scholarly journals Indole and (E)-2-hexenal, phytochemical potentiators of polymyxins against Pseudomonas aeruginosa and Escherichia coli.

1996 ◽  
Vol 40 (6) ◽  
pp. 1438-1441 ◽  
Author(s):  
A Kubo ◽  
C S Lunde ◽  
I Kubo
Keyword(s):  
Escherichia Coli ◽  
Pseudomonas Aeruginosa ◽  
Antimicrobial Activity ◽  
Biological Activity ◽  
Fold Increase ◽  
Polymyxin B ◽  
Gram Negative Bacteria ◽  
Gram Negative ◽  
Potential Efficacy ◽  
Colistin Methanesulfonate

Combinations of polymyxins and phytochemicals were tested for antimicrobial activity against two gram-negative bacteria. Various degrees of potentiation were found against Pseudomonas aeruginosa and Escherichia coli with (E)-2-hexenal and indole. Three-compound combinations were found to further increase the activity of polymyxin B sulfate and colistin methanesulfonate against both bacteria. Combinations with colistin against P. aeruginosa resulted in the highest degree of potentiation, with a 512-fold increase in colistin antimicrobial activity. These results indicate the potential efficacy of phytochemical combinations with antibiotics to enhance total biological activity.

Susceptibility of Gram-negative bacteria to the synergistic bactericidal action of serum and polymyxin B nonapeptide

1986 ◽  
Vol 32 (1) ◽  
pp. 66-69 ◽  
Author(s):  
Petri Viljanen ◽  
Helena Käyhty ◽  
Martti Vaara ◽  
Timo Vaara
Keyword(s):  
Escherichia Coli ◽  
Pseudomonas Aeruginosa ◽  
Enterobacter Cloacae ◽  
Polymyxin B ◽  
Gram Negative Bacteria ◽  
Bactericidal Action ◽  
Gram Negative ◽  
Degree Of Sensitization ◽  
Normal Human ◽  
Klebsiella Spp

Polymyxin B nonapeptide was able to sensitize Escherichia coli strains and strains of Salmonella typhimurium, Klebsiella spp., Enterobacter cloacae, Pseudomonas aeruginosa, and Haemophilus influenzae to the bactericidal action of fresh normal human serum. The degree of sensitization varied significantly within the strains. Strains of Proteus mirabilis, Neisseria gonorrhoeae, and N. meningitidis remained resistant.

Enhancement of photobactericidal activity of chlorin-e6-cellulose nanocrystals by covalent attachment of polymyxin B

2017 ◽  
Vol 5 (33) ◽  
pp. 6953-6962 ◽  
Author(s):  
Florent Le Guern ◽  
Tan-Sothea Ouk ◽  
Karine Grenier ◽  
Nicolas Joly ◽  
Vincent Lequart ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Pseudomonas Aeruginosa ◽  
Staphylococcus Epidermidis ◽  
Polymyxin B ◽  
Chlorin E6 ◽  
Covalent Attachment ◽  
Gram Negative Bacteria ◽  
Gram Negative ◽  
Gram Positive Bacteria

Following light irradiation, a new nanomaterial, elaborated from CNCs, chlorin-e6 and polymyxin B, demonstrated efficiency against Gram-negative bacteria (Escherichia coli,Pseudomonas aeruginosa) and Gram-positive bacteria (Staphylococcus aureus,Staphylococcus epidermidis).

scholarly journals Purification and Properties of Proline-Rich Antimicrobial Peptides from Sheep and Goat Leukocytes

1999 ◽  
Vol 67 (8) ◽  
pp. 4106-4111 ◽  
Author(s):  
Olga Shamova ◽  
Kim A. Brogden ◽  
Chengquan Zhao ◽  
Tung Nguyen ◽  
Vladimir N. Kokryakov ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Pseudomonas Aeruginosa ◽  
Antimicrobial Activity ◽  
Antimicrobial Peptides ◽  
Host Defense ◽  
Defense Mechanisms ◽  
Gram Negative Bacteria ◽  
Gram Negative ◽  
Purification And Properties

