One hundred twenty-five endophytic microorganisms were isolated from the roots,stems,and leaves of four prominent rice cultivars growing in temperate regions.Their potential to combat rice blast disease and promote pl...One hundred twenty-five endophytic microorganisms were isolated from the roots,stems,and leaves of four prominent rice cultivars growing in temperate regions.Their potential to combat rice blast disease and promote plant growth was investigated.The dual culture tests highlighted the strong antagonistic activity of five fungal(ranging from 89%–70%)and five bacterial(72%–61%)endophytes.Subsequent examination focused on volatile compounds produced by selected isolates to counter the blast pathogen.Among these,the highest chitinase(13.76μg mL−1)and siderophore(56.64%),was exhibited by Aspergillus flavus,and the highest HCN production was shown by Stenotrophomonas maltophilia(36.15μM mL−1).In terms of growth promotion traits,Aspergillus flavus and Enterobacter cloacae excelled in activities viz,phosphorous solubilization,ammonia production,auxin and gibberellic acid production,and nitrogen fixation.The Identity of these endophytes was confirmed through molecular analysis as Trichoderma afroharzianum,Trichoderma harzianum,Penicillium rubens,Aspergillus flavus,Stenotrophomonas rhizophila,Stenotrophomonas maltophilia,Bacillus cereus,Enterobacter cloacae,and Bacillus licheniformis.Under greenhouse conditions,the highest disease control was shown by isolate Bacillus licheniformis and A.flavus with an inhibition of 79%,followed by S.rhizophila(77%)and T.afroharzianum(73%).The overall results of this study showed that Bacillus licheniformis and Stenotrophomonas rhizophila have great potential to be used as bio-stimulant and biocontrol agents to manage rice blast disease.展开更多
Objective Development of monoclonal antibody based sandwich enzyme linked immunosorbant assay (sELISA) for rapid detection of Salmonella enterica serovar typhi (S. typhi) from food and water samples and optimizati...Objective Development of monoclonal antibody based sandwich enzyme linked immunosorbant assay (sELISA) for rapid detection of Salmonella enterica serovar typhi (S. typhi) from food and water samples and optimization of enrichment procedures for use with the developed sELISA to increase the detection sensitivity of the assay. Methods Spleen cells from BALB/c mice immunized with flagellin (H=d) antigen of S. typhi were fused with Sp2/0 myeloma cells. The hybridoma cell line specific to H=d antigen was established, characterized and ascites raised against one of these clones. The hyperimmune serum to flagellin antigen was raised in New Zealand White rabbits. An sELISA was developed using polyclonal antibody as capture and monoclonal antibody as detection antibody. To design the efficient culture strategies for use with the sELISA, different pre-enrichment and enrichment broths were evaluated. The media included buffered peptone water (BPW) and brain heart infusion broth for pre-enrichment and selenite F broth and Rappaport-Vassiliadis broth as enrichment broths. The developed sELISA with preceding enrichment step in BPW (Enrichment-ELISA) was evaluated in various food samples artificially inoculated with S. typhi bacteria. Various food (30) and water (35) samples collected from field were also tested by Enrichment-ELISA and culture method. Results Out of four specific clones to H=d antigen, one clone (# 2/56, IgG2a isotype) was used in sELISA. The sELISA had the detection limit of 10^4-10^5 cfu of S. typhi. Of the various broths used with sELISA, BPW was found to yield maximum ELISA values. Enrichment-ELISA, when tested in artificially inoculated food samples, generally, could detect 10^2 S. typhi cfu/mL within 10 h from various food rinses (meat, vegetable) and milk samples. After overnight enrichment in BPW, as less as 2 bacteria per 10 mL of milk, meat rinse, and chicken rinse could be detected. Only one of the field samples (water) gave false positive result by Enrichment-ELISA. Conclusion In comparison to culture, the Enrichment-ELISA is a rapid, sensitive, and specific method for detection of S. typhi from food or water samples. This method may be used as rapid screening procedure for environmental monitoring during outbreak situation.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
Hepatitis C virus(HCV)is a major cause of liver disease worldwide.HCV is able to evade host defense mechanisms,including both innate and acquired immune responses,to establish persistent infection,which results in a b...Hepatitis C virus(HCV)is a major cause of liver disease worldwide.HCV is able to evade host defense mechanisms,including both innate and acquired immune responses,to establish persistent infection,which results in a broad spectrum of pathogenicity,such as lipid and glucose metabolism disorders and hepatocellular carcinoma development.The HCV genome is characterized by a high degree of genetic diversity,which can be associated with viral sensitivity or resistance(reflected by different virological responses)to interferon(IFN)-based therapy.In this regard,it is of importance to note that polymorphisms in certain HCV genomic regions have shown a close correlation with treatment outcome.In particular,among the HCV proteins,the core and nonstructural proteins(NS)5A have been extensively studied for their correlation with responses to IFN-based treatment.This review aims to cover updated information on the impact of major HCV genetic factors,including HCV genotype,mutations in amino acids 70 and91 of the core protein and sequence heterogeneity in the IFN sensitivity-determining region and IFN/ribavirin resistance-determining region of NS5A,on virological responses to IFN-based therapy.展开更多
Objective:To isolate novel actinomycetes and to evaluate their antibacterial activity.Methods:Three soil samples were collected from Vengodu(village)in Kanchipuram district,Tamil Nadu,India.Actinomycetes were isolated...Objective:To isolate novel actinomycetes and to evaluate their antibacterial activity.Methods:Three soil samples were collected from Vengodu(village)in Kanchipuram district,Tamil Nadu,India.Actinomycetes were isolated using serial dilution and plating method on actinomycetes isolation agar.Results:Totally 35 isolates were obtained on the basis of colony characteristics on actinomycetes isolation agar.All the isolates were screened for antibacterial activity by cross streak method.Medium and optimization of day were done for the potent strains using Nathan's agar well diffusion method.Isolation of bioactive compounds from significant active isolates was done by using different media.The most active isolate VAS 10 was identified as Actinobacterium Loyola PBT VAS 10(accession No.JF501398)using 16s rRNA sequence method.The hexane,ethyl acetate,dichloromethane and butanol extracts of VAS 10 were tested against bacteria.The maximum antibacterial activity was observed in dichloromethane and ethyl acetate;maximum zones of inhibition were observed against Enterococcus durans.The rRNA secondary structure and the restriction sites of Actinobacterium Loyola VAS 10 were predicted using Genebee and NEBCutter online tools respectively.Conclusions:The present study showed that among the isolated actinomycetes,Actinobacterium Loyola PBT VAS 10(accession No.JF501398)showed good antibacterial activity against the tested bacteria.展开更多
Objective:To investigate the antibacterial activity of henna(Lawsonia inermis Linn) obtained from different regions of Oman against a wide array of micro-organisms.Methods:fresh henna samples were obtained from differ...Objective:To investigate the antibacterial activity of henna(Lawsonia inermis Linn) obtained from different regions of Oman against a wide array of micro-organisms.Methods:fresh henna samples were obtained from different regions of Oman as leaves and seeds,100 g fresh and dry leaves and SO g of fresh and dry seeds were separately soaked in 500 mL of ethanol for three days,respectively,with frequent agitation.The mixture was filtered,and the crude extract was collected.The crude extract was then heated,at 48 ℃ in a water bath to evaporate its liquid content.The dry crude henna extract was then tested for its antibacterial activity using well-diffusion antibiotic susceptibility technique.Henna extracts were investigated for their antibacterial activity at different concentrations against a wide array of different micro-organisms including a laboratory standard bacterial strain of Pseudomonas aeruginosa(NCTC 10662)(A aeruginosa) and eleven fresh clinical isolates of P.aeruginosa obtained from patients attending the Sultan Qaboos University Hospital(SQUH).2-Hydroxy-p-Nathoqinone-Tech(2-HPNT, MW=174.16,C_(10)H_40_3) was included as control(at 50%concentration) along with the henna samples tested.Results:Henna samples demonstrated antibacterial activity against all isolates but the highest susceptibility was against P.aeruginosa with henna samples obtained from Al-sharqyia region.Conclusions:Omani henna from Al-sharqyia region demonstrates high in vitro anti-P. aeruginosa activity compared with many henna samples from different regions of Oman.展开更多
