| overexpression of spinach non-symbiotic hemoglobin in arabidopsis resulted in decreased no content and lowered nitrate and other abiotic stresses tolerance. | a class 1 non-symbiotic hemoglobin family gene, sohb, was isolated from spinach. qrt-pcr showed that sohb was induced by excess nitrate, polyethylene glycol, nacl, h2o2, and salicylic acid. besides, sohb was strongly induced by application of nitric oxide (no) donor, while was suppressed by no scavenger, nitrate reductase inhibitor, and nitric oxide synthase inhibitor. overexpression of sohb in arabidopsis resulted in decreased no level and sensitivity to nitrate stress, as shown by reduced root ... | 2016 | 27211528 |
| cofactor specificity motifs and the induced fit mechanism in class i ketol-acid reductoisomerases. | although most sequenced members of the industrially important ketol-acid reductoisomerase (kari) family are class i enzymes, structural studies to date have focused primarily on the class ii karis, which arose through domain duplication. in the present study, we present five new crystal structures of class i karis. these include the first structure of a kari with a six-residue β2αb (cofactor specificity determining) loop and an nadph phosphate-binding geometry distinct from that of the seven- an ... | 2015 | 25849365 |
| molecular cloning of ga 2-oxidase3 from spinach and its ectopic expression in nicotiana sylvestris. | previous work has shown that 13-hydroxylated gibberellins (gas) are predominant in the long-day (ld) plant spinach (spinacia oleracea; ga53, ga44, ga19, ga20, ga1, ga8, and ga29). also present in spinach are 2-hydroxylated c20-gas: ga97, ga98, ga99, and ga110. levels of the most abundant ga, ga97, decreased when plants were transferred from short photoperiods (sd) to ld. when [14c]ga53 was fed to spinach plants, more ga53 was converted to ga97 in sd than in ld, and more radioactive ga20 was form ... | 2005 | 15821147 |
| development of a gene silencing dna vector derived from a broad host range geminivirus. | gene silencing is proving to be a powerful tool for genetic, developmental, and physiological analyses. the use of viral induced gene silencing (vigs) offers advantages to transgenic approaches as it can be potentially applied to non-model systems for which transgenic techniques are not readily available. however, many vigs vectors are derived from gemini viruses that have limited host ranges. we present a new, unipartite vector that is derived from a curtovirus that has a broad host range and w ... | 2009 | 19573239 |
| ectopic expression of mir156 represses nodulation and causes morphological and developmental changes in lotus japonicus. | the effects of microrna156 overexpression on general plant architecture, branching, flowering time and nodulation were investigated in the model legume, lotus japonicus. we cloned an mir156 homolog, ljmir156a, from l. japonicus, and investigated its squamosa promoter binding protein like (spl) genes and its biological function at enhancing vegetative biomass yield, extending flowering time, and its impact on nodulation. thirteen potential targets for ljmir156 were identified in vitro and their e ... | 2014 | 25293935 |
| recombinant nucleases cel i from celery and sp i from spinach for mutation detection. | the detection of unknown mutations is important in research and medicine. for this purpose, a mismatch-specific endonuclease cel i from celery has been established as a useful tool in high throughput projects. previously, cel i-like activities were described only in a variety of plants and could not be expressed in an active form in bacteria. | 2007 | 17543120 |
| a comparison of the retention of pathogenic escherichia coli o157 by sprouts, leaves and fruits. | the retention (binding to or association with the plant) of escherichia coli by cut leaves and fruits after vigorous water washing was compared with that by sprouts. retention by fruits and leaves was similar but differed from retention by sprouts in rate, effect of wounding and requirement for poly-β,1-6-n-acetyl-d-glucosamine. escherichia coli was retained by cut ends of lettuce leaves within 5 min while more than 1 h was required for retention by the intact epidermis of leaves and fruits, and ... | 2014 | 25351040 |
| discovery and characterization of the first archaeal dihydromethanopterin reductase, an iron-sulfur flavoprotein from methanosarcina mazei. | the microbial production of methane by methanogenic archaea is dependent on the synthesis of the pterin-containing cofactor tetrahydromethanopterin (h4mpt). the enzyme catalyzing the last step of h4mpt biosynthesis (dihydromethanopterin reductase) has not previously been identified in methane-producing microorganisms. previous complementation studies with the methylotrophic bacterium methylobacterium extorquens have indicated that an uncharacterized archaeal-flavoprotein-like flavoprotein (afpa) ... | 2014 | 23995635 |
| biosynthesis of levan, a bacterial extracellular polysaccharide, in the yeast saccharomyces cerevisiae. | levans are fructose polymers synthesized by a broad range of micro-organisms and a limited number of plant species as non-structural storage carbohydrates. in microbes, these polymers contribute to the formation of the extracellular polysaccharide (eps) matrix and play a role in microbial biofilm formation. levans belong to a larger group of commercially important polymers, referred to as fructans, which are used as a source of prebiotic fibre. for levan, specifically, this market remains untapp ... | 2013 | 24147008 |
| laser optical sensor, a label-free on-plate salmonella enterica colony detection tool. | we investigated the application capabilities of a laser optical sensor, bardot (bacterial rapid detection using optical scatter technology) to generate differentiating scatter patterns for the 20 most frequently reported serovars of salmonella enterica. initially, the study tested the classification ability of bardot by using six salmonella serovars grown on brain heart infusion, brilliant green, xylose lysine deoxycholate, and xylose lysine tergitol 4 (xlt4) agar plates. highly accurate discrim ... | 2014 | 24496794 |
| determination of nabam fungicide in crops by liquid chromatography with postcolumn reaction detection. | the ethylenebisdithiocarbamate (ebdc) fungicide, nabam, was determined in several crop matrixes using liquid chromatography with postcolumn reaction detection. after separation by micellar liquid chromatography, nabam (ebdc sodium salt) was acid hydrolyzed to ethylenediamine and fluorigenically labeled with o-phthalaldehyde-mercaptoethanol (opa-merc). standard curves were linear from the detection limit of ca 1 ng to 1000 ng. nabam was recovered in high yield (89 plus or minus 7.7%) over a range ... | 1998 | 1904852 |
| variable composition of cytochrome b6-f particles. | cytochrome b6-f particles were prepared from chloroplasts of spinach and the heterokont alga bumilleriopsis filiformis using digitonin in comparison with non-ionic detergents. the cytochrome b6-f particles are solubilized in different amounts according to chemical structure and hlb value of the detergent (see griffin, j. soc. cosmet. chem. 1, 311 [1949]). also the ratio of the two cytochromes in the isolated particle depends on the detergent used. in case of spinach, it varies from cyt b6:f=1.5: ... | 2002 | 136131 |
| trapping at low temperature of oriented chloroplasts: application to the study of antenna pigments and of the trap of photosystem-1. | a technique is described for the preparation of oriented samples from spinach chloroplasts whose linear dichroism is then studied by (flash) absorption spectroscopy. the chloroplasts are suspended in a glycerol-containing medium, oriented in a magnetic field, and slowly cooled in the magnet until the medium is rigid enough to avoid disorientation effects. the absorption spectra in polarized light have been measured at -50 degrees and -170 degrees c. they allow the orientation of chlorophyll b to ... | 1990 | 1003967 |
