Publications

antimicrobial effect of herb extracts against escherichia coli o157:h7, listeria monocytogenes, and salmonella typhimurium associated with beef.	the effects of plant extracts against pathogenic bacteria in vitro are well known, yet few studies have addressed the effects of these compounds against pathogens associated with muscle foods. a series of experiments was conducted to determine the effectiveness of a commercially available, generally recognized as safe, herb extract dispersed in sodium citrate (protecta one) or sodium chloride (protecta two) against escherichia coli o157:h7, salmonella typhimurium, and listeria monocytogenes asso ...	2000	10826716
a 9-month-old boy with fever and lethargy.		2000	10826077
an outbreak of listeria monocytogenes serotype 3a infections from butter in finland.	in february 1999, an outbreak of listeriosis caused by listeria monocytogenes serotype 3a occurred in finland. all isolates were identical. the outbreak strain was first isolated in 1997 in dairy butter. this dairy began delivery to a tertiary care hospital (tch) in june 1998. from june 1998 to april 1999, 25 case patients were identified (20 with sepsis, 4 with meningitis, and 1 with abscess; 6 patients died). patients with the outbreak strain were more likely to have been admitted to the tch t ...	2000	10823797
protective effect of a traditional japanese medicine, bu-zhong-yi-qi-tang (japanese name: hochu-ekki-to), on the restraint stress-induced susceptibility against listeria monocytogenes.	in this study, the effect of traditional japanese (chinese) medicine, bu-zhong-yi-qi-tang (japanese name: hochu-ekki-to, hot), on the restraint stress treatment (rst)-induced susceptibility against listeria monocytogenes (l. monocytogenes) was examined. when rst was performed every day for 10 h from the day of infection, the bacterial numbers were increased at 3 and 5 days after the infection. oral pretreatment with hot for 7 days prevented such increases. pretreatment with hot prevented the sup ...	2000	10822087
retinoid-mediated inhibition of interleukin-12 production in mouse macrophages suppresses th1 cytokine profile in cd4(+) t cells.	interleukin-12 (il-12) plays a central role in the immune system by driving the immune response towards t helper 1 (th1) type responses characterized by high ifn-gamma and low il-4 production. in this study we investigated whether retinoid-mediated inhibition of interleukin-12 production in mouse macrophages could regulate cytokine profile of antigen (ag)-primed cd4(+) th cells. pretreatment with retinoids (9-cis-ra, all-trans-ra, ttnpb) significantly inhibited il-12 production by mouse macropha ...	2000	10821786
yersinia enterocolitica-mediated translocation of defined fusion proteins to the cytosol of mammalian cells results in peptide-specific mhc class i-restricted antigen presentation.	yersinia enterocolitica delivers a set of effector proteins [yersinia outer proteins (yop)] into the cytosol of target cells to modulate host cell signal transduction pathways required for the extracellular survival of the bacterium. secretion and subsequent translocation of yop across the eukaryotic cell membrane are achieved via a type iii secretion system. about 50 - 100 amino acids of the n terminus of yop are required for chaperone-directed secretion and translocation. in this study, it is ...	2000	10820384
beta 2 integrins are involved in cytokine responses to whole gram-positive bacteria.	proinflammatory cytokines have an important pathophysiologic role in septic shock. cd14 is involved in cytokine responses to a number of purified bacterial products, including lps. however, little is known of monocyte receptors involved in cytokine responses to whole bacteria. to identify these receptors, human monocytes were pretreated with different mabs and tnf-alpha was measured in culture supernatants after stimulation with whole heat-killed bacteria. human serum and anti-cd14 abs significa ...	2000	10820267
listeria monocytogenes-infected human dendritic cells: uptake and host cell response.	dendritic cells (dcs) are potent antigen-presenting cells and play a crucial role in initiation and modulation of specific immune responses. various pathogens are able to persist inside dcs. however, internalization of the gram-positive bacterium listeria monocytogenes into human dcs has not yet been shown. in the present study, we demonstrate that human monocyte-derived immature dcs can efficiently phagocytose l. monocytogenes. this uptake is independent of listerial adhesion factors internalin ...	2000	10816528
interaction of listeria monocytogenes with human brain microvascular endothelial cells: an electron microscopic study.	internalization of listeria monocytogenes into human brain microvascular endothelial cells (hbmec) has recently been demonstrated to be dependent upon the inlb gene. in the present scanning electron microscopic study we show that l. monocytogenes efficiently interacts with the surface of hbmec in an inlb-independent manner which is also different from invasion. the inlb-dependent invasion of hbmec by l. monocytogenes is accompanied by intracellular multiplication, movement, and production of bac ...	2000	10816473
listeriolysin o as a reporter to identify constitutive and in vivo-inducible promoters in the pathogen listeria monocytogenes.	listeria monocytogenes is a facultative intracellular gram-positive bacterium capable of growing in the cytoplasm of infected host cells. bacterial escape from the phagosomal vacuole of infected cells is mainly mediated by the pore-forming hemolysin listeriolysin o (llo) encoded by hly. llo-negative mutants of l. monocytogenes are avirulent in the mouse model. we have developed a genetic system with hly as a reporter gene allowing the identification of both constitutive and in vivo-inducible pro ...	2000	10816469
cytolytic t-cell responses to human dendritic cells and macrophages infected with mycobacterium bovis bcg and recombinant bcg secreting listeriolysin.	cytolytic t-cell responses from 63 normal blood donors were monitored in a mycobacterium bovis bcg infection system in vitro. we wanted to know whether cultured dendritic cells were capable of potentiating the cytolytic t-cell responses to m. bovis bcg. infected cultured dendritic cells were up to ten times more effective antigen-presenting cells than macrophages in proliferative assays, while cytolytic t-cell induction did not differ significantly between dendritic cells and macrophages. separa ...	1999	10816080
antimicrobial and biological effects of ipemphos and amphos on bacterial and yeast strains.	in this study, the antimicrobial effects of monophosphazenes such as sm ipemphos and amphos were examined on bacterial and yeast strains. in addition, the biological effects of these compounds were tested on the lipid level of saccharomyces cerevisiae and candida albicans cells. the sm has an antimicrobial effect on the bacterial and yeast strains within the range of 100 and 1500 microg. when the concentration was increased, the inhibition zone expanded on the growth media ( p < 0.01; p < 0.001) ...	2000	10814970
