Publications
| Title | Abstract | Year(sorted ascending) Filter | PMID Filter |
|---|
| use of microbial antagonism to reduce pathogen levels on produce and meat products: a review. | lactic acid bacteria (lab) are often utilized to control food-borne pathogens on produce and on cooked, fermented, or refrigerated meats. most research to date has focused on the inhibition of listeria monocytogenes, escherichia coli o157:h7, salmonella, clostridium botulinum, and spoilage microorganisms. lab are excellent candidates for reducing pathogen levels on foods because they inhibit the growth of these microorganisms through various mechanisms without causing unacceptable sensory change ... | 2006 | 17215892 |
| [evaluation of selected listeria monocytogenes genotyping methods]. | listeria monocytogenes infections are found in poland and all world as sporadic episodes and large outbreaks of human illness as well, where bacteria-contaminated food is the source of infection. genotyping of strains isolated from outbreak is one of many other stages of epidemiologic investigation. in case of l. monocytogenes pulse-field gel electrophoresis (pfge) - "golden standard" of genotyping and also eric-pcr and rep-pcr could be used. the goal of this study was to evaluate the usefulness ... | 2006 | 17642310 |
| [evaluation of api coryne system, version 2.0, for diphteroid gram-positive rods identification with clinical relevance]. | the ability of the api coryne system, version 2.0, to identify 178 strains of gram-positive rods was evaluated. seventy eight isolates belonged to genus corynebacterium and one hundred to related genera, all strains were isolated from clinical samples at the laboratory of bacteriology, hospital de clínicas josé de san martin (uba) between 1995 and 2004. the isolates were identified according to von graevenitz and funke's scheme. one hundred and sixty two out of 178 strains (91%) were correctly i ... | 2006 | 17370571 |
| [foodborne listeria monocytogenes: are all the isolates equally virulent?]. | listeria monocytogenes is a foodborne human pathogen responsible for invasive infections presenting overall a high mortality. despite the ubiquity of the microorganism, the actual disease rate is quite low and the disease is most often associated with an underlying predisposition. foodborne and environmental isolates were traditionally considered of similar pathogenicity compared to clinical isolates. but the analysis of mutations in the genes encoding specific virulence factors (internalin, hem ... | 2006 | 17370579 |
| combination of immunomagnetic separation with flow cytometry for detection of listeria monocytogenes. | listeria monocytogenes can grow at the low temperature commonly used in the storage and transportation of food, and the number of cases of food poisoning caused by l. monocytogenes has increased recently in the us and europe. several methods of detecting l. monocytogenes cells have been proposed; however, all existing methods require approximately 48 h incubation. in this study, we attempted rapid detection of l. monocytogenes using flow cytometry (fcm). the method is based on measuring the numb ... | 2006 | 17723519 |
| new opto-plasmonic tweezers for manipulation and rotation of biological cells--design and fabrication. | opto-plasmonic tweezers are proposed as a new optical manipulator and rotator for biological cells. the approach utilizes polarized light to excite localized surface plasmon resonance (lspr) on an array of au nanostructure. large dielectrophoretic trapping force is expected to be induced by the highly non-uniform scattering field from the resonant oscillating dipoles. fine orientation control of the cells can be realized by tuning the polarization state of the input light. | 2006 | 17946622 |
| bacteriocin production, plasmid content and plasmid location of enterocin p structural gene in enterococci isolated from food sources. | to characterize bacteriocin production, antimicrobial spectrum and plasmid content in bacteriocinogenic enterococci from foods. | 2006 | 16599984 |
| inactivation of salmonella typhimurium and listeria monocytogenes using high-pressure treatments: destruction or sublethal stress? | to investigate potential resuscitation of listeria monocytogenes and salmonella typhimurium after high hydrostatic pressure treatments. | 2006 | 16599988 |
| the development of rapid fluorescence-based immunoassays, using quantum dot-labelled antibodies for the detection of listeria monocytogenes cell surface proteins. | listeria monocytogenes is an important food-borne pathogen with an extremely high mortality rate (approximately 30%). therefore, a highly sensitive, reproducible and rapid assay for its detection is vital. l. monocytogenes cells employ two surface bound proteins, internalin a (inla) and internalin b (inlb) to promote invasion into host cells. recombinant forms of both proteins were previously cloned and expressed in escherichia coli. in this paper we describe how the inlb protein was sub-divided ... | 2006 | 16600361 |
| pulsenet usa: a five-year update. | pulsenet usa is the molecular surveillance network for foodborne infections in the united states. since its inception in 1996, it has been instrumental in detection, investigation and control of numerous outbreaks caused by shiga toxin-producing escherichia coli o157:[h7] (stec o157), salmonella enterica, listeria monocytogenes, shigella spp., and campylobacter. this paper describes the current status of the network, including the methodologies used and its future possibilities. the currently pr ... | 2006 | 16602975 |
| canadian listeriosis reference service. | listeria monocytogenes, a psychrotrophic organism capable of growing at refrigeration temperatures, is of major concern in extended shelf life, refrigerated foods. considering that as much as 80-90% of human listeriosis cases are linked to the ingestion of contaminated food, human cases are predominantly seen in high-risk individuals, including organ-transplant recipients, patients with aids and hiv-infected individuals, pregnant women, cancer patients, and the elderly. in 2001, the canadian lis ... | 2006 | 16602988 |
| a comparison of listeria monocytogenes serovar 4b isolates of clinical and food origin in austria by automated ribotyping and pulsed-field gel electrophoresis. | in this study, two typing methods, automated ribotyping and pulsed-field gel electrophoresis (pfge), were evaluated for the subtyping of listeria monocytogenes serotype 4b. the strains originated from patients and food samples collected in austria during 2001-2005 and from europe and north america in the world health organization collaborative study on the subtyping of this species. the largest group of austrian clinical isolates was of the same pfge subtype as those isolated from foodborne outb ... | 2006 | 16602989 |
| virulence phenotyping and molecular characterization of a low-pathogenicity isolate of listeria monocytogenes from cow's milk. | a low-pathogenicity isolate of listeria monocytogenes from cow's milk, as screened in mouse and chicken embryonated egg models, was examined for virulence-related phenotypic traits. corresponding virulence genes (iap, prfa, plca, hly, mpl, acta, plcb, inla and inlb) were compared with l. monocytogenes reference strains 10403s and egd to elucidate the possible molecular mechanisms of low virulence. although l. monocytogenes h4 exhibited similar patterns to strain 10403s in terms of hemolytic acti ... | 2006 | 16604266 |
