In this study,the theory of minimum detectable activity concentration(MDAC)for airborne gamma-ray spectrometry(AGS)was derived,and the relationship between the MDAC and the intrinsic effi-ciency of a scintillation cou...In this study,the theory of minimum detectable activity concentration(MDAC)for airborne gamma-ray spectrometry(AGS)was derived,and the relationship between the MDAC and the intrinsic effi-ciency of a scintillation counter,volume,and energy res-olution of scintillation crystals,and flight altitude of an aircraft was investigated.To verify this theory,experi-mental devices based on NaI and CeBr 3 scintillation counters were prepared,and the potassium,uranium,and thorium contents in calibration pads obtained via the stripping ratio method and theory were compared.The MDACs of AGS under different conditions were calculated and analyzed using the proposed theory and the Monte Carlo method.The relative errors found via a comparison of the experimental and theoretical results were less than 4%.The theory of MDAC can guide the work of AGS in probing areas with low radioactivity.展开更多
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
Eucalyptus clones are selected according to productivity,wood quality,rooting capacity,and resistance to drought,frost and diseases.However,kinetic and morphological parameters that determine the absorption efficiency...Eucalyptus clones are selected according to productivity,wood quality,rooting capacity,and resistance to drought,frost and diseases.However,kinetic and morphological parameters that determine the absorption efficiency of nutrients such as nitrate(NO_(3)^(-)) and ammonium(NH_(4)^(+))are often not considered in breeding programs.The objective of this study was to evaluate the morphological,physiological and kinetic parameters of nitrogen uptake by clones of Eucalyptus saligna(32,864) and Eucalyptus grandis(GPC23).Morphological parameters in shoot and root systems,biomass and N concentrations in different organs,photosynthetic pigment concentrations,parameters of chlorophyll a fluorescence and photosynthetic rates were evaluated.Kinetic parameters,maximum absorption velocity(V_(max)),Michaelis-Menten constant(K_(m)),minimum concentration(C_(min)) and influx(I) were calculated for NO_(3)^(-)and NH_(4)^(+) in the two clones.E.granais clone was more efficient in the uptake of NO_(3)^(-)and NH_(4)^(+),and showed lower K_(m) and C_(min)values,allowing for the absorption of nitrogen at low concentrations due to the high affinity of the absorption sites of clone roots to NO_(3)^(-)and NH_(4)^(+).Higher root lengths,area and volume helped the E.grandis clone in absorption efficiency and consequently,resulted in higher root and shoot biomass.The E.saligna clone had higher K_(m) and Cmin for NO_(3)^(-)and NH_(4)^(+),indicating adaptation to environments with higher N availability.The results of NO_(3)^(-)and NH_(4)^(+) kinetic parameters indicate that they can be used in Eucalyptus clone selection and breeding programs as they can predict the ability of clones to absorb NO_(3)^(-)and NH_(4)^(+) at different concentrations.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
Background Epidural lidocaine can be used when regional anesthesia needs to be established quickly, but the effect of co-administering epidural fentanyl on the minimum local analgesic concentration (MLAC) of lidocai...Background Epidural lidocaine can be used when regional anesthesia needs to be established quickly, but the effect of co-administering epidural fentanyl on the minimum local analgesic concentration (MLAC) of lidocaine is not known. We compared the MLAC of epidural lidocaine in combination with different doses of fentanyl for epidural anesthesia in adults. Methods One hundred and twenty patients requiring epidural analgesia were randomly allocated to receive 20 ml of one of four solutions: lidocaine, or lidocaine plus fentanyl 1 pg/ml, 2 pg/ml, or 3 pg/ml. The first patient in each group was administered 1% lidocaine weight by volume; subsequent patients received a concentration determined by the response of the previous patient to a higher or lower concentration according to up and down sequential allocation in 0.1% increments. Efficacy was assessed using a visual analog pain scale, and accepted if this was 〈10 mm on a 100 mm scale within 30 minutes. The extent of motor block and of nausea and vomiting were recorded at 30 minutes after administration of the epidural solution and two hours after surgery, respectively. Results The MLAC of lidocaine in those receiving lidocaine alone was 0.785% (95%C/0.738-0.864). A significant dose-dependent reduction was observed with the addition of fentanyl: the MLAC of lidocaine with fentanyl at 2 pg/ml was 0.596% (95%C/0.537-0.660) and 0.387% with fentanyl at 3 pg/ml (95%C/0.329-0.446, P 〈0.001). Conclusion Epidural fentanyl significantly reduces the dose of lidocaine required for effective epidural analgesia in adults without causing adverse side effects. (Chi CTR-TRC-11001559)展开更多
