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listeria monocytogenes infection in pregnant mice: abnormalities in the function of non-adherent accessory light density dendritic cells.pregnant a/j mice were found to be more susceptible to the lethal effect of listeria monocytogenes bacteria than virgin females. however, during the first four days of post-infection there was no difference in the elimination of listeria from the spleens of pregnant and virgin mice. this suggests that the increase in the susceptibility of pregnant mice to pathogenic activity of l. monocytogenes was related to the diminution in listeria-specific cellular reactions. indeed, we found that non-adher ...19958589664
modulation of the antilisterial activity of human blood-derived macrophages by activating and deactivating cytokines.a concept of macrophage deactivation by hormones and cytokines that opposes activation was recently proposed. deactivation of the antilisterial activity of macrophages by il-4, il-10, and tgf-beta, as well as by dexamethasone, was studied here. il-4, il-10, and dexamethasone, but not tgf-beta, caused a complete loss of the competence of human blood-derived macrophages infected with listeria monocytogenes to control or eliminate ingested bacteria. il-10 and, to a lesser degree, dexamethasone less ...19958590313
hyperexpression of listeriolysin in the nonpathogenic species listeria innocua and high yield purification.listeriolysin, the hemolysin of the pathogenic species listeria monocytogenes, was expressed in the non-pathogenic species listeria innocua. coexpression of the positive regulatory factor prfa in the plasmid vector in conjunction with the structural gene hly increased the expression over 500-fold. purification from supernatant fluids was achieved by two steps of ion exchange chromatography. the procedure resulted in over 60% yield of a hemolytically active, homogeneous 58 kda protein which was u ...19958590646
phenotypic characterization of the cells of the inflammatory response in ovine encephalitic listeriosis.the brainstem (pons cerebri and medulla oblongata) of 22 sheep aged between 6 months and 3 years which had developed clinical signs of central nervous system dysfunction were examined. histopathological changes characterized by microabscesses, focal gliosis and perivascular cuffing compatible with natural infection with listeria monocytogenes were present. the brains were examined by lectin histochemistry and immunohistochemistry with markers for t lymphocytes (cd4+ and cd8+ subsets), b lymphocy ...19958592052
the application of the wlf equation to predict lag time as a function of temperature for three psychrotrophic bacteria.many mathematical models for microbial growth rates or lag times have been proposed. most of these models either predict well, but are empirical and offer no insight into mechanism or they reflect mechanism but are too complex or do not fit the data adequately. the williams-landel-ferry (wlf) equation (used by polymer chemists) is empirical, but shows some relation to first principles, and hence may offer some insight into mechanism. this model also has only three parameters and therefore a fair ...19958579982
combined effect of gamma radiation and heating on the destruction of listeria monocytogenes and salmonella typhimurium in cook-chill roast beef and gravy.the effect of heating alone (60, 65 or 70 degrees c), heating after irradiation (0.8 kgy) and heating after irradiation and storage for 14 days at 2-3 degrees c on the destruction of listeria monocytogenes and salmonella typhimurium in artifically inoculated minced cook-chill roast beef and gravy was investigated. inoculated minced roast beef samples (5 g) were heated in stomacher bags completely immersed in a water bath at each of the test temperatures. survivors were enumerated and d and z val ...19958579983
genomic subtraction in combination with pcr for enrichment of listeria monocytogenes-specific sequences.genomic dna from listeria innocua and listeria ivanovii was used in subtractive hybridization with dna from listeria monocytogenes involving two amplification strategies. subtraction was accomplished by labelling the subtracting dna with biotin and removal after liquid hybridization with tester dna (l. monocytogenes) by reaction with streptavidin and phenol extraction. in one strategy, l. monocytogenes dna was poly(a)-tailed with terminal transferase and amplified asymmetrically after subtractio ...19958579987
typing of listeria monocytogenes by random amplified polymorphic dna (rapd) analysis.the aim of the study was to determine the effectiveness of random amplified polymorphic dna analysis in typing listeria monocytogenes from human infections. twenty-five l. monocytogenes serogroup 1/2 and 70 serogroup 4 including 14 serovar 4b(x) were typed by rapd-pcr analysis. six primers were used to type each l. monocytogenes isolate and the dna amplification performed with supertaq dna polymerase in a hybaid thermal reactor. each bacterial strain was analysed separately with all primers and ...19958579993
exposure of the lateral enterocyte membrane by dissociation of calcium-dependent junctional complex augments endocytosis of enteric bacteria.intestinal bacterial translocation is facilitated in a variety of clinical conditions involving increased intestinal permeability, such as shock and trauma. because there is both in vivo and in vitro evidence that enteric bacteria can be internalized by intestinal epithelial cells, experiments were designed to test the effect of increased intestinal permeability on enterocyte endocytosis of enteric bacteria. mature, confluent cultures of ht-29 enterocytes were placed in a calcium-free solution f ...19958574756
heterogeneous endolysins in listeria monocytogenes bacteriophages: a new class of enzymes and evidence for conserved holin genes within the siphoviral lysis cassettes.listeria monocytogenes bacteriophages a118, a500 and a511 are members of three distinct phage groups with characteristic host ranges. their endolysin (ply) genes were cloned and expressed in escherichia coli as demonstrated by the conferred lytic phenotype when colonies of recombinant cells were overlaid with a lawn of listeria cells. the nucleotide sequences of the cloned dna fragments were determined and the individual enzymes (ply118, 30.8 kda; ply500, 33.4 kda; ply511, 36.5 kda) were shown t ...19958577256
[spontaneous bacterial peritonitis caused by listeria monocytogenes].listeria monocytogenes is a gram-positive coccobacillus that produces infections in both the normal and the compromised host. symptomatic bacteremia and pulmonary infection or meningitis are the most common clinical presentations in adults. according to a current review of the literature, listeria is a rare bacteria that may produce spontaneous bacterial peritonitis (23 cases reported). listeria peritonitis occurs in more than two-thirds of the cases in patients with chronic liver disease, but m ...19958562197
