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sigma(b) and sigma(l) contribute to listeria monocytogenes 10403s response to the antimicrobial peptides sdpc and nisin.the ability of the foodborne pathogen listeria monocytogenes to survive antimicrobial treatments is a public health concern; therefore, this study was designed to investigate genetic mechanisms contributing to antimicrobial response in l. monocytogenes. in previous studies, the putative bacteriocin immunity gene lmo2570 was predicted to be regulated by the stress responsive alternative sigma factor, sigma(b). as the alternative sigma factor sigma(l) controls expression of genes important for res ...200919642919
fulminant prosthetic valve endocarditis caused by listeria monocytogenes. 200919643625
mechanism involved in phagocytosis and killing of listeria monocytogenes by acanthamoeba polyphaga.intra-cellular pathogen, listeria monocytogenes, is capable of invasion and survival within mammalian cells. however, acanthamoeba polyphaga trophozoites phagocytose and rapidly degrade listeria cells. in order to provide more information on amoeba phagocytosis and killing mechanisms, this study used several inhibitor agents known to affect the phagocytosis and killing of bacteria by eukaryotes. amoebae were pre-treated with mannose, cytochalasin d, wortmannin, suramin, ammonium chloride, bafilo ...200919644706
high efficacy of a listeria-based vaccine against metastatic breast cancer reveals a dual mode of action.most cancer vaccines induce ctl responses to tumor-associated antigens (taa). killing of tumor cells occurs through taa-specific ctl-mediated cytolysis. here, we show that one preventive followed by two therapeutic immunizations with an attenuated listeria monocytogenes (lm)-based vaccine eradicates all metastases and almost the entire primary tumor in the syngeneic, aggressive mouse breast tumor model 4t1. we provide strong evidence that this is due to the combined result of direct kill by list ...200919584282
[headaches and aphasia in an immunocompromised patient].we report the case of a 81-year-old, immunocompromised patient, admitted to our hospital with new-onset headaches and word-finding difficulties. the mri of the brain revealed a temporal mass on the left with marginal contrast-enhancement. during the next days listeria monocytogenes grew in the bloodcultures so that the diagnosis of a brain-abscess caused by listeria was established. due to the localisation, surgical drainage of the abscess was not possible, so that a prolonged antibiotic therapy ...200919585445
anti-listerial activity and structure-activity relationships of the six major tyrocidines, cyclic decapeptides from bacillus aneurinolyticus.six major tyrocidines, purified from the antibiotic tyrothricin complex produced by bacillus aneurinolyticus, showed significant lytic and growth inhibitory activity towards the gram+ bacteria, micrococcus luteus and listeria monocytogenes, but not against the gram- bacterium, escherichia coli. the isolated natural tyrocidines were in particular more active against the leucocin a (antimicrobial peptide) resistant strain, l. monocytogenes b73-mr1, than the sensitive l. monocytogenes b73 strain. r ...200919586775
nisin, rosemary, and ethylenediaminetetraacetic acid affect the growth of listeria monocytogenes on ready-to-eat turkey ham stored at four degrees celsius for sixty-three days.the objectives of this study were to determine the anti-listeria and general antimicrobial properties of nisin, rosemary, and edta alone and in combination on listeria monocytogenes inoculated on ready-to-eat vacuum-packaged diced turkey ham and to ascertain the effects of the treatments on ph and objective color. the turkey hams were cut into 0.5-cm pieces, inoculated with a l. monocytogenes cocktail containing 5 strains of the bacterium, and treated with either no treatment and no inoculum (ne ...200919590093
seroprevalence of neospora caninum in dairy cattle ranches with high abortion rate: special emphasis to serologic co-existence with toxoplasma gondii, brucella abortus and listeria monocytogenes.the aim of this study was to determine seroprevalence of neospora caninum in dairy cattle ranches with higher abortion rates and co-existence of neospora caninum, toxoplasma gondii, brucella abortus, and listeria monocytogenes antibodies. the blood samples were collected from dairy cows with history of abortion (n=234) as well as from pregnant cows that were (n=323) kept in the same ranches. n. caninum seroprevalence was 10.77% (60/557). the co-existence rate of n. caninum seropositivity with t. ...200919592171
itch k63-ubiquitinates the nod2 binding protein, rip2, to influence inflammatory signaling pathways.the inability to coordinate the signaling pathways that lead to proper cytokine responses characterizes the pathogenesis of inflammatory diseases such as crohn's disease. the crohn's disease susceptibility protein, nod2, helps coordinate cytokine responses upon intracellular exposure to bacteria, and this signal coordination by nod2 is accomplished, in part, through k63-linked polyubiquitin chains that create binding surfaces for the scaffolding of signaling complexes.200919592251
an experimental and computational study of the effect of acta polarity on the speed of listeria monocytogenes actin-based motility.listeria monocytogenes is a pathogenic bacterium that moves within infected cells and spreads directly between cells by harnessing the cell's dendritic actin machinery. this motility is dependent on expression of a single bacterial surface protein, acta, a constitutively active arp2,3 activator, and has been widely studied as a biochemical and biophysical model system for actin-based motility. dendritic actin network dynamics are important for cell processes including eukaryotic cell motility, c ...200919593363
the origin of listeria monocytogenes 4b isolates is signified by subproteomic profiling.among the 13 known serovars of listeria monocytogenes, strains exhibiting the serovar 4b are the most prevalently involved in epidemics of human listeriosis. the molecular reasons for the major involvement of serovar 4b strains in all major foodborne outbreaks in contrast to the lower prevalence of this serovar among food isolates remain indefinite. in order to provide further insight in the protein expression of l. monocytogenes 4b strains, the cytoplasmic and extracellular proteomes of l. mono ...200919596086
selective inhibition of nicotinamide adenine dinucleotide kinases by dinucleoside disulfide mimics of nicotinamide adenine dinucleotide analogues.diadenosine disulfide (5) was reported to inhibit nad kinase from listeria monocytogenes and the crystal structure of the enzyme-inhibitor complex has been solved. we have synthesized tiazofurin adenosine disulfide (4) and the disulfide 5, and found that these compounds were moderate inhibitors of human nad kinase (ic(50)=110 microm and ic(50)=87 microm, respectively) and mycobacterium tuberculosis nad kinase (ic(50)=80 microm and ic(50)=45 microm, respectively). we also found that nad mimics wi ...200919596199
