| listeria monocytogenes surface proteins: from genome predictions to function. | the genome of the human food-borne pathogen listeria monocytogenes is predicted to encode a high number of surface proteins. this abundance likely reflects the ability of this bacterium to survive in diverse environments, including soil, food, and the human host. this review focuses on the various mechanisms by which listerial proteins are attached at the bacterial surface and their many functions, including peptidoglycan metabolism, protein processing, adhesion to host cells, and invasion of ho ... | 2007 | 17554049 |
| type ii phosphatidylinositol 4-kinases promote listeria monocytogenes entry into target cells. | interaction of the listeria surface protein inlb with the hepatocyte growth factor receptor met activates signalling events that trigger bacterial internalization into mammalian epithelial cells. we show here that purified phagosomes containing inlb-coated beads display type ii phosphatidylinositol 4-kinase (pi4k) activity. in human epithelial hela cells, both pi4kiialpha and pi4kiibeta isoforms are corecruited with met around inlb-coated beads or wild-type listeria during the early steps of int ... | 2007 | 17555516 |
| initial t cell receptor transgenic cell precursor frequency dictates critical aspects of the cd8(+) t cell response to infection. | adoptive-transfer experiments with relatively large input numbers ( approximately 10(6)) of t cell receptor-transgenic (tcr-tg) t cells are widely used to model endogenous t cell responses to infection or immunization. we show that input numbers of naive tcr-tg t cells sufficient to squelch the endogenous response to the same epitope substantially alter the kinetics, proliferative expansion, phenotype, and efficiency of memory generation by the tcr-tg t cells in response to infection. thus, resp ... | 2007 | 17555991 |
| probabilistic modeling approach for evaluating the compliance of ready-to-eat foods with new european union safety criteria for listeria monocytogenes. | among the new microbiological criteria that have been incorporated in eu regulation 2073/2005, of particular interest are those concerning listeria monocytogenes in ready-to eat (rte) foods, because for certain food categories, they no longer require zero tolerance but rather specify a maximum allowable concentration of 100 cfu/g or ml. this study presents a probabilistic modeling approach for evaluating the compliance of rte sliced meat products with the new safety criteria for l. monocytogenes ... | 2007 | 17557858 |
| nonsense-mutated inla and prfa not widely distributed in listeria monocytogenes isolates from ready-to-eat seafood products in japan. | inla is a surface protein participating in the entry of listeria monocytogenes into mammalian non-phagocytic cells. prfa is a positive regulatory factor that regulates the expression of a set of virulence genes. recent studies revealed that some l. monocytogenes strains have a truncated form of these proteins because of nonsense mutations in their sequences, and these truncations contribute to the significant reduction in virulence of this pathogen. in this study, sequence analyses of inla and p ... | 2007 | 17566579 |
| antibacterial properties and major bioactive components of cinnamon stick (cinnamomum burmannii): activity against foodborne pathogenic bacteria. | cinnamomum burmannii blume (cinnamon stick) from indonesia is a little-investigated spice. in this study, the antibacterial activity, minimum inhibitory concentration (mic), and minimum bactericidal concentration (mbc) of cinnamon stick extract were evaluated against five common foodborne pathogenic bacteria (bacillus cereus, listeria monocytogenes, staphylococcus aureus, escherichia coli, and salmonella anatum). cinnamon stick extract exhibited significant antibacterial properties. major compou ... | 2007 | 17567030 |
| structure and mechanism of the genomically encoded fosfomycin resistance protein, fosx, from listeria monocytogenes. | the fosfomycin resistance protein, fosx, catalyzes the hydration of the antibiotic fosfomycin, (1r,2s)-epoxypropylphosphonic acid. genes encoding the enzyme are found in several pathogenic microorganisms. the structure and mechanism of action of the genomically encoded fosx enzyme from listeria monocytogenes (fosxlmatcc) obtained from the american type culture collection are reported. the gene harbors 31 point mutations, and as a consequence, the protein differs in 10 amino acid residues from th ... | 2007 | 17567049 |
| listeria monocytogenes evades killing by autophagy during colonization of host cells. | listeria monocytogenes is an intracellular pathogen that is able to colonize the cytosol of macrophages. here we examined the interaction of this pathogen with autophagy, a host cytosolic degradative pathway that constitutes an important component of innate immunity towards microbial invaders. l. monocytogenes infection induced activation of the autophagy system in macrophages. at 1 h post infection (p.i.), a population of intracellular bacteria ( approximately 37%) colocalized with the autophag ... | 2007 | 17568179 |
| oxygen restriction increases the infective potential of listeria monocytogenes in vitro in caco-2 cells and in vivo in guinea pigs. | listeria monocytogenes has been implicated in several food borne outbreaks as well as sporadic cases of disease. increased understanding of the biology of this organism is important in the prevention of food borne listeriosis. the infectivity of listeria monocytogenes scotta, cultivated with and without oxygen restriction, was compared in vitro and in vivo. fluorescent protein labels were applied to allow certain identification of listeria cells from untagged bacteria in in vivo samples, and to ... | 2007 | 17570840 |
| [listeria monocytogenes encephalitis revealed by left progressive hemiparesis]. | central nervous system listeriosis is a diagnostic and therapeutic challenge for the clinician. | 2007 | 17571028 |
| [listeriosis in a patient with hemodialysis and iron overload]. | a case of listeriosis in a patient undergoing long-term hemodialysis is reported. the 69-year-old man with chronic renal failure due to polycystic renal dysplasia had received hemodialysis treatment for 10 years. renal anemia and iron overload developed within this time. in the course of a hemodialysis the patient presented with malaise, chills and fever to 38.7 degrees c. blood culture specimens were obtained and the patient received ampicillin-sulbactam. blood culture specimens subsequently sh ... | 2007 | 17571224 |
| inactivation of escherichia coli and listeria monocytogenes on iceberg lettuce by dip wash treatments with organic acids. | to study and compare the efficacy of organic acids and chlorine dipping in inactivation of escherichia coli and listeria monocytogenes on fresh-cut iceberg lettuce. | 2007 | 17576223 |
