Publications
| Title | Abstract | Year Filter | PMID(sorted ascending) Filter |
|---|
| increased vaccine efficacy against tuberculosis of recombinant mycobacterium bovis bacille calmette-guérin mutants that secrete listeriolysin. | the tuberculosis vaccine mycobacterium bovis bacille calmette-guérin (bcg) was equipped with the membrane-perforating listeriolysin (hly) of listeria monocytogenes, which was shown to improve protection against mycobacterium tuberculosis. following aerosol challenge, the hly-secreting recombinant bcg (hly+ rbcg) vaccine was shown to protect significantly better against aerosol infection with m. tuberculosis than did the parental bcg strain. the isogenic, urease c-deficient hly+ rbcg (deltaurec h ... | 2005 | 16110326 |
| [prokaryotic expression and bioactivity of the listeria monocytogenes listeriolysin o]. | to express the listeria monocytogenes hly gene in escherichia coli and study its primary biological characteristics, hly gene without signal peptide sequence was amplified from listeria monocytogenes serotype 4b by pcr and inserted into t-easy vector. sequencing showed this hly gene was 1518 bp and nucleotide homology was more than 99.8% compared with three listeria monocytogenes hly genes in genbank. the cloned hly gene was then inserted into prokaryotic expression vector pgex-6p-1 and transfor ... | 2004 | 16110954 |
| role of flif and flii of listeria monocytogenes in flagellar assembly and pathogenicity. | flagellar structures have been shown to participate in virulence in a variety of intestinal pathogens. here, we have identified two potential flagellar genes of listeria monocytogenes: lmo0713, encoding a protein similar to the flagellar basal body component flif, and lmo0716, encoding a protein similar to flii, the cognate atpase energizing the flagellar export apparatus. expression of flif and flii appears to be downregulated at 37 degrees c, like that of flaa, encoding flagellin. by construct ... | 2005 | 16113269 |
| pathogenicity and immunogenicity of a vaccine strain of listeria monocytogenes that relies on a suicide plasmid to supply an essential gene product. | listeria monocytogenes is a bacterial pathogen that elicits a strong cellular immune response and thus has potential use as a vaccine vector. an attenuated strain, l. monocytogenes dal dat, produced by deletion of two genes (dal and dat) used for d-alanine synthesis, induces cytotoxic t lymphocytes and protective immunity in mice following infection in the presence of d-alanine. in order to obviate the dependence of l. monocytogenes dal dat on supplemental d-alanine yet retain its attenuation an ... | 2005 | 16113297 |
| sex-dependent susceptibility to listeria monocytogenes infection is mediated by differential interleukin-10 production. | it is well documented that sex-dependent factors affect susceptibility to infection, with most mouse models demonstrating higher resistance in females. we made the unexpected observation that infection with the intracellular bacterium listeria monocytogenes showed an opposite pattern in several commonly used inbred mouse strains: female c57bl/6j, balb/c, c3h/hen, and cba/j mice were significantly more susceptible to listeria infection. the pronounced sensitivity of females to listeria, which was ... | 2005 | 16113316 |
| the mycobacterium tuberculosis esat-6 homologue in listeria monocytogenes is dispensable for growth in vitro and in vivo. | esat-6 is a virulence determinant in mycobacterium tuberculosis and a member of a conserved group of proteins in a variety of other bacteria. a targeted deletion of the homologous gene in listeria was generated, and in contrast to that observed for mycobacteria, this locus was not required for listeria virulence. | 2005 | 16113338 |
| involvement of reactive oxygen intermediate in the enhanced expression of virulence-associated genes of listeria monocytogenes inside activated macrophages. | listeriolysin o encoded by 1,587 bp hly is the essential virulence factor of listeria monocytogenes that replicates in the cytosolic space after escaping from phagosome of macrophages. by using murine macrophage-like j774.1 cells with or without activation by ifn-gamma plus lps, the expression of both hly and its positive regulator prfa was monitored by means of rt-pcr. in activated j774.1 cells, the level of hly expression was enhanced although the multiplication of bacteria was significantly s ... | 2005 | 16113511 |
| listeria hijacks the clathrin-dependent endocytic machinery to invade mammalian cells. | the bacterial pathogen listeria monocytogenes uses the surface protein inlb to invade a variety of cell types. the interaction of inlb with the hepatocyte growth-factor receptor, met, is crucial for infection to occur. remarkably, the ubiquitin ligase cbl is rapidly recruited to inlb-activated met. recent studies have shown that ligand-dependent endocytosis of met and other receptor tyrosine kinases is triggered by monoubiquitination of the receptor, a process that is mediated by cbl. here, we s ... | 2005 | 16113677 |
| a study on inhibitory effects of siğla tree (liquidambar orientalis mill. var. orientalis) storax against several bacteria. | in this study, siğla (liquidambar orientalis mill.) storax (styrax) was investigated for antibacterial activity against aeromonas hydrophila, bacillus amyloliquefaciens, b. brevis, b. cereus, b. megaterium, b. subtilis, corynebacterium xerosis, enterobacter aerogenes, enterococcus faecalis, escherichia coli, e. coli o157:h7, klebsiella pneumoniae, listeria monocytogenes, micrococcus luteus, mycobacterium smegmatis, proteus vulgaris, pseudomonas aeruginosa, p. fluorescens, staphylococcus aureus a ... | 2005 | 16114094 |
| intracellular bacteria differentially regulated endothelial cytokine release by mapk-dependent histone modification. | epigenetic histone modifications contribute to the regulation of eukaryotic gene transcription. the role of epigenetic regulation in immunity to intracellular pathogens is poorly understood. we tested the hypothesis that epigenetic histone modifications influence cytokine expression by intracellular bacteria. intracellular listeria monocytogenes, but not noninvasive listeria innocua, induced release of distinct cc and cxc chemokines, as well as th1 and th2 cytokines and growth factors by endothe ... | 2005 | 16116170 |
| in vivo generation of pathogen-specific th1 cells in the absence of the ifn-gamma receptor. | the precise mechanisms that govern the commitment of cd4 t cells to become th1 or th2 cells in vivo are incompletely understood. recent experiments demonstrate colocalization of the ifn-gammar chains with the tcr during activation of naive cd4 t cells, suggesting that association of these molecules may be involved in determining lineage commitment. to test the role of ifn-gamma and its receptor in the generation of th1 ag-specific cd4 t cells, we analyzed mice after infection with listeria monoc ... | 2005 | 16116201 |
| listeria monocytogenes phosphatidylinositol-specific phospholipase c has evolved for virulence by greatly reduced activity on gpi anchors. | listeria monocytogenes phosphatidylinositol-specific phospholipase c (pi-plc) plays a critical role in escape of this human pathogen from host cell vacuoles. unlike classical bacterial pi-plcs, the l. monocytogenes enzyme has very weak activity on glycosylphosphatidylinositol (gpi)-anchored proteins. previous crystal structure analysis has revealed that a small beta-strand (vb) is present in bacillus cereus pi-plc and is absent in the enzyme from l. monocytogenes. this vb beta-strand in b. cereu ... | 2005 | 16118276 |