Listeria monocytogenes is an important foodborne pathogen responsible for listeriosis,a fatal disease.It is widely distributed in various foods and environmental sources.In this review,we focused on addressing PCR-bas...Listeria monocytogenes is an important foodborne pathogen responsible for listeriosis,a fatal disease.It is widely distributed in various foods and environmental sources.In this review,we focused on addressing PCR-based technologies,including conventional PCR,qPCR and droplet digital PCR(ddPCR).Specifically,we described(a)conventional PCR and mono-,duplex-and multiplex-qPCR methodologies;(b)development and applications of gene HlyA-,Iap-,PrfA–and SsrA-based conventional and qPCR assays as well as PCR assays targeting newly identified gene targets for specific detection of L.monocytogenes;differentiation of viable from dead L.monocytogenes by qPCR in conjugation with propidium monoazide pretreatment;PCR-based serotype identification of L.monocytogenes isolates;PCR-based detection of L.ivanovii,infecting ruminants,differentiation of L.monocytogenes from other Listeria species;and sigB-gene based PCR identification of Listeria spp;(c)applications of ddPCR in detection of L.monocytogenes;and(d)application of qPCR assays in detection and subtyping of L.monocytogenes in milk and dairy products;meats,meat products and meat-processing environment;and seafood,seafood products and processing environment.Our goal was to provide a relatively comprehensive overview of PCR-based methodologies available in detection,characterization and subtyping of various strains of L.monocytogenes in foods and environmental sources.展开更多
BACKGROUND: It has been confirmed that brain-derived neurotrophic factor (BDNF) can promote the proliferation of neural stem cells (NSCs) and protect neuron-like cells in vitro. However, its effect on endogenous ...BACKGROUND: It has been confirmed that brain-derived neurotrophic factor (BDNF) can promote the proliferation of neural stem cells (NSCs) and protect neuron-like cells in vitro. However, its effect on endogenous NSCs in vivo is still unclear. OBJECTIVE: To evaluate whether BDNF can induce the endogenous NSCs to proliferate and differentiate into the neurons in the mice model of cerebral infarction. DESIGN: A synchronal controlled observation. SETTINGS: Department of Neurology, Microbiology Division of the Department of Laboratory, Tianjin First Central Hospital; Howard Florey Institute, Medical College, the University of Melbourne. MATERIALS: Twenty-four pure breed C57BL/6J mice at the age of 10 weeks old (12 males and 12 females) were divided into saline control group and BDNF-treated group, 6 males and 6 females in each group. METHODS: The experiments were performed at the University of Melbourne from July 2004 to February 2005. ① The left middle cerebral artery (MCA) was ligated in both groups to establish models of cerebral infarction and the Matsushita measuring method was used to monitor the blood flow of the lesioned region supplied by MCA. 75% reduction of blood flow should be reached in the lesioned region. ② At 24 hours after infarction, mice in the BDNF-treated group were administrated with BDNF, which was slowly delivered using an ALZET osmium pump design. BDNF was dissolved in saline at the dosage of 500 mg/kg and injected into the pump, which could release the solution consistently in the following 28 days. The mice in the saline control group accepted the same volume of saline at 24 hours after infarction. ③ The Rotarod function test began at 1 week preoperatively, the time stayed on Rotarod was recorded. The mice were tested once a day till the end of the experiment. At 4 weeks post cerebral infarction, double labeling of Nestin and GFAP, BIH tubulin and CNPase immunostaining was performed to observe the differentiation directions of the re-expressed endogenous NSCs, and the percentages of the cells differentiated into astrocytes, neurons and oligodendrocytes were calculated. MAIN OUTCOME MEASURES: ① The differentiation directions of the re-expressed endogenous NSCs, and the percentage of the cells differentiated into astrocytes, neurons and oligodendrocytes.② Comparison of motor function between the two groups. RESULTS: All the 24 pure C57BL/6J mice were involved in the analysis of results. ①Positively expressed endogenous NSCs appeared in the mice of both groups, and they mainly distributed around the focus of lesion, as well as the contralateral side. The expressed cells in the BDNF-treated group were obviously more than those in the saline control group. ②Activations of endogenous NSCs: At 4 weeks after infarction, re-expressions of endogenous NSCs appeared in both groups. The number of the re-expressed cells in the BDNF-treated group was about 4.2 times higher than that in the saline control group. The percentage of the cells differentiated into neurons in the BDNF-treated group was significantly higher than that in the saline control group (36%, 15%), the percentage of the cells differentiated into astrocytes was lower than that in the saline control group (54%, 77%), whereas the percentage of the cells differentiated into oligodendrocytes was similar to that in the saline control group (10%, 8%). ③ Results of motor functional test: Compared with before cerebral infarction, the mice in both groups manifested as obvious decrease in motor function at 1 week after infarction, whereas the recovery of motor function in the BDNF-treated group was significantly superior to that in the saline control group at 2, 3 and 4 weeks (P 〈 0.01). CONCLUSION: BDNF can promote the proliferation of endogenous NSCs in the brain of mice with cerebral infarction, it can decrease the differentiation rate of astrocytes, and increase the differentiation rate of neurons. BDNF has small influence on the differentiation of endogenous NSCs into oligodendrocytes, which was not benefit for the recovery of neural axon. Endogenous NSCs may improve the motor function of mice through the above pathways.展开更多
Objective:To assess the antimicrobial and cytotoxic effects of Methylobacterium sp.isolated from soil sample of Doddabetta forest,Nilgiris,Western Ghats of Tamil Nadu.Methods:Isolation of Methylobacterium was performe...Objective:To assess the antimicrobial and cytotoxic effects of Methylobacterium sp.isolated from soil sample of Doddabetta forest,Nilgiris,Western Ghats of Tamil Nadu.Methods:Isolation of Methylobacterium was performed from soils by serial dilution plate technique.The strain was grown in modified nutrient gulucose agar(MNGA)medium to study the morphology and biochemical characteristics.Methylobacterium sp.was screened for its antimicrobial activity against pathogenic bacteria and fungi.The strain was subjected to 16S rRNA analysis and was identified as Methylohacterium sp.The nucleotide sequence of the 16S rRNA gene of the isolate exhibited close similarity with other Methylobacterium sp.and has been submitted to Genbank.The antibacterial substances were extracted using chloroform and ethyl acetate from MNGA medium in which ERI-135 had grown for 5 d at 30℃.Cytotoxic effect was also studied.GC-MS analysis was carried out.The antimicrobial activity was assessed using broth micro dilution technique.Results:Ethyl acetate extract showed activity against bacteria such as Bacillus subtilis,Klebsiella pneumoniae(K.pneumoniae),Pseudomonas aeruginosa,Salmonella typkimurium,Shigella flexneri,Enterobacter aerogenes,Staphylococcus aureu and Staphylococcus epidermidis(S.epidermidis)and fungi such as,Candida albicans and Trichophyton rubrum.The lowest minimum inhibitory concentrations were:250μg/mL against 5.epidermidis and 250μg/mL against K.pneumonia.The isolate had the ability to produce enzymes such as protease.The exyract showed cytotoxic effect in human adenocarcinoma cancer cell line(A549).GC-MS analysis showed the presence of isovaleric acid(3.64%),2-Methylbulanoic acid(5.03%),isobutyramide(5.05%),N,Noimethylformamide-di-t-butylacetal(9.79%),benzeneacetamide(15.56%),octyl butyl phthalate(3.59%)and diisooctyl phthalate(5.79)in the extract.Conclusions:Methylobaeterium sp.(ERI-135)showed promising antibacterial and cytotoxic activity.This is the first report in the antimicrobial and cytotoxic effect of Methylobaeterium sp.展开更多