some emerging food and water borne pathogens.	emerging pathogens are those infective organisms whose incidence has recently increased or is likely to increase during the next two decades due to changes in demography, food habits, food technology, commerce, water sources and environmental factors. some important emerging food and water borne bacterial pathogens include listeria monocytogenes, campylobacter jejuni, yersinia enterocolitica, salmonella enteritidis, escherichia coli o157: h7, vibrio cholerae biotype e1 tor serotype 0139, vibrio ...	1999	10810592
mutational analysis of the sbo-alb locus of bacillus subtilis: identification of genes required for subtilosin production and immunity.	the bacillus subtilis 168 derivative jh642 produces a bacteriocin, subtilosin, which possesses activity against listeria monocytogenes. inspection of the amino acid sequence of the presubtilosin polypeptide encoded by the gene sboa and sequence data from analysis of mature subtilosin indicate that the precursor subtilosin peptide undergoes several unique and unusual chemical modifications during its maturation process. the genes of the sbo-alb operon are believed to function in the synthesis and ...	2000	10809709
[the multiplication dynamics of pathogenic bacteria in relation to the trophic and temperature cultivation conditions].	the comparative study of the dynamics of multiplication of listeria monocytogenes and yersinia pseudotuberculosis in organic and synthetic media and in distilled water at temperatures of 37 degrees c and 6 degrees c was carried out. this study revealed that in organic media the multiplication of bacteria was good at 37 degrees c and 6 degrees c. in mineral media and distilled water their multiplication was observed only at 6 degrees c. moreover, conditions necessary for the multiplication of pat ...	2000	10808565
innate defenses in the liver during listeria infection.	the majority of pathogens entering the bloodstream are cleared by the liver. listeria monocytogenes, an important natural pathogen of humans, is a useful tool for examining protective immune responses during systemic infections of mice. innate immunity contributes to blood clearance and eventual sterilization of the liver subsequent to listeria infections. effector mechanisms expressed in the liver early after infections are orchestrated by complex interactions between resident populations, i.e. ...	2000	10807514
cd8+ t-cell-mediated response to listeria monocytogenes taken up in the liver and replicating within hepatocytes.	like most other organisms that enter the bloodstream, the bulk of listeria monocytogenes injected i.v. into mice is taken up by the liver. listeriae not killed rapidly by infiltrating neutrophils are internalized by hepatocytes which constitute the principal site of intracellular replication in the liver. cd8+ t cells play a critical role in eliminating infected hepatocytes and resolving listerial infections of the liver; the specific mechanisms involved are not understood fully. here, we review ...	2000	10807511
internalization of listeria monocytogenes by nonprofessional and professional phagocytes.		2000	10804864
e. coli invasion of brain microvascular endothelial cells as a pathogenetic basis of meningitis.	a major limitation to advances in prevention and therapy of bacterial meningitis is our incomplete understanding of the pathogenesis of this disease. successful isolation and cultivation of bmec, which constitute the blood brain barrier, and the development of experimental hematogenous meningitis animal model, which mimics closely the pathogenesis of human meningitis, enabled us to dissect the pathogenetic mechanisms of bacterial meningitis. we have shown for the first time using e. coli as a pa ...	2000	10804851
[the effect of selected antibacterial antibiotics on production of interferon gamma (ifn-g) by mouse t lymphocytes stimulated by listeria monocytogenes].	the aim of the study was to determine the influence of certain antibiotics on the production of ifn-gamma by mouse lymphocytes t after four days incubation with listeria monocytogenes. the level of mouse ifn-gamma was determined by elisa method (inter test-gamma mouse ifn-gamma kit, genzyme). the strongest immunosuppression effect was demonstrated using rifampicin (39 ng/ml ifn-gamma) (control: 123 +/- 29 ng/ml ifn-gamma, p < 0.05). lower immunosuppression effects were observed also with cephrad ...	1999	10803271
[the influence of antibiotics on phagocytic and bacteriocidal activity of rabbit peritoneal macrophages stimulated by filtrates of cultured t-lymphocytes].	the aim of the study was to determine the influence of twelve antibacterial antibiotics (various concentrations) on the activation of rabbit peritoneal macrophages. macrophages were stimulated by filtrates of culture of lymphocytes t obtained from ova immunized rabbits. phagocytic activity and intracellular killing against listeria monocytogenes were tested by fluorescence method. penicillin g (0.4-50 mg/l), erythromycin and lincomycin (2.5-40 mg/l) used at all concentrations, were not exerting ...	1999	10803270
the trophoblast is a component of the innate immune system during pregnancy.	systemic infection with listeria monocytogenes, a gram-positive intracellular bacterium, has been used extensively to analyze the innate immune response. macrophages are central to this response, acting as both the host for and principal defense against this bacterium. during pregnancy l. monocytogenes has a predilection for replication at the maternal-placental interface and consequently is an important cause of fetal morbidity and mortality. however, macrophages are mostly excluded from the mu ...	2000	10802718
high susceptibility to bacterial infection, but no liver dysfunction, in mice compromised for hepatocyte nf-kappab activation.	based on the essential involvement of nf-kappab in immune and inflammatory responses and its apoptosis-rescue function in normal and malignant cells, inhibitors of this transcription factor are potential therapeutics for the treatment of a wide range of diseases, from bronchial asthma to cancer. yet, given the essential function of nf-kappab in the embryonic liver, it is important to determine its necessity in the liver beyond embryogenesis. nf-kappab is normally retained in the cytoplasm by its ...	2000	10802715
characterization of the interaction between zyxin and members of the ena/vasodilator-stimulated phosphoprotein family of proteins.	zyxin contains a proline-rich n-terminal domain that is similar to the c-terminal domain in the acta protein of the bacteria, listeria monocytogenes. we screened the entire amino acid sequence of human zyxin for mena-interacting peptides and found that, as with acta, proline-rich sequences were the sole zyxin sequences capable of binding to ena/vasodilator-stimulated phosphoprotein (vasp) family members in vitro. from this information, we tested zyxin mutants in which the proline-rich sequences ...	2000	10801818
