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chitin hydrolysis by listeria spp., including l. monocytogenes.listeria spp., including the food-borne pathogen listeria monocytogenes, are ubiquitous microorganisms in the environment and thus are difficult to exclude from food processing plants. the factors that contribute to their multiplication and survival in nature are not well understood, but the ability to catabolize various carbohydrates is likely to be very important. one major source of carbon and nitrogen in nature is chitin, an insoluble linear beta-1,4-linked polymer of n-acetylglucosamine (gl ...200818424542
prevention of allograft tolerance by bacterial infection with listeria monocytogenes.exposure to certain viruses and parasites has been shown to prevent the induction of transplantation tolerance in mice via the generation of cross-reactive memory t cell responses or the induction of bystander activation. bacterial infections are common in the perioperative period of solid organ allograft recipients in the clinic, and correlations between bacterial infections and acute allograft rejection have been reported. however, whether bacterial infections at the time of transplantation ha ...200818424719
genome classification by gene distribution: an overlapping subspace clustering approach.genomes of lower organisms have been observed with a large amount of horizontal gene transfers, which cause difficulties in their evolutionary study. bacteriophage genomes are a typical example. one recent approach that addresses this problem is the unsupervised clustering of genomes based on gene order and genome position, which helps to reveal species relationships that may not be apparent from traditional phylogenetic methods.200818430250
infected ruptured popliteal artery aneurysm by listeria monocytogenes. a case report and review of the literatures.we describe a case of a voluminous infected aneurysm of the popliteal artery, with listeria monocytogenes (lm) associated with rupture, in a 72-year old man. after radical resection of the aneurysm a reconstruction was not necessary, because of the sufficient blood supply, due to the pre-existent good development of collateral circulation. the patient was discharged on the 12th postoperative day with primary healing of the wound and viable leg. adequate antibiotic treatment was continued for 4 w ...200818431345
new bioactive biomaterials based on quaternized chitosan.chitosan was chemically modified to produce quaternary ammonium salts in order to improve its antimicrobial activity and physicochemical properties. quaternization of n-alkyl chitosan derivatives was carried out using alkyl iodide to elaborate water-soluble cationic polyelectrolytes ( n, n, n-trimethylchitosan, tmc). tmc was characterized by (1)h nmr spectroscopy; the quaternization degree was determined from (1)h nmr spectra and by titration of iodide ion. the antibacterial activity of hydroxyp ...200818271546
development of a listeria monocytogenes based vaccine against prostate cancer.prostate specific antigen (psa) is a likely immunotherapeutic target antigen for prostate cancer, the second leading cause of cancer-related death in american men. previously, we demonstrated that attenuated strains of listeria monocytogenes (lm) can be used as effective vaccine vectors for delivery of tumor antigens causing regression of established tumors accompanied by strong immune responses toward these antigens in murine models of cancer. in the present study, we have developed and charact ...200818273616
listeria monocytogenes meningoencephalitis presenting with hydrocephalus and ventriculitis. 200818277040
influence of processing steps in cold-smoked salmon production on survival and growth of persistent and presumed non-persistent listeria monocytogenes.cold-smoked salmon is a ready-to-eat product in which listeria monocytogenes sometimes can grow to high numbers. the bacterium can colonize the processing environment and it is believed to survive or even grow during the processing steps. the purpose of the present study was to determine if the steps in the processing of cold-smoked salmon affect survival and subsequent growth of a persistent strain of l. monocytogenes to a lesser degree than presumed non-persistent strains. we used a sequence o ...200818279988
activity of daptomycin against listeria monocytogenes isolates from cerebrospinal fluid.we tested the activity of daptomycin against 76 listeria monocytogenes isolates from cerebrospinal fluid by broth dilution and etest methods. for the broth dilution method, the mic range was 1.0 to 8.0 and the mic at which 90% of the isolates tested were inhibited (mic(90)) was 4.0 mg/liter. for the etest method, the mic range was 1.0 to 4.0 and the mic(90) was 4.0 mg/liter. presently, daptomycin cannot be recommended for the treatment of l. monocytogenes meningitis.200818285470
cutting edge: il-27 is a potent inducer of il-10 but not foxp3 in murine t cells.the cytokine il-27 is important for restricting inflammation in response to a wide variety of immune challenges. in this study, we demonstrate that il-27 induces expression of the anti-inflammatory cytokine il-10 by cd4+ and cd8+ t cells. il-27 relied upon the th1 transcription factor stat1 to induce il-10+ifn-gamma+foxp3- th1 cells, which were recently shown to be key negative regulators during certain infections. il27ra-/- mice generated fewer il-10+ t cells during both listeria monocytogenes ...200818292493
constitutive expression of il-7 receptor alpha does not support increased expansion or prevent contraction of antigen-specific cd4 or cd8 t cells following listeria monocytogenes infection.expression of il-7ralpha (cd127) has been suggested as a major determinant in the survival of memory t cell precursors. we investigated whether constitutive expression of il-7ralpha on t cells increased expansion and/or decreased contraction of endogenous ag-specific cd4 and cd8 t cells following infection with listeria monocytogenes. the results indicate that constitutive expression of il-7ralpha alone was not enough to impart an expansion or survival advantage to cd8 t cells responding to infe ...200818292507
mutation in the fas pathway impairs cd8+ t cell memory.fas death pathway is important for lymphocyte homeostasis, but the role of fas pathway in t cell memory development is not clear. we show that whereas the expansion and contraction of cd8+ t cell response against listeria monocytogenes were similar for wild-type (wt) and fas ligand (fasl) mutant mice, the majority of memory cd8+ t cells in fasl mutant mice displayed an effector memory phenotype in the long-term in comparison with the mainly central memory phenotype displayed by memory cd8+ t cel ...200818292515
stimulation of enhanced cd8 t cell responses following immunization with a hyper-antigen secreting intracytosolic bacterial pathogen.the intracytosolic niche for replication of listeria monocytogenes (lm) facilitates delivery of bacteria-derived ags into the mhc class i pathway for subsequent stimulation of cd8 effector t cells. using lm strains that are equivalent for in vivo virulence yet express marked differences in the level of secretion of a protective target ag, we have evaluated how these specific differences in secretion levels influences the magnitude and effector function of ag-specific cd8 t cell responses followi ...200818292567