| novel protein targets of the humoral immune response to listeria monocytogenes infection in rabbits. | the role of the humoral immune response in protective immunity against listerial infection has been overlooked and is essentially unknown. this study aimed to discover the protein targets of listeria monocytogenes that elicit an antibody response following infection in a rabbit model. a genomic expression library for l. monocytogenes was constructed and differentially screened to identify genes encoding proteins that reacted with antiserum from rabbits infected with live l. monocytogenes serotyp ... | 2007 | 17577052 |
| action of divergicin m35, a class iia bacteriocin, on liposomes and listeria. | the mode of action of divergicin m35, a class iia bacteriocin, was studied against listeria monocytogenes with sensitive (divs) and resistant (divm) phenotypes, as well as on synthetic phospholipid liposomes. | 2007 | 17578415 |
| identification of a macrophage antigen-processing event required for i-region-restricted antigen presentation to t lymphocytes. j. immunol. 1981. 127: 1869-1875. | | 2007 | 17579013 |
| manipulating the rate of memory cd8+ t cell generation after acute infection. | infection with listeria monocytogenes elicits expansion in numbers of ag-specific cd8+ t cells, which then undergo programmed contraction. the remaining cells undergo further phenotypic and functional changes with time, eventually attaining the qualities of memory cd8+ t cells. in this study, we show that l. monocytogenes-specific cd8+ t cell populations primed in antibiotic-pretreated mice undergo brief effector phase, but rapidly develop phenotypic (cd127(high), cd43(low)) and functional (gran ... | 2007 | 17579021 |
| a reduced antigen load in vivo, rather than weak inflammation, causes a substantial delay in cd8+ t cell priming against mycobacterium bovis (bacillus calmette-guérin). | regardless of the dose of ag, ag presentation occurs rapidly within the first few days which results in rapid expansion of the cd8+ t cell response that peaks at day 7. however, we have previously shown that this rapid priming of cd8+ t cells is absent during infection of mice with mycobacterium bovis (bacillus calmette-guérin (bcg)). in this study, we have evaluated the mechanisms responsible for the delayed cd8+ t cell priming. because bcg replicates poorly and survives within phagosomes we co ... | 2007 | 17579040 |
| nod1/rick and tlr signaling regulate chemokine and antimicrobial innate immune responses in mesothelial cells. | mesothelial cells that line the serous cavities and outer surface of internal organs are involved in inflammatory responses induced by microbial stimuli and bacterial infection. upon exposure to bacterial products, mesothelial cells secrete chemokines, but the signaling pathways by which these cells recognize bacteria to mediate innate immune responses remain largely unknown. we report that stimulation of primary peritoneal mesothelial cells via nucleotide-binding oligomerization domain (nod)1, ... | 2007 | 17579072 |
| listeria infections associated with infliximab: case reports. | infliximab is a human-murine chimeric monoclonal antibody directed against tumor necrosis factor alpha (tnfalpha). infliximab and other tnf blockers are used to treat inflammatory diseases such as rheumatoid arthritis (ra). tnf blockers are suspected to play a key role in some infections. we report here two cases of listeria monocytogenes sepsis associated with infliximab treatment for ra. the first patient developed a terminal ileitis and a bacteraemia after three doses of infliximab; the secon ... | 2007 | 17579802 |
| evaluation of quantitative recovery methods for listeria monocytogenes applied to stainless steel. | the ability of listeria monocytogenes to attach to various food contact surfaces, such as stainless steel, polypropylene, and rubber compounds, is well documented. the retention of these or other pathogenic bacteria on food contact surfaces increases the risk of transmission to food products. the objective of this study was to compare several methods for quantitative recovery of listeria monocytogenes from stainless steel surfaces. a cocktail of 4 serotypes of listeria monocytogenes mixed in equ ... | 2007 | 17580634 |
| acid adaptation and survival of listeria monocytogenes in italian-style soft cheeses. | the ability of listeria monocytogenes to survive and grow at high salt concentrations and low ph makes it a potential hazard after the consumption of milk and dairy products, often implicated in severe outbreaks of listeriosis. this study was designed to evaluate the behaviour of l. monocytogenes in traditional acid and salted italian-style soft cheeses and to investigate whether listeria occurrence and growth in these environments may represent a potential increase of hazard. | 2007 | 17584464 |
| microplate fluorescence assay for measurement of the ability of strains of listeria monocytogenes from meat and meat-processing plants to adhere to abiotic surfaces. | listeria monocytogenes is a significant food-borne pathogen that is capable of adhering to and producing biofilms on processing equipment, making it difficult to eliminate from meat-processing environments and allowing potential contamination of ready-to-eat (rte) products. we devised a fluorescence-based microplate method for screening isolates of l. monocytogenes for the ability to adhere to abiotic surfaces. strains of l. monocytogenes were incubated for 2 days at 30 degrees c in 96-well micr ... | 2007 | 17586676 |
| characterization of new l,d-endopeptidase gene product cwlk (previous ycdd) that hydrolyzes peptidoglycan in bacillus subtilis. | bacillus subtilis has various cell wall hydrolases, however, the functions and hydrolase activities of some enzymes are still unknown. b. subtilis cwlk (ycdd) exhibits high sequence similarity with the peptidoglycan hydrolytic l,d-endopeptidase (ply500) of listeria monocytogenes phage and cwlk has the vany motif which is a d-alanyl-d-alanine carboxypeptidase (pfam: http://www.sanger.ac.uk/software/pfam/). the beta-galactosidase activity observed on cwlk-lacz fusion indicated that the cwlk gene w ... | 2007 | 17588176 |
| sepsis and meningitis due to listeria monocytogenes. | this study focused on the effect of immuno-compromising conditions on the clinical presentation of severe listerial infection. patients and | 2007 | 17594151 |
| epsilon-poly-l-lysine and nisin a act synergistically against gram-positive food-borne pathogens bacillus cereus and listeria monocytogenes. | to test epsilon-poly-l-lysine and nisin a for possible synergistic activity against selected food-borne pathogens and food spoilage organisms. | 2007 | 17594454 |
| irreversible loss of membrane-binding activity of listeria-derived cytolysins in non-acidic conditions: a distinct difference from allied cytolysins produced by other gram-positive bacteria. | listeriolysin o (llo), a member of the cholesterol-dependent cytolysin (cdc) family, is a major virulence factor of listeria monocytogenes and contributes to bacterial escape from intracellular killing of macrophages. llo is activated under weakly acidic conditions; however, the molecular mechanism of this ph-dependent expression of cytolytic activity of llo is poorly understood. in this study, cdcs including llo, ivanolysin o (ilo), seeligeriolysin o (lso), pneumolysin (ply), streptolysin o (sl ... | 2007 | 17600069 |
