Publications

persistent and nonpersistent listeria monocytogenes contamination in meat and poultry processing plants.	contamination analysis of persistent and nonpersistent listeria monocytogenes strains in three meat processing plants and one poultry processing plant were performed in order to identify factors predisposing to or sustaining persistent plant contamination. a total of 596 l. monocytogenes isolates were divided into 47 pulsed-field gel electrophoresis (pfge) types by combining the restriction enzyme patterns of asci (42 patterns) and apai (38 patterns). persistent and nonpersistent strains were fo ...	2003	14627284
real-time multiplex sybr green i-based pcr assay for simultaneous detection of salmonella serovars and listeria monocytogenes.	a multiplex sybr green i-based pcr assay has been developed for simultaneous detection of salmonella serovars and listeria monocytogenes using a lightcycler. primers were designed to amplify an 85-bp sequence from the gene encoding a fimbrinlike protein (fimi) of salmonella enteritidis and a 98-bp sequence from the hemolysin gene (hly) of l. monocytogenes. these primers allowed the amplification of pcr products having distinct melting temperature values, resulting in the formation of two distinc ...	2003	14627296
isolation and characterization of buta, a secondary glycine betaine transport system operating in tetragenococcus halophila.	through functional complementation of an escherichia coli mutant defective in glycine betaine uptake, we identified a single-component glycine betaine transporter from tetragenococcus halophila, a moderate halophilic lactic acid bacterium. dna sequence analysis characterized the buta protein as a member of the betaine choline carnitine transporter (bcct) family, that includes a variety of previously characterized compatible solute transporters such as opud from bacillus subtilis, ectp and betp f ...	2003	14629018
a model of microbial survival curves in water treated with a volatile disinfectant.	to develop a method to calculate microbial survival parameters in water treated with a dissipating disinfectant and predict the inactivation patterns under different agent concentrations and decay rate regimes.	2003	14633001
pcr detection of listeria monocytogenes: a study of multiple factors affecting sensitivity.	to test, under comparable conditions, several parameters affecting sensitivity of pcr detection in order to establish a pcr procedure suitable for the routine detection of listeria monocytogenes in food.	2003	14633023
detection and characterization of the novel bacteriocin entomocin 9, and safety evaluation of its producer, bacillus thuringiensis ssp. entomocidus hd9.	to identify and characterize new bacteriocins from a collection of 41 strains belonging to 27 subspecies of bacillus thuringiensis, and to evaluate the safety of the producers.	2003	14633027
production of antibacterial substances by bifidobacterial isolates from infant stool active against listeria monocytogenes.	this study aimed to characterize new isolates of human bifidobacteria, evaluate some of their probiotic potential and to screen these isolates for their effectiveness at inhibiting listeria monocytogenes in vitro.	2003	14633035
inactivation of escherichia coli o157:h7, salmonella enteritidis and listeria monocytogenes on the surface of tomatoes by neutral electrolyzed water.	to determine the efficacy of neutral electrolyzed water (new) in killing escherichia coli o157:h7, salmonella enteritidis and listeria monocytogenes, as well as nonpathogenic e. coli, on the surface of tomatoes, and to evaluate the effect of rinsing with new on the organoleptic characteristics of the tomatoes.	2003	14633103
presence of listeria and salmonella spp. in retail chicken in northern ireland.	retail packs of fresh chicken in northern ireland were sampled to determine the frequency with which they were contaminated with salmonella and listeria spp.	2003	14633115
promiscuity of mhc class ib-restricted t cell responses.	murine infection with the gram-positive intracellular bacterium listeria monocytogenes activates cd8(+) t cells that recognize bacterially derived n-formyl methionine peptides in the context of h2-m3 mhc class ib molecules. three peptides, fmigwii, fmivil, and fmivtlf, are targets of l. monocytogenes-specific cd8(+) t cells. to investigate epitope cross-recognition by h2-m3-restricted cd8(+) t cells, we deleted the sequence encoding fmigwii from a virulent strain of l. monocytogenes. infection w ...	2003	14634106
activation of antigen-specific cd8 t cells results in minimal killing of bystander bacteria.	memory cd8 t cells play a critical role in protective immunity against intracellular pathogens. in addition to their ability to specifically recognize and lyse infected targets, activated cd8 t cells secrete cytokines that induce phagocytic cells to engulf and kill bacterial pathogens. in this study, we asked whether activation of ag-specific cd8 t cells results in nonspecific killing of bystander bacteria during a mixed infection. mice with epitope-specific memory cd8 t cells were coinfected wi ...	2003	14634115
listeria species escape from the phagosomes of interleukin-4-deactivated human macrophages independent of listeriolysin.	listeria monocytogenes is the causative agent of infections like sepsis and meningitis, especially in immunocompromised hosts. human macrophages are able to phagocytose and digest l. monocytogenes but il-4 prevents human macrophages from killing the bacteria, the mechanisms of which are unknown. in the present study, we examined various listeria species and strains including wild-type and deletion mutants in human macrophages pretreated with il-4. to analyse the il-4-mediated deactivation proces ...	2003	14636240
a three-tiered approach to differentiate listeria monocytogenes biofilm-forming abilities.	the purpose of this research was to develop a system for cultivating and evaluating listeria monocytogenes biofilms that produces consistent and reliable results. a three-tiered approach was used to evaluate biofilm-forming abilities of three l. monocytogenes strains that were originally associated with listeriosis outbreaks. a l. monocytogenes 'honeycomb' biofilm structure was described. l. monocytogenes strains scott a and v7 were comparable in developing biofilm network structures and f2365 w ...	2003	14638425
the listeria monocytogenes lema gene product is not required for intracellular infection or to activate fmigwii-specific t cells.	clearance of the intracellular bacterial pathogen listeria monocytogenes requires antigen-specific cd8(+) t cells. recently it was shown that activation of class ib major histocompatibility complex (mhc)-restricted cd8(+) t cells alone is sufficient for immune protection against listeriae. a major component of the class ib mhc-restricted t-cell response is t cells that recognize formylated peptide antigens presented by m3 molecules. although three n-formylated peptides derived from l. monocytoge ...	2003	14638756