selective expansion of the monocytic lineage directed by bacterial infection.ccr2-mediated recruitment of ly6c(high) monocytes is essential for defense against a range of microbial pathogens. although our understanding of monocyte trafficking to inflammatory sites is increasing, how innate immune inflammation influences monocyte development and maturation during microbial infection remains undefined. herein, we demonstrate that infection with the intracellular bacterial pathogen listeria monocytogenes specifically and selectively promotes monopoiesis. systemic infection ...200919596996
the role of anorexia in resistance and tolerance to infections in drosophila.most infections induce anorexia but its function, if any, remains unclear. because this response is common among animals, we hypothesized that infection-induced diet restriction might be an adaptive trait that modulates the host's ability to fight infection. two defense strategies protect hosts against infections: resistance, which is the ability to control pathogen levels, and tolerance, which helps the host endure infection-induced pathology. here we show that infected fruit flies become anore ...200919597539
characterization of listeria monocytogenes isolates from human listeriosis cases in italy.the objective of this study was to characterize by serotyping, pulsed-field gel electrophoresis (pfge), and pcr amplification of virulence genes and markers of epidemic clones i, ii, and iii (eci, ecii, and eciii) 54 human isolates from apparently sporadic cases of infection occurring in the lombardy region and in the province of florence, tuscany, italy, in the years 1996 to 2007. listeria monocytogenes isolates were provided by the clinical microbiology laboratories of the lombardy region and ...200919605584
the magnitude of cd4+ t cell recall responses is controlled by the duration of the secondary stimulus.the parameters controlling the generation of robust cd4(+) t cell recall responses remain poorly defined. in this study, we compare recall responses by cd4(+) and cd8(+) memory t cells following rechallenge. homologous rechallenge of mice immune to either lymphocytic choriomeningitis virus or listeria monocytogenes results in robust cd8(+) t cell recall responses but poor boosting of cd4(+) t cell recall responses in the same host. in contrast, heterologous rechallenge with a pathogen sharing on ...200919605694
relationship between the physicochemical properties of nonchitinolytic listeria and salmonella and their attachment to shrimp carapace.listeria and salmonella are important foodborne pathogens normally associated with the shrimp production chain. this study investigated the potential of salmonella typhimurium, salmonella senftenberg, and listeria monocytogenes (scott a and v7) to attach to and colonize shrimp carapace. attachment and colonization of listeria and salmonella were demonstrated. shrimp abdominal carapaces showed higher levels of bacterial attachment (p < 0.05) than did head carapaces. listeria consistently exhibite ...200919610328
inactivation of listeria monocytogenes, escherichia coli o157:h7, and salmonella typhimurium with compounds available in households.solutions of selected household products were tested for their effectiveness against listeria monocytogenes, escherichia coli o157:h7, and salmonella typhimurium. hydrogen peroxide (1.5 and 3%), vinegar (2.5 and 5% acetic acid), baking soda (11, 33, and 50% sodium bicarbonate), household bleach (0.0314, 0.0933, and 0.670% sodium hypochlorite), 5% acetic acid (prepared from glacial acetic acid), and 5% citric acid solutions were tested against the three pathogens individually (five-strain composi ...200919610330
effects of essential oil treatment, gas atmosphere, and storage temperature on listeria monocytogenes in a model vegetable system.natural antimicrobials such as plant essential oils (eos) may be useful for controlling pathogenic bacteria on fresh-cut vegetables. the antilisterial properties of eos (thyme, oregano, and rosemary), in combination with different storage atmospheres (air, 5% co2-2% o2-93% n2, and 20% co2-1% o2-79% n2) and temperatures (4 and 80c), were examined using a gas flow-through system combined with a vegetable agar model. the antimicrobial effects of the eos varied depending on the oil, the listeria str ...200919610331
short-term bactericidal efficacy of lauric arginate against listeria monocytogenes present on the surface of frankfurters.the antimicrobial lauric arginate (lae) alone or in combination with an antimicrobial liquid smoke extract was studied as a postlethality treatment against listeria monocytogenes on vacuum-packaged frankfurters. treatment with 2 ml of 5,000 ppm of lae reduced l. monocytogenes from 7.13 to 5.82 log cfu per package on day 0, and treatment with 3 ml reduced populations from 7.22 to 5.79 log cfu per package on day 0. treatment with lae and smoke flavor did not result in significantly different popul ...200919610332
broad range evaluation of the matrix solubilization (matrix lysis) strategy for direct enumeration of foodborne pathogens by nucleic acids technologies.a previously published rapid (<5 h) proof-of-concept protocol for the concentration of the foodborne pathogen listeria monocytogenes from milk, based on the solubilization of the food matrix, was further evaluated. the original protocol was modified to detect gram-negative and other gram-positive bacteria and to broaden the range of food matrices by using lutensol instead of sodium dodecyl sulfate as the main detergent in the buffer. a new protocol using a protease and sucrose buffer was establi ...200919610333
simultaneous identification of seven foodborne pathogens and escherichia coli (pathogenic and nonpathogenic) using capillary electrophoresis-based single-strand conformation polymorphism coupled with multiplex pcr.the objective of this study was to develop a novel technique for parallel analysis of eight important foodborne microbes using capillary electrophoresis-based single-strand conformation polymorphism (ce-sscp) coupled with multiplex pcr. specific primers for multiplex pcr amplification of the 16s rrna gene were designed, corresponding to eight species of bacteria, including escherichia coli, clostridium perfringens, campylobacter jejuni, salmonella enterica, listeria monocytogenes, vibrio parahae ...200919610337
prevalence and genetic diversity of listeria monocytogenes in vacuum-packaged ready-to-eat meat products at retail markets in latvia.nine groups of different retail ready-to-eat vacuum-packaged meat products from 10 baltic meat processing plants were analyzed for presence and numbers of listeria monocytogenes at the end of shelf life. a total of 38 (18%) of 211 samples tested positive for l. monocytogenes serotype 1/2a (88%) or 1/2c (12%). the prevalence of l. monocytogenes in cold-smoked, sliced, vacuum-packaged beef and pork products (42%) was significantly higher than in cooked, sliced, vacuum-packaged meat products (0.8%) ...200919610341
carnitine enhances the growth of listeria monocytogenes in infant formula at 7 degrees c.carnitine has beneficial vitamin-like qualities and functions as a compatible solute. the presence of l-carnitine in infant formula significantly promoted the growth of listeria monocytogenes at 7 degrees c, whereas disruption of the genes for carnitine and glycine betaine uptake compromised growth of the l. monocytogenes mutant in formula containing carnitine that was stored at 7 degrees c. thus, addition of carnitine to baby formula may pose a potential food safety risk.200919610343