| application of metagenomic sequencing to food safety: detection of shiga toxin-producing escherichia coli on fresh bagged spinach. | culture-independent diagnostics reduce the reliance on traditional (and slower) culture-based methodologies. here we capitalize on advances in next-generation sequencing (ngs) to apply this approach to food pathogen detection utilizing ngs as an analytical tool. in this study, spiking spinach with shiga toxin-producing escherichia coli (stec) following an established fda culture-based protocol was used in conjunction with shotgun metagenomic sequencing to determine the limits of detection, sensi ... | 2015 | 26386062 |
| strain-level discrimination of shiga toxin-producing escherichia coli in spinach using metagenomic sequencing. | consumption of fresh bagged spinach contaminated with shiga toxin-producing escherichia coli (stec) has led to severe illness and death; however current culture-based methods to detect foodborne stec are time consuming. since not all stec strains are considered pathogenic to humans, it is crucial to incorporate virulence characterization of stec in the detection method. in this study, we assess the comprehensiveness of utilizing a shotgun metagenomics approach for detection and strain-level iden ... | 2016 | 27930729 |
| genes ycfr, sira and yigg contribute to the surface attachment of salmonella enterica typhimurium and saintpaul to fresh produce. | salmonella enterica is a frequent contaminant of minimally-processed fresh produce linked to major foodborne disease outbreaks. the molecular mechanisms underlying the association of this enteric pathogen with fresh produce remain largely unexplored. in our recent study, we showed that the expression of a putative stress regulatory gene, ycfr, was significantly induced in s. enterica upon exposure to chlorine treatment, a common industrial practice for washing and decontaminating fresh produce d ... | 2013 | 23451197 |
| comparison of strand-specific transcriptomes of enterohemorrhagic escherichia coli o157:h7 edl933 (ehec) under eleven different environmental conditions including radish sprouts and cattle feces. | multiple infection sources for enterohemorrhagic escherichia coli o157:h7 (ehec) are known, including animal products, fruit and vegetables. the ecology of this pathogen outside its human host is largely unknown and one third of its annotated genes are still hypothetical. to identify genetic determinants expressed under a variety of environmental factors, we applied strand-specific rna-sequencing, comparing the solid and illumina systems. | 2014 | 24885796 |
| co-localization of glyceraldehyde-3-phosphate dehydrogenase with ferredoxin-nadp reductase in pea leaf chloroplasts. | in immunogold double-labeling of pea leaf thin sections with antibodies raised against ferredoxin-nadp reductase (ec 1.18.1.2, fnr) and antibodies directed against the a or b subunits of the nadp-linked glyceraldehyde-3-p dehydrogenase (gapd) (ec 1.2.1.13), many small and large gold particles were found together over the chloroplasts. nearest neighbor analysis of the distribution of the gold particles indicates that fnr and the nadp-linked gapd are co-localized, in situ. this suggests that fnr m ... | 2007 | 17945509 |
| metazoan trna introns generate stable circular rnas in vivo. | we report the discovery of a class of abundant circular noncoding rnas that are produced during metazoan trna splicing. these transcripts, termed trna intronic circular (tric)rnas, are conserved features of animal transcriptomes. biogenesis of tricrnas requires anciently conserved trna sequence motifs and processing enzymes, and their expression is regulated in an age-dependent and tissue-specific manner. furthermore, we exploited this biogenesis pathway to develop an in vivo expression system f ... | 2015 | 26194134 |
| cross-reactivity between aeroallergens and food allergens. | in patients with respiratory allergy, cross-reactivity between aeroallergens and foods may induce food allergy, symptoms ranging from oral allergy syndrome to severe anaphylaxis. clinical entities due to ige sensitization to cross-reactive aeroallergen and food allergen components are described for many sources of plant origin (pollen-food syndromes and associations, such as birch-apple, cypress-peach and celery-mugwort-spice syndromes, and mugwort-peach, mugwort-chamomile, mugwort-mustard, ragw ... | 2015 | 26140270 |
| selection and application of endophytic bacterium achromobacter xylosoxidans strain f3b for improving phytoremediation of phenolic pollutants. | while phytoremediation has been considered as an in situ bioprocess to remediate environmental contaminants, the application of functional endophytic bacteria within plants remains a potential strategy that could enhance the plants' efficiency in phytoremediation. in this study, 219 endophytes were isolated from plants that are predominantly located in a constructed wetland, including reed (phragmites australis) and water spinach (ipomoea aquatica). twenty-five strains of the isolated endophytes ... | 2012 | 22497718 |
| effect of metalloporphyrins on red autofluorescence from oral bacteria. | the aim of this study was to assess the red autofluorescence from bacterial species related to dental caries and periodontitis in the presence of different nutrients in the growth medium. bacteria were grown anaerobically on tryptic soy agar (tsa) supplemented with nutrients, including magnesium-porphyrins from spinach and iron-porphyrins from heme. the autofluorescence was then assessed at 405 nm excitation. on the tsa without additives, no autofluorescence was observed from any of the species ... | 2013 | 23659237 |
| occurrence and genetic diversity of arcobacter spp. in a spinach-processing plant and evaluation of two arcobacter-specific quantitative pcr assays. | some species of the genus arcobacter are considered to be emerging food pathogens. with respect to recent vegetable-borne outbreaks, the aim of this work was to investigate the occurrence and diversity of arcobacter within the production chain of a spinach-processing plant by a combination of cultivation and molecular methods. samples including spinach, water, and surface biofilm were taken over a period of three years from the entire processing line. ten 16s rrna (rrs) gene clone libraries were ... | 2013 | 23561260 |
| fascioliasis and intestinal parasitoses affecting schoolchildren in atlixco, puebla state, mexico: epidemiology and treatment with nitazoxanide. | the atlixco municipality, puebla state, at a mean altitude of 1840 m, was selected for a study of fasciola hepatica infection in schoolchildren in mexico. this area presents permanent water collections continuously receiving thaw water from popocatepetl volcano (5426 m altitude) through the community supply channels, conforming an epidemiological scenario similar to those known in hyperendemic areas of andean countries. | 2013 | 24278492 |
| a chloroplastic rna ligase activity analogous to the bacterial and archaeal 2´-5' rna ligase. | bacteria and archaea contain a 2'-5' rna ligase that seals in vitro 2',3'-cyclic phosphodiester and 5'-hydroxyl rna termini, generating a 2',5'-phosphodiester bond. in our search for an rna ligase able to circularize the monomeric linear replication intermediates of viroids belonging to the family avsunviroidae, which replicate in the chloroplast, we have identified in spinach (spinacea oleracea l.) chloroplasts a new rna ligase activity whose properties resemble those of the bacterial and archa ... | 2012 | 22336712 |
| elucidation of enterotoxigenic bacillus cereus outbreaks in austria by complementary epidemiological and microbiological investigations, 2013. | identifying bacillus cereus as the causative agent of a foodborne outbreak still poses a challenge. we report on the epidemiological and microbiological investigation of three outbreaks of food poisoning (a, b, and c) in austria in 2013. a total of 44% among 32 hotel guests (a), 22% among 63 employees (b) and 29% among 362 residents of a rehab clinic (c) fell sick immediately after meal consumption. b. cereus isolated from left overs or retained samples from related foods were characterized by t ... | 2016 | 27257745 |
