Publications
| Title | Abstract | Year Filter | PMID(sorted ascending) Filter |
|---|
| synthetic toll-like receptor 4 agonists stimulate innate resistance to infectious challenge. | a compound family of synthetic lipid a mimetics (termed the aminoalkyl glucosaminide phosphates [agps]) was evaluated in murine infectious disease models of protection against challenge with listeria monocytogenes and influenza virus. for the listeria model, intravenous administration of agps was followed by intravenous bacterial challenge 24 h later. spleens were harvested 2 days postchallenge for the enumeration of cfu. for the influenza virus model, mice were challenged with virus via the int ... | 2005 | 15845512 |
| construction and characterization of listeria monocytogenes mutants with in-frame deletions in the response regulator genes identified in the genome sequence. | two-component systems are widely distributed in prokaryotes where they control gene expression in response to diverse stimuli. to study the role of the sixteen putative two-component systems of listeria monocytogenes systematically, in frame deletions were introduced into 15 out of the 16 response regulator genes and the resulting mutants were characterized. with one exception the deletion of the individual response regulator genes has only minor effects on in vitro and in vivo growth of the bac ... | 2005 | 15845524 |
| brain stem encephalitis in listeriosis. | serious infection with the bacterium l. monocytogenes mainly manifests as sepsis and/or meningitis. a particular entity is listeria brain stem encephalitis, which is characterized by progressive brain stem deficits. the condition is fatal unless early treated. the purpose of the present study was to assess the incidence of brain stem encephalitis in a population-based listeriosis material. medical records from 212 of the 240 patients with serious listeriosis reported in norway from 1977 to 2000, ... | 2005 | 15849051 |
| differential requirements for the chemokine receptor ccr7 in t cell activation during listeria monocytogenes infection. | effective priming of t cell responses depends on cognate interactions between naive t cells and professional antigen-presenting cells (apcs). this contact is the result of highly coordinated migration processes, in which the chemokine receptor ccr7 and its ligands, ccl19 and ccl21, play a central role. we used the murine listeria monocytogenes infection model to characterize the role of the ccr7/ccr7 ligand system in the generation of t cell responses during bacterial infection. we demonstrate t ... | 2005 | 15851484 |
| methods to determine the growth domain in a multidimensional environmental space. | data from a database on microbial responses to the food environment (combase, see www.combase.cc) were used to study the boundary of growth several pathogens (aeromonas hydrophila, escherichia coli, listeria monocytogenes, yersinia enterocolitica). two methods were used to evaluate the growth/no growth interface. the first one is an application of the minimum convex polyhedron (mcp) introduced by baranyi et al. [baranyi, j., ross, t., mcmeekin, t., roberts, t.a., 1996. the effect of parameterisa ... | 2004 | 15854687 |
| a quasi-chemical model for the growth and death of microorganisms in foods by non-thermal and high-pressure processing. | predictive microbial models generally rely on the growth of bacteria in laboratory broth to approximate the microbial growth kinetics expected to take place in actual foods under identical environmental conditions. sigmoidal functions such as the gompertz or logistics equation accurately model the typical microbial growth curve from the lag to the stationary phase and provide the mathematical basis for estimating parameters such as the maximum growth rate (mgr). stationary phase data can begin t ... | 2004 | 15854689 |
| modelling the individual cell lag phase: effect of temperature and ph on the individual cell lag distribution of listeria monocytogenes. | the individual-based approach of the lag phase is gaining interest, especially for pathogens that initially contaminate food products in low amounts. in this paper, the effect of temperature (30, 10, 7, 4 and 2 degrees c) and ph (7.4, 6.1, 5.5, 5.0, 4.7 and 4.4) on the individual cell lag phase of listeria monocytogenes was examined in a factorial design, using od measurements. individual lag phases of about 100 individual cells per condition were examined and calculated using a linear extrapola ... | 2004 | 15854691 |
| modelling the effect of a temperature shift on the lag phase duration of listeria monocytogenes. | the aim of this work is to study and model the effect of a temperature shift on h(0), the product of the growth rate by the lag phase duration (mulambda). our work is based on the data of whiting and bagi [int. j. food microbiol. 73 (2002) 291], who studied the influence of both the pre-incubation temperature (t(prior)) and the growth temperature (t(growth)) on lambda values of listeria monocytogenes. we introduce a new model to describe the evolution of the parameter h(0) as a function of t(pri ... | 2004 | 15854694 |
| temperature effect on bacterial growth rate: quantitative microbiology approach including cardinal values and variability estimates to perform growth simulations on/in food. | temperature effect on growth rates of listeria monocytogenes, salmonella, escherichia coli, clostridium perfringens and bacillus cereus, was studied. growth rates were obtained in laboratory medium by using a binary dilutions method in which 15 optical density curves were generated to determine one mu value. the temperature was in the range from 2 to 48 degrees c, depending on the bacterial species. data were analysed after a square root transformation. no large difference between the strains of ... | 2004 | 15854703 |
| comparing predicting models for heat inactivation of listeria monocytogenes and pseudomonas aeruginosa at different ph. | under the same experimental conditions it has been demonstrated that whereas survival curves of listeria monocytogenes in the range of temperatures from 54 to 62 degrees c followed a first-order kinetic, those of pseudomonas aeruginosa in the range of temperatures from 50 to 56 degrees c were not linear showing a shoulder followed by a linear region. the first order kinetic model did not describe survival curves of p. aeruginosa. a model based on the weibull distribution (log(10)(n(t)/n(0))=(1/- ... | 2004 | 15854706 |
| development of a safety monitoring and assurance system for chilled food products. | the principles of a novel chill chain management policy, coded safety monitoring and assurance system (smas) for the optimisation of the distribution of chilled food products within the chill chain are developed. in this system, a new approach based on actual risk evaluation at important points of the chill chain is used in order to promote products to the next stage of distribution. this evaluation based on product's time-temperature history, variation in product's characteristics (e.g. a(w), p ... | 2004 | 15854710 |
| [investigation of electrophysical properties of listeria monocytogenes cells during the interaction with monoclonal antibodies]. | an electrooptical approach was used in studies of listeria monocytogenes-antibody binding. an electrooptical analyzer, which has been developed at the state research center for applied microbiology (obolensk, russia), was used as a basic instrument for electrooptical measurements. the analyzer consists of the following modules: a sample preparation module, a mixer, an ac field generator, an eo-flow cell, a microcontroller for transfer of liquid, a thermal system, an operator interface, and an im ... | 2005 | 15856991 |
