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distinct regulation of h2-m3-restricted memory t cell responses in lymph node and spleen.cd8 t cell populations restricted by h2-m3 mhc class ib molecules expand rapidly during primary listeria monocytogenes infection but only minimally upon reinfection. in contrast, cd8 t cells restricted by mhc class ia molecules undergo more delayed expansion during primary infection but rapid and robust expansion following reinfection. in this study we demonstrate that primary h2-m3-restricted cd8 t cell responses are unaffected by the frequency of naive mhc class ia-restricted t cells during l. ...200516237094
osteopontin is not required for the development of th1 responses and viral immunity.osteopontin (opn) has been defined as a key cytokine promoting the release of il-12 and hence inducing the development of protective cell-mediated immunity to viruses and intracellular pathogens. to further characterize the role of opn in antiviral immunity, opn-deficient (opn-/-) mice were analyzed after infection with influenza virus and vaccinia virus. surprisingly, we found that viral clearance, lung inflammation, and recruitment of effector t cells to the lung were unaffected in opn-/- mice ...200516237095
the importance of toll-like receptor 2 polymorphisms in severe infections.toll-like receptor 2 (tlr2) is a member of the tlr family, which plays a central role in the innate immune response to a wide variety of microorganisms. animal studies have shown that tlr2-knockout mice are more susceptible to septicemia due to staphylococcus aureus and listeria monocytogenes, meningitis due to streptococcus pneumoniae, and infection with mycobacterium tuberculosis, suggesting that functional tlr2 polymorphisms may impair host response to a certain spectrum of microbial pathogen ...200516237639
growth rate and growth probability of listeria monocytogenes in dairy, meat and seafood products in suboptimal conditions.to evaluate the performances of models predicting the growth rate or the growth probability of listeria monocytogenes in food.200516238733
the autolytic phenotype of the bacillus cereus group.to determine the autolytic phenotype of five species in the bacillus cereus group.200516238737
an investigation of the thermal inactivation of staphylococcus aureus and the potential for increased thermotolerance as a result of chilled storage.the aims of this study were; (i) to provide thermal inactivation data for staphylococcus aureus; (ii) to examine the kinetics, including decimal reduction times (d-value) and rate constants (k), that describe the thermal inactivation of staph. aureus and to compare two different methods of calculating d-values and (iii) to determine whether or not chilled storage would toughen these microorganisms resulting in increased thermotolerance.200516238754
gene silencing and overexpression of porcine peptidoglycan recognition protein long isoforms: involvement in beta-defensin-1 expression.peptidoglycan recognition proteins (pgrps) are a group of newly identified proteins with emerging functions in mammalian innate immunity. here we report the identification and characterization of two long isoforms of porcine pgrp. their complete cdna sequences encode predicted peptides of 252 and 598 residues and are named ppgrp-l1 and ppgrp-l2, respectively. these porcine isoforms share identical pgrp domains at their c terminus, which are highly conserved with human and mouse orthologs. ppgrp- ...200516239507
a prfa transposon mutant of listeria monocytogenes f2365, a serotype 4b strain, is able to survive in the gastrointestinal tract but does not cause systemic infection of the spleens and livers of intragastrically inoculated mice.prfa is a member of the crp/fnr family of global regulatory genes in listeria monocytogenes that has been shown previously to regulate several key virulence determinants both in vitro and in parenterally inoculated laboratory rodents. however, the role of prfa in the ability of l. monocytogenes to cause infection via the gastrointestinal (gi) tract has not been clearly established. in this study, we used a prfa transposon mutant of l. monocytogenes f2365, a serotype 4b strain, to assess the role ...200516239554
typing of food-borne listeria monocytogenes by polymerase chain reaction-restriction enzyme analysis and amplified fragment length polymorphism.the applicability of polymerase chain reaction-restriction enzyme analysis (pcr-rea) and amplified fragment length polymorphism (aflp) for typing of food borne listeria monocytogenes strains was tested. a panel of 43 l. monocytogenes strains isolated from food, mostly serovars 1/2b or 1/2a, were analysed by the optimized pcr-rea oriented to inla and inlb genes and by aflp. by pcr-rea, five types of profiles were obtained. by aflp, the strains were separated into 11 types and 18 subtypes forming ...200516240700
[spontaneous bacterial peritonitis by listeria monocytogenes in a patient with liver cirrhosis]. 200516266228
listeria monocytogenes meningitis following imatinib mesylate-induced monocytopenia in a patient with chronic myeloid leukemia. 200516267747
application of measurements of transepithelial electrical resistance of intestinal epithelial cell monolayers to evaluate probiotic activity.among five potentially probiotic lactobacilli investigated, lactobacillus plantarum mf1298 and lactobacillus salivarius dc5 showed the highest increase in the transepithelial electrical resistance (ter) of polarized monolayers of caco-2 cells, and this increase was shown to be dose dependent. furthermore, preincubation with mf1298 attenuated a decrease in ter induced by listeria monocytogenes.200516269795
occurrence of listeria spp. in effluents of french urban wastewater treatment plants.listeria spp. were found in most treated waters (84.4%) and raw sludge (89.2%) of six french urban wastewater treatment plants and one composting facility, examined monthly over a 1-year period. most strains belonged to listeria monocytogenes, serotypes 4b/4e being predominant. sludge composting and liming reduced or prevented listeria contamination.200516269804
factors influencing the ability of listeria monocytogenes to pass through a membrane filter by active infiltration.listeria monocytogenes infiltrated the reticulate structure of a membrane filter and passed through a filter with pore sizes of 0.45 microm and 0.2 microm in 6 to 24 h and 5 to 6 days, respectively. flagellar motility and expansive pressure generated by the growing bacterial population were indicated as the driving forces of infiltration.200516269806
thymus-dependent memory phenotype cd8 t cells in naive b6.h-2kb-/-db-/- animals mediate an antigen-specific response against listeria monocytogenes.b6.h-2kb-/-db-/- (dko) mice have greatly reduced numbers of mature cd8alphabeta t cells in their periphery. however, these non-class ia-selected cd8alphabeta t cells are able to mediate immune responses to a number of pathogens. approximately 60% of the cd8alphabeta t cells in the spleen and peripheral lymph nodes of naive dko mice display a memory (cd44high) phenotype. to investigate the origins of these non-class ia-selected cd8alphabetacd44high cells, we traced the phenotype of recent thymic ...200516272298