listeria monocytogenes mutants that fail to compartmentalize listerolysin o activity are cytotoxic, avirulent, and unable to evade host extracellular defenses.	listeria monocytogenes is a facultative intracellular bacterial pathogen that escapes from a phagosome and grows in the host cell cytosol. escape of the bacterium from the phagosome to the cytosol is mediated by the bacterial pore-forming protein listeriolysin o (llo). llo has multiple mechanisms that optimize activity in the phagosome and minimize activity in the host cytosol. mutants that fail to compartmentalize llo activity are cytotoxic and have reduced virulence. we sought to determine why ...	2003	14638761
characterization of an extracellular virulence factor made by group a streptococcus with homology to the listeria monocytogenes internalin family of proteins.	leucine-rich repeats (lrr) characterize a diverse array of proteins and function to provide a versatile framework for protein-protein interactions. importantly, each of the bacterial lrr proteins that have been well described, including those of listeria monocytogenes, yersinia pestis, and shigella flexneri, have been implicated in virulence. here we describe an 87.4-kda group a streptococcus (gas) protein (designated slr, for streptococcal leucine-rich) containing 10 1/2 sequential units of a 2 ...	2003	14638794
drosophila s2 cells: an alternative infection model for listeria monocytogenes.	listeria monocytogenes is a gram-positive facultative intracellular bacterial pathogen that infects humans and animals. its pathogenic strategy involves the expression of virulence proteins that mediate intracytosolic growth and cell-to-cell spread. a key virulence protein is the cholesterol-dependent cytolysin, listeriolysin o (llo), which is largely responsible for mediating escape from the phagosome into the host cytosol. to study further the host processes exploited during l. monocytogenes i ...	2003	14641173
exploration of host-pathogen interactions using listeria monocytogenes and drosophila melanogaster.	the facultative intracellular bacterial pathogen listeria monocytogenes is capable of replicating within a broad range of host cell types and host species. we report here the establishment of the fruit fly drosophila melanogaster as a new model host for the exploration of l. monocytogenes pathogenesis and host response to infection. listeria monocytogenes was capable of establishing lethal infections in adult fruit flies and larvae with extensive bacterial replication occurring before host death ...	2003	14641175
immunomodulation by yersinia enterocolitica: comparison of live and heat-killed bacteria.	this study compared the immunomodulating properties of viable and killed yersinia enterocolitica o9 in balb/c mice. at 10 days after infection by the intragastric route, ex vivo assays showed a suppression of spleen cell proliferation in response to salmonella lipopolysaccharide, concanavalin a and heat-killed yersiniae. mice infected with y. enterocolitica o9 for 10 days resisted the challenge with a lethal dose of listeria monocytogenes. in contrast, intravenous administration of heat-killed y ...	2003	14642307
restricted translocation across the cell wall regulates secretion of the broad-range phospholipase c of listeria monocytogenes.	the virulence of listeria monocytogenes is directly related to its ability to spread from cell to cell without leaving the intracellular milieu. during cell-to-cell spread, bacteria become temporarily confined to secondary vacuoles. among the bacterial factors involved in escape from these vacuoles is a secreted broad-range phospholipase c (pc-plc), the activation of which requires processing of an n-terminal prodomain. mpl, a secreted metalloprotease of listeria, is involved in the proteolytic ...	2003	14526005
the infectious origins of stillbirth.	our objective was to determine the relationship between various types of perinatal infections and stillbirths.	2003	14526331
seca2-dependent secretion of autolytic enzymes promotes listeria monocytogenes pathogenesis.	pathogenic bacteria secrete proteins that promote invasion of host tissues and resistance to immune responses. however, secretion mechanisms that contribute to the enormous morbidity and mortality of gram-positive bacteria are largely undefined. an auxiliary protein secretion system (seca2) has recently emerged in listeria monocytogenes and eight other gram-positive pathogens. here, a proteomics approach identified seventeen seca2-dependent secreted and surface proteins of l. monocytogenes, the ...	2003	14527997
[occurrence of listeria monocytogenes in pre-sliced vacuum-packaged].	there is scarce information in brazil and other south american countries about the occurrence of listeria monocytogenes in food, mainly refrigerated ready-to-eat products. the consumption of sliced vacuum-packaged meat products has increased in the last few years. nevertheless, a complete assessment of the risk associated with l. monocytogenes in these products is still necessary. because of the production and storage characteristics of these products, they can be considered potential vehicles f ...	2003	14528609
an snp-based pcr assay to differentiate between listeria monocytogenes lineages derived from phylogenetic analysis of the sigb gene.	the alternative sigma factor sigb gene is involved in the stress response regulation of listeria monocytogenes, and contributes towards growth and survival in adverse conditions. this gene was examined to determine if it could be a useful indicator of lineage differentiation, similar to the established method based on ribotyping. the sigb sequence was resolved in four local l. monocytogenes strains and the phylogenetic relationship among these, and a further 21 sigb gene sequences from strains o ...	2003	14529964
a 6 x 6 drop plate method for simultaneous colony counting and mpn enumeration of campylobacter jejuni, listeria monocytogenes, and escherichia coli.	a protocol was developed using 96-well plates and multichannel pipettes for serial dilutions, followed by drop plating on agar in a 6 x 6 format. this protocol permits simultaneous plating of six dilutions which greatly decreases the number of plates utilized thereby saving incubator space for organisms such as campylobacter which require unique environmental conditions.	2003	14529971
highly biased type 1 immune responses in mice deficient in lfa-1 in listeria monocytogenes infection are caused by elevated il-12 production by granulocytes.	lfa-1 (cd11a/cd18) plays a key role in various inflammatory responses. here we show that the acquired immune response to listeria monocytogenes is highly biased toward type 1 in the absence of lfa-1. at the early stage of listeriosis, numbers of ifn-gamma producers in the liver and spleen of lfa-1(-/-) mice were markedly increased compared with heterozygous littermates and valpha14(+)nkt cell-deficient mice, and nk cells were major ifn-gamma producers. numbers of il-12 producers were also marked ...	2003	14530315