| bacteriological quality of vegetables from organic and conventional production in different areas of korea. | foods grown in organic production systems have been described as representing an increased risk to public health compared with foods from conventional production. leafy vegetables (spinach, romaine lettuce, and green sesame leaves) grown in organic and conventional systems were collected from various areas in korea and examined using standard culture methods to compare the microbiological quality of the produce grown in the two agricultural systems. the 354 samples of these leafy vegetables were ... | 2014 | 25198606 |
| antibacterial, antiviral, and antifungal properties of wines and winery byproducts in relation to their flavonoid content. | grapes produce organic compounds that may be involved in the defense of the plants against invading phytopathogens. these metabolites include numerous phenolic compounds that are also active against human pathogens. grapes are used to produce a variety of wines, grape juices, and raisins. grape pomace, seeds, and skins, the remains of the grapes that are a byproduct of winemaking, also contain numerous bioactive compounds that differ from those found in grapes and wines. this overview surveys an ... | 2014 | 24945318 |
| unsaturated fatty acids from food and in the growth medium improve growth of bacillus cereus under cold and anaerobic conditions. | in a chemically defined medium and in luria broth, cold strongly reduced maximal population density of bacillus cereus atcc 14579 in anaerobiosis and caused formation of filaments. in cooked spinach, maximal population density of b. cereus in anaerobiosis was the same at cold and optimal temperatures, with normal cell divisions. the lipid containing fraction of spinach, but not the hydrophilic fraction, restored growth of b. cereus under cold and anaerobiosis when added to the chemically defined ... | 2013 | 24010589 |
| functional characterization of steroid hydroxylase cyp106a1 derived from bacillus megaterium. | in this study, we examined the catalytic activity of cyp106a1 from the bacillus megaterium american type culture collection 14581 strain. the cyp106a1 gene was cloned from b. megaterium, heterologously expressed in escherichia coli, and purified. potential electron partners and possible bacterial cyp106a1 substrates were identified by examining the oxidative activity toward a set of steroids in the presence of several reductase systems. the activities of cyp106a1 in a reconstituted system could ... | 2015 | 24988988 |
| application of bacillus subtilis to the roots of leafy greens, in the presence of listeria innocua and salmonella newport, induces closure of stomata. | plant growth-promoting rhizobacterium bacillus subtilis ud1022 has been shown to trigger an induced systemic response in arabidopsis thaliana. this interaction causes plant stomata to close, protecting the plant from infection by plant pathogens and thereby increasing crop yield. the purpose of this study was to determine whether ud1022 applied to the roots of plants is able to induce stomata closure in leafy greens as well as influence the persistence of human pathogens (listeria and salmonella ... | 2015 | 26270607 |
| imaging metabolite dynamics in living cells using a spinach-based riboswitch. | riboswitches are natural ligand-sensing rnas typically that are found in the 5' utrs of mrna. numerous classes of riboswitches have been discovered, enabling mrna to be regulated by diverse and physiologically important cellular metabolites and small molecules. here we describe spinach riboswitches, a new class of genetically encoded metabolite sensor derived from naturally occurring riboswitches. drawing upon the structural switching mechanism of natural riboswitches, we show that spinach can b ... | 2015 | 25964329 |
| comparison of plant growth-promotion with pseudomonas aeruginosa and bacillus subtilis in three vegetables. | our objective was to compare some plant growth promoting rhizobacteria (pgpr) properties of bacillus subtilis and pseudomonas aeruginosa as representatives of their two genera. solanum lycopersicum l. (tomato), abelmoschus esculentus (okra), and amaranthus sp. (african spinach) were inoculated with the bacterial cultures. at 60 days after planting, dry biomass for plants treated with b. subtilis and p. aeruginosa increased 31% for tomato, 36% and 29% for okra, and 83% and 40% for african spinach ... | 2008 | 24031240 |
| in-vitro degradation of starch granules isolated from spinach chloroplasts. | the initial reactions of transitory starch degradation in spinacia oleracea l. were investigated using an in-vitro system composed of native chloroplast starch granules, purified chloroplast and non-chloroplast forms of phosphorylase (ec 2.4.1.1) from spinach leaves, and α-amylase (ec 3.2.1.1) isolated from bacillus subtilis. starch degradation was followed by measuring the release of soluble glucans, by determining phosphorylase activity, and by an electron-microscopic evaluation following deep ... | 1983 | 24264852 |
| establishment of three new genera in the family geminiviridae: becurtovirus, eragrovirus and turncurtovirus. | the family geminiviridae includes plant-infecting circular single-stranded dna viruses that have geminate particle morphology. members of this family infect both monocotyledonous and dicotyledonous plants and have a nearly global distribution. with the advent of new molecular tools and low-cost sequencing, there has been a significant increase in the discovery of new geminiviruses in various cultivated and non-cultivated plants. in this communication, we highlight the establishment of three new ... | 2014 | 24658781 |
| intergeneric recombination between a new, spinach-infecting curtovirus and a new geminivirus belonging to the genus becurtovirus: first new world exemplar. | a novel curtovirus, spinach severe curly top virus (ssctv), was associated with symptomatic spinach plants collected from a commercial field in south-central arizona during 2009. in addition, a second viral molecule of about 2.9 kb from the same spinach plants was amplified, cloned and sequenced. the latter isolate, herein named spinach curly top arizona virus (sctav), was found to share 77 % pairwise sequence identity with beet curly top iran virus (bctiv), a leafhopper-transmitted geminivirus ... | 2013 | 23708296 |
| fulfilling koch's postulates for beet curly top iran virus and proposal for consideration of new genus in the family geminiviridae. | beet curly top iran virus (bctiv) is a divergent geminivirus with biological properties similar to those of curtoviruses; however, the virus is distinct from curtoviruses phylogenetically and in its genome organisation. the replication-associated protein is phylogenetically more closely related to those of mastreviruses than to those of curtoviruses whereas the capsid protein shares high amino acid sequence identity (77-83 %) with those of curtoviruses. the 17 bctiv genomes from iran share ~77 % ... | 2013 | 23081676 |
| revisiting the classification of curtoviruses based on genome-wide pairwise identity. | members of the genus curtovirus (family geminiviridae) are important pathogens of many wild and cultivated plant species. until recently, relatively few full curtovirus genomes have been characterised. however, with the 19 full genome sequences now available in public databases, we revisit the proposed curtovirus species and strain classification criteria. using pairwise identities coupled with phylogenetic evidence, revised species and strain demarcation guidelines have been instituted. specifi ... | 2014 | 24463952 |
