Background and Objective: In recent years, control of Enterococcus sp. It has been proven in the local medical environment to be a cause of acquired septicemia in various age groups, and medical instruments are consid...Background and Objective: In recent years, control of Enterococcus sp. It has been proven in the local medical environment to be a cause of acquired septicemia in various age groups, and medical instruments are considered an effective means of transmitting enterococcal septicemia, and catheters are at the forefront in terms of danger. Based on this risk, this study aimed to monitor the spread of Enterococcus sp., which causes blood poisoning acquired from catheters, and to compare its response to antibiotics with that of those isolated from clinical samples in children, as a first study locally. The effectiveness of alkaloids of different types of Papaver sp. In Syrian plants, they were tested against infection with this bacteria. Materials and Methods: The study dealt with two parts: The first part included collecting clinical samples from the University Children’s Hospital in Damascus/bacterial diagnostic laboratories/then isolating and diagnosing the bacteria by following a set of tests to identify the most prevalent genera and species and comparing their prevalence rate with Enterococcus. The second part;It included collecting plant samples, confirming the species taxonomically, then extracting alkaloids from plant parts (fruit, stem, Flowers), then comparing the extent of resistance of bacterial strains to antibiotics compared to the Enterococcus sp., and then confirming the antibacterial activity of the Papaver sp. alkaloids against Enterococcus sp. Result:In its first part, the study confirmed the significant contribution of the Enterococcus sp. to infections acquired from various sources, largely in catheter tip infections (9.09%) and to a lesser extent in other sources (3.7%), The second part was to confirm the effective-ness of the alkaloid extract of the Papaver sp., especially the two species Papaver syriacum, and Papaver dubium, against Enterococcus sp. with areole diameters that ranged between (15 - 26 mm) for the fruit extract and at a minimum inhibitory concentration (3.12 - 6.25 mml) and then the stem (5 - 20 mm). And the effectiveness of the Flowers extract is very weak to almost non-existent. Conclusions: The catheter and medical sources surrounding the patient constitute a dangerous source of multi-resistant Enterococcus sp., which poses a real threat to the lives of children, with new mechanisms represented by colonization of the skin and the ability to form biofilms Surfaces of medical instruments, with are resistant to a wide range of antibiotics. As an alternative and effective modern source to limit its spread in the future, the alkaloid extract of the fruits and stems of the wild Papaver sp. has proven a strong antibiotic effect, especially the two types: Papaver syriacum and Papaver dubium.展开更多
Objective:To investigate antimicrobial effects of ethanolic extract of Zingiber zerumbet(Z.zerumbet)(L.)Smith and its chloroform and petroleum ether soluble fractions against pathogenic bacteria and fungi.Methods:The ...Objective:To investigate antimicrobial effects of ethanolic extract of Zingiber zerumbet(Z.zerumbet)(L.)Smith and its chloroform and petroleum ether soluble fractions against pathogenic bacteria and fungi.Methods:The fresh rhizomes of Zingiber zerumbet were extracted in cold with ethanol(4.0 L)after concentration.The crude ethanol extract was fractionated by petroleum ether and chloroform to form a suspension of ethanol extract(15.0 g),petroleum ether fraction(6.6 g)and chloroform soluble fraction(5.0 g).The crude ethanol extract and its petroleum ether and chloroform fractions were evaluated for antibacterial and antifungal activity against thirteen pathogenic bacteria and three fungi by the disc diffusion method.Commercially available kanamycin(30μg/disc)was used as standard disc and blank discs impregnated with the respective solvents were used as negative control.Results:At a concentration of 400μg/disc,all the samples showed mild to moderate antibacterial and antifungal activity and produced the zone of inhibition ranging from 6 mm to 10 mm.Among the tested samples,the crude ethanol extract showed the highest activity against Vibrio parahemolyticus(V.parahemolyticus).The minimum inhibitory concentration(MIC)of the crude ethanol extract and its fractions were within the value of 128-256μg/mL against two Gram positive and four Gram negative bacteria and all the samples showed the lowest MIC value against V.parahemolyticus(128μg/mL).Conclusions:It can be concluded that,potent antibacterial and antifungal phytochemicals are present in ethanol extract of Z.zerumbet(L.).展开更多
