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[a case of listeria monocytogenes meningitis in an immunocompetent infant].listeria monocytogenes meningitis is a rare affection after the neonatal period, but in immunocompromised patients. listeria monocytogenes is a gram-positive, facultative intracellular bacterium frequently causing infection in pregnant women, in patients with cell-mediated immunity deficit and in the early and late stages of life. we present a case of listeria monocytogenes meningitis in an immunocompetent nomad 8-month-child, preceded by gastroenteritis. although gastrointestinal symptoms may b ...200617008849
rapid development of a gamma interferon-secreting glycolipid/cd1d-specific valpha14+ nk1.1- t-cell subset after bacterial infection.the phenotypic and functional changes of glycolipid presented by cd1d(glycolipid/cd1d) specific valpha14+ t cells in the liver of mice at early stages of bacterial infection were investigated. after listeria monocytogenes infection or interleukin-12 (il-12) treatment, alpha-galactosylceramide/cd1d tetramer-reactive (alpha-galcer/cd1d+) t cells coexpressing natural killer (nk) 1.1 marker became undetectable and, concomitantly, cells lacking nk1.1 emerged in both euthymic and thymectomized animals ...200616988270
antimicrobial activity of extracts of chemical races of the lichen pseudevernia furfuracea and their physodic acid, chloroatranorin, atranorin, and olivetoric acid constituents.the antimicrobial activity and the mic values of the ethanol, chloroform, diethyl ether, and acetone extracts of the chemical races of pseudevernia furfuracea (var. furfuracea and var. ceratea) and their physodic acid, chloroatranorin, atranorin, and olivetoric acid constituents have been investigated against some microorganisms. nearly all extracts of both chemical races showed antimicrobial activity against aeromonas hydrophila, bacillus cereus, bacillus subtilis, listeria monocytogenes, prote ...200616989308
listeria monocytogenes as a vector for tumor-associated antigens for cancer immunotherapy.as a facultative intracellular bacterium, listeria monocytogenes has adapted to live within the cytosol of the host cell. it is actively taken up by antigen-presenting cells through phagocytosis, and as listeria survive within these cells, it is an ideal vector for the delivery of antigens to be processed and presented through both the class i and ii antigen-processing pathways. once phagocytosed, listeria produces virulence factors within the phagolysosome of the host cell, which allows it to b ...200616989634
ribotype diversity of listeria monocytogenes isolates from two salmon processing plants in norway.the purpose of this study was to use automated ribotyping procedure to track listeria monocytogenes transmission in the cold smoked fish production chain and to characterize l. monocytogenes subtypes associated with the salmon processing industry. a total of 104 isolates, which had previously been obtained from a raw fish slaughter and processing plant (plant b) and an adjacent, downstream, salmon smoking operation (plant a), were characterized. these isolates had been obtained through a longitu ...200616990178
prevalence and survival of listeria monocytogenes in danish aquatic and fish-processing environments.listeria monocytogenes contamination of ready-to-eat food products such as cold-smoked fish is often caused by pathogen subtypes persisting in food-processing environments. the purpose of the present study was to determine whether these l. monocytogenes subtypes can be found in the outside environment, i.e., outside food processing plants, and whether they survive better in the aquatic environment than do other strains. a total of 400 samples were collected from the outside environment, fish sla ...200616995513
daily variability of listeria contamination patterns in a cold-smoked salmon processing operation.an understanding of listeria transmission and contamination patterns in processing environments of ready-to-eat foods is critical for improving control of listeria monocytogenes. a cold-smoked fish processing operation was the site used to study variability in listeria contamination in a processing environment associated with a ready-to-eat food product throughout one production week (five consecutive days). intensive testing was conducted on finished products and environmental samples collected ...200616995514
potassium lactate combined with sodium diacetate can inhibit growth of listeria monocytogenes in vacuum-packed cold-smoked salmon and has no adverse sensory effects.growth of listeria monocytogenes in ready-to-eat fish products such as cold-smoked salmon is an important food safety issue. the objective of this study was to evaluate the antilisterial activity of potassium lactate (pl) in combination with sodium acetate (sa) or sodium diacetate (sda) in cold-smoked salmon and to determine whether these compounds could be incorporated easily into the formulations and technology currently used by processors. a commercial brine injector was used to inject salmon ...200616995515
efficacy of electrolyzed water in the inactivation of planktonic and biofilm listeria monocytogenes in the presence of organic matter.the ability of electrolyzed (eo) water to inactivate listeria monocytogenes in suspension and biofilms on stainless steel in the presence of organic matter (sterile filtered chicken serum) was investigated. a five-strain mixture of l. monocytogenes was treated with deionized, alkaline eo, and acidic eo water containing chicken serum (0, 5, and 10 ml/liter) for 1 and 5 min. coupons containing l. monocytogenes biofilms were also overlaid with chicken serum (0, 2.5, 5.0, and 7.5 ml/liter) and then ...200616995516
comparison of media and sampling locations for isolation of listeria monocytogenes in queso fresco cheese.listeriosis associated with hispanic-style soft cheese is an ongoing public health concern. although rapid detection methods based on molecular and immunological technologies have been applied successfully for detecting listeria monocytogenes in foods, obtaining isolates of the pathogen is a critical procedure for epidemiologic studies and regulatory analysis. oxford agar, a medium recommended by the u.s. food and drug administration bacteriological analytical manual (bam) to isolate l. monocyto ...200616995517
virulence of listeria monocytogenes isolates from humans and smoked salmon, peeled shrimp, and their processing environments.the virulence of 82 listeria monocytogenes isolates from human cases and cold-smoked salmon, cooked peeled shrimp, and their production environments was assessed using the plaque-forming assay and a subcutaneous inoculation test in mice. these isolates were previously typed using serotyping and pulsed-field gel electrophoresis. the isolates from food-production environments were collected in several surveys over the period of 5 years. sixty-eight (99.8%) of 69 isolates tested from food and food- ...200616995518
occurrence of pathogens in raw and ready-to-eat meat and poultry products collected from the retail marketplace in edmonton, alberta, canada.a total of 800 meat and poultry products were purchased from the retail marketplace in edmonton, alberta, canada. the products consisted of raw ground beef, chicken legs, pork chops, and ready-to-eat fermented sausage, roast beef, processed turkey breast, chicken wieners, and beef wieners. the samples were analyzed to determine the prevalence of shiga toxin-producing escherichia coli, salmonella, campylobacter spp., and listeria monocytogenes. shiga toxin-producing e. coli 022: h8 was found in o ...200616995521