| antimicrobial susceptibility of listeria monocytogenes from food products. | this study was conducted to determine the susceptibility of listeria monocytogenes isolated from food products to antimicrobial agents commonly used for treatment of infections with gram-positive bacteria, and to disinfectants. a total of 114 l. monocytogenes retail isolates were tested for susceptibility to ceftiofur, chloramphenicol, ciprofloxacin, erythromycin, florfenicol, penicillin, spectinomycin, streptomycin, tetracycline, tiamulin, trimethoprim, and co-trimoxazole, and the disinfectants ... | 2007 | 17600489 |
| distribution of internalin gene profiles of listeria monocytogenes isolates from different sources associated with phylogenetic lineages. | listeria monocytogenes is a human foodborne pathogen with a broad range of hosts. while the l. monocytogenes genome encodes a number of internalins, which are leucine-rich repeat bacterial surface proteins with putative or confirmed roles in host cell attachment and invasion, the specific function of many internalins remains unclear. the distribution of 7 internalin genes (inlc, inlc2, inld, inle, inlf, inlg, and inlh) in 120 l. monocytogenes isolates from humans, foods, and animals was investig ... | 2007 | 17600490 |
| introduction to united states department of agriculture vetnet: status of salmonella and campylobacter databases from 2004 through 2005. | in 2003 the united states department of agriculture established usda vetnet. it was modeled after pulsenet usa, the national molecular subtyping network for foodborne disease surveillance. the objectives of usda vetnet are: to use pulsed-field gel electrophoresis (pfge) to subtype zoonotic pathogens submitted to the animal arm of the national antimicrobial resistance monitoring system (narms); examine vetnet and pulsenet pfge patterns; and use the data for surveillance and investigation of suspe ... | 2007 | 17600492 |
| construction and evaluation of a microbiological positive process internal control for pcr-based examination of food samples for listeria monocytogenes and salmonella enterica. | pcr assays for food-borne pathogens are widely available but have had more limited application to food testing compared with their use in clinical laboratories. when testing food samples, false negative pcr results can occur and may be due to interference with target-cell lysis necessary for nucleic acid extraction, nucleic acid degradation and/or direct inhibition of the pcr. therefore, it is essential to include appropriate controls for the application of pcr to the detection of pathogens in f ... | 2007 | 17604864 |
| a novel promoter trap identifies listeria monocytogenes promoters expressed at a low ph within the macrophage phagosome. | the gram-positive pathogen listeria monocytogenes encounters acid environments in low-ph foods, during passage through the stomach and within the macrophage phagosome during systemic infection. a novel promoter-trap system termed pgad-hly was developed, based on a plasmid containing a promoterless copy of gadb (required for survival at low ph) and hly (whose product facilitates escape from the macrophage phagosome) to identify loci that are induced under different stress conditions in vitro as w ... | 2007 | 17608802 |
| antimicrobial effects of a microemulsion and a nanoemulsion on enteric and other pathogens and biofilms. | some microemulsions and nanoemulsions may have antimicrobial properties and be effective anti-biofilm agents. we examined the abilities of two fine emulsions, designated bctp and teop, to inactivate suspensions of vegetative cells of salmonella spp. escherichia coli 0157:h7 (vt-), pseudomonas aeruginosa, staphylococcus aureus and listeria monocytogenes. bctp is an o/w nanoemulsion of soybean oil and tri-n-butyl phosphate emulsified with triton x-100, while teop is an o/w microemulsion of ethyl o ... | 2007 | 17610974 |
| effects of inoculation level, material hydration, and stainless steel surface roughness on the transfer of listeria monocytogenes from inoculated bologna to stainless steel and high-density polyethylene. | the influence of inoculation level, material hydration, and stainless steel surface roughness on the transfer of listeria monocytogenes from inoculated bologna to processing surfaces (stainless steel and polyethylene) was assessed. slices of bologna (14 g) were inoculated with listeria at different levels, from 10(5) to 10(9) cfu/cm2. transfer experiments were done at a constant contact time (30 s) and pressure (45 kpa) with a universal testing machine. after transfer, cells that had been transf ... | 2007 | 17612072 |
| predicting microbial heat inactivation under nonisothermal treatments. | the aim of this study was to develop an equation that accurately predicts microbial heat inactivation under nonisothermal treatments at constantly rising heating rates (from 0.5 to 5 degrees c/min) in media with different ph values (4.0 or 7.4). the survival curves of all bacteria (enterococcus faecium, escherichia coli, listeria monocytogenes, salmonella senftenberg 775w, salmonella typhimurium, and staphylococcus aureus) tested under isothermal treatments were nearly linear. for the most heat- ... | 2007 | 17612077 |
| low prevalence of listeria monocytogenes in foods from italy. | listeria monocytogenes is an important foodborne pathogen that causes gastrointestinal disorders, and, especially in immunocompromised people, serious extraintestinal diseases, such as septicemia and meningitis, as well as abortion in pregnant women. many foods, from both plant and animal origin, have been involved in listeriosis outbreaks. this article reports the results of a 12-year survey (1993 through 2004) on the presence of l. monocytogenes in several kinds of food marketed in italy. of 5 ... | 2007 | 17612085 |
| traceback identification of an ingredient (pork dewlap) as the possible source of listeria monocytogenes serotype 4b contamination in raw chicken products. | in surveys conducted on finished product samples from a single poultry processing plant in spain, listeria monocytogenes was found in 14 different uncooked products. to track contamination patterns, 77 l. monocytogenes isolates were characterized by pcr-based serotyping, pulsed-field gel electrophoresis (pfge) restriction analysis, and pcr-based allelic analysis of the virulence gene acta. serotyping revealed that 12 isolates (15.6%) were of the l. monocytogenes serotype 4b complex (serotype 4b ... | 2007 | 17612086 |
| combined effect of packaging atmosphere and storage temperature on growth of listeria monocytogenes on ready-to-eat shrimp. | cooked, peeled, and deveined shrimp were inoculated with a 5 strain mixture of listeria monocytogenes and packaged in air, vacuum, and a 100% carbon dioxide modified atmosphere. the packaged shrimp were then stored at 3, 7, and 12 degrees c for 15 days to monitor the growth of l. monocytogenes and psychrotrophic bacteria. uninoculated shrimp were also subjected to sensory evaluation by a trained panel to measure odor and appearance over the storage period. results demonstrated that shrimp packag ... | 2007 | 17613367 |