| behavior of listeria monocytogenes in ph-modified chicken salad during refrigerated storage. | the growth and inactivation kinetics of l. monocytogenes were evaluated at ph 4.0, 4.6, and 5.2 during storage at 5.0 degrees c, 7.2 degrees c, and 21.1 degrees c (41 degrees f, 45 degrees f, and 70 degrees f). using commercially produced pasteurized chicken salad, the authors adjusted the ph levels with acetic acid or sodium acetate. samples of 25 g each of the ph-modified salad were inoculated to approximately 1 x 10(6) cells per gram with a three-strain mixture of l. monocytogenes and stored ... | 2005 | 16121485 |
| expression and purification of human antimicrobial peptide, dermcidin, in escherichia coli. | human dermcidin, an anionic antimicrobial peptide expressed in the pons of the brain and the sweat glands, displays antimicrobial activity against pathogenic microorganisms such as staphylococcus aureus and candida albicans. here, we describe the recombinant production of a 48 amino acid dermcidin variant with c-terminal homoserine lactone (dcd-1hsl). dermcidin coding sequence was cloned downstream of a 125 amino acid ketosteroid isomerase gene and upstream of a his6tag sequence in pet-31b(+) ve ... | 2006 | 16125410 |
| a case of rhombencephalitis caused by listeria monocytogenes successfully treated with linezolid. | infection of the central nervous system due to listeria monocytogenes is uncommon. the treatment of choice is ampicillin. we describe in this report a case of rhombencephalitis caused by listeria monocytogenes successfully treated with linezolid. to the best of our knowledge, this is the first case in which linezolid was used to treat infection of the central nervous system caused by this organism. | 2006 | 16126275 |
| in vitro activity of daptomycin against clinical isolates of gram-positive bacteria. | we determined the activity of daptomycin, a recently fda-approved antimicrobial agent, against clinical isolates of gram-positive bacteria, including viridans group streptococci (16 streptococcus mitis species group, 12 s. mutans species group, 9 s. anginosus species group, 8 s. sanguinis species group, 5 s. salivarius species group) from patients with infective endocarditis, 32 methicillin-resistant staphylococcus aureus, 32 high-level penicillin-resistant streptococcus pneumoniae, 38 vancomyci ... | 2005 | 16133715 |
| no indication for a defect in toll-like receptor signaling in patients with hyper-ige syndrome. | hyper-ige syndrome is a rare primary immunodeficiency of unknown etiology characterized by recurrent infections of the skin and respiratory system, chronic eczema, elevated total serum ige, and a variety of associated skeletal symptoms. recent reports about susceptibility to pyogenic bacterial infections and high ige levels in patients and animals with defects in toll-like receptor (tlr) signaling pathways prompted us to search for tlr signaling defects as an underlying cause of hyper-ige syndro ... | 2005 | 16133988 |
| [listeria monocytogenes in women of reproductive age]. | listeria monocytogenes (lm) is gram-positive bacteria linear shaped which grows good also at refrigerator temperature (4 degrees c). the bacteria is resistant on high and low temperatures. this bacteria can be found in the dirt, rotted vegetation, vegetables and fruit, milk and dairy products, and also in the meat and processed meat. this bacteria cause disease called listeriosis. this bacteria attacks at first people with weak immune system like infants, pregnant women, people with chronic dise ... | 2005 | 16134751 |
| semiparametric methods for mapping quantitative trait loci with censored data. | statistical methods for the detection of genes influencing quantitative traits with the aid of genetic markers are well developed for normally distributed, fully observed phenotypes. many experiments are concerned with failure-time phenotypes, which have skewed distributions and which are usually subject to censoring because of random loss to follow-up, failures from competing causes, or limited duration of the experiment. in this article, we develop semiparametric statistical methods for mappin ... | 2005 | 16135030 |
| the adjuvant activity of cpg dna requires t-bet expression in dendritic cells. | treatment with synthetic oligodeoxynucleotides containing cpg motifs (cpg odns) is remarkably protective against otherwise lethal infection. here, we describe an essential role for the transcription factor t-bet in mediating the protective function of cpg odns. loss of t-bet in conventional cd11c(hi) dendritic cells (dcs) and in plasmacytoid dcs impaired production of ifns. strikingly, in contrast to rag2-/- mice, rag2-/- mice that also lacked t-bet (dko) could not be rescued from lethal listeri ... | 2005 | 16135562 |
| decrease in serum procalcitonin levels over time during treatment of acute bacterial meningitis. | the aim of this study was to describe the change in serum procalcitonin levels during treatment for community-acquired acute bacterial meningitis. | 2005 | 16137346 |
| toll-like receptor-2 deficiency is associated with enhanced brain tnf gene expression during pneumococcal meningitis. | tnf is a marker of disease activity in bacterial meningitis. to investigate tnf modulation by toll-like receptor-2 (tlr2), we studied temporal and anatomical expression patterns of tlr2 and tnf in a pneumococcal meningitis model in wild type (wt) and tlr2(-/-) mice. we show by in situ hybridization that transcripts of tlr2 and of the comolecules cd14, md-2, tlr1/6 strongly increased and colocalized with tnf in cd45-positive infiltrating cells in the ventricles, corpus callosum and the meninges. ... | 2005 | 16137770 |
| listeria monocytogenes egd lacking penicillin-binding protein 5 (pbp5) produces a thicker cell wall. | we report on the cloning of the structural gene for penicillin-binding protein 5 (pbp5), lmo2754. we also describe the enzymatic activity of pbp5 and characterize a mutant lacking this activity. purified pbp5 has dd-carboxypeptidase activity, removing the terminal d-alanine residue from murein pentapeptide side chains. it shows higher activity against low molecular weight monomeric pentapeptide substrates compared to dimeric pentapeptide compound. similarly, pbp5 preferentially cleaves monomeric ... | 2005 | 16140473 |
| [pulse-electrotypes of listeria monocytogenes strains, isolated in moscow]. | the characterization of the pulse-electrotypes of l. monocytogenes, isolated in 2003-2004 in moscow from different sources, is presented. among the cultures, isolated from humans, one outbreak pulse electrotype was detected and from different objects in buildings where a wide variety of food products was produced several probably related and unrelated pulse-electrotypes were obtained. the conclusion was made that several independent l. monocytogenes clones existed on the territory of moscow, and ... | 2005 | 16146221 |
| the ikappab protein bcl-3 negatively regulates transcription of the il-10 gene in macrophages. | nf-kappab/rel transcription factors, implicated in inflammatory and immune responses against pathogens, are regulated by ikappab proteins. the physiological and molecular function of the ikappab family member bcl-3 is understood only poorly. in this study, the role of bcl-3 in an innate immune response was examined by gene targeting. we demonstrate that bcl-3(-/-) mice are highly susceptible to listeria monocytogenes infection. this correlates with diminished production of il-12 p70 and ifn-gamm ... | 2005 | 16148099 |
| fusion to listeriolysin o and delivery by listeria monocytogenes enhances the immunogenicity of her-2/neu and reveals subdominant epitopes in the fvb/n mouse. | five overlapping fragments of rat her-2/neu have been expressed in recombinant listeria monocytogenes. each fragment of her-2/neu is secreted as a fusion protein with a truncated, nonhemolytic form of listeriolysin o (llo). lm-llo-ec1, lm-llo-ec2, and lm-llo-ec3 overlap the extracellular domain of her-2/neu, whereas lm-llo-ic1 and lm-llo-ic2 span the intracellular domain. all five strains controlled the growth of established nt-2 tumors, a rat her-2/neu-expressing tumor line derived from a spont ... | 2005 | 16148111 |