survival of staphylococcus aureus and listeria monocytogenes on vacuum-packaged beef jerky and related products stored at 21 degrees c.in the manufacture of beef jerky, a thermal lethality step is followed by drying to prevent growth of pathogenic bacterial postprocessing contaminants on the finished product. recent guidelines from the u.s. department of agriculture have raised the question of the maximum water activity (a(w)) in jerky products that will inhibit growth of pathogenic bacteria. the survival of the potential postprocessing contaminants staphylococcus aureus and listeria monocytogenes was evaluated on 15 vacuum-pac ...200616995535
activity of brassica oleracea leaf juice on foodborne pathogenic bacteria.many vegetables of the cruciferae family have been found to possess antimicrobial properties against several microorganisms of clinical importance. in this study, we reported the antibacterial effect of brassica oleracea juice on several food-borne pathogens. the juice was found to be effective in inhibiting the growth of salmonella enteritidis, verotoxigenic escherichia coli o157:h7, e. coli hb producing thermolabile toxin, nontoxigenic e. coli, and listeria monocytogenes, but not enterococcus ...200616995537
the uncoupling protein 2 modulates the cytokine balance in innate immunity.the uncoupling protein 2 (ucp2) is located in the inner mitochondrial membrane and downregulates the production of reactive oxygen species (ros). recent data suggested a role for ucp2 in the immune response. we analyzed further this hypothesis during acute listeria monocytogenes infection in mice. death of infected ucp2(-/-) mice was delayed in comparison with ucp2(+/+), suggesting a role of ucp2 in the early step of the immune response. in vitro, the higher resistance of ucp2(-/-) mice was not ...200616971137
involvement of closely related strains of a new clonal group of listeria monocytogenes in the 1998-99 and 2002 multistate outbreaks of foodborne listeriosis in the united states.in 1998-99, a multistate outbreak of listeriosis in the united states was associated with contaminated hot dogs and was caused by a strain of listeria monocytogenes serotype 4b that had been only rarely encountered before in the national pulsenet database. upon further characterization, the strains from this outbreak were designated as epidemic clone ii (ecii). ecii isolates exhibited diversification in a genomic region ("region 18") that was otherwise conserved among l. monocytogenes of serotyp ...200616972778
pulsed-field gel electrophoresis of listeria monocytogenes strains: the pulsenet europe feasibility study.a feasibility study on standardized subtyping of listeria monocytogenes by pulsed-field gel electrophoresis (pfge) was performed in 2003 in europe. the aim of the project was to identify veterinary, food, and public health reference laboratories that were willing to participate in the molecular surveillance of listeria infections in europe, as is done with pulsenet usa, and to test if the participants could generate results that were comparable with each other. a panel of strains and the methodo ...200616972779
alpha-defensins from blood leukocytes of the monkey papio hamadryas.three antimicrobial peptides named phd1-3 (papio hamadryas defensin) have been isolated from hamadryas baboon blood leukocytes using preparative electrophoresis and reverse-phase hplc. the primary structures of these peptides have been determined by automated edman degradation and mass-spectrometry. the results suggest that the peptides belong to the alpha-defensin family. structural homology analysis reveals that among alpha-defensins from other animal species, phd3 is the most closely related ...200616978151
use of native lactococci as vehicles for delivery of dna into mammalian epithelial cells.the use of the food-grade bacterium lactococcus lactis as a dna delivery vehicle at the mucosal level is an attractive dna vaccination strategy. previous experiments showed that recombinant l. lactis expressing the listeria monocytogenes inla gene can deliver a functional gene into mammalian cells. here, we explored the potential use of noninvasive l. lactis strains as a dna delivery vehicle. we constructed two escherichia coli-l. lactis shuttle plasmids, plig:blg1 and plig:blg2, containing a eu ...200616963550
listeria monocytogenes meningitis in two allogeneic hematopoietic stem cell transplant recipients. 200616966293
aberrant contraction of antigen-specific cd4 t cells after infection in the absence of gamma interferon or its receptor.several lines of evidence from different model systems suggest that gamma interferon (ifn-gamma) is an important regulator of t-cell contraction after antigen (ag)-driven expansion. to specifically investigate the role of ifn-gamma in regulating the contraction of ag-specific cd4 t cells, we infected ifn-gamma-/- and ifn-gammar1-/- mice with attenuated listeria monocytogenes and monitored the numbers of ag-specific cd4 t cells during the expansion, contraction, and memory phases of the immune re ...200616966404
the response regulator resd modulates virulence gene expression in response to carbohydrates in listeria monocytogenes.listeria monocytogenes is a versatile bacterial pathogen that is able to accommodate to diverse environmental and host conditions. presently, we have identified a l. monocytogenes two-component response regulator, resd that is required for the repression of virulence gene expression known to occur in the presence of easily fermentable carbohydrates not found inside host organisms. structurally and functionally, resd resembles the respiration regulator resd in bacillus subtilis as deletion of the ...200616968229
tnf is important for pathogen control and limits brain damage in murine cerebral listeriosis.cerebral listeriosis is a life-threatening disease. however, little is known about the bacterial virulence factors responsible for the severe course of disease and the factors of the immune system contributing to the control of listeria monocytogenes (lm) or even to the damage of the brain. to analyze the importance of the acta gene of lm, which mediates cell-to-cell spread of intracellular lm, the function of tnf in murine cerebral listeriosis was studied. c57bl/6 mice survived an intracerebral ...200616951360
listeriolysin o-deficient listeria monocytogenes as a vaccine delivery vehicle: antigen-specific cd8 t cell priming and protective immunity.strains of listeria monocytogenes (lm) that are deficient in the virulence factor listeriolysin o (llo) are highly attenuated and are thought not to elicit protective immunity. this failure has been attributed to the inability of the bacterium to enter the host cell cytosol and access mhc class i ag processing machinery. we reexamined this issue using recombinant strains of lm that are deficient in llo but express an additional cd8 t cell epitope derived from lymphocytic choriomeningitis virus. ...200616951364
chlamydia trachomatis infection alters the development of memory cd8+ t cells.the obligate intracellular bacterium chlamydia trachomatis is the most common cause of bacterial sexually transmitted disease in the united states and the leading cause of preventable blindness worldwide. prior exposure to c. trachomatis has been shown to provide incomplete protection against subsequent infection. one possible explanation for the limited immunity afforded by prior c. trachomatis infection is poor activation of chlamydia-specific memory cd8+ t cells. in this study, we examined th ...200616951365
