Publications

TitleAbstractYear
Filter
PMID(sorted ascending)
Filter
chitinase expression in listeria monocytogenes is positively regulated by the agr system.the food-borne pathogen listeria monocytogenes encodes two chitinases, chia and chib, which allow the bacterium to hydrolyze chitin, the second most abundant polysaccharide in nature. intriguingly, despite the absence of chitin in human and mammalian hosts, both of the chitinases have been deemed important for infection, through a mechanism that, at least in the case of chia, involves modulation of host immune responses. in this study, we show that the expression of the two chitinases is subject ...201424752234
predictive modeling for growth of non- and cold-adapted listeria monocytogenes on fresh-cut cantaloupe at different storage temperatures.the aim of this study was to determine the growth kinetics of listeria monocytogenes, with and without cold-adaption, on fresh-cut cantaloupe under different storage temperatures. fresh-cut samples, spot inoculated with a 4-strain cocktail of l. monocytogenes (∼3.2 log cfu/g), were exposed to constant storage temperatures held at 10, 15, 20, 25, or 30 °c. all growth curves of l. monocytogenes were fitted to the baranyi, modified gompertz, and huang models. regardless of conditions under which ce ...201424754226
technologies and mechanisms for safety control of ready-to-eat muscle foods: an updated review.ready-to-eat (rte) muscle foods refer to a general category of meat and poultry products that are fully cooked and consumable without reheating. these products, including whole and sliced pork, beef, turkey, chicken, and variety of meats, in the forms of ham, roast, rolls, sausage, and frankfurter, are widely available in the delicatessen section of retail stores or various food service outlets. however, difficulties in avoidance of contamination by foodborne pathogens, notably listeria monocyto ...201524754253
antimicrobial n-halamine modified polyethylene: characterization, biocidal efficacy, regeneration, and stability.development of antimicrobial materials that regenerate antimicrobial activity represents a novel technology in preventing microbial cross-contamination. we report a method for the application of regenerably antimicrobial n-halamines onto the surface of polyethylene (pe) materials through layer-by-layer (lbl) assembly of polyethyleneimine and poly(acrylic acid). a total of 5, 10, 15, and 20 bilayers were applied. modified pe had from 49.3 to 293.5 nmol cm(-2) antimicrobial n-halamines from 5 to 2 ...201424754818
evaluation of the potential of meat born lactic acid bacteria for use as protective cultures in the biopreservation of cooked meat products.in this study, 97 lactic acid bacteria were subjected to a step-by-step screening and characterisation to search for potential protective cultures to be used in the cooked cured meat industry. strains were first tested on their homofermentative and psychrotrophic character and salt tolerance. secondly, the antibacterial capacities towards listeria monocytogenes, leuconostoc mesenteroides, leuconostoc carnosum and brochotrix thermosphacta were determined in an agar spot test. finally, 12 selected ...200324757784
self-emulsification of alkaline-dissolved clove bud oil by whey protein, gum arabic, lecithin, and their combinations.low-cost emulsification technologies using food ingredients are critical to various applications. in the present study, a novel self-emulsification technique was studied to prepare clove bud oil (cbo) emulsions, without specialized equipment or organic solvents. cbo was first dissolved in hot alkaline solutions, added at 1% v/v into neutral solutions with 1% w/v emulsifier composed of whey protein concentrate (wpc), gum arabic, lecithin, or their equal mass mixtures, and adjusted to ph 7.0. the ...201424758517
bruker biotyper matrix-assisted laser desorption ionization-time of flight mass spectrometry system for identification of nocardia, rhodococcus, kocuria, gordonia, tsukamurella, and listeria species.we evaluated whether the bruker biotyper matrix-associated laser desorption ionization-time of flight mass spectrometry (maldi-tof ms) system provides accurate species-level identifications of 147 isolates of aerobically growing gram-positive rods (gprs). the bacterial isolates included nocardia (n = 74), listeria (n = 39), kocuria (n = 15), rhodococcus (n = 10), gordonia (n = 7), and tsukamurella (n = 2) species, which had all been identified by conventional methods, molecular methods, or both. ...201424759706
detailed sar and pca of the tyrocidines and analogues towards leucocin a-sensitive and leucocin a-resistant listeria monocytogenes.the tyrocidines, antimicrobial cyclic decapeptides from bacillus aneurinolyticus, have potent activity with drug/disinfectant potential, specifically against listeria monocytogenes. the tyrocidine activity is dependent on an amphipathic balance. structure-activity relationship (sar) analysis combined with principal component analysis showed the best activity correlation with hydropathy and solvent accessible volume (hydrophobicity parameters), mr and molecular volume (steric/size parameters), co ...201424766734
water-based oligochitosan and nanowhisker chitosan as potential food preservatives for shelf-life extension of minced pork.water-based chitosans in the forms of oligochitosan (oligocs) and nanowhisker chitosan (cswk) are proposed as a novel food preservative based on a minced pork model study. the high surface area with a positive charge over the neutral ph range (ph 5-8) of oligocs and cswk lead to an inhibition against gram-positive (staphylococcus aureus, listeria monocytogenes, and bacillus cereus) and gram-negative microbes (salmonella enteritidis and escherichia coli o157:h7). in the minced pork model, oligocs ...201424767083
presence and molecular characterization of the major serovars of listeria monocytogenes in ten sardinian fermented sausage processing plants.the aim of the present study was to investigate the occurrence of listeria monocytogenes in ten sardinian fermented sausage processing plants. a total of 230 samples were collected and 40 l. monocytogenes isolates were obtained and subjected to serotyping and investigated for the presence of ten virulence-associated genes using multiplex pcr assays. the isolates were further subjected to pfge and investigated for their adhesion abilities in polystyrene microtiter plates. l. monocytogenes was fou ...201424769142
investigating the control of listeria monocytogenes on alternatively-cured frankfurters using natural antimicrobial ingredients or post-lethality interventions.the objective of this study was to investigate natural antimicrobials including cranberry powder, dried vinegar and lemon juice/vinegar concentrate, and post-lethality interventions (lauric arginate, octanoic acid, thermal treatment and high hydrostatic pressure) for the control of listeria monocytogenes on alternatively-cured frankfurters. lauric arginate, octanoic acid, and high hydrostatic pressure (400 mpa) reduced l. monocytogenes populations by 2.28, 2.03, and 1.88 log 10 cfu per g compare ...201424769878
ox40 controls effector cd4+ t-cell expansion, not follicular t helper cell generation in acute listeria infection.to investigate the importance of ox40 signals for physiological cd4(+) t-cell responses, an endogenous antigen-specific population of cd4(+) t cells that recognise the 2w1s peptide was assessed and temporal control of ox40 signals was achieved using blocking or agonistic antibodies (abs) in vivo. following infection with listeria monocytogenes expressing 2w1s peptide, ox40 was briefly expressed by the responding 2w1s-specific cd4(+) t cells, but only on a subset that co-expressed effector cell m ...201424771127