Objective:To examine the anti-bacterial activity of leaf extracts of Morus alba L.(Moraceae)and Piper betel L.(Piperaceae),and seed extracts of Bombax ceiba L.(Borabacaceae).Methods:We have partially purified plant ex...Objective:To examine the anti-bacterial activity of leaf extracts of Morus alba L.(Moraceae)and Piper betel L.(Piperaceae),and seed extracts of Bombax ceiba L.(Borabacaceae).Methods:We have partially purified plant extracts by solvent extraction method,and evaluated the effect of individual fractions on bacterial growth using Escherichia coli(E.coli),Pseudomonas aeruginosa(P.aeruginosa) and Staphylococcus aureus(S.aureus) bacterial strains.Results:Compared with Morus and Bombax fractions,Piper fractions showed significant growth inhibition on all the three types of bacteria studied.The EtOAc-hexane fractions of Piper leaves exhibited significant antibacterial activity with minimum inhibitory concentrations(MIC) of 50 μg/mL culture against both gram-positive and gram-negative bacteria.The EtOAc-fractions Ⅰ,Ⅱ,and Ⅳ inhibited bacterial colony formation on soft agar in addition to growth inhibition.A combination treatment of piper fractions with ampicillin resulted in significant growth inhibition in E.coli and P.aeruginosa,and combination with anticancer drug geldanamycin(2 μg/mL) showed selective growth inhibition against P.aeruginosa and S.aureus.Three major compounds,i.e.,eugenol,3-hexene-ol and stigmasterol,were primarily identified from Piper betel leaf extractions.Among the individual compounds,eugenol treatment showed improved growth inhibition compared with stigmasterol and 3-hexene-ol.Conclusions:We are reporting potential anti-bacterial compounds from Piper betel against both gram-positive and gram-negative bacteria either alone or in combination with drug treatment.展开更多
AIM: To investigate the increasing the susceptibility pylon) to metronidazole. mechanisms of aspirin of Helicobacter pylori (H METHODS: Hpylori reference strain 26695 and two metronidazole-resistant isolates of H ...AIM: To investigate the increasing the susceptibility pylon) to metronidazole. mechanisms of aspirin of Helicobacter pylori (H METHODS: Hpylori reference strain 26695 and two metronidazole-resistant isolates of H pylori were included in this study. Strains were incubated in Brucella broth with or without aspirin (1 mmol/L). The rdxA gene of Hpylori was amplified by PCR and sequenced. The permeability of Hpylori to antimicrobials was determined by analyzing the endocellular radioactivity of the cells after incubated with [7-^3H]-tetracycline. The outer membrane proteins (OMPs) of Hpylori 26695 were depurated and analyzed by SDS-PAGE. The expression of 5 porins (hopA, hopB, hopC, hopD and hopE) and the putative RND efflux system (hefABC) of H pylori were analyzed using real-time quantitative PCR. RESULTS: The mutations in rdxA gene did not change in metronidazole resistant isolates treated with aspirin. The radioactivity of H pylori increased when treated with aspirin, indicating that aspirin improved the permeability of the outer membrane of H pylori. However, the expression of two OMP bands between 55 kDa and 72 kDa altered in the presence of aspirin.The expression of the mRNA of hopA, hopB, hopC, hopD, hopE and herA, hefB, hefC of H pylori did not change when treated with aspirin. CONCLUSION: Although aspirin increases the susceptibility of H pylori to metronidazole, it has no effect on the mutations of rdxA gene of Hpylori. Aspirin increases endocellular concentrations of antimicrobials probably by altering the OMP expression.展开更多
Staphylococcus aureus(SA) infections remain a major cause of morbidity and mortality despite the availability of numerous effective anti-staphylococcal antibiotics.This organism is responsible for both nosocomial and ...Staphylococcus aureus(SA) infections remain a major cause of morbidity and mortality despite the availability of numerous effective anti-staphylococcal antibiotics.This organism is responsible for both nosocomial and community-acquired infections ranging from relatively minor skin and soft tissue infections to life-threateningsystemic infections.The increasing incidence of methicillin-resistant strains has granted an increasing use of vancomycin causing a covert progressive increase of its minimum inhibitory concentration(MIC)(dubbed the MIC "creep").In this way,the emergence of vancomycinintermediate SA(VISA) strains and heteroresistantVISA has raised concern for the scarcity of alternative treatment options.Equally alarming,though fortunately less frequent,is the emergence of vancomycin-resistant SA.These strains show different mechanisms of resistance but have similar problems in terms of therapeutic approach.Ultimately,various debate issues have arisen regarding the emergence of SA strains with a minimum inhibitory concentration sitting on the superior limit of the sensitivity range(i.e.,MIC = 2 μg/mL).These strains have shown certain resilience to vancomycin and a different clinical behaviour regardless of vancomycin use,both in methicillin-resistant SA and in methicillin-sensitive SA.The aim of this text is to revise the clinical impact and consequences of the emergence of reduced vancomycin susceptibility SA strains,and the different optimal treatment options known.展开更多
