scholarly journals Improved activity of a synthetic indolicidin analog.

1997 ◽  
Vol 41 (4) ◽  
pp. 771-775 ◽  
Author(s):  
T J Falla ◽  
R E Hancock
Keyword(s):  
Escherichia Coli ◽  
Amino Acids ◽  
Candida Albicans ◽  
Short Length ◽  
Gram Negative Bacteria ◽  
Cationic Peptide ◽  
Gram Negative ◽  
Beta Galactosidase ◽  
Bovine Neutrophil ◽  
Positively Charged

A novel cationic peptide, CP-11, based on the structure of the bovine neutrophil peptide indolicidin, was designed to increase the number of positively charged residues, maintain the short length (13 amino acids), and enhance the amphipathicity relative to those of indolicidin. CP-11, and especially its carboxymethylated derivative, CP-11C, demonstrated improved activity against gram-negative bacteria and Candida albicans, while it maintained the activity of indolicidin against staphylococci and demonstrated a reduced ability to lyse erythrocytes. In Escherichia coli, CP-11 was better able than indolicidin to permeabilize both the outer membrane, as indicated by the enhancement of uptake of 1-N-phenylnaphthylamine, and the inner membrane, as determined by the unmasking of cytoplasmic beta-galactosidase, providing an explanation for its improved activity.

scholarly journals Requirements for the import of neisserial Omp85 into the outer membrane of human mitochondria

2013 ◽  
Vol 33 (2) ◽  
Author(s):  
Christine Ott ◽  
Mandy Utech ◽  
Monika Goetz ◽  
Thomas Rudel ◽  
Vera Kozjak-Pavlovic
Keyword(s):  
Escherichia Coli ◽  
Amino Acids ◽  
Outer Membrane ◽  
Gram Negative Bacteria ◽  
Mitochondrial Targeting ◽  
Gram Negative ◽  
Outer Membranes ◽  
Sorting Signal ◽  
Targeting Signal ◽  
And Function

β-Barrel proteins are present only in the outer membranes of Gram-negative bacteria, chloroplasts and mitochondria. Fungal mitochondria were shown to readily import and assemble bacterial β-barrel proteins, but human mitochondria exhibit certain selectivity. Whereas enterobacterial β-barrel proteins are not imported, neisserial ones are. Of those, solely neisserial Omp85 is integrated into the outer membrane of mitochondria. In this study, we wanted to identify the signal that targets neisserial β-barrel proteins to mitochondria. We exchanged parts of neisserial Omp85 and PorB with their Escherichia coli homologues BamA and OmpC. For PorB, we could show that its C-terminal quarter can direct OmpC to mitochondria. In the case of Omp85, we could identify several amino acids of the C-terminal β-sorting signal as crucial for mitochondrial targeting. Additionally, we found that at least two POTRA (polypeptide-transport associated) domains and not only the β-sorting signal of Omp85 are needed for its membrane integration and function in human mitochondria. We conclude that the signal that directs neisserial β-barrel proteins to mitochondria is not conserved between these proteins. Furthermore, a linear mitochondrial targeting signal probably does not exist. It is possible that the secondary structure of β-barrel proteins plays a role in directing these proteins to mitochondria.

Green Synthesis of Novel ethyl 3-amino-5-(methylthio)-4-(5-substituted phenyloxazol-2-yl)thiophene-2-carboxylate derivatives

2021 ◽  
pp. 105-110
Author(s):  
Satish M. Chavan
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Pseudomonas Aeruginosa ◽  
Candida Albicans ◽  
Aspergillus Niger ◽  
Microwave Irradiation ◽  
Gram Negative Bacteria ◽  
Gram Negative ◽  
Green Protocol ◽  
Gram Positive Bacteria

Synthesis of novel ethyl 3-amino-5-(methylthio)-4-(5-substituted phenyloxazol-2-yl) thiophene-2-carboxylate derivatives from 3-amino-4-carbamoyl-5-(methylthio)thiophene-2-carboxylate was carried out by traditional as well as microwave irradiation green protocol. Ethyl 3-amino-5-(methylthio)-4-(5-substituted phenyloxazol-2-yl) thiophene-2-carboxylate derivatives were screened for antimicrobial screening against gram positive bacteria Staphylococcus aureus (ATCC 29737), gram negative bacteria Escherichia coli (ATCC 25922), Pseudomonas aeruginosa (ATCC 27853) and Candida albicans (MTCC 277), Aspergillus niger (MCIM 545) fungi.

