Publications

control of il-12 and ifn-gamma production in response to live or dead bacteria by tnf and other factors.	when mice were infected i.v. with either listeria monocytogenes or brucella abortus, bioactive il-12 was briefly detected in serum and supernatants of spleen homogenates immediately ex vivo. although the time scale was more prolonged for the more slowly growing b. abortus, in both instances il-12 production ceased while bacteria still persisted in high numbers. production of il-12, detected in serum and spleen, was neither increased nor prolonged by injecting abs to il-10 or il-4. in contrast wi ...	1998	9686610
specificity of the bax polymerase chain reaction system for detection of the foodborne pathogen listeria monocytogenes.	the polymerase chain reaction (pcr) can be used for rapid and specific detection of foodborne pathogens. one commercial kit, the qualicon bax system uses pcr to detect listeria monocytogenes in enrichment cultures derived from food and environmental samples. the specificity and sensitivity of the bax system for detecting l. monocytogenes were characterized by using both pure and mixed cell cultures, and optimal conditions for production of cell lysates were determined. the bax system was highly ...	1998	9680707
listeriolysin o: cholesterol inhibits cytolysis but not binding to cellular membranes.	listeriolysin o (llo) binds to cholesterol-containing membranes in which it oligomerizes to form pores. preincubation of the toxin with cholesterol is known to inhibit haemolysis, whereas the oxidized form of cholesterol has no inhibitory effect. using immunoblot analyses and flow cytometry we demonstrate that preincubation with cholesterol does not influence binding of the listeriolysin-cholesterol complex to red blood cells, eukaryotic cells or artificial membranes. lytic activity of membrane- ...	1998	9680200
differential chemokine response of murine macrophages stimulated with cytokines and infected with listeria monocytogenes.	during inflammatory processes the infected macrophage is a rich source of chemokines which induce infiltration of leukocytes to the site of infection. we investigated the regulation of chemokine production by murine macrophages in response to infection with the intracellular bacterial pathogen, listeria monocytogenes. as a source of quiescent macrophages, murine bone marrow-derived macrophages (bmm) cultured under serum-free conditions were used. with rt-pcr, we detected induction of rna message ...	1998	9678756
heat stability of virulence-associated enzymes from listeria monocytogenes slcc 5764.	the enzyme activities of listeriolysin o (llo), phosphatidylinositol-specific phospholipase c (pi-plc), catalase (ca), and superoxide dismutase (sod) from listeria monocytogenes slcc 5764 were examined after heat treatment, growth at elevated temperatures, and anaerobic growth. growth at elevated temperatures may influence virulence as expressed by virulence enzyme activity. the enzymes were heated for 0 and 10 min at temperatures ranging from 40 to 100 degrees c. the production of llo was exami ...	1998	9678177
reducing total aerobic counts and listeria monocytogenes on the surface of king salmon (oncorhynchus tshawytscha).	a trial industrial-scale fin-fish washing system was assessed for its effectiveness in removing bacteria associated with the skin of gilled and gutted king salmon (oncorhynchus tshawytscha). exposure of the salmon to 200 ppm free chlorine at a turnover rate for the total volume of the wash solution of 2.25 cycles h-1 for 120 min resulted in decreases in the aerobic plate count (apc) recovered from the salmon ranging from 96.6 to 99.2%. in order to optimize the washing regime a laboratory-scale f ...	1998	9678168
effect of oxygen concentration and redox potential on recovery of sublethally heat-damaged cells of escherichia coli o157:h7, salmonella enteritidis and listeria monocytogenes.	the measured heat resistance of cells of escherichia coli o157:h7, salmonella enteritidis and listeria monocytogenes was up to eightfold greater when they were grown, heated and recovered anaerobically rather than aerobically. measured heat resistance was highest when anaerobic gas mixtures were used (time at 59 degrees c for a 6-decimal (6-d) reduction of e. coli o157:h7, 19-24 min); moderate when low concentrations of oxygen (0.5-1%) were included (time for a 6-d reduction, 5-17 min); and lowe ...	1998	9674145
bacteriocin inhibition of two glucose transport systems in listeria monocytogenes.	listeria monocytogenes transports glucose by proton motive force-mediated and phosphoenolpyruvate-dependent phosphotransferase systems (pep-dependent pts). inhibition of both systems by nisin, pediocin jd and leuconosin s is reported here for four strains of l. monocytogenes. intracellular and extracellular adenosine triphosphate (atp) and extracellular inorganic phosphate were measured in energized l. monocytogenes scott a cells to determine whether inhibition of the pep-dependent pts might occ ...	1998	9674123
molecular typing of listeria monocytogenes isolated in japan by pulsed-field gel electrophoresis.	a total of 40 strains of listeria monocytogenes which have been demonstrated to be serovar 1/2a, 1/2b, and 4b were genotyped by pulsed-field gel electrophoresis (pfge) after separate digestion with apa i, asc i, sma i, and sse 8387 i. twenty-seven unrelated strains including four representative strains showed distinctly different genotypes according to their pfge profiles. then nine strains isolated from shredded cheese of different lots and four strains isolated from the cheese-processing envir ...	1998	9673950
gelsolin, a protein that caps the barbed ends and severs actin filaments, enhances the actin-based motility of listeria monocytogenes in host cells.	the actin-based motility of listeria monocytogenes requires the addition of actin monomers to the barbed or plus ends of actin filaments. immunofluorescence micrographs have demonstrated that gelsolin, a protein that both caps barbed ends and severs actin filaments, is concentrated directly behind motile bacteria at the junction between the actin filament rocket tail and the bacterium. in contrast, capg, a protein that strictly caps actin filaments, fails to localize near intracellular listeria. ...	1998	9673261
interactions of the invasive pathogens salmonella typhimurium, listeria monocytogenes, and shigella flexneri with m cells and murine peyer's patches.	invasive enteric bacteria must pass through the intestinal epithelium in order to establish infection. it is becoming clear that a common target for intestinal mucosa penetration is the specialized epithelial cell of peyer's patches, the m cell. in order to gain a better understanding of how bacteria interact with m cells, we have compared the interactions of salmonella typhimurium, listeria monocytogenes, and shigella flexneri with m cells by using a murine ligated-loop model. our results indic ...	1998	9673259
listeria monocytogenes stimulates mucus exocytosis in cultured human polarized mucosecreting intestinal cells through action of listeriolysin o.	when the intracellular pathogen listeria monocytogenes infects cultured human mucosecreting polarized ht29-mtx cells apically, it induces the stimulation of mucus exocytosis without cell entry. using a set of isogenic mutants and purified listeriolysin o (llo), we identified the l. monocytogenes thiol-activated exotoxin llo as the agonist of mucus secretion. we demonstrated that the llo-induced mucus exocytosis did not result from the llo membrane-damaging activity. we found that llo-induced muc ...	1998	9673248