Objective:To evaluate the phytochemical and anti-bacterial efficacy of the seed kernel extract of Mangifera indica(M.indica) against the enteropathogen,Shigella dysenteriae(S.dysenteriae), isolated from the diarrhoeal...Objective:To evaluate the phytochemical and anti-bacterial efficacy of the seed kernel extract of Mangifera indica(M.indica) against the enteropathogen,Shigella dysenteriae(S.dysenteriae), isolated from the diarrhoeal stool specimens.Methods:The preliminary phytochemical screening was performed by the standard methods as described by Harborne.Cold extraction method was employed to extract the bioactive compounds from mango seed kernel.Disc diffusion method was adopted to screen antibacterial activity.Minimum inhibitory concentration(MIC) was evaluated by agar dilution method.The crude extracts were partially purified by thin layer chromatography(TLC) and the fractions were analyzed by high performance thin layer chromatography(HFTLC) to identify the bioactive compounds.Results:Phytochemical scrutiny of M.indica indicated the presence of phytochemical constituents such as alkaloids,gums, flavanoids,phenols,saponins,steroids,tannins and xanthoproteins.Antibacterial activity was observed in two crude extracts and various fractions viz.hexane,benzene,chlor of orm,methanol and water.MIC of methanol fraction was found to be(95±11.8)μg/mL.MIC of other fractions ranged from 130-380μg/mL Conclusions:The present study confirmed that each crude extracts and fractions of M.indica have significant antimicrobial activity against the isolated pathogen 5. dyserUeriae.The antibacterial activity may be due to the phytochemical constituents of the mango seed kernel.The phytochemical tannin could be the reason for its antibacterial activity.展开更多
Objective:To isolate and indentify the promising antimicrobial metabolite producing Streptomyces strains from marine sediment samples from Andraprudesh coast of India.Methods:Antagonistic aetinomycetes were isolated b...Objective:To isolate and indentify the promising antimicrobial metabolite producing Streptomyces strains from marine sediment samples from Andraprudesh coast of India.Methods:Antagonistic aetinomycetes were isolated by starch casein agar medium and modified nutrient agar medium with 1%glucose used as a base for primary screening.Significant antimicrobial metabolite producing strains were selected and identified by using biochemical and 16S rDNA level.Minimum inhibitory concentrations of the organic extracts were done by using broth micro dilution method.Results:Among the 210 actinomyeetes,64.3%exhibited activity against Gram positive bacteria,48.5%showed activity towards Cram negative bacteria,38.8%exhibited both Cram positive and negative bacteria and 80.85%isolates revealed significant antifungal activity.However,five isolates AP-5,AP-18,AP-41 and AP-70 showed significant antimicrobial activity.The analysis of cell wall hydrolysates showed the presence of LL-diaminopimelic acid and glycine in all the isolates.Sequencing analysis indicated that the isolates shared 98.5%-99.8%sequence identity to the 16S rDNA gene sequences of the Streptomyces taxons.The antimicrobial substances were extracted using hexane and ethyl acetate from spent medium in which strains were cultivated at 30X for five days.The antimicrobial activity was assessed using broth micro dilution technique.Each of the culture extracts from these five strains showed a typical polyenelike property.The lowest minimum inhibitory concentrations of ethyl acetate extracts against Escherichia coli and Cumularia lunula were 67.5 and 125.0μg/mL,respectively.Conclusions:It can be concluded that hexane and ethyl acetate soluble extracellular products of novel isolates are effective against pathogenic bacteria and fungi.展开更多
Objective:To observe the biochemical characters and antibiotic susceptibility of isolated Staphylococcia aureus(S.auerus) strains against some conventional and traditional antibiotics. Methods:Thirty post operative pa...Objective:To observe the biochemical characters and antibiotic susceptibility of isolated Staphylococcia aureus(S.auerus) strains against some conventional and traditional antibiotics. Methods:Thirty post operative pathogenic isolated S.aureus strains were used in this study. Bacterial culture was done in Mueller-Hinton broth at 37 ℃.Characters of these strains were determined by traditional biochemical tests such as hydrolysis test of gelatin,urea,galactose, starch and protein,and fermentation of lactose and sucrose.Antibiotic