| influence of bacteriocin-like substance, generation times, and genetic profiles of listeria innocua on the isolation of listeria monocytogenes. | inhibition of isolation of listeria monocytogenes by bacteriocin-like substance (bls)-producing listeria innocua after enrichment culture was investigated. when 26 l. monocytogenes strains were examined in combination with eight l. innocua strains using the spot on lawn method, 52/208 (25.0%) combinations showed the growth inhibition of l. monocytogenes. when two listeria species were cultured simultaneously in selective enrichment broth, inhibition of isolation of l. monocytogenes was observed ... | 2005 | 15857657 |
| evaluation of a chromogenic medium for identification and differentiation of listeria monocytogenes in selected foods. | listeria monocytogenes continues to be a threat to food safety in the united states despite a "zero tolerance" policy. when listeria species are identified by standard cultural methods, confirmation of l. monocytogenes takes days to complete. rapid'l.mono agar, developed by bio-rad laboratories, is a chromogenic medium that differentiates l. monocytogenes from other species of listeria by a simple color change reaction. differentiation is based on the specific detection of phosphatidylinositol p ... | 2005 | 15859079 |
| activity of three {beta}-lactams (ertapenem, meropenem and ampicillin) against intraphagocytic listeria monocytogenes and staphylococcus aureus. | assessment of the activity of three beta-lactams [ertapenem (a carbapenem with a prolonged half-life), meropenem and ampicillin] against intraphagocytic listeria monocytogenes and staphylococcus aureus. | 2005 | 15860552 |
| induction of acquired cellular resistance in mice with viable and macrophage-processed listeria monocytogenes. | intracutaneous immunization of mice with 10(5) or 10(6) viable listeria resulted in acquired cellular resistance (acr) of short duration (7 days). the period during which viable listeria monocytogenes had to be present in order to induce acr was estimated by killing the listeria at different times after immunization by injecting the bactericidal antibiotic amoxycillin. the killing of listeria within 6 h after injection prevented the induction of a cr completely, between 6 and 12 h partially, whi ... | 1982 | 15861581 |
| fate of listeria monocytogenes in experimentally contaminated french sausages. | listeria monocytogenes has been recognized as one of the most important foodborne pathogens dealt with by the food. the bacterium has been found in every part along the pork processing industry from the slaughterhouse to the cutting room and the delicatessen factories. during the fermentation and drying of sausages, l. monocytogenes tends to decrease substantially. however, despite the various hurdles in the dry sausage manufacturing process, l. monocytogenes is able to survive and is detected i ... | 2005 | 15862881 |
| growth of listeria monocytogenes on iceberg lettuce and solid media. | the growth of pathogenic bacterium listeria monocytogenes on fresh-cut iceberg lettuce under constant temperatures was modelled in order to investigate microbial safety during distribution of this vegetable. we examined the effects of several incubation temperatures, ranging from 5 to 25 degrees c, on bacterial growth. these data were fitted to the baranyi model and the curves showed a high correlation coefficient at all temperature (r2 > 0.95). in addition, the native bacterial flora of the let ... | 2005 | 15862883 |
| pesticides as a source of microbial contamination of salad vegetables. | ten commercially available pesticides (insecticides, herbicides and fungicides), used during the production of vegetable produce, were examined as potential sources of microbial contaminants. as purchased, none of the pesticides showed the presence of viable microorganisms (< 5 cfu/ml). using an agar plate diffusion assay, they did not inhibit a range of bacteria of spoilage and public health significance on vegetable produce. after reconstitution in sterile water to their recommended concentrat ... | 2005 | 15862885 |
| beyond allergen avoidance: update on developing therapies for peanut allergy. | food allergy has emerged as a significant health problem. peanut allergy is a major cause of food-induced fatal and near fatal anaphylactic reactions, and the incidence in children is increasing. attempts to manage peanut allergy by strict avoidance are often unsuccessful. the purpose of this review is to highlight the most promising novel approaches for treating peanut allergy beyond allergen avoidance. | 2005 | 15864090 |
| [neurolisteriosis with acute myelitis]. | listeriosis is a bacterial infection with listeria monocytogenes mostly affecting immunocompromised patients. in every fourth case, the cns is involved, usually as meningoencephalitis. this case report of an immunocompetent woman represents the first one of neurolisteriosis initially presenting as cervical myelitis and progressing to supratentorial areas of the brain. diagnosis was based on universal polymerase chain reaction from a cortical brain biopsy, followed by sequencing of the amplified ... | 2005 | 15864516 |
| dietary (n-3) polyunsaturated fatty acids do not affect the in vivo development and function of listeria-specific cd4+ and cd8+ effector and memory/effector t cells in mice. | we previously reported that in a mouse model, a diet high in (n-3) pufa diminishes host survival following an infection from listeria monocytogenes, a gram-positive bacterial pathogen. in this study we investigated the impact of (n-3) pufa on the adaptive immune response to l. monocytogenes. balb/c mice were fed experimental diets either devoid of or rich in (n-3) pufa from fish oil for 4 wk and then infected with 10(6) acta-deficient l. monocytogenes. at 7 and 35 d postchallenge, effector and m ... | 2005 | 15867296 |
| potential role of diploscapter sp. strain lkc25, a bacterivorous nematode from soil, as a vector of food-borne pathogenic bacteria to preharvest fruits and vegetables. | diploscapter, a thermotolerant, free-living soil bacterial-feeding nematode commonly found in compost, sewage, and agricultural soil in the united states, was studied to determine its potential role as a vehicle of salmonella enterica serotype poona, enterohemorrhagic escherichia coli o157:h7, and listeria monocytogenes in contaminating preharvest fruits and vegetables. the ability of diploscapter sp. strain lkc25 to survive on agar media, in cow manure, and in composted turkey manure and to be ... | 2005 | 15870330 |
| growth of listeria monocytogenes in the guinea pig placenta and role of cell-to-cell spread in fetal infection. | listeria monocytogenes causes foodborne outbreaks that lead to infection in human and other mammalian fetuses. to elucidate the molecular and cellular mechanisms involved in transplacental transmission, we characterized placental-fetal infection in pregnant guinea pigs inoculated with wild-type (wt) or mutant l. monocytogenes strains. the wt strain increased in number in the placenta by >1000-fold during the first 24 h after inoculation--an increase that was unparalleled in other maternal organs ... | 2005 | 15871123 |