| cytosolic recognition of flagellin by mouse macrophages restricts legionella pneumophila infection. | to restrict infection by legionella pneumophila, mouse macrophages require naip5, a member of the nucleotide-binding oligomerization domain leucine-rich repeat family of pattern recognition receptors, which detect cytoplasmic microbial products. we report that mouse macrophages restricted l. pneumophila replication and initiated a proinflammatory program of cell death when flagellin contaminated their cytosol. nuclear condensation, membrane permeability, and interleukin-1beta secretion were trig ... | 2006 | 16606669 |
| membrane perforations inhibit lysosome fusion by altering ph and calcium in listeria monocytogenes vacuoles. | listeria monocytogenes (lm) evade microbicidal defences inside macrophages by secreting a pore-forming cytolysin listeriolysin o (llo), which allows lm to escape vacuoles. llo also inhibits lm vacuole fusion with lysosomes, which indicates llo alters vacuole chemistry prior to release of lm into cytoplasm. using fluorescent probes to measure membrane permeability, calcium and ph, we identified small membrane perforations in vacuoles containing wild-type but not llo-deficient (hly-) lm. the small ... | 2006 | 16611227 |
| redox polymer and probe dna tethered to gold electrodes for enzyme-amplified amperometric detection of dna hybridization. | the detection of nucleic acids based upon recognition surfaces formed by co-immobilization of a redox polymer mediator and dna probe sequences on gold electrodes is described. the recognition surface consists of a redox polymer, [os(2,2'-bipyridine)2(polyvinylimidazole)(10)cl](+/2+), and a model single dna strand cross-linked and tethered to a gold electrode via an anchoring self-assembled monolayer (sam) of cysteamine. hybridization between the immobilized probe dna of the recognition surface a ... | 2006 | 16615783 |
| effect of temperature on synthesis of polyphosphates in yersinia pseudotuberculosis and listeria monocytogenes under starvation conditions. | it was found that at low temperature (6-8 degrees c) in the absence of nitrogen supply and at the presence of phosphate ions in the medium, yersinia pseudotuberculosis and listeria monocytogenes are able to actively synthesize reserve substances as polyphosphates. most of the bacterial polyphosphates are alkali-soluble, especially at the preliminary stage of cell growth (lag-phase). this is proved by electron microscopic studies of ultrastructure of model microorganisms. during a long starvation ... | 2006 | 16615864 |
| cytoplasmic listeria monocytogenes stimulates ifn-beta synthesis without requiring the adapter protein mavs. | the mitochondria-associated adapter protein mavs (also called ips-1, visa or cardif, designated mavs for reasons of simplicity in our manuscript) relays signals from cytoplasmic sensors of viral rna to the irf3 kinase complex and the interferon-beta (ifn-beta) gene. using sirna-mediated knock-down in macrophages we show that ifn-beta synthesis in response to transfected, intracellular double-stranded rna (dsrna), a pathogen-associated molecular pattern of viruses, is decreased in absence of mavs ... | 2006 | 16616525 |
| the mogr transcriptional repressor regulates nonhierarchal expression of flagellar motility genes and virulence in listeria monocytogenes. | flagella are surface structures critical for motility and virulence of many bacterial species. in listeria monocytogenes, mogr tightly represses expression of flagellin (flaa) during extracellular growth at 37 degrees c and during intracellular infection. mogr is also required for full virulence in a murine model of infection. using in vitro and in vivo infection models, we determined that the severe virulence defect of mogr-negative bacteria is due to overexpression of flaa. specifically, overp ... | 2006 | 16617375 |
| detection of genes encoding virulence factors and bacteriocins in fecal enterococci of poultry in portugal. | seventy-six enterococcus isolates (43 e. faecalis, 30 e. faecium, two e. durans, and one e. hirae) recovered from fecal samples of poultry in a slaughterhouse (one isolate per fecal sample and one fecal sample per lot of animals) were studied for bacteriocin production and for the presence of genes encoding bacteriocins and virulence factors. the presence of genes encoding virulence factors (cpd, gee, fsr, ace, agg, and esp) and bacteriocins (enta, entb, entp, entq, entas-48, entl50a/b, cyl, and ... | 2006 | 16617984 |
| serine protease inhibitor 6 protects cytotoxic t cells from self-inflicted injury by ensuring the integrity of cytotoxic granules. | how cytotoxic t lymphocytes (ctls) kill intracellular pathogens without killing themselves has been a recurring question ever since their discovery. by using mice deficient in serine protease inhibitor 6 (spi6), we show that by inhibiting granzyme b (grb), spi6 protects ctls from self-inflicted injury. infection with either lymphocytic choriomeningitis virus (lcmv) or listeria monocytogenes (lm) revealed increased apoptosis and diminished survival of spi6 knockout (ko) ctls, which was cell auton ... | 2006 | 16618603 |
| exploring the role of the ctl epitope region of listeriolysin o in the pathogenesis of listeria monocytogenes. | listeria monocytogenes is a facultative intracellular bacterial pathogen responsible for severe opportunistic infections in humans and animals. the secreted cholesterol-dependent cytolysin, listeriolysin o (llo), mediates phagosomal escape and allows bacterial growth in the cytosol of infected cells. in order to identify new llo determinants participating in bacterial pathogenesis, this study focused on a major target of llo proteolytic cleavage in vitro, the ctl epitope region (residues 91-99). ... | 2006 | 16622046 |
| how the bacterial pathogen listeria monocytogenes mediates the switch from environmental dr. jekyll to pathogenic mr. hyde. | 2006 | 16622185 | |
| macrophage-activation inhibitor factor from l5178y murine lymphoma and formation of hepatic abscesses in balb/c mice. | normal mice are naturally resistant to hepatic abscesses produced by listeria monocytogenes. a macrophage-activation inhibitor factor (maif) isolated from the cell-free ascitic fluid of l5178y lymphoma-bearing mice inhibited the lipopolysaccharide-induced production of nitric oxide (no) by the macrophages. because macrophages are also involved in the immune response towards l. monocytogenes, the present study had the objective of investigating whether maif was also capable of allowing l. monocyt ... | 2006 | 16624645 |
| enhanced bacterial clearance and sepsis resistance in caspase-12-deficient mice. | caspases function in both apoptosis and inflammatory cytokine processing and thereby have a role in resistance to sepsis. here we describe a novel role for a caspase in dampening responses to bacterial infection. we show that in mice, gene-targeted deletion of caspase-12 renders animals resistant to peritonitis and septic shock. the resulting survival advantage was conferred by the ability of the caspase-12-deficient mice to clear bacterial infection more efficiently than wild-type littermates. ... | 2006 | 16625199 |
| validation of a traditional italian-style salami manufacturing process for control of salmonella and listeria monocytogenes. | italian-style salami batter (formulated with pork shoulder) was inoculated with ca. 7.0 log cfu/g of either salmonella or listeria monocytogenes. salami links (55-mm cellulose casings) were fermented at 30 degrees c for 24, 40, or 72 h and then dried to target moisture/protein ratios (mprs) of 1.9:1 or 1.4:1. links were sampled after fermentation (24, 40, and 72 h) and after combined fermentation-drying treatments (mprs of 1.9:1 and 1.4:1 for all fermentation periods), and microbiological and pr ... | 2006 | 16629021 |