To investigate the scientific bases for t/te traditional use of Stachy-tarpheta angustifolia. Methods: In vitro antibacterial activity of the aqueous and ethanol extract of the plant was investigated using the agar cu...To investigate the scientific bases for t/te traditional use of Stachy-tarpheta angustifolia. Methods: In vitro antibacterial activity of the aqueous and ethanol extract of the plant was investigated using the agar cup plate diffusion method. Results: The ethanol extract of the plant showed antibacterial activity against Escherichia coli, Streptococcus faecalis, Shigella dysenterme, Slaphylococcus aureus (S. aureus) , Salmonella sp. , Pseudomonas aeruginosa and Neisseria gonor-r/iaeae, while the water extract was active against Escherichia coli, Streptococcus faecalis, Shigella dysenterme, Sta-phylococcus aureus and. Pseudomonas aeruginosa. The etlianol extract exhibited higher antibacterial activity than the water extract. The minimum inhibitory concentration (MIC) and minimum bactericidal, concentration (MBC} of the ethanol extract were 0. 65 mg/mt and 0. 85 mg/ml, respectively , against S. aureus. Treatment of the extract at higher temperature, 60℃ increased the sensitivity of the test organisms to the plant extract. Phytochemical analysis indicated t/tat the plant possesses tannins, saponins as well as phenols. Conclusion: A scientific basis exists that the plant possesses antibacterial activity and it could be a probable source of therapeutic agent.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
Lidar (Light detection and ranging) has special capabilities for remote sensing of many different behaviours of the atmosphere. One of the techniques which show a great deal of promise for several applications is Ra...Lidar (Light detection and ranging) has special capabilities for remote sensing of many different behaviours of the atmosphere. One of the techniques which show a great deal of promise for several applications is Raman scattering. The detecting capability, including maximum operation range and minimum detectable gas concentration is one of the most significant parameters for lidar remote sensing of pollutants. In this paper, based on the new method for evaluating the capabilities of a Raman lidar system, we present an evaluation of detecting capability of Raman lidar for monitoring atmospheric CO2 in Hefei. Numerical simulations about the influence of atmospheric conditions on lidar detecting capability were carried out, and a conclusion can be drawn that the maximum difference of the operation ranges caused by the weather conditions alone can reach about 0.4 to 0.5km with a measuring precision within 30ppmv. The range of minimum detectable concentration caused by the weather conditions alone can reach about 20 to 35 ppmv in vertical direction for 20000 shots at a distance of 1 km on the assumption that other parameters are kept constant. The other corresponding parameters under different conditions are also given. The capability of Raman lidar operated in vertical direction was found to be superior to that operated in horizontal direction. During practical measurement with the Raman lidar whose hardware components were fixed, aerosol scattering extinction effect would be a significant factor that influenced the capability of Raman lidar. This work may be a valuable reference for lidar system designing, measurement accuracy improving and data processing.展开更多
