scholarly journals The Effect of different crude methanolic extracts against some gram negative pathogenic bacteria

2010 ◽  
Vol 4 (2) ◽  
pp. 86-93
Author(s):  
Hussain Ali Farhan

This present study was conducted to evaluated the antibacterial activity of crude extracts (Methanolic) of punica granatum peel, Menthe longifolia and Olea eurpeae leaves against some gram negative bacteria like Pseudomonas aerugenosa, Serratia marcesens, Escherichia coli, Proteus vulgaris, Klebsiella pnemunoniae. The Agar-well diffusion was used to know the ability of inhibititory of crude extracts against bacteria. Results showed different susceptibility response of bacteria under study. It was observed that Pseudomonas aerugenosa the most susceptible to Methanolic extracts to all plants in (25, 50) mg/ml-1 concentrate. While the bacterial strains shown no responding against mint and pomegranate extracts in 10 mg/ml-1 except Pseudomonas aerugenosa and Escherichia coli, was inhibited with Olive extracts only. That ability to inhabitation less in concentrate 10 mg ml-1.

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Tessa B. Moyer ◽  
Ashleigh L. Purvis ◽  
Andrew J. Wommack ◽  
Leslie M. Hicks

Abstract Background Plant defensins are a broadly distributed family of antimicrobial peptides which have been primarily studied for agriculturally relevant antifungal activity. Recent studies have probed defensins against Gram-negative bacteria revealing evidence for multiple mechanisms of action including membrane lysis and ribosomal inhibition. Herein, a truncated synthetic analog containing the γ-core motif of Amaranthus tricolor DEF2 (Atr-DEF2) reveals Gram-negative antibacterial activity and its mechanism of action is probed via proteomics, outer membrane permeability studies, and iron reduction/chelation assays. Results Atr-DEF2(G39-C54) demonstrated activity against two Gram-negative human bacterial pathogens, Escherichia coli and Klebsiella pneumoniae. Quantitative proteomics revealed changes in the E. coli proteome in response to treatment of sub-lethal concentrations of the truncated defensin, including bacterial outer membrane (OM) and iron acquisition/processing related proteins. Modification of OM charge is a common response of Gram-negative bacteria to membrane lytic antimicrobial peptides (AMPs) to reduce electrostatic interactions, and this mechanism of action was confirmed for Atr-DEF2(G39-C54) via an N-phenylnaphthalen-1-amine uptake assay. Additionally, in vitro assays confirmed the capacity of Atr-DEF2(G39-C54) to reduce Fe3+ and chelate Fe2+ at cell culture relevant concentrations, thus limiting the availability of essential enzymatic cofactors. Conclusions This study highlights the utility of plant defensin γ-core motif synthetic analogs for characterization of novel defensin activity. Proteomic changes in E. coli after treatment with Atr-DEF2(G39-C54) supported the hypothesis that membrane lysis is an important component of γ-core motif mediated antibacterial activity but also emphasized that other properties, such as metal sequestration, may contribute to a multifaceted mechanism of action.


2014 ◽  
Vol 8 (3) ◽  
pp. 40-45
Author(s):  
Zina Hashem Shehab ◽  
Huda Suhail Abid ◽  
Sumaya Fadhil Hamad ◽  
Sara Haitham

The study was conducted to evaluate the inhibitory activity of methanol extract of Gardenia jasminoides leaves compared with leaf crude extracts for some organic solvents namely Methanol, Ethanol, Petroleum ether, Asetone and Chloroform on growth of some pathogenic bacteria and yeast, which included four gram positive isolates Staphylococcus aureus, Enterococcus faecalis, Streptococcus pyogenes and Bacillus cereus and gram negative isolates Escherichia coli, Salmonella typhi, Proteus vulgaris and Pseudomonas aeruginosa and some yeasts Candida albicans and Saccharomyces boulardii, by using well diffusion method. The inhibitory activity of extracts in the tested bacterial strains and yeasts was varied according to the type of extracting solvents and are tested microorganisms. The methanol callus extract which grown on Murashige and Skoog (MS) media by using (Naphthalen acitic acid) NAA and (Benzyle adenine) BA as growth regulator highly effective as compared to the other extracts as for inhibition of three gram positive bacteria and three gram negative bacteria,which include Staphylococcus aureus and, Proteus vulgaris, followed by acetone and ethanolic extracts which include two gram positive bacteria and two gram negative bacteria. All extracts had highly effect in growth of Candida albicans while all crude extracts didn’t show any sensitivity against Saccharomyces boulardii, and when we’d done (High Performance Liquid Chromatography) HPLC test for detection of some active compound we found Quinic acid, Iridiods glycosides and Crocin which its rate in fresh callus was higher than fresh leaves.


RSC Advances ◽  
2016 ◽  
Vol 6 (76) ◽  
pp. 72471-72478 ◽  
Author(s):  
Soumen Chandra ◽  
Angshuman Ray Chowdhuri ◽  
Triveni Kumar Mahto ◽  
Arpita Samui ◽  
Sumanta kumar Sahu

In this paper, we report a one-step strategy to synthesize amikacin modified fluorescent carbon dots (CDs@amikacin) for assaying pathogenic bacteria, Escherichia coli.


