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bioprotective leuconostoc strains against listeria monocytogenes in fresh fruits and vegetables.ten leuconostoc mesenteroides and one ln. citreum strains isolated from fresh fruit and vegetables were tested for their antagonistic capacity against listeria monocytogenes. genetic differences among strains were analyzed by random amplified polymorphic dna (rapd). all the isolates clustered together and differed from the type strain ln. mesenteroides atcc 8293 as well as from ln. fallax and ln. citreum. organic acids, hydrogen peroxide and bacteriocins were detected as main inhibition mechanis ...200818625532
carbon metabolism of listeria monocytogenes growing inside macrophages.the intracellular metabolism of listeria monocytogenes was studied by (13)c-isotopologue profiling using murine j774a.1 macrophages as host cells. six hours after infection, bacteria were separated from the macrophages and hydrolyzed. amino acids were converted into tert-butyl-dimethylsilyl derivatives and subjected to gas chromatography/mass spectrometry. when the macrophages were supplied with [u-(13)c(6)]glucose prior to infection, but not during infection, label was detected only in ala, asp ...200818627458
circumvention of regulatory cd4(+) t cell activity during cross-priming strongly enhances t cell-mediated immunity.immunization with purified antigens is a safe and practical vaccination strategy but is generally unable to induce sustained cd8(+) t cell-mediated protection against intracellular pathogens. most efforts to improve the cd8(+) t cell immunogenicity of these vaccines have focused on co-administration of adjuvant to support cross-presentation and dendritic cell maturation. in addition, it has been shown that cd4(+) t cell help during the priming phase contributes to the generation of protective cd ...200818465771
control of listeria monocytogenes on vacuum-packaged frankfurters sprayed with lactic acid alone or in combination with sodium lauryl sulfate.u.s. regulations require that processors employ lethal or inhibitory antimicrobial alternatives in production of ready-to-eat meat and poultry products that support growth of listeria monocytogenes and may be exposed to the processing environment after a lethality treatment. in this study, lactic acid (la; 5%, vol/vol) and sodium lauryl sulfate (sls; 0.5%, wt/vol) were evaluated individually or as a mixture (lasls) for control of l. monocytogenes on frankfurters. frankfurters were inoculated wit ...200818468026
monitoring hygiene on- and at-line is critical for controlling listeria monocytogenes during produce processing.the prevalence of listeria monocytogenes in different types of produce and on processing plant environments was investigated over a 4-year period in a large produce processing plant in poland. prevalence of l. monocytogenes was 46% in frozen vegetables and 41.3% in swab samples taken from the plant environment. survival studies using artificial inocula demonstrated that the number of listeria in frozen produce stored for 100 days did not significantly decrease in relation to the initial contamin ...200818468027
a radial basis function neural network approach to determine the survival of listeria monocytogenes in katiki, a traditional greek soft cheese.a radial basis function neural network was developed to determine the kinetic behavior of listeria monocytogenes in katiki, a traditional white acid-curd soft spreadable cheese. the applicability of the neural network approach was compared with the reparameterized gompertz, the modified weibull, and the geeraerd primary models. model performance was assessed with the root mean square error of the residuals of the model (rmse), the regression coefficient (r2), and the f test. commercially prepare ...200818468029
modification of the submerged coil to prevent microbial carryover error in thermal death studies.a submerged coil unit generates death rate data for foodborne pathogens through precise computer-controlled sequential sampling rather than the usual manually timed, labor-intensive single sampling associated with other approaches. our work with yersinia pseudotuberculosis and listeria monocytogenes scott a using the submerged coil unit indicated non-log-linear death rates with large degrees of tailing. varying degrees of cell adhesion to the surface of the exit port resulted in carryover that w ...200818468032
enhanced rapidity for qualitative detection of listeria monocytogenes using an enzyme-linked immunosorbent assay and immunochromatography strip test combined with immunomagnetic bead separation.an enzyme-linked immunosorbent assay (elisa), immunochromatography (icg) strip test, and immunomagnetic bead separation (imbs) system based on a monoclonal antibody were individually developed for the detection and isolation of listeria monocytogenes in meat samples. the three methods showed a strong reaction with listeria species and a weak reaction with staphylococcus aureus. to increase the rapidity of l. monocytogenes detection, combinations of the elisa and icg strip test with the imbs syst ...200818468033
prevalence of listeria monocytogenes and salmonella in ready-to-eat food in catalonia, spain.listeria monocytogenes and salmonella are pathogenic bacteria that can contaminate food products during or after processing. ready-to-eat (rte) food does not undergo any treatment to ensure its safety before consumption, and therefore risk of foodborne disease must be considered if these pathogens are present in the food. to evaluate the prevalence of these pathogens in rte food, 140 rte fish product samples, 501 rte meat product samples, 462 rte dairy samples, and 123 rte dishes and desserts, p ...200818468047
microbiological quality of sushi from sushi bars and retailers.sushi is a traditional japanese food, mostly consisting of rice and raw fish. fish is considered a healthy food, but as with other animal products, consumption of raw muscle incurs potential health risks such as ingestion of pathogenic bacteria or parasites. in this study, 250 sushi samples were analyzed for their microbiological status and the prevalence of pathogenic bacteria. a comparison was made between frozen sushi from supermarkets and fresh sushi from sushi bars. aerobic mesophilic bacte ...200818468048
endocarditis due to listeria: description of two cases and review of the literature.endocarditis due to listeria monocytogenes is a very uncommon and very serious disease that may lead to valve dysfunction and cardiac arrest. we report two cases of endocarditis caused by l. monocytogenes and review the papers previously published on the subject.200818471682
validation of nmkl method no. 136--listeria monocytogenes, detection and enumeration in foods and feed.a collaborative study was organised to define the performance characteristics of the revised nmkl method no.136 "listeria monocytogenes. detection and enumeration in foods". chromogenic l. monocytogenes specific plating medium, agar listeria according to ottaviani and agosti (aloa) was introduced in the revised method in order to improve the sensitivity and specificity of the method, and to shorten the analysis time. efficacy of aloa one day from aes (ready-to-use agar in bottles), listeria chro ...200818472176