scholarly journals Biotinylation Facilitates the Uptake of Large Peptides by Escherichia coli and Other Gram-Negative Bacteria

2005 ◽  
Vol 71 (4) ◽  
pp. 1850-1855 ◽  
Author(s):  
Jennifer R. Walker ◽  
Elliot Altman
Keyword(s):  
Escherichia Coli ◽  
Amino Acids ◽  
Pseudomonas Aeruginosa ◽  
Gram Negative Bacteria ◽  
Cell Fractionation ◽  
Peptide Antibiotics ◽  
Small Peptides ◽  
Gram Negative ◽  
E Coli ◽  
Serovar Typhimurium

ABSTRACT Gram-negative bacteria such as Escherichia coli can normally only take up small peptides less than 650 Da, or five to six amino acids, in size. We have found that biotinylated peptides up to 31 amino acids in length can be taken up by E. coli and that uptake is dependent on the biotin transporter. Uptake could be competitively inhibited by free biotin or avidin and blocked by the protonophore carbonyl m-chlorophenylhydrazone and was abolished in E. coli mutants that lacked the biotin transporter. Biotinylated peptides could be used to supplement the growth of a biotin auxotroph, and the transported peptides were shown to be localized to the cytoplasm in cell fractionation experiments. The uptake of biotinylated peptides was also demonstrated for two other gram-negative bacteria, Salmonella enterica serovar Typhimurium and Pseudomonas aeruginosa. This finding may make it possible to create new peptide antibiotics that can be used against gram-negative pathogens. Researchers have used various moieties to cause the illicit transport of compounds in bacteria, and this study demonstrates the illicit transport of the largest known compound to date.

scholarly journals Antimicrobial and antioxidant activity of the extracts from Origanum vulgare L. growing wild in Bosnia and Herzegovina

2018 ◽  
Vol 2 (2) ◽  
pp. 62
Author(s):  
Renata Bešta-Gajević ◽  
Erna Karalija ◽  
Anesa Jerković-Mujkić ◽  
Dženana Karadža ◽  
Lejla Smajlović-Skenderagić ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Antioxidant Activity ◽  
Bacillus Subtilis ◽  
Candida Albicans ◽  
Antioxidant Activities ◽  
Gram Negative Bacteria ◽  
Aqueous Extracts ◽  
Origanum Vulgare ◽  
Gram Negative

Antifungal, antimicrobial, insecticidal and antioxidant activities of Origanum vulgare L. provide the basis for suggesting that oregano plant extracts may be useful for prevention and treatment of many infection. The main goal of this study was to determine antimicrobial and antioxidant activities of methanolic and aqueous extracts from the leaves and flowers of Origanum vulgare. Antimicrobial testing of plant extracts was done using well diffusion method. Activity of extracts were tested against Gram positive bacteria: Staphylococcus aureus ATCC 25923, methicillin-resistant Staphylococcus aureus (MRSA) ATCC 33591, Bacillus subtilis ATCC 6633, Enterococcus faecalis ATCC 29212 and five Gram-negative bacteria: Salmonella abony ATCC 6017, Salmonella enterica serovar Enteritidis ATCC 31194, Pseudomonas aeruginosa ATCC 9027, Escherichia coli ATCC 25922, extended-spectrum β-lactamase (ESBL) producing Escherichia coli ATCC 35218 and fungi Candida albicans ATCC 1023. Antibiotics ampicillin, streptomycin and antimycotic nystatin were used as positive controle. The antioxidant activity was determined by using the DPPH (1,1-diphenyl-2-picrylhydrazyl) method. The highest values for inhibition zone for methanolic and aqueous extracts were recorded for Gram positive Bacillus subtilis, Staphylococcus aureus and MRSA. Methanolic extracts exhibited antibacterial activity against tested Gram negative bacteria in variable degree while the growth of these bacteria was not inhibited by aqueous extracts. Tested fungi Candida albicans was not susceptible to investigated oregano extracts. All the extracts showed moderate to potent antioxidant activity, among which the methanolic flower extract demonstrated the strongest antioxidant activity with the IC50 value of 0.205 mg/mL. Therefore it can be concluded that flower and leaf oregano extracts have great antibacterial and antioxidant potential.