deficient anti-listerial immunity in the absence of perforin can be restored by increasing memory cd8+ t cell numbers.	compared with wild-type (wt) mice, listeria monocytogenes (lm)-vaccinated perforin-deficient (pko) mice have elevated levels of cd8(+) t cell memory, but exhibit reduced levels of protection against virulent lm. in this study, ag-specific cd8(+) t cells from lm-vaccinated wt and pko mice were used in adoptive transfer assays to determine the contribution of perforin-dependent cytolysis in protective immunity to lm. perforin deficiency resulted in an approximately 5-fold reduction in the per-cell ...	2003	14530349
selective depletion of nonspecific t cells during the early stage of immune responses to infection.	transient t cell depletion occurs before the development of an effective immune response to infection. in this study we show that most t cells, regardless of specificity, are induced to express early activation markers soon after infection with listeria monocytogenes or lymphocytic choriomeningitis virus. ag-specific t cells are further activated to display late activation markers and undergo extensive proliferation. as ag-specific t cells begin to expand, nonspecific t cells are depleted en mas ...	2003	14530360
behaviour of listeria monocytogenes in anchovies during marination.		2003	14535420
enhanced immunogenicity of siv gag dna vaccines encoding chimeric proteins containing a c-terminal segment of listeriolysin o.	we investigated the potential of the c-terminal 59-amino acid segment of listeriolysin o (llo) in enhancing immune responses against the siv gag antigen in the context of dna immunization. genes with codons optimized for mammalian expression were synthesized for the sivmac239 gag, a secreted siv gag protein with the tissue plasminogen antigen (tpa) signal fused to its n-terminus (tpa/gag), as well as their corresponding chimeric proteins gag/llo and tpa/gag/llo containing the c-terminal 59 amino ...	2003	14550583
cell biology. how cells step out.		2003	14551414
[rhomboencephalitis caused by listeria monocytogenes infection in the central nervous system].	listeria monocytogenes infections can involve the central nervous system in the form of a rhomboencephalitis. three possible cases of rhomboencephalitis by listeria monocytogenes are reported (2 females, aged 44 and 49 and a man of 36 years old). the three cases were preceded by an unspecific prodrome of headache, vertigo and fever in absence of a meningeal syndrome. the neurological stage was defined by the unilateral involvement of cranial nerves and the cerebellum and a clear inflammatory cer ...	2003	14558248
requirement of the listeria monocytogenes broad-range phospholipase pc-plc during infection of human epithelial cells.	in this study, we investigated the requirement of the listeria monocytogenes broad-range phospholipase c (pc-plc) during infection of human epithelial cells. l. monocytogenes is a facultative intracellular bacterial pathogen of humans and a variety of animal species. after entering a host cell, l. monocytogenes is initially surrounded by a membrane-bound vacuole. bacteria promote their escape from this vacuole, grow within the host cell cytosol, and spread from cell to cell via actin-based motil ...	2003	14563864
listeria intracellular growth and virulence require host-derived lipoic acid.	listeria monocytogenes is a gram-positive intracytosolic pathogen that causes severe disease in pregnant and immunocompromised individuals. we found that l. monocytogenes lacking the lipoate protein ligase lpla1 was defective for growth specifically in the host cytosol and was less virulent in animals by a factor of 300. a major target for lpla1, the e2 subunit of pyruvate dehydrogenase (pdh), lacked a critical lipoyl modification when the deltalpla1 strain was grown intracellularly, which sugge ...	2003	14564012
bactofection of mammalian cells by listeria monocytogenes: improvement and mechanism of dna delivery.	bacteria-mediated transfer of plasmid dna into mammalian cells (bactofection) is a potent approach to express plasmid-encoded heterologous proteins (protein antigens, toxins or enzymes) in a large set of different cell types including phagocytic and nonphagocytic mammalian cells. previously, we have described a listeria monocytogenes-mediated dna delivery system, which releases plasmid dna directly into the cytosol of mammalian cells by partial self-destruction of the carrier bacteria. here we r ...	2003	14566363
development of a protocol for the isolation of listeria monocytogenes from sludge.	given the high level of background flora in sludge, methods for detecting listeria monocytogenes are not well established. in this study, two critical parameters for the detection of l. monocytogenes were evaluated: the concentration of listeria sp. in a modified fraser broth (first stage of the method) and the proportion of l. monocytogenes on palcam agar (second stage of the method). concentrations of listeria sp. estimated in 118 modified fraser enrichment broths inoculated with four types of ...	2003	14568068
effect of asphalt fume inhalation exposure at simulated road paving conditions prior to bacterial infection on lung defense responses in rats.	asphalt fume inhalation has been suspected of affecting immune function in exposed workers. the objective of this study was to evaluate the effect of asphalt exposure on lung immune responses in rats using a bacterial infectivity model. pathogen-free male sprague-dawley rats were exposed by inhalation to asphalt fumes (72.6 +/- 4.95 mg/m3) or filtered air for 6 h/day for 5 days. one day after the final asphalt exposure, rats were intratracheally inoculated with 5 x 10(5) listeria monocytogenes. ...	2003	14569497
ena/vasp proteins: regulators of the actin cytoskeleton and cell migration.	ena/vasp proteins are a conserved family of actin regulatory proteins made up of evh1, evh2 domains, and a proline-rich central region. they have been implicated in actin-based processes such as fibroblast migration, axon guidance, and t cell polarization and are important for the actin-based motility of the intracellular pathogen listeria monocytogenes. mechanistically, these proteins associate with barbed ends of actin filaments and antagonize filament capping by capping protein (capz). in add ...	2003	14570581
transcriptional regulation and posttranslational activity of the betaine transporter betl in listeria monocytogenes are controlled by environmental salinity.	while the genetic elements contributing to the salinity tolerance of listeria monocytogenes have been well characterized, the regulatory signals and responses (genetic and/or biochemical) that govern these mechanisms have yet to be elucidated. encoded by betl, the first genetic element to be linked to listerial osmotolerance, the secondary betaine uptake system betl is a member of the betaine-carnitine-choline transporter family. preceded by consensus sigma(a)- and sigma(b)-dependent promoter si ...	2003	14645273