regulation of hly expression in listeria monocytogenes by carbon sources and ph occurs through separate mechanisms mediated by prfa.	expression of the prfa-controlled virulence gene hly (encoding the pore-forming cytolysin listeriolysin) is under negative regulation by readily metabolized carbon sources in listeria monocytogenes. however, the hyperhemolytic strain nctc 7973 exhibits deregulated hly expression in the presence of repressing sugars, raising the possibility that a defect in carbon source regulation is responsible for its anomalous behavior. we show here that the activity of a second glucose-repressed enzyme, alph ...	1998	9673243
the role of protegrins and other elastase-activated polypeptides in the bactericidal properties of porcine inflammatory fluids.	the mammalian host response to infection includes the production and secretion of antimicrobial peptides from phagocytes and epithelial cells. protegrins, a group of broadly microbicidal peptides isolated originally from porcine neutrophil lysates, were found to be stored as inactive proforms in porcine neutrophil granules but could be activated extracellularly by neutrophil elastase. we assessed the biological role of protegrins and other elastase-activated polypeptides in the microbicidal acti ...	1998	9673240
pathogenicity and immunogenicity of a listeria monocytogenes strain that requires d-alanine for growth.	listeria monocytogenes is an intracellular bacterial pathogen that elicits a strong cellular immune response following infection and therefore has potential use as a vaccine vector. however, while infections by l. monocytogenes are fairly rare and can readily be controlled by a number of antibiotics, the organism can nevertheless cause meningitis and death, particularly in immunocompromised or pregnant patients. we therefore have endeavored to isolate a highly attenuated strain of this organism ...	1998	9673233
disseminated herpes simplex virus infection in a neonate.	the emergency department (ed) evaluation of the neonate with sepsis or symptoms suggesting sepsis usually includes a complete blood count, catheterized urinalysis with culture, blood cultures, cerebrospinal fluid analysis and culture, and possibly a chest radiograph. admission for observation for neonates at high risk for sepsis is universal. depending on the patient's presentation and the preference of the admitting physician, intravenous antibiotics are started. typically, ampicillin and eithe ...	1998	9672455
interactions of listeria monocytogenes with mammalian cells during entry and actin-based movement: bacterial factors, cellular ligands and signaling.	although <50 kb of its 3.3 megabase genome is known, listeria monocytogenes has received much attention and an impressive amount of data has contributed in raising this bacterium among the best understood intracellular pathogens. the mechanisms that listeria uses to enter cells, escape from the phagocytic vacuole and spread from one cell to another using an actin-based motility process have been analysed in detail. several bacterial proteins contributing to these events have been identified, inc ...	1998	9669997
diagnosis of meningococcal meningitis by broad-range bacterial pcr with cerebrospinal fluid.	we used broad-range bacterial pcr combined with dna sequencing to examine prospectively cerebrospinal fluid (csf) samples from patients with suspected meningitis. fifty-six csf samples from 46 patients were studied during the year 1995. genes coding for bacterial 16s and/or 23s rrna genes could be amplified from the csf samples from five patients with a clinical picture consistent with acute bacterial meningitis. for these patients, the sequenced pcr product shared 98.3 to 100% homology with the ...	1998	9665992
effect of in vitro monocyte activation by listeria monocytogenes antigens on phagocytosis and production of reactive oxygen and nitrogen radicals in bovines.	macrophages by virtue of their phagocytic and antibacterial activities play an important role in the host resistance to intracellular pathogens including listeria monocytogenes. however, the precise killing mechanism adopted by macrophages in the case of l. monocytogenes and the role of macrophage activation in bacterial killing are still unclear. in the present investigation, different antigens of pathogenic l. monocytogenes and three non-specific activators, namely, lipopoly-saccharide (lps), ...	1998	9661264
general stress transcription factor sigmab and its role in acid tolerance and virulence of listeria monocytogenes.	the gene encoding the general stress transcription factor sigmab in the gram-positive bacterium listeria monocytogenes was isolated with degenerate pcr primers followed by inverse pcr amplification. evidence for gene identification includes the following: (i) phylogenetic analyses of reported amino acid sequences for sigmab and the closely related sigmaf proteins grouped l. monocytogenes sigmab in the same cluster with the sigmab proteins from bacillus subtilis and staphylococcus aureus, (ii) th ...	1998	9658010
listeria monocytogenes and serratia marcescens infections as models for th1/th2 immunity in laboratory cats.	five species of bacteria known to be naturally-occurring pathogens of cats were screened for their ability to grow in feline macrophages in vitro, and to induce antibodies and delayed type hypersensitivity (dth) responses in vivo. two of these organisms, l. monocytogenes and s. marcescens, were selected for further study based on clear-cut differences in their in vitro and in vivo behavior. listeria was macrophage tropic, induced dth, and evoked poor antibody responses post-recovery, whereas ser ...	1998	9656444
targeted disruption of the interferon-gamma receptor 2 gene results in severe immune defects in mice.	to study the role of the interferon- (ifn) gammar2 chain in ifn-gamma signaling and immune function, ifn-gammar2-deficient mice have been generated and characterized. cells derived from ifn-gammar2 -/- mice are unable to activate either jak/stat signaling proteins or gene transcription in response to ifn-gamma. the lack of ifn-gamma responsiveness alters ifn-gamma-induced ig class switching by b cells from these mice. in vitro cultures of t cells demonstrate that the t cells from the ifn-gammar2 ...	1998	9653170
evolution of a complex t cell receptor repertoire during primary and recall bacterial infection.	the mechanisms underlying the genesis and maintenance of t cell memory remain unclear. in this study, we examined the evolution of a complex, antigen-specific t cell population during the transition from primary effector to memory t cells after listeria monocytogenes infection. t cell populations specific for listeriolysin o (llo)91-99, the immunodominant epitope recognized by h2-kd-restricted t lymphocytes, were directly identified in immune spleens using tetrameric h2-kd-epitope complexes. the ...	1998	9653084
interaction of human arp2/3 complex and the listeria monocytogenes acta protein in actin filament nucleation.	actin filament assembly at the cell surface of the pathogenic bacterium listeria monocytogenes requires the bacterial acta surface protein and the host cell arp2/3 complex. purified arp2/3 complex accelerated the nucleation of actin polymerization in vitro, but pure acta had no effect. however, when combined, the arp2/3 complex and acta synergistically stimulated the nucleation of actin filaments. this mechanism of activating the host arp2/3 complex at the l. monocytogenes surface may be similar ...	1998	9651243
