Publications

TitleAbstractYear
Filter
PMID(sorted ascending)
Filter
listeria monocytogenes arca contributes to acid tolerance.the foodborne pathogen listeria monocytogenes is able to colonize the human and animal intestinal tracts and subsequently crosses the intestinal barrier, causing systemic infection. for successful establishment of infection, l. monocytogenes must survive and adapt to the low ph environment of the stomach. gene sequence analysis indicates that lmo0043, an orthologue of arca, encodes a protein containing conserved motifs and critical active amino acids characteristic of arginine deiminase that med ...201323518652
fluoro-phenyl-styrene-sulfonamide, a novel inhibitor of σb activity, prevents the activation of σb by environmental and energy stresses in bacillus subtilis.sigma b (σ(b)) is an alternative sigma factor that regulates the general stress response in bacillus subtilis and in many other gram-positive organisms. σ(b) activity in b. subtilis is tightly regulated via at least three distinct pathways within a complex signal transduction cascade in response to a variety of stresses, including environmental stress, energy stress, and growth at high or low temperatures. we probed the ability of fluoro-phenyl-styrene-sulfonamide (fpss), a small-molecule inhibi ...201323524614
histophilus somni-induced infections in cattle from southern brazil.the sudden death of three calves, one diarrheic calf, and one aborted fetus from four farms in southern brazil was investigated. two histophilus somni-associated syndromes were identified: systemic histophilosis (n = 4) and abortion (n = 1). the principal pathological findings included vasculitis, meningoencephalitis with thrombosis, necrotizing myocarditis, renal infarctions, hepatic abscesses, and bronchopneumonia. pcr assays were used to amplify specific amplicons of the ovine herpesvirus 2, ...201323526124
efficacies of garlic and l. sakei in wine-based marinades for controlling listeria monocytogenes and salmonella spp. in chouriço de vinho, a dry sausage made from wine-marinated pork.chouriço de vinho is made from roughly minced (10 to 30 mm) pork and fat, seasoned with a marinade made from wine, salt, garlic, and other facultative seasonings used according to the recipe of each producer. the batter is maintained at 4 to 7 ºc for 24 to 48 h. it is then stuffed into natural thin pork gut, cold smoked and matured at a low temperature for 1 to 4 wk. the effect of garlic used in wine-based marinade and a starter culture of indigenous lactobacillus sakei on the behavior of lister ...201323527659
[analysis of international programs of the hygienic monitoring of foodborne pathogens].the article gives an overview of information international networks of monitoring the microbiological food safety in the world. the most famous are the european network of food safety (efsn), global network for disease surveillance, foodborne (gfn), international network for the determination of molecular subtypes of bacterial food patogens (pulsenet), international network of food safety (infosan). the network efsn is engaged development of information database and of warning systems to assess ...201223530431
comparative analysis of the exoproteomes of listeria monocytogenes strains grown at low temperatures.this article presents the major differences in the exoproteomes of listeria monocytogenes strains grown at 11°c and 20°c, and their comparison to 37°c, the optimal temperature of growth of this foodborne pathogenic bacteria. a set of four strains previously characterized and representing the genetic diversity of the species was used. two were virulent, of which one was persistent, and two were low virulent strains. the proteins secreted by the strains grown in minimal medium were separated by so ...201323531123
[cerebral listeria abscess in a patient with gastric cancer].history and presentation on admission: a 70-year-old woman with a history of gastric cancer and palliative chemotherapy was admitted with disturbed consciousness.201323533043
combination use of pfge and drug-resistant analysis in the epidemiological investigation of listeria monocytogenes. 201323534473
in vitro assessment of functional properties of lactic acid bacteria isolated from faecal microbiota of healthy dogs for potential use as probiotics.lactic acid bacteria were isolated and identified in the faeces of chinese crested and yorkshire terrier pups and their probiotic features were investigated in vitro. thirty seven isolates were identified as lactobacillus or enterococcus. out of these isolates, 31 were lactic acid bacteria (lab) and belonged to the species lactobacillus reuteri (16/37; 43.3%), lactobacillus animalis (7/37; 18.9%), lactobacillus acidophilus (3/37; 8.1%), lactobacillus sanfranciscensis (2/37; 5.4%), lactobacillus ...201323538205
how does listeria monocytogenes combat acid conditions?listeria monocytogenes, a major foodborne pathogen, possesses a number of mechanisms that enable it to combat the challenges posed by acidic environments, such as that of acidic foods and the gastrointestinal tract. one mechanism employed by l. monocytogenes for survival at low ph is the adaptive acid tolerance response (atr) in which a short adaptive period at a nonlethal ph induces metabolic changes that allow the organism to survive a lethal ph. overcoming acid conditions by l. monocytogenes ...201223540331
the application of high-concentration short-time chlorine dioxide treatment for selected specialty crops including roma tomatoes (lycopersicon esculentum), cantaloupes (cucumis melo ssp. melo var. cantaloupensis) and strawberries (fragaria×ananassa).the effects of high-concentration short-time chlorine dioxide (clo2) gas treatment on food-borne pathogens inoculated onto the surface of tomatoes, cantaloupes, and strawberries were studied. produce were spot-inoculated with a mixture of salmonella enterica (serotypes montevideo, javiana and baildon), escherichia coli o157:h7 (serotypes 204 p, edl 933 and c792) or listeria monocytogenes (serotypes scott a, f 5069 and lcdc 81-861), and treated with clo2 gas at 10 mg/l for 180 s. after clo2 gas t ...201323541196
the pathogen-annotated tracking resource network (patrn) system: a web-based resource to aid food safety, regulatory science, and investigations of foodborne pathogens and disease.investigation of foodborne diseases requires the capture and analysis of time-sensitive information on microbial pathogens that is derived from multiple analytical methods and sources. the web-based pathogen-annotated tracking resource network (patrn) system (www.patrn.net) was developed to address the data aggregation, analysis, and communication needs important to the global food safety community for the investigation of foodborne disease. patrn incorporates a standard vocabulary for describin ...201323541197
antimicrobial resistance and co-selection phenomenon in listeria spp. recovered from food and food production environments.antimicrobial resistance (amr), co-selection phenomenon, and the relationship between reduced susceptibility (rsc) to ciprofloxacin (cip) and resistance to other antimicrobials in listeria spp. (n = 103) recovered from food processing environments (fpe) and food were investigated. resistance of listeria monocytogenes and other listeriae, respectively, to cefoxitin (fox; 98% vs. 88%), cip (7% vs. 4%), clindamycin (cli; 33% vs. 59%) and tetracycline (6% vs. 8%) was observed, as was rsc to cip (67% ...201323541198