removal of listeria monocytogenes biofilms from stainless steel by use of ultrasound and ozone.the objective of this study was to determine the efficacy of power ultrasound and ozonation used individually, and in tandem, for the removal of listeria monocytogenes biofilms from stainless steel chips. stainless steel chips were inoculated with l. monocytogenes. power ultrasound (20 khz, 100% amplitude, 120 w) was applied for 30 or 60 s at a distance of 2.54 cm from a biofilm chip while it was submerged in 250 ml of sterile potassium phosphate buffer (ph 7.0). ozone was cycled through the 250 ...200919610346
real-time pcr as a tool for detection of pathogenic bacteria on contaminated food contact surfaces by using a single enrichment medium.foodborne pathogens such as escherichia coli o157:h7, listeria monocytogenes, and salmonella can easily transfer from food to food contact surfaces. methods for rapid detection of these pathogenic bacteria are important in order to avoid contamination of food. here, we describe the detection and quantification of bacterial pathogens on contaminated surfaces by real-time pcr (rt-pcr) and culture methods using a single enrichment medium. surfaces of wood, polypropylene, and stainless steel were in ...200919610347
nonculturable response of animal enteropathogens in the agricultural environment and implications for food safety.concerns about animal enteropathogen contamination of fresh horticultural products have,increased worldwide and are mainly due to the ability of bacteria to survive under stress conditions in the agricultural environment and during raw-vegetable processing. this review challenges the idea that the viable but nonculturable phenomenon that has been proven to occur in plant-associated environments contributes to human pathogen survival and might be correlated with foodborne infection. factors assoc ...200919610353
listeriosis in pregnancy complicated by postpartum heart block.listeria monocytogenes is a food-borne pathogen that primarily affects pregnant women. cardiac involvement is an uncommon complication of infection. we present a case of a gravida with listeria bacteremia at 36 weeks of gestation.200919622946
myd88 and type i interferon receptor-mediated chemokine induction and monocyte recruitment during listeria monocytogenes infection.monocytes play a central role in defense against infection, but the mechanisms promoting monocyte recruitment and activation remain incompletely defined. defense against listeria monocytogenes, an intracellular bacterial pathogen, requires in vivo mcp-1 induction and ccr2-dependent recruitment of ly6c(high) monocytes from bone marrow to sites of infection. herein, we demonstrate that infection of bone marrow-derived macrophages with virulent l. monocytogenes induces mcp-1 expression in two phase ...200919553532
listeria monocytogenes l-forms respond to cell wall deficiency by modifying gene expression and the mode of division.cell wall-deficient bacteria referred to as l-forms have lost the ability to maintain or build a rigid peptidoglycan envelope. we have generated stable, non-reverting l-form variants of the gram-positive pathogen listeria monocytogenes, and studied the cellular and molecular changes associated with this transition. stable l-form cells can occur as small protoplast-like vesicles and as multinucleated, large bodies. they have lost the thick, multilayered murein sacculus and are surrounded by a cyt ...200919555455
decoupling internalization, acidification and phagosomal-endosomal/lysosomal fusion during phagocytosis of inla coated beads in epithelial cells.phagocytosis has been extensively examined in 'professional' phagocytic cells using ph sensitive dyes. however, in many of the previous studies, a separation between the end of internalization, beginning of acidification and completion of phagosomal-endosomal/lysosomal fusion was not clearly established. in addition, very little work has been done to systematically examine phagosomal maturation in 'non-professional' phagocytic cells. therefore, in this study, we developed a simple method to meas ...200919557127
inos-producing inflammatory dendritic cells constitute the major infected cell type during the chronic leishmania major infection phase of c57bl/6 resistant mice.leishmania major parasites reside and multiply in late endosomal compartments of host phagocytic cells. immune control of leishmania growth absolutely requires expression of inducible nitric oxide synthase (inos/nos2) and subsequent production of no. here, we show that cd11b+ cd11c+ ly-6c+ mhc-ii+ cells are the main inos-producing cells in the footpad lesion and in the draining lymph node of leishmania major-infected c57bl/6 mice. these cells are phenotypically similar to inos-producing inflamma ...200919557162
identification of a novel two-peptide lantibiotic, lichenicidin, following rational genome mining for lanm proteins.lantibiotics are ribosomally synthesized peptide antimicrobials which contain considerable posttranslational modifications. given their usually broad host range and their highly stable structures, there have been renewed attempts to identify and characterize novel members of the lantibiotic family in recent years. the increasing availability of bacterial genome sequences means that in addition to traditional microbiological approaches, in silico screening strategies may now be employed to the sa ...200919561184
antioxidant and antilisterial effect of seed essential oil and organic extracts from zizyphus jujuba.hydrodistilled volatile oil from the seeds of zizyphus jujuba was analyzed by gc-ms. twenty three compounds representing 91.59% of the total oil was identified. the oil and organic extracts revealed a great potential of antilisterial effect against all five strains of listeria monocytogenes atcc 19111, 19116, 19118, 19166 and 15313. also the oil had strong detrimental effect on the viable count of the tested bacteria. the samples were also subjected to screening for the antioxidant activity by u ...200919563858
cellular accumulation and pharmacodynamic evaluation of the intracellular activity of cem-101, a novel fluoroketolide, against staphylococcus aureus, listeria monocytogenes, and legionella pneumophila in human thp-1 macrophages.cem-101 is a novel fluoroketolide with lower mics than those of telithromycin and macrolides. our aim was to assess the cellular accumulation and intracellular activity of cem-101 using models developed for analyzing the pharmacokinetics and pharmacological properties of antibiotics against phagocytized bacteria. we used thp-1 macrophages and staphylococcus aureus (atcc 25923 [methicillin (meticillin) sensitive]), listeria monocytogenes (strain egd), and legionella pneumophila (atcc 33153). cem- ...200919564365
blockade of cd137 signaling counteracts polymicrobial sepsis induced by cecal ligation and puncture.sepsis, a leading cause of death worldwide, involves proinflammatory responses and inefficient bacterial clearance. previously, we have shown that cd137 (4-1bb), a member of the tumor necrosis factor receptor superfamily, plays critical roles in eradicating infective listeria monocytogenes, a gram-positive bacterium, and that stimulation of cd137 protects mice from sepsis-induced death. in this study, we unexpectedly found that cd137 activation aggravated polymicrobial sepsis due to mixed gram-p ...200919564374
