hand-side-substituted NBTI. Consistent with its mode of action, macromolecular labeling studies revealed a specific effect of AM-8722 to dose dependently inhibit bacterial DNA synthesis. AM-8722 displayed greater intrinsic enzymatic potency than levofloxacin versus both DNA gyrase and topoisomerase IV fromStaphylococcus aureusandEscherichia coliand displayed selectivity against human topoisomerase II. AM-8722 was rapidly bactericidal and exhibited whole-cell activity versus a range of Gram-negative and Gram-positive organisms, with no whole-cell potency shift due to the presence of DNA or human serum. Frequency-of-resistance studies demonstrated an acceptable rate of resistance emergencein vitroat concentrations 16- to 32-fold the MIC. AM-8722 displayed acceptable pharmacokinetic properties and was shown to be efficacious in mouse models of bacterial septicemia. Overall, AM-8722 is a selective and potent NBTI that displays broad-spectrum antimicrobial activityin vitroandin vivo.

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Design, Synthesis, and Antibacterial Screening of Some Novel Heteroaryl-Based Ciprofloxacin Derivatives as DNA Gyrase and Topoisomerase IV Inhibitors

Pharmaceuticals ◽

10.3390/ph14050399 ◽

2021 ◽

Vol 14 (5) ◽

pp. 399

Author(s):

Lamya H. Al-Wahaibi ◽

Amer A. Amer ◽

Adel A. Marzouk ◽

Hesham A.M. Gomaa ◽

Bahaa G. M. Youssif ◽

...

Keyword(s):

Antibacterial Activity ◽

Dna Gyrase ◽

Bacterial Strains ◽

Topoisomerase Iv ◽

Gram Positive ◽

Gram Negative ◽

E Coli ◽

Antibacterial Screening ◽

Ic50 Values

A novel series of ciprofloxacin hybrids comprising various heterocycle derivatives has been synthesized and structurally elucidated using 1H NMR, 13C NMR, and elementary analyses. Using ciprofloxacin as a reference, compounds 1–21 were screened in vitro against Gram-positive bacterial strains such as Staphylococcus aureus and Bacillus subtilis and Gram-negative strains such as Escherichia coli and Pseudomonas aeruginosa. As a result, many of the compounds examined had antibacterial activity equivalent to ciprofloxacin against test bacteria. Compounds 2–6, oxadiazole derivatives, were found to have antibacterial activity that was 88 to 120% that of ciprofloxacin against Gram-positive and Gram-negative bacteria. The findings showed that none of the compounds tested had antifungal activity against Aspergillus flavus, but did have poor activity against Candida albicans, ranging from 23% to 33% of fluconazole, with compound 3 being the most active (33% of fluconazole). The most potent compounds, 3, 4, 5, and 6, displayed an IC50 of 86, 42, 92, and 180 nM against E. coli DNA gyrase, respectively (novobiocin, IC50 = 170 nM). Compounds 4, 5, and 6 showed IC50 values (1.47, 6.80, and 8.92 µM, respectively) against E. coli topo IV in comparison to novobiocin (IC50 = 11 µM).

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Characterization of the Novel DNA Gyrase Inhibitor AZD0914: Low Resistance Potential and Lack of Cross-Resistance in Neisseria gonorrhoeae

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.04456-14 ◽

2014 ◽

Vol 59 (3) ◽

pp. 1478-1486 ◽

Cited By ~ 37

Author(s):

Richard A. Alm ◽

Sushmita D. Lahiri ◽

Amy Kutschke ◽

Linda G. Otterson ◽

Robert E. McLaughlin ◽

...

Keyword(s):

Neisseria Gonorrhoeae ◽

Oral Treatment ◽

Bacterial Species ◽

Treatment Options ◽

Dna Gyrase ◽

Cross Resistance ◽

Topoisomerase Iv ◽

Content Type

ABSTRACTThe unmet medical need for novel intervention strategies to treatNeisseria gonorrhoeaeinfections is significant and increasing, as rapidly emerging resistance in this pathogen is threatening to eliminate the currently available treatment options. AZD0914 is a novel bacterial gyrase inhibitor that possesses potentin vitroactivities against isolates with high-level resistance to ciprofloxacin and extended-spectrum cephalosporins, and it is currently in clinical development for the treatment ofN. gonorrhoeaeinfections. The propensity to develop resistance against AZD0914 was examined inN. gonorrhoeaeand found to be extremely low, a finding supported by similar studies withStaphylococcus aureus. The genetic characterization of both first-step and second-step mutants that exhibited decreased susceptibilities to AZD0914 identified substitutions in the conserved GyrB TOPRIM domain, confirming DNA gyrase as the primary target of AZD0914 and providing differentiation from fluoroquinolones. The analysis of available bacterial gyrase and topoisomerase IV structures, including those bound to fluoroquinolone and nonfluoroquinolone inhibitors, has allowed the rationalization of the lack of cross-resistance that AZD0914 shares with fluoroquinolones. Microbiological susceptibility data also indicate that the topoisomerase inhibition mechanisms are subtly different betweenN. gonorrhoeaeand other bacterial species. Taken together, these data support the progression of AZD0914 as a novel treatment option for the oral treatment ofN. gonorrhoeaeinfections.

