Publications

compression forces generated by actin comet tails on lipid vesicles.	polymerizing networks of actin filaments generate force for a variety of movements in living cells, including protrusion of filopodia and lamellipodia, intra- and intercellular motility of certain bacterial and viral pathogens, and motility of endocytic vesicles and other membrane-bound organelles. during actin-based motility, coexisting populations of actin filaments exert both pushing and retarding forces on the moving cargo. to examine the distribution and magnitude of forces generated by act ...	2003	12738883
bioprotectives and probiotics for dry sausages.	the microbial stability of dry sausages is determined by the combination and timing of different factors referred to as the hurdle-concept. however, the hurdles present in dry sausage are not sufficient to prevent the survival of listeria monocytogenes or enterohemorrhagic escherichia coli o157:h7. recently bioprotective lactic acid bacteria, which in addition to the production of antimicrobial lactic acid, have been found to contribute to the safety of the dry sausage by producing antimicrobial ...	2003	12745229
susceptibility of listeria monocytogenes isolated from food in italy to antibiotics.	the susceptibility of 148 strains of listeria monocytogenes isolated from food to antibiotics currently used in veterinary and human therapy was determined by standard agar dilution and disk diffusion methods. the antibiotics included amikacin, amoxicillin, cefazolin, chloramphenicol, erythromycin, flumequine, fosfomycin, gentamicin, kanamycin, lincomycin, oxytetracycline, rifampicin, spiramycin, streptomycin, tetracycline, tobramycin and vancomycin. soussy's breakpoints and mic(50)-mic(90) valu ...	2003	12745237
comparison of recovery methods for freeze-injured listeria monocytogenes, salmonella typhimurium, and campylobacter coli in cell suspensions and associated with pork surfaces.	cells injured as a result of freezing, heating, and acidification treatments may not grow during conventional microbiological procedures owing to the presence of selective agents, compounds, or dyes in the media, impairing the cell's ability to repair itself and grow. injured cells can be recovered by combining selective and nonselective media into a single system. with such combinations, the diffusion of the selective compounds or dyes is controlled, allowing for the resuscitation of injured ce ...	2003	12747688
predictive model for the combined effect of temperature, sodium lactate, and sodium diacetate on the heat resistance of listeria monocytogenes in beef.	the effects of heating temperature (60 to 73.9 degrees c), sodium lactate (nal; 0.0 to 4.8% [wt/wt]), and/or sodium diacetate (sda; 0.0 to 0.25% [wt/wt]) and of the interactions of these factors on the heat resistance of a five-strain mixture of listeria monocytogenes in 75% lean ground beef were examined. thermal death times for l. monocytogenes in filtered stomacher bags in a circulating water bath were determined. the recovery medium was tryptic soy agar supplemented with 0.6% yeast extract a ...	2003	12747689
reducing levels of listeria monocytogenes contamination on raw salmon with acidified sodium chlorite.	the antimicrobial activity of acidified sodium chlorite (asc) against listeria monocytogenes in salmon was studied. raw salmon (whole fish and fillets) inoculated with l. monocytogenes (10(3) cfu/cm2 or 10(4) cfu/g) were washed with asc solution (50 ppm) for 1 min and stored at -18 degrees c for 1 month (whole salmon) or in ice for 7 days (fillets). l. monocytogenes populations were determined for whole salmon after frozen storage and for fillets on days 1, 3, 5, and 7 of storage. a wash with as ...	2003	12747690
gamma irradiation of fine-emulsion sausage containing sodium diacetate.	listeria monocytogenes, a psychrotrophic foodborne pathogen, is a frequent postprocess contaminant of ready-to-eat (rte) meat products, including frankfurters and bologna. ionizing radiation can eliminate l. monocytogenes from rte meats. sodium diacetate (sda) incorporated into fine-emulsion sausages inhibits the growth of l. monocytogenes. irradiation of l. monocytogenes suspended in sda solutions resulted in synergistic reductions of the microorganism. l. monocytogenes populations were reduced ...	2003	12747691
impact of ph enhancement on populations of salmonella, listeria monocytogenes, and escherichia coli o157:h7 in boneless lean beef trimmings.	boneless lean beef trimmings were inoculated with multiple strains of salmonellae, listeria monocytogenes, and escherichia coli o157:h7 at levels of ca. 6 log10 cfu/g. ph enhancement with ammonia gas was then used to increase the ph of the trimmings to ca. 9.6. the product was then frozen, chipped, and compressed into blocks. ph enhancement reduced the populations of salmonellae, l. monocytogenes, and e. coli o157:h7 by approximately 4, 3, and 1 log10 cycles, respectively. after the product had ...	2003	12747699
multiple cerebral abscesses because of listeria monocytogenes: three case reports and a literature review of supratentorial listerial brain abscess(es).	central nervous system involvement often follows bacteremia because of listeria monocytogenes. meningitis is clinically the most common manifestation, while brain abscess occurs in about 1% of patients. brain abscess is usually solitary but in recent years, probably in part because of the availability of computerized tomography and magnetic resonance imaging, several reports have described two or more separate supratentorial abscesses.	2003	12748019
syringomyelia following listeria meningoencephalitis: report of a case.	a case of symptomatic syringomyelia which appeared six years after listeria meningoencephalitis is described. chronic spinal arachnoiditis, as shown by standard mri and dynamic phase contrast (pc) cine-mri, may occur after spinal infection and is likely the cause of syringomyelia. to our knowledge, there are no previous reports of delayed spinal complications following listeria monocytogenes infection. the possibility of developing syringomyelia should be always considered in any patient with a ...	2003	12754657
actin-based motility as a self-organized system: mechanism and reconstitution in vitro.	site-directed actin polymerisation in response to signalling is responsible for the formation of cell protrusions. these elementary 'actin-based motility processes' are involved in cell locomotion, cell metastasis, organ morphogenesis and microbial pathogenesis. we have reconstituted actin-based propulsive movement of particles of various sizes and geometries (rods, microspheres) in a minimum motility medium containing five pure proteins. the atp-supported treadmilling of actin filaments, regula ...	2003	12754935
intestinal m cells and their role in bacterial infection.	m cells are located in the epithelia overlying mucosa-associated lymphoid tissues such as peyer's patches where they function as the antigen sampling cells of the mucosal immune system. paradoxically, some pathogens exploit m cells as a route of invasion. here we review our current knowledge of intestinal m cells with particular emphasis on the mechanisms underlying bacterial infection of these atypical epithelial cells.	2003	12755364