| microbiological aspects of the investigation that traced the 1998 outbreak of listeriosis in the united states to contaminated hot dogs and establishment of molecular subtyping-based surveillance for listeria monocytogenes in the pulsenet network. | a multistate outbreak of listeriosis occurred in the united states in 1998 with illness onset dates between august and december. the outbreak caused illness in 108 persons residing in 24 states and caused 14 deaths and four miscarriages or stillbirths. this outbreak was detected by public health officials in tennessee and new york who observed significant increases over expected listeriosis cases in their states. subsequently, the centers for disease control and prevention (cdc) began laboratory ... | 2005 | 15872265 |
| listeria-associated arthritis in a patient undergoing etanercept therapy: case report and review of the literature. | listeriosis can be a cause of infectious arthritis. here, we present a case of articular listeriosis in a patient with rheumatoid arthritis receiving treatment with etanercept, a tumor necrosis factor antagonist. we review the literature of articular listeriosis and discuss the role of tumor necrosis factor blockade in precipitating listeriosis. | 2005 | 15872306 |
| listeria meningitis in transplant recipients. | meningitis is a rare complication following organ and stem-cell transplantation and can be caused by a variety of microorganisms. | 2005 | 15875764 |
| tracing listeria monocytogenes isolates from cold-smoked salmon and its processing environment in iceland using pulsed-field gel electrophoresis. | listeria spp. and listeria monocytogenes contamination of cold-smoked salmon (n=125) and its processing environment (n=522) were evaluated during surveys conducted in 1997-1998 and 2001 as well as in samples of final products analysed in 2001. the overall frequencies of listeria spp. and l. monocytogenes in samples from all sources were 15.1% and 11.3%, respectively, but the incidence of l. monocytogenes in cold-smoked salmon final products was only 4%. a total of 201 l. monocytogenes isolates w ... | 2005 | 15878405 |
| effect of prior growth temperature, type of enrichment medium, and temperature and time of storage on recovery of listeria monocytogenes following high pressure processing of milk. | a five-isolate cocktail of listeria monocytogenes (10(3) cfu/ml in skim or whole raw milk) was subjected to 450 mpa for 900 s or 600 mpa for 90 s. the effects of prior growth temperature, type of milk (skim vs. whole), type of recovery-enrichment media (optimized penn state university [opsu] broth, listeria enrichment broth [leb], buffered leb [bleb], modified bleb [mbleb], and milk), storage temperature and storage time on the recovery of l. monocytogenes were examined. optimized psu broth sign ... | 2005 | 15878406 |
| rapid clearance of a recombinant salmonella vaccine carrier prevents enhanced antigen-specific cd8 t-cell responses after oral boost immunizations. | the type iii secretion system of salmonella enterica serovar typhimurium can be used to target heterologous antigens directly into the cytosol of antigen-presenting cells. our laboratory has previously reported that the single oral immunization of mice with a recombinant salmonella strain expressing the translocated yersinia outer protein e fused to the immunodominant antigen p60 from listeria monocytogenes results in the efficient induction of p60-specific cd8 t cells and confers protection aga ... | 2005 | 15878680 |
| internalin-expressing lactococcus lactis is able to invade small intestine of guinea pigs and deliver dna into mammalian epithelial cells. | the use of the food-grade bacterium lactococcus lactis as antigen delivery vehicle at the mucosal level is an attractive vaccination strategy intensively explored during the last decade. in this study, we developed l. lactis strains which could be used as a dna delivery vector to combine both advantages of mucosal delivery and of dna vaccination. to render lactococci capable of invading epithelial cells, the listeria monocytogenes inla gene was cloned and expressed in l. lactis under transcripti ... | 2005 | 15878681 |
| cutting edge: re-evaluating the in vivo cytokine responses of cd8+ t cells during primary and secondary viral infections. | virus-specific cd8(+) t cells produce ifn-gamma after ag contact and, in the absence of this cytokine, the host often cannot eradicate infection. however, our ability to identify cells that are actively expressing this critical effector function in vivo is limited, because the protein is rapidly secreted. in this study, we describe a simple approach that circumvents the need for ex vivo ag stimulation and allows the enumeration of cd8(+) t cells that are actively synthesizing ifn-gamma in vivo d ... | 2005 | 15879085 |
| large-scale quantitative analysis of sources of variation in the actin polymerization-based movement of listeria monocytogenes. | during the actin polymerization-based movement of listeria monocytogenes, individual bacteria are rapidly propelled through the host cell cytoplasm by the growth of a filamentous actin tail. the rate of propulsion varies significantly among individuals and over time. to study this variation, we used a high-throughput tracking technique to record the movement of a large number (approximately 7900) of bacteria in xenopus frog egg extract. most bacteria (70%) appeared to maintain an individual char ... | 2005 | 15879472 |
| rat hepatocyte invasion by listeria monocytogenes and analysis of tnf-alpha role in apoptosis. | listeria monocytogenes, etiological agent of severe human foodborne infection, uses sophisticated mechanisms of entry into host cytoplasm and manipulation of the cellular cytoskeleton, resulting in cell death. the host cells and bacteria interaction may result in cytokine production as tumor necrosis factor (tnf) alpha. hepatocytes have potential to produce pro-inflammatory cytokines as tnf-alpha when invaded by bacteria. in the present work we showed the behavior of hepatocytes invaded by l. mo ... | 2005 | 15880217 |
| [influence of gaseous metabolites of soil bacteria on the multiplication of listeria monocytogenes and yersinia pseudotuberculosis]. | the influence of gaseous metabolites of saprophytic soil bacteria on the growth and multiplication of l. monocytogenes and y. pseudotuberculosis was studied. the study revealed that all cultures under study exhibited selectively both inhibiting and stimulating action on the multiplication of test cultures. bacteria of the genera pseudomonas and acinetobacter showed the highest inhibiting activitywith respect to the test cultures. volatile metabolites of bacteria of the genus aeromonas showed the ... | 2005 | 15881930 |
| understanding how listeria monocytogenes targets and crosses host barriers. | human listeriosis is caused by the gram-positive bacterium listeria monocytogenes. in humans, this pathogen has the ability to cross the intestinal, placental and blood-brain barriers, leading to gastroenteritis, maternofetal infections and meningoencephalitis, respectively. the entry of l. monocytogenes into cultured human epithelial cells is mediated by the interaction of an l. monocytogenes surface protein, internalin, with its human receptor, e-cadherin. the internalin-e-cadherin interaction ... | 2005 | 15882192 |
| the listeria protein internalin b mimics hepatocyte growth factor-induced receptor trafficking. | increased hepatocyte growth factor receptor (hgfr) signaling correlates closely with neoplastic invasion and metastatic potential of many human cancers. hepatocyte growth factor receptor signaling is initiated by binding the physiological ligand hgf or the internalin b (inlb) protein of listeria monocytogenes. subsequent degradation of endocytosed hgfr terminates receptor signaling. previously reported discrepancies in inlb and hgf-induced hgfr signaling could reflect differences in receptor int ... | 2005 | 15882443 |