microbiological examination of ready-to-eat foods and ready-to-bake frozen pastries from university canteens.during a 10-year inspection survey (2001-2010), a microbiological study of ready-to-eat (rte) foods and ready-to-bake frozen pastries from 15 canteens of the university campus was undertaken to determine their microbiological quality. the cumulative study revealed that the aerobic colony counts for the rte product groups were as follows: from 10(6) to 10(8) cfu/g for 50% of sandwiches; under the detection limit (<10 cfu/g) for 88.6% of oven baked pastries; <10(5) cfu/g for 86.5% of desserts oven ...201323541200
the effect of american cranberry (vaccinium macrocarpon) constituents on the growth inhibition, membrane integrity, and injury of escherichia coli o157:h7 and listeria monocytogenes in comparison to lactobacillus rhamnosus.the antimicrobial properties of the american cranberry were studied against escherichia coli o157:h7, listeria monocytogenes, and lactobacillus rhamnosus to determine the effects on growth inhibition, membrane permeability, and injury. cranberry powder was separated using a c-18 sep-pak cartridge into sugars plus organic acids (f1), monomeric phenolics (f2), and anthocyanins plus proanthocyanidins (f3). fraction 3 was further separated into anthocyanins (f4) and proanthocyanidins (f5) using an l ...201323541202
biochemical, antimicrobial and molecular characterization of a noncytotoxic bacteriocin produced by lactobacillus plantarum st71ks.lactobacillus (lb.) plantarum st71ks was isolated from homemade goat feta cheese and identified using biochemical and molecular biology techniques. as shown by tricine-sds-page, this lactic acid bacterium produces a bacteriocin (st71ks) with an estimated molecular weight of 5.0 kda. bacteriocin st71ks was not affected by the presence of α-amylase, catalase and remained stable in a wide range of ph and after treatment with triton x-100, triton x-114, tween 20, tween 80, nacl, sds, urea and edta. ...201323541205
magnetic nano-beads based separation combined with propidium monoazide treatment and multiplex pcr assay for simultaneous detection of viable salmonella typhimurium, escherichia coli o157:h7 and listeria monocytogenes in food products.we developed a rapid and reliable technique for simultaneous detection of salmonella typhimurium, escherichia coli o157:h7 and listeria monocytogenes that can be used in food products. magnetic nano-beads (mnbs) based immunomagnetic separation (ims) was used to separate the target bacterial cells while multiplex pcr (mpcr) was used to amplify the target genes. to detect only the viable bacteria, propidium monoazide (pma) was applied to selectively suppress the dna detection from dead cells. the ...201323541211
impaired neutrophil function in 24p3 null mice contributes to enhanced susceptibility to bacterial infections.lipocalin 24p3 (24p3) is a neutrophil secondary granule protein. 24p3 is also a siderocalin, which binds several bacterial siderophores. it was therefore proposed that synthesis and secretion of 24p3 by stimulated macrophages or release of 24p3 upon neutrophil degranulation sequesters iron-laden siderophores to attenuate bacterial growth. accordingly, 24p3-deficient mice are susceptible to bacterial pathogens for which siderophores would normally be chelated by 24p3. specific granule deficiency ...201323543755
the tyrosine kinase btk regulates the macrophage response to listeria monocytogenes infection.in this study we investigated the role of bruton's tyrosine kinase (btk) in the immune response to the gram-positive intracellular bacterium listeria monocytogenes (lm). in response to lm infection, btk was activated in bone marrow-derived macrophages (bmms) and btk (-/-) bmms showed enhanced tnf-α, il-6 and il-12p40 secretion, while type i interferons were produced at levels similar to wild-type (wt) bmms. although btk-deficient bmms displayed reduced phagocytosis of e. coli fragments, there wa ...201323544144
physical-mechanical and antimicrobial properties of nanocomposite films with pediocin and zno nanoparticles.this work aimed to develop nanocomposite films of methyl cellulose (mc) incorporated with pediocin and zinc oxide nanoparticles (nanozno) using the central composite design and response surface methodology. this study evaluated film physical-mechanical properties, including crystallography by x-ray diffraction, mechanical resistance, swelling and color properties, microscopy characterization, thermal stability, as well as antimicrobial activity against staphylococcus aureus and listeria monocyto ...201323544529
cd137 expressed on neutrophils plays dual roles in antibacterial responses against gram-positive and gram-negative bacterial infections.severe sepsis and septic shock caused mainly by bacterial infections are life-threatening conditions that urge the development of novel therapies. however, host responses to and pathophysiology of sepsis have not been clearly understood, which remains a major obstacle for the development of effective therapeutics. recently, we have shown that stimulation of a costimulatory molecule, cd137, enhanced survival of mice infected with the gram-positive (g(+)) intracellular bacterium listeria monocytog ...201323545301
modeling the growth of listeria monocytogenes in mold-ripened cheeses.this study presents possible applications of predictive microbiology to model the safety of mold-ripened cheeses with respect to bacteria of the species listeria monocytogenes during (1) the ripening of camembert cheese, (2) cold storage of camembert cheese at temperatures ranging from 3 to 15°c, and (3) cold storage of blue cheese at temperatures ranging from 3 to 15°c. the primary models used in this study, such as the baranyi model and modified gompertz function, were fitted to growth curves. ...201323548297
cd30l/cd30 is critical for maintenance of il-17a-producing γδ t cells bearing vγ6 in mucosa-associated tissues in mice.cd30 ligand (cd30l, cd153), a member of the tumor necrosis factor (tnf) superfamily, and its receptor cd30 are important for differentiation and activation of cd4(+) t helper type 17 (th17) cells. in this report, we demonstrate that the interleukin 17a (il-17a)-producing γδ t cells normally developed in the fetal thymus, whereas vγ1(-)vγ4(-) γδ t cells expressed vγ6/vδ1 gene transcript selectively decreased in mucosa-associated tissues in naive cd30ko or cd30lko mice. moreover, cd30 and cd30l we ...201323549449
photoinactivation of bacteria attached to glass and acrylic surfaces by 405 nm light: potential application for biofilm decontamination.attachment of bacteria to surfaces and subsequent biofilm formation remains a major cause of cross-contamination capable of inducing both food-related illness and nosocomial infections. resistance to many current disinfection technologies means facilitating their removal is often difficult. the aim of this study was to investigate the efficacy of 405 nm light for inactivation of bacterial attached as biofilms to glass and acrylic. escherichia coli biofilms (10(3)-10(8) cfu ml(-1)) were generated ...201323550978
