Publications

listeriosis in a cockatiel (nymphicus hollandicus).	listeriosis was diagnosed in a 4-yr-old female cockatiel (nymphicus hollandicus) that died after exhibiting clinical signs that included a fluffed-up appearance, weakness, and loss of weight of several days duration. grossly, the bird was moderately emaciated, and the liver and spleen were enlarged. microscopically, there was mild-to-moderate inflammation associated with rod-shaped, gram-positive bacteria in the liver, spleen, kidneys, adrenal glands, bone marrow, and esophagus. listeria monocyt ...	2007	17992946
results of a 12-month long enhanced surveillance of listeriosis in italy.	since 1993, the reporting of listeriosis has been mandatory in italy. the surveillance system based on case notifications from physicians is managed by the ministry of health. the information collected includes only gender, age and case distribution by region. to gather more information, an active surveillance was conducted for 12 months (2002-2003). all hospital microbiological laboratories in italy (n=103) were given clinical and food questionnaires and were requested to report positive cases ...	2007	18005656
a staphylococcus aureus regulatory system that responds to host heme and modulates virulence.	staphylococcus aureus, a bacterium responsible for tremendous morbidity and mortality, exists as a harmless commensal in approximately 25% of humans. identifying the molecular machinery activated upon infection is central to understanding staphylococcal pathogenesis. we describe the heme sensor system (hssrs) that responds to heme exposure and activates expression of the heme-regulated transporter (hrtab). inactivation of the hss or hrt systems leads to increased virulence in a vertebrate infect ...	2007	18005689
designer bugs: structural engineering to build a better mouse model.	many animal models of bacterial diseases are hampered by differences in tissue tropism and the course of pathogenesis. in a recent issue of cell, by rationally mutating a surface invasion protein (inla) to have higher binding affinity for its cognate host receptor (e-cadherin), wollert et al. were able to "murinize"listeria monocytogenes, creating a strain capable of invading intestinal epithelial cells in mice, mimicking the route of infection in humans.	2007	18005702
invasive and adherent bacterial pathogens co-opt host clathrin for infection.	infection by the bacterium listeria monocytogenes depends on host cell clathrin. to determine whether this requirement is widespread, we analyzed infection models using diverse bacteria. we demonstrated that bacteria that enter cells following binding to cellular receptors (termed "zippering" bacteria) invade in a clathrin-dependent manner. in contrast, bacteria that inject effector proteins into host cells in order to gain entry (termed "triggering" bacteria) invade in a clathrin-independent ma ...	2007	18005755
spontaneous splenic rupture associated with listeria endocarditis.		2007	18022517
reversible nk1.1 surface expression on invariant liver natural killer t cells during listeria monocytogenes infection.	the invariant (i) natural killer (nk)t cells consistently express the valpha14 chain of the t cell receptor (tcr) and recognize alpha-galactosylceramide (alpha-galcer) presented by the nonpolymorphic presentation molecule cd1d. despite their name, the inkt cells represent a heterogeneous population, which can be divided on the basis of nk1.1 surface expression. here we show that nk1.1 surface expression on liver inkt cells in mice fluctuates during listeria monocytogenes infection. at early stag ...	2007	18024119
defective t cell development and function in the absence of abelson kinases.	thymocyte proliferation, survival, and differentiation are tightly controlled by signaling from the pre-tcr. in this study, we show for the first time that the abelson (abl) kinases regulate proximal signaling downstream of the pre-tcr. conditional deletion of abl kinases in thymocytes reveals a cell-autonomous role for these proteins in t cell development. the conditional knockout mice have reduced numbers of thymocytes, exhibit an increase in the percentage of the cd4(-)cd8(-) double-negative ...	2007	18025176
activation of immature hepatic nk cells as immunotherapy for liver metastatic disease.	nk cells can identify and eliminate emerging tumors due to altered expression of activating and inhibitory ligands on aberrant cells, a process that is greatly enhanced following nk cell activation. as a principal site of both tumor metastases and immature nk cells, the liver represents a unique anatomic location in which activation of the innate immune system could provide substantial therapeutic benefit. we describe here the nk cell-dependent destruction of a primary hepatic tumor following in ...	2007	18025181
extensive characterization of ifn-induced gtpases mgbp1 to mgbp10 involved in host defense.	ifn-gamma orchestrates a potent antimicrobial host response. however, the underlying molecular basis for this immunological defense system is largely unknown. in a systematic approach to identify ifn-gamma-regulated host effector molecules, a notable number of transcripts with consensus gtp-binding motives were obtained. further extensive transcriptome and genome analyses identified five novel family members of murine guanylate-binding proteins (mgbps) now designated mgbp6, 7, 8, 9, and 10. more ...	2007	18025219
production of nisin z by lactococcus lactis isolated from dahi.	lactococcus lactis cm1, an isolate from homemade "dahi," a traditional fermented milk from india, used maltose as carbon source to produce a high level of bacteriocin. the bacterial cell mass and the bacteriocin production correlated with the initial ph of the medium and were highest when the initial ph was 11.0. the level of bacteriocin reached its peak at the late log phase with concomitant reduction of culture ph to 4.2, regardless of the initial ph of the medium. a combination of maltose and ...	2007	18025595
characteristics and frequency of detection of fecal listeria monocytogenes shed by livestock, wildlife, and humans.	listeria monocytogenes is a facultative intracellular pathogen that can be carried asymptomatically in various animals and can be shed in feces. we investigated the prevalence and characteristics of l. monocytogenes isolated from livestock, wildlife, and human potential sources of contamination in 2 areas in ontario, canada. from february 2003 to november 2005, a total of 268 fecal samples were collected from different animals. listeria monocytogenes was isolated using selective enrichment, isol ...	2007	18026208
neuroinfections due to listeria monocytogenes.	listeria monocytogenes is not a rare pathogen causing meningitis, mainly in small children and in close contacts to livestock. the pathogen is naturally resistant to cephalosporins and some glycopeptides as well, therefore despite of syndromologic diagnosis of meningitis and initial therapy with 3rd generation cephalosporins according to the guidelines therapeutic failures with clinical consequences may occur.	2007	18030269
