scholarly journals Lauryl-poly-L-lysine: A New Antimicrobial Agent?

2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
Laetitia Vidal ◽  
Véronique Thuault ◽  
Arturo Mangas ◽  
Rafael Coveñas ◽  
Anne Thienpont ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Antibacterial Activity ◽  
Fatty Acid ◽  
Antimicrobial Agent ◽  
Inhibitory Concentration ◽  
Antibacterial Effect ◽  
Gram Negative Bacteria ◽  
Multiple Antibiotic Resistance ◽  
Good Ability

The development of multiple antibiotic resistance is a global problem. It is necessary to find new tools whose mechanisms of action differ from those of currently used antibiotics. It is known that fatty acids and cationic polypeptides are able to fight bacteria. Here, we describe the synthesis of fatty acids linked to a polypeptide with antibacterial activity. The linkage of fatty acids to a polypeptide is reported to increase the antibacterial effect of the linked fatty acid in comparison with free fatty acids (FA) or free poly-L-lysine (PLL) or a mixture of both (FA free + PLL free). A number of C6–C18 fatty acids were linked to PLL to obtain new synthetic products. These compounds were assessed in vitro to evaluate their antibacterial activity. Some fatty acid-PLLs showed a good ability to fight bacteria. Their bactericidal activity was evaluated, and, lauryl linked to PLL was found to be the most active product against both Gram-positive and Gram-negative bacteria. This new active component showed a good degree of specificity and reproducibility and its minimum inhibitory concentration (MIC) was comparatively good. The antibacterial activity of the lauryl-PLL compound suggests that it is a new and promising antimicrobial agent.

Diphenhydramine and levofloxacin combination therapy against antimicrobial resistance in respiratory tract infections

2021 ◽  
Vol 16 (6) ◽  
pp. 409-420
Author(s):  
Sadaf Areej ◽  
Adeel Sattar ◽  
Aqeel Javeed ◽  
Sohail Raza
Keyword(s):  
Antibacterial Activity ◽  
Concentration Index ◽  
Respiratory Tract Infections ◽  
Inhibitory Concentration ◽  
Antibacterial Effect ◽  
Gram Negative Bacteria ◽  
H1 Receptor ◽  
In Vitro Antibacterial Activity ◽  
Tract Infections

Background: Antibiotics are in use since decades to treat various infections caused by Gram-positive and Gram-negative bacteria such as Staphylococcus aureus and Pseudomonas aeruginosa. Diphenhydramine, an H1 receptor blocker possesses a weak antibiotic action but when combined with other antibiotics may potentiate their antibacterial activity. Materials & methods: This study investigated in vitro antibacterial activity of diphenhydramine when used alone and in combination with levofloxacin against methicillin-resistant S. aureus and P. aeruginosa. Results: The combined antibacterial effect of the drugs against bacteria showed a fractional inhibitory concentration index of ≤0.5, in other words, synergism. No cytotoxicity was observed as percentage cell viability was >50%. Conclusion: The combination of diphenhydramine and levofloxacin exerted antibacterial activity, and was not found to be cytotoxic when given in combination against P. aeruginosa and S. aureus.

scholarly journals In vitro antibacterial activity of essential oils from Lamiaceae species

2016 ◽  
Vol 5 (4) ◽  
pp. 141-144
Author(s):  
Vinod Kumar ◽  
◽  
C. S. Mathela ◽  
Amit Panwar ◽  
◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Antibacterial Activity ◽  
Essential Oils ◽  
Broad Spectrum ◽  
Antibacterial Effect ◽  
Gram Negative Bacteria ◽  
Bacterial Strains ◽  
Gram Negative ◽  
In Vitro Antibacterial Activity

Essential oils from Calamintha umbrosa and Nepeta species viz. N. leucophylla; N. hindostana; N. ciliaris and N. clarkei (family Lamiaceae), was tested against six bacterial strains. To evaluate the correlation between the antimicrobial activity and the essential oils, PCA and HCA analysis was done. PCA and HCA analysis of the antibacterial activity revealed that essential oils of Nepeta species had a strong and broad spectrum antibacterial effect against bacterial strains of P. aeruginosa and S. scandidus. The N. leucophylla oil showed higher activity against Gram-negative bacteria P. aeruginosa (10.5 mm, MIC 10 µL/mL) and K. pneumonia (9.1 mm, MIC 45 µL/mL) among all Nepeta oils which may be due to presence of active antimicrobial iridoids compounds.

scholarly journals Synthesis of an acyl-acyl carrier protein synthetase inhibitor to study fatty acid recycling