microbial diversity and prevalence of foodborne pathogens in cheap and junk foods consumed by primary schoolchildren.aerobic plate counts (apc), coliforms, bacillus cereus, escherichia coli and eight foodborne pathogens were tested in 1008 cheap and junk foods, including candies, dried cakes, chewing gum, chocolate, dried and seasoned seafood, ice cream, and sugary foods. apcs were positive for 342 samples (33·9%), and the majority of the counts were 2-3 log cfu g(-1) or ml(-1) (average: 1·10 log cfu g(-1) or ml(-1) ). most samples (97·3%) contained no coliforms (average: 0·07 log cfu g(-1) or ml(-1) ). bacill ...201323551123
listeria monocytogenes pleuritis: report of a geriatric case. 201323551348
production and evaluation of the utility of novel phage display-derived peptide ligands to salmonella spp. for magnetic separation.the objectives of this study were to produce salmonella-specific peptide ligands by phage display biopanning and evaluate their use for magnetic separation (ms).201323551658
developing the potential of using galleria mellonella larvae as models for studying brain infection by listeria monocytogenes. 201323552811
connexin43 is dispensable for phagocytosis.macrophages that lack connexin43 (cx43), a gap junction protein, have been reported to exhibit dramatic deficiencies in phagocytosis. in this study, we revisit these findings using well-characterized macrophage populations. cx43 knockout (cx43(-/-)) mice die soon after birth, making the harvest of macrophages from adult cx43(-/-) mice problematic. to overcome this obstacle, we used several strategies: mice heterozygous for the deletion of cx43 were crossed to produce cx43(+/+) (wild type [wt]) a ...201323554311
listeria monocytogenes dairy isolates show a different proteome response to sequential exposure to gastric and intestinal fluids.the gastrointestinal system poses different stresses to the foodborne pathogen, listeria monocytogenes, including the low ph of the stomach and the presence of bile and the high osmolality of the intestinal fluid. the present study evaluated how previous exposure of three l. monocytogenes dairy isolates (c882 and t8, serovar 4b isolates and a9 serovar 1/2a or 3b isolate) to a cheese-simulated medium (p h5.5 and 3.5% nacl [w/v], adapted cultures) affected subsequent survival in a simulated gastro ...201323558187
inactivation of listeria monocytogenes on frankfurters by plant-derived antimicrobials alone or in combination with hydrogen peroxide.listeria monocytogenes is a significant foodborne pathogen associated with outbreaks involving contaminated ready-to-eat (rte) products, including frankfurters. the usda-fsis has established a zero tolerance policy for l. monocytogenes in rte products, thereby warranting effective post-processing interventions to control the pathogen on these foods. in the present study, the antilisterial activity of gras (generally recognized as safe)-status plant-derived antimicrobials (pdas), namely β-resorcy ...201323558194
characterization of functional, safety, and gut survival related characteristics of lactobacillus strains isolated from farmhouse goat's milk cheeses.a set of 80 lactobacillus strains (36 lactobacillus plantarum and 44 lactobacillus paracasei) isolated from spanish farmhouse cheeses have been studied as to their functional and safety properties and their survival under gut-related conditions. none of these 80 lactobacillus strains were able to hydrolyse starch. a high percentage of l. plantarum and l. paracasei strains were, however, capable of hydrolysing casein (86.1% and 68.2% respectively). for the other characteristics investigated, l. p ...201323558197
effect of a combination of low level ozone and metal ions on reducing escherichia coli o157:h7 and listeria monocytogenes.ozonated water has been used as a strong antimicrobial agent against foodborne pathogens. in this study, the combined effect of low level ozonated water and different added components, including 0.2% starch and metal ions (1 mm cucl2·2h2o and 0.1 mm agno3), on inactivation of escherichia coli o157:h7 and listeria monocytogenes was investigated. treatment with 0.4 ppm ozonated water for 30 min resulted in a maximum log reduction in e. coli o157:h7 and l. monocytogenes compared to initial bacteria ...201323558542
active films based on cocoa extract with antioxidant, antimicrobial and biological applications.novel films of ethylene-vinyl alcohol copolymer (evoh) containing flavonoid-rich cocoa were developed. to understand their potential application as active packaging material, antioxidant and antimicrobial properties of the films were determined as well as the antioxidant activity of the release compounds in caco-2 human epithelial colorectal adenocarcinoma cells. exposure of the films to aqueous food simulant showed antioxidant capacity. the release of cocoa extract components was dependent on t ...201323561077
ligands affecting silver antimicrobial efficacy on listeria monocytogenes and salmonella enterica.although silver is being extensively used in food or other applications as the key component to control microbial proliferation, many factors affecting its real potential are still unknown. in the present work, the presence of specific ligands or the contents in organic matter was correlated with silver speciation and its antibacterial performance. silver was found to be only active in form of free silver ions (fsi). the presence of chloride ions produced an equilibrium of stable silver chloride ...201323561107
antibacterial activity-guided purification and identification of a novel c-20 oxygenated ent-kaurane from rabdosia serra (maxim.) hara.the objective of this work was to conduct an activity-guided isolation of antibacterial compounds from rabdosia serra. the ethanol extracts of r. serra leaf and stem were partitioned sequentially into petroleum ether, ethyl acetate, butanol and water fractions, respectively. the ethanol extract of leaf evidenced broad-spectrum antibacterial activity against gram-positive bacterial, including bacillus subtilis, bacillus cereus, staphylococcus aureus, and listeria monocytogenes. the ethyl acetate ...201323561188
molluskan fasciclin-1 domain-containing protein: molecular characterizationand gene expression analysis of fasciclin 1-like protein from disk abalone (haliotis discus discus).cell-to-cell contacts play a key role in multicellular systems and organisms. fasciclin-1 (fas-1) is a lipid-linked membrane associated glycoprotein that is a member of a newly recognized family of cell adhesion molecules sharing features with the immunoglobulins, cadherins, integrins, and selectins. here, we report the identification and molecular characterization of a novel fas-1 domain-containing cdna from disk abalone (haliotis discus discus), including its gene expression profile and immune ...201323562785