| death of salmonella, escherichia coli o157:h7, and listeria monocytogenes in shelf-stable, dairy-based, pourable salad dressings. | the objectives of this study were to determine the death rates of salmonella, escherichia coli o157:h7, and listeria monocytogenes in three commercially manufactured full-fat ranch salad dressings, three reduced-fat ranch salad dressings, two full-fat blue cheese salad dressings, and two reduced-fat blue cheese salad dressings and to affirm the expectation that these dressings do not support the growth of these pathogens. the respective initial ph values of the four types of shelf-stable, dairy- ... | 2006 | 16629022 |
| prevalence and typing of listeria monocytogenes in raw catfish fillets. | raw channel catfish fillets collected from three processing plants during four time periods were tested for the presence of listeria species. listeria monocytogenes was the predominant listeria species found in these catfish fillets, with 25 to 47% prevalence. other listeria species, such as l. welshimeri, l. innocua, l. ivanovii, l. grayi, and l. seeligeri, were also found. l. monocytogenes isolates were further fingerprinted by a repetitive element pcr. forty distinctive electrophoretic types ... | 2006 | 16629023 |
| growth of listeria monocytogenes in fresh-cut coconut as affected by storage conditions and inoculum size. | in this study, the effects of packaging atmosphere (air and modified atmosphere, 65% n2, 30% co2, and 5% o2), temperature (2, 4, 8, and 12 degrees c) and inoculum size (low inoculum, 102 cfu/g; high inoculum, 5 x 10(5) cfu/g) on the growth of listeria monocytogenes in minimally processed coconut were investigated. growth data were fitted to the gompertz equation, and the sanitary risk time (the time, in days, necessary to observe an increase of 2 log cfu/g in the level of the pathogen) was also ... | 2006 | 16629024 |
| formation of biofilm at different nutrient levels by various genotypes of listeria monocytogenes. | strains of listeria monocytogenes differ in their ability to form biofilms. the objectives of this study were to determine whether genetically related strains have similar biofilm-forming capacities and what effect nutrient concentration has on the ability of different strains to produce biofilms. biofilms of 30 strains of l. monocytogenes, obtained from a variety of sources were grown on stainless steel in tryptic soy broth (tsb) or in a 1:10 dilution of tsb (dtsb) for 24 h at 32 degrees c. the ... | 2006 | 16629025 |
| molecular typing to trace listeria monocytogenes isolated from cold-smoked fish to a contamination source in a processing plant. | in this study, listeria monocytogenes contamination in a cold-smoked fish processing plant in osaka, japan, was examined from 2002 to 2004. a total of 430 samples were collected and divided into five categories: raw fish, materials during processing, processing equipment, environment, and finished products. a total of 59 finished products were examined throughout this study. l. monocytogenes was isolated from four of these samples during summer and autumn but was not found during winter or sprin ... | 2006 | 16629026 |
| comparison of listeria monocytogenes virulence in a mouse model. | listeriosis results from exposure to the foodborne pathogen listeria monocytogenes. although many different strains of l. monocytogenes are isolated from food, no definitive tests currently predict which isolates are most virulent. the objectives of this study were to address two major data gaps for risk assessors, variability among l. monocytogenes strains in pathogenicity and virulence. strains used in our monkey clinical trial or additional food isolates were evaluated for their virulence and ... | 2006 | 16629027 |
| prevalence and concentration of listeria monocytogenes in sliced ready-to-eat meat products in the hellenic retail market. | the aim of this work was to estimate the prevalence and concentration of listeria monocytogenes in packaged precut (slices or cubes) ready-to-eat (rte) meat products available in the hellenic retail market. samples of these rte meat products (n = 209) were taken from local supermarkets during a 3-month period and analyzed for the presence of l. monocytogenes with an automated enzymatic qualitative immunoassay followed by biochemical confirmation of positive results. the concentration of the path ... | 2006 | 16629044 |
| interactions of nisin with glutathione in a model protein system and meat. | loss of nisin activity in meat has been ascribed, in part, to the formation of a nisin-glutathione adduct. activity is lost more quickly in raw meat than in cooked meat, and this has been taken as evidence that the reaction is enzyme mediated. formation of the nisin-glutathione adduct has been confirmed but is shown not to be enzyme mediated. retention of activity in cooked meat is shown to be due to the loss of free sulfhydryl groups during cooking as a result of the reaction of glutathione wit ... | 2006 | 16629047 |
| effect of environmental stresses on antibody-based detection of escherichia coli o157:h7, salmonella enterica serotype enteritidis and listeria monocytogenes. | to study the reaction patterns of selected antibodies to escherichia coli o157:h7, salmonella enterica serotype enteritidis and listeria monocytogenes cells exposed to various environmental stresses. | 2006 | 16630002 |
| optimization of the components concentrations of the lactoperoxidase system by rsm. | the aim of this work was to use response surface methodology (rsm) approach, a statistical mathematical tool, to model effects and interactions of glucose oxidase (god), glucose, lactoperoxidase (lpo) and ph-values on the thiocyanate (scn-) peroxidation, to determine the best concentrations of lactoperoxidase system (lp-s) components in order to obtain maximal scn- peroxidation and so to enhance the lp-s antibacterial effects. | 2006 | 16630004 |
| coexpression of virulence and fosfomycin susceptibility in listeria: molecular basis of an antimicrobial in vitro-in vivo paradox. | discrepancies between resistance in vitro and therapeutic efficacy in vivo are generally attributed to failure of laboratory susceptibility tests to reflect an antibiotic's pharmacokinetic or pharmacodynamic properties. we show here that this phenomenon can result from differential in vitro-in vivo expression of bacterial determinants of antibiotic susceptibility. we found that an in vivo-induced virulence factor, hpt, also mediates uptake of fosfomycin in listeria monocytogenes. these bacteria ... | 2006 | 16633349 |
| quantitative and simultaneous detection of four foodborne bacterial pathogens with a multi-channel spr sensor. | we report the quantitative and simultaneous detection of four species of bacteria, escherichia coli o157:h7, salmonella choleraesuis serotype typhimurium, listeria monocytogenes, and campylobacter jejuni, using an eight-channel surface plasmon resonance (spr) sensor based on wavelength division multiplexing. detection curves showing spr response versus analyte concentration were established for each species of bacteria in buffer at ph 7.4, apple juice at native ph 3.7, and apple juice at an adju ... | 2006 | 16635568 |