viable cell detection by the combined use of fluorescent glucose and fluorescent glycine.	the combined use of a fluorescent glucose (2nbdg) and a fluorescent glycine (nbd-gly) was tried for the detection of viable cells of significant foodborne pathogenic strains in addition to several escherichia coli strains and coliforms. thirty-five out of 41 strains showed marked uptake of 2nbdg but 6 strains were not able to take in 2nbdg. five out of these 6 strains showed nbd-gly uptake.	2003	14646209
food handling behaviors of special importance for pregnant women, infants and young children, the elderly, and immune-compromised people.	this study used a web-based delphi process with a group of nationally recognized food safety experts to identify food-handling behaviors of special importance in reducing the risk of foodborne illness among pregnant women, infants and young children, elderly people, and people with compromised immune systems because of disease or pharmacologic therapy. behaviors were related to 13 pathogens. top-rated behaviors for pregnant women were associated with listeria monocytogenes, toxoplasma gondii, an ...	2003	14647094
a case of sporadic ovine mastitis caused by listeria monocytogenes and its effect on contamination of raw milk and raw-milk cheeses produced in the on-farm dairy.	we describe a case of listerial mastitis in a flock of 130 sheep. the animals were housed at a farm where the bulk raw ewe milk was processed to produce raw milk soft cheese. list. monocytogenes was shed from the right mammary complex. shedding was observed over a period of 99 d. a mean level of 4-56 x 10(4) cfu (colony forming units) listeria monocytogenes/ml was recovered from the raw milk originating from the infected udder. the numbers ranged from 9 x10(1) to 2.95 x 10(5). the bulk milk was ...	2003	14649410
listeria monocytogenes sepsis in patients treated with anti-tumor necrosis factor-alpha.		2003	14650115
survival of listeria monocytogenes in wilted and additive-treated grass silage.	grass was field-dried to 3 different dry matter (dm) levels (200, 430 and 540 g/kg) and inoculated with 10(6)-10(7) cfu/g of a listeria monocytogenes strain sharing a phagovar occasionally involved in foodborne outbreaks of listeriosis. formic acid (3 ml/kg) or lactic acid bacteria (8 x 10(5)/g) with cellulolytic enzymes were applied only to forages with low and intermediate dm levels. forages were ensiled in laboratory silos (1700 ml) and were stored at 25 degrees c for 30 or 90 days. after 90 ...	2003	14650546
[molecular characterization of listeria monocytogenes and the significance for food hygiene].	research on the pathogen listeria monocytogenes is a key issue both for the clinical and the food microbiologist owing to the unique pathway of infection and the exposure of humans via contaminated foods. although, in austria, the incidence of listeriosis is about 870-fold lower than the incidence for salmonella infection, the food law manages both foodborne pathogens with a comparable stringency. the current risk management is based on the assumption that environmental l. monocytogenes isolates ...	2003	14655623
[quantification of the probability of milk contamination by listeria monocytogenes during manufacture of hard cheese].	the present work is concerned with the probability of contamination by listeria monocytogenes in the artisanal manufacture of swiss emmental hard cheese made from raw milk. the simulation model follows the evolution of the contaminant flora from raw milk at the farm to milk mixing, storage at the cheese factory and to the cheese manufacturing process.	2003	14657796
variation in biofilm formation among strains of listeria monocytogenes.	contamination of food by listeria monocytogenes is thought to occur most frequently in food-processing environments where cells persist due to their ability to attach to stainless steel and other surfaces. once attached these cells may produce multicellular biofilms that are resistant to disinfection and from which cells can become detached and contaminate food products. because there is a correlation between virulence and serotype (and thus phylogenetic division) of l. monocytogenes, it is impo ...	2003	14660383
role of the glycine betaine and carnitine transporters in adaptation of listeria monocytogenes to chill stress in defined medium.	the food-borne pathogen listeria monocytogenes proliferates at refrigeration temperatures, rendering refrigeration ineffective in the preservation of listeria-contaminated foods. the uptake and intracellular accumulation of the potent compatible solutes glycine betaine and carnitine has been shown to be a key mediator of the pathogen's cold-tolerant phenotype. to date, three compatible solute systems are known to operate in l. monocytogenes: glycine betaine porter i (betl), glycine betaine porte ...	2003	14660402
effect of food processing-related stresses on acid tolerance of listeria monocytogenes.	stationary-phase cells of listeria monocytogenes grown in glucose-free or glucose-containing media were exposed for 90 min to various stresses, including acid stress (ph 4.0 to 7.0), osmotic stress (10.5 to 20.5% nacl), and various temperatures (-5 to 50 degrees c), and were further exposed to ph 3.5. exposure to a mildly acidic (ph 5.0 to 6.0) environment provided protection of the pathogen against acid upon subsequent exposure. this adaptive response, however, was found to be strongly dependen ...	2003	14660405
structural aspects of adhesion to and invasion of host cells by the human pathogen listeria monocytogenes.		2003	14661268
the interaction of gamma delta t cells with activated macrophages is a property of the v gamma 1 subset.	immunoregulation is an emerging paradigm of gammadelta t cell function. the mechanisms by which gammadelta t cells mediate this function, however, are not clear. studies have identified a direct role for gammadelta t cells in resolving the host immune response to infection, by eliminating populations of activated macrophages. the aim of this study was to identify macrophage-reactive gammadelta t cells and establish the requirements/outcomes of macrophage-gammadelta t cell interactions during the ...	2003	14662848
listeria monocytogenes serotype identification by pcr.	serotyping is a universally accepted subtyping method for listeria monocytogenes. identification of the strain serotype permits differentiation between important food-borne strains (1/2a, 1/2b, and 4b) and provides a "gold standard" for comparing isolates analyzed in different labs and with different techniques. although an efficient enzyme-linked immunosorbent assay serotyping protocol was described recently, identification of pcr serotyping primers would further increase the ease and accessibi ...	2003	14662936