vaccination of mice with attenuated mutants of listeria monocytogenes: requirement for induction of macrophage la expression.isogenic mutant strains of listeria monocytogenes demonstrating graded attenuation in mice were used to analyse the correlation between bacterial virulence, ability to induce class ii mhc (la) molecules in antigen presenting cells and ability to vaccinate against secondary infection. the mutants used differed only in the amino acid sequence of the thiol-activated hemolysin, listeriolysin o (llo). the results indicate that l. monocytogenes mutants of reduced virulence have the potential to act as ...19958551944
[wallenberg syndrome as a sign of rhombencephalitis-meningitis due to listeria monocytogenes].we report a case of rhombencephalitis with meningitis in a 36-years-old previously healthy man; neurological signs and symptoms were initially consistent with a diagnosis of wallenberg syndrome. analysis of cerebrospinal fluid showed predominantly lymphocytic pleocytosis and elevated protein levels. a ct brain scan was normal. mri of the brain showed a hypertensive type lesion in t2, in the right pontomedullary region that suggested inflammation. a blood culture grew listeria monocytogenes. the ...19958554785
influence of steric stabilization of liposome-encapsulated hemoglobin on listeria monocytogenes host defense.liposome-encapsulated hemoglobin (leh) products are being investigated as potential blood substitutes. to determine if changes in leh composition can modify the immune response, red blood cell substitutes based on conventional lipids containing phosphatidylinositol (leh1) and sterically stabilized lipid vesicles containing polyethylene glycol phosphatidylethanolamine (leh2) were tested for effects on host resistance. on day 0, groups of 18 to 20 female cd-1 mice were given an intravenous (i.v.) ...19958556140
occurrence of listeria species in ready to eat foods.over 8000 ready to eat foods were examined for the presence of listeria species. overall, 5% of foods were found to contain these organisms. higher occurrence was found in some foods such as chicken (11%) and fish (14%). most of the listeria species isolated were l. monocytogenes (49%) and l. innocua (36%) with lower numbers of other species. no seasonal pattern in the recovery of l. monocytogenes was found. unsatisfactory or potentially hazardous levels of l. monocytogenes were found in 14 prod ...19958557084
[role of macrolides in the treatment of respiratory tract infections in children].macrolides are antibiotics with high intracellular concentrations. they have a bacteriostatic activity but are also bactericides for concentrations five times greater than the minimal inhibitory concentration, concentrations in which they reach in the respiratory tract. they are usually active on streptococcus, neisseria, moraxella catarrhalis, listeria monocytogenes, bordetella pertussis, pasteurella multocida, chlamydia, mycoplasma pneumoniae, legionella pneumophila and helicobacter pylori. th ...19958548000
influences on the antimicrobial activity of surface-adsorbed nisin.the efficacy of the antimicrobial peptide nisin was examined after adsorption to silica surfaces. three protocols were used to evaluate nisin's activity against adhered cells of listeria monocytogenes: bioassay using pediococcus pentosaceous fbb 61-2 as the sensitive indicator strain; visualization and enumeration of cells by microscopic image analysis; and viability of adhered cells as determined by lodonitrotetrazolium violet uptake and crystallization. the activity of adsorbed nisin was highl ...19958519481
[acute hydrocephalus in listeria monocytogenes meningitis]. 19958523935
[phosphatidylinositol specific phospholipase c (pi-plc) in differentiation of listeria monocytogenes and listeria innocua].listeria strains were investigated as regard: the production of pi-plc and lecytinase, haemolytic and camp activity survival in mouse tissues. although all the examined l. monocytogenes strains produced pi-plc, they showed a very different activity of this enzyme. it was surprising that one of the four l. innocua strains demonstrated a weak activity of pi-plc. l. monocytogenes bacteria with strong pi-plc activity survived in mouse spleens for a much longer period of time than l. monocytogenes mi ...19958523967
cryptdins: endogenous antibiotic peptides of small intestinal paneth cells.we purified three peptides ("cryptdins") from the small intestines of mice, established their primary amino acid sequences and examined their antimicrobial activity. their primary sequences revealed approximately 50% identity to a group of antimicrobial defensins that we had previously isolated from the granules of rat neutrophils. in addition to their ability to kill gram-positive (l. monocytogenes) and gram-negative bacteria (e. coli and s. typhimurium) in vitro, the peptides were much more ac ...19958525919
division of listeria monocytogenes serovar 4b strains into two groups by pcr and restriction enzyme analysis.altogether, 133 strains of listeria monocytogenes serovar 4b were investigated. a segment of 2,916 bp containing parts of the two genes inla and inlb in l. monocytogenes was amplified by the pcr technique. the pcr product obtained was cleaved with the restriction enzyme alui, and the fragments generated were separated by gel electrophoresis, leading to two distinct groups: pcr-restriction enzyme analysis groups i and ii, containing 37 and 96 strains, respectively. the pcr-restriction enzyme anal ...19958526498
development of nasba, a nucleic acid amplification system, for identification of listeria monocytogenes and comparison to elisa and a modified fda method.nasba, an isothermal nucleic acid amplification system was used for identification of listeria monocytogenes. a primer set and a species-specific probe were selected from the 16s rrna sequence. the probe was shown to hybridize specifically to the amplified single-stranded rna of l. monocytogenes. no hybridization occurred with amplification product of l. seeligeri, l. innocua, l. ivanovii, and l. welshimeri. detection sensitivity for the nasba assay was determined at 10(6) cfu/ml. the possibilit ...19958527330
efficacy of a lactic acid/sodium benzoate wash solution in reducing bacterial contamination of raw chicken.raw chicken wings inoculated with salmonella, campylobacter jejuni, listeria monocytogenes, staphylococcus aureus, or escherichia coli o157:h7 were washed in water (control) or a solution of a 0.5% lactic acid/0.05% sodium benzoate (lb) (ph 2.64) for 30 min. viable cells of pathogenic bacteria and naturally occurring psychrotrophic bacteria on wings were enumerated after 0, 2, 4, 6, and 8 days of storage at 4 degrees c. lower populations of pathogenic and psychrotrophic bacteria were detected on ...19958527331