mutations in gltb and gltc reduce oxidative stress tolerance and biofilm formation in listeria monocytogenes 4b g.the foodborne pathogen listeria monocytogenes has the capability to persist on surfaces in food-processing environments, and the organism is resistant to environmental stresses. in this study, a tn917 insertion mutant of l. monocytogenes 4b g showing reduced biofilm formation and sensitivity to oxidative stress was identified and characterized. the transposon insertion site within the gltb gene was identified by inverse pcr. the gltc gene is located upstream and is reported to be transcribed div ...201323562858
nation-wide study of the occurrence of listeria monocytogenes in french soils using culture-based and molecular detection methods.soil is a potential reservoir of human pathogens and a possible source of contamination of animals, crops and water. in order to study the distribution of listeria monocytogenes in french soils, a real-time pcr taqman assay targeting the phosphoribosylpyrophosphate synthetase (prs) gene of l. monocytogenes was developed for the specific detection and quantification of this bacterium within a collection of 1315 soil dnas originated from the french soil quality monitoring network. the prs real-tim ...201323566826
listeriosis in patients receiving biologic therapies.the evolution of inflammatory diseases has radically changed since the introduction of biologic therapies, such as tumour necrosis factor alpha inhibitors (anti-tnfα). they, therefore, represent a widely used therapeutic modality. nevertheless, post-marketing studies reveal an increased risk of infection in patients taking these drugs, especially granulomatous infections such as listeriosis. we aimed to evaluate the reported cases of listeriosis in patients treated with biologic treatments. we u ...201323568606
simultaneous detection of listeria monocytogenes and salmonella spp. in dairy products using real time pcr-melt curve analysis.the present investigation reports development of post real time pcr (rti-pcr) - melt curve analysis for simultaneous detection of listeria monocytogenes and salmonella spp. the optimal sybr green i (sg-i) concentration of 1.6 μm resulted in two specific peaks with melting temperature (tm) of 79.90 ± 0.39 °c and 86.29 ± 0.13 °c for l. monocytogenes and salmonella spp respectively. the detection sensitivity of the assay in reconstituted non-fat dried milk (nfdm; 11%) spiked with the target pathoge ...201123572847
behavior of salmonella spp., listeria monocytogenes, and staphylococcus aureus in chouriço de vinho, a dry fermented sausage made from wine-marinated meat.portuguese chouriço de vinho is made by drying coarsely minced meat and fat that has been previously marinated with wine (usually red), salt, and garlic for 1 to 2 days at a low temperature (4 to 8 °c). this procedure may improve the microbiological safety of the product. the aim of this study was to evaluate the behavior of three pathogens in this product, salmonella spp., listeria monocytogenes, and staphylococcus aureus, to establish the minimum period of drying and maturation necessary to re ...201323575119
reduction by competitive bacteria of listeria monocytogenes in biofilms and listeria bacteria in floor drains in a ready-to-eat poultry processing plant.the ability of listeria monocytogenes and two competitive exclusion (ce) bacteria, lactococcus lactis subsp. lactis strain c-1-92 and enterococcus durans strain 152, to form biofilms on coupons composed of different materials (stainless steel, plastic, rubber, glass, and silicone) was determined at 4 and 8 °c. biofilm characteristics were determined by scanning electron microscopy. l. monocytogenes produced well-formed biofilms within 24 h at 37 °c on coupon surfaces. treating listeria-laden bio ...201323575121
incidence of listeria monocytogenes and listeria spp. in a small-scale mushroom production facility.listeria monocytogenes is a foodborne pathogen of significant concern to the agricultural and food processing industry because of its ability to grow and persist in cool and moist environments and its association with listeriosis, a disease with a very high mortality rate. although there have been no listeriosis outbreaks attributed to fresh mushrooms in the united states, retail surveys and recalls are evidence that l. monocytogenes contamination of mushrooms (agaricus bisporus) can occur. the ...201323575122
diagnostic exercise: suppurative rhombencephalitis and meningitis in a goat.a 1-year-old female boer goat was presented for necropsy following spontaneous death and history of acute recumbency, nystagmus, and sialorrhea. a swollen area was grossly observed in the brainstem at the level of the pons. on cut surface, the right cerebellar peduncles were expanded by a focal, pale, poorly demarcated, slightly depressed, and soft area of malacia. microscopically, this area contained diffuse edema and necrosis, with microabscesses, neuronal necrosis, neuronophagia, axonal spher ...201423576239
optimized multilocus variable-number tandem-repeat analysis assay and its complementarity with pulsed-field gel electrophoresis and multilocus sequence typing for listeria monocytogenes clone identification and surveillance.populations of the food-borne pathogen listeria monocytogenes are genetically structured into a small number of major clonal groups, some of which have been implicated in multiple outbreaks. the goal of this study was to develop and evaluate an optimized multilocus variable number of tandem repeat (vntr) analysis (mlva) subtyping scheme for strain discrimination and clonal group identification. we evaluated 18 vntr loci and combined the 11 best ones into two multiplexed pcr assays (mlva-11). a c ...201323576539
comparison of quantitative pcr and flow cytometry as cellular viability methods to study bacterial membrane permeabilization following supercritical co2 treatment.foodborne illness due to bacterial pathogens is increasing worldwide as a consequence of the higher consumption of fresh and minimally processed food products, which are more easily cross-contaminated. the efficiency of food pasteurization methods is usually measured by c.f.u. plate counts, a method discriminating viable from dead cells on the basis of the ability of cells to replicate and form colonies on standard growth media, thus ignoring viable but not cultivable cells. supercritical co2 (s ...201323579687
arcanobacterium haemolyticum osteomyelitis and sepsis: a diagnostic conundrum.arcanobacterium haemolyticum can cause severe systemic infections and sepsis. thus, accurate and timely identification of the organism is essential.201323581632
host and bacterial factors that regulate lc3 recruitment to listeria monocytogenes during the early stages of macrophage infection.listeria monocytogenes is a bacterial pathogen that can escape the phagosome and replicate in the cytosol of host cells during infection. we previously observed that a population (up to 35%) of l. monocytogenes strain 10403s colocalize with the macroautophagy marker lc3 at 1 h postinfection. this is thought to give rise to spacious listeria-containing phagosomes (slaps), a membrane-bound compartment harboring slow-growing bacteria that is associated with persistent infection. here, we examined t ...201323584039
