Previous studies have shown that glycine and proline are pharmacophores that display antibacterial activity.In the present study,glycine and proline were derivated to diketopiperazine compounds by chemical synthesis m...Previous studies have shown that glycine and proline are pharmacophores that display antibacterial activity.In the present study,glycine and proline were derivated to diketopiperazine compounds by chemical synthesis method,and their antibacterial activities were evaluated by three strains of spoilage bacteria,Escherichia coli,Pseudomonas aeruginosa and Shewanella putrefaciens,and the relationship of their antibacterial activities and structures was also investigated.Uv-vis spectrophotometry was used to determine the growth curves of three kinds of active indicator bacteria.Minimum inhibitory concentration(MIC)was determined by micro broth dilution method.The results showed that 2-methyl-3-(methylthio)pyrazine had significant antibacterial activity against three strains of the bacteria,and its MIC was 1.25%.It indicates 2-methyl-3-(methylthio)pyrazine has the potential to be developed as a kind of preservative in future.展开更多
This study aimed to explore the anti-bacterial and anti-fungal activities of extracts from different parts of plants in the Zingiberaceae family.The inhibitory rate,minimum inhibitory concentration(MIC),and minimum ba...This study aimed to explore the anti-bacterial and anti-fungal activities of extracts from different parts of plants in the Zingiberaceae family.The inhibitory rate,minimum inhibitory concentration(MIC),and minimum bactericidal concentration(MBC)of leaf and stem,and root and rhizome extracts from Alpinia katsumadai Hayata,Alpinia oxyphylla Miq×Alpinia henryi K.Schumann,Alpinia oblongifolia Hayata,Alpinia nigra(Gaertn.)Burtt,Amomum villosum Lour,Alpinia zerumbet(Pers.)Burtt.et Smith and Alpinia oxyphylla Miq were determined using the fungus cake method and double dilution method.The seven Zingiberaceae plants exhibited characteristic antibacterial activities against pathogenic bacteria and fungi.At a 1.5 mg mL^(−1),A.zerumbet root and rhizome extracts exhibited strong inhibitory activity against S.aureus and E.coli,with 83.23%and 79.62%,respectively.In addition,A.zerumbet leaf and stem extracts had an inhibitory rate of 90.85%against P.aeruginosa.At the same concentration,the leaf and stem,root and rhizome extracts of A.katsumadai had the best anti-bacterial effect against F.oxysporum,with inhibition rates of 84.46%and 84.73%,respectively.Moreover,A.katsumadai and A.zerumbet leaf and stem extracts had the most significant antibacterial effect against S.aureus,with a MIC of 0.063 mg mL^(−1).Thus,both A.katsumadai and A.zerumbet extracts had significant antibacterial activity.In addition,by comparing the inhibitory effect of extracts from different parts,it was found that the inhibitory rate and average inhibitory rate of extracts from leaf and stem were higher than those from root and rhizome.The chemical constituents of A.katsumadai and A.zerumbet,determined by the high-performance liquid chromatography-tandem mass spectrometry(UPLC-MS/MS),revealed that citric acid(CA),alpinetin,and pinocembrin(PNCB)were the functional constituents yielding the antibacterial activity.Overall,A.katsumadai and A.zerumbet have the potential to be developed as new plant fungicides and bactericides.展开更多
This study explores the efficacy of advanced antibiotic compounds against P. aeruginosa, focusing on Antibiotic B, an enhanced derivative of Ceftriaxone. The study measured the intracellular uptake of Antibiotic B and...This study explores the efficacy of advanced antibiotic compounds against P. aeruginosa, focusing on Antibiotic B, an enhanced derivative of Ceftriaxone. The study measured the intracellular uptake of Antibiotic B and introduced a novel adjuvant, Influximax, which augmented its antibacterial activity. Results showed a diminished potential for resistance emergence with Antibiotic B, particularly when used in combination with Influximax. The study suggests that optimizing antibiotic delivery into bacterial cells and leveraging syner-gistic adjuvant combinations can enhance drug resistance combat. .展开更多
AIM:To evaluate the anti-Helicobacter pylori (H.pylori) activity of 50 traditional Chinese herbal medicines in order to provide the primary evidence for their use in clinical practice.METHODS:A susceptibility test of ...AIM:To evaluate the anti-Helicobacter pylori (H.pylori) activity of 50 traditional Chinese herbal medicines in order to provide the primary evidence for their use in clinical practice.METHODS:A susceptibility test of water extract from 50 selected traditional Chinese herbal medicines for in vitro H.pylori Sydney strain 1 was performed with broth dilution method.Anti-H.pylori activity of the selected Chinese herbal medicines was evaluated according to their minimum inhibitory concentration (MIC).RESULTS:The water extract from Rhizoma Coptidis,Radix Scutellariae and Radix isatidis could significantly inhibit the H.pylori activity with their MIC less than 7.8 mg/mL,suggesting that traditional Chinese herbal medicines have anti-inflammatory and antibacterial effects and can thus be used in treatment of H.pylori infection.CONCLUSION:Rhizoma Coptidis,Radix Scutellariae and Radix isatidis are the potential sources for the synthesis of new drugs against H.pylori.展开更多
Two Klebsiella pneumoniae isolates (Kpcl and Kpc2) were obtained from liver samples of seven dead chickens and identified with Vitek-32 automated identification system. Antimicrobial susceptibilities were determined...Two Klebsiella pneumoniae isolates (Kpcl and Kpc2) were obtained from liver samples of seven dead chickens and identified with Vitek-32 automated identification system. Antimicrobial susceptibilities were determined by the microdilution broth method. Detection of genes encoding class A β-lactamases was performed by PCR amplification, and cloning of the ESBL gene was by plasmid restriction and fragments ligation. Conjugation assay, transformation experiments and plasmid profile analysis were performed. The incompatibility group of ESBL-carrying plasmid was determined by the PCR-based replicon typing method. Lastly, the genetic environment was analysed by direct sequencing of the DNA surrounding the ESBL gene. The genes associated with tetracycline and gentamicin resistance were also sought by PCR. The results revealed that the ESBL phenotype-negative strain Kpc2 only showed resistance to ampicillin, amoxicillin, tetracycline, and doxycycline and carried bla TEM-1 and tet(A) genes. The ESBL-producing strain Kpcl exhibited multidrug resistant phenotype and harbored bla TEM-1 , bla CTX-M-14, tet(A), tet(B), and rmtB genes. K. pneumoniae Kpcl contained four plasmids with molecular sizes of approximately 59, 6.9, 2.8, and 1.6 kb, but only a 59-kb plasmid, carried bla TEM-1 and blac CTM-14 genes, was observed in its transconjugant. The incompatibility group of plasmid carrying blaCTX-M-14 gene could not be determined. The bla CTX-M-14 gene was flanked upstream by an ISEcpl insertion sequence and downstream by an IS903 element. This work shows that CTX-M-14 is present in K. pneumoniae isolates from chickens in China. The bla CTX -M-4 gene was associated with an upstream ISEcpl insertion sequence. Our results underline the need for continuous surveillance of the prevalence and evolution of this CTX-M-type β-lactamase in China.展开更多
Aqueous extracts from various plant parts of fenugreek(3%)(aerial parts:leaves and stems(LS),roots(R),ground seeds(GS)and not ground seeds(NGS))and petroleum ether,ethyl acetate and methanolic fractions of the aerial ...Aqueous extracts from various plant parts of fenugreek(3%)(aerial parts:leaves and stems(LS),roots(R),ground seeds(GS)and not ground seeds(NGS))and petroleum ether,ethyl acetate and methanolic fractions of the aerial parts were assayed to determine their antifungal potential against Botrytis cinerea,Fusarium graminearum,Alternaria sp.,Pythium aphanidermatum,and Rhizoctinia solani.All fenugreek plant parts showed antifungal potential and the magnitude of their inhibitory effects was species and plant parts d...展开更多