| prevalence and level of listeria monocytogenes and other listeria species in retail pre-packaged mixed vegetable salads in the uk. | as part of the european commission (ec) co-ordinated programme for 2005, a study of pre-packaged ready-to-eat (rte) mixed salads containing meat or seafood ingredients from retail premises was undertaken in the uk to determine the frequency and level of listeria monocytogenes in these products. almost all (99.8%; 2682/2686) samples were of satisfactory/acceptable microbiological quality. two (0.1%) samples exceeded ec legal food safety criteria due to the presence of l. monocytogenes in excess o ... | 2007 | 17613368 |
| class i/class iia bacteriocin cross-resistance phenomenon in listeria monocytogenes. | variants resistant to nisin a (va), nisin z (vz), pediocin pa-1 (vp), divergicin m35 (vd) and to bacteriocin-like compounds produced by bifidobacterium thermophilum subsp. infantis rbl67 (vb) were developed from listeria monocytogenes lsd530. lactic acid production, specific growth rate, potassium ion efflux, susceptibility to 13 antibiotics, cell-envelope fatty acid composition and bacteriocin cross-resistance were evaluated. lactic acid production decreased to 75% or less of that by strain lsd ... | 2007 | 17613369 |
| inactivation kinetics of inoculated escherichia coli o157:h7, listeria monocytogenes and salmonella enterica on strawberries by chlorine dioxide gas. | inactivation kinetics of inoculated escherichia coli o157:h7, listeria monocytogenes and salmonella enterica on strawberries by chlorine dioxide gas at different concentrations (0.5, 1, 1.5, 3 and 5 mgl(-1)) for 10 min were studied. a cocktail of three strains of each targeted organism (100 microl) was spotted onto the surface of the strawberries (approximately 8-9 log ml(-1)) separately followed by air drying, and then treated with clo(2) gas at 22 degrees c and 90-95% relative humidity. approx ... | 2007 | 17613371 |
| description of the bacteriocins produced by two strains of enterococcus faecium isolated from italian goat milk. | in this study two strains of enterococcus faecium, m241 and m249, isolated from goat milk, were studied for their capability to produce antibacterial compounds. it was determined that the bacteriocins produced by both strains were active towards listeria monocytogenes and clostridium butyricum, and they did not have any activity with respect to other species of lactic acid bacteria. enterocins a and b were targeted by polymerase chain reaction (pcr) and sequenced, after cloning, in both strains. ... | 2007 | 17613373 |
| growth and bacteriocin production by lactic acid bacteria in vegetable broth and their effectiveness at reducing listeria monocytogenes in vitro and in fresh-cut lettuce. | the fresh-cut fruit and vegetable industry is searching for alternatives to replace chemical treatments with biopreservative approaches that ensure the safety of the product and fulfil consumer preferences for minimally processed foods. in this study, the use of bacteriocins produced by lactic acid bacteria has been tested as a substitute for chemical disinfection of fresh-cut iceberg lettuce. first, the ability of several non-plant origin bacteriocinogenic strains (nisin z(+), plantaricin c(+), ... | 2007 | 17613374 |
| effect of a simple chlorine dioxide method for controlling five foodborne pathogens, yeasts and molds on blueberries. | the effect of aqueous chlorine dioxide (clo(2)) on controlling foodborne pathogens, yeasts, and molds on blueberries was studied. five pathogens were spot-inoculated on the skin of blueberries. a sachet containing necessary chemicals for generation of clo(2) was used to provide 320 ppm of clo(2) in 7.5 l of water. the efficacy of different concentrations (1, 3, 5, 10, and 15 ppm) of clo(2) and various contact times (10s; 1, 5, 10, 20, 30 min; and 1h and 2h) were studied. clo(2) was most effectiv ... | 2007 | 17613378 |
| active bacterial myocarditis: a case report and review of the literature. | bacterial myocarditis (bm) is an uncommon cause of infectious myocarditis. bm is usually seen in the context of overwhelming sepsis or as part of a specific bacterial syndrome. the definitive diagnosis of bacterial myocarditis requires biopsy or morphologically proven active myocarditis with evidence of bacterial invasion or positive tissue cultures. the management of bacterial myocarditis consists of aggressive and early antibiotic or anti-toxin treatment, appropriate hemodynamic support, and t ... | 2007 | 17613408 |
| bacteriocin-based strategies for food biopreservation. | bacteriocins are ribosomally-synthesized peptides or proteins with antimicrobial activity, produced by different groups of bacteria. many lactic acid bacteria (lab) produce bacteriocins with rather broad spectra of inhibition. several lab bacteriocins offer potential applications in food preservation, and the use of bacteriocins in the food industry can help to reduce the addition of chemical preservatives as well as the intensity of heat treatments, resulting in foods which are more naturally p ... | 2007 | 17614151 |
| nucleoside analogues are activated by bacterial deoxyribonucleoside kinases in a species-specific manner. | to investigate the bactericidal activity of antiviral and anticancer nucleoside analogues against a variety of pathogenic bacteria and characterize the activating enzymes, deoxyribonucleoside kinases (dnks). | 2007 | 17615154 |
| type i ifn induction in response to listeria monocytogenes in human macrophages: evidence for a differential activation of ifn regulatory factor 3 (irf3). | listeria monocytogenes is a prototypic bacterium for studying innate and adaptive cellular immunity as well as host defense. using human monocyte-derived macrophages, we report that an infection with a wild-type strain, but not a listeriolysin o-deficient strain, of the gram-positive bacterium l. monocytogenes induces expression of ifn-beta and a bioactive type i ifn response. investigating the activation of signaling pathways in human macrophages after infection revealed that a wild-type strain ... | 2007 | 17617610 |
| listeriology (1926-2007): the rise of a model pathogen. | listeria monocytogenes is an ubiquitous gram positive bacterium responsible for a severe food borne disease in human and animals which has become a multifaceted model. indeed, it is a facultative intracellular bacterium that induces an amazingly rapid and sterilizing t-cell response and has been--and still is--widely used by immunologists. listeria's strategies to invade non-phagocytic cells and spread from cell to cell have been and still are outstandingly instrumental to address key questions ... | 2007 | 17618157 |
| src, cortactin and arp2/3 complex are required for e-cadherin-mediated internalization of listeria into cells. | listeria monocytogenes is a food-borne pathogen able to invade non-phagocytic cells. inla, a l. monocytogenes surface protein, interacts with human e-cadherin to promote bacterial entry. l. monocytogenes internalization is a dynamic process involving co-ordinated actin cytoskeleton rearrangements and host cell membrane remodelling at the site of bacterial attachment. interaction between e-cadherin and catenins is required to promote listeria entry, and for the establishment of adherens junctions ... | 2007 | 17627624 |
