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pulsenet: the molecular subtyping network for foodborne bacterial disease surveillance, united states.pulsenet, the national molecular subtyping network for foodborne disease surveillance, was established by the centers for disease control and prevention and several state health department laboratories to facilitate subtyping bacterial foodborne pathogens for epidemiologic purposes. pulsenet, which began in 1996 with 10 laboratories typing a single pathogen (escherichia coli o157:h7), now includes 46 state and 2 local public health laboratories and the food safety laboratories of the u.s. food a ...200111384513
immunology. brief encounter. 200111385554
microbiology. cracking listeria's password. 200111387462
a transgenic model for listeriosis: role of internalin in crossing the intestinal barrier.listeria monocytogenes is responsible for severe food-borne infections, but the mechanisms by which bacteria cross the intestinal barrier are unknown. listeria monocytogenes expresses a surface protein, internalin, that interacts with a host receptor, e-cadherin, to promote entry into human epithelial cells. murine e-cadherin, in contrast to guinea pig e-cadherin, does not interact with internalin, excluding the mouse as a model for addressing internalin function in vivo. in guinea pigs and tran ...200111387478
analysis of sigma(54)-dependent genes in enterococcus faecalis: a mannose pts permease (eii(man)) is involved in sensitivity to a bacteriocin, mesentericin y105.the sigma(54) rna polymerase subunit has a prominent role in susceptibility of listeria monocytogenes and enterococcus faecalis to mesentericin y105, a class iia bacteriocin. consequently, sigma(54)-dependent genes as well as specific activators also required for expression of these genes were sought. five putative sigma(54)-associated activators were detected in the genome of e. faecalis v583, and all but one could activate the transcription of permease genes belonging to sugar phosphotransfera ...200111390688
[isolation of pathogenic bacteria in pasteurized type c milk sold in recife city, pernambuco, brazil].in order to improve information about the microbiological quality of the milk commercially available in the city of recife, 250 samples of pasteurized type-c milk and 50 samples of raw milk were analyzed for yersinia enterocolitica and listeria monocytogenes and verify the possible occurrence of yersinia enterocolitica and listeria monocytogenes. these bacteria can develop in refrigeration temperatures and are responsible for food-born diseases. neither y. enterocolitica nor l. monocytogenes wer ...200111391438
listeria monocytogenes lineage group classification by mama-pcr of the listeriolysin gene.nucleotide sequence differences within several virulence genes, including the listeriolysin o (hly) gene, are associated with three evolutionary lineage groups of listeria monocytogenes. because the ability of l. monocytogenes to cause disease may vary by evolutionary lineage group, rapid discrimination among the three lineage types may be important for estimating pathogenic potential. a mismatch amplification mutation assay (mama) was developed and used to rapidly screen and characterize l. mon ...200111391477
can food-related environmental factors induce different behaviour in two key serovars, 4b and 1/2a, of listeria monocytogenes?listeria monocytogenes isolates (81 in total; 42 isolated from cases of human listeriosis: 39 isolated from food), belonging to serovars 1/2a or 4b, were studied for any group differences between serovars to selected factors associated with foods (two bacteriocins and mild heat treatment), growth kinetics at 37 degrees c and pathogenicity for chick embryos. the isolates were tested for sensitivity to two bacteriocins at 4 degrees c and 37 degrees c, and were tested for the remaining parameters b ...200111393689
diesel exhaust particles suppress macrophage function and slow the pulmonary clearance of listeria monocytogenes in rats.in this study, we tested the hypothesis that exposure to diesel exhaust particles (dep) may increase susceptibility of the host to pulmonary infection. male sprague-dawley rats received a single dose of dep (5 mg/kg), carbon black (cb, 5 mg/kg), or saline intratracheally. three days later, the rats were inoculated intratracheally with approximately 5,000 listeria monocytogenes and sacrificed at 3, 5, and 7 days postinfection, and we determined the number of viable listeria in the left lobe of lu ...200111401764
endogenous interleukin-10 is required for prevention of a hyperinflammatory intracerebral immune response in listeria monocytogenes meningoencephalitis.to analyze the role of interleukin-10 (il-10) in bacterial cerebral infections, we studied cerebral listeriosis in il-10-deficient (il-10(-/-)) and wild-type (wt) mice, the latter of which express high levels of il-10 in both primary and secondary cerebral listeriosis. il-10(-/-) mice succumbed to primary as well as secondary listeriosis, whereas wt mice were significantly protected from secondary listeriosis by prior intraperitoneal immunization with listeria monocytogenes. meningoencephalitis ...200111402000
variation in the infectivity of listeria monocytogenes isolates following intragastric inoculation of mice.the infectivities of 66 listeria monocytogenes isolates were assessed by intragastric inoculation of mice. eight were poorly infective. serovars 4b and 1/2 were more infective than serovars 3 and 4nonb. a noninfective isolate was cleared more rapidly from the cecum than were infective isolates, suggesting that survival in the gut may relate to infectivity.200111402011