the use of listeriolysin to identify in vivo induced genes in the gram-positive intracellular pathogen listeria monocytogenes.	listeria monocytogenes is capable of growth within the cytoplasm of infected host cells. escape from the host cell phagosome is mediated primarily through secretion of listeriolysin, a haemolytic factor which functions to actively lyse the phagosomal membrane. listeriolysin negative mutants of l. monocytogenes are non-haemolytic on blood agar plates and demonstrate a significant reduction of virulence in the mouse model of infection. we have developed a system for the identification of in vivo i ...	2000	10792735
prfa mediates specific binding of rna polymerase of listeria monocytogenes to prfa-dependent virulence gene promoters resulting in a transcriptionally active complex.	there is accumulating evidence that the coordinate transcription of the virulence genes in listeria monocytogenes constitutes a very complex regulation mechanism which might require other factors in addition to prfa. we previously described an unknown proteinaceous component from crude bacterial cell extracts, which, together with prfa, formed a specific complex (ci) in electrophoretic mobility shift assays (emsa) with an hly promoter probe. here we identify the rna polymerase (rnap) of l. monoc ...	2000	10792734
treatment of sanitary-important bacteria by bacteriocin substance v24 in cattle dung water.	quantification of sanitary-important bacteria (e.g. enterobacteriaceae), as well as indicators of environmental contamination, was assessed in samples of cattle dung from 25 cattle farms in 15 north-eastern slovakia districts. the inhibitory effect of crude bacteriocin extract cbe v24 from enterococcus faecalis v24 against listeria monocytogenes ohio and yersinia enterocolitica ye85 was examined in cattle dung water with the aim of finding a new way of eliminating the health risk of the animal s ...	2000	10792671
improved detection of listeria monocytogenes in soft mould-ripened cheese.	in comparison with standard methods, enrichment in half-fraser broth for 24 h at 30 degrees c, followed by plating out onto listeria monocytogenes blood agar (lmba) and palcam medium combined with an additional streak proved to be the most rapid and specific method for the detection of indigenous l. monocytogenes populations from soft mould-ripened cheese. this procedure, with a high sensitivity (93%) and a low detection limit (1-10 cfu 25 g-1), provided negative and presumptive positive results ...	2000	10792548
thermal inactivation of listeria monocytogenes and yersinia enterocolitica in minced beef under laboratory conditions and in sous-vide prepared minced and solid beef cooked in a commercial retort.	d-values were obtained for listeria monocytogenes and yersinia enterocolitica at 50, 55 and 60 degrees c in vacuum-packed minced beef samples heated in a laboratory water-bath. the experiment was repeated using vacutainers, which allowed heating of the beef to the desired temperature before inoculation. d-values of between 0.15 and 36.1 min were obtained for l. monocytogenes. pre-heating the beef samples significantly affected (p < 0.05) the d60 value only. d-values for y. enterocolitica ranged ...	2000	10792520
limitation of adhesion and growth of listeria monocytogenes on stainless steel surfaces by staphylococcus sciuri biofilms.	the adhesion and subsequent development of listeria monocytogenes on stainless steel was studied in the absence and in the presence of a staphylococcus sciuri biofilm. in the three growth media studied, the percentage of adherent cells was reduced to nearly the same extent by the presence of 1-day biofilms of staph. sciuri for the two strains of l. monocytogenes studied. one-day biofilms of staph. sciuri exhibited the same exopolysaccharide content per square centimetre, although they colonized ...	2000	10792517
production of a nisin-like bacteriocin by lactococcus lactis subsp. lactis a164 isolated from kimchi.	lactococcus lactis subsp. lactis a164 was isolated from kimchi (korean traditional fermented vegetables). the bacteriocin produced by strain a164 was active against closely related lactic acid bacteria and some food-borne pathogens including staphylococcus aureus, listeria monocytogenes and salmonella typhimurium. the antimicrobial spectrum was nearly identical to that of nisin. bacteriocin activity was not destroyed by exposure to elevated temperatures at low ph values, but the activity was los ...	2000	10792514
modelling the growth of listeria monocytogenes in dynamic conditions.	a recurrent neural network for the prediction of listeria monocytogenes growth under ph and a(w) variable conditions was developed. the use of this model offered the possibility to take into account the consequences of the variations of the factors on l. monocytogenes growth. the effects of solutions, such as nacl, acetic acid and naoh, and their interactions on the response of l. monocytogenes cells were studied. furthermore, the results showed the capacity of the recurrent neural network to pr ...	2000	10791744
proteins variations in listeria monocytogenes exposed to high salinities.	listeria monocytogenes scott a grown in the minimal chemically defined medium m6lt was challenged to a concentration of either 35 or 65 g l(-1) of nacl for 1 h in the presence of a [35s]cysteine-[35s]methionine labelling mix. the protein patterns were analysed by 2d-electrophoresis in the two conditions and isoosmotic condition (5 g l(-1) of nacl in m6lt). a great number of proteins which were synthesized under isoosmotic conditions were either completely repressed or expressed at a reduced leve ...	2000	10791735
mechanism of action of pulsed high electric field (phef) on the membranes of food-poisoning bacteria is an 'all-or-nothing' effect.	salmonella typhimurium (cra 1005) was more sensitive than listeria monocytogenes (nctc 11994) to pulsed high electric field (phef) treatment in distilled water (10, 15 and 20 kv/cm), 10 mm tris-maleate buffer ph 7.4 (15 kv/cm) and model beef broth (0.75% w/v: 15 kv/cm). sublethal injury could not be detected using a selective medium plating technique, indicating that bacterial inactivation by phef may be an 'all-or-nothing' event. phef-induced membrane permeabilization resulted in increased uv-l ...	2000	10791731
acid responses of listeria monocytogenes.	the acid response and the correlated protein synthesis in listeria monocytogenes were studied. the lowest ph value which l. monocytogenes could resist was dependent on the strain and the kind of acid used. previous adaptation to an intermediary ph augmented bacterial resistance to a subsequent lethal acidic ph. the acid tolerance was also growth phase dependent. organic volatile acids exerted a more deleterious effect on l. monocytogenes than inorganic acids, because weak acids infer a lower int ...	2000	10791729
immobilization with metal hydroxides as a means to concentrate food-borne bacteria for detection by cultural and molecular methods.	the application of nucleic acid amplification methods to the detection of food-borne pathogens could be facilitated by concentrating the organisms from the food matrix before detection. this study evaluated the utility of metal hydroxide immobilization for the concentration of bacterial cells from dairy foods prior to detection by cultural and molecular methods. using reconstituted nonfat dry milk (nfdm) as a model, two food-borne pathogens (listeria monocytogenes and salmonella enterica serovar ...	2000	10788338