[comment on the letter to the editor: "acute hydrocephalus and cerebral abscess in meningitis due to listeria monocytogenes"].		1998	9646634
attenuated listeria monocytogenes carrier strains can deliver an hiv-1 gp120 t helper epitope to mhc class ii-restricted human cd4+ t cells.	listeria monocytogenes is a facultative intracellular pathogen which, following uptake by macrophages, escapes from the phagosome and replicates in the cytoplasm. this property has been exploited using recombinant l. monocytogenes as a carrier for the intracytoplasmic expression of antigens when mhc class i-restricted cytotoxic t lymphocyte responses are required. much less is known of the ability of these bacteria to trigger mhc class ii-restricted responses. here, we demonstrate that after ing ...	1998	9645361
[a case of listeria monocytogenes sepsis in an elderly who survived].	a 81-year-old man who complained of fever and disturbance of consciousness was admitted to our hospital. listeria monocytogenes type 1/2aa was cultured from only the blood. he was treated with gamma-globrine and sensitive antibiotics (papm/bp, em) immediately after admission, and recovered in spite of multiple organ failure due to septic shock. he was not an immunocompromised host and did not have complication of meningitis, but had rhabdomyolysis and liver dysfunction.	1998	9642946
altered intestinal immune system but normal antibacterial resistance in the absence of p-selectin and icam-1.	icam-1 and p-selectin are adhesion molecules that regulate leukocyte migration, extravasation to inflammatory sites, and other immune cell interactions. t cell-mediated resistance against acute infection with listeria monocytogenes and chronic infection with mycobacterium bovis calmette-guérin bacillus was investigated in mutant mice lacking p-selectin and/or icam-1. mice deficient in p-selectin (psel-/-), icam-1 (icam-/-), or the combination of both (psel-/- x icam-/-) showed normal bacterial c ...	1998	9637528
il-6 produced by kupffer cells induces stat protein activation in hepatocytes early during the course of systemic listerial infections.	kupffer cells were the principal source of il-6 produced in the livers of mice following i.v. inoculation of listeria monocytogenes. il-6 mrna expression and the production of il-6 were reduced drastically within the nonparenchymal liver cell population derived from mice rendered kupffer cell depleted by pretreatment with liposome-encapsulated dichloromethylene diphosphonate. a sharp increase in the appearance of activated stat3 occurred in extracts of purified hepatocytes derived from normal mi ...	1998	9637522
th1 cells specific for a secreted protein of listeria monocytogenes are protective in vivo.	in the present study we have investigated the role of the secreted p60 protein from listeria monocytogenes as an ag for cd4 t cells. the p60 protein is an abundant extracellular protein that is highly conserved within the members of the genus listeria. our results show that l. monocytogenes infection induces a potent p60-specific th1 immune response. remarkably, we found that p60-specific th1 clones mediate significant protection against l. monocytogenes infection. for one p60-specific clone, th ...	1998	9637521
nonhemolytic strains of listeria monocytogenes detected in milk products using vidas immunoassay kit.	in december 1995 detection of listeria monocytogenes sv 1/2a in milk products that were routinely sampled for investigation at the austrian federal food inspection laboratory (vienna) led the food manufacturer in question to withdraw his product from the market. while one of seven listeria strains isolated from this food product using "vidas l. monocytogenes kit" was undoubtedly l. monocyotogenes, six strains were nonhemolytic. in classical bacteriology haemolysin is used as an important phenoty ...	1997	9636989
aberrant expression and potential function for parotid secretory protein (psp) in the nod (non-obese diabetic) mouse.		1998	9634989
evaluation of the extent and type of bacterial contamination at different stages of processing of cooked ham.	in an attempt to determine the composition and origin of the spoilage flora of refrigerated vacuum-packed cooked ham, the changes in microbial numbers and types were followed along the processing line. results revealed lactobacillus sake and leuconostoc mesenteroides ssp. mesenteroides as the major causative agents of spoilage of sliced ham stored at 4 degrees c and 12 degrees c, due to recontamination in the cutting room. on the contrary, the progressive deterioration of whole ham under the sam ...	1998	9633662
sensitivity to commercial disinfectants, and the occurrence of plasmids within various listeria monocytogenes genotypes isolated from poultry products and the poultry processing environment.	the european suspension test was used to assess the relative resistance of 19 individual listeria monocytogenes genotypes, isolated from the poultry processing environment, to three commercially used disinfectants employed in the plant at the time of their isolation. to establish the relative resistance between the strains, the concentration of each disinfectant was reduced until inter-strain variation became apparent. for darasan 214 and 7058, variation was detected at 0.1% and 0.5% v/v, respec ...	1998	9633661
radiation inactivation of some food-borne pathogens in fish as influenced by fat levels.	the influence of low (0.39-1.1%), medium (4.25%) and high (7.1-32.5%) fat levels in fish on radiation inactivation of four food-borne pathogens was investigated. cells of listeria monocytogenes 036, yersinia enterocolitica f5692, bacillus cereus and salmonella typhimurium at logarithmic phase were inoculated in 10% fish homogenates and subjected to gamma irradiation at ice temperature (0-1 degree c) with doses ranging from 0.05 to 0.8 kgy. the radiation survival curves of l. monocytogenes and b. ...	1998	9633646
polymorphism of listeria monocytogenes and listeria innocua strains isolated from short-ripened cheeses.	thirty isolates of listeria monocytogenes and 18 of l. innocua obtained from different short-ripened cheeses manufactured in asturias (northern spain), were compared with each other and with reference strains using serotype, phage type and pulsed-field restriction endonuclease digestion profiles analysis of the total dna. restriction enzymes apai and smai defined five clusters in l. monocytogenes (m1 to m5) and two main clusters in l. innocua (i1 and i2). cluster i2 was further arranged into thr ...	1998	9633640
heat resistance of listeria monocytogenes in dairy products as affected by the growth medium.	listeria monocytogenes strains 1151 and scott a were grown in broth at 30 degrees c and transferred to half cream, double cream and butter stored at 5 degrees c to determine the influence of dairy product composition on heat resistance at 52, 56, 60, 64 and 68 degrees c. strain 1151 showed a higher heat resistance than strain scott a. the heat resistance of both strains was higher in the dairy products than in broth, particularly at lower temperatures. a significant difference was observed betwe ...	1998	9633638