staphylococcal alpha-toxin is not sufficient to mediate escape from phagolysosomes in upper-airway epithelial cells.intracellular staphylococcus aureus has been implicated in the establishment of chronic infections. it is therefore imperative to understand by what means s. aureus is able to survive within cells. here we use two expression systems with a fluorescent readout to assay alpha-toxin expression and function within phagolysosomes of infected upper-airway epithelial cells: avirulent staphylococcus carnosus tm300 and phenotypically alpha-toxin-negative s. aureus laboratory strains. data from cfu recove ...200919564384
first results on the detection of listeria monocytogenes in raw milk: comparison of two different analytical methods. 200919568945
listeria monocytogenes membrane trafficking and lifestyle: the exception or the rule?listeria monocytogenes is an intracellular bacterial pathogen that promotes its internalization within nonprofessional phagocytes by interacting with specific host cell receptors. l. monocytogenes resides transiently in a membrane-bound compartment before escaping into the host cell cytosol where bacterial proliferation takes place. actin-based motility then promotes cell-to-cell pathogen spread. extensive studies on cytoskeleton rearrangements, membrane trafficking, and other events have establ ...200919575658
a novel fas ligand in mollusk abalone: molecular characterization, immune responses and biological activity of the recombinant protein.fas ligand is a member of the tnf superfamily that plays an important role by inducing apoptosis and homeostasis of immune responses. the gene encoding fas ligand was isolated from a disk abalone (haliotis discus discus) cdna library, denoted as the abfas ligand. it contains an 1832bp transcript with a 945bp open reading frame, encoding 315 amino acids. the abfas ligand showed characteristic transmembrane and tnf family signature domains. the deduced amino acid comparison showed that the abfas l ...200919576285
a correlation between the virulence and the adhesion of listeria monocytogenes to silicon nitride: an atomic force microscopy study.listeria monocytogenes is a facultative intracellular gram-positive bacterium that is widely distributed in the environment. despite being pathogenic at the species level, l. monocytogenes in fact comprises a diversity of strains from pathogenic ones that can result in disease and/or mortality to others that are relatively avirulent. the main goal of the current study was to answer the question on whether enhanced binding or attachment of l. monocytogenes to inert surfaces bears any relationship ...200919576735
manipulations of metallothionein gene dose accelerate the response to listeria monocytogenes.metallothioneins (mts) are cysteine-rich proteins that assist in cellular homeostasis and protect against oxidant injury. mts can be induced by heavy metals and inflammatory mediators and function as free radical scavengers, reservoirs for essential heavy metals, and immunomodulators. in light of mts' roles in responses to stress, we evaluated the in vivo effects of mt gene dose on the course of listeria monocytogenes (lm) infection. lm burden was measured in livers and spleens, and flow cytomet ...200919576872
study on the application of an interspecific competition model for the prediction of microflora behaviour during the fermentation process of s. angelo pgi salami. 200919578949
essential oils against foodborne pathogens and spoilage bacteria in minced meat.the antimicrobial activity of essential oils of oregano, thyme, basil, marjoram, lemongrass, ginger, and clove was investigated in vitro by agar dilution method and minimal inhibitory concentration (mic) determination against gram-positive (staphylococcus aureus and listeria monocytogenes) and gram-negative strains (escherichia coli and salmonella enteritidis). mic(90%) values were tested against bacterial strains inoculated experimentally in irradiated minced meat and against natural microbiota ...200919580445
gene transcription and virulence potential of listeria monocytogenes strains after exposure to acidic and nacl stress.gene transcription and virulence potential of two strains of listeria monocytogenes, egd-e and 4140, were compared by quantitative real-time polymerase chain reaction and in a caco-2 in vitro model after exposure to acidic (ph 5.5) and nacl (4.5% w/v) stress. strain-dependent differences in gene transcription were observed both after exposure to shock (six genes) and after long-term adaptation to stress (18 genes). in the shock experiments, a transient induction of clpc and clpe was seen for bot ...200919580450
human alpha-defensins inhibit hemolysis mediated by cholesterol-dependent cytolysins.many pathogenic gram-positive bacteria release exotoxins that belong to the family of cholesterol-dependent cytolysins. here, we report that human alpha-defensins hnp-1 to hnp-3 acted in a concentration-dependent manner to protect human red blood cells from the lytic effects of three of these exotoxins: anthrolysin o (alo), listeriolysin o, and pneumolysin. hd-5 was very effective against listeriolysin o but less effective against the other toxins. human alpha-defensins hnp-4 and hd-6 and human ...200919581399
some listeria monocytogenes outbreak strains demonstrate significantly reduced invasion, inla transcript levels, and swarming motility in vitro.listeria monocytogenes can cause a severe invasive food-borne disease known as listeriosis, and large outbreaks of this disease occur occasionally. based on molecular-subtype data, epidemic clone (ec) strains have been defined, including eci and ecia, which have caused listeriosis outbreaks on different continents. while a number of molecular-subtyping studies of outbreak strains have been reported, few comprehensive data sets of virulence-associated characteristics of these strains are availabl ...200919581477
cloning and comparison of phylogenetically related chitinases from listeria monocytogenes egd and enterococcus faecalis v583.to compare enzymatic activities of two related chitinases, chia and ef0361, encoded by listeria monocytogenes and enterococcus faecalis, respectively.200919583793
behavior of escherichia coli o157:h7, listeria monocytogenes, and salmonella typhimurium in teewurst, a raw spreadable sausage.the fate of listeria monocytogenes, salmonella typhimurium, or escherichia coli o157:h7 were separately monitored both in and on teewurst, a traditional raw and spreadable sausage of germanic origin. multi-strain cocktails of each pathogen (ca. 5.0 log cfu/g) were used to separately inoculate teewurst that was subsequently stored at 1.5, 4, 10, and 21 degrees c. when inoculated into commercially-prepared batter just prior to stuffing, in general, the higher the storage temperature, the greater t ...200919269050