phytochemistry and preliminary assessment of the antibacterial activity of chloroform extract of amburana cearensis (allemão) a.c. sm. against klebsiella pneumoniae carbapenemase-producing strains.the chloroform extract of the stem bark of amburana cearensis was chemically characterized and tested for antibacterial activity.the extract was analyzed by gas chromatography and mass spectrometry. the main compounds identified were 4-methoxy-3-methylphenol (76.7%), triciclene (3.9%), α -pinene (1.0%), β -pinene (2.2%), and 4-hydroxybenzoic acid (3.1%). preliminary antibacterial tests were carried out against species of distinct morphophysiological characteristics: escherichia coli, salmonella ...201424772183
the drosophila deubiquitinating enzyme dusp36 acts in the hemocytes for tolerance to listeria monocytogenes infections.listeria monocytogenes is a facultative intracellular pathogen which can infect drosophila melanogaster. upon infection, drosophila mounts an immune response including antimicrobial peptide production and autophagy activation. a set of previously published results prompted us to study the role of the deubiquitinating enzyme dusp36 in response to l. monocytogenes infections. we show in this report that flies with dusp36-specific inactivation in hemocytes are susceptible to l. monocytogenes infect ...201424777180
a rifamycin inactivating phosphotransferase family shared by environmental and pathogenic bacteria.many environmental bacteria are multidrug-resistant and represent a reservoir of ancient antibiotic resistance determinants, which have been linked to genes found in pathogens. exploring the environmental antibiotic resistome, therefore, reveals the diversity and evolution of antibiotic resistance and also provides insight into the vulnerability of clinically used antibiotics. in this study, we describe the identification of a highly conserved regulatory motif, the rifampin (rif) -associated ele ...201424778229
longitudinal requirement for cd4+ t cell help for adenovirus vector-elicited cd8+ t cell responses.despite the widespread use of replication-incompetent recombinant adenovirus (ad) vectors as candidate vaccine platforms, the mechanism by which these vectors elicit cd8(+) t cell responses remains poorly understood. our data demonstrate that induction and maintenance of cd8(+) t cell responses by ad vector immunization is longitudinally dependent on cd4(+) t cell help for a prolonged period. depletion of cd4(+) t cells in wild type mice within the first 8 d following ad immunization resulted in ...201424778441
responding to bioterror concerns by increasing milk pasteurization temperature would increase estimated annual deaths from listeriosis.in a 2005 analysis of a potential bioterror attack on the food supply involving a botulinum toxin release into the milk supply, the authors recommended adopting a toxin inactivation step during milk processing. in response, some dairy processors increased the times and temperatures of pasteurization well above the legal minimum for high temperature, short time pasteurization (72 °c for 15 s), with unknown implications for public health. the present study was conducted to determine whether an inc ...201424780323
listeria monocytogenes transfer during mechanical dicing of celery and growth during subsequent storage.the transfer of listeria monocytogenes to previously uncontaminated product during mechanical dicing of celery and its growth during storage at various temperatures were evaluated. in each of three trials, 275 g of retail celery stalks was immersed in an aqueous five-strain l. monocytogenes cocktail to obtain an average of 5.6 log cfu/g and then was diced using a hand-operated dicer, followed by sequential dicing of 15 identical 250-g batches of uninoculated celery using the same dicer. each bat ...201424780331
delivery of selective agents via time-delayed release tablets improves recovery of listeria monocytogenes injured by acid and nitrite.listeria selective enrichment media are designed to enhance the isolation of the organism and increase the chances of detection. drawbacks include the requirements for prolonged sample incubation (48 to 72 h) and manual addition of selective agents, which may be a source of contamination. modified listeria recovery broth (mlrb) is a proprietary enrichment medium formulated to facilitate the recovery of injured cells; its selective agents are incorporated into a format that allows delayed release ...201424780332
effects of different nitrite concentrations from a vegetable source with and without high hydrostatic pressure on the recovery of listeria monocytogenes on ready-to-eat restructured ham.sodium nitrite exerts an inhibitory effect on the growth of listeria monocytogenes. the objective of this study was to investigate the effects of various nitrite concentrations from a vegetable source with and without high hydrostatic pressure (hhp) on the recovery and growth of l. monocytogenes on ready-to-eat restructured ham. a preconverted celery powder was used as the vegetable source of nitrite. targeted concentrations of natural nitrite investigated were 0, 50, and 100 mg/kg. hhp treatmen ...201424780333
evaluation of the thin agar layer method for the recovery of pressure-injured and heat-injured listeria monocytogenes.a sublethally injured bacterial cell has been defined as a cell that survives a stress such as heating, freezing, acid treatment, or other antimicrobial intervention but can repair the cellular damage exerted by the stressor and later regain its original ability to grow. consequently, sublethally injured cells are not likely to be included in conventional enumeration procedures, which could result in unrealistically low counts unless efforts are made to encourage recovery of the injured cells be ...201424780340
survival of listeria monocytogenes on fresh blueberries (vaccinium corymbosum) stored under controlled atmosphere and ozone.listeria monocytogenes is a foodborne pathogen that represents a high risk for consumers because it can grow under refrigeration conditions and can also develop acid tolerance. fresh blueberries are hand-picked, packed, and transported under refrigeration without receiving a microbial inactivation treatment. the aim of this work was to study the survival of l. monocytogenes in fresh highbush blueberries stored at 4 or 12 °c under different controlled atmosphere conditions, including air (control ...201424780341
development of performance objectives for listeria monocytogenes contaminated salmon (salmo salar) intended used as sushi and sashimi based on analyses of naturally contaminated samples.raw salmon is commonly used in sushi and sashimi, indicating that fresh salmon may be considered as a ready-to-eat product. listeria monocytogenes is occasionally present in fresh salmon, but studies of prevalence and growth of the bacterium in this matrix have been few. in the present study, salmon from a company where l. monocytogenes is present in low levels has been investigated in order to develop performance objectives for l. monocytogenes in fresh salmon intended for use in ready-to-eat p ...201424784883
infective endocarditis caused by listeria monocytogenes forming a pseudotumor.a 73-year-old woman with breast cancer and metastasis under chemotherapy suffered from fever, pleural effusion and pericardial effusion. despite the administration of treatment with cefozopran and prednisolone, the patient's fever relapsed. an electrocardiogram identified a new complete atrioventricular block and an echocardiogram revealed vegetation with an unusual pseudotumoral mass in the right atrium. blood cultures grew listeria monocytogenes. the patient was eventually diagnosed with right ...201424785898