[Objective]This study aimed to observe the antibacterial activity of Berberis julianae Schneid and Cinnamomum camphora( L.) Presl. aqueous extracts and their antibiotical effect when being used with commonly used an...[Objective]This study aimed to observe the antibacterial activity of Berberis julianae Schneid and Cinnamomum camphora( L.) Presl. aqueous extracts and their antibiotical effect when being used with commonly used antibiotics in- vitro. [Method] Broth microdilution method and checkerboard dilution method were used and the reference strain E. coli ATCC25922 and clinical sample separation strains of E. coli and Salmonella were selected to determine the minimum inhibitory concentration( MIC) and fractional inhibitory concentration( FIC). [Result] The MICs of Berberis julianae Schneid and Cinnamomum camphora( L.) Presl. for E. coli and Salmonella were both 1 mg /mL,and that of other antibiotics for the two strains were in the quality control range provided by NCCLS. [Conclusion] The synergistic effect or additive effect were observed when they were applied with the commonly used antibiotics.展开更多
Three benzopyranocoumarins(OBH, OMH and ODH) were synthesized and characterized via IR, ^1H NMR and HRMS. The HB energy in OBH, OMH and ODH was performed with the density functional theory(DFT) [B3LYP/6-31G*] met...Three benzopyranocoumarins(OBH, OMH and ODH) were synthesized and characterized via IR, ^1H NMR and HRMS. The HB energy in OBH, OMH and ODH was performed with the density functional theory(DFT) [B3LYP/6-31G*] method. The in vitro antibacterial activity of OBH, OMH and ODH against drug-sensitive S. aureus(S. aureus ATCC 29213) strain, MRSA strain(MRSA XJ 75302), drug-sensitive S. epidermidis strain(S. epidermidis ATCC 14990) and methicillin-resistant S. epidermidis strain(MRSE XJ 75284) was evaluated by observing the minimum inhibitory concentration. The results showed that among the three compounds, ODH exhibited the most potent antibacterial activity.展开更多
Multiple drug resistant(MDR)and methicillin-resistant Staphylococcus aureus(MRSA)have become increasingly prevalent as a community acquired infection.As a result limited treatment options are available with convention...Multiple drug resistant(MDR)and methicillin-resistant Staphylococcus aureus(MRSA)have become increasingly prevalent as a community acquired infection.As a result limited treatment options are available with conventional synthetic antibiotics.Bioprospecting natural products with potent antimicrobial activity show promise for developing new drugs against this pathogen.In this study,we have investigated the antimicrobial activity of a purple violet pigment(PVP)from an Antarctic bacterium,Janthinobacterium sp.Ant5-2 on 15 clinical MDR and MRSA strains.The colorimetric resazurin assay was employed to determine the minimum inhibitory concentration(MIC90)of PVP against MDR and MRSA.The MIC90 ranged between 1.57μg/mL and 3.13μg/mL,which are significantly lower than many antimicrobials tested from natural sources against this pathogen.The spectrophotometrically determined growth analysis and total microscopic counts using Live/dead®BacLight™fluorescent stain exhibited a steady decrease in viability of both MDR and MRSA cultures following treatment with PVP at the MIC levels.In silico predictive molecular docking study revealed that PVP could be a DNA-targeting minor groove binding antimicrobial compound.The continued development of novel antimicrobials derived from natural sources with the combination of a suite of conventional antibiotics could stem the rising pandemic of MDR and MRSA along with other deadly microbial pathogens.展开更多
The purpose of this study was to first evaluate the antimicrobial effects of powder and extracts of berries (rose-hip, aronia, sea buckthorn and hawthorn) on the development of antibiotic-resistant <i><span s...The purpose of this study was to first evaluate the antimicrobial effects of powder and extracts of berries (rose-hip, aronia, sea buckthorn and hawthorn) on the development of antibiotic-resistant <i><span style="font-family:Verdana;">L</span></i><span style="font-family:Verdana;">. </span><i><span style="font-family:Verdana;">monocitogenes</span></i><span style="font-family:Verdana;">. </span><i><span style="font-family:Verdana;">Listeria</span></i> <i><span style="font-family:Verdana;">monocytogenes</span></i><span style="font-family:Verdana;"> is considered one of the most important pathogens responsible for food-borne infection. Antimicrobial properties were evaluated using the standard Kirby-Bauer disk diffusion method. Bacterial inactivation networks were determined and compared, as well as the possibility of using powders and extracts of berries to control the risk of </span><i><span style="font-family:Verdana;">Listeria</span></i> <i><span style="font-family:Verdana;">monocytogees</span></i><span style="font-family:Verdana;"> infestation in the milk and dairy industry as well as in the meat industry. The effect of pH (4.78 - 4.43) and water activity (0.90 - 0.80) on the relationship between optical density (OD) at 600 nm and the plate count (CFU ml<sup>-</sup></span><span style="font-family:Verdana;"><sup>1</sup></span><span style="font-family:Verdana;">) was investigated for </span><i><span style="font-family:Verdana;">Listeria</span></i> <i><span style="font-family:Verdana;">monocytogenes</span></i><span style="font-family:Verdana;">. It was determined Minimum Inhibitory Concentration (MIC), Minimum Bactericidal Concentration (MBC) </span><span style="font-family:Verdana;">of berries for</span><span style="font-family:;" "=""> </span><i><span style="font-family:Verdana;">L. monocytogenes</span></i><span style="font-family:Verdana;">. </span><span style="font-family:Verdana;">The most relevant bacteriostatic and bactericidal </span><span style="font-family:;" "=""><span style="font-family:Verdana;">effect on </span><i><span style="font-family:Verdana;">L. monocytogenes</span></i><span style="font-family:Verdana;"> in the tested berries demonstrated sea buckthorn and rosehip.</span></span>展开更多
<span style="font-family:Verdana;">Coordination compounds of 2-amino-3-methylbutanoic acid were synthesized with chromium(III) and oxovanadium(IV) ions. M:L;1:2. Adducts of these complexes using 1,10-p...<span style="font-family:Verdana;">Coordination compounds of 2-amino-3-methylbutanoic acid were synthesized with chromium(III) and oxovanadium(IV) ions. M:L;1:2. Adducts of these complexes using 1,10-phenantroline and ethylenediamine were further synthesized, M:L, (1:2). These compounds were characterized using electronic, infra-red spectrophotometry, magnetic susceptibility measurement and percentage metal analyses. The zones of inhibition and minimum inhibitory concentrations of the compounds against eight microbes were studied. The results obtained indicated an octahedral geometry for the Cr(III) complexes, indicative of additional coordination of two water molecules. On the other hand a square pyramid geometry was obtained for the binary oxovanadium complex and its 1,10-phenantroline adduct. However</span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">,</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;"> for the oxovanadium ethylenediamine adduct a distorted octahedral geometry was proposed. The result for the antibacterial studies indicated that both mixed ligand complexes of 1,10-phenantroline exhibited good antibacterial activity, and in some cases better activity than the standard, streptomycin.</span></span></span>展开更多
