scholarly journals Potentiation of Antibiotic Activity by a Meldrum’s Acid Arylamino Methylene Derivative against Multidrug-Resistant Bacterial Strains

2020 ◽  
Author(s):  
Maria M. C. da Silva ◽  
José B. de Araújo-Neto ◽  
Ana C. J. de Araújo ◽  
Priscilla R. Freitas ◽  
Cícera D. de M. Oliveira-Tintino ◽  
...  
Keyword(s):  
Multidrug Resistant ◽  
Antibiotic Activity ◽  
Meldrum's Acid ◽  
Bacterial Strains ◽  
Meldrum’S Acid ◽  
Methylene Derivative

scholarly journals Enhancement of Antibiotic Activity by 1,8-Naphthyridine Derivatives against Multi-Resistant Bacterial Strains

Molecules ◽  
2021 ◽  
Vol 26 (23) ◽  
pp. 7400
Author(s):  
José B. de Araújo-Neto ◽  
Maria M. C. da Silva ◽  
Cícera D. de M. Oliveira-Tintino ◽  
Iêda M. Begnini ◽  
Ricardo A. Rebelo ◽  
...  
Keyword(s):  
Bacterial Infections ◽  
Bacterial Resistance ◽  
Antimicrobial Properties ◽  
Multidrug Resistant ◽  
Antibiotic Activity ◽  
Bacterial Strains ◽  
Microdilution Method ◽  
Fluoroquinolone Antibiotics ◽  
Broth Microdilution Method ◽  
Resistant Strains

The search for new antibacterial agents has become urgent due to the exponential growth of bacterial resistance to antibiotics. Nitrogen-containing heterocycles such as 1,8-naphthyridine derivatives have been shown to have excellent antimicrobial properties. Therefore, the purpose of this study was to evaluate the antibacterial and antibiotic-modulating activities of 1,8-naphthyridine derivatives against multi-resistant bacterial strains. The broth microdilution method was used to determine the minimum inhibitory concentration (MIC) of the following compounds: 7-acetamido-1,8-naphthyridin-4(1H)-one and 3-trifluoromethyl-N-(5-chloro-1,8-naphthyridin-2-yl)-benzenesulfonamide. The antibiotic-modulating activity was analyzed using subinhibitory concentrations (MIC/8) of these compounds in combination with norfloxacin, ofloxacin, and lomefloxacin. Multi-resistant strains of Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus aureus were used in both tests. Although the compounds had no direct antibacterial activity (MIC ≥ 1.024 µg/mL), they could decrease the MIC of these fluoroquinolones, indicating synergism was obtained from the association of the compounds. These results suggest the existence of a structure–activity relationship in this group of compounds with regard to the modulation of antibiotic activity. Therefore, we conclude that 1,8-naphthyridine derivatives potentiate the activity of fluoroquinolone antibiotics against multi-resistant bacterial strains, and thereby interesting candidates for the development of drugs against bacterial infections caused by multidrug resistant strains.

An Expeditious One-Pot Three-Component Synthesis of 4-Aryl-3,4-dihydrobenzo[g] quinoline-2,5,10(1H)-triones under Green Conditions

2020 ◽  
Vol 23 (23) ◽  
pp. 2626-2634
Author(s):  
Saiedeh Kamalifar ◽  
Hamzeh Kiyani
Keyword(s):  
Reaction Medium ◽  
Meldrum's Acid ◽  
Meldrum’S Acid ◽  
One Pot ◽  
One Pot Synthesis ◽  
Substituted Benzaldehydes ◽  
High Yields ◽  
First Time ◽  
Green Conditions

: An efficient and facial one-pot synthesis of 4-aryl-3,4-dihydrobenzo[g]quinoline- 2,5,10(1H)-triones was developed for the first time. The process proceeded via the three-component cyclocondensation of 2-amino-1,4-naphthoquinone with Meldrum’s acid and substituted benzaldehydes under green conditions. The fused 3,4-dihydropyridin-2(1H)- one-ring naphthoquinones have been synthesized with good to high yields in refluxing ethanol as a green reaction medium. This protocol is simple and effective as well as does not involve the assistance of the catalyst, additive, or hazardous solvents.