involvement of cell fatty acid composition and lipid metabolism in adhesion mechanism of listeria monocytogenes.the cell fatty acid (fa) composition of adhered and floating cells of two listeria monocytogenes strains, selected on the basis of the biofilm forming ability, was taken into consideration. anteiso-15:0, iso-c15:0 and anteiso-17:0 resulted the principal fas in floating cells. on the other hand the adhered cells of the two strains presented a fas profile characterized by a prevalence of straight fas such as hexadecanoic acid (16:0) and octadecanoic acid (18:0). when adhered and free floating cell ...200818160165
the proteasome immunosubunit multicatalytic endopeptidase complex-like 1 is a t-cell-intrinsic factor influencing homeostatic expansion.homeostatic regulatory mechanisms maintain the constant ratios between different lymphocyte subsets in the secondary lymphoid organs. how this dynamic equilibrium is achieved, in particular following the clonal expansion and subsequent contraction of different cells after infection, remains poorly understood. expression of the proteasome immunosubunits has been shown to influence not only major histocompatibility complex class i (mhc-i) antigen processing and thereby t-cell responses, but also t ...200818160473
card6 is interferon inducible but not involved in nucleotide-binding oligomerization domain protein signaling leading to nf-kappab activation.we have previously reported the cloning and characterization of card6, a caspase recruitment domain (card)-containing protein that is structurally related to the interferon (ifn)-inducible gtpases. card6 associates with microtubules and with receptor-interacting protein 2 (rip2). rip2 mediates nf-kappab activation induced by the intracellular nucleotide-binding oligomerization domain (nod) receptors that sense bacterial peptidoglycan. here we report that the expression of card6 and rip2 in bone ...200818160713
early invasive listeria monocytogenes infection after orthotopic liver transplantation: case report and review of the literature.infection with listeria monocytogenes is rare, with a reported annual incidence of 4.4 cases per million individuals. it is caused by a gram-positive rod-shaped bacterium (listeria monocytogenes) that can be found in soil, vegetation, water, sewage, and silage and in feces of humans and animals. it is a facultative intracellular pathogen with the ability to survive and multiply in phagocytic host cells, even in adverse environmental circumstances. listeriosis has rarely been reported after ortho ...200818161771
preparation of listeria monocytogenes specimens for molecular detection and identification.listeria monocytogenes is a common foodborne pathogen that has the capacity to cause severe clinical illness in vulnerable human population groups. the availability of rapid and specific laboratory tests to identify this bacterium is essential for preventing an otherwise easily treated malaise from developing into a life-threatening disease. to this end, a variety of rapid, sensitive and precise nucleic acid-based assays have been developed, contributing to the improved diagnosis of listeriosis. ...200818164775
radical scavenging, antioxidant and antimicrobial activities of halophytic species.for the first time, both antioxidant and antimicrobial activities are simultaneously reported in halophytic plants, particularly on polar fractions. chloroformic and methanolic extracts of the halophytes eryngium maritimum l., crithmum maritimum l. and cakile maritima scop. were tested for their antimicrobial activities against 12 bacterial and yeast strains. in addition, radical scavenging and antioxidant activities were assessed, as well as total phenol contents. only one bacterial strain (lis ...200818164885
acid and heat tolerance of persistent and nonpersistent listeria monocytogenes food plant strains.acid and heat tolerance of 17 persistent and 23 nonpersistent listeria monocytogenes strains, recovered from three meat-processing plants, were investigated.200818179448
developmental switch of intestinal antimicrobial peptide expression.paneth cell-derived enteric antimicrobial peptides provide protection from intestinal infection and maintenance of enteric homeostasis. paneth cells, however, evolve only after the neonatal period, and the antimicrobial mechanisms that protect the newborn intestine are ill defined. using quantitative reverse transcription-polymerase chain reaction, immunohistology, reverse-phase high-performance liquid chromatography, and mass spectrometry, we analyzed the antimicrobial repertoire in intestinal ...200818180308
type i ifn are host modulators of strain-specific listeria monocytogenes virulence.type i ifn (ifn-i) increase the sensitivity of cells and mice to lethal infection with listeria monocytogenes. therefore the amount of ifn-i produced during infection might be an important factor determining listeria virulence. two commonly used strains of l. monocytogenes, egd and lo28, were identified as, respectively, low and high inducers of ifn-i synthesis in infected macrophages. increased ifn-i production resulted from the stronger ability of the lo28 strain to trigger the irf3 signalling ...200818182083
quantification of bacterial cells based on autofluorescence on a microfluidic platform.bacterial counts provide important information during the processes such as pathogen detection and hygiene inspection and these processes are critical for public health and food/pharmaceutical production. in this study, we demonstrate the quantification of the number of bacterial cells based on the autofluorescence from the cell lysate on a microfluidic chip. we tested three model pathogenic bacteria (listeria monocytogenes f4244, salmonella enteritidis pt1 and escherichia coli o157:h7 edl 933). ...200818187141
in vitro efficacy of diclofenac against listeria monocytogenes.chemotherapy is often futile in systemic listeriosis, translating to being a peril to public health. there is, thus, an imperative need for novel antilisterial compounds, possibly acting through mechanisms dissimilar to those of existing drugs. the present study describes one such agent-the non-steroidal anti-inflammatory drug (nsaid) diclofenac sodium (dc). the national committee for clinical laboratory standards (nccls) minimum inhibitory concentration (mic), mode of action, and two mechanisms ...200818188616
pseudomonas aeruginosa activates caspase 1 through ipaf.the innate immune system encodes cytosolic nod-like receptors (nlrs), several of which activate caspase 1 processing and il-1beta and il-18 secretion. macrophages respond to salmonella typhimurium infection by activating caspase 1 through the nlr ipaf. this activation is mediated by cytosolic flagellin through the activity of the virulence-associated type iii secretion system (t3ss). we demonstrate here that pseudomonas aeruginosa activates caspase 1 and induces il-1beta secretion in infected ma ...200818256184