characterisation of persistent and sporadic listeria monocytogenes strains by pulsed-field gel electrophoresis (pfge) and amplified fragment length polymorphism (aflp).	this study was set up to evaluate the genetic similarity or dissimilarity of persistent and sporadic listeria monocytogenes strains existing in eleven food processing facilities, including fish, dairy, meat and poultry processing plants. in each plant persistent and sporadic strains were selected on the basis of pfge typing results. a total of 17 strains representing persistent strains and 38 sporadic strains originating from eleven food processing plants were included in the study. pfge macrore ...	2003	14666982
in vitro activity of naturally occurring peptides (defensins) against listeria monocytogenes.	autoclaved distilled water samples were inoculated with l. monocytogenes strain v7 and strain vph-1, and incubated aerobically, at 30 c for 48 hours. each strain was tested individually, and growth curves were determined at 1, 2, 3, 4, 5, 21, 24, and 48 hours. the growth or survival of l. monocytogenes was similar for both strains, with survivors at 24 hour-incubation. the microbicidal activity of one synthetic cationic peptide (np-2) was examined against l. monocytogenes strain v7, in a water s ...	2003	14676929
mechanistic diversity of fosfomycin resistance in pathogenic microorganisms.	microbial resistance to the antibiotic fosfomycin [(1r,2s)-epoxypropylphosphonic acid, 1] is known to be mediated by thiol transferase enzymes fosa and fosb, which catalyze the addition of glutathione and l-cysteine to c1 of the oxirane, respectively. a probe of the microbial genome database reveals a related group of enzymes (fosx). the genes mlr3345 from mesorhizobium loti and lmo1702 from listeria monocytogenes were cloned and the proteins expressed. this heretofore unrecognized group of enzy ...	2003	14677948
periprosthetic knee joint infection following colonoscopy. a case report.		2003	14668516
phosphorylation of the stat1 transactivation domain is required for full-fledged ifn-gamma-dependent innate immunity.	stat1 is phosphorylated on serine 727 within its transactivating domain (tad) in response to interferons or other immunological signals. we generated gene-targeted mutant mice expressing a serine727-alanine mutant of stat1. these animals showed increased mortality upon infection with listeria monocytogenes and impaired clearance of the bacteria from spleen and liver. the stat1s727a mice were more resistant to the lps-induced septic shock syndrome, suggesting that stat1 serine phosphorylation pro ...	2003	14670297
sequential myd88-independent and -dependent activation of innate immune responses to intracellular bacterial infection.	microbial infections induce chemokine and cytokine cascades that coordinate innate immune defenses. infection with the intracellular bacterial pathogen listeria monocytogenes induces ccr2-dependent monocyte recruitment and activation, an essential response for host survival. herein we show that invasive l. monocytogenes, but not killed or noninvasive bacteria, induce secretion of mcp-1, the requisite chemokine for monocyte recruitment. induction of mcp-1, but not tnf or il-12, following l. monoc ...	2003	14670305
survival and growth of listeria monocytogenes and enterohemorrhagic escherichia coli o157:h7 in minimally processed artichokes.	the ability of listeria monocytogenes and escherichia coli o157:h7 inoculated by immersion (at 4.6 and 5.5 log cfu/ g, respectively) to survive on artichokes during various stages of preparation was determined. peeling, cutting, and disinfecting operations (immersion in 50 ppm of a free chlorine solution at 4 degrees c for 5 min) reduced populations of l. monocytogenes and e. coli o157:h7 by only 1.6 and 0.8 log units, respectively. an organic acid rinse (0.02% citric acid and 0.2% ascorbic acid ...	2003	14672214
nitrite-induced injury of listeria monocytogenes and the effect of selective versus nonselective recovery procedures on its isolation from frankfurters.	sodium nitrite (nano2) is used as a curing agent in frankfurters. although previous studies have documented the bacteriostatic abilities of nano2 toward listeria monocytogenes, few if any studies have been conducted that consider the possibility of sublethal injury to l. monocytogenes by exposure to nano2. the goals of this study were to determine whether nano2 has the ability to injure l. monocytogenes, to determine whether nitrite injury is reversible, and to compare the recovery of l. monocyt ...	2003	14672221
microbiology of charcoal-broiled european river lampreys (lampetra fluviatilis) stored at 3 and 22 degrees c.	the microbiological quality of 30 production lots of charcoal-broiled river lampreys was studied at three lamprey processing plants (plants a, b, and c). samples were taken directly after charcoal broiling and stored at 22 and 3 degrees c. lampreys were examined on the day of manufacture, and those kept at 22 degrees c were examined every second day for 6 days. samples kept at 3 degrees c were examined every fourth day for up to 24 days. on the production day, the mean aerobic plate counts (apcs ...	2003	14672233
pathogenicity of food and clinical listeria monocytogenes isolates in a mouse bioassay.	serotype distributions of listeria monocytogenes in clinical samples and foods often differ. it is unknown whether such differences reflect a variation in the virulence of strains or are due to other factors that are not directly related to the strains' ability to cause illnesses. fifty-two food and eight clinical isolates of l. monocytogenes were obtained from france, japan, and the united states. their pathogenicity in nonimmunocompromised female icr mice was determined by intraperitoneal (i.p ...	2003	14672239
an essential role of th1 responses and interferon gamma in infection-mediated suppression of neoplastic growth.	we had previously demonstrated that in mice acute toxoplasmosis leads to systemic inhibition of angiogenesis and, consequently, strong suppression of neoplastic growth. here we investigated the role of th1 cytokines, in particular interferon gamma (ifn-gamma), in this phenomenon. besides toxoplasma, neoplastic growth was readily blocked during acute infection with other th1 response-inducing pathogens such as listeria monocytogenes and lymphocytic choriomeningitis virus (lcmv). in contrast, chro ...	2003	14688478
the antimicrobial activity of extracts of the lichen cetraria aculeata and its protolichesterinic acid constituent.	in this study, the antimicrobial activity of the acetone, diethyl ether and ethanol extracts of the lichen cetraria aculeata has been investigated. the extracts were tested against twelve bacteria and eight fungi and found active against escherichia coli, staphylococcus aureus, aeromonas hydrophila, proteus vulgaris, streptococcus faecalis, bacillus cereus, bacillus subtilis, pseudomonas aeruginosa, listeria monocytogenes. no antimicrobial activity against the fungi was detected. it was determin ...	2003	14713164