2016 ◽  
Vol 1 (1) ◽  
pp. 10
Author(s):  
Asma Bibi ◽  
A. Thangamani ◽  
V. Venkatesalu

The present study was aimed to determine the antimicrobial activity of some endemic plant species used in folkloric medicine by the inhabitants of Andaman Islands, India. The ethanol extracts prepared from the leaves of four plants viz; Alstonia kurzii, Tabernaemontana crispa, Mangifera andamanica and Vitex diversifolia were assessed for antibacterial activity against clinically isolated human pathogenic bacteria and antifungal activity against some phytopathogenic fungi. The ethanol extracts showed more inhibition towards Gram positive than Gram negative bacteria and the bacterial strains showed more susceptibility than the fungal strains tested. Among the plants, Vitex diversifolia exhibited the highest antibacterial activity and Mangifera andamanica showed the highest antifungal activity.


2023 ◽  
Vol 83 ◽  
Author(s):  
S. Mumtaz ◽  
S. Mumtaz ◽  
S. Ali ◽  
H. M. Tahir ◽  
S. A. R. Kazmi ◽  
...  

Abstract Now a day’s multidrug resistance phenomenon has become the main cause for concern and there has been an inadequate achievement in the development of novel antibiotics to treat the bacterial infections. Therefore, there is an unmet need to search for novel adjuvant. Vitamin C is one such promising adjuvant. The present study was aimed to elucidate the antibacterial effect of vitamin C at various temperatures (4°C, 37°C and 50°C) and pH (3, 8, and 11), against Gram-positive and Gram-negative bacteria at various concentrations (5-20 mg/ml) through agar well diffusion method. Growth inhibition of all bacterial strains by vitamin C was concentration-dependent. Vitamin C significantly inhibited the growth of Gram-positive bacteria: Bacillus licheniformis (25.3 ± 0.9 mm), Staphylococcus aureus (22.0 ± 0.6 mm), Bacillus subtilis (19.3 ± 0.3 mm) and Gram-negative bacteria: Proteus mirabilis (27.67 ± 0.882 mm), Klebsiella pneumoniae (21.33±0.9 mm), Pseudomonas aeruginosa (18.0 ± 1.5 mm) and Escherichia coli (18.3 ± 0.3 mm). The stability of vitamin C was observed at various pH values and various temperatures. Vitamin C showed significant antibacterial activity at acidic pH against all bacterial strains. Vitamin C remained the stable at different temperatures. It was concluded that vitamin C is an effective and safe antibacterial agent that can be used in the future as an adjunct treatment option to combat infections in humans.


Molecules ◽  
2020 ◽  
Vol 25 (10) ◽  
pp. 2374
Author(s):  
Paula C. Alves ◽  
Patrícia Rijo ◽  
Catarina Bravo ◽  
Alexandra M. M. Antunes ◽  
Vânia André

We report herein three novel complexes whose design was based on the approach that consists of combining commercially available antibiotics with metals to attain different physicochemical properties and promote antimicrobial activity. Thus, new isostructural three-dimensional (3D) hydrogen bonding frameworks of pipemidic acid with manganese (II), zinc (II) and calcium (II) have been synthesised by mechanochemistry and are stable under shelf conditions. Notably, the antimicrobial activity of the compounds is maintained or even increased; in particular, the activity of the complexes is augmented against Escherichia coli, a representative of Gram-negative bacteria that have emerged as a major concern in drug resistance. Moreover, the synthesised compounds display similar general toxicity (Artemia salina model) levels to the original antibiotic, pipemidic acid. The increased antibacterial activity of the synthesised compounds, together with their appropriate toxicity levels, are promising outcomes.


2011 ◽  
Vol 2011 ◽  
pp. 1-9 ◽  
Author(s):  
Ahmed Tafesh ◽  
Naim Najami ◽  
Jeries Jadoun ◽  
Fares Halahlih ◽  
Herbert Riepl ◽  
...  

Polyphenols or phenolic compounds are groups of secondary metabolites widely distributed in plants and found in olive mill wastewater (OMW). Phenolic compounds as well as OMW extracts were evaluatedin vitrofor their antimicrobial activity against Gram-positive (Streptococcus pyogenesandStaphylococcus aureus) and Gram-negative bacteria (Escherichia coliandKlebsiella pneumoniae). Most of the tested phenols were not effective against the four bacterial strains when tested as single compounds at concentrations of up to 1000 μg mL−1. Hydroxytyrosol at 400 μg mL−1caused complete growth inhibition of the four strains. Gallic acid was effective at 200, and 400 μg mL−1againstS. aureus, andS. pyogenes, respectively, but not against the gram negative bacteria. An OMW fraction called AntiSolvent was obtained after the addition of ethanol to the crude OMW. HPLC analysis of AntiSolvent fraction revealed that this fraction contains mainly hydroxytyrosol (10.3%), verbascoside (7.4%), and tyrosol (2.6%). The combinations of AntiSolvent/gallic acid were tested using the low minimal inhibitory concentrations which revealed that 50/100–100/100 μg mL−1caused complete growth inhibition of the four strains. These results suggest that OMW specific fractions augmented with natural phenolic ingredients may be utilized as a source of bioactive compounds to control pathogenic bacteria.


2018 ◽  
Vol 24 (6) ◽  
pp. 327-332 ◽  
Author(s):  
Yogesh D. Mane ◽  
Smita S. Patil ◽  
Dhanraj O. Biradar ◽  
Bhimrao C. Khade

Abstract Ten 5-bromoindole-2-carboxamides were synthesized, characterized and evaluated for antibacterial activity against pathogenic Gram-negative bacteria Klebsiella pneumoniae, Escherichia coli, Pseudomonas aeruginosa and Salmonella Typhi using gentamicin and ciprofloxacin as internal standards. Compounds 7a–c, 7g and 7h exhibit high antibacterial activity with a minimum inhibitory concentration (MIC) of 0.35–1.25 μg/mL. Compounds 7a–c exhibit antibacterial activities that are higher than those of the standards against E. coli and P. aeruginosa.


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