Evaluation of Pseudomonas aeruginosa Deacetylase LpxC Inhibitory Activity of Dual PDE4−TNFα Inhibitors:  A Multiscreening Approach

2007 ◽  
Vol 47 (3) ◽  
pp. 1188-1195 ◽  
Author(s):  
Rameshwar U. Kadam ◽  
Divita Garg ◽  
Archana Chavan ◽  
Nilanjan Roy
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Inhibitory Activity ◽  
Tnfα Inhibitors

The Study of Bacillus Subtils Antimicrobial Activity on Some of the Pathological Isolates

2019 ◽  
Vol 9 (02) ◽  
Author(s):  
Hussein A Kadhum ◽  
Thualfakar H Hasan2
Keyword(s):  
Staphylococcus Aureus ◽  
Pseudomonas Aeruginosa ◽  
Antimicrobial Activity ◽  
Bacillus Subtilis ◽  
Bacterial Growth ◽  
Broad Spectrum ◽  
Inhibitory Activity ◽  
Bacterial Pathogens ◽  
Inhibitory Ability ◽  
Selection Of

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.

scholarly journals Natural Product Rottlerin Derivatives Targeting Quorum Sensing

Molecules ◽  
2021 ◽  
Vol 26 (12) ◽  
pp. 3745
Author(s):  
Dittu Suresh ◽  
Shekh Sabir ◽  
Tsz Tin Yu ◽  
Daniel Wenholz ◽  
Theerthankar Das ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Quorum Sensing ◽  
Growth Inhibition ◽  
Natural Product ◽  
Bacterial Growth ◽  
Inhibitory Activity ◽  
Chalcone Derivatives ◽  
Synthetic Strategy ◽  
The Mannich Reaction ◽  
Bacterial Growth Inhibition

Rottlerin is a natural product consisting of chalcone and flavonoid scaffolds, both of which have previously shown quorum sensing (QS) inhibition in various bacteria. Therefore, the unique rottlerin scaffold highlights great potential in inhibiting the QS system of Pseudomonas aeruginosa. Rottlerin analogues were synthesised by modifications at its chalcone- and methylene-bridged acetophenone moieties. The synthesis of analogues was achieved using an established five-step synthetic strategy for chalcone derivatives and utilising the Mannich reaction at C6 of the chromene to construct morpholine analogues. Several pyranochromene chalcone derivatives were also generated using aldol conditions. All the synthetic rottlerin derivatives were screened for QS inhibition and growth inhibition against the related LasR QS system. The pyranochromene chalcone structures displayed high QS inhibitory activity with the most potent compounds, 8b and 8d, achieving QS inhibition of 49.4% and 40.6% and no effect on bacterial growth inhibition at 31 µM, respectively. Both compounds also displayed moderate biofilm inhibitory activity and reduced the production of pyocyanin.

scholarly journals Synthetic Antimicrobial Peptides Exhibit Two Different Binding Mechanisms to the Lipopolysaccharides Isolated from Pseudomonas aeruginosa and Klebsiella pneumoniae

2014 ◽  
Vol 2014 ◽  
pp. 1-13 ◽  
Author(s):  
Hanbo Chai ◽  
William E. Allen ◽  
Rickey P. Hicks
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Klebsiella Pneumoniae ◽  
Antimicrobial Peptides ◽  
Inhibitory Activity ◽  
Binding Conformation ◽  
Cd Studies ◽  
Synthetic Antimicrobial Peptides ◽  
Activity Mechanism ◽  
Binding Mechanisms

Circular dichroism and 1H NMR were used to investigate the interactions of a series of synthetic antimicrobial peptides (AMPs) with lipopolysaccharides (LPS) isolated from Pseudomonas aeruginosa and Klebsiella pneumoniae. Previous CD studies with AMPs containing only three Tic-Oic dipeptide units do not exhibit helical characteristics upon interacting with small unilamellar vesicles (SUVs) consisting of LPS. Increasing the number of Tic-Oic dipeptide units to six resulted in five analogues with CD spectra that exhibited helical characteristics on binding to LPS SUVs. Spectroscopic and in vitro inhibitory data suggest that there are two possible helical conformations resulting from two different AMP-LPS binding mechanisms. Mechanism one involves a helical binding conformation where the AMP binds LPS very strongly and is not efficiently transported across the LPS bilayer resulting in the loss of inhibitory activity. Mechanism two involves a helical binding conformation where the AMP binds LPS very loosely and is efficiently transported across the LPS bilayer resulting in an increase in inhibitory activity. Mechanism three involves a nonhelical binding conformation where the AMP binds LPS very loosely and is efficiently transported across the LPS bilayer resulting in an increase in inhibitory activity.

scholarly journals Evaluation of the antimicrobial and anti-Varroa destructor L. activity of the essential oil of clove (Syzygium aromaticum L. Myrtaceae)