the probability of growth of listeria monocytogenes in cooked salmon and tryptic soy broth as affected by salt, smoke compound, and storage temperature.the objectives of this study were to examine and model the probability of growth of listeria monocytogenes in cooked salmon containing salt and smoke (phenol) compound and stored at various temperatures. a growth probability model was developed, and the model was compared to a model developed from tryptic soy broth (tsb) to assess the possibility of using tsb as a substitute for salmon. a 6-strain mixture of l. monocytogenes was inoculated into minced cooked salmon and tsb containing 0-10% nacl ...200919269565
a filtration-based real-time pcr method for the quantitative detection of viable salmonella enterica and listeria monocytogenes in food samples.we developed a novel filtration-based method that can eliminate dead or severely damaged salmonella enterica and listeria monocytogenes in food samples. this new method can recover all viable bacteria in less than 30 min, and can be coupled with a subsequent bacterial dna extraction and real-time pcr. no statically significant differences (p<0.01) were found between real-time pcr results obtained separately from s. enterica and l. monocytogenes when different ratios of living and dead cells were ...200919269574
[tasks and duties of veterinary reference laboratories for food borne zoonoses].reference laboratories are of central importance for consumer protection. field expertise and high scientific competence are basic requirements for the nomination of a national reference laboratory. to ensure a common approach in the analysis of zoonotic hazards, standards have been developed by the reference laboratories together with national official laboratories on the basis of art. 33 of directive (eg) no. 882/2004. reference laboratories function as arbitrative boards in the case of ambiva ...200919271255
cx3cr1+ cd115+ cd135+ common macrophage/dc precursors and the role of cx3cr1 in their response to inflammation.cx(3)cr1 expression is associated with the commitment of csf-1r(+) myeloid precursors to the macrophage/dendritic cell (dc) lineage. however, the relationship of the csf-1r(+) cx(3)cr1(+) macrophage/dc precursor (mdp) with other dc precursors and the role of cx(3)cr1 in macrophage and dc development remain unclear. we show that mdps give rise to conventional dcs (cdcs), plasmacytoid dcs (pdcs), and monocytes, including gr1(+) inflammatory monocytes that differentiate into tipdcs during infection ...200919273628
listeria monocytogenes in two different poultry facilities: manual and automatic evisceration.listeriosis is a serious foodborne disease caused by listeria monocytogenes, a pathogen often found in food processing plants. poultry meat and its derivatives may harbor l. monocytogenes even if good manufacturing practices are implanted in abattoirs. little information exists in brazil on the frequency of l. monocytogenes contamination, even though the country is considered the top poultry meat exporter in the world. this study attempted to compare 2 exporters poultry facilities following same ...200919276422
growth inhibition of pathogenic bacteria and some yeasts by selected essential oils and survival of l. monocytogenes and c. albicans in apple-carrot juice.food safety is a fundamental concern of both consumers and the food industry. the increasing incidence of foodborne diseases increases the demand of using antimicrobials in foods. spices and plants are rich in essential oils and show inhibition activity against microorganisms, which are composed of many compounds. in this research, effects of garlic, bay, black pepper, origanum, orange, thyme, tea tree, mint, clove, and cumin essential oils on listeria monocytogenes aufe 39237, escherichia coli ...200919278342
lmo0038 is involved in acid and heat stress responses and specific for listeria monocytogenes lineages i and ii, and listeria ivanovii.the genus listeria comprises two pathogenic species, l. monocytogenes and l. ivanovii, as well as four nonpathogenic species, l. innocua, l. weishimeri, l. seeligeri, and l. grayi. within l. monocytogenes, lineages i and ii are responsible for most listeriosis cases, while lineage iii strains are rarely associated with human morbidity but providing important clues for listeria evolution. the gene lmo0038, belonging to the peptidylarginine deiminase family, was involved in the optimal growth unde ...200919278345
outbreak of listeria monocytogenes in an oncology unit associated with sandwiches consumed in hospital.in may 2003, two adult patients in an oncology unit were diagnosed with listeriosis, and sandwiches consumed in the hospital were identified as a common risk factor. both patients were infected by the same strain of listeria monocytogenes. sandwiches collected from the hospital and external sandwich producer, as well as sites within the manufacturing environment, were contaminated by the same strain of l. monocytogenes. sandwiches consumed in other hospitals have been associated with small clust ...200919278752
epidemiology of listeriosis in austria.a total of 150 human cases of listeriosis (case definition based on isolation of listeria monocytogenes from normally sterile material) were reported in austria between 1997 and 2007. of these, 14 cases (9.3%) were pregnancy-associated (mother/child illness considered as a single case) with a mean age of 29.3 years (median: 26.5; range 24-36). among the non-pregnancy-associated cases (n = 136), 75 were male (55.2%) and 61 female (44.9%); patients in this group had a mean age of 64.3 years (media ...200919280136
an outbreak of febrile gastroenteritis associated with jellied pork contaminated with listeria monocytogenes.in september 2008, the austrian agency for health and food safety (ages) learned of an outbreak of diarrheal illness that included a 71-year-old patient hospitalized for gastroenteritis with a blood culture positive for listeria monocytogenes. three stool specimens provided by seven of 19 persons attending a day trip to a foreign city, including a final break at an austrian tavern, yielded l. monocytogenes. all isolates were of serovar 4b and had fingerprints indistinguishable from each other. a ...200919280142
listeria monocytogenes phosphatidylinositol-specific phospholipase c: kinetic activation and homing in on different interfaces.the phosphatidylinositol-specific phospholipase c (pi-plc) from listeria monocytogenes forms aggregates with anionic lipids leading to low activity. the specific activity of the enzyme can be enhanced by dilution of the protein or by addition of both zwitterionic and neutral amphiphiles (e.g., diheptanoylphosphatidylcholine or triton x-100) or 0.1-0.2 m inorganic salts. activation by amphiphiles occurs with both micellar (phosphatidylinositol dispersed in detergents) and monomeric [dibutroylphos ...200919281241
community-acquired bacterial meningitis in elderly patients: experience over 30 years.clinical characteristics, etiologies, evolution, and prognostic factors of community-acquired bacterial meningitis in elderly patients are not well known. to improve this knowledge, all episodes of community-acquired bacterial meningitis were prospectively recorded and cases occurring in patients >or=65 years old were selected. during the period 1977-2006, 675 episodes in adults (aged >or=18 yr) were recorded, with 185 (27%) in patients aged >or=65 years old; 76 were male and 109 were female, wi ...200919282702