selected prfa* mutations in recombinant attenuated listeria monocytogenes strains augment expression of foreign immunogens and enhance vaccine-elicited humoral and cellular immune responses.while recombinant listeria monocytogenes strains can be explored as vaccine candidates, it is important to develop attenuated but highly immunogenic l. monocytogenes vaccine vectors. here, prfa* mutations selected on the basis of upregulated expression of l. monocytogenes prfa-dependent genes and proteins were assessed to determine their abilities to augment expression of foreign immunogens in recombinant l. monocytogenes vectors and therefore enhance vaccine-elicited immune responses (a prfa* m ...200818474644
growth kinetics of listeria monocytogenes in broth and beef frankfurters--determination of lag phase duration and exponential growth rate under isothermal conditions.the objective of this study was to develop a new kinetic model to describe the isothermal growth of microorganisms. the new model was tested with listeria monocytogenes in tryptic soy broth and frankfurters, and compared with 2 commonly used models-baranyi and modified gompertz models. bias factor (bf), accuracy factor (af), and root mean square errors (rmse) were used to evaluate the 3 models. either in broth or in frankfurter samples, there were no significant differences in bf (approximately ...200818576996
edible coatings for enhancing microbial safety and extending shelf life of hard-boiled eggs.hard-boiled eggs were coated with chitosan-lysozyme (cl), whey protein isolate (wpi), or bake sheen (bs), inoculated with listeria monocytogenes or salmonella enterica ser. enteritidis at 10(4) cfu/g, and stored for 4 wk at 10 degrees c. microbial populations were enumerated weekly. two nonchallenge studies were also conducted with hard-boiled eggs: coated shell-on eggs packaged in plastic containers or peeled eggs coated and vacuum-packaged. total plate counts (tpc), coliforms, yeasts, molds, w ...200818577005
control of listeria monocytogenes in ready-to-eat meats containing sodium levulinate, sodium lactate, or a combination of sodium lactate and sodium diacetate.this study investigated the use of sodium levulinate to prevent outgrowth of listeria monocytogenes in refrigerated ready-to-eat (rte) meat products. turkey breast roll and bologna were formulated to contain 1%, 2%, or 3% (w/w) sodium levulinate, 2% sodium lactate, a 2% combination of sodium lactate and sodium diacetate (1.875% sodium lactate and 0.125% sodium diacetate), or no antimicrobial (control). samples of the rte products were sliced, inoculated with 10(2) to 10(3) cfu/cm(2) of a 5-strai ...200818577007
genomic and proteomic analysis of the alkali-tolerance response (altr) in listeria monocytogenes 10403s.information regarding the alkali-tolerance response (altr) in listeria monocytogenes is very limited. treatment of alkali-adapted cells with the protein synthesis inhibitor chloramphenicol has revealed that the altr is at least partially protein-dependent. in order to gain a more comprehensive perspective on the physiology and regulation of the altr, we compared differential gene expression and protein content of cells adapted at ph 9.5 and un-adapted cells (ph 7.0) using complementary dna (cdna ...200818577215
close packing of listeria monocytogenes acta, a natively unfolded protein, enhances f-actin assembly without dimerization.studies of the biochemistry of listeria monocytogenes virulence protein acta have typically focused on the behavior of bacteria in complex systems or on the characterization of the protein after expression and purification. although prior in vivo work has proposed that acta forms dimers on the surface of l. monocytogenes, dimerization has not been demonstrated in vitro, and little consideration has been given to the surface environment where acta performs its pivotal role in bacterial actin-base ...200818577520
the effect of an acidic, copper sulfate-based commercial sanitizer on indicator, pathogenic, and spoilage bacteria associated with broiler chicken carcasses when applied at various intervention points during poultry processing.studies were conducted to evaluate 1) the effect of an acidic, copper sulfate-based commercial sanitizer on pathogenic, indicator, and spoilage bacteria in a model scalder system, 2) the effect of this sanitizer on total aerobic bacteria (apc) and escherichia coli counts, and salmonella prevalence on broiler chicken carcasses when applied during scalding or scalding and postpick dipping, and 3) the ability of sanitizer to extend the shelf-life of broiler chicken carcasses. exposure of salmonella ...200818577627
[neurological complications in renal transplant recipients].renal transplantation is method of choice for treatment of patients with end-stage renal disease without contraindications for immunosuppressive therapy. neurological complications occur frequently in renal transplant recipients. they may be the consequence of immunosuppressive treatment, but more often evolve as the consequence of previous disturbances which developed during the state of uraemia and treatment with dialysis. the most pronounced neurotoxic effect has calcineurin inhibitors tacrol ...200818578336
serum procalcitonin for discrimination between septic and non-septic arthritis.early differentiation between septic and non-septic arthritis is difficult. a previous study showed promising diagnostic accuracy of serum procalcitonin (pct) in septic arthritis, limited by a low sensitive pct test kit.200818578968
efns guideline on the management of community-acquired bacterial meningitis: report of an efns task force on acute bacterial meningitis in older children and adults.acute bacterial meningitis (abm) is a potentially life-threatening neurological emergency. an agreed protocol for early, evidence-based and effective management of community-acquired abm is essential for best possible outcome. a literature search of peer-reviewed articles on abm was used to collect data on the management of abm in older children and adults. based on the strength of published evidence, a consensus guideline was developed for initial management, investigations, antibiotics and sup ...200818582342
the dead-box helicase ddx3x is a critical component of the tank-binding kinase 1-dependent innate immune response.tank-binding kinase 1 (tbk1) is of central importance for the induction of type-i interferon (ifn) in response to pathogens. we identified the dead-box helicase ddx3x as an interaction partner of tbk1. tbk1 and ddx3x acted synergistically in their ability to stimulate the ifn promoter, whereas rnai-mediated reduction of ddx3x expression led to an impairment of ifn production. chromatin immunoprecipitation indicated that ddx3x is recruited to the ifn promoter upon infection with listeria monocyto ...200818583960