[nonspecific host defense mechanism by macrophages--analysis by nf-il6 deficient mice]. 19958532864
differentiation of epidemic-associated strains of listeria monocytogenes by restriction fragment length polymorphism in a gene region essential for growth at low temperatures (4 degrees c).the growth of listeria monocytogenes in food stored in the cold has often been implicated in outbreaks of listeriosis. many subtyping schemes have suggested that epidemic-associated strains belong to a unique genetic group. it has not yet been possible, however, to identify molecular or bacteriologic markers unique to epidemic-associated strains. recently we cloned three genes of l. monocytogenes, ltra, ltrb, and ltrc, which are essential for growth at low temperatures (4 degrees c). the use of ...19958534098
[azithromycin, pharmacodynamic evaluation in animal models].several experimental models have been used in order to evaluate the in vivo efficacy of azithromycin against numerous human pathogenic bacteria and parasites, including comparison between azithromycin and other antibiotics belonging or not to the macrolide family. using the experimental models, three major objectives can be distinguished: the comparative studies of the efficacy dose 50 (ed50) of azithromycin compared to other orally given antibiotics, the azithromycin efficacy in animal infected ...19958539074
a monoclonal antibody against t-cell receptor alpha beta induces endogenous cytokines and prevents mice from a lethal infection with listeria monocytogenes.in vivo induction of cytokines by a monoclonal antibody (mab) against t-cell receptor (tcr) alpha beta and the protective effect induced by the mab on a lethal infection with listeria monocytogenes were studied. injection of anti-tcr alpha beta mab induced rapid production of endogenous tumour necrosis factor in the spleens, and gamma interferon and interleukin-6 in the blood streams and spleens of mice. administration of anti-cd4 mab, anti-cd8 mab, or anti-thy1.2 mab resulted in suppression of ...19958541810
efficacy of meropenem in experimental meningitis.meropenem and comparator antibiotics, including ceftriaxone, ceftazidime, benzyl penicillin and a combination of ampicillin plus gentamicin, were evaluated in a model of bacterial meningitis in the guinea-pig. the model is an acute infection in which challenge with each organism, if untreated, causes an increase in numbers of white blood cells, elevation of protein concentrations and 6-8 log10 cfu/ml of bacteria in the csf. infections caused by haemophilus influenzae, neisseria meningitidis, thr ...19958543501
colony-stimulating factor 1 in the human response to neonatal listeriosis.immunity to listeria monocytogenes, an important pathogen in human neonatal sepsis, is mediated by mononuclear phagocytes, which are regulated by the hematopoietic growth factor colony-stimulating factor 1. neonates with listeriosis had higher circulating colony-stimulating factor 1 levels and subsequent monocyte counts than those of both noninfected newborns and newborns infected with nonlisterial organisms.19957890428
influence of ibuprofen on the infection with listeria monocytogenes.listeria monocytogenes is a bacterial infection, which is facultatively localized in monocytes and macrophages. the influence of ibuprofen (cas 15687-27-1), a nonsteroidal anti-inflammatory drug (nsaid), on this bacterial infection in balb/c mice was investigated. one day prior to sublethal infection, balb/c mice were treated intravenously with various therapeutic concentrations of ibuprofen alone or ibuprofen in combination with a suboptimal dosage of murine recombinant interferon gamma, a lymp ...19957893261
the role of peptide metabolism in the growth of listeria monocytogenes atcc 23074 at high osmolarity.the growth of listeria monocytogenes atcc 23074 in defined medium is sensitive to high osmolarity when compared with its growth in complex media, such as brain heart infusion (bhi). the two major contributors to this difference in growth rate are the availability in bhi of the osmoprotectant glycine betaine and peptides. peptone plays two major roles: firstly as a nutritional supplement for protein synthesis, and secondly as a source of amino acids and peptides that serve as a mechanism of maint ...19957894718
relapsing bacterial meningitis. 19957894994
a di- and tripeptide transport system can supply listeria monocytogenes scott a with amino acids essential for growth.listeria monocytogenes takes up di- and tripeptides via a proton motive force-dependent carrier protein. this peptide transport system resembles the recently cloned and sequenced secondary di- and tripeptide transport system of lactococcus lactis (a. hagting, e. r. s. kunji, k. j. leenhouts, b. poolman, and w. n. konings, j. biol. chem. 269:11391-11399, 1994). the peptide permease of l. monocytogenes has a broad substrate specificity and allows transport of the nonpeptide substrate 5-aminolevuli ...19957887604
proposals for optimization of the international phage typing system for listeria monocytogenes: combined analysis of phage lytic spectrum and variability of typing results.combined analysis of 5,179 serial phage reactions of 20 listeria monocytogenes propagating strains over 14 years and phage typing results from 2,659 further l. monocytogenes strains allowed us to estimate lytic spectrum specificity and the variability of the lytic reactions of 35 phages. these included the 26 phages recommended for the international method for phage typing defined in 1985 by rocourt et al. (j. rocourt, a. audurier, a. l. courtieu, j. durst, s. ortel, a. schrettenbrunner, and a. ...19957887610
cd14 is not involved in rhodobacter sphaeroides diphosphoryl lipid a inhibition of tumor necrosis factor alpha and nitric oxide induction by taxol in murine macrophages.taxol, a microtubule stabilizer with anticancer activity, mimics the actions of lipopolysaccharide (lps) on murine macrophages in vitro. recently, it was shown that taxol-induced macrophage activation was inhibited by the lps antagonist rhodobacter sphaeroides diphosphoryl lipid a (rsdpla). to investigate the mechanisms of taxol-induced macrophage activation, the present study focused on the interaction of lps, rsdpla, and taxol in the activation of and binding to macrophages. taxol alone induce ...19957529746
targeted disruption of the nf-il6 gene discloses its essential role in bacteria killing and tumor cytotoxicity by macrophages.to investigate the role of nf-il6 in vivo, we have generated nf-il6 (-/-) mice by gene targeting. nf-il6 (-/-) mice were highly susceptible to infection by listeria monocytogenes. electron microscopic observation revealed the escape of a larger number of pathogens from the phagosome to the cytoplasm in activated macrophages from nf-il6 (-/-) mice. furthermore, the tumor cytotoxicity of macrophages from nf-il6 (-/-) mice was severely impaired. however, cytokines involved in macrophage activation, ...19957530603