| assessment of interleukin-12, gamma interferon, and tumor necrosis factor alpha secretion in sera from mice fed with dietary lipids during different stages of listeria monocytogenes infection. | recent experimental observations have determined that long-chain n-3 polyunsaturated fatty acids suppress immune functions and are involved in the reduction of infectious disease resistance. balb/c mice were fed for 4 weeks with one of four diets containing either olive oil (oo), fish oil (fo), hydrogenated coconut oil, or a low fat level. interleukin-12p70 (il-12p70), gamma interferon (ifn-gamma), and tumor necrosis factor alpha (tnf-alpha) production in the sera of mice fed these diets and cha ... | 2005 | 16148177 |
| [pathophysiology and epidemiology of listeriosis]. | listeriosis is a severe infectious disease occurring both in humans and in most other animal species. it is caused by a gram-positive bacterium, listeria monocytogenes. this facultative intracellular pathogen is widespread in nature and infects humans through contaminated food. after ingestion, bacteria can cross the gut mucosa and disseminate via the bloodstream. they may then invade the central nervous system and the placenta, causing severe meningoencephalitis and fetoplacental infections, re ... | 2005 | 16149214 |
| omega-3 polyunsaturated fatty acid impairment of early host resistance against listeria monocytogenes infection is independent of neutrophil infiltration and function. | the primary objective of this study was to determine whether the n-3 pufa-mediated changes in host response to a listeria monocytogenes infection (e.g., cytokine production and bacterial clearance) were dependent upon neutrophils. balb/c mice were fed one of two semi-purified diets that contained either 0 or 41 g of n-3 pufa/kg. after 4 week, mice were injected with a neutrophil-depleting (rb6-8c5) or isotype-control antibody 24 h prior to infection. bacterial clearance from the liver and spleen ... | 2005 | 16150430 |
| membrane damage and microbial inactivation by chlorine in the absence and presence of a chlorine-demanding substrate. | the relationship between cell inactivation and membrane damage was studied in two gram-positive organisms, listeria monocytogenes and bacillus subtilis, and two gram-negative organisms, yersinia enterocolitica and escherichia coli, exposed to chlorine in the absence and presence of 150 ppm of organic matter (trypticase soy broth). l. monocytogenes and b. subtilis were more resistant to chlorine in distilled water. the addition of small amounts of organic matter to the chlorination medium drastic ... | 2005 | 16151082 |
| identification of genes induced in listeria monocytogenes during growth and attachment to cut cabbage, using differential display. | the food-borne pathogen listeria monocytogenes is a ubiquitous soil bacterium with the potential to contaminate fresh produce during cultivation and postharvest processing. in order to identify potential mechanisms by which l. monocytogenes may successfully attach to and colonize fresh produce, gene expression in l. monocytogenes cells inoculated onto fresh-cut cabbage was compared to gene expression in cells grown under control conditions. differential display of reverse transcriptase pcr fragm ... | 2005 | 16151109 |
| surface attachment of listeria monocytogenes is induced by sublethal concentrations of alcohol at low temperatures. | sublethal concentrations of ethanol or isopropanol increased attachment of listeria monocytogenes at 10, 20, or 30 degrees c; no induction occurred at 37 degrees c. the alcohol induction phenotype was retained in sigb and cesrk mutants; however, the degree of induction was affected. these results suggest that alcohol may contribute to the persistence of l. monocytogenes. | 2005 | 16151157 |
| secretion of recombinant pediocin pa-1 by bifidobacterium longum, using the signal sequence for bifidobacterial alpha-amylase. | a recombinant dna, encoding the chimeric protein of the signal sequence for bifidobacterial alpha-amylase mature pediocin pa-1, was introduced into bifidobacterium longum mg1. biologically active pediocin pa-1 was successfully secreted from the strain and showed bactericidal activity against listeria monocytogenes and the same molecular mass as native pediocin pa-1. | 2005 | 16151166 |
| molecular characterization of listeria monocytogenes of the serotype 4b complex (4b, 4d, 4e) from two turkey processing plants. | most foodborne outbreaks of listeriosis have been found to involve a small number of closely related strains of listeria monocytogenes serotype 4b. the ecology of these organisms and their reservoirs in nature or in the processing plant environment, however, remain poorly understood. surveys of environmental samples from two turkey processing plants in the united states indicated presence of l. monocytogenes of the serotype 4b complex (serotype 4b and the closely related serotypes 4d and 4e). in ... | 2005 | 16156700 |
| prevalence of antimicrobial resistance genes in listeria monocytogenes isolated from dairy farms. | antimicrobial resistance of listeria monocytogenes (n = 38) isolated from the four dairy farms to 15 antimicrobial agents was evaluated. all 38 l. monocytogenes isolates from the four farms evaluated were resistant to more than one antimicrobial in different combinations. all l. monocytogenes isolates evaluated were resistant to cephalosporin c (minimum inhibitory concentration [mic] > or = 512 microg/ml), streptomycin (mic > or = 32) and trimethoprim (mic > or = 512). most l. monocytogenes isol ... | 2005 | 16156701 |
| cetylpyridinium chloride treatment of ready-to-eat polish sausages: effects on listeria monocytogenes populations and quality attributes. | ready-to-eat polish sausages were inoculated with listeria monocytogenes at either low (3 log(10) cfu/g) or high (7 log(10) cfu/g) levels, treated with a 1% cetylpyridinium chloride (cpc) spray (20 psi, 25 degrees c, 30-sec exposure), vacuum packaged, and stored for 42 days at 0 degrees c or 4 degrees c. non-inoculated samples were similarly treated, packaged, and stored to determine effects on color, firmness, and naturally occurring bacterial populations such as aerobic plate counts (apc). at ... | 2005 | 16156704 |
| predictive modelling and validation of listeria innocua growth at superatmospheric oxygen and carbon dioxide concentrations. | the effect of superatmospheric oxygen and carbon dioxide concentrations on the growth of listeria innocua, which was used as a model organism for the pathogen listeria monocytogenes, was evaluated. the bacteria were grown on a nutrient agar surface at 7 degrees c. three carbon dioxide levels (0%, 12.5% and 25%) were combined with different levels of high oxygen concentrations (above 20%) based on a mixture design. the applied oxygen concentrations did not significantly influence the growth. high ... | 2005 | 16157408 |
| use of rna interference in drosophila s2 cells to identify host pathways controlling compartmentalization of an intracellular pathogen. | three genome-wide rna interference screens were performed in drosophila s2 cells to dissect the contribution of host processes to listeria monocytogenes entry, vacuolar escape, and intracellular growth. among the 116 genes identified, several host pathways previously unrecognized as playing a role in listerial pathogenesis were identified: knockdowns affecting vacuolar trafficking to and from the multivesicular body bypassed the requirement for the essential pore-forming toxin listeriolysin o in ... | 2005 | 16157870 |