[investigation of listeria monocytogenes in soft cheeses].	listeria monocytogenes has been recognized as a bacteria that produces severe illness in animals and humans. considering the importance of the presence of l. monocytogenes in soft paste cheeses, a study of diverse cheeses from supermarkets of direct sale to the public was carried out. from the 35 analyzed cheeses, 4 strains were isolated (11.4%). the result of the serological study showed that all the strains corresponded to the serotype 4. the proteic profiles of the isolated strains showed sim ...	2000	10785944
listeria meningitis in children: report of two cases.	we report two cases of meningitis caused by listeria monocytogenes in children. the first patient was a healthy 14-month-old boy and the second patient a 3-year-old girl with byler disease which, however, is not reported as a predisposing factor for listeriosis. we present these cases because listeria infection, although common in neonates, is extremely infrequent during infancy and childhood.	2000	10782402
an outbreak of febrile gastroenteritis associated with corn contaminated by listeria monocytogenes.	on may 21, 1997, numerous cases of febrile gastrointestinal illness were reported among the students and staff of two primary schools in northern italy, all of whom had eaten at cafeterias served by the same caterer.	2000	10781619
smoking decreases alveolar macrophage function during anesthesia and surgery.	smoking changes numerous alveolar macrophage functions and is one of the most important risk factors for postoperative pulmonary complications. the current study tested the hypothesis that smoking impairs antimicrobial and proinflammatory responses in alveolar macrophages during anesthesia and surgery.	2000	10781271
specific binding of recombinant listeria monocytogenes p60 protein to caco-2 cells.	the listeria monocytogenes p60 is a major extracellular protein, which is believed to be involved in the invasion of these bacteria into their host cells. so far the mechanism by which p60 participates in the internalization or penetration of l. monocytogenes is still veiled. to determine the possibility of a direct interaction of p60 with the host cell surface, the iap gene was recombinantly expressed in escherichia coli and used for binding studies with the enterocyte-like caco-2 cells. fluore ...	2000	10779709
the use of immuno-magnetic separation (ims) as a tool in a sample preparation method for direct detection of l. monocytogenes in cheese.	a sample preparation procedure was developed for direct detection of l. monocytogenes in cheese. the sample preparation protocol consisted of a 10-fold dilution and homogenization, a centrifugation step to precipitate large food particles, passage of the supernatant over a sieve and through a separatory funnel to further eliminate food particles and fat, a centrifugation step to recover the bacterial pellet and finally enzymatic digestion of the suspension to degrade the remaining small food par ...	2000	10777071
a combined discrete-continuous model describing the lag phase of listeria monocytogenes.	food microbiologists generally use continuous sigmoidal functions such as the empirical gompertz equation to obtain the kinetic parameters specific growth rate (mu) and lag phase duration (lambda) from bacterial growth curves. this approach yields reliable information on mu; however, values for lambda are difficult to determine accurately due, in part, to our poor understanding of the physiological events taking place during adaptation of cells to new environments. existing models also assume a ...	2000	10777067
development of a simple recovery-enrichment system for enhanced detection of heat-injured listeria monocytogenes in pasteurized milk.	a simple anaerobic recovery-enrichment system, semisolid penn state university (sspsu) broth, that enhances recovery of heat-injured listeria monocytogenes, was rapidly achieved in 10-ml screw-capped tubes by adding bacto-agar (2.5 g/liter) and l-cysteine (0.5 g/liter) to penn state university broth. glucose was removed from the formulation for sspsu broth to prevent the growth of thermoduric lactobacilli. ferric ammonium citrate was added to sspsu broth to detect esculin hydrolysis and to indic ...	2000	10772211
modeling microbial survival during exposure to a lethal agent with varying intensity.	traditionally, the efficacy of preservation and disinfection processes has been assessed on the basis of the assumption that microbial mortality follows a first-order kinetic. however, as departures from this assumed kinetics are quite common, various other models, based on higher-order kinetics or population balance, have also been proposed. the database for either type of models is a set of survival curves of the targeted organism or spores determined under constant conditions, that is, consta ...	2000	10770273
osmotic and chill activation of glycine betaine porter ii in listeria monocytogenes membrane vesicles.	listeria monocytogenes is a foodborne pathogen known for its tolerance to conditions of osmotic and chill stress. accumulation of glycine betaine has been found to be important in the organism's tolerance to both of these stresses. a procedure was developed for the purification of membranes from l. monocytogenes cells in which the putative atp-driven glycine betaine permease glycine betaine porter ii (gbu) is functional. as is the case for the l. monocytogenes sodium-driven glycine betaine uptak ...	2000	10762257
substantial in vivo proliferation of cd4(+) and cd8(+) t lymphocytes during secondary listeria monocytogenes infection.	in mice listeria monocytogenes infection induces a strong t cell response. in an attempt to quantitatively analyze the magnitude and kinetics of the cd4(+) and cd8(+) t cell response during l. monocytogenes infection in vivo we used a t cell transfer system that is independent of in vitro cell culture techniques and information about the identity of immunogenic t cell epitopes. our results demonstrate substantial expansion of the in vivo primed and transferred t cell populations in response to l ...	2000	10760793
the clpp serine protease is essential for the intracellular parasitism and virulence of listeria monocytogenes.	we identified the stress-induced clpp of listeria monocytogenes and demonstrated its crucial role in intracellular survival of this pathogen. clpp is a 21.6 kda protein belonging to a family of proteases highly conserved in prokaryotes and eukaryotes. a clpp-deleted mutant enabled us to demonstrate that clpp is involved in proteolysis and is required for growth under stress conditions. intramacrophage survival of this mutant was strongly restricted, thus resulting in loss of virulence for the mo ...	2000	10760131