rapid exonuclease digestion of pcr-amplified targets for improved microarray hybridization.		2007	18030700
comparison of 3m petrifilm environmental listeria plates against standard enrichment methods for the detection of listeria monocytogenes of epidemiological significance from environmental surfaces.	environmental monitoring using sensitive methods for detection and elimination of harborage sites of listeria monocytogenes is key to the control of this organism. the 3m petrifilm environmental listeria (el) plate-a no enrichment method-was compared with the usda/fsis, modified usda/fsis (musda), and iso methods for detection/recovery of l. monocytogenes on 4 environmental surfaces (brick, dairy board, stainless steel, and epoxy resin). the efficacy of 3 sampling devices including the microbial ...	2007	18034727
antimicrobial chitosan-lysozyme (cl) films and coatings for enhancing microbial safety of mozzarella cheese.	this study investigated the antimicrobial activities of chitosan-lysozyme (cl) composite films and coatings against tested microorganisms inoculated onto the surface of mozzarella cheese. cl film-forming solutions (ffs) with a ph of 4.4 to 4.5 were prepared by incorporating 0% or 60% lysozyme (per dry weight of chitosan) into chitosan ffs with or without a ph adjustment to 5.2. sliced cheese was subjected to 3 cl package applications: film, lamination on a multilayer coextruded film, and coating ...	2007	18034728
antimicrobial effect of electrolyzed oxidizing water against escherichia coli o157:h7 and listeria monocytogenes on fresh strawberries (fragaria x ananassa).	antibacterial activity of electrolyzed oxidizing (eo) water prepared from 0.05% or 0.10% (w/v) sodium chloride (nacl) solutions against indigenous bacteria associated with fresh strawberries (fragaria x ananassa) was evaluated. the efficacy of eo water and sodium hypochlorite (naocl) solution in eliminating and controlling the growth of listeria monocytogenes and escherichia coli o157:h7 inoculated onto strawberries stored at 4 +/- 1 degrees c up to 15 d was investigated at exposure time of 1, 5 ...	2007	18034734
combined effect of aqueous chlorine dioxide and modified atmosphere packaging on inhibiting salmonella typhimurium and listeria monocytogenes in mungbean sprouts.	this study was conducted to investigate the effect of chlorine dioxide (clo2) combined with modified atmosphere packaging (map) on inhibiting total mesophilic microorganisms, salmonella typhimurium, and listeria monocytogenes in mungbean sprouts during refrigerated storage. mungbean sprouts were packaged using 4 different methods (air, vacuum, co2 gas, and n2 gas) following treatment with water or 100 ppm clo2 for 5 min and stored at 5 +/- 2 degrees c. the population of total mesophilic microorg ...	2007	18034740
a role for translational control in listerial osmoregulation and strain variation?		2007	18041949
phenotypic and molecular characterization of listeria monocytogenes strains isolated from a marine environment in morocco.	microbiological analysis of 1025 marine samples, including 345 from seawater, 337 from shellfish, and 343 from sediments collected between january 2000 and december 2002 from 18 shellfish sites on the atlantic coast of mid-west of morocco (agadir region), yielded 143 strains of listeria (listeria monocytogenes: 38; l. innocua: 109; l. ivanovii: 1). the overall incidence of listeria sp. in the coastal environment was 5.3%. thirteen l. monocytogenes strains were isolated from seawater, 7 from sedi ...	2007	18041951
antibacterial activity of guava (psidium guajava l.) and neem (azadirachta indica a. juss.) extracts against foodborne pathogens and spoilage bacteria.	the antibacterial activity of guava (psidium guajava) and neem (azadirachta indica) extracts against 21 strains of foodborne pathogens were determined--listeria monocytogenes (five strains), staphylococcus aureus (four strains), escherichia coli o157:h7 (six strains), salmonella enteritidis (four strains), vibrio parahaemolyticus, and bacillus cereus, and five food spoilage bacteria: pseudomonas aeroginosa, p. putida, alcaligenes faecalis, and aeromonas hydrophila (two strains). guava and neem e ...	2007	18041957
how university researchers can contribute to farm-to-table risk assessments: listeria monocytogenes as an example.	as a part of the sanitary and phytosanitary (sps) agreement, the world trade organization requires that member countries establish sps measures on the basis of an appropriate risk assessment. in addition, many governments use risk assessment in their management of food safety. consequently, a number of risk assessments for different foodborne pathogens have been conducted. risk assessments have also been successfully used as a research tool. while, historically, risk assessments are typically in ...	2007	18041962
inhibition of the rage products increases survival in experimental models of severe sepsis and systemic infection.	the receptor for advanced glycation end products (rage), a multi-ligand member of the immunoglobulin superfamily, contributes to acute and chronic disease processes, including sepsis.	2007	18042296
effect of biofilm dryness on the transfer of listeria monocytogenes biofilms grown on stainless steel to bologna and hard salami.	listeria monocytogenes continues to be a major cause of class i food recalls in the united states. very little is known about its transfer and cross-contamination in processing scenarios. the objective of this study was to evaluate the effect of hydration level on l. monocytogenes biofilms grown on stainless steel and its effect on the biofilm transfer to foods. biofilms were grown on stainless steel in diluted tryptic soy broth 1:20 for 48 h at 32 degrees c. after this, biofilms were equilibrat ...	2007	18044424
modeling and predicting the growth of lactic acid bacteria in lightly preserved seafood and their inhibiting effect on listeria monocytogenes.	a cardinal parameter model was developed to predict the effect of diacetate, lactate, co2, smoke components (phenol), ph, nacl, temperature, and the interactions between all parameters on the growth of lactic acid bacteria (lab) in lightly preserved seafood. a product-oriented approach based on careful chemical characterization and growth of bacteria in ready-to-eat seafoods was used to develop this new lab growth model. initially, cardinal parameter values for the inhibiting effect of diacetate ...	2007	18044425
inhibition of listeria monocytogenes in cooked ham through active packaging with natural antimicrobials and high-pressure processing.	enterocins a and b and sakacin k at 200 and 2,000 activity units (au)/cm2, nisin at 200 au/cm2, 1.8% potassium lactate, and a combination of 200 au/cm2 of nisin and 1.8% lactate were incorporated into interleavers, and their effectiveness against listeria monocytogenes spiked in sliced, cooked ham was evaluated. antimicrobial-packaged cooked ham was then subjected to high-pressure processing (hpp) at 400 mpa. in nonpressurized samples, nisin plus lactate-containing interleavers were the most eff ...	2007	18044426
