scholarly journals Novel Tetrazole-Based Antimicrobial Agents Targeting Clinical Bacteria Strains: Exploring the Inhibition of Staphylococcus aureus DNA Topoisomerase IV and Gyrase

2021 ◽  
Vol 23 (1) ◽  
pp. 378
Author(s):  
Piotr Roszkowski ◽  
Jolanta Szymańska-Majchrzak ◽  
Michał Koliński ◽  
Sebastian Kmiecik ◽  
Małgorzata Wrzosek ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Antimicrobial Agents ◽  
Antimicrobial Properties ◽  
Docking Studies ◽  
Binding Modes ◽  
Bacterial Strains ◽  
Topoisomerase Iv ◽  
Drug Candidates ◽  
Antimicrobial Studies ◽  
Initial Stage

Eleven novel imide-tetrazoles were synthesized. In the initial stage of research, in silico structure-based pharmacological prediction was conducted. All compounds were screened for antimicrobial activity using standard and clinical strains. Within the studied group, compounds 1–3 were recognized as leading structures with the most promising results in antimicrobial studies. Minimal inhibitory concentration values for compounds 1, 2, 3 were within the range of 0.8–3.2 μg/mL for standard and clinical Gram-positive and Gram-negative bacterial strains, showing in some cases higher activity than the reference Ciprofloxacin. Additionally, all three inhibited the growth of all clinical Staphylococci panels: Staphylococcus aureus (T5592; T5591) and Staphylococcus epidermidis (5253; 4243) with MIC values of 0.8 μg/mL. Selected compounds were examined in topoisomerase IV decatenation assay and DNA gyrase supercoiling assay, followed by suitable molecular docking studies to explore the possible binding modes. In summary, the presented transition from substrate imide-thioureas to imide-tetrazole derivatives resulted in significant increase of antimicrobial properties. The compounds 1–3 proposed here provide a promising basis for further exploration towards novel antimicrobial drug candidates.

scholarly journals Silver (I) N-Heterocyclic Carbene Complexes: A Winning and Broad Spectrum of Antimicrobial Properties

2021 ◽  
Vol 22 (5) ◽  
pp. 2497
Author(s):  
Filippo Prencipe ◽  
Anna Zanfardino ◽  
Michela Di Napoli ◽  
Filomena Rossi ◽  
Stefano D’Errico ◽  
...  
Keyword(s):  
Bacterial Infections ◽  
Antimicrobial Agents ◽  
Antimicrobial Properties ◽  
Resistance Mechanisms ◽  
Heterocyclic Carbenes ◽  
Significant Activity ◽  
Bacterial Strains ◽  
Development Of Resistance ◽  
Starting Point ◽  
Catalytic Chemistry

The evolution of antibacterial resistance has arisen as the main downside in fighting bacterial infections pushing researchers to develop novel, more potent and multimodal alternative drugs.Silver and its complexes have long been used as antimicrobial agents in medicine due to the lack of silver resistance and the effectiveness at low concentration as well as to their low toxicities compared to the most commonly used antibiotics. N-Heterocyclic Carbenes (NHCs) have been extensively employed to coordinate transition metals mainly for catalytic chemistry. However, more recently, NHC ligands have been applied as carrier molecules for metals in anticancer applications. In the present study we selected from literature two NHC-carbene based on acridinescaffoldand detailed nonclassicalpyrazole derived mono NHC-Ag neutral and bis NHC-Ag cationic complexes. Their inhibitor effect on bacterial strains Gram-negative and positivewas evaluated. Imidazolium NHC silver complex containing the acridine chromophore showed effectiveness at extremely low MIC values. Although pyrazole NHC silver complexes are less active than the acridine NHC-silver, they represent the first example of this class of compounds with antimicrobial properties. Moreover all complexesare not toxic and they show not significant activity againstmammalian cells (Hek lines) after 4 and 24 h. Based on our experimental evidence, we are confident that this promising class of complexes could represent a valuable starting point for developing candidates for the treatment of bacterial infections, delivering great effectiveness and avoiding the development of resistance mechanisms.

scholarly journals Synthesis and Characterization of Cobalt(III) and Copper(II) Complexes of 2-((E)-(6-Fluorobenzo[d]thiazol-2-ylimino) methyl)-4-chlorophenol: DNA Binding and Nuclease Studies—SOD and Antimicrobial Activities

2018 ◽  
Vol 2018 ◽  
pp. 1-15 ◽  
Author(s):  
K. Savithri ◽  
B. C. Vasantha Kumar ◽  
H. K. Vivek ◽  
H. D. Revanasiddappa
Keyword(s):  
Metal Complexes ◽  
Antimicrobial Activities ◽  
Spectroscopic Studies ◽  
Docking Studies ◽  
Bacterial Strains ◽  
Spectral Techniques ◽  
Light Reduction ◽  
Drug Candidates ◽  
Ft Ir