regulation of expression of type i signal peptidases in listeria monocytogenes.the role of type i signal peptidases (spases i) is to remove the signal peptides of preproteins exported by the general secretory pathway. the genome of listeria monocytogenes contains a locus encoding three contiguous spases i (denoted sipx, sipy and sipz). the authors recently showed that sipx and sipz perform distinct functions in protein secretion and bacterial pathogenicity. here, the regulation of sip gene expression in broth and in infected eukaryotic cells was studied. the results show t ...200516272398
stochastically modeling listeria monocytogenes growth in farm tank milk.this article presents a listeria monocytogenes growth model in milk at the farm bulk tank stage. the main objective was to judge the feasibility and value to risk assessors of introducing a complex model, including a complete thermal model, within a microbial quantitative risk assessment scheme. predictive microbiology models are used under varying temperature conditions to predict bacterial growth. input distributions are estimated based on data in the literature, when it is available. if not, ...200516297223
loading history determines the velocity of actin-network growth.directional polymerization of actin filaments in branched networks is one of the most powerful force-generating systems in eukaryotic cells. growth of densely cross-linked actin networks drives cell crawling, intracellular transport of vesicles and organelles, and movement of intracellular pathogens such as listeria monocytogenes. using a modified atomic force microscope (afm), we obtained force-velocity (fv) measurements of growing actin networks in vitro until network elongation ceased at the ...200516299496
neurological complications in kidney transplant recipients.neurological complications are frequent in renal transplant recipients and may largely contribute to morbidity and mortality. the postransplant neurological complications may be categorized into five areas: 1) immunosuppressive medications, 2) stroke, 3) peripheral neuropathies, 4) infection, and 5) malignancies. a number of complications are directly caused by the neurotoxicity of immunosuppressive agents. calcineurin-inhibitors may cause mild symptoms, such as tremors and paresthesia, or sever ...200516299677
use of oligonucleotide array for identification of six foodborne pathogens and pseudomonas aeruginosa grown on selective media.identification of presumptive foodborne pathogens grown on selective media may take one to several days and requires a different battery of biochemical tests for each microorganism. a molecular identification method was developed in which universal primers were used to amplify the 16s to 23s rdna intergenic spacer of target microorganisms, and pcr products were hybridized to a panel of species-specific oligonucleotides that were immobilized on a nylon membrane. the seven target microorganisms we ...200516300063
quantifying the robustness of a broth-based model for predicting listeria monocytogenes growth in meat and poultry products.given the importance of listeria monocytogenes as a risk factor in meat and poultry products, there is a need to evaluate the relative robustness of predictive growth models applied to meat products. the u.s. department of agriculture-agricultural research service pathogen modeling program is a tool widely used by the food industry to estimate pathogen growth, survival, and inactivation in food. however, the robustness of the pathogen modeling program broth-based l. monocytogenes growth model in ...200516300067
listeria monocytogenes inhibition by whey protein films and coatings incorporating lysozyme.the effects of whey protein isolate (wpi) films and coatings incorporating lysozyme (lz) on the inhibition of listeria monocytogenes both in and on microbial media, as well as on cold-smoked salmon, were studied. the antimicrobial effects of lz were examined using various growth media by turbidity and plate counting tests. disc-covering and disc-surface-spreading tests were also used to evaluate the effects of wpi films incorporating lz. smoked salmon was used as a model food to test the antimic ...200516300068
application of predictive models to estimate listeria monocytogenes growth on frankfurters treated with organic acid salts.organic acid salts including sodium lactate, sodium diacetate, potassium benzoate, potassium sorbate, and their combinations were assessed as potential inhibitors of listeria monocytogenes growth on frankfurters. predictive models for l. monocytogenes growth on frankfurters treated with these salts were compared to select a proper l. monocytogenes growth curve model under these conditions. sigmoidal equations, including logistic and gompertz equations, are widely used to describe bacterial growt ...200516300069
power ultrasound treatment of listeria monocytogenes in apple cider.inactivation experiments with listeria monocytogenes 10403s, an ultrasound-resistant strain, were conducted at sublethal (20, 30, and 40 degrees c) and lethal (50, 55, and 60 degrees c) temperatures in saline solution (ph 7.0), acidified saline solution (ph 3.4), and apple cider (ph 3.4) with and without application of ultrasound (20 khz, 457 mw.ml(-l)). the survival of recoverable l. monocytogenes 10403s in apple cider was evaluated, and the effects of temperature, ultrasound, ph, and food matr ...200516300070
starter cultures and high-pressure processing to improve the hygiene and safety of slightly fermented sausages.the effectiveness of selected starter cultures and high hydrostatic pressure after ripening was evaluated to improve the safety and quality of slightly fermented sausages. inhibition of common foodborne pathogens, spoilage bacteria, and biogenic amine content was studied. random amplification of polymorphic dna and plasmid profiles were used to monitor the competitiveness of the starter cultures during fermentation and ripening. lactobacillus sakei ctc6626 and staphylococcus xylosus ctc6013 domi ...200516300071
efficacy of cetylpyridinium chloride against listeria monocytogenes and its influence on color and texture of cooked roast beef.sliced (cut) and exterior (intact) surfaces of restructured cooked roast beef were inoculated with listeria monocytogenes, treated with cetylpyridinium chloride (cpc; immersion in 500 ml of 1% solution for 1 min), individually vacuum packaged, and stored for 42 days at 0 or 4 degrees c. noninoculated samples were similarly treated, packaged, and stored to determine effects on quality (color and firmness) and on naturally occurring bacterial populations, including aerobic plate counts and lactic ...200516300072