pcr-based detection in a micro-fabricated platform.we present a novel, on-chip system for the electrokinetic capture of bacterial cells and their identification using the polymerase chain reaction (pcr). the system comprises a glass-silicon platform with a set of micro-channels, -chambers, and -electrodes. a platinum thin film resistor, placed in the proximity of the chambers, is used for temperature monitoring. the whole chip assembly is mounted on a printed circuit board (pcb) and wire-bonded to it. the pcb has an embedded heater that is utili ...200818584089
anti-infective mode of action of eps 7630 at the molecular level.clinical trials have shown that eps 7630, an aqueous ethanolic extract from the roots of pelargonium sidoides, is an efficacious treatment for respiratory tract infections. a large body of in vitro studies has provided evidence for an anti-infective principle associated with activation of the non-specific immune system. however, the mode of action at the cellular and molecular level is still insufficiently defined. this study, therefore, aimed to provide further insight into the underlying princ ...200818584813
loss of flagellum-based motility by listeria monocytogenes results in formation of hyperbiofilms.biofilm formation by the gram-positive, motile, food-borne pathogen listeria monocytogenes was demonstrated to occur by an ordered series of stages. biofilm development involves flagellum-based motility, which when blocked decreases initial bacterial surface attachment but subsequently leads to the formation of hyperbiofilms, surface-attached communities reaching high density.200818586947
differences in survival among 13 listeria monocytogenes strains in a dynamic model of the stomach and small intestine.thirteen listeria monocytogenes strains were compared for the ability to survive in a dynamic gastrointestinal model. strains displayed various degrees of susceptibility to gastric acidity; however, strain-to-strain variations became evident mainly after 90 min of exposure (ph 2.0). cell levels transferred to the intestine depended on initial populations, while reductions during intestinal exposure were relatively small for all strains.200818586963
[analysis of antibiotic susceptibility of foodborne listeria monocytogenes in china].to study the antibiotic susceptibility of foodborne listeria monocytogenes in china.200818589603
acid and nacl limits to growth of listeria monocytogenes and influence of sequence of inimical acid and nacl levels on inactivation kinetics.variability in growth limits of listeria monocytogenes in response to low ph (adjusted with hcl) or high salinity (nacl) was evaluated for 127 strains in brain heart infusion broth at 25 degrees c. over 95% of strains habituated at ph 5.0 grew subsequently at ph 4.2, while 25% were able to grow at ph 4.1. more than 85% of strains preadapted to growth at 8.5% nacl (wt/vol) subsequently grew in the presence of 11.3% nacl, while 25% were able to grow at 13% nacl, and 4.7% grew in the presence of 13 ...200818592742
identification and characterization of enterococcus spp. in greek spontaneous sausage fermentation.a total of 108 enterococcal strains previously isolated from spontaneously fermented sausages were identified using phenotypic traits, pulsed-field gel electrophoresis (pfge), and sequencing of the 16s rrna gene. the proteolytic and lipolytic activities of these isolates and their ability to decarboxylate lysine, tyrosine, ornithine, and histidine and to produce antimicrobial compounds also were assessed. all strains were identified as enterococcus faecium, and a lack of correlation between data ...200818592753
role of the u.s. food and drug administration in the regulatory management of human listeriosis in the united states.from 1986 to 2006, the incidence of listeriosis in the united states dropped from approximately seven to three cases per million population, a reduction that most likely reflects the joint efforts of industry, government, consumers, and academia. herein, we describe the u.s. food and drug administration (fda) strategy over the past three decades to combat listeriosis. specifically, we discuss early actions taken to address outbreaks during the 1980s, policy decisions regarding the presence of li ...200818592761
incidence and growth of listeria monocytogenes in persimmon (diospyros kaki) fruit.the incidence of listeria monocytogenes on persimmon (diospyros kaki) surface of 'fuyu' and 'rama forte' was evaluated during a 5-month-period (from march to july) of two seasons periods (years 2005 and 2006). the fruits were collected in wholesale and street markets and retail in sao paulo and campinas city, brazil. a total of 582 fruits were analyzed using the bax system which is based on the polymerase chain reaction. the ability of this pathogen to grow on the peel and pulp of the two persim ...200818599141
a novel cell wall-anchored peptidoglycan hydrolase (autolysin), ispc, essential for listeria monocytogenes virulence: genetic and proteomic analysis.we have recently concluded that a listeria monocytogenes 86 kda immunogenic surface protein, ispc, is a cell wall-anchored peptidoglycan hydrolase (autolysin), capable of degrading the cell wall peptidoglycan of the bacterium itself. to determine if this enzyme has any biological functions and/or plays a role in virulence, we in-frame-deleted the ispc gene from the l. monocytogenes chromosome. this deltaispc mutant exhibited complete abrogation of expression of ispc and displayed no defects in i ...200818599819
point mutations within the streptococcal regulator of virulence (srv) alter protein-dna interactions and srv function.group a streptococcus (gas) possesses a complex regulatory system enabling the organism to colonize a range of physiologically distinct host sites. within this network of regulators is the streptococcal regulator of virulence (srv). srv is a member of the crp/fnr family of transcriptional regulators and is most similar to pleiotropic regulatory factor a (prfa), a positive regulator of virulence in listeria monocytogenes. members of this family possess a characteristic c-terminal helix-turn-helix ...200818599828
risk profiles of pork and poultry meat and risk ratings of various pathogen/product combinations.risk profiles of pork and poultry meat were carried out using an excel-based software program, risk ranger. it is a semi-quantitative risk estimator answering various questions relating to the probability of exposure to a hazard, susceptibility of the population of interest, severity of the illness caused by the hazard if present and probability of food containing an infectious dose. therefore, qualitative and quantitative inputs were used to estimate and rank the risk of various hazards/food co ...200818602180
the evaluation of the immunomodulating properties of era-63 a pharmaceutical with estrogenic activity.this paper describes studies performed with era-63 a low molecular weight pharmaceutical with intended immunomodulatory effects. since this compound was also known to have estrogenic activity a non-conventional approach was taken in order to differentiate between estrogenic and non-estrogenic-induced immunomodulatory effects. ee was included not only for qualitative comparison (hazard identification) between immunomodulatory effects but also, in case of similar effects, to facilitate the extrapo ...200818602456