The objective of the studies in this paper was to expand on the published toxicological assessment of <i><span style="font-family:Verdana;">Aurantiochytrium</span></i> <i><sp...The objective of the studies in this paper was to expand on the published toxicological assessment of <i><span style="font-family:Verdana;">Aurantiochytrium</span></i> <i><span style="font-family:Verdana;">limacinum</span></i><span style="font-family:Verdana;"> (AURA) with further strain characterization and to investigate the potential for the biomass or extracted oil to have antimicrobial properties or undesirable substances. AURA is being investigated as a novel source of the omega-3 long-chain polyunsaturated fatty acid docosahexaenoic acid (DHA) for enriching foods of animal origin by means of feed supplementation. In the first studies, we provide</span><span style="font-family:Verdana;">d</span><span style="font-family:Verdana;"> the 18S rRNA identification of the novel marine isolated thraustochytrid, established the nutritional composition of AURA biomass for application as a food or feed ingredient including proximate analysis and fatty acid profiling, and confirmed the DHA production potential of the strain. We determined through minimum inhibitory concentration (MIC) analysis that the unextracted AURA biomass was safe, showing no antimicrobial influence and no evidence of any deleterious effects of this product or its extracts at concentrations up to 1% w/w on the reference human intestinal bacteria</span><span style="font-family:;" "=""> </span><span style="font-family:Verdana;">tested. This would indicate that AURA should not stimulate selective pressure on the commensal microbiota and is therefore unlikely to aid development of antimicrobial resistance and the concomitant harm to humans and animals. Further analysis revealed that the AURA biomass produced through industrial heterotrophic fermentation was free from undesirables;toxic marine microalgal metabolites, heavy metals, pesticides, microbial contaminants, and mycotoxins. Including heterotrophically-grown AURA in food or feed, up to 1% w/w, is a safe and environmentally beneficial strategy for DHA supplementation.</span>展开更多
Dermatophytes were earlier reported to respond well to anti-fungal agents;however, an upsurge in resistance with the high cost of these agents increased the use of medicinal plants for treatment. This study investigat...Dermatophytes were earlier reported to respond well to anti-fungal agents;however, an upsurge in resistance with the high cost of these agents increased the use of medicinal plants for treatment. This study investigated the sensitivity pattern of dermatophytes to oral anti-fungal drugs and aqueous leaf extract of the plant, <em>Acacia nilotica</em>. The extract was tested against seven strains of dermatophytes <em>Arthroderma otae</em>, <em>Trichophyton interdigitale</em>, <em>Trichophyton mentagrophyte</em>, <em>Microsporum ferrugineum</em>, <em>Arthroderma vespertilii</em>, <em>Arthroderma quadrifidum</em>, and <em>Arthroderma multifidum</em>, previously isolated from diabetic patients. The minimum inhibitory and fungicidal concentrations of the plant extracts and the standard antifungal agents were evaluated using modifications of the broth macro dilution method of the National Committee for Clinical Laboratory Standards M38-A2 protocol. There was a significant difference in the Minimum Inhibitory concentrations (MIC) of the dermatophytes to the three antifungal drugs tested (p < 0.001). The dermatophytes were mostly susceptible to itraconazole followed by Nystatin. All the dermatophytes tested were resistant to griseofulvin. <em>Acacia nilotica</em> had an inhibitory effect on all the dermatophytes tested, and showed anti-fungal activity in a dose-dependent relationship between 0.625 - 1.25 mg/ml. Though the inhibitions of the dermatophytes were significantly higher with the standard anti-fungal drugs as compared to the plant extract (p < 0.001);however, the dermatophyte, <em>Arthroderma quadrifidum</em>, which was resistant to all the anti-fungal drugs, had the highest inhibition with <em>A. nilotica</em>. Some circulating dermatophyte strains in Nigeria are griseofulvin and/or itraconazole resistant which may influence the spread of infection and <em>A. nilotica</em> aqueous leaf extract showed a strong anti-dermatophytic activity.展开更多
One of the serious problems the world is facing today is the antimicrobial resistance on available antibiotics by most bacterial pathogens and the rising cost of finding effective antimicrobial agents. In recent years...One of the serious problems the world is facing today is the antimicrobial resistance on available antibiotics by most bacterial pathogens and the rising cost of finding effective antimicrobial agents. In recent years, efforts to find new drugs especially from natural sources have been boosted by the demand for an effective cure for infectious diseases. Only the antibacterial activity of <em>apis mellifera</em> honey and not stingless bee honey from western Kenya has been reported. This study was therefore carried out to determine the effect of <em>Plebenia hylderbrandii </em>and <em>Meliponula bocandei </em>honey samples on the growth of control;sensitive cases of Escherichia coli (ATCC 25922) and <em>Staphylococcus aureus</em> (ATCC 25923). Different honey concentrations (1.18% - 17.65% v/v) of the two samples were tested against the two micro-organisms. The samples were screened for their antibacterial potential against <em>Escherichia coli </em>and <em>Staphylococcus aureus</em> by agar well dilution method. The Partial inhibitory concentration (PIC), minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) values were determined by in vitro method. The inhibitory effect of <em>Plebenia hylderbrandii</em> honey on <em>E. coli</em> and <em>S. aureus</em> growth was apparent at concentrations 3.53% and 1.76% (v/v) respectively. On the other hand, the inhibitory effect of <em>Meliponula bocandei </em>honey on <em>S. aureus</em> growth was at concentration 16.47% (v/v). <em>Plebenia hylderbrandii</em> honey had bactericidal effect on both <em>E. coli </em>and <em>S. aureus</em> at concentrations 4.71% and 2.35% (v/v) respectively. However, <em>Meliponula bocandei</em> honey exerted bactericidal effect on <em>S. aureus </em>only at 16.47% (v/v) concentration. <em>Plebenia hylderbrandii </em>honey had higher antibacterial potency and can be a potential source of antibacterial substances. Moreover, the honeys tested in this study showed great antibacterial potential for <em>S. aureus</em>.展开更多
<em>B. aegyptiaca</em>, it is a species of economic and cultural importance in various countries, with diverse uses that include: medicinal, charcoal, pesticides and forage and<em> in vitro </em&g...<em>B. aegyptiaca</em>, it is a species of economic and cultural importance in various countries, with diverse uses that include: medicinal, charcoal, pesticides and forage and<em> in vitro </em>callus production is important to have many applications in both basic and industrial research on this specie. For the induction of callus, B. aegyptica seed cotyledons were surface sterilized with 90% ethanol for 1 minute and cultivated in MS media supplemented with 2,4-D, BAP and NAA. Both the callus and seed were collected and dried in an oven at 40<span style="font-family:Verdana, Arial, Helvetica, sans-serif;font-size:13px;white-space:normal;background-color:#FEFEF2;">°</span>C - 45<span style="font-family:Verdana, Arial, Helvetica, sans-serif;font-size:13px;white-space:normal;background-color:#FEFEF2;">°</span>C. Cotyledon’s seed and callus were grounded into the powdered form using mortar and pestle and stored at room temperature for further use. Five grams (5 g) each of the powder were mixed with 50 ml of the solvents: methanol and n-hexane (1:10) w/v, agitated vigorously and kept on an orbital shaker at 150 rpm for 24 h, then filtered. The extracts of the plant sample were evaluated in agar dilution method which was used to determine the MIC and MBC of the extracts. The auxin NAA in low concentrations (0.5 mg/L) in the presence of a dose of 0.5 mg/L of the cytokinin BAP induced 100% callus formation. The 50 and 100 mg/ml methanolic extracts were more effective than the n-hexane extracts for both the gram-positive and gram-negative bacteria. By callus extracts under 100 and 50 mg/ml reveals that methanolic extracts of callus had the highest zone of inhibition. An effective protocol for callus induction has been developed that can use for germplasm conservation or for genetic engineering. Evidence from the present study revealed both extracts possess strong broad-spectrum antibacterial effect. Therefore, methanolic extract of seed kernel callus of<em> B. aegyptiaca</em> can be utilized as a new source of broad spectrum antibacterial drugs for effective control of bacteria related diseases.展开更多