| apoptotic death of listeria monocytogenes-infected human macrophages induced by lactoferricin b, a bovine lactoferrin-derived peptide. | listeria monocytogenes, an intracellular facultative food-borne pathogen, was reported to induce apoptosis in vitro and in vivo in a variety of cell types with the exception of murine macrophages. these cells represent the predominant compartment of bacterial multiplication and die as a result of necrosis. in this study we showed that human non-activated and ifn-gamma-activated macrophagic-like (thp-1) cells infected with l. monocytogenes, mainly die by necrosis rather than by an apoptotic proce ... | 2005 | 15888254 |
| diagnosis of partially treated culture-negative bacterial meningitis using 16s rrna universal primers and restriction endonuclease digestion. | cerebrospinal fluid (csf) obtained from patients with partially treated and culture-negative meningitis was subjected to pcr using 16s rdna universal primers followed by restriction endonuclease digestion. in all, 43 patients and 7 controls were enrolled in this study. twenty-one meningitic samples were positive by pcr. mycobacterium tuberculosis was the causative agent in seven cases followed by haemophilus influenzae (four), streptococcus pneumoniae (two), listeria monocytogenes (one), escheri ... | 2005 | 15888461 |
| dendritic cells maximize the memory cd8 t cell response to infection. | costimulatory signals from dendritic cells (dcs) are required for naive t cells to respond to antigenic stimulation. to what extent dcs reactivate memory t cells during recall responses is not known. here, an in vivo depletion system has been used to analyze the role of dcs in reactivating cd8 memory t cells during recall responses to three different microbial infections. we show a profound decrease in the numbers of responding memory cd8 t cells in both lymphoid and nonlymphoid tissues during t ... | 2005 | 15894274 |
| enhanced toll-like receptor responses in the absence of signaling adaptor dap12. | dap12 is a signaling adaptor containing an immunoreceptor tyrosine-based activation motif (itam) that pairs with receptors on myeloid cells and natural killer cells. we examine here the responses of mice lacking dap12 to stimulation through toll-like receptors (tlrs). unexpectedly, dap12-deficient macrophages produced higher concentrations of inflammatory cytokines in response to a variety of pathogenic stimuli. additionally, macrophages deficient in spleen tyrosine kinase (syk), which signals d ... | 2005 | 15895090 |
| comprehensive survey of pasteurized fluid milk produced in the united states reveals a low prevalence of listeria monocytogenes. | a comprehensive survey was undertaken to generate contemporary data on the prevalence of listeria monocytogenes in pasteurized fluid milk produced in the united states. samples (5,519) near the sell-by expiration date were purchased at retail outlets over a 5-week period and analyzed for presence of l. monocytogenes. products consisted of whole milk, nonfat milk, and chocolate milk packaged in gallon, half gallon, quart, pint, and half-pint containers. samples were collected from both large and ... | 2005 | 15895729 |
| distribution of listeria monocytogenes subtypes within a poultry further processing plant. | samples from environmental sites and raw product in a chicken further processing plant were collected every 6 weeks for 12 months. each sample site was examined before and after a complete production shift. all samples were examined for the presence of listeria monocytogenes, which was detected in floor drains on the raw product side of the plant preoperation and in drains on both raw and cooked sides following 8 h of processing operation. l. monocytogenes also was detected in raw product and on ... | 2005 | 15895730 |
| efficacy of electrolyzed water in inactivating salmonella enteritidis and listeria monocytogenes on shell eggs. | the efficacy of acidic electrolyzed (eo) water produced at three levels of total available chlorine (16, 41, and 77 mg/ liter) and chlorinated water with 45 and 200 mg/liter of residual chlorine was investigated for inactivating salmonella enteritidis and listeria monocytogenes on shell eggs. an increasing reduction in listeria population was observed with increasing chlorine concentration from 16 to 77 mg/liter and treatment time from 1 to 5 min, resulting in a maximal reduction of 3.70 log cfu ... | 2005 | 15895731 |
| postprocessing antimicrobial treatments to control listeria monocytogenes in commercial vacuum-packaged bologna and ham stored at 10 degrees c. | the antilisterial effect of chemical dipping solutions on commercial bologna and ham slices, inoculated (3 to 4 log cfu/ cm2) after processing, was evaluated during storage in vacuum packages at 10 degrees c. samples were inoculated with a 10-strain composite of listeria monocytogenes and subsequently immersed (25+/-2 degrees c) for 2 min in 2.5% acetic acid (aa), 2.5% lactic acid (la), 5% potassium benzoate (pb), or 0.5% nisaplin (commercial form of nisin, equivalent to 5,000 iu/ml of nisin) so ... | 2005 | 15895732 |
| prewashing with acidified sodium chlorite reduces pathogenic bacteria in lightly fermented chinese cabbage. | efficacy of prewashing with acidified sodium chlorite (asc) for the sanitation of lightly fermented chinese cabbage was evaluated. the population of the natural microflora on the cabbage leaves was reduced about 2.0 log cfu/g just after washing with asc, a significant reduction compared with the control distilled water wash (p < or = 0.05). in the control experiment, viable aerobic bacteria increased gradually when incubated at 10 degrees c; however, asc-washed cabbage maintained a lower microbi ... | 2005 | 15895733 |
| antimicrobial activity of nisin adsorbed to surfaces commonly used in the food industry. | the adsorption isotherms of nisin to three food contact surfaces, stainless steel, polyethyleneterephthalate (pet), and rubber at 8, 25, 40, and 60 degrees c, were calculated. for all surfaces, the increase in temperature led to a decrease in the affinity between nisin and the surface. the rubber adsorbed a higher amount of nisin (0.697 microg/cm2) in comparison with pet (0.665 microg/cm2) and stainless steel (0.396 microg/cm2). adsorption of nisin to the stainless steel surface described l-2 ty ... | 2005 | 15895735 |
| bacteriophage control of foodborne bacteriat. | bacteriophages are measurable components of the natural microflora in the food production continuum from the farm to the retail outlet. phages are remarkably stable in these environments and are readily recovered from soil, sewage, water, farm and processing plant effluents, feces, and retail foods. purified high-titer phage lysates have been used for the species-specific control of bacteria during the pre- and postharvest phases of food production and storage. for example, the inhibition of the ... | 2005 | 15895751 |
| unity in organisation and regulation of catabolic operons in lactobacillus plantarum, lactococcus lactis and listeria monocytogenes. | global regulatory circuits together with more specific local regulators play a notable role when cells are adapting to environmental changes. lactococcus lactis is a lactic acid bacterium abundant in nature fermenting most mono- and disaccharides. comparative genomics analysis of the operons encoding the proteins and enzymes crucial for catabolism of lactose, maltose and threhalose revealed an obvious unity in operon organisation . the local regulator of each operon was located in a divergent tr ... | 2005 | 15900965 |