the solution structure of pgolemi, a high affinity mena evh1 binding miniature protein, suggests explanations for paralog-specific binding to ena/vasp homology (evh) 1 domains.ena/vasp homology 1 (evh1) domains are polyproline binding domains that are present in a wide range of adaptor proteins, among them ena/vasp proteins involved in actin remodeling and axonal guidance. the interaction of acta, a transmembrane protein from the food-borne pathogen listeria monocytogenes, with evh1 domains has been shown to be crucial for recruitment of the host's actin skeleton and, as a consequence, for the infectivity of this bacterium. we present the structure of a synthetic high ...200919284291
infection and stillbirth.infection may cause stillbirth by several mechanisms, including direct infection, placental damage, and severe maternal illness. various organisms have been associated with stillbirth, including many bacteria, viruses, and protozoa. in developed countries, between 10% and 25% of stillbirths may be caused by an infection, whereas in developing countries, which have much higher stillbirth rates, the contribution of infection is much greater. in developed countries, ascending bacterial infection, b ...200919285457
abl tyrosine kinases in t-cell signaling.stimulation of the t-cell antigen receptor (tcr) leads to the activation of signaling pathways that are essential for t-cell development and the response of mature t cells to antigens. the tcr has no intrinsic catalytic activity, but tcr engagement results in tyrosine phosphorylation of downstream targets by non-receptor tyrosine kinases. three families of tyrosine kinases have long been recognized to play critical roles in tcr-dependent signaling. they are the src, zeta-associated protein of 70 ...200919290927
in vitro synergistic effect of gentamicin with the anti-inflammatory agent diclofenac against listeria monocytogenes.a total of nine listeria monocytogenes strains (seven serotypes) were studied to ascertain whether the non-steroidal anti-inflammatory drug diclofenac (dc) used in combination with the conventional antilisterial antibiotic gentamicin (gm) or ampicillin (am) synergistically augments the efficacy of the antibiotic in vitro.200919291208
the impact of growth history and flagellation on the adhesion of various listeria monocytogenes strains to polystyrene.the contribution of growth history and flagella to adhesion of listeria monocytogenes was analysed. an in-frame deletion on the flagellin encoding gene (flaa) was performed in l. monocytogenes egd-e to compare its adhesion ability with the parental strain, after cultivation at various ph values and temperatures. the ph, as well as the temperature, affected the adhesion of l. monocytogenes egd-e. in addition, the adhesion of l. monocytogenes egd-e was reduced in energy-depressed cells. conversely ...200919295651
cytoskeleton rearrangements during listeria infection: clathrin and septins as new players in the game.the study of an infection process can reveal how microbes exploit the host, and can illuminate unknown host cellular functions. invasive pathogens have evolved efficient strategies to promote their internalization within normally non-phagocytic host cells. the so-called "zippering" bacteria present to host cell receptors molecules that mimic endogenous ligands, thereby inducing specific intracellular signaling cascades ultimately resulting in actin polymerization and uptake. here we review how t ...200919296488
abhisin: a potential antimicrobial peptide derived from histone h2a of disk abalone (haliotis discus discus).antimicrobial peptides (amps) play an important role in the immune defense against pathogenic microorganisms. in this study, a histone h2a full-length cdna was cloned from disk abalone haliotis discus discus. we identified a 40-amino acid amp designated as abhisin from the n-terminus of the abalone histone h2a sequence. abhisin shows the characteristic features of amps including net positive charge (+13), higher hydrophobic residues (27%) and 2.82 kcal/mol protein binding potential. abhisin shar ...200919706329
combined effect of organic acids and supercritical carbon dioxide treatments against nonpathogenic escherichia coli, listeria monocytogenes, salmonella typhimurium and e. coli o157:h7 in fresh pork.to evaluate the effectiveness of organic acids and supercritical carbon dioxide (sc-co(2)) treatments as well as their combined effect for the reduction of nonpathogenic escherichia coli and three pathogenic bacteria in fresh pork.200919709368
effect of mixed antimicrobial agents and flavors in active packaging films.active packaging is an emerging food technology to improve the quality and safety of food products. many works have been developed to study the antimicrobial activity of essential oils. essential oils have been traditionally used as flavorings in food, so they have an important odor impact but they have as well antimicrobial properties that could be used to protect the food. recent developments in antimicrobial active packaging showed the efficiency of essential oils versus bread and bakery prod ...200919711918
cd8 t cell immunity to plasmodium permits generation of protective antibodies after repeated sporozoite challenge.individuals living in malaria endemic areas are subject to repeated infections yet fail to develop sterilizing immunity, however, immunization of mice with attenuated sporozoites or subunit vaccines has shown the ability to protect mice against a sporozoite challenge. we recently reported that mice primed with dendritic cells coated with the dominant circumsporozoite cd8 t cell epitope from plasmodium berghei followed by a boost with recombinant listeria monocytogenes expressing the same epitope ...200919712771
usda fsis, fda bam, aoac, and iso culture methods bd bbl chromagar listeria media.bbl chromagar listeria media (cl) was evaluated for detection of listeria monocytogenes in raw ground beef, smoked salmon, lettuce, and brie cheese. the recovery of l. monocytogenes on cl was compared to the u.s. food and drug administration (fda) bacteriological analytical manual (bam), u.s. department of agriculture (usda) food safety and inspection service (fsis), aoac, and international organization for standardization (iso) reference-plated media using the recommended pre-enrichments and se ...200919714979
preparation of antimicrobial membranes: coextrusion of poly(lactic acid) and nisaplin in the presence of plasticizers.nisin is a naturally occurring antimicrobial polypeptide and is popularly used in the food and food-packaging industries. nisin is deactivated at temperatures higher than 120 degrees c and, therefore, cannot be directly incorporated into poly(l-lactic acid) (pla), a biomass-derived biodegradable polymer, by coextrusion because pla melts at temperatures around 160 degrees c or above. however, pla can remain in a melt state at temperatures below the t(m) in the presence of lactic acid or other pla ...200919715335
evidence-based semiquantitative methodology for prioritization of foodborne zoonoses.to prioritize an extended list of food- and water-borne zoonoses to allow food safety authorities to focus on the most relevant hazards in the food chain.200919715429