multiple-locus variable-number tandem-repeat analysis as a tool for subtyping listeria monocytogenes strains.listeria monocytogenes, like many other food-borne bacteria, has certain strains that are commonly linked to outbreaks. due to the relatively low numbers of affected individuals, outbreaks of l. monocytogenes can be difficult to detect. the current technique of molecular subtyping in pulsenet laboratories to identify genetically similar strains is pulsed-field gel electrophoresis (pfge). while pfge is state-of-the-art, interlaboratory comparisons are difficult because the results are highly susc ...200818256218
prophages in listeria monocytogenes contain single-nucleotide polymorphisms that differentiate outbreak clones within epidemic clones.a fragment end ligation-mediated pcr strategy was used to analyze the asci pulsed-field gel electrophoresis patterns of listeria monocytogenes epidemic clone ii (ecii), which led to the identification of single-nucleotide polymorphisms (snps) in prophage regions that differentiated the two ecii outbreak clones. snps in prophages that differentiated the outbreak clones of eciii and -iv were also identified.200818256228
platelet-derived cd154 enables t-cell priming and protection against listeria monocytogenes challenge.collagen exposure in tissue activates platelets, initiates wound healing, and modulates adaptive immunity. in this report, data are presented to demonstrate a requirement for platelet-derived cd154 for both collagen-induced augmentation of t-cell immunity and induction of pro-tective immunity to listeria challenge. specifically, we demonstrate that ad5 encoding the membrane-bound form of ovalbumin (ad5-mova) delivered in collagen induces higher ovalbumin-specific cytotoxic t lymphocyte (ctl) act ...200818256321
a role for membrane-bound cd147 in nod2-mediated recognition of bacterial cytoinvasion.nod2 is an intracellular receptor for the bacterial cell wall component muramyl dipeptide. mutations in the leucine-rich repeat region of nod2, which lead to an impaired recognition of muramyl dipeptide, have been associated with chronic inflammatory diseases of barrier organs such as crohn disease, asthma and atopic eczema. in this study we identify cd147 (also known as bsg and emmprin), a membrane-bound regulator of cellular migration, differentiation and inflammatory processes, as a protein i ...200818256385
marked intra-strain variation in response of listeria monocytogenes dairy isolates to acid or salt stress and the effect of acid or salt adaptation on adherence to abiotic surfaces.during food processing, and particularly in cheese manufacturing processes, listeria monocytogenes may be exposed routinely to environments of low ph or high salt concentration. it has been suggested that these environmental conditions may contribute to bacterial adherence to abiotic surfaces and increased resistance to disinfection. in this study strains isolated from the environment of artisanal cheese-making dairies were used to investigate the behaviour of l. monocytogenes in response to aci ...200818258322
the cytosolic sensors nod1 and nod2 are critical for bacterial recognition and host defense after exposure to toll-like receptor ligands.the cytosolic sensors nod1 and nod2 and toll-like receptors (tlrs) activate defense signaling pathways in response to microbial stimuli. however, the role of nod1 and nod2 and their interplay with tlrs during systemic bacterial infection remains poorly understood. here, we report that macrophages or mice made insensitive to tlrs by previous exposure to microbial ligands remained responsive to nod1 and nod2 stimulation. furthermore, nod1- and nod2-mediated signaling and gene expression are enhanc ...200818261938
anti-listerial activity of a polymeric film coated with hybrid coatings doped with enterocin 416k1 for use as bioactive food packaging.in this study, enterocin 416k1, a bacteriocin produced by enterococcus casseliflavus im 416k1, was entrapped in an organic-inorganic hybrid coating applied to a ldpe (low-density polyethylene) film for its potential use in the active food packaging field. the antibacterial activity of the coated film was evaluated against listeria monocytogenes nctc 10888 by qualitative modified agar diffusion assay, quantitative determination in listeria saline solution suspension and direct contact with artifi ...200818262299
x-ray and neutron small-angle scattering analysis of the complex formed by the met receptor and the listeria monocytogenes invasion protein inlb.the listeria monocytogenes surface protein inlb binds to the extracellular domain of the human receptor tyrosine kinase met, the product of the c-met proto-oncogene. inlb binding activates the met receptor, leading to uptake of listeria into normally nonphagocytic host cells. the n-terminal half of inlb (inlb(321)) is sufficient for met binding and activation. the complex between this met-binding domain of inlb and various constructs of the met ectodomain was characterized by size exclusion chro ...200818262542
response of listeria monocytogenes to liquid smoke.to investigate the effect of liquid smoke on growth, survival, proteomic pattern and haemolytic potential of listeria monocytogenes.200818266702
stimulation of inducible nitric oxide synthase expression by beta interferon increases necrotic death of macrophages upon listeria monocytogenes infection.murine macrophage death upon infection with listeria monocytogenes was previously shown to be increased by beta interferon, produced by the infected cells. we saw that interferon-upregulated caspase activation or other interferon-inducible, death-associated proteins, including trail, protein kinase r, and p53, were not necessary for cell death. macrophage death was reduced when inducible nitric oxide synthase (inos) was inhibited during infection, and inos-deficient macrophages were less suscept ...200818268032
bioprotection of golden delicious apples and iceberg lettuce against foodborne bacterial pathogens by lactic acid bacteria.lactic acid bacteria were isolated from fresh vegetables and fruit and its ability to inhibit the growth of foodborne human pathogens (escherichia coli, listeria monocytogenes, pseudomonas aeruginosa, salmonella typhimurium, and staphylococcus aureus) was tested using the agar spot assay. eighteen isolates showed a strong antagonistic capacity and were further characterised and identified using 16s rdna sequencing and api 50ch. most of them pertained to leuconostoc spp. and lactobacillus plantar ...200818191266
teichoic acid glycosylation mediated by gtca is required for phage adsorption and susceptibility of listeria monocytogenes serotype 4b.an insertion mutant of gtca, responsible for serotype-specific glycosylation of the cell wall teichoic acid in serotype 4b strains of listeria monocytogenes, was also resistant to both listeria genus- and serotype 4b-specific phages. the sugar substituents on teichoic acid appeared essential for the adsorption of phages a500 (serotype 4b specific) and a511 (listeria genus specific) to serotype 4b l. monocytogenes.200818192405