ventriculoperitoneal shunt infection due to listeria monocytogenes. 19957677902
antimicrobial susceptibilities of corynebacterium species and other non-spore-forming gram-positive bacilli to 18 antimicrobial agents.the susceptibilities of 265 strains of corynebacterium species and other non-spore-forming gram-positive bacilli to 18 antimicrobial agents were tested. most strains were susceptible to vancomycin, doxycycline, and fusidic acid. corynebacterium jeikeium and corynebacterium urealyticum were the most resistant organisms tested. resistance to beta-lactams, clindamycin, erythromycin, azythromycin, ciprofloxacin and gentamicin was common among strains of corynebacterium xerosis and corynebacterium mi ...19957695308
listeria monocytogenes infection and serotype distribution among hiv-infected persons in los angeles county, 1985-1992.persons infected with human immunodeficiency virus (hiv) are at greater risk of infection with listeria monocytogenes (lm) than the general population. we quantify the risk of listeriosis in persons with acquired immune deficiency syndrome (aids) and hiv infection in los angeles county (lac) and report the lm serotype distribution among hiv-infected patients with listeriosis. active surveillance for listeriosis was performed in lac during most of the period from 1985 through 1992. thirty-four (1 ...19957697442
prophenin-1, an exceptionally proline-rich antimicrobial peptide from porcine leukocytes.we purified and characterized an unusual antimicrobial peptide, prophenin-1 (pf-1), from porcine leukocytes. the peptide had a mass of 8,683 and contained 79 residues, including 42 (53.2%) prolines and 15 (19.0%) phenylalanines. its n-terminal 60 residues consisted of three perfect and three nearly perfect repeats of a decamer, fpppnfpgpr. prophenin-1 was encoded on a cathelin-containing precursor and showed substantially more activity against e. coli, a gram-negative bacterium, than against lis ...19957698355
the actin-polymerization protein from listeria ivanovii is a large repeat protein which shows only limited amino acid sequence homology to acta from listeria monocytogenes.within infected eukaryotic cells the two pathogenic listeria species, l. monocytogenes and l. ivanovii, induce polymerization of cellular actin and the formation of a propulsive actin tail at one bacterial pole. for l. monocytogenes it has been shown that the product of the listerial acta gene is required for this process which is regarded as a model for actin-based motility. we have now cloned and sequenced a functionally analogous gene from l. ivanovii; its product, as deduced from the dna seq ...19957705602
immune complexes inhibit antimicrobial responses through interleukin-10 production. effects in severe combined immunodeficient mice during listeria infection.the presence of soluble antigen-antibody complexes renders mice highly susceptible to infection with the intracellular pathogen listeria monocytogenes. in this report we show that this inhibition is manifest at the level of the innate immune response and is mediated by il-10. like immuno-competent mice, mice with the severe combined immunodeficient mutation (scid) injected with immune complexes died from a sublethal dose of l. monocytogenes. these mice were protected if pretreated with neutraliz ...19957706470
reduction in the incidence of human listeriosis in the united states. effectiveness of prevention efforts? the listeriosis study group.food-borne transmission is now recognized as a major cause of human listeriosis.19957707600
membrane permeabilization by listeria monocytogenes phosphatidylinositol-specific phospholipase c is independent of phospholipid hydrolysis and cooperative with listeriolysin o.we have examined potential cooperative interactions of listeria monocytogenes phosphatidylinositol-specific phospholipase c (pi-plc) and listeriolysin o (llo), a pore-forming hemolysin, in a liposome lysis assay. large unilamellar vesicles, approximately 0.1 micron in diameter, encapsulating the fluorescent probe calcein, were treated with pi-plc or llo at ph 6.0, and each was capable of causing dye release. with phosphatidylcholine/phosphatidylinositol/cholesterol liposomes at 0.1 microm lipid, ...19957708759
activation of gamma delta t cells for production of ifn-gamma is mediated by bacteria via macrophage-derived cytokines il-1 and il-12.gamma delta t cells are found at sites of microbial infection and have been reported to proliferate in response to bacterial ags. we show here that although the response by listeria-elicited peritoneal gamma delta t cells to heat-killed bacteria in the presence of macrophage accessory cells may be partially mediated via the tcr, it is predominantly mediated via cytokines produced by the macrophages. macrophage cytokines il-12 and il-1 synergize to induce some proliferation and considerable ifn-g ...19957538532
altered responses to bacterial infection and endotoxic shock in mice lacking inducible nitric oxide synthase.mice deficient in inducible nitric oxide synthase (inos) were generated to test the idea that inos defends the host against infectious agents and tumor cells at the risk of contributing to tissue damage and shock. inos-/-mice failed to restrain the replication of listeria monocytogenes in vivo or lymphoma cells in vitro. bacterial endotoxic lipopolysaccharide (lps) caused shock and death in anesthetized wild-type mice, but in inos-/-mice, the fall in central arterial blood pressure was markedly ...19957538909
sets of ecori fragments containing ribosomal rna sequences are conserved among different strains of listeria monocytogenes.to classify listeria monocytogenes using taxonomic characters derived from the rrna operons and their flanking sequences, we studied a sample of 1346 strains within the taxon. dna from each strain was digested with a restriction endonuclease, ecori. the fragments were separated by gel electrophoresis, immobilized on a membrane, and hybridized with a labeled rrna operon from escherichia coli. the pattern of bands, positions, and intensities of hybridized fragments were electronically captured. so ...19957539145
types of listeria monocytogenes predicted by the positions of ecori cleavage sites relative to ribosomal rna sequences.by using taxonomic characters derived from ecori restriction endonuclease digestion of genomic dna and hybridization with a labeled rrna operon from escherichia coli, a polymorphic structure of listeria monocytogenes, characterized by fragments with different frequencies of occurrence, was observed. this structure was expanded by creating predicted patterns through a recursive process of observation, expectation, prediction, and assessment of completeness. this process was applied, in turn, to n ...19957539146