inactivation of escherichia coli o1 57:h7, listeria monocytogenes, and lactobacillus leichmannii by combinations of ozone and pulsed electric field.pulsed electric field (pef) and ozone technologies are nonthermal processing methods with potential applications in the food industry. this research was performed to explore the potential synergy between ozone and pef treatments against selected foodborne bacteria. cells of lactobacillus leichmannii atcc 4797, escherichia coli o157:h7 atcc 35150, and listeria monocytogenes scott a were suspended in 0.1% nacl and treated with ozone, pef, and ozone plus pee cells were treated with 0.25 to 1.00 mic ...200111403125
evaluation of a polymerase chain reaction-based system for detection of salmonella enteritidis, escherichia coli o157:h7, listeria spp., and listeria monocytogenes on fresh fruits and vegetables.a polymerase chain reaction (pcr)-based detection system, bax, was evaluated for its sensitivity in detecting salmonella enteritidis, escherichia coli o157:h7, listeria sp., and listeria monocytogenes on fresh produce. fifteen different types of produce (alfalfa sprouts, green peppers, parsley, white cabbage, radishes, onions, carrots, mushrooms, leaf lettuce, tomatoes, strawberries, cantaloupe, mango, apples, and oranges) were inoculated, in separate studies, with salmonella enteritidis, e. col ...200111403127
validation of a 5-log10 reduction of listeria monocytogenes following simulated commercial processing of lebanon bologna in a model system.recently, numerous product recalls and one devastating outbreak that claimed 21 lives were attributed to listeria monocytogenes in ready-to-eat meat products. consequently, the food safety and inspection service published a federal register notice requiring manufacturers of ready-to-eat meat and poultry products to reassess their hazard analysis and critical control point plans for these products as specified in 9 cfr 417.4(a). lebanon bologna is a moist, fermented ready-to-eat sausage. because ...200111403142
antimicrobial effects of corn zein films impregnated with nisin, lauric acid, and edta.bacterial growth during food transport and storage is a problem that may be addressed with packaging materials that release antimicrobials during food contact. in a series of five experiments, edta, lauric acid (la), nisin, and combinations of the three antimicrobial agents were incorporated into a corn zein film and exposed to broth cultures of listeria monocytogenes and salmonella enteritidis for 48 h (sampled at 2, 4, 8, 12, 24, and 48 h). four experiments used starting cultures of 10(8) cfu/ ...200111403145
subtraction hybridization in microplates: an improved method to generate strain-specific pcr primers.an improved subtraction hybridization technique was developed and evaluated. the hybridization is performed in a microplate with the subtractor-dna immobilized in the plate while the probe-dna is in solution. after hybridization the probe-specific dna can easily be removed from the microwell and submitted to further analysis. this new technique has been successfully applied to generate several strain-specific pcr-primers for lactococcus lactis subsp. lactis, pediococcus spec., saccharomyces spec ...200111403389
intracellular bacteria as targets and carriers for vaccination.in this review we discuss intracellular bacteria as targets and carriers for vaccines. for clarity and ease of comprehension, we focus on three microbes, mycobacterium tuberculosis, listeria monocytogenes and salmonella, with an emphasis on tuberculosis, one of the leading causes of death from infectious disease. novel vaccination strategies against these pathogens are currently being considered. one approach favors the use of live attenuated vaccines and vaccine carrier strains thereof, either ...200111405217
bacteria-mediated transfer of eukaryotic expression plasmids into mammalian host cells.invasive intracellular bacteria are able to transfer eukaryotic expression plasmids into mammalian host cells in vitro and in vivo. this can be used to induce immune responses toward protein antigens encoded by the plasmid or to complement genetic defects. plasmid transfer takes place when the recombinant bacterium dies within the host cell, either due to metabolic attenuation or induction of autolysis. alternatively, antibiotics can be used and spontaneous transfer has also been observed, indic ...200111405218
[what is your diagnosis? basal meningitis and rhombencephalitis. blood culture positive for listeria monocytogenes]. 200111407238
comparative in vitro activity of abt-773, a novel antibacterial ketolide.the in vitro activities of abt-773, erythromycin, clarithromycin, and azithromycin were compared. abt-773 was the most active compound against macrolide-susceptible streptococcus pneumoniae, streptococcus pyogenes, staphylococcus aureus, staphylococcus epidermidis, listeria monocytogenes, and enterococcus spp. and multidrug-resistant streptococcus pneumoniae. it also had good activity against gram-negative and atypical respiratory tract pathogens and helicobacter pylori.200111408246
a simple chemiluminescence-based method for rapid enumeration of listeria spp. microcolonies.listeria monocytogenes is capable, under certain conditions, of producing chemiluminescence which is amplified by luminol. this property was used to detect and count microcolonies of listeria spp. in a few hours, without the use of a microscope.200111412329