identification of the significant factors in food safety using global sensitivity analysis and the accept-and-reject algorithm: application to the cold chain of ham.deterministic models describing heat transfer and microbial growth in the cold chain are widely studied. however, it is difficult to apply them in practice because of several variable parameters in the logistic supply chain (e.g., ambient temperature varying due to season and product residence time in refrigeration equipment), the product's characteristics (e.g., ph and water activity) and the microbial characteristics (e.g., initial microbial load and lag time). this variability can lead to dif ...201424786551
genome sequences of three frequently used listeria monocytogenes and listeria ivanovii strains.we present the complete de novo assembled genome sequences of listeria monocytogenes strains wslc 1001 (atcc 19112) and wslc 1042 (atcc 23074) and listeria ivanovii wslc 3009, three strains frequently used for the propagation and study of bacteriophages because they are presumed to be free of inducible prophages.201424786957
isolation of listeria monocytogenes from food and water: official and experimental protocols.listeria monocytogenes is frequently encountered in foods but often at low concentrations and typically in the presence of other microbiota, including nonpathogenic listeria spp. the potential of l. monocytogenes to cause severe human disease mandates sensitive, accurate, and rapid detection in foods. isolation of l. monocytogenes from foods is critical, not only for routine surveillance, but also for epidemiologic investigations. isolation of the pathogen from water (especially surface water us ...201424789600
traditional methods for isolation of listeria monocytogenes.conventional methods for the detection of listeria monocytogenes in foods and environmental samples relies on selective pre-enrichment, enrichment, and plating. this is followed by confirmation of suspected colonies by testing a limited number of biochemical markers.201424792545
serotype assignment by sero-agglutination, elisa, and pcr.for assessing isolates of listeria monocytogenes serotype designation is the foremost subtyping method used. traditionally, serotyping has been done with agglutination reactions. in the last decade, alternative serotyping methods were described using enzyme-linked immunosorbent assay (elisa) and polymerase chain reaction (pcr). herein are described the three methods, and the advantages and disadvantages of each.201424792547
pulsed-field gel electrophoresis (pfge) analysis of listeria monocytogenes.pfge is a valuable tool for assessing listeria monocytogenes strain interrelatedness. it is based on the study of total bacterial dna restriction patterns. cells are embedded in agarose plugs before being lysed. the released dna is then digested into large fragments by restriction enzymes. as dna fragments are too large to be separated by traditional electrophoresis in an agarose gel, changes in the direction of the electrical current are periodically applied in order to allow the proper migrati ...201424792548
multilocus sequence typing (mlst) of listeria monocytogenes.nucleotide sequence-based methods focusing on the single nucleotide polymorphisms (snps) of listeria monocytogenes housekeeping genes facilitate the rapid and interlaboratory comparison on open accessible databases, such as the multilocus sequence typing (mlst) databases that are available. mlst has advantages over other methods as it can reconstruct ancestral and evolutionary linkage between l. monocytogenes isolates. mlst detects all genetic variations within the amplified housekeeping gene th ...201424792549
ribotyping and automated ribotyping of listeria monocytogenes.ribotyping is a molecular technique that allows identification and typing of bacteria to the strain level. it is based on restriction endonuclease cleavage of total genomic dna followed by electrophoretic separation, southern blot transfer, and hybridization of transferred dna fragments with a radiolabeled ribosomal operon probe. following autoradiography, only those bands containing a portion of the ribosomal operon are visualized. the number of fragments generated by ribotyping is a reflection ...201424792550
fluorescent amplified fragment length polymorphism (faflp) analysis of listeria monocytogenes.fluorescent amplified fragment length polymorphism (faflp) is based on the selective pcr amplification of restriction fragments from a digest of total genomic dna. genomic dna extracted from a purified bacterial isolate is completely digested with two endonucleases generating fragments which are ligated to specific double-stranded adaptors. the ligated fragments are then amplified by pcr using fluorescently labelled primers. fluorescent amplified fragments are separated by size on an automated s ...201424792551
high-throughput characterization of listeria monocytogenes using the omnilog phenotypic microarray.high-throughput biochemical screening techniques are an important tool in phenotypic analysis of bacteria. new methods, simultaneously measuring many phenotype responses, increase the output of such investigations and allow a more complete overview of the bacterial phenotype, and how this may relate its genotype. this chapter describes the application of omnilog phenotype microarray analysis, a high-throughput assay for the phenotypic characterization of bacterial strains across a variety of dif ...201424792552
analysis of listeria monocytogenes subproteomes.the proteomic approaches have considerably evolved over the past two decades. this opened the doors for larger scale and deeper explorations of cellular physiology. like for other living organisms, using the tools of proteomics has undoubtedly improved knowledge about the foodborne pathogen listeria monocytogenes. among the different technologies and approaches permanently evolving in the field of proteomics, the 2-de is an analytical separation method of choice to resolve thousands of proteins ...201424792553
the listeria cell wall and associated carbohydrate polymers.understanding molecular interactions of bacteria with their environment requires the purification and characterization of cell wall components. here, we describe detailed experimental methods for the extraction, purification, and analysis of wall teichoic acids (wta), which assume important roles as major constituents of gram-positive cell walls, such as mediating interaction with cell wall-associated proteins, eukaryotic host cells, and bacteriophages. specifically, we present a procedure for c ...201424792554
virulence characterization of listeria monocytogenes.listeria monocytogenes, a foodborne intracellular pathogen, is responsible for about 300 deaths every year in the usa. it has the ability to escape host defense mechanisms and causes listeriosis more frequently in immunocompromised individuals. virulence mechanisms in l. monocytogenes are highly regulated and tightly controlled. a number of virulence factors that play important roles in pathogenesis of listeriosis have been identified and characterized. this review highlights the power of compar ...201424792556