Listeria monocytogenes,one of the most important foodborne pathogens,can cause listeriosis,a lethal disease for humans.L.ivanovii,which is closely related to L.monocytogenes,is also widely distributed in nature and in...Listeria monocytogenes,one of the most important foodborne pathogens,can cause listeriosis,a lethal disease for humans.L.ivanovii,which is closely related to L.monocytogenes,is also widely distributed in nature and infects mainly warm-blooded ruminants,causing economic loss.Thus,there are high priority needs for methodologies for rapid,specific,cost-effective and accurate detection,characterization and subtyping of L.monocytogenes and L.ivanovii in foods and environmental sources.In this review,we(A)described L.monocytogenes and L.ivanovii,world-wide incidence of listeriosis,and prevalence of various L.monocytogenes strains in food and environmental sources;(B)comprehensively reviewed different types of traditional and newly developed methodologies,including culture-based,antigen/antibody-based,LOOP-mediated isothermal amplification,matrix-assisted laser desorption ionization-time of flight-mass spectrometry,DNA microarray,and genomic sequencing for detection and characterization of L.monocytogenes in foods and environmental sources;(C)comprehensively summarized different subtyping methodologies,including pulsed-field gel electrophoresis,multi-locus sequence typing,ribotyping,and phage-typing,and whole genomic sequencing etc.for subtyping of L.monocytogenes strains from food and environmental sources;and(D)described the applications of these methodologies in detection and subtyping of L.monocytogenes in foods and food processing facilities.展开更多
A novel bioactive foam emulsion bioreactor for benzene,toluene and xylene(BTX)contaminated air streams treatment has been developed.The gas-liquid interfacial area by biocompatible foam and driving force for mass tran...A novel bioactive foam emulsion bioreactor for benzene,toluene and xylene(BTX)contaminated air streams treatment has been developed.The gas-liquid interfacial area by biocompatible foam and driving force for mass transfer by a water immiscible organic phase were increased in this reactor.The effect of several parameters such as gas residence time,oxygen content,and organic phase concentration on bioreactor performance was studied. Experimental results showed an average elimination capacity(EC)of 220 g·m3·h -1with removal efficiency(RE) of 89.59%for BTX inlet concentration of 1 g·m3at 15 s gas residence time in the bioreactor.The statistical developed model predicted that the maximum elimination capacity of the reactor for BTX could be reached to 423.45 g·m3·h -1.Continues operation of the bioreactor with high EC and RE was demonstrated by optimizing the operational parameters of the bioreactor.Overall the results suggest that the bioreactor developed can be very effective systems to treat BTX vapors.展开更多
Hepatitis C virus(HCV) infection often causes chronic hepatitis, liver cirrhosis, and hepatocellular carcinoma. The development of a HCV cell culture system enabled us to investigate its whole HCV life cycle and devel...Hepatitis C virus(HCV) infection often causes chronic hepatitis, liver cirrhosis, and hepatocellular carcinoma. The development of a HCV cell culture system enabled us to investigate its whole HCV life cycle and develop a better understanding of the pathogenesis of this virus. Post-translational modification plays a crucial role in HCV replication and in the maturation of viral particles. There is growing evidence also suggesting that the ubiquitin-proteasome pathway and the ubiquitin-independent proteasome pathway are involved in the stability control of HCV proteins. Many viruses are known to manipulate the proteasome pathways to modulate the cell cycle, inhibit apoptosis, evade the immune system, and activate cell signaling, thereby contributing to persistent infection and viral carcinogenesis. The identification of functional interactions between HCV and the proteasome pathways will therefore shed new light on the life cycle and pathogenesis of HCV. This review summarizes the current knowledge on the involvement of the ubiquitin-dependent and-independent proteasome pathways in HCV infection and discusses the roles of these two distinct mechanisms in HCV pathogenesis.展开更多
Objective: To evaluate the insulin sensitivity action of ferulic acid(FA) in skeletal muscle and hypothalamus of high-fat diet(HFD)-induced obese mice. Methods: Obese mouse model was induced by HFD(45 kcal% lard fat) ...Objective: To evaluate the insulin sensitivity action of ferulic acid(FA) in skeletal muscle and hypothalamus of high-fat diet(HFD)-induced obese mice. Methods: Obese mouse model was induced by HFD(45 kcal% lard fat) for 16 weeks. After 8 weeks of HFD feeding, these obese mice were orally treated with FA at doses of 25 and 50 mg/kg/day for 8 weeks. At the end of all treatments, the epididymal fat, pancreas, skeletal muscle and hypothalamus were removed for biochemical parameter and protein expression examinations. Results: FA treatment significantly decreased leptin level in fat tissue and insulin level in pancreas(P < 0.05). Interestingly, obese mice treated with FA increased the protein expressions of insulin receptor substrate-1, phosphatidylinositol 3-kinase, and phosphorylated-protein kinase B in both muscle and brain(P < 0.05). The phosphorylations of adenosine monophosphate-activated protein kinase and acetyl-CoA carboxylase in muscle, and leptin receptor protein in hypothalamus were also increased(P < 0.05). The pancreatic islets histology showed smaller size in obese mice treated with FA compared to untreated obese mice. Conclusions: These findings indicate the beneficial effect of FA in improving insulin resistance in HFD-induced obese mice. These effects are probably mediated via modulating the insulin receptor substrate/phosphatidylinositol 3-kinase/protein kinase B or adenosine monophosphate-activated protein kinase pathways.展开更多
Objective:To examine the effect of water extract of Thunbergia laurifolia on hepatic insulin resistance in high-fat diet-induced obese mice.Methods:High-fat diet with 45 kcal%lard fat was used for obesity induction in...Objective:To examine the effect of water extract of Thunbergia laurifolia on hepatic insulin resistance in high-fat diet-induced obese mice.Methods:High-fat diet with 45 kcal%lard fat was used for obesity induction in ICR mice.The mice were fed with high-fat diet for 16 weeks,and during the last 8 weeks,they were treated with 200 mg/kg/day of water extracts from Thunbergia laurifolia leaf,stem and flower.Serum biochemistry,liver histology,and protein expression were examined after the treatment.Results:Extracts from all of the three parts of Thunbergia laurifolia significantly alleviated hyperglycemia,hyperlipidemia,hyperinsulinemia,and hyperleptinemia.The stem and flower extracts improved glucose tolerance.All of the extracts significantly reduced serum TNFαand monocyte chemoattractant protein-1 levels.Liver weight,triglyceride levels,and lipid accumulation were also decreased.Moreover,hepatic glucose-6-phosphatase level was significantly decreased,while the levels of PPARα,phosphorylated AMPK,and phosphorylated Akt were significantly increased with treatment of Thunbergia laurifolia extracts.Conclusions:Thunbergia laurifolia extracts can ameliorate hepatic insulin resistance in high-fat diet-induced obese mice by improving glucose and lipid homeostasis,which may be associated with stimulating phosphorylation of AMPK and Akt pathways.展开更多
Human noroviruses(No V) are associated with large proportion of non-bacterial diarrhea outbreaks together with > 50% of food-associated diarrheas. The function of histo-blood group antigens(HBGAs) in pathogenesis o...Human noroviruses(No V) are associated with large proportion of non-bacterial diarrhea outbreaks together with > 50% of food-associated diarrheas. The function of histo-blood group antigens(HBGAs) in pathogenesis of virus infection was implicated. Until recently however, due to lack of a robust animal and in vitro models of human NoV infection, only the partial knowledge concerning the virus pathogenesis(receptor, coreceptor and target cell) and absence of viable vaccine candidates were the frequently referenced attributes of this acute diarrheal illness. Recently, a novel group of enteric caliciviruses(CV) of rhesus macaque host origin was discovered and described. The new genus within the family Caliciviridae was identified: Rhesus Enteric CV, i.e., "Recovirus"(Re CV). Re CVs are genetically and biologically close relatives of human NoV s, exhibit similar genetic and biological features and are capable of being propagated in cell culture. ReC Vs cause symptomatic disease(diarrhea and fever) in experimentally inoculated macaques. Formulation and evaluation of efficient NoV vaccine might take several years. As suggested by recent studies, inhibition of HBGAs or HBGAbased antivirals could meanwhile be exploited as vaccine alternatives. The purpose of this minireview is to provide the guidance in respect to newly available primate model of enteric CV infection and its similarities with human NoV in utilizing the HBGAs as potential virus co-receptors to indirectly address the unresolved questions of NoV pathogenesis and immunity.展开更多