comparison of selective and non-selective enrichment media in the detection of listeria monocytogenes from meat containing listeria innocua.this study investigated whether the higher incidence of recovery from meat of listeria innocua compared with l. monocytogenes could be due to the laboratory media used, leading to an artificially lower detection of the pathogenic species, l. monocytogenes.200111412330
listeria monocytogenes adheres to many materials found in food-processing environments.to investigate the adhesion of listeria monocytogenes 10403s to 17 different, food-use approved materials representing metals, rubbers and polymers.200111412331
influence of strain and trisodium phosphate concentration on growth parameters of listeria monocytogenes in vitro.the present study was conducted to determine the influence of strain and trisodium phosphate (tsp) concentration in the growth of listeria monocytogenes in vitro.200111412357
separation of listeria from cheese and enrichment media using antibody-coated microbeads and centrifugation.an immunoseparation system for the separation of listeria from enriched cheese samples was developed. the system utilizes polystyrene microbeads (3.8 microm in diameter) coated with covalently bound anti-listeria genus-specific antibody. the beads were incubated with cheese enriched in half-fraser broth and the bead-bacterial complex was separated by centrifugation at 110 g then spread on selective agar plates. although cross-reactivity with certain gram-positive bacteria (staphylococcus saproph ...200111412914
evaluation of enhanced haemolysis agar for detection of listeria spp. and l. monocytogenes from production lines of fresh to cold-smoked fish.enhanced haemolysis agar (eha) was compared to the two conventional listeria isolation agars oxford and palcam for its ability to detect listeria spp. from production lines of fresh to cold-smoked fish. the ability of eha for distinguishing l. monocytogenes colonies from other listeria spp. was also evaluated.a total of 243 fish and environmental samples were analysed. overall, 42 samples were found to contain listeria spp. only 34 samples were positive simultaneously by the three plating media. ...200111412926
functional dichotomy in natural killer cell signaling: vav1-dependent and -independent mechanisms.the product of the protooncogene vav1 participates in multiple signaling pathways and is a critical regulator of antigen-receptor signaling in b and t lymphocytes, but its role during in vivo natural killer (nk) cell differentiation is not known. here we have studied nk cell development in vav1-/- mice and found that, in contrast to t and nk-t cells, the absolute numbers of phenotypically mature nk cells were not reduced. vav1-/- mice produced normal amounts of interferon (ifn)-gamma in response ...200111413196
gc1q-r/p33, a member of a new class of multifunctional and multicompartmental cellular proteins, is involved in inflammation and infection.human gc1q-r (p33, p32, c1qbp, tap) is a ubiquitously expressed, multiligand-binding, multicompartmental cellular protein involved in various ligand-mediated cellular responses. although expressed on the surface of cells, an intriguing feature of the membrane-associated form of gc1q-r is that its translated amino acid sequence does not predict the presence of either a sequence motif compatible with a transmembrane segment or a consensus site for a glycosylphosphatidylinositol anchor. moreover, t ...200111414365
protection against murine listeriosis by oral vaccination with recombinant salmonella expressing hybrid yersinia type iii proteins.in the present study, we have investigated the possibility to engage the yersinia outer protein e (yope) as a carrier molecule for heterologous ag delivery by the type iii secretion system of salmonella typhimurium. defined secretion and translocation domains of yope were fused to the immunodominant t cell ags listeriolysin o and p60 of listeria monocytogenes. in vitro experiments showed that s. typhimurium allows secretion and translocation of large hybrid yope proteins in a type iii-dependent ...200111418671
recurrent listeria monocytogenes infection: relapse or reinfection with a unique strain confirmed by molecular subtyping.we report a case of recurrent listeriosis for which molecular subtyping by automated ribotyping and pulsed-field gel electrophoresis confirmed either relapse of infection or reinfection due to a common source almost 9 months after initial infection due to a unique listeria monocytogenes strain in a patient with colorectal cancer. this case report illustrates the potential use of molecular subtyping to further understand the pathogenesis and epidemiology of listeriosis and the potential for relap ...200111418887
biological response modifier activity of an exopolysaccharide from paenibacillus jamilae cp-7.an extracellular polysaccharide was purified from culture supernatants of paenibacillus jamilae cp-7, a gram-positive bacillus that was isolated from compost prepared with olive mill wastewaters. the extracellular polysaccharide was produced under aerobic conditions in a medium containing olive mill wastewaters (80% [vol/vol]). this exopolymer had a low level of acute toxicity when it is administered to balb/c mice by the intraperitoneal route. interesting immunomodulatory effects were detected ...200111427415
correlations between molecular subtyping and serotyping of listeria monocytogenes.to define relationships between listeria monocytogenes genetic lineages, ribotypes, and serotypes, 235 l. monocytogenes isolates were characterized by serotyping and automated ecori ribotyping. genetic lineage predicted the following serovar clusters: lineage i, comprising serotypes 1/2b, 3b, 3c, and 4b; lineage ii, comprising serotypes 1/2a, 1/2c, and 3a; and lineage iii, comprising serotypes 4a and 4c. some ecori ribotypes contained multiple serotypes; a subset of these isolates was further di ...200111427601