scholarly journals Comparison of the Effects of Gram- Negative Bacteria and Their Sterile Supernatants on Candida albicans Biofilm

2021 ◽  
Author(s):  
Mayram Hacıoğlu ◽  
Özlem Oyardı
Keyword(s):  
Escherichia Coli ◽  
Pseudomonas Aeruginosa ◽  
Candida Albicans ◽  
Inhibitory Effect ◽  
Gram Negative Bacteria ◽  
Gram Negative ◽  
E Coli ◽  
Candida Albicans Biofilms ◽  
Microscopy Images ◽  
Antagonist Effect

Objective: Polymicrobial biofilms consisting of a combination of various bacteria and/or fungi are generally much more resistant than monomicrobial biofilms formed by these species alone. In this study, it was aimed to investigate how Candida albicans biofilms were affected in the presence of Escherichia coli, Klebsiella pneumoniae, Acinetobacter baumannii or Pseudomonas aeruginosa or supernatants of these bacteria. Method: C. albicans with Gram-negative polymicrobial biofilms were formed on sterile microplates by using control strains of C. albicans SC 5314, E. coli ATCC 25922, K. pneumoniae ATCC 700603, A. baumannii ATCC 19606 and P. aeruginosa PA01. The number of C. albicans in biofilms was determined in the presence of both Gram- negative bacteria and sterile supernatants. Results: According to our results, all Gram negative bacteria displayed an antagonist effect against C. albicans in the biofilm and a three log decrease was observed compared to the control. Sterile supernatants were shown to have an inhibitory effect on the C. albicans biofilms and reduce the number of yeasts by at least one log. MTT assay and fluorescence microscopy images also confirmed the results. Conclusion: In C. albicans-Gram-negative polymicrobial biofilms that can occur in many infections, bacteria affected C. albicans biofilm cells as antagonist agents, both with their cells and sterile cell-free supernatants

scholarly journals STUDY OF MICROORGANISMS SUSCEPTIBILITY TO LYSOZYME COMBINATION WITH MEDICINAL SUBSTANCES

2016 ◽  
Author(s):  
I. I. Romanovska ◽  
S. S. Dekina ◽  
І. B. Psakhis ◽  
B. Y. Psakhis
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Pseudomonas Aeruginosa ◽  
Candida Albicans ◽  
Antimicrobial Action ◽  
Gram Negative Bacteria ◽  
Chlorhexidine Digluconate ◽  
Disodium Edta ◽  
Gram Negative ◽  
Medicinal Substances

The susceptibility of Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli and Candida albicans strains to lysozyme, disodium EDTA, chlorhexidine digluconate, and their combinations was studied. It is shown that the addition of chlorhexidine bigluconate wides the spectrum of antimicrobial action of the enzyme in the all cases. The addition of chelator to the composition is effective against gram-negative bacteria Escherichia coli and yeastfungus Candida albicans.

scholarly journals Antibacterial and Antifungal Activity of the Triiodide [Na(12-Crown-4)2]I3 on the Pathogens Escherichia coli, Streptococcus pyogenes, Streptococcus faecalis, Bacillus subtilis, Proteus mirabilis, Pseudomonas aeruginosa, Klebsiella pneumoniae and Candida albicans

2017 ◽  
Author(s):  
Zehra Edis ◽  
Samir Haj Bloukh ◽  
Hamed Abu Sara
Keyword(s):  
Escherichia Coli ◽  
Pseudomonas Aeruginosa ◽  
Antimicrobial Activity ◽  
Bacillus Subtilis ◽  
Candida Albicans ◽  
Klebsiella Pneumoniae ◽  
Streptococcus Pyogenes ◽  
Proteus Mirabilis ◽  
Gram Negative Bacteria ◽  
Gram Negative