Two novel pyran annulated heterocyclic compounds (1 and 2) were synthesized and characterized via IR, lH NMR and H RMS. The structure of compound 1 was verified by single-crystal X-ray diffraction. The in vitro anti...Two novel pyran annulated heterocyclic compounds (1 and 2) were synthesized and characterized via IR, lH NMR and H RMS. The structure of compound 1 was verified by single-crystal X-ray diffraction. The in vitro antibacterial activities of the two compounds against Staphylococcus aureus (S. aureus ATCC 29213), methicillin-resistant S. aureus (MRSA XJ 75302), vancomycin-intermediate S. aureus (Mu50 ATCC 700699), and USA 300 (Los Angeles County clone, LAC) were evaluated by observing the minimum inhibitory concentration.展开更多
L.stoechas subsp.luisieri is one of the five spontaneous species of the genus Lavandula that occurs spontaneously in Portugal.The chemical profile and antifungal activity of L.stoechas subsp.luisieri essential oils we...L.stoechas subsp.luisieri is one of the five spontaneous species of the genus Lavandula that occurs spontaneously in Portugal.The chemical profile and antifungal activity of L.stoechas subsp.luisieri essential oils were investigated.The essential oil of two phenological stages was isolated by hydrodistillation and their chemical components analyzed by GC-FID/GC-MS.The minimum inhibitory concentration(MIC)and the minimum fungicidal concentration(MFC)of both essential oils were determinate to verify antifungal activity against different strains of fungi isolated from strawberry tree.The fungi tested were Aspergillus carbonarius,Rhizopus stolonifer,Penicillium brevicompactum,Aureobasidium pullulans and Saccothecium rubi.Essential oils were characterized by a high percentage of oxygenated monoterpenes(46-64%)such as trans-α-necrodyl acetate(12.58%),fenchone(5.97%),1,8-cineole(4.84%)and 5-methylene-2,3,4,4-tetramethylcyclopenten-2-enone(10.97%)were the major compounds in essential oil from dormancy stage,while the main compounds in flowering stage were trans-α-necrodyl acetate(26.90%),trans-α-necrodol(13.02%),lavandulyl acetate(6.53%)and linalool(5.82%).A strong antifungal activity of the essential oils was found against all strains,with MIC and MFC values ranged from 0.07-0.29μL/mL and 0.58-9.33μL/mL,respectively.展开更多
Essential oils (EOs) are natural bioactive compounds with antibacterial activity against a variety of microorganisms including phytopathogens. The use of EOs and their components as viable therapeutic antibacterials i...Essential oils (EOs) are natural bioactive compounds with antibacterial activity against a variety of microorganisms including phytopathogens. The use of EOs and their components as viable therapeutic antibacterials is however greatly compromised by their volatile nature, hydrophobicity and instability when exposed to environmental and physiological factors. Encapsulation of these compounds in an appropriate carrier system can alleviate these challenges. This study therefore aimed at developing, characterizing and evaluating the efficacy of antibacterial potential of thymol and eugenol loaded chitosan nanoparticles (TCNPs and ECNPs) against <i>Ralstonia solanacearum</i>, the bacterial wilt-causing pathogen in potatoes. Synthesis of TCNP and ECNP was achieved via ionic gelation method and the prepared nanoparticles characterized by their particle size distributions, encapsulation efficiency, loading capacity (LC) and <i>in-vitro</i> release characteristics. Antibacterial activities of the nanoparticles were investigated using agar dilution and colony counting methods and their minimum inhibitory concentration (MIC) determined by 96-well broth micro-dilution method. Scanning electron microscope images of TCNPs and ECNPs showed that the nanoparticles were spherical in shape and were well separated with an average particle size of 590 nm and 555 nm respectively. The average size of chitosan nanoparticles alone was however 375 nm. The encapsulation efficiency was 72.9% for TCNP (with 48.3% LC) and 71.7% for ECNP (with 49.5% LC). The release of thymol and eugenol from the microcapsules was found to be pH dependent with the highest release at pH 1.5. The growth inhibition of <i>R. solanacearum</i> was 92% and 94% for TCNP and ECNPs respectively. The MIC of thymol and eugenol before encapsulation was 175 μg/ml and 275 μg/ml respectively, but this reduced significantly to 22.5 μg/ml and 45 μg/ml after encapsulation. Thus, encapsulation of thymol and eugenol in chitosan nanoparticles has shown promising potential as a bactericide alternative for <i>R. solanacearum</i> and could be useful in managing the soil borne phytopathogen.展开更多
Background:Medicinal herbs have always been closely associated with human beings,and no one deny their medicinal effects and uses.There are over 7,500 plant species in the rich flora of Iran.This study,intends to inve...Background:Medicinal herbs have always been closely associated with human beings,and no one deny their medicinal effects and uses.There are over 7,500 plant species in the rich flora of Iran.This study,intends to investigate the anti-bacterial properties of three different plant species from Iranian flora,including Echinops persicus,Cardamine uliginosa,and Vaccaria oxyodontha Boiss.Materials and methods:This cross-sectional study was performed after confirmation and identification of collected plants.The plants were dried in the shade for extraction.Then the methanol extract of these plants was extracted by the classical extraction method.The plants’antimicrobial effects of the plants were evaluated by agar disk diffusion,minimum inhibitory concentration,and minimum bactericidal concentration.The mentioned plants’anti-bacterial activity was compared with the antibiotic discs of gentamicin(10 mg)and vancomycin(30 mg).SPSS software v20 was used for data analysis of Kruskal-Wallis and Dunn’s tests(P<0.05).Results:The lowest minimum inhibitory concentration obtained from the methanol extract of Cardamine uliginosa on standard strains of Staphylococcus aureus and Escherichia coli at 15.62 mg/mL for methanol extracts of Echinops persicus and Vaccaria oxyodontha Boiss on S.aureus and E.coli at 31.25 mg/mL and 125 mg/mL,respectively.The highest diameter of inhibition zone caused by methanol extract of Cardamine uiliginosa was against S.aureus and E.coli with an inhibition zone of 23.9±0.29 mm and 20.4±0.43 mm,respectively.Compared with the antibiotics gentamicin and vancomycin,the Cardamine uliginosa showed a stronger inhibitory effect(P<0.05).Conclusion:Echinops persicus,Cardamine uliginosa,and Vaccaria oxyodontha Boiss have anti-bacterial properties.The anti-bacterial property of Cardamine uilignosa is higher than the other two herbal medicine.展开更多
The in vitro antibacterial activities of 18β-glycyrrhetinic acid alone or combined with first-line antituberculosis drugs including isoniazid(INH),rifampicin(RFP) and streptomycin(SM) against Mycobacterium tube...The in vitro antibacterial activities of 18β-glycyrrhetinic acid alone or combined with first-line antituberculosis drugs including isoniazid(INH),rifampicin(RFP) and streptomycin(SM) against Mycobacterium tuberculosis were detected using MABA method.The minimum inhibitory concentrations(MICs) of18β-glycyrrhetinic acid against M.tuberculosis H37Rv(ATCC 27294) and M.bovis(ATCC 19210) were 50 and 100 μg/m L,respectively.The MICs of two clinical drug-susceptible isolates and six drug-resistant isolates were 25-50 and 100-200 μg/m L,respectively.As 18β-glycyrrhetinic acid combined with INH,RFP and SM,they exhibited synergistic effects against six drug-resistant isolates,and MICs decreased significantly:MIC of INH decreased by 2-32 folds(FICIs 0.125-0.375);MIC of RFP decreased by 4-8 folds(FICIs 0.240-0.490);MIC of SM decreased by 4-16 folds(FICIs 0.165-0.460).Traditional medicine monomer had low cytotoxicity on normal cell BHK-21 and could restraint SMMC fission.The results showed that 18β-glycyrrhetinic acid combined with anti-TB drugs(INH,RFP and SM) had good antibacterial activity against M.tuberculosis.These findings indicated that 18β-glycyrrhetinic acid might serve as the potential therapeutic compound for future development of anti-TB drugs.展开更多
基金Supported by The Tackling-plan Project of Henan Department of Science and Technology (222102310388)Key Scientific Research Plan of Colleges in Henan Province (22B350002)Henan Provincial Medical Science and Technology Research Plan Joint Construction Project (LHGJ20191520).