systemic and local cc chemokines production in a murine model of listeria monocytogenes infection.repeated intragastric inoculation of listeria monocytogenes into balb/c mice resulted in prolonged bacteraemia and severe hepatic infection. bacteria could also be isolated from the brain tissue of all experimental mice. during the inflammatory process, chemokine concentrations typically increased at the local site in comparison to the systemic level. the liver-to-serum ratio was more pronounced in the case of macrophage inflammatory protein 1 alpha (mip-1 alpha), suggesting its role in the infl ...200616951491
identification of an essential gene of listeria monocytogenes involved in teichoic acid biogenesis.listeria monocytogenes is a facultative intracellular gram-positive bacterium responsible for severe opportunistic infections in humans and animals. we had previously identified a gene encoding a putative udp-n-acetylglucosamine 2-epimerase, a precursor of the teichoic acid linkage unit, in the genome of l monocytogenes strain egd-e. this gene, now designated lmo2537, encodes a protein that shares 62% identity with the cognate epimerase mnaa of bacillus subtilis and 55% identity with cap5p of st ...200616952950
the interferon response to bacterial and viral infections.type i interferons (ifns) were first described several decades ago as soluble factors that were capable of 'interfering' with viral replication when added to infected cells. type i ifns have been shown to be induced by recognition of viral dna and rna via three distinct pathways: (i) a trif-dependent pathway in macrophages via tlrs 3 and 4; (ii) a myd88-dependent pathway in plasmacytoid dendritic cells (pdcs) via tlrs 7/8 and 9; and (iii) an intracellular recognition pathway utilizing the cytopl ...200616953977
cytosolic entry controls cd8+-t-cell potency during bacterial infection.interaction with host immunoreceptors during microbial infection directly impacts the magnitude of the ensuing innate immune response. how these signals affect the quality of the adaptive t-cell response remains poorly understood. utilizing an engineered strain of the intracellular pathogen listeria monocytogenes that infects cells but fails to escape from the phagosome, we demonstrate the induction of long-lived memory t cells that are capable of secondary expansion and effector function but ar ...200616954391
visible-light-induced bactericidal activity of a nitrogen-doped titanium photocatalyst against human pathogens.the antibacterial activity of photocatalytic titanium dioxide (tio(2)) substrates is induced primarily by uv light irradiation. recently, nitrogen- and carbon-doped tio(2) substrates were shown to exhibit photocatalytic activities under visible-light illumination. their antibacterial activity, however, remains to be quantified. in this study, we demonstrated that nitrogen-doped tio(2) substrates have superior visible-light-induced bactericidal activity against escherichia coli compared to pure t ...200616957236
quencher extension for single nucleotide polymorphism quantification in bacterial typing and microbial community analyses.quencher extension is a novel single-step closed tube real-time method to quantify single nucleotide polymorphisms (snps) in combination with primer extension. a probe with a 5'-reporter is single-base extended with a dideoxy nucleotide containing a quencher if the target snp allele is present. the reaction is measured from the quenching (reduced fluorescence) of the reporter. the relative amount of a specific snp allele is determined from the nucleotide incorporation rate in a thermocycling rea ...200616957351
the sigma factor rpon (sigma54) is involved in osmotolerance in listeria monocytogenes.listeria monocytogenes is able to grow under conditions of high osmolarity. we constructed a deletion mutant of rpon, encoding the alternative sigma factor rpon, and analyzed its response to osmotic stress. in a minimal medium with 4% nacl and 1 mm betaine, the mutant showed a similar growth to that of the parental strain, egd. in the same medium with 4% nacl and 1 m carnitine, the growth rate of the mutant was greatly reduced, when the optical density at 600 nm (od600) at the starting point of ...200616958851
the role of clathrin-dependent endocytosis in bacterial internalization.internalization of bacteria into mammalian host cells has been studied extensively in the past two decades. these studies have highlighted the amazingly diverse strategies used by bacterial pathogens to induce their entry in non-phagocytic cells. the roles of actin and of the whole cytoskeletal machinery have been investigated in great detail for several invasive organisms, such as salmonella, shigella, yersinia and listeria. recent results using listeria highlight a role for the endocytosis mac ...200616962776
development of macrophages with altered actin organization in the absence of mafb.in the hematopoietic system the bzip transcription factor mafb is selectively expressed at high levels in monocytes and macrophages and promotes macrophage differentiation in myeloid progenitors, whereas a dominant-negative allele can inhibit this process. to analyze the requirement of mafb for macrophage development, we generated mafb-deficient mice and, due to their neonatal lethal phenotype, analyzed macrophage differentiation in vitro, in the embryo, and in reconstituted mice. surprisingly w ...200616943423
a novel fluorescence imaging technique combining deconvolution microscopy and spectral analysis for quantitative detection of opportunistic pathogens.a novel fluorescence imaging technique based on deconvolution microscopy and spectral analysis is presented here as an alternative to confocal laser scanning microscopy. it allowed rapid, specific and simultaneous identification of five major opportunistic pathogens, relevant for public health, in suspension and provided quantitative results.200616887225
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
symbiotic bacteria direct expression of an intestinal bactericidal lectin.the mammalian intestine harbors complex societies of beneficial bacteria that are maintained in the lumen with minimal penetration of mucosal surfaces. microbial colonization of germ-free mice triggers epithelial expression of regiiigamma, a secreted c-type lectin. regiiigamma binds intestinal bacteria but lacks the complement recruitment domains present in other microbe-binding mammalian c-type lectins. we show that regiiigamma and its human counterpart, hip/pap, are directly antimicrobial prot ...200616931762
[characterization of a recombinant listeria monocytogenes strain containing the fusion protein gene of newcastle disease virus].homologous recombination was utilized for construction of a recombinant strain of l. monocytogenes carrying a gene from the newcastle diseases virus by insertional mutation targeting its listeriolysin o gene (hly). the gene encoding fusion protein of the newcastle disease virus (ndv-f) was used as the model heterologous gene. the f gene was inserted into hly downstream to its promoter and signal sequence by overlapping extension polymerase chain reaction, which was then subcloned into the shuttl ...200616933618