heavy-metal and benzalkonium chloride resistance of listeria monocytogenes isolates from the environment of turkey-processing plants.the resistance of listeria monocytogenes to cadmium and arsenic has been used extensively for strain subtyping. however, limited information is available on the prevalence of such resistance among isolates from the environment of food-processing plants. in addition, it is not known whether the resistance of such isolates to heavy metals may correlate with resistance to quaternary ammonium compounds extensively used as disinfectants in the food-processing industry. in this study, we characterized ...200818192428
distinct tlr- and nlr-mediated transcriptional responses to an intracellular pathogen.how the innate immune system tailors specific responses to diverse microbial infections is not well understood. cells use a limited number of host receptors and signaling pathways to both discriminate among extracellular and intracellular microbes, and also to generate responses commensurate to each threat. here, we have addressed these questions by using dna microarrays to monitor the macrophage transcriptional response to the intracellular bacterial pathogen listeria monocytogenes. by utilizin ...200818193943
influence of temperature on biofilm formation by listeria monocytogenes on various food-contact surfaces: relationship with motility and cell surface hydrophobicity.to assess the ability of listeria monocytogenes to form biofilm on different food-contact surfaces with regard to different temperatures, cellular hydrophobicity and motility.200818194252
crosstalk between the alpha2beta1 integrin and c-met/hgf-r regulates innate immunity.data from several investigators suggest that the alpha2beta1 integrin, a receptor for collagens, laminins, decorin, e-cadherin, matrix metalloproteinase-1, endorepellin, and several viruses, is required for innate immunity and regulation of autoimmune/allergic disorders. we demonstrated that the innate immune response to listeria monocytogenes required alpha2beta1 integrin expression by peritoneal mast cells (pmcs). ligation of the alpha2beta1 integrin by c1q contained in immune complexes compri ...200818198349
listeriolysin o allows listeria monocytogenes replication in macrophage vacuoles.listeria monocytogenes is an intracellular bacterial pathogen that replicates rapidly in the cytosol of host cells during acute infection. surprisingly, these bacteria were found to occupy vacuoles in liver granuloma macrophages during persistent infection of severe combined immunodeficient (scid) mice. here we show that l. monocytogenes can replicate in vacuoles within macrophages. in livers of scid mice infected for 21 days, we observed bacteria in large lamp1(+) compartments that we termed sp ...200818202661
isolation of lactic acid bacteria with inhibitory activity against pathogens and spoilage organisms associated with fresh meat.the use of lactic acid bacteria (lab) as protective cultures in vacuum-packed chill-stored meat has potential application for assuring and improving food quality, safety and market access. in a study to identify candidate strains suitable for evaluation in a meat model, agar-based methods were employed to screen 181 chilled meat and meat process-related lab for strains inhibitory to pathogens and spoilage organisms of importance to the meat industry. six meat-derived strains, including lactobaci ...200818206764
control of listeria monocytogenes on ham steaks by antimicrobials incorporated into chitosan-coated plastic films.contamination of ready-to-eat (rte) meat products such as ham steaks with listeria monocytogenes has been a concern for the meat processing industry. the objective of this study was to evaluate the antilisterial efficacy of chitosan-coated plastic films alone or incorporating five generally recognized as safe (gras) antimicrobials. effect of chitosan-coated plastic film on the growth of l. monocytogenes was first investigated in an aqueous system of culture medium broth and chitosan-coated films ...200818206768
succession of dominant and antagonistic lactic acid bacteria in fermented cucumber: insights from a pcr-based approach.the goal of the investigation was to study the succession of major groups of lactic acid bacteria (lab) and their antagonism in salt-fermented cucumber using pcr. in a direct detection method as well as a short enrichment process, pcr enabled detection of leuconostoc and lactobacillus during early hours of fermentation. subsequently, lactobacillus and pediococcus emerged as the dominant genera. nucleic acid sequence of culture-independent clones confirmed the detection of pediococcus as a domina ...200818206770
use of mild-heat treatment following high-pressure processing to prevent recovery of pressure-injured listeria monocytogenes in milk.this study examined the inactivation of listeria monocytogenes in milk by high-pressure processing (hpp) and bacterial recovery during storage after hpp. we developed a technique to inhibit the bacterial recovery during storage after hpp (550 mpa for 5 min) using a mild-heat treatment (30-50 degrees c). various mild-heat treatments were conducted following hpp to investigate the condition on which the bacterial recovery was prevented. immediately after hpp of 550 mpa at 25 degrees c for 5 min, n ...200818206771
heat and acid tolerance of listeria monocytogenes after exposure to single and multiple sublethal stresses.the majority of published studies on the adaptive heat or acid tolerance response of listeria monocytogenes have been performed with a single strain exposed to a single adaptation treatment; however, in food ecosystems, microorganisms commonly exist as multi-species communities and encounter multiple stresses, which may result in "stress hardening". therefore, the present study evaluated the adaptive responses to heat (52, 57 and 63 degrees c) or lactic acid (ph 3.5) of a 10-strain composite of ...200818206772
microbiological quality of retail cheeses made from raw, thermized or pasteurized milk in the uk.two studies of retail fresh, ripened and semi-hard cheeses made from raw, thermized or pasteurized milk were undertaken in the uk during 2004 and 2005 to determine the microbiological quality of these products. using microbiological criteria in european commission recommendations 2004/24/ec and 2005/175/ec, 2% of both raw, thermized (37/1819 samples) and pasteurized (51/2618 samples) milk cheeses were of unsatisfactory quality. raw or thermized milk cheeses were of unsatisfactory quality due to ...200818206773
microbial ecology of food contact surfaces and products of small-scale facilities producing traditional sausages.the microbial status in 7 small-scale facilities (ssfs) producing traditional fermented and/or dry sausages was investigated. it was shown that the hygienic status of the processing environment and equipment plays an essential role in the microbial stability and safety of the final products. the current study revealed that the majority of the sampling sites (control points) tested were highly (>4 log cfu/cm(2)) contaminated by spoilage flora (i.e. pseudomonas, enterobacteriaceae), with knives, t ...200818206774