experimental validation of low virulence in field strains of listeria monocytogenes.	several reports have described listeria monocytogenes strains which were nonpathogenic or weakly pathogenic, but little is known about these low-virulence strains. we found that 9 field l. monocytogenes strains were hypovirulent and 17 were avirulent, based on the number of mice contaminated and the colonization of their spleens after subcutaneous inoculation. all these strains possessed the known virulence genes. we have now assessed the low virulence of these strains in other assays before det ...	2003	12761127
attenuated yersinia pseudotuberculosis carrier vaccine for simultaneous antigen-specific cd4 and cd8 t-cell induction.	yersinia pseudotuberculosis employs a type iii secretion system for targeting of several virulence factors directly to the cytosol of eukaryotic cells. this protein translocation mechanism mediates the ability of yersinia to resist phagocytosis and is required for sustained extracellular bacterial replication. in the present study, the yersinia outer protein e (yope) was used as a carrier molecule for type iii-dependent secretion and translocation of listeriolysin o (llo) from listeria monocytog ...	2003	12761131
deletion of the gene encoding p60 in listeria monocytogenes leads to abnormal cell division and loss of actin-based motility.	protein p60 encoded by the iap gene is regarded as an essential gene product of listeria monocytogenes. here we report, however, the successful construction of a viable iap deletion mutant of l. monocytogenes egd. the mutant, which produces no p60, shows abnormal septum formation and tends to form short filaments and hooked forms during logarithmic growth. these abnormal bacterial cells break into almost normal sized single bacteria in the late-stationary-growth phase. the iap mutant is strongly ...	2003	12761132
listeriolysin o-mediated calcium influx potentiates entry of listeria monocytogenes into the human hep-2 epithelial cell line.	to investigate factors which modulate the entry of listeria monocytogenes into mammalian cells, we have analyzed the role of ca(2+). we show that l. monocytogenes induced ca(2+) transients into the human hep-2 epithelial cell line. the nonpathogenic species l. innocua or a l. monocytogenes mutant strain defective in listeriolysin o (llo) production was unable to induce these calcium fluxes. addition of plasma membrane calcium channel antagonists or chelation of extracellular calcium markedly red ...	2003	12761148
growth and survival of selected pathogens in margarine-style table spreads.	although margarine-style table spreads can have a ph above 4.6 and a water activity greater than 0.85, there is some question if such products can support the growth of pathogenic bacteria. the objective of this study was to evaluate the growth and survival of staphylococcus aureus, listeria monocytogenes, escherichia coli o157:h7, and salmonella typhi in 60-percent- and 70-percent-vegetable-oil, margarine-style, water-in-oil-emulsion table spreads stored at different temperatures. samples of 25 ...	2003	12762119
induction of immune responses by attenuated isogenic mutant strains of listeria monocytogenes.	we have generated isogenic listeria monocytogenes mutant strains to study the induction of protective immunity in mice. these strains harbored either a specific deletion within the actin nucleator (acta) and/or have multiple deletions within the acta and phospholipase b (plcb) genes. in comparison to the wild type parental l. monocytogenes egde strains, the mutant strains were extremely low in virulence and were rapidly eliminated by the host during the first days of infection. nevertheless, a s ...	2003	12763691
methodologies for the characterization of microbes in industrial environments: a review.	there is growing interest in research and development to develop novel tools to study, detect, and characterize microbes and their communities in industrial environments. however, knowledge about their validity in practical industrial use is still scarce. this review describes the advantages and limitations of traditional and molecular methods used for biofilm and/or planktonic cell studies, especially those performed with listeria monocytogenes, bacillus cereus, and/or clostridium perfringens. ...	2003	12764674
anti-oxidant properties of n-acetyl-l-cysteine do not improve the immune resistance of mice fed dietary lipids to listeria monocytogenes infection.	current knowledge of the potential effects that several dietary lipids exert on immune functions indicates that these substances participate actively in the modulation of immune system by which they contribute to the improvement of the conditions of patients suffering from inflammatory disorders. however, long-chain n-3 polyunsaturated fatty acids induce an immunosuppressive status that leads to a reduction of the host natural resistance to infectious agents as well as to an enhancement of oxida ...	2003	12765672
potential role of the epec translocated intimin receptor (tir) in host apoptotic events.	apoptosis, or programmed cell death, is a well-ordered process that allows damaged or diseased cells to be removed from an organism without severe inflammatory reactions. multiple factors, including microbial infection, can induce programmed death and trigger reactions in both host and microbial cellular pathways. whereas an ultimate outcome is host cell death, these apoptotic triggering mechanisms may also facilitate microbial spread and prolong infection. to gain a better understanding of the ...	2003	12766478
recombinant e. coli efficiently delivers antigen and maturation signals to human dendritic cells: presentation of mart1 to cd8+ t cells.	the generation of tumour-specific cytotoxic t-lymphocyte (ctl) responses is the primary focus in the design of immunotherapeutic cancer vaccines. we have recently demonstrated generation of ovalbumin (ova)-specific ctls and tumour-protection in a murine tumour model using vaccination with dendritic cells (dcs) pulsed with e. coli expressing listeriolysin o (llo) and ova as a model antigen. in this system paraformaldehyde fixation of e. coli/llo provided an additional safety feature without compr ...	2003	12767067
immune changes during acute cold/restraint stress-induced inhibition of host resistance to listeria.	experiments were conducted to delineate the cellular changes modulated by acute cold/restraint stress (acrs), a physical and psychological stressor, in response to a listeria monocytogenes(lm) infection. in addition to wild type (wt) balb/c mice, cd4-deficient (cd4-/-) balb/c mice, which have no effective adaptive immunity, were used to determine the involvement of adaptive versus innate immunity. acrs-induced suppression of host resistance to lm was not observed in cd4-/- mice, suggesting the i ...	2003	12773754
a crucial role for profilin-actin in the intracellular motility of listeria monocytogenes.	we have examined the effect of covalently crosslinked profilin-actin (pxa), which closely matches the biochemical properties of ordinary profilin-actin and interferes with actin polymerization in vitro and in vivo, on listeria monocytogenes motility. pxa caused a marked reduction in bacterial motility, which was accompanied by the detachment of bacterial tails. the effect of pxa was dependent on its binding to proline-rich sequences, as shown by the inability of ph133sxa, which cannot interact w ...	2003	12776739