| unidirectional development of cd8+ central memory t cells into protective listeria-specific effector memory t cells. | three distinct subsets of antigen-experienced cd8(+) t cells have been identified so far: short-living effector t cells (t(ec)) and two long-living subsets, described as central (t(cm)) and effector memory (t(em)) t cells. the lineage relationships of these subpopulations as well as their involvement in protection have not yet been conclusively determined. we recently described a novel marker combination (cd127 and cd62l) to identify all three major cd8(+) t cell subsets in mice infected with li ... | 2006 | 16637009 |
| roche/biotecon diagnostics lightcycler foodproof l. monocytogenes detection kit in combination with shortprep foodproof ii kit. performance-tested method 070401. | a method was developed for the detection of l. monocytogenes in food based on real-time polymerase chain reaction (pcr). this advanced pcr method was designed to reduce the time needed to achieve results from pcr reactions and to enable the user to monitor the amplification of the pcr product simultaneously, in real-time. after dna isolation using the roche/biotecon diagnostics shortprep foodproof ii kit (formerly called listeria shortprep kit) designed for the rapid preparation of l. monocytoge ... | 2006 | 16640287 |
| leucocins 4010 from leuconostoc carnosum cause a matrix related decrease in intracellular ph of listeria monocytogenes. | a mixed culture of single cells of listeria monocytogenes and the bacteriocin producing leuconostoc carnosum 4010 showed growth inhibition of l. monocytogenes, although the intracellular ph (phi) of l. monocytogenes followed by fluorescence ratio imaging microscopy was not affected. furthermore, l. monocytogenes was exposed to the bacteriocins leucocins 4010 and nisin either in a liquid filled chamber or on the surface of an agar containing bacteriocins. both bacteriocins caused dissipation of t ... | 2006 | 16640575 |
| cellular accumulation and activity of quinolones in ciprofloxacin-resistant j774 macrophages. | ciprofloxacin is the substrate for a multidrug resistance-related protein (mrp)-like multidrug transporter in j774 mouse macrophages, which also modestly affects levofloxacin but only marginally affects garenoxacin and moxifloxacin (j.-m. michot et al., antimicrob. agents chemother. 49:2429-2437, 2005). two clones of ciprofloxacin-resistant cells were obtained by a stepwise increase in drug concentration (from 34 to 51 to 68 mg/liter) in the culture fluid. compared to wild-type cells, ciprofloxa ... | 2006 | 16641436 |
| bacterial entry into cells: a role for the endocytic machinery. | increasing evidence indicates that pathogens have evolved highly efficient strategies to induce their internalization within host cells. viruses and bacteria express and expose on their surface, molecules that mimic endogenous ligands to cell receptors, thereby inducing specific intracellular signalling cascades. more recently it has become clear that, as most viruses, bacteria can enter cells via the clathrin-mediated pathway, indicating a key role for endocytosis in pathogens entry into cells. ... | 2006 | 16650411 |
| elemental analysis of the mycobacterium avium phagosome in balb/c mouse macrophages. | using a hard x-ray microprobe, we showed recently that in unstimulated peritoneal macrophages from c57bl/6 mice, the phagosome of pathogenic mycobacteria (mycobacterium tuberculosis and mycobacterium avium) can accumulate iron. we expanded our studies to the m. avium infection of peritoneal macrophages of balb/c mice that show a similar degree of m. tuberculosis and m. avium-related chronic disease, but a higher susceptibility towards other intracellular pathogens such as listeria monocytogenes, ... | 2006 | 16650826 |
| cytokine modulation of the innate immune response in feline immunodeficiency virus-infected cats. | in vitro data suggest that innate immune function in human immunodeficiency virus type 1-infected patients is compromised; however, in vivo studies are lacking. feline immunodeficiency virus (fiv) infection in cats provides an excellent model to explore innate immune function in vivo. the innate response against listeria monocytogenes is well understood, making it a useful immune probe. | 2006 | 16652280 |
| listeriosis due to infection with a catalase-negative strain of listeria monocytogenes. | a strain of listeria monocytogenes recovered from blood and cerebrospinal fluid had no detectable catalase activity, a characteristic used for primary identification. the sporadic occurrence of pathogenic catalase-negative strains highlights the need for a reconsideration of diagnostic criteria and questions the role of catalase in the pathogenesis of listeria infection. | 2006 | 16672441 |
| control of listeria spp. by competitive-exclusion bacteria in floor drains of a poultry processing plant. | in previous studies workers determined that two lactic acid bacterium isolates, lactococcus lactis subsp. lactis c-1-92 and enterococcus durans 152 (competitive-exclusion bacteria [ce]), which were originally obtained from biofilms in floor drains, are bactericidal to listeria monocytogenes or inhibit the growth of l. monocytogenes both in vitro and in biofilms at 4 to 37 degrees c. we evaluated the efficacy of these isolates for reducing listeria spp. contamination of floor drains of a plant in ... | 2006 | 16672472 |
| role of efflux pumps in adaptation and resistance of listeria monocytogenes to benzalkonium chloride. | in this study, potential mechanisms underlying resistance and adaptation to benzalkonium chloride (bc) in listeria monocytogenes were investigated. two groups of strains were studied. the first group consisted of strains naturally sensitive to bc which could be adapted to bc. the second group consisted of naturally resistant strains. for all adapted isolates, there was a correlation between the resistance to bc and ethidium bromide, but this was not the case for the naturally resistant isolates. ... | 2006 | 16672496 |
| listeric meningoencephalomyelitis in a cougar (felis concolor): characterization by histopathologic, immunohistochemical, and molecular methods. | listeria monocytogenes has been recognized as an important food-borne pathogen in animals. records of the disease caused by this bacterium in large felids are, however, rare. the nervous form of listeriosis was diagnosed in a 12-year-old male cougar (felis concolor) with a several-day history of neurologic disease characterized by excess salivation, head pressing, and circling that progressed to recumbency and death. microscopically, the main alteration in the brain and spinal cord was a variabl ... | 2006 | 16672590 |
| the bacterial quality of red meat and offal in casablanca (morocco). | the present study aimed to evaluate the bacteriological quality of beef (n = 52), lamb (n = 52) and beef offal (n = 52) marketed in casablanca, morocco. meat and offal samples (n = 156), were collected randomly from butcheries, supermarkets, and slaughterhouses. two sampling periods were considered, one during the hot season and the second one during the cold season. the samples were analyzed for the presence of the following bacteria: escherichia coli, coagulase-positive staphylococcus, clostri ... | 2006 | 16676376 |
| bactericidal effects of cao (scallop-shell powder) on foodborne pathogenic bacteria. | this study was investigated the bactericidal effects of calcium oxide (cao) on three common foodborne pathogenic bacteria: escherichia coli, listeria monocytogenes, and salmonella typhimurium. each bacteria level was determined in a cao solution (0.01, 0.03, 0.05, 0.10, 0.15, and 0.20% [w/v]) exposed for either 15 sec, 30 sec, 1 min, 2 min, 3 min, 5 min, 10 min, or 30 min. all three bacteria were not greatly affected by cao solutions at concentrations of 0.01 and 0.03%, however, the decline of e ... | 2006 | 16681035 |
