| nonthermal inactivation of escherichia coli k-12 on spinach leaves, using dense phase carbon dioxide. | while the use of some chemical sanitizers is approved for inactivation of microbes on the surfaces of fruits and vegetables, these compounds often degrade product quality with limited improvement in product safety. the application of dense phase carbon dioxide (dpcd, or high-pressure co2) is a nonthermal process for inactivation of foodborne pathogens inoculated into various juices and model solutions. in this work, dpcd was evaluated for its potential to inactivate escherichia coli k-12 inocula ... | 2008 | 18522038 |
| secondary metabolites from nonhost plants affect the motility and viability of phytopathogenic aphanomyces cochlioides zoospores. | the motile zoospores of the damping-off pathogen aphanomyces cochlioides aggregate on host plants (e.g., sugar beet, spinach) guided by the host-specific plant signal cochliophilin a before infection. to assess the potential role of secondary metabolites in nonhost resistance, acetone extracts of 200 nonhost traditional medicinal plants from chinese and bangladeshi origins were tested for the motility behaviour of a. cochlioides zoospores using a particle bioassay method. nearly one third of the ... | 2008 | 18533468 |
| the use of bacterial alkaline phosphatase assay for rapid monitoring of bacterial counts on spinach. | this study was undertaken to evaluate the applicability of bacterial alkaline phosphatase (alp) activity for rapid monitoring of total mesophilic bacteria counts in spinach. a set of fresh and decayed spinach mixtures were tested to rapidly (10 min) monitor spinach bacterial counts. to assay alp activity, lumigen aps-5 was used as a substrate. bovine alp was reduced after heat treatment at 75 degrees c for 1 min; in contrast, bacterial alp activity increased. to differentiate bacterial alp from ... | 2008 | 18577006 |
| dietary flavonoid sources in australian adults. | evidence from laboratory-based in vitro studies provides compelling evidence supporting the involvement of dietary flavonoid intake in human cancer risk. associations between intakes of individual flavonoids and disease outcomes at the population level are emerging from recent epidemiological studies. as an important step in the development of methods to assess flavonoid intakes across populations, the major sources of dietary flavonoids in the adult australian population were identified. data f ... | 2008 | 18584477 |
| anti-tumor effect of orally administered spinach glycolipid fraction on implanted cancer cells, colon-26, in mice. | we succeeded in purifying a major glycolipid fraction from a green vegetable, spinach. this fraction consists mainly of three glycolipids: monogalactosyl diacylglycerol (mgdg), digalactosyl diacylglycerol (dgdg), and sulfoquinovosyl diacylglycerol (sqdg). in a previous study, we found that the glycolipid fraction inhibited dna polymerase activity, cancer cell growth and tumor growth with subcutaneous injection. we aimed to clarify oral administration of the glycolipid fraction, suppressing colon ... | 2008 | 18594894 |
| dietary intake of carotenoid isomers in israel. | controversy exists regarding the possible protective role of carotenoids against cancer. evidence is mainly against all-e-beta-carotene, while there is no evidence against other carotenoids or against mixtures of beta-carotene stereoisomers. carotenoid isomers could account for the variability in study results but are rarely estimated, and reference to the degree of their consumption is lacking. the aim of our study was to create a comprehensive database of carotenoid isomers content in food ite ... | 2007 | 18622950 |
| expression of active spinach glycolate oxidase in aspergillus nidulans. | the biocatalytic production of glyoxylic acid from glycolic acid requires two enzymes: glycolate oxidase, which catalyzes the oxidation of glycolic acid by oxygen to produce glyoxylic acid and hydrogen peroxide, and catalase, which decomposes the byproduct hydrogen peroxide. as an alternative to isolation from the leaf peroxisomes of spinach, glycolate oxidase has now been cloned and expressed in transformants of aspergillus nidulans t580 at levels ranging from 1.7 to 36 iu/g dry wt. cells. the ... | 1996 | 18626962 |
| presence and potential for horizontal transfer of antibiotic resistance in oxidase-positive bacteria populating raw salad vegetables. | to assess whether domestically grown fresh salad vegetables constitute a possible reservoir of antibiotic resistance for canadian consumers, aerobic bacteria capable of forming colonies at 30 degrees c on nutrient-limited media were recovered from a single sampling of romaine lettuce, savoy spinach and alfalfa sprouts, then examined for their susceptibility to ten antibiotics and the carriage of potentially mobile r-plasmids and integrons. of the 140 isolates resistant to one or more antibiotic, ... | 2008 | 18632174 |
| [fructose-1,6-bisphosphatase--marker of damage to proximal renal tubules]. | pathological processes disturbing function of renal proximal tubules, increase activity of fructose-1,6-bisphosphatase (fbp-1) in urine. fbp-1 is cytosolic enzyme which occured mainly in cells of proximal renal tubules, and to small extent in cells of pars recta. after damage to the cell membrane fbp-1 is more rapidly excreted to the urine, than enzymes residing in other cell organelles. fructose-1,6-bisphosphatase was isolated from rabbit muscle in 1943 by gomori, and from spinach in 1958 by ra ... | 2008 | 18634268 |
| rapid assembly of photosystem i monolayers on gold electrodes. | photosystem i (psi) has drawn widespread interest for use in biomimetically inspired energy conversion devices upon extracting it from plants or cyanobacteria and assembling it at surfaces. here, we demonstrate that a critically dense monolayer of spinach-derived psi must be formed on an electrode surface to achieve optimal photocurrents, and we introduce a new method for preparing these dense psi monolayers that reduces the time required for assembly by approximately 80-fold in comparison to th ... | 2008 | 18636757 |
| analysis of eight organophosphorus pesticide residues in fresh vegetables retailed in agricultural product markets of nanjing, china. | a method to effectively remove pigments in fresh vegetables using activated carbon followed cleanup through solid phase extraction (spe) cartridge to further reduce matrix interference and contamination, was established to determine eight organophosphorous pesticides (opps) by gas chromatography (gc) with nitrogen-phosphorus detection (npd) in this study, and it has been successfully applied for the determination of eight opps in various fresh vegetables with the recoveries ranging from 61.8% to ... | 2008 | 18651087 |
| modulation of plasma all-trans retinoic acid concentrations by the consumption of carotenoid-rich vegetables. | a human intervention trial was conducted to determine the effects of consumption of carotenoid-rich vegetables on levels of retinol (rol) and the active vitamin a metabolite all-trans retinoic acid (atra). | 2008 | 18653315 |
| importance of a single disulfide bond for the psbo protein of photosystem ii: protein structure stability and soluble overexpression in escherichia coli. | psbo protein is an important constituent of the water-oxidizing complex, located on the lumenal side of photosystem ii. we report here the efficient expression of the spinach psbo in e. coli where the solubility depends entirely on the formation of the disulfide bond. the psbo protein purified from a pet32 system that includes thioredoxin fusion is properly folded and functionally active. urea unfolding experiments imply that the reduction of the single disulfide bridge decreases stability of th ... | 2008 | 18709441 |