t cells bite the hand that feeds them.		2003	12778158
molecular subtyping to detect human listeriosis clusters.	we analyzed the diversity (simpson's index, d) and distribution of listeria monocytogenes in human listeriosis cases in new york state (excluding new york city) from november 1996 to june 2000 by using automated ribotyping and pulsed-field gel electrophoresis (pfge). we applied a scan statistic (p<or=0.05) to detect listeriosis clusters caused by a specific listeria monocytogenes subtype. among 131 human isolates, 34 (d=0.923) ribotypes and 74 (d=0.975) pfge types were found. nine (31% of cases) ...	2003	12781006
protective effects of chlorella vulgaris in lead-exposed mice infected with listeria monocytogenes.	chlorella vulgaris extract (cve) was examined for its chelating effects on the myelosuppression induced by lead in listeria monocytogenes-infected mice. the reduction in the number of bone marrow granulocyte-macrophage progenitors (cfu-gm) observed after the infection was more severe in the groups previously exposed to lead. extramedullar hematopoiesis, which was drastically increased after the infection, was not altered by the presence of lead. treatment with cve, given simultaneously or follow ...	2003	12781705
the effect of growth atmosphere on the ability of listeria monocytogenes to survive exposure to acid, proteolytic enzymes and bile salts.	four isolates of listeria monocytogenes from food, human and environmental sources were grown separately in broth (ph 6.0 at 8 degrees c) under atmospheres of air, 100% n(2), 40% co(2):60% n(2) or 100% co(2). exponential and stationary phase cells were harvested to determine if growth atmosphere and growth phase influenced this pathogen's ability to survive exposure to an acid environment coupled with proteolytic enzymes, and the activity of bile salts. in general, isolates were more resistant t ...	2003	12781937
stress response of listeria monocytogenes isolated from cheese and other foods.	the responses to ph and sodium chloride of four strains of listeria monocytogenes isolated from portuguese cheese, with a sodium chloride concentration of about 2% (w/v) and a ph value from 5.1 to 6.2, were studied. two isolates from meat and two clinical isolates related to food-borne listeriosis, in which the implicated food product had about 2-3.5% (w/v) sodium chloride, also were studied. the effect of temperature on ph and sodium chloride sensitivity was also determined. the results show th ...	2003	12781943
simultaneous detection of escherichia coli o157:h7, listeria monocytogenes and salmonella strains by real-time pcr.	a protocol enabling simultaneous detection of escherichia coli o157:h7, listeria monocytogenes and salmonella strains was devised and evaluated using artificially contaminated fresh produce. association of official analytical chemists (aoac)-approved polymerase chain reaction (pcr) detection methods for three human pathogens were modified to enable simultaneous and real-time detection with high throughput capability. the method includes a melting-curve analysis of pcr products, which serves as c ...	2003	12781944
effects of a bacteriocin-like inhibitory substance from carnobacterium piscicola against human and salmon isolates of listeria monocytogenes.	the aim of this study was to characterize the antagonism of a bacteriocin-like inhibitory substance (blis) produced by carnobacterium piscicola l103 against listeria monocytogenes strains isolated from salmon and human samples. the inhibitory effect of the blis was evaluated in tryptic soy agar (tsa) during different growth phases of l. monocytogenes at 5 degrees c, using the well diffusion method. also, the type of inhibition, either bacteriostatic or bactericidal of the blis in tryptic soy bro ...	2003	12781946
rapid enumeration of listeria monocytogenes in milk using competitive pcr.	competitive polymerase chain reaction (cpcr) was used to develop a direct enumeration method of listeria monocytogenes in milk. sterile milk was artificially inoculated with l. monocytogenes and dna was extracted using guanidine thiocyanate/phenol/chloroform, followed by pcr. several primers for l. monocytogenes hlya gene were tested for specific detection and dg69/dg74 primer set was selected. the primer set produced a 636-bp band from l. monocytogenes, but no band appeared from the other six l ...	2003	12781957
haemolysin a and listeriolysin--two vaccine delivery tools for the induction of cell-mediated immunity.	haemolysin a of escherichia coli and listeriolysin of listeria monocytogenes represent important bacterial virulence factors. while such cytolysins are usually the reason for morbidity and even mortality, vaccine researchers have turned haemolysin a and listeriolysin into tools for vaccine delivery. both cytolysins have found widespread application in vaccine research and are highly suitable for the elicitation of cell-mediated immunity. in this paper, we will review vaccine delivery mediated by ...	2003	12782050
identification of listeria monocytogenes genes involved in salt and alkaline-ph tolerance.	the capacity of listeria monocytogenes to tolerate salt and alkaline stresses is of particular importance, as this pathogen is often exposed to such environments during food processing and food preservation. we screened a library of tn917-lacz insertional mutants in order to identify genes involved in salt and/or alkaline tolerance. we isolated six mutants sensitive to salt stress and 12 mutants sensitive to salt and alkaline stresses. the position of the insertion of the transposon was located ...	2003	12788708
development of a listeria monocytogenes egde partial proteome reference map and comparison with the protein profiles of food isolates.	a partially annotated proteome reference map of the food pathogen listeria monocytogenes was developed for exponentially growing cells under standardized, optimal conditions by using the sequenced strain egde (serotype 1/2a) as a model organism. the map was developed by using a reproducible total protein extraction and two-dimensional (2-d) polyacrylamide gel electrophoresis analysis procedure, and it contained 33 identified proteins representing the four main protein functional classes. in orde ...	2003	12788738
adhesion, invasion, and translocation characteristics of listeria monocytogenes serotypes in caco-2 cell and mouse models.	adhesion is a crucial first step in listeria monocytogenes pathogenesis. in this study, we examined how the adhesion properties of serotypes correlate with their invasion efficiencies in a cell culture model (caco-2) and in a mouse model. adhesion characteristics of all 13 serotypes of l. monocytogenes (25 strains) were analyzed, which yielded three distinct groups (p < 0.05) with high-, medium-, and low-level-adhesion profiles. the efficiency of these strains in invading the caco-2 cell line wa ...	2003	12788773