scholarly journals Cover Feature: Cp*Rh(III)‐Catalyzed C8 C−H Alkylation of Quinoline N ‐Oxides with Diazo Meldrum's Acid (Eur. J. Org. Chem. 3/2021)

2021 ◽  
Vol 2021 (3) ◽  
pp. 325-325
Author(s):  
Malcolm P. Huestis ◽  
Jean‐Philippe Leclerc ◽  
Robin Larouche‐Gauthier ◽  
Samuel Aubert‐Nicol ◽  
Arun Yadav ◽  
...  
Keyword(s):  
Meldrum's Acid ◽  
Meldrum’S Acid

scholarly journals Ventilation-Associated Particulate Matter Is a Potential Reservoir of Multidrug-Resistant Organisms in Health Facilities

Life ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 639
Author(s):  
Evgenia Chezganova ◽  
Olga Efimova ◽  
Vera Sakharova ◽  
Anna Efimova ◽  
Sergey Sozinov ◽  
...  
Keyword(s):  
Particulate Matter ◽  
Prevalence Ratio ◽  
Multidrug Resistant ◽  
Viable Count ◽  
Health Facilities ◽  
Hospital Environment ◽  
Bacterial Strains ◽  
Multidrug Resistant Organisms ◽  
Potential Reservoir ◽  
Healthcare Associated

Most healthcare-associated infections (HCAIs) develop due to the colonisation of patients and healthcare workers by multidrug-resistant organisms (MDRO). Here, we investigated whether the particulate matter from the ventilation systems (Vent-PM) of health facilities can harbour MDRO and other microbes, thereby acting as a potential reservoir of HCAIs. Dust samples collected in the ventilation grilles and adjacent air ducts underwent a detailed analysis of physicochemical properties and biodiversity. All Vent-PM samples included ultrafine PM capable of reaching the alveoli. Strikingly, >70% of Vent-PM samples were contaminated, mostly by viruses (>15%) or multidrug-resistant and biofilm-producing bacterial strains (60% and 48% of all bacteria-contaminated specimens, respectively). Total viable count at 1 m from the ventilation grilles was significantly increased after opening doors and windows, indicating an association between air flow and bacterial contamination. Both chemical and microbial compositions of Vent-PM considerably differed across surgical vs. non-surgical and intensive vs. elective care units and between health facilities located in coal and chemical districts. Reduced diversity among MDRO and increased prevalence ratio in multidrug-resistant to the total Enterococcus spp. in Vent-PM testified to the evolving antibiotic resistance. In conclusion, we suggest Vent-PM as a previously underestimated reservoir of HCAI-causing pathogens in the hospital environment.

Structural, Bioactivity, Molecular Docking, Spectroscopic and Electronic Properties of a Synthesized Meldrum's Acid Derivative

2021 ◽  
Vol 6 (19) ◽  
pp. 4698-4718
Author(s):  
Halil Gökce ◽  
Gökhan Alpaslan ◽  
Serdal Kaya ◽  
Nezaket Çakır
Keyword(s):  
Molecular Docking ◽  
Electronic Properties ◽  
Acid Derivative ◽  
Meldrum's Acid ◽  
Meldrum’S Acid

scholarly journals Antimicrobial Activity of Cyclic-Monomeric and Dimeric Derivatives of the Snail-Derived Peptide Cm-p5 against Viral and Multidrug-Resistant Bacterial Strains

Biomolecules ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 745
Author(s):  
Melaine González-García ◽  
Fidel Morales-Vicente ◽  
Erbio Díaz Pico ◽  
Hilda Garay ◽  
Daniel G. Rivera ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Antimicrobial Activity ◽  
Antifungal Activity ◽  
Multidrug Resistant ◽  
Moderate Activity ◽  
Dependent Manner ◽  
Bacterial Strains ◽  
Acinetobacter Baumanii ◽  
Concentration Dependent Manner ◽  
Conventional Antibiotics