文摘Previous studies have shown that glycine and proline are pharmacophores that display antibacterial activity.In the present study,glycine and proline were derivated to diketopiperazine compounds by chemical synthesis method,and their antibacterial activities were evaluated by three strains of spoilage bacteria,Escherichia coli,Pseudomonas aeruginosa and Shewanella putrefaciens,and the relationship of their antibacterial activities and structures was also investigated.Uv-vis spectrophotometry was used to determine the growth curves of three kinds of active indicator bacteria.Minimum inhibitory concentration(MIC)was determined by micro broth dilution method.The results showed that 2-methyl-3-(methylthio)pyrazine had significant antibacterial activity against three strains of the bacteria,and its MIC was 1.25%.It indicates 2-methyl-3-(methylthio)pyrazine has the potential to be developed as a kind of preservative in future.
基金funded by the Forestry Science and Technology Innovation Project of Guangdong Province,China(2020KJCX010).
文摘This study aimed to explore the anti-bacterial and anti-fungal activities of extracts from different parts of plants in the Zingiberaceae family.The inhibitory rate,minimum inhibitory concentration(MIC),and minimum bactericidal concentration(MBC)of leaf and stem,and root and rhizome extracts from Alpinia katsumadai Hayata,Alpinia oxyphylla Miq×Alpinia henryi K.Schumann,Alpinia oblongifolia Hayata,Alpinia nigra(Gaertn.)Burtt,Amomum villosum Lour,Alpinia zerumbet(Pers.)Burtt.et Smith and Alpinia oxyphylla Miq were determined using the fungus cake method and double dilution method.The seven Zingiberaceae plants exhibited characteristic antibacterial activities against pathogenic bacteria and fungi.At a 1.5 mg mL^(−1),A.zerumbet root and rhizome extracts exhibited strong inhibitory activity against S.aureus and E.coli,with 83.23%and 79.62%,respectively.In addition,A.zerumbet leaf and stem extracts had an inhibitory rate of 90.85%against P.aeruginosa.At the same concentration,the leaf and stem,root and rhizome extracts of A.katsumadai had the best anti-bacterial effect against F.oxysporum,with inhibition rates of 84.46%and 84.73%,respectively.Moreover,A.katsumadai and A.zerumbet leaf and stem extracts had the most significant antibacterial effect against S.aureus,with a MIC of 0.063 mg mL^(−1).Thus,both A.katsumadai and A.zerumbet extracts had significant antibacterial activity.In addition,by comparing the inhibitory effect of extracts from different parts,it was found that the inhibitory rate and average inhibitory rate of extracts from leaf and stem were higher than those from root and rhizome.The chemical constituents of A.katsumadai and A.zerumbet,determined by the high-performance liquid chromatography-tandem mass spectrometry(UPLC-MS/MS),revealed that citric acid(CA),alpinetin,and pinocembrin(PNCB)were the functional constituents yielding the antibacterial activity.Overall,A.katsumadai and A.zerumbet have the potential to be developed as new plant fungicides and bactericides.
文摘This study explores the efficacy of advanced antibiotic compounds against P. aeruginosa, focusing on Antibiotic B, an enhanced derivative of Ceftriaxone. The study measured the intracellular uptake of Antibiotic B and introduced a novel adjuvant, Influximax, which augmented its antibacterial activity. Results showed a diminished potential for resistance emergence with Antibiotic B, particularly when used in combination with Influximax. The study suggests that optimizing antibiotic delivery into bacterial cells and leveraging syner-gistic adjuvant combinations can enhance drug resistance combat. .
基金Supported by The Cooperation Project in Industry,Education and Research of Guangdong Province and Ministry of Education of China,No.2009B090300280
文摘AIM:To evaluate the anti-Helicobacter pylori (H.pylori) activity of 50 traditional Chinese herbal medicines in order to provide the primary evidence for their use in clinical practice.METHODS:A susceptibility test of water extract from 50 selected traditional Chinese herbal medicines for in vitro H.pylori Sydney strain 1 was performed with broth dilution method.Anti-H.pylori activity of the selected Chinese herbal medicines was evaluated according to their minimum inhibitory concentration (MIC).RESULTS:The water extract from Rhizoma Coptidis,Radix Scutellariae and Radix isatidis could significantly inhibit the H.pylori activity with their MIC less than 7.8 mg/mL,suggesting that traditional Chinese herbal medicines have anti-inflammatory and antibacterial effects and can thus be used in treatment of H.pylori infection.CONCLUSION:Rhizoma Coptidis,Radix Scutellariae and Radix isatidis are the potential sources for the synthesis of new drugs against H.pylori.
基金funded by the National Natural Science Foundation of China (31072170)
文摘Two Klebsiella pneumoniae isolates (Kpcl and Kpc2) were obtained from liver samples of seven dead chickens and identified with Vitek-32 automated identification system. Antimicrobial susceptibilities were determined by the microdilution broth method. Detection of genes encoding class A β-lactamases was performed by PCR amplification, and cloning of the ESBL gene was by plasmid restriction and fragments ligation. Conjugation assay, transformation experiments and plasmid profile analysis were performed. The incompatibility group of ESBL-carrying plasmid was determined by the PCR-based replicon typing method. Lastly, the genetic environment was analysed by direct sequencing of the DNA surrounding the ESBL gene. The genes associated with tetracycline and gentamicin resistance were also sought by PCR. The results revealed that the ESBL phenotype-negative strain Kpc2 only showed resistance to ampicillin, amoxicillin, tetracycline, and doxycycline and carried bla TEM-1 and tet(A) genes. The ESBL-producing strain Kpcl exhibited multidrug resistant phenotype and harbored bla TEM-1 , bla CTX-M-14, tet(A), tet(B), and rmtB genes. K. pneumoniae Kpcl contained four plasmids with molecular sizes of approximately 59, 6.9, 2.8, and 1.6 kb, but only a 59-kb plasmid, carried bla TEM-1 and blac CTM-14 genes, was observed in its transconjugant. The incompatibility group of plasmid carrying blaCTX-M-14 gene could not be determined. The bla CTX-M-14 gene was flanked upstream by an ISEcpl insertion sequence and downstream by an IS903 element. This work shows that CTX-M-14 is present in K. pneumoniae isolates from chickens in China. The bla CTX -M-4 gene was associated with an upstream ISEcpl insertion sequence. Our results underline the need for continuous surveillance of the prevalence and evolution of this CTX-M-type β-lactamase in China.