generation of food-grade lactococcal starters which produce the lantibiotics lacticin 3147 and lacticin 481.	transconjugant lactococcal starters which produce both lantibiotics lacticin 3147 and lacticin 481 were generated via conjugation of large bacteriocin-encoding plasmids. a representative of one of the resultant strains proved more effective at killing lactobacillus fermentum and inhibiting the growth of listeria monocytogenes lo28h than either of the single bacteriocin-producing parental strains, demonstrating the potential of these transconjugants as protection cultures for food safety applicat ...	2003	12788782
aromatic amino acids at the surface of inlb are essential for host cell invasion by listeria monocytogenes.	the surface protein inlb of the pathogen listeria monocytogenes promotes invasion of this bacterium into host cells by binding to and activating the receptor tyrosine kinase met. the curved leucine-rich repeat (lrr) domain of inlb, which is essential for this process, contains a string of five surface-exposed aromatic amino acid residues positioned along its concave face. here, we show that the replacement of four of these residues (f104, w124, y170 or y214) by serine leads to a complete loss of ...	2003	12791136
isolation of listeria monocytogenes mutants with high-level in vitro expression of host cytosol-induced gene products.	the facultative intracellular bacterial pathogen listeria monocytogenes dramatically increases the expression of several key virulence factors upon entry into the host cell cytosol. acta, the protein product of which is required for cell-to-cell spread of the bacterium, is expressed at low to undetectable levels in vitro and increases in expression more than 200-fold after l. monocytogenes escape from the phagosome. to identify bacterial factors that participate in the intracellular induction of ...	2003	12791137
report of an additional case of anti-tumor necrosis factor therapy and listeria monocytogenes infection: comment on the letter by glück et al.		2003	12794847
heterogeneity of virulence-related properties in listeria monocytogenes strains isolated from patients with haematological malignancies.	listeria monocytogenes is an intracellular foodborne pathogen of humans and animals for which there are indications of virulence differences among strains. various virulence properties related to different phases of infection process were investigated in l. monocytogenes strains isolated from patients affected by haematological malignancies. in these isolates, besides to the clinical history, we analysed the haemolysin production, the survival to acidic ph, the ability to enter and proliferate i ...	2003	12797902
il-12-assisted immunization generates cd4+ t cell-mediated immunity to listeria monocytogenes.	mice infected with virulent listeria monocytogenes develop long-lived acquired immunity. we previously reported that acquired immunity to listeria could also be elicited by immunizing mice with non-viable listeria or listerial proteins/peptides in combination with il-12. here we show that this il-12-assisted immunization strategy was effective in class i but not in class ii mhc-deficient mice, suggesting that antigen-specific cd4(+) t cells are selectively generated using this adjuvant system. w ...	2003	12798303
membrane filter (pore size, 0.22-0.45 micro m; thickness, 150 micro m) passing-through activity of pseudomonas aeruginosa and other bacterial species with indigenous infiltration ability.	bacteria growing on mf-millipore filters (thickness, 150 micro m) passed through the underlying membrane by their infiltration activity. bacillus subtilis, staphylococcus aureus, klebsiella pneumoniae, and escherichia coli passed through a 0.45- micro m pore size filter within 48-96 h. pseudomonas aeruginosa, serratia marcescens, and listeria monocytogenes passed through a 0.3- micro m pore size filter. p. aeruginosa passed through a 0.22- micro m pore size filter. the membranes which allowed pa ...	2003	12798998
a branched chain fatty acid promotes cold adaptation in bacteria.		2003	12799482
micro-assembly of functionalized particulate monolayer on c18-derivatized sio2 surfaces.	this work describes a simple approach to immobilize functionalized colloidal microstructures onto a c(18)-coated sio(2) substrate via specific or non-specific bio-mediated interactions. biotinylated bovine serum albumin pre-adsorbed onto a c(18) surface was used to mediate the surface assembly of streptavidin-coated microbeads (2.8 microm), while a bare c(18) surface was used to immobilize anti-listeria antibody-coated microbeads (2.8 microm) through hydrophobic interactions. for a c(18) surface ...	2003	12800136
survival and recovery of listeria monocytogenes on ready-to-eat meats inoculated with a desiccated and nutritionally depleted dustlike vector.	dust from construction was theorized to serve as a vector for l. monocytogenes transmission to ready-to-eat (rte) meats after heat processing but before packaging. a five-strain listeria monocytogenes culture including serotype 4b was continually stressed on a sand vector under four sets of nutritionally depleted and dry conditions to simulate postprocessing contamination by dustlike particulates. the stresses included that associated with sand stored at different temperatures (10 and 22 degrees ...	2003	12800995
acid adaptation does not promote survival or growth of listeria monocytogenes on fresh beef following acid and nonacid decontamination treatments.	the objective of this study was to evaluate the survival and growth of acid-adapted and nonadapted listeria monocytogenes inoculated onto fresh beef subsequently treated with acid or nonacid solutions. beef slices (2.5 by 5 by 1 cm) from top rounds were inoculated with acid-adapted or nonadapted l. monocytogenes (4.6 to 5.0 log cfu/cm2) and either left untreated (control) or dipped for 30 s in water at 55 degrees c, water at 75 degrees c, 2% lactic acid at 55 degrees c, or 2% acetic acid at 55 d ...	2003	12800998
ionizing radiation sensitivity of listeria monocytogenes atcc 49594 and listeria innocua atcc 51742 inoculated on endive (cichorium endiva).	ionizing radiation inactivates the pathogenic bacteria that can contaminate leafy green vegetables. leaf pieces and leaf homogenate of endive (cichorium endiva) were inoculated with the pathogen listeria monocytogenes (atcc 49594) or listeria innocua (atcc 51742), a nonpathogenic surrogate bacterium. the radiation sensitivity of the two strains was similar, although l. innocua was more sensitive to the type of suspending leaf preparation. during refrigerated storage after irradiation, the popula ...	2003	12800999
inhibition of listeria monocytogenes in ph-adjusted pasteurized liquid whole egg.	although the transmission of l. monocytogenes to humans via pasteurized egg products has not been documented, l. monocytogenes and other listeria species have been isolated from commercially broken raw liquid whole egg (lwe) in both the united states and ireland. recent listeria thermal inactivation studies indicate that conventional minimal egg pasteurization processes would effect only a 2.1- to 2.7-order-of-magnitude inactivation of l. monocytogenes in lwe; thus, the margin of safety provided ...	2003	12801000