| statistical analysis of inactivation of listeria monocytogenes subjected to high hydrostatic pressure and heat in milk buffer. | previous unpublished experimental results of fractional factorial experiments showed that significant external factors affecting high-pressure processing (hpp) inactivation were pressure, temperature, and pressure holding time. based on these results, response surface methodology (rsm) was employed in the present work, and a quadratic equation for hpp inactivation was built with rsm. by analyzing response surface plots and their corresponding contour plots and by solving the quadratic equation, ... | 2006 | 16158281 |
| magnetic nanoparticle-antibody conjugates for the separation of escherichia coli o157:h7 in ground beef. | the immunomagnetic separation with magnetic nanoparticle-antibody conjugates (mncs) was investigated and evaluated for the detection of escherichia coli o157:h7 in ground beef samples. mncs were prepared by immobilizing biotin-labeled polyclonal goat anti-e. coli antibodies onto streptavidin-coated magnetic nanoparticles. for bacterial separation, mncs were mixed with inoculated ground beef samples, then nanoparticle-antibody-e. coli o157:h7 complexes were separated from food matrix with a magne ... | 2005 | 16161677 |
| antimicrobial activity of cetylpyridinium chloride against listeria monocytogenes on frankfurters and subsequent effect on quality attributest. | frankfurters inoculated with listeria monocytogenes were treated with 1% cetylpyridinium chloride (cpc) or with 1% cpc followed by a water rinse at various combinations of spray temperatures (25, 40, and 55 degrees c), spray pressures (20, 25, and 35 psi), and times of exposure (30, 40, and 60 s). no significant differences (p > 0.05) were observed in the reductions achieved by 1% cpc + water wash and those achieved with 1% cpc treatment alone. l. monocytogenes populations were reduced by ca. 1. ... | 2005 | 16161680 |
| a field study of the microbiological quality of fresh produce. | the centers for disease control and prevention has reported that foodborne disease outbreaks associated with fruits and vegetables increased during the past decade. this study was conducted to characterize the routes of microbial contamination in produce and to identify areas of potential contamination from production through postharvest handling. we report here the levels of bacterial indicator organisms and the prevalence of selected pathogens in produce samples collected from the southern uni ... | 2005 | 16161682 |
| occurrence of campylobacter and listeria monocytogenes in a poultry processing plant. | the occurrence of campylobacter and listeria monocytogenes was studied in 645 samples from surfaces, water, and poultry products (chicken carcasses, chicken parts, viscera, and spoils) in a poultry processing plant in southern brazil. the automated mini-vidas system was used to detect the presence of campylobacter and l. monocytogenes on the samples. the positive samples were confirmed by conventional methods. campylobacter and l. monocytogenes were found in 16.6 and 35.6% of the analyzed sample ... | 2005 | 16161691 |
| multiplex pcr assay simplifies serotyping and sequence typing of listeria monocytogenes associated with human outbreaks. | listeria monocytogenes serotypes 1/2a and 4b are responsible for the majority of cases of human listeriosis worldwide. in this study, a multiplex pcr assay was developed to allow rapid identification and easily interpretable differentiation of serotypes 1/2a and 4b from other serotypes of l. monocytogenes by simultaneously targeting two virulence genes (inlb and inlc) and two serotype-specific genes (orf2372 and imo0171). a subsequent gel extraction and sequence typing analysis of the highly pol ... | 2005 | 16161692 |
| achieving continuous improvement in reductions in foodborne listeriosis--a risk-based approach. | listeria monocytogenes is a foodborne pathogen that can cause listeriosis, a severe disease that can lead to septicemia, meningitis, and spontaneous abortion. ongoing efforts are needed to further reduce the incidence of listeriosis, due to its high mortality rate. the focus of this report is the use of a risk-based approach to identify strategies that will have the greatest impact on reducing foodborne listeriosis. a continuum of risk for listeriosis is observed in the human population, ranging ... | 2005 | 16161698 |
| rat cytomegalovirus and listeria monocytogenes infection enhance chronic rejection after allogenic rat lung transplantation. | the role of infection in the pathomechanism of obliterative bronchiolitis (ob) after human lung transplantation is controversial. in a rat lung transplantation model, we analyzed the effect of viral [rat cytomegalovirus (rcmv)] and bacterial infection [listeria monocytogenes (lm)] on the development of chronic allograft rejection. fisher rats underwent single left lung transplantation with allografts from lewis rats. postoperatively, animals were infected with either rcmv or lm, or served as non ... | 2005 | 16162104 |
| effect of laser and environmental parameters on reducing microbial contamination of stainless steel surfaces with nd:yag laser irradiation. | the effect of laser (pulse repetition frequency, pulse energy and exposure time) and environmental parameters (ph, nacl concentration and wet or dry samples) of nd:yag laser decontamination of stainless steel inoculated with escherichia coli, staphylococcus aureus and listeria monocytogenes was investigated. | 2005 | 16162246 |
| antimicrobial susceptibility of nisin resistant listeria monocytogenes of dairy origin. | the antibiotic susceptibility of wild listeria monocytogenes strains and their corresponding nisin resistant variants was assessed. the resistant strains were more sensitive to most of the tested antibiotics than their wild-type counterparts. a slight increase in mic was observed for a few antibiotics including the membrane disturbing polymixin b. cross-resistance was detected with two synthetic antimicrobial peptides. a lower c15/c17 ratio in the membrane fatty acid composition of the nisin res ... | 2005 | 16165322 |
| novel collectin/c1q receptor mediates mast cell activation and innate immunity. | mast cells play a critical role in innate immunity, allergy, and autoimmune diseases. the receptor/ligand interactions that mediate mast cell activation are poorly defined. the alpha2beta1 integrin, a receptor for collagens, laminins, decorin, e-cadherin, matrix metalloproteinase-1 (mmp-1), endorepellin, and several viruses, has been implicated in normal developmental, inflammatory, and oncogenic processes. we recently reported that alpha2 integrin subunit-deficient mice exhibited markedly dimin ... | 2006 | 16166590 |
| conductivity and ph dual detection of growth profile of healthy and stressed listeria monocytogenes. | in this study, growth of listeria monocytogenes in a low conductivity growth medium (lcgm) was simultaneously monitored by conductivity and ph measurements. detection times obtained from the conductivity and ph growth curves were inversely related to the initial concentration of l. monocytogenes in the medium. linear responses were found by plotting detection times obtained from both conductivity and ph growth curves as a function of initial cell concentration in the range of 10(2) to 10(7) cfu/ ... | 2005 | 16167332 |