endophthalmitis caused by listeria monocytogenes.listeria monocytogenes was isolated from the aqueous chamber of an immunodepressed patient with acute hypertensive uveitis, who developed a dark hypopyon and pigment dispersion. no extraocular septic focus was found. treatment was successful with intravitreal vancomycin, anterior chamber irrigation with vancomycin, orally administered ciprofloxacin, and topical fortified vancomycin.200111427612
industrial application of an antilisterial strain of lactobacillus sakei as a protective culture and its effect on the sensory acceptability of cooked, sliced, vacuum-packaged meats.the application of a protective lactic acid bacterium (lab) during the commercial production of cooked meat products is described. the lab, a strain of lactobacillus sakei, was previously isolated from cooked ham and inhibited growth of listeria monocytogenes and escherichia coli o157:h7 in this product. l. sakei was applied to the cooked products at a concentration of 10(5)-10(6) cfu/g immediately before slicing and vacuum-packaging using a hand-operated spraying bottle. the lab strain inhibite ...200111428578
effects of sodium lactate and other additives in a cooked ham product on sensory quality and development of a strain of lactobacillus curvatus and listeria monocytogenes.cooked cured ham products were produced according to a standard recipe for cooked ham with various levels of sodium lactate, sodium diacetate or buffered sodium citrate. they were compared with a reference ham product with respect to sensory quality and growth of lactobacillus curvatus and listeria monocytogenes. for this, a part of the products was sensory analysed directly after preparation. another part of the cooked ham products was minced and homogeneously inoculated with l. curvatus (10(4) ...200111428579
regulation of virulence genes in listeria.as in all pathogenic bacteria, virulence of the facultative intracellular listeria species is a multifactorial trait. the expression of the bacterial genes involved in the different steps of the infectious process--invasion, intracellular multiplication and spreading--is temporally and spatially controlled, thus ensuring the presence of the respective gene products at the right moment and place. so far, one network which is involved in the regulation of listerial virulence, the prfa regulon, has ...200111437337
cervical lymphadenitis--a rare case of focal listeriosis.cervical lymphadenopathy is a condition with a broad differential diagnosis. malignant tumors, allergic reactions, autoimmune diseases as well as various infectious agents can be the cause. we report the case of a 75-year-old man who had a cervical lymphadenopathy without symptoms of infection. the draining lymph nodes were excised. histology revealed a granulomatous abscess and culture yielded pure growth of listeria monocytogenes. because food is occasionally contaminated with l. monocytogenes ...200111440390
cutting edge: ifn-inducible elr- cxc chemokines display defensin-like antimicrobial activity.recent reports highlighted the chemotactic activities of antimicrobial peptide defensins whose structure, charge, and size resemble chemokines. by assaying representative members of the four known families of chemokines we explored the obverse: whether some chemokines exert antimicrobial activity. in a radial diffusion assay, only recombinant monokine induced by ifn-gamma (mig/cxcl9), ifn-gamma-inducible protein of 10 kda (ip-10/cxcl10), and ifn-inducible t cell alpha chemoattractant (i-tac/cxcl ...200111441062
spontaneous nisin-resistant listeria monocytogenes mutants with increased expression of a putative penicillin-binding protein and their sensitivity to various antibiotics.a concern regarding the use of bacteriocins, as for example the lantibiotic nisin, for biopreservation of certain food products is the possibility of resistance development and potential cross-resistance to antibiotics in the target organism. the genetic basis for nisin resistance development is as yet unknown. we analyzed changes in gene expression following nisin resistance development in listeria monocytogenes 412 by restriction fragment differential display. the mutant had increased expressi ...200111442339
listeria monocytogenes: a continuing challenge.as a leading cause of death from a foodborne pathogen, listeria monocytogenes continues to cause sporadic cases and outbreaks of illness. the most recent of these outbreaks in the united states involved consumption of hot dogs, with 101 cases of illness and 21 deaths reported to the centers for disease control and prevention for the years 1998-1999. epidemiologic analysis determined that contamination levels in hot dogs were remarkably low (0.3 cfu [colony-forming units] l monocytogenes serotype ...200111444596
identification and characterization of a novel secreted immunoglobulin binding protein from group a streptococcus.immunoglobulin binding proteins are one of several pathogenicity factors which have been associated with invasive disease caused by group a streptococci. the surface-bound m and m-like proteins of streptococcus pyogenes are the most characterized of these immunoglobulin binding proteins, and in most cases they bind only a single antibody class. here we report the identification of a novel non-m-type secreted protein, designated siba (for secreted immunoglobulin binding protein from group a strep ...200111447160