New antibacterial agents are needed to overcome the increasing number of infectious diseases caused by pathogenic microorganisms due to the emergence of multi-drug resistant strains.  In this context, halogens, especially Iodine is known since ages for its antimicrobial activity. Therefore, especially triiodides encapsulated in organometallic complexes can be helpful as new agents against microorganisms. The aims of this work was to study the biological activity of [Na(12-Crown-4)2]I3 against gram positive Streptococcus pyogenes, Streptococcus faecalis, the spore forming bacteria Bacillus subtilis and gram negative bacteria Escherichia coli, Proteus mirabilis, Pseudomonas aeruginosa and Klebsiella pneumoniae, as well as the yeast Candida albicans. The antimicrobial and antifungal activities of the triiodide were determined by zone of inhibition plate studies. [Na(12-Crown-4)2]I3 exhibited potent antimicrobial activity on gram positive Streptochocci and the yeast C. albicans. Furthermore, the gram negative bacteria P. aeruginosa and K. pneumoniae were less effectively inhibited, while E. coli and P. mirabilis proved to be even resistant.

scholarly journals Novel Ethyl 1,5-Disubstituted-1H-Pyrazole-3-Carboxylates as a New Class of Antimicrobial Agents

2014 ◽  
Vol 64 (3) ◽  
pp. 335-344 ◽  
Author(s):  
Awwad A. Radwan ◽  
Mostafa M. Ghorab ◽  
Mansour S. Alsaid ◽  
Fares K. Alanazi
Keyword(s):  
Escherichia Coli ◽  
Pseudomonas Aeruginosa ◽  
Antimicrobial Activity ◽  
Candida Albicans ◽  
Antimicrobial Agents ◽  
Gram Negative Bacteria ◽  
Pyrazole Derivatives ◽  
Reference Drug ◽  
Gram Negative ◽  
New Class

Abstract A series of pyrazole derivatives 9-22 were designed and synthesized. All the newly synthesized compounds were assayed for their antimicrobial activity against the Grampositive bacteria Staphyllococcus aureus and Bacillius subtilis and the Gram-negative bacteria Escherichia coli, Pseudomonas aeruginosa, in addition to the fungi organisms, Candida albicans, C. parapsilosis and C. tropicalis. Ethyl 5-(2,5-dimethylthiophen- 3-yl)-1-phenyl-1H-pyrazole-3-carboxylate (21) (MICE.coli = 0.038 μmol mL-1, MICP. aerug. = 0.067 μmol mL-1) is nearly as active as ampicillin (MIC = 0.033 and 0.067 μmol mL-1), respectively. Ethyl 5-(4-bromo-2-chlorophenyl)- 1-phenyl-1H-pyrazole-3-carboxylate (16) (MIC = 0.015 μmol mL-1) is more active than fluconazole (0.020 μmol mL-1) as a reference drug against C. parapsilosis.

Antimicrobial and cytotoxic activity of Macrophomina phaseolina isolated from gummosis infected citrus reticulata

2013 ◽  
pp. 125-133
Author(s):  
Rubal C Das ◽  
Rajib Banik ◽  
Robiul Hasan Bhuiyan ◽  
Md Golam Kabir
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Brine Shrimp ◽  
Inhibitory Concentration ◽  
Lethal Dose ◽  
Macrophomina Phaseolina ◽  
Chloroform Extract ◽  
Citrus Reticulata ◽  
Gram Negative Bacteria ◽  
Gram Negative

Macrophomina phaseolina is one of the pathogenic organisms of gummosis disease of orange tree (Citrus reticulata). The pathogen was identified from the observation of their colony size, shape, colour, mycelium, conidiophore, conidia, hyaline, spore, and appressoria in the PDA culture. The crude chloroform extracts from the organism showed antibacterial activity against a number of Gram positive and Gram-negative bacteria. The crude chloroform extract also showed promising antifungal activity against three species of the genus Aspergillus. The minimum inhibitory concentration (MIC) of the crude chloroform extract from M. phaseolina against Bacillus subtilis, Staphylococcus aureus, Escherichia coli, and Shigella sonnie were 128 ?gm, 256 ?gm, 128 ?gm and 64 ?gm/ml respectively. The LD50 (lethal dose) values of the cytotoxicity assay over brine shrimp of the crude chloroform extract from M. phaseolina was found to be 51.79 ?gm/ml. DOI: http://dx.doi.org/10.3329/cujbs.v5i1.13378 The Chittagong Univ. J. B. Sci.,Vol. 5(1 &2):125-133, 2010

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