| the oral bioavailability of nitrate from nitrate-rich vegetables in humans. | high dietary nitrate intake may pose a risk to human health. since up to 80-85% of dietary nitrate intake comes from vegetables, the aim of this study was to determine the absolute bioavailability of nitrate from three nitrate-rich vegetables. in an open, four-way cross-over, single dose study, 12 human subjects underwent the following treatments: (1) intravenous infusion of 500mg sodium nitrate, (2) oral administration of 300g cooked spinach, (3) oral administration of 300g raw lettuce, and (4) ... | 2008 | 18723086 |
| bacteriophages reduce experimental contamination of hard surfaces, tomato, spinach, broccoli, and ground beef by escherichia coli o157:h7. | a bacteriophage cocktail (designated ecp-100) containing three myoviridae phages lytic for escherichia coli o157:h7 was examined for its ability to reduce experimental contamination of hard surfaces (glass coverslips and gypsum boards), tomato, spinach, broccoli, and ground beef by three virulent strains of the bacterium. the hard surfaces and foods contaminated by a mixture of three e. coli o157:h7 strains were treated with ecp-100 (test samples) or sterile phosphate-buffered saline buffer (con ... | 2008 | 18723643 |
| survival and transfer of murine norovirus 1, a surrogate for human noroviruses, during the production process of deep-frozen onions and spinach. | the reduction of murine norovirus 1 (mnv-1) on onions and spinach by washing was investigated as was the risk of contamination during the washing procedure. to decontaminate wash water, the industrial sanitizer peracetic acid (paa) was added to the water, and the survival of mnv-1 was determined. in contrast to onions, spinach undergoes a heat treatment before freezing. therefore, the resistance of mnv-1 to blanching of spinach was examined. mnv-1 genomic copies were detected with a real-time re ... | 2008 | 18724752 |
| using yeast two-hybrid system to detect interactions of atp synthase subunits from spinacia oleracea. | subunit interactions among the chloroplast atp synthase subunits were studied using the yeast two-hybrid system. various pairwise combinations of genes encoding alpha, beta, gamma, delta and epsilon subunits of spinach atp synthase fused to the binding domain or activation domain of gal4 dna were introduced into yeast and then expression of a reporter gene encoding beta-galactosidase was detected. of all the combinations, that of gamma and epsilon subunit genes showed the highest level of report ... | 2000 | 18726369 |
| biochemical characterization of a mitochondrial-like organelle from blastocystis sp. subtype 7. | a mitochondrion-like organelle (mlo) was isolated from isotonic homogenates of blastocystis. the organelle sedimented at 5000 g for 10 min, and had an isopycnic density in sucrose of 1.2 g ml(-1). biochemical characterization enabled the demonstration of several key enzymes that allowed the construction of a metabolic pathway consisting of an incomplete krebs cycle linked to the oxygen-sensitive enzymes pyruvate : nadp(+) oxidoreductase (pno), acetate : succinate coa transferase (asct) and succi ... | 2008 | 18757809 |
| flippase activity in proteoliposomes reconstituted with spinacea oleracea endoplasmic reticulum membrane proteins: evidence of biogenic membrane flippase in plants. | phospholipid translocation (flip-flop) in biogenic (self-synthesizing) membranes such as the endoplasmic reticulum of eukaryotic cells (rat liver) and bacterial cytoplasmic membranes is a fundamental step in membrane biogenesis. it is known that flip-flop in these membranes occurs without a metabolic energy requirement, bidirectionally with no specificity for phospholipid headgroup. in this study, we demonstrate for the first time atp-independent flippase activity in endoplasmic reticulum membra ... | 2008 | 18767811 |
| isolation and spectral characterization of photosystem ii reaction center from synechocystis sp. pcc 6803. | we isolated highly-purified photochemically active photosystem (ps) ii reaction center (rc) complexes from the cyanobacterium synechocystis sp. pcc 6803 using a histidine-tag introduced to the 47 kda chlorophyll protein, and characterized their spectroscopic properties. purification was carried out in a one-step procedure after isolation of ps ii core complex. the rc complexes consist of five polypeptides, the same as in spinach. the pigment contents per two molecules of pheophytin a were 5.8 +/ ... | 2008 | 18780157 |
| 55mn-endor of the s2-state multiline signal of photosystem ii from thermosynechococcus elongatus. | pulse epr and 55mn-endor (electron nuclear double resonance) experiments at 34 ghz (q-band) were performed on the s2 state of the oec (oxygen-evolving complex) in psii (photosystem ii) from thermosynechococcus elongatus. the endor spectra are discussed with respect to earlier data obtained from x- (9 ghz) and q-band experiments on psii preparations from spinach with and without the addition of methanol. | 2008 | 18793178 |
| failure to induce oral tolerance in mice is predictive of dietary allergenic potency among foods with sensitizing capacity. | animal models are needed to assess novel proteins produced through biotechnology for potential dietary allergenicity. currently proposed rodent models evaluate sensitizing potential of food extracts or proteins following parenteral administration or oral administration with adjuvant. however, food allergy requires not only the potential to induce immunoglobulin (ig) e but also the capacity to avoid induction of oral tolerance (specific inhibition of ige production). here we describe a mouse mode ... | 2008 | 18806252 |
| spinach-associated escherichia coli o157:h7 outbreak, utah and new mexico, 2006. | in 2006, utah and new mexico health departments investigated a multistate cluster of escherichia coli o157:h7. a case-control study of 22 case-patients found that consuming bagged spinach was significantly associated with illness (p<0.01). the outbreak strain was isolated from 3 bags of 1 brand of spinach. nationally, 205 persons were ill with the outbreak strain. | 2008 | 18826833 |
| interaction of salmonella enterica with basil and other salad leaves. | contaminated salad leaves have emerged as important vehicles for the transmission of enteric pathogens to humans. a recent outbreak of salmonella enterica serovar senftenberg (s. senftenberg) in the united kingdom has been traced to the consumption of contaminated basil. using the outbreak strain of s. senftenberg, we found that it binds to basil, lettuce, rocket and spinach leaves showing a pattern of diffuse adhesion. flagella were seen linking s. senftenberg to the leaf epidermis, and the del ... | 2009 | 18830276 |
| arsenic uptake by two vegetables grown in two soils amended with as-bearing animal manures. | organoarsenicals are widely used as growth promoters in animal feed, resulting in unabsorbed arsenic (as) left in animal manures. a pot experiment was conducted to investigate the growth and as uptake of amaranth (amaranthus tricolor linn, a crop with an axial root system) and water spinach (ipomoea aquatica forsk, a crop with a fibrous root system) grown in a paddy soil (ps) and a lateritic red soil (lrs) amended with 2% and 4% (w/w) as-bearing chicken manure and pig manure, respectively. soils ... | 2009 | 18929443 |
| pi-interaction tuning of the active site properties of metalloproteins. | the influence of pi-interactions with a his ligand have been investigated in a family of copper-containing redox metalloproteins. the met16phe and met16trp pseudoazurin, and leu12phe spinach and leu14phe phormidium laminosum plastocyanin variants possess active-site pi-contacts between the introduced residue and his81 and his87/92 respectively. the striking overlap of the side chain of phe16 in the met16phe variant and that of met16 in wild type pseudoazurin identifies that this position provide ... | 2008 | 18939838 |