effects of ethanol on cellular immunity to facultative intracellular bacteria.alcohol abuse has been associated with an increase in infectious diseases caused by pathogenic and opportunistic microorganisms. study results obtained from this laboratory and other laboratories have shown that consumption of large amounts of ethanol is associated with numerous changes in the immune system. the purpose of this article is to report findings obtained from this laboratory, as well as review those obtained from other laboratories, from experiments designed to evaluate the effects o ...19957539599
the identification of bacterial gene expression differences using mrna-based isothermal subtractive hybridization.we describe a method for isolating and determining differences in gene expression between related bacterial strains. the method is based upon differences in mrna expression. to demonstrate this procedure, cdna generated from total rna of listeria monocytogenes serotype 1/2a was hybridized to total rna from a tn916 mutant of serogroup 1/2a (m3) that was deficient in the production of listeriolysin o, the product of the hly gene. the single-stranded cdna fragments remaining after hybridization rep ...19957720012
in vitro generation of ifn-gamma-producing listeria-specific t cells is dependent on ifn-gamma production by non-nk cells.in vitro 5-day cultures of naive spleen cells with viable listeria monocytogenes (vlm), but not heat-killed l. monocytogenes, induced cd4+ t cells that produced ifn-gamma upon secondary antigen stimulation. the vlm-induced listeria-specific t cells produced ifn-gamma but lacked expression of il-2 and il-4. to study the role of ifn-gamma in the induction of the ifn-gamma-producing t cells, we added anti-ifn-gamma mab to the primary culture and analyzed ifn-gamma production upon secondary antigen ...19957720082
cd8 t lymphocytes specific for the secreted p60 antigen protect against listeria monocytogenes infection.the ability of listeria monocytogenes to gain access to the cytoplasm of infected cells results in the processing and presentation of bacterial ags through the mhc class i pathway. as a result, cd8 t cells are the most effective mediators of acquired immunity in the mouse model of l. monocytogenes infection. cd8 t cells specific for a single nonamer epitope derived from the secreted virulence factor listeriolysin o (llo) can protect h-2d mice against lethal infection. bacteria lacking llo are av ...19957722316
listeria monocytogenes intracellular migration: inhibition by profilin, vitamin d-binding protein and dnase i.infection of host cells by listeria monocytogenes results in the recruitment of cytoplasmic actin into a tail-like appendage that projects from one end of the bacterium. each filamentous actin tail progressively lengthens, providing the force which drives the bacterium in a forward direction through the cytoplasm and later results in listeria cell-to-cell spread. host cell actin monomers are incorporated into the filamentous actin tail at a discrete site, the bacterial-actin tail interface. we h ...19957728867
a focal adhesion factor directly linking intracellularly motile listeria monocytogenes and listeria ivanovii to the actin-based cytoskeleton of mammalian cells.the surface-bound acta polypeptide of the intracellular bacterial pathogen listeria monocytogenes is the sole listerial factor needed for recruitment of host actin filaments by intracellularly motile bacteria. here we report that following listeria infection the host vasodilator-stimulated phosphoprotein (vasp), a microfilament- and focal adhesion-associated substrate of both the camp- and cgmp-dependent protein kinases, accumulates on the surface of intracytoplasmic bacteria prior to the detect ...19957729410
immunocytochemical evidence of listeria, escherichia coli, and streptococcus antigens in crohn's disease.infectious agents have long been suspected of playing a role in the initiation of crohn's disease. the objective of this study was to search for likely microbial agents in diseased tissues using immunocytochemical techniques.19957729631
listeria: the latest putative pathogenetic microorganism in crohn's disease. 19957729652
intracellular killing of listeria monocytogenes in the j774.1 macrophage-like cell line and the lipopolysaccharide (lps)-resistant mutant lps1916 cell line defective in the generation of reactive oxygen intermediates after lps treatment.listeria monocytogenes is a facultative intracellular pathogen and survives within phagocytic cells by escaping from phagosomes into the cytoplasm. it has been reported that, in vivo, l. monocytogenes is effectively eliminated through cell-mediated immunity, especially by macrophages which have been immunologically activated by cytokines such as gamma interferon (ifn-gamma). however, this killing mechanism for l. monocytogenes and the role of macrophage activation in this bacterial killing are u ...19957729897
listeria monocytogenes p60 supports host cell invasion by and in vivo survival of attenuated salmonella typhimurium.the extracellular protein p60 is a major virulence factor of the intracellular bacterium listeria monocytogenes. its roles in pathogen survival in vivo and host cell invasion in vitro were studied. to this end, salmonella typhimurium sl7207 was used as carrier for secreted p60-hlya fusion protein by escherichia coli hlyb and hlyd transport proteins. c57bl/6 mice infected intravenously with this strain suffered from increased bacterial numbers in livers and spleens compared with the p60-nonexpres ...19957729919
activity of p-aminobenzoic acid compared with other organic acids against selected bacteria.the antibacterial activity of p-aminobenzoic acid against listeria monocytogenes, salmonella enteritidis and escherichia coli was compared with the activity of commonly used acidulants: formic, propionic, acetic, lactic and citric acids. viable count evaluations and mic determinations indicated that p-aminobenzoic acid caused greater inhibitory effects than the other organic acids. the activity of p-aminobenzoic acid on the growth of the test organisms at selected ph values indicated that p-amin ...19957730199
antibacterial effect of protamine assayed by impedimetry.impedimetric measurements were used to assay the antibacterial effect of protamine. a good linear correlation between the impedance detection time and the initial cell counts was obtained (r = 0.99, n = 2). as basic peptides may cause clumping of cells, this correlation curve was used when estimating the cell number after protamine treatment, rather than colony counts. protamine from salmon killed growing gram-positive bacteria and significantly inhibited growth of gram-negative bacteria in tryp ...19957730206
