Publications

effect of inhibitory liquid smoke fractions on listeria monocytogenes during long-term storage of frankfurters.	listeria monocytogenes is a potential health hazard that sometimes finds harborage in facilities that manufacture ready-to-eat meats, including frankfurters. our objectives were to examine the effect of select liquid smoke extracts on control of l. monocytogenes on frankfurters. frankfurters were either obtained locally at retail (containing lactate-diacetate) or manufactured for us in-house or by a local processor (without added lactate-diacetate). in challenge studies of retail franks containi ...	2007	17340873
use of octanoic acid as a postlethality treatment to reduce listeria monocytogenes on ready-to-eat meat and poultry products.	the antilisterial efficacy and organoleptic impact of an octanoic acid (oa)-based treatment for ready-to-eat (rte) meat and poultry products were investigated. whole-muscle and comminuted rte products were inoculated with a five-strain mixture of listeria monocytogenes. the oa treatments were applied to the surface of rte products by dispensing a specific volume of solution directly into the final package prior to vacuum sealing. once sealed, the vacuum-packaged rte products containing oa were i ...	2007	17340874
influence of salt, smoke, and high pressure on growth of listeria monocytogenes and spoilage microflora in cold-smoked dolphinfish (coryphaena hippurus).	the effects of different salting and smoking conditions on the growth of listeria monocytogenes in cold-smoked dolphinfish (coryphaena hippurus) fillets were evaluated. high concentrations of phenol (72.47 ppm) and salt (3.25%) in muscle inhibited l. monocytogenes growth in smoked fish stored at 20 degrees c for 4 days. the antibacterial effect of high pressure in cold-smoked dolphinfish during long-term chilled (5 degrees c) storage was evaluated in fillets prepared according to two different s ...	2007	17340875
listeria monocytogenes f2365 carries several authentic mutations potentially leading to truncated gene products, including inlb, and demonstrates atypical phenotypic characteristics.	searches of the genome annotation of listeria monocytogenes f2365, an isolate from the 1985 listeriosis epidemic in california, showed that this strain carries 20 authentic mutations resulting in premature stop codons, including a nonsense mutation in inlb. here we showed that l. monocytogenes f2365 demonstrates atypical virulence-associated characteristics, including significantly (p < 0.05) reduced invasion efficiency in caco-2 cells as compared with a closely related lineage i serotype 4b str ...	2007	17340887
bacteria-eating virus approved as food additive.	not all viruses harm people. the food and drug administration has approved a mixture of viruses as a food additive to protect people. the additive can be used in processing plants for spraying onto ready-to-eat meat and poultry products to protect consumers from the potentially life-threatening bacterium listeria monocytogenes (l. monocytogenes).	2007	17342833
localization of protein kinase c epsilon to macrophage vacuoles perforated by listeria monocytogenes cytolysin.	three proteins secreted by listeria monocytogenes facilitate escape from macrophage vacuoles: the cholesterol-dependent cytolysin listeriolysin o (llo), a phosphoinositide-specific phospholipase c (pi-plc) and a broad-range phospholipase c (pc-plc). llo and pi-plc can activate several members of the protein kinase c (pkc) family during infection. pkcepsilon is a novel pkc that contributes to macrophage activation, defence against bacterial infection, and phagocytosis; however, a role for pkcepsi ...	2007	17346313
improved luciferase tagging system for listeria monocytogenes allows real-time monitoring in vivo and in vitro.	an improved system for luciferase tagging listeria monocytogenes was developed by constructing a highly active, constitutive promoter. this construct gave 100-fold-higher activity in broth than any native promoter tested and allowed for imaging of lux-tagged l. monocytogenes in food products, during murine infections, and in tumor targeting studies.	2007	17351089
effect of a previous heat shock on the thermal resistance of listeria monocytogenes and pseudomonas aeruginosa at different phs.	in this work we study the effect of heat shocks of various durations up to 60 min, at different temperatures between 35 and 45 degrees c, in media of ph 4.0, 5.5 and 7.4 on the heat resistance of listeria monocytogenes and pseudomonas aeruginosa. the pattern of survival curves after heat treatment did not change with the application of a previous heat shock. however, the kinetics of inactivation was different for the two microorganisms studied. whereas the inactivation of l. monocytogenes was si ...	2007	17355896
3,4-dichloropropionaniline suppresses normal macrophage function.	macrophages are a critical part of the innate immune response and natural surveillance mechanisms. as such, proper macrophage function is crucial for engulfing bacterial pathogens through phagocytosis and destroying them by generation of reactive oxygen species (ros) and reactive nitrogen species (rns). the production of a number of cytokines by macrophages, such as tumor necrosis factor-alpha (tnf-alpha), interleukin (il)-1beta, and il-6, plays an important role in the initiation of the acquire ...	2007	17355946
sterol and ph interdependence in the binding, oligomerization, and pore formation of listeriolysin o.	listeriolysin o (llo) is the most important virulence factor of the intracellular pathogen listeria monocytogenes. its main task is to enable escape of bacteria from the phagosomal vacuole into the cytoplasm. llo belongs to the cholesterol-dependent cytolysin (cdc) family but differs from other members, as it exhibits optimal activity at low ph. its pore forming ability at higher ph values has been largely disregarded in listeria pathogenesis. here we show that high cholesterol concentrations in ...	2007	17358050
interactions between the environmental pathogen listeria monocytogenes and a free-living protozoan (acanthamoeba castellanii).	listeria monocytogenes can cause severe disease in animal hosts, but it has no recognized animal host reservoir. we tested the hypothesis that l. monocytogenes retains virulence traits to survive predation by amoebae and that listeriolysin o plays a crucial role in this process. co-culturing of l. monocytogenes and acanthamoeba castellanii demonstrated that l. monocytogenes does not actively kill amoebae, but in the presence of amoebae, high bacterial population densities can be maintained over ...	2007	17359263
survey on the listeria contamination of ready-to-eat food products and household environments in vienna, austria.	qualitative and quantitative contamination of ready-to-eat food-stuffs with the pathogen listeria monocytogenes was studied in 1586 samples collected from 103 supermarkets (n = 946) and 61 households (n = 640) in vienna, austria. seventeen groups of ready-to-eat foods were classified into three risk categories for contamination (cp1-cp3). three to four samples were randomly collected at the retail level from each cp. regarding the households, the sampling procedure was started with food items of ...	2007	17359442