sensitivity of food pathogens to garlic (allium sativum).	the inhibitory activity of garlic (allium sativum) against staphylococcus aureus, salmonella typhi, escherichia coli and listeria monocytogenes was measured by the 'turbidity' method. minimum inhibitory concentration (mic) of garlic at 80% inhibition level was calculated for these bacteria. all bacterial pathogenic strains tested were inhibited by garlic; e. coli was most sensitive and listeria monocytogenes was least sensitive. therefore, garlic has potential for the preservation of processed f ...	1998	9633635
qsars for the effect of benzaldehydes on foodborne bacteria and the role of sulfhydryl groups as targets of their antibacterial activity.	quantitative structure activity relationships (qsars) were obtained describing the activity of a series of benzaldehydes against three different foodborne bacteria, listeria monocytogenes f6861, serotype 4b, salmonella enteritidis, phage type 4, p167807 and lactobacillus plantarum int.l11. mic values at ph 6.2 and 35 degrees c were obtained for 11 phenolic benzaldehydes to produce multiple linear regression and artificial neural network models. for each organism, the models contained a steric pa ...	1998	9633634
mathematical modelling of the heat resistance of listeria monocytogenes.	the heat resistance of listeria monocytogenes phagovar 2389/2425/3274/2671/47/108/340 (1992 french outbreak strain) in broth was studied at 55, 60 and 65 degrees c. experiments were carried out on bacterial cultures in three different physiological states: cultures at the end of the log phase, cultures heat-shocked at 42 degrees c for 1 h, and subcultures of cells resistant to prolonged heating. survivor curves were better fitted using a sigmoidal equation than the classical log-linear model. th ...	1998	9633632
detection and characterization of a bacteriocin produced by lactococcus lactis subsp. cremoris r isolated from radish.	bacteria isolated from radish were identified as lactococcus lactis subsp. cremoris r and their bacteriocin was designated lactococcin r. lactococcin r was sensitive to some proteolytic enzymes (proteinase-k, pronase-e, proteases, pepsin, alpha-chymotrypsin) but was resistant to trypsin, papain, catalase, lysozyme and lipase, organic solvents, or heating at 90 degrees c for 15, 30 and 60 min, or 121 degrees c for 15 min. lactococcin r remained active after storage at -20 and -70 degrees c for 3 ...	1998	9633097
nonspecific early protective immunity in francisella and listeria infections can be dependent on lymphocytes.	normal mice, but not lymphocyte-deficient or b-cell-deficient mice, given a sublethal infection of francisella tularensis lvs survive a secondary lethal challenge of more than 10,000 50% lethal doses given 3 days later. in this work, we show that similar early protection that is also strongly lymphocyte dependent operates in listeria monocytogenes infection. since sublethal infection with either lvs or l. monocytogenes protects against heterologous lethal challenge, this early protection is nons ...	1998	9632626
the inla gene of listeria monocytogenes lo28 harbors a nonsense mutation resulting in release of internalin.	internalin is a surface protein that mediates entry of listeria monocytogenes egd into epithelial cells expressing the cell adhesion molecule human e-cadherin or its chicken homolog, l-cam, which act as receptors for internalin. after observing that entry of l. monocytogenes lo28 into s180 fibroblasts, in contrast to that of egd, did not increase after transfection with l-cam, we examined both the expression and the structure of internalin in strain lo28. we discovered a nonsense mutation in inl ...	1998	9632615
construction and vaccine potential of acapsular mutants of erysipelothrix rhusiopathiae: use of excision of tn916 to inactivate a target gene.	we previously showed that acapsular transposon tn916 mutants of erysipelothrix rhusiopathiae are avirulent for mice. in this study, we constructed nonreverting acapsular mutants and examined the vaccine potential of the mutants in mice. a representative acapsular transposon mutant, 33h6, was plated on selective agar containing autoclaved chlortetracycline and quinaldic acid, and two tetracycline-sensitive mutants were obtained. sequence analysis of chromosomal regions of the mutants in which tn9 ...	1998	9632592
purification of the inlb gene product of listeria monocytogenes and demonstration of its biological activity.	entry of listeria monocytogenes into nonphagocytic cells requires the inlab gene products. inla and inlb are bacterial cell wall-associated polypeptides that can be released by sodium dodecyl sulfate treatment. by applying more gentle extraction methods, we have purified inlb in its native form. treatment of bacteria with various nondenaturating agents including mutanolysin, thiol reagents, sodium chloride, and detergents like triton x-100 or 3-[(3-cholamidopropyl)-dimethylammonio]-1-propanesulf ...	1998	9632576
metal ion homeostasis and intracellular parasitism.	bacteria possess multiple mechanisms for the transport of metal ions. while many of these systems may have evolved in the first instance to resist the detrimental effects of toxic environmental heavy metals, they have since become adapted to a variety of important homeostatic functions. the 'p'-type atpases play a key role in metal ion transport in bacteria. a cu+-atpase from the intracellular bacterium listeria monocytogenes is implicated in pathogenesis, and similar pumps in mycobacterium tube ...	1998	9632246
long-lived protective immunity to listeria is conferred by immunization with particulate or soluble listerial antigen preparations coadministered with il-12.	the ability of il-12 to promote the development of th1-type immune responses, and thus promote cellular immunity, has been well documented. in a previous report, we showed that coadministration of il-12 with heat-killed listeria monocytogenes elicited intense antigen-specific t cell responses that conferred protective listerial immunity. herein, we have extended those studies by demonstrating that multiple injections of heat-killed l. monocytogenes and il-12 elicit memory responses that confer l ...	1998	9630835
suppression of major histocompatibility complex class i and class ii gene expression in listeria monocytogenes-infected murine macrophages.	macrophage cells play a central role during infection with listeria monocytogenes by both providing a major habitat for bacterial multiplication and presenting bacterial antigens to the immune system. in this study, we investigated the influence of l. monocytogenes infection on the expression of mhc class i and class ii genes in two murine macrophage cell lines. steady-state levels of i-abeta chain mrna were decreased in both resting j774a.1 and p388d1 macrophages infected with l. monocytogenes ...	1998	9626934
survey of food safety awareness among hiv positive individuals.	a survey was carried out by personal interview to assess the awareness of basic food hygiene and food safety amongst 77 hiv-positive individuals attending a single hospital. there was some confusion and lack of knowledge about aspects of food storage and despite the fact that 74% of subjects had modified their diet since learning their hiv status (mainly for nutritional reasons) only 25% reported receiving information on food safety. of the subjects interviewed 96%, 66% and 23% were aware of the ...	1998	9625907