listeria monocytogenes survival in refrigerator dill pickles.listeria monocytogenes can survive and grow in refrigerated foods with ph values of approximately 4.0 to 5.0 and salt concentrations of 3 to 4%. home-fermented refrigerator dill pickles fit this description. contamination of this product with l. monocytogenes could cause serious problems because these items are not heated prior to consumption. l. monocytogenes survival and growth patterns were investigated in refrigerator dill pickles at 1.3, 3.8, and 7.6% salt concentrations. pickling cucumbers ...200516300073
consequences of the development of nisin-resistant listeria monocytogenes in fermented dairy products.wild listeria isolates representing serovars found in artisanal cheeses commercialized in asturias (northern spain) were assessed for their susceptibility to several bacteriocins. pediocin pa-1 was the most active bacteriocin followed by enterocin as-48, nisin, and plantaricin c. however, some listeria monocytogenes and listeria innocua strains were already highly resistant to pa-1. among the wild l. monocytogenes populations, the frequency of development of nisin resistance ranged from 10(-6) u ...200516300077
thermal tolerance of acid-adapted and unadapted salmonella, escherichia coli o157:h7, and listeria monocytogenes in cantaloupe juice and watermelon juice.a study was performed to determine d values of acid-adapted and unadapted cells of salmonella, escherichia coli o157:h7, and listeria monocytogenes in cantaloupe juice and watermelon juice.200516305669
[experimental study on impact of salmon milt dna on t-cellular immunity].the impact of a biologically active food supplement containing salmon milt dna on cellular immunity was experimentally studied. it was shown that the dna had a dose-dependent stimulating effect on lymphocyte transformation, stimulated the dth response and protected from experimental listeriosis infection.200516308934
retinoic acid amplifies the host immune response to lps through increased t lymphocytes number and lps binding protein expression.vitamin a deficiency is associated with increased susceptibility to infection but the effects of vitamin a supplementation on host response to pathogens are controversial. this study investigated the mechanisms by which all-trans retinoic acid (atra) modulates the host immune response in an experimental model of vitamin a supplementation before and after challenge with lps in rats. we show here that a supplementation with five daily injections of 10mg/kg atra increased the number of t lymphocyte ...200516309824
the activity of pathway-selective estrogen receptor ligands in experimental septic shock.estrogen receptors (er) are widely expressed in multiple genital and nongenital tissues. upon engagement of these receptors, multiple genes are affected in target tissues via estrogen response elements. nonsteroidal pathway-selective er ligands have recently been identified that inhibit nf-kappab transcriptional activity and are devoid of conventional estrogenic activities on genital tissues. these pathway-selective ligands are potent anti-inflammatory agents in vivo and may prove to be of thera ...200516317384
[misleading presentation of rhombencephalitis due to listeria monocytogenes].rhombencephalitis due to listeria monocytogenes may present in a variety of forms.200516317592
sources of interferon-gamma (ifn-gamma) in early immune response to listeria monocytogenes.early, innate production of interferon-gamma (ifn-gamma) is a critical step in immunological defense against certain pathogens such as intracellular bacteria (e.g. listeria monocytogenes), viruses and fungi. while activated t cells and activated natural killer (nk) cells were initially thought to be the only relevant source of ifn-gamma, macrophages (mphi) and dendritic cells can also be stimulated to produce ifn-gamma in vitro under certain conditions. however, a convincing analysis at single c ...200516323704
behaviour of the pathogen surrogates listeria innocua and clostridium sporogenes during production of parsley in fields fertilized with contaminated amendments.the survival and transfer of listeria innocua and clostridium sporogenes, used as surrogates of the food borne pathogens listeria monocytogenes and clostridium botulinum, were quantitatively assessed under field conditions. in the soil, spores of c. sporogenes declined by less than 0.7 log cycles within 16 months and were detected on parsley leaves throughout the experiment. in contrast, l. innocua in the soil declined by 7 log cycles in 90 days and was detected on leaves in low numbers (>0.04 m ...200516332327
effect of immersion solutions containing enterocin as-48 on listeria monocytogenes in vegetable foods.the effect of immersion solutions containing enterocin as-48 alone or in combination with chemical preservatives on survival and proliferation of listeria monocytogenes cect 4032 inoculated on fresh alfalfa sprouts, soybean sprouts, and green asparagus was tested. immersion treatments (5 min at room temperature) with as-48 solutions (25 microg/ml) reduced listeria counts of artificially contaminated alfalfa and soybean sprouts by approximately 2.0 to 2.4 log cfu/g compared to a control immersion ...200516332751
triphenylmethane reductase from citrobacter sp. strain kctc 18061p: purification, characterization, gene cloning, and overexpression of a functional protein in escherichia coli.we purified to homogeneity an enzyme from citrobacter sp. strain kctc 18061p capable of decolorizing triphenylmethane dyes. the native form of the enzyme was identified as a homodimer with a subunit molecular mass of about 31 kda. it catalyzes the nadh-dependent reduction of triphenylmethane dyes, with remarkable substrate specificity related to dye structure. maximal enzyme activity occurred at ph 9.0 and 60 degrees c. the enzymatic reaction product of the triphenylmethane dye crystal violet wa ...200516332773
exogenous isoleucine and fatty acid shortening ensure the high content of anteiso-c15:0 fatty acid required for low-temperature growth of listeria monocytogenes.previous studies have demonstrated that the branched-chain fatty acid anteiso-c15:0 plays a critical role in the growth of listeria monocytogenes at low temperatures by ensuring sufficient membrane fluidity. studies utilizing a chemically defined minimal medium revealed that the anteiso fatty acid precursor isoleucine largely determined the fatty acid profile and fatty acid response of the organism to lowered growth temperature. when isoleucine was sufficient, the fatty acid profile was very uni ...200516332779
relatedness of listeria monocytogenes isolates recovered from selected ready-to-eat foods and listeriosis patients in the united states.pulsed-field gel electrophoresis and serotyping were performed for 544 isolates of listeria monocytogenes, including 502 isolates recovered from contaminated samples from 31,705 retail ready-to-eat (rte) food products and 42 isolates recovered from human cases of listeriosis. the isolates were from maryland (294 isolates) and california (250 isolates) and were collected in 2000 and 2001. the isolates were placed into 16 asci pulsogroups (level of relatedness within each group, > or =66%), 139 as ...200516332793