an evaluation of the neonatal immune system using a listeria infection model.	t helper 1 (th1)/t helper 2 (th2)-biased cytokine regulation may be another reason that neonates are much more susceptible to infectious disease than are adults.	2007	17361091
modeling individual cell lag time distributions for listeria monocytogenes.	the food industry faces two paradoxical demands: on the one hand, foods need to be microbiologically safe for consumption and on the other hand, consumers want fresh, minimally processed foods. to meet these demands, more insight into the mechanisms of microbial growth is needed, which includes, among others, the microbial lag phase. this is the time needed by bacterial cells to adapt to a new environment (for example, after food product contamination) before starting an exponential growth regim ...	2007	17362412
behavior of listeria monocytogenes at 7 degrees c in commercial turkey breast, with or without antimicrobials, after simulated contamination for manufacturing, retail and consumer settings.	uncured turkey breast, commercially available with or without a mixture of potassium lactate and sodium diacetate, was sliced, inoculated with a 10-strain composite of listeria monocytogenes, vacuum-packaged, and stored at 4 degrees c, to simulate contamination after a lethal processing step at the plant. at 5, 15, 25 and 50 days of storage, packages were opened, slices were tested, and bags with remaining slices were reclosed with rubber bands; this simulated home use of plant-sliced and -packa ...	2007	17367676
growth characteristics of listeria monocytogenes, listeria welshimeri and listeria innocua strains in broth cultures and a sliced bologna-type product at 4 and 7 degrees c.	the growth characteristics of meat processing plant-derived field strains of listeria monocytogenes, l. welshimeri and l. innocua were analyzed. the strains were inoculated in bhi broth cultures and incubated at 4 and 7 degrees c. growth curves were determined by colony counting for 28 days. significant variations were detected in the growth properties of these field-derived strains. in particular some of the l. monocytogenes strains displayed better cold stress tolerance. these discrepancies in ...	2007	17367677
product unit neural network models for predicting the growth limits of listeria monocytogenes.	a new approach to predict the growth/no growth interface of listeria monocytogenes as a function of storage temperature, ph, citric acid (ca) and ascorbic acid (aa) is presented. a linear logistic regression procedure was performed and a non-linear model was obtained by adding new variables by means of a neural network model based on product units (punn). the classification efficiency of the training data set and the generalization data of the new logistic regression punn model (lrpu) were compa ...	2007	17367678
major role of levofloxacin in the treatment of a case of listeria monocytogenes meningitis.	we report a case of acute bacterial meningitis due to listeria monocytogenes whose successful treatment was mainly attributable to high-dose levofloxacin therapy (500 mg iv bid). this supports the hypothesis that levofloxacin may be an effective option for the treatment of listerial meningitis.	2007	17368798
characterization of rela and cody mutants of listeria monocytogenes: identification of the cody regulon and its role in virulence.	listeria monocytogenes is a gram-positive intracellular parasite and the causative organism of human listeriosis. in this article we demonstrate that l. monocytogenes encodes a functional member of the cody family of global regulatory proteins that is responsive to both gtp and branched chain amino acids. by transcript analyses we identified the cody regulon in l. monocytogenes and demonstrated that it comprises genes involved in amino acid metabolism, nitrogen assimilation as well as genes invo ...	2007	17302820
[bacterial meningitis in denmark 2002-2003. a nation-wide laboratory-based registration].	notification of bacterial meningitis (bm) is likely to be incomplete, and a recent danish study indicated that unbalanced notification may bias expected aetiology of bm. therefore the danish bacterial meningitis group initiated a national registration of culture-positive bm.	2007	17303030
identification and molecular characterization of listeria monocytogenes isolated in raw milk in the region of algiers (algeria).	listeria monocytogenes was isolated from raw milk, whey and curdled milk produced and collected in the region of algiers and blida between september 2003 and july 2004. four out of 153 (2.61%) farm milk samples and 6 out of 80 (7.50%) tankers' samples tested positive for l. monocytogenes. all samples of whey and curdled milk (n=12) tested negative for l. monocytogenes, but 2 of 22 (9%) samples of whey were contaminated by l. innocua. l. monocytogenes isolates were grouped by a multiplex pcr assa ...	2007	17303276
investigation of the mechanism of binding between internalin b and heparin using surface plasmon resonance.	listeria monocytogenes, a food-borne pathogen that infects immunocompromised patients, enters and proliferates within mammalian cells by taking advantage of host cell machinery. while entry into macrophages and other phagocytic cells occurs constitutively, intracellular invasion of nonphagocytic cells, such as epithelial and endothelial cells, occurs through induced phagocytosis. invasion of these nonphagocytic cell types is under the control of the secreted l. monocytogenes protein internalin b ...	2007	17305366
application of single strand conformation polymorphism --pcr method for distinguishing cheese bacterial communities that inhibit listeria monocytogenes.	the aim of this study was to compare the microbial communities of different cheeses where listeria monocytogenes either grew or did not grow. for this purpose, (i) isolates from the most inhibitory cheese ecosystem were identified and their ability to produce anti-listeria substances was determined, (ii) bacterial communities of cheeses with and without l. monocytogenes growth were compared using the single strand conformation polymorphism method. the study showed sscp to be an effective tool fo ...	2007	17306399
modelling the bacterial survival/death interface induced by high pressure processing.	the survival/death interface model was developed for prediction of inactivation of listeria monocytogenes by high pressure processing (hpp). the model was derived from data sets comprising 360 combinations of environmental factors such as pressure (200, 300 400, and 500 mpa), pressure-holding time (1, 3, 5, 10, 20, 30 min), ph (3, 4, 5, 6, 7), and inoculum level (3, 5, 7 log(10) cfu/ml). the determination of survival/death of l. monocytogenes after hpp was confirmed by the presence/absence of co ...	2007	17307266
a mariner-based transposition system for listeria monocytogenes.	in this study, we developed a new mariner-based transposition system for listeria monocytogenes. the mariner-based system has a high rate of transposition and a low rate of plasmid retention, and transposition is very random, making it an ideal tool for high-throughput transposon mutagenesis in l. monocytogenes.	2007	17308180