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Gepotidacin (GSK2140944) In Vitro Activity against Gram-Positive and Gram-Negative Bacteria

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.00468-17 ◽

2017 ◽

Vol 61 (7) ◽

Cited By ~ 19

Author(s):

R. K. Flamm ◽

D. J. Farrell ◽

P. R. Rhomberg ◽

N. E. Scangarella-Oman ◽

H. S. Sader

Keyword(s):

Postantibiotic Effect ◽

Gram Positive ◽

Bacterial Dna ◽

Gram Negative ◽

Content Type ◽

E Coli ◽

Time Kill ◽

Synergy Testing ◽

Potential Use

ABSTRACT Gepotidacin is a first-in-class, novel triazaacenaphthylene antibiotic that inhibits bacterial DNA replication and has in vitro activity against susceptible and drug-resistant pathogens. Reference in vitro methods were used to investigate the MICs and minimum bactericidal concentrations (MBCs) of gepotidacin and comparator agents for Staphylococcus aureus, Streptococcus pneumoniae, and Escherichia coli. Gepotidacin in vitro activity was also evaluated by using time-kill kinetics and broth microdilution checkerboard methods for synergy testing and for postantibiotic and subinhibitory effects. The MIC90 of gepotidacin for 50 S. aureus (including methicillin-resistant S. aureus [MRSA]) and 50 S. pneumoniae (including penicillin-nonsusceptible) isolates was 0.5 μg/ml, and for E. coli (n = 25 isolates), it was 4 μg/ml. Gepotidacin was bactericidal against S. aureus, S. pneumoniae, and E. coli, with MBC/MIC ratios of ≤4 against 98, 98, and 88% of the isolates tested, respectively. Time-kill curves indicated that the bactericidal activity of gepotidacin was observed at 4× or 10× MIC at 24 h for all of the isolates. S. aureus regrowth was observed in the presence of gepotidacin, and the resulting gepotidacin MICs were 2- to 128-fold higher than the baseline gepotidacin MICs. Checkerboard analysis of gepotidacin combined with other antimicrobials demonstrated no occurrences of antagonism with agents from multiple antimicrobial classes. The most common interaction when testing gepotidacin was indifference (fractional inhibitory concentration index of >0.5 to ≤4; 82.7% for Gram-positive isolates and 82.6% for Gram-negative isolates). The postantibiotic effect (PAE) of gepotidacin was short when it was tested against S. aureus (≤0.6 h against MRSA and MSSA), and the PAE–sub-MIC effect (SME) was extended (>8 h; three isolates at 0.5× MIC). The PAE of levofloxacin was modest (0.0 to 2.4 h), and the PAE-SME observed varied from 1.2 to >9 h at 0.5× MIC. These in vitro data indicate that gepotidacin is a bactericidal agent that exhibits a modest PAE and an extended PAE-SME against Gram-positive and -negative bacteria and merits further study for potential use in treating infections caused by these pathogens.

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Ceftobiprole Activity against Gram-Positive and -Negative Pathogens Collected from the United States in 2006 and 2016

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.01566-18 ◽

2018 ◽

Vol 63 (1) ◽

Cited By ~ 8

Author(s):

Michael A. Pfaller ◽

Robert K. Flamm ◽

Rodrigo E. Mendes ◽

Jennifer M. Streit ◽

Jennifer I. Smart ◽

...

Keyword(s):

United States ◽

The United States ◽

Large Set ◽

Coagulase Negative Staphylococci ◽

Gram Positive ◽

Gram Negative ◽

Content Type ◽

Highly Active ◽

Serious Infections

ABSTRACT Ceftobiprole is an advanced cephalosporin with potent activity against Gram-positive and Gram-negative bacteria that has been approved in many European and non-European countries to treat community- and hospital-acquired pneumonia (excluding ventilator-associated pneumonia). This study reports on the activity of ceftobiprole against a large set of clinical isolates obtained from hospitalized patients in the United States in 2016 that caused serious infections, including pneumonia, bacteremia, and skin and skin structure infections. To assess any potential temporal changes in ceftobiprole activity, the 2016 results were compared to corresponding MIC data from a 2006 U.S. survey that included key target pathogens. Ceftobiprole exhibited potent activity against Staphylococcus aureus (including methicillin-resistant S. aureus isolates, which were 99.3% susceptible), coagulase-negative staphylococci (100% susceptible), Enterococcus faecalis (100% susceptible), Streptococcus pneumoniae (99.7% susceptible), and other tested streptococci. Similarly, ceftobiprole was highly active against Enterobacteriaceae isolates that did not exhibit an extended-spectrum β-lactamase (ESBL) phenotype, including Escherichia coli (99.8% susceptible) and Klebsiella pneumoniae (99.6% susceptible). A total of 99.6% of all Haemophilus influenzae and Moraxella catarrhalis isolates were inhibited at ≤1 mg/liter ceftobiprole, and 72.7% of the Pseudomonas aeruginosa isolates were susceptible to ceftobiprole. With the exception of decreased cephalosporin susceptibility among Enterobacteriaceae isolates, which correlates with an increased prevalence of ESBL-producing isolates, ceftobiprole had similar activities against the isolate sets collected in 2006 and 2016. Therefore, ceftobiprole remains highly active when tested in vitro against a large number of current Gram-positive or Gram-negative pathogens that cause serious infections.