| a novel method for measuring lag times in division of individual bacterial cells using image analysis. | a method is presented for determining the time to first division of individual bacterial cells growing on agar media. bacteria were inoculated onto agar-coated slides and viewed by phase-contrast microscopy. digital images of the growing bacteria were captured at intervals and the time to first division estimated by calculating the "box area ratio". this is the area of the smallest rectangle that can be drawn around an object, divided by the area of the object itself. the box area ratios of cell ... | 2006 | 16169621 |
| immunization with a gene encoding granulocyte-macrophage colony-stimulating factor inserted with a single helper t-cell epitope of an intracellular bacterium induces a specific t-cell subset and protective immunity. | we evaluated here the effect of immunization with a gene encoding granulocyte-macrophage colony-stimulating factor (gm-csf) inserted with a helper t cell (th) epitope, listeriolysin o (llo) 215-226 derived from listeria monocytogenes on induction of a specific th by gene gun bombardment. immunization of c3h/he mice with pgm215m plasmid encoding murine gm-csf inserted with llo 215-226 th epitope gave the epitope-specific proliferative responses of cd4(+) t lymphocytes. in addition, specific inter ... | 2006 | 16169635 |
| genomic fingerprinting of bacteriocin-producer strains of staphylococcus aureus. | among 363 strains of staphylococcus aureus, 21 were shown to produce bacteriocins (bac), antimicrobial peptides with potential biotechnological applications. this collection includes strains which are either isolated from food, patients and healthy cattle, or are involved in subclinical bovine mastitis. from these 21 strains, 17 were shown to carry closely-related 8.0-kb bac plasmids encoding bacteriocins either identical to or similar to aureocin a70, a bacteriocin able to inhibit strains of li ... | 2005 | 16171981 |
| high pressure processing for food safety. | food preservation using high pressure is a promising technique in food industry as it offers numerous opportunities for developing new foods with extended shelf-life, high nutritional value and excellent organoleptic characteristics. high pressure is an alternative to thermal processing. the resistance of microorganisms to pressure varies considerably depending on the pressure range applied, temperature and treatment duration, and type of microorganism. generally, gram-positive bacteria are more ... | 2005 | 16175246 |
| expression of t-bet by cd4 t cells is essential for resistance to salmonella infection. | despite the recognized role of the t-bet transcription factor in the differentiation of th1 cells, t-bet-deficient mice can develop small numbers of ifn-gamma-producing cd4 t cells. although these are not sufficient to allow normal handling of some pathogens, t-bet-deficient mice do resolve infection with the intracellular pathogen listeria monocytogenes. in contrast, we report that expression of t-bet is required for resistance to salmonella infection. t-bet-deficient mice succumbed to infectio ... | 2005 | 16177105 |
| a novel role of cd30/cd30 ligand signaling in the generation of long-lived memory cd8+ t cells. | memory cd8+ t cells can be divided into two subsets, central memory (t(cm)) and effector memory (t(em)) cd8+ t cells. we found that cd30, a member of the tnfr-associated factor (traf)-linked tnfr superfamily, signaling is involved in differentiation of long-lived cd8+ t(cm) cells following listeria monocytogenes infection. although cd8+ t(em) cells transiently accumulated in the nonlymphoid tissues of cd30 ligand (cd153-/-) mice after infection, long-lived memory cd8+ t(cm) cells were poorly gen ... | 2005 | 16177108 |
| th1 cytokines are essential for placental immunity to listeria monocytogenes. | the fetal allograft poses an immunological challenge: how is it protected while immunity to pathogens, particularly those that replicate in the placenta, is maintained? several theories have been proposed to explain this fetal protection, including a pregnancy-based bias towards a th2 rather than th1 cytokine profile in order to avoid generating cytotoxic t cells that could threaten the fetus. listeria monocytogenes preferentially replicates in the placenta and systemically requires a th1 respon ... | 2005 | 16177303 |
| characterization of listeria monocytogenes expressing anthrolysin o and phosphatidylinositol-specific phospholipase c from bacillus anthracis. | two virulence factors of listeria monocytogenes, listeriolysin o (llo) and phosphatidylinositol-specific phospholipase c (pi-plc), mediate escape of this pathogen from the phagocytic vacuole of macrophages, thereby allowing the bacterium access to the host cell cytosol for growth and spread to neighboring cells. we characterized their orthologs from bacillus anthracis by expressing them in l. monocytogenes and characterizing their contribution to bacterial intracellular growth and cell-to-cell s ... | 2005 | 16177340 |
| lpxtg protein inlj, a newly identified internalin involved in listeria monocytogenes virulence. | listeria monocytogenes expresses surface proteins covalently anchored to the peptidoglycan by sortase enzymes. inactivation of srta attenuates listeria virulence in mice (h. bierne, s. k. mazmanian, m. trost, m. g. pucciarelli, g. liu, p. dehoux, l. jansch, f. garcia-del portillo, o. schneewind, and p. cossart, mol. microbiol. 43:869-881, 2002). we show here that an srta mutant is more attenuated than an internalin mutant in orally infected guinea pigs and transgenic mice expressing human e-cadh ... | 2005 | 16177371 |
| [current topics and risk management of listeria monocytogenes in food]. | 2005 | 16180692 | |
| p-ser-hpr--a link between carbon metabolism and the virulence of some pathogenic bacteria. | hpr kinase/phosphorylase phosphorylates hpr, a phosphocarrier protein of the phosphoenolpyruvate:carbohydrate phosphotransferase system, at serine-46. p-ser-hpr is the central regulator of carbon metabolism in gram-positive bacteria, but also plays a role in virulence development of certain pathogens. in listeria monocytogenes, several virulence genes, which depend on the transcription activator prfa, are repressed by glucose, fructose, etc., in a catabolite repressor (ccpa)-independent mechanis ... | 2005 | 16182622 |
| arhgap10 is necessary for alpha-catenin recruitment at adherens junctions and for listeria invasion. | e-cadherin mediates the formation of adherens junctions between epithelial cells. it serves as a receptor for listeria monocytogenes, a bacterial pathogen that enters epithelial cells. the l. monocytogenes surface protein, inla, interacts with the extracellular domain of e-cadherin. in adherens junctions, this ectodomain is involved in homophilic interactions whereas the cytoplasmic domain binds beta-catenin, which then recruits alpha-catenin. alpha-catenin binds to actin directly, or indirectly ... | 2005 | 16184169 |
| automated image analysis of bacterial colony growth as a tool to study individual lag time distributions of immobilized cells. | a method to determine the individual lag time (lag) distributions of immobilized bacteria was presented. the method was based on the image analysis of the bacterial colony growth. the lag distributions were retrieved from the distributions of the detection times (td) required to form macroscopically visible colonies. using this method, the lag distributions on agar for listeria monocytogenes cells previously subjected to two situations reproducing conditions encountered during the contamination ... | 2006 | 16185781 |
| rhesus macaques with high levels of vaccine induced ifn-gamma producing cells better control viral set-point following challenge with siv239. | hiv-1 specific cellular immune responses play a significant part in controlling hiv-1 viral replication and are an important component of an hiv-1 vaccine induced immune response. we reported earlier that recombinant dna vaccine delivered intramuscularly, and recombinant listeria monocytogenes, delivered orally induced cd8+ and cd4+ t cell immune responses in rhesus macaques and that this vaccine protocol showed partial protection against an siv239 challenge. in this paper, we have analyzed the ... | 2006 | 16185790 |