| characterization of a resistance locus (pfs-1) to the spinach downy mildew pathogen (peronospora farinosa f. sp. spinaciae) and development of a molecular marker linked to pfs-1. | downy mildew is a destructive disease of spinach worldwide. there have been 10 races described since 1824, six of which have been identified in the past 10 years. race identification is based on qualitative disease reactions on a set of diverse host differentials which include open-pollinated cultivars, contemporary hybrid cultivars, and older hybrid cultivars that are no longer produced. the development of a set of near-isogenic open-pollinated spinach lines (nils), having different resistance ... | 2008 | 18943207 |
| spinach curly top virus: a newly described curtovirus species from southwest texas with incongruent gene phylogenies. | abstract a curtovirus associated with a disease of spinach was isolated in southwest texas during 1996. disease symptoms included severe stunting and chlorosis, with younger leaves curled, distorted, and dwarfed. viral dna was purified and an infectious clone obtained. agroinoculation using a construct bearing full-length tandem repeats of the cloned viral genome resulted in systemic infection of species in six of seven plant families tested, indicating that the virus has a wide host range. symp ... | 2004 | 18943911 |
| use of a nitrate-nonutilizing mutant and selective media to examine population dynamics of fusarium oxysporum f. sp. spinaciae in soil. | abstract determining the population density of the spinach wilt pathogen fusarium oxysporum f. sp. spinaciae in soil with conventional fusarium-selective media is quite difficult because nonpathogenic strains of f. oxysporum also grow on those media and are indistinguishable from the pathogen. therefore, a nitrate-nonutilizing (nit) mutant of the pathogen and corresponding selective media were tested in an experimental approach to determine the population density of the pathogen. colony forming ... | 2003 | 18944103 |
| seed transmission of cucumber mosaic virus in spinach. | abstract spinach (spinacia oleracea) seed from a commercial breeding line suspected of harboring cucumber mosaic virus (cmv) was analyzed for seed transmission of the virus. initial seed grow-out tests and enzymelinked immunosorbent assay studies indicated that cmv was present in this seed lot at a level of nearly 15%. to verify these results and gain insight into the mechanism of seed transmission, four combinations of crosses between healthy and/or infected parent plants were conducted. none o ... | 1997 | 18945063 |
| utility of rodent models for evaluating protein allergenicity. | animal models are needed to assess novel proteins produced through biotechnology for potential dietary allergenicity. the exact characteristics that give certain foods allergenic potential are unclear, but must include both the potential to sensitize (induce ige) as well as the capacity to avoid induction of oral tolerance (specific inhibition of ige production). epa has developed two complementary mouse models; one which distinguishes allergenic from non-allergenic food extracts using oral sens ... | 2009 | 18957311 |
| optical mapping and 454 sequencing of escherichia coli o157 : h7 isolates linked to the us 2006 spinach-associated outbreak. | optical maps for five representative clinical, food-borne and bovine-derived isolates from the 2006 escherichia coli o157 : h7 outbreak linked to fresh spinach in the united states showed a common set of 14 distinct chromosomal markers that define the outbreak strain. partial 454 dna sequencing was used to characterize the optically mapped chromosomal markers. the markers included insertions, deletions, substitutions and a simple single nucleotide polymorphism creating a bamhi site. the shiga to ... | 2008 | 18957604 |
| irradiation in the production, processing and handling of food. final rule. | the food and drug administration (fda) is amending the food additive regulations to provide for the safe use of ionizing radiation for control of food-borne pathogens, and extension of shelf-life, in fresh iceberg lettuce and fresh spinach (hereinafter referred to in this document as "iceberg lettuce and spinach") at a dose up to 4.0 kilo gray (kgy). this action is in partial response to a petition filed by the national food processors association on behalf of the food irradiation coalition. | 2008 | 18958941 |
| [overexpression of spinacia oleracea betaine aldehyde dehydrogenase (sobadh) gene confers the salt and cold tolerant in gossypium hirsutum l]. | the open reading frame of spinacia oleracea betaine aldehyde dehydrogenase (sobadh) was retrieved from spinacia oleracea and inserted into the agrobacterium tumefaciens binary vector pbin438, which was driven by camv35s promoter, and produced the new binary vector pbsb. a. tumefaciens lba4404 carrying this plasmid was used in genetic transformation of plants. forty-five primary transgenic plants were detected by pcr and verified by the southern blotting from 65 regenerated plants, of which 27 tr ... | 2008 | 18998552 |
| affinity tags can reduce merohedral twinning of membrane protein crystals. | this work presents a comparison of the crystal packing of three eukaryotic membrane proteins: human aquaporin 1, human aquaporin 5 and a spinach plasma membrane aquaporin. all were purified from expression constructs both with and without affinity tags. with the exception of tagged aquaporin 1, all constructs yielded crystals. two significant effects of the affinity tags were observed: crystals containing a tag typically diffracted to lower resolution than those from constructs encoding the prot ... | 2008 | 19020358 |
| determination of arsenic levels in lake water, sediment, and foodstuff from selected area of sindh, pakistan: estimation of daily dietary intake. | the aim of present study was to develop a database of arsenic (as) in lake water, ground water, sediment, soil, vegetables, grain crops and fish to evaluate the potential human health risks posed by higher level of as, in south east part of sindh, pakistan during 2005-2007. the total concentration of as in various samples under study was determined by electrothermal atomic absorption spectrophotometry (etaas). the reliability and accuracy of technique was checked by different certified reference ... | 2009 | 19041679 |
| diverse and newly recognized effects associated with short interfering rna binding site modifications on the tomato bushy stunt virus p19 silencing suppressor. | the tomato bushy stunt virus-encoded p19 forms dimers that bind duplex short interfering rnas (sirnas) to suppress rna silencing. p19 is also involved in multiple host-specific activities, including the elicitation of symptoms, and in local and/or systemic spread. to study the correlation between those various roles and the sirna binding by p19, predicted sirna-interacting sites were modified. twenty-two mutants were generated and inoculated onto nicotiana benthamiana plants, to reveal that (i) ... | 2009 | 19052093 |
| development of food-based complementary feeding recommendations for 9- to 11-month-old peri-urban indonesian infants using linear programming. | effective population-specific, food-based complementary feeding recommendations (cfr) are required to combat micronutrient deficiencies. to facilitate their formulation, a modeling approach was recently developed. however, it has not yet been used in practice. this study therefore aimed to use this approach to develop cfr for 9- to 11-mo-old indonesian infants and to identify nutrients that will likely remain low in their diets. the cfr were developed using a 4-phase approach based on linear and ... | 2009 | 19056658 |