| rapid determination of multi-locus sequence types of listeria monocytogenes by microtemperature-gradient gel electrophoresis. | this report presents a new method for identifying multi-locus sequence types of listeria monocytogenes by microtemperature-gradient gel electrophoresis (mu-tgge). genomic comparison of l. monocytogenes serovar 1/2a strains egd-e and f6854 allowed selection of novel polymorphic sequences lmo0386 and lmo0428 as optimum regions for mu-tgge analysis, in addition to the previously identified lmo0297 gene. sequence analysis of a total of 48 standard strains revealed that the strains could be grouped i ... | 2007 | 17628727 |
| prevalence of listeria monocytogenes in fresh and fermented italian sausages and ribotyping of contaminating strains. | listeria monocytogenes has been detected in fresh as well as dry and semidry fermented sausages, rendering preparation and consumption of these products as a potential risk to human health. the aims of this study were (1) to evaluate the l. monocytogenes prevalence in 288 fresh and 237 fermented sausages produced in northern italy; (2) to quantify the average pathogen most probable number (mpn) per g of sausage; (3) to evaluate the sausage strain genetic diversity by automated pvuii ribotyping; ... | 2007 | 17629582 |
| use of antimicrobial biodegradable packaging to control listeria monocytogenes during storage of cooked ham. | the antimicrobial effect against l. monocytogenes of biodegradable films (alginate, zein and polyvinyl alcohol) containing enterocins was investigated. survival of the pathogen was studied by means of challenge tests performed at 6 degrees c during 8 and 29 days, for air-packed and vacuum-packed sliced cooked ham, respectively. air packaging was tested with two concentrations of enterocins (200 and 2000 au/cm2). control air-packed cooked ham showed an increase of l. monocytogenes from 10(4) to 1 ... | 2007 | 17629977 |
| distribution and characteristics of listeria monocytogenes isolates from surface waters of the south nation river watershed, ontario, canada. | listeria monocytogenes is a facultative intracellular pathogen thought to be widely distributed in the environment. we investigated the prevalence and characteristics of l. monocytogenes isolates from surface waters derived from catchments within the south nation river watershed (ontario, canada). this watershed is dominated by urban and rural development, livestock and crop production, and wildlife habitats. from june to november 2005, a total of 314 surface water samples were collected biweekl ... | 2007 | 17630309 |
| protein synthesis in lactic acid and pathogenic bacteria during recovery from a high pressure treatment. | recovery of injured bacteria after high hydrostatic pressure (hhp) treatment is a key point in food safety. in this study, protein synthesis during the recovery of meat environment bacteria listeria monocytogenes ctc1011, lactobacillus sakei 23k, l. sakei ctc494, enterococcus faecalis ctc6365 and enterococcus faecium ctc6375 after a 400 mpa hhp treatment was analyzed by two-dimensional gel electrophoresis and peptide mass fingerprinting. after 2 h recovery from hhp treatment, the four species in ... | 2007 | 17631981 |
| [case of relapsing polychondritis followed by cognitive impairment]. | a 64-year-old man developed cognitive impairment. a neurological examination showed hypereactive tendon reflex. a cerebrospinal fluid (csf) examination showed a mild increase in both the number of mononuclear cells (14 cells/mm3) and the protein level (45 mg/dl). an electroencephalogram showed diffuse slow wave activity. brain mr images revealed multifocal lesions in the limbic area and white matter regions. he was suspected to have autoimmune encephalitis and his symptoms improved after treated ... | 2007 | 17633109 |
| myd88-mediated signals induce the bactericidal lectin regiii gamma and protect mice against intestinal listeria monocytogenes infection. | listeria monocytogenes is a food-borne bacterial pathogen that causes systemic infection by traversing the intestinal mucosa. although myd88-mediated signals are essential for defense against systemic l. monocytogenes infection, the role of toll-like receptor and myd88 signaling in intestinal immunity against this pathogen has not been defined. we show that clearance of l. monocytogenes from the lumen of the distal small intestine is impaired in myd88(-/-) mice. the distal ileum of wild-type (wt ... | 2007 | 17635956 |
| quantitative risk assessment of listeria monocytogenes in french cold-smoked salmon: i. quantitative exposure assessment. | a quantitative assessment of the exposure to listeria monocytogenes from cold-smoked salmon (css) consumption in france is developed. the general framework is a second-order (or two-dimensional) monte carlo simulation, which characterizes the uncertainty and variability of the exposure estimate. the model takes into account the competitive bacterial growth between l. monocytogenes and the background competitive flora from the end of the production line to the consumer phase. an original algorith ... | 2007 | 17640216 |
| listeriolysin o expressed in a bacterial vaccine suppresses cd4+cd25high regulatory t cell function in vivo. | cd4(+)cd25(high) regulatory t cells (treg) protect the host from autoimmune diseases but are also obstacles against cancer therapies. an ideal cancer vaccine would stimulate specific cytotoxic responses and reduce/suppress treg function. in this study, we showed that escherichia coli expressing listeriolysin o and ova (e. coli llo/ova) demonstrated remarkable levels of protection against ova-expressing tumor cells. by contrast, e. coli expressing ova only (e. coli ova) showed poor protection. hi ... | 2007 | 17641019 |
| [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 |
| a synthetic polypeptide based on human e-cadherin inhibits invasion of human intestinal and liver cell lines by listeria monocytogenes. | internalin a is a surface protein of the facultative intracellular pathogen listeria monocytogenes that interacts with the human host cell protein e-cadherin to facilitate invasion of epithelial cells. a single amino acid substitution at position 16 in mouse e-cadherin prevents this interaction. synthetic polypeptides of 30 aa encompassing position 16 of human and mouse e-cadherin were tested for their ability to inhibit in vitro invasion of caco-2, hepg2 and tib73 cell lines by l. monocytogenes ... | 2007 | 17644706 |
| clinical features of liver involvement in adult patients with listeriosis. review of the literature. | clinical features of liver involvement due to listeria monocytogenes infection in adults are rarely reported in literature. this is surprising, regarding the current opinion that the portal system is extensively involved in the first stages of pathogenesis in invasive l. monocytogenes disease. a literature search in the pubmed and embase database revealed 34 cases with clinical features of hepatic involvement due to listeriosis. we systematically analyzed all case reports with respect to clinica ... | 2007 | 17646920 |