enumeration and growth of naturally occurring listeria spp. in unpackaged ham.a total of 301 unpackaged retail ham samples were tested for the presence and number of listeria spp. after 7 days at 5 degrees c to simulate domestic storage. thirteen samples (4.3%) contained listeria monocytogenes, with the highest count being 1.6 x 10(3)cfu g(-1). thirteen samples contained other listeria spp. genotyping showed that only one l. monocytogenes isolate from the 14 tested was of a type previously identified in new zealand human cases. listeria-contaminated batches were incubated ...200818206784
[arthritis due to listeria monocytogenes].a 69-year-old man with liver cirrhosis presented to a surgeon, complaining of pain and swelling involving the right knee joint. a cloudy yellow synovial fluid was aspirated. the examination revealed polymorphonuclear leukocytes and listeria monocytogenes was grown in the culture. the patient was treated with oral cotrimoxazole. further follow-up was uneventful. the literature on listerial joint infections is briefly reviewed.200818210136
elimination of listeria monocytogenes on hotdogs by infrared surface treatment.the objective of this research was to develop an infrared pasteurization process with automatic temperature control for inactivation of surface-contaminated listeria monocytogenes on ready-to-eat meats such as hotdogs. the pasteurization system contained 4 basic elements: an infrared emitter, a hotdog roller, an infrared sensor, and a temperature controller. the infrared sensor was used to monitor the surface temperature of hotdogs while the infrared emitter, modulated by a power controller, was ...200818211358
avoiding death by autophagy: interactions of listeria monocytogenes with the macrophage autophagy system.autophagy restricts the growth of a variety of intracellular pathogens. however, cytosol-adapted pathogens have evolved ways to evade restriction by this innate immune mechanism. listeria monocytogenes is a gram-positive bacterial pathogen that utilizes a cholesterol-dependent pore-forming toxin, listeriolysin o (llo), to escape from the phagosome. autophagy targets l. monocytogenes in llo-damaged phagosomes and also in the cytosol under some experimental conditions. however, this bacterium has ...200818216493
disinfectant test against monoculture and mixed-culture biofilms composed of technological, spoilage and pathogenic bacteria: bactericidal effect of essential oil and hydrosol of satureja thymbra and comparison with standard acid-base sanitizers.to assess the antimicrobial action of three natural-derived products (essential oil, decoction and hydrosol of satureja thymbra) against biofilms, composed of useful, spoilage and pathogenic bacteria (formed as monoculture or/and mixed-culture), and to compare their efficiency with three standard acid and alkaline chemical disinfectants.200818217930
a study on the kinetic behavior of listeria monocytogenes in ice cream stored under static and dynamic chilling and freezing conditions.the kinetic behavior of listeria monocytogenes in 2 commercial ice cream products (a and b) that were inoculated and stored under static chilling (4 to 16 degrees c), static freezing (-5 to -33 degrees c), dynamic chilling, and dynamic chilling-freezing conditions was studied, simulating conditions of the aging process and of normal or abuse conditions during distribution and storage. the ice cream products a and b had different compositions but similar ph (6.50 and 6.67, respectively) and water ...200818218738
prevalence of listeria species in food products in isfahan, iran.a total of 617 meat and meat products, diary, vegetables and ready to eat food samples were collected. listeria spp. isolated by using usda method of isolation and l. monocytogenes identified by biochemical and polymerase chain reaction (pcr). the incidence of listeria spp. was 4.6% in all food samples. l. monocytogenes was found in 1.2% of food samples. it was found that listeria spp. was present in 6.7% of meat and meat product samples, 1.3% of diary samples, 1.2% of vegetable samples and 12% ...200818221811
transcription of the listeria monocytogenes fri gene is growth-phase dependent and is repressed directly by fur, the ferric uptake regulator.the listeria monocytogenes fri gene encodes the only ferritin-like protein of this pathogen, a dps protein (dna binding protein from starved cells). listeria dps is endowed with the capacity to detoxify concurrently free iron and h(2)o(2), is essential for virulence and is required for efficient bacterial growth at early stages of the infection process. the transcription of fri is known to depend on sigma(a) and sigma(b) factors, to be affected by growth conditions and to be derepressed in a per ...200818222616
novel bacterial artificial chromosome vector puvbbac for use in studies of the functional genomics of listeria spp.bacterial artificial chromosome (bac) vectors are important tools for microbial genome research. we constructed a novel bac vector, puvbbac, for replication in both gram-negative and gram-positive bacterial hosts. the puvbbac vector was used to generate a bac library for the facultative intracellular pathogen listeria monocytogenes egd-e. the library had insert sizes ranging from 68 to 178 kb. we identified two recombinant bacs from the l. monocytogenes puvbbac library that each contained the en ...200818223114
temporal transcriptomic analysis of the listeria monocytogenes egd-e sigmab regulon.the opportunistic food-borne gram-positive pathogen listeria monocytogenes can exist as a free-living microorganism in the environment and grow in the cytoplasm of vertebrate and invertebrate cells following infection. the general stress response, controlled by the alternative sigma factor, sigmab, has an important role for bacterial survival both in the environment and during infection. we used quantitative real-time pcr analysis and immuno-blot analysis to examine sigmab expression during grow ...200818226246
activity against listeria monocytogenes of human milk during lactation. a preliminary study.human milk samples from three healthy donors were investigated in order to evaluate the antibacterial activity during lactation against escherichia coli atcc 25922 and listeria monocytogenes. the concentration of the main human-milk antimicrobial proteins (lactoferrin (lf), lysozyme (lz) and secretory immunoglobulin a (siga)) was determined by elisa. results showed that human milk exhibited antibacterial activity against list. monocytogenes, although it was weakly active against esch. coli atcc ...200818226304
the listeria monocytogenes virulence factor inlj is specifically expressed in vivo and behaves as an adhesin.the food-borne pathogen listeria monocytogenes is adapted to a diversity of environments, such as soil, food, body fluids, and the cytosol of eukaryotic cells. the transition between saprophytic and pathogenic life is mediated through complex regulatory pathways that modulate the expression of virulence factors. here we examined the expression of inlj, a recently identified gene encoding a protein of the lpxtg-internalin family and involved in pathogenesis. we show that inlj expression is contro ...200818227172