| co-detection of bartonella henselae, borrelia burgdorferi, and anaplasma phagocytophilum in ixodes pacificus ticks from california, usa. | presence of bartonella dna was explored in 168 questing adult ixodes pacificus ticks from santa cruz county, california. bartonella henselae type i dna was amplified from 11 ticks (6.55%); previously, two (1.19%) were found to be infected with borrelia burgdorferi and five (2.98%) with anaplasma phagocytophilum. detection of b. henselae was not dependent on co-infection. the present study offers additional evidence that ixodes spp. ticks may act as hosts and possibly vectors for b. henselae. | 2006 | 16584332 |
| dependence of the lethal effect of pore-forming haemolysins of gram-positive bacteria on cytolytic activity. | among bacterial haemolysins, cholesterol-dependent cytolysins (cdcs) produced by various gram-positive bacteria are known to exhibit a lethal activity in mice. in this study, recombinant cdcs of streptolysin o, pneumolysin, ivanolysin o, listeriolysin o and several listeriolysin o mutants were constructed and the relationship between cytolytic activity and the lethal activity of each recombinant protein in mice was examined. specific activity for cytolysis was determined by a quantitative haemol ... | 2006 | 16585635 |
| construction and analysis of fractional multifactorial designs to study attachment strength and transfer of listeria monocytogenes from pure or mixed biofilms after contact with a solid model food. | the aim of this study was to establish which of seven factors influence the adhesion strength and hence bacterial transfer between biofilms containing listeria monocytogenes (pure and two-species biofilms) and tryptone soya agar (tsa) as a solid organic surface. the two-species biofilms were made of l. monocytogenes and one of the following species of bacteria: the nonpathogenic organisms kocuria varians, pseudomonas fluorescens, and staphylococcus sciuri and ccl 63, an unidentified gram-negativ ... | 2006 | 16597925 |
| bioenergetic mechanism for nisin resistance, induced by the acid tolerance response of listeria monocytogenes. | this study examined the bioenergetics of listeria monocytogenes, induced to an acid tolerance response (atr). changes in bioenergetic parameters were consistent with the increased resistance of atr-induced (atr(+)) cells to the antimicrobial peptide nisin. these changes may also explain the increased resistance of l. monocytogenes to other lethal factors. atr(+) cells had lower transmembrane ph (deltaph) and electric potential (deltapsi) than the control (atr(-)) cells. the decreased proton moti ... | 2006 | 16597957 |
| assessment of the roles of luxs, s-ribosyl homocysteine, and autoinducer 2 in cell attachment during biofilm formation by listeria monocytogenes egd-e. | luxs is responsible for the production of autoinducer 2 (ai-2), which is involved in the quorum-sensing response of vibrio harveyi. ai-2 is found in several other gram-negative and gram-positive bacteria and is therefore considered a good candidate for an interspecies communication signal molecule. in order to determine if this system is functional in the gastrointestinal pathogen listeria monocytogenes egd-e, an ai-2 bioassay was performed with culture supernatants. the results indicated that t ... | 2006 | 16597969 |
| novel luciferase reporter system for in vitro and organ-specific monitoring of differential gene expression in listeria monocytogenes. | in this paper we describe construction of a luciferase-based vector, ppl2lux, and use of this vector to study gene expression in listeria monocytogenes. ppl2lux is a derivative of the listerial integration vector ppl2 and harbors a synthetic luxabcde operon encoding a fatty acid reductase complex (luxcde) involved in synthesis of the fatty aldehyde substrate for the bioluminescence reaction catalyzed by the luxab luciferase. we constructed ppl2lux derivatives in which the seca and hlya promoters ... | 2006 | 16597994 |
| adhesion characteristics of listeria adhesion protein (lap)-expressing escherichia coli to caco-2 cells and of recombinant lap to eukaryotic receptor hsp60 as examined in a surface plasmon resonance sensor. | listeria adhesion protein (lap) is an important adhesion factor in listeria monocytogenes and interacts with its cognate receptor, mammalian heat shock protein 60 (hsp60). the genetic identity of lap was determined to be alcohol acetaldehyde dehydrogenase (aad). a recombinant escherichia coli strain expressing aad confirmed the involvement of aad in adhesion to caco-2 cells. binding kinetics (ka) of recombinant lap (rlap) to hsp60 was examined in a surface plasmon resonance sensor and was determ ... | 2006 | 16499624 |
| bayesian synthesis of a pathogen growth model: listeria monocytogenes under competition. | the bayesian synthesis method is applied to data from two studies of listeria monocytogenes grown in broth monocultures to draw inferences about the joint distribution of two baranyi growth model parameters-lag time and maximum specific growth rate. the resultant joint distribution is then combined with prior distributions for the initial and maximum pathogen density parameters under competitive growth conditions. finally, the pathogen growth model is updated using the sampling/importance resamp ... | 2006 | 16499986 |
| autoinducer-2 bioassay is a qualitative, not quantitative method influenced by glucose. | autoinducer-2 (ai-2) is a cell-to-cell signaling molecule which is thought to be utilized for quorum sensing processes by a variety of prokaryotic species. this molecule is usually detected using a so-called autoinducer bioassay, which relies on the ability of a vibrio harveyi reporter strain to produce light in response to ai-2. however, as previously reported, the presence of glucose in the sample can inhibit the bioluminescence of the reporter strain, a fact that is often ignored by investiga ... | 2006 | 16564586 |
| secondary memory cd8+ t cells are more protective but slower to acquire a central-memory phenotype. | the formation of memory cd8 t cells is an important goal of vaccination. however, although widespread use of booster immunizations in humans generates secondary and tertiary cd8 t cell memory, experimental data are limited to primary cd8 t cell memory. here, we show that, compared with primary memory cd8 t cells, secondary memory cd8 t cells exhibit substantially delayed conversion to a central-memory phenotype, as determined by cd62l expression and interleukin (il)-2 production. this delayed co ... | 2006 | 16567385 |
| multiplex real-time single nucleotide polymorphism detection and quantification by quencher extension. | multiplex quencher extension (multiplex-qext) is a novel closed tube single-step method for detection and quantification of several single nucleotide polymorphisms (snps) simultaneously. the principle of multiplex-qext is that 5' reporter-labeled probes are 3' single-base-extended with tamra dideoxy nucleotides if the respective snp alleles are present. tamra can serve as either an energy acceptor (quencher-based detection) or donor [fluorescence resonance energy transfer (fret)-based detection] ... | 2006 | 16568821 |