effect of combining nisin and/or lysozyme with in-package pasteurization on thermal inactivation of listeria monocytogenes in ready-to-eat turkey bologna.	achieving a targeted lethality with minimum exposure to heat and preservation of product quality during pasteurization is a challenge. the objective of this study was to evaluate the effect of nisin and/or lysozyme in combination with in-package pasteurization of a ready-to-eat low-fat turkey bologna on the inactivation of listeria monocytogenes. sterile bologna samples were initially treated with solutions of nisin (2 mg/ml = 5,000 au/ml = 31.25 au/cm2), lysozyme (10 mg/ml = 80 au/ml = 0.5 au/c ...	2007	18044427
listeria prevalence and listeria monocytogenes serovar diversity at cull cow and bull processing plants in the united states.	listeria monocytogenes, the causative agent of epidemic and sporadic listeriosis, is routinely isolated from many sources, including cattle, yet information on the prevalence of listeria in beef processing plants in the united states is minimal. from july 2005 through april 2006, four commercial cow and bull processing plants were sampled in the united states to determine the prevalence of listeria and the serovar diversity of l. monocytogenes. samples were collected during the summer, fall, win ...	2007	18044437
resistance of listeria monocytogenes f2365 cells to synthetic gastric fluid is greater following growth on ready-to-eat deli turkey meat than in brain heart infusion broth.	ready-to-eat (rte) deli meats have been categorized as high-risk foods for contraction of foodborne listeriosis. several recent listeriosis outbreaks have been associated with the consumption of rte deli turkey meat. in this study, we examined whether the growth of listeria monocytogenes f2365 on commercially prepared rte deli turkey meat causes listerial cells to become more resistant to inactivation by synthetic gastric fluid (sgf). listerial cells grown on turkey meat to late logarithmic-earl ...	2007	18044439
prevalence, types, and geographical distribution of listeria monocytogenes from a survey of retail queso fresco and associated cheese processing plants and dairy farms in sonora, mexico.	in the first part of this study, samples were collected from farms, cheese processing plants (cpps), and retail markets located in various geographical areas of sonora, mexico, over a 12-month period during the summer of 2004 and winter of 2005. four (all queso fresco [qf] from retail markets) of 349 total samples tested positive for listeria monocytogenes (lm). of these four positive samples, three were collected in the northern region and one in the southern region of sonora. additionally, two ...	2007	18044440
survival and growth of listeria monocytogenes in broth as a function of temperature, ph, and potassium lactate and sodium diacetate concentrations.	the objective of this study was to determine the antimicrobial effect of a combination of potassium lactate and sodium diacetate (0, 1.8, 3, and 4.5%; purasal p opti. form 4, 60% solution) on the survival and growth of listeria monocytogenes scott a in ph-adjusted broth (5.5, 6.0, 6.5, and 7.0) stored at 4, 10, 17, 24, 30, and 37 degrees c. appropriate dilutions of broth were enumerated by spiral plating on tryptose agar and counted with an automated colony counter. growth data were iteratively ...	2007	18044445
effects of essential oils of oregano and nutmeg on growth and survival of yersinia enterocolitica and listeria monocytogenes in barbecued chicken.	the in vitro effects of plant essential oils (eos) against pathogenic bacteria are well known, yet few studies have addressed the effects of these compounds against pathogens associated with ready-to-cook foods. experiments were conducted to determine the effectiveness of oregano and nutmeg eos on the growth and survival of yersinia enterocolitica and listeria monocytogenes in broth culture and in iranian barbecued chicken. ready-to-cook iranian barbecued chicken was prepared according to the co ...	2007	18044446
antimicrobial efficacy of eugenol microemulsions in milk against listeria monocytogenes and escherichia coli o157:h7.	the antimicrobial activity of eugenol microemulsions (eugenol encapsulated in surfactant micelles) in ultrahigh-temperature pasteurized milk containing different percentages of milk fat (0, 2, and 4%) was investigated. antimicrobial microemulsions were prepared from a 5% (wt) aqueous surfactant solution (surfynol 485w) with 0.5% (wt) eugenol. two strains each of listeria monocytogenes and escherichia coli o157:h7 previously shown to be the least and most resistant to the microemulsion in microbi ...	2007	18044447
determination of 5-log reduction times for food pathogens in acidified cucumbers during storage at 10 and 25 degrees c.	outbreaks of acid-resistant foodborne pathogens in acid foods with ph values below 4.0, including apple cider and orange juice, have raised concerns about the safety of acidified vegetable products. for acidified vegetable products with ph values between 3.3 and 4.6, previous research has demonstrated that thermal treatments are needed to achieve a 5-log reduction in the numbers of escherichia coli o157:h7, listeria monocytogenes, or salmonella enterica. for some acidified vegetable products wit ...	2007	18044448
impact of dilution ratios on listeria monocytogenes growth during university of vermont medium enrichment of deli meats.	in the u.s. department of agriculture (usda) method for listeria detection, a 25-g composite food sample is enriched in 225 ml of university of vermont medium (uvm), giving a detection limit of 0.04 cfu/g. however, in a recent large-scale four-state deli meat survey for l. monocytogenes, 125-g samples enriched in 1,125 ml of uvm were requested to increase the detection limit to 0.008 cfu/g. to circumvent problems associated with large volumes of uvm, the impact on l. monocytogenes growth of lowe ...	2007	18044452
the glutamate decarboxylase acid resistance mechanism affects survival of listeria monocytogenes lo28 in modified atmosphere-packaged foods.	the contribution of the glutamate decarboxylase (gad) acid resistance system to survival and growth of listeria monocytogenes lo28 in modified atmosphere-packaged foods was examined.	2007	18045416
physical properties of nisin-incorporated gelatin and corn zein films and antimicrobial activity against listeria monocytogenes.	edible films of gelatin and corn zein were prepared by incorporating nisin to the film-forming solutions. corn zein film with nisin of 12,000 iu/ml had an increase of 11.6 mpa in tensile strength compared with the control, whereas gelatin film had a slight increase with the increase of nisin concentration added. water vapor permeability for both corn zein and gelatin films decreased with the increase of nisin concentration, thus providing a better barrier against water. antimicrobial activity ag ...	2007	18050958