2021 ◽  
Vol 13 (4) ◽  
pp. 404-408
Author(s):  
K. Mekademi ◽  
D. Kebour ◽  
N.A. Ouchene-Khelifi ◽  
N. Ouchene
Keyword(s):  
Escherichia Coli ◽  
Pseudomonas Aeruginosa ◽  
Candida Albicans ◽  
Essential Oil ◽  
Inhibitory Activity ◽  
Varroa Destructor ◽  
Inhibition Zone ◽  
Syzygium Aromaticum ◽  
Penicillium Sp ◽  
Natural Treatment

Abstract. Antimicrobial and anti-Varroa destructor L. activity of the essential oil (EO) of clove (Syzygium aromaticum L. Myrtaceae) was evaluated in this study. Antimicrobial activity concerned 9 bacterial strains (Bacillus cereus, Escherichia coli ATCC 25911, Staphylococcus aureus 29213 ATCC, Proteus mirabilis, Serratia marcescens, Enterobacter sakazakii, Pseudomonas aeruginosa ATCC, Escherichia coli and Acinetobacter sp.), a fungal strain (Penicillium sp.) and a yeast species (Candida albicans). The extraction of the EO was carried out by the method of hydrodistillation. Results showed that EO has no toxicity on bees Apis mellifera. EO demonstrated effective and stable anti-V. destructor activity, indicating the absence of possible resistance, in contrast to what was observed for Amitraz. The inhibitory activity of EO revealed an inhibition zone of diameter varying between 20 mm and 42 mm for bacteria. However, no inhibition zones were observed for Pseudomonas aeruginosa ATCC. The inhibitory activity of EO on Penicillium sp and Candida albicans revealed an inhibition zone of 39 mm in diameter. This study shows that the EO of cloves constitutes a simple and natural treatment, without inconveniences, with a high activity antimicrobial and anti-Varroa destructor which merits it to be proposed as a means to fight against varroosis and the tested pathogens.

scholarly journals Caspofungin and Polymyxin B Reduce the Cell Viability and Total Biomass of Mixed Biofilms of Carbapenem-Resistant Pseudomonas aeruginosa and Candida spp.

2020 ◽  
Vol 11 ◽  
Author(s):  
Luciana Fernandes ◽  
Bruna Nakanishi Fortes ◽  
Nilton Lincopan ◽  
Kelly Ishida
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Inhibitory Activity ◽  
Inhibitory Concentration ◽  
Polymyxin B ◽  
Antibiofilm Activity ◽  
Total Biomass ◽  
Planktonic Cells ◽  
Carbapenem Resistant ◽  
Cell Counts ◽  
Viable Cells

Pseudomonas aeruginosa and Candida spp. are biofilm-forming pathogens commonly found colonizing medical devices, being mainly associated with pneumonia and bloodstream infections. The coinfection by these pathogens presents higher mortality rates when compared to those caused by a single microbial species. This study aimed to evaluate the antibiofilm activity of echinocandins and polymyxin B (PMB) against polymicrobial biofilms of carbapenem-resistant (CR) Pseudomonas aeruginosa and Candida spp. (C. albicans, C. parapsilosis, C. tropicalis, and C. glabrata). In addition, we tested the antimicrobial effect on their planktonic and monomicrobial biofilm counterparties. Interestingly, beyond inhibition of planktonic [minimum inhibitory concentration (MIC) = 0.5 μg/ml] and biofilm [minimum biofilm inhibitory concentration (MBIC)50 ≤ 2–8 μg/ml] growth of P. aeruginosa, PMB was also effective against planktonic cells of C. tropicalis (MIC = 2 μg/ml), and polymicrobial biofilms of CR P. aeruginosa with C. tropicalis (MBIC50 ≤ 2 μg/ml), C. parapsilosis (MBIC50 = 4–16 μg/ml), C. glabrata (MBIC50 = 8–16 μg/ml), or C. albicans (MBIC50 = 8–64 μg/ml). On the other hand, while micafungin (MFG) showed highest inhibitory activity against planktonic (MIC ≤ 0.008–0.5 μg/ml) and biofilm (MBIC50 ≤ 2–16 μg/ml) growth of Candida spp.; caspofungin (CAS) displays inhibitory activity against planktonic cells (MIC = 0.03–0.25 μg/ml) and monomicrobial biofilms (MBIC50 ≤ 2–64 μg/ml) of Candida spp., and notably on planktonic and monomicrobial biofilms of CR P. aeruginosa (MIC or MBIC50 ≥ 64 μg/ml). Particularly, for mixed biofilms, while CAS reduced significantly viable cell counts of CR P. aeruginosa and Candida spp. at ≥32 and ≥ 2 μg/ml, respectively; PMB was effective in reducing viable cells of CR P. aeruginosa at ≥2 μg/ml and Candida spp. at ≥8 μg/ml. Similar reduction of viable cells was observed for CAS (32–64 μg/ml) combined with PMB (2 μg/ml). These findings highlight the potential of PMB and CAS for the treatment of polymicrobial infections caused by Candida spp. and critical priority CR P. aeruginosa.

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