[the importance of a complete diagnostic workup in patients with nontraumatic (partial) paraplegia].	in two women, aged 86 and 56 years, respectively, who suffered from back pain and loss of strength, and in a 55-year-old man who lost sensation and strength in his left leg, spinal-cord compression in connection with vertebral destruction was seen on radiological examination. when spinal-cord compression is the result of a local malignant tumour, the therapy often entails emergency radiotherapy. in the first two patients, histological examination revealed a solitary plasmocytoma and curative hig ...	2003	14723022
absence of interferon-gamma-inducible gene igtp does not significantly alter the development of chagasic cardiomyopathy in mice infected with trypanosoma cruzi (brazil strain).	interferon-gamma (ifn-gamma) contributes to host resistance during acute infection with trypanosoma cruzi, the causative agent of chagas' disease. inducibly expressed guanosine triphosphatase (igtp), a 48-kda guanosine triphosphatase (gtpase), is a member of a family of gtpase proteins inducibly expressed by ifn-gamma. the expression pattern of igtp suggests that it may mediate ifn-gamma-induced responses in a variety of cell types. igtp has been demonstrated to be important for control of toxop ...	2003	14740917
listeria monocytogenes contamination of finishing pigs: an exploratory epidemiological survey in france.	listeria monocytogenes is a foodborne pathogen of major concern for public health in industrialised countries. since l. monocytogenes carriage by pigs at the herd level could be a primary source for carcass contamination, control measures should be designed to reduce the l. monocytogenes load at the pre-harvest stage. for this purpose, an exploratory analytical survey was carried out in 2000-2001 in 93 french farrow-to-finish pig farms concerning l. monocytogenes contamination in pigs before the ...	2003	14746769
treatment of experimental sepsis-induced immunoparalysis with tnf.	following a severe septic abdominal infection induced by sublethal cecal ligation and puncture (clp) in mice, a phase of depressed immune reactivity occurred two days after clp characterized by a reduced capacity to produce tnf. to determine whether this reduced tnf production causes immunoparalysis as determined by increased susceptibility to bacterial infection and whether therapeutic tnf substitution can be beneficial during this phase, a super-infection with salmonella enterica serovar typhi ...	2003	14748511
increased salt- and nisin-sensitivity of pressure-injured bioluminescent listeria monocytogenes.	suspensions of a bioluminescent (luxab) transformant of listeria monocytogenes in ph 7.0 phosphate buffer were pressurised and the effect of the pressure treatment was monitored by plate counting. when the bacteria were suspended in nacl- and nisin-free buffer the number of colony forming units (cfu) decreased by 3 and 6 log cycles after 300 mpa for 10 and 30 min, respectively. supplementing the plating medium with 5% nacl did not influence the colony forming capacity of non-pressurised cells, h ...	2003	14750435
development of a rapid 1-h fluorescence-based cytotoxicity assay for listeria species.	listeria monocytogenes is cytotoxic to the lymphocyte-origin hybridoma ped-2e9 cell line. the relative cytotoxicity can be calculated by assaying the release of alkaline phosphatase (alp) from the infected cell line. in this study, a fluorogenic substrate (4-methylumbelliferyl phosphate, mup) was used to quantify the alp activity. the assay is 3.5-fold more sensitive than the colorimetric-based assay and requires only 1 h to differentiate virulent from avirulent strains. in addition to various l ...	2003	14499993
host resistance of cd18 knockout mice against systemic infection with listeria monocytogenes.	mice with targeted mutations of cd18, the common beta2 subunit of cd11/cd18 integrins, have leukocytosis, impaired transendothelial neutrophil emigration, and reduced host defense to streptococcus pneumoniae, a gram-positive extracellular bacterium. previous studies using blocking monoclonal antibodies suggested roles for cd18 and cd11b in hepatic neutrophil recruitment and host innate response to listeria monocytogenes, a gram-positive intracellular bacterium. we induced systemic listeriosis in ...	2003	14500519
genome-scale design of pcr primers and long oligomers for dna microarrays.	during the last years, the demand for custom-made cdna chips/arrays as well as whole genome chips is increasing rapidly. the efficient selection of gene-specific primers/oligomers is of the utmost importance for the successful production of such chips. we developed genomepride, a highly flexible and scalable software for designing primers/oligomers for large-scale projects. the program is able to generate either long oligomers (40-70 bases), or pcr primers for the amplification of gene-specific ...	2003	14500820
real-time closed tube single nucleotide polymorphism (snp) quantification in pooled samples by quencher extension (qext).	quencher extension (qext) is a novel single step closed tube real-time method to quantify snps using reporters and quenchers in combination with primer extension. a probe with a 5'-reporter dye is single base extended with a dideoxy nucleotide containing a quencher dye if the target snp allele is present. the extension is recorded from the quenching (reduced fluorescence) of the reporter dye. this avoids the influence of the unincorporated dye-labeled nucleotides, resulting in high accuracy and ...	2003	14500845
"effectiveness of electrolyzed acidic water in killing escherichia coli o157:h7, salmonella enteritidis, and listeria monocytogenes on the surfaces of tomatoes," a comment on: j. food prot. 66(4):542-548 (2003).		2003	14503702
microbiological quality of open ready-to-eat salad vegetables: effectiveness of food hygiene training of management.	during september and october 2001, a microbiological study of open, ready-to-eat, prepared salad vegetables from catering or retail premises was undertaken to determine their microbiological quality. the study focused on those salad vegetables that were unwrapped and handled either by staff or customers in the premises where the sample was taken. examination of salad vegetables from food service areas and customer self-service bars revealed that most (97%; 2,862 of 2,950) were of satisfactory or ...	2003	14503709
survival of escherichia coli o157:h7, listeria monocytogenes, and salmonella in juice concentrates.	the survival of escherichia coli o157:h7, listeria monocytogenes, and salmonella was studied in apple, orange, pineapple, and white grape juice concentrates and banana puree. pouches of juice concentrate or puree were inoculated with pathogens at a level > or = 10(3) cfu/g and stored at -23 degrees c (-10 degrees f). pathogen survival was monitored at 6 and 24 h, once a week for four consecutive weeks, and biweekly thereafter until 12 weeks. when pathogens were not detectable by direct plating, ...	2003	14503711
