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
Parent compounds of cyclopentadienyltitanium substituted heteropolytungstates with Keggin structure,An[(CpTi)XW11O39]·xH2O(A=Me4N,K;X=P,Si,Co;Cp=η5-C5H5) were synthesized in aqueous phase.By allowing parent hete...Parent compounds of cyclopentadienyltitanium substituted heteropolytungstates with Keggin structure,An[(CpTi)XW11O39]·xH2O(A=Me4N,K;X=P,Si,Co;Cp=η5-C5H5) were synthesized in aqueous phase.By allowing parent heteropoly compounds to react with protonated 8-quinolinol,the title supermolecular compounds(C9H8NO)mAn[(CpTi)XW11O39]·xH2O(A=Me4N,H;X=P,Si,Co) were synthesized.The title compounds were characterized by means of elementary analysis,IR,UV,1H NMR,XRD and TG-DSC.The results indicate that the title compounds are new heteropoly compounds,and there is a charge transfer interaction between the organic cation and heteropoly anion.The results obtained from thermal analysis show that QCpTiPW,QCpTiSiW and QCpTiCoW begin to decompose at 212.4,194.2 and 171.2 ℃,respectively.The results obtained from antibacterial test reveal that QCpTiSiW has the best antibacterial activity,and the MIC values of QCpTiSiW against Escherichia coli and Staphylococcus aurous are 64.0 and 0.500 μg·mL-1,respectively.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 dependent.R extract was shown less toxic(30.38%),whereas NGS extract expressed the strongest inhibition,with an average of 71.44%,followed by GS(58.56%)and LS(57.1%).Screening indicated that P.aphanidermatum was the most resistant species,with an average inhibition of 34.5%.F.graminearum,Alternaria sp.and R.solani were the most sensitive species,and were similarly inhibited (63.5%).The stability test indicated that the aqueous extracts of all plant parts lost approximately 50%of their relative activity after one month of storage at 4°C,whilst they lost 60%–90%of their activity when stored at ambient temperature for one month.The antifungal activity resided mainly in the methanol fraction and the minimum inhibitory concentration(MIC)of methanol fraction witch caused total inhibition of R.solani and Alternaria sp.was 60μg/ml.Results of current study suggested that the constituents of Trigonella foenum-graecum have potential against harmful pathogenic fungi.Therefore,fenugreek could be an important source of biologically active compounds useful for developing better new antifungal drugs.展开更多
The tomato(Solanum lycopersicum L.)is one of the world’s most important vegetable crops.Still,phytopathogenic bacteria affect the yield and quality of tomato cultivation,like Agrobacterium tumefeciens(At),Clavibacter...The tomato(Solanum lycopersicum L.)is one of the world’s most important vegetable crops.Still,phytopathogenic bacteria affect the yield and quality of tomato cultivation,like Agrobacterium tumefeciens(At),Clavibacter michiganensis subsp.michiganensis(Cmm),Pseudomonas syringae pv.tomato(Pst),Ralstonia solanacearum(Rs),and Xanthomonas axonopodis(Xa).Synthetic chemical products are used mostly on disease plant control,but overuse generates resistance to bacterial control.This study aimed to evaluate the in vitro antibacterial activity of the ethanolic extract of Moringa oleifera Lam.leaves against At,Cmm,Pst,Rs,and Xa,as well as information about this plant species’chemical composition.Antibacterial activity against pathogens observed by microplate technique,phytochemical screening,and FTIR analysis revealed different bio-active compounds on ethanolic extracts with antibacterial activity.The growth inhibition rate ranged between 0.08%and 99.94%.The inhibitory concentration,IC50,required to inhibit 50%of At,Cmm,Pst,Rs,and Xa bacterial growth,was 276.67,350.48,277.85,351.49,and 283.22 mg/L,respectively.Inhibition of phytopathogen bacteria’s growth increased as the concentrations of the extract also increased.Moringa oleifera extract can be recommended as a potent bio-bactericide.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
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
Antifungal activities of the commercial rice wine extracts of Allium fistulosum were analyzed. Antifungal activities were tested against 7 pathogenic fungi by using agar disc diffusion and tube dilution tests. The res...Antifungal activities of the commercial rice wine extracts of Allium fistulosum were analyzed. Antifungal activities were tested against 7 pathogenic fungi by using agar disc diffusion and tube dilution tests. The results show that the commercial rice wine extracts of Allium fistulosum have strong antifungal activity against Aspergillus brasiliensis ATCC 16404, Candida albicans ATCC 10231, Microsporumcanis ATCC 36299, M. gypseum ATCC 24102, Trichophyton mentagrophytes ATCC 9533, T. rubrum ATCC 28188, and T. tonsurans ATCC 28942. The commercial rice wine extracts of different A. fistulosum parts were found to exhibit significant antifungal activities with the minimal inhibitory concentration (MIC) in the range of 0.2 - 1.0 mg/mL. The antifungal activity of the extracts of different A. fistulosum parts was in the order of AFS (stem) > AFI (plant body) > AFL (leaf) > AFR (root).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