morphological changes induced in listeria monocytogenes v7 by a bacteriocin produced by pediococcus acidilactici.	pediococcus acidilactici produces bacteriocin, which kills listeria monocytogenes. the bactericidal mode of action of the bacteriocin against l. monocytogenes v7 was investigated by transmission electron microscopy. the bacteriocin was purified partially from the cell-free extract using micro-cel and cation-exchange chromatography, and the specific activity was increased 1,791 fold. the bacteriocin (6,400 au/ ml) was inoculated with l. monocytogenes v7 and incubated for 0.5 h, 1 h, 3 h, and 6 h. ...	2007	18051280
production of monoclonal antibody against listeria monocytogenes and its application to immunochromatography strip test.	an immunochromatography (icg) strip test based on a monoclonal antibody for the rapid detection of l. monocytogenes in meat and processed-meat samples was developed in this study. a monoclonal antibody (mab) specific to l. monocytogenes was produced from cloned hybridoma cells (fklm-3b12-37) and used to develop an icg strip test. the antibody showed a stronger binding to l. monocytogenes than other listeria species, and a weak cross-reaction to s. aureus based on an elisa. the detection limit of ...	2007	18051327
high-throughput sequence alignment using graphics processing units.	the recent availability of new, less expensive high-throughput dna sequencing technologies has yielded a dramatic increase in the volume of sequence data that must be analyzed. these data are being generated for several purposes, including genotyping, genome resequencing, metagenomics, and de novo genome assembly projects. sequence alignment programs such as mummer have proven essential for analysis of these data, but researchers will need ever faster, high-throughput alignment tools running on ...	2007	18070356
mapping quantitative trait loci from a single-tail sample of the phenotype distribution including survival data.	a new effective bayesian quantitative trait locus (qtl) mapping approach for the analysis of single-tail selected samples of the phenotype distribution is presented. the approach extends the affected-only tests to single-tail sampling with quantitative traits such as the log-normal survival time or censored/selected traits. a great benefit of the approach is that it enables the utilization of multiple-qtl models, is easy to incorporate into different data designs (experimental and outbred popula ...	2007	18073434
post-colonoscopic listeria septicemia in ulcerative colitis during immunosuppressive therapy.	a 78-year-old man who had been diagnosed with ulcerative colitis was admitted because of uncontrolled severe, frequent, bloody diarrhea. he was treated with immunosuppressive therapy that included corticosteroid and azathioprine. colonoscopy was used to assess disease activity. this revealed that the mucosa of his digestive tract from the rectum to the ileum was damaged. he developed a high-grade fever soon after colonoscopy. blood culture demonstrated listeria monocytogenes. treatment was chang ...	2007	18084128
outbreak of listeriosis in the czech republic, late 2006--preliminary report.		2007	17370949
functional plasticity in memory t helper cell responses.	following activation, naive cd4+ th cells can differentiate to selectively produce either the th1 lineage-specific cytokine ifn-gamma or the th2 cytokine il-4 and, in so doing, lose the capacity to produce cytokines of the alternative lineage. lineage commitment of murine cd4+ t cells has largely been considered to be absolute with little flexibility to produce cytokines of the opposing lineage. in this study, we demonstrate that cells within th2 memory populations can produce ifn-gamma if react ...	2007	17371962
nk dendritic cells are innate immune responders to listeria monocytogenes infection.	nk dendritic cells (nkdc) are recently described immunologic cells that possess both lytic and ag-presenting function and produce prolific quantities of ifn-gamma. the role of nkdc in innate immunity to bacterial infection is unknown. because ifn-gamma is important in the immune response to listeria monocytogenes (lm), we hypothesized that nkdc play a critical role during lm infection in mice. we found that lm increased the frequency and activation state of nkdc in vivo. using in vivo intracellu ...	2007	17371998
tyk2 signaling in host environment plays an important role in contraction of antigen-specific cd8+ t cells following a microbial infection.	tyrosine kinase 2 (tyk2), a member of jak signal transducer family contributes to the signals triggered by il-12 for ifn-gamma production. to elucidate potential roles of tyk2 in generation and maintenance of ag-specific cd8+ t cells, we followed the fate of ova-specific cd8+ t cells in tyk2-deficient (-/-) mice after infection with recombinant listeria monocytogenes expressing ova (rlm-ova). results showed that the numbers of ova(257-264)/k(b) tetramer-positive cd8+ t cells in tyk2(-/-) mice we ...	2007	17372006
il-12 and type-i ifn synergize for ifn-gamma production by cd4 t cells, whereas neither are required for ifn-gamma production by cd8 t cells after listeria monocytogenes infection.	differentiation of ag-specific t cells into ifn-gamma producers is essential for protective immunity to intracellular pathogens. in addition to stimulation through the tcr and costimulatory molecules, ifn-gamma production is thought to require other inflammatory cytokines. two such inflammatory cytokines are il-12 and type i ifn (ifn-i); both can play a role in priming naive t cells to produce ifn-gamma in vitro. however, their role in priming ag-specific t cells for ifn-gamma production during ...	2007	17372008
quantitative recovery of listeria monocytogenes and select salmonella serotypes from environmental sample media.	environmental sampling has become increasingly important in the food industry for monitoring the presence of specific pathogens such as listeria monocytogenes and salmonella enterica. several microbiological media are available for storage and transport of environmental samples from the processing plant to the test laboratory. in this study, we quantified the survival of l. monocytogenes, s. typhimurium, s. enteritidis, and s. typhi in environmental sampling media over several time and temperatu ...	2007	17373457
inactivation of foodborne pathogens using a one atmosphere uniform glow discharge plasma.	this study was conducted to determine the efficacy of a one atmosphere uniform glow discharge plasma (oaugdp) for inactivation of foodborne pathogens and to evaluate the influence of growth temperature, ph, and culture age on their inactivation. escherichia coli o157:h7, listeria monocytogenes, staphylococcus aureus, bacillus cereus, salmonella enteritidis, vibrio parahaemolyticus, yersinia enterocolitica, and shigella flexneri were evaluated. three-strain mixtures of each bacterium were inocula ...	2007	17378708