| transcriptional analysis of complementary sense genes in spinach curly top virus and functional role of c2 in pathogenesis. | spinach curly top virus (sctv), the fifth characterized curtovirus species belonging to the family geminiviridae, is an agriculturally significant plant pathogen representing an emerging disease threat in the southern united states. the sctv genome comprises a single dna chromosome of approximately 3.0 kb, with the potential to code for seven proteins larger than 10 kda but which relies extensively on the host for replication and transcription of its genome. in this study, we have identified vir ... | 2007 | 17313170 |
| molecular characterization and variation of the broad bean wilt virus 2 isolates based on analyses of complete genome sequences. | the full-genome sequences of fourteen isolates of broad bean wilt virus 2 (bbwv2), collected from broad bean, pea, spinach, bell pepper and paprika plants in korea during the years 2006-2012, were determined and analyzed comparatively along with fifteen previously reported bbwv2 genome sequences. sequence analyses showed that rna-1 and rna-2 sequences of bbwv2 korean isolates consisted of 5950-5956 and 3568-3604 nucleotides, respectively. full-length genome sequence-based phylogenetic analyses r ... | 2013 | 25288968 |
| identification of sequences required for al2-mediated activation of the tomato golden mosaic virus-yellow vein br1 promoter. | a 108 bp sequence has been identified in the tomato golden mosaic virus-yellow vein (yvtgmv) b component that is necessary and sufficient for al2-mediated activation of the br1 promoter. the sequence appears to have a bipartite arrangement, with elements located between -144 to -77 and -59 to -36 from the transcription start site, with both being required for activation by al2. these sequences are located upstream of a tata box and bind nuclear proteins from spinach, tomato and arabidopsis. thes ... | 2013 | 23486662 |
| isolation of campylobacter from feral swine (sus scrofa) on the ranch associated with the 2006 escherichia coli o157:h7 spinach outbreak investigation in california. | we report the isolation of campylobacter species from the same population of feral swine that was investigated in san benito county, california, during the 2006 spinach-related escherichia coli o157:h7 outbreak. this is the first survey of campylobacter in a free-ranging feral swine population in the united states. campylobacter species were cultured from buccal and rectal-anal swabs, colonic faeces and tonsils using a combination of selective enrichment and antibiotic-free membrane filtration m ... | 2012 | 22405465 |
| sequence-specific interaction between s1f, a spinach nuclear factor, and a negative cis-element conserved in plastid-related genes. | the nuclear gene rps1 coding for the spinach plastid ribosomal protein cs1 exhibits both a constitutive and leaf-specific expression pattern. in contrast to other chloroplast-related genes like rbcs and cab, the leaf induction of rps1 expression is light-independent. these unique features of rps1 expression provide good models to study the mechanisms regulating plastid development and differentiation in higher plants. we report on the identification of a spinach leaf nuclear factor, designated s ... | 1992 | 1429696 |
| diverse mechanisms of plant resistance to cauliflower mosaic virus revealed by leaf skeleton hybridization. | plants not hosts for cauliflower mosaic virus (camv) may prevent systemic camv infection by interfering with dissemination of infection through the plant or by preventing viral replication and maturation. leaf skeleton hybridization allows distinction between these two barriers. the technique assesses the spatial distribution of camv in an inoculated leaf by hybridization of a skeleton of the leaf with a camv dna probe. leaves or leaflets of soybean, cucumber, peanut, tomato, lettuce, spinach, p ... | 1992 | 1562237 |
| biosensor for selective detection of e. coli in spinach using the strong affinity of derivatized mannose with fimbrial lectin. | escherichia coli (e. coli) contamination in foods and water resources represents a major threat for human health and the environment. this work exploits the strong affinity of mannose-containing oligosaccharides with the fimbrial lectin of e. coli to design novel biosensors. modified carbohydrate ligands were synthesized by introducing phenyl residues and aliphatic chains to mannose via reductive amination in order to increase both the affinity and selectivity to e. coli compared to other pathog ... | 2014 | 24906084 |
| an experimental platform using human intestinal epithelial cell lines to differentiate between hazardous and non-hazardous proteins. | human intestinal epithelial cell lines (t84, caco-2, and hct-8) grown on permeable transwell™ filters serve as models of the gastrointestinal barrier. in this study, this in vitro model system was evaluated for effectiveness at distinguishing between hazardous and non-hazardous proteins. indicators of cytotoxicity (ldh release, mtt conversion), monolayer barrier integrity ([(3)h]-inulin flux, horseradish peroxidase flux, trans-epithelial electrical resistance [teer]), and inflammation (il-8, il- ... | 2016 | 27060235 |
| e88, a new cyclic-di-gmp class i riboswitch aptamer from clostridium tetani, has a similar fold to the prototypical class i riboswitch, vc2, but differentially binds to c-di-gmp analogs. | c-di-gmp has emerged as a ubiquitous second messenger, which regulates the transition between sessile and motile lifestyles and virulence factor expression in many pathogenic bacteria using both rna riboswitches and protein effectors. we recently showed that two additional class i c-di-gmp riboswitch aptamers (ct-e88 and cb-17b) bind c-di-gmp with nanomolar affinity, and that ct-e88 rna binds 2'-f-c-di-gmp 422 times less tightly than class i vc2 rna. based on sequence comparison, it was conclude ... | 2014 | 24430255 |
| determination of essential and toxic elements in cordyceps kyushuensis kawam by inductively coupled plasma mass spectrometry. | in this study, a total of 20 elements (essential, non-essential and toxic): lithium (li), sodium (na), potassium (k), gallium (ga), magnesium (mg), zinc (zn), iron (fe), copper (cu), manganese (mn), vanadium (v), chromium (cr), nickel (ni), cobalt (co), molybdenum (mo), selenium (se), barium (ba), tin (sn), arsenic (as), lead (pb) cadmium (cd) and mercury (hg) in natural and cultured cordyceps kyushuensis have been determined by means of inductively coupled plasma mass spectrometry (icp-ms). cul ... | 2013 | 23102516 |
| postharvest survival of porcine sapovirus, a human norovirus surrogate, on phytopathogen-infected leafy greens. | leafy greens are increasingly being recognized as an important vehicle for human noroviruses (hunov), which cause recurring gastroenteritis outbreaks. leafy greens often become infected by phytopathogens in the field, which may cause symptoms on the edible parts. whether plant pathogen infections enhance the survival of hunov on leafy greens is unknown. lettuce and spinach plants were infected with a bacterium, xanthomonas campestris pv. vitians strain 701a, and with cucumber mosaic virus strain ... | 2015 | 26219360 |
| microbiological survey of imported produce available at retail across canada. | increasing consumption and year-round consumer demand for fresh, minimally processed green vegetables have been observed in canada and other developed countries. however, in the past two decades, produce has been increasingly implicated in outbreaks and correspondingly recognized as a vector for the transmission of pathogenic microorganisms. to this end, we examined the microbiological quality of imported produce available at retail across canada during a period of limited domestic availability. ... | 2013 | 23416548 |
| a study on prevalence of microbial contamination on the surface of raw salad vegetables. | the present work evaluates the microbiological quality of raw salad vegetables (rsv) consumed in dhanbad city, india. a total of 480 samples of 8 different raw salad vegetables from local market were examined for overall microbial quality in terms of aerobic mesophilic, psychrotrophic counts, yeast, mould and total coliform levels. e. coli o157:h7, listeria monocytogenes and salmonella sp. were detected by real-time polymerase chain reaction (qpcr) subsequent to isolation. results showed that al ... | 2017 | 28391475 |