| in vivo bactofection: listeria can function as a dna-cancer vaccine. | the development of an effective therapeutic vaccine to induce cancer-specific immunity remains an unsolved yet pressing priority requiring novel vaccine strategies. here we have generated a series of vaccines in which bacteria deliver a plasmid encoding a tumor antigen under the control of a mammalian promoter in an attempt to induce an antitumor immune response. utilizing a plasmid release mechanism involving the suicide of the carrier bacteria, we were able to engineer listeria monocytogenes t ... | 2006 | 16569193 |
| bac 32, a novel bacteriocin widely disseminated among clinical isolates of enterococcus faecium. | a total of 636 vancomycin-resistant enterococcus faecium (vre) isolates that had been obtained between 1994 and 1999 from the medical school hospital of the university of michigan, ann arbor, were tested for bacteriocin production. two hundred seventy-seven (44%) of the strains were bacteriocinogenic; and 193 of these exhibited activity against enterococcus faecium, enterococcus hirae, and enterococcus durans. strain vre200 harbors the highly efficient conjugative gentamicin resistance plasmid p ... | 2006 | 16569830 |
| n-3 pufa fail to affect in vivo, antigen-driven cd8+t-cell proliferation in the spleen of naïve mice. | one of the most frequently reported immunomodulatory actions of n-3 pufa is their ability to diminish in vitro lymphocyte proliferation. the purpose of this study was to determine if n-3 pufa intake affects the kinetics or magnitude of the antigen-driven expansion of cd8(+)t-lymphocytes in vivo. in this study we utilized a well-characterized model of t-cell immunity (i.e. infection with the intracellular bacterium, listeria monocytogenes). weanling balb/c mice were fed one of two experimental di ... | 2006 | 16571165 |
| [investigation of relationships between marine diatoms and the bacterium listeria monocytogenes]. | relationships between marine diatoms and the bacterium listeria monocytogenes have been studied by routine algological methods and high-resolution video-enhanced differential interference contrast light microscopy. the study showed that the relationship between the listeria and the benthic diatom navicula sp. has a parasitic character, whereas the relationship between the listeria and the planktonic diatom phaeodactylum tricornutum is protocooperative. | 2006 | 16579449 |
| associations among listeria monocytogenes genotypes and distinct clinical manifestations of listeriosis in cattle. | to determine whether specific strains of listeria monocytogenes, as determined by genetic characteristics and virulence phenotypes, were associated with distinct clinical manifestations of listeriosis in cattle and thus may potentially have tissue specificity. | 2006 | 16579754 |
| recombinant escherichia coli expressing invasin targets the peyer's patches: the basis for a bacterial formulation for oral vaccination. | we have investigated the tropism of nonpathogenic recombinant invasive escherichia coli in the gastrointestinal tract and the efficacy of this invasive e. coli as an oral vaccine for cancer immunotherapy. e. coli expressing invasin from yersinia pseudotuberculosis selectively invade nonphagocytic cells in which beta(1)-integrin is expressed and accessible. following internalization the e. coli are degraded in the phagosome. coexpression of listeriolysin o (llo) mediates release of the content of ... | 2006 | 16581299 |
| consumer phase risk assessment for listeria monocytogenes in deli meats. | the foodborne disease risk associated with the pathogen listeria monocytogenes has been the subject of recent efforts in quantitative microbial risk assessment. building upon one of these efforts undertaken jointly by the u.s. food and drug administration and the u.s. department of agriculture (usda), the purpose of this work was to expand on the consumer phase of the risk assessment to focus on handling practices in the home. one-dimensional monte carlo simulation was used to model variability ... | 2006 | 16492183 |
| risk assessment of listeria monocytogenes: impact of individual cell variability on the exposure assessment step. | recently, the lag phase research in predictive microbiology is focusing more on the individual cell variability, especially for pathogenic microorganisms that typically occur in very low contamination levels, like listeria monocytogenes. in this study, the effect of this individual cell lag phase variability was introduced in an exposure assessment study for l. monocytogenes in a liver pâté. a basic framework was designed to estimate the contamination level of pâté at the time of consumption, ta ... | 2006 | 16492184 |
| the onset of cd8+-t-cell contraction is influenced by the peak of listeria monocytogenes infection and antigen display. | the cd8+-t-cell response to infection with listeria monocytogenes consists of expansion, contraction, and memory phases. the transition between expansion and contraction is reported to occur on different days postinfection with virulent (8 to 9 days) and attenuated (deltaacta) (7 days) l. monocytogenes strains. we hypothesized that differences in the infectious courses, and therefore antigen (ag) display, determine the precise time of the expansion/contraction transition in response to these inf ... | 2006 | 16495523 |
| induced biliary excretion of listeria monocytogenes. | listeria monocytogenes is a ubiquitous gram-positive bacterium that can cause systemic and often life-threatening disease in immunocompromised hosts. this organism is largely an intracellular pathogen; however, we have determined that it can also grow extracellularly in animals, in the lumen of the gallbladder. the significance of growth in the gallbladder with respect to the pathogenesis and spread of listeriosis depends on the ability of the bacterium to leave this organ and be disseminated to ... | 2006 | 16495556 |
| characteristics of listeria monocytogenes isolated from imported meat in japan. | the genomic structure of the iap region in listeria monocytogenes (serovar 4b), isolated from chicken imported into japan, was compared with those from japanese strains. the isolate was similar to the japanese strains in a comparatively new, rare group. such strains might be imported from foreign countries. | 2006 | 16495636 |
| [neonatal maculopapular exanthema revealing septicemia due to klebsiella pneumoniae via maternofetal infection]. | neonatal exanthema of bacterial origin is caused very rarely by gram-negative bacilli. we report a case of neonatal maculopapular exanthema evocative of klebsiella pneumoniae septicemia resulting from maternofetal infection. | 2006 | 16495848 |
| pathogen reduction in unpasteurized apple cider: adding cranberry juice to enhance the lethality of warm hold and freeze-thaw steps. | u.s. food and drug administration (fda) regulations require processors of apple cider sold wholesale to use processing steps that ensure a 5-log reduction in numbers of the pertinent pathogen, generally considered to be escherichia coli o157:h7. current widely used validated pathogen-reduction steps are thermal pasteurization and uv light treatment. these techniques may be unaffordable or undesirable for some processors. this study investigated the cran-cider process, which is the addition of cr ... | 2006 | 16496568 |