an internalin a probe-based genosensor for listeria monocytogenes detection and differentiation.internalin a (inla), a protein required for listeria monocytogenes virulence, is encoded by the inla gene, which is only found in pathogenic strains of this genus. one of the best ways to detect and confirm the pathogenicity of the strain is the detection of one of the virulence factors produced by the microorganism. this paper focuses on the design of an electrochemical genosensor used to detect the inla gene in listeria strains without labelling the target dna. the electrochemical sensor was o ...201323586053
fibronectin-binding protein, fbpa, is the adhesin responsible for pathogenesis of listeria monocytogenes infection.the role of fibronectin binding protein a (fbpa) in listeria monocytogenes infection and its pathogenesis were studied in vivo and in vitro by constructing a fbpa-deficient mutant of l. monocytogenes (δfbpa). in vivo, δfbpa was less pathogenic in mutant mice than was wild-type l. monocytogenes. fbpa did not affect the amounts of various virulence-determining factors, including internalin b and listeriolysin o. however, adherence to, and invasion of, mouse hepatocytes by the δfbpa mutant were red ...201323586629
an improved susceptibility test based on amberlite reveals the potential antilisterial activity of fosfomycin in vitro.listeria monocytogenes is resistant to fosfomycin in vitro but is susceptible in vivo due to increased expression of positive regulator factor a (prfa) and its dependent factor, hexose phosphate transporter (hpt), upon infection of host cells. amberlite, a polymeric adsorbent resin, could induce prfa-dependent gene expression and thus, in theory, improve the sensitivity of l. monocytogenes to fosfomycin in vitro. in the current study, an improved susceptibility test based on amberlite was develo ...201323586749
predictive model for the reduction of heat resistance of listeria monocytogenes in ground beef by the combined effect of sodium chloride and apple polyphenols.we investigated the combined effect of three internal temperatures (57.5, 60, and 62.5°c) and different concentrations (0 to 3.0 wt/wt.%) of sodium chloride (nacl) and apple polyphenols (app), individually and in combination, on the heat-resistance of a five-strain cocktail of listeria monocytogenes in ground beef. a complete factorial design (3×4×4) was used to assess the effects and interactions of heating temperature, nacl, and app. all 48 combinations were tested twice, to yield 96 survival ...201323587714
prevalence of listeria monocytogenes in idiazabal cheese.raw-milk cheese has been identified in risk assessment as a food of greater concern to public health due to listeriosis.201223588469
listeria monocytogenes sequence type 6 and increased rate of unfavorable outcome in meningitis: epidemiologic cohort study.we analyzed clinical characteristics, treatment, genetic diversity, and outcome of 92 adults with listeria monocytogenes meningitis included in 2 prospective nationwide cohort studies.201323592828
genomic and enzymatic results show bacillus cellulosilyticus uses a novel set of lpxta carbohydrases to hydrolyze polysaccharides.alkaliphilic bacillus species are intrinsically interesting due to the bioenergetic problems posed by growth at high ph and high salt. three alkaline cellulases have been cloned, sequenced and expressed from bacillus cellulosilyticus n-4 (bcell) making it an excellent target for genomic sequencing and mining of biomass-degrading enzymes.201323593409
[in vitro activity of doripenem against strains from pediatric diseases and strains causing purulent meningitis].this study evaluated the in vitro activity of doripenem (drpm) against 200 streptococcus pneumoniae and 197 haemophilus influenzae from children and adults in 2007, 50 h. influenzae type b in 2006, 20 listeria monocytogenes in 1990-2005, 23 neisseria meningitidis in 2007-2009 and 83 bordetella pertussis in 1989-2003. all strains were isolated from japanese clinical facilities. we also investigated in vitro activity of other carbapenems (meropenem, imipenem, panipenem, biapenem), cephems (ceftria ...201223593734
weissellicin l, a novel bacteriocin from sian-sianzih-isolated weissella hellenica 4-7.to identify and characterize novel bacteriocins from weissella hellenica 4-7.201323594122
evaluation of the haccp system in a university canteen: microbiological monitoring and internal auditing as verification tools.food safety is essential in mass catering. in europe, regulation (ec) no. 852/2004 requires food business operators to put in place, implement and maintain permanent procedures based on hazard analysis and critical control point (haccp) principles. each haccp plan is specifically implemented for the processing plant and processing methods and requires a systematic collection of data on the incidence, elimination, prevention, and reduction of risks. in this five-year-study, the effectiveness of t ...201323594937
the tat pathway is prevalent in listeria monocytogenes lineage ii and is not required for infection and spread in host cells.listeria monocytogenes, a foodborne pathogenic bacterium, remains a serious public health concern due to its frequent occurrence in food products coupled with a high mortality rate. bacterial pathogenicity depends greatly on the ability to secrete virulence factors to or beyond the bacterial cell surface. the tat pathway, one of the secretion systems present in l. monocytogenes, was until now only investigated in silico. in l. monocytogenes strain egde two genes constitute this pathway, tatc(lmo ...201323595063
targeting agr- and agr-like quorum sensing systems for development of common therapeutics to treat multiple gram-positive bacterial infections.invasive infection by the gram-positive pathogen staphylococcus aureus is controlled by a four gene operon, agr that encodes a quorum sensing system for the regulation of virulence. while agr has been well studied in s. aureus, the contribution of agr homologues and analogues in other gram-positive pathogens is just beginning to be understood. intriguingly, other significant human pathogens, including clostridium perfringens, listeria monocytogenes, and enterococcus faecalis contain agr or analo ...201323598501
listeriosis infection of an abdominal aortic aneurysm in a diabetic patient.a rare case of an abdominal aortic aneurysm (aaa) infected by listeria monocytogenes in a 72-year-old male diabetic farmer, is reported. our patient had a history of a recent pneumonia that could have been caused by listeria too. aneurysm infection was manifested by fever and abdominal and back pain, which prompted investigation with ct scanning that revealed a 4.9 cm aaa with typical signs of infection. he underwent urgent aaa repair with aortobifemoral bypass grafting and had an uneventful cou ...201323599616
architecture and assembly of the gram-positive cell wall.the bacterial cell wall is a mesh polymer of peptidoglycan--linear glycan strands cross-linked by flexible peptides--that determines cell shape and provides physical protection. while the glycan strands in thin 'gram-negative' peptidoglycan are known to run circumferentially around the cell, the architecture of the thicker 'gram-positive' form remains unclear. using electron cryotomography, here we show that bacillus subtilis peptidoglycan is a uniformly dense layer with a textured surface. we f ...201323600697