susceptibility were carried out by minimum inhibilory concentration test,minium bactericidal concentration test,disc agar diffusion test and brain heart infusion oxacillin screening agar.Results:Prom this study,it was observed that 100%S.aureus isolates showed positive results in gelatin,urea and galactose hydrolysis test.50%isolates were positive in starch hydrolysis test,35%in protein hydrolysis test. 100%isolates in lactose fermenting test,but no isolate was positive in sucrose fermenting test. Antibiotic susceptibility testing suggested that 20%of isolates were resistant to kanamycin and 46.67%were resistant to oxacillin.Conclusions:These findings show that all these isolates have gelatin,urea,galactose hydrolysis and lactose fermenting activity.20%of these isolates were resistant to kanamvcin and 46.67%were resistant to oxacillin.展开更多
Objective:To isolate,partially purify and evaluate the cytotoxic and antitumor activity of a serine protease from the chosen Indian earthworm Pheretima posthuma.Methods:Whole animal extract was prepared and purified i...Objective:To isolate,partially purify and evaluate the cytotoxic and antitumor activity of a serine protease from the chosen Indian earthworm Pheretima posthuma.Methods:Whole animal extract was prepared and purified its protein constituents by size and charge based chromatographic separation techniques using Sephadex G-50 and DEAE-Cellulose resin respectively.Average molecular weight of the protein isolate was determined and analyzed for its cytotoxic property against Vero cells in different dilutions(1:20 and 1:40)and anti-tumor activity by MTT assay(a colorimetric assay)using breast cancer cell line MCF-7,with tamoxifen as standard.Results:One of the protein constituents after purification was characterized as serine protease by Caseinolytic plate diffusion assay.Average molecular weight of this purified isolate was determined,by SDS-PAGE analysis with standard protein ladder,as of 15 kDa.The performed tests suggested that the 15kDa fraction has potent cytotoxic activity and satisfactory antitumor activity as well in vitro.Conclusions:Exact molecular mechanism of the cytotoxic and antitumor activities is yet to be explored and currently we are working on ultra-purification and biophysical characterization of this fraction.Further investigation into the mechanism(s)of cytotoxic and antitumor activities at molecular level would be useful in treatment of various classes of cancer and viral infections in future.展开更多
Aqueous extracts from various plant parts of fenugreek(3%)(aerial parts:leaves and stems(LS),roots(R),ground seeds(GS)and not ground seeds(NGS))and petroleum ether,ethyl acetate and methanolic fractions of the aerial ...Aqueous extracts from various plant parts of fenugreek(3%)(aerial parts:leaves and stems(LS),roots(R),ground seeds(GS)and not ground seeds(NGS))and petroleum ether,ethyl acetate and methanolic fractions of the aerial parts were assayed to determine their antifungal potential against Botrytis cinerea,Fusarium graminearum,Alternaria sp.,Pythium aphanidermatum,and Rhizoctinia solani.All fenugreek plant parts showed antifungal potential and the magnitude of their inhibitory effects was species and plant parts d...展开更多
Objective: To determine the bioactive phytochemicals and antimicrobial activity of leaf and stem ethanolic extracts from Muntingia calabura L.(M. calabura).Methods: Dried leaves and stems of M. calabura were extracted...Objective: To determine the bioactive phytochemicals and antimicrobial activity of leaf and stem ethanolic extracts from Muntingia calabura L.(M. calabura).Methods: Dried leaves and stems of M. calabura were extracted with 95% ethanol. The antibacterial and antifungal activities of the extracts were examined using the disc diffusion assay. The minimum inhibitory concentration(MIC) of each extract showing antimicrobial activity was determined. The dried extracts were subjected to phytochemical screening to determine the presence of bioactive components. Total phenolic and flavonoid contents were also determined by the Folin–Ciocalteu method and the aluminum chloride method, respectively.Results: Varying degrees of antimicrobial activity were exhibited by the leaf and stem extracts against Pseudomonas aeruginosa(P. aeruginosa), Salmonella typhimurium,Staphylococcus aureus(S. aureus), Bacillus subtilis, and Candida albicans(C. albicans),with minimal activity against Escherichia coli. Based on the MIC, the extracts showed the highest activity against C. albicans, S. aureus and P. aeruginosa. Phytochemical screening revealed the presence of sterols, flavonoids, alkaloids, saponins, glycosides and tannins in the leaf extract; however, no triterpenes were detected. In the stem extract,triterpenes were detected along with relative amounts of flavonoids, saponins, glycosides and tannins. Alkaloids and sterols were absent in the stem extract.Conclusions: M. calabura leaf and stem ethanol extracts are potential sources of antibacterial agents against P. aeruginosa and S. aureus. This study reports for the first time the high degree of antifungal activity of M. calabura ethanolic extract, especially against C. albicans.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