| enhanced antimicrobial activity based on a synergistic combination of sub-lethal levels of stresses induced by uv-a light and organic acids. | reduction of microbial load in food and water systems is critical for their safety and shelf-life. conventionally, physical processes such as heat or light are used for rapid inactivation of microbes, while natural compounds such as lactic acid may be used as preservatives after the initial physical process. this study demonstrates enhanced and rapid inactivation of bacteria based on a synergistic combination of sub-lethal levels of stresses induced by uv-a light and two food grade organic acids ... | 2017 | 28363964 |
| effect of fermented spinach as sources of pre-converted nitrite on color development of cured pork loin. | the effect of fermented spinach extracts on color development in cured meats was investigated in this study. the ph values of raw cured meats without addition of fermented spinach extract or nitrite (negative control) were higher (p<0.05) than those added with fermented spinach extract. the ph values of raw and cooked cured meats in treatment groups were decreased with increasing addition levels of fermented spinach extract. the lightness and yellowness values of raw cured meats formulated with ... | 2017 | 28316477 |
| prevalence and phylogenetic characterization of escherichia coli and hygiene indicator bacteria isolated from leafy green produce, beef, and pork obtained from farmers' markets in pennsylvania. | the popularity of farmers' markets in the united states has led to over 8,400 farmers' markets being in operation in 2015. as farmers' markets have increased in size and complexity in the kinds of foods sold at these venues, so have the potential food safety risks. since 2008, seven major foodborne illness outbreaks and two recalls associated with food products from farmers' markets have occurred, causing 80 known reported illnesses and one death. various researchers also have observed vendors p ... | 2017 | 28221988 |
| rapid identification of shiga toxin-producing escherichia coli o serogroups from fresh produce and raw milk enrichment cultures by luminex bead-based suspension array. | the u.s. food and drug administration's bacteriological analytical manual (bam) chapter 4a describes a luminex microbead-based suspension array used to screen colonies for 11 clinically relevant shiga toxin-producing escherichia coli (stec) serogroups: o26, o45, o91, o103, o104, o111, o113, o121, o128, o145, and o157. we evaluated the usefulness of this method to identify stec-positive enrichment samples before agar plating. twelve e. coli strains were added to three types of fresh produce (bagg ... | 2016 | 28221928 |
| characterization and virulence potential of serogroup o113 shiga toxin-producing escherichia coli strains isolated from beef and cattle in the united states. | shiga toxin-producing escherichia coli (stec) of serotype o113:h21 have caused severe diseases but are unusual in that they do not produce the intimin protein required for adherence to intestinal epithelial cells. strains of serogroup o113 are one of the most common stec found in ground beef and beef products in the united states, but their virulence potential is unknown. we used a microarray to characterize 65 o113 strains isolated in the united states from ground beef, beef trim, cattle feces, ... | 2017 | 28199145 |
| live cell imaging of endogenous mrna using rna-based fluorescence "turn-on" probe. | messenger rna (mrna) plays a critical role in cellular growth and development. however, there have been limited methods available to visualize endogenous mrna in living cells with ease. we have designed rna-based fluorescence "turn-on" probes that target mrna by fusing an unstable form of spinach with target-complementary sequences. these probes have been demonstrated to be selective, stable, and capable of targeting various mrnas for live e. coli imaging. | 2017 | 28103687 |
| cryo-em structure of the spinach chloroplast ribosome reveals the location of plastid-specific ribosomal proteins and extensions. | ribosomes are the protein synthesizing machines of the cell. recent advances in cryo-em have led to the determination of structures from a variety of species, including bacterial 70s and eukaryotic 80s ribosomes as well as mitoribosomes from eukaryotic mitochondria, however, to date high resolution structures of plastid 70s ribosomes have been lacking. here we present a cryo-em structure of the spinach chloroplast 70s ribosome, with an average resolution of 5.4 å for the small 30s subunit and 3. ... | 2016 | 27986857 |
| a genetically encoded fluorescent trna is active in live-cell protein synthesis. | transfer rnas (trnas) perform essential tasks for all living cells. they are major components of the ribosomal machinery for protein synthesis and they also serve in non-ribosomal pathways for regulation and signaling metabolism. we describe the development of a genetically encoded fluorescent trna fusion with the potential for imaging in live escherichia coli cells. this trna fusion carries a spinach aptamer that becomes fluorescent upon binding of a cell-permeable and non-toxic fluorophore. we ... | 2016 | 27956502 |
| purification and characterization of the principal antimutagenic bioactive as ethoxy-substituted phylloquinone from spinach (spinacea oleracea l.) based on evaluation in models including human lymphoblast tk(+/-) cells. | during in vitro analysis, spinach (spinacea oleracea l.) leaf extracts displayed varying antimutagenicity when analyzed in models including human lymphoblast (tk(+/-)) cell line (thymidine kinase gene mutation assay) and escherichia coli mg1655 (rifampicin resistance assay) against chemically (ethyl methanesulfonate and 5-azacytidine) induced mutagenicity. highest antimutagenicity was displayed by the quinone extract. the principal bioactive compound exhibited fluorescence in tlc at 366 nm (term ... | 2016 | 27806562 |
| cryo-em structure of the large subunit of the spinach chloroplast ribosome. | protein synthesis in the chloroplast is mediated by the chloroplast ribosome (chloro-ribosome). overall architecture of the chloro-ribosome is considerably similar to the escherichia coli (e. coli) ribosome but certain differences are evident. the chloro-ribosome proteins are generally larger because of the presence of chloroplast-specific extensions in their n- and c-termini. the chloro-ribosome harbours six plastid-specific ribosomal proteins (psrps); four in the small subunit and two in the l ... | 2016 | 27762343 |
| developing and optimizing bacteriophage treatment to control enterohemorrhagic escherichia coli on fresh produce. | bacteriophages are potentially useful in controlling foodborne pathogens on minimally processed products since phage application is a non-destructive treatment. the purpose of this study was to evaluate the efficacy of a newly isolated environmental bacteriophage against enterohemorrhagic escherichia coli on fresh produce, and optimize the treatment with consideration for potential application. seven anti e. coli o157:h7 edl933 bacteriophages were isolated from various sources; the most promisin ... | 2016 | 27454784 |
| aggregative adherence fimbriae i (aaf/i) mediate colonization of fresh produce and abiotic surface by shiga toxigenic enteroaggregative escherichia coli o104:h4. | the shiga toxigenic escherichia coli o104:h4 isolated during the 2011 european outbreak expresses shiga toxin 2a and possess virulence genes associated with the enteroaggregative e. coli (eaec) pathotype. it produces plasmid encoded aggregative adherence fimbriae i (aaf/i) which mediate cell aggregation and biofilm formation in human intestine and promote shiga-toxin adsorption, but it is not clear whether the aaf/i fimbriae are involved in the colonization and biofilm formation on food and envi ... | 2016 | 27099984 |