virulence aspects of listeria monocytogenes lo28 high pressure-resistant variants.high pressure treatment is a novel food processing approach for reducing pathogens in foods and food ingredients. however, relatively little is known about the pathogenic potential of organisms that survive the treatment. twelve previously isolated and characterized variants of listeria monocytogenes lo28 obtained after a high pressure treatment were assessed for their virulence potential and antibiotic susceptibility. ten variants showed attenuated virulence while two variants retained full vir ...201323603274
nontoxic radioactive listeria(at) is a highly effective therapy against metastatic pancreatic cancer.no significant improvement in therapy of pancreatic cancer has been reported over the last 25 y, underscoring the urgent need for new alternative therapies. here, we coupled a radioisotope, (188)rhenium, to an attenuated (at) live listeria monocytogenes (listeria(at)) using listeria-binding antibodies, thus creating a unique radioactive listeria(at) (rl). we then demonstrated in a highly metastatic pancreatic mouse tumor model (panc-02) that rl delivered radioactivity to the metastases and less ...201323610422
evaluation of characteristics of pediococcus spp. to be used as a vaginal probiotic.the aim of our research was to select, identify and characterize an isolate of lactic acid bacteria to be considered as a vaginal probiotic.201323611355
[effects of the deletion of rsbv gene on virulence of listeria monocytogenes].to study the effect of rsbv gene deletion on the virulence of listeria monocytogenes.201323614241
analyzing indicator microorganisms, antibiotic resistant escherichia coli, and regrowth potential of foodborne pathogens in various organic fertilizers.this study analyzed various organic fertilizers for indicator microorganisms, pathogens, and antibiotic-resistant escherichia coli, and evaluated the growth potential of e. coli o157:h7 and salmonella in fertilizers. a microbiological survey was conducted on 103 organic fertilizers from across the united states. moisture content ranged from approximately 1% to 86.4%, and the average ph was 7.77. the total aerobic mesophiles ranged from approximately 3 to 9 log colony-forming units (cfu)/g. enter ...201323614803
screening for polyphenols, antioxidant and antimicrobial activitiesof extracts from eleven helianthemum taxa (cistaceae) used in folk medicine in south-eastern spain.the helianthemum genus contains approximately one hundred taxa. some of them are important medicinal plants used in several countries for many different purposes. however, studies addressing the phytochemistry of many of these species or their biological activities are currently nonexistent.201323615124
stereotactic biopsy and drainage of a brainstem abscess caused by listeria monocytogenes.listerial rhombencephalitis and brain abscesses are rare, but potentially life-threatening conditions. early initiation of antibiotic therapy is crucial, but establishing the diagnosis of listerial brainstem abscess can be difficult. stereotactic biopsy and drainage of space-occupying abscesses of the brainstem should be considered especially in cases of rapid clinical deterioration. we successfully performed stereotactic biopsy and drainage of a listerial brainstem abscess in a 42-year-old male ...201323615421
ovalbumin-related protein x is a heparin-binding ov-serpin exhibiting antimicrobial activities.ovalbumin family contains three proteins with high sequence similarity: ovalbumin, ovalbumin-related protein y (ovay), and ovalbumin-related protein x (ovax). ovalbumin is the major egg white protein with still undefined function, whereas the biological activity of ovax and ovay has not yet been explored. similar to ovalbumin and ovay, ovax belongs to the ovalbumin serine protease inhibitor family (ov-serpin). we show that ovax is specifically expressed by the magnum tissue, which is responsible ...201323615912
influence of internalin a murinisation on host resistance to orally acquired listeriosis in mice.the bacterial surface protein internalin (inla) is a major virulence factor of the food-born pathogen listeria monocytogenes. it plays a critical role in the bacteria crossing the host intestinal barrier by a species-specific interaction with the cell adhesion molecule e-cadherin. in mice, the interaction of inla with murine e-cadherin is impaired due to sequence-specific binding incompatibilities. we have previously used the approach of 'murinisation' to establish an oral listeriosis infection ...201323617550
the effect of vaccines based on ovalbumin coupled to gas-filled microbubbles for reducing infection by ovalbumin-expressing listeria monocytogenes.gas-filled microbubbles (mb) are a very promising alternative to the currently evaluated lipid- or polymer-based particulate ag delivery systems. we recently demonstrated the ability of mb to deliver associated ag to dc, to activate them and thereby induce both humoral and cellular immune responses. we now extended the characterization of mb as antigen-delivery system by appraising the efficiency of mb-associated ovalbumin (ova-mb) at protecting mice against pathogen infection. ultrasound-mediat ...201323618628
refinement of the listeria monocytogenes σb regulon through quantitative proteomic analysis.σ(b) is an alternative σ factor that regulates stress response and virulence genes in the foodborne pathogen listeria monocytogenes. to gain further insight into σ(b)-dependent regulatory mechanisms in l. monocytogenes, we (i) performed quantitative proteomic comparisons between the l. monocytogenes parent strain 10403s and an isogenic δsigb mutant and (ii) conducted a meta-analysis of published microarray studies on the 10403s σ(b) regulon. a total of 134 genes were found to be significantly po ...201323618998
on-chip parallel detection of foodborne pathogens using loop-mediated isothermal amplification.according to estimates issued by the center for disease control and prevention, one out of six americans will get sick during this year due to consumption of contaminated products and there will be 50,000 related hospitalizations. to control and treat the responsible foodborne diseases, rapid and accurate detection of pathogens is extremely important. a portable device capable of performing nucleic acid amplification will enable the effective detection of infectious agents in multiple settings, ...201323620454
the effect of ozone and open air factor on surface-attached and biofilm environmental listeria monocytogenes.the effects of gaseous ozone and open air factor (oaf) on environmental listeria monocytogenes attached to three common food contact surfaces were investigated.201323621101
probing determinants of cyclopiazonic acid sensitivity of bacterial ca2+-atpases.cyclopiazonic acid (cpa) is a specific and potent inhibitor of the sarcoplasmic reticulum ca(2+)-atpase 1a (serca1a). despite high sequence similarity to serca1a, listeria monocytogenes ca(2+)-atpase 1 (lmca1) is not inhibited by cpa. to test whether a cpa binding site could be created while maintaining the functionality of the atpase we targeted four amino acid positions in lmca1 for mutational studies based on a multiple sequence alignment of serca-like ca(2+)-atpases and structural analysis o ...201323621633