Plastic scintillation detectors based whole body β/γ contamination monitors are developed for use in radiation facilities.This microcontroller-based multi-detector system uses 13 plastic scintillator detectors,with ...Plastic scintillation detectors based whole body β/γ contamination monitors are developed for use in radiation facilities.This microcontroller-based multi-detector system uses 13 plastic scintillator detectors,with minimized dead detection zones,monitoring the whole body,and conforming to the contamination limit prescribed by the regulatory authority.This system has the features for monitoring hands,feet,head,and faceβ/γusing contamination monitors and portal exit monitors.It can detect gamma sources at a dose rate of 10 n Gyh^(-1).The system is calibrated using b sources^(90)Sr/^(90)Y,^(204)Tl,and^(36)Cl,and the efficiency is found to be 29%,22%,and 18%,respectively.Theminimumdetectableβ/γcontaminationis0.15 Bqcm^(-2),which is significantly less than the minimum detection objectives on head,face,hands,and feet.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
AIM: To understand the pathogen characteristics and its sensitivity against antimicrobial agents in fatal bacterial granuloma after eyelid trauma (FBGT) in vitro, and to provide laboratory evidence for diagnosis. METH...AIM: To understand the pathogen characteristics and its sensitivity against antimicrobial agents in fatal bacterial granuloma after eyelid trauma (FBGT) in vitro, and to provide laboratory evidence for diagnosis. METHODS: The FBGT pathogens were isolaated and cultured with reformed rabbit-brain anaerobic enriched broth (RRAB), and identified by ATB/API 20A system. The minimum inhibiting concentration (MIC) was determined by anaerobic broth dilution method. RESULTS: A total of 22 strains of pathogen were separated from 21 patients with FBGT and identified as Propionibacterium acnes (PA) by ATB/API 20A system. The MIC of ciprofloxacin for 22 PA strains was 0.0625-0.5mg/L, the MIC of penicillin, ampicillin, ampicillin/sulbactam, cefoperazone, lincomycin, and imipenem/cilastatin were 0.125-0.5mg/L, the MIC of ticarcillin/clavulanic acid was 0.250-1.000mg/L, and the MIC of metronidazole was 64-256mg/L. The pathogen of FBGT was strictly anaerobic PA, which growed slowly and better in nutritious RRAB broth. All PA were resistant to metronidazole, but susceptive to other routine antimicrobial agents, such as penicillin, ampicillin and lincomycin. CONCLUSION: FBGT should not be treated with metronidazole. Clinicians should choose combined use of drugs or operation to treat FBGT according to patients' individual condition and the results of drug sensitivity test.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
Bifurcaria bifurcata is a seaweed of the Order Fucales(Ochrophyta,Phaeophyceae)that can be found all year round along the Portuguese Atlantic shore.Although it is considered edible in some countries,its biotechnologic...Bifurcaria bifurcata is a seaweed of the Order Fucales(Ochrophyta,Phaeophyceae)that can be found all year round along the Portuguese Atlantic shore.Although it is considered edible in some countries,its biotechnological potential has not yet been assessed in detail and here we report its antimicrobial potential against human dermatophyte fungi.Three samples were harvested from Baleal Island(Peniche,Portugal)harvested in winter(BbPe);from Aguda Beach(Arcozelo,Vila Nova de Gaia,Portugal),harvested in autumn(BbAg)and a sample obtained by culturing the Aguda sample under laboratory conditions(BbLC).A broth macrodilution assay was applied to determine the MIC(minimum inhibitory concentration)and MLC(minimum lethal concentration)of the B.bifurcata extracts.Results show that the BbPe MeOH extracts were the most effective and had higher antifungal activity against all the tested dermatophyte strains than the BbLC and BaAg extracts[Epidermophyton floccosum FF9(100–200μg/mL MIC;200μg/mL MLC),Microsporum canis FF1(400μg/mL MIC;≥400μg/mL MLC),Trichophyton mentagrophytes FF7(100μg/mL MIC;>800μg/mL MLC),M.gypseum CECT 2908(800μg/mL MIC;≥800μg/mL MLC),T.mentagrophytes var.interdigitale CECT 2958(800μg/mL MIC;≥800μg/mL MLC),T.rubrum CECT 2794(200μg/mL MIC;≥400μg/mL MLC)].In fact,only E.floccosum FF9 was sensitive to BbAg and BbLC MeOH extracts.To our knowledge,this is the first report of antifungal activity of B.bifurcata against human dermatophyte fungi.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
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
基金This work was supported by the Sichuan Science and Technology Program(No.2020JDRC0108)the National Science Foundation of China(Nos.41774147 and 41774190).