文摘Aqueous extracts from various plant parts of fenugreek(3%)(aerial parts:leaves and stems(LS),roots(R),ground seeds(GS)and not ground seeds(NGS))and petroleum ether,ethyl acetate and methanolic fractions of the aerial parts were assayed to determine their antifungal potential against Botrytis cinerea,Fusarium graminearum,Alternaria sp.,Pythium aphanidermatum,and Rhizoctinia solani.All fenugreek plant parts showed antifungal potential and the magnitude of their inhibitory effects was species and plant parts d...
基金Funded by the Student Innovation Project of Southwest University for Nationalities in 2012(201210656017)
文摘[Objective]This study aimed to observe the antibacterial activity of Berberis julianae Schneid and Cinnamomum camphora( L.) Presl. aqueous extracts and their antibiotical effect when being used with commonly used antibiotics in- vitro. [Method] Broth microdilution method and checkerboard dilution method were used and the reference strain E. coli ATCC25922 and clinical sample separation strains of E. coli and Salmonella were selected to determine the minimum inhibitory concentration( MIC) and fractional inhibitory concentration( FIC). [Result] The MICs of Berberis julianae Schneid and Cinnamomum camphora( L.) Presl. for E. coli and Salmonella were both 1 mg /mL,and that of other antibiotics for the two strains were in the quality control range provided by NCCLS. [Conclusion] The synergistic effect or additive effect were observed when they were applied with the commonly used antibiotics.
文摘Three benzopyranocoumarins(OBH, OMH and ODH) were synthesized and characterized via IR, ^1H NMR and HRMS. The HB energy in OBH, OMH and ODH was performed with the density functional theory(DFT) [B3LYP/6-31G*] method. The in vitro antibacterial activity of OBH, OMH and ODH against drug-sensitive S. aureus(S. aureus ATCC 29213) strain, MRSA strain(MRSA XJ 75302), drug-sensitive S. epidermidis strain(S. epidermidis ATCC 14990) and methicillin-resistant S. epidermidis strain(MRSE XJ 75284) was evaluated by observing the minimum inhibitory concentration. The results showed that among the three compounds, ODH exhibited the most potent antibacterial activity.
文摘Multiple drug resistant(MDR)and methicillin-resistant Staphylococcus aureus(MRSA)have become increasingly prevalent as a community acquired infection.As a result limited treatment options are available with conventional synthetic antibiotics.Bioprospecting natural products with potent antimicrobial activity show promise for developing new drugs against this pathogen.In this study,we have investigated the antimicrobial activity of a purple violet pigment(PVP)from an Antarctic bacterium,Janthinobacterium sp.Ant5-2 on 15 clinical MDR and MRSA strains.The colorimetric resazurin assay was employed to determine the minimum inhibitory concentration(MIC90)of PVP against MDR and MRSA.The MIC90 ranged between 1.57μg/mL and 3.13μg/mL,which are significantly lower than many antimicrobials tested from natural sources against this pathogen.The spectrophotometrically determined growth analysis and total microscopic counts using Live/dead®BacLight™fluorescent stain exhibited a steady decrease in viability of both MDR and MRSA cultures following treatment with PVP at the MIC levels.In silico predictive molecular docking study revealed that PVP could be a DNA-targeting minor groove binding antimicrobial compound.The continued development of novel antimicrobials derived from natural sources with the combination of a suite of conventional antibiotics could stem the rising pandemic of MDR and MRSA along with other deadly microbial pathogens.
文摘The purpose of this study was to first evaluate the antimicrobial effects of powder and extracts of berries (rose-hip, aronia, sea buckthorn and hawthorn) on the development of antibiotic-resistant <i><span style="font-family:Verdana;">L</span></i><span style="font-family:Verdana;">. </span><i><span style="font-family:Verdana;">monocitogenes</span></i><span style="font-family:Verdana;">. </span><i><span style="font-family:Verdana;">Listeria</span></i> <i><span style="font-family:Verdana;">monocytogenes</span></i><span style="font-family:Verdana;"> is considered one of the most important pathogens responsible for food-borne infection. Antimicrobial properties were evaluated using the standard Kirby-Bauer disk diffusion method. Bacterial inactivation networks were determined and compared, as well as the possibility of using powders and extracts of berries to control the risk of </span><i><span style="font-family:Verdana;">Listeria</span></i> <i><span style="font-family:Verdana;">monocytogees</span></i><span style="font-family:Verdana;"> infestation in the milk and dairy industry as well as in the meat industry. The effect of pH (4.78 - 4.43) and water activity (0.90 - 0.80) on the relationship between optical density (OD) at 600 nm and the plate count (CFU ml<sup>-</sup></span><span style="font-family:Verdana;"><sup>1</sup></span><span style="font-family:Verdana;">) was investigated for </span><i><span style="font-family:Verdana;">Listeria</span></i> <i><span style="font-family:Verdana;">monocytogenes</span></i><span style="font-family:Verdana;">. It was determined Minimum Inhibitory Concentration (MIC), Minimum Bactericidal Concentration (MBC) </span><span style="font-family:Verdana;">of berries for</span><span style="font-family:;" "=""> </span><i><span style="font-family:Verdana;">L. monocytogenes</span></i><span style="font-family:Verdana;">. </span><span style="font-family:Verdana;">The most relevant bacteriostatic and bactericidal </span><span style="font-family:;" "=""><span style="font-family:Verdana;">effect on </span><i><span style="font-family:Verdana;">L. monocytogenes</span></i><span style="font-family:Verdana;"> in the tested berries demonstrated sea buckthorn and rosehip.</span></span>
文摘<span style="font-family:Verdana;">Coordination compounds of 2-amino-3-methylbutanoic acid were synthesized with chromium(III) and oxovanadium(IV) ions. M:L;1:2. Adducts of these complexes using 1,10-phenantroline and ethylenediamine were further synthesized, M:L, (1:2). These compounds were characterized using electronic, infra-red spectrophotometry, magnetic susceptibility measurement and percentage metal analyses. The zones of inhibition and minimum inhibitory concentrations of the compounds against eight microbes were studied. The results obtained indicated an octahedral geometry for the Cr(III) complexes, indicative of additional coordination of two water molecules. On the other hand a square pyramid geometry was obtained for the binary oxovanadium complex and its 1,10-phenantroline adduct. However</span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">,</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;"> for the oxovanadium ethylenediamine adduct a distorted octahedral geometry was proposed. The result for the antibacterial studies indicated that both mixed ligand complexes of 1,10-phenantroline exhibited good antibacterial activity, and in some cases better activity than the standard, streptomycin.</span></span></span>