thermal inactivation, growth, and survival studies of listeria monocytogenes strains belonging to three distinct genotypic lineages.	twenty-one listeria monocytogenes strains belonging to three different genotypic lineages were evaluated for differences between lineages and between individual strains with respect to thermal inactivation, growth, and survival. three sets of heat inactivation conditions (60 degrees c, ph 6.0, and 0.5 m lactate; 55 degrees c, ph 6.0, and 0.5 m lactate; and 50 degrees c, ph 4.0, and 0.5 m lactate) were used on strains grown in modified brain heart infusion (bhi) broth with and without glucose. tw ...	2003	14503714
thermal inactivation of listeria monocytogenes on ready-to-eat turkey breast meat products during postcook in-package pasteurization with hot water.	the inactivation of listeria monocytogenes during postcook in-package pasteurization was evaluated for fully cooked turkey breast meat products (4-kg packages). the products were surface-inoculated to contain 10(7) cfu of l. monocytogenes per cm2 of product surface. the inoculated products were vacuum-packaged in different thicknesses (0.08 to 0.33 mm) of packaging films and treated with hot water at 96 degrees c. after heat treatment, the products were immediately cooled in an ice water bath at ...	2003	14503715
prepackage surface pasteurization of ready-to-eat meats with a radiant heat oven for reduction of listeria monocytogenes.	in this paper, a thermal process for the surface pasteurization of ready-to-eat (rte) meat products for the reduction of listeria monocytogenes on such products (turkey bologna, roast beef, corned beef, and ham) is described. the process involves the passage of products through a "tunnel" of heated coils on a stainless steel conveyor belt at various treatment times relevant to the manufacture of processed meat for the surface pasteurization of rte meat products. two inoculation procedures, dip a ...	2003	14503716
synergy between nisin and select lactates against listeria monocytogenes is due to the metal cations.	listeria monocytogenes, a major foodborne pathogen, has been responsible for many outbreaks and recalls. organic acids and antimicrobial peptides (bacteriocins) such as nisin are produced by lactic acid bacteria and are commercially used to control pathogens in some foods. this study examined the effects of lactic acid (la) and its salts in combination with a commercial nisin preparation on the growth of l. monocytogenes scott a and its nisin-resistant mutant. because of an increase in its activ ...	2003	14503717
inactivation of escherichia coli o157:h7, listeria monocytogenes, and salmonella in cranberry, lemon, and lime juice concentrates.	the production of thermally concentrated fruit juices uses temperatures high enough to achieve at least a 5-log reduction of pathogenic bacteria that can occur in raw juice. however, the transportation and storage of concentrates at low temperatures prior to final packaging is a common practice in the juice industry and introduces a potential risk for postconcentration contamination with pathogenic bacteria. the present study was undertaken to evaluate the likelihood of escherichia coli o157:h7, ...	2003	14503718
a pcr method based on 16s rrna sequence for simultaneous detection of the genus listeria and the species listeria monocytogenes in food products.	the genus listeria comprises six closely related species, of which only listeria monocytogenes is a human pathogen. the rapid and sensitive detection of l. monocytogenes is important in the food industry as well as in medical diagnosis. in this study, a pcr-based method for the rapid, specific, and sensitive detection of l. monocytogenes in food products was developed. the pcr is based on dna sequences and primer pairs that are found within the 16s subunit of the rrna gene and are specific to th ...	2003	14503721
evaluation of several modifications of an ecometric technique for assessment of media performance.	recovery of listeria monocytogenes 101m, jonesia denitrificans, salmonellae, and pediococcus sp. nrrl b-2354 across nine media was evaluated with three modified versions of an ecometric method. two approaches involved the use of broth cultures (10(8) to 10(9) cfu/ml) of individual strains and either large (10-microl) or small (1-microl) presterilized plastic loops. the third approach involved precultured slants and the inoculation of media with presterilized plastic inoculating needles (10(4) cf ...	2003	14503736
the role of human dendritic cells in meningococcal and listerial meningitis.	few bacteria are capable of causing infections of the central nervous system (cns), one of the most subtly shielded anatomical structures within the human body. neisseria meningitidis is an important cause of bacterial meningitis and commonly affects otherwise healthy infants and adolescents. in contrast, listeria monocytogenes is a cause of septicaemia and meningitis in neonates and immunocompromised adults. dendritic cells (dcs) provide the physical link between the innate and adaptive immune ...	2003	14503789
characterization of a unique sigma54-dependent pts operon of the lactose family in listeria monocytogenes.	the sigma(54) subunit of the rna polymerase directs the expression of specific operons in association with cognate activators. three different activators have been detected in the listeria monocytogenes genome on the basis of the high conservation of a specific domain. among them, the lacr activator, of the levr family, was found just upstream from a newly described sigma(54)-dependent operon, lpo, which presents a classical -24/-12 consensus promoter. the lpo operon encodes proteins similar to ...	2003	14505817
genome and proteome of listeria monocytogenes phage psa: an unusual case for programmed + 1 translational frameshifting in structural protein synthesis.	psa is a temperate phage isolated from listeria monocytogenes strain scott a. we report its complete nucleotide sequence, which consists of a linear 37 618 bp dna featuring invariable, 3'-protruding single stranded (cohesive) ends of 10 nucleotides. the physical characteristics were confirmed by partial denaturation mapping and electron microscopy of dna molecules. fifty-seven open reading frames were identified on the psa genome, which are apparently organized into three major transcriptional u ...	2003	14507382
immunological function in mice exposed to jp-8 jet fuel in utero.	immunological parameters, host resistance, and thyroid hormones were evaluated in f1 mice exposed in utero to jet propulsion fuel-8 (jp-8). c57bl/6 pregnant dams (mated with c3h/hej males) were gavaged daily on gestation days 6-15 with jp-8 in a vehicle of olive oil at 0, 1000, or 2000 mg/kg. at weaning (3 weeks of age), no significant differences were observed in body, liver, spleen, or thymus weight, splenic and thymic cellularity, splenic cd4/cd8 lymphocyte subpopulations, or t-cell prolifera ...	2003	14514957