stress-induced clpp serine protease of listeria monocytogenes is essential for induction of listeriolysin o-dependent protective immunity.the stress-induced protease clpp is required for virulence of the facultative intracellular pathogen listeria monocytogenes. we previously found that in the absence of clpp, the virulence of this pathogen was strongly reduced, mainly due to the decreased production of functional listeriolysin o (llo), a major immunodominant virulence factor promoting intracellular growth. in this work, a clpp deletion mutant of l. monocytogenes was used to study the generation of anti-listeria protective immunit ...200111447171
identification of listeria monocytogenes in vivo-induced genes by fluorescence-activated cell sorting.listeria monocytogenes is a gram-positive, intracellular, food-borne pathogen capable of causing severe infections in immunocompromised or pregnant individuals, as well as numerous animal species. genetic analysis of listeria pathogenesis has identified several genes which are crucial for virulence. the transcription of most of these genes has been shown to be induced upon entry of listeria into the host cell. to identify additional genes that are induced in vivo and may be required for l. monoc ...200111447181
systemic and intracerebral infections of mice with listeria monocytogenes successfully treated with linezolid.linezolid is an oxazolidinone derivative which is active mostly against gram-positive bacteria. in this work its activity against the facultatively intracellular bacterium listeria monocytogenes was examined in vitro, in tissue culture and in animal models of systemic and intracerebral infection and compared with ampicillin which is the antibiotic of choice for treatment of listeriosis. all strains of l. monocytogenes were susceptible to the substance, with minimal inhibitory concentrations (mic ...200111450884
activities of gemifloxacin and five other antimicrobial agents against listeria monocytogenes and coryneform bacteria isolated from clinical samples.the in vitro activities of gemifloxacin, ciprofloxacin, ampicillin, doxycycline, gentamicin, and vancomycin were evaluated against 15 listeria monocytogenes strains and 205 coryneform bacteria isolated from clinical samples. the percentages of strains inhibited by gemifloxacin at 0.5 microg/ml were 100% (l. monocytogenes), 93.3% (brevibacterium spp.), 90% (corynebacterium minutissimum), 42.5% (corynebacterium amycolatum), 20% (corynebacterium striatum), 12.5% (corynebacterium jeikeium), and 10% ...200111451706
effect of age on respiratory defense mechanisms: pulmonary bacterial clearance in fischer 344 rats after intratracheal instillation of listeria monocytogenes.to examine the lung defense mechanisms of both young and aged rats before and after pulmonary challenge with a bacterial pathogen.200111451845
optimizing detection of heat-injured listeria monocytogenes in pasteurized milk.optimal conditions for the detection of heat-injured cells of listeria monocytogenes in modified pennsylvania state university (mpsu) broth were determined using a response surface design generated by a computer program, echip. different combinations of incubation temperatures and lithium, magnesium, and d-serine concentrations were evaluated to determine the optimum conditions for the detection of heat-injured l. monocytogenes in filter-sterilized whole milk inoculated with selected problematic ...200111456184
antimicrobial activity of essential oils from plants against selected pathogenic and saprophytic microorganisms.the beneficial health effects of extracts from many types of plants that are used as seasoning agents in foods and beverages have been claimed for centuries. the purpose of this study was to examine the effectiveness of selected herb and spice essential oils for control of growth and survival of microorganisms. inhibition of growth was tested by the paper disc agar diffusion method. antibiotic susceptibility discs were used as control. minimum lethal concentration (mlc) was determined by the tub ...200111456186
evaluation of thin agar layer method for recovery of acid-injured foodborne pathogens.the thin agar layer (tal) method of kang and fung was used to enumerate acid-injured foodborne pathogens. this method involves overlaying 14 ml of nonselective medium (tryptic soy agar [tsa]) onto a prepoured and solidified pathogen-specific, selective medium in a petri dish. after surface plating, injured cells resuscitated and grew on tsa during the first few hours of incubation; then, the selective agents from the selective medium diffused to the top layer, interacted with the recovered micro ...200111456194
fate of escherichia coli o157:h7, salmonella typhimurium dt 104, and listeria monocytogenes in fresh meat decontamination fluids at 4 and 10 degrees c.bacterial pathogens may colonize meat plants and increase food safety risks following survival, stress hardening, or proliferation in meat decontamination fluids (washings). the objective of this study was to evaluate the ability of escherichia coli o157:h7, salmonella typhimurium dt 104, and listeria monocytogenes to survive or grow in spray-washing fluids from fresh beef top rounds sprayed with water (10 or 85 degrees c) or acid solutions (2% lactic or acetic acid, 55 degrees c) during storage ...200111456202