autophagic control of listeria through intracellular innate immune recognition in drosophila.autophagy, an evolutionally conserved homeostatic process for catabolizing cytoplasmic components, has been linked to the elimination of intracellular pathogens during mammalian innate immune responses. however, the mechanisms underlying cytoplasmic infection-induced autophagy and the function of autophagy in host survival after infection with intracellular pathogens remain unknown. here we report that in drosophila, recognition of diaminopimelic acid-type peptidoglycan by the pattern-recognitio ...200818604211
inactivation of barotolerant strains of listeria monocytogenes and escherichia coli o157:h7 by ultra high pressure and tert-butylhydroquinone combination.antimicrobial efficacy of ultra-high-pressure (uhp) can be enhanced by application of additional hurdles. the objective of this study was to systematically assess the enhancement in pressure lethality by tbhq treatment, against barotolerant strains of escherichia coli o157:h7 and listeria monocytogenes. two l. monocytogenes scott a and the barotolerant osy-328 strain, and two e. coli o157:h7 strains, edl-933 and its barotolerant mutant, osy-asm, were tested. cell suspensions containing tbhq (50 ...200818604498
intracellular bacteriolysis triggers a massive apoptotic cell death in shigella-infected epithelial cells.infected epithelial cells, which act as a first barrier against pathogens, seldom undergo apoptosis. rather, infected epithelial cells undergo a slow cell death that displays hallmarks of necrosis. here, we demonstrate that rapid intracellular lysis of shigella flexneri, provoked by either the use of a diaminopimelic acid auxotroph mutant or treatment of infected cells with antibiotics of the beta-lactam family, resulted in a massive and rapid induction of apoptotic cell death. this intracellula ...200818606244
granzymes drive a rapid listeriolysin o-induced t cell apoptosis.the listeria monocytogenes protein listeriolysin o (llo) is a pore-forming protein essential for virulence. although the major role for llo is to allow l. monocytogenes entry into the cytosol, it also induces apoptosis of activated lymphocytes, an obligatory cellular response that modulates the infection. induction of apoptosis by llo proceeds through a fast, caspase-dependent pathway and a slow, caspase-independent pathway. polyclonal t cell lines were generated from either normal mice or mice ...200818606691
identification of formyl peptides from listeria monocytogenes and staphylococcus aureus as potent chemoattractants for mouse neutrophils.the prototypic formyl peptide n-formyl-met-leu-phe (fmlf) is a major chemoattractant found in escherichia coli culture supernatants and a potent agonist at human formyl peptide receptor (fpr) 1. consistent with this, fmlf induces bactericidal functions in human neutrophils at nanomolar concentrations. however, it is a much less potent agonist for mouse fpr (mfpr) 1 and mouse neutrophils, requiring micromolar concentrations for cell activation. to determine whether other bacteria produce more pot ...200818606697
rapid identification and typing of listeria species by matrix-assisted laser desorption ionization-time of flight mass spectrometry.listeria monocytogenes is a food-borne pathogen that is the causative agent of human listeriosis, an opportunistic infection that primarily infects pregnant women and immunologically compromised individuals. rapid, accurate discrimination between listeria strains is essential for appropriate therapeutic management and timely intervention for infection control. a rapid method involving matrix-assisted laser desorption ionization-time of flight mass spectrometry (maldi-tof ms) that shows promise f ...200818606788
listeria monocytogenes and staphylococcus aureus coinfection of a prosthetic joint. 200818534891
antimicrobial activity of bacterial isolates from different floral sources of honey.more than two thousand bacterial strains isolated from six us domestic honeys and two manuka honeys from new zealand were screened for production of antimicrobial compounds. a high incidence of antimicrobial inhibition determined by deferred inhibition assays was observed with the bacterial isolates from all eight honey samples. in total, 2217 isolates out of 2398 strains (92.5% of total isolates) exhibited antimicrobial activity against at least one of the tested microorganisms. antifungal acti ...200818538876
sel, a selective enrichment broth for simultaneous growth of salmonella enterica, escherichia coli o157:h7, and listeria monocytogenes.multipathogen detection on a single-assay platform not only reduces the cost for testing but also provides data on the presence of pathogens in a single experiment. to achieve this detection, a multipathogen selective enrichment medium is essential to allow the concurrent growth of pathogens. sel broth was formulated to allow the simultaneous growth of salmonella enterica, escherichia coli o157:h7, and listeria monocytogenes. the results were compared to those obtained with the respective indivi ...200818539786
isolation and partial characterization of a bacteriocin produced by pediococcus pentosaceus k23-2 isolated from kimchi.screening and partial characterization of a bacteriocin produced by pediococcus pentosaceus k23-2 isolated from kimchi, a traditional korean fermented vegetable.200818540969
growth and persistence of listeria monocytogenes isolates on the plant model arabidopsis thaliana.while the majority of human listeriosis cases appear to be linked to consumption of processed ready-to-eat foods (e.g., deli meats), a few listeriosis outbreaks have been linked to consumption of contaminated vegetables. in this study, we assessed four isolates representing the major listeria monocytogenes lineages for their abilities to attach to and grow on arabidopsis thaliana, a well-characterized plant model. when plants were dipped for 5min into 3ml of water containing 8.8logcfu of l. mono ...200818541169
chemical composition and inhibitory parameters of essential oil and extracts of nandina domestica thunb. to control food-borne pathogenic and spoilage bacteria.the aim of this study was to examine the chemical composition of the essential oil isolated from the floral parts of nandina domestica thunb. by hydrodistillation, and to test the efficacy of essential oil and various organic extracts against a panel of food-borne pathogenic and spoilage bacteria such as bacillus subtilis atcc6633, listeria monocytogenes atcc19166, staphylococcus aureus kctc1916, s. aureus atcc6538, pseudomonas aeruginosa kctc2004, salmonella typhimurium kctc2515, salmonella ent ...200818541324
constitutive activation of the prfa regulon enhances the potency of vaccines based on live-attenuated and killed but metabolically active listeria monocytogenes strains.recombinant vaccines derived from the facultative intracellular bacterium listeria monocytogenes are presently undergoing early-stage clinical evaluation in oncology treatment settings. this effort has been stimulated in part due to preclinical results that illustrate potent activation of innate and adaptive immune effectors by l. monocytogenes vaccines, combined with efficacy in rigorous animal models of malignant and infectious disease. here, we evaluated the immunologic potency of a panel of ...200818541651