A biofilm contains a consortium of cohesive bacterial cells forming a complex structure that is a sedentary, but dynamic, community. Biofilms adhere on biotic and abiotic surfaces, including the surfaces of practicall...A biofilm contains a consortium of cohesive bacterial cells forming a complex structure that is a sedentary, but dynamic, community. Biofilms adhere on biotic and abiotic surfaces, including the surfaces of practically all medical devices. Biofilms are reported to be responsible for approximately 60% of nosocomial infections due to implanted medical devices, such as intravenous catheters, and they also cause other foreign-body infections and chronic infections. The presence of biofilm on a medical device may result in the infection of surrounding tissues and failure of the device, necessitating the removal and replacement ofthe device. Bacteria from biofilms formed on medical devices may be released and disperse, with the potential for the formation of new biofilms in other locations and the development of a systemic infection. Regardless of their location, bacteria in biofilms are tolerant of the activities of the immune system, antimicrobial agents, and antiseptics. Concentrations of antimicrobial agents sufficient to eradicate planktonic cells have no effect on the same microorganism in a biofilm. Depending on the microbial consortium or component of the biofilm that is involved, various combinations of factors have been suggested to explain the recalcitrant nature of biofilms toward killing by antibiotics. In this mini-review, some of the factors contributing to antimicrobial resistance in biofilms are discussed.展开更多
Fasciola hepatica,an endemic parasite in Turkey,is still a very rare cause of cholestasis worldwide.Through ingestion of contaminated water plants like watercress,humans can become the definitive host of this parasite...Fasciola hepatica,an endemic parasite in Turkey,is still a very rare cause of cholestasis worldwide.Through ingestion of contaminated water plants like watercress,humans can become the definitive host of this parasite.Cholestatic symptoms may be sudden but in some cases they may be preceeded by a long period of fever,eosinophilia and vague gastrointestinal symptoms.We report a woman with cholangitis symptoms of sudden onset which was proved to be due to Fasciola hepatica infestation by an endoscopic retrograde cholangiography.展开更多
Objective: To examine the effect of Brassica oleracea extract(BO) on impaired glucose and lipid homeostasis in high-fat diet(HFD)-induced obese mice. Methods: Obesity of ICR mice was induced by feeding a HFD(45 kcal% ...Objective: To examine the effect of Brassica oleracea extract(BO) on impaired glucose and lipid homeostasis in high-fat diet(HFD)-induced obese mice. Methods: Obesity of ICR mice was induced by feeding a HFD(45 kcal% lard fat) for 16 weeks. During the last 8 weeks of study period, obese mice were additionally administered with BO(100 and 200 mg/kg/day). The metabolic parameters were determined. The gene expressions of hepatic lipogenesis were also studied. Results: After 8 weeks of treatment, BO(100 and 200 mg/kg) significantly reduced hyperglycemia and improved insulin sensitivity(P < 0.05). The serum lipid(total cholesterol, triglyceride, and non-esterified fatty acid) and hepatic triglyceride and nonesterified fatty acid were decreased(P < 0.05). The levels of insulin and leptin in serum were also decreased(P < 0.05). Moreover, the expressions of hepatic lipogenic genes including sterol regulatory element-binding protein 1 c, fatty acid synthase, and acetyl-CoA carboxylase were decreased by BO treatment(P < 0.05). Conclusions: These results suggest that BO is a new therapeutic agent for improving the homeostasis of glucose and lipid in HFD-induced obese mice probably by suppression of lipogenic genes in liver tissue.展开更多
Objective: To study the minimum inhibitory concentration(MIC) of sulbactam against carbapenem-resistant Acinetobacter baumannii(CR-AB) and to determine the dosage regimens reaching target time of free drug concentrati...Objective: To study the minimum inhibitory concentration(MIC) of sulbactam against carbapenem-resistant Acinetobacter baumannii(CR-AB) and to determine the dosage regimens reaching target time of free drug concentration remaining above the MIC(f T>MIC). Methods: Clinical isolates of CR-AB from patients admitted to Phramongkutklao Hospital, Thailand from January 2014 to December 2015 were obtained. The MIC of sulbactam for each CR-AB isolate was determined using the agar dilution method. Each sulbactam regimen was simulated using the Monte Carlo technique to calculate the probability of target attainment(PTA) and the cumulative fraction of response(CFR) in critically ill patients. PTA was defined by how likely a specific drug dose was to reach 40% and 60% f T>MIC. The CFR was the probability of drug dose covering the MIC range of CR-AB. Dosing regimens reaching above 80% of PTA and CFR, were considered as the optimal dosage for documented and empirical therapy, respectively. Results: A total of 118 CR-AB isolates were included in the study. The percentile at the fiftieth and ninetieth MIC of sulbactam were 64 and 192 μg/m L, respectively. For a MIC of sulbactam of 4 μg/m L, all dosage regimens achieved PTA target. However, only a sulbactam dosage of 12 g intravenous daily using 2-4 h infusion or continuous infusion that covered for isolates with a sulbactam MIC of 96 μg/m L, met the PTA or CFR targets. Conclusions: The MIC of sulbactam against CR-AB is quite high. The sulbactam dose of 12 g/day using prolonged infusion was required to achieve the target f T>MIC for CR-AB treatment.展开更多
Soybeans have been shown to contain larger concentrations of isoflavones than other plant foods. The colonic micro-floras of some individuals metabolize isoflavones, including the soy phytoestrogen daidzein, to compou...Soybeans have been shown to contain larger concentrations of isoflavones than other plant foods. The colonic micro-floras of some individuals metabolize isoflavones, including the soy phytoestrogen daidzein, to compounds with altered estrogenic activity that may affect health. Monkeys have been used as models to predict the effect of colonic microorganisms on the metabolism of phytoestrogens. We studied the effect of consumption of a diet rich in soy protein on the metabolism of added daidzein by the intestinal microfloras of monkeys. The metabolism of daidzein by cultures of the colonic microfloras from eight males and eight females of Macaca fascicularis, 6 - 12 years old, consuming diets containing either soy or casein, and two males and three females of Macaca nemestrina, 3 - 5 months old, consuming infant formula, was investigated using high-performance liquid chromatographic analyses. Cultures from ten of the 16 adult monkeys and all five infant monkeys metabolized the added daidzein within 24 h. Daidzein was metabolized within 48 h by cultures from five other monkeys, but it remained even after 72 h in a culture from one female monkey on a casein diet. Equol and dihydrodaidzein were the only metabolites found. Individual variation among monkeys in the efficiency of daidzein metabolism was observed, but there appeared to be no correlation between diet and daidzein metabolism by the intestinal microflora. The intestinal microfloras of most monkeys tested were efficient in the biotransformation of daidzein to equol, regardless of the animals’ consumption of soy protein. Differences in the metabolism of isoflavones by the colonic microfloras of humans and experimental animals should be considered when extrapolating results from animals to humans.展开更多
基金The authors extend their appreciation to the Researchers Supporting Project Number(RSP2023R298),King Saud University,Riyadh,Saudi Arabia.