| metrics proposed to prevent the harvest of leafy green crops exposed to floodwater contaminated with escherichia coli. | the california leafy green products handler marketing agreement (lgma) requires leafy green crops within 9 m of the edge of a flooded field not be harvested due to potential contamination (california leafy green products handler marketing board, commodity specific flood safety guidelines for the production and harvest of lettuce and leafy greens, 2012). further, previously flooded soils should not be replanted for 60 days. in this study, the suitability of the lgma metrics for farms in the mid-a ... | 2016 | 27084022 |
| influence of extracellular cellulose and colanic acid production on the survival of shiga toxin-producing escherichia coli on spinach and lettuce after chlorine treatment. | shiga toxin-producing escherichia coli (stec) strains produce extracellular cellulose and colanic acid, which may influence stress tolerance. this study investigates the role of these extracellular polymers on the tolerance of stec to chlorine treatment after attachment to lettuce and spinach. four stec strains, two wild-type cellulose-producing and their cellulose-deficient derivatives, were used. one strain pair produced colanic acid in addition to cellulose. spinach and lettuce with attached ... | 2016 | 27052873 |
| comparison of assurance gds(®) mpx id for top stec with reference culture methods for the detection of e. coli top 6 stec; direct confirmation of top 6 stec from isolation plates and determination of equivalence of pickpen(®) and fsis octomacs™ concentration protocols. | assurance gds(®) mpx id for top shiga toxin-producing escherichia coli (stec; mpx id) was validated according to the aoac international methods committee guidelines for validation of microbiological methods for foods and environmental surfaces as (1) a secondary screening method for specific detection of the top 6 stec serogroups (o26, o45, o103, o111, o121, and o145) in raw beef trim, raw ground beef, raw spinach, and on stainless steel; and (2) as a confirmatory method for the identification o ... | 2017 | 26997139 |
| microbiological quality of fresh produce obtained from retail stores on the eastern shore of maryland, united states of america. | the aim of this study was to investigate the microbiological quality of six types of fresh produce obtained from three retail stores located on the eastern shore of maryland, usa. a total of 414 samples representing basil, cilantro, lettuce, scallion, spinach, and parsley were analyzed for total aerobic bacteria (apc), total coliforms, escherichia coli, and three pathogenic bacteria (e. coli o157:h7, listeria monocytogenes, and salmonella), using standard methods. presumptive pathogenic isolates ... | 2016 | 26919815 |
| expression of spinach ferredoxin-thioredoxin reductase using tandem t7 promoters and application of the purified protein for in vitro light-dependent thioredoxin-reduction system. | thioredoxins (trxs) regulate the activity of target proteins in the chloroplast redox regulatory system. in vivo, a disulfide bond within trxs is reduced by photochemically generated electrons via ferredoxin (fd) and ferredoxin-thioredoxin reductase (ftr: ec 1.8.7.2). ftr is an αβ-heterodimer, and the β-subunit has a 4fe-4s cluster that is indispensable for the electron transfer from fd to trxs. reconstitution of the light-dependent fd/trx system, including ftr, is required for the biochemical c ... | 2016 | 26773743 |
| an integrated paper-based sample-to-answer biosensor for nucleic acid testing at the point of care. | with advances in point-of-care testing (poct), lateral flow assays (lfas) have been explored for nucleic acid detection. however, biological samples generally contain complex compositions and low amounts of target nucleic acids, and currently require laborious off-chip nucleic acid extraction and amplification processes (e.g., tube-based extraction and polymerase chain reaction (pcr)) prior to detection. to the best of our knowledge, even though the integration of dna extraction and amplificatio ... | 2016 | 26759062 |
| impacts of climate and management variables on the contamination of preharvest leafy greens with escherichia coli. | the observed seasonality of foodborne disease suggests that climatic conditions play a role and that changes in the climate may affect the presence of pathogens. however, it is hard to determine whether this effect is direct or whether it works indirectly through other factors, such as farm management. this study aimed to identify the climate and management variables that are associated with the contamination (presence and concentration) of leafy green vegetables with e. coli. this study used da ... | 2016 | 26735025 |
| mimicking respiratory phosphorylation using purified enzymes. | the enzymes of oxidative phosphorylation is a striking example of the functional association of multiple enzyme complexes, working together to form atp from cellular reducing equivalents. these complexes, such as cytochrome c oxidase or the atp synthase, are typically investigated individually and therefore, their functional interplay is not well understood. here, we present methodology that allows the co-reconstitution of purified terminal oxidases and atp synthases in synthetic liposomes. the ... | 2016 | 26707617 |
| crystal diagnostics xpress™ e7 stec kit for the rapid multiplex detection of e. coli o157 and non-o157 shiga toxin-producing e. coli. | the crystal diagnostics (cdx) xpress e7 stec kit is a rapid and sensitive detection assay for the detection of escherichia coli o157 and six non-o157 shiga toxin-producing e. coli (serogroups o26, o45, o1o3, o111, o121, and o145, collectively referred to as stec) at 1 cfu/325 g of raw ground beef and raw beef trim, or 200 g of spinach. the system comprises an automatic crystal diagnostics xpress system reader that integrates immunochemical and optical processes for the liquid crystal-based detec ... | 2015 | 26651567 |
| selection of intracellularly functional rna mimics of green fluorescent protein using fluorescence-activated cell sorting. | fluorescence-activated cell sorting (facs) was exploited to isolate escherichia coli cells that were highly fluorescent due to the expression of rna aptamers that induce fluorescence of 3,5-difluoro-4-hydroxybenzylidene imidazolinone. two different aptamers, named zt-26 and zt-324, were identified by this method and compared to the fluorescence-signaling properties of spinach, a previously reported rna aptamer. aptamer zt-26 exhibits significantly enhanced fluorescence over spinach only in vitro ... | 2015 | 26573804 |
| broad and efficient control of major foodborne pathogenic strains of escherichia coli by mixtures of plant-produced colicins. | enterohemorrhagic escherichia coli (ehec) is one of the leading causes of bacterial enteric infections worldwide, causing ∼100,000 illnesses, 3,000 hospitalizations, and 90 deaths annually in the united states alone. these illnesses have been linked to consumption of contaminated animal products and vegetables. currently, other than thermal inactivation, there are no effective methods to eliminate pathogenic bacteria in food. colicins are nonantibiotic antimicrobial proteins, produced by e. coli ... | 2015 | 26351689 |
| role of cellulose and colanic acid in attachment of shiga toxin-producing escherichia coli to lettuce and spinach in different water hardness environments. | this study investigated the role of extracellular cellulose production by shiga toxin-producing escherichia coli (stec) on attachment to lettuce and spinach in different water hardness environments. two cellulose-producing wild-type stec strains, 19 (o5:h-) and 49 (o103:h2), and their cellulose-deficient derivatives were used. strain 49 also produced colanic acid as a constituent of its extracellular polymeric substances. attached cells were determined by plate counts on the surface and cut edge ... | 2015 | 26219358 |