acid shock of listeria monocytogenes at low environmental temperatures induces prfa, epithelial cell invasion, and lethality towards caenorhabditis elegans.the saprophytic pathogen listeria monocytogenes has to cope with a variety of acidic habitats during its life cycle. the impact of low-temperature coupled with ph decrease for global gene expression and subsequent virulence properties, however, has not been elucidated.201323622257
in-house validation of a multiplex real-time pcr method for simultaneous detection of salmonella spp., escherichia coli o157 and listeria monocytogenes.a wide variety of qpcr methods currently exist for salmonella spp., escherichia coli o157 and listeria monocytogenes detection. these methods target several genes and use different detection chemistries, either in simplex or in multiplex formats. however, the majority of these methods have not been carefully validated, and the number of validated methods that use multiplex qpcr is even lower. the aim of the present study was to develop and validate a multiplex qpcr method from previously validat ...201323624537
the antimicrobial effects of wood-associated polyphenols on food pathogens and spoilage organisms.the antimicrobial effects of the wood-associated polyphenolic compounds pinosylvin, pinosylvin monomethyl ether, astringin, piceatannol, isorhapontin, isorhapontigenin, cycloxme, dhimp, arx, and arxoh were assessed against both gram-negative (salmonella) and gram-positive bacteria (listeria monocytogenes, staphylococcus epidermidis, staphylococcus aureus) and yeasts (candida tropicalis, saccharomyces cerevisiae). particularly the stilbenes pinosylvin, its monomethyl ether and piceatannol demonst ...201323624538
persistent listeria monocytogenes subtypes isolated from a smoked fish processing facility included both phage susceptible and resistant isolates.contamination of ready-to-eat foods with listeria monocytogenes can typically be traced back to post-processing contamination from environmental sources; contamination is often linked to subtypes that persist in food associated environments. although phage-based biocontrol strategies have been proposed for controlling this pathogen, information on the efficacy of phage treatment against diverse l. monocytogenes subtypes from food associated environments is still limited. we identified subtypes t ...201323628613
molecular subtyping and virulence gene analysis of listeria monocytogenes isolates from food.a total of 67 listeria monocytogenes isolates from 698 raw meat samples were characterized for molecular serogroup identification and antimicrobial susceptibility. approximately one third (32.8%) of the isolates belonged to molecular serogroup 1/2a, 3a, followed by 1/2c, 3c (26.9%), 1/2b, 3b, 7 (22.4%), 4b, 4d, 4e (16.4%) and 4a, 4c (1.5%). most of the l. monocytogenes isolates were susceptible to 14 antimicrobials tested but several were resistant to tetracycline, ciprofloxacin and nitrofuranto ...201323628615
effect of combination of essential oils and bacteriocins on the efficacy of gamma radiation against salmonella typhimurium and listeria monocytogenes.using essential oils (eo) alone or combined eo with nisin to enhance the lethality of salmonella typhimurium and listeria monocytogenes to γ-irradiation treatment.201323631567
myeloid-derived suppressor cells have a central role in attenuated listeria monocytogenes-based immunotherapy against metastatic breast cancer in young and old mice.myeloid-derived suppressor cells (mdscs) are present in large numbers in blood of mice and humans with cancer, and they strongly inhibit t-cell and natural killer (nk) cell responses, at young and old age. we found that a highly attenuated bacterium listeria monocytogenes (listeria(at))-infected mdsc and altered the immune-suppressing function of mdsc.201323640395
4-1bb signal stimulates the activation, expansion, and effector functions of γδ t cells in mice and humans.we show here that the expression of 4-1bb is rapidly induced in γδ t cells following antigenic stimulation in both mice and humans, and ligation of the newly acquired 4-1bb with an agonistic anti-4-1bb augments cell division and cytokine production. we further demonstrate that γδ rather than αβ t cells protect mice from listeria monocytogenes (lm) infection and 4-1bb stimulation enhances the γδ t-cell activities in the acute phase of lm infection. ifn-γ produced from γδ t cells was the major sol ...201323640752
implementation of statistical tools to support identification and management of persistent listeria monocytogenes contamination in smoked fish processing plants.listeria monocytogenes persistence in food processing plants is a key source of postprocessing contamination of ready-to-eat foods. thus, identification and elimination of sites where l. monocytogenes persists (niches) is critical. two smoked fish processing plants were used as models to develop and implement environmental sampling plans (i) to identify persistent l. monocytogenes subtypes (ecori ribotypes) using two statistical approaches and (ii) to identify and eliminate likely l. monocytogen ...201323643121
refined liquid smoke: a potential antilisterial additive to cold-smoked sockeye salmon (oncorhynchus nerka).cold-smoked salmon (css) is a potentially hazardous ready-to-eat food product due to the high risk of contamination with listeria monocytogenes and lack of a listericidal step. we investigated the antilisterial property of liquid smokes (ls) against listeria innocua atcc 33090 (surrogate to l. monocytogenes) as a potential supplement to vacuum-packaged css. a full-strength ls (code 10-poly), and three commercially refined fractions (am-3, am-10, and 1291) having less color and flavor (lower cont ...201323643122
effect of the temperature of the dipping solution on the antimicrobial effectiveness of various chemical decontaminants against pathogenic and spoilage bacteria on poultry.the influence of the temperature of the dipping solution on the antimicrobial effectiveness of several chemical poultry decontaminants was assessed. a total of 765 poultry legs were inoculated with gram-positive bacteria (listeria monocytogenes, staphylococcus aureus, bacillus cereus, or brochothrix thermosphacta) or gram-negative bacteria (salmonella enterica serotype enteritidis, escherichia coli, yersinia enterocolitica, or pseudomonas fluorescens). samples were dipped for 15 min in solutions ...201323643125
growth potential of salmonella and listeria monocytogenes in ready-to-eat lettuce and collard greens packaged under modified atmosphere and in perforated film.this study was aimed at determining the effects of different storage scenarios on the growth potential of salmonella strains and listeria monocytogenes in ready-to-eat (rte) mixes of iceberg and crisp lettuces (lactuca sativa) and collard greens (brassica oleracea). vegetables were submitted to minimal processing, experimentally contaminated to achieve 10(1) and 10(2) cfu/g, packed under modified atmosphere and in perforated film, and submitted to the following storage scenarios: i = 100 % of th ...201323643135