listeria monocytogenes food monitoring data and incidence of human listeriosis in hungary, 2004.food samples were monitored for contamination with listeria monocytogenes, and the incidence of human listeriosis was evaluated according to the data obtained in hungary in the year 2004. of the food samples tested, the bacterium was most often detectable in milk and dairy products, as 72.1% of all l. monocytogenes strains were isolated from these samples. the food samples most commonly yielded strains of serotype 1/2a (45.1%) and 4b (27.0%). in 2004, 3 perinatal and 14 nonperinatal human lister ...200616934896
whole-genome sequence of listeria welshimeri reveals common steps in genome reduction with listeria innocua as compared to listeria monocytogenes.we present the complete genome sequence of listeria welshimeri, a nonpathogenic member of the genus listeria. listeria welshimeri harbors a circular chromosome of 2,814,130 bp with 2,780 open reading frames. comparative genomic analysis of chromosomal regions between l. welshimeri, listeria innocua, and listeria monocytogenes shows strong overall conservation of synteny, with the exception of the translocation of an f(o)f(1) atp synthase. the smaller size of the l. welshimeri genome is the resul ...200616936040
inactivation of adhesion and invasion of food-borne listeria monocytogenes by bacteriocin-producing bifidobacterium strains of human origin.three bacteriocin-producing bifidobacterial isolates from newborns were identified as bifidobacterium thermacidophilum (two strains) and b. thermophilum (one strain). this study was undertaken to evaluate the ability of these strains to compete with food-borne listeria monocytogenes for adhesion and invasion sites on caco-2 and ht-29 cells. the bifidobacteria adhered at levels ranging from 4% to 10% of the cfu added, but none of the bifidobacteria were able to invade cells. the abilities of list ...200616936051
adoptive transfer of t-cell precursors enhances t-cell reconstitution after allogeneic hematopoietic stem cell transplantation.immunoincompetence after allogeneic hematopoietic stem cell transplantation (hsct) affects in particular the t-cell lineage and is associated with an increased risk for infections, graft failure and malignant relapse. to generate large numbers of t-cell precursors for adoptive therapy, we cultured mouse hematopoietic stem cells (hscs) in vitro on op9 mouse stromal cells expressing the notch-1 ligand delta-like-1 (op9-dl1). we infused these cells, together with t-cell-depleted mouse bone marrow o ...200616936725
outcome of 8-hour dosing intervals with beta-lactam antibiotics in adult acute bacterial meningitis.the outcome of dosing with beta-lactam antibiotics at 8-h intervals for adult patients with community-acquired acute bacterial meningitis was retrospectively analysed at sahlgrenska university hospital, gothenburg, sweden. 80 medical records were identified for a 6-y period from 1999 to 2004. the most common pathogens noted were streptococcus pneumoniae (47.5%), neiseria meningitidis (12.5%), and listeria monocytogenes (5.0%). other bacteria were diagnosed in 16.3% of all episodes, but the bacte ...200616938730
neurolisteriosis mimicking herpes simplex encephalitis in an immunocompromized patient.brain mri was performed in an immunocompromized febrile and lethargic patient, revealing an asymmetric bilateral temporal lobe involvement, strongly suggestive of herpetic encephalitis. nevertheless, pcr in csf for listeria monocytogens was positive. this case implies that listeria might be considered in patients with clinical and imaging suspicion of herpetic encephalitis.200616938743
modulation of phosphoinositide metabolism by pathogenic bacteria.phosphoinositide metabolism plays a pivotal role in the regulation of receptor-mediated signal transduction, actin remodelling and membrane dynamics. phosphoinositides co-ordinate these processes by recruiting protein effectors to distinct cellular membranes in a time- and organelle-dependent manner. intracellular bacterial pathogens interfere with phosphoinositide metabolism to direct their entry into eukaryotic cells, form replication-permissive vacuoles, modulate apoptosis, or trigger fluid s ...200616939534
vaginal protection and immunity after oral immunization of mice with a novel vaccine strain of listeria monocytogenes expressing human immunodeficiency virus type 1 gag.natural transmission of human immunodeficiency virus (hiv) occurs at mucosal surfaces. during acute infection, intestinal and other mucosae are preferential sites of virus replication and rapidly become depleted of cd4(+) t cells. therefore, mucosal immunity may be critical to control both initial infection and the massive early spread of virus. an attenuated d-alanine-requiring strain of the oral intracellular microorganism listeria monocytogenes expressing hiv type 1 gag was shown to induce pr ...200616940500
[genes, encoding invasion factors in listeria monocytogenes strains isolated in the european part and the far east of russia].the collection of 76 listeria monocytogenes strains isolated from humans, animals and food products was screened with pcr to reveal genes, which encode invasion factors of the internalin family. obtained results demonstrated the correlation between the strain specific polymorphism of the revealed internalin genes and the source of the strain.200616941869
lessons from the organization of a proficiency testing program in food microbiology by interlaboratory comparison: analytical methods in use, impact of methods on bacterial counts and measurement uncertainty of bacterial counts.the proficiency testing program in food microbiology raema (réseau d'analyses et d'echanges en microbiologie des aliments), created in 1988, currently includes 450 participating laboratories. this interlaboratory comparison establishes proficiency in detection of salmonella and listeria monocytogenes, as well as enumeration of aerobic micro-organisms, enterobacteriaceae, coliforms, beta-glucuronidase-positive escherichia coli, anaerobic sulfito-reducing bacteria, clostridium perfringens, coagula ...200616942983
non-lactic acid, contaminating microbial flora in ready-to-eat foods: a potential food-quality index.the bacteriological profile of 87 samples of commercially available ready-to-eat (rte) dairy and meat-products, packaged sandwiches and salads was obtained by testing for aerobic colony count, for lactic acid bacterial (lab) count, for the presence and the extent of non-lab microflora (contaminating microflora), and by testing for certain food-borne pathogens. the pathogens listeria monocytogenes, salmonella spp. and sulfite-reducing clostridia were not detected in any of the analysed samples. w ...200616942992
shedding of foodborne pathogens by caenorhabditis elegans in compost-amended and unamended soil.a study was done to characterize the shedding of foodborne pathogenic bacteria by caenorhabditis elegans, evaluate the persistence of worm populations cocultured with foodborne pathogens, and determine if c. elegans disperses ingested pathogens in soil as a result of shedding. escherichia. coli o157:h7, salmonella enterica serotype poona, and listeria monocytogenes, as well as e. coli op50, a non-pathogenic strain, were studied. synchronous populations of c. elegans were fed for 24 h on confluen ...200616942998