the synergistic effect of nisin and lactoferrin on the inhibition of listeria monocytogenes and escherichia coli o157:h7.	the goal of this study was to determine whether nisin and lactoferrin would act synergistically to inhibit the growth of listeria monocytogenes and escherichia coli o157:h7.	2007	17309501
effectiveness of cell-adsorbed bacteriocin produced by lactobacillus curvatus cwbi-b28 and selected essential oils to control listeria monocytogenes in pork meat during cold storage.	to study the effectiveness of a combination of cell-adsorbed bacteriocin (cab; a suspension of producer cells on which maximum bacteriocin has been immobilized by ph adjustments) of a lactobacillus curvatus strain with oregano or savory essential oil to control listeria monocytogenes in pork meat at 4 degrees c.	2007	17309503
characteristics of bacteriocin-like inhibitory substances from dochi-isolated enterococcus faecium d081821 and d081833.	to characterize bacteriocin-like inhibitory substances (blis) from two dochi-isolated enterococcus faecium.	2007	17309511
effect of nacl and kcl on fate and growth/no growth interfaces of listeria monocytogenes scott a at different ph and nisin concentrations.	the fate of listeria monocytogenes scott a, was studied in broth, at different a(w)s (by adding nacl or kcl from 0.0 to 1.4 mol l(-1)), phs (from 4.0 to 7.3 by adding lactic acid), and nisin concentrations (from 0 to 100 iu ml(-1)).	2007	17309630
targeting of antigen to dendritic cells with poly(gamma-glutamic acid) nanoparticles induces antigen-specific humoral and cellular immunity.	nanoparticles are considered to be efficient tools for inducing potent immune responses by an ag carrier. in this study, we examined the effect of ag-carrying biodegradable poly(gamma-glutamic acid) (gamma-pga) nanoparticles (nps) on the induction of immune responses in mice. the nps were efficiently taken up by dendritic cells (dcs) and subsequently localized in the lysosomal compartments. gamma-pga nps strongly induced cytokine production, up-regulation of costimulatory molecules, and the enha ...	2007	17312143
interleukin-1 receptor type 1 is essential for control of cerebral but not systemic listeriosis.	listeria monocytogenes may infect the central nervous system and several peripheral organs. to explore the function of il-1 receptor type 1 (il-1r1) in cerebral versus systemic listeriosis, il-1r1(-/-) and wild-type mice were infected either intracerebrally or intraperitoneally with l. monocytogenes. after intracerebral infection with various numbers of attenuated listeria, il-1r1(-/-) mice succumbed due to an insufficient control of intracerebral listeria, whereas all wild-type mice survived, e ...	2007	17322383
immunoediting sculpts tumor epitopes during immunotherapy.	immunoediting of tumor-associated antigens occurs in response to immune pressure. we show that the mutation of residues within epitopes of her-2/neu leads to the outgrowth of autochthonous tumors after immunizing her-2/neu transgenic mice with listeria monocytogenes therapeutic vaccines expressing fragments of her-2/neu. three of these vaccines target the extracellular domain (lmllo-ec1, lmllo-ec2, and lmllo-ec3), and two of these vaccines target the intracellular domain (lm-llo-ic1 and lm-llo-i ...	2007	17332314
asymmetric t lymphocyte division in the initiation of adaptive immune responses.	a hallmark of mammalian immunity is the heterogeneity of cell fate that exists among pathogen-experienced lymphocytes. we show that a dividing t lymphocyte initially responding to a microbe exhibits unequal partitioning of proteins that mediate signaling, cell fate specification, and asymmetric cell division. asymmetric segregation of determinants appears to be coordinated by prolonged interaction between the t cell and its antigen-presenting cell before division. additionally, the first two dau ...	2007	17332376
listeria--review of epidemiology and pathogenesis.	listeria monocytogenes (commonly called listeria) is a gram-positive facultatively intracellular foodborne pathogen often found in food and elsewhere in nature. it can cause a rare but serious disease called listeriosis, especially among pregnant women, the elderly or individuals with a weakened immune system. in serious cases, it can lead to brain infection and even death. listeria is more likely to cause death than other bacteria that cause food poisoning. in fact, 20 to 30% of food borne list ...	2007	17332901
a p60 mutant of listeria monocytogenes is impaired in its ability to cause infection in intragastrically inoculated mice.	a spontaneous p60 mutant of listeria monocytogenes was less able to cause systemic infection in a/j mice, following intragastric inoculation, than the parental wild type strain (slcc 5764, serotype 1/2a). significantly fewer cfu were recovered from internal organs (spleen, liver, gall bladder) and from the cecum of mice inoculated intragastrically with the p60 mutant than mice inoculated with wild type l. monocytogenes. the p60 mutant also exhibited a diminished ability to invade and multiply wi ...	2007	17336491
quantification of gene expression of listeria monocytogenes by real-time reverse transcription pcr: optimization, evaluation and pitfalls.	in the current study, various steps in the real-time reverse transcription pcr (real-time rt-pcr) method for determination of rna expression levels starting from different numbers of listeria monocytogenes cells were evaluated and optimized. our results showed that the rna isolation method as well as the cdna synthesis may influence the sensitivity of the procedure. for high bacterial cell numbers (10(9) bacterial cells), the rnaqueous kit and the rneasy mini kit were equally useful, whereas for ...	2007	17337308
occurrence and persistence of listeria spp. in the environment of ewe and cow's milk cheese dairies in portugal unveiled by an integrated analysis of identification, typing and spatial-temporal mapping along production cycle.	eight dairies, located in two distant geographic regions of portugal, were screened along the production cycle in order to evaluate the presence and distribution of listeria spp. in their environment. three dairies in each region were positive for the presence of listeriae and 213 isolates were obtained. based on an integrated analysis of rapd fingerprints with three primers, molecular identification and genomic typing of isolates was performed followed by spatial and temporal mapping on dairy p ...	2007	17337311
the alternative sigma factor sigma b and the virulence gene regulator prfa both regulate transcription of listeria monocytogenes internalins.	some listeria monocytogenes internalins are recognized as contributing to invasion of mammalian tissue culture cells. while prfa is well established as a positive regulator of l. monocytogenes virulence gene expression, the stress-responsive sigma(b) has been recognized only recently as contributing to expression of virulence genes, including some that encode internalins. to measure the relative contributions of prfa and sigma(b) to internalin gene transcription, we used reverse transcription-pc ...	2007	17337550