activity of tigecycline against coryneform bacteria of clinical interest and listeria monocytogenes.the activities of tigecycline and eight other agents were evaluated against 220 coryneform bacteria and 42 listeria monocytogenes isolates. all strains were inhibited by tigecycline at 0.5 mug/ml, except for 11 corynebacterium striatum strains that were inhibited at 1 mug/ml. tigecycline shows good in vitro activity against coryneform bacteria and l. monocytogenes.200818227183
differential gene expression of listeria monocytogenes during high hydrostatic pressure processing.high hydrostatic pressure processing (hpp) is currently being used as a treatment for certain foods to control the presence of food-borne pathogens, such as listeria monocytogenes. genomic microarray analysis was performed to determine the effects of hpp on l. monocytogenes in order to understand how it responds to mechanical stress injury. reverse transcriptase pcr analysis of tufa and rpoc indicated that the reduction of mrna expression in hpp-treated cells was dependent on intensity and time ...200818227250
inla and inlc2 of listeria monocytogenes serotype 4b are two internalin proteins eliciting humoral immune responses common to listerial infection of various host species.the internalins inla and inlc2 are encoded proteins from two strongly immunoreactive clones recently identified by differential immunoscreening of a listeria monocytogenes serotype 4b genomic expression library during the search of the gene products of l. monocytogenes specifically induced in vivo during infection (yu wl, dan h, lin m. j med microbiol 56:888-895, 2007). in this study, we examined the humoral immune response against inla and inlc2 in various l. monocytogenes-infected hosts using ...200818228097
effects of co2 on the resuscitation of listeria monocytogenes injured by various bactericidal treatments.to assure the microbiological safety and quality of a food product, a combination of preservation hurdles is often used. therefore, the effects of carbon dioxide at concentrations of 0, 20, 40 and 60% in modified atmospheres on the resuscitation of listeria monocytogenes cells injured by mild bactericidal treatments during storage at 7 degrees c were examined. the bactericidal treatments were intense light pulses (ilp), chlorine dioxide (clo(2)), lactic acid (la) and heat. the results indicated ...200818230409
moxifloxacin versus ampicillin + gentamicin in the therapy of experimental listeria monocytogenes meningitis.this study aimed to compare the antibacterial activity of moxifloxacin and ampicillin + gentamicin in the treatment of listeria monocytogenes meningitis in a rabbit meningitis model.200818230687
effect of chemical sanitizers with and without ultrasonication on listeria monocytogenes as a biofilm within polyvinyl chloride drain pipes.as part of a biofilm in a floor drain, listeria monocytogenes is exceedingly difficult to eradicate with standard sanitizing protocols. the objective of these studies was to test the use of ultrasonication to break up biofilm architecture and allow chemical sanitizers to contact cells directly. l. monocytogenes biofilms were created in model polyvinyl chloride drain pipes. chemical sanitizers (quaternary ammonium, peroxide, or chlorine) were applied to the drain pipes with and without a 30-s ult ...200818236664
high-pressure processing of turkish white cheese for microbial inactivation.high-pressure processing (hpp) of turkish white cheese and reduction of listeria monocytogenes, total enterobacteriaceae, total aerobic mesophilic bacteria, total molds and yeasts, total lactococcus spp., and total lactobacillus spp. were investigated. cheese samples were produced from raw milk and pasteurized milk and were inoculated with l. monocytogenes after brining. both inoculated (ca. 10(7) to 10(8) cfu/g) and noninoculated samples were subjected to hpp in a high-pressure food processor a ...200818236669
inactivation of bacterial pathogens in human milk by high-pressure processing.low-temperature, long-time (ltlt) pasteurization assures the safety of banked human milk; however, heat can destroy important nutritional biomolecules. high-pressure processing (hpp) shows promise as an alternative for pasteurization of breast milk. the purpose of this study was to investigate the efficacy of hpp for inactivation of selected bacterial pathogens in human milk. human milk was inoculated with one of five pathogens (10(8) to 10(9) cfu/ml), while 0.1% peptone solution solutions with ...200818236670
antimicrobial properties of milkfat globule membrane fractions.milkfat globule membranes (mfgms) were prepared from bovine cream according to standard procedures. these membranes and peptide hydrolysates, which were generated by proteolysis with immobilized digestive enzymes, were screened for antibacterial activity against escherichia coli o157:h7, listeria monocytogenes, salmonella enterica typhimurium, pseudomonas fluorescens, bacillus cereus, lactobacillus acidophilus, and lactobacillus gasseri. assays were first performed on beef heart infusion (bhi) p ...200818236672
effect of surface roughness and stainless steel finish on listeria monocytogenes attachment and biofilm formation.the purpose of this study was to evaluate the effect of surface roughness (ra) and finish of mechanically polished stainless steel (ra = 0.26 +/- 0.05, 0.49 +/- 0.10, and 0.69 +/- 0.05 microm) and electropolished stainless steel (ra = 0.16 +/- 0.06, 0.40 +/- 0.003, and 0.67 +/- 0.02 microm) on listeria adhesion and biofilm formation. a four-strain cocktail of listeria monocytogenes was used. each strain (0.1%) was added to 200 ml of tryptic soy broth (tsb), and coupons were inserted to the mixtu ...200818236679
transfer of surface-dried listeria monocytogenes from stainless steel knife blades to roast turkey breast.listeria contamination of food contact surfaces can lead to cross-contamination of ready-to-eat foods in delicatessens. recognizing that variations in listeria biofilm-forming ability exist, the goal of this study was to determine whether these differences in biofilm formation would affect the listeria transfer rate during slicing of delicatessen turkey meat. in this study, six previously identified strong and weak biofilm-forming strains of listeria monocytogenes were grown at 22 degrees c for ...200818236680
radioresistance of salmonella species and listeria monocytogenes on minimally processed arugula (eruca sativa mill.): effect of irradiation on flavonoid content and acceptability of irradiated produce.this work studied the radiation resistance of listeria monocytogenes and salmonella species and the effect of irradiation on leaf flavonoid content and sensory acceptability of minimally processed arugula. immersion in ozone-treated water reduced the analyzed microorganisms by 1 log. l. monocytogenes and salmonella were not isolated from samples. samples of this vegetable were inoculated with a cocktail of salmonella spp. and l. monocytogenes and exposed to gamma irradiation. d10 values for salm ...200818237127