Cm-p5 is a snail-derived antimicrobial peptide, which demonstrated antifungal activity against the pathogenic strains of Candida albicans. Previously we synthetized a cyclic monomer as well as a parallel and an antiparallel dimer of Cm-p5 with improved antifungal activity. Considering the alarming increase of microbial resistance to conventional antibiotics, here we evaluated the antimicrobial activity of these derivatives against multiresistant and problematic bacteria and against important viral agents. The three peptides showed a moderate activity against Pseudomonas aeruginosa, Klebsiella pneumoniae Extended Spectrum β-Lactamase (ESBL), and Streptococcus agalactiae, with MIC values > 100 µg/mL. They exerted a considerable activity with MIC values between 25–50 µg/mL against Acinetobacter baumanii and Enterococcus faecium. In addition, the two dimers showed a moderate activity against Pseudomonas aeruginosa PA14. The three Cm-p5 derivatives inhibited a virulent extracellular strain of Mycobacterium tuberculosis, in a dose-dependent manner. Moreover, they inhibited Herpes Simplex Virus 2 (HSV-2) infection in a concentration-dependent manner, but had no effect on infection by the Zika Virus (ZIKV) or pseudoparticles of Severe Acute Respiratory Syndrome Corona Virus 2 (SARS-CoV-2). At concentrations of >100 µg/mL, the three new Cm-p5 derivatives showed toxicity on different eukaryotic cells tested. Considering a certain cell toxicity but a potential interesting activity against the multiresistant strains of bacteria and HSV-2, our compounds require future structural optimization.

scholarly journals 1564. Activity of bacteriophage against multidrug resistant Klebsiella pneumoniae

2020 ◽  
Vol 7 (Supplement_1) ◽  
pp. S782-S782
Author(s):  
Sailaja Puttagunta ◽  
Maya Kahan-Haanum ◽  
Sharon Kredo-Russo ◽  
Eyal Weinstock ◽  
Efrat Khabra ◽  
...  
Keyword(s):  
Klebsiella Pneumoniae ◽  
Unmet Need ◽  
Multidrug Resistant ◽  
Beta Lactamase ◽  
Bacterial Strains ◽  
Antibiotic Resistant ◽  
Extended Spectrum Beta Lactamase ◽  
Novel Approach ◽  
Infection Types

Abstract Background The prevalence of extended-spectrum beta-lactamase (ESBL) producing and carbapenem resistant (CR) Klebsiella pneumoniae (KP) has significantly risen in all geographic regions. Infections due to these bacteria are associated with high mortality across different infection types. Even with newer options, there remains an unmet need for safe and effective therapeutic options to treat infections caused by ESBL and CR KP. Phage therapy offers a novel approach with an unprecedented and orthogonal mechanism of action for treatment of diseases caused by pathogenic bacterial strains that are insufficiently addressed by available antibiotics. Phage-based therapies confer a high strain-level specificity and have a strong intrinsic safety profile. Here we describe the identification of novel phages that can effectively target antibiotic resistant KP strains. Host range of the 21 phages on 33 strain KP panel via solid culture infectivity assays. Red marks resistance to infection while sensitivity to phage is marked in green Methods KP clinical strains were isolated from human stool specimens preserved in glycerol. Selective culturing was carried, followed by testing of individual colonies for motility, indole and urease production, sequenced and analyzed by Kleborate tool to determine antibiotic resistant genes. Natural phages were isolated from plaques that developed on susceptible bacterial targets, sequenced and characterized. Results Antibiotic-resistant KP strains encoding beta lactamase genes or a carbapenemase (n=33) were isolated from healthy individuals (n=3), and patients with inflammatory bowel disease (n=26) or primary sclerosing cholangitis (n=3). Isolates sequencing revealed bla CTX-M15 and/or bla SHV encoding strains and carbapenamase KPC-2. A panel of 21 phages targeting the beta-lactamase- and carbapenemase-producing KP strains were identified. Phage sequencing revealed that all phages belong to the Caudovirales order and include 6 Siphoviridae, 14 Myoviridae, and 1 Podoviridae. In vitro lytic activity of the phages was tested on the isolated bacteria and revealed a coverage of 70% of the 33 isolated antibiotic resistant strains, >50% of which were targeted by multiple phages. Conclusion Collectively, these results demonstrate the feasibility of identifying phage with potent activity against antibiotic resistant KP strains, and may provide a novel therapeutic approach for treatment of ESBL and CR KP infections. Disclosures All Authors: No reported disclosures

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