文摘The objective of the studies in this paper was to expand on the published toxicological assessment of <i><span style="font-family:Verdana;">Aurantiochytrium</span></i> <i><span style="font-family:Verdana;">limacinum</span></i><span style="font-family:Verdana;"> (AURA) with further strain characterization and to investigate the potential for the biomass or extracted oil to have antimicrobial properties or undesirable substances. AURA is being investigated as a novel source of the omega-3 long-chain polyunsaturated fatty acid docosahexaenoic acid (DHA) for enriching foods of animal origin by means of feed supplementation. In the first studies, we provide</span><span style="font-family:Verdana;">d</span><span style="font-family:Verdana;"> the 18S rRNA identification of the novel marine isolated thraustochytrid, established the nutritional composition of AURA biomass for application as a food or feed ingredient including proximate analysis and fatty acid profiling, and confirmed the DHA production potential of the strain. We determined through minimum inhibitory concentration (MIC) analysis that the unextracted AURA biomass was safe, showing no antimicrobial influence and no evidence of any deleterious effects of this product or its extracts at concentrations up to 1% w/w on the reference human intestinal bacteria</span><span style="font-family:;" "=""> </span><span style="font-family:Verdana;">tested. This would indicate that AURA should not stimulate selective pressure on the commensal microbiota and is therefore unlikely to aid development of antimicrobial resistance and the concomitant harm to humans and animals. Further analysis revealed that the AURA biomass produced through industrial heterotrophic fermentation was free from undesirables;toxic marine microalgal metabolites, heavy metals, pesticides, microbial contaminants, and mycotoxins. Including heterotrophically-grown AURA in food or feed, up to 1% w/w, is a safe and environmentally beneficial strategy for DHA supplementation.</span>
文摘Dermatophytes were earlier reported to respond well to anti-fungal agents;however, an upsurge in resistance with the high cost of these agents increased the use of medicinal plants for treatment. This study investigated the sensitivity pattern of dermatophytes to oral anti-fungal drugs and aqueous leaf extract of the plant, <em>Acacia nilotica</em>. The extract was tested against seven strains of dermatophytes <em>Arthroderma otae</em>, <em>Trichophyton interdigitale</em>, <em>Trichophyton mentagrophyte</em>, <em>Microsporum ferrugineum</em>, <em>Arthroderma vespertilii</em>, <em>Arthroderma quadrifidum</em>, and <em>Arthroderma multifidum</em>, previously isolated from diabetic patients. The minimum inhibitory and fungicidal concentrations of the plant extracts and the standard antifungal agents were evaluated using modifications of the broth macro dilution method of the National Committee for Clinical Laboratory Standards M38-A2 protocol. There was a significant difference in the Minimum Inhibitory concentrations (MIC) of the dermatophytes to the three antifungal drugs tested (p < 0.001). The dermatophytes were mostly susceptible to itraconazole followed by Nystatin. All the dermatophytes tested were resistant to griseofulvin. <em>Acacia nilotica</em> had an inhibitory effect on all the dermatophytes tested, and showed anti-fungal activity in a dose-dependent relationship between 0.625 - 1.25 mg/ml. Though the inhibitions of the dermatophytes were significantly higher with the standard anti-fungal drugs as compared to the plant extract (p < 0.001);however, the dermatophyte, <em>Arthroderma quadrifidum</em>, which was resistant to all the anti-fungal drugs, had the highest inhibition with <em>A. nilotica</em>. Some circulating dermatophyte strains in Nigeria are griseofulvin and/or itraconazole resistant which may influence the spread of infection and <em>A. nilotica</em> aqueous leaf extract showed a strong anti-dermatophytic activity.
文摘One of the serious problems the world is facing today is the antimicrobial resistance on available antibiotics by most bacterial pathogens and the rising cost of finding effective antimicrobial agents. In recent years, efforts to find new drugs especially from natural sources have been boosted by the demand for an effective cure for infectious diseases. Only the antibacterial activity of <em>apis mellifera</em> honey and not stingless bee honey from western Kenya has been reported. This study was therefore carried out to determine the effect of <em>Plebenia hylderbrandii </em>and <em>Meliponula bocandei </em>honey samples on the growth of control;sensitive cases of Escherichia coli (ATCC 25922) and <em>Staphylococcus aureus</em> (ATCC 25923). Different honey concentrations (1.18% - 17.65% v/v) of the two samples were tested against the two micro-organisms. The samples were screened for their antibacterial potential against <em>Escherichia coli </em>and <em>Staphylococcus aureus</em> by agar well dilution method. The Partial inhibitory concentration (PIC), minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) values were determined by in vitro method. The inhibitory effect of <em>Plebenia hylderbrandii</em> honey on <em>E. coli</em> and <em>S. aureus</em> growth was apparent at concentrations 3.53% and 1.76% (v/v) respectively. On the other hand, the inhibitory effect of <em>Meliponula bocandei </em>honey on <em>S. aureus</em> growth was at concentration 16.47% (v/v). <em>Plebenia hylderbrandii</em> honey had bactericidal effect on both <em>E. coli </em>and <em>S. aureus</em> at concentrations 4.71% and 2.35% (v/v) respectively. However, <em>Meliponula bocandei</em> honey exerted bactericidal effect on <em>S. aureus </em>only at 16.47% (v/v) concentration. <em>Plebenia hylderbrandii </em>honey had higher antibacterial potency and can be a potential source of antibacterial substances. Moreover, the honeys tested in this study showed great antibacterial potential for <em>S. aureus</em>.
文摘<em>B. aegyptiaca</em>, it is a species of economic and cultural importance in various countries, with diverse uses that include: medicinal, charcoal, pesticides and forage and<em> in vitro </em>callus production is important to have many applications in both basic and industrial research on this specie. For the induction of callus, B. aegyptica seed cotyledons were surface sterilized with 90% ethanol for 1 minute and cultivated in MS media supplemented with 2,4-D, BAP and NAA. Both the callus and seed were collected and dried in an oven at 40<span style="font-family:Verdana, Arial, Helvetica, sans-serif;font-size:13px;white-space:normal;background-color:#FEFEF2;">°</span>C - 45<span style="font-family:Verdana, Arial, Helvetica, sans-serif;font-size:13px;white-space:normal;background-color:#FEFEF2;">°</span>C. Cotyledon’s seed and callus were grounded into the powdered form using mortar and pestle and stored at room temperature for further use. Five grams (5 g) each of the powder were mixed with 50 ml of the solvents: methanol and n-hexane (1:10) w/v, agitated vigorously and kept on an orbital shaker at 150 rpm for 24 h, then filtered. The extracts of the plant sample were evaluated in agar dilution method which was used to determine the MIC and MBC of the extracts. The auxin NAA in low concentrations (0.5 mg/L) in the presence of a dose of 0.5 mg/L of the cytokinin BAP induced 100% callus formation. The 50 and 100 mg/ml methanolic extracts were more effective than the n-hexane extracts for both the gram-positive and gram-negative bacteria. By callus extracts under 100 and 50 mg/ml reveals that methanolic extracts of callus had the highest zone of inhibition. An effective protocol for callus induction has been developed that can use for germplasm conservation or for genetic engineering. Evidence from the present study revealed both extracts possess strong broad-spectrum antibacterial effect. Therefore, methanolic extract of seed kernel callus of<em> B. aegyptiaca</em> can be utilized as a new source of broad spectrum antibacterial drugs for effective control of bacteria related diseases.