effect of vanillin on the fate of listeria monocytogenes and escherichia coli o157:h7 in a model apple juice medium and in apple juice.the effects of vanillin on the fates of listeria monocytogenes and escherichia coli o157:h7 at ph values between 3.5 and 4.5 were verified in a model apple juice (maj) medium and in apple juice incubated at 4 or 15 degrees c. viable e. coli o157:h7 cells were recovered from maj for up to 10 days, but l. monocytogenes did not survive at ph 3.5. supplementation with 40 mm vanillin exerted a lethal effect that was species, concentration, ph and temperature dependant. e. coli o157:h7 was more sensit ...200616943001
effect of cold temperature on the composition of different lipid classes of the foodborne pathogen listeria monocytogenes: focus on neutral lipids.in this work a thorough consideration of the membrane lipid composition of listeria monocytogenes together with dsc analysis is described in order to estimate the biological importance of lipid changes during low-temperature adaptation. furthermore, these studies provide comparative data for fatty acid changes for neutral, nl and polar lipids, pl separately. the cold adaptation (5 degrees c) response of l. monocytogenes showed (i) an increase in the level of nl content (30%) among the total lipi ...200616943003
comparison of pathogenic and spoilage bacterial levels on refrigerated poultry parts following treatment with trisodium phosphate.this study was undertaken to determine whether trisodium phosphate decontamination of poultry could give a competitive advantage to pathogens and increase microbiological risk to consumers. chicken legs were co-inoculated with similar concentrations of pathogenic (salmonella enteritidis or listeria monocytogenes) and spoilage (pseudomonas fluorescens or brochothrix thermosphacta) bacteria. samples were dipped in tsp (12%, 15 min) or were non-treated (control). microbiological analyses were carri ...200616943004
inhibition of listeria monocytogenes by a lactic acid bacterium isolated from italian salami.listeria monocytogenes is an opportunistic psychrotroph foodborne pathogen that has been used as a model organism to study the efficacy of many different preservation methods. this work aimed to test the antilisterial activity of lactic acid bacteria isolated from italian salami and study the development of resistance. isolates were obtained from naturally fermented italian salami and cultures that retained activity in the supernatants after ph neutralization and catalase treatment were further ...200616943007
effects of physicochemical surface characteristics of listeria monocytogenes strains on attachment to glass.seven strains of listeria monocytogenes frequently involved in foodborne disease (epidemic strains) and 14 sporadic strains were examined to compare the attachment and subsequent biofilm growth on glass slides at 37 degrees c. epidemic strains at 3 h incubation had significantly higher attachment values than sporadic strains (p<0.001), but subsequent biofilm growth over 24 h was not dependent on initial attachment. to better understand this phenomenon, the surface hydrophobicity and charge, as w ...200616943011
analyses of the putative crp/fnr family of transcriptional regulators of a serotype 4b strain of listeria monocytogenes.a whole-genome sequence analysis of listeria monocytogenes strain f2365 revealed 15 potential members of the crp/fnr family of transcriptional regulatory proteins. each gene and the flanking regions were cloned, subjected to in vitro transpositional mutagenesis, and recombined into strain f2365. mutant strains, produced for 14 of the family members, were compared to strain f2365 for differences in carbon utilization, resistance to oxidative stress, and growth under reduced oxygen conditions that ...200616943018
investigation for possible source(s) of contamination of ready-to-eat meat products with listeria spp. and other pathogens in a meat processing plant in trinidad.in 2003, there was a recall of three processed (chicken franks, spice ham and turkey ham ready-to-eat (rte) meat products by a large processing plant in trinidad as a result of contamination by listeria monocytogenes. the study was conducted to investigate the possible source(s) of listeria contamination of recalled rte meat products and to determine the prevalence of listeria spp., salmonella spp., escherichia coli and campylobacter spp. in the products and air within the plant. raw and process ...200616943025
anti-listerial inhibitory lactic acid bacteria isolated from commercial cold smoked salmon.the natural microflora of cold-smoked fish at the end of shelf-life are lactic acid bacteria (lab). some of these display a capacity to inhibit spoilage as well as several strains of pathogenic micro-organisms, e.g. listeria monocytogenes which is isolated frequently from cold-smoked salmon (css). eight batches of sliced vacuum-packed css from norway, scotland and spain were collected at retail. packs were stored at 5 degrees c and examined for chemical and microbiological characteristics, at pu ...200616943030
the interaction of the non-bacteriocinogenic lactobacillus sakei 10a and lactocin s producing lactobacillus sakei 148 towards listeria monocytogenes on a model cooked ham.two lactic acid bacteria, lactobacillus sakei subsp. carnosus (10a) and lactocin s producing lactobacillus sakei 148 (ls5), were examined for their usefulness as protective culture in the biopreservation of cooked meat products. co-culture experiments on a model cooked ham (mch) between 10a or ls5 and a cocktail of three listeria monocytogenes strains were performed to examine the influence of inoculum level (10(5) vs. 10(6)cfu/g), storage temperature (4 vs. 7 degrees c) and packaging type (vacu ...200616943045
survival curves of listeria monocytogenes in chorizos modeled with artificial neural networks.using artificial neural networks (anns), a highly accurate model was developed to simulate survival curves of listeria monocytogenes in chorizos as affected by the initial water activity (a(w0)) of the sausage formulation, temperature (t), and air inflow velocity (f) where the sausages are stored. the ann-based survival model (r(2)=0.970) outperformed the regression-based cubic model (r(2)=0.851), and as such was used to derive other models (using regression) that allow prediction of the times n ...200616943052
upstream sample processing facilitates pcr detection of listeria monocytogenes in mayonnaise-based ready-to-eat (rte) salads.sample pretreatment to reduce volume and concentrate cells of the target organism(s) prior to molecular detection offers a useful supplement or alternative to cultural enrichment. the purpose of this study was to develop an upstream processing method to facilitate the detection of listeria monocytogenes in ready-to-eat (rte) salads by pcr. potato salad, a model rte commodity, was seeded with l. monocytogenes and processed by two alternative upstream sample processing methods (designated one-step ...200616943055
antimicrobial properties of salt (nacl) used for the preservation of natural casings.the antimicrobial properties of salt (nacl) used for the preservation of natural casings were studied by investigating the survival of six bacterial species in natural casings at different water activity (aw) levels. individual sheep casings were inoculated with ca. 10(5) colony-forming units (cfu) g(-1) of escherichia coli, salmonella typhimurium, listeria monocytogenes, staphylococcus aureus, clostridium perfringens and 10(2)cfu g(-1) of e. coli o157:h7. the casings were stored at 20+/-1.5 deg ...200616943065