文摘One hundred twenty-five endophytic microorganisms were isolated from the roots,stems,and leaves of four prominent rice cultivars growing in temperate regions.Their potential to combat rice blast disease and promote plant growth was investigated.The dual culture tests highlighted the strong antagonistic activity of five fungal(ranging from 89%–70%)and five bacterial(72%–61%)endophytes.Subsequent examination focused on volatile compounds produced by selected isolates to counter the blast pathogen.Among these,the highest chitinase(13.76μg mL−1)and siderophore(56.64%),was exhibited by Aspergillus flavus,and the highest HCN production was shown by Stenotrophomonas maltophilia(36.15μM mL−1).In terms of growth promotion traits,Aspergillus flavus and Enterobacter cloacae excelled in activities viz,phosphorous solubilization,ammonia production,auxin and gibberellic acid production,and nitrogen fixation.The Identity of these endophytes was confirmed through molecular analysis as Trichoderma afroharzianum,Trichoderma harzianum,Penicillium rubens,Aspergillus flavus,Stenotrophomonas rhizophila,Stenotrophomonas maltophilia,Bacillus cereus,Enterobacter cloacae,and Bacillus licheniformis.Under greenhouse conditions,the highest disease control was shown by isolate Bacillus licheniformis and A.flavus with an inhibition of 79%,followed by S.rhizophila(77%)and T.afroharzianum(73%).The overall results of this study showed that Bacillus licheniformis and Stenotrophomonas rhizophila have great potential to be used as bio-stimulant and biocontrol agents to manage rice blast disease.
文摘Objective Development of monoclonal antibody based sandwich enzyme linked immunosorbant assay (sELISA) for rapid detection of Salmonella enterica serovar typhi (S. typhi) from food and water samples and optimization of enrichment procedures for use with the developed sELISA to increase the detection sensitivity of the assay. Methods Spleen cells from BALB/c mice immunized with flagellin (H=d) antigen of S. typhi were fused with Sp2/0 myeloma cells. The hybridoma cell line specific to H=d antigen was established, characterized and ascites raised against one of these clones. The hyperimmune serum to flagellin antigen was raised in New Zealand White rabbits. An sELISA was developed using polyclonal antibody as capture and monoclonal antibody as detection antibody. To design the efficient culture strategies for use with the sELISA, different pre-enrichment and enrichment broths were evaluated. The media included buffered peptone water (BPW) and brain heart infusion broth for pre-enrichment and selenite F broth and Rappaport-Vassiliadis broth as enrichment broths. The developed sELISA with preceding enrichment step in BPW (Enrichment-ELISA) was evaluated in various food samples artificially inoculated with S. typhi bacteria. Various food (30) and water (35) samples collected from field were also tested by Enrichment-ELISA and culture method. Results Out of four specific clones to H=d antigen, one clone (# 2/56, IgG2a isotype) was used in sELISA. The sELISA had the detection limit of 10^4-10^5 cfu of S. typhi. Of the various broths used with sELISA, BPW was found to yield maximum ELISA values. Enrichment-ELISA, when tested in artificially inoculated food samples, generally, could detect 10^2 S. typhi cfu/mL within 10 h from various food rinses (meat, vegetable) and milk samples. After overnight enrichment in BPW, as less as 2 bacteria per 10 mL of milk, meat rinse, and chicken rinse could be detected. Only one of the field samples (water) gave false positive result by Enrichment-ELISA. Conclusion In comparison to culture, the Enrichment-ELISA is a rapid, sensitive, and specific method for detection of S. typhi from food or water samples. This method may be used as rapid screening procedure for environmental monitoring during outbreak situation.
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 Health and Labour Sciences Research Grant from the Ministry of Health,Labour and Welfare,Japan,a SATREPS Grant from Japan Science and Technology Agency and Japan International Cooperation Agencythe Japan Initiative for Global Research Network on Infectious Diseases(J-GRID)program from the Ministry of Education,Culture,Sports,Science and Technology,Japan
文摘Hepatitis C virus(HCV)is a major cause of liver disease worldwide.HCV is able to evade host defense mechanisms,including both innate and acquired immune responses,to establish persistent infection,which results in a broad spectrum of pathogenicity,such as lipid and glucose metabolism disorders and hepatocellular carcinoma development.The HCV genome is characterized by a high degree of genetic diversity,which can be associated with viral sensitivity or resistance(reflected by different virological responses)to interferon(IFN)-based therapy.In this regard,it is of importance to note that polymorphisms in certain HCV genomic regions have shown a close correlation with treatment outcome.In particular,among the HCV proteins,the core and nonstructural proteins(NS)5A have been extensively studied for their correlation with responses to IFN-based treatment.This review aims to cover updated information on the impact of major HCV genetic factors,including HCV genotype,mutations in amino acids 70 and91 of the core protein and sequence heterogeneity in the IFN sensitivity-determining region and IFN/ribavirin resistance-determining region of NS5A,on virological responses to IFN-based therapy.
基金Supported by Entomology Research Institute.Loyola College,Chennai Grant No.ER1/03/2011)
文摘Objective:To isolate novel actinomycetes and to evaluate their antibacterial activity.Methods:Three soil samples were collected from Vengodu(village)in Kanchipuram district,Tamil Nadu,India.Actinomycetes were isolated using serial dilution and plating method on actinomycetes isolation agar.Results:Totally 35 isolates were obtained on the basis of colony characteristics on actinomycetes isolation agar.All the isolates were screened for antibacterial activity by cross streak method.Medium and optimization of day were done for the potent strains using Nathan's agar well diffusion method.Isolation of bioactive compounds from significant active isolates was done by using different media.The most active isolate VAS 10 was identified as Actinobacterium Loyola PBT VAS 10(accession No.JF501398)using 16s rRNA sequence method.The hexane,ethyl acetate,dichloromethane and butanol extracts of VAS 10 were tested against bacteria.The maximum antibacterial activity was observed in dichloromethane and ethyl acetate;maximum zones of inhibition were observed against Enterococcus durans.The rRNA secondary structure and the restriction sites of Actinobacterium Loyola VAS 10 were predicted using Genebee and NEBCutter online tools respectively.Conclusions:The present study showed that among the isolated actinomycetes,Actinobacterium Loyola PBT VAS 10(accession No.JF501398)showed good antibacterial activity against the tested bacteria.