| [bioavailability of as, cu and zn in two soils as affected by application of chicken manure and pig manure]. | animal manures contain higher as, cu and zn since organoarsenicals, copper and zinc additives are widely used in modern intensive animal production. a pot experiment in water spinach was conducted to investigate as, cu and zn bioavailability in a paddy soil (ps) and a lateritic red soil (lrs) applied with 2% and 4% (mass fraction) chicken manure (cm) and pig manure (pm), respectively. soils without any fertilizer were included as the checks (ck). the results show that nearly all treatments with ... | 2008 | 19068649 |
| identifying efficacious approaches to chemoprevention with chlorophyllin, purified chlorophylls and freeze-dried spinach in a mouse model of transplacental carcinogenesis. | the carcinogenic potential of dibenzo[a,l]pyrene (dbp) has been well characterized in numerous animal models. we have previously documented that a single dose of 15 mg/kg dbp to pregnant mice late in gestation (gd 17) produces an aggressive t-cell lymphoma as well as lung and liver cancer in offspring. the current study examines the chemopreventative properties of chlorophyllin (chl) and chlorophyll (chl) in this transplacental carcinogenesis model. pregnant b6129sf1 females, bred to 129s1/svim ... | 2009 | 19073876 |
| steam cooking significantly improves in vitro bile acid binding of collard greens, kale, mustard greens, broccoli, green bell pepper, and cabbage. | bile acid binding capacity has been related to the cholesterol-lowering potential of foods and food fractions. lowered recirculation of bile acids results in utilization of cholesterol to synthesize bile acid and reduced fat absorption. secondary bile acids have been associated with increased risk of cancer. bile acid binding potential has been related to lowering the risk of heart disease and that of cancer. previously, we have reported bile acid binding by several uncooked vegetables. however, ... | 2008 | 19083431 |
| cellular transport of lutein is greater from uncooked rather than cooked spinach irrespective of whether it is fresh, frozen, or canned. | lutein, a carotenoid found in significant levels in spinach, has attracted a great deal of attention owing to its reported function as a shield against the photooxidative effects of blue light. therefore, the rationale of this study was to examine the effects of various processing and cooking methods on lutein bioavailability from spinach (spinacia oleracea) using an in vitro digestion procedure coupled with the use of a human intestinal caco-2 cell model. fresh, frozen, and canned spinach were ... | 2008 | 19083456 |
| dietary sources of aldose reductase inhibitors: prospects for alleviating diabetic complications. | activation of polyol pathway due to increased aldose reductase activity is one of the several mechanisms that have been implicated in the development of various secondary complications of diabetes. though numerous synthetic aldose reductase inhibitors have been tested, these have not been very successful clinically. therefore, a number of common plant/ natural products used in indian culinary have been evaluated for their aldose reductase inhibitory potential in the present study. the aqueous ex ... | 2008 | 19114390 |
| a statistical analysis to assess the maturity and stability of six composts. | despite the long-time application of organic waste derived composts to crops, there is still no universally accepted index to assess compost maturity and stability. the research presented in this article investigated the suitability of seven types of seeds for use in germination bioassays to assess the maturity and phytotoxicity of six composts. the composts used in the study were derived from cow manure, sea weeds, olive pulp, poultry manure and municipal solid waste. the seeds used in the germ ... | 2009 | 19117746 |
| effects of organic matter on acidic electrolysed water for reduction of foodborne pathogens on lettuce and spinach. | to evaluate the efficacy of acidic electrolysed water (ew) in the presence of organic matter (bovine serum) on the inoculated surfaces of lettuce and spinach. | 2008 | 19120630 |
| a comparative study of the extractability of arsenic species from silverbeet and amaranth vegetables. | there is still no reliable standard extraction method for the speciation of arsenic (as) in plant tissue, and hence there is great interest in developing one for plants that are used as human food. speciation and bioavailability are critical for accurate human health risk assessment, as as species vary in both their toxicity and bioavailability. recent incidences of as poisoning in many countries have led to significant research into the fate and dynamics of as in the soil and water environment, ... | 2009 | 19125339 |
| studies of interaction of homo-dimeric ferredoxin-nad(p)+ oxidoreductases of bacillus subtilis and rhodopseudomonas palustris, that are closely related to thioredoxin reductases in amino acid sequence, with ferredoxins and pyridine nucleotide coenzymes. | ferredoxin-nadp(+) oxidoreductases (fnrs) of bacillus subtilis (yumc) and rhodopseudomonas palustris cga009 (rpa3954) belong to a novel homo-dimeric type of fnr with high amino acid sequence homology to nadph-thioredoxin reductases. these fnrs were purified from expression constructs in escherichia coli cells, and their steady-state reactions with [2fe-2s] type ferredoxins (fds) from spinach and r. palustris, [4fe-4s] type fd from b. subtilis, nad(p)(+)/nad(p)h and ferricyanide were studied. fro ... | 2009 | 19162251 |
| replacement of chlorophyll with di-vinyl chlorophyll in the antenna and reaction center complexes of the cyanobacterium synechocystis sp. pcc 6803: characterization of spectral and photochemical properties. | chlorophyll (chl) a in a cyanobacterium synechocystis sp. pcc 6803 was replaced with di-vinyl (dv)-chl a by knock-out of the specific gene (slr1923), responsible for the reduction of a 8-vinyl group, and optical and photochemical properties of purified photosystem (ps) ii complexes (dv-ps ii) were investigated. we observed differences in the peak wavelengths of absorption and fluorescence spectra; however, replacement of chl a with dv-chl a had limited effects. on the contrary, photochemical rea ... | 2009 | 19168027 |
| disulphide proteomes and interactions with thioredoxin on the track towards understanding redox regulation in chloroplasts and cyanobacteria. | light-dependent disulphide/dithiol exchange catalysed by thioredoxin is a classical example of redox regulation of chloroplast enzymes. recent proteome studies have mapped thioredoxin target proteins in all chloroplast compartments ranging from the envelope to the thylakoid lumen. progress in the methodologies has made it possible to identify which cysteine residues interact with thioredoxin and to tackle membrane-bound thioredoxin targets. to date, more than hundred targets of thioredoxin and g ... | 2009 | 19185068 |
| crystallization and preliminary crystallographic characterization of the extrinsic psbp protein of photosystem ii from spinacia oleracea. | preliminary x-ray diffraction analysis of the extrinsic psbp protein of photosystem ii from spinach (spinacia oleracea) was performed using n-terminally his-tagged recombinant psbp protein overexpressed in escherichia coli. recombinant psbp protein (thrombin-digested recombinant his-tagged psbp) stored in bis-tris buffer ph 6.00 was crystallized using the sitting-drop vapour-diffusion technique with peg 550 mme as a precipitant and zinc sulfate as an additive. sds-page analysis of a dissolved cr ... | 2009 | 19193998 |