文摘In this study,the theory of minimum detectable activity concentration(MDAC)for airborne gamma-ray spectrometry(AGS)was derived,and the relationship between the MDAC and the intrinsic effi-ciency of a scintillation counter,volume,and energy res-olution of scintillation crystals,and flight altitude of an aircraft was investigated.To verify this theory,experi-mental devices based on NaI and CeBr 3 scintillation counters were prepared,and the potassium,uranium,and thorium contents in calibration pads obtained via the stripping ratio method and theory were compared.The MDACs of AGS under different conditions were calculated and analyzed using the proposed theory and the Monte Carlo method.The relative errors found via a comparison of the experimental and theoretical results were less than 4%.The theory of MDAC can guide the work of AGS in probing areas with low radioactivity.
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funded partly by the Conselho Nacional de Desenvolvimento Científico and Tecnológico(CNPq)。
文摘Eucalyptus clones are selected according to productivity,wood quality,rooting capacity,and resistance to drought,frost and diseases.However,kinetic and morphological parameters that determine the absorption efficiency of nutrients such as nitrate(NO_(3)^(-)) and ammonium(NH_(4)^(+))are often not considered in breeding programs.The objective of this study was to evaluate the morphological,physiological and kinetic parameters of nitrogen uptake by clones of Eucalyptus saligna(32,864) and Eucalyptus grandis(GPC23).Morphological parameters in shoot and root systems,biomass and N concentrations in different organs,photosynthetic pigment concentrations,parameters of chlorophyll a fluorescence and photosynthetic rates were evaluated.Kinetic parameters,maximum absorption velocity(V_(max)),Michaelis-Menten constant(K_(m)),minimum concentration(C_(min)) and influx(I) were calculated for NO_(3)^(-)and NH_(4)^(+) in the two clones.E.granais clone was more efficient in the uptake of NO_(3)^(-)and NH_(4)^(+),and showed lower K_(m) and C_(min)values,allowing for the absorption of nitrogen at low concentrations due to the high affinity of the absorption sites of clone roots to NO_(3)^(-)and NH_(4)^(+).Higher root lengths,area and volume helped the E.grandis clone in absorption efficiency and consequently,resulted in higher root and shoot biomass.The E.saligna clone had higher K_(m) and Cmin for NO_(3)^(-)and NH_(4)^(+),indicating adaptation to environments with higher N availability.The results of NO_(3)^(-)and NH_(4)^(+) kinetic parameters indicate that they can be used in Eucalyptus clone selection and breeding programs as they can predict the ability of clones to absorb NO_(3)^(-)and NH_(4)^(+) at different concentrations.
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.