evaluation of a select strain of lactobacillus delbrueckii subsp. lactis as a biological control agent for pathogens on fresh-cut vegetables stored at 7 degrees c.	raw vegetables inoculated with selected pathogenic bacteria were treated with a strain of lactobacillus delbrueckii subsp. lactis, which was selected for its ability to produce hydrogen peroxide at refrigerated temperatures. the vegetables inoculated included broccoli, cabbage, carrots, and lettuce. each vegetable was rinsed, chopped, and stored under conditions similar to those used for ready-to-eat vegetables sold at retail. portions of each vegetable were separately inoculated with one of two ...	2003	12801002
reduction of bacteria on pork carcasses associated with chilling method.	in addition to reducing the temperature of pork carcasses immediately after slaughter and before fabrication, blast chilling (snap chill) or conventional chilling can reduce bacterial populations associated with fresh meats. however, there is little information on bacteria survival resulting from the freeze or chill injury of meat products. in this study, porcine fecal slurries with and without pathogens (listeria monocytogenes, salmonella typhimurium, and campylobacter coli) were inoculated ont ...	2003	12801003
antimicrobial properties of commercial annatto extracts against selected pathogenic, lactic acid, and spoilage microorganisms.	annatto preparations are used to impart distinctive flavor and color to foods and are a primary colorant in dairy foods such as cheese and butter. there are several reports indicating that certain fractions of the annatto plant have biological activities against microorganisms of significance in food fermentation, food preservation, and human health. however, little is reported describing the nature of the antimicrobial compound(s) or their potential presence in commercial annatto colorant prepa ...	2003	12801012
modelling the individual cell lag phase. isolating single cells: protocol development.	to develop a protocol to isolate single cells in wells of a microtitre plate, having a high certainty of individual cells, combined with a sufficient yield.	2003	12803551
survivability and long-term preservation of bacteria in water and in phosphate-buffered saline.	to evaluate the suitability of using sterile water and phosphate-buffered saline (pbs) for preservation of bacteria pathogenic to plants or humans.	2003	12803555
enhancement of immune responses to an hiv env dna vaccine by a c-terminal segment of listeriolysin o.	an effective vaccine against aids should induce both cellular and humoral immune responses. here we report that immunization of mice with a dna plasmid encoding a chimeric protein consisting of hiv89.6 env gp140 and the listeriolysin o (llo) c-terminal segment (59 amino acids) significantly enhanced both humoral and cellular immune responses against the hiv89.6 env protein. plasmid dna expression vectors with genes codon-optimized for mammalian expression were synthesized for hiv89.6 gp140 as we ...	2003	12803999
induction of interleukin-12 production in mouse macrophages by berberine, a benzodioxoloquinolizine alkaloid, deviates cd4+ t cells from a th2 to a th1 response.	in this study we investigated whether berberine-mediated induction of interleukin-12 (il-12) production in antigen-presenting cells could regulate a cytokine profile of antigen-primed cd4+ t helper (th) cells. pretreatment with berberine induced il-12 production in both macrophages and dendritic cells, and significantly increased the levels of il-12 production in lipopolysaccharide-stimulated macrophages and in cd40 ligand-stimulated dendritic cells. importantly, berberine pretreatment of macrop ...	2003	12807487
anti-human immunodeficiency virus-gag cd8+ memory t cells generated in vitro from listeria-immunized mice.	the goal of vaccination is the generation of immune memory, an immune state that permits rapid and intense recall responses to a pathogen. considerable effort is being made to understand the nature of memory t cells. we report here that by extending the length of in vitro culture following a single restimulation with specific peptide, preparations of highly enriched, highly active antigen-specific cd8+ memory t cells could be obtained. these cultures were begun with splenocytes from mice primed ...	2003	12807492
comparative study of protective effects of chitin, chitosan, and n-acetyl chitohexaose against pseudomonas aeruginosa and listeria monocytogenes infections in mice.	we conducted a comparative study of the protective effects of chitin, chitosan, and n-acetyl chitohexaose (nacos-6) against mice infected intravenously or intraperitoneally with pseudomonas aeruginosa and listeria monocytogenes. mice pretreated with chitin, chitosan, and nacos-6 showed resistance to intraperitoneal infections by both microbes. only mice pretreated with chitin and chitosan showed resistance to intravenous infections by both microbes. the number, active oxygen generation, and myel ...	2003	12808311
cytosolic delivery of antisense oligonucleotides by listeriolysin o-containing liposomes.	antisense oligodeoxynucleotides (odns) possess great potential as sequence-specific therapeutic agents. sufficient concentrations of intact odn must bypass membrane barriers and access the cytosol and nucleus, for odns to be therapeutically effective. a cytosolic delivery strategy was designed to improve the efficiency of odn delivery in bone-marrow-derived macrophages. this liposome-based formulation utilizes listeriolysin o (llo), the endosomolytic hemolysin from listeria monocytogenes, to med ...	2003	12808441
the effect of processed meat and meat starter cultures on gastrointestinal colonization and virulence of listeria monocytogenes in mice.	listeria monocytogenes is a foodborne pathogen of major concern to the food industry in general and the meat industry in particular. the aim of this study was firstly to identify a strain of listeria that was virulent in spf balb/c mice. secondly, to investigate if a traditional meat starter culture (floracarn) and nontraditional meat starter (ntms) cultures of dairy product and human origin (lactobacillus and bifidobacteria) inhibit this pathogen in vivo. in addition, the inhibition of listeria ...	2003	12810289
relevance of microbial interactions to predictive microbiology.	microbial interaction can be ignored in predictive microbiology under most conditions. we show that interactions are only important at high population densities, using published data on inhibition of growth of listeria monocytogenes in broth. our analysis using growth models from predictive microbiology indicated that interactions only occur at population densities of approximately 10(8) cfu/ml of the protective cultures. spoilage is evident at these levels, except for fermented foods. in bacter ...	2003	12810290
genetic variability among isolates of listeria monocytogenes from food products, clinical samples and processing environments, estimated by rapd typing.	rapd analysis with four primers was used to examine the genetic relationship among 432 strains of listeria monocytogenes isolated from clinical and veterinarian cases of listeriosis, dairy, vegetable, meat- and fish-based food items, environmental samples and samples collected from one transport terminal, one poultry-processing company and four atlantic salmon-processing plants. the purpose of the study was to determine whether clinical isolates belonged to a specific genetic group, whether link ...	2003	12810292