intracellular staining for tnf and ifn-gamma detects different frequencies of antigen-specific cd8(+) t cells.	cd8(+) t lymphocytes are important mediators of adaptive immunity against certain viral, protozoan and bacterial pathogens. activated cd8(+) t cells are able to induce cytolysis of infected cells (perforin and cd95-cd95l mediated pathways) and also elaborate cytokines, including ifn-gamma and tnf after appropriate mhc class i-peptide recognition. new technologies for the detection of antigen-specific cd8(+) t cells, including tetrameric mhc class i-peptide complexes, intracellular ifn-gamma stai ...	2000	10758241
effect of benzylpenicillin on murein biosynthesis, turnover and structure in listeria monocytogenes cells.	the action of beta-lactam antibiotics such as ampicillin and benzylpenicillin on cells of listeria monocytogenes appears to be bacteriostatic. however, after approximately two hours in the presence of 10 x mic of benzylpenicillin the cells begin to rapidly lose viability without undergoing lysis. in this report we present the results of studies on the biosynthesis of murein in l. monocytogenes cells during the first 120 min of their exposure to benzylpenicillin as measured by the continuous and ...	1999	10756717
intracellular growth of listeria monocytogenes insertional mutant deprived of protein p60.	the study of the mutant strain described here demonstrates that several characteristics contribute to maximal virulence of pathogenic strains of l. monocytogenes. the invasion levels of l. monocytogenes jb1115, a p60-deficient strain, were the same as for the parent strain l. monocytogenes 1043s in j774 macrophage-like cells. the invasion level of listeria strains in int407 cells was 100 times lower than in j774 cells. in epithelial int407 cells, the time of division of p60- strain l. monocytoge ...	1999	10756716
development of a new lysis solution for releasing genomic dna from bacterial cells for dna amplification by polymerase chain reaction.	a new lysis solution designated tz, consisting of 2.0% triton x-100 plus 2.5 mg sodium azide/ml in 0.1 m tris-hcl buffer at ph 8.0, yielded higher levels of genomic dna from escherichia coli o157:h7 cells compared with a number of other commonly used cell lysis methods. ethidium bromide stained dna bands resulting from pcr amplification of target dna from 100 cfu of e. coli o157:h7 were readily detected following electrophoresis of agarose gels. in contrast, conventional cell lysis methods faile ...	2000	10756522
differing roles of inflammation and antigen in t cell proliferation and memory generation.	recent studies have demonstrated that viral and bacterial infections can induce dramatic in vivo expansion of ag-specific t lymphocytes. although presentation of ag is critical for activation of naive t cells, it is less clear how dependent subsequent in vivo t cell proliferation and memory generation are upon ag. we investigated t cell expansion and memory generation in mice infected alternately with strains of listeria monocytogenes that contained or lacked an immunodominant, mhc class i-restr ...	2000	10754299
monitoring cellular responses to listeria monocytogenes with oligonucleotide arrays.	listeria monocytogenes is a pathogenic intracellular microorganism whose infection induces pleiotropic biological changes associated with host cell gene expression regulation. here we define the gene expression profiles of the human promyelocytic thp1 cell line before and after l. monocytogenes infection. gene expression was measured on a large scale via oligonucleotide microarrays with probe sets corresponding to 6,800 human genes. we assessed and discussed the reproducibility of the hybridizat ...	2000	10753925
listeria monocytogenes meningitis during the incubation period of hepatitis a disease.		2000	10749478
listeria monocytogenes subtypes associated with mortality among fallow deer (dama dama).	different subtypes of listeria monocytogenes were isolated from various animal and environmental samples during an episode of increased mortality on a fallow deer (dama dama) farm. during a 4-wk period, six fallow deer died, including four does, one fawn, and one adult buck. prior to death, one of the does had exhibited central nervous system signs characteristic of listeriosis. postmortem examination of the six deer showed no histologic changes typical of listeriosis, although inflammatory chan ...	1999	10749443
sensitivity of nisin-resistant listeria monocytogenes to heat and the synergistic action of heat and nisin.	nisin, a bacteriocin produced by some strains of lactococcus lactis, acts against foodborne pathogen listeria monocytogenes. a single exposure of cells to nisin can generate nisin-resistant (nisr) mutants, which may compromise the use of nisin in the food industry. the objective of this research was to compare the heat resistance of nisr and wild type (wt) listeria monocytogenes. the synergistic effect of heat-treatment (55 degrees c) and nisin (500 iu ml-1) on the nisr cells and the wt l. monoc ...	2000	10747260
activity of hydrolysed lactoferrin against foodborne pathogenic bacteria in growth media: the effect of edta.	lactoferrin was hydrolysed with pepsin and the antimicrobial activity of the resulting hydrolysate (hlf) was studied in 1% peptone, 0.05% yeast extract, 1% glucose (pyg) medium and tryptic soy broth (tsb). hlf was effective against listeria monocytogenes, enterohaemorrhagic escherichia coli and salmonella enteritidis in pyg, however, the highest studied concentration (1.6 mg ml-1) did not inhibit growth of any of these organisms in tsb. the addition of edta enhanced the activity of hlf in tsb, i ...	2000	10747257
variations in virulence between different electrophoretic types of listeria monocytogenes.	a total of 245 strains of listeria monocytogenes, representing 33 different electrophoretic types (ets), were examined quantitatively for haemolytic activity. no significant difference was observed in the mean haemolytic activity between different ets. eighty four out of 91 strains examined were found to be virulent for chick embryos. strains belonging to et 2 and et 4 were found to be less virulent than strains of other ets (p = 0.0447). furthermore, strains from clinical cases were found to be ...	2000	10747256
the growth and resistance to sodium hypochlorite of listeria monocytogenes in a steady-state multispecies biofilm.	a constant-depth film fermenter (cdff) was used to culture a steady-state multispecies biofilm consisting of one strain each of listeria monocytogenes, pseudomonas fragi and staphylococcus xylosus. these bacteria were initially grown together in a conventional chemostat to achieve a steady state before being inoculated into the cdff over an 18-h period. a dilute tryptone soya broth (tsb) medium was supplied to the cdff and the biofilm allowed to develop over a 28-d period. this mature biofilm wa ...	2000	10747232
anti-listeria effect of enterocin a, produced by cheese-isolated enterococcus faecium efm01, relative to other bacteriocins from lactic acid bacteria.	enterocin a produced by enterococcus faecium efm01 displayed a narrow antimicrobial spectrum, mainly directed against listeria spp. in particular, the bacteriocin was extremely active against 13 listeria monocytogenes strains. this high specificity of action of enterocin a for listeria spp. relative to lactic acid bacteria, together with its broad range of activity from ph 4.0 to ph 9.0, are factors which may be of great interest with respect to the potential antilisterial use of this bacterioci ...	2000	10747225