temperature-dependent expression of listeria monocytogenes internalin and internalin-like genes suggests functional diversity of these proteins among the listeriae.	the listeria monocytogenes genome contains genes encoding several internalins and internalin-like proteins. as l. monocytogenes is present in many environments and can infect numerous, diverse host species, the environmental temperature was hypothesized to be a signal that might affect internalin gene transcription. a subgenomic microarray was used to investigate temperature-dependent transcription of 24 members of the internalin gene family in l. monocytogenes 10403s. the levels of internalin g ...	2007	17337561
effect of heat and high-pressure treatments on microbiological quality and immunoglobulin g stability of caprine colostrum.	caprine colostrums (6 batches) were subjected to heat (56 degrees c for 60 min and 63 degrees c for 30 min) and high-pressure (400 and 500 mpa for 10 min at 20 degrees c) treatments at laboratory scale, and analyses of the main microbial groups and the extent of igg denaturation (determined by immunodiffusion) were performed. overall mean microbial values in raw colostrums were: total count, 5.55 log cfu/ml; enterobacteriaceae, 2.64 log cfu/ml; lactococci, 5.41 log cfu/ml; lactobacilli, 2.34 log ...	2007	17235160
expression and function of synaptotagmin vii in ctls.	the ca(2+) sensor synaptotagmin (syt) vii regulates the exocytosis of conventional lysosomes in several cell types. in ctls, the ca(2+)-regulated exocytosis of lytic granules/secretory lysosomes is responsible for the perforin/granzyme-mediated lysis of target cells. to investigate the role of syt vii in ctl effector function, the expression and function of syt vii were examined in wild-type and syt vii-deficient mice. in comparison with syt vii(+/+) controls, syt vii(-/-) animals were impaired ...	2007	17237398
suppression of the bacterial antigen-specific t cell response and the dendritic cell migration to the lymph nodes by osteopontin.	osteopontin (opn) has been reported to enhance the interferon (ifn)-gamma-producing th1-type t cell response through the induction of interleukin (il)-12 and the suppression of il-10. we therefore investigated whether opn could enhance th1 induction by vaccination against bacterial antigen in vivo. unexpectedly, the co-inoculation of opn suppressed the induction of ifn-gamma-producing cd4(+) t cells and t cell proliferative response after the subcutaneous heat-killed listeria monocytogenes(hklm) ...	2007	17237609
a novel surface autolysin of listeria monocytogenes serotype 4b, ispc, contains a 23-residue n-terminal signal peptide being processed in e. coli.	the 86-kda protein ispc of 774 amino acids in listeria monocytogenes serotype 4b has been recently identified as the target of humoral immune response to listerial infection and as a novel surface autolysin. a signal peptide is predicted at the n-terminal end of ispc, but no biochemical data has been shown to confirm the presence of the cleavage site of a signal peptidase. to address this and prepare sufficient amount of the protein for biochemical and structural characterization, we present a s ...	2007	17239349
fcgammariii-dependent inhibition of interferon-gamma responses mediates suppressive effects of intravenous immune globulin.	intravenous immune globulin (ivig) suppresses autoantibody-mediated inflammation by inducing and activating the inhibitory fc receptor fcgammariib and downstream negative signaling pathways. we investigated the effects of ivig on cellular responses to interferon-gamma (ifn-gamma), a potent macrophage activator that exacerbates inflammation. our study showed that ivig blocked ifn-gamma signaling and ifn-gamma-induced gene expression and suppressed ifn-gamma function in vivo during immune response ...	2007	17239631
exploring the performance of logistic regression model types on growth/no growth data of listeria monocytogenes.	several model types have already been developed to describe the boundary between growth and no growth conditions. in this article two types were thoroughly studied and compared, namely (i) the ordinary (linear) logistic regression model, i.e., with a polynomial on the right-hand side of the model equation (type i) and (ii) the (nonlinear) logistic regression model derived from a square root-type kinetic model (type ii). the examination was carried out on the basis of the data described in vermeu ...	2007	17239980
upregulation of vascular endothelial growth factor by heat-killed listeria monocytogenes in macrophages.	we investigated the effect of heat-killed listeria monocytogenes (hklm) on the expression of vascular endothelial growth factor (vegf) in raw264.7 macrophage-like cells. the expression of vegf was induced in raw264.7 cells treated with hklm. pretreatment of cells with cycloheximide, a protein synthesis inhibitor, inhibited the induction of vegf mrna by hklm. induction of vegf by hklm was partially inhibited by treatment of cells with sb203580, a p38 mitogen-activated protein kinase (mapk) inhibi ...	2007	17240354
genotypic and phenotypic diversity of lactococcus lactis isolates from batzos, a greek pdo raw goat milk cheese.	the genotypic and phenotypic variability of 40 lactococcus lactis isolates obtained from three cheese-making trials of batzos cheese made one in each, winter, spring and summer was investigated. rapd-pcr, plasmid profiling and pfge were used to study the genetic variability and distinguish closely related isolates. results showed a high degree of heterogeneity among strains. according to pfge data, all strains except one were clustered together (at a similarity level of approximately 50%) with t ...	2007	17241681
a pair of 9s: it's in the cards.	new work shows that card9, the recently identified member of the caspase recruitment domain-containing family, directly interacts with the cytoplasmic protein nod2 in the detection of intracellular bacteria.	2007	17242682
reduction in the incidence of invasive listeriosis in foodborne diseases active surveillance network sites, 1996-2003.	listeriosis is a leading cause of death among patients with foodborne diseases in the united states. monitoring disease incidence is an important element of listeriosis surveillance and control.	2007	17243053
listeria monocytogenes infection from foods prepared in a commercial establishment: a case-control study of potential sources of sporadic illness in the united states.	listeria monocytogenes has been estimated to cause >2500 illnesses and 500 deaths annually in the united states. efforts to reduce foodborne listeriosis have focused on foods frequently implicated in outbreaks. potential sources for l. monocytogenes infection not associated with outbreaks remain poorly understood.	2007	17243054
what can we do to prevent listeriosis in 2006?		2007	17243055
