scholarly journals Antimicrobial Activity of Pigments Extracted from Auxenochlorella protothecoides SC3 against Pseudomonas aeruginosa

2021 ◽  
Vol 10 (2) ◽  
pp. 163-167
Author(s):  
Elif ARSLAN ◽  
Şeymanur ÇOBANOĞLU ◽  
Ayşenur YAZICI
2019 ◽  
Vol 9 (02) ◽  
Author(s):  
Hussein A Kadhum ◽  
Thualfakar H Hasan2

The study involved the selection of two isolates from Bacillus subtilis to investigate their inhibitory activity against some bacterial pathogens. B sub-bacteria were found to have a broad spectrum against test bacteria such as Staphylococcus aureus and Pseudomonas aeruginosa. They were about 23-30 mm and less against Klebsiella sp. The sensitivity of some antibodies was tested on the test samples. The results showed that the inhibitory ability of bacterial growth in the test samples using B. subtilis extract was more effective than the antibiotics used.


2019 ◽  
Vol 70 (10) ◽  
pp. 3603-3610
Author(s):  
Madalina Mihalache ◽  
Cornelia Guran ◽  
Aurelia Meghea ◽  
Vasile Bercu ◽  
Ludmila Motelica ◽  
...  

The three copper complexes having a-ketoglutaric acid (H2A) and 1- (o-tolyl) biguanide (TB) ligands have been synthesized and characterized. The proposed formulas for these complexes are: [Cu(TB)(HA)]Cl (C1), [Cu(TB)(HA)CH3COO]�H2O (C2) and [Cu(TB)(HA)](NO3) (C3) where HA represents deprotonated H2A. The complexes obtained were tested for antibacterial activity against Staphylococcus aureus ATCC 25923 and Pseudomonas aeruginosa ATCC 27853, antifungal activity on Candida albicans ATCC 10231 and antitumor activity on HeLa tumor cells. Due to the antitumor, antifungal, antimicrobial activity and inhibition of inert substrate adhesion, complexes synthesized could be used for potential therapeutic applications.


Antibiotics ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 751
Author(s):  
Marwa Reda Bakkar ◽  
Ahmed Hassan Ibrahim Faraag ◽  
Elham R. S. Soliman ◽  
Manar S. Fouda ◽  
Amir Mahfouz Mokhtar Sarguos ◽  
...  

COVID-19 is a pandemic disease caused by the SARS-CoV-2, which continues to cause global health and economic problems since emerging in China in late 2019. Until now, there are no standard antiviral treatments. Thus, several strategies were adopted to minimize virus transmission, such as social distancing, face covering protection and hand hygiene. Rhamnolipids are glycolipids produced formally by Pseudomonas aeruginosa and as biosurfactants, they were shown to have broad antimicrobial activity. In this study, we investigated the antimicrobial activity of rhamnolipids against selected multidrug resistant bacteria and SARS-CoV-2. Rhamnolipids were produced by growing Pseudomonas aeruginosa strain LeS3 in a new medium formulated from chicken carcass soup. The isolated rhamnolipids were characterized for their molecular composition, formulated into nano-micelles, and the antibacterial activity of the nano-micelles was demonstrated in vitro against both Gram-negative and Gram-positive drug resistant bacteria. In silico studies docking rhamnolipids to structural and non-structural proteins of SARS-CoV-2 was also performed. We demonstrated the efficient and specific interaction of rhamnolipids with the active sites of these proteins. Additionally, the computational studies suggested that rhamnolipids have membrane permeability activity. Thus, the obtained results indicate that SARS-CoV-2 could be another target of rhamnolipids and could find utility in the fight against COVID-19, a future perspective to be considered.


Biomolecules ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 745
Author(s):  
Melaine González-García ◽  
Fidel Morales-Vicente ◽  
Erbio Díaz Pico ◽  
Hilda Garay ◽  
Daniel G. Rivera ◽  
...  

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.


1983 ◽  
Vol 29 (10) ◽  
pp. 1339-1343 ◽  
Author(s):  
M. C. Modrzakowski ◽  
D. Dosch-Meier ◽  
R. L. Hodinka

Granule contents from rat polymorphonuclear neutrophils were prepared by extraction with 0.2 M acetate buffer (pH 4.0), dialyzed against phosphate-buffered saline (pH 7.0), and tested for bactericidal activity against selected target bacteria. Salmonella typhimurium LT-2 and a series of progressively rough lipopolysaccharide outer membrane mutants derived from it were used to monitor antimicrobial activity. Although an antimicrobial potential was present in rat granule contents for S. typhimurium, the growth of Pseudomonas aeruginosa PAO-1 in antimicrobial assay mixtures containing rat granule contents was substantially enhanced over control values. The growth enhancement property of the granule protein was heat resistant and promoted increased oxygen consumption by whole cells.


Author(s):  
María Díez-Aguilar ◽  
Marta Hernández-García ◽  
María-Isabel Morosini ◽  
Ad Fluit ◽  
Michael M Tunney ◽  
...  

