scholarly journals Antibacterial Role of SO42− , NO3− , C2O42− and CH3CO2− Anions on Cu(II) and Zn(II) Complexes of a Thiadiazole-derived Pyrrolyl Schiff Base

2002 ◽  
Vol 8 (5) ◽  
pp. 263-267 ◽  
Author(s):  
Zahid H. Chohan ◽  
Humayun Pervez ◽  
Abdul Rauf ◽  
Claudiu T. Supuran
Keyword(s):  
Schiff Base ◽  
Metal Ion ◽  
Condensation Reaction ◽  
Analytical Data ◽  
Bacterial Strains ◽  
Antibiotic Resistant ◽  
Novel Approach ◽  
Resistant Strains ◽  
New Compounds

A condensation reaction of 2-amino-1,3,4-thiadiazole with 2-pyrrolecarboxaldehyde to form tridentate NNN donor Schiff base has been performed. The prepared Schiff base was further used for the formation of metal complexes having stoichiometry [M(L)2]Xn , where M=Cu(II) or Zn(II), L=N-(2-pyrrolylmethylene)-2-amino-1,3,4-thiadiazole, X=SO42− , NO3− , C2O42− or CH3CO2− and n=1 or 2. The new compounds described here have been characterized by their physical, spectral and analytical data, and have been screened against several bacterial strains such as Escherichia coli, Staphylococcus aureus, and Pseudomonas aeruginosa. The antibacterial potency of the Schiff base increased upon chelation/complexation, having the same metal ion (cation) but different anions opening up a novel approach in finding new ways to fight against antibiotic resistant strains.

scholarly journals Antibacterial Co(II), Cu(II), Ni(II) and Zn(II) Complexes of Thiadiazoles Schiff Bases

2001 ◽  
Vol 8 (2) ◽  
pp. 95-101 ◽  
Author(s):  
Zahid H. Chohan ◽  
Maimoon F. Jaffery ◽  
Claudiu T. Supuran
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Antibacterial Activity ◽  
Schiff Bases ◽  
Bacterial Species ◽  
Analytical Data ◽  
Bacterial Strains ◽  
Antibiotic Resistant ◽  
Resistant Strains ◽  
New Compounds

Schiff bases were obtained by condensation of 2-amino-l,3,4-thiadiazole with 5-substituted-salicylaldehydes which were further used to obtain complexes of the type [M(L)2]Cl2, where M=Co(II), Cu(II), Ni(II) or Zn(II). The new compounds described here have been characterized by physical, spectral and analytical data, and have been screened for antibacterial activity against several bacterial strains such as Escherichia coli, Staphylococcus aureus, and Pseudomonas aeruginosa. The antibacterial potency of these Schiff bases increased upon chelation/complexation, against the tested bacterial species, opening new aproaches in the fight against antibiotic resistant strains.

scholarly journals Antibacterial Co(II) and Ni(II) Complexes of N-(2-Furanylmethylene)-2-Aminothiadiazole and Role of SO42− ,NO3− , C2O42− and CH3CO2− anions on Biological Properties

2002 ◽  
Vol 8 (5) ◽  
pp. 287-291 ◽  
Author(s):  
Zahid H. Chohan ◽  
Abdul Rauf ◽  
Claudiu T. Supuran
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Schiff Base ◽  
Analytical Data ◽  
Biological Properties ◽  
Octahedral Geometry ◽  
Complexation Reaction ◽  
Bacterial Strains ◽  
Tridentate Ligands

Co(II) and Ni(II) complexes with a Schiff base, N-(2-furanylmethylene)-2-aminothiadiazole have been prepared and characterized by their physical, spectral and analytical data. The synthesized Schiff-bases act as tridentate ligands during the complexation reaction with Co(II) and Ni(II. metal ions. They possess the composition [M(L)2]Xn (where M=Co(II) or Ni(II), L=, X=NO3− , SO42− , C2O42− or CH3CO2− and n=1 or 2) and show an octahedral geometry. In order to evaluate the effect of anions upon chelation, the Schiff-base and its complexes have been screened for antibacterial activity against bacterial strains e.g., Escherichia coli, Staphylococcus aureus, and Pseudomonas aeruginosa.