cytosolic expression of seca2 is a prerequisite for long-term protective immunity.	induction of efficient adaptive t cell-mediated immunity against the intracellular bacterium listeria monocytogenes requires its successful invasion of host cell cytosol. however, it is not clear whether its cytosolic escape and growth are sufficient to induce t cell-mediated clearance and protection upon secondary infection. to investigate this issue, we have searched for mutants that do not induce long-term protective immunity yet invade the cytosol of infected cells. we found that mice immuni ...	2007	17244189
differential susceptibility of bone marrow-derived dendritic cells and macrophages to productive infection with listeria monocytogenes.	dendritic cells (dc) are required for the immune response against listeria monocytogenes and are permissive for infection in vivo and in vitro. however, it is unclear if dc provide a desirable intracellular niche for bacterial growth. to address this issue, we have compared the behaviour of l. monocytogenes in murine bone marrow-derived dc and macrophages (bmm). similar to bmm, bacteria escaped to the cytosol in dc, replicated, and spread to adjacent cells. however, dc infection was less robust ...	2007	17250592
carriage of four bacterial pathogens by beef cattle in northern ireland at time of slaughter.	to determine the prevalence of four bacterial zoonotic pathogens in beef cattle at time of slaughter in northern ireland (ni), in order to assess their potential for reducing beef safety.	2007	17257247
inhibition of listeria monocytogenes by freeze-dried piscicocin cs526 fermentate in food.	the effectiveness of freeze-dried powder, fermented with bacteriocin producing carnobacterium piscicola cs526, was evaluated for the inhibition of listeria monocytogenes in a food model.	2007	17257251
limitations in the use of drosophila melanogaster as a model host for gram-positive bacterial infection.	to examine sensitivities of various drosophila melanogaster strains towards human pathogenic and nonpathogenic gram-positive bacteria.	2007	17257264
a molecular beacon-based real time nasba assay for detection of listeria monocytogenes in food products: role of target mrna secondary structure on nasba design.	a molecular beacon-based real-time nasba (qnasba) assay for detection and identification of listeria monocytogenes has been developed. a correlation between targeting highly accessible mrna sequences and qnasba efficiency and sensitivity was demonstrated. the assay targets a sequence from the mrna transcript of the hly gene which is specific for this bacterium; and includes an internal amplification control to disclose failure of the reaction. it was fully selective and consistently detected dow ...	2007	17258831
identification of new noncoding rnas in listeria monocytogenes and prediction of mrna targets.	to identify noncoding rnas (ncrnas) in the pathogenic bacterium listeria monocytogenes, we analyzed the intergenic regions (igrs) of strain egd-e by in silico-based approaches. among the twelve ncrnas found, nine are novel and specific to the listeria genus, and two of these ncrnas are expressed in a growth-dependent manner. three of the ncrnas are transcribed in opposite direction to overlapping open reading frames (orfs), suggesting that they act as antisense on the corresponding mrnas. the ot ...	2007	17259222
piezotolerant small-colony variants with increased thermotolerance, antibiotic susceptibility, and low invasiveness in a clonal staphylococcus aureus population.	following a pressure treatment of a clonal staphylococcus aureus culture with 400 mpa for 30 min, piezotolerant variants were isolated. among 21 randomly selected survivors, 9 were piezotolerant and all formed small colonies on several agar media. the majority of the isolates showed increased thermotolerance, impaired growth, and reduced antibiotic resistance compared to the wild type. however, several nonpiezotolerant isolates also demonstrated impaired growth and the small-colony phenotype. in ...	2007	17259364
ischemic cerebral attacks due to a pseudo-aneurysm of the internal carotid artery with listeria monocytogenes.		2007	17260177
in vitro and in vivo activities of pd 0305970 and pd 0326448, new bacterial gyrase/topoisomerase inhibitors with potent antibacterial activities versus multidrug-resistant gram-positive and fastidious organism groups.	pd 0305970 and pd 0326448 are new bacterial gyrase and topoisomerase inhibitors (quinazoline-2,4-diones) that possess outstanding in vitro and in vivo activities against a wide spectrum of bacterial species including quinolone- and multidrug-resistant gram-positive and fastidious organism groups. the respective mics (microg/ml) for pd 0305970 capable of inhibiting>or=90% of bacterial strains tested ranged from 0.125 to 0.5 versus staphylococci, 0.03 to 0.06 versus streptococci, 0.25 to 2 versus ...	2007	17261623
evaluation of housekeeping genes in listeria monocytogenes as potential internal control references for normalizing mrna expression levels in stress adaptation models using real-time pcr.	listeria monocytogenes is an important food-borne pathogen that can tolerate a wide range of stress conditions. however, its stress adaptation processes are still poorly understood. real-time-based quantitative rt-pcr (qrt-pcr) provides a tool to probe gene expression changes underlying stress adaptation. but, a limitation to study mrna levels by real-time qrt-pcr is that validated reference genes are required for normalization. such genes are currently lacking for experimental models that may b ...	2007	17263845
biofilm formation by multidrug-resistant salmonella enterica serotype typhimurium phage type dt104 and other pathogens.	the biofilm-forming capability of salmonella enterica serotypes typhimurium and heidelberg, pseudomonas aeruginosa, listeria monocytogenes, escherichia coli o157:h7, klebsiella pneumoniae, and acinetobacter baumannii isolated from humans, animal farms, and retail meat products was evaluated by using a microplate assay. the tested bacterial species showed interstrain variation in their capabilities to form biofilms. strong biofilm-forming strains of s. enterica serotypes, e. coli o157: h7, p. aer ...	2007	17265855
recovery of salmonella, listeria monocytogenes, and mycobacterium bovis from cheese entering the united states through a noncommercial land port of entry.	a joint multiagency project was initiated in response to a salmonella outbreak in san diego county, california, in 2004. samples of cheese were collected during four 1-day operations at the san ysidro port of entry, along the united states-mexico border. surveyed participants were persons crossing the border as pedestrians or in vehicles who had a minimum of 2.27 kg of cheese, which may suggest a potential diversion to illegal marketing. in addition, data were collected about the cheese to ident ...	2007	17265859
rapid enrichment strategy for isolation of listeria from bovine hide, carcass, and meat samples.	since the outbreak of foodborne illness linked to escherichia coli o157:h7 bacteria in ground beef in the early 1980s, the beef processing industry has focused on increasing the safety of beef products by implementing procedures for surveying live cattle, carcasses, and beef products for bacterial pathogens. effective methods are in place for screening cattle and beef products for the presence of e. coli o157:h7 contamination, and recent work has established the acceptability of these methods fo ...	2007	17265860