| attributing risk to listeria monocytogenes subgroups: dose response in relation to genetic lineages. | the objective of this study was to evaluate the hypothesis that the dose-response relationship for listeria monocytogenes in humans varies with genotypic lineage or subtype. the linkages between molecular subtyping data and enumeration data for l. monocytogenes subtypes in foods consumed by the at-risk population were examined to test this hypothesis. we applied a conditional probability model to conduct a subtype-specific dose-response analysis, with the focus on invasive listeriosis. l. monocy ... | 2006 | 16496574 |
| a solid agar overlay method for recovery of heat-injured listeria monocytogenes. | a solid agar overlay method was developed for recovery of heat-injured listeria monocytogenes. presolidified nonselective tryptic soy agar with 0.6% yeast extract (tsaye, 2% agar) was overlaid on top of solidified modified oxford agar (mox). heat injury of l. monocytogenes was conducted at 58 degrees c for 6 min in a jacketed flask filled with tryptic soy broth. both noninjured and heat-treated l. monocytogenes cells were plated onto tsaye, mox, and tsaye-mox plates. no significant differences ( ... | 2006 | 16496588 |
| acidified sodium chlorite treatment for inhibition of listeria monocytogenes growth on the surface of cooked roast beef. | the effects of acidified sodium chlorite (asc) against listeria monocytogenes on the surface of cooked roast beef were investigated. l. monocytogenes, strain v7, serotype 1/2a, was inoculated at numbers of 6.0 log cfu/g onto 5-g cubes of cooked regular or spicy roast beef. the samples were allowed to air dry for 1 h. the cooked roast beef samples were dipped into asc or sprayed with asc solutions of 250, 500, 750, or 1,000 ppm, then placed in bags with or without a vacuum and refrigerated at 4 d ... | 2006 | 16496589 |
| prevalence and genetic characterization of listeria monocytogenes in retail broiler meat in estonia. | the prevalence and genetic diversity of listeria monocytogenes in raw broiler legs at the retail level in estonia were studied. a total of 240 raw broiler legs (120 from estonia and 120 of foreign origin, which had been imported to estonia from denmark, finland, hungary, sweden, and the united states) from 12 retail stores in the two largest cities in estonia (tallinn and tartu) were investigated from january to december 2002. of these, 70% were positive for l. monocytogenes. the prevalence of l ... | 2006 | 16496590 |
| incidence of enterohemorrhagic escherichia coli, escherichia coli o157, salmonella, and listeria monocytogenes in retail fresh ground beef, sprouts, and mushrooms. | the objective of this study was to determine the prevalence of enterohemorrhagic escherichia coli (ehec), e. coli o157, salmonella, and listeria monocytogenes in retail food samples from seattle, wash. a total of 2,050 samples of ground beef (1,750 samples), mushrooms (100 samples), and sprouts (200 samples) were collected over a 12-month period and analyzed for the presence of these pathogens. pcr assays, followed by culture confirmation were used to determine the presence or absence of each or ... | 2006 | 16496591 |
| radiation processing to ensure safety of minimally processed carrot (daucus carota) and cucumber (cucumis sativus): optimization of dose for the elimination of salmonella typhimurium and listeria monocytogenes. | minimally processed vegetables are in demand, because they offer convenience to consumers. however, these products are often unsafe because of possible contamination with pathogens, such as salmonella, escherichia coli o157:h7, and shigella species. therefore, this study was carried out to optimize the radiation dose necessary to ensure the safety of precut carrot and cucumber. decimal reduction doses (d-values) of salmonella typhimurium mtcc 98 were ca. 0.164 kgy in carrot samples and 0.178 kgy ... | 2006 | 16496592 |
| surface pasteurization of vacuum-sealed precooked ready-to-eat meat products. | pathogens may contaminate ready-to-eat meat products after cooking but before packaging. listeria monocytogenes is a formidable contaminant in the food processing environment and is relatively heat resistant compared with other non-spore-forming pathogens. as a consequence, this microorganism is commonly chosen for evaluation in postpackage pasteurization studies. the aim of this study was to review information on the thermal surface pasteurization of vacuum-sealed precooked ready-to-eat meat pr ... | 2006 | 16496595 |
| ladr, a new padr-related transcriptional regulator from listeria monocytogenes, negatively regulates the expression of the multidrug efflux pump mdrl. | the listeria monocytogenes genome encodes putative multidrug efflux transporters but only the mdrl transporter has been partially characterized in the wild-type lo28 strain. here, we show in the lo28 strain, that the expression of mdrl is repressed at the transcriptional level, under standard growth conditions, by the product of a new gene ladr (lmo1408), and the expression of mdrl is induced in the presence of rhodamine. phylogenetic analysis in related firmicutes shows that ladr, conserved in ... | 2006 | 16451184 |
| liposome-doped nanocomposites as artificial-cell-based biosensors: detection of listeriolysin o. | listeriolysin o (llo) is a pore-forming hemolysin secreted by the foodborne pathogen listeria monocytogenes and is required for bacterial virulence. current detection methods for l. monocytogenes are time-consuming, labor-intensive, and expensive, which is impractical considering the limitations of food storage. to overcome these problems, we developed a liposome-doped silica nanocomposite as a simple, inexpensive, and highly stable biosensor material that mimics existing whole-cell assays for l ... | 2006 | 16454489 |
| the wild-derived inbred mouse strain spret/ei is resistant to lps and defective in ifn-beta production. | although activation of toll-like receptor 4 (tlr4)-positive cells is essential for eliminating gram-negative bacteria, overactivation of these cells by the tlr4 ligand lps initiates a systemic inflammatory reaction and shock. here we demonstrate that spret/ei mice, derived from mus spretus, exhibit a dominant resistance against lps-induced lethality. this resistance is mediated by bone marrow-derived cells. macrophages from these mice exhibit normal signaling and gene expression responses that d ... | 2006 | 16455798 |
| production, characterisation and potential application of a novel monoclonal antibody for rapid identification of virulent listeria monocytogenes. | a panel of hybridomas was produced using intact listeria monocytogenes serotype 1/2a cells as the immunogen. an igg2a monoclonal antibody (mab) 'mab2b3' was isolated that reacted with l. monocytogenes but not with a representative panel of related listeria spp. and non-listeria spp. binding activity was greatest against l. monocytogenes serotype 1/2a and was significantly enhanced when cells were prepared in listeria enrichment broth (leb). the reactive epitope was deduced, by immunoblot analysi ... | 2006 | 16457899 |
| patho-biotechnology: using bad bugs to do good things. | pathogenic bacteria have evolved sophisticated strategies to overcome host defences, to interact with the immune system and to interfere with essential host systems. we coin the term 'patho-biotechnology' to describe the exploitation of these valuable traits in biotechnology, medicine and food. this approach shows promise for the development of novel vaccine and drug delivery systems, as well as for the design of more technologically robust and effective probiotic cultures with improved biotechn ... | 2006 | 16459072 |