a new twist on an old pathway--accessory sec [corrected] systems.the export of proteins from their site of synthesis in the cytoplasm across the inner membrane is an important aspect of bacterial physiology. because the location of extracytoplasmic proteins is ideal for host-pathogen interactions, protein export is also important to bacterial virulence. in bacteria, there are conserved protein export systems that are responsible for the majority of protein export: the general secretion (sec) pathway and the twin-arginine translocation pathway. in some bacteri ...200818544071
shelf life evaluation for ready-to-eat sliced uncured turkey breast and cured ham under probable storage conditions based on listeria monocytogenes and psychrotroph growth.the growth variability of three listeria monocytogenes ribotypes in ready-to-eat (rte) sliced uncured turkey breast and cured ham was studied under storage conditions that rte foods are likely to encounter. three product treatments studied were: (1) a control; (2) a formulation subjected to high pressure processing to reduce initial microbial load (hpp); (3) a formulation containing 2.0% potassium lactate and 0.2% sodium diacetate (pl/sd). after separate inoculation with individual l. monocytoge ...200818544466
contrasting effects of human thp-1 cell differentiation on levofloxacin and moxifloxacin intracellular accumulation and activity against staphylococcus aureus and listeria monocytogenes.listeria monocytogenes and staphylococcus aureus invade and multiply in thp-1 monocytes. fluoroquinolones accumulate in these cells, but are less active against intracellular than extracellular forms of l. monocytogenes and s. aureus. we examined whether differentiation of thp-1 monocytes into adherent, macrophage-like cells increases fluoroquinolone uptake and activity.200818544595
urinary retention secondary to listeria meningitis.we report a rare case of urinary retention secondary to listeria meningitis. a 90-year-old woman presented with high fever, nausea, diarrhea, and incontinence of urination and feces. lumbar puncture was performed. the total cell number of the cerebrospinal fluid (csf) was elevated indicating that the glucose level was decreased. a csf culture and a blood culture revealed listeria monocytogenes (l. monocytogenes). we treated this bacterial meningitis with antibiotic medicine. one month after onse ...200818552472
development of multiple strain competitive index assays for listeria monocytogenes using pimc; a new site-specific integrative vector.the foodborne, gram-positive pathogen, listeria monocytogenes, is capable of causing lethal infections in compromised individuals. in the post genomic era of l. monocytogenes research, techniques are required to identify and validate genes involved in the pathogenicity and environmental biology of the organism. the aim here was to develop a widely applicable method to tag l. monocytogenes strains, with a particular emphasis on the development of multiple strain competitive index assays.200818554399
interactions in dual species biofilms between listeria monocytogenes egd-e and several strains of staphylococcus aureus.six environmental isolates of staphylococcus aureus and one collection strain were investigated for their ability to form monospecies biofilms and dual species biofilms with listeria monocytogenes egd-e on stainless steel coupons. all isolates were able to grow as biofilms but their ability to form monospecies biofilms differed. the population of l. monocytogenes egd-e in dual species biofilms was not affected by the presence of s. aureus isolates except for strain cip 53.156. the effect of l. m ...200818554739
photoactivated chlorophyllin-based gelatin films and coatings to prevent microbial contamination of food products.the aim of this work was to develop antimicrobial photosensitizer-containing edible films and coatings based on gelatin as the polymer matrix, incorporating sodium magnesium chlorophyllin (e-140) and sodium copper chlorophyllin (e-141). chlorophyllins were incorporated into the gelatin film-forming solution and the inhibiting effect of the cast films was tested against staphylococcus aureus and listeria monocytogenes. the results demonstrated that water soluble sodium magnesium chlorophyllin and ...200818555550
growth of l. monocytogenes strain f2365 on ready-to-eat turkey meat does not enhance gastrointestinal listeriosis in intragastrically inoculated a/j mice.there have been significant outbreaks of listeriosis associated with consumption of contaminated ready-to-eat (rte) turkey meat products. in this study, we investigated whether growth on rte deli turkey meat sends environmental signals to listerial cells that makes them more virulent in the gastrointestinal tract of mice. l. listeria monocytogenes strain f2365 grew from a starting inoculum of 10(3) cfu/ml to final numbers of 10(8)-10(9) cfu/ml (within 12 days at 10 degrees c) when inoculated ont ...200818559288
a listeria monocytogenes mutant defective in bacteriophage attachment is attenuated in orally inoculated mice and impaired in enterocyte intracellular growth.a listeria monocytogenes bacteriophage was used to identify a phage-resistant tn917 insertion mutant of the mouse-virulent listerial strain f6214-1. the mutant was attenuated when it was inoculated orally into female a/j mice and failed to replicate efficiently in cultured mouse enterocytes. phage binding studies indicated that the mutant had a cell surface alteration that precluded phage attachment. all phenotypes associated with the mutation could be complemented in trans by a single open read ...200818559424
curvature and torsion in growing actin networks.intracellular pathogens such as listeria monocytogenes and rickettsia rickettsii move within a host cell by polymerizing a comet-tail of actin fibers that ultimately pushes the cell forward. this dense network of cross-linked actin polymers typically exhibits a striking curvature that causes bacteria to move in gently looping paths. theoretically, tail curvature has been linked to details of motility by considering force and torque balances from a finite number of polymerizing filaments. here we ...200818560043
structural analysis of the l-alanoyl-d-glutamate endopeptidase domain of listeria bacteriophage endolysin ply500 reveals a new member of the las peptidase family.similar to many other bacterial cell-wall-hydrolyzing enzymes, the listeria bacteriophage a500 endopeptidase ply500 has a modular architecture consisting of an enzymatically active domain (ead) linked to a cell-wall-binding domain (cbd) in a single polypeptide chain. the crystal structure of the ead of ply500 has been solved at 1.8 a resolution. the shape of the enzyme resembles a sofa chair: one alpha-helix and three antiparallel beta-strands form the seat, which is supported by two more alpha- ...200818560152