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Madeline F. Currie ◽  
Dylan M. Persaud ◽  
Niralee K. Rana ◽  
Amanda J. Platt ◽  
Joris Beld ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Vibrio Cholerae ◽  
Fatty Acid Synthase ◽  
Acyl Carrier Protein ◽  
Carrier Protein ◽  
Gram Negative Bacteria ◽  
Gram Negative ◽  
Antibiotic Development

Abstract Fatty acids are essential to most organisms and are made endogenously by the fatty acid synthase (FAS). FAS is an attractive target for antibiotics and many inhibitors are in clinical development. However, some gram-negative bacteria harbor an enzyme known as the acyl-acyl carrier protein synthetase (AasS), which allows them to scavenge fatty acids from the environment and shuttle them into FAS and ultimately lipids. The ability of AasS to recycle fatty acids may help pathogenic gram-negative bacteria circumvent FAS inhibition. We therefore set out to design and synthesize an inhibitor of AasS and test its effectiveness on an AasS enzyme from Vibrio harveyi, the most well studied AasS to date, and from Vibrio cholerae, a pathogenic model. The inhibitor C10-AMS [5′-O-(N-decanylsulfamoyl)adenosine], which mimics the tightly bound acyl-AMP reaction intermediate, was able to effectively inhibit AasS catalytic activity in vitro. Additionally, C10-AMS stopped the ability of Vibrio cholerae to recycle fatty acids from media and survive when its endogenous FAS was inhibited with cerulenin. C10-AMS can be used to study fatty acid recycling in other bacteria as more AasS enzymes continue to be annotated and provides a platform for potential antibiotic development.

scholarly journals Antibacterial evaluation of some benzimidazole derivatives and their zinc(II) complexes

2007 ◽  
Vol 72 (5) ◽  
pp. 459-466 ◽  
Author(s):  
S.O. Podunavac-Kuzmanovic ◽  
D.M. Cvetkovic
Keyword(s):  
Staphylococcus Aureus ◽  
Antimicrobial Activity ◽  
Antibacterial Activity ◽  
Inhibitory Concentration ◽  
Benzimidazole Derivatives ◽  
Gram Negative Bacteria ◽  
Gram Negative ◽  
In Vitro Antibacterial Activity ◽  
Antibacterial Evaluation

Zinc(II) chloride was reacted with some 1-benzylbenzimidazole derivatives (L) to give complexes of the formula ZnL2Cl2. All the ligands and their zinc(II) complexes were evaluated for their in vitro antibacterial activity against Pseudomonas aeruginosa, Bacillus cereus, Staphylococcus aureus and Sarcina lutea. Themajority of the investigated compounds displayed in vitro antimicrobial activity against very persistent microorganisms. It was found that all the tested compounds were more active against gram-positive than gram-negative bacteria. The minimum inhibitory concentration (MIC) was determined for all ligands and their complexes. The effect of the structure of the ligands and complexes on the antimicrobial activity is discussed. The complexes were found to be more toxic than the ligands.

In Vitro Antibacterial activity of ethanolic extract of Myrsine africana against laboratory Strains of Pathogenic Organisms

2016 ◽  
Vol 5 (04) ◽  
pp. 4512
Author(s):  
Jackie K. Obey ◽  
Anthoney Swamy T* ◽  
Lasiti Timothy ◽  
Makani Rachel
Keyword(s):  
Antibacterial Activity ◽  
Minimum Inhibitory Concentration ◽  
Inhibitory Concentration ◽  
Ethanolic Extract ◽  
Ethanol Extract ◽  
E Coli ◽  
Zones Of Inhibition ◽  
In Vitro Antibacterial Activity ◽  
Myrsine Africana

The determination of the antibacterial activity (zone of inhibition) and minimum inhibitory concentration of medicinal plants a crucial step in drug development. In this study, the antibacterial activity and minimum inhibitory concentration of the ethanol extract of Myrsine africana were determined for Escherichia coli, Bacillus cereus, Staphylococcus epidermidis and Streptococcus pneumoniae. The zones of inhibition (mm±S.E) of 500mg/ml of M. africana ethanol extract were 22.00± 0.00 for E. coli,20.33 ±0.33 for B. cereus,25.00± 0.00 for S. epidermidis and 18. 17±0.17 for S. pneumoniae. The minimum inhibitory concentration(MIC) is the minimum dose required to inhibit growth a microorganism. Upon further double dilution of the 500mg/ml of M. africana extract, MIC was obtained for each organism. The MIC for E. coli, B. cereus, S. epidermidis and S. pneumoniae were 7.81mg/ml, 7.81mg/ml, 15.63mg/ml and 15.63mg/ml respectively. Crude extracts are considered active when they inhibit microorganisms with zones of inhibition of 8mm and above. Therefore, this study has shown that the ethanol extract of M. africana can control the growth of the four organisms tested.