基金Supported by Sultan Qaboos University(Grant No.IG/MED/ANAT/06/01)
文摘Objective:To investigate the antibacterial activity of henna(Lawsonia inermis Linn) obtained from different regions of Oman against a wide array of micro-organisms.Methods:fresh henna samples were obtained from different regions of Oman as leaves and seeds,100 g fresh and dry leaves and SO g of fresh and dry seeds were separately soaked in 500 mL of ethanol for three days,respectively,with frequent agitation.The mixture was filtered,and the crude extract was collected.The crude extract was then heated,at 48 ℃ in a water bath to evaporate its liquid content.The dry crude henna extract was then tested for its antibacterial activity using well-diffusion antibiotic susceptibility technique.Henna extracts were investigated for their antibacterial activity at different concentrations against a wide array of different micro-organisms including a laboratory standard bacterial strain of Pseudomonas aeruginosa(NCTC 10662)(A aeruginosa) and eleven fresh clinical isolates of P.aeruginosa obtained from patients attending the Sultan Qaboos University Hospital(SQUH).2-Hydroxy-p-Nathoqinone-Tech(2-HPNT, MW=174.16,C_(10)H_40_3) was included as control(at 50%concentration) along with the henna samples tested.Results:Henna samples demonstrated antibacterial activity against all isolates but the highest susceptibility was against P.aeruginosa with henna samples obtained from Al-sharqyia region.Conclusions:Omani henna from Al-sharqyia region demonstrates high in vitro anti-P. aeruginosa activity compared with many henna samples from different regions of Oman.
文摘Listeria monocytogenes is an important foodborne pathogen responsible for listeriosis,a fatal disease.It is widely distributed in various foods and environmental sources.In this review,we focused on addressing PCR-based technologies,including conventional PCR,qPCR and droplet digital PCR(ddPCR).Specifically,we described(a)conventional PCR and mono-,duplex-and multiplex-qPCR methodologies;(b)development and applications of gene HlyA-,Iap-,PrfA–and SsrA-based conventional and qPCR assays as well as PCR assays targeting newly identified gene targets for specific detection of L.monocytogenes;differentiation of viable from dead L.monocytogenes by qPCR in conjugation with propidium monoazide pretreatment;PCR-based serotype identification of L.monocytogenes isolates;PCR-based detection of L.ivanovii,infecting ruminants,differentiation of L.monocytogenes from other Listeria species;and sigB-gene based PCR identification of Listeria spp;(c)applications of ddPCR in detection of L.monocytogenes;and(d)application of qPCR assays in detection and subtyping of L.monocytogenes in milk and dairy products;meats,meat products and meat-processing environment;and seafood,seafood products and processing environment.Our goal was to provide a relatively comprehensive overview of PCR-based methodologies available in detection,characterization and subtyping of various strains of L.monocytogenes in foods and environmental sources.
文摘BACKGROUND: It has been confirmed that brain-derived neurotrophic factor (BDNF) can promote the proliferation of neural stem cells (NSCs) and protect neuron-like cells in vitro. However, its effect on endogenous NSCs in vivo is still unclear. OBJECTIVE: To evaluate whether BDNF can induce the endogenous NSCs to proliferate and differentiate into the neurons in the mice model of cerebral infarction. DESIGN: A synchronal controlled observation. SETTINGS: Department of Neurology, Microbiology Division of the Department of Laboratory, Tianjin First Central Hospital; Howard Florey Institute, Medical College, the University of Melbourne. MATERIALS: Twenty-four pure breed C57BL/6J mice at the age of 10 weeks old (12 males and 12 females) were divided into saline control group and BDNF-treated group, 6 males and 6 females in each group. METHODS: The experiments were performed at the University of Melbourne from July 2004 to February 2005. ① The left middle cerebral artery (MCA) was ligated in both groups to establish models of cerebral infarction and the Matsushita measuring method was used to monitor the blood flow of the lesioned region supplied by MCA. 75% reduction of blood flow should be reached in the lesioned region. ② At 24 hours after infarction, mice in the BDNF-treated group were administrated with BDNF, which was slowly delivered using an ALZET osmium pump design. BDNF was dissolved in saline at the dosage of 500 mg/kg and injected into the pump, which could release the solution consistently in the following 28 days. The mice in the saline control group accepted the same volume of saline at 24 hours after infarction. ③ The Rotarod function test began at 1 week preoperatively, the time stayed on Rotarod was recorded. The mice were tested once a day till the end of the experiment. At 4 weeks post cerebral infarction, double labeling of Nestin and GFAP, BIH tubulin and CNPase immunostaining was performed to observe the differentiation directions of the re-expressed endogenous NSCs, and the percentages of the cells differentiated into astrocytes, neurons and oligodendrocytes were calculated. MAIN OUTCOME MEASURES: ① The differentiation directions of the re-expressed endogenous NSCs, and the percentage of the cells differentiated into astrocytes, neurons and oligodendrocytes.② Comparison of motor function between the two groups. RESULTS: All the 24 pure C57BL/6J mice were involved in the analysis of results. ①Positively expressed endogenous NSCs appeared in the mice of both groups, and they mainly distributed around the focus of lesion, as well as the contralateral side. The expressed cells in the BDNF-treated group were obviously more than those in the saline control group. ②Activations of endogenous NSCs: At 4 weeks after infarction, re-expressions of endogenous NSCs appeared in both groups. The number of the re-expressed cells in the BDNF-treated group was about 4.2 times higher than that in the saline control group. The percentage of the cells differentiated into neurons in the BDNF-treated group was significantly higher than that in the saline control group (36%, 15%), the percentage of the cells differentiated into astrocytes was lower than that in the saline control group (54%, 77%), whereas the percentage of the cells differentiated into oligodendrocytes was similar to that in the saline control group (10%, 8%). ③ Results of motor functional test: Compared with before cerebral infarction, the mice in both groups manifested as obvious decrease in motor function at 1 week after infarction, whereas the recovery of motor function in the BDNF-treated group was significantly superior to that in the saline control group at 2, 3 and 4 weeks (P 〈 0.01). CONCLUSION: BDNF can promote the proliferation of endogenous NSCs in the brain of mice with cerebral infarction, it can decrease the differentiation rate of astrocytes, and increase the differentiation rate of neurons. BDNF has small influence on the differentiation of endogenous NSCs into oligodendrocytes, which was not benefit for the recovery of neural axon. Endogenous NSCs may improve the motor function of mice through the above pathways.