systemic dissemination by intrarectal infection with listeria monocytogenes in mice.	orally ingested listeria monocytogenes is known to penetrate into peyer's patches (pp) and translocate to the spleen and liver. herein, extraintestinal dissemination of the bacterium independent of pp was investigated. dissemination of listeriae to the spleen and liver was observed in intrarectally infected mice as well as in intragastrically infected animals in spite that no listeriae were detected in the small intestines of mice infected intrarectally. decreased numbers of intestinal intraepit ...	1998	9623921
induction of cytokine messenger rna transcripts in mouse macrophages by listeria monocytogenes isolated from channel catfish.	to determine whether differences exist in induction and quantity of tumor necrosis factor alpha (tnf-alpha), interleukin (il)1 beta, and il-10 mrna transcripts when mouse j774a.1 macrophages are infected with listeria monocytogenes, including 2 isolates originating from channel catfish, the wild-type virulent (egd) strain, and a nonhemolytic strain (atcc 15313).	1998	9622740
model of the influence of time and mild temperature on listeria monocytogenes nonlinear survival curves.	heat treatment has long been regarded as one of the most widely used and most effective means of destroying pathogens in food. up to now the linear relationship between the death rate and the temperature has been used when choosing the best heat treatment to apply. however, the information given by this linear relationship is no longer sufficient when nonlinear survival curves are observed. consequently, the agri-food industry needs a tool to choose the best mild heat treatment to apply in the c ...	1998	9620126
antimicrobial spectrum and target site of d-3-phenyllactic acid.	geotrichum candidum excretes d-3-phenyllactic acid, which inhibits the growth of listeria monocytogenes. it was found to inhibit a range of gram-positive bacteria found in humans and foodstuffs, such as staphylococcus aureus and enterococcus faecalis, and gram-negative bacteria from humans, such as providencia stuartii and klebsiella oxytoca. scanning electron microscope studies on the effect of d-3-phenyllactic acid on l. monocytogenes showed that it caused changes in bacterial behavior and str ...	1998	9620125
prediction of listeria spp. growth as affected by various levels of chemicals, ph, temperature and storage time in a model broth.	the effects of concentration of nacl (0.5 to 12.5%), methyl paraben (0.0 to 0.2%), sodium propionate (0.3%), sodium benzoate (0.1%), potassium sorbate (0.3%), ph (> 5.9) temperature (4 to 30 degrees c), storage time (up to 58 d) and inoculum (> 10(5) to > 10(-2) per ml) on the log10 probability percentage of one cell of listeria spp. to initiate growth in a broth system were evaluated in a factorial design study. at ph 5.96 and temperature ranging from 4 to 30 degrees c the concentrations of sod ...	1998	9620122
effects of great lakes fish consumption on the immune system of sprague-dawley rats investigated during a two-generation reproductive study.	the effects of great lakes fish contaminants on several quantitative and functional aspects of the immune system were investigated in the first (f1) and second (f2) generations of sprague-dawley rats. the f0 rats were fed either a control diet or diets containing 5 or 20% lyophilized chinook salmon from the credit river of lake ontario (lo) and owen sound point of lake huron (lh). the f1 and f2 pups were exposed to fish in utero, through the dam's milk to 21 days old, and through the dam's respe ...	1998	9618333
docosahexaenoic acid, a constituent of fetal and neonatal serum, inhibits nitric oxide production by murine macrophages stimulated by ifn gamma plus lps, or by ifn gamma plus listeria monocytogenes.	murine macrophage activation is deficient in the fetus and the neonate, and in areas of the placenta perfused by the fetal circulation. fetal and neonatal serum concentrations of docosahexaenoic acid (dha) are 150 microm, or approximately 50-fold higher than in the adult. we previously showed that dha inhibits activation of the gene for inducible nitric oxide synthase (inos) in murine macrophages stimulated in vitro with interferon gamma (ifn gamma) plus lipopolysaccharide (lps). we have now pur ...	1998	9616876
studying the effect of temperature on microbial growth using multiplicative model.	the specific growth rates of brochothrix thermosphacta, listeria monocytogenes, yersinia enterocolitica, bacillus cereus, escherichia coli o157:h7, salmonella spp., staphylococcus aureus and clostridium perfringens at various temperatures were taken from the food micromodel database, and the data sets of specific growth rate versus temperature were fitted using the multiplicative model (r = a td, r = specific growth rate; t = temperature; a, d = regression parameters). the exponential d-value de ...	1998	9615472
[antibacterial activity of lactobacilli].	the antagonistic action of lactobacilli is an important factor in the protection of the vagina of fertile women from infection by other microorganisms. in the present study the authors investigated 17 strains of lactobacilli, incl. 11 of vaginal origin. the objective was to investigate in more detail the antibacterial activity of lactobacilli and to attempt to assess substances responsible for inhibition. the investigated lactobacilli inhibited some strains of escherichia coli, serratia marcesce ...	1998	9611889
[endocarditis caused by listeria monocytogenes on a prosthetic valve: presentation of a case and review of the bibliography].		1998	9611883
molecular characterization of an autolytic amidase of listeria monocytogenes egd.	the gene encoding a 102 kda autolysin has been cloned from an expression library of listeria monocytogenes egd genomic dna, using a direct screening protocol. the encoded protein has two domains, an n-terminal enzymic domain showing a high level of homology to the amidase domain of the major autolysin (atl) of staphylococcus aureus, and a c-terminal, putative cell-wall-binding domain containing four imperfect direct repeats. in order to examine the role of the enzyme, the autolysin-encoding gene ...	1998	9611810
the focal adhesion phosphoprotein, vasp.	vasodilator-stimulated phosphoprotein (vasp) is associated with focal adhesions and areas of dynamic membrane activity, where it is thought to have an important role in actin filament assembly and cell motility. vasp contains a central proline-rich sequence which recruits the g-actin binding protein profilin. localization of vasp to the leading edge of a migrating cell can lead to local accumulation of profilin, which in turn can supply actin monomers to growing filament ends. vasp binds to the ...	1998	9611773
[listeria monocytogenes meningitis. case reports in patients from the federal district].	it has been shown the role of listeria monocytogenes as a etiological agent identified by bacteriological analysis among cases of human meningitis in distrito federal, brazil. laboratorial characteristics and some clinical and epidemiological aspects are reported.	1998	9608235
brain abscesses in children with cancer.	brain abscesses in pediatric patients are rare events, and the causative organism and prognosis vary with the population under study. children with cancer seem to be particularly susceptible to the development of brain abscesses because of the immunological changes induced by cancer and its treatment. we reviewed the records of children who developed a brain abscess during treatment of a malignancy to define the clinical characteristics, prognosis, and management of these patients.	1998	9607425