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

Cytotoxicity and Antibacterial Studies of Newly Synthesized Novel Heterocylcic Pyridine Derivative and its Metal Complexes

2021 ◽  
Vol 6 (4) ◽  
pp. 243-249
Author(s):  
B.R. Chaitanya Kumar ◽  
K. Sudhakar Babu ◽  
J. Latha
Keyword(s):  
Metal Complexes ◽  
Cell Lines ◽  
Cancer Cell ◽  
Metal Ion ◽  
Analytical Data ◽  
Cancer Cell Lines ◽  
Diffusion Method ◽  
Pyridine Derivative ◽  
Bacterial Strains ◽  
Physico Chemical

A pyridine derivative 2-((E)-1-(2-hydrazinyl-4-methyl-6-phenyl-pyridine-3-carboyl)ethyl)pyridine-4- carbonitrile (CPHPC) ligand and its 3d-metal(II) complexes has been synthesized (where [M = Co(II), Ni(II) and Cu(II)]. The physico-chemical, analytical data, UV-Vis, FT-IR, 1H NMR and ESR spectrum methods were used to characterize all of the synthesized complexes. Spectral investigations of metal(II) complexes revealed that the metal ion is surrounded by an octahedral geometry. Low conductance values indicated that the metal(II) complexes behave as non-electrolyte. The cytotoxic activity on lung cancer cell lines and hepatic cancer cell lines A549 and HepG2, respectively, with the ligand and their metal complexes were tested with MTT assay. The ligand and its metal complexes were tested for diverse harmful bacterial strains using the agar well diffusion method on Gram-negative bacteria such as Pseudomonas desmolyticum, Escherichia coli and Klebsiella aerogenes, as well as Gram-positive bacteria Staphylococcus aureus.

scholarly journals Synthesis and Characterization of new Schiff base Ligand type [N4O4] from 3-(Ethoxymethylene)pentane-2.4-dione and its Niп Complex

2019 ◽  
Vol 7 (1) ◽  
pp. 40
Author(s):  
Eman I. Alsalihi
Keyword(s):  
Schiff Base ◽  
Powder Diffraction ◽  
Metal Ion ◽  
Condensation Reaction ◽  
Molar Conductance ◽  
Diffusion Method ◽  
Agar Disc ◽  
Ligand Type ◽  
1H Nuclear Magnetic Resonance ◽  
Layer Chromatography

The Schiff base reaction plays an important role in the condensation reaction between 3-(ethoxymethylene) pentane- 2.4-dione and 3,3’-diaminobenzidine in the presence of calculated amounts of KOH as a catalyst. This reaction has been carried out in the ethanol under reflux and overnight stirring condition. All syntheses were carried out under an atmosphere of hydrogen forming a new ligand [3,3’,3’’,3’’’-(1E,1’E,1’’E,1’’’E)-(biphenyl-3,3’,4,4’-tetrayltetrakis (azan-1-yl-1-ylidene)) tetrakis (methan-1- yl-1-ylidene) tetrakis (4-methoxybut-3-en-2-one)] type [N4O4]. The ligand and its Niп complex of the general formula [Ni2(L)] have been characterized by spectroscopic methods (Fourier transform infrared and ultraviolet-visible), elemental analysis (C.H.N), metal content, magnetic susceptibility measurement, thin-layer chromatography, mass spectrometry, X-ray powder diffraction powder diffraction, 1H-nuclear magnetic resonance, molar conductance, and biological activity. The ligand and its Ni complex were exposed to two types of bacteria (Staphylococcus aureus and Bacillus subtilis), using the agar disc diffusion method, and the ligand and its Niп complex exhibited significant activities against these two types of bacteria. Our study revealed the formation of a new ligand type [N4O4] and four-coordinate tetrahedral structure around Niп metal ion with the ratio of 1:2 (ligand:metal) stable compounds which can be used in many fields, such as medicine and industry.

scholarly journals Integrating fish models in tuberculosis vaccine development

2020 ◽  
Vol 13 (8) ◽  
pp. dmm045716
Author(s):  
Anni K. Saralahti ◽  
Meri I. E. Uusi-Mäkelä ◽  
Mirja T. Niskanen ◽  
Mika Rämet
Keyword(s):  
Immune Responses ◽  
Vaccine Development ◽  
Bacillus Calmette Guerin ◽  
Antibiotic Resistant ◽  
Vaccine Candidates ◽  
Preclinical Evaluation ◽  
Vaccination Strategies ◽  
Resistant Strains ◽  
New Vaccines