survival of escherichia coli o157:h7, salmonella typhimurium and listeria monocytogenes in and on vacuum packaged lebanon bologna stored at 3.6 and 13.0 degrees c.escherichia coli o157:h7, salmonella typhimurium, or listeria monocytogenes was spread onto the surface of lebanon bologna luncheon slices using sterile glass rods. the inoculated slices were stacked and vacuum packaged. the packages were stored at 3.6 or 13 degrees c. the foodborne pathogens. e. coli o157:h7, salmonella typhimurium, or l. monocytogenes were reduced in lebanon bologna during storage at 3.6 or 13 degrees c. the higher storage temperature (13.0 degrees c) resulted in significantly ...200111456203
prevalence of listeria monocytogenes in broilers at the abattoir, processing plant, and retail level.the environment and products from two broiler abattoirs and processing plants and raw broiler pieces at the retail level were sampled for listeria monocytogenes in order to evaluate the contamination level of the broiler carcasses and products. sampling started in the slaughtering process and finished with raw broiler meat or ready-to-eat cooked product. sampling sites positive for l. monocytogenes at the broiler abattoir were the air chiller, the skin-removing machine, and the conveyor belt lea ...200111456209
outbreak of listeriosis associated with homemade mexican-style cheese--north carolina, october 2000-january 2001.on november 13, 2000, health-care providers at a hospital in winston-salem, north carolina, contacted the local health department about three cases of listeriosis within a 2-week period in recent mexican immigrants. the north carolina general communicable disease control branch, in collaboration with the forsyth county health department, the north carolina departments of agriculture and consumer services (ncda&cs) and environment and natural resources, the food and drug administration (fda), and ...200111456331
protective ctl response is induced in the absence of cd4+ t cells and ifn-gamma by gene gun dna vaccination with a minigene encoding a ctl epitope of listeria monocytogenes.our work was undertaken to learn the mechanism of induction of protective cytotoxic t lymphocytes (ctl) by gene gun dna vaccination with p91m encoding an h-2kd-restricted t cell epitope of listeriolysin o (llo). vaccination with p91m induced vigorous antigen-specific cd8+ ctl that produce ifn-gamma and was able to confer partial protection against listerial challenge. however, the p91m-induced protective immunity was revealed to be independent of the ifn-gamma and cd4+ t cell help. the ctl induc ...200111457557
inactivation of lrg-47 and irg-47 reveals a family of interferon gamma-inducible genes with essential, pathogen-specific roles in resistance to infection.the cytokine interferon (ifn)-gamma regulates immune clearance of parasitic, bacterial, and viral infections; however, the underlying mechanisms are poorly understood. recently, a family of ifn-gamma-induced genes has been identified that encode 48-kd gtp-binding proteins that localize to the endoplasmic reticulum of cells. the prototype of this family, igtp, has been shown to be required for host defense against acute infections with the protozoan parasite toxoplasma gondii, but not for normal ...200111457893
retrospective evidence for nosocomial listeria infection. 200111461136
recovery of intraoperative microbicidal and inflammatory functions of alveolar immune cells after a tobacco smoke-free period.tobacco smoking inhibits alveolar macrophage function, but cessation of smoking markedly reduces the risk of postoperative pulmonary complications. the authors therefore evaluated the effect of nonsmoking duration on both antimicrobial and inflammatory functions of alveolar macrophages during anesthesia and surgery.200111465626
brain abscess due to listeria monocytogenes: five cases and a review of the literature. 200111470983
initiation of alcoholic fatty liver and hepatic inflammation with a specific recall immune response in alcohol-consuming c57bl/6 mice.whether immunological responses are involved in initiation and progression of alcoholic liver disease is unclear. we describe a mouse model of alcoholic liver injury characterized by steatosis and hepatic inflammation initiated by a recall immune response. mice immune to listeria monocytogenes fed a liquid diet containing ethanol and challenged with viable bacteria developed steatosis within 24 h and, at a later time, elevated serum alanine aminotransferase levels, indicating more liver damage i ...200111472435
automated ribotyping using different enzymes to improve discrimination of listeria monocytogenes isolates, with a particular focus on serotype 4b strains.to develop improved automated subtyping approaches for listeria monocytogenes, we characterized the discriminatory power of different restriction enzymes for ribotyping. when 15 different restriction enzymes were used for automated ribotyping of 16 selected l. monocytogenes isolates, the restriction enzymes ecori, pvuii, and xhoi showed high discriminatory ability (simpson's index of discrimination > 0.900) and produced complete and reproducible restriction cut patterns. these three enzymes were ...200111474034
[microbial growth and cold. study of the particular case of listeria monocytogenes].some of micro-organisms are able to adapt themselves to hardest environmental conditions. so, about cold conditions, most of them can still grow at very low temperatures under 0 degree celsius (nitrogen liquefied at -169 degrees c is the best way for preserving microbes). by another way some germs, qualified psychrotophic bacteria, grow quite easily between 0 degree c and +10 degrees c. among these bacteria the author draw the attention to listeria monocytogenes, a germ contaminating often foods ...200111474584