| osmoregulated periplasmic glucans are needed for competitive growth and biofilm formation by salmonella enterica serovar typhimurium in leafy-green vegetable wash waters and colonization in mice. | osmoregulated periplasmic glucans (opgs) are major periplasmic constituents of gram-negative bacteria. the role of opgs has been postulated in symbiotic as well as pathogenic host-microorganism interactions. here, we report the role of opgs from salmonella enterica serovar typhimurium during growth and biofilm formation in leafy-green vegetable wash water. the opggh mutant strain, which was defective in opg biosynthesis, initiated the growth at a slower rate in wash waters obtained from spinach, ... | 2009 | 19222578 |
| new insights into the catalytic cycle of plant nitrite reductase. electron transfer kinetics and charge storage. | nitrite reductase, which reduces nitrite to ammonium in a six-electron reaction, was characterized through kinetic analysis of an electron transfer cascade involving photoexcited photosystem i and ferredoxin. this cascade was studied at physiological ph by flash-absorption spectroscopy. two different forms of the enzyme were studied: one isolated from spinach leaf and one histidine-tagged recombinant form. when the enzyme is oxidized in the absence of nitrite, single-enzyme reduction leads mostl ... | 2009 | 19226104 |
| effect of electrolyzed water for reduction of foodborne pathogens on lettuce and spinach. | the ability of electrolyzed water (ew) to inactivate foodborne pathogens on the surfaces of lettuce and spinach was investigated. lettuce and spinach leaves were inoculated with a cocktail of 3 strains each of escherichia col o157:h7, salmnonella typhimurium, and listeria monocytogenes and treated with acidic electrolyzed water (ac-ew), alkaline electrolyzed water (ak-ew), alkaline electrolyzed water followed by acidic electrolyzed water (sequential treatment, ak-ew + ac-ew), deionized water fol ... | 2008 | 19241556 |
| coliforms and prevalence of escherichia coli and foodborne pathogens on minimally processed spinach in two packing plants. | minimally processed spinach has been recently associated with outbreaks of foodborne illnesses. this study investigated the effect of commercial minimal processing of spinach on the coliform and escherichia coli counts and the prevalence of e. coli o157:h7, salmonella, shigella spp., and listeria monocytogenes on two types of spinach before and after minimal processing. a total of 1,356 spinach samples (baby spinach, n = 574; savoy spinach, n = 782) were collected daily in two processing plants ... | 2008 | 19244890 |
| reduction of escherichia coli o157:h7 and salmonella on baby spinach, using electron beam radiation. | the effect of low-dose electron beam (e-beam) radiation on the reduction of escherichia coli o157:h7 and salmonella in spinach was studied. fresh baby spinach (spinacia oleracea) was inoculated with a bacterial cocktail containing multiple strains of rifampin-resistant e. coli o157:h7 and rifampin-resistant salmonella. inoculated samples were exposed to e-beam radiation from a linear accelerator and tested for counts of both e. coli o157:h7 and salmonella. irradiated spinach was also stored for ... | 2008 | 19244893 |
| escherichia coli o157:h7 stress and virulence gene expression on romaine lettuce using comparative real-time pcr. | foodborne outbreaks attributed to the contamination of fresh produce with escherichia coli o157:h7 are a growing concern. in particular, leafy-green vegetables, including lettuce and spinach, are susceptible to contamination by irrigation water, manure, and food processing and storage practices. the survival of e. coli o157:h7 and natural microflora on romaine lettuce stored at 4 degrees c and 15 degrees c over a 9-day period was evaluated by plate counts. a two-step reverse-transcription compar ... | 2009 | 19248811 |
| multistate outbreak of escherichia coli o157:h7 infection associated with consumption of packaged spinach, august-september 2006: the wisconsin investigation. | escherichia coli o157:h7 infection often causes hemorrhagic colitis and hemolytic uremic syndrome. | 2009 | 19265476 |
| biofunctionalized magnetic nanoparticle integrated mid-infrared pathogen sensor for food matrixes. | magnetic nanoparticles functionalized with anti-escherichia coli o157:h7 or anti-salmonella typhimurium antibodies that can specifically bind to their target organisms were used to isolate e. coli o157:h7 and s. typhimurium separately from a cocktail of bacteria and from food matrixes. the pathogens were then detected using label-free ir fingerprinting. the binding and detection protocol was first validated using a benchtop ft-ir spectrometer and then applied to a portable mid-ir spectrometer to ... | 2009 | 19281189 |
| thylakoids promote release of the satiety hormone cholecystokinin while reducing insulin in healthy humans. | the effects of a promising new appetite suppressor named "thylakoids" (membrane proteins derived from spinach leaves) were examined in a single meal in man. thylakoids inhibit the lipase/colipase hydrolysis of triacylglycerols in vitro and suppress food intake, decrease body-weight gain and raise the satiety hormone cholecystokinin (cck) in rats, but their effects in man remain unclear. the aim of this study was to investigate whether thylakoids, when added to a test meal, affect appetite regula ... | 2009 | 19308799 |
| [estimation of the daily intake of nitrate based on analysis of total diet samples]. | the concentrations of nitrates in total diet samples prepared at 11 places were determined according to the market basket method, and the daily intake of nitrates was estimated based on the analysis results. the mean estimated daily intake of nitrates was 200 mg/man/day (4.0 mg/kg/day) and exceeded the adi (3.7 mg/kg/day) set by the jecfa by 8%. the principal sources of the nitrates were colored vegetables (7th food group) and other vegetables, seaweeds and mushrooms (8th food group), and the in ... | 2009 | 19325223 |
| gene expression induced in escherichia coli o157:h7 upon exposure to model apple juice. | escherichia coli o157:h7 has caused serious outbreaks of food-borne illness via transmission in a variety of food vehicles, including unpasteurized apple juice, dried salami, and spinach. to understand how this pathogen responds to the multiple stresses of the food environment, we compared global transcription patterns before and after exposure to model apple juice. transcriptomes of mid-exponential- and stationary-phase cells were evaluated after 10 min in model apple juice (ph 3.5) using micro ... | 2009 | 19346340 |
| evaluation of treatments for elimination of foodborne pathogens on the surface of leaves and roots of lettuce (lactuca sativa l.). | several outbreaks of salmonella and escherichia coli o157:h7 infections have been associated with consumption of leafy greens. questions remain concerning the ability of these pathogens to become internalized within lettuce and spinach tissues. an effective validated surface disinfection method for lettuce is needed before factors affecting internalization of pathogens can be studied. the objective of this study was to develop a surface disinfection method for lettuce leaves and roots. iceberg l ... | 2009 | 19350966 |
| a microbiological survey of selected alberta-grown fresh produce from farmers' markets in alberta, canada. | previously there was no available information on the levels of indicator bacteria and the prevalence of pathogens in fresh produce grown in alberta, canada. baseline information on the occurrence and levels of escherichia coli and the prevalence of foodborne pathogens in selected produce items available to consumers from farmers' and public markets in two large urban centers and surrounding areas in alberta was obtained. a total of 10 large markets with between 1 and 12 produce vendors and 26 sm ... | 2009 | 19350990 |