post-processing application of chemical solutions for control of listeria monocytogenes, cultured under different conditions, on commercial smoked sausage formulated with and without potassium lactate-sodium diacetate.this study evaluated post-processing chemical solutions for their antilisterial effects on commercial smoked sausage formulated with or without 1.5% potassium lactate plus 0.05% sodium diacetate, and contaminated (approximately 3-4 log cfu/cm(2)) with 10-strain composite listeria monocytogenes inocula prepared under various conditions. inoculated samples were left untreated, or were immersed (2 min, 25 +/- 2 degrees c) in solutions of acetic acid (2.5%), lactic acid (2.5%), potassium benzoate (5 ...200616943080
effect of nisin on growth boundaries of listeria monocytogenes scott a, at various temperatures, ph and water activities.the effect of nisin on growth boundaries of listeria monocytogenes scott a in tryptone soy broth (tsb) under different a(w)s, ph, and temperatures was studied. growth/no growth turbidity data was modeled using logistic regression. combinations of various temperatures (5-35 degrees c), ph (4.05-6.70) adjusted with hcl, a(w)s (0.937-0.998) nacl (0.5-10.5%) and nisin (0-100 iu/ml) were used to monitor the growth/no growth response of l. monocytogenes scott a for 60 days. the concordance of the logi ...200616943082
control of meatborne listeria monocytogenes and brochothrix thermosphacta by a bacteriocinogenic brochothrix campestris atcc 43754.the effect of a bacteriocinogenic brochothrix campestris atcc 43754 upon the growth of brochothrix thermosphacta and a 4 strain mixture of listeria monocytogenes was determined in all purpose tween (apt) broth and on pork adipose tissue discs at 4 degrees c. inocula were prepared to give initial numbers of b. campestris of 6-7 log cfu/ml or cm(2) and 3-4 log cfu/ml or cm(2) of b. thermosphacta and l. monocytogenes. adipose tissue discs were evaluated by a sensory panel to determine the intensity ...200616943083
il-10 is required for optimal cd8 t cell memory following listeria monocytogenes infection.il-10 is an important immunoregulatory cytokine that plays a central role in maintaining a balance between protective immunity against infection and limiting proinflammatory responses to self or cross-reactive ags. we examined the full effects of il-10 deficiency on the establishment and quality of t cell memory using murine listeriosis as a model system. il-10(-/-) mice had reduced bacterial loads and a shorter duration of primary infection than did wild-type mice. however, the number of ag-spe ...200616888018
cada, the cd2+-atpase from listeria monocytogenes, can use cd2+ as co-substrate.cada is a membrane protein of the p-type atpase family which is the major determinant of the resistance to cd2+ in listeria monocytogenes. during its catalytic cycle, cada undergoes auto-phosphorylation from atp at asp398, which allows cd2+ translocation across the membrane. in the reverse mode, asp398 is phosphorylated from pi. from the data obtained so far, the cada catalytic mechanism is similar to that proposed for the sarcoplasmic reticulum ca2+-atpase, the model of the p-type atpase family ...200616889884
aurelin, a novel antimicrobial peptide from jellyfish aurelia aurita with structural features of defensins and channel-blocking toxins.a novel 40-residue antimicrobial peptide, aurelin, exhibiting activity against gram-positive and gram-negative bacteria, was purified from the mesoglea of a scyphoid jellyfish aurelia aurita by preparative gel electrophoresis and rp-hplc. molecular mass (4296.95 da) and complete amino acid sequence of aurelin (aacsdrahghicesfksfckdsgrngvklranckktcglc) were determined. aurelin has six cysteines forming three disulfide bonds. the total rna was isolated from the jellyfish mesoglea, rt-pcr and cloni ...200616890198
heat-treatment of bovine colostrum. ii: effects of heating duration on pathogen viability and immunoglobulin g.batches (30-l) of first-milking bovine colostrum, inoculated with mycoplasma bovis (10(8) cfu/ml), listeria monocytogenes (10(6) cfu/ml), escherichia coli o157:h7 (10(6) cfu/ml), salmonella enteritidis (10(6) cfu/ml), and mycobacterium avium subsp. paratuberculosis (map; 10(3) cfu/ml), were heat-treated at 60 degrees c for 120 min in a commercial on-farm batch pasteurizer system. duplicate 50-ml subsamples of colostrum were collected at 15-min intervals throughout the heat-treatment process for ...200616899682
[listeria meningitis in a patient with crohn's disease--a seldom, but clinically relevant adverse event of therapy with infliximab].a 42-year-old man with steroid-dependent crohn's disease developed fever, vomiting and headache after the second administration of infliximab. extensive microbiological and biochemical work-up revealed an atypical meningitis caused by listeria monocytogenes. after antibiotic therapy of 21 days duration, the patient could be discharged from hospital totally recovered without any further complications. as previously demonstrated, tnf-alpha plays an important role in resistance to listeria monocyto ...200616902896
control of listeria superoxide dismutase by phosphorylation.superoxide dismutases (sods) are enzymes that protect organisms against superoxides and reactive oxygen species (ros) produced during their active metabolism. ros are major mediators of phagocytes microbicidal activity. here we show that the cytoplasmic listeria monocytogenes mnsod is phosphorylated on serine and threonine residues and less active when bacteria reach the stationary phase. we also provide evidence that the most active nonphosphorylated form of mnsod can be secreted via the seca2 ...200616905535
evaluation of a new chromogenic agar for the detection of listeria in food.rapid identification of listeria in food is important in protecting consumers from infection. the development of chromogenic media such as agar listeria according to ottaviani and agosti (aloa) has allowed more rapid detection of listeria monocytogenes, with presumptive identification of this pathogenic species after only 24 h of incubation. the aim of this study was to evaluate oxoid chromogenic listeria agar (ocla) in comparison with aloa and a traditional, nonchromogenic medium, oxford agar.200616907821
an outbreak of salmonella abortusovis abortions in sheep in south croatia.the aim of the study was to give an account of the epidemic of abortions in sheep caused by salmonella enterica ssp. enterica serovar abortusovis, which occurred in dalmatia, south croatia, in winter 2003-2004. five sheep flocks with rate of abortion ranging from 22% to 38% during the last-third of gestation were examined. salmonella abortusovis was isolated from 13 vaginal smears and two fetuses. direct inoculation was found to be superior to pre-enrichment and enrichment in selective broth for ...200616907961
single-cell analysis divides bovine monocyte-derived dendritic cells into subsets expressing either high or low levels of inducible nitric oxide synthase.dendritic cells (dc) are important cells at the interface between innate and adaptive immunity. dc have a key role in antigen processing and presentation to t cells. effector functions of dc related to innate immunity have not been explored extensively. we show that bovine monocyte-derived dc (mdc) express inducible nitric oxide synthase (inos) mrna and protein and produce no upon triggering with interferon-gamma (ifn-gamma) and heat-killed listeria monocytogenes (hklm). an immunocytochemical an ...200616908072