A bidentate (N- and O-) imine-based ligand (L1) and its metal complexes of types [CuII(L1)2] (C1), [CuII(L1)(Phen)] (C2), [CoIII(L1)2] (C3), and [CoIII(L1)(Phen)] (C4) (L1 = 2-((E)-(6-fluorobenzo[d]thiazol-2-ylimino)methyl)-4-chlorophenol and phen = 1,10-phenanthroline) were synthesized as potential chemotherapeutic drug candidates. The prepared complexes were structurally characterized by spectral techniques (NMR, FT-IR, LC-MS, EPR, and electronic absorption), thermogravimetric analysis (TGA/DTA), magnetic moment, and CHNO elemental analysis. Spectroscopic studies suggested the distorted octahedral structure for all complexes. In vitro bioassay studies include binding and nuclease activities of the ligand and its complexes with target calf thymus- (CT-) DNA were carried out by employing UV-Vis, fluorescence spectroscopy, viscosity, and gel electrophoresis techniques. The extent of binding propensity was determined quantitatively by Kb and Ksv values which revealed a higher binding affinity for C2 and C4 as compared to C1 and C3. In addition, the scavenging superoxide anion free radical (O∙-2) activity of metal complexes was determined by nitroblue tetrazolium (NBT) light reduction assay. Molecular docking studies with DNA and SOD enzyme were also carried out on these compounds. The antimicrobial study has shown that all the compounds are potential antibacterial agents against Gram-negative bacterial strains and better antifungal agents with respect to standard drugs used.

Antimicrobial Properties of Human Lysozyme Transgenic Mouse Milk

1998 ◽  
Vol 61 (1) ◽  
pp. 52-56 ◽  
Author(s):  
ELIZABETH A. MAGA ◽  
GARY B. ANDERSON ◽  
JAMES S. CULLOR ◽  
WAYNE SMITH ◽  
JAMES D. MURRAY
Keyword(s):  
Staphylococcus Aureus ◽  
Transgenic Mice ◽  
Antimicrobial Properties ◽  
Transgenic Animals ◽  
Average Concentration ◽  
Bacterial Strains ◽  
Human Lysozyme ◽  
Pseudomonas Fragi ◽  
E Coli ◽  
Industry Standard

The antimicrobial properties of standard human lysozyme and the milk of transgenic mice expressing human lysozyme were investigated using bacterial strains important to the dairy industry. Standard human lysozyme was found to be effective at significantly slowing the growth of the milk cold-spoilage organism Pseudomonas fragi (P < 0.001), of a clinical isolate of the mastitis-causing organism Staphylococcus aureus (P < 0.005), and of a nonpathogenic strain of E. coli (P < 0.05). Milk from transgenic mice secreting human lysozyme in their milk at an average concentration of 0.38 mg/ml was found to be bacteriostatic against the cold-spoilage organisms Pseudomonas fragi and Lactobacillus viscous and a mastitis-causing strain of Staphylococcus aureus, but not against a pathogenic strain of E. coli. These results demonstrate that transgenic animals producing human lysozyme in their milk can affect the microbial nature of milk.

scholarly journals Obtaining and Characterizing Thin Layers of Magnesium Doped Hydroxyapatite by Dip Coating Procedure

Coatings ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 510 ◽  
Author(s):  
Daniela Predoi ◽  
Simona Liliana Iconaru ◽  
Mihai Valentin Predoi ◽  
Mikael Motelica-Heino ◽  
Nicolas Buton ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Antimicrobial Properties ◽  
Dip Coating ◽  
Thin Layers ◽  
Precipitation Method ◽  
Bacterial Strains ◽  
Antimicrobial Studies ◽  
Hydroxyapatite Coatings ◽  
Coating Procedure ◽  
Co Precipitation

