scholarly journals Antibacterial Activity and Mechanism of Linalool against Shewanella putrefaciens

Molecules ◽  
2021 ◽  
Vol 26 (1) ◽  
pp. 245
Author(s):  
Fengyu Guo ◽  
Qiong Liang ◽  
Ming Zhang ◽  
Wenxue Chen ◽  
Haiming Chen ◽  
...  

The demand for reduced chemical preservative usage is currently growing, and natural preservatives are being developed to protect seafood. With its excellent antibacterial properties, linalool has been utilized widely in industries. However, its antibacterial mechanisms remain poorly studied. Here, untargeted metabolomics was applied to explore the mechanism of Shewanella putrefaciens cells treated with linalool. Results showed that linalool exhibited remarkable antibacterial activity against S. putrefaciens, with 1.5 µL/mL minimum inhibitory concentration (MIC). The growth of S. putrefaciens was suppressed completely at 1/2 MIC and 1 MIC levels. Linalool treatment reduced the membrane potential (MP); caused the leakage of alkaline phosphatase (AKP); and released the DNA, RNA, and proteins of S. putrefaciens, thus destroying the cell structure and expelling the cytoplasmic content. A total of 170 differential metabolites (DMs) were screened using metabolomics analysis, among which 81 species were upregulated and 89 species were downregulated after linalool treatment. These DMs are closely related to the tricarboxylic acid (TCA) cycle, glycolysis, amino acid metabolism, pantothenate and CoA biosynthesis, aminoacyl-tRNA biosynthesis, and glycerophospholipid metabolism. In addition, linalool substantially affected the activity of key enzymes, such as succinate dehydrogenase (SDH), pyruvate kinase (PK), ATPase, and respiratory chain dehydrogenase. The results provided some insights into the antibacterial mechanism of linalool against S. putrefaciens and are important for the development and application of linalool in seafood preservation.

Author(s):  
Daieni Alves Vieira Amado ◽  
Giovani Andrey Bet Helmann ◽  
Alessandra Maria Detoni ◽  
Sérgio Luiz Colucci de Carvalho ◽  
Caroline Mariana de Aguiar ◽  
...  

Abstract The antioxidant and antibacterial activity and toxicity of natural products can change according to plant variety, as well as the part of the plant which is analyzed. In this study, peel, pulp and seed of four avocado varieties (Quintal, Fortuna, Margarida, and Hass) were analyzed for antioxidant and antibacterial properties and toxicity. There are few studies in the literature comparing these three first varieties. Antioxidant capacity was measured using the DPPH (2,2-diphenyl-1-picrylhydrazil), ABTS [2,2'-azino-bis- (3-ethylbenzothiazoline-6-sulfonic acid)], and FRAP (Ferric Reducing Ability Power) methods, along with the content of phenolic compounds and flavonoids. Principal component analysis was applied for antioxidant tests. Antibacterial activity against food pathogens was assessed by the minimum inhibitory concentration and minimum bactericidal concentration tests. Toxicity was evaluated against Artemia salina and also by hemolytic activity. The ethanolic extract of Quintal variety peel presented the greatest antioxidant and antibacterial activity. This same extract showed no toxicity in the preliminary tests, and shows great potential for food industry application as an additive.


Author(s):  
Francesco Misuri ◽  
Laura Marri

Abstract The antibacterial properties of a wood distillate obtained from residual virgin chestnut biomass were investigated by means of quantitative MIC (minimum inhibitory concentration) test and a whole-cell assay that specifically responds to different classes of antimicrobials on the basis of the mode of action. Results indicate that wood distillate is active against gram-positive and gram-negative bacteria related to human and/or fish diseases with a mechanism, which could mainly affect wall components and plasma membrane of the bacterial cells. These findings highlight the possible sustainable use of chestnut residues as a source of bioactive natural compounds with antibacterial properties.


Author(s):  
Vesna KALABA ◽  
Željko SLADOJEVIĆ ◽  
Željka MARJANOVIĆ BALABAN ◽  
Dragana KALABA ◽  
Ivona PANIĆ

Natural extracts made from fresh plant material and biologically active compounds isolated from different plant species that have been used in folk medicine for centuries, may present valuable sources for production of novel natural preservatives and medicinal preparations. White lily-Lilium candidum is also used, for a long period of time, in folk medicine for healing of burns and frostbites, otitis and rhinitis as well as balm for washing wounds and cuts. Roots, leaves and flowers have medical properties. Nevertheless, there is little information in literature related to antibacterial effect of white lily extract on certain pathogens and there is a need to determine the justification for its use in traditional medicine. Antibacterial activity of White lily extract on five reference cultures (Escherichia coli WDCM 00090, Listeria monocytogenes WDCM 00020, Salmonella enterica WDCM 00030, Pseudomonas aeruginosa WDCM 00024) and seven bacterial cultures (Escherichia coli, Providencia stuartii, Pseudomonas spp. ß-hemolytic Escherichia coli, coagulase positive staphylococcus, Staphylococcus aureus, group D Sreptococcus) from Laboratory for Microbiology, Public Veterinary Institute of Republic of Srpska "Dr. Vaso Butozan", Banja Luka, were examined in this study. Results confirmed that white lily extract show certain antibacterial activity against examined pathogens used in this study. Antibacterial activity of White lily extract was in the range from 5.33 mm to 18.88 mm depending of bacterial strain and concentration of white lily extract.