internalization assays for listeria monocytogenes.listeria monocytogenes is a model intracellular pathogen that can invade the cytoplasm of host mammalian cells. cellular invasion can be measured using standard techniques such as the classical gentamicin protection assay, based on the quantification of colony-forming units from lysates of infected cells. in addition, there are methods based on immunofluorescence microscopy which allow for assaying invasion in a medium- to high-throughput manner. in the following sections we detail two different ...201424792557
extraction and analysis of plasmid dna from listeria monocytogenes.a plasmid preparation is a method used to extract and purify plasmid dna. methods developed to purify plasmid dna from bacteria generally involve harvesting and alkaline lysis of the bacteria and precipitation of chromosomal dna and protein, followed by purification of the plasmid dna. here, we describe the mini-preparation of plasmid dna by a rapid small-scale method, adapted for listeria monocytogenes. the quality of plasmid dna isolated using this method is sufficient for analytical purposes ...201424792558
generation of nonpolar deletion mutants in listeria monocytogenes using the "soeing" method.the ability to manipulate chromosomally encoded genes is a fundamental biological tool for the analysis of gene function. here, we provide in greater depth protocols for the creation of nonpolar unlabeled gene deletions in listeria (l.) monocytogenes that are facilitated by the splicing overlap extension pcr technique. for mutagenesis in l. monocytogenes, we describe two different plasmid-based approaches, which facilitate the introduction of this spliced amplicon in place of the corresponding s ...201424792559
mutant construction and integration vector-mediated gene complementation in listeria monocytogenes.genes that play role in stress response mechanisms and other phenotypes of bacteria can be identified by construction and screening of mutant libraries. in this chapter, we describe the construction and screening of mutant libraries of listeria monocytogenes using a plasmid, pmc38, carrying a mariner-based transposon system (tc1/mariner) and constructed by cao et al. (appl environ microbiol 73:2758-2761, 2007). following screening of the mutant library, putative mutants are identified and the tr ...201424792560
absolute and relative gene expression in listeria monocytogenes using real-time pcr.reverse transcription combined with the polymerase chain reaction (rt-pcr) is a viable method widely used to quantify gene expression. there are two ways to quantify gene expression by real-time pcr: relative quantification and absolute quantification. relative quantification relates the pcr signal of the target gene to a control gene, normally a housekeeping gene. absolute quantification determines the input copy number, usually by relating the pcr signal to a standard curve. here we describe b ...201424792561
genome sequencing of listeria monocytogenes.genome sequencing is a key technology in microbiology. a genome sequence is the prerequisite for understanding the molecular basis of a given phenotype; this is of particular importance for pathogens. particularly for the foodborne pathogen listeria monocytogenes, which is an important model organism in infection biology, genome sequencing has proven to be invaluable in advancing our understanding of its virulence mechanisms and epidemiology. in this chapter, current technologies and software to ...201424792562
using enhanced green fluorescent protein (egfp) promoter fusions to study gene regulation at single cell and population levels.reporter gene fusions based on the enhanced green fluorescent protein (egfp) are powerful experimental tools that allow real-time changes in gene expression to be monitored both in single cells and in populations. here we describe the development of a chromosomally integrated transcriptional reporter fusion in listeria monocytogenes that allows real-time measurements of gene expression. to construct a single copy of an egfp-based fluorescent reporter fused to a promoter of interest (px) in l. mo ...201424792563
control of listeria monocytogenes in the processing environment by understanding biofilm formation and resistance to sanitizers.listeria monocytogenes can colonize in the food processing environment and thus pose a greater risk of cross-contamination to food. one of the proposed mechanisms that facilitates such colonization is biofilm formation. as part of a biofilm, it is hypothesized that l. monocytogenes can survive sanitization procedures. in addition, biofilms are difficult to remove and may require additional physical and chemical mechanisms to reduce their presence and occurrence. the initial stage of biofilm form ...201424792564
vaccination studies: detection of a listeria monocytogenes-specific t cell immune response using the elispot technique.during systemic infection by listeria monocytogenes the host develops a robust t cell-mediated immune response against the major immunodominant antigens of the pathogen. the enzyme-linked immuno-spot (elispot) test is an accurate and reproducible means of measuring the extent of this t cell response. here we describe a detailed elispot protocol for measuring an epitope-specific cd8+ t cell-mediated immune response in mice vaccinated with low doses of l. monocytogenes. the basic approach can be e ...201424792565
short communication: homologous expression of recombinant and native thurincin h in an engineered natural producer.the bacillus bacteriocin thurincin h exhibits a wide inhibitory spectrum of activity against various foodborne pathogens, such as listeria monocytogenes, and dairy spoilage bacteria, especially different bacillus species commonly existing in dairy products. previously, we constructed 3 plasmids to express native thurincin h homologously in an engineered natural producer, bacillus thuringiensis sf361thnh(-). this host is deficient in thurincin h production because of an in-frame deletion of struc ...201424792808
oral infection drives a distinct population of intestinal resident memory cd8(+) t cells with enhanced protective function.the intestinal mucosa promotes t cell responses that might be beneficial for effective mucosal vaccines. however, intestinal resident memory t (trm) cell formation and function are poorly understood. we found that oral infection with listeria monocytogenes induced a robust intestinal cd8 t cell response and blocking effector t cell migration showed that intestinal trm cells were critical for secondary protection. intestinal effector cd8 t cells were predominately composed of memory precursor eff ...201424792910
segmented continuous-flow multiplex polymerase chain reaction microfluidics for high-throughput and rapid foodborne pathogen detection.high-throughput and rapid identification of multiple foodborne bacterial pathogens is vital in global public health and food industry. to fulfill this need, we propose a segmented continuous-flow multiplex polymerase chain reaction (scf-mpcr) on a spiral-channel microfluidic device. the device consists of a disposable polytetrafluoroethylene (ptfe) capillary microchannel coiled on three isothermal blocks. within the channel, n segmented flow regimes are sequentially generated, and m-plex pcr is ...201424793853
in vitro evaluation of antimicrobial features of vasopressors.drugs administered as intravenous infusion may be contaminated during several stages of production or preparation. however studies focusing on antibacterial effects of vasopressor drugs are very rare. this study investigates the in vitro antimicrobial activity of the clinically used forms of vasopressors.201424794449