listeria monocytogenes perr mutants display a small-colony phenotype, increased sensitivity to hydrogen peroxide, and significantly reduced murine virulence.deletion of perr in listeria monocytogenes results in a small-colony phenotype (deltaperrsm) that is slow growing and exhibits increased sensitivity to h2o2. at a relatively high frequency, large-colony variants (deltaperrlg) arise, which are more resistant to h2o2 than the wild-type and ultimately dominate the culture. transcriptional analysis revealed that the kat gene (catalase) is up-regulated in both types of mutants and that the highest level is apparent in deltaperrsm mutants, demonstrati ...200516332818
contingency locus in ctsr of listeria monocytogenes scott a: a strategy for occurrence of abundant piezotolerant isolates within clonal populations.in a recent study we demonstrated that a high-hydrostatic-pressure-tolerant isolate of listeria monocytogenes lacks a codon in the class 3 heat shock regulator gene ctsr. this mutation in the region that encodes four consecutive glycines was directly responsible for the observed piezotolerance, increased stress resistance, and reduced virulence. the aim of the present study was to determine whether mutations in ctsr are frequently associated with piezotolerance in l. monocytogenes. wild-type cul ...200516332826
select listeria monocytogenes subtypes commonly found in foods carry distinct nonsense mutations in inla, leading to expression of truncated and secreted internalin a, and are associated with a reduced invasion phenotype for human intestinal epithelial cells.the surface protein internalin a (inla) contributes to the invasion of human intestinal epithelial cells by listeria monocytogenes. screening of l. monocytogenes strains isolated from human clinical cases (n=46), foods (n=118), and healthy animals (n=58) in the united states revealed mutations in inla leading to premature stop codons (pmscs) in l. monocytogenes ribotypes dup-1052a and dup-16635a (pmsc mutation type 1), dup-1025a and dup-1031a (pmsc mutation type 2), and dup-1046b and dup-1062a ( ...200516332872
a novel real-time pcr for listeria monocytogenes that monitors analytical performance via an internal amplification control.we describe a novel quantitative real-time (q)-pcr assay for listeria monocytogenes based on the coamplification of a target hly gene fragment and an internal amplification control (iac). the iac is a chimeric double-stranded dna containing a fragment of the rapeseed bnaccg8 gene flanked by the hly-specific target sequences. this iac is detected using a second taqman probe labeled with a different fluorophore, enabling the simultaneous monitoring of the hly and iac signals. the hly-iac assay had ...200516332910
[evaluation of the antimicrobial action of honey against staphylococcus aureus, staphylococcus epidermidis, pseudomonas aeruginosa, escherichia coli, salmonella enteritidis, listeria monocytogenes and aspergillus niger. evaluation of its microbiological charge].the evaluation of the microbiological charge present in costa rican samples as the evaluation of its antimicrobial activity over different microorganisms, including those associated to wound infections, will allow to emit criteria referred to its use in therapeutic treatments, specially as alternative therapy for cases involving antibiotic resistant bacteria. the microbiological charge of 25 honey samples, acquired in costa rican markets was evaluated through several indicators including total p ...200516335227
listeriolysin o, a cytolysin derived from listeria monocytogenes, inhibits generation of ovalbumin-specific th2 immune response by skewing maturation of antigen-specific t cells into th1 cells.listeriolysin o (llo), a cholesterol-dependent cytolysin derived from listeria monocytogenes, is a potent inducer of interleukin (il)-12, il-18 and interferon (ifn)-gamma. we have shown that llo facilitates development of t cells mediating protective immunity against l. monocytogenes through the induction of ifn-gamma production at an early stage. based on this finding, it is postulated that llo inhibits differentiation of th2 cells and the th2 immune response. by using a murine model of ovalbum ...200516232213
effectiveness of antimicrobial food packaging materials.antimicrobial additives have been used successfully for many years as direct food additives. the literature provides evidence that some of these additives may be effective as indirect food additives incorporated into food packaging materials. antimicrobial food packaging is directed toward the reduction of surface contamination of processed, prepared foods such as sliced meats and frankfurter sausages (hot dogs). the use of such packaging materials is not meant to be a substitute for good sanita ...200516227182
response of escherichia coli o157:h7, listeria monocytogenes, salmonella typhimurium, and staphylococcus aureus to the thermal stress occurring in model manufactures of grana padano cheese.the purpose of this research was to investigate the effect of temperature in the technology of production of grana cheese against escherichia coli o157:h7, listeria monocytogenes, salmonella typhimurium, and staphylococcus aureus. according to the technology of production, the cheese curds are cooked at 55 degrees c and then cooled at room temperature (25 degrees c). a curd-cooling model was developed to estimate the temperature variation across the curd during cooling, and the thermal stress wa ...200516230687
evaluation of chromogenic media for the detection of listeria species in food.the aim of this study was to evaluate the performance of chromogenic agars, agar listeria according to ottaviani and agosti (aloa) and rapid l. mono agar, compared with oxford agar for the enumeration and detection of listeria species in food.200516313406
environmental factors influencing the relationship between optical density and cell count for listeria monocytogenes.the effect of temperature (2-30 degrees c), ph (4.8-7.4) and water activity (0.946-0.995) on the relationship between optical density (od) at 600 nm and the plate count (cfu ml(-1)) was investigated for listeria monocytogenes.200516313423
anti-bacterial activity of lactobacillus plantarum strain sk1 against listeria monocytogenes is due to lactic acid production.the aim of this research was to investigate the potential of lactobacillus plantarum strain sk1 for use as a biological control agent against listeria monocytogenes and determine its mechanism of anti-listerial activity.200516313424
membrane tumor necrosis factor confers partial protection to listeria infection.tumor necrosis factor (tnf) plays a critical role in the host response to the intracellular pathogen listeria monocytogenes (lm). tnf exists in soluble and membrane-bound forms and exhibits both unique and overlapping activities. we examined the role of membrane tnf in the absence of secreted tnf for host resistance in knockin mice in which the endogenous tnf was replaced by a regulated, noncleavable allele (mem-tnf). macrophages expressing mem-tnf produced nitric oxide and displayed normal bact ...200516314479