transglutaminase 2-/- mice reveal a phagocytosis-associated crosstalk between macrophages and apoptotic cells.	tissue transglutaminase (tgase2) is a protein-crosslinking enzyme known to be associated with the in vivo apoptosis program. here we report that apoptosis could be induced in tgase2-/- mice; however, the clearance of apoptotic cells was defective during the involution of thymus elicited by dexamethasone, anti-cd3 antibody, or gamma-irradiation, and in the liver after induced hyperplasia. the lack of tgase2 prevented the production of active transforming growth factor-beta1 in macrophages exposed ...	2003	12810961
cytoplasmic bacteria can be targets for autophagy.	autophagy is an important constitutive cellular process involved in size regulation, protein turnover and the removal of malformed or superfluous subcellular components. the process involves the sequestration of cytoplasm and organelles into double-membrane autophagic vacuoles for subsequent breakdown within lysosomes. in this work, we demonstrate that the intracellular pathogen listeria monocytogenes can also be a target for autophagy. if infected macrophages are treated with chloramphenicol af ...	2003	12814436
the uterine nk cell population requires il-15 but these cells are not required for pregnancy nor the resolution of a listeria monocytogenes infection.	during pregnancy in mice, uterine natural killer (unk) cells abundantly accumulate on the mesometrial side of the placenta. in this study, we show that the presence of both mature and immature unk cells requires il-15. bone marrow transplantation of nk cell-negative mice due to null mutations in the recombination-activating gene (rag) 2/common cytokine receptor gamma-chain (rag2(-/-)gamma(c)(-/-)) genes indicated that unk cells originate from the bone marrow and require il-15 to develop. nk cell ...	2003	12816981
class ia mhc-deficient balb/c mice generate cd8+ t cell-mediated protective immunity against listeria monocytogenes infection.	cd8(+) t cells are required for protective immunity against intracellular pathogens such as listeria monocytogenes. in this study, we used class ia mhc-deficient mice, which have a severe reduction in circulating cd8(+) t cells, to determine the protective capacity of class ib mhc-restricted t cells during l. monocytogenes infection. the k(b-/-)d(b-/-) mutation was backcrossed onto a c.b10 (balb/c congenic at h-2 locus with c57bl/10) background, because balb/c mice are more susceptible to lister ...	2003	12817010
cd44-regulated intracellular proliferation of listeria monocytogenes.	cd44 has been implicated in immune and inflammatory processes. we have analyzed the role of cd44 in the outcome of listeria monocytogenes infection in murine bone marrow-derived macrophages (bmm). surprisingly, a dramatically decreased intracellular survival of l. monocytogenes was observed in cd44(-/-) bmm. cd44(-/-) heart or lung fibroblast cultures also showed reduced bacterial levels. moreover, livers from cd44(-/-)-infected mice showed diminished levels of l. monocytogenes. in contrast, int ...	2003	12819101
listeriosis in second trimester of pregnancy: case report from india.	although listeria monocytogenes infection occurs in sporadic and epidemic forms throughout the world, there are certain countries (especially asian countries) that have reported only a few cases or failed to report even a single case. during her third visit at 17(+5) weeks of gestation, a 22-year-old primigravida presented with the complaint of an acute painful abdomen, leaking per vaginum and low-grade fever for the 2 preceding days. on ultrasonography, a single live fetus with no amniotic flui ...	2003	12824687
successful replacement of systemic immunosuppression by local graft irradiation in the management of listeria meningitis.		2003	12826148
infection with listeria monocytogenes following orthotopic liver transplantation: case report and review of the literature.	infection with listeria monocytogenes is rare with a reported annual incidence of 4.4 cases/million individuals. epidemiological data have identified certain groups to be higher risk of developing listeriosis, including neonates, pregnant women, adults older than 60 years of age, individuals afflicted with hematologic malignancies, acquired immunodeficicency syndrome, cirrhosis, and those receiving corticosteroid therapy and organ transplants. within this last group, multiple cases have been des ...	2003	12826201
pathogen, host and environmental factors contributing to the pathogenesis of listeriosis.	listeriosis is a severe human and animal disease caused by two species of pathogenic bacteria from the genus listeria, l. monocytogenes and l. ivanovii. in humans, listeriosis is overwhelmingly a foodborne disease, yet much remains to be learned regarding the transmission dynamics of pathogenic listeria from the environment, through food, to humans. similarly, our understanding of the various host, pathogen and environmental factors that impact the pathogenesis of listeriosis at the cellular and ...	2003	12827280
the smtb/arsr family of metalloregulatory transcriptional repressors: structural insights into prokaryotic metal resistance.	the smtb/arsr family of prokaryotic metalloregulatory transcriptional repressors represses the expression of operons linked to stress-inducing concentrations of di- and multivalent heavy metal ions. derepression results from direct binding of metal ions by these homodimeric "metal sensor" proteins. an evolutionary analysis, coupled with comparative structural and spectroscopic studies of six smtb/arsr family members, suggests a unifying "theme and variations" model, in which individual members h ...	2003	12829264
tumor cell killing enabled by listeriolysin o-liposome-mediated delivery of the protein toxin gelonin.	gelonin is a type i plant toxin that has potential as an effective anti-tumor agent by virtue of its enzymatic capacity to inactivate ribosomes and arrest protein synthesis, thereby effectively limiting the growth of cancer cells. being a hydrophilic macromolecule, however, gelonin has limited access to its target subcellular compartment, the cytosol; it is effectively plasma membrane-impermeant and subject to rapid degradation within endosomes and lysosomes upon cellular uptake as it lacks the ...	2003	12832408
adsa foundation scholar award--an integrated science-based approach to dairy food safety: listeria monocytogenes as a model system.	transmission of food- and milkborne pathogens often involves complex interactions among the pathogen, the environment, and one or multiple host species. a complete understanding of these interactions is critical to allow the development of science-based, effective intervention strategies for foodborne infectious diseases. this article summarizes our studies on the transmission, ecology, pathogenesis and population genetics of listeria monocytogenes, which we have used as model for a food- and mi ...	2003	12836921
effects of carbon dioxide on bacterial growth parameters in milk as measured by conductivity.	inhibition of bacterial growth by dissolved carbon dioxide (co2) has been well established in many foods including dairy foods. however, the effects of dissolved co2 on specific growth parameters such as length of lag phase, time to maximum growth rate, and numbers of organisms at the stationary phase have not been quantified for organisms of concern in milk. the effect of dissolved co2 concentrations of 0.6 to 61.4 mm on specific bacterial growth parameters in raw or single organism inoculated ...	2003	12836927