| shiga toxin-producing escherichia coli (stec) in fresh produce--a food safety dilemma. | produce contains high levels of mixed microflora, including coliforms and escherichia coli, but occasionally pathogens may also be present. enterotoxigenic e. coli and shigatoxin-producing e. coli (stec) have been isolated from various produce types, especially spinach. the presence of stec in produce is easily detected by pcr for the shiga toxin (stx) gene, stx, but this is insufficient for risk analysis. stec comprises hundreds of serotypes that include known pathogenic serotypes and strains t ... | 2014 | 26104197 |
| assessment of microbial risk factors and impact of meteorological conditions during production of baby spinach in the southeast of spain. | there is a timely need to evaluate the effect agricultural factors and meteorological conditions on fresh produce contamination. this study evaluated those risk factors and described, for the first time, the distribution of indicator microorganisms (escherichia coli, enterococcus, coliforms, and enterobacteriaceae) and the prevalence of foodborne pathogens (enterohaemorrhagic e. coli, listeria monocytogenes and salmonella spp.) in baby spinach grown in the southeast of spain. a longitudinal stud ... | 2015 | 25846928 |
| violaxanthin de-epoxidase disulphides and their role in activity and thermal stability. | violaxanthin de-epoxidase (vde) catalyses the conversion of violaxanthin to zeaxanthin at the lumen side of the thylakoids during exposure to intense light. vde consists of a cysteine-rich n-terminal domain, a lipocalin-like domain and a negatively charged c-terminal domain. that the cysteines are important for the activity of vde is well known, but in what way is less understood. in this study, wild-type spinach vde was expressed in e. coli as inclusion bodies, refolded and purified to give a h ... | 2015 | 25764016 |
| multifactorial effects of ambient temperature, precipitation, farm management, and environmental factors determine the level of generic escherichia coli contamination on preharvested spinach. | a repeated cross-sectional study was conducted to identify farm management, environment, weather, and landscape factors that predict the count of generic escherichia coli on spinach at the preharvest level. e. coli was enumerated for 955 spinach samples collected on 12 farms in texas and colorado between 2010 and 2012. farm management and environmental characteristics were surveyed using a questionnaire. weather and landscape data were obtained from national resources information databases. a tw ... | 2015 | 25636850 |
| crystal diagnostics multipath system™. | the crystal diagnostics multipath system™ provides rapid detection of escherichia coli o157 in fresh raw ground beef, raw beeftrim, and spinach. the crystal diagnostics system combines patented liquid crystal technology with antibody-coated paramagnetic microspheres to selectively capture and detect e. coli o157 in food matrixes. this is the only liquid crystal-based biosensor commercially available for the detection of pathogens. the crystal diagnostics system expeditiously provides the sensiti ... | 2015 | 25632437 |
| using spinach aptamer to correlate mrna and protein levels in escherichia coli. | in vivo gene expression measurements have traditionally relied on fluorescent proteins such as green fluorescent protein (gfp) with the help of high-sensitivity equipment such as flow cytometers. however, fluorescent proteins report only on the protein level inside the cell without giving direct information about messenger rna (mrna) production. in 2011, an aptamer termed spinach was presented that acts as an rna mimic of gfp when produced in escherichia coli and mammalian cells. it was later sh ... | 2015 | 25605386 |
| real-time pathogen monitoring during enrichment: a novel nanotechnology-based approach to food safety testing. | we describe a new approach for the real-time detection and identification of pathogens in food and environmental samples undergoing culture. surface enhanced raman scattering (sers) nanoparticles are combined with a novel homogeneous immunoassay to allow sensitive detection of pathogens in complex samples such as stomached food without the need for wash steps or extensive sample preparation. sers-labeled immunoassay reagents are present in the cultural enrichment vessel, and the signal is monito ... | 2015 | 25590258 |
| a ph-dependent kinetic model of dihydrolipoamide dehydrogenase from multiple organisms. | dihydrolipoamide dehydrogenase is a flavoenzyme that reversibly catalyzes the oxidation of reduced lipoyl substrates with the reduction of nad(+) to nadh. in vivo, the dihydrolipoamide dehydrogenase component (e3) is associated with the pyruvate, α-ketoglutarate, and glycine dehydrogenase complexes. the pyruvate dehydrogenase (pdh) complex connects the glycolytic flux to the tricarboxylic acid cycle and is central to the regulation of primary metabolism. regulation of pdh via regulation of the e ... | 2014 | 25517164 |
| comparison of eight different agars for the recovery of clinically relevant non-o157 shiga toxin-producing escherichia coli from baby spinach, cilantro, alfalfa sprouts and raw milk. | the fda bacteriological analytical manual (bam) chapter 4a recommends several agars for isolating non-o157 shiga toxin-producing escherichia coli (stec); not all have been thoroughly tested for recovering stecs from food. using e. coli strains representing ten clinically relevant o serogroups (o26, o45, o91, o103, o104, o111, o113, o121, o128, o145) in artificially-contaminated fresh produce--bagged baby spinach, alfalfa sprouts, cilantro, and raw milk--we evaluated the performance of 8 differen ... | 2015 | 25475297 |
| broccoli: rapid selection of an rna mimic of green fluorescent protein by fluorescence-based selection and directed evolution. | genetically encoded fluorescent ribonucleic acids (rnas) have diverse applications, including imaging rna trafficking and as a component of rna-based sensors that exhibit fluorescence upon binding small molecules in live cells. these rnas include the spinach and spinach2 aptamers, which bind and activate the fluorescence of fluorophores similar to that found in green fluorescent protein. although additional highly fluorescent rna-fluorophore complexes would extend the utility of this technology, ... | 2014 | 25337688 |
| escherichia coli common pilus (ecp) targets arabinosyl residues in plant cell walls to mediate adhesion to fresh produce plants. | outbreaks of verotoxigenic escherichia coli are often associated with fresh produce. however, the molecular basis to adherence is unknown beyond ionic lipid-flagellum interactions in plant cell membranes. we demonstrate that arabinans present in different constituents of plant cell walls are targeted for adherence by e. coli common pilus (ecp; or meningitis-associated and temperature-regulated (mat) fimbriae) for e. coli serotypes o157:h7 and o18:k1:h7. l-arabinose is a common constituent of pla ... | 2014 | 25320086 |
| effect of gamma radiation on the reduction of salmonella strains, listeria monocytogenes, and shiga toxin-producing escherichia coli and sensory evaluation of minimally processed spinach (tetragonia expansa). | this study evaluated the effects of irradiation on the reduction of shiga toxin-producing escherichia coli (stec), salmonella strains, and listeria monocytogenes, as well as on the sensory characteristics of minimally processed spinach. spinach samples were inoculated with a cocktail of three strains each of stec, salmonella strains, and l. monocytogenes, separately, and were exposed to gamma radiation doses of 0, 0.2, 0.4, 0.6, 0.8, and 1.0 kgy. samples that were exposed to 0.0, 1.0, and 1.5 kg ... | 2014 | 25285495 |