identification of unusual bacterial glycosylation by tandem mass spectrometry analyses of intact proteins.the characterization of protein glycosylation can be a complex and time-consuming procedure, especially for prokaryote o-linked glycoproteins, which often comprise unusual oligosaccharide structures with no known glycosylation motif. in this report, we describe a "top-down" approach that provides information on the extent of glycosylation, the molecular masses, and the structure of oligosaccharide residues on bacterial flagella, important structural proteins involved in the motility of pathogeni ...200516316188
enzyme-electropolymer-based amperometric biosensors: an innovative platform for time-temperature integrators.a novel exogenous time-temperature integrator (tti) based on an amperometric glucose oxidase biosensor is presented. the tti consists of the enzyme entrapped within an electrochemically generated poly(o-phenylenediamine) (popd) thin film deposited on the interior wall of a platinum (pt) or a platinized stainless steel (pt-ss) capsule. after thermal treatment, the tti is mounted in a continuous flow system and connected to a potentiostat for amperometric detection of residual enzyme activity. a m ...200516277377
detection and characterization of tet(m) in tetracycline-resistant listeria strains from human and food-processing origins in belgium and france.in the present study, three listeria monocytogenes strains and one listeria innocua strain out of a collection of 241 listeria isolates from human and food-processing sources were found to display resistance to tetracycline (tc) due to the presence of the tet(m) gene. through sequence analysis, it was shown that tet(m) genes in two of the isolates belong to sequence homology group (shg) ii, a group comprising chromosomally encoded tet(m) genes previously found in staphylococcus aureus and in lac ...200516278428
surveillance of listeria infections in europe.in addition to the economic consequences and threats associated with outbreaks, listeriosis remains of great public health concern, as it has one of the highest case fatality rates of all the foodborne infections (20%-30%), and has common source epidemic potential. changes in the way food is produced, distributed and stored have created the potential for diffuse and widespread outbreaks involving many countries. in 2002, a survey was carried out to assess the need for and the feasibility of a eu ...200516282642
cellular lipid fatty acid pattern heterogeneity between reference and recent food isolates of listeria monocytogenes as a response to cold stress.cells of four reference strains (scott a, lo 28, cnl 895807 and atcc 19115) and of five recent food isolates (a00m011, a00m018, a00m087, a00m092 and a00m123) of listeria monocytogenes were grown until late exponential phase in brain heart broth at two different temperatures (37 degrees c and 4 degrees c). our results show that significant differences exist between the cellular lipid fatty acid profile of reference and recent food isolates. like the reference strains, and in keeping with previous ...200516284926
[focal peritonitis as a form of clinical presentation of listeriosis].infections by germs of listeria genus can occur sporadically or in epidemic outbreaks and have different clinical presentations. abdominal origin is very unusual among them, especially in no immunocompromised patients or without concurrent liver illness. we present a young healthy man who is lacking in underlying diseases, suffering from focal peritonitis caused by listeria monocytogenes. the patient had to be operated on, requiring immediate colectomy and evacuation of a retroperitoneal abscess ...200516288580
evaluation of farm management practices as risk factors for clinical listeriosis and fecal shedding of listeria monocytogenes in ruminants.to assess seasonal variation in prevalence of listeria monocytogenes on ruminant farms and identify management practices associated with ruminant listeriosis and fecal shedding of l. monocytogenes.200516350271
[meningoencephalitis by listeria in the lupus disease].we present a patient with lupus nephropathy of 20 years of evolution in treatment with oral steroids who developed a meningoencephalitis associated to bacteraemia by listeria monocytogenes. the patient was treated successfully with gentamicin and ampicillin for 6 weeks. infection by listeria monocytogenes occurs more frequently in individuals with some form of immunodeficiency like lupus disease, with a mortality around 30%.200516351491
listeria monocytogenes as the possible cause of the spontanous abortion in female of the fertile age.listeria monocytogenes is a gram-positive, weakly pathogenic bacterium able to grow also at the temperature of 40 degrees c. a man most often gets affected by consuming contaminated food and water. animals can carry bacteria although they have not to appear ill, then their meat and milk products are the source of infection of human being. the disease most often attacks with the weak immune system, newborns and pregnant women. that what is significant, listeria penetrates through the placenta and ...200516351605
listeriosis in pregnancy: a case report.listeria monocytogenes is an alimentary infection which can be extremely dangerous for pregnant women. a 34-year-old pregnant woman was hospitalized with fetal cardiac rate alterations and influenza-like symptoms. a caesarean section due to fetal distress was performed. a maternal-fetal listeriosis diagnosis was possible only after the birth through bacteriological and histological examination on both the placenta and the newborn.200516390801
simultaneous deficiency of both mura and p60 proteins generates a rough phenotype in listeria monocytogenes.we examined eight spontaneously occurring rough mutants of listeria monocytogenes for their ability to express two previously reported autolysins, p60 and mura. all mutants lack mura expression and show strongly reduced levels of extracellular p60. one rough strain harbors a variant of the p60 protein with a partially truncated catalytic domain. in seven cases there were shifts in the localization of p60 to the membrane fraction. mutations within the seca2 gene, encoding an auxiliary protein sec ...200516321943
immunosuppression related to collagen-vascular disease or its treatment.collagen-vascular diseases are associated with immune dysregulation and inflammation, leading to tissue destruction or compromise. immunosuppression is more commonly associated with the drugs used to treat these disorders than with the diseases themselves. the newest agents being used to treat collagen-vascular diseases are the tumor necrosis factor (tnf)-alpha inhibitors. u.s. food and drug administration-approved tnf-alpha inhibitors have differing effects on the immune system, reflecting thei ...200516322600