基金Supported by Entomology Research Institute.Loyolacollege,Chennai,Tamil Nadu,India(Grant No.ER1/2011/MB-05)
文摘Objective:To assess the antimicrobial and cytotoxic effects of Methylobacterium sp.isolated from soil sample of Doddabetta forest,Nilgiris,Western Ghats of Tamil Nadu.Methods:Isolation of Methylobacterium was performed from soils by serial dilution plate technique.The strain was grown in modified nutrient gulucose agar(MNGA)medium to study the morphology and biochemical characteristics.Methylobacterium sp.was screened for its antimicrobial activity against pathogenic bacteria and fungi.The strain was subjected to 16S rRNA analysis and was identified as Methylohacterium sp.The nucleotide sequence of the 16S rRNA gene of the isolate exhibited close similarity with other Methylobacterium sp.and has been submitted to Genbank.The antibacterial substances were extracted using chloroform and ethyl acetate from MNGA medium in which ERI-135 had grown for 5 d at 30℃.Cytotoxic effect was also studied.GC-MS analysis was carried out.The antimicrobial activity was assessed using broth micro dilution technique.Results:Ethyl acetate extract showed activity against bacteria such as Bacillus subtilis,Klebsiella pneumoniae(K.pneumoniae),Pseudomonas aeruginosa,Salmonella typkimurium,Shigella flexneri,Enterobacter aerogenes,Staphylococcus aureu and Staphylococcus epidermidis(S.epidermidis)and fungi such as,Candida albicans and Trichophyton rubrum.The lowest minimum inhibitory concentrations were:250μg/mL against 5.epidermidis and 250μg/mL against K.pneumonia.The isolate had the ability to produce enzymes such as protease.The exyract showed cytotoxic effect in human adenocarcinoma cancer cell line(A549).GC-MS analysis showed the presence of isovaleric acid(3.64%),2-Methylbulanoic acid(5.03%),isobutyramide(5.05%),N,Noimethylformamide-di-t-butylacetal(9.79%),benzeneacetamide(15.56%),octyl butyl phthalate(3.59%)and diisooctyl phthalate(5.79)in the extract.Conclusions:Methylobaeterium sp.(ERI-135)showed promising antibacterial and cytotoxic activity.This is the first report in the antimicrobial and cytotoxic effect of Methylobaeterium sp.
文摘Listeria monocytogenes,one of the most important foodborne pathogens,can cause listeriosis,a lethal disease for humans.L.ivanovii,which is closely related to L.monocytogenes,is also widely distributed in nature and infects mainly warm-blooded ruminants,causing economic loss.Thus,there are high priority needs for methodologies for rapid,specific,cost-effective and accurate detection,characterization and subtyping of L.monocytogenes and L.ivanovii in foods and environmental sources.In this review,we(A)described L.monocytogenes and L.ivanovii,world-wide incidence of listeriosis,and prevalence of various L.monocytogenes strains in food and environmental sources;(B)comprehensively reviewed different types of traditional and newly developed methodologies,including culture-based,antigen/antibody-based,LOOP-mediated isothermal amplification,matrix-assisted laser desorption ionization-time of flight-mass spectrometry,DNA microarray,and genomic sequencing for detection and characterization of L.monocytogenes in foods and environmental sources;(C)comprehensively summarized different subtyping methodologies,including pulsed-field gel electrophoresis,multi-locus sequence typing,ribotyping,and phage-typing,and whole genomic sequencing etc.for subtyping of L.monocytogenes strains from food and environmental sources;and(D)described the applications of these methodologies in detection and subtyping of L.monocytogenes in foods and food processing facilities.
文摘A novel bioactive foam emulsion bioreactor for benzene,toluene and xylene(BTX)contaminated air streams treatment has been developed.The gas-liquid interfacial area by biocompatible foam and driving force for mass transfer by a water immiscible organic phase were increased in this reactor.The effect of several parameters such as gas residence time,oxygen content,and organic phase concentration on bioreactor performance was studied. Experimental results showed an average elimination capacity(EC)of 220 g·m3·h -1with removal efficiency(RE) of 89.59%for BTX inlet concentration of 1 g·m3at 15 s gas residence time in the bioreactor.The statistical developed model predicted that the maximum elimination capacity of the reactor for BTX could be reached to 423.45 g·m3·h -1.Continues operation of the bioreactor with high EC and RE was demonstrated by optimizing the operational parameters of the bioreactor.Overall the results suggest that the bioreactor developed can be very effective systems to treat BTX vapors.
基金Supported by(in part)Grants in-aid from the Ministry of Health,Labour and Welfare,and the Ministry of Education,Culture,Sports,Science,and Technology,Japan
文摘Hepatitis C virus(HCV) infection often causes chronic hepatitis, liver cirrhosis, and hepatocellular carcinoma. The development of a HCV cell culture system enabled us to investigate its whole HCV life cycle and develop a better understanding of the pathogenesis of this virus. Post-translational modification plays a crucial role in HCV replication and in the maturation of viral particles. There is growing evidence also suggesting that the ubiquitin-proteasome pathway and the ubiquitin-independent proteasome pathway are involved in the stability control of HCV proteins. Many viruses are known to manipulate the proteasome pathways to modulate the cell cycle, inhibit apoptosis, evade the immune system, and activate cell signaling, thereby contributing to persistent infection and viral carcinogenesis. The identification of functional interactions between HCV and the proteasome pathways will therefore shed new light on the life cycle and pathogenesis of HCV. This review summarizes the current knowledge on the involvement of the ubiquitin-dependent and-independent proteasome pathways in HCV infection and discusses the roles of these two distinct mechanisms in HCV pathogenesis.
基金supported by the Faculty of Medicine Research Fund(GEN2-01/2016),Thammasat University,Thailand
文摘Objective: To evaluate the insulin sensitivity action of ferulic acid(FA) in skeletal muscle and hypothalamus of high-fat diet(HFD)-induced obese mice. Methods: Obese mouse model was induced by HFD(45 kcal% lard fat) for 16 weeks. After 8 weeks of HFD feeding, these obese mice were orally treated with FA at doses of 25 and 50 mg/kg/day for 8 weeks. At the end of all treatments, the epididymal fat, pancreas, skeletal muscle and hypothalamus were removed for biochemical parameter and protein expression examinations. Results: FA treatment significantly decreased leptin level in fat tissue and insulin level in pancreas(P < 0.05). Interestingly, obese mice treated with FA increased the protein expressions of insulin receptor substrate-1, phosphatidylinositol 3-kinase, and phosphorylated-protein kinase B in both muscle and brain(P < 0.05). The phosphorylations of adenosine monophosphate-activated protein kinase and acetyl-CoA carboxylase in muscle, and leptin receptor protein in hypothalamus were also increased(P < 0.05). The pancreatic islets histology showed smaller size in obese mice treated with FA compared to untreated obese mice. Conclusions: These findings indicate the beneficial effect of FA in improving insulin resistance in HFD-induced obese mice. These effects are probably mediated via modulating the insulin receptor substrate/phosphatidylinositol 3-kinase/protein kinase B or adenosine monophosphate-activated protein kinase pathways.
基金supported by the research grant from the National Research Council of Thailand(Contract number 37/2560)
文摘Objective:To examine the effect of water extract of Thunbergia laurifolia on hepatic insulin resistance in high-fat diet-induced obese mice.Methods:High-fat diet with 45 kcal%lard fat was used for obesity induction in ICR mice.The mice were fed with high-fat diet for 16 weeks,and during the last 8 weeks,they were treated with 200 mg/kg/day of water extracts from Thunbergia laurifolia leaf,stem and flower.Serum biochemistry,liver histology,and protein expression were examined after the treatment.Results:Extracts from all of the three parts of Thunbergia laurifolia significantly alleviated hyperglycemia,hyperlipidemia,hyperinsulinemia,and hyperleptinemia.The stem and flower extracts improved glucose tolerance.All of the extracts significantly reduced serum TNFαand monocyte chemoattractant protein-1 levels.Liver weight,triglyceride levels,and lipid accumulation were also decreased.Moreover,hepatic glucose-6-phosphatase level was significantly decreased,while the levels of PPARα,phosphorylated AMPK,and phosphorylated Akt were significantly increased with treatment of Thunbergia laurifolia extracts.Conclusions:Thunbergia laurifolia extracts can ameliorate hepatic insulin resistance in high-fat diet-induced obese mice by improving glucose and lipid homeostasis,which may be associated with stimulating phosphorylation of AMPK and Akt pathways.