evaluation of the pathogenicity of listeria spp. in caenorhabditis elegans.	caenorhabditis has proven to be a useful model for studying host-pathogen interactions as well as the ability of nematodes to serve as vectors for the dispersal of foodborne pathogens. in this study, we evaluated whether c. elegans can serve as a host for listeria spp. while there was an effect of growth media on c. elegans killing, c. elegans exposed to l. monocytogenes and l. innocua pregrown in luria-bertani medium showed reduced survival when compared to nonpathogenic e. coli op50, while l. ...	2007	17378710
development of listeria monocytogenes-specific immunomagnetic beads using a single-chain antibody fragment.	a method for coupling single-chain antibody fragments (scfvs) to immunomagnetic beads (imbs) was developed and evaluated using scfvs specific for listeria monocytogenes. a plasmid vector, pbad380, was constructed that allowed the expression of histidine-tagged biotinylated scfvs in escherichia coli. the gene encoding a scfv specific for l. monocytogenes was cloned into pbad380 and the 6-histidine-tagged biotinylated anti-l. monocytogenes scfvs were coupled to streptavidin-coated imbs. the abilit ...	2007	17378711
influence of immunomodulation on the development of listeria monocytogenes infection in aged guinea pigs.	we investigated the impact of immunomodulation on the development of listeriosis within an aged population of guinea pigs after an intragastric challenge with listeria monocytogenes. supplementation with vitamin e for 35 days significantly increased the level of cytotoxic t cells (cd8(+)), while treatment with cyclosporin a resulted in a 25% decrease of cd8(+) t cells. in the animals receiving the low dose (10(2) cfu) of l. monocytogenes, 50% of the control-group animals became infected. only 22 ...	2007	17378902
a naturally occurring mutation k220t in the pleiotropic activator prfa of listeria monocytogenes results in a loss of virulence due to decreasing dna-binding affinity.	the sequencing of prfa, encoding the transcriptional regulator of virulence genes, in 26 low-virulence field listeria monocytogenes strains showed that eight strains exhibited the same single amino-acid substitution: prfak220t. these strains exhibited no expression of prfa-regulated proteins and thus no virulence. this substitution inactivated prfa, since expression of the prfak220t mutant gene in an egddeltaprfa strain did not restore the haemolytic and phosphatidylcholine phospholipase c activ ...	2007	17379709
molecular characterization of the fur protein of listeria monocytogenes.	iron is essential for the survival of almost all organisms, although excess iron can result in the generation of free radicals which are toxic to cells. to avoid the toxic effects of free radicals, the concentration of intracellular iron is generally regulated by the ferric uptake regulator fur in bacteria. the 150 aa fur orf from listeria monocytogenes was cloned into prseta, and the his-tagged fusion protein was purified by nickel affinity column chromatography. dna binding activity of this pr ...	2007	17379719
immunology. asymmetry and immune memory.		2007	17379796
antimicrobial activity of bacillus subtilis and bacillus pumilus during the fermentation of african locust bean (parkia biglobosa) for soumbala production.	to examine predominant isolates of bacillus subtilis and b. pumilus isolated from soumbala for their antimicrobial activity against indicator microorganisms as micrococcus luteus, staphyloccocus aureus, bacillus cereus, enterococus facium, listeria monocytogenes, escherichia coli, salmonella typhimurium, shigella dysenteriae, yersinia enterocolitica, aspergillus ochraceus and penicillium roqueforti.	2007	17381739
role of caspase-8 in hepatocyte response to infection and injury in mice.	caspase-8 has been implicated in signaling for apoptotic cell death and for certain nonapoptotic functions. however, knowledge of actual physiological or pathophysiological processes to which this enzyme contributes is lacking. using a mouse model and employing the conditional knockout approach to delete the caspase-8 gene specifically in the liver, we found that caspase-8 deficiency in hepatocytes facilitates infection of the liver by listeria monocytogenes, attenuates the hepatocyte proliferat ...	2007	17385212
rapid detection of escherichia coli o157:h7 spiked into food matrices.	food poisoning causes untold discomfort to many people each year. one of the primary culprits in food poisoning is escherichia coli o157:h7. while most cases cause intestinal discomfort, up to 7% of the incidences lead to a severe complication called hemolytic uremic syndrome which may be fatal. the traditional method for detection of e. coli o157:h7 in cases of food poisoning is to culture the food matrices and/or human stool. additional performance-based antibody methods are also being used. t ...	2007	17386586
axonal transport of listeria monocytogenes and nerve-cell-induced bacterial killing.	listeria monocytogenes (l. monocytogenes) can cause fatal brainstem encephalitis in both sheep and humans. here we review evidence that the bacteria can be incorporated into axons following a primary cycle of replication in macrophages/dendritic cells after subcutaneous injection in projection areas of peripheral neurons. the molecular mechanisms for the rocketing of l. monocytogenes in the cytosol by asymmetric cometic tails and the utility of this phenomenon for bacterial migration intraaxonal ...	2007	17387705
isolation and molecular characterization of antibiotic-resistant lactic acid bacteria from poultry and swine meat products.	the transfer via the food chain from animals to humans of microbes that are resistant to antimicrobial agents is of increasing concern. to determine the contributions of nonpathogenic microflora to the occurrence and spread of antibiotic resistance (ar) genes in the food chain, 123 lactic acid bacteria were isolated from 29 samples of raw and processed pork and chicken meat products that had previously tested positive for one or more ar genes that encode clinically relevant ars: tet(m), tet(o), ...	2007	17388042
distribution of epidemic clonal genetic markers among listeria monocytogenes 4b isolates.	recent genome sequencing of isolates of listeria monocytogenes serotype 4b implicated in some major outbreaks of foodborne listeriosis has revealed unique genetic markers in these isolates. the isolates were grouped into two distinct epidemic clones, eci and ecii. in the present study, selected eci- and ecii-specific genetic markers were detected in 16 and 15 of 89 l. monocytogenes 4b isolates, respectively. the eci markers were found in 6 of 34 clinical isolates, 9 of 50 food isolates, and 1 of ...	2007	17388044
sodium chloride enhances adherence and aggregation and strain variation influences invasiveness of listeria monocytogenes strains.	some subtypes of listeria monocytogenes can persist in the food-processing industry, but the reasons for such persistence are not known. in the present study, 10 strains of l. monocytogenes representing known persistent randomly amplified polymorphic dna (rapd) types from fish processing plants were compared to eight strains of different rapd type and origin (clinical, food, and animal). all 18 strains of l. monocytogenes had similar growth patterns at different temperatures (5 or 37 degrees c) ...	2007	17388046