listeria monocytogenes in crohn's disease.	in an immunohistochemical study a higher rate of reactivity of intestinal tissues to the antibody against listeria monocytogenes was reported in crohn's disease as compared with controls.	1998	9605266
effects of above-optimum growth temperature and cell morphology on thermotolerance of listeria monocytogenes cells suspended in bovine milk.	the thermotolerances of two different cell forms of listeria monocytogenes (serotype 4b) grown at 37 and 42.8 degrees c in commercially pasteurized and laboratory-tyndallized whole milk (wm) were investigated. test strains, after growth at 37 or 42.8 degreesc, were suspended in wm at concentrations of approximately 1.5 x 10(8) to 3.0 x 10(8) cells/ml and were then heated at 56, 60, and 63 degrees c for various exposure times. survival was determined by enumeration on tryptone-soya-yeast extract ...	1998	9603815
production of bacteriocin-like-substance by listeria innocua against listeria monocytogenes.	cultures and culture filtrates of 129 listeria innocua strains were examined for inhibitory activity against 18 strains of listeria monocytogenes. of the strains examined, 114 (88.4%) cultures and 126 (97.7%) culture filtrates had an inhibitory activity against strains of l. monocytogenes and most filtrates were sensitive to trypsin treatment. the authors concluded that most l. innocua strains produce a trypsin sensitive bacteriocin-like substance against l. monocytogenes.	1998	9600620
predicted and observed growth of listeria monocytogenes in seafood challenge tests and in naturally contaminated cold-smoked salmon.	the performance of the pathogen modelling program, the food micromodel, the murphy-model and the ross-model for growth of l. monocytogenes was evaluated by comparison with data from 100 seafood challenge tests and data from 13 storage trials with naturally contaminated sliced vacuum-packed cold-smoked salmon. challenge tests with both cured and noncured products were studied, and graphs as well as the bias- and the accuracy factors were used for comparison of the observed and predicted growth. t ...	1998	9600616
enhanced detection and enumeration of listeria monocytogenes from foodstuffs and food-processing environments.	listeria monocytogenes blood agar (lmba) was compared to listeria selective agar based on lithium chloride and ceftazidime (la) and to the oxford and palcam media recommended by iso and idf for the detection and enumeration of l. monocytogenes from foodstuffs and food-processing environments. lmba is based on trypticase soy agar with the following additions: sheep blood (5%) and as selective agents lithium chloride (10 g/l), polymyxin b sulphate (10 mg/l) and ceftazidime (20 mg/l), whereas the s ...	1998	9600613
the combined effect of nisin, leucocin f10, ph, nacl and edta on the survival of listeria monocytogenes in broth.	the combined effect of the bacteriocins nisin (1-2100 iu/ml) and leucocin f10 (1-2100 au/ml), ph (4.7-6.5), nacl (0.7-4.5% w/l), ethylene diaminetetraacetic acid disodium salt (edta, 0.08-4.72 mmol/l) and inoculum level (10(3)-10(8) cfu/ml) on the survival of a pool of three strains of listeria monocytogenes in broth was evaluated in three factorial experiments. several factor combinations were found to prevent growth. logistic regression analysis of the categorical data (survival/no survival) w ...	1998	9600612
synergistic effect of nisin and the lactoperoxidase system on listeria monocytogenes in skim milk.	nisin added at 10 or 100 iu/ml to ultra-high temperature processed (uht) skim milk had no effect on counts of listeria monocytogenes after 24 h at 30 degrees c, whereas addition of the lactoperoxidase system (lps) resulted in counts of viable cells three log units lower than those of control milk after 24 h at 30 degrees c. addition of nisin and lps showed a synergistic effect and resulted in counts up to 5.6 log units lower than the control milk. when the two preservatives were added to activel ...	1998	9600608
endogenous interleukin-4 does not suppress the resistance against a primary or a secondary listeria monocytogenes infection in mice.	interleukin-4 (il-4), a cytokine produced by t-helper 2 (th2) cells, can inhibit the development of t-helper 1 (th1) cells, which results in a decreased release of cytokines by the latter. as interferon-gamma (ifn-gamma), produced by th1 cells, is involved in the resistance against a listeria monocytogenes infection, the role of endogenously formed il-4 during a listeria infection in mice was investigated. neutralization of endogenously formed cytokines by subcutaneously injected alginate-encaps ...	1998	9600319
listeria monocytogenes-infected hepatocytes are targets of major histocompatibility complex class ib-restricted antilisterial cytotoxic t lymphocytes.	subclinical infection of balb/c mice with the intracellular bacterial pathogen listeria monocytogenes results in the development of protective antilisterial immunity. l. monocytogenes can infect hepatocytes, and antilisterial cytotoxic t lymphocytes (ctl) lyse listeria-infected hepatocytes in a major histocompatibility complex (mhc) class ia-restricted manner. it remained to be determined whether l. monocytogenes-infected hepatocytes are susceptible to mhc class ib-restricted cytolysis. in this ...	1998	9596753
secretory phospholipase a2 is the principal bactericide for staphylococci and other gram-positive bacteria in human tears.	we examined human tears for molecules that killed gram-positive bacteria. the principal mediator of bactericidal activity against staphylococci proved to be a calcium-dependent enzyme, secretory phospholipase a2. whereas the concentration of secretory phospholipase a2 in the normal tear film exceeded 30 microg/ml, only 1.1 ng (<0.1 nm) of the enzyme per ml sufficed to kill listeria monocytogenes and 15 to 80 ng/ml killed staphylococcus aureus. despite its efficacy against gram-positive bacteria, ...	1998	9596749
cytochalasin-induced actin disruption of polarized enterocytes can augment internalization of bacteria.	cytochalasin-induced actin disruption has often been associated with decreased bacterial internalization by cultured epithelial cells, although polarized enterocytes have not been systematically studied. in assays using confluent polarized ht-29 enterocytes, cytochalasin d appeared to increase internalization of wild-type salmonella typhimurium, proteus mirabilis, and escherichia coli. hela and hep-2 epithelial cells, as well as ht-29 and caco-2 enterocytes, were used to clarify this unexpected ...	1998	9596696
host cell protein tyrosine kinases are activated during the entry of listeria monocytogenes. possible role of pp60c-src family protein kinases.	listeria monocytogenes is able to invade a wide range of cell types by inducing its own internalization. little is known, however, about the host cell proteins affecting the entry process which involves triggering the host cell signal transduction mechanism. we report here that entry of l. monocytogenes strains (serotypes 4b and 1/2a) into caco-2 cells induced tyrosine phosphorylation of several host cell proteins including pp60c-src substrates. using specific synthetic peptide substrates, we sh ...	1998	9595679