efficacy of neutral electrolyzed water (new) for reducing microbial contamination on minimally-processed vegetables.consumption of minimally-processed, or fresh-cut, fruit and vegetables has rapidly increased in recent years, but there have also been several reported outbreaks associated with the consumption of these products. sodium hypochlorite is currently the most widespread disinfectant used by fresh-cut industries. neutral electrolyzed water (new) is a novel disinfection system that could represent an alternative to sodium hypochlorite. the aim of the study was to determine whether new could replace sod ...200818237810
microbiological quality of fresh, minimally-processed fruit and vegetables, and sprouts from retail establishments.a survey of fresh and minimally-processed fruit and vegetables, and sprouts was conducted in several retail establishments in the lleida area (catalonia, spain) during 2005-2006 to determine whether microbial contamination, and in particular potentially pathogenic bacteria, was present under these commodities. a total of 300 samples--including 21 ready-to-eat fruits, 28 whole fresh vegetables, 15 sprout samples and 237 ready-to-eat salads containing from one to six vegetables--were purchased fro ...200818237811
adoptive cd8 t cell control of pathogens cannot be improved by combining protective epitope specificities.adoptive transfer of cd8 t cells has the potential to cure infectious or malignant diseases that are refractory to conventional chemotherapy. a practically important but still unanswered question is whether mixtures of protective cd8 t cells with different epitope specificities mediate more efficient effector cell functions than do the monospecific individual cd8 t cell populations. in this study, we have addressed this issue for models of viral and bacterial infection. cd8 t cell-mediated cytot ...200818240950
identification of drosophila mutants altering defense of and endurance to listeria monocytogenes infection.we extended the use of drosophila beyond being a model for signaling pathways required for pattern recognition immune signaling and show that the fly can be used to identify genes required for pathogenesis and host-pathogen interactions. we performed a forward genetic screen to identify drosophila mutations altering sensitivity to the intracellular pathogen listeria monocytogenes. we recovered 18 mutants with increased susceptibility to infection, none of which were previously shown to function ...200818245331
alkyl deoxy-arabino-hexopyranosides: synthesis, surface properties, and biological activities.octyl and dodecyl glycosides possessing 2-deoxy-arabino-hexopyranoside moieties belonging to the d- and l-series in their alpha- and beta-forms were synthesized by reaction of an acetyl protected glycal with octanol or dodecanol, catalyzed by triphenylphosphine hydrobromide, followed by deprotection. their surface properties were studied and discussed in terms of the adsorption and aggregation parameters, pc(20), cmc, and gamma(cmc). the antimicrobial activities were assessed using the paper dis ...200818249550
secreted enteric antimicrobial activity localises to the mucus surface layer.the intestinal mucosa is constantly exposed to a dense and highly dynamic microbial flora and challenged by a variety of enteropathogenic bacteria. antibacterial protection is provided in part by paneth cell-derived antibacterial peptides such as the alpha-defensins. the mechanism of peptide-mediated antibacterial control and its functional importance for gut homeostasis has recently been appreciated in patients with crohn's ileitis. in the present study, the spatial distribution of antimicrobia ...200818250125
antigen controls il-7r alpha expression levels on cd8 t cells during full activation or tolerance induction.the high-affinity chain of the il-7 receptor, il-7ralpha (cd127), is expressed by effector cd8 t cells that have the capacity to become memory cells. il-7ralpha expression is uniformly high on naive cd8 t cells, and the majority of these cells down-regulate expression upon antigenic challenge. at the peak of expansion, the fraction of effectors expressing high il-7ralpha varies depending on the response examined. the signals that a cd8 t cell receives during a response to ag that lead to altered ...200818250416
novel vaccination protocol with two live mucosal vectors elicits strong cell-mediated immunity in the vagina and protects against vaginal virus challenge.most hiv infections result from heterosexual transmission to women. because cellular immunity plays a key role in the control of the infection, we sought to strengthen cellular immune responses in vaginal tissue. we explored a novel prime-boost protocol that used two live mucosal agents that trigger different pathways of innate immunity and induce strong cellular immunity. adenovirus serotype 5 (ad5) has frequently been used as a boost for dna vaccines. in this study we used attenuated, recombin ...200818250460
characterization and partial purification of entomocin 110, a newly identified bacteriocin from bacillus thuringiensis subsp. entomocidus hd110.a new bacteriocin produced by bacillus thuringiensis subsp. entomocidus was identified. the antibacterial activity termed entomocin 110 was produced starting at mid-logarithmic growth phase, reaching its maximum at the early and during stationary phase. the bacteriocin obtained from culture supernatant was inhibitory to several gram-positive bacteria including listeria monocytogenes, paenibacillus larvae and other bacillus species. entomocin 110 was shown to be heat stable and resistant to ph va ...200819216106
[differentiantion of listeria monocytogenes strains isolated in the far east and european part of russia on the basis of polymorphism of genes encoding invasion factors].forty listeria monocytogenes isolates obtained in european and far east regions of russia were differentiated on the basis of polymorphism of 5 markergenes. total length of concatemers obtained after sequencing of internal fragments of genes inla, inlb, inlc, inle and prs was 3029 b.p. comparative analysis of concatemers' sequences revealed 237 variable nucleotides. totally, 25 sequence types were revealed, and isolates from european and far east regions belonged to different types. on the dendr ...200819186537
[growth media for isolation, accumulation, and identification of listeria in laboratory diagnostics of mix-infections in women with obstetric-gynecological pathology].isolation of lysteria monocytogenes from clinical specimens in obstetric-gynecological pathology is often difficult owing to the presence of the mixed microbial flora. results of study of new russian growth media for isolation of listeria for microbiological diagnostics of listeriosis in pregnancy are presented. they show diagnostic efficacy of the developed media for laboratory diagnostics of mix-infections in women with obstetric-gynecological pathology.200819186555