a multiplex pcr assay for simultaneous detection of escherichia coli o157:h7, bacillus cereus, vibrio parahaemolyticus, salmonella spp., listeria monocytogenes, and staphylococcus aureus in korean ready-to-eat food.a multiplex polymerase chain reaction (pcr) assay was developed for simultaneous detection of escherichia coli o157:h7, bacillus cereus, vibrio parahaemolyticus, salmonella spp., listeria monocytogenes, and staphylococcus aureus in various korean ready-to-eat foods. the six specific primer pairs for multiplex pcr were selected based on the o157 antigen (rfbe) gene of e. coli o157:h7, the dna gyrase subunit b (gyrb) gene of b. cereus, the toxin regulatory protein (toxr) gene of v. parahaemolyticu ...201424796416
phenotypic t cell exhaustion in a murine model of bacterial infection in the setting of pre-existing malignancy.while much of cancer immunology research has focused on anti-tumor immunity both systemically and within the tumor microenvironment, little is known about the impact of pre-existing malignancy on pathogen-specific immune responses. here, we sought to characterize the antigen-specific cd8+ t cell response following a bacterial infection in the setting of pre-existing pancreatic adenocarcinoma. mice with established subcutaneous pancreatic adenocarcinomas were infected with listeria monocytogenes, ...201424796533
multifaceted activity of listeriolysin o, the cholesterol-dependent cytolysin of listeria monocytogenes.the cholesterol-dependent cytolysins (cdcs) are a large family of pore-forming toxins that are produced by numerous gram-positive bacterial pathogens. these toxins are released in the extracellular environment as water-soluble monomers or dimers that bind to cholesterol-rich membranes and assemble into large pore complexes. depending upon their concentration, the nature of the host cell and membrane (cytoplasmic or intracellular) they target, the cdcs can elicit many different cellular responses ...201424798012
biochemical and antimicrobial activity of phloretin and its glycosilated derivatives present in apple and kumquat.phloretin and its glycosylated derivatives (phlorizin and phloretin 3',5'-di-c-glucoside) are dihydrochalcones that have many interesting biological properties. the results obtained showed that the dihydrochalcones are able to inhibit growth of gram positive bacteria, in particular staphylococcus aureus atcc 6538, listeria monocytogenes atcc 13932 and methicillin-resistant s. aureus clinical strains. moreover, phloretin is active also against the gram negative bacteria salmonella typhimurium atc ...201424799241
trial watch: dna vaccines for cancer therapy.during the past 2 decades, the possibility that preparations capable of eliciting tumor-specific immune responses would mediate robust therapeutic effects in cancer patients has received renovated interest. in this context, several approaches to vaccinate cancer patients against their own malignancies have been conceived, including the administration of dna constructs coding for one or more tumor-associated antigens (taas). such dna-based vaccines conceptually differ from other types of gene the ...201424800178
temperature- and nitrogen source-dependent regulation of glnr target genes in listeria monocytogenes.the ubiquitous pathogen listeria monocytogenes lives either saprophytically in the environment or within cells in a vertebrate host, thus adapting its lifestyle to its ecological niche. growth experiments at 24 and 37 °c (environmental and host temperature) with ammonium or glutamine as nitrogen sources revealed that ammonium is the preferred nitrogen source of l. monocytogenes. reduced growth on glutamine is more obvious at 24 °c. global transcriptional microarray analyses showed that the most ...201424801548
rapid differentiation of listeria monocytogenes epidemic clones iii and iv and their intact compared with heat-killed populations using fourier transform infrared spectroscopy and chemometrics.the objectives of this study were to determine if fourier transform infrared (ft-ir) spectroscopy and multivariate statistical analysis (chemometrics) could be used to rapidly differentiate epidemic clones (ecs) of listeria monocytogenes, as well as their intact compared with heat-killed populations. ft-ir spectra were collected from dried thin smears on infrared slides prepared from aliquots of 10 μl of each l. monocytogenes ecs (eciii: j1-101 and r2-499; eciv: j1-129 and j1-220), and also from ...201424802119
use of essential oils and extracts from spices in meat protection.the hydro distillation method was used in this study to get essential oils (eos) from cumin (cuminum cyminum l.), clove (eugenia caryohyllata) and elecampane (inula helenium l.) and the co-hydro distillation method (addition of fatty acid ethyl esters as extraction cosolvents) to get functional extracts (efs). the mic (minimum inhibitory concentration) and the mbc (minimum bactericidal concentration) were determined on five pathogenic strains (escherichia coli o157:h7, salmonella, listeria monoc ...201124803704
comparative lethality kinetic curves and predictive models of f-value for listeria monocytogenes using different sanitizers.the objective of this work was to evaluate the kinetic of inactivation of listeria monocytogenes using peracetic acid, chlorhexidine, and organic acids as active agent, determining the respective d-, z-, and f-values. from our knowledge, these important results from an industrial view point are not available in the current literature, mainly for organic acids, pointing out the main contribution of the present work. lower d-values were obtained for peracetic acid and chlorhexidine, compared with ...201324804011
low-fat frankfurters from protein concentrates of tilapia viscera and mechanically separated tilapia meat.in order to develop a healthy low-fat frankfurter-type sausage, different formulations were developed with tilapia viscera surimi (t1) and two with mechanically separated tilapia meat (mstm) surimi (t2 and t3), all without pig lard addition. due to technological problems observed for t1 sausage during cooking, it was not further investigated. the functionality of the other two formulations was evaluated based on proximate composition, ph, water activity, and texture. finally, microbiological and ...201324804055
how listeria monocytogenes organizes its surface for virulence.listeria monocytogenes is a gram-positive pathogen responsible for the manifestation of human listeriosis, an opportunistic foodborne disease with an associated high mortality rate. the key to the pathogenesis of listeriosis is the capacity of this bacterium to trigger its internalization by non-phagocytic cells and to survive and even replicate within phagocytes. the arsenal of virulence proteins deployed by l. monocytogenes to successfully promote the invasion and infection of host cells has b ...201424809022
the bacterial pathogen listeria monocytogenes and the interferon family: type i, type ii and type iii interferons.interferons (ifns) are secreted proteins of the cytokine family that regulate innate and adaptive immune responses to infection. although the importance of ifns in the antiviral response has long been appreciated, their role in bacterial infections is more complex and is currently a major focus of investigation. this review summarizes our current knowledge of the role of these cytokines in host defense against the bacterial pathogen listeria monocytogenes and highlights recent discoveries on the ...201424809023