ABSTRACT We purified three proline-rich antimicrobial peptides from elastase-treated extracts of sheep and goat leukocytes and subjected two of them, OaBac5α and ChBac5, to detailed analysis. OaBac5α and ChBac5 were homologous to each other and to bovine Bac5. Both exhibited potent, broad-spectrum antimicrobial activity under low-concentration salt conditions. While the peptides remained active againstEscherichia coli, Pseudomonas aeruginosa,Bacillus subtilis, and Listeria monocytogenesin 100 mM NaCl, they lost activity against Staphylococcus aureus and Candida albicans under these conditions. ChBac5 was shown to bind lipopolysaccharide, a property that could enhance its ability to kill gram-negative bacteria. Proline-rich Bac5 peptides are highly conserved in ruminants and may contribute significantly to their innate host defense mechanisms.

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.

scholarly journals MexAB-OprM Efflux Pump Interaction with the Peptidoglycan of Escherichia coli and Pseudomonas aeruginosa

2021 ◽  
Vol 22 (10) ◽  
pp. 5328
Author(s):  
Miao Ma ◽  
Margaux Lustig ◽  
Michèle Salem ◽  
Dominique Mengin-Lecreulx ◽  
Gilles Phan ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Pseudomonas Aeruginosa ◽  
Cell Division ◽  
Membrane Proteins ◽  
Outer Membrane ◽  
Efflux Pump ◽  
Gram Negative Bacteria ◽  
Gram Negative ◽  
Active Efflux

One of the major families of membrane proteins found in prokaryote genome corresponds to the transporters. Among them, the resistance-nodulation-cell division (RND) transporters are highly studied, as being responsible for one of the most problematic mechanisms used by bacteria to resist to antibiotics, i.e., the active efflux of drugs. In Gram-negative bacteria, these proteins are inserted in the inner membrane and form a tripartite assembly with an outer membrane factor and a periplasmic linker in order to cross the two membranes to expulse molecules outside of the cell. A lot of information has been collected to understand the functional mechanism of these pumps, especially with AcrAB-TolC from Escherichia coli, but one missing piece from all the suggested models is the role of peptidoglycan in the assembly. Here, by pull-down experiments with purified peptidoglycans, we precise the MexAB-OprM interaction with the peptidoglycan from Escherichia coli and Pseudomonas aeruginosa, highlighting a role of the peptidoglycan in stabilizing the MexA-OprM complex and also differences between the two Gram-negative bacteria peptidoglycans.

scholarly journals Emergence of Colistin Resistant Gram-Negative Bacteria in a Tertiary Care Rural Hospital in 2019

KYAMC Journal ◽  
2020 ◽  
Vol 11 (2) ◽  
pp. 87-90
Author(s):  
Abdullah Akhtar Ahmed ◽  
Nusrat Akhtar Juyee ◽  
SM Ali Hasan
Keyword(s):  
Escherichia Coli ◽  
Pseudomonas Aeruginosa ◽  
Tertiary Care ◽  
Salmonella Typhi ◽  
Rural Hospital ◽  
Gram Negative Bacteria ◽  
Bacterial Isolates ◽  
Colistin Resistance ◽  
Sensitivity Testing ◽  
Gram Negative