listeria monocytogenes peritonitis in a patient on peritoneal dialysis: a case report and review of the literature.listeria monocytogenes (lm) is one of the rare microorganisms causing peritonitis in peritoneal dialysis (pd) patients. we report a sporadic case of peritonitis caused by lm in a young female pd patient with lupus receiving corticosteroid therapy, who presented with abdominal pain, cloudy pd effluent, nausea, and conjunctivitis. the effluent showed a high pd effluent white cell count and monocytosis, and gram staining showed gram-positive bacilli in single or short chains and pd effluent culture ...200818563614
how to manage infections in the era of biologics?biologic agents are immunosuppressants that target cytokines or specific immune cell subpopulations. many therapies interfere with the normal inflammatory cascade and with the immune system, causing an increase in the incidence of infections. in particular, treatment with tumor necrosis factor (tnf)-alpha antagonists in psoriasis patients is associated with an increased risk of infection caused by intracellular microorganisms. tnf-alpha plays an important role in host resistance against infectio ...200818564248
antimicrobial resistance of listeria monocytogenes isolated from a poultry further processing plant.the aim of this study was to compare antimicrobial resistance profiles of distinct types of listeria monocytogenes isolated from a commercial poultry cooking plant. one hundred fifty-seven l. monocytogenes isolates representing 14 different acta types were tested for susceptibility to 19 antimicrobial drugs using the broth microdilution method. all isolates were susceptible to antimicrobials except for ceftriaxone (153 isolates [97%] intermediate or resistant), oxacillin with 2% nacl (142 isolat ...200818564907
sigmab- and prfa-dependent transcription of genes previously classified as putative constituents of the listeria monocytogenes prfa regulon.mounting evidence suggests that sigma(b) and prfa coregulate transcription of multiple genes in listeria monocytogenes, therefore, the relative contributions of sigma(b) and prfa to transcript levels of genes identified previously as differentially regulated by prfa were measured. group i genes are recognized virulence genes that are positively regulated by prfa; group ii genes were reported previously as negatively regulated by prfa; and multiple group iii genes were proposed to be coregulated ...200818564909
analysis of survival rates and cellular fatty acid profiles of listeria monocytogenes treated with supercritical carbon dioxide under the influence of cosolvents.in the present study, we identified several process variables that significantly affect the efficiency of supercritical carbon dioxide inactivation of the food-borne pathogen listeria monocytogenes. treatment with sc-co(2) completely disabled the colony-forming activity of the cells (8-log reduction) within specific treatment time (10-50 min), pressure (80-150 bar), and temperature ranges (35-45 degrees c). microorganism inactivation rates increased proportionally with pressure and temperature, ...200818565606
immunity gene pedb enhances production of pediocin pa-1 in naturally resistant lactococcus lactis strains.heterologous production of the antilisterial bacteriocin pediocin pa-1 in lactococci is an attractive objective to increase the safety of dairy products. in a previous paper, we developed a system for the heterologous production of the bacteriocin pediocin pa-1 in pediocin-resistant lactococcal hosts through a leader exchange strategy. the system was based on 3 genes, 1 encoding the fusion between the lactococcin a leader and propediocin pa-1, and the other 2 encoding the lactococcin a secretion ...200818565917
innate responses to systemic infection by intracellular bacteria trigger recruitment of ly-6chigh monocytes to the brain.blood borne listeria monocytogenes enter the cns via migration of parasitized ly-6chigh monocytes, but the signals that trigger this migration are not known. to understand more completely events leading to monocyte recruitment, experiments presented here combined microarray analysis of gene expression in the brains of experimentally infected mice with measurements of bacterial cfu and serum cytokines following i.v. infection with l. monocytogenes. at 24 and 48 h postinfection, the brain was ster ...200818566419
systemic listeriosis in caged canaries (serinus canarius).the occurrence of listeriosis in 12 caged canaries is described where 50% of the birds, including the female and all of the offspring, died within 2 weeks without clinical signs. at necropsy, multifocal necrotizing and partly granulomatous hepatitis, splenitis, myocarditis, interstitial nephritis, and exudative pericarditis with intra-lesional listeria monocytogenes were the predominant findings as shown by histopathology and immunohistochemistry. microbiology, serology and polymerase chain reac ...200818568661
flavonoid treatment of murine macrophages does not alter ingestion or intracellular survival of listeria monocytogenes.it was recently reported that the aryl hydrocarbon receptor (ahr) plays a role in innate immunity to listeria monocytogenes infection in mice. in this study the authors analyzed whether incubation of murine macrophages with various flavonoids that have agonist or antagonist activity for the ahr (beta-naphthoflavone, alpha-naphthoflavone, quercetin, luteolin) affect the uptake and survival of l. monocytogenes. using the raw264.7 and j774 murine macrophage cell lines and bone marrow-derived macrop ...200818569079
microarray evaluation of the listeria monocytogenes infection and amoxicillin treatment in mice.by using affymetrix mouse genome arrays and 20 biological replicates per experimental condition, the predictive value of liver and blood gene expression profiles previously identified was validated as predictive of listeria monocytogenes infection severity (lethal and nonlethal infection). the ability of these genes to predict the outcome of antibiotic treatment was also assessed. lethally infected balb/c mice were treated with amoxicillin at 10 or 20 mg/kg; only the higher dose prevented death. ...200818569167
staphylococcus saprophyticus atcc 15305 is internalized into human urinary bladder carcinoma cell line 5637.invasion of bacteria into nonphagocytic host cells is an important pathogenicity factor for escaping the host defence system. gram-positive organisms, for example staphylococcus aureus and listeria monocytogenes, are invasive in nonphagocytic cells, and this mechanism is discussed as an important part of the infection process. uropathogenic escherichia coli and staphylococcus saprophyticus can cause acute and recurrent urinary tract infections as well as bloodstream infections. staphylococcus sa ...200818573154
safety improvement and preservation of typical sensory qualities of traditional dry fermented sausages using autochthonous starter cultures.traditional dry fermented sausages are manufactured without addition of starter cultures in small-scale processing units, their fermentation relying on indigenous microflora. characterisation and control of these specific bacteria are essential for the sensory quality and the safety of the sausages. the aim of this study was to develop an autochthonous starter culture that improves safety while preserving the typical sensory characteristics of traditional sausages. an autochthonous starter compo ...200818573561