internalin b is essential for adhesion and mediates the invasion of listeria monocytogenes into human endothelial cells.	listeria monocytogenes causes rhombencephalitis in humans and animals and also affects the fetus in utero, causing disseminated sepsis. in both instances, the infection occurs by the crossing of endothelial cells lining a physiological barrier, the blood-brain barrier or the transplacental barrier. in this study, the ability of l. monocytogenes wild-type egd to invade human umbilical vein endothelial cells (huvecs) was evaluated using wild-type bacteria and isogenic listeria mutants. here, we sh ...	1998	9593298
h2-m3 restricted presentation of a listeria-derived leader peptide.	protective immunity to infection by many intracellular pathogens requires recognition by cytotoxic t lymphocytes (ctls) of antigens presented on major histocompatibility complex (mhc) class i molecules. to be presented for recognition by pathogen-specific ctls, these antigens must gain access to the host cell class i processing pathway. in the case of intracellular bacterial pathogens, the majority of bacterial proteins are retained within the bacterial membrane and therefore remain inaccessible ...	1998	9584149
neural wiskott-aldrich syndrome protein is implicated in the actin-based motility of shigella flexneri.	shigella, the causative agent of bacillary dysentery, is capable of directing its own movement in the cytoplasm of infected epithelial cells. the bacterial surface protein virg recruits host components mediating actin polymerization, which is thought to serve as the propulsive force. here, we show that neural wiskott-aldrich syndrome protein (n-wasp), which is a critical target for filopodium formation downstream of cdc42, is required for assembly of the actin tail generated by intracellular s.f ...	1998	9582270
listeria monocytogenes rhomboencephalitis with cranial-nerve palsies: a case report.	listeria monocytogenes rhomboencephalitis is an uncommon complication of l. monocytogenes meningitis. it presents in a typical biphasic pattern characterized by a non-specific prodromal period followed by any combination of asymmetrical, cranial-nerve palsies; cerebellar signs; hemiparesis or hypesthesia; and diminished consciousness. the survival rate is greater than 70% when appropriate antibiotic therapy is initiated early. however, approximately 60 percent of the survivors develop neurologic ...	1998	9581507
pyrimethamine impairs host resistance to infection with listeria monocytogenes in balb/c mice.	increased mortality has been observed when hiv-infected patients were treated with pyrimethamine (pyr) as prophylaxis for toxoplasmic encephalitis, suggesting that pyr might possess immunosuppressive activity. to analyze this in an animal model, immune function was assessed in balb/c mice using a battery of in vivo and ex vivo assays and an in vivo model of host resistance to listeria monocytogenes infection. treatment for 30 days with 60 mg/kg pyr decreased circulating white blood cell and lymp ...	1998	9579021
ampicillin-aminoglycoside interaction studies using listeria monocytogenes.		1998	9578172
computerized analysis of restriction fragment length polymorphism patterns: comparative evaluation of two commercial software packages.	two computerized restriction fragment length polymorphism pattern analysis systems, the bioimage system and the gelcompar system (molecular analyst fingerprinting plus in the united states), were compared. the two systems use different approaches to compare patterns from different gels. in gelcompar, a standard reference pattern in one gel is used to normalize subsequent gels containing lanes with the same reference pattern. in bioimage, the molecular sizes of the fragments are calculated from s ...	1998	9574697
mhc class i/peptide stability: implications for immunodominance, in vitro proliferation, and diversity of responding ctl.	infection of balb/c mice with listeria monocytogenes primes cd8+ cytotoxic t cells specific for four different h2-kd-restricted peptides. in vitro restimulation of l. monocytogenes immune splenocytes with each of these peptides resulted in larger t cell responses to p60 217-225 and mpl 84-92 than to llo 91-99 and p60 449-457. direct frequency analyses of immune splenocytes, however, revealed that llo 91-99 and p60 217-225 elicit dominant t cell responses, while p60 449-457 and mpl 84-92 elicit m ...	1998	9574549
effects of endotoxemia and sepsis on bilirubin oxidation by rat brain mitochondrial membranes.	sepsis is believed to increase the risk of bilirubin brain toxicity, but the mechanism is not known. adult male sprague-dawley rats were injected intraperitoneally with either 20 mg/kg escherichia coli lipopolysaccharide, approximately 5 x 10(9)/kg cfu listeria monocytogenes or vehicle 48 h prior to sacrifice. rats were killed with an intraperitoneal injection of pentobarbital. mitochondrial membrane fractions were produced by homogenization of the brains and differential centrifugation in 0.32 ...	1998	9573465
roles for tumor necrosis factor and gamma interferon in resistance to enteric listeriosis.	listeria monocytogenes normally infects the host by translocating from the intestinal lumen. experiments were carried out to determine if, when, and where tumor necrosis factor (tnf) and gamma interferon (ifn-gamma) function in antibacterial resistance during enteric listeriosis. groups of normal mice and severe combined immunodeficient (scid) mice were injected with neutralizing monoclonal antibodies (mab) specific for each cytokine and then inoculated intragastrically with l. monocytogenes. th ...	1998	9573134
disruption of the cellular inflammatory response to listeria monocytogenes infection in mice with disruptions in targeted genes.	the results of this study to dissect the nature of the acquired immune response to infection with listeria monocytogenes in mice with targetted gene disruptions show that successful resolution of disease requires the essential presence of alphabeta t cells and the capacity to elaborate gamma interferon. in the absence of either of these entities, mice experience increasingly severe hepatitis and tissue necrosis and die within a few days. the data from this study support the hypothesis that the p ...	1998	9573119
production of proinflammatory cytokines and inflammatory mediators in human intestinal epithelial cells after invasion by trichinella spiralis.	epithelial cells are the first point of host contact for invasive intestinal pathogens and may initiate mucosal inflammatory responses via production of proinflammatory cytokines and mediators. the aim of the present study was to investigate in vitro the initial invasion of a parasitic nematode (trichinella spiralis), to measure the early production of specific epithelial cytokines and inflammatory mediators after invasion, and to compare these responses with those to invasive bacteria. monolaye ...	1998	9573108
sequence analysis of the acta gene of listeria monocytogenes isolated from human.	the region encoding proline-rich units of acta genes was amplified from 24 strains of listeria monocytogenes using polymerase chain reaction (pcr). pcr products of 13 strains showed the expected size of 623 bp, whereas those of 11 strains showed a short size of 518 bp. the shortening of these pcr products resulted from the deletion of one proline-rich unit. these results indicate that acta proteins are divided into at least two different types which are unrelated to bacterial serotypes.	1998	9572045