TetR-family transcriptional repressor Thermus thermophilus FadR controls fatty acid degradation

Microbiology ◽  
2011 ◽  
Vol 157 (6) ◽  
pp. 1589-1601 ◽  
Author(s):  
Yoshihiro Agari ◽  
Kazuko Agari ◽  
Keiko Sakamoto ◽  
Seiki Kuramitsu ◽  
Akeo Shinkai
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Target Genes ◽  
Thermus Thermophilus ◽  
Acyl Chain ◽  
Metabolic Energy ◽  
Straight Chain ◽  
Fatty Acid Degradation ◽  
Acid Degradation

In the extremely thermophilic bacterium Thermus thermophilus HB8, one of the four TetR-family transcriptional regulators, which we named T. thermophilus FadR, negatively regulated the expression of several genes, including those involved in fatty acid degradation, both in vivo and in vitro. T. thermophilus FadR repressed the expression of the target genes by binding pseudopalindromic sequences covering the predicted −10 hexamers of their promoters, and medium-to-long straight-chain (C10–18) fatty acyl-CoA molecules were effective for transcriptional derepression. An X-ray crystal structure analysis revealed that T. thermophilus FadR bound one lauroyl (C12)-CoA molecule per FadR monomer, with its acyl chain moiety in the centre of the FadR molecule, enclosed within a tunnel-like substrate-binding pocket surrounded by hydrophobic residues, and the CoA moiety interacting with basic residues on the protein surface. The growth of T. thermophilus HB8, with palmitic acid as the sole carbon source, increased the expression of FadR-regulated genes. These results indicate that in T. thermophilus HB8, medium-to-long straight-chain fatty acids can be used for metabolic energy under the control of FadR, although the major fatty acids found in this strain are iso- and anteiso-branched-chain (C15 and 17) fatty acids.

Synthesis,Characterization and Evaluation of Biological Activity of Sulfonylhydrazide-Schiff Base" (E)- N’-(2,5-dimethoxybenzalidene) naphthalene-2-sulfonohydrazide"

2020 ◽  
Vol 8 (1) ◽  
pp. 01-11
Author(s):  
Sameer Amereih ◽  
Abd Daraghmeh ◽  
Ismail Warad ◽  
Mohammed Al-Nuri
Keyword(s):  
Schiff Base ◽  
Inhibitory Concentration ◽  
Condensation Reaction ◽  
Gram Negative Bacteria ◽  
Biological Applications ◽  
Bacteriostatic Effect ◽  
1H And 13C Nmr ◽  
13C Nmr Analysis ◽  
Ft Ir

Condensation reaction of naphthalene -2-Sulfonylhydrazide, as starting material with 2,5-dimethoxy benzaldehyde was used to produce (E)-N’-(2,5-dimethoxybenzalidene)naphthalene-2-sulfonohydrazide. The Schiff base product was isolated, purified and then spectrally characterized via UV-Vis, GC/MS, FT-IR, 1H and 13C NMR analysis, where strong evidences confirmed the formation of the desired product. Antimicrobial activity of Schiff base product was evaluated in vitro against several types of bacteria such as: Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, Klebsiella pneumoniae and MRSA by Minimum Inhibitory Concentration (MIC) test using tetracycline (TE) as a standard antibiotic. The tests showed a promising bacteriostatic effect of this compound against gram negative bacteria such as P. aeruginosa and K. pneumoniae, such character is valuable for biological applications.

In-Vitro Studies on the Sensitivity of Staphylococcus aureus to Some Ethno-Medicinal Preparations Sold around Kano, Nigeria

2011 ◽  
Vol 4 (1) ◽  
pp. 22-25 ◽  
Author(s):  
M Bashir ◽  
I Yusuf ◽  
AS Kutama
Keyword(s):  
Staphylococcus Aureus ◽  
Antibacterial Activity ◽  
Minimum Inhibitory Concentration ◽  
Inhibitory Concentration ◽  
Test Organism ◽  
Ethanolic Extract ◽  
Screening Tests ◽  
Phytochemical Screening ◽  
Herbal Preparations