文摘Background and Objective: In recent years, control of Enterococcus sp. It has been proven in the local medical environment to be a cause of acquired septicemia in various age groups, and medical instruments are considered an effective means of transmitting enterococcal septicemia, and catheters are at the forefront in terms of danger. Based on this risk, this study aimed to monitor the spread of Enterococcus sp., which causes blood poisoning acquired from catheters, and to compare its response to antibiotics with that of those isolated from clinical samples in children, as a first study locally. The effectiveness of alkaloids of different types of Papaver sp. In Syrian plants, they were tested against infection with this bacteria. Materials and Methods: The study dealt with two parts: The first part included collecting clinical samples from the University Children’s Hospital in Damascus/bacterial diagnostic laboratories/then isolating and diagnosing the bacteria by following a set of tests to identify the most prevalent genera and species and comparing their prevalence rate with Enterococcus. The second part;It included collecting plant samples, confirming the species taxonomically, then extracting alkaloids from plant parts (fruit, stem, Flowers), then comparing the extent of resistance of bacterial strains to antibiotics compared to the Enterococcus sp., and then confirming the antibacterial activity of the Papaver sp. alkaloids against Enterococcus sp. Result:In its first part, the study confirmed the significant contribution of the Enterococcus sp. to infections acquired from various sources, largely in catheter tip infections (9.09%) and to a lesser extent in other sources (3.7%), The second part was to confirm the effective-ness of the alkaloid extract of the Papaver sp., especially the two species Papaver syriacum, and Papaver dubium, against Enterococcus sp. with areole diameters that ranged between (15 - 26 mm) for the fruit extract and at a minimum inhibitory concentration (3.12 - 6.25 mml) and then the stem (5 - 20 mm). And the effectiveness of the Flowers extract is very weak to almost non-existent. Conclusions: The catheter and medical sources surrounding the patient constitute a dangerous source of multi-resistant Enterococcus sp., which poses a real threat to the lives of children, with new mechanisms represented by colonization of the skin and the ability to form biofilms Surfaces of medical instruments, with are resistant to a wide range of antibiotics. As an alternative and effective modern source to limit its spread in the future, the alkaloid extract of the fruits and stems of the wild Papaver sp. has proven a strong antibiotic effect, especially the two types: Papaver syriacum and Papaver dubium.
基金Supported by Innovation Technology,Research and Development Project,Ministry of Science.Information and Communication Technology.Republic of Bangladesh Government(No.12)
文摘Objective:To investigate antimicrobial effects of ethanolic extract of Zingiber zerumbet(Z.zerumbet)(L.)Smith and its chloroform and petroleum ether soluble fractions against pathogenic bacteria and fungi.Methods:The fresh rhizomes of Zingiber zerumbet were extracted in cold with ethanol(4.0 L)after concentration.The crude ethanol extract was fractionated by petroleum ether and chloroform to form a suspension of ethanol extract(15.0 g),petroleum ether fraction(6.6 g)and chloroform soluble fraction(5.0 g).The crude ethanol extract and its petroleum ether and chloroform fractions were evaluated for antibacterial and antifungal activity against thirteen pathogenic bacteria and three fungi by the disc diffusion method.Commercially available kanamycin(30μg/disc)was used as standard disc and blank discs impregnated with the respective solvents were used as negative control.Results:At a concentration of 400μg/disc,all the samples showed mild to moderate antibacterial and antifungal activity and produced the zone of inhibition ranging from 6 mm to 10 mm.Among the tested samples,the crude ethanol extract showed the highest activity against Vibrio parahemolyticus(V.parahemolyticus).The minimum inhibitory concentration(MIC)of the crude ethanol extract and its fractions were within the value of 128-256μg/mL against two Gram positive and four Gram negative bacteria and all the samples showed the lowest MIC value against V.parahemolyticus(128μg/mL).Conclusions:It can be concluded that,potent antibacterial and antifungal phytochemicals are present in ethanol extract of Z.zerumbet(L.).