| circular code motifs in the ribosome decoding center. | a translation (framing) code based on the circular code was proposed in michel (2012) with the identification of x circular code motifs (x motifs shortly) in the bacterial rrna of thermus thermophilus, in particular in the ribosome decoding center. three classes of x motifs are now identified in the rrnas of bacteria escherichia coli and thermus thermophilus, archaea pyrococcus furiosus, nuclear eukaryotes saccharomyces cerevisiae, triticum aestivum and homo sapiens, and chloroplast spinacia ole ... | 2014 | 25215650 |
| immunomagnetic separation and visual fluorescence detection of e. coli o157 using aoac approved sas molecular tests. | the sas molecular tests method for the detection of e. coli o157 in various food matrixes has been certified by the aoac research institute and designated performance tested method no. 031203. the current method modification includes the optional immunomagnetic separation (ims) to enrich the bacteria as well as optional visual fluorescence readout without the use of a turbidimeter. the following study was conducted to validate the proposed modifications against the u.s. department of agriculture ... | 2014 | 25145140 |
| sas molecular tests salmonella detection kit. performance tested method 021202. | the sas molecular tests salmonella detection method, a loop-mediated isothermal amplification method, performed as well as or better than the u.s. department of agriculture-food safety inspection service microbiology laboratory guidebook and the u.s. food and drug administration bacteriological analytical manual reference methods for ground beef, beef trim, ground turkey, chicken carcass rinses, bagged mixed lettuce, and fresh spinach. the ground beef (30% fat, 25 g test portion), poultry matrix ... | 2014 | 25051629 |
| sas molecular tests escherichia coli o157 detection kit. performance tested method 031203. | the sas molecular tests escherichia coli o157 detection method, a loop-mediated isothermal amplification method, performed as well as or better than the u.s. department of agriculture, food safety inspection service microbiology laboratory guidebook and the u.s. food and drug administration bacteriological analytical manual reference methods for ground beef, beef trim, bagged mixed lettuce, and fresh spinach. ground beef (30% fat, 25 g test portion) was validated for 7-8 h enrichment, leafy gree ... | 2014 | 25051628 |
| method for enhancement of plant redox-related protein expression and its application for in vitro reduction of chloroplastic thioredoxins. | plant redox-related proteins were overexpressed using a genetic codon substitution downstream of the translation initiation codon. this method significantly improved recombinant protein expression levels of arabidopsis chloroplastic thioredoxins and cytosolic nicotinamide adenine dinucleotide phosphate (nadph)-dependent thioredoxin reductase (e.c. 1.8.1.9) in escherichia coli. using these proteins, the in vitro chloroplastic thioredoxins-reduction system was reconstituted in an nadph-dependent m ... | 2014 | 25017253 |
| mechanistic studies on formation of the dinitrosyl iron complex of the [2fe-2s] cluster of soxr protein. | the transcriptional activation of soxr in escherichia coli occurs through direct modification of the [2fe-2s] by nitric oxide (no) to form a dinitrosyl iron complex (dnic). here, we investigated the reactions of no with [2fe-2s] clusters of soxr; the results were compared with those obtained for spinach ferredoxin (fd). uv-visible absorption and esr spectra of soxr upon treatment with an no donor showed the formation of dnic of soxr efficiently, whereas those of fd exhibited small changes. upon ... | 2014 | 24747116 |
| escherichia coli ric is able to donate iron to iron-sulfur clusters. | escherichia coli ric (repair of iron centers) is a diiron protein previously reported to be involved in the repair of iron-sulfur proteins damaged by oxidative or nitrosative stresses, and proposed to act as an iron donor. this possible role of ric was now examined specifically by evaluating its ability to donate iron ions to apo-iron-sulfur proteins, determining the iron binding constants and assessing the lability of its iron ions. we show, by uv-visible, epr and resonance raman spectroscopies ... | 2014 | 24740378 |
| soluble expression of spinach psbc gene in escherichia coli and in vitro reconstitution of cp43 coupled with chlorophyll a only. | cp43 is a chlorophyll a (chl a) and β-carotene (β-car) binding protein encoded by psbc gene. in this study, psbc gene isolated from spinach was expressed in escherichia coli in soluble state. after lysis of the cells, the apoproteins purified by nickel affinity chromatography were examined by sds-page and western-blot. next, reconstitution experiment was carried out in vitro and the formation of stable pigment-protein complex was analyzed by partially denaturing electrophoresis. after purifying ... | 2014 | 24675567 |
| detection of five shiga toxin-producing escherichia coli genes with multiplex pcr. | escherichia coli serogroup o157 is the pathogen most commonly associated with foodborne disease outbreaks, but epidemiological studies suggest that non-o157 shiga toxin-producing e. coli (stec) is a major player as well. the ten most clinically relevant stecs belong to serogroups o26, o103, o111, o145, o157, o91, o113, o128, o45, and o121; but emerging strains, such as o104:h4 that was identified with the 2011 german outbreak, could become more prevalent in the future. a 75-min conventional mult ... | 2014 | 24549195 |
| farm management, environment, and weather factors jointly affect the probability of spinach contamination by generic escherichia coli at the preharvest stage. | the national resources information (nri) databases provide underutilized information on the local farm conditions that may predict microbial contamination of leafy greens at preharvest. our objective was to identify nri weather and landscape factors affecting spinach contamination with generic escherichia coli individually and jointly with farm management and environmental factors. for each of the 955 georeferenced spinach samples (including 63 positive samples) collected between 2010 and 2012 o ... | 2014 | 24509926 |
| using spinach-based sensors for fluorescence imaging of intracellular metabolites and proteins in living bacteria. | genetically encoded fluorescent sensors can be valuable tools for studying the abundance and flux of molecules in living cells. we recently developed a novel class of sensors composed of rnas that can be used to detect diverse small molecules and untagged proteins. these sensors are based on spinach, an rna mimic of gfp, and they have successfully been used to image several metabolites and proteins in living bacteria. here we discuss the generation and optimization of these spinach-based sensors ... | 2014 | 24356773 |
| regio- and stereospecific hydroxylation of various steroids at the 16α position of the d ring by the streptomyces griseus cytochrome p450 cyp154c3. | cytochrome p450 monooxygenases (p450s), which constitute a superfamily of heme-containing proteins, catalyze the direct oxidation of a variety of compounds in a regio- and stereospecific manner; therefore, they are promising catalysts for use in the oxyfunctionalization of chemicals. in the course of our comprehensive substrate screening for all 27 putative p450s encoded by the streptomyces griseus genome, we found that escherichia coli cells producing an s. griseus p450 (cyp154c3), which was fu ... | 2014 | 24334658 |
| flagella interact with ionic plant lipids to mediate adherence of pathogenic escherichia coli to fresh produce plants. | bacterial attachment to plant and animal surfaces is generally thought to constitute the initial step in colonization, requiring adherence factors such as flagella and fimbriae. we describe the molecular mechanism underpinning flagella-mediated adherence to plant tissue for the foodborne pathogen, enterohaemorrhagic escherichia coli. escherichia coli h7 flagella interacted with a sulphated carbohydrate (carrageenan) on a glycan array, which occurred in a dose-dependent manner. adherence of e. co ... | 2014 | 24148193 |