protein variations in listeria monocytogenes exposed to sodium lactate, sodium diacetate, and their combination.	most studies of the effect of adverse conditions on survival of listeria monocytogenes have focused on stress caused by acid or sodium chloride. however, no information is available on resistance of this pathogen to stress caused by salts of organic acids. sodium lactate and sodium diacetate are generally recognized as safe substances and are approved as ingredients for use in foods. we evaluated antilisterial properties of each of these salts and the enhanced inhibition effected by their combin ...	2007	17265861
effect of acid adaptation on growth during storage at 10 degrees c and resistance to simulated gastric fluid of listeria monocytogenes inoculated onto bologna formulated with or without antimicrobials.	the fate of acid-adapted and nonadapted listeria monocytogenes inoculated onto bologna slices (formulated with or without antimicrobials) was examined during storage and after exposure to in vitro gastric challenge. bologna slices formulated with no antimicrobials (control), 3% sodium lactate (sl), or 1.8% sl plus 0.25% sodium diacetate (sd) were inoculated (2 log cfu/cm2) with a 10-strain composite of acid-adapted or nonadapted l. monocytogenes strains. growth or survival of the two inocula on ...	2007	17265862
modeling and predicting the growth boundary of listeria monocytogenes in lightly preserved seafood.	the antimicrobial effect of diacetate and lactate against listeria monocytogenes was evaluated in challenge tests with vacuum-packaged or modified atmosphere packaged (map) cold-smoked salmon, marinated salmon, cold-smoked greenland halibut, marinated greenland halibut, and gravad salmon. map cold-smoked salmon with the addition of 0.15% (wt/wt) diacetate prevented the growth of l. monocytogenes for more than 40 days at 8 degrees c, whereas the addition of 0.15% (wt/wt) diacetate reduced the gro ...	2007	17265863
efficacy of neutral electrolyzed water to inactivate escherichia coli, listeria monocytogenes, pseudomonas aeruginosa, and staphylococcus aureus on plastic and wooden kitchen cutting boards.	this study evaluated the efficacy of neutral electrolyzed water (new; 64.1 mg/liter of active chlorine) to reduce populations of escherichia coli, pseudomonas aeruginosa, staphylococcus aureus, and listeria monocytogenes on plastic and wooden kitchen cutting boards. its effectiveness was compared with that of a sodium hypochlorite solution (naclo; 62.3 mg/liter of active chlorine). inoculated portions of cutting boards were rinsed in either new or naclo solutions, or deionized water (control). p ...	2007	17265867
adhesive and chemokine stimulatory properties of potentially probiotic lactobacillus strains.	five lactobacillus plantarum strains and two lactobacillus johnsonii strains, stemming either from african traditionally fermented milk products or children's feces, were investigated for probiotic properties in vitro. the relationship between the hydrophobic-hydrophilic cell surface and adhesion ability to ht29 intestinal epithelial cells was investigated, and results indicated that especially the l. johnsonii strains, which exhibited both hydrophobic and hydrophilic surface characteristics, ad ...	2007	17265871
inhibition of listeria monocytogenes in turkey and pork-beef bologna by combinations of sorbate, benzoate, and propionate.	the control of listeria monocytogenes was evaluated with ready-to-eat uncured turkey and cured pork-beef bologna with combinations of benzoate, propionate, and sorbate. three treatments of each product type were formulated to include control with no antimycotic agents; a combination of 0.05% sodium benzoate and 0.05% sodium propionate; and a combination of 0.05% sodium benzoate and 0.05% potassium sorbate. ingredients were mixed, stuffed into fibrous, moisture-impermeable casings, cooked to an i ...	2007	17265884
heat shock protein gp96 is a master chaperone for toll-like receptors and is important in the innate function of macrophages.	gp96 is an endoplasmic reticulum chaperone for cell-surface toll-like receptors (tlrs). little is known about its roles in chaperoning other tlrs or in the biology of macrophage in vivo. we generated a macrophage-specific gp96-deficient mouse. despite normal development and activation by interferon-gamma, tumor necrosis factor-alpha, and interleukin-1beta, the mutant macrophages failed to respond to ligands of both cell-surface and intracellular tlrs including tlr2, tlr4, tlr5, tlr7, and tlr9. f ...	2007	17275357
imatinib mesylate inhibits antigen-specific memory cd8 t cell responses in vivo.	imatinib mesylate (im) is effective at inducing complete cytogenetic remission in patients with chronic myelogenous leukemia. because its influence on cd8 t cell responsiveness in vivo is unknown, we investigated the effects of im by analyzing the response of ot-1 cd8 t cells to listeria monocytogenes (lm) that express the cognate epitope ova(257-264) (lm-ova). in vitro, im had no effect on ag-specific expansion, cell division, cell cycle progression, or ifn-gamma expression in naive or memory o ...	2007	17277106
regulation of cd8+ t lymphocyte effector function and macrophage inflammatory cytokine production by retinoic acid receptor gamma.	vitamin a and its derivatives regulate a broad array of immune functions. the effects of these retinoids are mediated through members of retinoic acid receptors (rars) and retinoid x receptors. however, the role of individual retinoid receptors in the pleiotropic effects of retinoids remains unclear. to dissect the role of these receptors in the immune system, we analyzed immune cell development and function in mice conditionally lacking rargamma, the third member of the rar family. we show that ...	2007	17277115
rapid clonal expansion and prolonged maintenance of memory cd8+ t cells of the effector (cd44highcd62llow) and central (cd44highcd62lhigh) phenotype by an archaeosome adjuvant independent of tlr2.	vaccines capable of eliciting long-term t cell immunity are required for combating many diseases. live vectors can be unsafe whereas subunit vaccines often lack potency. we previously reported induction of cd8(+) t cells to ag entrapped in archaeal glycerolipid vesicles (archaeosomes). in this study, we evaluated the priming, phenotype, and functionality of the cd8(+) t cells induced after immunization of mice with ova-methanobrevibacter smithii archaeosomes (ms-ova). a single injection of ms-ov ...	2007	17277146
expression of the p60 autolysin enhances nk cell activation and is required for listeria monocytogenes expansion in ifn-gamma-responsive mice.	both peptidoglycan and muropeptides potently modulate inflammatory and innate immune responses. the secreted listeria monocytogenes p60 autolysin digests peptidoglycan and promotes bacterial infection in vivo. here, we report that p60 contributes to bacterial subversion of nk cell activation and innate ifn-gamma production. l. monocytogenes deficient for p60 (deltap60) competed well for expansion in mice doubly deficient for ifnar1 and ifn-gammar1 or singly deficient for ifn-gammar1, but not in ...	2007	17277147