| an attempt to determine the incidence of listeria monocytogenes in the brain of mammals. | | 1959 | 17649178 |
| modelling transfer of listeria monocytogenes during slicing of 'gravad' salmon. | transfer of a rifampicin-resistant mutant of listeria monocytogenes from an inoculated slicing blade to slices of 'gravad' salmon (salmo salar), and from inoculated salmon fillet to the slicing machine and subsequently to slices of uninoculated fillet was studied. the effect of slicing temperature (0 degrees c, 10 degrees c and room temperature), inoculum level (approx. 3, 5 and 8 log cfu/blade), and attachment time of inoculum to blade (10 min and 2.5 h) were investigated and predictive models ... | 2007 | 17651853 |
| antioxidant and antibacterial activities of aqueous extract of seabuckthorn (hippophae rhamnoides) seeds. | seabuckthorn (hippophae rhamnoides) seeds aqueous extract was screened for antioxidant and antibacterial activities. the antioxidant activities (reducing power, dpph and liposome model system) showed a good antioxidant activity. the extract was also found to possess antibacterial activity with a mic values with respect to listeria monocytogenes and yersinia enterocolitica found to be 750 and 1000 ppm, respectively. the antioxidant and antimicrobial effects of the extract implicate its potential ... | 2007 | 17651916 |
| cell-free extract systems and the cytoskeleton: preparation of biochemical experiments for transmission electron microscopy. | cell-free systems can be used to reconstitute complex actin or microtubule-based phenomena. for example, a number of extracts support actin-dependent propulsion of listeria monocytogenes, whereas xenopus laevis extracts support formation of a microtubule-based meiotic spindle. working in vitro opens these complex processes to biochemical dissection. here, we describe methods to view these in vitro preparations by thin-section electron microscopy. | 2007 | 17656752 |
| porcine beta-defensin 2 displays broad antimicrobial activity against pathogenic intestinal bacteria. | defensins are small antimicrobial peptides that play an important role in the innate immune system of mammals. here, we describe the antimicrobial activity of pbd-2, a recently discovered new porcine defensin that is produced in the intestine. a synthetic peptide corresponding to the mature protein showed high antimicrobial activity against a broad range of pathogenic bacteria, while it only showed limited hemolytic activity against porcine red blood cells. highest activity was observed against ... | 2008 | 17658606 |
| characterization of the osmoprotectant transporter opuc from pseudomonas syringae and demonstration that cystathionine-beta-synthase domains are required for its osmoregulatory function. | the plant pathogen pseudomonas syringae may cope with osmotic stress on plants, in part, by importing osmoprotective compounds. in this study, we found that p. syringae pv. tomato strain dc3000 was distinct from most bacterial species in deriving greater osmoprotection from exogenous choline than from glycine betaine. this superior osmoprotection was correlated with a higher capacity for uptake of choline than for uptake of glycine betaine. of four putative osmoregulatory abc transporters in dc3 ... | 2007 | 17660277 |
| recombination and positive selection contribute to evolution of listeria monocytogenes inla. | the surface molecule inla interacts with e-cadherin to promote invasion of listeria monocytogenes into selected host cells. dna sequencing of inla for 40 l. monocytogenes isolates revealed 107 synonymous and 45 nonsynonymous substitutions. a frameshift mutation in a homopolymeric tract encoding part of the inla signal peptide was identified in three lineage ii isolates, which also showed reduced ability to invade human intestinal epithelial cells. phylogenies showed clear separation of inla sequ ... | 2007 | 17660431 |
| from hot dogs to host cells: how the bacterial pathogen listeria monocytogenes regulates virulence gene expression. | environmental pathogens are organisms that normally spend a substantial part of their lifecycle outside of human hosts, but when introduced into humans are capable of causing disease. such organisms are often able to transition between disparate environments ranging from the soil to the cytosol of host cells. the food-borne bacterial pathogen listeria monocytogenes serves as a model system for understanding how an environmental organism makes the transition into mammalian hosts. a transcriptiona ... | 2006 | 17661688 |
| intracytosolic listeria monocytogenes induces cell death through caspase-1 activation in murine macrophages. | listeria monocytogenes induces apoptosis in vitro and in vivo in a variety of cell types. however, the mechanism of cell death in l. monocytogenes-infected macrophages was initially reported to be distinct from apoptosis. here, we studied the mechanism of l. monocytogenes-induced cell death using sensitive fluorescent techniques. we found that caspase-1 activation preceded cell death of macrophages infected with l. monocytogenes, using fluorogenic substrates. caspase-1 activation was diminished ... | 2008 | 17662073 |
| listeria inlb takes a different route to met. | inlb, a surface protein of the human bacterial pathogen listeria monocytogenes, interacts with the receptor tyrosine kinase met on host cells to enable bacterial invasion. in this issue, niemann et al. (2007) provide the first structural evidence that inlb does not compete for the same interaction site on met as the natural ligand hgf. | 2007 | 17662936 |
| structure of the human receptor tyrosine kinase met in complex with the listeria invasion protein inlb. | the tyrosine kinase met, the product of the c-met proto-oncogene and the receptor for hepatocyte growth factor/scatter factor (hgf/sf), mediates signals critical for cell survival and migration. the human pathogen listeria monocytogenes exploits met signaling for invasion of host cells via its surface protein inlb. we present the crystal structure of the complex between a large fragment of the human met ectodomain and the met-binding domain of inlb. the concave face of the inlb leucine-rich repe ... | 2007 | 17662939 |
| [pleural effusion due to listeria monocytogenes in a woman with cirrhosis of the liver]. | | 2007 | 17663897 |
| t-cell-independent humoral immunity is sufficient for protection against fatal intracellular ehrlichia infection. | although humoral immunity has been shown to contribute to host defense during intracellular bacterial infections, its role has generally been ancillary. instead, cd4 t cells are often considered to play the dominant role in protective immunity via their production of type i cytokines. our studies of highly pathogenic ehrlichia bacteria isolated from ixodes ovatus (ioe) reveal, however, that this paradigm is not always correct. immunity to ioe infection can be induced by infection with a closely ... | 2007 | 17664264 |