| [lymphocytis meningitis: listeria monocytogenes is a potential risk in a immunocompetent child]. | meningoencephalitis due to listeria monocytogenes is a rare and serious form of brainstem infection in childhood. observation: we report the case of a 7 year-old girl presenting lymphocytic meningitis with a high crp level. parenteral antibiotics combining ceftriaxone and vancomycine led initially to clinical improvement. ten days later, secondary brainstem inflammation with hydrocephalus appeared and led to the detection of l. monocytogenes during external ventricular bypass. conclusion: this o ... | 2005 | 16185855 |
| effectiveness of steam pasteurization in controlling microbiological hazards of cull cow carcasses in a commercial plant. | the purpose of the study, carried out in a beef processing plant, was to evaluate the effectiveness of a new prototype for steam pasteurization treatment in controlling microbiological hazards. samples were taken by swabbing randomly selected sites before and after pasteurization and again after chilling to obtain total aerobic counts (tac), total coliform counts (tcc), and generic escherichia coli counts (ecc) on petrifilm plates and to determine the prevalence of salmonella spp., listeria mono ... | 2005 | 16187550 |
| bacteriophage p100 for control of listeria monocytogenes in foods: genome sequence, bioinformatic analyses, oral toxicity study, and application. | listeria monocytogenes is an opportunistic foodborne pathogen responsible for listeriosis, a frequently fatal infection. this investigation represents a comprehensive approach to characterize and evaluate the broad host range, strictly virulent phage p100, which can infect and kill a majority of listeria monocytogenes strains. first, the complete nucleotide sequence (131,384 basepairs) of the genome of p100 was determined, predicted to encode 174 gene products and 18 trnas. bioinformatic analyse ... | 2005 | 16188359 |
| potential antimicrobial effects of human lactoferrin against oral infection with listeria monocytogenes in mice. | listeria monocytogenes is a food-borne pathogen that causes serious listeriosis in humans. antimicrobial effects of human lactoferrin (hlf) against l. monocytogenes have been clearly demonstrated in in vitro studies. however, in vivo studies have not been reported yet. this study investigated whether the oral administration of hlf could inhibit oral infection of listeria in balb/c mice. the mics for several strains of l. monocytogenes were determined, and the most sensitive strain was used for t ... | 2005 | 16192436 |
| neuropathological findings in 9 cases of listeria monocytogenes brain stem encephalitis. | brain stem encephalitis is a particular manifestation of infection with the bacterium listeria monocytogenes. here, we present the neuropathological findings in 9 such cases. in the brain stem, the inflammatory infiltrates were located predominantly within nuclei and tracts of cranial nerves innervating the oropharynx. these findings support the hypothesis that the food-borne bacterium listeria monocytogenes invades the brain stem along cranial nerves. | 2005 | 16196384 |
| symmetry-breaking motility. | locomotion of bacteria by actin polymerization and in vitro motion of spherical beads coated with a protein catalyzing polymerization are examples of active motility. starting from a simple model of forces locally normal to the surface of a bead, we construct a phenomenological equation for its motion. the singularities at a continuous transition between moving and stationary beads are shown to be related to the symmetries of its shape. universal features of the phase behavior are calculated ana ... | 2005 | 16197183 |
| phospholipase c-gamma2 is essential for nk cell cytotoxicity and innate immunity to malignant and virally infected cells. | phospholipase c-gamma2 (plc-gamma2) is a key component of signal transduction in leukocytes. in natural killer (nk) cells, plc-gamma2 is pivotal for cellular cytotoxicity; however, it is not known which steps of the cytolytic machinery it regulates. we found that plc-gamma2-deficient nk cells formed conjugates with target cells and polarized the microtubule-organizing center, but failed to secrete cytotoxic granules, due to defective calcium mobilization. consequently, cytotoxicity was completel ... | 2006 | 16204312 |
| identification and characterization of di- and tripeptide transporter dtpt of listeria monocytogenes egd-e. | listeria monocytogenes is a gram-positive intracellular pathogen responsible for opportunistic infections in humans and animals. here we identified and characterized the dtpt gene (lmo0555) of l. monocytogenes egd-e, encoding the di- and tripeptide transporter, and assessed its role in growth under various environmental conditions as well as in the virulence of l. monocytogenes. uptake of the dipeptide pro-[14c]ala was mediated by the dtpt transporter and was abrogated in a deltadtpt isogenic de ... | 2005 | 16204487 |
| long-term survival of pathogenic and sanitation indicator bacteria in experimental biowaste composts. | for economic, agricultural, and environmental reasons, composting is frequently used for organic waste recycling. one approach to limiting the potential risk from bacterial food-borne illnesses is to ensure that soil amendments and organic fertilizers are disinfected. however, more knowledge concerning the microbiological safety of composted substrates other than sludge and manure is necessary. experimental in-vessel biowaste composts were used to study the survival of seeded listeria monocytoge ... | 2005 | 16204488 |
| microarray analysis of a two-component regulatory system involved in acid resistance and proteolytic activity in lactobacillus acidophilus. | two-component regulatory systems are one primary mechanism for environmental sensing and signal transduction. annotation of the complete genome sequence of the probiotic bacterium lactobacillus acidophilus ncfm revealed nine two-component regulatory systems. in this study, the histidine protein kinase of a two-component regulatory system (lba1524hpk-lba1525rr), similar to the acid-related system lisrk from listeria monocytogenes (p. d. cotter et al., j. bacteriol. 181:6840-6843, 1999), was inser ... | 2005 | 16204490 |
| genetic diversity of listeria monocytogenes strains from a high-prevalence dairy farm. | listeria monocytogenes is a significant food-borne human and veterinary pathogen. contaminated silage commonly leads to disease in livestock, but the pervasive nature of the bacterium can make it difficult to identify the source of infection. an investigation of bovine listeriosis that occurred on a pacific northwest dairy farm ("farm a") revealed that the clinical strain was closely related to fecal strains from asymptomatic cows, and that farm environment was heavily contaminated with a divers ... | 2005 | 16204502 |
| investigation of specific substitutions in virulence genes characterizing phenotypic groups of low-virulence field strains of listeria monocytogenes. | several models have shown that virulence varies from one strain of listeria monocytogenes to another, but little is known about the cause of low virulence. twenty-six field l. monocytogenes strains were shown to be of low virulence in a plaque-forming assay and in a subcutaneous inoculation test in mice. using the results of cell infection assays and phospholipase activities, the low-virulence strains were assigned to one of four groups by cluster analysis and then virulence-related genes were s ... | 2005 | 16204519 |