use of high-affinity cell wall-binding domains of bacteriophage endolysins for immobilization and separation of bacterial cells.	immobilization and magnetic separation for specific enrichment of microbial cells, such as the pathogen listeria monocytogenes, depends on the availability of suitable affinity molecules. we report here a novel concept for the immobilization and separation of bacterial cells by replacing antibodies with cell wall-binding domains (cbds) of bacteriophage-encoded peptidoglycan hydrolases (endolysins). these polypeptide modules very specifically recognize and bind to ligands on the gram-positive cel ...	2007	17277212
community-acquired listeria monocytogenes meningitis in adults.		2007	17278080
immunostimulatory rna is a potent inducer of antigen-specific cytotoxic and humoral immune response in vivo.	single-stranded rna stimulates immune cells and induces the secretion of pro-inflammatory cytokines and type i ifn. as adjuvant rna can induce a t(h)2 type of humoral response, however, its potency in the induction of cytotoxic t cells in vivo has not been analyzed. here we show that immunization with the antigen ovalbumin (ova) and the adjuvant phosphodiester rna complexed to the cationic lipid n-[1-(2,3-dioleoyloxy)propyl]-n,n,n-trimethylammonium methylsulfate (dotap) induced a toll-like recep ...	2007	17289655
[determination of the minimum enrichment time for the qualitative detection of listeria monocytogenes in minced pork meat using multiplex-pcr, microarray and elisa].	a qualitative detection of listeria monocytogenes was performed in spiked minced pork meat using elisa, multiplex-pcr, microarray and cultural reference method. minced pork meat in batches of 10 or 25 g was spiked with 25 cfu listeria monocytogenes per gram and incubated in selective enrichment solutions. during enrichment samples were collected continiously and a listeria monocytogenes-elisa, a multiplex-pcr with electrophoretical detection (listeria duplex) and a pcr with detection by microarr ...	2007	17290946
priming of cd8+ t cell responses by pathogens typically depends on cd70-mediated interactions with dendritic cells.	the cd27/cd70-interaction has been shown to provide a costimulatory and survival signal for t cells in vitro and in vivo. recently, cd70 expression by dc was found to be important for the priming of cd8+ t cells. we show here that blocking cd70 interactions has a significant impact on priming of cd8+ t cell responses by vaccinia virus (vv), listeria monocytogenes and vesicular stomatitis virus (vsv) in mice. however, the priming of specific cd8+ t cells upon infection with lymphocytic choriomeni ...	2007	17295392
disposable electrochemical genosensor for the simultaneous analysis of different bacterial food contaminants.	this paper deals with the use of an electrochemical genosensor array for the rapid and simultaneous detection of different food-contaminating pathogenic bacteria. the method includes pcr amplification followed by analysis of the amplicons by hybridisation with toxin-specific oligonucleotide probes. a screen-printed array of four gold electrodes, modified using thiol-tethered oligonucleotide probes, was used. unmodified pcr products were captured at the sensor interface via sandwich hybridisation ...	2007	16846731
cholestasis protects the liver from ischaemic injury and post-ischaemic inflammation in the mouse.	cholestasis is associated with high morbidity and mortality in patients undergoing major liver surgery, but the mechanisms responsible remain elusive. increased ischaemic liver injury and inflammation may contribute to the poor outcome.	2007	16763052
effects of plant extracts on microbial growth, color change, and lipid oxidation in cooked beef.	the effects of butylated hydroxyanisole/butylated hydroxytoluene (bha/bht), grape seed extract (activin), pine bark extract (pycnogenol), and oleoresin rosemary (herbalox) on microbial growth, color change, and lipid oxidation were investigated in cooked ground beef. when compared to the control, 1.0% activin and pycnogenol) effectively reduced the numbers of escherichia coli o157:h7 and salmonella typhimurium, and retarded the growth of listeria monocytogenes and aeromonas hydrophila. pycnogeno ...	2007	16943089
effect of preincubation temperature and ph on the individual cell lag phase of listeria monocytogenes, cultured at refrigeration temperatures.	the impact of precultural temperature and ph on the distribution of the lag phase of individual listeria monocytogenes cells was assessed during preincubation at 7 degrees c, using a dilution protocol to obtain single cells, and optical density measurements to estimate the individual lag phase. firstly, the pure temperature effect (37, 15, 10, 7, 4 and 2 degrees c) was investigated on a subsequent growth at 7 degrees c and ph 7.4. secondly, low precultural temperatures (10, 7 and 4 degrees c) we ...	2007	16943092
reduction of counts of listeria monocytogenes in cheese by means of high hydrostatic pressure.	inactivation of listeria monocytogenes (strains nctc 11994 and scott a) was evaluated in model cheeses submitted to 10 min hhp treatments of 300, 400 or 500 mpa at 5 or 20 degrees c. counts were measured immediately after high hydrostatic pressure (hhp) treatment (day 1) and after 2, 15 and 30 days of storage at 8 degrees c. both strains behaved significantly different after 400 and 500 mpa, being nctc 11994 more sensitive. scarce differences were found among final values at both hhp treatment t ...	2007	16943095
inhibition of escherichia coli o157:h7, listeria monocytogenes and staphylococcus aureus on sliced roast beef by cetylpyridinium chloride and acidified sodium chlorite.	the effects of 0.5% cetylpyridinium chloride (cpc), 0.12% acidified sodium chlorite (asc) and a mix of equal volume of the two (0.25% cpc-0.06% asc) on escherichia coli o157:h7, listeria monocytogenes and staphylococcus aureus were evaluated on inoculated sliced roast beef. the antimicrobial agents were, respectively, sprayed on the beef surfaces and tray absorbent pads, and samples were stored at 4 degrees c for 10 days (d). at 0 d, l. monocytogenes and s. aureus were reduced to undetectable le ...	2007	16943099
detection of antimicrobial activities and bacteriocin structural genes in faecal enterococci of wild animals.	the production of antimicrobial activities as well as the presence of bacteriocin structural genes (enta, entb, entp, entq, cyll, entas-48, bac31, and entl50a/b) were studied in 140 non-selected faecal enterococcal isolates recovered from wild animals. eight different indicator strains (including listeria monocytogenes, pediococcus pentosaceus, and different enterococcal species) were used for antimicrobial activity detection. twenty-five of the 140 enterococci (18%) showed antimicrobial activit ...	2007	16872815