基金Supported by Council of Scientific and Industrial Research(CSIR),Government of India
文摘Objective:To examine the anti-bacterial activity of leaf extracts of Morus alba L.(Moraceae)and Piper betel L.(Piperaceae),and seed extracts of Bombax ceiba L.(Borabacaceae).Methods:We have partially purified plant extracts by solvent extraction method,and evaluated the effect of individual fractions on bacterial growth using Escherichia coli(E.coli),Pseudomonas aeruginosa(P.aeruginosa) and Staphylococcus aureus(S.aureus) bacterial strains.Results:Compared with Morus and Bombax fractions,Piper fractions showed significant growth inhibition on all the three types of bacteria studied.The EtOAc-hexane fractions of Piper leaves exhibited significant antibacterial activity with minimum inhibitory concentrations(MIC) of 50 μg/mL culture against both gram-positive and gram-negative bacteria.The EtOAc-fractions Ⅰ,Ⅱ,and Ⅳ inhibited bacterial colony formation on soft agar in addition to growth inhibition.A combination treatment of piper fractions with ampicillin resulted in significant growth inhibition in E.coli and P.aeruginosa,and combination with anticancer drug geldanamycin(2 μg/mL) showed selective growth inhibition against P.aeruginosa and S.aureus.Three major compounds,i.e.,eugenol,3-hexene-ol and stigmasterol,were primarily identified from Piper betel leaf extractions.Among the individual compounds,eugenol treatment showed improved growth inhibition compared with stigmasterol and 3-hexene-ol.Conclusions:We are reporting potential anti-bacterial compounds from Piper betel against both gram-positive and gram-negative bacteria either alone or in combination with drug treatment.
基金Supported by The National Natural Science Foundation of China, No. 30470777
文摘AIM: To investigate the increasing the susceptibility pylon) to metronidazole. mechanisms of aspirin of Helicobacter pylori (H METHODS: Hpylori reference strain 26695 and two metronidazole-resistant isolates of H pylori were included in this study. Strains were incubated in Brucella broth with or without aspirin (1 mmol/L). The rdxA gene of Hpylori was amplified by PCR and sequenced. The permeability of Hpylori to antimicrobials was determined by analyzing the endocellular radioactivity of the cells after incubated with [7-^3H]-tetracycline. The outer membrane proteins (OMPs) of Hpylori 26695 were depurated and analyzed by SDS-PAGE. The expression of 5 porins (hopA, hopB, hopC, hopD and hopE) and the putative RND efflux system (hefABC) of H pylori were analyzed using real-time quantitative PCR. RESULTS: The mutations in rdxA gene did not change in metronidazole resistant isolates treated with aspirin. The radioactivity of H pylori increased when treated with aspirin, indicating that aspirin improved the permeability of the outer membrane of H pylori. However, the expression of two OMP bands between 55 kDa and 72 kDa altered in the presence of aspirin.The expression of the mRNA of hopA, hopB, hopC, hopD, hopE and herA, hefB, hefC of H pylori did not change when treated with aspirin. CONCLUSION: Although aspirin increases the susceptibility of H pylori to metronidazole, it has no effect on the mutations of rdxA gene of Hpylori. Aspirin increases endocellular concentrations of antimicrobials probably by altering the OMP expression.