beta-naphthoflavone causes an ahr-independent inhibition of invasion and intracellular multiplication of listeria monocytogenes in murine hepatocytes.we recently reported a heretofore unknown role for the aryl hydrocarbon receptor in host resistance to listeriosis in mice. hepatocytes are an important site for listeria monocytogenes multiplication in vivo. in this study, we investigated whether activation of ahr in tib73 murine embryonic hepatocytes affects the ingestion and intracellular multiplication of l. monocytogenes. treatment of tib73 cells with the ahr agonist beta-naphthoflavone (bnf) significantly inhibited the ingestion and intrac ...200919715752
prolonged hospital and community-based listeriosis outbreak caused by ready-to-eat scalded sausages.listeria monocytogenes is a foodborne bacterial pathogen. immunocompromised patients are at higher risk of developing invasive listeriosis with high fatality rates. after notification of two patients with listeria that had stayed in the same hospital (hospital a) before the onset of infection, we began an investigation to ascertain the extent of the outbreak, identify its source and prevent further infections. we conducted active case finding by contacting hospital a, reviewing medical records a ...200919716628
multiplexed bead-based mesofluidic system for detection of food-borne pathogenic bacteria.in the present study, a simple and rapid multiplexed bead-based mesofluidic system (bms) was developed for simultaneous detection of food-borne pathogenic bacteria, including staphylococcus aureus, vibrio parahaemolyticus, listeria monocytogenes, salmonella, enterobacter sakazakii, shigella, escherichia coli o157:h7, and campylobacter jejuni. this system is based on utilization of isothiocyanate-modified microbeads that are 250 mum in diameter, which were immobilized with specific amino-modified ...200919717622
inhibition of listeria monocytogenes in cooked ham by virulent bacteriophages and protective cultures.protective cultures can be used successfully as an additional hurdle together with phages to reduce growth of listeria monocytogenes on sliced cooked ham. addition of phages resulted in a rapid 10-fold reduction of l. monocytogenes. after 14 to 28 days of storage, a 100-fold reduction was observed in samples with phages and protective culture compared to results for samples with phages alone.200919717623
[influence of mutation l,d-carboxypeptidase-coding gene on dynamics of listeria infection].to study the progress of infection caused by mutant listeria monocytogenes with deletion of imo0028 gene coding l,d-carboxypeptidase (protein involved in metabolism of peptidoglycan).200919718829
communication and autoinduction in the species listeria monocytogenes: a central role for the agr system.in order to withstand changes in their environment, bacteria have evolved mechanisms to sense the surrounding environment, integrate these signals and adapt their physiology to thrive under fluctuating conditions. among these mechanisms, the ability of bacteria to exchange information between cells has become a dynamic field of interest for microbiologists over the past four decades. first described by nelson et al.,1 this phenomenon often referred as either cell-cell communication, quorum sensi ...200919721895
effect of acid stress, antibiotic resistance, and heat shock on the resistance of listeria monocytogenes to uv light when suspended in distilled water and fresh brine.exposure to sublethal processing treatments can stimulate bacterial stress responses. the purpose of this research was to determine whether adaptation to common food processing stresses encountered during the preparation of ready-to-eat foods affects the dose of uv light required to significantly reduce listeria monocytogenes populations in sterile distilled water and a 9% nacl solution, using uridine as a chemical actinometer. l. monocytogenes strains n1-227 (from hot dog batter), n3-031 (from ...200919722394
assay of enterocin as-48 for inhibition of foodborne pathogens in desserts.enterocin as-48 was tested against staphylococcus aureus, bacillus cereus, and listeria monocytogenes in different kinds of desserts. the highest activity against s. aureus was detected in baker cream. however, in yogurt-type soy-based desserts and in gelatin pudding, as-48 (175 arbitrary units [au]/g) reduced viable cell counts of s. aureus by only 1.5 to 1.8 log units at most. the efficacy of as-48 in puddings greatly depended on inoculum size, and viable s. aureus counts decreased below detec ...200919722396
complete transcriptional profile of an environmental pathogen.evaluation of: toledo-arana a, dussurget o, nikitas g et al.: the listeria transcriptional landscape from saprophytism to virulence. nature 459 (7249), 950-956 (2009). bacteria adapt to a variety of environmental conditions through changes in gene regulation and gene expression. listeria monocytogenes is an environmental bacterium that exists as a saprophyte but is capable of transitioning into a pathogen upon ingestion by a susceptible host. in this report, toledo-arana et al. present the compl ...200919722832
control of listeria monocytogenes by lauric arginate on frankfurters formulated with or without lactate/diacetate.listeria monocytogenes (lm) is a food safety concern that can be associated with ready-to-eat (rte) meat and poultry products because of its persistence in the processing environment. listeriosis has a fatality rate of 28% in immuno-compromised individuals. rte meats receive a lethal heat treatment but may become contaminated by lm after this treatment. federal regulators and manufacturers of rte meats are working to find additional ways to control postprocess contamination by lm in rte meats. t ...200919723207
assessment of cell surface properties and adhesion potential of selected probiotic strains.to evaluate the physicochemical cell surface and adhesive properties of selected probiotic strains for human use.200919725886
suppression of cell-mediated immunity following recognition of phagosome-confined bacteria.listeria monocytogenes is a facultative intracellular pathogen capable of inducing a robust cell-mediated immune response to sub-lethal infection. the capacity of l. monocytogenes to escape from the phagosome and enter the host cell cytosol is paramount for the induction of long-lived cd8 t cell-mediated protective immunity. here, we show that the impaired t cell response to l. monocytogenes confined within a phagosome is not merely a consequence of inefficient antigen presentation, but is the r ...200919730694
viability of listeria monocytogenes in co-culture with acanthamoeba spp.listeria monocytogenes is a human pathogen, ubiquitous in the environment, and can grow and survive under a wide range of environmental conditions. it contaminates foods via raw materials or food-processing environments. however, the current knowledge of its ecology and, in particular, the mode of environmental survival and transmission of this intracellular pathogen remains limited. research has shown that several intracellular pathogens are able to survive or replicate within free-living amoeb ...200919645820