listeria monocytogenes listeriolysin o and phosphatidylinositol-specific phospholipase c affect adherence to epithelial cells.listeria monocytogenes, a foodborn intracellular animal and human pathogen, produces several exotoxins contributing to virulence. among these are listeriolysin o (llo), a pore-forming cholesterol-dependent hemolysin, and a phosphatidylinositol-specific phospholipase c (pi-plc). llo is known to play an important role in the escape of bacteria from the primary phagocytic vacuole of macrophages, and pi-plc supports this process. evidence is accumulating that llo and pi-plc are multifunctional virul ...200516391652
trimethoprim-sulfamethoxazole-induced aseptic meningitis.we present a 46-year-old african-american man with aids who was admitted on two different occasions within three weeks for signs and symptoms of meningitis after using trimethoprim/sulfamethoxazole (tmp/smx). tmp/smx is primarily used for the treatment of pneumocystis carinii pneumonia prophylaxis in aids patients. drug-induced aseptic meningitis (diam) is commonly seen with nonsteroidal anti-inflammatory drugs (nsaids), antibiotics (with tmp/smx being the most frequently implicated), intravenou ...200516396068
fosfomycin resistance proteins: a nexus of glutathione transferases and epoxide hydrolases in a metalloenzyme superfamily.three similar but mechanistically distinct fosfomycin resistance proteins that catalyze the opening of the oxirane ring of the antibiotic are known. fosa is a mn(ii) and k(+)-dependent glutathione transferase. fosb is a mg(2+)-dependent l-cysteine thiol transferase. fosx is a mn(ii)-dependent fosfomycin-specific epoxide hydrolase. the expression, purification, kinetic, and physical characteristics of six fosfomycin resistance proteins including the fosa proteins from transposon tn2921 and pseudo ...200516399398
[neurolisteriosis in adults: report of six clinical cases].listeria monocytogenes shows a special attraction to infect the central nervous system and its meningeals coats. it affects newborn as well as elderly people, patients with deficiencies in their cellular immune systems, and healthy adults. it presents most commonly as an acute meningitis, although it can present itself as cerebritis, brain stem encephalitis (rhomboencephalitis), and exceptionally as myelitis.200516400430
growth inhibition of escherichia coli o157:h7 and listeria monocytogenes by carvacrol and eugenol encapsulated in surfactant micelles.growth inhibition of four strains of escherichia coli o157:h7 (h1730, f4546, 932, and e0019) and listeria monocytogenes (scott a, 101, 108, and 310) by essential oil components (carvacrol and eugenol) solubilized in nonionic surfactant micelles (surfynol 465 and 485w) was investigated. concentrations of encapsulated essential oil components ranged from 0.02 to 1.25% depending on compound, surfactant type, and surfactant concentration (0.5 to 5%). eugenol encapsulated in surfynol 485w micelles wa ...200516355826
evaluation of detection methods for screening meat and poultry products for the presence of foodborne pathogens.rapid and molecular technologies such as enzyme-linked immunosorbent assay (elisa), pcr, and lateral flow immunoprecipitation can reduce the time and labor involved in screening food products for the presence of pathogens. these technologies were compared with conventional culture methodology for the detection of salmonella, campylobacter, listeria, and escherichia coli o157:h7 inoculated in raw and processed meat and poultry products. recommended protocols were modified so that the same enrichm ...200516355836
multicenter validation of a multiplex pcr assay for differentiating the major listeria monocytogenes serovars 1/2a, 1/2b, 1/2c, and 4b: toward an international standard.the performance of a multiplex pcr assay that separates the four major serovars of the pathogenic listeria monocytogenes into four distinct pcr groups was evaluated through a multicenter typing study. identical panels of 90 listeria isolates were distributed to five participating laboratories that were blind to the nature of the isolates. isolates were characterized using the previously standardized protocol. overall concordance was 96.6 to 100%, sufficient for the assay to be used as an alterna ...200516355837
adhesion of selected bifidobacterium strains to human intestinal mucus and the role of adhesion in enteropathogen exclusion.the ability of potential probiotic strains to adhere to the intestinal mucosa and exclude and displace pathogens is of utmost importance for therapeutic manipulation of the enteric microbiota. the ability of seven selected human bifidobacterial strains and five human enteropathogenic strains to adhere to human intestinal mucus was analyzed and compared with that of four strains isolated from chicken intestines. the adhesion of the bifidobacterial strains ranged from 3 to 16% depending on the str ...200516355841
subtyping listeria monocytogenes from bulk tank milk using automated repetitive element-based pcr.sixty-one listeria monocytogenes strains from raw milk were analyzed with an automated repetitive element-based pcr (rep-pcr) system to examine the utility of this system for serotype grouping and to determine whether specific regional relationships could be identified. results of the similarity analysis revealed two primary clusters of l. monocytogenes isolates. cluster 2 exclusively contained serogroup 1/2a isolates; however, two 1/2a isolates were also found in cluster 1. isolates of serogrou ...200516355847
listeria monocytogenes septic arthritis in a patient treated with etanercept for rheumatoid arthritis. 200516357718
respiratory infection of turkeys with listeria monocytogenes scott a.the pathogenesis of l. monocytogenes strain scott a was studied by challenging day-old male turkey poults by air sac inoculation with tryptose phosphate broth containing 10(0) cfu (control), 10(4), 10(5), and 10(6) cfu (low challenge), or 10(7) and 10(8) cfu (high challenge) of the scott a (serotype 4b) strain of l. monocytogenes. mortality at 2 wk postinfection (pi) ranged from 25% for low challenge to 100% for high challenge (p= 0.0001). gross and histopathological lesions were observed in hea ...200516404998
how seryl-phosphorylated hpr inhibits prfa, a transcription activator of listeria monocytogenes virulence genes.listeria monocytogenes prfa, a transcription activator for several virulence genes, including the hemolysin-encoding hly, is inhibited by rapidly metabolizable carbon sources (glucose, fructose, etc.). this inhibition is not mediated via the major carbon catabolite repression mechanism of gram-positive bacteria, since inactivation of the catabolite control protein a (ccpa) did not prevent the repression of virulence genes by the above sugars. in order to test whether the catabolite co-repressor ...200516415595
[endocarditis due to listeria monocytogenes associated with aortic stenosis]. 200516419604