detection of anti-listeriolysin o and listeria monocytogenes in experimentally infected buffaloes (bubalus bubalis).the kinetics of antibody production against listeriolysin o (allo) and the recovery pattern of listeria monocytogenes from bacteriological samples were studied following oral infection of buffalo calves with 3 x 10(9) cells each of pathogenic l. monocytogenes. antibodies to llo appeared by 7-10 days post infection (pi), with a shallow peak between days 16 and 36 pi, when tested by indirect plate-elisa. the titres of allo in all the animals then declined slowly but remained detectable up to day 7 ...200111474862
listeria monocytogenes: a causative agent of gastroenteritis?the intestinal tract is the major portal of entry for listeria monocytogenes, which becomes ingested via contaminated food. the pathogenic strains penetrate the mucosal tissue either directly, via engulfment by enterocytes, or indirectly, via active penetration of the peyer's patches. there are now several reports clearly demonstrating that, in some cases, acute enteritis may be the only symptom of listeria infection or may precede the typical symptoms of listeriosis such as sepsis and meningiti ...200111476434
dicynthaurin: an antimicrobial peptide from hemocytes of the solitary tunicate, halocynthia aurantium.we isolated a novel antimicrobial peptide, dicynthaurin, from hemocytes of a tunicate, halocynthia aurantium. the native peptide had a mass of approximately 6.2 kda and was composed of two 30-residue monomers without sequence homology to any previously identified peptides (ilqkavldclkaagsslskaaitaiynkit). most cynthaurin molecules were c-terminally amidated and were linked covalently by a single cystine disulfide bond. when performed in membrane-mimetic environments, circular dichroism studies o ...200111479030
effects of trimethoprim and co-trimoxazole on the morphology of listeria monocytogenes in culture medium and after phagocytosis.the purpose of this study was to compare the extra- and intracellular activity of antifolates on listeria monocytogenes. the fortuitous discovery of elongated bacteria in response to trimethoprim revealed a novel effect on the morphology of listeria in cell culture medium and after phagocytosis. this phenomenon permitted the quantification of trimethoprim activity, revealing comparable activity intra- and extracellularly. subinhibitory concentrations of trimethoprim resulted in bacterial elongat ...200111481287
the in vitro activity of daptomycin against 514 gram-positive aerobic clinical isolates.the in vitro activity of daptomycin was assessed in comparison with that of vancomycin and penicillin against a wide range of gram-positive aerobic clinical isolates. mics were determined by an agar dilution method on mueller-hinton agar (nccls/eucast) and on isotonic agar adjusted to contain 50 mg/l free calcium (bsac). both media were enriched with 5% horse blood for fastidious organisms. daptomycin mics for all 172 staphylococci, including methicillin-susceptible and methicillin-resistant sta ...200111481291
implication of milk and milk products in food-borne diseases in france and in different industrialised countries.a study was carried out to estimate the proportion of diseases due to milk and milk products among food-borne diseases recorded in france and in other countries since 1980. particular attention was given to whether the milk involved was heat-treated or not. four etiologic agents were considered: salmonella spp., staphylococcus aureus, listeria monocytogenes, and pathogenic escherichia coli. an overview of food-borne disease annual reports from seven countries indicated that milk and milk product ...200111482557
measurements and predictions of growth for listeria monocytogenes and salmonella during fluctuating temperature ii. rapidly changing temperatures.growth of listeria monocytogenes and salmonella was examined during various rates of increase and decrease in temperature from and to the minimum for growth. growth was little affected by even the most rapid changes and injury or lag was not observed. subsequent investigations of growth during periods of rapid variation in temperature from and to temperatures below the growth minimum again had little effect and growth was satisfactorily predicted using the dynamic model of baranyi and roberts [i ...200111482561
acta and human zyxin harbour arp2/3-independent actin-polymerization activity.the actin cytoskeleton is a dynamic network that is composed of a variety of f-actin structures. to understand how these structures are produced, we tested the capacity of proteins to direct actin polymerization in a bead assay in vitro and in a mitochondrial-targeting assay in cells. we found that human zyxin and the related protein acta of listeria monocytogenes can generate new actin structures in a vasodilator-stimulated phosphoprotein-dependent (vasp) manner, but independently of the arp2/3 ...200111483954
m-csf transgenic mice: role of m-csf in infection and autoimmunity.in this study, transgenic cd2f1 mouse lines (c-1.1-c-1.11) bearing a transgene encoding the murine growth factor m-csf under the control of the liver specific alpha-1-antitrypsin gene promoter were generated. transgenic c-1.4 mice showed elevated expression of transgene-encoded m-csf in the liver and displayed a 2-3-fold increase of m-csf plasma levels and of macrophage numbers in the liver as compared with non-transgenic littermates. m-csf transgenic mice showed increased resistance against sub ...200111484835