文摘Staphylococcus aureus(SA) infections remain a major cause of morbidity and mortality despite the availability of numerous effective anti-staphylococcal antibiotics.This organism is responsible for both nosocomial and community-acquired infections ranging from relatively minor skin and soft tissue infections to life-threateningsystemic infections.The increasing incidence of methicillin-resistant strains has granted an increasing use of vancomycin causing a covert progressive increase of its minimum inhibitory concentration(MIC)(dubbed the MIC "creep").In this way,the emergence of vancomycinintermediate SA(VISA) strains and heteroresistantVISA has raised concern for the scarcity of alternative treatment options.Equally alarming,though fortunately less frequent,is the emergence of vancomycin-resistant SA.These strains show different mechanisms of resistance but have similar problems in terms of therapeutic approach.Ultimately,various debate issues have arisen regarding the emergence of SA strains with a minimum inhibitory concentration sitting on the superior limit of the sensitivity range(i.e.,MIC = 2 μg/mL).These strains have shown certain resilience to vancomycin and a different clinical behaviour regardless of vancomycin use,both in methicillin-resistant SA and in methicillin-sensitive SA.The aim of this text is to revise the clinical impact and consequences of the emergence of reduced vancomycin susceptibility SA strains,and the different optimal treatment options known.
文摘Objective:To evaluate the phytochemical and anti-bacterial efficacy of the seed kernel extract of Mangifera indica(M.indica) against the enteropathogen,Shigella dysenteriae(S.dysenteriae), isolated from the diarrhoeal stool specimens.Methods:The preliminary phytochemical screening was performed by the standard methods as described by Harborne.Cold extraction method was employed to extract the bioactive compounds from mango seed kernel.Disc diffusion method was adopted to screen antibacterial activity.Minimum inhibitory concentration(MIC) was evaluated by agar dilution method.The crude extracts were partially purified by thin layer chromatography(TLC) and the fractions were analyzed by high performance thin layer chromatography(HFTLC) to identify the bioactive compounds.Results:Phytochemical scrutiny of M.indica indicated the presence of phytochemical constituents such as alkaloids,gums, flavanoids,phenols,saponins,steroids,tannins and xanthoproteins.Antibacterial activity was observed in two crude extracts and various fractions viz.hexane,benzene,chlor of orm,methanol and water.MIC of methanol fraction was found to be(95±11.8)μg/mL.MIC of other fractions ranged from 130-380μg/mL Conclusions:The present study confirmed that each crude extracts and fractions of M.indica have significant antimicrobial activity against the isolated pathogen 5. dyserUeriae.The antibacterial activity may be due to the phytochemical constituents of the mango seed kernel.The phytochemical tannin could be the reason for its antibacterial activity.
文摘Objective:To isolate and indentify the promising antimicrobial metabolite producing Streptomyces strains from marine sediment samples from Andraprudesh coast of India.Methods:Antagonistic aetinomycetes were isolated by starch casein agar medium and modified nutrient agar medium with 1%glucose used as a base for primary screening.Significant antimicrobial metabolite producing strains were selected and identified by using biochemical and 16S rDNA level.Minimum inhibitory concentrations of the organic extracts were done by using broth micro dilution method.Results:Among the 210 actinomyeetes,64.3%exhibited activity against Gram positive bacteria,48.5%showed activity towards Cram negative bacteria,38.8%exhibited both Cram positive and negative bacteria and 80.85%isolates revealed significant antifungal activity.However,five isolates AP-5,AP-18,AP-41 and AP-70 showed significant antimicrobial activity.The analysis of cell wall hydrolysates showed the presence of LL-diaminopimelic acid and glycine in all the isolates.Sequencing analysis indicated that the isolates shared 98.5%-99.8%sequence identity to the 16S rDNA gene sequences of the Streptomyces taxons.The antimicrobial substances were extracted using hexane and ethyl acetate from spent medium in which strains were cultivated at 30X for five days.The antimicrobial activity was assessed using broth micro dilution technique.Each of the culture extracts from these five strains showed a typical polyenelike property.The lowest minimum inhibitory concentrations of ethyl acetate extracts against Escherichia coli and Cumularia lunula were 67.5 and 125.0μg/mL,respectively.Conclusions:It can be concluded that hexane and ethyl acetate soluble extracellular products of novel isolates are effective against pathogenic bacteria and fungi.