基金supported by the Innovation plan of science and technology of Shaanxi Province(2014KTCL03-03)
文摘Two novel pyran annulated heterocyclic compounds (1 and 2) were synthesized and characterized via IR, lH NMR and H RMS. The structure of compound 1 was verified by single-crystal X-ray diffraction. The in vitro antibacterial activities of the two compounds against Staphylococcus aureus (S. aureus ATCC 29213), methicillin-resistant S. aureus (MRSA XJ 75302), vancomycin-intermediate S. aureus (Mu50 ATCC 700699), and USA 300 (Los Angeles County clone, LAC) were evaluated by observing the minimum inhibitory concentration.
基金CENTRO 2020,PROVERE-Operational Program CENTRO-04-3928-FEDER-000009,Strawberry TreeInnovation Platform Action,Portugal 2020 and European Union by FEDER and by COOP4PAM-Cooperar para crescer no setor das plantas aromáticas e medicinais-Projeto INTERREG/Programa Espanha-Portugal(POCTEP),0665_COOP4PAM_4_P.
文摘L.stoechas subsp.luisieri is one of the five spontaneous species of the genus Lavandula that occurs spontaneously in Portugal.The chemical profile and antifungal activity of L.stoechas subsp.luisieri essential oils were investigated.The essential oil of two phenological stages was isolated by hydrodistillation and their chemical components analyzed by GC-FID/GC-MS.The minimum inhibitory concentration(MIC)and the minimum fungicidal concentration(MFC)of both essential oils were determinate to verify antifungal activity against different strains of fungi isolated from strawberry tree.The fungi tested were Aspergillus carbonarius,Rhizopus stolonifer,Penicillium brevicompactum,Aureobasidium pullulans and Saccothecium rubi.Essential oils were characterized by a high percentage of oxygenated monoterpenes(46-64%)such as trans-α-necrodyl acetate(12.58%),fenchone(5.97%),1,8-cineole(4.84%)and 5-methylene-2,3,4,4-tetramethylcyclopenten-2-enone(10.97%)were the major compounds in essential oil from dormancy stage,while the main compounds in flowering stage were trans-α-necrodyl acetate(26.90%),trans-α-necrodol(13.02%),lavandulyl acetate(6.53%)and linalool(5.82%).A strong antifungal activity of the essential oils was found against all strains,with MIC and MFC values ranged from 0.07-0.29μL/mL and 0.58-9.33μL/mL,respectively.
文摘Essential oils (EOs) are natural bioactive compounds with antibacterial activity against a variety of microorganisms including phytopathogens. The use of EOs and their components as viable therapeutic antibacterials is however greatly compromised by their volatile nature, hydrophobicity and instability when exposed to environmental and physiological factors. Encapsulation of these compounds in an appropriate carrier system can alleviate these challenges. This study therefore aimed at developing, characterizing and evaluating the efficacy of antibacterial potential of thymol and eugenol loaded chitosan nanoparticles (TCNPs and ECNPs) against <i>Ralstonia solanacearum</i>, the bacterial wilt-causing pathogen in potatoes. Synthesis of TCNP and ECNP was achieved via ionic gelation method and the prepared nanoparticles characterized by their particle size distributions, encapsulation efficiency, loading capacity (LC) and <i>in-vitro</i> release characteristics. Antibacterial activities of the nanoparticles were investigated using agar dilution and colony counting methods and their minimum inhibitory concentration (MIC) determined by 96-well broth micro-dilution method. Scanning electron microscope images of TCNPs and ECNPs showed that the nanoparticles were spherical in shape and were well separated with an average particle size of 590 nm and 555 nm respectively. The average size of chitosan nanoparticles alone was however 375 nm. The encapsulation efficiency was 72.9% for TCNP (with 48.3% LC) and 71.7% for ECNP (with 49.5% LC). The release of thymol and eugenol from the microcapsules was found to be pH dependent with the highest release at pH 1.5. The growth inhibition of <i>R. solanacearum</i> was 92% and 94% for TCNP and ECNPs respectively. The MIC of thymol and eugenol before encapsulation was 175 μg/ml and 275 μg/ml respectively, but this reduced significantly to 22.5 μg/ml and 45 μg/ml after encapsulation. Thus, encapsulation of thymol and eugenol in chitosan nanoparticles has shown promising potential as a bactericide alternative for <i>R. solanacearum</i> and could be useful in managing the soil borne phytopathogen.
文摘Background:Medicinal herbs have always been closely associated with human beings,and no one deny their medicinal effects and uses.There are over 7,500 plant species in the rich flora of Iran.This study,intends to investigate the anti-bacterial properties of three different plant species from Iranian flora,including Echinops persicus,Cardamine uliginosa,and Vaccaria oxyodontha Boiss.Materials and methods:This cross-sectional study was performed after confirmation and identification of collected plants.The plants were dried in the shade for extraction.Then the methanol extract of these plants was extracted by the classical extraction method.The plants’antimicrobial effects of the plants were evaluated by agar disk diffusion,minimum inhibitory concentration,and minimum bactericidal concentration.The mentioned plants’anti-bacterial activity was compared with the antibiotic discs of gentamicin(10 mg)and vancomycin(30 mg).SPSS software v20 was used for data analysis of Kruskal-Wallis and Dunn’s tests(P<0.05).Results:The lowest minimum inhibitory concentration obtained from the methanol extract of Cardamine uliginosa on standard strains of Staphylococcus aureus and Escherichia coli at 15.62 mg/mL for methanol extracts of Echinops persicus and Vaccaria oxyodontha Boiss on S.aureus and E.coli at 31.25 mg/mL and 125 mg/mL,respectively.The highest diameter of inhibition zone caused by methanol extract of Cardamine uiliginosa was against S.aureus and E.coli with an inhibition zone of 23.9±0.29 mm and 20.4±0.43 mm,respectively.Compared with the antibiotics gentamicin and vancomycin,the Cardamine uliginosa showed a stronger inhibitory effect(P<0.05).Conclusion:Echinops persicus,Cardamine uliginosa,and Vaccaria oxyodontha Boiss have anti-bacterial properties.The anti-bacterial property of Cardamine uilignosa is higher than the other two herbal medicine.
基金Supported by Scientific Research Project at Universities of Inner Mongolia Autonomous Region(NJZY14332)
文摘The in vitro antibacterial activities of 18β-glycyrrhetinic acid alone or combined with first-line antituberculosis drugs including isoniazid(INH),rifampicin(RFP) and streptomycin(SM) against Mycobacterium tuberculosis were detected using MABA method.The minimum inhibitory concentrations(MICs) of18β-glycyrrhetinic acid against M.tuberculosis H37Rv(ATCC 27294) and M.bovis(ATCC 19210) were 50 and 100 μg/m L,respectively.The MICs of two clinical drug-susceptible isolates and six drug-resistant isolates were 25-50 and 100-200 μg/m L,respectively.As 18β-glycyrrhetinic acid combined with INH,RFP and SM,they exhibited synergistic effects against six drug-resistant isolates,and MICs decreased significantly:MIC of INH decreased by 2-32 folds(FICIs 0.125-0.375);MIC of RFP decreased by 4-8 folds(FICIs 0.240-0.490);MIC of SM decreased by 4-16 folds(FICIs 0.165-0.460).Traditional medicine monomer had low cytotoxicity on normal cell BHK-21 and could restraint SMMC fission.The results showed that 18β-glycyrrhetinic acid combined with anti-TB drugs(INH,RFP and SM) had good antibacterial activity against M.tuberculosis.These findings indicated that 18β-glycyrrhetinic acid might serve as the potential therapeutic compound for future development of anti-TB drugs.