evaluation of the transfer of listeria monocytogenes from stainless steel and high-density polyethylene to bologna and american cheese.	the objective of this study was to determine the factors involved in the transfer of listeria monocytogenes from surfaces to foods. we evaluated the influence of surface type (stainless steel and high-density polyethylene), inoculation method (biofilm growth and attached cells), hydration level (visibly dry and wet), and food type (bologna and american cheese). each experiment included all 16 combinations and was repeated 11 times. a four-strain cocktail of l. monocytogenes was used to inoculate ...	2007	17388047
quantitative effect of refrigerated storage time on the enumeration of campylobacter, listeria, and salmonella on artificially inoculated raw chicken meat.	active monitoring of pathogens on retail foods has been recommended and implemented in a number of developed countries. because only a portion of retail food is contaminated with pathogens, a cost-effective and informative surveillance program at the retail level often involves a two-stage approach of initial presence-absence analysis and subsequent pathogen enumeration in any positive samples. most-probable-number (mpn) methods are more resource intensive and therefore used only for samples con ...	2007	17388068
modeling the growth of listeria monocytogenes in pasteurized white asparagus.	growth of listeria monocytogenes in pasteurized white asparagus was monitored at different storage temperatures (4, 10, 20, and 30 degrees c). among the main microbial kinetic parameters, growth rate (mu) per hour was calculated at each temperature using the baranyi-roberts model. l. monocytogenes was able to grow at all temperatures, although at 4 degrees c only a slight increment of the microbial population was observed (approximately 1 log cfu/g) after 300 h of storage. subsequently, two diff ...	2007	17388071
ultrasonic cleaning of conveyor belt materials using listeria monocytogenes as a model organism.	persistent listeria monocytogenes contamination of food industry equipment is a difficult problem to solve. ultrasonic cleaning offers new possibilities for cleaning conveyors and other equipment that are not easy to clean. ultrasonic cleaning was tested on three conveyor belt materials: polypropylene, acetal, and stainless steel (cold-rolled, aisi 304). cleaning efficiency was tested at two temperatures (30 and 45 degrees c) and two cleaning times (30 and 60 s) with two cleaning detergents (koh ...	2007	17388072
functional genomic studies of the intestinal response to a foodborne enteropathogen in a humanized gnotobiotic mouse model.	members of the genus listeria provide a model for defining host responses to invasive foodborne enteropathogens. active translocation of listeria monocytogenes across the gut epithelial barrier is mediated by interaction of bacterial internalin (inla) and its species-specific host receptor, e-cadherin, whereas translocation across peyer's patches through m-cells is inla-independent. to define microbial determinants and molecular correlates of the host response to translocation via these two rout ...	2007	17389602
bacterial ligands generated in a phagosome are targets of the cytosolic innate immune system.	macrophages are permissive hosts to intracellular pathogens, but upon activation become microbiocidal effectors of innate and cell-mediated immunity. how the fate of internalized microorganisms is monitored by macrophages, and how that information is integrated to stimulate specific immune responses is not understood. activation of macrophages with interferon (ifn)-gamma leads to rapid killing and degradation of listeria monocytogenes in a phagosome, thus preventing escape of bacteria to the cyt ...	2007	17397264
prevalence and growth of listeria monocytogenes in naturally contaminated cold-smoked salmon.	to investigate listeria monocytogenes contamination and behaviour in naturally contaminated french cold-smoked salmon (css).	2007	17397479
cutting edge: recombinant listeria monocytogenes expressing a single immune-dominant peptide confers protective immunity to herpes simplex virus-1 infection.	the vast majority of the world's population is infected with hsv. although antiviral therapy can reduce the incidence of reactivation and asymptomatic viral shedding, and limit morbidity and mortality from active disease, it cannot cure infection. therefore, the development of an effective vaccine is an important global health priority. in this study, we demonstrate that recombinant listeria monocytogenes (lm) expressing the h-2k(b) glycoprotein b (gb)(498-505) peptide from hsv-1 triggers a robu ...	2007	17404252
beta1-adrenergic receptors on immune cells impair innate defenses against listeria.	cold restraint (cr) for 1 h elicits a psychological and physiological stress that inhibits host defenses against listeria monocytogenes (lm). previous analyses indicated that this inhibition is not due to depletion of b or t cells but is instead dependent on signaling through beta-adrenoceptors (betaars). we now show that impaired host resistance by cr cannot be accounted for by a decrease in lm-specific (listeriolysin o(91-99) tetramer(+)) effector cd8(+) t cells; this result is consistent with ...	2007	17404268
myd88-dependent activation of b220-cd11b+ly-6c+ dendritic cells during brucella melitensis infection.	ifn-gamma is a key cytokine controlling brucella infection. one of its major function is the stimulation of brucella-killing effector mechanisms, such as inducible no synthase (inos)/nos2 activity, in phagocytic cells. in this study, an attempt to identify the main cellular components of the immune response induced by brucella melitensis in vivo is made. ifn-gamma and inos protein were analyzed intracellularly using flow cytometry in chronically infected mice. although tcrbeta(+)cd4(+) cells wer ...	2007	17404301
[one episode of meningoencephalitis, three diagnoses].	meningo-encephalitis is a set of threatening diseases. the treatment needs to be started quickly for pathogens such as herpes simplex virus type 1 or listeria monocytogenes. apart from these classical etiologies, many other diseases may induce meningo-encephalitis. we report the case of a patient, infected with hiv, who presented a history of meningo-encephalitis due to herpes simplex type 1. three weeks later, he presented an encephalopathy due to aciclovir and then we discovered a chronic meni ...	2007	17404526