1994 ◽  
Vol 73 (8) ◽  
pp. 1437-1443 ◽  
Author(s):  
S. Imazato ◽  
M. Torii ◽  
Y. Tsuchitani ◽  
J.F. McCabe ◽  
R.R.B. Russell

Attempts to produce resin composite with antibacterial properties by incorporation of an antibacterial agent such as chlorhexidine have been reported, but problems can arise due to release of the inhibitory agent from the composite. Such problems may include toxic effects, influence on mechanical properties, and loss of effectiveness. A new monomer, methacryloyloxydodecylpyridinium bromide (MDPB), was synthesized by combining an antibacterial agent and methacryloyl group. The monomer was incorporated into resin composite to develop a non-releasing antibacterial composite. The ability of composite incorporating MDPB to inhibit growth and plaque accumulation by Streptococcus mutans in vitro was assayed, elution of antibacterial components from the material was investigated, and the influence of incorporation of MDPB on the mechanical properties of composite was studied. Uncured MDPB revealed antibacterial activity against S. mutans and six other species of oral streptococci, with the minimum inhibitory concentration for S. mutans being comparable with that of triclosan. After composite incorporating MDPB was cured, no elution of the antibacterial components was observed from the material, even after 90 days' immersion in water or other solvents. Growth of S. mutans on agar under specimens of MDPBcontaining composite was inhibited compared with controls. In a bacterial accumulation study, S. mutans accumulated to a lesser degree on the surface of composite incorporating MDPB (p < 0.05) than on control. Incorporation of MDPB had no significant influence on the mechanical properties of the composite.


2021 ◽  
pp. 1330-1341
Author(s):  
Mbarga M. J. Arsène ◽  
I. V. Podoprigora ◽  
Anyutoulou K. L. Davares ◽  
Marouf Razan ◽  
M. S. Das ◽  
...  

Background and Aim: The gradual loss of efficacy of conventional antibiotics is a global issue. Plant material extracts and green-synthesized nanoparticles are among the most promising options to address this problem. Therefore, the aim of this study was to assess the antibacterial properties of aqueous and hydroalcoholic extracts of grapefruit peels as well as their inclusion in green-synthesized silver nanoparticles (AgNPs). Materials and Methods: Aqueous and hydroalcoholic extracts (80% v/v) were prepared, and the volume and mass yields were determined. The synthesis of AgNPs was done in an eco-friendly manner using AgNO3 as a precursor. The nanoparticles were characterized by ultraviolet–vis spectrometry and photon cross-correlation spectroscopy. The antibacterial activity of the extracts was tested on three Gram-positive bacteria (Staphylococcus aureus ATCC 6538, clinical Enterococcus faecalis, and S. aureus) and two Gram-negative bacteria (two clinical Escherichia coli) using various concentrations of extracts (100, 50, 25, 12, and 5 mg/mL and 5% dimethyl sulfoxide as negative control). Minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were determined using the microdilution method. Modulation of cefazoline and ampicillin on resistant E. coli and S. aureus strains was added to the mixture design response surface methodology with extreme vertices design, with the diameters of inhibition and the fractional inhibitory concentration index as responses and factors, respectively. The antibiotic, the ethanolic extract, and water varied from 0.1 MIC to 0.9 MIC for the first two and from 0 to 0.8 in proportion for the third. Validating the models was done by calculating the absolute average deviation, bias factor, and accuracy factor. Results: The volume yield of the EE and aqueous extract (AE) was 96.2% and 93.8% (v/v), respectively, whereas their mass yields were 7.84% and 9.41% (m/m), respectively. The synthesized AgNPs were very uniform and homogeneous, and their size was dependent on the concentration of AgNO3. The antibacterial activity of the two extracts was dose-dependent, and the largest inhibition diameter was observed for the Gram-positive bacteria (S. aureus ATCC 6538; AE, 12; EE, 16), whereas AgNPs had a greater effect on Gram-negative bacteria. The MICs (mg/mL) of the AEs varied from 3.125 (S. aureus ATCC 6538) to 12.5 (E. coli 1 and E. coli 2), whereas the MICs of the EEs varied from 1.5625 (S. aureus 1, S. aureus ATCC 6538, and E. faecalis) to 6.25 (E. coli 1). There was a significant difference between the MICs of AEs and EEs (p=0.014). The MBCs (mg/mL) of the AEs varied from 12.5 (S. aureus ATCC 6538) to 50 (S. aureus 1), whereas those of the EEs varied from 6.25 (S. aureus 1) to 25 (E. coli 1 and E. faecalis). Ethanolic grapefruit extracts demonstrated an ability to modulate cefazolin on E. coli and S. aureus but were completely indifferent to ampicillin on E. coli. Conclusion: Grapefruit peel extracts and their AgNPs exhibit antibacterial properties that can be exploited for the synthesis of new antimicrobials and their EEs may be efficiently used synergistically with other antibiotics against bacteria with intermediate susceptibility.