structural study of binding of flagellin by toll-like receptor 5.	in order to predict the binding regions within the complex formed by toll-like receptor 5 (tlr-5) and flagellin, a complementary hydropathy between the two proteins was sought. a region common to the flagellins of salmonella enterica serovar typhimurium, pseudomonas aeruginosa, and listeria monocytogenes was shown to be hydropathically complementary to the 552-to-561 fragment of tlr-5, whose sequence is eildisrnql. the hydrophobicity profile of this region is shared with flagellins of 377 bacter ...	2003	12837800
salmonella enterica serovar typhimurium and listeria monocytogenes acid tolerance response induced by organic acids at 20 degrees c: optimization and modeling.	an acid tolerance response (atr) has been demonstrated in listeria monocytogenes and salmonella enterica serovar typhimurium in response to low ph poised (i.e., adapted) with acetic or lactic acids at 20 degrees c and modeled by using dynamic differential equations. the atr was not immediate or prolonged, and optimization occurred after exposure of l. monocytogenes for 3 h at ph 5.5 poised with acetic acid and for 2 h at ph 5.5 poised with lactic acid and after exposure of s. enterica serovar ty ...	2003	12839765
temporal stability and biodiversity of two complex antilisterial cheese-ripening microbial consortia.	the temporal stability and diversity of bacterial species composition as well as the antilisterial potential of two different, complex, and undefined microbial consortia from red-smear soft cheeses were investigated. samples were collected twice, at 6-month intervals, from each of two food producers, and a total of 400 bacterial isolates were identified by fourier-transform infrared spectroscopy and 16s ribosomal dna sequence analysis. coryneform bacteria represented the majority of the isolates ...	2003	12839776
early-onset listeriosis in prematurity.	listeria monocytogenes has been recognized as a human pathogen for more than 70 years. it causes illness mainly in pregnant women, newborns, elderly, and immunocompromised persons. although l. monocytogenes is a relatively uncommon pathogen in neonates, it can cause considerable morbidity and mortality in this age group, especially in the early-onset form of the disease. in taiwan, neonatal listeriosis is rarely reported. we report one case of a premature newborn with early-onset listeria sepsis ...	2003	12845854
cutting edge: protective cell-mediated immunity to listeria monocytogenes in the absence of myeloid differentiation factor 88.	in addition to their role in triggering innate immune responses, toll-like receptors are proposed to play a key role in linking the innate and adaptive arms of the immune response. the majority of cellular responses downstream of toll-like receptors are mediated through the adapter molecule myeloid differentiation factor 88 (myd88), and mice with a targeted deletion of myd88 are highly susceptible to bacterial infections, including primary infection with listeria monocytogenes (lm). in contrast, ...	2003	12847214
identification of uteroglobin-related protein 1 and macrophage scavenger receptor with collagenous structure as a lung-specific ligand-receptor pair.	high in normal (hin)-1 is a secreted protein highly expressed in normal breast epithelium and down-regulated in breast carcinomas. by searching genbank expressed sequence tag databases, we identified hin-2, a protein homologous to hin-1. hin-2 is identical with a recently identified protein called uteroglobin-related protein 1 (ugrp1). northern blot analysis demonstrated that ugrp1 is specifically expressed by lung, but not by the other tissues examined. by in situ hybridization experiments, ugr ...	2003	12847263
endogenous bacterial endophthalmitis: a 17-year prospective series and review of 267 reported cases.	endogenous bacterial endophthalmitis is a rare but serious condition that occurs when bacteria cross the blood-ocular barrier and multiply within the eye. we provide an overview of endogenous bacterial endophthalmitis by reviewing 267 reported cases and integrating this with our experience of an additional 19 cases. the majority of patients with endogenous bacterial endophthalmitis are initially misdiagnosed and many have an underlying disease known to predispose to infection. this condition is ...	2003	12850229
design of n-substituted peptomer ligands for evh1 domains.	ena/vasp proteins are implicated in cytoskeletal reorganization during actin-dependent motility processes. recruitment to subcellular sites of actin polymerization is mediated by the highly conserved n-terminal evh1 domain, which interacts with target proteins containing proline-rich motifs. the vasp evh1 domain specifically binds peptides with the consensus motif fpppp present in all its binding partners, including the listerial acta protein. previous studies have shown that the phe and first a ...	2003	12857736
rational approaches to immune regulation.	our laboratory is interested in the properties of proteins that render them immunogenic, and how such immunogenicity may be modulated in vivo. we are attempting to enhance the immune response in the design of more effective vaccines against viral diseases, such as hiv, and against tumor antigens expressed on breast, ovarian, and cervical cancer and b cell lymphomas. our main approach is to use a facultative intracellular bacterium, listeria monocytogenes, which has the unusual ability to live an ...	2003	12857988
application of leuconostoc carnosum for biopreservation of cooked meat products.	to optimize the practical use of the bacteriocin producing leuconostoc carnosum 4010 in order to inhibit the growth of listeria monocytogenes in sliced meat products.	2003	12859754
characteristics and identification of enterocins produced by enterococcus faecium jcm 5804t.	to screen bacteriocin-producing lactic acid bacteria (lab) in 52 type and reference strains, which have not previously been studied, with respect to bacteriocins, and to characterize the presence of bacteriocins.	2003	12859761
typing of listeria monocytogenes isolates by random amplification of polymorphic dna.	listeria monocytogenes is an important food-borne pathogen causing meningitis and septicaemia in newborns and immunocompromised persons, abortion and preterm labour in pregnant women. though various methods are available for typing l. monocytogenes, rapd analysis has been used for epidemiological purposes in developed countries due to its greater discriminating ability. however, as there are no published reports from india on the typing of l. monocytogenes by rapd technique the present study was ...	2003	12866822
an improved amplified fragment length polymorphism (aflp) protocol for discrimination of listeria isolates.	nine restriction enzyme combinations and 108 different primer combinations were initially tested for suitability for amplified fragment length polymorphism (aflp) analysis of listeria monocytogenes; the combination of hindiii and hpych4iv showed consistently strong signals on gels, amplified an adequate number of dna fragments and detected polymorphism among closely related strains based on asci macrorestriction profiles. aflp also distinguished between l. monocytogenes, l. innocua, l. ivanovii, ...	2003	12866850