[survey of the presence of listeria monocytogenes in meat products sold in retail].	the present study evaluates the presence of listeria spp and particularly of l. monocytogenes in bovine, pork and poultry meats sold by retail in supermarkets and butchers in the city of cassino. the sensibility to the antibiotics mostly used in the veterinary practice has been tested on the isolated strains. the different species of listeria have shown a considerable variation of isolation based on the meat's typology and on the different store's provenance. moreover our results show greater de ...	2007	17405508
a rare case of brainstem encephalitis by listeria monocytogenes with isolated mesencephalic localization. case report and review.	we describe a case of brainstem infection by listeria monocytogenes with right oculomotor palsy and lip drop, facial hypoesthesia, left arm paresthesia, positive blood culture, and sterile liquor in a 63-year-old man. magnetic resonance imaging revealed an isolated mesencephalic lesion. localization of this kind accounted for 3% of 111 cases reviewed.	2007	17408902
listeria inlb takes a different route to met.	inlb, a surface protein of the human bacterial pathogen listeria monocytogenes, interacts with the receptor tyrosine kinase met on host cells to enable bacterial invasion. in this issue, niemann et al. (2007) provide the first structural evidence that inlb does not compete for the same interaction site on met as the natural ligand hgf.	2007	17662936
structure of the human receptor tyrosine kinase met in complex with the listeria invasion protein inlb.	the tyrosine kinase met, the product of the c-met proto-oncogene and the receptor for hepatocyte growth factor/scatter factor (hgf/sf), mediates signals critical for cell survival and migration. the human pathogen listeria monocytogenes exploits met signaling for invasion of host cells via its surface protein inlb. we present the crystal structure of the complex between a large fragment of the human met ectodomain and the met-binding domain of inlb. the concave face of the inlb leucine-rich repe ...	2007	17662939
[pleural effusion due to listeria monocytogenes in a woman with cirrhosis of the liver].		2007	17663897
t-cell-independent humoral immunity is sufficient for protection against fatal intracellular ehrlichia infection.	although humoral immunity has been shown to contribute to host defense during intracellular bacterial infections, its role has generally been ancillary. instead, cd4 t cells are often considered to play the dominant role in protective immunity via their production of type i cytokines. our studies of highly pathogenic ehrlichia bacteria isolated from ixodes ovatus (ioe) reveal, however, that this paradigm is not always correct. immunity to ioe infection can be induced by infection with a closely ...	2007	17664264
the lmo1078 gene encoding a putative udp-glucose pyrophosphorylase is involved in growth of listeria monocytogenes at low temperature.	the gram-positive bacterium listeria monocytogenes is a food-borne pathogen with the ability to grow at low temperature. given the importance of refrigeration as a means of food preservation, the psychrotolerant nature of this microorganism poses a significant public health hazard. in order to better understand the mechanisms underlying cold adaptation of l. monocytogenes, a library of tn917-lac insertional mutants was screened. a cold-sensitive mutant, named cs1, was isolated and found to be al ...	2007	17666069
heme coordination by staphylococcus aureus isde.	staphylococcus aureus is a gram-positive bacterial pathogen and a leading cause of hospital acquired infections. because the free iron concentration in the human body is too low to support growth, s. aureus must acquire iron from host sources. heme iron is the most prevalent iron reservoir in the human body and a predominant source of iron for s. aureus. the iron-regulated surface determinant (isd) system removes heme from host heme proteins and transfers it to isde, the cognate substrate-bindin ...	2007	17666394
purification and antimicrobial activity studies of the n-terminal fragment of ubiquitin from human amniotic fluid.	a 4.3-kda antimicrobial peptide was isolated from human amniotic fluid by dialysis, ultrafiltration, and c18 reversed-phase high performance liquid chromatography. this peptide, which we named amniotic fluid peptide-1 (afp-1), possessed antimicrobial activity but lacked hemolytic activity. in addition, afp-1 potently inhibited the growth of a variety of bacteria (escherichia coli, salmonella typhimurium, listeria monocytogenes and staphylococcus aureus), filamentous fungi (botrytis cinerea, aspe ...	2007	17669700
nuclear receptor err alpha and coactivator pgc-1 beta are effectors of ifn-gamma-induced host defense.	macrophage activation by the proinflammatory cytokine interferon-gamma (ifn-gamma) is a critical component of the host innate response to bacterial pathogenesis. however, the precise nature of the ifn-gamma-induced activation pathway is not known. here we show using genome-wide expression and chromatin-binding profiling that ifn-gamma induces the expression of many nuclear genes encoding mitochondrial respiratory chain machinery via activation of the nuclear receptor err alpha (estrogen-related ...	2007	17671090
[influence of chemical and physical characteristics of seashore soils in primorsky region on preservation and reproduction of listeria and yersinia].	influence of chemical and physical characteristics of two types of seashore soils (tidal marsh and maritime meadow soils) in primorsky region on reproduction of listeria monocytogenes and yersinia pseudotuberculosis was studied. results of experiments proved the possibility of preservation and active reproduction of these bacteria in studied soils. characteristics of maritime meadow soil are more favorable for mentioned microorganisms than tidal march soil that located closer to the sea.	2007	17672139
[biological characteristics of listeria cultivating on the novel media for their accumulation and isolation].	biological characteristics of isolated strains of listeria cultivating on growth media developed for accumulation and isolation of these microorganisms. stability of main cultural-morphologic characteristics, pathogenic enzyme synthesis, profile of plasmid dna and specific bacteriophage lysing of listeria during their cultivation on novel media was shown.	2007	17672141
[culture media for study of biologic characteristics of listeria].	the commercial nutrient media for study of biologic properties of listeria monocytogenes were developed. the efficacy of developed media for assessing of motility and lecithinase activity of listeria during establishment of the isolated strain was shown. developed media allow clear visual registration of mobility and lecithinase activity of listeria during identification of the isolated strains thereby improving the diagnostics of listeriosis.	2007	17672142
monitoring of blood vessels and tissues by a population of monocytes with patrolling behavior.	the cellular immune response to tissue damage and infection requires the recruitment of blood leukocytes. this process is mediated through a classical multistep mechanism, which involves transient rolling on the endothelium and recognition of inflammation followed by extravasation. we have shown, by direct examination of blood monocyte functions in vivo, that a subset of monocytes patrols healthy tissues through long-range crawling on the resting endothelium. this patrolling behavior depended on ...	2007	17673663