| a multidomain fusion protein in listeria monocytogenes catalyzes the two primary activities for glutathione biosynthesis. | glutathione is the predominant low-molecular-weight peptide thiol present in living organisms and plays a key role in protecting cells against oxygen toxicity. until now, glutathione synthesis was thought to occur solely through the consecutive action of two physically separate enzymes, gamma-glutamylcysteine ligase and glutathione synthetase. in this report we demonstrate that listeria monocytogenes contains a novel multidomain protein (termed gshf) that carries out complete synthesis of glutat ... | 2005 | 15901709 |
| activated antigen-presenting cells select and present chemically modified peptides recognized by unique cd4 t cells. | cd4 t cells recognized posttranslationally modified peptides of the protein hen egg-white lysozyme (hel), consisting of nitration of tyrosines and modifications of tryptophans in the t cell contact residues of the peptides. t cells were directed against modifications of a chemically dominant hel peptide as well as a minor hel peptide, bound to the class ii histocompatibility molecule i-a(k). the modified peptides were generated in vivo after immunization with native hel molecules or were generat ... | 2005 | 15901898 |
| dynamic regulation of ifn-gamma signaling in antigen-specific cd8+ t cells responding to infection. | ifn-gamma plays a critical role in the cd8(+) t cell response to infection, but when and if this cytokine directly signals cd8(+) t cells during an immune response is unknown. we show that naive ag-specific cd8(+) t cells receive ifn-gamma signals within 12 h after in vivo infection with listeria monocytogenes and then become unresponsive to ifn-gamma throughout the ensuing ag-driven expansion phase. ag-specific cd8(+) t cells regain partial ifn-gamma responsiveness throughout the contraction ph ... | 2005 | 15905520 |
| the role of protein kinase a anchoring via the rii alpha regulatory subunit in the murine immune system. | intracellular camp may inhibit t cell activation and proliferation via activation of the camp-dependent protein kinase, pka. pka signaling is maintained through interactions of the regulatory subunit with a-kinase anchoring proteins (akaps). we demonstrated that t cells contain akaps and now ask whether pka anchoring to akaps via the riialpha regulatory subunit is necessary for camp-mediated inhibition of t cell activation. we studied the immune systems of mice lacking the riialpha regulatory su ... | 2005 | 15905526 |
| the antiapoptotic protein bcl-xl is dispensable for the development of effector and memory t lymphocytes. | the antiapoptotic protein bcl-x(l) is induced in activated t lymphocytes upon costimulation through cd28, 4-1bb, and ox40. bcl-x(l) is also highly enriched in memory t lymphocytes. based on this body of evidence, it was thought that bcl-x(l) plays an essential role in the generation of effector and memory t lymphocytes. we report that mice with a conditional deletion of bcl-x in t lymphocytes develop a normal cd8(+) t cell response to listeria monocytogenes infection. furthermore, bcl-x conditio ... | 2005 | 15905539 |
| risk factors for intramammary infections and relationship with somatic-cell counts in italian dairy goats. | routine examination of milk was performed on five herds of lactating goats in northern italy as part of a milk quality-monitoring program in the year 2000. as part of the study, aseptic samples of foremilk were collected monthly from both half udders during the entire lactation for 305 goats, resulting in a total of 4571 samples. the samples were tested with cytological and bacteriological analyses to evaluate the relationship between mammary infections and somatic-cell count (scc; fossomatic (t ... | 2005 | 15907567 |
| cationic microparticles consisting of poly(lactide-co-glycolide) and polyethylenimine as carriers systems for parental dna vaccination. | cationic microparticles for dna adsorption were formulated by blending poly(lactide-co-glycolide) (plga) (50:50), with different cationic agents, either pei 25 kda (polyethylenimine) or ctab (cetyl-trimethyl-ammonium-bromide). the aim was to create adjuvant delivery systems increasing the efficiency of dna vaccines. microparticles formulated with 10% pei exhibited a highly positive zeta-potential, small particle sizes, in contrast to particles prepared with ctab, which revealed highly aggregated ... | 2005 | 15907586 |
| contribution of nitric oxide to cpg-mediated protection against listeria monocytogenes. | immunostimulatory cpg oligodeoxynucleotides (odn) improve host resistance to listeriae. cpg odn trigger immune cells to produce gamma interferon and "prime" host cells to secrete nitric oxide in response to bacterial exposure. cpg treatment does not protect inducible nitric oxide synthase 2 knockout mice, indicating that no is critical to cpg-mediated protection against listeriae. | 2005 | 15908417 |
| analysis of the prevalence of tetracycline resistance genes in clinical isolates of enterococcus faecalis and enterococcus faecium in a japanese hospital. | prevalence of seven tetracycline resistance (tc(r)) genes--tet(l), tet(m), tet(k), tet(o), tet(s), tet(t), and tet(u)--which are known to be distributed to gram-positive cocci was analyzed for 224 enterococcus faecalis and 46 enterococcus faecium clinical isolates obtained in a japanese hospital. any of the tc(r) genes was detected in 75.9% of all the enterococcal strains. the tet(m) was detected at highest rates in both e. faecalis (75.0%) and e. faecium (69.6%), followed by tet(l), which was h ... | 2005 | 15910229 |
| characterization of anti-self cd8 t-cell responses stimulated by recombinant listeria monocytogenes expressing the melanoma antigen trp-2. | a potential approach to activate tumor-specific t cells is to use live bacterial vectors to deliver appropriate antigens in a highly immunostimulatory context. we constructed a recombinant strain of listeria monocytogenes (rlm) expressing murine tyrosinase-related protein-2 (trp-2), a nonmutated melanocyte-derived differentiation antigen highly expressed in melanomas. immunization of c57bl/6 mice with this rlm strain efficiently primed cd8 t cells to recognize the mhc class i-restricted trp-2180 ... | 2005 | 15913853 |
| uncaria tomentosa extract increases the number of myeloid progenitor cells in the bone marrow of mice infected with listeria monocytogenes. | in this study, we demonstrated that uncaria tomentosa extract (ute) protects mice from a lethal dose of listeria monocytogenes when administered prophylactically at 50, 100, 150 and 200 mg/kg for 7 days, with survival rates up to 35%. these doses also prevented the myelosuppression and the splenomegaly caused by a sublethal infection with l. monocytogenes, due to increased numbers of granulocyte-macrophage progenitors (cfu-gm) in the bone marrow. non-infected mice treated with 100 mg/kg ute also ... | 2005 | 15914328 |
| gastrointestinal phase of listeria monocytogenes infection. | 2005 | 15916648 | |
| proteomic and microscopic analysis of biofilms formed by listeria monocytogenes 568. | biofilm formation may be important in the colonization of the food-processing environment by the food-borne pathogen listeria monocytogenes. listeria monocytogenes 568 formed adherent multicellular layers on a variety of test surfaces following growth at 37 degrees c with multiple transfers of the test surface into fresh medium. microscopic examination of these adherent layers suggest that the cells were surrounded by extracellular material. the presence of a carbohydrate containing extracellula ... | 2005 | 15920617 |