decreased susceptibility of mice to infection with listeria monocytogenes in the absence of interleukin-18.the induction of proinflammatory cytokines such as gamma interferon (ifn-gamma) and tumor necrosis factor alpha is crucial for the early control of bacterial infections. since interleukin-18 (il-18) acts as a potent inducer of ifn-gamma, it might play an important role in the induction of a protective immune response in listeriosis. we used a murine model of systemic listeria monocytogenes infection to study the immune response to these intracellular bacteria in the absence of il-18. for this pu ...200818573894
diverse myeloid and lymphoid cell subpopulations produce gamma interferon during early innate immune responses to francisella tularensis live vaccine strain.francisella tularensis, a small gram-negative intracellular bacterium responsible for causing tularemia, is highly pathogenic and classified as a category a agent of bioterrorism. as for other intracellular pathogens, successful protective immune responses to francisella tularensis require rapid and efficient induction of gamma interferon (ifn-gamma) production. studies using intracellular bacteria such as listeria monocytogenes as well as francisella suggest that natural killer (nk) and t cells ...200818573901
rapid eradication of listeria monocytogenes by moxifloxacin in a murine model of central nervous system listeriosis.listeriosis is a rare but life-threatening infection. a favorable outcome is greatly aided by early administration of antibiotics with rapid bactericidal activity against listeria monocytogenes. moxifloxacin, a new-generation fluoroquinolone with extended activity against gram-positive bacteria, has proved its effectiveness in vitro against intracellular reservoirs of bacteria. the efficacies of moxifloxacin and amoxicillin were compared in vivo by survival curve assays and by studying the kinet ...200818573932
cooperation between prokaryotic (lde) and eukaryotic (mrp) efflux transporters in j774 macrophages infected with listeria monocytogenes: studies with ciprofloxacin and moxifloxacin.antibiotic efflux is observed in both eukaryotic and prokaryotic cells, modulating accumulation and resistance. the present study examines whether eukaryotic and prokaryotic fluoroquinolone transporters can cooperate in the context of an intracellular infection. we have used (i) j774 macrophages (comparing a ciprofloxacin-resistant cell line overexpressing an mrp-like transporter with wild-type cells with basal expression), (ii) listeria monocytogenes (comparing a clinical isolate [clip21369] di ...200818573933
antimicrobial activity of dc-159a, a new fluoroquinolone, against 1,149 recently collected clinical isolates.the activity of dc-159a, a novel orally administered fluorinated quinolone, was evaluated by reference broth microdilution or agar dilution methods against 1,149 recently collected clinical isolates from five continents. against pathogens associated with community-acquired respiratory tract infections (ca-rtis), the mic(90)s were 0.12 microg/ml for streptococcus pneumoniae, 0.015 to 0.03 microg/ml for haemophilus influenzae, 0.03 microg/ml for moraxella catarrhalis, and 0.12 microg/ml for beta-h ...200818573936
[detection and identification of seven clinical common pathogenic bacteria by oligonucleotide microarray].using 16s rdna and 23s rdna genes as the target sequences to develop a system based on oligonucleotide microarray and to detect the seven clinical pathogenic bacteria, commonly seen.200819103121
surveillance of listeriosis in navarre, spain, 1995-2005--epidemiological patterns and characterisation of clinical and food isolates.we monitored the incidence of human listeriosis in navarre, a region in north of spain between 1995 and 2005, and carried out the characterisation of listeria monocytogenes isolates obtained from clinical samples and ready-to-eat products (sliced cooked meat, smoked salmon and liver pate). the active surveillance requesting hospitals to notify all listeriosis cases (n=40) yielded higher incidence rates (average annual rate 0.65/100,000 inhabitants, range 0.18-1.18/100,000 inhabitants) than expec ...200819081001
new insights into determinants of listeria monocytogenes virulence.listeria monocytogenes is the causative agent of human listeriosis, a potentially fatal foodborne infection. clinical manifestations range from febrile gastroenteritis to more severe invasive forms including meningitis, encephalitis, abortions, and perinatal infections. this gram-positive facultative intracellular pathogen has evolved multiple strategies to face extracellular innate defense mechanisms of the host and to invade and multiply intracellularly within macrophages and nonphagocytic cel ...200819081533
identification of a new molecular target of class iia bacteriocins in listeria monocytogenes egde.it was shown recently (calvez et al. 2007) that glpq and pde genes are involved in intermediate resistance of enterococcus faecalis jh2-2 to dvnv41, a class iia bacteriocin produced by carnobacterium divergens v41. the listerial orthologs of lpq and pde genes might be lmo0052 and lmo1292 genes, respectively. here, the role of lmo0052 and lmo1292 genes in resistance of listeria monocytogenes egde to dvnv41 and mesy105 was investigated. l. monocytogenes egde was inactivated in lmo0052 and/or lmo12 ...200819085076
concurrent generation of effector and central memory cd8 t cells during vaccinia virus infection.it is generally thought that during the contraction phase of an acute anti-viral t cell reponse, the effector t cells that escape activation-induced cell death eventually differentiate into central memory t cells over the next several weeks. here we report that antigen-specific cd8t cells with the phenotype and function of central memory cells develop concomitantly with effector t cells during vaccinia virus (vv) infection. as soon as 5 days after an intraperitoneal infection with vv, we could i ...200819116651
effects of organic matter on acidic electrolysed water for reduction of foodborne pathogens on lettuce and spinach.to evaluate the efficacy of acidic electrolysed water (ew) in the presence of organic matter (bovine serum) on the inoculated surfaces of lettuce and spinach.200819120630
isolation and characterization of bacteriocin-producing bacteria from the gastrointestinal tract of broiler chickens for probiotic use.to isolate and characterize the bacteriocin-producing bacteria (bpb) from the gastrointestinal tract of broiler chickens for probiotic use.200819120666
anti-listerial activity of bacteriocin-producing lactobacillus curvatus cwbi-b28 and lactobacillus sakei cwbi-b1365 on raw beef and poultry meat.the study aimed to evaluate the effect of the bacteriocins produced by lactobacillus sakei cwbi-b1365 and lactobacillus curvatus cwbi-b28 on the growth and survival of listeria monocytogenes in raw beef and poultry meat.200819120930