histone modifications induced by a family of bacterial toxins.	upon infection, pathogens reprogram host gene expression. in eukaryotic cells, genetic reprogramming is induced by the concerted activation/repression of transcription factors and various histone modifications that control dna accessibility in chromatin. we report here that the bacterial pathogen listeria monocytogenes induces a dramatic dephosphorylation of histone h3 as well as a deacetylation of histone h4 during early phases of infection. this effect is mediated by the major listerial toxin ...	2007	17675409
agr system of listeria monocytogenes egd-e: role in adherence and differential expression pattern.	in this study, we investigated the agrbdca operon in the pathogenic bacterium listeria monocytogenes egd-e. in-frame deletion of agra and agrd resulted in an altered adherence and biofilm formation on abiotic surfaces, suggesting the involvement of the agr system of l. monocytogenes during the early stages of biofilm formation. real-time pcr experiments indicated that the transcript levels of agrbdca depended on the stage of biofilm development, since the levels were lower after the initial atta ...	2007	17675424
sigmab-dependent and sigmab-independent mechanisms contribute to transcription of listeria monocytogenes cold stress genes during cold shock and cold growth.	the role of the stress response regulator sigma(b) (encoded by sigb) in directing the expression of selected putative and confirmed cold response genes was evaluated using listeria monocytogenes 10403s and an isogenic deltasigb mutant, which were either cold shocked at 4 degrees c in brain heart infusion (bhi) broth for up to 30 min or grown at 4 degrees c in bhi for 12 days. transcript levels of the housekeeping genes rpob and gap, the sigma(b)-dependent genes opuca and bsh, and the cold stress ...	2007	17675428
absence of serotype-specific surface antigen in laboratory variants of epidemic-associated listeria monocytogenes strains.	variants that lacked reactivity with the serotype 4b-specific monoclonal antibody c74.22 and that lost susceptibility to certain listeria- or serotype 4b-specific phages were identified in the course of genetic studies with serotype 4b listeria monocytogenes strains h7550 and f2381l (epidemic clones i and ii, respectively). our findings suggest that such variants can become inadvertently established under laboratory conditions and suggest caution in work involving serotype 4b strains and genetic ...	2007	17675434
generation of cd8 t cell memory is regulated by il-12.	various signals during infection influence cd8 t cell memory generation, but these factors have yet to be fully defined. il-12 is a proinflammatory cytokine that has been shown to enhance ifn-gamma-producing t cell responses and has been widely tested as a vaccine adjuvant. in this study, we show that il-12-deficient mice generate a weaker primary cd8 t cell response and are more susceptible to listeria monocytogenes infection, but have substantially more memory cd8 t cells and greater protectiv ...	2007	17675465
chronic immunodeficiency in mice lacking rasgrp1 results in cd4 t cell immune activation and exhaustion.	the ras-guanyl nucleotide exchange factor rasgrp1 is an important link between tcr-mediated signaling and the activation of ras and its downstream effectors. rasgrp1 is especially critical for the survival and differentiation of developing thymocytes whereas negative selection of thymocytes bearing an autoreactive tcr appears to be rasgrp1 independent. despite apparently normal central tolerance, rasgrp1(-/-) mice spontaneously acquire an acutely activated and proliferating cd4 t cell population ...	2007	17675473
a role for ifn-gamma from antigen-specific cd8+ t cells in protective immunity to listeria monocytogenes.	whether ifn-gamma contributes to the per-cell protective capacity of memory cd8(+) t cells against listeria monocytogenes (lm) has not been formally tested. in this study, we generated lm ag-specific memory cd8(+) t cells via immunization of wild-type (wt) and ifn-gamma-deficient (gamma knockout (gko)) mice with lm peptide-coated dendritic cells and compared them phenotypically and functionally. immunization of wt and gko mice resulted in memory cd8(+) t cells that were similar in number, functi ...	2007	17675507
listeria endocarditis with acute thoracoabdominal aortic dissection.	the patient was 71-year-old male under treatment at a clinic for hypertension, aortic regurgitation, alcoholic hepatitis and dental treatment. he mainly complained fever and anorexia. since blood culture examination revealed listeria monocytogenes and echocardiography exhibited vegetation at the mitral leaflet, the patient was diagnosed as infective endocarditis. fever and inflammatory reaction were improved after penicillin administration; however, he had fever on the 24th hospital day. ct reve ...	2007	17675771
[listeria monocytogenes bacteremia: analysis of 110 episodes].	over the last years, we registered an increase in the number of listeriosis cases. the aim of this study was to analyze the co-morbidity, clinical presentation and prognosis of listeria monocytogenes bacteremia episodes diagnosed over 15 years.	2007	17678604
listeriolysin o secreted by listeria monocytogenes into the host cell cytosol is degraded by the n-end rule pathway.	the intracellular pathogen listeria monocytogenes escapes from a phagosomal compartment into the cytosol by secreting the pore-forming cytolysin listeriolysin o (llo). during the proliferation of l. monocytogenes bacteria in the mammalian cell cytosol, the secreted llo is targeted for degradation by the ubiquitin system. we report here that llo is a substrate of the ubiquitin-dependent n-end rule pathway, which recognizes llo through its n-terminal lys residue. specifically, we demonstrated by r ...	2007	17682039
cdc42 and phosphoinositide 3-kinase drive rac-mediated actin polymerization downstream of c-met in distinct and common pathways.	activation of c-met, the hepatocyte growth factor (hgf)/scatter factor receptor induces reorganization of the actin cytoskeleton, which drives epithelial cell scattering and motility and is exploited by pathogenic listeria monocytogenes to invade nonepithelial cells. however, the precise contributions of distinct rho-gtpases, the phosphatidylinositol 3-kinases, and actin assembly regulators to c-met-mediated actin reorganization are still elusive. here we report that hgf-induced membrane rufflin ...	2007	17682062
multiplex pcr for the identification and serotyping of l. monocytogenes isolated from sheep cheese-processing plants.		2007	17682914
hygienic evaluation of marinated sea bass and challenge test for listeria monocytogenes.		2007	17682916