Abstract Background Murepavadin, a novel peptidomimetic antibiotic, is being developed as an inhalation therapy for treatment of Pseudomonas aeruginosa respiratory infection in people with cystic fibrosis (CF). It blocks the activity of the LptD protein in P. aeruginosa causing outer membrane alterations. Objectives To determine the in vitro activity of murepavadin against CF P. aeruginosa isolates and to investigate potential mechanisms of resistance. Methods MIC values were determined by both broth microdilution and agar dilution and results compared. The effect of artificial sputum and lung surfactant on in vitro activity was also measured. Spontaneous mutation frequency was estimated. Bactericidal activity was investigated using time–kill assays. Resistant mutants were studied by WGS. Results The murepavadin MIC50 was 0.125 versus 4 mg/L and the MIC90 was 2 versus 32 mg/L by broth microdilution and agar dilution, respectively. Essential agreement was >90% when determining in vitro activity with artificial sputum or lung surfactant. It was bactericidal at a concentration of 32 mg/L against 95.4% of the strains within 1–5 h. Murepavadin MICs were 2–9 two-fold dilutions higher for the mutant derivatives (0.5 to >16 mg/L) than for the parental strains. Second-step mutants were obtained for the PAO mutS reference strain with an 8×MIC increase. WGS showed mutations in genes involved in LPS biosynthesis (lpxL1, lpxL2, bamA2, lptD, lpxT and msbA). Conclusions Murepavadin characteristics, such as its specific activity against P. aeruginosa, its unique mechanism of action and its strong antimicrobial activity, encourage the further clinical evaluation of this drug.


2011 ◽  
Vol 63 (1) ◽  
pp. 29-35 ◽  
Author(s):  
Gordana Zavisic ◽  
Zeljka Radulovic ◽  
Valentina Vranic ◽  
Jelena Begovic ◽  
L. Topisirovic ◽  
...  

The aim of this study was to investigate the probiotic potential of bacteriocin-producing lactobacilli strain Lactobacillus plantarum G2 isolated from the vaginal mucus of healthy women. The antimicrobial effect of G2 was confirmed in the mixed culture with pathogenic Escherichia coli, Staphylococcus aureus, Salmonella abony and Pseudomonas aeruginosa, while bacteriocine activity was detected against S. aureus and S. abony only. The strain showed an excellent survival rate in low pH and in the presence of bile salts. The percentage of adhered cells of L. plantarum G2 to hexadecane was 63.85?2.0 indicating the intermediate hydrophobicity.


Author(s):  
Hamza Mohamed Ahmed ◽  
Ashraf Mahmoud Ramadhani ◽  
Ibrahim Yaagoub Erwa ◽  
Omer Adam Omer Ishag ◽  
Mohamed Bosharh Saeed

cinnamon dating from 1000 AD when it was firstly recorded in English due to its important as aroma and as herbs. The aim of this study was to investigate phytochemicals constitutes, chemical composition and antimicrobial activity of the essential oil of commercial samples of Cinnamon verum bark. The essential oil was extracted by hydrodistillation, while the crude extracts were prepared by three different solvents methanol (70%), acetone and aqueous. Phytochemical screening of crude extracts was performed using standard methods. The essential oil was subjected to GC-MS analysis and tested against Staphylococcus aureus, Salmonella typhimurium, Pseudomonas aeruginosa, Eschericchia coli and Candida albicans. The obtained results indicated the presence of alkaloids, flavonoids, coumarin, tannins, terpenoids, saponin, glycoside, anthrocyanin and phenolic compounds in the methanolic, aqoueous and acetone extracts of C. verum bark; while the major components of the extracted essential oil of C. verum bark were cinnamaldehyde (85.50%), stigmasterol (3.69%), Cadinene (1.37%), (E)-cinnamaldehyde (1.35%), alpha-amorphene (1.33%), hydrocinnamaldehyde (1.28%), alpha-cubebene (1.25) and ergosterol (1.09%) respectively. The antimicrobial activity result indicated the high activity of the extracted essential oil against all tested microorganisms at high concentration; except in S. typhimurium and C. albicans at concentrations of 25% and 12.5% no activity was noticed. Based in our obtained results the essential oil of C. verum bark had high potential as antimicrobial agent, therefore, recommended for more advanced studies to be conducted on this abundant plant as natural source of antibiotics.


2020 ◽  
Vol 19 (5) ◽  
pp. 909-918
Author(s):  
Saqer Alarifi ◽  
Salam Massadeh ◽  
Mohammed Al-Agamy ◽  
Manal A.l. Aamery ◽  
Abdulkareem Al Bekairy ◽  
...  

Purpose: To incorporate ciprofloxacin (CIP) into solid lipid nanoparticles (SLN) in order to enhance its biopharmaceutical properties and antibacterial activity.Methods: A sonication melt-emulsification method was employed for the preparation of CIP-loaded SLN. The composition of the SLN was varied in order to investigate factors such as lipid type and combination ratio, drug to lipid ratio, and surfactant ratio. The produced SLN formulations wereevaluated for their particle size and shape, zeta potential, and entrapment efficiency. In addition, the effect of SLN formulation composition on its drug release profile and antimicrobial activity against Escherichia coli, Pseudomonas Aeruginosa, and Staphylococcus Aureus was also investigated.Results: The generated nanoparticles had particle size in the range of 165 to 320 nm. The zetapotential values were generally low within ± 5. All formulations exhibited entrapment efficiency between 50 and 90 %. CIP release exhibited a biphasic release profile with a low burst phase, followed by uniform controlled-release behavior of various rates. SLN-loaded CIP exhibited one-fold reduction in minimum inhibitory concentration (MIC) and caused significant inhibition of all the three bacterial strains tested, when compared with pure CIP.Conclusion: Loading of CIP into SLN significantly enhances its antimicrobial activity in vitro which can translate to significant enhancement of therapeutic outcomes by minimizing the dose-dependent adverse and side effects and/or enhancing the antimicrobial spectrum of activity. Keywords: Solid lipid nanoparticles, Sonication melt-emulsification, Ciprofloxacin, Escherichia coli, Pseudomonas aeruginosa


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