listeria monocytogenes bacteremia in a twin pregnancy with differential outcome: fetus papyraceus and a full-term delivery.a 41-year-old saudi woman, gravida 7, para 5, aborta 1 with sickle cell disease at week 12 of gestation of diamniotic dichorionic twin pregnancy was admitted with fever. blood cultures grew listeria monocytogenes. she was treated with intravenous ampicillin and had death of one of the fetuses after 10 days. an ultrasound at 19 weeks of gestation showed a normal intrauterine gestation and the presence of significantly collapsed second twin gestational sac consistent with fetal papyraceus. at 37 w ...200819122927
[listeria monocytogenes induced-chronic arthritis in an immunoincompetent child]. 200819128757
molecular template for a voltage sensor in a novel k+ channel. iii. functional reconstitution of a sensorless pore module from a prokaryotic kv channel.kvlm is a prokaryotic voltage-gated k(+) (kv) channel from listeria monocytogenes. the sequence of the voltage-sensing module (transmembrane segments s1-s4) of kvlm is atypical in that it contains only three of the eight conserved charged residues known to be deterministic for voltage sensing in eukaryotic kv's. in contrast, the pore module (pm), including the s4-s5 linker and cytoplasmic tail (linker-s5-p-s6-c-terminus) of kvlm, is highly conserved. here, the full-length (fl)-kvlm and the kvlm- ...200819029373
[characterization and prevalence of clones of listeria monocytogenes isolated from patients in 2001-2008 in the czech republic].to characterize human isolates of listeria monocytogenes by typing methods and to test them for use in epidemiological investigations.200819069026
[rapid detection method of three types of bacterial pathogens in aquatic products established by multiplex pcr].to develop a rapid multiplex pcr (m-pcr) assay for simultaneously detection of three foodborne pathogens in aquatic products.200819069666
modulation of prfa activity in listeria monocytogenes upon growth in different culture media.prfa is the major transcriptional activator of most virulence genes of listeria monocytogenes. its activity is modulated by a variety of culture conditions. here, we studied the prfa activity in the l. monocytogenes wild-type strain egd and an isogenic prfa deletion mutant (egddeltaprfa) carrying multiple copies of the wild-type prfa or the mutant prfa* gene (strains egddeltaprfapprfa and egddeltaprfapprfa*) in response to growth in brain heart infusion (bhi), luria-bertani broth (lb) or a defin ...200819047753
rapid and sensitive detection of listeria monocytogenes using a pcr-enzymelinked immunosorbent assay.a pcr-enzyme-linked immunosorbent assay (pcr-elisa) was developed for the rapid and sensitive detection of l. monocytogenes. pcr primers generating a 132-bp amplicon and a capture probe able to hybridize to the pcr amplicon were designed based on the l. monocytogenes-specific hly gene encoding listeriolysin. the detection limit of pcr-elisa for l. monocytogenes was determined to be as low as 10 cells per pcr reaction, and this level of detection was achieved within 5 h. these results indicate th ...200819047833
il-12 produced by dendritic cells augments cd8+ t cell activation through the production of the chemokines ccl1 and ccl17.il-12 family members are an important link between innate and adaptive immunity. il-12 drives th1 responses by augmenting ifn-gamma production, which is key for clearance of intracellular pathogens. il-23 promotes the development of il-17-producing cd4(+) t cells that participate in the control of extracellular pathogens and the induction of autoimmunity. however, recent studies have shown that these cytokines can modulate lymphocyte migration and cellular interactions. therefore, we sought to d ...200819050277
acid stress responses in listeria monocytogenes. 200819026862
the role of sigma b (sigma b) in the stress adaptations of listeria monocytogenes: overlaps between stress adaptation and virulence. 200819026864
listeria monocytogenes infection in patients with rheumatic diseases on tnf-alpha antagonist therapy: the spanish study group experience.the prognosis of patients with rheumatic diseases has improved considerably following the use of biological therapies. however, an increase in the frequency of bacterial infections has been observed in patients receiving these therapies. in the present study we aimed to assess the frequency of listeria monocytogenes infection in a large series of patients with rheumatic diseases on treatment with tumor necrosis factor (tnf)-alpha blockers because of active disease refractory to conventional ther ...200819032819
kbma listeria monocytogenes is an effective vector for dc-mediated induction of antitumor immunity.vaccine strategies that utilize human dcs to enhance antitumor immunity have yet to realize their full potential. approaches that optimally target a spectrum of antigens to dcs are urgently needed. here we report the development of a platform for loading dcs with antigen. it is based on killed but metabolically active (kbma) recombinant listeria monocytogenes and facilitates both antigen delivery and maturation of human dcs. highly attenuated kbma l. monocytogenes were engineered to express an e ...200819033668
antimicrobial peptides effectively kill a broad spectrum of listeria monocytogenes and staphylococcus aureus strains independently of origin, sub-type, or virulence factor expression.host defense peptides (hdps), or antimicrobial peptides (amps), are important components of the innate immune system that bacterial pathogens must overcome to establish an infection and hdps have been suggested as novel antimicrobial therapeutics in treatment of infectious diseases. hence it is important to determine the natural variation in susceptibility to hdps to ensure a successful use in clinical treatment regimes.200819036162
listeria associated mural and valvular endocarditis in an alpaca.an alpaca presented for emergency evaluation of respiratory distress. physical examination revealed weakness, pyrexia, and a grade v/vi left apical holosystolic murmur. initial thoracic examination and radiographs were consistent with left sided congestive heart failure. blood cultures, echocardiographic evaluation, and necropsy findings established a diagnosis of bacterial endocarditis associated with a listeria monocytogenes infection. left ventricular endocarditis is uncommon in ruminants, an ...200819036668
influence of zinc, sodium bicarbonate, and citric acid on the antibacterial activity of ovotransferrin against escherichia coli o157:h7 and listeria monocytogenes in model systems and ham.the influence of nahco(3) and citric acid on the antibacterial activity of apo-ovotransferrin in model systems and ham was investigated. the antibacterial activity of 20 mg/ml of ovotransferrin solution with added nahco(3) (0, 25, 50, or 100 mm) or citric acid (0.25 or 0.5%) was evaluated against escherichia coli o157:h7 and listeria monocytogenes in brain heart infusion broth. the antimicrobial activity of ovotransferrin saturated with fe(2+) or zn(2+) against both pathogens was also measured. ...200819038824
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