| [a new complex approaches for the identification of listeria isolated during production of fermented sausages]. | distribution l. monocytogenes and other listeria spp. in raw meat and during manufacturing of fermented meat products is investigated. the high contamination of raw materials and semi finished foods--in 36.5% of samples, ready-to-eat sausages--31.8% by listeria spp. is established. detection l. monocytogenes in 9.7% cases from the surfaces of equipment indicates the intensive circulation of listeriosis agents on meat plants. for identification 49 isolated strains the approach providing applicati ... | 2005 | 15921204 |
| thalidomide enhances both primary and secondary host resistances to listeria monocytogenes infection by a neutrophil-related mechanism in female b6c3f1 mice. | previously, we have reported that thalidomide can modulate the immune responses in female b6c3f1 mice. furthermore, thalidomide immunomodulation increased primary host resistance to intravenously infected listeria monocytogenes. the present study was intended to evaluate the mechanisms underlying the enhanced host resistance to l. monocytogenes by focusing on the neutrophils. female b6c3f1 mice were treated intraperitoneally with thalidomide (100 mg/kg) for 15 days. exposure to thalidomide incre ... | 2005 | 15921716 |
| cd1d-independent regulation of nkt cell migration and cytokine production upon listeria monocytogenes infection. | natural killer t (nkt) cells are a unique t-cell population that is positively selected by cd1d-expressing cells. in this study, we examined the kinetics of conventional cd4+tcrbeta+ and cd4-tcrbeta+ cells along with various nkt cell populations from wt and cd1d ko mice after oral listeria monocytogenes (lm) infection at different time points in tissue compartments. we found that cd4+tcrbeta+ cells expressing nk1.1+ (nkt) were constitutively expressed in the lung of both strains of mice, but dis ... | 2004 | 15922714 |
| prevalence of listeria monocytogenes in 13 dried sausage processing plants and their products. | the aims of the present study were: (i) to investigate the occurrence of listeria monocytogenes in dried sausage processing plants on surfaces before and during processing, (ii) to study the contamination in meat and sausages at different stages of maturation, (iii) to assess the distribution of l. monocytogenes in the different plants and products studied. thirteen dried sausage processing plants were sampled at two different times of the working day. the studies were repeated twice to evaluate ... | 2005 | 15925005 |
| cytotoxic activity of murine resident peritoneal cells against listeria monocytogenes-infected hepatocytes in vitro. | sterile immunity to the gram-positive facultative intracellular bacterium listeria monocytogenes critically depends on cytotoxic cd8+ t lymphocytes. however, the cytotoxic cell population able to kill infected cells before specific t cells are generated is not well characterised. based on histological observations and the use of monoclonal antibodies abrogating the cd11b/cd18-dependent cellular influx into infected organs as well as granulocyte-depleting antibodies, some authors favour pmns as b ... | 2005 | 15925534 |
| survival of listeria monocytogenes on fresh and frozen strawberries. | cut or intact surfaces of fresh strawberries were spot inoculated with a five-strain cocktail of nalidixic-acid resistant listeria monocytogenes (10(6) (low inoculum) and 10(8) (high inoculum) cfu per three-berry sample). inoculated strawberries were dried for 1 h at 24 degrees c and were stored in loosely closed containers at 4 or 24 degrees c. an initial population reduction of approximately 0.6 and 1.2 log cycles, high and low inoculum, respectively, was observed on intact but not cut berries ... | 2005 | 15925709 |
| cell division theory and individual-based modeling of microbial lag: part i. the theory of cell division. | this series of two papers deals with the theory of cell division and its implementation in an individual-based modeling framework. in this first part, the theory of cell division is studied on an individual-based level in order to learn more about the mechanistic principles behind microbial lag phenomena. while some important literature on cell division theory dates from 30 to 40 years ago, until now it has hardly been introduced in the field of predictive microbiology. yet, it provides a large ... | 2005 | 15925713 |
| synergism between active listeriolysin o and dimethyldioctadecylammonium bromide to activate cd8(+) t cells. | purified recombinant listeriolysin o (llo) was assessed for its ability to induce t cell responses in mice. intraperitoneal immunisation with llo, as a fusion with glutathione-s-transferase (gst), induced the production of llo-specific cd8(+) t cells, but not llo-specific cd4(+) t cells. the generation of this response could be blocked by pre-treatment with cholesterol, indicating a requirement for llo pore formation. an increase in the llo-specific response of both cd8(+) and cd4(+) t cells cou ... | 2005 | 15927321 |
| the marked increase of listeria monocytogenes isolation from contents of swine cecum. | the actual prevalence of listeria monocytogenes from contents of swine cecum was investigated. the efficiency of listeria enrichment broth (leb) for isolation was examined by the recovery of artificially inoculated l. monocytogenes in contents of swine cecum. the numbers of organisms did not increase after 48 h incubation, but increased when the rapid decrease in ph of the leb was adjusted. between 1991 and 1993, 250 contents of swine cecum were examined for the prevalence of l. monocytogenes us ... | 2005 | 15932770 |
| presence of gadd1 glutamate decarboxylase in selected listeria monocytogenes strains is associated with an ability to grow at low ph. | the glutamate decarboxylase (gad) system is critical to the survival of listeria monocytogenes lo28 at low-ph stress (<ph 4.0). the gad system classically involves two proteins, a glutamate decarboxylase enzyme coupled to a glutamate/gamma-aminobutyrate antiporter, which results in the consumption of an intracellular proton for each glutamate entering the system. uniquely among prokaryotes, some strains of l. monocytogenes, including strain lo28, possess genes encoding three decarboxylases (gadd ... | 2005 | 15932974 |
| influence of stress on individual lag time distributions of listeria monocytogenes. | the effects of nine common food industry stresses on the times to the turbidity (t(d)) distribution of listeria monocytogenes were determined. it was established that the main source of the variability of t(d) for stressed cells was the variability of individual lag times. the distributions of t(d) revealed that there was a noticeable difference in response to the stresses encountered by the l. monocytogenes cells. the applied stresses led to significant changes of the shape, the mean, and the v ... | 2005 | 15932988 |
| amplified intergenic locus polymorphism as a basis for bacterial typing of listeria spp. and escherichia coli. | dna-based methods are increasingly important for bacterial typing. the high number of polymorphic sites present among closely related bacterial genomes is the basis for the presented method. the method identifies multilocus genomic polymorphisms in intergenic regions termed ailp (amplified intergenic locus polymorphism). for each locus, a pair of unique pcr primers was designed to amplify an intergenic sequence from one open reading frame (orf) to the adjacent orf. presence, absence, and size va ... | 2005 | 15933014 |