| rsa 2004: combined basic research satellite symposium-mechanisms of alcohol-mediated organ and tissue damage: inflammation and immunity and alcohol and mitochondrial metabolism: at the crossroads of life and death session one: alcohol, cellular and organ damage. | this article summarizes content proceedings of a satellite meeting held at the 2004 research society on alcoholism annual scientific meeting in vancouver, canada. the aim of the satellite conference was to facilitate the interaction of scientists investigating the mechanisms of alcohol-mediated organ or tissue damage, and enable the discussion and sharing of new ideas and concepts that may be common in each of the organs or tissues affected by chronic ethanol consumption. the original planned pr ... | 2005 | 16205374 |
| sigmab contributes to listeria monocytogenes invasion by controlling expression of inla and inlb. | the ability of listeria monocytogenes to invade non-phagocytic cells is important for development of a systemic listeriosis infection. the authors previously reported that a l. monocytogenes delta sigb strain is defective in invasion into human intestinal epithelial cells, in part, due to decreased expression of a major invasion gene, inla. to characterize additional invasion mechanisms under the control of sigmab, mutants were generated carrying combinations of in-frame deletions in inla, inlb ... | 2005 | 16207905 |
| multi-virulence-locus sequence typing clarifies epidemiology of recent listeriosis outbreaks in the united states. | multi-virulence-locus sequence typing (mvlst) was used to analyze isolates from two major listeriosis outbreaks in the united states in 1998 and 2002 that were due to consumption of contaminated hot dogs and turkey deli meat, respectively. mvlst demonstrated high epidemiological relevance and indicated that the two outbreaks were the result of one epidemic. | 2005 | 16208000 |
| paradoxical anti-inflammatory actions of tnf-alpha: inhibition of il-12 and il-23 via tnf receptor 1 in macrophages and dendritic cells. | il-12 and tnf-alpha are central proinflammatory cytokines produced by macrophages and dendritic cells. disregulation of tnf-alpha is associated with sepsis and autoimmune diseases such as rheumatoid arthritis. however, new evidence suggests an anti-inflammatory role for tnf-alpha. tnf-alpha-treated murine macrophages produced less il-12p70 and il-23, after stimulation with ifn-gamma and lps. frequency of il-12p40-producing macrophages correspondingly decreased as measured by intracellular cytoki ... | 2005 | 16210605 |
| attenuation of th1 response in decoy receptor 3 transgenic mice. | the soluble decoy receptor 3 (dcr3) is a member of the tnfr superfamily. because dcr3 is up-regulated in tumor tissues and is detectable in the sera of cancer patients, it is regarded as an immunosuppressor to down-regulate immune responses. to understand the function of dcr3 in vivo, we generated transgenic mice overexpressing dcr3 systemically. in comparison with hnt-tcr (hnt) transgenic mice, up-regulation of il-4 and il-10 and down-regulation of ifn-gamma, il-12, and tnf-alpha were observed ... | 2005 | 16210617 |
| purification of bovine milk lactoperoxidase and investigation of antibacterial properties at different thiocyanate mediated. | bovine lactoperoxidase (lpo) was purified with amberlite cg 50 h+ resin, cm sephadex c-50 ion-exchange chromatography, and sephadex g-100 gel filtration chromatography from skim milk. the activity of lactoperoxidase was measured by using 2.2-azino-bis (3-ethylbenzthiazoline-6 sulfonic acid) diammonium salt (abts) as a choromogenic substrate at ph 6.0. purification degree for the purified enzyme was controlled with sds-page and rz value (a412/a280). rz value for the purified lpo was 0.8. km value ... | 2005 | 16212035 |
| response regulator degu of listeria monocytogenes regulates the expression of flagella-specific genes. | an isogenic mutant of listeria monocytogenes egd with a deletion of the response regulator gene degu showed a lack of motility due to the absence of flagella. in the present study, we used two-dimensional gel electrophoresis, mass-spectrometry and microarray analyses to identify the listerial genes that depend on degu for expression. we found that the two l. monocytogenes operons encoding flagella-specific genes and the monocistronically transcribed flaa gene are positively regulated by degu at ... | 2005 | 16213668 |
| correlation of probiotic lactobacillus salivarius growth phase with its cell wall-associated proteome. | lactobacillus salivarius subsp. salivarius ucc118 is a probiotic bacterium that was originally isolated from human intestinal tissues and was subsequently shown in a pilot study to alleviate symptoms associated with mild-moderate crohn's disease. strain ucc118 can adhere to animal and human intestinal tissue, and to both healthy and inflamed ulcerative colitis mucosa, irrespective of location in the gut. in this study, an enzymatic technique has been combined with proteomic analysis to correlate ... | 2005 | 16214296 |
| comparative characterization of listeria monocytogenes isolated from portuguese farmhouse ewe's cheese and from humans. | in order to investigate the possible relationships between listeria monocytogenes strains isolated from farmhouse ewe's cheese and clinical strains collected, in partially overlapping dates, from the same geographical area in portugal, a total of 109 isolates from seven ewe's cheese manufactures (n=94) and from humans (n=15) were characterized by serotyping, rapd, pfge and allelic analysis of the virulent acta gene. serotyping indicated the presence of four different serovars: 1/2a, 1/2b, 1/2c a ... | 2006 | 16216366 |
| effect of temperature, water-phase salt and phenolic contents on listeria monocytogenes growth rates on cold-smoked salmon and evaluation of secondary models. | salting and smoking are ancient processes for fish preservation. the effects of salt and phenolic smoke compounds on the growth rate of l. monocytogenes in cold-smoked salmon were investigated through physico-chemical analyses, challenge tests on surface of cold-smoked salmon at 4 degrees c and 8 degrees c, and a survey of the literature. estimated growth rates were compared to predictions of existing secondary models, taking into account the effects of temperature, water phase salt content, phe ... | 2006 | 16216370 |
| use of bayesian modelling in risk assessment: application to growth of listeria monocytogenes and food flora in cold-smoked salmon. | an attempt to use a bayesian approach to model variability and uncertainty separately in microbial growth in a risk assessment is presented. it was conducted within the framework of a french project aiming at assessing the exposure to listeria monocytogenes in cold-smoked salmon. the chosen model describes the effect of time and temperature on bacterial growth. a bayesian approach close to the one proposed by pouillot et al. [int. j. food microbiol. 81 (2003) 87] is used to estimate the variabil ... | 2006 | 16216374 |
| [do we need pathogen-free livestock for food safety?]. | the reduction of the entry of pathogens in the food chain is an important premise in improving the safety of food of animal origin. since food animals are the main reservoir for pathogens, the prevalence of pathogens in livestock is of great importance. unfortunately, classical measures to improve animal health can not exclude the presence of the main food-borne zoonotic agents (salmonella, campylobacter, listeria monocytogenes, verotoxinogene escherichia coli, toxoplasma gondii) in "clinically ... | 2005 | 16218183 |