survival of listeria monocytogenes, listeria innocua, and lactic acid bacteria in chill brines.listeria monocytogenes is the pathogen of concern in ready-to-eat (rte) meat products. salt brines are used to chill processed meats. l. monocytogenes and lactic acid bacteria (lab) can grow under saline conditions, and may compete with each other for nutrients. the objective of this study was to determine the effect of lactic acid bacteria (enterococcus faecalis, carnobacterium gallinarum, and lactobacillus plantarum) on the survival of l. monocytogenes and listeria innocua in brines stored und ...200919646051
c3 promotes expansion of cd8+ and cd4+ t cells in a listeria monocytogenes infection.it is known that c3 is required for optimal expansion of t cells during acute viral infections. however, it is not yet determined whether t cell responses to intracellular bacterial infections require c3. therefore, we have investigated the requirement for c3 to elicit potent t cell responses to listeria monocytogenes (lm). we show that expansion of ag-specific cd8 and cd4 t cells during a primary response to lm was markedly reduced in the absence of c3 activity. further studies indicated that, ...200919648268
estimating risk from small inocula by using population growth parameters.risk from an uncertain small inoculum depends on variability of single-cell lag times. however, quantifying single-cell variability is technically challenging. it is possible to estimate this variability using population growth parameters. we demonstrate this possibility using data from literature and show a bayesian scheme for performing this task.200919648368
competition of listeria monocytogenes serotype 1/2a and 4b strains in mixed-culture biofilms.the majority of listeria monocytogenes isolates recovered from foods and the environment are strains of serogroup 1/2, especially serotypes 1/2a and 1/2b. however, serotype 4b strains cause the majority of human listeriosis outbreaks. our investigation of l. monocytogenes biofilms used a simulated food-processing system that consisted of repeated cycles of growth, sanitation treatment, and starvation to determine the competitive fitness of strains of serotypes 1/2a and 4b in pure and mixed-cultu ...200919648379
listeria monocytogenes - from saprophyte to intracellular pathogen.listeria monocytogenes is a bacterium that lives in the soil as a saprophyte but is capable of making the transition into a pathogen following its ingestion by susceptible humans or animals. recent studies suggest that l. monocytogenes mediates its saprophyte-to-cytosolic-parasite transition through the careful modulation of the activity of a virulence regulatory protein known as prfa, using a range of environmental cues that include available carbon sources. in this progress article we describe ...200919648949
development and validation of a predictive model for listeria monocytogenes scott a as a function of temperature, ph, and commercial mixture of potassium lactate and sodium diacetate.the objective of this study was to develop and validate secondary models that can predict growth parameters of l. monocytogenes scott a as a function of concentrations (0-3%) of a commercial potassium lactate (pl) and sodium diacetate (sda) mixture, ph (5.5-7.0), and temperature (4-37oc). a total of 120 growth curves were fitted to the baranyi primary model that directly estimates lag time (lt) and specific growth rate (sgr). the effects of the variables on l. monocytogenes scott a growth kineti ...200919652521
effect of batch and fed-batch growth modes on biofilm formation by listeria monocytogenes at different temperatures.the influence of listeria monocytogenes (l. monocytogenes) biofilm formation feeding conditions (batch and fed-batch) at different temperatures on biofilm biomass and activity was determined. biofilm biomass and cellular metabolic activity were assessed by crystal violet (cv) staining and 2,3-bis(2-methoxy-4-nitro-5-sulfophenyl)-2h-tetrazolium-5-carboxanilide inner salt (xtt) colorimetric method, respectively. live/dead staining was also performed in order to get microscopic visualization of the ...200919653035
differential fluorescent staining of listeria monocytogenes and a whey food soil for quantitative analysis of surface hygiene.the accurate monitoring of surface cleanliness in terms of bacterial contamination is usually carried out using methods such as plate counts or replica plating. however these methods take at least eighteen hours to obtain results and do not determine the presence or amount of residual organic material on a surface, which may interfere with cleaning and disinfection. this work describes the application of fluorescent stains to cells (listeria monocytogenes) and food soil (solubilized whey) to opt ...200919654071
efficacy of sodium hypochlorite and peracetic acid in sanitizing green coconuts.to evaluate the efficacy of sanitizing green coconuts (cocos nucifera l.) through the treatment applied by juice industries using sodium hypochlorite and peracetic acid.200919627481
antimicrobial activity of pomegranate (punica granatum l.) fruit peels.food-borne diseases such as listeriosis and diseases caused by the emergence of multi-drug resistant pathogens (e.g. staphylococcus aureus) are globally recognized as environmental hazards to the food supply and human health. natural inhibitors for pathogenic microorganisms have been explored in many plants. the antimicrobial activity against some food-borne pathogens by various extracts from pomegranate fruit peels was evaluated using both in vitro (agar diffusion) and in situ (food) methods. t ...200919632734
optimization of medium composition for the production of antimicrobial activity by bacillus subtilis b38.an antimicrobial activity produced by bacillus subtilis b38 was found to be effective against several bacteria, including pathogenic and spoilage microorganisms such as, listeria monocytogenes, salmonella enteridis, and clinical isolates of methicillin-resistant staphylococcus species. nutrients such as carbon, nitrogen sources, and inorganic salts enhanced the production level of the antibacterial activity by b. subtilis b38. a first screening step showed that lactose, ammonium succinate, and m ...200919634172
bacteriocin production by staphylococcus aureus involved in bovine mastitis in brazil.in the present study, 257 staphylococcus spp. strains were isolated from bovine mastitis cases in 56 different brazilian dairy herds located in the southeast region of the country and tested for antimicrobial substance (ams) production. forty-six strains (17.9%) exhibited ams production and their identification as staphylococcus aureus was based on the presence of gram-positive cocci and on positive results in tests for the ability to coagulate rabbit plasma, to ferment mannitol, and to produce ...200919635553
[development of single base extension-tags microarray for the detection of food-borne pathogens].we developed single base extension-tags (sbe-tags) microarray to detect eight common food-borne pathogens, including staphylococcus aureus, vibrio parahaemolyticus, listeria monocytogenes, salmonella, enterobacter sakazaki, shigella, escherichia coli o157:h7 and campylobacter jejuni. with specific pcr primers identified and integrated for eight food-borne pathogens, target sequences were amplified and purified as template dna of single base extension-tags reaction. the products were hybridized t ...200919637631
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