multiplex-pcr serotyping of listeria monocytogenes isolated from human clinical specimens.the genus listeria is composed of six species of which listeria monocytogenes is considered the single pathogenic species that causes listeriosis in humans. of the 13 serovars of l. monocytogenes, 1/2a, 1/2b and 4b are responsible for the majority of clinical cases. the aim of this work was to detect l. monocytogenes in the cerebrospinal fluid sample of premature newborns and to characterize this sample using biotyping, serotyping and molecular typing. the results indicated the presence of l. mo ...200819148426
[rapid detection of vibrio parahaemolyticus by taqman-based real-time pcr assay targeting the toxr gene].we designed a pair of specific primers and a taqman fluorescent probe targeting the toxr gene of vibrio parahaemolyticus (vp). after optimizing the conditions, the specialty, sensitivity and reproducibility of the detection method were evaluated. results: (1) the developed real-time pcr assay protocol detected only vp and was not affected by other normal food pathogens such as staphylococcus aureus, salmonela, listeria monocytogenes. (2) the limit of detection was 25 copies of toxr gene in the d ...200819149202
[listeria monocytogenes induced-chronic arthritis in an immunoincompetent child]. 200819128757
listeria monocytogenes bacteremia in a twin pregnancy with differential outcome: fetus papyraceus and a full-term delivery.a 41-year-old saudi woman, gravida 7, para 5, aborta 1 with sickle cell disease at week 12 of gestation of diamniotic dichorionic twin pregnancy was admitted with fever. blood cultures grew listeria monocytogenes. she was treated with intravenous ampicillin and had death of one of the fetuses after 10 days. an ultrasound at 19 weeks of gestation showed a normal intrauterine gestation and the presence of significantly collapsed second twin gestational sac consistent with fetal papyraceus. at 37 w ...200819122927
effects of organic matter on acidic electrolysed water for reduction of foodborne pathogens on lettuce and spinach.to evaluate the efficacy of acidic electrolysed water (ew) in the presence of organic matter (bovine serum) on the inoculated surfaces of lettuce and spinach.200819120630
isolation and characterization of bacteriocin-producing bacteria from the gastrointestinal tract of broiler chickens for probiotic use.to isolate and characterize the bacteriocin-producing bacteria (bpb) from the gastrointestinal tract of broiler chickens for probiotic use.200819120666
anti-listerial activity of bacteriocin-producing lactobacillus curvatus cwbi-b28 and lactobacillus sakei cwbi-b1365 on raw beef and poultry meat.the study aimed to evaluate the effect of the bacteriocins produced by lactobacillus sakei cwbi-b1365 and lactobacillus curvatus cwbi-b28 on the growth and survival of listeria monocytogenes in raw beef and poultry meat.200819120930
concurrent generation of effector and central memory cd8 t cells during vaccinia virus infection.it is generally thought that during the contraction phase of an acute anti-viral t cell reponse, the effector t cells that escape activation-induced cell death eventually differentiate into central memory t cells over the next several weeks. here we report that antigen-specific cd8t cells with the phenotype and function of central memory cells develop concomitantly with effector t cells during vaccinia virus (vv) infection. as soon as 5 days after an intraperitoneal infection with vv, we could i ...200819116651
[detection and identification of seven clinical common pathogenic bacteria by oligonucleotide microarray].using 16s rdna and 23s rdna genes as the target sequences to develop a system based on oligonucleotide microarray and to detect the seven clinical pathogenic bacteria, commonly seen.200819103121
the poloxamer p85 is protective against listeria monocytogenes invasion.listeria monocytogenes remains an important foodborne pathogen, and strategies designed to decrease the susceptibility of selected patient populations to foodborne pathogens are therefore desirable. our objective was to determine if the poloxamer p85 was protective against l. monocytogenes infection. caco-2 cells were treated with 0.1% (w/v) p85 and challenged with 10(7) l. monocytogenes egd for 1 hour. a standard gentamicin protection assay was performed to determine invasion differences betwee ...200818991538
novel functions of type i interferons revealed by infection studies with listeria monocytogenes.infection of cells and mice with listeria monocytogenes stimulates production of type i interferons (ifn). these in turn sensitise the listeria host to lethal sequelae of infection with these bacteria. here, we summarise recent findings on the production and biological effects of type i ifn in the course of l. monocytogenes infection.200818926303
evaluation of enterococcus mundtii st4sa and lactobacillus plantarum 423 as probiotics by using a gastro-intestinal model with infant milk formulations as substrate.enterococcus mundtii st4sa and lactobacillus plantarum 423 produce bacteriocins with activity against a number of gram-positive and gram-negative bacteria. both strains survived intestinal conditions simulated in a gastro-intestinal model (gim) with infant milk formulations as substrate and prevented the growth of listeria monocytogenes scotta. the strains are inhibited by the antibiotics amoxicillin, cefadroxil, roxithromycin and doxycycline, anti-inflammatory medicaments containing meloxicam, ...200818963159
[listeria monocytogenes: old bug, permanent challenge]. 200818949141
[listeria monocytogenes outbreaks: a review of the routes that favor bacterial presence].listeria monocytogenes is a foodborne pathogen that causes serious invasive illness, mainly in certain well-defined high-risk groups, including immunocompromised patients, pregnant women and neonates. l. monocytogenes primarily causes abortion, septicaemia or infections of the central nervous systems. listeriosis outbreaks have mostly been linked to consumption of raw milk or cheese made of unpasteurized milk. previous outbreaks of listeriosis have been linked to a variety of foods especially pr ...200818949142
[listeria monocytogenes infection in pregnancy: experience of pontificia universidad católica de chile university hospital].listeria monocytogenes is gram-positive facultative intracellular pathogen often foodborne and found elsewhere. it is an uncommon cause of illness in the general population. however, it is an important cause of severe infection in neonates, pregnant women, elderly and immunosuppressed patients. listeriosis has unique preference for pregnant women. maternal listeriosis is a diagnostic challenge, and intrauterine infection can lead to severe complications such as amnionitis, preterm labor, spontan ...200818949143
[listeria monocytogenes: report of a rise in pregnant women and literature review].listeria monocytogenes, rare pathogen in the general population, causes serious infections in patients at the extreme ages of life, pregnant woman, and those with immunosuppression. the clinical manifestations are essential to suspect the disease in patients at risk, allowing an early prescription of antimicrobial therapy, before the results of the cultures are available. clinical course and prognosis depends on how early treatment is started and, in pregnant women, the gestational age. in clíni ...200818949144
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