improvement of the detection of listeria monocytogenes by the application of aloa, a diagnostic, chromogenic isolation medium.	a new selective agar medium, aloa, for the selective and differential isolation of listeria monocytogenes has been evaluated. all stressed cultures of l. monocytogenes serovars tested grew on the medium as bluish colonies surrounded by a distinctive opaque halo and gave a productivity ratio of at least 0.95. non-pathogenic listeria sp. produced bluish colonies without a halo as was also the case for some enterococci and bacilli. special attention must be paid to some bacillus cereus strains and ...	2000	10747223
acting like actin. the dynamics of the nematode major sperm protein (msp) cytoskeleton indicate a push-pull mechanism for amoeboid cell motility.		2000	10747081
gc1q-r/p32, a c1q-binding protein, is a receptor for the inlb invasion protein of listeria monocytogenes.	inlb is a listeria monocytogenes protein that promotes entry of the bacterium into mammalian cells by stimulating tyrosine phosphorylation of the adaptor proteins gab1, cbl and shc, and activation of phosphatidyl- inositol (pi) 3-kinase. using affinity chromatography and enzyme-linked immunosorbent assay, we demonstrate a direct interaction between inlb and the mammalian protein gc1q-r, the receptor of the globular part of the complement component c1q. soluble c1q or anti-gc1q-r antibodies impai ...	2000	10747014
identification of new loci involved in adhesion of listeria monocytogenes to eukaryotic cells. european listeria genome consortium.	insertional mutagenesis was performed with tn1545 in the genetic background of an iniab deletion mutant to identify new adhesion determinants in listeria monocytogenes. four insertion mutants defective in adhesion to eukaryotic cells were identified. insertion sites were cloned by inverse-pcr and sequenced. the genetic organization of insertion regions was further analysed by screening and sequencing dna fragments from a hindiii library and by searching databases. three adhesion-defective mutant ...	2000	10746777
inhibitory combinations of nisin, sodium chloride, and ph on listeria monocytogenes atcc 15313 in broth by an experimental design approach.	the influence of ph (5.0-8.2), nacl concentrations (0-6% w/v), and incubation time (0-24 h) on the inhibitory activity of nisin (0-100 i.u./ml) against listeria monocytogenes (10(3) cfu/ml) was studied using the doehlert experimental design and was confirmed by kinetic experiments. predicted values were in agreement with experimental values. experiments were carried out at 22 degrees c in reconstituted tsb-ye1 broth with or without nacl. nisin had an immediate ph-dependent bactericidal effect, w ...	2000	10746580
local activation of nonspecific defense against a respiratory model infection by application of interferon-gamma: comparison between rat alveolar and interstitial lung macrophages.	pulmonary macrophages play a crucial role in the defense of inhaled pathogens. we characterized functional properties of alveolar (am) and interstitial (im) macrophages from rats. am exhibited a pronounced microbicidal capacity as shown by an elevated production of reactive oxygen intermediates (roi), nitric oxide (no), tumor necrosis factor (tnf)-alpha, and tumor cytotoxicity when compared with im. in contrast, im were superior to am regarding mechanisms mainly involved in the induction and mai ...	2000	10745029
outbreak of listeria monocytogenes serovar 4b infection in france.		2000	10743331
significance of inoculum size in the lag time of listeria monocytogenes.	the lag time of listeria monocytogenes growing under suboptimal conditions (low nutrient concentrations, ph 6, and 6.5 degrees c) was extended when the inoculum was severely stressed by starvation and the inoculum size was very small. predictive microbiology should deal with bacterial stress and stochastic approaches to improve its value for the agro-food industry.	2000	10742265
influence of catalase and superoxide dismutase on ozone inactivation of listeria monocytogenes.	the effects of ozone at 0.25, 0.40, and 1.00 ppm on listeria monocytogenes were evaluated in distilled water and phosphate-buffered saline. differences in sensitivity to ozone were found to exist among the six strains examined. greater cell death was found following exposure at lower temperatures. early stationary-phase cells were less sensitive to ozone than mid-exponential- and late stationary-phase cells. ozonation at 1.00 ppm of cabbage inoculated with l. monocytogenes effectively inactivate ...	2000	10742219
the interaction of intestinal epithelial cells and intraepithelial lymphocytes in host defense.	intestinal intraepithelial lymphocytes (i-iel) are located at the basolateral surfaces of intestinal epithelial cells (i-ec) and play important roles in the homeostasis of intestinal microenvironment. i-iel comprise unique t cell populations including cd4-cd8alphaalpha+ t cells expressing t cell receptor (tcr)alphabeta or tcrgammadelta and cd4+ cd8alphaalpha+ t cells expressing tcr alphabeta. we show here that cd4+ cd8alphaalpha+ i-iel belongs to th1 type t cells capable of responding to self-mh ...	1999	10741862
anchor structure of cell wall surface proteins in listeria monocytogenes.	many surface proteins of gram-positive bacteria are anchored to the cell wall by a mechanism requiring a cooh-terminal sorting signal with a conserved lpxtg motif. in staphylococcus aureus, surface proteins are cleaved between the threonine and the glycine of the lpxtg motif. the carboxyl of threonine is subsequently amide linked to the amino group of the pentaglycine cell wall crossbridge. here we investigated the anchor structure of surface proteins in listeria monocytogenes. a methionine and ...	2000	10736172
physiological effects of high hydrostatic pressure treatments on listeria monocytogenes and salmonella typhimurium.	the effect of a high hydrostatic pressure treatment on the gram-positive listeria monocytogenes strain scott a and the gram-negative salmonella typhimurium strain mutton (atcc13 311) has been determined in stationary phase cell suspensions. pressure treatments were done at room temperature for 10 min in sodium citrate (ph 5.6) and sodium phosphate (ph 7.0) suspension buffers. increasing pressure treatments resulted in an exponential decrease of cell counts. salmonella typhimurium suspended at lo ...	2000	10735987
characteristics of the biologically active 35-kda metalloprotease virulence factor from listeria monocytogenes.	listeria monocytogenes, a facultative intracellular pathogen, synthesizes an extracellular protease which is responsible for the maturation of phosphatidylcholine phospholipase c (lecithinase), a virulence factor involved in cell-to-cell spread. this work describes the environmental parameters necessary for increased production of mature, 35-kda active protease in strains of l. monocytogenes, and its detection using polyclonal antibodies raised against bacillus subtilis neutral protease. high pe ...	2000	10735252