prevalence and characterization of listeria monocytogenes, salmonella and shiga toxin-producing escherichia coli isolated from small mexican retail markets of queso fresco.queso fresco (qf) is a handmade cheese consumed and produced in latin america. in mexico, qf production is associated with a microbiological risk. the aim of the study was to determine the incidence and characterization of listeria monocytogenes, salmonella spp., and shiga toxin-producing escherichia coli (stec) in qf from retail markets of the north-western state of sinaloa, mexico, and to assess the effect of physicochemical parameters on listeria presence. a total of 75 qf samples were obtain ...201524809389
cytosolic double-stranded dna induces nonnecroptotic programmed cell death in trophoblasts via ifi16.the mechanisms underlying the immune defense by trophoblasts against pathogens remain ill defined. we demonstrated that placental cell death was increased upon in vivo exposure to listeria monocytogenes. the death of infected cells is an important host innate defense mechanism. meanwhile, double-stranded dna (dsdna) derived from intracellular bacteria or dsdna viruses is emerging as a potent pathogen-associated molecular pattern recognized by host cells. we sought to characterize trophoblast dea ...201424812048
listeria monocytogenes infection in a sugar glider (petaurus breviceps) - new mexico, 2011.listeria monocytogenes is a gram-positive, facultative anaerobic, rod-shaped bacterium that can infect and cause disease in many species. in this case report, we describe a case of l. monocytogenes infection causing sepsis in a sugar glider (petaurus breviceps). the sugar glider consumed a varied diet consisting of human food items, including cantaloupe. a nationwide outbreak of l. monocytogenes foodborne illness associated with cantaloupes occurred simultaneously with this incident case. in thi ...201524815369
impact of the prevalence of different pathogens on the performance of sampling plans in lettuce products.prevalence and concentration of listeria monocytogenes, salmonella spp. and enteric pathogenic viruses (namely hepatitis a-hav, and noroviruses genogroup i-novgi and genogroup ii-novgii) were determined in raw and rte lettuce from a spanish processing premise. fifteen samplings were made from september 2010 to february 2012 (n=600 samples). sampling strategies for pathogen detection were suggested by the characterization of the uncertainty in prevalence associated with the performance of two-cla ...201424815427
staphylococcus pseudintermedius for camp-test.camp test reliably detects listeria monocytogenes (lm) and streptococcus agalactiae (group b streptococcus, gbs); it is traditionally performed streaking the tested isolate perpendicularly to staphylococcus aureus (sa), provided that reference sa strains (that produce β-hemolysin) are used. in a zone of β-hemolysin activity, in fact, gbs and lm form typical arrow-shaped hemolytic areas. while sa production of the toxin is strain-dependent, however, that of staphylococcus pseudintermedius (sp), a ...201424817971
role of tumor suppressor tsc1 in regulating antigen-specific primary and memory cd8 t cell responses to bacterial infection.the serine/threonine kinase mammalian/mechanistic target of rapamycin (mtor) integrates various environmental cues such as the presence of antigen, inflammation, and nutrients to regulate t cell growth, metabolism, and function. the tuberous sclerosis 1 (tsc1)/tsc2 complex negatively regulates the activity of an mtor-containing multiprotein complex called mtor complex 1. recent studies have revealed an essential cell-intrinsic role for tsc1 in t cell survival, quiescence, and mitochondrial homeo ...201424818661
what is new in listeriosis?listeriosis is a disease caused by listeria monocytogenes (l. monocytogenes). l. monocytogenes is bacteria that usually infects some determined inhabitants, especially high risk patients such as the elderly, immunosuppressed patients and pregnant women. however, it can also affect people who do not have these risk factors. l. monocytogenes is widespread in nature being part of the faecal flora of many mammals and it is a common foodborne source. it is acquired by humans primarily through consump ...201424822197
investigating the control of listeria monocytogenes on a ready-to-eat ham product using natural antimicrobial ingredients and postlethality interventions.ready-to-eat (rte) meat and poultry products manufactured with natural or organic methods are at greater risk for listeria monocytogenes growth, if contaminated, than their conventional counterparts due to the required absence of preservatives and antimicrobials. thus, the objective of this study was to investigate the use of commercially available natural antimicrobials and postlethality interventions in the control of l. monocytogenes growth and recovery on a rte ham product. antimicrobials ev ...201424824223
investigation of listeria, salmonella, and toxigenic escherichia coli in various pet foods.the veterinary laboratory investigation and response network (vet-lirn), in collaboration with the food emergency response network (fern) and its microbiology cooperative agreement program (mcap) laboratories, conducted a study to evaluate the prevalence of selected microbial organisms in various types of pet foods. the goal of this blinded study was to help the center for veterinary medicine prioritize potential future pet food-testing efforts. the study also increased the fern laboratories' sc ...201424824368
prevalence and contamination patterns of listeria monocytogenes in flammulina velutipes plants.four mushroom (flammulina velutipes) production plants were sampled to investigate the prevalence and contamination source of listeria monocytogenes. among 295 samples, the prevalence of l. monocytogenes was 18.6%; the contamination appeared to originate from the mycelium-scraping machinery, contaminating both the product and upstream packaging equipment. of 55 l. monocytogenes isolates, lineages i.1 (1/2a-3a) and ii.2 (1/2b-3b-7) accounted for 65.5% and 34.5%, respectively. in addition, lineage ...201424824447
undecaprenyl diphosphate synthase inhibitors: antibacterial drug leads.there is a significant need for new antibiotics due to the rise in drug resistance. drugs such as methicillin and vancomycin target bacterial cell wall biosynthesis, but methicillin-resistant staphylococcus aureus (mrsa) and vancomycin-resistant enterococci (vre) have now arisen and are of major concern. inhibitors acting on new targets in cell wall biosynthesis are thus of particular interest since they might also restore sensitivity to existing drugs, and the cis-prenyl transferase undecapreny ...201424827744
colonization of plants by human pathogenic bacteria in the course of organic vegetable production.in recent years, increasing numbers of outbreaks caused by the consumption of vegetables contaminated with human pathogenic bacteria were reported. the application of organic fertilizers during vegetable production is one of the possible reasons for contamination with those pathogens. in this study laboratory experiments in axenic and soil systems following common practices in organic farming were conducted to identify the minimal dose needed for bacterial colonization of plants and to identify ...201424829562
anti-pd-1 antibody significantly increases therapeutic efficacy of listeria monocytogenes (lm)-llo immunotherapy.one of the significant tumor immune escape mechanisms and substantial barrier for successful immunotherapy is tumor-mediated inhibition of immune response through cell-to-cell or receptor/ligand interactions. programmed death receptor-1 (pd-1) interaction with its ligands, pd-l1 and pd-l2, is one of the important strategies that many tumors employ to escape immune surveillance. upon pd-ls binding to pd-1, t cell receptor (tcr) signaling is dampened, causing inhibition of proliferation, decreased ...201324829751