prevalence and diversity of tetracycline resistant lactic acid bacteria and their tet genes along the process line of fermented dry sausages.	in order to study the prevalence and diversity of tetracycline resistant lactic acid bacteria (tc(r) lab) along the process line of two different fermented dry sausage (fds) types, samples from the raw meat, the meat batter and the fermented end product were analysed quantitatively and qualitatively by using a culture-dependent approach. both the diversity of the tet genes and their bacterial hosts in the different stages of fds production were determined. quantitative analysis showed that all r ...	2003	12866855
gata-3 promotes maturation, ifn-gamma production, and liver-specific homing of nk cells.	the gata-3 transcription factor has a determinant role in t cell specification and is an essential mediator of t helper 2-type polarized immune responses. while both committed nk precursors and mature nk cells express gata-3, a role of this transcription factor in murine nk cell differentiation is not known. we found that nk cells, in contrast to t cells, can be generated in the absence of gata-3. however, while gata-3 antagonizes ifn-gamma production in differentiating t cells, gata-3-deficient ...	2003	14614857
identification and characterization of a peptidoglycan hydrolase, mura, of listeria monocytogenes, a muramidase needed for cell separation.	a novel cell wall hydrolase encoded by the mura gene of listeria monocytogenes is reported here. mature mura is a 66-kda cell surface protein that is recognized by the well-characterized l. monocytogenes-specific monoclonal antibody em-7g1. mura displays two characteristic features: (i) an n-terminal domain with homology to muramidases from several gram-positive bacterial species and (ii) four copies of a cell wall-anchoring lysm repeat motif present within its c-terminal domain. purified recomb ...	2003	14617644
[meningitis due to listeria monocytogenes as a complication of infliximab therapy].		2003	14619208
survival of listeria monocytogenes on sliced cooked sausage after treatment with pediocin ach.	a preparation with pediocin ach bound to its heat-killed producer cells lactobacillus plantarum whe 92 (starter culture alc01, wisby, denmark) by adjusting the ph of the preparation to 6.0 was studied for its effects against listeria monocytogenes atcc 7644 and (spoilage) lactic acid bacteria on sliced cooked sausage. the pediocin ach preparation or 0.9% (w/w) nacl dilution (as a control) were randomly distributed dropwise on the surface of the slices. treated slices were vacuum-packed and store ...	2003	14623394
the vit technology for rapid detection of listeria monocytogenes and other listeria spp.	detection of listeria monocytogenes is generally performed in a two-step cultural enrichment process and takes on average 1 week until the biochemical identification of a l. monocytogenes suspicious colony is completed. however, food processing companies depend increasingly on test methods, which attempt to generate results comparable to standard methods but in reduced time-frame and which allow to release produced batches dependent on such results. in the present study, the vermicon identificat ...	2003	14623395
memory cd8+ t cells provide innate immune protection against listeria monocytogenes in the absence of cognate antigen.	interferon (ifn)-gamma plays an important role in the innate immune response against intracellular bacterial pathogens. it is commonly thought that natural killer cells are the primary source of this cytokine that is involved in activating antibacterial effects in infected cells and polarizing cd4+ t cells toward the th1 subset. however, here we show that both effector and memory cd8+ t cells have the potential to secrete ifn-gamma in response to interleukin (il)-12 and il-18 in the absence of c ...	2003	14623912
carbon starvation survival of listeria monocytogenes in planktonic state and in biofilm: a proteomic study.	the proteomes of listeria monocytogenes expressed in suspension and biofilm state, in the presence and absence of a carbon source, were analysed by two-dimensional electrophoresis with the help of computer software. the up-regulated proteins in each case were identified by peptide sequencing using electrospray ionisation tandem mass spectrometry and a database search against the listeria genome was performed. relevant functions could be attributed to a number of the induced proteins which contri ...	2003	14625868
the possible effect of a sanitization program on intraspecies differentiation of listeria monocytogenes strains isolated from a fish processing plant.	forty-seven listeria monocytogenes strains isolated during a year in a selected polish fish-processing plant as well as 7 l. monocytogenes strains of different origins (including a reference strain) were analyzed in our studies. strains were isolated from raw fish fillets (flounder), frozen coated flounder fillets, coating ingredients, and the processing environment. isolation of strains covered the period of a sanitization program introduced in the plant. l. monocytogenes was identified using c ...	2003	14626905
attraction of a free-living nematode, caenorhabditis elegans, to foodborne pathogenic bacteria and its potential as a vector of salmonella poona for preharvest contamination of cantaloupe.	caenorhabditis elegans was studied to determine the potential role of free-living microbivorous nematodes as vectors for preharvest contamination of fruits and vegetables with foodborne pathogens. the propensity of c. elegans to be attracted to seven strains of escherichia coli o157:h7, eight serotypes of salmonella, six strains of listeria monocytogenes, and cantaloupe juice was investigated. twenty to 30 adult worms were placed on the surface of k agar midway between a 24-h bacterial colony an ...	2003	14627270
radiation (gamma) resistance and postirradiation growth of listeria monocytogenes suspended in beef bologna containing sodium diacetate and potassium lactate.	listeria monocytogenes, a psychrotrophic foodborne pathogen, is a frequent postprocessing contaminant of ready-to-eat (rte) meat products, including frankfurters and bologna. ionizing radiation can eliminate l. monocytogenes from rte meats. when they are incorporated into fine-emulsion sausages, sodium diacetate (sda) and potassium lactate (pl) mixtures inhibit the growth of l. monocytogenes. the radiation resistance of l. monocytogenes, and its ability to proliferate during long-term refrigerat ...	2003	14627282
pressure death and tailing behavior of listeria monocytogenes strains having different barotolerances.	the objectives of this study were to investigate the variability among listeria monocytogenes strains in response to high-pressure processing, identify the most resistant strain as a potential target of pressure processing, and compare the inactivation kinetics of pressure-resistant and pressure-sensitive strains under a wide range (350 to 800 mpa) of pressure treatments. the pressure resistance of listeria innocua and nine strains of l. monocytogenes was compared at 400 or 500 mpa and 30 degree ...	2003	14627283