| the lmo1078 gene encoding a putative udp-glucose pyrophosphorylase is involved in growth of listeria monocytogenes at low temperature. | the gram-positive bacterium listeria monocytogenes is a food-borne pathogen with the ability to grow at low temperature. given the importance of refrigeration as a means of food preservation, the psychrotolerant nature of this microorganism poses a significant public health hazard. in order to better understand the mechanisms underlying cold adaptation of l. monocytogenes, a library of tn917-lac insertional mutants was screened. a cold-sensitive mutant, named cs1, was isolated and found to be al ... | 2007 | 17666069 |
| heme coordination by staphylococcus aureus isde. | staphylococcus aureus is a gram-positive bacterial pathogen and a leading cause of hospital acquired infections. because the free iron concentration in the human body is too low to support growth, s. aureus must acquire iron from host sources. heme iron is the most prevalent iron reservoir in the human body and a predominant source of iron for s. aureus. the iron-regulated surface determinant (isd) system removes heme from host heme proteins and transfers it to isde, the cognate substrate-bindin ... | 2007 | 17666394 |
| purification and antimicrobial activity studies of the n-terminal fragment of ubiquitin from human amniotic fluid. | a 4.3-kda antimicrobial peptide was isolated from human amniotic fluid by dialysis, ultrafiltration, and c18 reversed-phase high performance liquid chromatography. this peptide, which we named amniotic fluid peptide-1 (afp-1), possessed antimicrobial activity but lacked hemolytic activity. in addition, afp-1 potently inhibited the growth of a variety of bacteria (escherichia coli, salmonella typhimurium, listeria monocytogenes and staphylococcus aureus), filamentous fungi (botrytis cinerea, aspe ... | 2007 | 17669700 |
| nuclear receptor err alpha and coactivator pgc-1 beta are effectors of ifn-gamma-induced host defense. | macrophage activation by the proinflammatory cytokine interferon-gamma (ifn-gamma) is a critical component of the host innate response to bacterial pathogenesis. however, the precise nature of the ifn-gamma-induced activation pathway is not known. here we show using genome-wide expression and chromatin-binding profiling that ifn-gamma induces the expression of many nuclear genes encoding mitochondrial respiratory chain machinery via activation of the nuclear receptor err alpha (estrogen-related ... | 2007 | 17671090 |
| [influence of chemical and physical characteristics of seashore soils in primorsky region on preservation and reproduction of listeria and yersinia]. | influence of chemical and physical characteristics of two types of seashore soils (tidal marsh and maritime meadow soils) in primorsky region on reproduction of listeria monocytogenes and yersinia pseudotuberculosis was studied. results of experiments proved the possibility of preservation and active reproduction of these bacteria in studied soils. characteristics of maritime meadow soil are more favorable for mentioned microorganisms than tidal march soil that located closer to the sea. | 2007 | 17672139 |
| [biological characteristics of listeria cultivating on the novel media for their accumulation and isolation]. | biological characteristics of isolated strains of listeria cultivating on growth media developed for accumulation and isolation of these microorganisms. stability of main cultural-morphologic characteristics, pathogenic enzyme synthesis, profile of plasmid dna and specific bacteriophage lysing of listeria during their cultivation on novel media was shown. | 2007 | 17672141 |
| [culture media for study of biologic characteristics of listeria]. | the commercial nutrient media for study of biologic properties of listeria monocytogenes were developed. the efficacy of developed media for assessing of motility and lecithinase activity of listeria during establishment of the isolated strain was shown. developed media allow clear visual registration of mobility and lecithinase activity of listeria during identification of the isolated strains thereby improving the diagnostics of listeriosis. | 2007 | 17672142 |
| monitoring of blood vessels and tissues by a population of monocytes with patrolling behavior. | the cellular immune response to tissue damage and infection requires the recruitment of blood leukocytes. this process is mediated through a classical multistep mechanism, which involves transient rolling on the endothelium and recognition of inflammation followed by extravasation. we have shown, by direct examination of blood monocyte functions in vivo, that a subset of monocytes patrols healthy tissues through long-range crawling on the resting endothelium. this patrolling behavior depended on ... | 2007 | 17673663 |
| histone modifications induced by a family of bacterial toxins. | upon infection, pathogens reprogram host gene expression. in eukaryotic cells, genetic reprogramming is induced by the concerted activation/repression of transcription factors and various histone modifications that control dna accessibility in chromatin. we report here that the bacterial pathogen listeria monocytogenes induces a dramatic dephosphorylation of histone h3 as well as a deacetylation of histone h4 during early phases of infection. this effect is mediated by the major listerial toxin ... | 2007 | 17675409 |
| agr system of listeria monocytogenes egd-e: role in adherence and differential expression pattern. | in this study, we investigated the agrbdca operon in the pathogenic bacterium listeria monocytogenes egd-e. in-frame deletion of agra and agrd resulted in an altered adherence and biofilm formation on abiotic surfaces, suggesting the involvement of the agr system of l. monocytogenes during the early stages of biofilm formation. real-time pcr experiments indicated that the transcript levels of agrbdca depended on the stage of biofilm development, since the levels were lower after the initial atta ... | 2007 | 17675424 |
| sigmab-dependent and sigmab-independent mechanisms contribute to transcription of listeria monocytogenes cold stress genes during cold shock and cold growth. | the role of the stress response regulator sigma(b) (encoded by sigb) in directing the expression of selected putative and confirmed cold response genes was evaluated using listeria monocytogenes 10403s and an isogenic deltasigb mutant, which were either cold shocked at 4 degrees c in brain heart infusion (bhi) broth for up to 30 min or grown at 4 degrees c in bhi for 12 days. transcript levels of the housekeeping genes rpob and gap, the sigma(b)-dependent genes opuca and bsh, and the cold stress ... | 2007 | 17675428 |
| absence of serotype-specific surface antigen in laboratory variants of epidemic-associated listeria monocytogenes strains. | variants that lacked reactivity with the serotype 4b-specific monoclonal antibody c74.22 and that lost susceptibility to certain listeria- or serotype 4b-specific phages were identified in the course of genetic studies with serotype 4b listeria monocytogenes strains h7550 and f2381l (epidemic clones i and ii, respectively). our findings suggest that such variants can become inadvertently established under laboratory conditions and suggest caution in work involving serotype 4b strains and genetic ... | 2007 | 17675434 |