evaluation of vidas up listeria assay (lpt) for the detection of listeria in a variety of foods and environmental surfaces: first action 2013.10.the vidas up listeria (lpt) is an automated rapid screening enzyme phage-ligand based assay for the detection of listeria species in human food products and environmental samples. the vidas lpt method was compared in a multi-laboratory collaborative study to aoac official method 993.12 listeria monocytogenes in milk and dairy products reference method following current aoac guidelines. a total of 14 laboratories participated, representing government and industry, throughout the united states. on ...201424830156
evaluation of vidas listeria monocytogenes xpress (lmx) for the detection of listeria monocytogenes in a variety of foods: first action 2013.11.the vidas listeria monocytogenes xpress (lmx) is an automated rapid screening enzyme immunoassay for the detection of listeria monocytogenes in food products. the vidas lmx method was compared in a multi-laboratory collaborative study to aoac official method 993.12 listeria monocytogenes in milk and dairy products reference method following current aoac guidelines. a total of 14 laboratories participated, representing government and industry, throughout the united states. one matrix, queso fresc ...201424830157
cu(i)-mediated allosteric switching in a copper-sensing operon repressor (csor).the copper-sensing operon repressor (csor) is representative of a major cu(i)-sensing family of bacterial metalloregulatory proteins that has evolved to prevent cytoplasmic copper toxicity. it is unknown how cu(i) binding to tetrameric csors mediates transcriptional derepression of copper resistance genes. a phylogenetic analysis of 227 duf156 protein members, including biochemically or structurally characterized csor/rcnr repressors, reveals that geobacillus thermodenitrificans (gt) csor charac ...201424831014
the function of the chemokine receptor cxcr6 in the t cell response of mice against listeria monocytogenes.the chemokine receptor cxcr6 is expressed on different t cell subsets and up-regulated following t cell activation. cxcr6 has been implicated in the localization of cells to the liver due to the constitutive expression of its ligand cxcl16 on liver sinusoidal endothelial cells. here, we analyzed the role of cxcr6 in cd8+ t cell responses to infection of mice with listeria monocytogenes. cd8+ t cells responding to listerial antigens acquired high expression levels of cxcr6. however, deficiency of ...201424832098
optimization of a real time pcr based method for the detection of listeria monocytogenes in pork meat.the aim of this study was to optimize a real-time pcr protocol for a rapid detection of listeria monocytogenes in pork meat, using reduced volumes of primary selective enrichment broth and times of incubation to decrease the cost and time for analysis. forty-five samples of pork meat were artificially contaminated with two different levels of l. monocytogenes (1-10 cfu per sample and 10-100 cfu per sample), homogenized in three different volumes of half fraser broth (1:3; 1:5 and 1:10) and incub ...201424835318
[listeriosis and pregnancy].listeria monocytogenes is a ubiquitous gram-positive bacillus widespread in nature. it is responsible for febrile abortion and encephalitis in cattle. it survives and multiplies at 4°c and does not alter the taste of food. listeria monocytogenes is able to cross 3 host barriers: the intestinal, blood-brain and placental barriers. maternal infection is rare but still severe in france, with 30 to 50 annual cases. maternal infection is frequently asymptomatic, or manifests as isolated fever, wherea ...201424836302
comparative genomic and morphological analyses of listeria phages isolated from farm environments.the genus listeria is ubiquitous in the environment and includes the globally important food-borne pathogen listeria monocytogenes. while the genomic diversity of listeria has been well studied, considerably less is known about the genomic and morphological diversity of listeria bacteriophages. in this study, we sequenced and analyzed the genomes of 14 listeria phages isolated mostly from new york dairy farm environments as well as one related enterococcus faecalis phage to obtain information on ...201424837381
[application and evaluation of loop-mediated isothermal amplification method for detecting of listeria monocytogenes in food].the loop-mediated isothermal amplification (lamp) detection method was applied to detect listeria monocytogenes in food. the specificity and sensitivity of this method were evaluated through comparing it with real-time pcr and conventional detection method.201424844836
novel strategies to enforce an epithelial phenotype in mesenchymal cells.e-cadherin downregulation in cancer cells is associated with epithelial-to-mesenchymal transition (emt) and metastatic prowess, but the underlying mechanisms are incompletely characterized. in this study, we probed e-cadherin expression at the plasma membrane as a functional assay to identify genes involved in e-cadherin downregulation. the assay was based on the e-cadherin-dependent invasion properties of the intracellular pathogen listeria monocytogenes. on the basis of a functional readout, a ...201424845104
antibacterial activity and immune responses of a molluscan macrophage expressed gene-1 from disk abalone, haliotis discus discus.the membrane-attack complex/perforin (macpf) domain-containing proteins play an important role in the innate immune response against invading microbial pathogens. in the current study, a member of the macpf domain-containing proteins, macrophage expressed gene-1 (mpeg1) encoding 730 amino acids with the theoretical molecular mass of 79.6 kda and an isoelectric point (pi) of 6.49 was characterized from disk abalone haliotis discus discus (abmpeg1). we found that the characteristic macpf domain (v ...201424852343
green conversion of agroindustrial wastes into chitin and chitosan by rhizopus arrhizus and cunninghamella elegans strains.this article sets out a method for producing chitin and chitosan by cunninghamella elegans and rhizopus arrhizus strains using a green metabolic conversion of agroindustrial wastes (corn steep liquor and molasses). the physicochemical characteristics of the biopolymers and antimicrobial activity are described. chitin and chitosan were extracted by alkali-acid treatment, and characterized by infrared spectroscopy, viscosity and x-ray diffraction. the effectiveness of chitosan from c. elegans and ...201424853288
temperature effects on the antimicrobial efficacy of condensed smoke and lauric arginate against listeria and salmonella.condensed smoke or liquid smoke (ls) and lauric arginate (lae) are antimicrobials used in food preservation. they have demonstrated abilities to reduce or inhibit pathogenic and spoilage organisms. few studies, however, have reported on the effectiveness of ls or lae over the range of temperatures typically encountered in food marketing channels. therefore, the effects of temperature on the antimicrobial properties of two commercial ls fractions, an ls derived from pecan shells, and lae against ...201424853515