| conformational changes in a plant ketol-acid reductoisomerase upon mg(2+) and nadph binding as revealed by two crystal structures. | ketol-acid reductoisomerase (kari; ec 1.1.1.86) is an enzyme in the branched-chain amino acid biosynthesis pathway where it catalyzes the conversion of 2-acetolactate into (2r)-2,3-dihydroxy-3-isovalerate or the conversion of 2-aceto-2-hydroxybutyrate into (2r,3r)-2,3-dihydroxy-3-methylvalerate. kari catalyzes two reactions-alkyl migration and reduction-and requires mg(2+) and nadph for activity. to date, the only reported structures for a plant kari are those of the spinach enzyme-mn(2+)-(phosp ... | 2009 | 19362563 |
| detection of live salmonella sp. cells in produce by a taqman-based quantitative reverse transcriptase real-time pcr targeting inva mrna. | salmonella enterica contamination in foods is a significant concern for public health. when dna detection methods are used for analysis of foods, one of the major concerns is false-positive results from the detection of dead cells. to circumvent this crucial issue, a taqman quantitative real-time rt-pcr (qrt-pcr) assay with an rna internal control was developed. inva rna standards were used to determine the detection limit of this assay as well as to determine inva mrna levels in mid-exponential ... | 2009 | 19376910 |
| epr signals of oxidized plastocyanin in intact algae. | (1) an electron paramagnetic resonance (epr) signal was observed at g = 2.05 in the low temperature spectra of intact cells of green, red and blue-green algae and of spinach chloroplasts. the g-value and the shape of the signal were similar to that of purified, soluble plastocyanin. (2) the amount of the copper protein, determined from the epr signal height, was estimated to be nearly the same in all the studied organisms on the basis of the concentration of chlorophyll. furthermore, it was foun ... | 1974 | 19400039 |
| identification and structural basis of the reaction catalyzed by cyp121, an essential cytochrome p450 in mycobacterium tuberculosis. | the gene encoding the cytochrome p450 cyp121 is essential for mycobacterium tuberculosis. however, the cyp121 catalytic activity remains unknown. here, we show that the cyclodipeptide cyclo(l-tyr-l-tyr) (cyy) binds to cyp121, and is efficiently converted into a single major product in a cyp121 activity assay containing spinach ferredoxin and ferredoxin reductase. nmr spectroscopy analysis of the reaction product shows that cyp121 catalyzes the formation of an intramolecular c-c bond between 2 ty ... | 2009 | 19416919 |
| [experimental tolerance to boron of the plant species nicotiana glauca, jacaranda mimosifolia, tecoma stans, medicago sativa y spinacea oleracea in argentina]. | the activity of boron industries is a punctual and diffuse source of air, soil and water pollution. therefore, it is a priority to study possible ways of reducing this impact. a relatively new technology for reducing soil pollution is phytoremediation, which uses plants and associate microorganisms. the first step in phytoremediation is to detect tolerant plant species, which is the objective of this work. a laboratory experiment to assess the germination, survival and growth of different specie ... | 2008 | 19419027 |
| efficacy of chlorine and acidified sodium chlorite on microbial population and quality changes of spinach leaves. | efficacy of washing with distilled water, chlorine solution, and acidified sodium chlorite (asc) solution on populations of microorganisms on spinach leaves was evaluated. washing with chlorine (100 mg/l) and asc (sodium chlorite, 15 mg/l; citric acid, 200 mg/l) resulted in significant population reduction (1.1-1.9 log cfu/g) of aerobic microflora, coliform, and escherichia coli o157:h7 (p < 0.05). there was no remarkable difference in decontamination efficacy between chlorine and asc solution. ... | 2009 | 19422304 |
| structure of the c14 rotor ring of the proton translocating chloroplast atp synthase. | the structure of the membrane integral rotor ring of the proton translocating f(1)f(0) atp synthase from spinach chloroplasts was determined to 3.8 a resolution by x-ray crystallography. the rotor ring consists of 14 identical protomers that are symmetrically arranged around a central pore. comparisons with the c(11) rotor ring of the sodium translocating atpase from ilyobacter tartaricus show that the conserved carboxylates involved in proton or sodium transport, respectively, are 10.6-10.8 a a ... | 2009 | 19423706 |
| distribution and major sources of flavonoid intakes in the middle-aged japanese women. | we estimated the intake of individual flavonoids in a cross sectional study and clarified the major sources contributing to the flavonoid levels in the middle-aged japanese women by a 24-h weighed dietary record study. the subjects included in the study were 516 free-living women. each subject completed a 24-h weighed dietary record and received a health check-up. we used the functional food factor database for estimating the intake of 5 major flavonoid intakes, i.e. flavan-3-ols, isoflavones, f ... | 2009 | 19430611 |
| effect of integral membrane proteins on the lateral mobility of plastoquinone in phosphatidylcholine proteoliposomes. | pyrene fluorescence quenching by plastoquinone was used to estimate the rate of plastoquinone lateral diffusion in soybean phosphatidylcholine proteoliposomes containing the following integral membrane proteins: gramicidin d, spinach cytochrome bf complex, spinach cytochrome f, reaction centers from rhodobacter sphaeroides, beef heart mitochondrial cytochrome bc(1), and beef heart mitochondrial cytochrome oxidase. the measured plastoquinone lateral diffusion coefficient varied between 1 and 3 . ... | 1990 | 19431774 |
| is the cry1ab protein from bacillus thuringiensis (bt) taken up by plants from soils previously planted with bt corn and by carrot from hydroponic culture? | the uptake of the insecticidal cry1ab protein from bacillus thuringiensis (bt) by various crops from soils on which bt corn had previously grown was determined. in 2005, the cry1ab protein was detected by western blot in tissues (leaves plus stems) of basil, carrot, kale, lettuce, okra, parsnip, radish, snap bean, and soybean but not in tissues of beet and spinach and was estimated by enzyme-linked immunosorbent assay (elisa) to be 0.05 +/- 0.003 ng g(-1) of fresh plant tissue in basil, 0.02 +/- ... | 2009 | 19444360 |
| production of biofilm and quorum sensing by escherichia coli o157:h7 and its transfer from contact surfaces to meat, poultry, ready-to-eat deli, and produce products. | multistate outbreaks of escherichia coli o157:h7 infections through consumption of contaminated foods including produce products have brought a great safety concern. the objectives of this study were to determine the effect of biofilm and quorum sensing production on the attachment of e. coli o157:h7 on food contact surfaces and to evaluate the transfer of the pathogen from the food contact to various food products. e. coli o157:h7 produced maximum levels of ai-2 signals in 12 h of incubation in ... | 2009 | 19465248 |
| evaluating the effect of environmental factors on pathogen regrowth in compost extract. | pathogenic microorganisms may survive the composting process in low numbers and subsequently regrow to high levels under favorable conditions. the objective of this study was to investigate the regrowth potential of salmonella spp., escherichia coli o157:h7, and listeria monocytogenes in dairy-based composts under different environmental conditions. water extract of commercially available dairy compost was used as a model system. cocktails of five rifampin-resistant strains of each pathogen prev ... | 2009 | 19468701 |