antibacterial activity of bioconverted eicosapentaenoic (epa) and docosahexaenoic acid (dha) against foodborne pathogenic bacteria.	the antimicrobial activity of bioconversion extracts of epa and dha against a range of foodborne pathogenic bacteria was investigated. the bioconverted epa and dha exhibited antibacterial activities against four gram-positive bacteria, bacillus subtilis, listeria monocytogenes, staphylococcus aureus (atcc 6538) and s. aureus (kctc 1916) and seven gram-negative bacteria, enterobacter aerogenes, escherichia coli, e. coli o157:h7, e. coli o157:h7 (human), pseudomonas aeruginosa, salmonella enteriti ...	2007	16860896
an important step in listeria lipoprotein research.		2007	17071755
clinical features, prognostic and risk factors of central nervous system infections in patients with systemic lupus erythematosus.	the purpose of this study is to describe the etiology, characteristics and outcomes of central nervous system (cns) infections in patients with systemic lupus erythematosus (sle), while also identifying prognostic and risk factors. thirty-eight sle patients with cns infections were identified from review of all charts of patients with sle hospitalized from january 1995 to june 2005. these patients were divided into 3 groups, i.e., mycobacterium tuberculosis (tb), non-tb bacterial and fungal infe ...	2007	17021668
more than one variant of listeria monocytogenes isolated from each of two human cases of invasive listeriosis.	two variants of listeria monocytogenes were isolated from blood cultures from each of two patients with listeriosis. each variant displayed a two-band difference in dna profile from the other by pulsed-field gel electrophoresis. although this difference in profile is insufficient to distinguish clearly between the variants, the possibility of co-infection with different strains of l. monocytogenes needs to be considered. we suggest that more than one colony should be selected for molecular typin ...	2007	17109771
proteinase-activated receptors induce nonoxidative, antimicrobial peptides and increased antimicrobial activity in human mononuclear phagocytes.	as thrombin and sfllrnpndkyepf (sfllrn-14), a synthetic ligand, mainly of the proteinase-activated receptor-1 (par-1), induce in monocytes the synthesis and secretion of chemokines, the par pathway can be viewed as a mononuclear phagocyte-activating principle. classically, antimicrobial activity of mononuclear phagocytes is the measure for activation. here, we investigated whether thrombin or sfllrn-14 increases the antimicrobial activity of human monocytes and compared these effects to those of ...	2007	17095611
estimation of microbial contamination of food from prevalence and concentration data: application to listeria monocytogenes in fresh vegetables.	a normal distribution and a mixture model of two normal distributions in a bayesian approach using prevalence and concentration data were used to establish the distribution of contamination of the food-borne pathogenic bacteria listeria monocytogenes in unprocessed and minimally processed fresh vegetables. a total of 165 prevalence studies, including 15 studies with concentration data, were taken from the scientific literature and from technical reports and used for statistical analysis. the pre ...	2007	17098926
markov chain approach to analyze the dynamics of pathogen fecal shedding--example of listeria monocytogenes shedding in a herd of dairy cattle.	fecal shedding is an important mechanism of spreading of a number of human and animal pathogens. understanding of the dynamics of pathogen fecal shedding is critical to be able to control or prevent the spread of diseases caused by these pathogens. the objective of this study was to develop a model for analysis of the dynamics of pathogen fecal shedding. fecal shedding of listeria monocytogenes in dairy cattle was used as a model system. a markov chain model (mcm) with two states, shedding and n ...	2007	17092523
partial purification and characterization of protease of bacillus proteolyticus cfr3001 isolated from fish processing waste and its antibacterial activities.	bacillus proteolyticus cfr3001 isolated from fish processing wastes (both fresh water and marine) produced an alkaline protease. the optimum conditions for cell growth and protease production were 37 degrees c, 96 h, agitation speed of 100 rpm and medium ph 9. the partially purified protease obtained from had specific activity of 22.05 at 37 degrees c was active between 40 degrees c and 50 degrees c and lost >20% of its activity around 60 degrees c. its molecular weight was approximately 29 kda ...	2007	17092708
interference of components of the phosphoenolpyruvate phosphotransferase system with the central virulence gene regulator prfa of listeria monocytogenes.	analysis of listeria monocytogenes ptsh, hprk, and ccpa mutants defective in carbon catabolite repression (ccr) control revealed significant alterations in the expression of prfa-dependent genes. the hprk mutant showed high up-regulation of prfa-dependent virulence genes upon growth in glucose-containing medium whereas expression of these genes was even slightly down-regulated in the ccpa mutant compared to the wild-type strain. the ptsh mutant could only grow in a rich culture medium, and here ...	2007	17085572
a single-nucleotide-polymorphism-based multilocus genotyping assay for subtyping lineage i isolates of listeria monocytogenes.	listeria monocytogenes is a facultative intracellular pathogen responsible for food-borne disease with high mortality rates in humans and is the leading microbiological cause of food recalls. lineage i isolates of l. monocytogenes are a particular public health concern because they are responsible for most sporadic cases of listeriosis and the vast majority of epidemic outbreaks. rapid, reproducible, and sensitive methods for differentiating pathogens below the species level are required for eff ...	2007	17085705
compartmentalization of the broad-range phospholipase c activity to the spreading vacuole is critical for listeria monocytogenes virulence.	listeria monocytogenes is a bacterial pathogen that multiplies in the cytosol of host cells and spreads directly from cell to cell by using an actin-based mechanism of motility. the broad-range phospholipase c (pc-plc) of l. monocytogenes contributes to bacterial escape from vacuoles formed upon cell-to-cell spread. pc-plc is made as an inactive proenzyme whose activation requires cleavage of an n-terminal propeptide. during infection, pc-plc is activated specifically in acidified vacuoles. to a ...	2007	17060464
essential role of ccl2 in clustering of splenic ertr-9+ macrophages during infection of balb/c mice by listeria monocytogenes.	early interactions between pathogens and host cells are often decisive for the subsequent course of infection. here we investigated early events during infection by listeria monocytogenes, a ubiquitously occurring facultative intracellular microorganism that exhibits severe pathogenicity, mainly in immunocompromised individuals. we show that the inflammatory chemokine ccl2 is highly up-regulated early after listeria infection in spleens of balb/c mice. ertr-9+ macrophages of the marginal zone we ...	2007	17074847