A simple dip coating procedure was used to prepare the magnesium doped hydroxyapatite coatings. An adapted co-precipitation method was used in order to obtain a Ca25−xMgx(PO4)6(OH)2, 25MgHAp (xMg = 0.25) suspension for preparing the coatings. The stabilities of 25MgHAp suspensions were evaluated using ultrasound measurements, zeta potential (ZP), and dynamic light scattering (DLS). Using transmission electron microscopy (TEM) and scanning electron microscopy (SEM) information at nanometric resolution regarding the shape and distribution of the 25MgHAp particles in suspension was obtained. The surfaces of obtained layers were evaluated using SEM and atomic force microscopy (AFM) analysis. The antimicrobial evaluation of 25MgHAp suspensions and coatings on various bacterial strains and fungus were realized. The present study presents important results regarding the physico-chemical and antimicrobial studies of the magnesium doped hydroxyapatite suspensions, as well as the coatings. The studies have shown that magnesium doped hydroxyapatite suspensions prepared with xMg = 0.25 presented a good stability and relevant antimicrobial properties. The coatings made using 25MgHAp suspension were homogeneous and showed remarkable antimicrobial properties. Also, it was observed that the layer realized has antimicrobial properties very close to those of the suspension. Both samples of the 25MgHAp suspensions and coatings have very good biocompatible properties.

scholarly journals Chemically modified polystyrene co-loaded with antimicrobial agents

2021 ◽  
Vol 2120 (1) ◽  
pp. 012012
Author(s):  
Y X Koh ◽  
H L Choo ◽  
Y H Wong ◽  
C H Yeong
Keyword(s):  
Antimicrobial Agent ◽  
Antimicrobial Agents ◽  
Antimicrobial Properties ◽  
Silver Ions ◽  
Exchange Capacity ◽  
Secondary Process ◽  
Ionic Exchange ◽  
Bacterial Strains ◽  
Surgical Guides ◽  
Antimicrobial Material

Abstract A recent study showed that at least 50% of nosocomial infections are due to medical indwelling devices like surgical guides and prosthetics. This amounts to about 2 million patients affected a year. The reason for such statistics is the growth of microorganisms on the surfaces of the medical devices. There have been many attempts to create antimicrobial materials but most materials are unable to hold more than one antimicrobial agent without a secondary process. The study related to antimicrobial material with more than one type of agent is rarely found in literature. Hence, the objective of this project is to produce an antimicrobial material that can hold more than one antimicrobial agent without the need for a secondary process. The material is produced by sulfonating high impact polystyrene (HIPS) and attaching copper and silver ions. The optimum time of sulfonation of the HIPS was determined by the degree of sulfonation and ion exchange capacity. Then, the sulfonated HIPS were loaded with both copper and silver ions at different ratios. The 6-hour sample yielded the highest degree of sulfonation and ionic exchange capacity of 33.7% and 2.57 meq/g, respectively. In future work, the characterization of the 6-hour sulfonated HIPS sample loaded with copper and silver ions at different concentration ratios will be performed using TGA, DSC and FTIR spectroscopy. Lastly, the efficacy of the antimicrobial properties of the sulfonated HIPS will be tested using different bacterial strains.

scholarly journals Synthesis, Molecular Docking and Antimicrobial Activities of 5-(4-substituted-benzyl)-2-(furan/thiophen-2-ylmethylene hydrazono)thiazolidin-4-ones

2021 ◽  
Vol 11 (4) ◽  
pp. 12434-12446
Keyword(s):  
Escherichia Coli ◽  
Molecular Docking ◽  
1H Nmr Spectroscopy ◽  
Antimicrobial Properties ◽  
Antimicrobial Activities ◽  
Docking Studies ◽  
Binding Affinities ◽  
Bacterial Strains ◽  
Effective Synthesis

In our present work, we reported an effective synthesis, molecular docking, and antimicrobial properties of novel 5-(4-substituted-benzyl)-2-(furan/thiophen-2-ylmethylene hydrazono) thiazolidin-4-ones (6a-g) and (7a-i). The structures of the synthesized compounds (6a-g) and (7a-i) were elucidated by 1H-NMR spectroscopy. The molecular docking studies were performed for all the synthesized compounds against GlcN-6P using AutoDock-tools-1.5.6 and recorded the extent of H-bonding and binding affinities. The preselected compounds via molecular docking were further tested for in vitro antimicrobial activity against five bacterial strains (Escherichia coli, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, Staphylococcus aureus) and two fungal strains (Candida albicans and Cryptococcus neoformans). The antimicrobial findings exhibited that the compounds possessed significant antimicrobial potential.

scholarly journals New Urea Derivatives as Potential Antimicrobial Agents: Synthesis, Biological Evaluation, and Molecular Docking Studies

Antibiotics ◽  
2019 ◽  
Vol 8 (4) ◽  
pp. 178 ◽  
Author(s):  
Mahadev Patil ◽  
Anurag Noonikara-Poyil ◽  
Shrinivas D. Joshi ◽  
Shivaputra A. Patil ◽  
Siddappa A. Patil ◽  
...  
Keyword(s):  
Molecular Docking ◽  
Growth Inhibition ◽  
Acinetobacter Baumannii ◽  
Antimicrobial Agents ◽  
Docking Studies ◽  
Biological Evaluation ◽  
Bacterial Strains ◽  
Binding Interaction ◽  
Urea Derivatives ◽  
Molecular Docking Studies