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Factors Influencing the Microbial Composition of Metalworking Fluids and Potential Implications for Machine Operator's Lung

Applied and Environmental Microbiology ◽

10.1128/aem.06230-11 ◽

2011 ◽

Vol 78 (1) ◽

pp. 34-41 ◽

Cited By ~ 26

Author(s):

Jean-Benjamin Murat ◽

Frédéric Grenouillet ◽

Gabriel Reboux ◽

Emmanuelle Penven ◽

Adam Batchili ◽

...

Keyword(s):

Metal Cutting ◽

Hypersensitivity Pneumonitis ◽

Environmental Parameters ◽

Metalworking Fluids ◽

Microbial Composition ◽

Gram Positive ◽

Gram Negative ◽

Content Type ◽

Kinetics Of

ABSTRACTHypersensitivity pneumonitis, also known as “machine operator's lung” (MOL), has been related to microorganisms growing in metalworking fluids (MWFs), especiallyMycobacterium immunogenum. We aimed to (i) describe the microbiological contamination of MWFs and (ii) look for chemical, physical, and environmental parameters associated with variations in microbiological profiles. We microbiologically analyzed 180 MWF samples from nonautomotive plants (e.g., screw-machining or metal-cutting plants) in the Franche-Comté region in eastern France and 165 samples from three French automotive plants in which cases of MOL had been proven. Our results revealed two types of microbial biomes: the first was from the nonautomotive industry, showed predominantly Gram-negative rods (GNR), and was associated with a low risk of MOL, and the second came from the automotive industry that was affected by cases of MOL and showed predominantly Gram-positive rods (GPR). Traces ofM. immunogenumwere sporadically detected in the first type, while it was highly prevalent in the automotive sector, with up to 38% of samples testing positive. The use of chromium, nickel, or iron was associated with growth of Gram-negative rods; conversely, growth of Gram-positive rods was associated with the absence of these metals. Synthetic MWFs were more frequently sterile than emulsions. Vegetable oil-based emulsions were associated with GNR, while mineral ones were associated with GPR. Our results suggest that metal types and the nature of MWF play a part in MWF contamination, and this work shall be followed by furtherin vitrosimulation experiments on the kinetics of microbial populations, focusing on the phenomena of inhibition and synergy.

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In vitro synergy of 5-nitrofurans, vancomycin and sodium deoxycholate against Gram-negative pathogens

Journal of Medical Microbiology ◽

10.1099/jmm.0.001304 ◽

2021 ◽

Author(s):

Catrina Olivera ◽

Vuong Van Hung Le ◽

Catherine Davenport ◽

Jasna Rakonjac

Keyword(s):

Growth Inhibition ◽

Type Species ◽

Sodium Deoxycholate ◽

Gram Positive ◽

Bacterial Killing ◽

Gram Negative ◽

Content Type ◽

Link Type ◽

Time Kill

Introduction. There is an urgent need for effective therapies against bacterial infections, especially those caused by antibiotic-resistant Gram-negative pathogens. Hypothesis. Synergistic combinations of existing antimicrobials show promise due to their enhanced efficacies and reduced dosages which can mitigate adverse effects, and therefore can be used as potential antibacterial therapy. Aim. In this study, we sought to characterize the in vitro interaction of 5-nitrofurans, vancomycin and sodium deoxycholate (NVD) against pathogenic bacteria. Methodology. The synergy of the NVD combination was investigated in terms of growth inhibition and bacterial killing using checkerboard and time-kill assays, respectively. Results. Using a three-dimensional checkerboard assay, we showed that 5-nitrofurans, sodium deoxycholate and vancomycin interact synergistically in the growth inhibition of 15 out of 20 Gram-negative strains tested, including clinically significant pathogens such as carbapenemase-producing Escherichia coli , Klebsiella pneumoniae and Acinetobacter baumannii , and interact indifferently against the Gram-positive strains tested. The time-kill assay further confirmed that the triple combination was bactericidal in a synergistic manner. Conclusion. This study demonstrates the synergistic effect of 5-nitrofurans, sodium deoxycholate and vancomycin against Gram-negative pathogens and highlights the potential of the combination as a treatment for Gram-negative and Gram-positive infections.

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