| bacteriocin from honeybee beebread enterococcus avium, active against listeria monocytogenes. | enterococcus avium isolated from apis mellifera beebread produces a thermoresistant bacteriocin with a strain-dependent inhibitory effect on listeria and without effect on gram-negative bacteria. the bacteriocin appeared to be a polypeptide of about 6 kda. genetic analyses revealed no extrachromosomal material in e. avium. | 2005 | 15933045 |
| cd70+ antigen-presenting cells control the proliferation and differentiation of t cells in the intestinal mucosa. | one unresolved issue in gut immunity is how mucosal t lymphocytes are activated and which antigen-presenting cell (apc) is critical for the regulation of this process. we have identified a unique population of apcs that is exclusively localized in the lamina propria. these apcs constitutively expressed the costimulatory molecule cd70 and had antigen-presenting functions. after oral infection of mice with listeria monocytogenes, proliferation and differentiation of antigen-specific t cells occurr ... | 2005 | 15937486 |
| immune responses of mice to vaccinia virus recombinants expressing either listeria monocytogenes partial listeriolysin or brucella abortus ribosomal l7/l12 protein. | the brucella abortus l7/l12 gene encoding ribosomal protein l7/l12 and the listeria monocytogenes partial hly gene encoding the protective region of the hemolysin (partial listeriolysin, pllo) were cloned into vaccinia virus by homologous recombination to produce recombinants wrl7/l12 and wrpllo, respectively. the ability of these recombinants to induce humoral, cell mediated and protective immune response in mice was assessed. although mice inoculated with wrl7/l12 recombinant produced antibodi ... | 2005 | 15941627 |
| in vivo modulation of t cell responses and protective immunity by tcr antagonism during infection. | infectious agents are known to express altered peptide ligands that antagonize t cells in vitro; however, direct evidence of tcr antagonism during infection is still lacking, and its importance in the context of infection remains to be established. in this study, we used a murine model of infection with recombinant listeria monocytogenes and addressed three issues that are critical for assessing the role of tcr antagonism in the modulation of the immune response. first, we demonstrated that the ... | 2005 | 15944303 |
| phosphatidylinositol-specific phospholipase c of bacillus anthracis down-modulates the immune response. | phosphatidylinositol-specific phospholipases (pi-plcs) are virulence factors produced by many pathogenic bacteria, including bacillus anthracis and listeria monocytogenes. bacillus pi-plc differs from listeria pi-plc in that it has strong activity for cleaving gpi-anchored proteins. treatment of murine dcs with bacillus, but not listeria, pi-plc inhibited dendritic cell (dc) activation by tlr ligands. infection of mice with listeria expressing b. anthracis pi-plc resulted in a reduced ag-specifi ... | 2005 | 15944308 |
| detection of bacterial toxins with monosaccharide arrays. | a large number of bacterial toxins, viruses and bacteria target carbohydrate derivatives on the cell surface to attach and gain entry into the cell. we report here the use of a monosaccharide-based array to detect protein toxins. the array-based technique provides the capability to perform simultaneous multianalyte analyses. arrays of n-acetyl galactosamine (galnac) and n-acetylneuraminic acid (neu5ac) derivatives were immobilized on the surface of a planar waveguide and were used as receptors f ... | 2006 | 15946840 |
| unusual inflammatory and fibrogenic pulmonary responses to single-walled carbon nanotubes in mice. | single-walled carbon nanotubes (swcnt) are new materials of emerging technological importance. as swcnt are introduced into the life cycle of commercial products, their effects on human health and environment should be addressed. we demonstrated that pharyngeal aspiration of swcnt elicited unusual pulmonary effects in c57bl/6 mice that combined a robust but acute inflammation with early onset yet progressive fibrosis and granulomas. a dose-dependent increase in the protein, ldh, and gamma-glutam ... | 2005 | 15951334 |
| accelerated cd8+ t-cell memory and prime-boost response after dendritic-cell vaccination. | efficient boosting of memory t-cell numbers to protective levels generally requires a relatively long interval between immunizations. decreasing this interval could be crucial in biodefense and cancer immunotherapy, in which rapid protective responses are essential. here, we show that vaccination with peptide-coated dendritic cells (dcs) generated cd8+ t cells with the phenotype and function of memory cells within 4-6 d. these early memory cd8+ t cells underwent vigorous secondary expansion in r ... | 2005 | 15951824 |
| the increase in mucin exocytosis and the upregulation of muc genes encoding for membrane-bound mucins induced by the thiol-activated exotoxin listeriolysin o is a host cell defence response that inhibits the cell-entry of listeria monocytogenes. | in vivo listeria monocytogenes infection results in the massive release of mucus by goblet cells into the lumen of the intestine. we have previously reported that apical infection by l. monocytogenes is followed by listeriolysin o (llo)-dependent stimulation of mucus exocytosis, and the upregulation of the muc genes. here, we report that l. monocytogenes egd wild-type bacteria enter cultured human polarized, mucin-secreting, ht29-mtx cells apically by an inla-dependent mechanism. the llo-induced ... | 2005 | 15953034 |
| comparison of the microflora on organically and conventionally grown spring mix from a california processor. | considerable speculation has occurred concerning the potential for higher numbers of foodborne pathogens on organically grown produce compared with produce not grown organically. the microflora composition of spring mix or mesclun, a mixture of multiple salad ingredients, grown either by organic or conventional means was determined. unwashed or washed spring mix was obtained from a commercial california fresh-cut produce processor who does not use manure in their cultivation practices. fifty-fou ... | 2005 | 15954699 |
| influence of dietary vitamin e on behavior of listeria monocytogenes and color stability in ground turkey meat following electron beam irradiation. | there is growing concern that the free radical scavenging effect of antioxidants added to meats might reduce the antimicrobial effectiveness of ionizing radiation. a study was conducted to determine the effect of vitamin e on the behavior (growth) of listeria monocytogenes and color stability in turkey meat following electron beam irradiation. raw ground turkey breast meat from birds fed diets containing 0 (control), 50, 100, and 200 iu/kg of vitamin e was inoculated with a five-strain mixture o ... | 2005 | 15954702 |
| evaluation of gaseous chlorine dioxide as a sanitizer for killing salmonella, escherichia coli o157:h7, listeria monocytogenes, and yeasts and molds on fresh and fresh-cut produce. | gaseous chlorine dioxide (clo2) was evaluated for effectiveness in killing salmonella, escherichia coli o157:h7, and listeria monocytogenes on fresh-cut lettuce, cabbage, and carrot and salmonella, yeasts, and molds on apples, peaches. tomatoes, and onions. inoculum (100 microl, ca. 6.8 log cfu) containing five serotypes of salmonella enterica, five strains of e. coli o157:h7, or five strains of l. monocytogenes was deposited on the skin and cut surfaces of fresh-cut vegetables, dried for 30 min ... | 2005 | 15954704 |