ABSTRACTTuberculosis is a chronic infection by Mycobacterium tuberculosis that results in over 1.5 million deaths worldwide each year. Currently, there is only one vaccine against tuberculosis, the Bacillus Calmette–Guérin (BCG) vaccine. Despite widespread vaccination programmes, over 10 million new M. tuberculosis infections are diagnosed yearly, with almost half a million cases caused by antibiotic-resistant strains. Novel vaccination strategies concentrate mainly on replacing BCG or boosting its efficacy and depend on animal models that accurately recapitulate the human disease. However, efforts to produce new vaccines against an M. tuberculosis infection have encountered several challenges, including the complexity of M. tuberculosis pathogenesis and limited knowledge of the protective immune responses. The preclinical evaluation of novel tuberculosis vaccine candidates is also hampered by the lack of an appropriate animal model that could accurately predict the protective effect of vaccines in humans. Here, we review the role of zebrafish (Danio rerio) and other fish models in the development of novel vaccines against tuberculosis and discuss how these models complement the more traditional mammalian models of tuberculosis.

scholarly journals Synthesis, Characterization and Spectroscopic Studies of A Novel 2-[(E)-[(2,4-dichlorophenyl)imino]methyl]phenol Schiff Base and Its Metal Complexes

2012 ◽  
Vol 9 (3) ◽  
pp. 1543-1549
Author(s):  
Eman Turky Shamkhy ◽  
Isam Hussain T. Al-Karkhi
Keyword(s):  
Schiff Base ◽  
Metal Complexes ◽  
Metal Ion ◽  
Glacial Acetic Acid ◽  
Condensation Reaction ◽  
Spectroscopic Studies ◽  
Chloride Salt ◽  
Complexation Reaction ◽  
Spectroscopic Techniques ◽  
Physico Chemical

A novel Schiff base 2-{(E)-[(2,4-dichlorophenyl)imino]methyl}phenol (LB) was synthesized from the condensation reaction of 2,4-dichloroaniline with salicyladehyde in [1:1] ratio in the presence of glacial acetic acid as catalyst. Complexation reaction of this Schiff base with copper (II), cobalt (II) as nitrate salts and with Rhodium (III) as chloride salt to produce three coordinate metal complexes, with a Schiff base: Metal ion ratio of 2:1. These compounds have been characterized by a variety of physico-chemical and spectroscopic techniques. The ligand and its metal complexes were expected to show an interesting bioactivity and cytotoxicity.

Comparison of the activity spectra against pathogens of bacterial strains producing a mutacin or a lantibiotic

2001 ◽  
Vol 47 (4) ◽  
pp. 322-331 ◽  
Author(s):  
Hélène Morency ◽  
Marilaine Mota-Meira ◽  
Gisèle LaPointe ◽  
Christophe Lacroix ◽  
Marc C Lavoie
Keyword(s):  
Drug Resistance ◽  
Campylobacter Jejuni ◽  
Bacterial Pathogens ◽  
The Other ◽  
Bacterial Strains ◽  
Antibiotic Resistant ◽  
Major Threat ◽  
Antibiotic Compounds ◽  
Resistant Strains ◽  
Further Development

The increase of drug resistance among bacterial pathogens is currently a major threat in hospital settings. New and more efficient antibiotic compounds have to be developed to fight infectious diseases. In the present work, a deferred antagonism test was used to determine the activity of different bacterial strains producing either a mutacin or a lantibiotic against bacterial pathogens. The mutacins A, B, C, D, I, K, L, M, and nisins A and Z were active against all enterococci tested. Mutacins A and B, and nisins A and Z inhibited all the staphylococci tested. Except for the strains producing mutacins P, Q, and X, all the other producing strains inhibited the streptococci tested. Mutacins A, B, I, J, T, nisins A and Z, and epidermin inhibited the two antibiotic-resistant strains of Neisseria gonorrhoeae tested. Mutacins A, B, C, D, and nisins A and Z inhibited Campylobacter jejuni and Helicobacter pylori. Thus, the wide activity spectra of nisin A and Z are confirmed. These results also indicate that many of the mutacins, especially those of groups A, B, C, D, I, J, K, L, M, and T, could be candidates for further development as useful antibiotics.Key words: mutacin, lantibiotic, bacteriocin, antibiotic.