| the effect of pre-treatment and sonication of centrifugal ultrafiltration devices on virus recovery. | enteric viruses such as norovirus (nv) and hepatitis a (hav) are responsible for a large proportion of food and water-borne illnesses. most human pathogenic enteric viruses cannot be cultured so they must be detected by molecular techniques. male specific (f(+)) rna coliphages, a potential surrogate for human enteric viruses, can be detected by culture and molecular assays. numbers of viruses and f-rna coliphages in contaminated food or water may be too low for direct detection. ultrafiltration ... | 2009 | 19555721 |
| in silico genomic analyses reveal three distinct lineages of escherichia coli o157:h7, one of which is associated with hyper-virulence. | many approaches have been used to study the evolution, population structure and genetic diversity of escherichia coli o157:h7; however, observations made with different genotyping systems are not easily relatable to each other. three genetic lineages of e. coli o157:h7 designated i, ii and i/ii have been identified using octamer-based genome scanning and microarray comparative genomic hybridization (mcgh). each lineage contains significant phenotypic differences, with lineage i strains being the ... | 2009 | 19563677 |
| analysis of the genome of the escherichia coli o157:h7 2006 spinach-associated outbreak isolate indicates candidate genes that may enhance virulence. | in addition to causing diarrhea, escherichia coli o157:h7 infection can lead to hemolytic-uremic syndrome (hus), a severe disease characterized by hemolysis and renal failure. differences in hus frequency among e. coli o157:h7 outbreaks have been noted, but our understanding of bacterial factors that promote hus is incomplete. in 2006, in an outbreak of e. coli o157:h7 caused by consumption of contaminated spinach, there was a notably high frequency of hus. we sequenced the genome of the strain ... | 2009 | 19564389 |
| fluorescence measurement by a streak camera in a single-photon-counting mode. | we describe here a recently developed fluorescence measurement system that uses a streak camera to detect fluorescence decay in a single photon-counting mode. this system allows for easy measurements of various samples and provides 2d images of fluorescence in the wavelength and time domains. the great advantage of the system is that the data can be handled with ease; furthermore, the data are amenable to detailed analysis. we describe the picosecond kinetics of fluorescence in spinach photosyst ... | 2009 | 19568951 |
| the endogenous level of ga(1) is upregulated by high temperature during stem elongation in lettuce through lsga3ox1 expression. | bolting of lettuce is promoted by high temperatures. gibberellins (gas) play an important role in the bolting of several plant species, and it has been reported that exogenous gas induce bolting and early flowering in lettuce. to clarify the role of gas in this process, we examined the expression of genes involved in ga metabolism (lsga20ox-1 and -2, lsga3ox-1 and -2, and lsga2ox-1 and -2) and endogenous gas in lettuce stems. quantitative reverse-transcription pcr indicated that the expression o ... | 2009 | 19576660 |
| iron bioavailability of rats fed liver, lentil, spinach and their mixtures. | to study the effects of dietary iron source (basal diet-feso4 x 7h2o, liver, lentil, spinach, liver + lentil, liver+spinach and lentil+spinach) on iron bioavailability, fifty-six albino sprague dawley derived male 21 days old rats were fed on iron-deficient diet (7.8 mg fe kg(-1) diet) and the mentioned seven iron containing diets (40 mg fe kg(-1) diet) for 10 days. rats fed liver diet showed higher iron apparent absorption (52.1%), hemoglobin (hb) gain (0.94 g/100 ml), hb-iron gain (1.2 mg), hb ... | 2009 | 19579971 |
| recent advances in the microbial safety of fresh fruits and vegetables. | foodborne illness outbreaks linked to fresh produce are becoming more frequent and widespread. high impact outbreaks, such as that associated with spinach contaminated with escherichia coli o157:h7, resulted in almost 200 cases of foodborne illness across north america and >$300 m market losses. over the last decade there has been intensive research into gaining an understanding on the interactions of human pathogens with plants and how microbiological safety of fresh produce can be improved. th ... | 2009 | 19595387 |
| prevalence of salmonella in vegetables from mexico. | the present study is an overview of the role of vegetables as a transmission vehicle of salmonella in mexico. one hundred samples of each of 17 different vegetables were analyzed during a period of 18 months. salmonella was isolated from 98 samples. salmonella enterica serovar typhimurium was isolated from the highest percentage of samples with typeable salmonella isolates (23.9%), followed by s. enterica subsp. arizonae and salmonella choleraesuis each from 16.9%, salmonella gallinarum from 11. ... | 2009 | 19610340 |
| government as biosecurity communicator: the 2006 spinach advisory. | in 2006, after the united states food and drug administration (fda) traced escherichia coli o157:h7 cases to spinach, the fda went beyond communicating with consumers and enlisted the cooperation of the food industry to prevent further spinach consumption. understanding the factors that increased or frustrated industry participation provides lessons for communicating about accidental contamination and intentional attacks on the american food supply. this qualitative research about fda's risk com ... | 2009 | 19634999 |
| identification and characterization of a bacterial cytochrome p450 for the metabolism of diclofenac. | the bacterium actinoplanes sp. atcc 53771 is known to perform drug metabolism of several xenobiotics similarly to humans. we identified a cytochrome p450 enzyme from this strain, cyp107e4, and expressed it in escherichia coli using the pet101 vector. the purified enzyme showed the characteristic reduced-co difference spectra with a peak at 450 nm, indicating the protein is produced in the active form with proper heme incorporation. the cyp107e4 enzyme was found to bind the drug diclofenac. using ... | 2010 | 19636551 |
| determination of lead and cadmium concentration limits in agricultural soil and municipal solid waste compost through an approach of zero tolerance to food contamination. | cadmium and lead are important environmental pollutants with high toxicity to animals and human. soils, though have considerable metal immobilizing capability, can contaminate food chain via plants grown upon them when their built-up occurs to a large extent. present experiment was carried out with the objective of quantifying the limits of pb and cd loading in soil for the purpose of preventing food chain contamination beyond background concentration levels. two separate sets of pot experiment ... | 2010 | 19662502 |
| transcriptomic response of escherichia coli o157:h7 to oxidative stress. | chlorinated water is commonly used in industrial operations to wash and sanitize fresh-cut, minimally processed produce. here we compared 42 human outbreak strains that represented nine distinct escherichia coli o157:h7 genetic lineages (or clades) for their relative resistance to chlorine treatment. a quantitative measurement of resistance was made by comparing the extension of the lag phase during growth of each strain under exposure to sublethal concentrations of sodium hypochlorite in luria- ... | 2009 | 19666735 |
| a multifactorial risk prioritization framework for foodborne pathogens. | we develop a prioritization framework for foodborne risks that considers public health impact as well as three other factors (market impact, consumer risk acceptance and perception, and social sensitivity). canadian case studies are presented for six pathogen-food combinations: campylobacter spp. in chicken; salmonella spp. in chicken and spinach; escherichia coli o157 in spinach and beef; and listeria monocytogenes in ready-to-eat meats. public health impact is measured by disability-adjusted l ... | 2010 | 19671103 |