purification and some characteristics of enterocin on-157, a bacteriocin produced by enterococcus faecium niai 157.	bacteriocin-like activity (bla) was screened in 690 strains of lactic acid bacteria isolated from plant materials such as silages and fermented vegetables. among them, a strain identified as enterococcus faecium niai 157 showed a clear bla against the indicator strain, ent. faecium ifo 13712. the proteinaceous nature and antimicrobial activity against closely related species strongly indicated that this bla was a bacteriocin and was designated enterocin on-157. the bacteriocin activity of this s ...	2000	10735246
the growth of listeria monocytogenes in cheese packed under a modified atmosphere.	the effect of modified atmosphere packaging (map) on the growth of listeria monocytogenes in mould ripened cheeses was studied at refrigeration temperatures (2-8.3 degrees c) over a storage period of 6 weeks. control experiments in cling film with no atmospheric modification produced a lag time before growth of up to 1 week and rapid subsequent growth. map with a co2 concentration of less than 20% allowed growth to occur but when o2 was incorporated; the lag time was reduced from 3 to 2 weeks an ...	2000	10735243
growth of listeria monocytogenes and yersinia enterocolitica colonies under modified atmospheres at 4 and 8 degrees c using a model food system.	the growth of listeria monocytogenes and yersinia enterocolitica colonies was studied on solid media at 4 and 8 degrees c under modified atmospheres (mas) of 5% o2: 10% co2: 85% n2 (ma1), 30% co2: 70% n2 (ma2) and air (control). colony radius, determined using computer image analysis, allowed specific growth rates (mu) and the time taken to detect bacterial colonies to be estimated, after colonies became visible. at 4 degrees c both mas decreased the growth rates of l. monocytogenes by 1.5- and ...	2000	10735241
pregnancy-associated glycoprotein levels in pregnant goats inoculated with toxoplasma gondii or listeria monocytogenes: a retrospective study.	the pregnancy-associated glycoprotein (pag) concentration profiles of goats that had been experimentally inoculated with either toxoplasma gondii or listeria monocytogenes are described. all goats were examined regularly by ultrasonography. in t. gondii-infected females (n = 5), a slow decrease of pag was observed throughout a period of 55 to 74 d after inoculation. afterwards, the goats either aborted (n = 4) or kidded 1 dead and 1 weak fetus (n = 1). in l. monocytogenes-infected females (n = 8 ...	1999	10735115
listeriosis, france.		2000	10734782
[listeria monocytogenes endocarditis of a prosthetic valve].		2000	10734764
efficiency of four secondary enrichment protocols in differentiation and isolation of listeria spp. and listeria monocytogenes from smoked fish processing chains.	four secondary enrichment protocols (conventional methods: uvm ii, fraser 24 h and fraser 48 h: impedimetric method: listeria electrical detection medium) were studied for their ability to isolate listeria spp. and listeria monocytogenes from fish and environmental samples collected along the processing chain of cold-smoked fish. from all methods, listeria spp. and l. monocytogenes were respectively present in 56 and 34 of 315 samples analysed. fraser broth incubated for 48 h gave the fewest fal ...	1999	10733247
listeria monocytogenes septicemia in a thoroughbred foal.	listeria monocytogenes septicemia was diagnosed in a 6-day-old thoroughbred foal. primary clinical signs included fever, depression, diarrhea, and respiratory distress. hematologic abnormalities included leukopenia, neutropenia, degenerative left shift, and hyperfibrinogenemia. clinical chemistry and blood gas abnormalities included metabolic acidosis, hypoxemia, hypocapnia, hypoglycemia, and hyponatremia. despite aggressive therapeutic intervention and intensive care, the foal died within 12 ho ...	2000	10730952
behaviour of listeria spp. in naturally contaminated chorizo (spanish fermented sausage).	counts of listeria spp. were determined during the manufacture and drying of 21 lots of five chorizo varieties produced by three different manufacturers. presumptive listeria were not isolated from any of the batches produced in a large factory (f3) using starter, sorbate and controlled ripening at high temperatures. initial levels in factory 1 (f1), with no starter added, but controlled ripening at low temperatures, were ca 3.5 log10 cfu/g while those in factory 2 (f2), with no starter added an ...	1999	10728617
validation of predictive models describing the growth of listeria monocytogenes.	in this study, predictions for growth rate of listeria on food products were evaluated by both general applicable models and specific growth models. literature values, obtained from a large number of publications, for growth rates in/on a variety of foods were compared by graphical and mathematical analysis with predictions given by various models. apart for the great advantage of being generally applicable, the general models performed best. however, only small differences between the various m ...	1999	10728614
osmoprotectants and cryoprotectants for listeria monocytogenes.	listeria monocytogenes is a foodborne pathogen that can grow in high osmotic strength environments and at refrigeration temperatures. glycine betaine, proline betaine, acetylcarnitine, carnitine, gamma-butyrobetaine and 3-dimethylsulphoniopropionate all acted as osmoprotectants, as evidenced by an increase in growth rate of l. monocytogenes 10403s and scott a when provided with these compounds, while being stressed in defined medium containing 0.7 m nacl. these same compounds exhibited cryoprote ...	2000	10728555
oral delivery of dna vaccines using attenuated salmonella typhimurium as carrier.	the efficacious delivery of eukaryotic expression plasmids to inductive cells of the immune system constitutes a key prerequisite for the generation of effective dna vaccines. here, we have explored the use of bacteria as vehicles to orally deliver expression plasmids. attenuated salmonella typhimurium aroa harbouring eukaryotic expression plasmids that encoded virulence factors of listeria monocytogenes were administered orally to balb/c mice. strong cytotoxic and helper t cell responses as wel ...	2000	10727890
novel bacterial systems for the delivery of recombinant protein or dna.	on the basis of attenuated intracellular bacteria, we have developed two delivery systems for either heterologous proteins or dna vaccine vectors. the first system utilizes attenuated strains of gram-negative bacteria which are engineered to secrete heterologous antigens via the alpha-hemolysin secretion system of escherichia coli. the second system is based on attenuated suicide strains of listeria monocytogenes, which are used for the direct delivery of eukaryotic antigen expression vectors in ...	2000	10727885