基金Supported by a grant from Department of Biotechnology,India(No:BT/PR10861/NNT/28/131/2008)
文摘Objective:To observe the biochemical characters and antibiotic susceptibility of isolated Staphylococcia aureus(S.auerus) strains against some conventional and traditional antibiotics. Methods:Thirty post operative pathogenic isolated S.aureus strains were used in this study. Bacterial culture was done in Mueller-Hinton broth at 37 ℃.Characters of these strains were determined by traditional biochemical tests such as hydrolysis test of gelatin,urea,galactose, starch and protein,and fermentation of lactose and sucrose.Antibiotic susceptibility were carried out by minimum inhibilory concentration test,minium bactericidal concentration test,disc agar diffusion test and brain heart infusion oxacillin screening agar.Results:Prom this study,it was observed that 100%S.aureus isolates showed positive results in gelatin,urea and galactose hydrolysis test.50%isolates were positive in starch hydrolysis test,35%in protein hydrolysis test. 100%isolates in lactose fermenting test,but no isolate was positive in sucrose fermenting test. Antibiotic susceptibility testing suggested that 20%of isolates were resistant to kanamycin and 46.67%were resistant to oxacillin.Conclusions:These findings show that all these isolates have gelatin,urea,galactose hydrolysis and lactose fermenting activity.20%of these isolates were resistant to kanamvcin and 46.67%were resistant to oxacillin.
基金supported by the Research Grant for Faculty(Grant No.R&J/Budget/2011-12/251)
文摘Objective:To isolate,partially purify and evaluate the cytotoxic and antitumor activity of a serine protease from the chosen Indian earthworm Pheretima posthuma.Methods:Whole animal extract was prepared and purified its protein constituents by size and charge based chromatographic separation techniques using Sephadex G-50 and DEAE-Cellulose resin respectively.Average molecular weight of the protein isolate was determined and analyzed for its cytotoxic property against Vero cells in different dilutions(1:20 and 1:40)and anti-tumor activity by MTT assay(a colorimetric assay)using breast cancer cell line MCF-7,with tamoxifen as standard.Results:One of the protein constituents after purification was characterized as serine protease by Caseinolytic plate diffusion assay.Average molecular weight of this purified isolate was determined,by SDS-PAGE analysis with standard protein ladder,as of 15 kDa.The performed tests suggested that the 15kDa fraction has potent cytotoxic activity and satisfactory antitumor activity as well in vitro.Conclusions:Exact molecular mechanism of the cytotoxic and antitumor activities is yet to be explored and currently we are working on ultra-purification and biophysical characterization of this fraction.Further investigation into the mechanism(s)of cytotoxic and antitumor activities at molecular level would be useful in treatment of various classes of cancer and viral infections in future.
文摘Aqueous extracts from various plant parts of fenugreek(3%)(aerial parts:leaves and stems(LS),roots(R),ground seeds(GS)and not ground seeds(NGS))and petroleum ether,ethyl acetate and methanolic fractions of the aerial parts were assayed to determine their antifungal potential against Botrytis cinerea,Fusarium graminearum,Alternaria sp.,Pythium aphanidermatum,and Rhizoctinia solani.All fenugreek plant parts showed antifungal potential and the magnitude of their inhibitory effects was species and plant parts d...
基金Supported by Outright Research Grant(Project No.151516PNSE)the Natural Sciences Research Institute
文摘Objective: To determine the bioactive phytochemicals and antimicrobial activity of leaf and stem ethanolic extracts from Muntingia calabura L.(M. calabura).Methods: Dried leaves and stems of M. calabura were extracted with 95% ethanol. The antibacterial and antifungal activities of the extracts were examined using the disc diffusion assay. The minimum inhibitory concentration(MIC) of each extract showing antimicrobial activity was determined. The dried extracts were subjected to phytochemical screening to determine the presence of bioactive components. Total phenolic and flavonoid contents were also determined by the Folin–Ciocalteu method and the aluminum chloride method, respectively.Results: Varying degrees of antimicrobial activity were exhibited by the leaf and stem extracts against Pseudomonas aeruginosa(P. aeruginosa), Salmonella typhimurium,Staphylococcus aureus(S. aureus), Bacillus subtilis, and Candida albicans(C. albicans),with minimal activity against Escherichia coli. Based on the MIC, the extracts showed the highest activity against C. albicans, S. aureus and P. aeruginosa. Phytochemical screening revealed the presence of sterols, flavonoids, alkaloids, saponins, glycosides and tannins in the leaf extract; however, no triterpenes were detected. In the stem extract,triterpenes were detected along with relative amounts of flavonoids, saponins, glycosides and tannins. Alkaloids and sterols were absent in the stem extract.Conclusions: M. calabura leaf and stem ethanol extracts are potential sources of antibacterial agents against P. aeruginosa and S. aureus. This study reports for the first time the high degree of antifungal activity of M. calabura ethanolic extract, especially against C. albicans.
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.