listeria monocytogenes as a probe of immune function.for almost half a century, the mouse model of listeria monocytogenes infection has been used to analyse both innate and adaptive components of immunity and to discover key immune genes. vast accumulated knowledge about the disease in mice provides a unique framework for identifying and characterising immune molecules using a variety of experimental approaches. to illustrate the range of questions that can be addressed using modern genetics and genomics tools, the authors provide an overview of t ...200516420751
antimicrobial spectrum and potency of dalbavancin tested against clinical isolates from europe and north america (2003): initial results from an international surveillance protocol.dalbavancin is a bactericidal dimethylaminopropyl amide glycopeptide derivative possessing an extended serum elimination half-life in humans that allows once-weekly dosing for the therapy of gram-positive infections. strains from this baseline surveillance protocol in north america (na; usa and canada) and europe (eu, 14 countries) were sampled in 2003. a total of 7,765 gram-positive isolates (3,695 from na and 4,070 from eu) were tested by reference broth microdilution methods against dalbavanc ...200516433188
detection and identification of intestinal pathogenic bacteria by hybridization to oligonucleotide microarrays.to detect the common intestinal pathogenic bacteria quickly and accurately.200516437687
susceptibility to mycobacterial infections due to interferon-gamma and interleukin-12 pathway defects.a case of interferon-gamma (ifn-gamma)/interleukin-12 (il-12) pathway defect is presented. pathophysiology, clinical characteristics, diagnostic test, and case management are reviewed. clinical pearls and pitfalls include: (1) a high probability of a defect in the ifn-gamma/il-12 cascade exists in patients with disseminated or recurrent infection due to poorly pathogenic mycobacteria or systemic infections caused by non-typhi salmonella species that are persistent and recurrent despite antibioti ...200516450579
[mutagenesis on biofilm formation of listeria monocytogenes by tn917 transposon insertion].surface-attached populations of bacteria comprising either single or multiple species were referred to as biofilm. the bacteria in the biofilm had more resistant ability against antibiotics and disinfectors, which could cause the constituent clinical affection or food contamination. in order to isolate and characterize the genes involved in biofilm formation of listeria monocytogenes, the plasmid ptv1-ok containing the transposon tn917 was transformed into the protoplasm of listeria monocytogene ...200516496710
listeria monocytogenes: silage, sandwiches and science.listeria monocytogenes is amongst the most intriguing and well studied of the pathogenic bacteria. however, the understanding and perspective one has of l. monocytogenes depends to a large extent on the microbiological issues with which one is faced as a part of your professional duties. the focus of the veterinary clinician or investigator is likely to be foremost on the neurologic (circling disease) and reproductive diseases l. monocytogenes causes. to the food microbiologist, the principal co ...200516583783
analysis of the murein of a listeria monocytogenes egd mutant lacking functional penicillin binding protein 5 (pbp5).cells of a mutant of listeria monocytogenes lacking functional pbp5, an enzyme with dd-carboxypeptidase activity, make thicker cells walls. in this study we show that the muropeptide profile of the mutant, obtained after hplc analysis of a muramidase digest of cell wall murein, differs from that for the wild type strain. the main differences embrace strongly reduced disaccharide-tripeptide content, strongly increased amounts of pentapeptide-containing muropeptides and a shift in profile from les ...200516599308
listeria meningitis complicating infliximab treatment for crohn's disease.infliximab, a monoclonal antibody directed against tumour necrosis factor-alpha, is an effective therapy for crohn's disease. though uncommon, serious opportunistic infections, including reactivation of tuberculosis, have occurred in patients after infliximab administration.meningitis caused by listeria monocytogenes developed in a 37-year-old man six days after the second infusion of infliximab. the patient, who also was treated with azathioprine and corticosteroids, had an uneventful recovery ...200518159561
application of electrolyzed oxidizing water to reduce listeria monocytogenes on ready-to-eat meats.experiments were conducted to determine the effectiveness of acidic (eoa) or basic electrolyzed oxidizing (eob) water, alone or in combination, on ready-to-eat (rte) meats to reduce listeria monocytogenes (lm). frankfurters or ham surfaces were experimentally inoculated with lm and subjected to dipping or spraying treatments (25 or 4°c for up to 30 min) with eoa, eob, and other food grade compounds. lm was reduced the greatest when frankfurters were treated with eoa and dipped at 25°c for 15 min ...200522064233
use of ionizing radiation doses of 2 and 4kgy to control listeria spp. and escherichia coli o157:h7 on frozen meat trimmings used for dry fermented sausage production.this study evaluated survival of listeria spp. (four-strain mixture of listeria innocua plus a non-virulent listeria monocytogenes strain) and escherichia coli o157:h7 strain atcc 43888 during fermentation and ripening of greek dry sausages formulated from meat and pork fat trimmings previously inoculated with ca. 6logcfug(-1) of the target bacteria and then irradiated in frozen (-25°c) blocks at doses of 0 (control), 2 or 4kgy. irradiation of the trimmings at 2kgy reduced initial contamination ...200522063296
viability of listeria monocytogenes on commercially-prepared hams surface treated with acidic calcium sulfate and lauric arginate and stored at 4°c.we demonstrated the effectiveness of delivering an antimicrobial purge/fluid into shrink-wrap bags immediately prior to introducing the product and vacuum sealing, namely the "sprayed lethality in container" (slic™) intervention delivery method. the pathogen was listeria monocytogenes, the antimicrobials were acidic calcium sulfate (acs; calcium sulfate plus lactic acid; 1:1 or 1:2 in dh(2)o) and lauric arginate (lae; ethyl-n-dodecanoyl-l-arginate hydrochloride; 5% or 10% in dh(2)o), and the pro ...200522064055
characterisation of naturally fermented sausages produced in the north east of italy.in the friuli venezia giulia region, in the north east of italy, a traditional fermented sausage is produced without the use of microbial starters. it is characterized at the end of the ripening period by accentuated acidity, slight sourness and elastic, semi-hard consistency. in this study, three fermentations, carried out in different seasons (winter, spring and summer) were followed analyzing the microbiological, physicochemical and sensory aspects of this product. the sausages were character ...200522062975