evaluation of five imidazopyrazinone-type chemiluminescent superoxide probes and their application to the measurement of superoxide anion generated by listeria monocytogenes.	superoxide-triggered chemiluminescence of five new imidazopyrazinone derivatives was investigated using the hypoxanthine-xanthine oxidase system as the source of superoxide anion. the results showed that they are highly sensitive and have favorable properties in measuring superoxide anion. with those new probes, the generation of superoxide anion from the bacteria listeria monocytogenes was examined. the results confirmed the previous report that l. monocytogenes is an unusual organism that extr ...	1998	9570834
the clpc atpase of listeria monocytogenes is a general stress protein required for virulence and promoting early bacterial escape from the phagosome of macrophages.	under stress conditions, the facultative intracellular pathogen listeria monocytogenes produces a clpc atpase, which is a general stress protein encoded by clpc and belonging to the hsp-100/clp family. a clpc-deficient mutant was obtained by gene disruption in strain lo28, which became highly susceptible to stress conditions in vitro. intracellular growth of this mutant was restricted within macrophages, one of the major target cells of l. monocytogenes, during the infectious process. a quantita ...	1998	9570408
protective effect of administration of skim milk on exogenous and endogenous infection in mice.	in order to minimize the denaturation of proteins in milk, normal cow's milk was pasteurized at 61 c for 20 min. the protective effects of the thus prepared skim milk (low-heat skim milk) on exogenous and endogenous infection were examined as compared with conventional skim milk which was pasteurized at 121 c for 2 sec. the antibody titers to listeria monocytogenes and escherichia coli of low-heat skim milk were almost equal to that of raw milk, while no antibody was detected in the conventional ...	1998	9570286
plantaricin d, a bacteriocin produced by lactobacillus plantarum bfe 905 ready-to-eat salad.	lactobacillus plantarum bfe 905 isolated from 'waldorf' salad produced a bacteriocin termed plantaricin d which was active against lact. sake and listeria monocytogenes strains. plantaricin d was heat stable, retaining activity after heating at 121 degrees c. the bacteriocin was inactivated by alpha-chymotrypsin, trypsin, pepsin and proteinase k, but not by papain and other non-proteolytic enzymes tested. plantaricin d was stable at ph values ranging from 2.0 to 10.0. the bacteriocin inhibited g ...	1998	9569716
inhibition effect of enterocin ccm 4231 in the rumen fluid environment.	enterocin ccm 4231 is a bacteriocin with a broad antimicrobial spectrum produced by the ruminal strain enterococcus faecium ccm 4231. its inhibitory effect towards enterococci, ent. faecium ef 26/42, staphylococci, streptococcus bovis ao 24/85 and escherichia coli, as well as towards listeria monocytogenes ohio strain, in the rumen fluid environment was studied during culture at 37 and 30 degrees c for 24 h and 20 days. enterocin ccm 4231 was added to the samples at a concentration of 3200 au ml ...	1998	9569712
antimicrobial properties of plant essential oils and essences against five important food-borne pathogens.	the antimicrobial properties of 21 plant essential oils and two essences were investigated against five important food-borne pathogens, campylobacter jejuni, salmonella enteritidis, escherichia coli, staphylococcus aureus and listeria monocytogenes. the oils of bay, cinnamon, clove and thyme were the most inhibitory, each having a bacteriostatic concentration of 0.075% or less against all five pathogens. in general, gram-positive bacteria were more sensitive to inhibition by plant essential oils ...	1998	9569693
activation and suppression of natural cellular immune functions by pneumocystis carinii.	the regulatory role of soluble cytokines in innate cellular immune responses induced by pneumocystis carinii was assessed in vitro in direct comparison to induction by listeria monocytogenes. this report shows that p. carinii organisms, as well as l. monocytogenes, stimulated in whole spleen cell cultures of scid mice the release of ifn-gamma, tnf-alpha/beta, il-10, il-12, and ino. this response was independent of functional t cells. both macrophages (m phi) and natural killer (nk) cells were ne ...	1998	9562861
prevalence of listeria species in raw milk from farm bulk tanks in nagano prefecture.	raw milk samples from bulk tanks of a total of 943 farms, which corresponded to approximately 60% of all dairy farms in nagano prefecture were examined for listeria species between december 1990 and april 1991. listeria spp. were isolated from 29 (3.1%) of 943 milk specimens. in the southern, central, eastern and northern areas of the prefecture, listeria spp. were isolated from 6.1% (22/362), 1.5% (4/272), 1.4% (2/143) and 0.6% (1/166) of samples, respectively. listeria monocytogenes was isolat ...	1998	9560778
mycobacterium bovis bacille calmette-guérin strains secreting listeriolysin of listeria monocytogenes.	recombinant (r) mycobacterium bovis strains were constructed that secrete biologically active listeriolysin (hly) fusion protein of listeria monocytogenes. the r-bcg strains pat261:hly or pmv306:hly expressed plasmid multicopies or chromosomal single copies of the hly gene, respectively. human and murine macrophage-like cell lines were infected with r-bcg pat261:hly and pmv306:hly strains. interestingly, intracellular persistence of both r-bcg strains was reduced in macrophages as compared with ...	1998	9560270
discrimination of listeria monocytogenes strains of serotype 4b by restriction enzyme analysis of chromosomal dna.	epidemiologically related cheese and environmental strains and epidemiologically unrelated strains of listeria monocytogenes serotype 4b were examined by restriction enzyme analysis of chromosomal dna with a total of 10 restriction enzymes. the dna fingerprint patterns generated from each restriction enzyme digest of total dna of all strains were classified. the restriction enzyme patterns of seven strains recovered from cheese and environmental samples in the same plant were identical to each o ...	1997	9559441
impaired macrophage function and enhanced t cell-dependent immune response in mice lacking ccr5, the mouse homologue of the major hiv-1 coreceptor.	the cc-chemokine receptor ccr5 has been shown to be the major coreceptor for hiv-1 entry into cells, and humans with homozygous mutation in the ccr5 gene are highly resistant to hiv-1 infection, despite the existence of many other hiv-1 coreceptors. to investigate the physiologic function of ccr5 and to understand the cellular mechanisms of these clinical observations, we generated a ccr5-deficient mouse model (ccr5[-/-]) by targeted deletion of the ccr5 gene. we found that although developed no ...	1998	9558111
effect of antigen-processing efficiency on in vivo t cell response magnitudes.	t lymphocytes eradicate and provide long-term immunity to infections caused by intracellular pathogens. the mechanisms that determine in vivo t cell response sizes are poorly understood. although it is speculated that the relative processing efficiency of different epitopes determines the hierarchy of t cell responses following immunization, this hypothesis has not been rigorously tested. we therefore mutagenized the secreted p60 ag of listeria monocytogenes to alter the efficiency of t cell epi ...	1998	9558105