Five traditional herbal preparations were sampled between May-June, 2009 in Kano. The samples were investigated for invitro antibacterial activities against clinical isolates of Staphylococcus aureus. Likewise, phytochemical screening tests were conducted to determine some of the phytochemicals present in the ethanolic and water extracts of the samples. Various concentrations of the extracts were prepared using serial doubling dilutions (5000=l/ml, 2500=g/ml, 1250=g/ml, 625=g/ml and 312.5=g/ml). All the test extracts showed slight antibacterial activity against the test organism, with ethanolic extract of sample E having the highest zone diameter of inhibition, while sample H had the lowest diameter of inhibition. The standard antibiotic disc (Gentamicin) had demonstrated the highest activity on the test organisms. The results of the Phytochemical screening revealed the presence of steroid in all the samples, tannin in samples A, C, D and E, reducing sugars in sample A, D and E respectively. The result of the minimum inhibitory concentration (MIC) was found to be above 312.5=g/ml for samples C, D and E. Keywords: Staphylococcus aureus, Herbal preparations, antibacterial activity, Phytochemical screening and minimum inhibitory concentration.

In Vitro antibacterial activity of lactic acid bacteria isolated from goat’s raw milk of Mostaganem (West Algeria) against Gram negative bacteria responsible for urinary tract infections

2016 ◽  
Vol 6 (1) ◽  
pp. 15-22
Author(s):  
Zergoug Amina ◽  
Cheriguene Abderrahim ◽  
Chougrani Fadela
Keyword(s):  
Antibacterial Activity ◽  
Lactic Acid ◽  
Urinary Tract ◽  
Lactic Acid Bacteria ◽  
Raw Milk ◽  
Gram Negative Bacteria ◽  
Gram Negative ◽  
Tract Infections ◽  
West Algeria

Urinary tract infections (UTI) are a serious bacterial pathological challenges all over the world, leading to respiratory infections, that’s why new strategies don’t cease to develop. Lactic acid bacteria having shown beneficial effects for years in various areas, may prove to be excellent candidates in medical field. The current research focused on the selection of lactic acid bacteria having the potential of an antibacterial activity against Gram negative bacteria responsible for UTI, for an eventual use as a therapeutic agent. A total of 40 isolates were isolated from goat’s raw milk of Mostaganem (West Algeria). In vitro tests were conducted in order to determine the efficiency of the isolates to produce antibacterial agents in interaction with uropathogens. Among 40 isolates, only 10 isolates identified as Lactobacilli and Lactococci were performant. The Screening showed that the inhibitor agent was proteinaceous substance. Therfore, it is noted that a treatment with presence of LAB is very encouraging as a result of the production of bacteriocin-like substance. On the other hand, LAB can be considered as a good alter-native to the large extent to the antibiotics in the treatment of UTI.

Phytochemical Screening, Antibacterial and Synergistic activity of Dittrichia Viscosa Extracts against Multi-Resistant Pathogenic Bacteria

2019 ◽  
Vol 2 (1) ◽  
pp. 01-06
Author(s):  
Rhazi Fouzia
Keyword(s):  
Antibacterial Activity ◽  
Pathogenic Bacteria ◽  
Antibacterial Effect ◽  
Synergistic Activity ◽  
Phytochemical Screening ◽  
Bacterial Strains ◽  
Dittrichia Viscosa ◽  
Study Results ◽  
Ethanolic Extracts

Study contextual: Faced with the global problem of antimicrobial resistance, and the use of traditional medicine for the research of antibacterial biomolecules. Aim: our work focused on the valorization of a medicinal plant Dittrichia viscosa which has many therapeutic and culinary virtues worldwide. Methods: To do this, a phytochemical screening of the leafy stems of the plant is carried out according to a set of physicochemical reactions, as well as an in vitro evaluation of the antibacterial activity, of the aqueous and ethanolic extracts against multi-resistant bacterial strains, by microdilution technique on microplates. An evaluation of the synergistic interaction between extracts and weakened antibiotics against pathogenic bacteria was also highlighted in this study. Results: The tests revealed the richness of Dittrichia viscosa species by tannins, flavonoids, saponosides, sterols and triterpenes. As for the antibacterial effect, the MICs range from 0.858±0.29 to 66.66 ± 0.00 mg / ml and the MBCs from 4.300 ± 1.01 to 11.610 ± 2.31 mg / ml is an interesting antibacterial activity. Regarding the combination of extracts with antibiotics tested, it revealed a synergistic action inducing an amplification of the antibacterial power of Penicillin, Imipenem and Erythromycin with a rate that reaches 471%. Conclusion: The results of this study show that the aqueous and ethanolic extracts of Dittrichia viscosa have interesting and promising antibacterial activity in the pharmaceutical, food and cosmetic industries.

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