Background: Colistin-resistant Gram-negative bacteria is a rapidly emerging global threatgenerated a sense of public alarm. Objective: To combat this challenge a study was designedto evaluate the fast spreading infections by colistin-resistant pathogens in the tertiary care rural hospital of Bangladesh. Materials and Methods: To study isolation ofpathogenic gram-negative bacilli,clinical sample (n-640) of hospitalized patients of Khwaja Yunus Ali Medical College Hospital in Enayetpur, Bangladesh during the 1st quarter of the year 2019 were used. The bacterial isolates were screened for meropenem and colistin-resistance. Results: A total of 156 bacterial isolates were studied which included Escherichia coli (n-112), Klebsiella pneumoniae (n-14), Pseudomonas aeruginosa (n-27), and Salmonella typhi (n-3). Antibiotic sensitivity testing showed that 32/156(20%) and 119/156 (76%) isolates were resistant to meropenem and colistin, respectively. whereas 50/156 (32%) isolates were resistant to both antibiotics. Escherichia coli, K. pneumoniae, pseudomonas aeruginosa, and Salmonella typhi isolates respectivelywere 112/156 (72%), 14/156 (9%). 27/156 (17%), and 3/156 (2%). Conclusion: Colistin is typically used as salvage therapy, or last-line treatment, for MDR gramnegative infections.But there is worrisome therapeutic scenario in our study finding of colistin resistance is 76% in Gram-negative bacteria of the clinical isolates. The restricted and rational use of colistin drug is the need of hour. KYAMC Journal Vol. 11, No.-2, July 2020, Page 87-90

scholarly journals Comparative Evaluation of Antimicrobial Activity and Composition of Rose Oils from Various Geographic Origins, in Particular Bulgarian Rose Oil

2008 ◽  
Vol 3 (7) ◽  
pp. 1934578X0800300 ◽  
Author(s):  
Velizar Gochev ◽  
Katrin Wlcek ◽  
Gerhard Buchbauer ◽  
Albena Stoyanova ◽  
Anna Dobreva ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Antimicrobial Activity ◽  
Essential Oils ◽  
Bacillus Cereus ◽  
Phenolic Compound ◽  
Comparative Evaluation ◽  
Gram Negative Bacteria ◽  
Gram Negative ◽  
Geographic Origins ◽  
Rose Oil

In the present study we evaluated the composition and antimicrobial activity of various rose oils from Bulgaria, Turkey, Morocco, Iran and China against three Gram-positive, three Gram-negative bacteria and two yeasts. The composition of the studied essential oils was determined by GC and GC/MS. Citronellol was the major compound of all the oil samples: 31.7% (Chinese oil); 32.6% (Iranian oil); 33.6% (Moroccan oil); 34.9% (Bulgarian oil) and 38,7 % (Turkish oil). For the Bulgarian oil we could determine the highest activity against all microorganisms. Bacillus cereus ATCC 11778 was the most sensitive strain to Bulgarian rose oil (MCC 128 μg/mL) and Pseudomonas aeruginosa ATCC 9627 and P. fluorescens were more resistible strains (MCC 4096 μg/mL). Antimicrobial activity of rose oils is mainly due to the action of oxygenated acyclic monoterpenes citronellol, geraniol, nerol and linalool, their acetate derivatives and the phenolic compound eugenol.

scholarly journals National Surveillance of Antimicrobial Susceptibility of Bacteremic Gram-Negative Bacteria with Emphasis on Community-Acquired Resistant Isolates: Report from the 2019 Surveillance of Multicenter Antimicrobial Resistance in Taiwan (SMART)

2020 ◽  
Vol 64 (10) ◽  
Author(s):  
Po-Yu Liu ◽  
Yu-Lin Lee ◽  
Min-Chi Lu ◽  
Pei-Lan Shao ◽  
Po-Liang Lu ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Pseudomonas Aeruginosa ◽  
Antimicrobial Resistance ◽  
Klebsiella Pneumoniae ◽  
Gram Negative Bacteria ◽  
National Surveillance ◽  
Gram Negative ◽  
Content Type ◽  
E Coli ◽  
Carbapenem Resistant

ABSTRACT A multicenter collection of bacteremic isolates of Escherichia coli (n = 423), Klebsiella pneumoniae (n = 372), Pseudomonas aeruginosa (n = 300), and Acinetobacter baumannii complex (n = 199) was analyzed for susceptibility. Xpert Carba-R assay and sequencing for mcr genes were performed for carbapenem- or colistin-resistant isolates. Nineteen (67.8%) carbapenem-resistant K. pneumoniae (n = 28) and one (20%) carbapenem-resistant E. coli (n = 5) isolate harbored blaKPC (n = 17), blaOXA-48 (n = 2), and blaVIM (n = 1) genes.

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