recombinant listeria monocytogenes as a live vaccine vehicle for the induction of protective anti-viral cell-mediated immunity.listeria monocytogenes (lm) is a gram-positive bacterium that is able to enter host cells, escape from the endocytic vesicle, multiply within the cytoplasm, and spread directly from cell to cell without encountering the extracellular milieu. the ability of lm to gain access to the host cell cytosol allows proteins secreted by the bacterium to efficiently enter the pathway for major histocompatibility complex class i antigen processing and presentation. we have established a genetic system for ex ...19957732018
immunotoxicologic studies with ci-959, a novel benzothiophene cell activation inhibitor.ci-959 is an orally effective inhibitor of cellular activation in both in vitro and animal models. to assess the effects of ci-959 on immune function, male fischer 344 rats were evaluated for splenic t- and b-lymphocyte populations, antibody-forming cell response to sheep red blood cells (srbc), concanavalin a and pokeweed mitogen-induced lymphocyte proliferation, natural killer cell activity, and reticuloendothelial system clearance of srbc. host resistance was measured in female b6c3f1 mice us ...19957740540
evaluation of enrichment broths for their ability to recover heat-injured listeria monocytogenes.listeria selective enrichment broth (leb), university of vermont (uvm) broth, modified uvm (muvm) broth and fraser broth (fb) were compared for their ability to recover cells of l. monocytogenes from heated tryptose phosphate broth. three strains of l. monocytogenes were heated at 54 degrees c for 30 min, inoculated into enrichment broths supplemented with 400 micrograms catalase ml-1, and incubated for 8 h at 30 degrees c. after incubation for 4 h, the total viable cell populations either decre ...19957744721
brainstem abscess and meningitis due to listeria monocytogenes in an adult with juvenile chronic arthritis. 19957746378
heterologous expression of the lactacin f peptides by carnobacterium piscicola lv17.the lactacin f complex, composed of lafa and lafx peptides, is produced by lactobacillus johnsonii vpi 11088 and is active against five other lactobacillus species and enterococcus faecalis. the genetic determinants encoding the lactacin f complex are organized in a 1-kb polycistronic operon which comprises three genes, lafa, lafx, and orfz (encoding the putative immunity protein). the lafa and lafx genes encode the bacteriocin precursors with n-terminal extensions characterized by a gly-gly-1*x ...19957747957
efficacy of marinades against listeria monocytogenes cells in suspension or associated with green shell mussels (perna canaliculus).in order to determine the listericidal efficacies of three marinades used in the production of marinated green shell mussels (perna canaliculus), decimal reduction times (d values) were determined for a mixture of seven strains of listeria monocytogenes exposed to marinades in the presence and absence of mussels. with an acetic acid (1.5%, wt/vol) marinade, calculated d values in the presence and absence of mussels were 77.3 and 33.3 h, respectively. likewise, for an acetic acid (0.75%)-lactic a ...19957747968
utilization of exogenous siderophores and natural catechols by listeria monocytogenes.listeria monocytogenes does not produce siderophores for iron acquisition. we demonstrate that a number of microbial siderophores and natural iron-binding compounds are able to promote the growth of iron-starved l. monocytogenes. we suggest that the ability of l. monocytogenes to use a variety of exogenous siderophores and natural catechols accounts for its ubiquitous character.19957747980
characterization of five esterases from listeria monocytogenes and use of their electrophoretic polymorphism for strain typing.esterases from listeria monocytogenes strains isolated from cheeses were analyzed by starch gel electrophoresis. five esterases, numbered from est 1 to est 5 in order of decreasing anodal migration, were identified. the est 1, est 3, est 4, and est 5 set was most active toward alpha-naphthyl propionate, while est 2 was most active toward alpha-naphthyl acetate. results from inhibitor studies suggest that all of these esterases were ec class 3.1.1.1 carboxylesterases, except that est 1 and est 3 ...19957747982
live tularemia vaccine but not proteins purified from francisella tularensis can confer protection against lethal listeria infection in mice.immunization of balb/c mice with francisella tularensis vaccine strain 15/10 conferred significant protection against subsequent listerial infection. since immunostimulatory activities could apparently be relevant to surface components of the bacterium, a technique for purification of cell wall proteins was developed. the scheme designed consisted of triton x-100 extraction with subsequent fplc chromatography steps, and resulted in the isolation of homogeneous proteins with molecular masses of 5 ...19957748535
changes in bacterial phagocytosis of macrophages in experimental ulcerative colitis.we previously reported that numerous macrophages which phagocytosed dextran sulfate sodium were observed to have accumulated in the mucosal lesions and in the spleen in experimental ulcerative colitis induced in mice with dextran sulfate sodium. in this paper, we investigated the bacterial phagocytic ability of macrophages which were isolated from spleens of mice treated with 3% dextran sulfate sodium for 6 months. in this model, the number of phagocytosed bacteria (listeria monocytogenes) and t ...19957750670
spinal manifestation of neurolisteriosis.spinal symptoms in acute bacterial meningitis are rare. in a series of 10 cases of neurolisteriosis, we observed 2 spinal complications, one due to an acute intramedullary abscess, the other caused by chronic spinal arachnoiditis. therefore, if spinal symptoms develop in acute bacterial meningitis, listeria monocytogenes infection should be considered and early adequate antibiotic treatment be implemented.19957751858
listeriosis in a patient with long-term hemodialysis but without iron overload. 19957753284
[listeriosis in the nonpregnant adult during an epidemic outbreak on grand canary].twenty-two cases of community-acquired epidemic listeriosis were recorded from december 31st, 1991, to may 15th, 1993, at the nuestra señora del pino hospital, las palmas. the incidence during this outbreak was 31 times higher than the corresponding incidence in the last few years. twelve cases occurred in pregnant women and/or neonates and ten in non-pregnant adult individuals. our aim was to study the clinical, biological, radiological, and evolutive issues in non-pregnant adult patients. six ...19957754149