文摘Human noroviruses(No V) are associated with large proportion of non-bacterial diarrhea outbreaks together with > 50% of food-associated diarrheas. The function of histo-blood group antigens(HBGAs) in pathogenesis of virus infection was implicated. Until recently however, due to lack of a robust animal and in vitro models of human NoV infection, only the partial knowledge concerning the virus pathogenesis(receptor, coreceptor and target cell) and absence of viable vaccine candidates were the frequently referenced attributes of this acute diarrheal illness. Recently, a novel group of enteric caliciviruses(CV) of rhesus macaque host origin was discovered and described. The new genus within the family Caliciviridae was identified: Rhesus Enteric CV, i.e., "Recovirus"(Re CV). Re CVs are genetically and biologically close relatives of human NoV s, exhibit similar genetic and biological features and are capable of being propagated in cell culture. ReC Vs cause symptomatic disease(diarrhea and fever) in experimentally inoculated macaques. Formulation and evaluation of efficient NoV vaccine might take several years. As suggested by recent studies, inhibition of HBGAs or HBGAbased antivirals could meanwhile be exploited as vaccine alternatives. The purpose of this minireview is to provide the guidance in respect to newly available primate model of enteric CV infection and its similarities with human NoV in utilizing the HBGAs as potential virus co-receptors to indirectly address the unresolved questions of NoV pathogenesis and immunity.
文摘A biofilm contains a consortium of cohesive bacterial cells forming a complex structure that is a sedentary, but dynamic, community. Biofilms adhere on biotic and abiotic surfaces, including the surfaces of practically all medical devices. Biofilms are reported to be responsible for approximately 60% of nosocomial infections due to implanted medical devices, such as intravenous catheters, and they also cause other foreign-body infections and chronic infections. The presence of biofilm on a medical device may result in the infection of surrounding tissues and failure of the device, necessitating the removal and replacement ofthe device. Bacteria from biofilms formed on medical devices may be released and disperse, with the potential for the formation of new biofilms in other locations and the development of a systemic infection. Regardless of their location, bacteria in biofilms are tolerant of the activities of the immune system, antimicrobial agents, and antiseptics. Concentrations of antimicrobial agents sufficient to eradicate planktonic cells have no effect on the same microorganism in a biofilm. Depending on the microbial consortium or component of the biofilm that is involved, various combinations of factors have been suggested to explain the recalcitrant nature of biofilms toward killing by antibiotics. In this mini-review, some of the factors contributing to antimicrobial resistance in biofilms are discussed.
文摘Fasciola hepatica,an endemic parasite in Turkey,is still a very rare cause of cholestasis worldwide.Through ingestion of contaminated water plants like watercress,humans can become the definitive host of this parasite.Cholestatic symptoms may be sudden but in some cases they may be preceeded by a long period of fever,eosinophilia and vague gastrointestinal symptoms.We report a woman with cholangitis symptoms of sudden onset which was proved to be due to Fasciola hepatica infestation by an endoscopic retrograde cholangiography.
文摘Objective: To examine the effect of Brassica oleracea extract(BO) on impaired glucose and lipid homeostasis in high-fat diet(HFD)-induced obese mice. Methods: Obesity of ICR mice was induced by feeding a HFD(45 kcal% lard fat) for 16 weeks. During the last 8 weeks of study period, obese mice were additionally administered with BO(100 and 200 mg/kg/day). The metabolic parameters were determined. The gene expressions of hepatic lipogenesis were also studied. Results: After 8 weeks of treatment, BO(100 and 200 mg/kg) significantly reduced hyperglycemia and improved insulin sensitivity(P < 0.05). The serum lipid(total cholesterol, triglyceride, and non-esterified fatty acid) and hepatic triglyceride and nonesterified fatty acid were decreased(P < 0.05). The levels of insulin and leptin in serum were also decreased(P < 0.05). Moreover, the expressions of hepatic lipogenic genes including sterol regulatory element-binding protein 1 c, fatty acid synthase, and acetyl-CoA carboxylase were decreased by BO treatment(P < 0.05). Conclusions: These results suggest that BO is a new therapeutic agent for improving the homeostasis of glucose and lipid in HFD-induced obese mice probably by suppression of lipogenic genes in liver tissue.
文摘Objective: To study the minimum inhibitory concentration(MIC) of sulbactam against carbapenem-resistant Acinetobacter baumannii(CR-AB) and to determine the dosage regimens reaching target time of free drug concentration remaining above the MIC(f T>MIC). Methods: Clinical isolates of CR-AB from patients admitted to Phramongkutklao Hospital, Thailand from January 2014 to December 2015 were obtained. The MIC of sulbactam for each CR-AB isolate was determined using the agar dilution method. Each sulbactam regimen was simulated using the Monte Carlo technique to calculate the probability of target attainment(PTA) and the cumulative fraction of response(CFR) in critically ill patients. PTA was defined by how likely a specific drug dose was to reach 40% and 60% f T>MIC. The CFR was the probability of drug dose covering the MIC range of CR-AB. Dosing regimens reaching above 80% of PTA and CFR, were considered as the optimal dosage for documented and empirical therapy, respectively. Results: A total of 118 CR-AB isolates were included in the study. The percentile at the fiftieth and ninetieth MIC of sulbactam were 64 and 192 μg/m L, respectively. For a MIC of sulbactam of 4 μg/m L, all dosage regimens achieved PTA target. However, only a sulbactam dosage of 12 g intravenous daily using 2-4 h infusion or continuous infusion that covered for isolates with a sulbactam MIC of 96 μg/m L, met the PTA or CFR targets. Conclusions: The MIC of sulbactam against CR-AB is quite high. The sulbactam dose of 12 g/day using prolonged infusion was required to achieve the target f T>MIC for CR-AB treatment.
文摘Soybeans have been shown to contain larger concentrations of isoflavones than other plant foods. The colonic micro-floras of some individuals metabolize isoflavones, including the soy phytoestrogen daidzein, to compounds with altered estrogenic activity that may affect health. Monkeys have been used as models to predict the effect of colonic microorganisms on the metabolism of phytoestrogens. We studied the effect of consumption of a diet rich in soy protein on the metabolism of added daidzein by the intestinal microfloras of monkeys. The metabolism of daidzein by cultures of the colonic microfloras from eight males and eight females of Macaca fascicularis, 6 - 12 years old, consuming diets containing either soy or casein, and two males and three females of Macaca nemestrina, 3 - 5 months old, consuming infant formula, was investigated using high-performance liquid chromatographic analyses. Cultures from ten of the 16 adult monkeys and all five infant monkeys metabolized the added daidzein within 24 h. Daidzein was metabolized within 48 h by cultures from five other monkeys, but it remained even after 72 h in a culture from one female monkey on a casein diet. Equol and dihydrodaidzein were the only metabolites found. Individual variation among monkeys in the efficiency of daidzein metabolism was observed, but there appeared to be no correlation between diet and daidzein metabolism by the intestinal microflora. The intestinal microfloras of most monkeys tested were efficient in the biotransformation of daidzein to equol, regardless of the animals’ consumption of soy protein. Differences in the metabolism of isoflavones by the colonic microfloras of humans and experimental animals should be considered when extrapolating results from animals to humans.