| h2-m3-restricted cd8+ t cells are not required for mhc class ib-restricted immunity against listeria monocytogenes. | studies using major histocompatibility complex (mhc)-ia-deficient mice have shown that mhc-ib-restricted cd8+ t cells can clear infections caused by intracellular pathogens such as listeria monocytogenes. m3-restricted cd8+ t cells, which recognize short hydrophobic n-formylated peptides, appear to comprise a substantial portion of the mhc-ib-restricted t cell response in the mouse model of l. monocytogenes infection. in this study, we isolated formyltransferase (fmt) mutant strains of l. monocy ... | 2006 | 16461341 |
| reliable and rapid identification of listeria monocytogenes and listeria species by artificial neural network-based fourier transform infrared spectroscopy. | differentiation of the species within the genus listeria is important for the food industry but only a few reliable methods are available so far. while a number of studies have used fourier transform infrared (ftir) spectroscopy to identify bacteria, the extraction of complex pattern information from the infrared spectra remains difficult. here, we apply artificial neural network technology (ann), which is an advanced multivariate data-processing method of pattern analysis, to identify listeria ... | 2006 | 16461640 |
| biocontrol of the food-borne pathogens listeria monocytogenes and salmonella enterica serovar poona on fresh-cut apples with naturally occurring bacterial and yeast antagonists. | fresh-cut apples contaminated with either listeria monocytogenes or salmonella enterica serovar poona, using strains implicated in outbreaks, were treated with one of 17 antagonists originally selected for their ability to inhibit fungal postharvest decay on fruit. while most of the antagonists increased the growth of the food-borne pathogens, four of them, including gluconobacter asaii (t1-d1), a candida sp. (t4-e4), discosphaerina fagi (st1-c9), and metschnikowia pulcherrima (t1-e2), proved ef ... | 2006 | 16461659 |
| determination of essential and variable residues in pediocin pa-1 by nnk scanning. | pediocin pa-1 is an antimicrobial peptide (called bacteriocin) that shows inhibitory activity against the food-borne pathogen listeria monocytogenes. to elucidate which residue(s) is responsible for this function, the antimicrobial activities of pediocin pa-1 mutants were evaluated and compared. each of the 44 native codons was replaced with the nnk triplet oligonucleotide in a technique termed nnk scanning, and 35 mutations at each position were examined for antimicrobial activities using a mod ... | 2006 | 16461660 |
| two subpopulations of listeria monocytogenes occur at subinhibitory concentrations of leucocin 4010 and nisin. | in situ analyses of single listeria monocytogenes cells at subinhibitory concentrations of leucocin 4010 and nisin revealed two subpopulations when measured by fluorescence ratio imaging microscopy (frim) after staining with 5(6)-carboxyfluorescein diacetate succinimidyl ester. one subpopulation consisted of cells with a dissipated ph gradient (deltaph), and the other consisted of cells that maintained deltaph. the proportion of cells belonging to each subpopulation was estimated, and the concen ... | 2006 | 16461719 |
| caenorhabditis elegans is a model host for listeria monocytogenes. | here we report that caenorhabditis elegans nematodes fed listeria monocytogenes die over the course of several days, as a consequence of an accumulation of bacteria in the worm intestine. mutant strains previously shown to be important for virulence in mammalian models were also found to be attenuated in their virulence in c. elegans. however, acta, which is required for actin-based intracellular motility, appears to be dispensable during infection of c. elegans, indicating that l. monocytogenes ... | 2006 | 16461732 |
| 13c isotopologue perturbation studies of listeria monocytogenes carbon metabolism and its modulation by the virulence regulator prfa. | the carbon metabolism of listeria monocytogenes (lm) egd and the two isogenic mutant strains lmdeltaprfa and lmdeltaprfapprfa* (showing no or enhanced expression, respectively, of the virulence factor prfa) was determined by 13c isotopologue perturbation. after growth of the bacteria in a defined medium containing a mixture of [u-13c6]glucose and glucose with natural 13c abundance (1:25, wt/wt), 14 amino acids were isolated and analyzed by nmr spectroscopy. multiply 13c-labeled isotopologues wer ... | 2006 | 16461909 |
| sensor molecules in intestinal innate immunity against bacterial infections. | toll-like receptors (tlrs) and nucleotide-binding oligomerization domain (nod)-containing proteins are innate immune sensors for microbial signature molecules. this review highlights new insights into the functions of these sensors in intestinal physiology. | 2006 | 16462163 |
| population-based incidence of infection with selected bacterial enteric pathogens in children younger than five years of age, 1996-1998. | previous studies of bacterial enteric infections have suggested a disproportionate disease burden for children younger than 5 years of age. | 2006 | 16462289 |
| monocyte emigration from bone marrow during bacterial infection requires signals mediated by chemokine receptor ccr2. | monocytes recruited to tissues mediate defense against microbes or contribute to inflammatory diseases. regulation of the number of circulating monocytes thus has implications for disease pathogenesis. however, the mechanisms controlling monocyte emigration from the bone marrow niche where they are generated remain undefined. we demonstrate here that the chemokine receptor ccr2 was required for emigration of ly6c(hi) monocytes from bone marrow. ccr2(-/-) mice had fewer circulating ly6c(hi) monoc ... | 2006 | 16462739 |
| species specificity of the listeria monocytogenes inlb protein. | inla and inlb mediate l. monocytogenes entry into eukaryotic cells. inla is required for the crossing of the intestinal and placental barriers. inla uses e-cadherin as receptor in a species-specific manner. the human e-cadherin but not the mouse e-cadherin is a receptor for inla. in human cells, inlb uses met and gc1qr as receptors. by studying the role of inlb in vivo, we found that activation of met by inlb is species-specific. in mice, inlb is important for liver and spleen colonization, but ... | 2006 | 16469057 |
| genomic dissection of microbial pathogenesis in cultured drosophila cells. | recent rna interference screens that were performed at a genome-wide level have identified host factors that are important for the growth of listeria monocytogenes in cultured cells from the fruit fly drosophila melanogaster. the screens identified genes that are involved in phagocytosis but did not detect genes known to be involved in immune signaling pathways. these studies provide a foundation for the identification of host factors and virulence mechanisms. | 2006 | 16473012 |
| listeria monocytogenes internalins are highly diverse and evolved by recombination and positive selection. | to probe the evolution of internalins with confirmed or suspected roles in listeria monocytogenes virulence we sequenced the full inlb, inlc2, inlc, inld, inle, inlf, inlg, and inlh orfs from 40 l. monocytogenes isolated from human (n=10) and animal (n=10) clinical cases, foods (n=10), and the natural environment (n=10). inlb and inle were present in all isolates, representing 26 and 20 alleles, respectively. inlc was found in all lineage i and ii isolates and represented 21 alleles. inlc2 and i ... | 2006 | 16473049 |