evaluation of a restriction fragment length polymorphism typing method for listeria monocytogenes.the results of an evaluation of restriction fragment length polymorphism (rflp) typing for listeria monocytogenes are presented. the method depends on the use of cloned dna fragments from an l. monocytogenes (serovar 4b) strain to probe southern blotted ncii restriction fragments derived from l. monocytogenes strains. analyses of 862 isolates of serogroups 1/2, 3 and 4 were performed and a total of 32 rflp patterns were observed. interstrain rflps were common within serogroup 1/2 and the numeric ...19957754226
typing listeria monocytogenes: a comparison of random amplification of polymorphic dna with 5 other methods.one hundred listeria monocytogenes strains were typed by random amplification of polymorphic dna (rapd) with three different primers, and the results were compared with those obtained by serotyping, ribotyping, multilocus enzyme electrophoresis, restriction enzyme analysis and phage typing. the rapd patterns of strains appear to be stable during epidemics even over periods of several years. reproducibility of the rapd patterns was good. the discriminatory power of rapd typing was the best among ...19957754227
polymerase chain reaction (pcr) for detection of pathogenic microorganisms in bacteriological monitoring of dairy products.the presence of pathogenic bacteria poses a serious problem in sustaining the safety of dairy products. microbiological routine controls of these products make use of selective culture techniques. to detect pathogenic species, isolated colonies are characterized by specific metabolic activities and by serotyping. we present an alternative biochemical approach that does not require culture of bacteria. the total bacterial populations of food samples were isolated by centrifugation and analysed by ...19957754231
actin-based bacterial motility.listeria monocytogenes and other bacterial pathogens move in the host cell cytoplasm, propelled by continuous actin assembly at one pole of the bacterium. this actin-based motility requires the presence of the bacterial proteins acta on l. monocytogenes and icsa on shigella flexneri. there have been several major discoveries in the past year: the discovery of the polar distribution of acta and icsa on the bacterial surface; the demonstration that bacterial acta is phosphorylated in infected host ...19957755995
organization and structure of actin filament bundles in listeria-infected cells.during its motion inside host cells, listeria monocytogenes promotes the formation of a column of actin filaments that extends outward from the distal end of the moving bacterium. the column is constructed of short actin filaments that polymerize at the bacteria-column interface. to get a measure of filament organization in the column, listeria grown in cultured ptk2 cells were studied with steady state fluorescence polarization, confocal microscopy, and whole cell intermediate voltage electron ...19957758139
polysaccharide (ank-102) from polianthes tuberosa cells deteriorates the resistance of mice to listeria monocytogenes infection.modulatory effect on the murine self defense system by a newly discovered acidic polysaccharide (ank-102) produced by p. tuberosa cells in liquid culture was examined. pretreatment with ank-102 deteriorated the murine survival against lethal infection of listeria monocytogenes, an intracellular gram-positive bacterium eliminated mainly by macrophages through t-cell mediated immune response. pretreatment with ank-102 resulted in the accumulation of mac 1 and mac 2 positive cells in the peritoneal ...19957759775
no lumbar puncture in the evaluation for early neonatal sepsis: will meningitis be missed?we performed this investigation to assess whether selective approaches to performing lumbar puncture (lp) in the early neonatal period will result in a missed or delayed diagnosis of bacterial meningitis.19957761203
the incidence, numbers and types of listeria monocytogenes isolated from farm bulk tank milks.bulk tank milk from 160 producers was tested for listeria monocytogenes at three monthly intervals over 1 year. twenty-five producers were positive, most on a single occasion, only seven were positive on three or more of the four samplings. listeria monocytogenes numbers were low, usually < 1 ml-1, the highest was 35 ml-1. all isolates were serotype 1, the use of multilocus enzyme electrophoresis on representative isolates gave nine different electrophoretic types, two have been associated with ...19957765870
rapid rapd analysis for distinguishing listeria species and listeria monocytogenes serotypes using a capillary air thermal cycler.using a novel capillary thermal cycler, randomly amplified polymorphic dna (rapd) generated dna fingerprints were obtained in 3 h. the rapd profiles were produced using a random 10-mer primer (5'-accgcctgct-3') which discriminated between different listeria spp. unique fragment profiles of listeria monocytogenes serotypes were produced from serotypes 1a, 2, 3a, 4ab, 4a and 4c but serotypes, 1/2a, 4b, 4d and 7 had similar profiles.19957766080
the direct application of the polymerase chain reaction to dna extracted from foods.two methods for the successful extraction of dna from foods are described. the rapid lysis method uses a proteinase k buffer system to lyse cells and solubilize food samples. dna is then precipitated using isopropanol. the second method achieves cell lysis using toluene and mutanolysin, and solubilization using guanidium thiocyanate. following protein removal with organic solvents dna is precipitated with isopropanol. both methods enabled the polymerase chain reaction to be applied directly to d ...19957766115
development of a direct viable count procedure for some gram-positive bacteria.the direct viable count (dvc) is a procedure for enumerating viable-nonculturable cells. it should be noted, however, that bacteria demonstrating the viable but nonculturable phase have to date included only gram-negative species, mainly because the dvc procedure does not lend itself to the analysis of gram-positive bacteria since the dvc procedure is dependent on the bacterium being sensitive to nalidixic acid. the authors report here concerning studies on an analogous procedure for the direct ...19957766118
listeriolysin o secretion by listeria monocytogenes in the presence of cysteine and sorbate.the influence of cysteine or cysteine-hcl and their combination with potassium sorbate on growth of listeria monocytogenes and listeriolysin o (llo) secretion, and on activation of llo in the haemolysin assay system was studied. both cysteine and cysteine-hcl (10 and 20 mmol l-1) enhanced llo secretion in tryptic soy broth supplemented with yeast extract during 24 h incubation at 35 degrees c. while sorbate did not affect growth, it suppressed both llo secretion and llo activation by cysteine in ...19957766229