effect of mayonnaise ph and storage temperature on the behavior of listeria monocytogenes in ham salad and potato salad.this study examined and modeled the behavior of listeria monocytogenes in ham salad and potato salad as affected by the ph of mayonnaise and storage temperature. an eight-strain cocktail of l. monocytogenes was inoculated on the surface of diced cooked ham or potato. the inoculated ham or potato was then mixed with regular mayonnaise (ph 3.8) or mayonnaise that was adjusted with naoh to ph 4.2 or 4.6. the cell counts of l. monocytogenes in the salads during storage at 4, 8, or 12 degrees c were ...200521132970
listeria monocytogenes in an atlantic salmon (salmo salar) processing environment.the behavior of two strains of listeria monocytogenes (147 and atcc 19111) was evaluated at different stages of salmon processing. at lower temperatures of 2, 7, and 11 degrees c, l. monocytogenes survived on dry wood surfaces for at least 3 days without added nutrients but was unrecoverable after 2 days at 22 degrees c. moisture or minimal nutrients on the wood surface increased viability of l. monocytogenes at all incubation temperatures. when large amounts of nutrients were provided, the reco ...200521132971
pasteurization of rainbow trout roe: listeria monocytogenes and sensory analyses.d- and z-values for a mixture of four listeria monocytogenes strains originating from the roe of different fish species were determined in rainbow trout (oncorhynchus mykiss) roe. the d60- and d63-values obtained were 1.60 and 0.44 min, respectively, and the z-value was 5.36 degrees c accordingly. in pilot-scale experiments, rainbow trout roe (100 g) was vacuum packaged into glass jars and pasteurized both at 62 and 65 degrees c for 10 min. these treatments were enough to destroy 10(8) cfu/ g of ...200521132972
microbiological quality of ready-to-eat foods: results from a long-term surveillance program (1995 through 2003).the coordination of food sampling activities across wales, a part of the united kingdom with a population of approximately 3 million, led to the establishment in 1995 of a coordinated food-sampling program designed to monitor on a long-term basis the microbiological quality and safety of specific ready-to-eat products. this surveillance system has been ongoing for 9 years and has generated a database of microbiological and associated demographic results for 15,228 ready-to-eat food samples. the ...200521132974
altered sensitivity to a quaternary ammonium sanitizer in stressed listeria innocua.chemical sanitizers are commonly used to inactivate listeria monocytogenes and other listeria species that persist in food-processing environments after cleaning. in this study, listeria innocua cultures were exposed to acid, heat, cold, and starvation stress and then assessed for sensitivity to the quaternary ammonium compound cetrimide. unstressed and stressed cultures were exposed to cetrimide for 3 min, neutralized, and plated on tryptic soy agar with yeast extract to determine the percentag ...200521132975
prevalence of salmonella enterica and listeria monocytogenes contamination in foods of animal origin in italy.the present survey collected and analyzed the results of routine testing for salmonella enterica and listeria monocytogenes on foods of animal origin submitted for official controls in italy during 2001 to 2002. salmonella was detected in 2.2% of 71,643 food samples examined, and the isolation rates ranged from 9.9% for raw poultry meat to less than 0.1% for dairy products. isolation rates were also high in raw pork (4.9%) and processed meats (5.3%), which often involved pork. low rates were obs ...200521132987
efficacy of aerosolized peroxyacetic acid as a sanitizer of lettuce leaves.aerosolized sanitizer was investigated as a potential alternative to aqueous and gaseous sanitizers for produce. peroxyacetic acid was aerosolized (5.42 to 11.42 microm particle diameter) by a commercially available nebulizer into a model cabinet. iceberg lettuce leaves were inoculated with three strains each of escherichia coli o157:h7, listeria monocytogenes, and salmonella typhimurium and then treated with aerosolized peroxyacetic acid for 10, 30, or 60 min in a model aerosol cabinet at room ...200521132990
listeria-based anti-infective vaccine strategies.listeria monocytogenes is a gram-positive intracellular bacterium that has accounted for a significant proportion of human foodborne infections in recent decades. although infection with sublethal level of l. monocytogenes generates enduring immunity, it is impractical to apply intact virulent strains as vaccine. through use of killed, attenuated, naturally avirulent, subcellular and dna vaccine preparations, significant protection has been achieved in experimental animals against listeriosis. b ...200618221153
characterization of listeria monocytogenes protein lmo0327 with murein hydrolase activity.listeria monocytogenes is an ubiquitous gram-positive, opportunistic food-borne human and animal pathogen. to date, five l. monocytogenes autolysins have been characterized: p60, p45, ami, mura and auto and the preliminary results of our studies show that flaa, a flagellar protein of l. monocytogenes, also has murein-degrading activity. in this study, a gene coding a 144 kda protein (lmo0327) with murein hydrolase activity was identified from a lambda zap expression library of l. monocytogenes e ...200616763838
from hot dogs to host cells: how the bacterial pathogen listeria monocytogenes regulates virulence gene expression.environmental pathogens are organisms that normally spend a substantial part of their lifecycle outside of human hosts, but when introduced into humans are capable of causing disease. such organisms are often able to transition between disparate environments ranging from the soil to the cytosol of host cells. the food-borne bacterial pathogen listeria monocytogenes serves as a model system for understanding how an environmental organism makes the transition into mammalian hosts. a transcriptiona ...200617661688
brain-stem listeriosis: a comparison of spect and mri findings.listeria monocytogenes, although uncommon as a cause of illness in the general population, can result in serious illness when it affects pregnant women, neonates, the elderly, and immunocompromised individuals. typically, it is a food-borne organism. this report describes a case of brain-stem listeriosis in a previously healthy 51-year-old woman. the diagnosis was based on clinical findings, the results of cerebrospinal fluid (csf) analysis, csf culture, and magnetic resonance imaging (mri) find ...200617415328
susceptibility of listeria monocytogenes strains isolated from dairy products and frozen vegetables to antibiotics inhibiting murein synthesis and to disinfectants.the susceptibility of 96 strains of listeria monocytogenes isolated from food to antibiotics and disinfectants currently used in human therapy, veterinary, medicine and food industry was determined by a standard operating procedure--broth dilution method. antimicrobial agents included the beta-lactams ampicillin and penicillin, the lantibiotic nisin, and the disinfectants benzalkonium chloride and chlorhexidine gluconate. among the studied strains we found 13 strains with 8-fold, 7 strains with ...200617416064
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