A series of new urea derivatives, containing aryl moieties as potential antimicrobial agents, were designed, synthesized, and characterized by 1H NMR, 13C NMR, FT-IR, and LCMS spectral techniques. All newly synthesized compounds were screened in vitro against five bacterial strains (Escherichia coli, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Staphylococcus aureus) and two fungal strains (Candida albicans and Cryptococcus neoformans). Variable levels of interaction were observed for these urea derivatives. However, and of major importance, many of these molecules exhibited promising growth inhibition against Acinetobacter baumannii. In particular, to our delight, the adamantyl urea adduct 3l demonstrated outstanding growth inhibition (94.5%) towards Acinetobacter baumannii. In light of this discovery, molecular docking studies were performed in order to elucidate the binding interaction mechanisms of the most active compounds, as reported herein.

Synthesis, Antimicrobial Evaluation and In silico Studies of Novel 2,4- disubstituted-1,3-thiazole Derivatives

2018 ◽  
Vol 16 (2) ◽  
pp. 160-173 ◽  
Author(s):  
Mir Mohammad Masood ◽  
Mohammad Irfan ◽  
Shadab Alam ◽  
Phool Hasan ◽  
Aarfa Queen ◽  
...  
Keyword(s):  
In Silico ◽  
Bacterial Infections ◽  
Antimicrobial Agents ◽  
Docking Studies ◽  
Bacterial Strains ◽  
Thiazole Derivatives ◽  
Standard Drug ◽  
Hek 293 ◽  
In Silico Studies

Background: 2,4-disubstituted-1,3-thiazole derivatives (2a–j), (3a–f) and (4a–f) were synthesized, characterized and screened for their potential as antimicrobial agents. In the preliminary screening against a panel of bacterial strains, nine compounds showed moderate to potent antibacterial activity (IC50 = 13.7-90.8 μg/ml). </P><P> Methods: In the antifungal screening, compound (4c) displayed potent antifungal activity (IC50 = 26.5 &#181;g/ml) against Candida tropicalis comparable to the standard drug, fluconazole (IC50 = 10.5 &#181;g/ml). Based on in vitro antimicrobial results, compounds 2f, 4c and 4e were selected for further pharmacological investigations. Hemolytic activity using human red blood cells (hRBCs) and cytotoxicity by MTT assay on human embryonic kidney (HEK-293) cells revealed non-toxic nature of the selected compounds (2f, 4c and 4e). To ascertain their possible mode of action, docking studies with the lead inhibitors (2f, 4c and 4e) were performed using crystal structure coordinates of bacterial methionine aminopeptidases (MetAPs), an enzyme involved in bacterial protein synthesis and maturation. Results: The results of in vitro and in silico studies provide a rationale for selected compounds (2f, 4c and 4e) to be carried forward for further structural modifications and structure-activity relationship (SAR) studies against these bacterial infections. Conclusion: The study suggested binding with one or more key amino acid residues in the active site of Streptococcus pneumoniae MetAP (SpMetAP) and Escherichia coli MetAP (EcMetAP). In silico physicochemical properties using QikProp confirmed their drug likeliness.

scholarly journals Carbon nanotubes as antimicrobial agents for water disinfection and pathogen control

2018 ◽  
Vol 16 (2) ◽  
pp. 171-180 ◽  
Author(s):  
Dan Liu ◽  
Yiqin Mao ◽  
Lijun Ding
Keyword(s):  
Carbon Nanotubes ◽  
Antimicrobial Agents ◽  
Microbial Control ◽  
Antimicrobial Properties ◽  
Water Disinfection ◽  
Water Remediation ◽  
Waterborne Diseases ◽  
Bacterial Strains ◽  
Pathogen Control ◽  
Bacteria Resistance

Abstract Waterborne diseases significantly affect human health and are responsible for high mortality rates worldwide. Antibiotics have been known for decades for treatment of bacterial strains and their overuse and irrational applications are causing increasing bacteria resistance. Therefore, there is a strong need to find alternative ways for efficient water disinfection and microbial control. Carbon nanotubes (CNTs) have demonstrated strong antimicrobial properties due to their remarkable structure. This paper reviews the antimicrobial properties of CNTs, discusses diverse mechanisms of action against microorganisms as well as their applicability for water disinfection and microbial control. Safety concerns, challenges of CNTs as antimicrobial agents and future opportunities for their application in the water remediation process are also highlighted.

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