Aim: To evaluate in vitro the effectiveness of several anti-infective agents alone and in combination against Leishmania donovani. Method: A convenient stratified sampling method was used to obtain selected anti-infec...Aim: To evaluate in vitro the effectiveness of several anti-infective agents alone and in combination against Leishmania donovani. Method: A convenient stratified sampling method was used to obtain selected anti-infective agents. For individual drug samples, Half Maximal Inhibitory Concentrations (IC<sub>50</sub>) were obtained using the broth dilution method. The IC<sub>50’s</sub> of the drugs which were active against L. donovani were used as reference values to prepare drug combinations for the modified microdilution checkerboard method. Results: Five (5) out of the fifty-six (56) drugs used showed activity (inhibition of cell growth) against L. donovani cells. They include Quinine sulphate (IC<sub>50</sub> = 0.089 μg/ml), gentamicin (IC<sub>50</sub> = 8.1 μg/ml), amodiaquine (IC<sub>50</sub> = 138 μg/ml) and the two standard drugs: Amphotericin B (IC<sub>50</sub> = 6.3 μg/ml) and Pentamidine (IC<sub>50</sub> = 25 μg/ml). The remaining fifty-one (51) drugs did not show any inhibition within the range of concentrations used (1.25 - 160 μg/ml). The drug combinations of Pentamidine/Amodiaquine, Pentamidine/ Quinine sulphate, Pentamidine/Gentamicin, Amphotericin B/Quinine Sulphate, Amphotericin B/ Gentamicin, Amodiaquine/Quinine sulphate and Amodiaquine/Gentamicin showed synergistic effects against L. donovani whereas the Amphotericin B/Amodiaquine combination was antagonistic. Notable in the results obtained was the high effectiveness of quinine sulphate in inhibiting the growth of L. donovani. Quinine sulphate, though not indicated for leishmania treatment, was more effective than the two standard drugs and has a potential of playing a significant role in the treatment of leishmaniasis. Conclusion: This study has revealed five (5) anti-infective agents that by themselves or in combinations show activity against L. donovani. Some of the drug combinations which showed synergism should further be investigated. These results have to be confirmed by in vivo studies to define their roles in leishmaniasis treatment.展开更多
Although nowadays there are methods for determining the Minimal Bactericidal Concentration and Minimal Fungicidal Concentration, it is indispensable that?the establishment of innovative methodologies?could be more pra...Although nowadays there are methods for determining the Minimal Bactericidal Concentration and Minimal Fungicidal Concentration, it is indispensable that?the establishment of innovative methodologies?could be more practical and cheaper. The new methodology Flash microbiocide is an assay in which one aliquot from 96 well plate of Minimal Inhibitory Concentration test is transferred to another plate containing different culture medium. The correspondence with the reference methods described in the National Committee for Clinical Laboratory Standards (NCCLS-CLSI) document M26-A was achieved, denoting the efficiency of this fast and simple method.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supported by the chemical materials institute China academy of engineering physics,the doctoral innovation research assistance program of science and technology review
文摘Parent compounds of cyclopentadienyltitanium substituted heteropolytungstates with Keggin structure,An[(CpTi)XW11O39]·xH2O(A=Me4N,K;X=P,Si,Co;Cp=η5-C5H5) were synthesized in aqueous phase.By allowing parent heteropoly compounds to react with protonated 8-quinolinol,the title supermolecular compounds(C9H8NO)mAn[(CpTi)XW11O39]·xH2O(A=Me4N,H;X=P,Si,Co) were synthesized.The title compounds were characterized by means of elementary analysis,IR,UV,1H NMR,XRD and TG-DSC.The results indicate that the title compounds are new heteropoly compounds,and there is a charge transfer interaction between the organic cation and heteropoly anion.The results obtained from thermal analysis show that QCpTiPW,QCpTiSiW and QCpTiCoW begin to decompose at 212.4,194.2 and 171.2 ℃,respectively.The results obtained from antibacterial test reveal that QCpTiSiW has the best antibacterial activity,and the MIC values of QCpTiSiW against Escherichia coli and Staphylococcus aurous are 64.0 and 0.500 μg·mL-1,respectively.
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 dependent.R extract was shown less toxic(30.38%),whereas NGS extract expressed the strongest inhibition,with an average of 71.44%,followed by GS(58.56%)and LS(57.1%).Screening indicated that P.aphanidermatum was the most resistant species,with an average inhibition of 34.5%.F.graminearum,Alternaria sp.and R.solani were the most sensitive species,and were similarly inhibited (63.5%).The stability test indicated that the aqueous extracts of all plant parts lost approximately 50%of their relative activity after one month of storage at 4°C,whilst they lost 60%–90%of their activity when stored at ambient temperature for one month.The antifungal activity resided mainly in the methanol fraction and the minimum inhibitory concentration(MIC)of methanol fraction witch caused total inhibition of R.solani and Alternaria sp.was 60μg/ml.Results of current study suggested that the constituents of Trigonella foenum-graecum have potential against harmful pathogenic fungi.Therefore,fenugreek could be an important source of biologically active compounds useful for developing better new antifungal drugs.