a comparative study of fine polished stainless steel, tin and tin/ag surfaces: adhesion and attachment strength of listeria monocytogenes as well as anti-listerial effect.magnetron sputtering was used to produce nanocomposite tin and tin/ag coatings on stainless steel surfaces. the surface chemistry (edx), physicochemical properties (contact angles), topography and roughness parameters (wlp and afm) of the fine polished stainless steel (fpss), tin and tin/8.6 at.% ag surfaces were examined. real-time initial adhesion of two listeria monocytogenes strains (egde and 64) to the three surfaces was determined under flow conditions, and their attachment strength after ...201323643915
survival of listeria monocytogenes cells and the effect of extended frozen storage (-20°c) on the expression of its virulence gene.listeria monocytogenes is the main bacteria incriminated in contaminating cold storage food and ready-to-eat products. survival of four l. monocytogenes food isolates was examined during freezing and cold storage. slices of artisanal cheese were inoculated with listeria strains and incubated at -20 °c. their survival rate was recorded during the storage period. then, transcript levels of four virulence genes (hlya, iap, fri, and flaa) were evaluated using a semiquantitative reverse transcriptase ...201323649307
a new hybrid bacteriocin, ent35-mccv, displays antimicrobial activity against pathogenic gram-positive and gram-negative bacteria.bacteriocins and microcins are ribosomally synthesized antimicrobial peptides that are usually active against phylogenetically related bacteria. thus, bacteriocins are active against gram-positive while microcins are active against gram-negative bacteria. the narrow spectrum of action generally displayed by bacteriocins from lactic acid bacteria represents an important limitation for the application of these peptides as clinical drugs or as food biopreservatives. the present study describes the ...201223650575
prfa led to reduced biofilm formation and contributed to altered gene expression patterns in biofilm-forming listeria monocytogenes.the foodborne pathogen listeria monocytogenes has the ability to develop biofilm in the food-processing environment, which becomes a major concern for food safety. prfa, a key transcriptional activator that regulates most of the known listerial virulence gene expression, has been shown to promote l. monocytogenes biofilm formation. in this study, the whole-genome microarray was used to identify differentially expressed genes associated with the putative interaction between biofilm formation and ...201323652633
age-dependent differences in systemic and cell-autonomous immunity to l. monocytogenes.host defense against infection can broadly be categorized into systemic immunity and cell-autonomous immunity. systemic immunity is crucial for all multicellular organisms, increasing in importance with increasing cellular complexity of the host. the systemic immune response to listeria monocytogenes has been studied extensively in murine models; however, the clinical applicability of these findings to the human newborn remains incompletely understood. furthermore, the ability to control infecti ...201323653659
rig-i detects triphosphorylated rna of listeria monocytogenes during infection in non-immune cells.the innate immune system senses pathogens by pattern recognition receptors in different cell compartments. in the endosome, bacteria are generally recognized by tlrs; facultative intracellular bacteria such as listeria, however, can escape the endosome. once in the cytosol, they become accessible to cytosolic pattern recognition receptors, which recognize components of the bacterial cell wall, metabolites or bacterial nucleic acids and initiate an immune response in the host cell. current knowle ...201323653683
occurrence of mutations impairing sigma factor b (sigb) function upon inactivation of listeria monocytogenes genes encoding surface proteins.bacteria of the genus listeria contain the largest family of lpxtg surface proteins covalently anchored to the peptidoglycan. the extent to which these proteins may function or be regulated cooperatively is at present unknown. because of their unique cellular location, we reasoned that distinct lpxtg proteins could act as elements contributing to cell wall homeostasis or influencing the stability of other surface proteins bound to peptidoglycan. to test this hypothesis, we used proteomics to ana ...201323657685
live-attenuated listeria-based immunotherapy.for decades listeria monocytogenes has been used as a model of host-disease immunology, and a considerable body of knowledge has been amassed regarding the complex immune response to l. monocytogenes. attenuated strains of l. monocytogenes are currently being assessed as therapeutic bacterial vectors to present tumor-associated antigens to the immune system for the clinical treatment of cancer. l. monocytogenes immunotherapy utilizes many synchronous and disparate action mechanisms that stimulat ...201323659298
effects of flower and fruit extracts of melastoma malabathricum linn. on growth of pathogenic bacteria: listeria monocytogenes, staphylococcus aureus, escherichia coli, and salmonella typhimurium.melastoma malabathricum linn. is a shrub that comes with beautiful pink or purple flowers and has berries-like fruits rich in anthocyanins. this study was carried out with the aim to evaluate the inhibitory activities of different concentrations of the m. malabathricum linn. flower and fruit crude extracts against listeria monocytogenes imr l55, staphylococcus aureus imr s244, escherichia coli imr e30, and salmonella typhimurium imr s100 using the disc diffusion method. the lowest concentrations ...201323662136
survey of listeria monocytogenes, salmonella spp. and escherichia coli o157:h7 in raw ingredients and ready-to-eat products by commercial real-time pcr kits.real-time pcr (rtipcr) assays including enrichment stage were evaluated for the rapid detection of listeria monocytogenes, salmonella spp. and escherichia coli o157:h7 in raw ingredients and ready-to-eat products using molecular beacon probes available as commercial kits (warnex genevision, canada & aes chemunex detection system, france). the accuracy of the assays was evaluated analyzing 1032 naturally contaminated food samples in combination to the conventional cultural methods. presence/absen ...201323664258
crystal structures of bifunctional penicillin-binding protein 4 from listeria monocytogenes.penicillin-binding proteins (pbps), which catalyze the biosynthesis of the peptidoglycan chain of the bacterial cell wall, are the major molecular target of bacterial antibiotics. here, we present the crystal structures of the bifunctional peptidoglycan glycosyltransferase (gt)/transpeptidase (tp) pbp4 from listeria monocytogenes in the apo-form and covalently linked to two β-lactam antibiotics, ampicillin and carbenicillin. the orientation of the tp domain with respect to the gt domain is disti ...201323669378
Refresh
firstprev
...131132133134135136137138139140...
nextlast
Displaying items 13501 - 13600 of 16792