| light absorption by isolated chloroplasts and leaves: effects of scattering and 'packing'. | light absorption was quantified in the following systems: isolated chloroplasts and leaves of spinach (spinacea oleracea l.), a mutant of geranium (pelargonium zonale l.) widely differing in pigment content, and coleus (coleus blumei benth.) at different stages of leaf ontogenesis. for these species and pea (pisum sativum l.), scattering-compensated absorption spectra of chloroplast suspensions are presented. comparison of leaf and chloroplast spectra showed considerable changes in the extent of ... | 2009 | 19672688 |
| a novel approach to enhance food safety: industry-academia-government partnership for applied research. | an independent collaborative approach was developed for stimulating research on high-priority food safety issues. the fresh express produce safety research initiative was launched in 2007 with $2 million in unrestricted funds from industry and independent direction and oversight from a scientific advisory panel consisting of nationally recognized food safety experts from academia and government agencies. the program had two main objectives: (i) to fund rigorous, innovative, and multidisciplinary ... | 2009 | 19681279 |
| a novel approach to investigate the uptake and internalization of escherichia coli o157:h7 in spinach cultivated in soil and hydroponic medium. | internalization of escherichia coli o157:h7 into spinach plants through root uptake is a potential route of contamination. a tn7-based plasmid vector was used to insert a green fluorescent protein gene into the atttn7 site in the e. coli chromosome. three green fluorescent protein-labeled e. coli inocula were used: produce outbreak o157:h7 strains rm4407 and rm5279 (inoculum 1), ground beef outbreak o157:h7 strain 86-24h11 (inoculum 2), and commensal strain hs (inoculum 3). these strains were cu ... | 2009 | 19681280 |
| effect of route of introduction and host cultivar on the colonization, internalization, and movement of the human pathogen escherichia coli o157:h7 in spinach. | human pathogens can contaminate leafy produce in the field by various routes. we hypothesized that interactions between escherichia coli o157:h7 and spinach are influenced by the route of introduction and the leaf microenvironment. e. coli o157:h7 labeled with green fluorescent protein was dropped onto spinach leaf surfaces, simulating bacteria-laden raindrops or sprinkler irrigation, and survived on the phylloplane for at least 14 days, with increasing titers and areas of colonization over time ... | 2009 | 19681281 |
| interaction of escherichia coli o157:h7 with leafy green produce. | enterohemorrhagic escherichia coli (ehec) is a foodborne pathogen responsible for human diarrheal disease. ehec lives in the intestinal tract of cattle and other farm and wild animals, which may be the source of environmental contamination particularly of agricultural fields. human infections are associated with consumption of tainted animal products and fresh produce. how the bacteria interact with the plant phyllosphere and withstand industrial decontamination remain to be elucidated. the goal ... | 2009 | 19681282 |
| inactivation of escherichia coli o157:h7 and natural microbiota on spinach leaves using gaseous ozone during vacuum cooling and simulated transportation. | the aim of this study was to integrate an ozone-based sanitization step into existing processing practices for fresh produce and to evaluate the efficacy of this step against escherichia coli o157:h7. baby spinach inoculated with e. coli o157:h7 (approximately 10(7) cfu/g) was treated in a pilot-scale system with combinations of vacuum cooling and sanitizing levels of ozone gas (sanvac). the contribution of process variables (ozone concentration, pressure, and treatment time) to lethality was in ... | 2009 | 19681283 |
| association of escherichia coli o157:h7 with filth flies (muscidae and calliphoridae) captured in leafy greens fields and experimental transmission of e. coli o157:h7 to spinach leaves by house flies (diptera: muscidae). | the recent outbreak of escherichia coli o157:h7 infection associated with contaminated spinach led to an investigation of the role of insects, which frequent fields of leafy greens and neighboring rangeland habitats, in produce contamination. four leafy greens fields adjacent to cattle-occupied rangeland habitats were sampled using sweep nets and sticky traps. agromyzid flies, anthomyiid flies, and leafhoppers were caught consistently in both rangeland and leafy greens production fields at all s ... | 2009 | 19681284 |
| use of the systems approach to determine the fate of escherichia coli o157:h7 on fresh lettuce and spinach. | lettuce and spinach inoculated with escherichia coli o157:h7 were processed and handled in ways that might occur in commercial situations, including variations in holding times before and after product cooling, transportation conditions and temperatures, wash treatments, and product storage temperatures and times. populations of background microflora and e. coli o157:h7 were enumerated after each step in the system. data analysis was done to predict response variables with a combination of indep ... | 2009 | 19681286 |
| microbial antagonists of escherichia coli o157:h7 on fresh-cut lettuce and spinach. | fresh-cut lettuce and spinach can become contaminated with pathogens at numerous points from the field to the retail market. natural microflora present on fresh produce may help reduce the pathogen load. the objective of this study was to isolate natural microflora from fresh-cut iceberg lettuce and baby spinach and to determine whether these bacteria were antagonistic toward escherichia coli o157:h7. samples were collected under conditions that mimicked actual practices between production and r ... | 2009 | 19681287 |
| factors impacting the regrowth of escherichia coli o157:h7 in dairy manure compost. | the environmental variables affecting escherichia coli o157:h7 regrowth in dairy manure compost were investigated. factors evaluated were moisture content, strain variation, growth medium of inoculum, level of background microflora and inoculum, different days of composting, and acclimation at room temperature. a mathematical model was applied to describe e. coli o157 regrowth potential in compost. repopulation occurred in autoclaved compost with a moisture content as low as 20% (water activity ... | 2009 | 19681288 |
| mineral contents of organically and conventionally grown spinach (spinacea oleracea l.) during two successive seasons. | spinach (spinacea oleracea l.) plants were grown organically and conventionally during two successive seasons (late autumn and early winter) in order to examine the nutrient content of the plants. in a series of 17 organic applications including chicken manure (cm), farmyard manure (fm), blood meal (bm), and one mineral fertilizer treatment and one control, collectively 19 treatments, were used at each season. the optimum doses to be recommended should be divided into groups depending on the min ... | 2009 | 19685878 |
| dimerization and endocytosis of the sucrose transporter stsut1 in mature sieve elements. | the sucrose transporter stsut1 from solanum tuberosum was shown to be regulated post-translationally by redox reagents. its activity is increased at least 10-fold in the presence of oxidizing agents if expressed in yeast. oxidation has also an effect on plasma membrane targeting and dimerization of the protein. in response to oxidizing agents, stsut1 is targeted to lipid raft-like microdomains and sut1 protein is detectable in the detergent resistant membrane fraction of plant plasma membranes. ... | 2008 | 19704459 |