modified-atmosphere storage under subatmospheric pressure and beef quality: i. microbiological effects.the microflora was studied in beef stored in stainless steel containers kept under reduced pressure (20 to 30 kpa) in a modified atmosphere (70% n2 + 30% co2 or pure co2) at 3 to 4 degrees c and 0 to 1 degrees c at a headspace:meat volume ratio of 2:1. samples were obtained at weekly intervals, 1 to 3 times. total colony counts (tcc) for pseudomonas spp. and brochothrix thermosphacta were generally 1 to 2 log10 cfu greater than in the control group of vacuum-packaged beef cuts stored at the same ...200616908649
molecular template for a voltage sensor in a novel k+ channel. i. identification and functional characterization of kvlm, a voltage-gated k+ channel from listeria monocytogenes.the fundamental principles underlying voltage sensing, a hallmark feature of electrically excitable cells, are still enigmatic and the subject of intense scrutiny and controversy. here we show that a novel prokaryotic voltage-gated k(+) (kv) channel from listeria monocytogenes (kvlm) embodies a rudimentary, yet robust, sensor sufficient to endow it with voltage-dependent features comparable to those of eukaryotic kv channels. the most conspicuous feature of the kvlm sequence is the nature of the ...200616908725
molecular template for a voltage sensor in a novel k+ channel. ii. conservation of a eukaryotic sensor fold in a prokaryotic k+ channel.kvlm, a novel bacterial depolarization-activated k(+) (kv) channel isolated from the genome of listeria monocytogenes, contains a voltage sensor module whose sequence deviates considerably from the consensus sequence of a kv channel sensor in that only three out of eight conserved charged positions are present. surprisingly, kvlm exhibits the steep dependence of the open channel probability on membrane potential that is characteristic of eukaryotic kv channels whose sensor sequence approximates ...200616908726
[listeria monocytogenes meningoencephalitis lacking meningeal signs].we report a fatal case of meningoencephalitis due to listeria monocytogenes. a 74-year old alcoholic man presented with high-grade fever lasting for four days without headache and meningeal signs. routine blood analysis showed leukocytosis, but serum c-reactive protein (crp) was not significantly elevated. he developed altered consciousness with focal seizure, and cerebrospinal fluid (csf) examination showed a minor degree of pleocytosis, elevated protein, and hypoglycorrhachia. repeated csf exa ...200616910472
composition of the essential oils of thymus and origanum species from algeria and their antioxidant and antimicrobial activities.the composition of the essential oils of origanum and thymus species restricted to algeria and the north africa region was determined. antioxidant and antibacterial activities of the isolated essential oils were also determined. the oils of oregano plants were strongly characterized by p-cymene (16.8-24.9%), gamma-terpinene (16.8-24.9%), thymol (8.4-36.0%), and carvacrol (1.1-29.7%), a thymol chemotype for origanum floribundum and a alpha-terpineol chemotype for thymus numidicus being described ...200616910725
evaluation of aloa plating medium for its suitability to recover high pressure-injured listeria monocytogenes from ground chicken meat.to evaluate a chromogenic plating medium for the isolation of sublethally injured cells of listeria monocytogenes from processed foods.200616910938
the protein secretion systems in listeria: inside out bacterial virulence.listeria monocytogenes, the etiologic agent of listeriosis, remains a serious public health concern with its frequent occurrence in food coupled with a high mortality rate. the capacity of a bacterium to secrete proteins to or beyond the bacterial cell surface is of crucial importance in the understanding of biofilm formation and bacterial pathogenesis to further develop defensive strategies. recent findings in protein secretion in listeria together with the availability of complete genome seque ...200616911044
prophylactic administration of withania somnifera extract increases host resistance in listeria monocytogenes infected mice.in this study, we demonstrated that withania somnifera l. extract (wse) protects mice from a lethal dose of listeria monocytogenes when administered prophylactically at 100, 250 and 500 mg/kg for 10 days, with survival rates up to 30%. 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. investigation of the production of colony-stimul ...200616919825
towards the definition of pathogenic microbe.identification and typing of spoilage and pathogenic microorganisms have become major objectives over the past decade in microbiology. in food, strain typing is necessary to ensure food safety and for linking cases of foodborne infections to suspected items. recent advances in molecular biology have resulted in the development of numerous dna-based methods for discrimination among bacterial strains. here, we present the use of simple sequence repeats (ssr, or microsatellites) for bacterial typin ...200616919836
prophylactic anti-tumor immunity against a murine fibrosarcoma triggered by the salmonella type iii secretion system.the potential of an attenuated salmonella enterica serovar typhimurium strain as a prophylactic anti-tumor vaccine against the murine fibrosarcoma wehi 164 was evaluated. tumor cells were transfected with the dna sequence encoding the mhc class i-restricted peptide p60(217-225) from listeria monocytogenes. balb/c mice received a single orogastric immunization with salmonella that translocates a chimeric p60 protein via its type iii secretion system. mice were subsequently challenged subcutaneous ...200616919987
t cell conditioning explains early disappearance of the memory cd8 t cell response to infection.memory cd8 t cells respond more rapidly to acute intracellular infections than naive cd8 t cells. an understanding of the biological processes involved in memory cd8 t cell recognition of ag and up-regulation of effector mechanism necessitates analyzing memory cd8 t cells at early time points after infection. in the current study, we show that memory cd8 t cells ostensibly disappear from the spleens, blood, and peripheral organs of mice early after infection with listeria monocytogenes. this dis ...200616920937
effectiveness of radiation processing in elimination of salmonella typhimurium and listeria monocytogenes from sprouts.the effectiveness of radiation treatment in eliminating salmonella typhimurium and listeria monocytogenes on laboratory inoculated ready-to-eat sprouts was studied. decimal reduction doses (d10-values) for salmonella typhimurium and l. monocytogenes in dry seeds of mung (green gram), matki (dew gram), chana (chick pea), and vatana (garden pea) ranged from 0.189 to 0.303 kgy and 0.294 to 0.344 kgy, respectively. in sprouts made from these seeds, the d10-values ranged from 0.192 to 0.208 kgy for s ...200616924910
efficacy of selected acidulants in pureed green beans inoculated with pathogens (escherichia coli o157:h7 and listeria monocytogenes).studies were conducted to evaluate the combined effect of selected acidulants (acetic, citric, malic, and phosphoric acid) and heat on foodborne pathogens (escherichia coli o157:h7 and listeria monocytogenes) in pureed green beans. to establish a consistent reference point for comparison, the molar concentrations of the acids remained constant while the acid-to-puree ratio, titratable acidity, and undissociated acid were either measured or calculated for a target acidified green beans at a ph of ...200616924911