| raw and processed fish show identical listeria monocytogenes genotypes with pulsed-field gel electrophoresis. | a total of 257 raw fish samples at two different sites were examined for the presence of listeria monocytogenes. the prevalence of l. monocytogenes was 4%. from 11 positive samples, nine different l. monocytogenes pulsed-field gel electrophoresis genotypes were recovered. from nine pulsotypes recovered from raw fish and 32 pulsotypes shown by 101 fish product isolates, two raw fish and fish product pulsotypes were indistinguishable from each other. although the prevalence of l. monocytogenes in ... | 2005 | 15954713 |
| avirulence of viable but non-culturable listeria monocytogenes cells demonstrated by in vitro and in vivo models. | the virulence of viable but non-culturable (vbnc) cells of 4 strains of listeria monocytogenes was investigated in both a human adenocarcinoma cell line (ht-29) and a mouse model. lo 28, atcc 19115 and cnl 895807 strains of listeria monocytogenes became vbnc when incubated in microcosm water at 20 degrees c and scott a strain at 4 degrees c. no culturable bacteria were detected in the vbnc state, although 104 active cells/ml were found by the direct viable count (dvc) and ctc-dapi double stainin ... | 2005 | 15955283 |
| declines of zoonotic agents in liquid livestock wastes stored in batches on-farm. | to measure the decline rates of zoonotic agents introduced into liquid livestock wastes in on-farm storage tanks. | 2005 | 15960665 |
| shelf life and safety aspects of chilled cooked and peeled shrimps (pandalus borealis) in modified atmosphere packaging. | to evaluate the growth of listeria monocytogenes and shelf life of cooked and peeled shrimps in modified atmosphere packaging (map). | 2005 | 15960666 |
| occurrence of sublethal injury after pulsed electric fields depending on the micro-organism, the treatment medium ph and the intensity of the treatment investigated. | the objective was to investigate the occurrence of sublethal injury after pulsed electric field (pef) depending on the treatment time, the electric field strength and the ph of the treatment media in two gram-positive (bacillus subtilis ssp. niger, listeria monocytogenes) and six gram-negative (escherichia coli, escherichia coli o157:h7, pseudomonas aeruginosa, salmonella serotype senftenberg 775w, salmonella serotype typhimurium, yersinia enterocolitica) bacterial strains. | 2005 | 15960669 |
| an extract from teak (tectona grandis) bark inhibited listeria monocytogenes and methicillin resistant staphylococcus aureus. | the aim of this study was to characterize the inhibitory mechanism in teak (tectona grandis) bark and to determine its effectiveness against listeria monocytogenes and methicillin resistant staphylococcus aureus (mrsa). | 2005 | 15960759 |
| "lanespector", a tool for membrane proteome profiling based on sodium dodecyl sulfate-polyacrylamide gel electrophoresis/liquid chromatography-tandem mass spectrometry analysis: application to listeria monocytogenes membrane proteins. | proteomics is required to provide insight into any type of subproteome. while the workflow based on two-dimensional polyacrylamide gel electrophoresis (2-d page) can be applied for many subproteomes and comprises well-established strategies for data presentation and data analysis, the comprehensive investigation of membrane proteomes remains a challenging task. we present a number of procedures that provide an insight into such systems. we have established a novel protocol for the efficient prep ... | 2005 | 15966022 |
| the cost and benefit of listeria monocytogenes food safety measures. | the objectives of this study were to evaluate economic techniques used to determine the cost and benefit of listeria monocytogenes control and to estimate the economic optimum of l. monocytogenes food safety measures. the level of food safety measures is optimal if marginal benefit and marginal cost equate. estimates of benefit and cost of l. monocytogenes food safety measures, from available published literature, are derived from different methods of economic analysis (willingness to pay, cost ... | 2004 | 15969324 |
| listeriolysin o-induced membrane permeation mediates persistent interleukin-6 production in caco-2 cells during listeria monocytogenes infection in vitro. | listeriolysin o (llo), a major virulence factor of listeria monocytogenes, is a member of the cholesterol-dependent cytolysin family and plays important roles not only in survival of this bacterium in phagocytes but also in induction of various cellular responses, including cytokine production. in this work, we examined the involvement of llo in induction of the cytokine response in intestinal epithelial cells, the front line of host defense against food-borne listeriosis. infection of caco-2 ce ... | 2005 | 15972472 |
| infection-stimulated fibrin deposition controls hemorrhage and limits hepatic bacterial growth during listeriosis. | bacterial infections are major causes of human mortality. the activation of coagulation pathways leading to the deposition of insoluble fibrin frequently accompanies bacterial infection, and much attention has focused upon the pathological attributes of infection-stimulated fibrin deposition. nevertheless, here we present conclusive evidence that infection-stimulated fibrin deposition can perform critical protective functions during bacterial infection. specifically, we demonstrate that coagulat ... | 2005 | 15972474 |
| involvement of listeria monocytogenes phosphatidylinositol-specific phospholipase c and host protein kinase c in permeabilization of the macrophage phagosome. | we have previously shown that phosphatidylinositol-specific phospholipase c (pi-plc) produced by listeria monocytogenes activates a host protein kinase c (pkc) cascade which promotes escape of the bacterium from a macrophage-like cell phagosome. here, we provide evidence linking bacterial pi-plc and host pkc beta to phagosome permeabilization, which precedes escape. | 2005 | 15972539 |
| cross-recognition of n-formylmethionine peptides is a general characteristic of h2-m3-restricted cd8+ t cells. | h2-m3-restricted cd8+ t cells can exhibit cross-reactivity to different bacterially derived n-formylmethionine peptides. the extent of this promiscuity is unclear. we deleted the nonredundant fmivtlf epitope and found that listeria monocytogenes still primed fmivtlf-specific t cells. thus, cross-reactivity appears to be a more general characteristic of h2-m3-restricted t cells. | 2005 | 15972542 |
| cd8alpha+ dendritic cells selectively present mhc class i-restricted noncytolytic viral and intracellular bacterial antigens in vivo. | cd8alpha(+) dendritic cells (dcs) have been shown to be the principal dc subset involved in priming mhc class i-restricted ctl immunity to a variety of cytolytic viruses, including hsv type 1, influenza, and vaccinia virus. whether priming of ctls by cd8alpha(+) dcs is limited to cytolytic viruses, which may provide dead cellular material for this dc subset, or whether these dcs selectively present intracellular ags, is unknown. to address this question, we examined ag presentation to a noncytol ... | 2005 | 15972648 |
| simultaneous th1-type cytokine expression is a signature of peritoneal cd4+ lymphocytes responding to infection with listeria monocytogenes. | the robust murine response to infection with listeria monocytogenes makes an excellent model to study the functional development of immune cells. we investigated the cellular immune response to i.p. infection using intracellular cytokine staining to identify ag-specific lymphocytes. cd4(+) peritoneal exudate cells obtained 10 days postinfection predominantly coexpressed tnf-alpha, ifn-gamma, and il-2 after polyclonal or ag stimulation. a population of cells simultaneously making tnf-alpha and if ... | 2005 | 15972673 |