in vivo role of ifn-gamma produced by antigen-presenting cells in early host defense against intracellular pathogens.	antigen-presenting cells (apc), including dendritic cells and macrophages, produce a large amount of interferon (ifn)-gamma, a crucial cytokine for the control of infectious diseases. to elucidate the role of ifn-gamma from apc in vivo, we employed cytokine receptor common gamma subunit (gamma c) and recombination-activating gene (rag)-2 double-knockout (gamma c(-/-(y))-rag-2(-/-)) mice, which are severely impaired in ifn-gamma production and are extremely susceptible to infection of intracellul ...	2003	14515250
differences in maintenance of cd8+ and cd4+ bacteria-specific effector-memory t cell populations.	our knowledge about the kinetics and dynamics of complex pathogen-specific cd8(+) t cell responses and the in vivo development of cd8(+) memory t cells has increased substantially over the past years; in comparison, relatively little is known about the cd4(+) t cell compartment. we monitored and directly compared the phenotypical changes of pathogen (listeria monocytogenes)-specific cd8(+) and cd4(+) t cell responses under conditions leading to effective and long-lasting protective immunity. we ...	2003	14515271
bacterial pathogenesis: exploiting cellular adherence.	cell adhesion molecules, such as integrins, cadherins, the immunoglobulin superfamily of cell adhesion molecules and selectins, play important structural roles and are involved in various signal transduction processes. as an initial step in the infectious process, many bacterial pathogens adhere to cell adhesion molecules as a means of exploiting the underlying signaling pathways, entering into host cells or establishing extracellular persistence. often, bacteria are able to bind to cell adhesio ...	2003	14519399
[active surveillance on listeria monocytogenes in seven kinds of food in 11 provinces of china in 2001].	to carry out national active surveillance on listeria monocytogenes in foods in china.	2003	14521783
listeria monocytogenes rotates around its long axis during actin-based motility.		2003	14521850
heteroduplex mobility assay for the identification of listeria sp and listeria monocytogenes strains: application to characterisation of strains from sludge and food samples.	one hundred and ten listeria sp. isolates from sewage sludge were identified according to phenotypic and genotypic methods. the listeria sp. strains isolated from five types of sludge from three sewage treatment plants in angers (france) and the surrounding area included l. monocytogenes (55.5%), l. innocua (29.1%), l. seeligeri (13.6%) and l. welshimeri (1.8%). the majority of l. monocytogenes strains belonged to serotypes 4b, 1/2b and 1/2a. moreover, a heteroduplex mobility assay based on the ...	2003	14522461
listeria monocytogenes infection in patients with cancer.	listeriosis (lt) is an important infection in immunocompromised patients, but no large series of lt in cancer patients have been recently described. we reviewed the records of 34 cancer patients with lt at our institution (1990-2001). twenty patients (59%) had an underlying hematologic malignancy. in 11 patients, lt complicated bone marrow transplantation. lymphocytopenia was observed in 62% of the patients. twenty-six patients (76%) received prior corticosteroids. bacteremia was the most common ...	2003	14522512
in vitro antimicrobial activity of moxifloxacin compared to other quinolones against recent clinical bacterial isolates from hospitalized and community-based cancer patients.	the in vitro spectrum of moxifloxacin (a c-8-methoxyquinolone) was compared to that of ciprofloxacin and levofloxacin against 924 recent clinical isolates from cancer patients. moxifloxacin was more active than the comparator agents against gram-positive pathogens, with potent activity against aerococcus spp., listeria monocytogenes, micrococcus spp., rhodococcus equi, and stomatococcus mucilaginous, methicillin-susceptible staphylococcus spp., all beta hemolytic streptococci, viridans streptoco ...	2003	14522520
immobilized enzyme-linked dna-hybridization assay with electrochemical detection for cryptosporidium parvum hsp70 mrna.	an electrochemical enzyme-linked immobilized dna-hybridization assay for the detection of cryptosporidium parvum in water has been developed. the target molecule was a 121-nucleotide sequence from the c. parvum heat shock protein 70 (hsp70 mrna from u71181 gene). this analyte offers the possibility of distinguishing dead from live oocysts. the assay involves covalent attachment of a primary dna probe via its 5'-amine-terminus to self-assembled monolayers of mercaptoundecanoic acid to a gold surf ...	2003	14572058
antibacterial activities of phenolic benzaldehydes and benzoic acids against campylobacter jejuni, escherichia coli, listeria monocytogenes, and salmonella enterica.	we evaluated the bactericidal activities of 35 benzaldehydes, 34 benzoic acids, and 1 benzoic acid methyl ester against campylobacter jejuni, escherichia coli o157:h7, listeria monocytogenes, and salmonella enterica when these compounds were substituted on the benzene ring with 0, 1, 2, or 3 hydroxy (oh) and/or methoxy (och3) groups in a ph 7.0 buffer. dose-response plots were used to determine the percentage of the sample that induced a 50% decrease in cfu after 60 min (ba50). of the 70 compoun ...	2003	14572218
prevalence of listeria monocytogenes in, and microbiological and sensory quality of, rainbow trout, whitefish, and vendace roes from finnish retail markets.	the prevalence of listeria monocytogenes in retail roe, as well as the microbiological and sensory qualities of the roe, were studied for three fish species under three different storage conditions. a total of 147 finnish rainbow trout (oncorhynchus mykiss), whitefish (coregonus lavaretus), vendace (coregonus albula), and burbot (lota lota) roe samples were bought fresh, frozen, or frozen-thawed from finnish retail markets. the overall prevalence of l. monocytogenes was 5%; however, the prevalen ...	2003	14572220
survival of listeria monocytogenes in a simulated recirculating brine chiller system.	contamination by listeria monocytogenes of processed meats after cooking presents a significant food safety risk. the purpose of this study was to determine the survival of l. monocytogenes in a simulated recirculating brine chiller system using ph values of 5, 6, and 7 with free chlorine concentrations of 0, 3, 5, and 10 ppm in 20% salt brine at -12 degrees c. at ph values of 5, 6, and 7 with chlorine concentrations of 2 and 3 ppm, using 10(8) cfu in a test tube system, an immediate drop of 0.2 ...	2003	14572221
consumer food-handling behaviors associated with prevention of 13 foodborne illnesses.	to be effective in reducing the incidence of foodborne illness, consumers and food safety educators need information about behaviors that will decrease exposure to foodborne pathogens. a four-round delphi technique was used to survey nationally recognized experts in food microbiology, epidemiology, food safety education, and food safety policy with the aim of identifying and ranking food-handling and consumption behaviors associated with 13 major foodborne pathogens. the food safety experts rank ...	2003	14572229