| generation of cd8 t cell memory is regulated by il-12. | various signals during infection influence cd8 t cell memory generation, but these factors have yet to be fully defined. il-12 is a proinflammatory cytokine that has been shown to enhance ifn-gamma-producing t cell responses and has been widely tested as a vaccine adjuvant. in this study, we show that il-12-deficient mice generate a weaker primary cd8 t cell response and are more susceptible to listeria monocytogenes infection, but have substantially more memory cd8 t cells and greater protectiv ... | 2007 | 17675465 |
| chronic immunodeficiency in mice lacking rasgrp1 results in cd4 t cell immune activation and exhaustion. | the ras-guanyl nucleotide exchange factor rasgrp1 is an important link between tcr-mediated signaling and the activation of ras and its downstream effectors. rasgrp1 is especially critical for the survival and differentiation of developing thymocytes whereas negative selection of thymocytes bearing an autoreactive tcr appears to be rasgrp1 independent. despite apparently normal central tolerance, rasgrp1(-/-) mice spontaneously acquire an acutely activated and proliferating cd4 t cell population ... | 2007 | 17675473 |
| a role for ifn-gamma from antigen-specific cd8+ t cells in protective immunity to listeria monocytogenes. | whether ifn-gamma contributes to the per-cell protective capacity of memory cd8(+) t cells against listeria monocytogenes (lm) has not been formally tested. in this study, we generated lm ag-specific memory cd8(+) t cells via immunization of wild-type (wt) and ifn-gamma-deficient (gamma knockout (gko)) mice with lm peptide-coated dendritic cells and compared them phenotypically and functionally. immunization of wt and gko mice resulted in memory cd8(+) t cells that were similar in number, functi ... | 2007 | 17675507 |
| listeria endocarditis with acute thoracoabdominal aortic dissection. | the patient was 71-year-old male under treatment at a clinic for hypertension, aortic regurgitation, alcoholic hepatitis and dental treatment. he mainly complained fever and anorexia. since blood culture examination revealed listeria monocytogenes and echocardiography exhibited vegetation at the mitral leaflet, the patient was diagnosed as infective endocarditis. fever and inflammatory reaction were improved after penicillin administration; however, he had fever on the 24th hospital day. ct reve ... | 2007 | 17675771 |
| [listeria monocytogenes bacteremia: analysis of 110 episodes]. | over the last years, we registered an increase in the number of listeriosis cases. the aim of this study was to analyze the co-morbidity, clinical presentation and prognosis of listeria monocytogenes bacteremia episodes diagnosed over 15 years. | 2007 | 17678604 |
| listeriolysin o secreted by listeria monocytogenes into the host cell cytosol is degraded by the n-end rule pathway. | the intracellular pathogen listeria monocytogenes escapes from a phagosomal compartment into the cytosol by secreting the pore-forming cytolysin listeriolysin o (llo). during the proliferation of l. monocytogenes bacteria in the mammalian cell cytosol, the secreted llo is targeted for degradation by the ubiquitin system. we report here that llo is a substrate of the ubiquitin-dependent n-end rule pathway, which recognizes llo through its n-terminal lys residue. specifically, we demonstrated by r ... | 2007 | 17682039 |
| cdc42 and phosphoinositide 3-kinase drive rac-mediated actin polymerization downstream of c-met in distinct and common pathways. | activation of c-met, the hepatocyte growth factor (hgf)/scatter factor receptor induces reorganization of the actin cytoskeleton, which drives epithelial cell scattering and motility and is exploited by pathogenic listeria monocytogenes to invade nonepithelial cells. however, the precise contributions of distinct rho-gtpases, the phosphatidylinositol 3-kinases, and actin assembly regulators to c-met-mediated actin reorganization are still elusive. here we report that hgf-induced membrane rufflin ... | 2007 | 17682062 |
| multiplex pcr for the identification and serotyping of l. monocytogenes isolated from sheep cheese-processing plants. | | 2007 | 17682914 |
| hygienic evaluation of marinated sea bass and challenge test for listeria monocytogenes. | | 2007 | 17682916 |
| prevalence and characterisation of populations of listeria monocytogenes during sausage ripening. | | 2007 | 17682918 |
| variable adhesion of listeria monocytogenes isolates from food-processing facilities and clinical cases to inert surfaces. | one hundred one strains of listeria monocytogenes isolated from seafood and cheese industry samples and from patients with listeriosis were assessed using a microtiter plate method for adhesion to polystyrene and stainless steel surfaces. the adhesion rate for these strains ranged from 3.10 to 35.29% with an inoculum of 8 x 10(8) cells per well. a strong correlation was found between adhesion to polystyrene and stainless steel microtiter plates, indicating that the intrinsic ability of l. monocy ... | 2007 | 17685327 |
| inactivation of listeria monocytogenes on frankfurters by monocaprylin alone or in combination with acetic acid. | the antilisterial activity of monocaprylin (mc) and its combination with acetic acid (aa) on frankfurters was investigated. each frankfurter was surface inoculated with a three-strain mixture of listeria monocytogenes to obtain an inoculation level of 4.0 log cfu per frankfurter, and then dipped for 35 s in sterile deionized water (45 or 50 degrees c) containing 1% ethanol (control), 50 mm mc plus 1% ethanol, 1% aa plus 1% ethanol, or 50 mm mc plus 1% aa plus 1% ethanol. samples were vacuum pack ... | 2007 | 17685330 |
| could modifications of processing parameters enhance the growth and selection of lactic acid bacteria in cold-smoked salmon to improve preservation by natural means? | several smoking conditions were examined with the objective of enhancing the numbers of lactic acid bacteria (lab) by natural means in vacuum-packaged cold-smoked salmon during 21 days of storage at 5 degrees c. three combinations of salting, drying, and smoking were used: (i) dry salting x time of salting (2 or 6 h); (ii) wet salting (6 h) x dry salting (6 h) x with or without sugar; and (iii) wet salting (6 h) x dry salting (6 h) x different times of smoking (2 or 6 h of drying and 2 or 6 h of ... | 2007 | 17685332 |
| real-time pcr detection of 16s rrna genes speeds most-probable-number enumeration of foodborne listeria monocytogenes. | quantifying foodborne pathogens at concentrations of 0.1 to 1,000 cfu/g of food generally involves most-probable-number (mpn) enumeration, which takes at least 4 days. a real-time pcr assay (rti-pcr) was developed to accelerate mpn enumeration of foodborne listeria monocytogenes. foods were spiked from 70 to 110 cfu/g, and triplicate subportions from 0.0001 to 1 g were selectively enriched for 48 h at 30 degrees c. for standard mpn enumeration, the enrichments were subcultured on oxford agar (48 ... | 2007 | 17685338 |