基金This work was supported by PRODEP throughthe support of the postdoctoral fellowship granted to the first author(Trade No.511-6/18-391)The authors thank the academic body of Ecología Aplicada(UAT-CA-156)for the support obtained from their researchers to conductthis investigation.
文摘The tomato(Solanum lycopersicum L.)is one of the world’s most important vegetable crops.Still,phytopathogenic bacteria affect the yield and quality of tomato cultivation,like Agrobacterium tumefeciens(At),Clavibacter michiganensis subsp.michiganensis(Cmm),Pseudomonas syringae pv.tomato(Pst),Ralstonia solanacearum(Rs),and Xanthomonas axonopodis(Xa).Synthetic chemical products are used mostly on disease plant control,but overuse generates resistance to bacterial control.This study aimed to evaluate the in vitro antibacterial activity of the ethanolic extract of Moringa oleifera Lam.leaves against At,Cmm,Pst,Rs,and Xa,as well as information about this plant species’chemical composition.Antibacterial activity against pathogens observed by microplate technique,phytochemical screening,and FTIR analysis revealed different bio-active compounds on ethanolic extracts with antibacterial activity.The growth inhibition rate ranged between 0.08%and 99.94%.The inhibitory concentration,IC50,required to inhibit 50%of At,Cmm,Pst,Rs,and Xa bacterial growth,was 276.67,350.48,277.85,351.49,and 283.22 mg/L,respectively.Inhibition of phytopathogen bacteria’s growth increased as the concentrations of the extract also increased.Moringa oleifera extract can be recommended as a potent bio-bactericide.
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Antifungal activities of the commercial rice wine extracts of Allium fistulosum were analyzed. Antifungal activities were tested against 7 pathogenic fungi by using agar disc diffusion and tube dilution tests. The results show that the commercial rice wine extracts of Allium fistulosum have strong antifungal activity against Aspergillus brasiliensis ATCC 16404, Candida albicans ATCC 10231, Microsporumcanis ATCC 36299, M. gypseum ATCC 24102, Trichophyton mentagrophytes ATCC 9533, T. rubrum ATCC 28188, and T. tonsurans ATCC 28942. The commercial rice wine extracts of different A. fistulosum parts were found to exhibit significant antifungal activities with the minimal inhibitory concentration (MIC) in the range of 0.2 - 1.0 mg/mL. The antifungal activity of the extracts of different A. fistulosum parts was in the order of AFS (stem) > AFI (plant body) > AFL (leaf) > AFR (root).
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.
文摘Aim: To evaluate in vitro the effectiveness of several anti-infective agents alone and in combination against Leishmania donovani. Method: A convenient stratified sampling method was used to obtain selected anti-infective agents. For individual drug samples, Half Maximal Inhibitory Concentrations (IC<sub>50</sub>) were obtained using the broth dilution method. The IC<sub>50’s</sub> of the drugs which were active against L. donovani were used as reference values to prepare drug combinations for the modified microdilution checkerboard method. Results: Five (5) out of the fifty-six (56) drugs used showed activity (inhibition of cell growth) against L. donovani cells. They include Quinine sulphate (IC<sub>50</sub> = 0.089 μg/ml), gentamicin (IC<sub>50</sub> = 8.1 μg/ml), amodiaquine (IC<sub>50</sub> = 138 μg/ml) and the two standard drugs: Amphotericin B (IC<sub>50</sub> = 6.3 μg/ml) and Pentamidine (IC<sub>50</sub> = 25 μg/ml). The remaining fifty-one (51) drugs did not show any inhibition within the range of concentrations used (1.25 - 160 μg/ml). The drug combinations of Pentamidine/Amodiaquine, Pentamidine/ Quinine sulphate, Pentamidine/Gentamicin, Amphotericin B/Quinine Sulphate, Amphotericin B/ Gentamicin, Amodiaquine/Quinine sulphate and Amodiaquine/Gentamicin showed synergistic effects against L. donovani whereas the Amphotericin B/Amodiaquine combination was antagonistic. Notable in the results obtained was the high effectiveness of quinine sulphate in inhibiting the growth of L. donovani. Quinine sulphate, though not indicated for leishmania treatment, was more effective than the two standard drugs and has a potential of playing a significant role in the treatment of leishmaniasis. Conclusion: This study has revealed five (5) anti-infective agents that by themselves or in combinations show activity against L. donovani. Some of the drug combinations which showed synergism should further be investigated. These results have to be confirmed by in vivo studies to define their roles in leishmaniasis treatment.
基金supported by University of Ribeirao Preto(UNAERP),FAPESP 2010/07970-7 and Ourofino.
文摘Although nowadays there are methods for determining the Minimal Bactericidal Concentration and Minimal Fungicidal Concentration, it is indispensable that?the establishment of innovative methodologies?could be more practical and cheaper. The new methodology Flash microbiocide is an assay in which one aliquot from 96 well plate of Minimal Inhibitory Concentration test is transferred to another plate containing different culture medium. The correspondence with the reference methods described in the National Committee for Clinical Laboratory Standards (NCCLS-CLSI) document M26-A was achieved, denoting the efficiency of this fast and simple method.