infrared sensor-based aerosol sanitization system for controlling escherichia coli o157:h7, salmonella typhimurium, and listeria monocytogenes on fresh produce.an economical aerosol sanitization system was developed based on sensor technology for minimizing sanitizer usage, while maintaining bactericidal efficacy. aerosol intensity in a system chamber was controlled by a position-sensitive device and its infrared value range. the effectiveness of the infrared sensor-based aerosolization (isa) system to inactivate escherichia coli o157:h7, salmonella typhimurium, and listeria monocytogenes on spinach leaf surfaces was compared with conventional aerosoli ...201424853521
viability of listeria monocytogenes on uncured turkey breast commercially prepared with and without buffered vinegar during extended storage at 4 and 10°c.we determined the viability of listeria monocytogenes on uncured turkey breast containing buffered vinegar (bv) and surface treated with a stabilized solution of sodium chlorite in vinegar (vsc). commercially produced, uncured, deli-style turkey breast was formulated with bv (0.0, 2.0, 2.5, or 3.0%), sliced (ca. 100 g and ca. 1.25 cm thick), and subsequently surface inoculated (ca. 4.3 log cfu per slice) in each of two trials with a five-strain cocktail of l. monocytogenes. next, 1 ml per side o ...201424853523
dynamic functional modulation of cd4+ t cell recall responses is dependent on the inflammatory environment of the secondary stimulus.the parameters that modulate the functional capacity of secondary th1 effector cells are poorly understood. in this study, we employ a serial adoptive transfer model system to show that the functional differentiation and secondary memory potential of secondary cd4+ effector t cells are dependent on the inflammatory environment of the secondary challenge. adoptive transfer of tcr transgenic lymphocytic choriomeningitis virus (lcmv) glycoprotein-specific smarta memory cells into lcmv-immune hosts, ...201424854337
lowest numbers of primary cd8(+) t cells can reconstitute protective immunity upon adoptive immunotherapy.patients undergoing allogeneic hematopoietic stem cell transplantation (allo-hsct) are threatened by potentially lethal viral manifestations like cytomegalovirus (cmv) reactivation. because the success of today's virostatic treatment is limited by side effects and resistance development, adoptive transfer of virus-specific memory t cells derived from the stem cell donor has been proposed as an alternative therapeutic strategy. in this context, dose minimization of adoptively transferred t cells ...201424855206
release of silver and copper nanoparticles from polyethylene nanocomposites and their penetration into listeria monocytogenes.since infection is a major cause of death in a patient whose immune responses have been compromised (immunocompromised patient), considerable attention has been focused on developing materials for the prevention of infections. this has been directed primarily at suppressing or eliminating the host's endogenous microbial burden and decreasing the acquisition of new organisms. in this study, the antibacterial properties of two nanocomposites, polyethylene modified with silver nanoparticles (pe-agn ...201424857461
selection and characterization of dna aptamers specific for listeria species.single-stranded (ss) dna aptamers with binding affinity to listeria spp. were selected using a whole-cell selex (systematic evolution of ligands by exponential enrichment) method. listeria monocytogenes cells were grown at 37°c and harvested at mid-log phase or early stationary phase to serve as the targets in selex. a total of 10 unique aptamer sequences were identified, six associated with log phase cells and four with stationary phase cells. binding affinity of the aptamers was determined usi ...201424857773
numerical spatio-temporal characterization of listeria monocytogenes biofilms.as the structure of biofilms plays a key role in their resistance and persistence, this work presents for the first time the numerical characterization of the temporal evolution of biofilm structures formed by three listeria monocytogenes strains on two types of stainless-steel supports, aisi 304 ss no. 2b and aisi 316 ss no. 2r. counting methods, motility tests, fluorescence microscopy and image analysis were combined to study the dynamic evolution of biofilm formation and structure. image anal ...201424858448
attenuated listeria monocytogenes: a powerful and versatile vector for the future of tumor immunotherapy.for over a century, inactivated or attenuated bacteria have been employed in the clinic as immunotherapies to treat cancer, starting with the coley's vaccines in the 19th century and leading to the currently approved bacillus calmette-guérin vaccine for bladder cancer. while effective, the inflammation induced by these therapies is transient and not designed to induce long-lasting tumor-specific cytolytic t lymphocyte (ctl) responses that have proven so adept at eradicating tumors. therefore, in ...201424860789
selective pharmacologic inhibition of a pasta kinase increases listeria monocytogenes susceptibility to β-lactam antibiotics.while β-lactam antibiotics are a critical part of the antimicrobial arsenal, they are frequently compromised by various resistance mechanisms, including changes in penicillin binding proteins of the bacterial cell wall. genetic deletion of the penicillin binding protein and serine/threonine kinase-associated protein (pasta) kinase in methicillin-resistant staphylococcus aureus (mrsa) has been shown to restore β-lactam susceptibility. however, the mechanism remains unclear, and whether pharmacolo ...201424867981
[rapid detection of listeria monocytogenes in pork samples by real-time pcr with taqman probe].to develop a real-time pcr method for detection listeria monocytogenes in pork samples.201424868965
episomal expression of truncated listeriolysin o in lmdda-llo-e7 vaccine enhances antitumor efficacy by preferentially inducing expansions of cd4+foxp3- and cd8+ t cells.studies have shown that listeria monocytogenes (lm)-based vaccine expressing a fusion protein comprising truncated listeriolysin o (llo) and human papilloma virus (hpv) e7 protein (lm-llo-e7) induces a decrease in regulatory t cells (treg) and complete regression of established, transplanted hpv-tc-1 tumors in mice. however, how the lm-based vaccine causes a decrease in tregs remains unclear. using a highly attenuated lm dal dat δacta strain (lmdda)-based vaccine, we report here that the vector ...201424872025
microwave-assisted hydrodistillation of essential oil from rosemary.effects of microwave assisted hydrodistillation (mahd) and conventional hydrodistillation (hd) methods on yield, composition, specific gravity, refractive index, and antioxidant and antimicrobial activities of essential oil of rosmarinus officinalis l were studied. the main aroma compounds of rosemary essential oil were found as 1,8-cineole and camphor. trolox equivalent antioxidant capacity (teac) values for essential oils extracted by mahd and hd were 1.52 mm/ml oil and 1.95 mm/ml oil, respect ...201424876637
biosynthesis of silver nanoparticles using acacia leucophloea extract and their antibacterial activity.the immense potential of nanobiotechnology makes it an intensely researched field in modern medicine. green nanomaterial synthesis techniques for medicinal applications are desired because of their biocompatibility and lack of toxic byproducts. we report the toxic byproducts free phytosynthesis of stable silver nanoparticles (agnps) using the bark extract of the traditional medicinal plant acacia leucophloea (fabaceae). visual observation, ultraviolet-visible spectroscopy, and transmission elect ...201424876776
Refresh
firstprev
...141142143144145146147148149150...
nextlast
Displaying items 14301 - 14400 of 16792