[evidence of antimicrobial activity of the follicular fluid: an evaluation and analytical study of samples obtained in an assisted reproduction program].due to lack of evidence of infection in patients for ovarian punction for ovular capture, the hypothesis of possible antibacterial action that could exist in follicular fluid, was evaluated. one hundred and ten samples of such fluid, were taken for antibacterial analysis, 37 of which, were studied, as they were the clearest ones and not contaminated. such samples were obtained from hyperstimulated patients, ready for ovular capture through vagina by ultrasonographic guide. a bacterial inoculum, ...19957768471
interleukin-6-deficient mice are highly susceptible to listeria monocytogenes infection: correlation with inefficient neutrophilia.we have produced interleukin-6 (il-6)-deficient mice to examine, in vivo, the wide variety of biological activities attributed to this multifunctional cytokine. to investigate the role of il-6 during infectious disease, il-6-deficient mice were challenged with sublethal doses of listeria monocytogenes, a facultative intracellular bacterium. while normal control animals were able to clear the infection, mutant animals exhibited a high mortality rate and showed uncontrolled replication of the bact ...19957768607
human t-cell recognition of listeria monocytogenes: recognition of listeriolysin o by tcr alpha beta + and tcr gamma delta + t cells.the cell-mediated immune response to listeria monocytogenes has been well characterized in the mouse. listeriolysin o (llo) is a major antigen in murine t-cell recognition of l. monocytogenes. in this study, we show that llo is also recognized by human tcr alpha beta t cells and tcr gamma delta t cells. human peripheral blood mononuclear cells (pbmc) cultured in vitro with live listeriae and then expanded with interleukin 2 were shown to respond to purified llo. the generation of llo-responsive ...19957768611
an atp-dependent l-carnitine transporter in listeria monocytogenes scott a is involved in osmoprotection.listeria monocytogenes is a gram-positive, psychotrophic, food-borne pathogen which is able to grow in osmotically stressful environments. carnitine (beta-hydroxy-l-tau-n-trimethyl aminobutyrate) can contribute significantly to growth of l. monocytogenes at high osmolarity (r. r. beumer, m. c. te giffel, l. j. cox, f. m. rombouts, and t. abee, appl. environ. microbiol. 60:1359-1363, 1994). transport of l-[n-methyl-14c]carnitine in l. monocytogenes was shown to be energy dependent. analysis of ce ...19957768820
rapid diagnosis of listeria monocytogenes by immunohistochemistry in formalin-fixed brain tissue. 19957771062
identification of bacterial genes that contribute to survival and growth in an intracellular environment. 19957773592
[meningoencephalitis caused by listeria monocytogenes in excessive ultraviolet light irradiation in the whole-body solarium]. 19957776941
[the occurrence of listeria monocytogenes in fecal samples of pigeons].listeria spp. were isolated from faeces samples from 12 (3.4%) of 350 pigeons examined. three isolates were identified as l. monocytogenes (1x serovar 1/2a, 1/2b, and 4ab), eight isolates were l. innocua (2x serovar 6a, 6x serovar 6b), and two isolates l. seeligeri (serovar 6b). one fecal sample yielded a mixed culture of l. monocytogenes and l. innocua. the results indicate that pigeons are not important in the epidemiology of listeriosis in man and animals.19957779072
molecular studies on the virulence of listeria monocytogenes. 19957779515
detection of anti-listeriolysin o in dairy cattle experimentally infected with listeria monocytogenes.a dot-blot assay and an enzyme-linked immunosorbent assay (elisa) to detect listeriosis in dairy cattle were developed that detected anti-listeriolysin o antibodies in the serum of cows experimentally infected with listeria monocytogenes. the tests utilized purified listeriolysin o (llo) as the detection antigen and streptolysin o (slo) to absorb cross-reacting antibodies. the two tests were compared with an agglutination test that used formalin-killed whole l. monocytogenes cells. blood samples ...19957779970
the fate of potentially pathogenic bacteria in swiss hard and semihard cheeses made from raw milk.this study examined the ability of potentially pathogenic bacteria to grow and to survive during the manufacture and ripening of swiss hard and semihard cheese varieties made from raw milk. the results show that hard cheeses are hygienically safe; 1 wk after fabrication, the inoculated pathogens (aeromonas hydrophila. campylobacter jejuni, escherichia coli, listeria monocytogenes, pseudomonas aeruginosa, salmonella spp., staphylococcus aureus, and yersinia enterocolitica) could no longer be dete ...19957782504
[validation trial of a neonatal prophylactic antibiotic protocol in the delivery room].maternofetal infection occurs in 1 to 10 of every 1,000 newborns. prognosis is poor and an extremely rapid the clinical course is sometimes observed. the situation suggests that widespread use of antibiotics and more than 90% of the newborns receiving antibiotics are not infected. a prospective study based on simple, recognized criteria predictive of maternal-fetal infection was conducted in 3,392 deliveries to evaluate the effect of an antibiotic prophylaxy protocol. specificity, sensitivity, p ...19957782594
pneumonia caused by listeria monocytogenes.pneumonia due to listeria monocytogenes is extremely uncommon. we report the case of an 87-year-old woman with no underlying immunosuppressive disease who presented with listerial pneumonia. cutaneous anergy and a decrease in total lymphocyte count in this elderly woman could predispose her to listerial infection.19957784707
efficacies of abt-719 and related 2-pyridones, members of a new class of antibacterial agents, against experimental bacterial infections.the 2-pyridones are a new class of broad-spectrum orally bioavailable antibacterial agents. these compounds are potent bacterial dna gyrase inhibitors which differ from fluoroquinolones by placement of the nitrogen atom in the ring juncture. abt-719 is an s isomer and a representative 2-pyridone. abt-719 administered orally or subcutaneously was 4- to 10-fold more effective than ciprofloxacin against staphylococcus aureus, streptococcus pneumoniae, and streptococcus pyogenes infections in normal ...19957786005
sensitivity of campylobacter spp. to irradiation in poultry meat.the sensitivity of campylobacter jejuni (three strains), camp. coli (three strains), camp. fetus (one strain) and camp. lari (one strain) to irradiation in poultry meat was investigated. there was no significant difference in the counts obtained on blood or skirrows agar. preston agar gave a significantly lower recovery of the pathogens after irradiation so these results were not included in calculations of d10 values. the d10 values ranged from 0.12 to 0.25 kgy and there was a significant diffe ...19957786498
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