selective enrichment media affect the antibody-based detection of stress-exposed listeria monocytogenes due to differential expression of antibody-reactive antigens identified by protein sequencing.selective enrichment broths are frequently used to recover stressed listeria cells to detectable levels, but the ability of antibodies to detect these cells from various commonly used enrichment media is unknown. in this study, a polyclonal (pab) and monoclonal (mab) antibody were used to examine the variation in antigen expression on healthy or stress-recovered listeria monocytogenes cells grown in brain heart infusion broth, buffered listeria enrichment broth (bleb), listeria repair broth (lrb ...200616924913
isolation and preliminary characterization of a bacteriocin produced by lactobacillus plantarum n014 isolated from nham, a traditional thai fermented pork.lactobacillus plantarum n014 was isolated from nham, a traditional thai fermented pork, and exhibited antimicrobial activity against listeria monocytogenes. its bacteriocin had a broad inhibitory spectrum toward both gram-positive and gram-negative bacteria. the bacteriocin activity was sensitive to all proteolytic enzymes used in this study, including papain, pepsin, pronase e, proteinase k, and trypsin, but was resistant to the other enzymes, such as alpha-amylase, lipase a, and lysozyme. furt ...200616924920
production of piscicolin 126 by carnobacterium maltaromaticum ual26 is controlled by temperature and induction peptide concentration.carnobacterium maltaromaticum ual26 produces the antimicrobial peptides (bacteriocins) piscicolin 126, first isolated from c. maltaromaticum jg126, and carnobacteriocin bm1, first isolated from c. maltaromaticum lv17. c. maltaromaticum ual26 is especially inhibitory to strains of listeria monocytogenes. bacteriocin activity is not observable in the supernatant of cultures of ual26 grown in liquid media at 25 degrees c, but at temperatures less than 19 degrees c bacteriocin activity can be detect ...200616927067
elucidation of mechanisms of acid stress in listeria monocytogenes by proteomic analysis. 200616929674
acute and chronic alcohol abuse modulate immunity.this article represents the proceedings of the alcohol and immunology research interest group (airig) meeting, a satellite workshop held at the 37th annual meeting of the society for leukocyte biology. the meeting was sponsored by the airig and the national institute on alcohol abuse and alcoholism. the presentations were as follows: (1) effects of ethanol on immune response to hepatitis c virus by jack r. wands, (2) alcohol and alveolar macrophage dysfunction: the role of chronic oxidant stress ...200616930226
comparison of listeria monocytogenes strain types in irish smoked salmon and other foods.an investigation of listeria monocytogenes in irish retail smoked salmon products and other unrelated food products was undertaken. serotyping and genotyping methods were applied. twenty-six l. monocytogenes isolates cultured from ready-to-eat smoked salmon and an additional 20 l. monocytogenes isolates from various commercially available food products (other than smoked salmon) were compared. four serotypes, 12 ribotypes, 12 amplified fragment length polymorphism (aflp) types and 17 pulsed-fiel ...200616872895
cytoplasmic bacteria and the autophagic pathway.cytoplasmic bacteria may assist in our study of the autophagic pathway. this review highlights the use of listeria monocytogenes for examining the assembly of autophagic vacuoles in mammalian cells. inhibiting protein synthesis of cytoplasmic l. monocytogenes results in their being sequestered into the autophagic pathway. autophagic vacuoles form around the easily identified bacterial particles making the assembly process easy to study using morphological and biochemical methods. l. monocytogene ...200616874112
survival of listeria monocytogenes scott a on metal surfaces: implications for cross-contamination.listeria monocytogenes is an important re-emerging pathogen which is commonly found in the environment. many outbreaks have been associated with the contamination of food produce, often linked to cross-contamination from surfaces or equipment to prepared foodstuffs. in the present study a number of copper-base metal alloys have been used to assess the survival times of l. monocytogenes on different materials, in comparison with stainless steel. high concentrations (10(7)) of bacteria were placed ...200616876278
deformations in actin comets from rocketing beads.the mechanical and dynamical properties of the actin network are essential for many cellular processes like motility or division, and there is a growing body of evidence that they are also important for adhesion and trafficking. the leading edge of migrating cells is pushed out by the polymerization of actin networks, a process orchestrated by cross-linkers and other actin-binding proteins. in vitro physical characterizations show that these same proteins control the elastic properties of actin ...200616877512
genotypes of listeria monocytogenes strains isolated from 2000 to 2002 in poland.pulsed field gel electrophoresis (pfge), multiplex pcr and multilocus sequence typing (mlst) methods were used for genotyping study of seventy-three l. monocytogenes isolates collected in poland between 2000 and 2002 from human, food, environment and a diseased goat. the multiplex pcr, which is an alternative method to classical serotyping, divided the isolates into four pcr groups, iia (42.5%), iib (27.4%), iic (4.1%) and ivb (26%). the isolates displayed 33 distinct pfge profiles. twenty eight ...200616878601
modification of a virulence-associated phenotype after growth of listeria monocytogenes on food.to assess the effect of different foods, which have been implicated or not in cases of listeriosis, on the in vitro virulence-associated phenotype level of different listeria monocytogenes strains.200616882137
listeria monocytogenes induced rac1-dependent signal transduction in endothelial cells.infection of endothelial cells by listeria monocytogenes is an essential step in the pathogenesis of listeriosis. small gtpases of the rho family act as molecular switches in signal transduction. we tested the hypothesis that rho gtpases contribute to the regulation of cytokine expression following l. monocytogenes infection. l. monocytogenes induced release of distinct cc and cxc, as well as th1 and th2 cytokines and growth factors by endothelial cells and activated rhoa and rac1. inhibition of ...200616884694
synergistic effect of tumor necrosis factor-alpha and interferon-gamma on enterocyte shedding of syndecan-1 and associated decreases in internalization of listeria monocytogenes and staphylococcus aureus.syndecan-1 is a heparan sulfate proteoglycan expressed on epithelia, and its ectodomain can be shed into the extracellular milieu, affecting a variety of cellular functions. using two bacteria known to react with heparan sulfate, listeria monocytogenes and staphylococcus aureus, experiments were designed to clarify the effect of syndecan-1 shedding on bacterial internalization by human ht-29 enterocytes. mature enterocytes were incubated with tumor necrosis factor (tnf)-alpha and/or interferon ( ...200616884912
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