| antibacterial and antioxidant activities of essential oils isolated from thymbra capitata l. (cav.) andoriganum vulgare l. | antilisterial activities of thymbra capitata and origanum vulgare essential oils were tested against 41 strains of listeria monocytogenes. the oil of t. capitata was mainly constituted by one component, carvacrol (79%), whereas for o. vulgare three components constituted 70% of the oil, namely, thymol (33%), gamma-terpinene (26%), and p-cymene (11%). t. capitata essential oil had a significantly higher antilisterial activity in comparison to o. vulgare oil and chloramphenicol. no significant dif ... | 2005 | 16218659 |
| outbreak of clinical listeriosis in sheep: evaluation from possible contamination routes from feed to raw produce and humans. | we report the results of clinical and microbiological investigations on listeria monocytogenes infections in a flock of 55 sheep and describe the implications for the safety of the raw milk and raw-milk cheeses produced in the on-farm dairy. the outbreak was caused by feeding grass silage, which was contaminated with 5 log10 cfu l. monocytogenes/g. clinically, although having been fed from the same batch of silage, abortive (nine ewes), encephalitic (one ewe) and septicaemic (four ewes) forms of ... | 2005 | 16219091 |
| effects of electrolyzed oxidizing water on reducing listeria monocytogenes contamination on seafood processing surfaces. | the effects of electrolyzed oxidizing (eo) water on reducing listeria monocytogenes contamination on seafood processing surfaces were studied. chips (5 x 5 cm(2)) of stainless steel sheet (ss), ceramic tile (ct), and floor tile (ft) with and without crabmeat residue on the surface were inoculated with l. monocytogenes and soaked in tap or eo water for 5 min. viable cells of l. monocytogenes were detected on all chip surfaces with or without crabmeat residue after being held at room temperature f ... | 2006 | 16219378 |
| methods for the isolation and identification of listeria spp. and listeria monocytogenes: a review. | listeria monocytogenes is an important food-borne pathogen and is widely tested for in food, environmental and clinical samples. identification traditionally involved culture methods based on selective enrichment and plating followed by the characterization of listeria spp. based on colony morphology, sugar fermentation and haemolytic properties. these methods are the gold standard; but they are lengthy and may not be suitable for testing of foods with short shelf lives. as a result more rapid t ... | 2004 | 16219509 |
| use of phenolic compounds for sensitizing listeria monocytogenes to high-pressure processing. | three listeria monocytogenes strains (scott a, osy-8578, and osy-328) that differ considerably in barotolerance were grown to stationary phase and suspended individually in phosphate buffer (ph 7.0). twelve phenolic compounds, including commercially used food additives, were screened for the ability to sensitize l. monocytogenes to high-pressure processing (hpp). each l. monocytogenes strain was exposed to each of the 12 phenolic compounds (100 ppm each) for 60 min; this was followed by a pressu ... | 2006 | 16226329 |
| effectiveness of antimicrobial food packaging materials. | antimicrobial additives have been used successfully for many years as direct food additives. the literature provides evidence that some of these additives may be effective as indirect food additives incorporated into food packaging materials. antimicrobial food packaging is directed toward the reduction of surface contamination of processed, prepared foods such as sliced meats and frankfurter sausages (hot dogs). the use of such packaging materials is not meant to be a substitute for good sanita ... | 2005 | 16227182 |
| response of escherichia coli o157:h7, listeria monocytogenes, salmonella typhimurium, and staphylococcus aureus to the thermal stress occurring in model manufactures of grana padano cheese. | the purpose of this research was to investigate the effect of temperature in the technology of production of grana cheese against escherichia coli o157:h7, listeria monocytogenes, salmonella typhimurium, and staphylococcus aureus. according to the technology of production, the cheese curds are cooked at 55 degrees c and then cooled at room temperature (25 degrees c). a curd-cooling model was developed to estimate the temperature variation across the curd during cooling, and the thermal stress wa ... | 2005 | 16230687 |
| sequencing and expression analysis of the sakacin p bacteriocin produced by a lactobacillus sakei strain isolated from naturally fermented sausages. | a lactobacillus sakei strain, designated as i151 and isolated from naturally fermented sausages, was found to produce the sakacin p bacteriocin which is active against listeria monocytogenes. in this study, we performed the sequencing of the gene cluster involved in the production of the sakacin p, and we followed the expression of the sppa gene, encoding for the bacteriocin, in vitro, using rogosa-sharpe medium, and in situ, inoculating the strain in fermented sausages as starter culture. the r ... | 2006 | 16231175 |
| listeriolysin o, a cytolysin derived from listeria monocytogenes, inhibits generation of ovalbumin-specific th2 immune response by skewing maturation of antigen-specific t cells into th1 cells. | listeriolysin o (llo), a cholesterol-dependent cytolysin derived from listeria monocytogenes, is a potent inducer of interleukin (il)-12, il-18 and interferon (ifn)-gamma. we have shown that llo facilitates development of t cells mediating protective immunity against l. monocytogenes through the induction of ifn-gamma production at an early stage. based on this finding, it is postulated that llo inhibits differentiation of th2 cells and the th2 immune response. by using a murine model of ovalbum ... | 2005 | 16232213 |
| purification and characterization of a bacteriocin produced by lactococcus lactis subsp. lactis h-559 isolated from kimchi. | lactic acid bacteria were isolated from kimchi and screened for bacteriocin production. strain h-559, identified as lactococcus lactis subsp. lactis, exhibited the strongest antibacterial activity among them and was active against pathogenic bacteria such as listeria monocytogenes and staphylococcus aureus as well as many lactic acid bacteria. the antimicrobial substance produced by l. lactis subsp. lactis h-559 was inactivated by alpha-chymotrypsin, and protease type ix and xiv and was confirme ... | 1999 | 16232590 |
| characterization of bacteriocin n15 produced by enterococcus faecium n15 and cloning of the related genes. | enterococcus faecium n15 was isolated from nuka (japanese rice-bran paste), which is utilized as starter in the fermenting of vegetables, and was found to produce a bacteriocin that exhibited a broad spectrum of activity, including activity against listeria monocytogenes and bacillus circulans jcm2504. the bacteriocin was sensitive to proteases (alpha-chymotrypsin, proteinase k, trypsin, and pepsin) and alpha-amylase, but it was resistant to lipase. the bacteriocin was resistant to heat treatmen ... | 2001 | 16233010 |
| functional consequences of genome evolution in listeria monocytogenes: the lmo0423 and lmo0422 genes encode sigmac and lstr, a lineage ii-specific heat shock system. | listeria monocytogenes strains belonging to phylogenetic lineage ii (serotypes 1/2a, 1/2c, and 3a) carry a lineage-specific genome segment encoding a putative sigma subunit of rna polymerase (lmo0423, herein referred to as sigc), a gene of unknown function (lmo0422) similar to the padr family of regulators, and a gene that is similar to the roda-ftsw family of cell wall morphology genes (lmo0421). to understand the function of this set of genes, their expression patterns and the effects of null ... | 2005 | 16237008 |