文摘Background Epidural lidocaine can be used when regional anesthesia needs to be established quickly, but the effect of co-administering epidural fentanyl on the minimum local analgesic concentration (MLAC) of lidocaine is not known. We compared the MLAC of epidural lidocaine in combination with different doses of fentanyl for epidural anesthesia in adults. Methods One hundred and twenty patients requiring epidural analgesia were randomly allocated to receive 20 ml of one of four solutions: lidocaine, or lidocaine plus fentanyl 1 pg/ml, 2 pg/ml, or 3 pg/ml. The first patient in each group was administered 1% lidocaine weight by volume; subsequent patients received a concentration determined by the response of the previous patient to a higher or lower concentration according to up and down sequential allocation in 0.1% increments. Efficacy was assessed using a visual analog pain scale, and accepted if this was 〈10 mm on a 100 mm scale within 30 minutes. The extent of motor block and of nausea and vomiting were recorded at 30 minutes after administration of the epidural solution and two hours after surgery, respectively. Results The MLAC of lidocaine in those receiving lidocaine alone was 0.785% (95%C/0.738-0.864). A significant dose-dependent reduction was observed with the addition of fentanyl: the MLAC of lidocaine with fentanyl at 2 pg/ml was 0.596% (95%C/0.537-0.660) and 0.387% with fentanyl at 3 pg/ml (95%C/0.329-0.446, P 〈0.001). Conclusion Epidural fentanyl significantly reduces the dose of lidocaine required for effective epidural analgesia in adults without causing adverse side effects. (Chi CTR-TRC-11001559)
文摘To investigate the scientific bases for t/te traditional use of Stachy-tarpheta angustifolia. Methods: In vitro antibacterial activity of the aqueous and ethanol extract of the plant was investigated using the agar cup plate diffusion method. Results: The ethanol extract of the plant showed antibacterial activity against Escherichia coli, Streptococcus faecalis, Shigella dysenterme, Slaphylococcus aureus (S. aureus) , Salmonella sp. , Pseudomonas aeruginosa and Neisseria gonor-r/iaeae, while the water extract was active against Escherichia coli, Streptococcus faecalis, Shigella dysenterme, Sta-phylococcus aureus and. Pseudomonas aeruginosa. The etlianol extract exhibited higher antibacterial activity than the water extract. The minimum inhibitory concentration (MIC) and minimum bactericidal, concentration (MBC} of the ethanol extract were 0. 65 mg/mt and 0. 85 mg/ml, respectively , against S. aureus. Treatment of the extract at higher temperature, 60℃ increased the sensitivity of the test organisms to the plant extract. Phytochemical analysis indicated t/tat the plant possesses tannins, saponins as well as phenols. Conclusion: A scientific basis exists that the plant possesses antibacterial activity and it could be a probable source of therapeutic agent.
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.
基金Project supported by National High Technology Development Program of China (Grant No 2002AA135030)
文摘Lidar (Light detection and ranging) has special capabilities for remote sensing of many different behaviours of the atmosphere. One of the techniques which show a great deal of promise for several applications is Raman scattering. The detecting capability, including maximum operation range and minimum detectable gas concentration is one of the most significant parameters for lidar remote sensing of pollutants. In this paper, based on the new method for evaluating the capabilities of a Raman lidar system, we present an evaluation of detecting capability of Raman lidar for monitoring atmospheric CO2 in Hefei. Numerical simulations about the influence of atmospheric conditions on lidar detecting capability were carried out, and a conclusion can be drawn that the maximum difference of the operation ranges caused by the weather conditions alone can reach about 0.4 to 0.5km with a measuring precision within 30ppmv. The range of minimum detectable concentration caused by the weather conditions alone can reach about 20 to 35 ppmv in vertical direction for 20000 shots at a distance of 1 km on the assumption that other parameters are kept constant. The other corresponding parameters under different conditions are also given. The capability of Raman lidar operated in vertical direction was found to be superior to that operated in horizontal direction. During practical measurement with the Raman lidar whose hardware components were fixed, aerosol scattering extinction effect would be a significant factor that influenced the capability of Raman lidar. This work may be a valuable reference for lidar system designing, measurement accuracy improving and data processing.
文摘Plastic scintillation detectors based whole body β/γ contamination monitors are developed for use in radiation facilities.This microcontroller-based multi-detector system uses 13 plastic scintillator detectors,with minimized dead detection zones,monitoring the whole body,and conforming to the contamination limit prescribed by the regulatory authority.This system has the features for monitoring hands,feet,head,and faceβ/γusing contamination monitors and portal exit monitors.It can detect gamma sources at a dose rate of 10 n Gyh^(-1).The system is calibrated using b sources^(90)Sr/^(90)Y,^(204)Tl,and^(36)Cl,and the efficiency is found to be 29%,22%,and 18%,respectively.Theminimumdetectableβ/γcontaminationis0.15 Bqcm^(-2),which is significantly less than the minimum detection objectives on head,face,hands,and feet.