2020 ◽  
Vol 24 (8) ◽  
pp. 817-854
Author(s):  
Anil Kumar ◽  
Nishtha Saxena ◽  
Arti Mehrotra ◽  
Nivedita Srivastava

Quinolone derivatives have attracted considerable attention due to their medicinal properties. This review covers many synthetic routes of quinolones preparation with their antibacterial properties. Detailed study with structure-activity relationship among quinolone derivatives will be helpful in designing new drugs in this field.


2020 ◽  
Vol 17 (1) ◽  
pp. 71-84
Author(s):  
Riham M. Bokhtia ◽  
Siva S. Panda ◽  
Adel S. Girgis ◽  
Hitesh H. Honkanadavar ◽  
Tarek S. Ibrahim ◽  
...  

Background: Bacterial infections are considered as one of the major global health threats, so it is very essential to design and develop new antibacterial agents to overcome the drawbacks of existing antibacterial agents. Method: The aim of this work is to synthesize a series of new fluoroquinolone-3-carboxamide amino acid conjugates by molecular hybridization. We utilized benzotriazole chemistry to synthesize the desired hybrid conjugates. Result: All the conjugates were synthesized in good yields, characterized, evaluated for their antibacterial activity. The compounds were screened for their antibacterial activity using methods adapted from the Clinical and Laboratory Standards Institute. Synthesized conjugates were tested for activity against medically relevant pathogens; Escherichia coli (ATCC 25922), Pseudomonas aeruginosa (ATCC 27856) Staphylococcus aureus (ATCC 25923) and Enterococcus faecalis (ATCC 19433). Conclusion: The observed antibacterial experimental data indicates the selectivity of our synthesized conjugates against E.Coli. The protecting group on amino acids decreases the antibacterial activity. The synthesized conjugates are non-toxic to the normal cell lines. The experimental data were supported by computational studies.


2016 ◽  
Vol 5 (04) ◽  
pp. 4512
Author(s):  
Jackie K. Obey ◽  
Anthoney Swamy T* ◽  
Lasiti Timothy ◽  
Makani Rachel

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.


2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Dunfang Wang ◽  
Xuran Ma ◽  
Shanshan Guo ◽  
Yanli Wang ◽  
Tao Li ◽  
...  

As a classic prescription, Huangqin Tang (HQT) has been widely applied to treat ulcerative colitis (UC), although its pharmacological mechanisms are not clear. In this study, urine metabolomics was first analysed to explore the therapeutic mechanisms of HQT in UC rats induced by TNBS. We identified 28 potential biomarkers affected by HQT that might cause changes in urine metabolism in UC rats, mapped the network of metabolic pathways, and revealed how HQT affects metabolism of UC rats. The results showed that UC affects amino acid metabolism and biosynthesis of unsaturated fatty acids and impairs the tricarboxylic acid cycle (TCA cycle). UC induced inflammatory and gastrointestinal reactions by inhibiting the transport of fatty acids and disrupting amino acid metabolism. HQT plays key roles via regulating the level of biomarkers in the metabolism of amino acids, lipids, and so on, normalizing metabolic disorders. In addition, histopathology and other bioinformatics analysis further confirm that HQT altered UC rat physiology and pathology, ultimately affecting metabolic function of UC rats.


Pathogens ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 105
Author(s):  
Kun Mi ◽  
Da Sun ◽  
Mei Li ◽  
Haihong Hao ◽  
Kaixiang Zhou ◽  
...  

Haemophilus parasuis can cause high morbidity and mortality in swine. Cefquinome possesses excellent antibacterial activity against pathogens causing diseases of the respiratory tract. This study aimed to establish the clinical breakpoint (CBP) of cefquinome against H. parasuis and to monitor the resistance change. Referring to the minimum inhibitory concentration (MIC) distribution of cefquinome against 131 H. parasuis isolates, the MIC50 and MIC90 were determined to be 0.125 and 1 μg/mL, respectively. And the epidemiological cutoff (ECOFF) value was 1 μg/mL. HPS42 was selected as a representative strain for the pharmacodynamic (PD) experiment, pharmacokinetic (PK) experiment and clinical experiments. The PK/PD index values, area under concentration-time curve (AUC)/MIC, of the bacteriostatic, bactericidal, and bacterial elimination effects were 23, 41, and 51 h, respectively. The PK/PD cutoff was calculated as 0.125 μg/mL by Monte Carlo simulation (MCS), and the clinical cutoff was 0.25−4 μg/mL by WindoW. Combing these three values, the CBP of cefquinome against H. parasuis was found to be 1 μg/mL. In conclusion, this was the first study to integrate various cutoffs to establish the CBP in the laboratory. It is helpful to distinguish wild type H. parasuis and reduce the probability of treatment failure.


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