Lipids of antibiotic-resistant and -susceptible members of the Enterobacteriaceae

1977 ◽  
Vol 23 (8) ◽  
pp. 1045-1051 ◽  
Author(s):  
William J. Suling ◽  
William M. O'Leary
Keyword(s):  
Fatty Acids ◽  
Fatty Acid Analysis ◽  
Lower Amount ◽  
Bacterial Strains ◽  
Antibiotic Resistant ◽  
Cyclopropane Fatty Acids ◽  
Resistant Strains ◽  
Lower Ratio ◽  
Layer Chromatography ◽  
Chloroform Methanol

Lipids of antibiotic-resistant and related -susceptible strains of the Enterobacteriaceae were extracted with chloroform–methanol and characterized by thin-layer chromatography, densitometry, and fatty acid analysis using gas chromatography. Quantitative differences which correlated with antibiotic resistance existed among the phospholipids and fatty acids. A relatively higher concentration of a ninhydrin-positive phospholipid concomitant with a lower amount of phosphatidylethanolamine was observed in antibiotic-resistant strains of Serratia marcescens. Bacterial strains which harbored R-factor 222 had a higher ratio of phosphatidylglycerol to diphosphatidylglycerol than their respective parent strains while those strains which were resistant to the polymyxins had a lower ratio of these phospholipids. Differences in the relative amounts of certain unsaturated and cyclopropane fatty acids were observed between susceptible and resistant strains. Such differences, however, were dependent upon a particular genus and species.

scholarly journals Synthesis, Characterization, Cyclic Voltammetry, and Biological Studies of Co(II), Ni(II), and Cu(II) Complexes of a Tridentate Schiff Base, 1-((E)-(2-Mercaptophenylimino) Methyl) Naphthalen-2-ol (H2L1)

2020 ◽  
Vol 2020 ◽  
pp. 1-21
Author(s):  
Maurice Kuate ◽  
Mariam Asseng Conde ◽  
Evans Ngandung Mainsah ◽  
Awawou G. Paboudam ◽  
Francis Merlin M. Tchieno ◽  
...  
Keyword(s):  
Cyclic Voltammetry ◽  
Schiff Base ◽  
Antifungal Activity ◽  
Condensation Reaction ◽  
Azomethine Nitrogen ◽  
Bacterial Strains ◽  
Redox Systems ◽  
Biological Studies ◽  
Tridentate Schiff Base

A novel tridentate Schiff base, 1-((E)-(2-mercaptophenylimino) methyl) naphthalen-2-ol (H2L1), was synthesized by the condensation reaction of 2-hydroxy-1-naphthaldehyde with 2-aminothiophenol in absolute ethanol. The resulting ligand was reacted with Co(II), Ni(II), and Cu(II) ions to obtain tetrahedral CoL1, NiL1, and square planar CuL1 complexes. The Schiff base and its metal complexes were characterized using 1H-NMR, microanalysis, FT-IR, UV-visible, and mass spectroscopy (ESI-MS). All the compounds are soluble in DMSO and DMF. Spectroscopic studies show that the ligand coordinates to the metal center through the azomethine nitrogen, naphthoxide oxygen, and thiophenoxide sulfur to form a tridentate chelate system. Conductance measurements show that these compounds are molecular in solution. Cyclic voltammetry studies show Co(III)/Co(II) and Cu(II)/Cu(I) redox systems to be quasi-reversible involving a monoelectronic transfer while Ni(III)/Ni(II) was irreversible. In vitro antibacterial and antifungal activity against five bacterial strains (Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, Enterococcus faecalis, and Proteus mirabilis) and five fungal strains (Candida albicans, Candida glabrata, Candida tropicalis, Candida krusei, and Candida parapsilosis) showed no antifungal activity but moderate antibacterial activity on E. coli, S. aureus, P. aeruginosa, and P. mirabilis bacterial strains. Antioxidant studies reveal that the ligand and its Cu(II) complex are more potent than Co(II) and Ni(II) complexes to eliminate free radicals.

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