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...
文摘AIM: To understand the pathogen characteristics and its sensitivity against antimicrobial agents in fatal bacterial granuloma after eyelid trauma (FBGT) in vitro, and to provide laboratory evidence for diagnosis. METHODS: The FBGT pathogens were isolaated and cultured with reformed rabbit-brain anaerobic enriched broth (RRAB), and identified by ATB/API 20A system. The minimum inhibiting concentration (MIC) was determined by anaerobic broth dilution method. RESULTS: A total of 22 strains of pathogen were separated from 21 patients with FBGT and identified as Propionibacterium acnes (PA) by ATB/API 20A system. The MIC of ciprofloxacin for 22 PA strains was 0.0625-0.5mg/L, the MIC of penicillin, ampicillin, ampicillin/sulbactam, cefoperazone, lincomycin, and imipenem/cilastatin were 0.125-0.5mg/L, the MIC of ticarcillin/clavulanic acid was 0.250-1.000mg/L, and the MIC of metronidazole was 64-256mg/L. The pathogen of FBGT was strictly anaerobic PA, which growed slowly and better in nutritious RRAB broth. All PA were resistant to metronidazole, but susceptive to other routine antimicrobial agents, such as penicillin, ampicillin and lincomycin. CONCLUSION: FBGT should not be treated with metronidazole. Clinicians should choose combined use of drugs or operation to treat FBGT according to patients' individual condition and the results of drug sensitivity test.
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.
基金the support of Fundacao para a Ciência e Tecnologia(FCT),through the strategic project UID/MAR/04292/2013 granted to MAREthe support from the European Union through EASME Blue Labs project AMALIA-Algae-to-MArket Lab IdeAs(EASME/EMFF/2016/1.2.1.4/03/SI2.750419)+2 种基金funding from European Structural&Investment Funds through the COMPETE ProgrammeNational Funds through FCT-Fundacao para a Ciência e a Tecnologia under the Programme grant SAICTPAC/0019/2015the support of ALGAplus for giving the opportunity of culturing the B.bifurcata sample
文摘Bifurcaria bifurcata is a seaweed of the Order Fucales(Ochrophyta,Phaeophyceae)that can be found all year round along the Portuguese Atlantic shore.Although it is considered edible in some countries,its biotechnological potential has not yet been assessed in detail and here we report its antimicrobial potential against human dermatophyte fungi.Three samples were harvested from Baleal Island(Peniche,Portugal)harvested in winter(BbPe);from Aguda Beach(Arcozelo,Vila Nova de Gaia,Portugal),harvested in autumn(BbAg)and a sample obtained by culturing the Aguda sample under laboratory conditions(BbLC).A broth macrodilution assay was applied to determine the MIC(minimum inhibitory concentration)and MLC(minimum lethal concentration)of the B.bifurcata extracts.Results show that the BbPe MeOH extracts were the most effective and had higher antifungal activity against all the tested dermatophyte strains than the BbLC and BaAg extracts[Epidermophyton floccosum FF9(100–200μg/mL MIC;200μg/mL MLC),Microsporum canis FF1(400μg/mL MIC;≥400μg/mL MLC),Trichophyton mentagrophytes FF7(100μg/mL MIC;>800μg/mL MLC),M.gypseum CECT 2908(800μg/mL MIC;≥800μg/mL MLC),T.mentagrophytes var.interdigitale CECT 2958(800μg/mL MIC;≥800μg/mL MLC),T.rubrum CECT 2794(200μg/mL MIC;≥400μg/mL MLC)].In fact,only E.floccosum FF9 was sensitive to BbAg and BbLC MeOH extracts.To our knowledge,this is the first report of antifungal activity of B.bifurcata against human dermatophyte fungi.
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>.