bacterial meningitis.	with nearly 8,000 cases in the united states per year, and 2,000 deaths annually, bacterial meningitis continues to be a significant source of morbidity and mortality. the principal pathogens are neisseria meningitidis, streptococcus pneumoniae, group b streptococci, and hemophilus influenzae. in immunocompromised patients, listeria monocytogenes is also an important pathogen. rapid identification and evaluation of the patient with bacterial meningitis and prompt initiation of antibiotics are th ...	2000	10725671
cd8(+) t-cell priming against a nonsecreted listeria monocytogenes antigen is independent of the antimicrobial activities of gamma interferon.	sublethal infection of mice with recombinant listeria monocytogenes expressing a model epitope in either secreted or nonsecreted form results in similar cd8(+) t-cell priming. since nonsecreted bacterial proteins have no obvious access to the endogenous major histocompatibility complex (mhc) class i presentation pathway, presentation of these antigens requires destruction of the bacterium to reveal the nonsecreted molecules to an exogenous mhc class i presentation pathway. gamma interferon (ifn- ...	2000	10722620
purified lipopolysaccharide from francisella tularensis live vaccine strain (lvs) induces protective immunity against lvs infection that requires b cells and gamma interferon.	previous results have demonstrated that nonspecific protective immunity against lethal francisella tularensis live vaccine strain (lvs) or listeria monocytogenes infection can be stimulated either by sublethal infection with bacteria or by treatment with bacterial dna given 3 days before lethal challenge. here we characterize the ability of purified lipopolysaccharide (lps) from f. tularensis lvs to stimulate similar early protective immunity. treatment of mice with surprisingly small amounts of ...	2000	10722593
macrophage class a scavenger receptor-mediated phagocytosis of escherichia coli: role of cell heterogeneity, microbial strain, and culture conditions in vitro.	macrophage class a scavenger receptors (sr-ai and sr-aii) contribute to host defense by binding polyanionic ligands such as lipopolysaccharide and lipoteichoic acid. sr-a knockout (sr-a(-/-)) mice are more susceptible to endotoxic shock and listeria monocytogenes infection in vivo, possibly due to decreased clearance of lipopolysaccharide and microorganisms, respectively. we have used flow cytometry to analyze the role of sr-a and other scavenger-like receptors in phagocytosis of bacteria in vit ...	2000	10722588
twenty-four-hour direct presumptive enumeration of listeria monocytogenes in food and environmental samples using the iso-grid method with lm-137 agar.	a new culture medium, lm-137 agar, was developed for use with the iso-grid hydrophobic grid membrane filter system for direct presumptive enumeration of listeria monocytogenes in 24 h. the method was validated against three-replicate, three-dilution most probable number procedures based on enrichment methods specified by the u.s. department of agriculture, the association of official analytical chemists international and the u.s. food and drug administration. the study encompassed meats, dairy p ...	2000	10716565
development and evaluation of a 24-hour method for the detection and quantification of listeria monocytogenes in meat products.	a 24-h filter monitor-based test, listeria-select, has been developed to quantify listeria monocytogenes organisms in meat samples with a sensitivity of < or = 1.0 cfu/g. the technique comprises a filter monitor-based system and a colony lift immunoassay to identify and enumerate the target organism. meat homogenates were centrifuged and the eluate was filtered to trap and immobilize the microorganisms on the filter. fraser broth was then added to the filter apparatus to allow the organisms to b ...	2000	10716564
rapid polymerase chain reaction/dna probe membrane-based assay for the detection of listeria and listeria monocytogenes in food.	we describe the development of polymerase chain reaction (pcr)/dna probe membrane-based colorimetric assays for the detection and identification of listeria and l. monocytogenes. pcr primers designed from the 16s to 23s rrna intergenic spacer region amplified products that were reverse hybridized to membrane-bound oligonucleotide probes specific for listeria and l. monocytogenes with a detection limit of 1 to 10 cfu/25 ml in inoculated raw and pasteurized milk samples. these qualitative assays h ...	2000	10716562
single-strand conformation polymorphisms in the hly gene and polymerase chain reaction analysis of a repeat region in the iap gene to identify and type listeria monocytogenes.	two novel methods that allow the powerful identification of listeria monocytogenes by polymerase chain reaction (pcr) and simultaneous differentiation by special electrophoresis formats are described. the first method involves a pcr-driven single-strand conformation polymorphism (sscp-pcr) assay using a portion of the noncoding region of the hlv gene. the assay was evaluated with 120 genetically distinct l. monocytogenes strains of either foodborne or clinical origin. distribution of listerial s ...	2000	10716561
infections and intoxications associated with animal feed and forage which may present a hazard to human health.	animal feed or forage may be the source of a limited number of infections for farm animals that could lead to human illness. likely organisms include salmonella enterica, toxoplasma gondii, trichinella spiralis and possibly the agent of bovine spongiform encephalopathy. the risk to human health from other infectious agents which may contaminate either feed or forage appear to be either negligible, e.g. bacillus anthracis and mycobacterium bovis, or non-existent, e.g. clostridium botulinum toxin ...	2000	10712800
does administration of infliximab increase susceptibility to listeriosis?		2000	10710107
human toll-like receptors 2 and 4 are targets for deactivation of mononuclear phagocytes by interleukin-4.		2000	10709778
genes for the synthesis of the osmoprotectant glycine betaine from choline in the moderately halophilic bacterium halomonas elongata dsm 3043, usa.	the genes involved in the oxidative pathway of choline to glycine betaine in the moderate halophile halomonas elongata dsm 3043 were isolated by functional complementation of an escherichia coli strain defective in glycine betaine synthesis. the cloned region was able to mediate the oxidation of choline to glycine betaine in e. coli, but not the transport of choline, indicating that the gene(s) involved in choline transport are not clustered with the glycine betaine synthesis genes. nucleotide s ...	2000	10708384
erratum: volume 45, number 1, january 2000	the legend to the issue's cover figure was incorrectly printed. it should have read: cover micrograph: actin-comet tails induced by the bacterial pathogen listeria monocytogenes. vero cells were infected by listeria monoctyogenes. after fixation, cells were labeled with fitc-phalloidin (green) and anti-listeria antibodies (red). photo courtesy of inigo lasa and pascale cossart.	2000	10706779