acta from listeria monocytogenes can interact with up to four ena/vasp homology 1 domains simultaneously.the facultative intracellular human pathogenic bacterium listeria monocytogenes actively recruits host actin to its surface to achieve motility within infected cells. the bacterial surface protein acta is solely responsible for this process by mimicking fundamental steps of host cell actin dynamics. acta, a modular protein, contains an n-terminal actin nucleation site and a central proline-rich motif of the 4-fold repeated consensus sequence fpppp (fp(4)). this motif is specifically recognized b ...200111489888
a critical role for interleukin 18 in primary and memory effector responses to listeria monocytogenes that extends beyond its effects on interferon gamma production.the stimulation of interferon (ifn)-gamma by interleukin (il)-12 has been shown to provide protection from intracellular pathogens such as listeria monocytogenes. tumor necrosis factor (tnf) is also a major player in the resolution of listeria infections and is suggested to have more global effects than can be explained by the induction of ifn-gamma alone. since il-18 synergizes with il-12 to induce ifn-gamma production by natural killer and t helper (th)1 cells, we determined its role in respon ...200111489953
dynamic antigen presentation patterns of listeria monocytogenes-derived cd8 t cell epitopes in vivo.little information exists regarding the presentation of antigenic peptides in infected tissues. in this study the in vivo presentation of four different cd8 t cell epitopes of listeria monocytogenes was monitored. peptide presentation was measured by a new, highly sensitive, ex vivo ag presentation assay that was based on the testing of freshly isolated cells from infected spleens with peptide-specific cd8 t cell lines in an ifn-gamma-specific elispot assay. remarkably, the peptide presentation ...200111490007
starvation survival in listeria monocytogenes: characterization of the response and the role of known and novel components.the starvation survival response (ssr) of listeria monocytogenes egd is induced under glucose- or multiple-nutrient-, but not amino-acid limitation. 0.01-0.2% of the population remain viable even after 20 d and the survivors show a reduced cell size and increased cross-protection to several environmental stresses. the development of the ssr may therefore be important in l. monocytogenes survival in the food environment. the initiation, but not the maintenance, of the ssr involves both protein an ...200111496004
curved tails in polymerization-based bacterial motility.the curved actin "comet-tail" of the bacterium listeria monocytogenes is a visually striking signature of actin polymerization-based motility. similar actin tails are associated with shigella flexneri, spotted-fever rickettsiae, the vaccinia virus, and vesicles and microspheres in related in vitro systems. we show that the torque required to produce the curvature in the tail can arise from randomly placed actin filaments pushing the bacterium or particle. we find that the curvature magnitude det ...200111497617
induction of specific cytotoxic lymphocytes in mice vaccinated with brucella abortus rb51.a safe, more sensitive, nonradioactive, neutral red uptake assay was adopted to replace the traditional 51cr release assay for detection of brucella-specific cytotoxic t lymphocyte (ctl) activity. our studies indicated that brucella abortus strain rb51 vaccination of mice induced specific ctls against both strain rb51- and strain 2308-infected j774.a1 macrophages but not against listeria monocytogenes-infected j774.a1 cells. the antigen-specific cytotoxic activity was exerted by t lymphocytes bu ...200111500423
development of a competitive index assay to evaluate the virulence of listeria monocytogenes acta mutants during primary and secondary infection of mice.we developed a competitive index assay for murine listeriosis that tests the virulence of listeria monocytogenes strains in different organs and at various times postinoculation. studies presented here demonstrate the reproducibility of this assay during primary and secondary infection of inbred and outbred mice. we verified the validity of this assay by performing competitive index analysis of a well-characterized strain of l. monocytogenes lacking the acta gene. in addition, we found that whil ...200111500481
effect of enterocin ccm 4231 on listeria monocytogenes in saint-paulin cheese.the bacteriocin production by enterococcus faecium strain in cheese milk and cheese was demonstrated. purified enterocin ccm 4231 exhibited an anti-listerial effect during saint-paulin cheese manufacture. during cheese production the strain grew to a final concentration of 10.1 +/- 0.01 log cfu per ml per g in cheese. then only a slight decrease of the cell concentration was noticed during ripening and was almost stable for 8 weeks. no significant differences in ph were observed between the expe ...200111501405
production of bacteriocins by different enterococcal isolates.bacteriocins produced by ruminal as well as environmental isolates were found to be heat-stable antimicrobial substances with a broad inhibitory spectrum (including gram-negative species and sanitary-important species). the exponential phase of growth and ph 4-7 were optimal for their production. after purification, some of them were sequenced and specified.200111501476
recombinant listeria strains producing the nontoxic l-chain of botulinum neurotoxin a in a soluble form.fragments of clostridium botulinum neurotoxin a (bont/a) gene (bota) were expressed in listeria monocytogenes atcc10527 to produce the l-chain of the toxin in a soluble form. a shuttle vector pat19 (emr) was used to make plasmid pat-rl containing a bota gene fragment placed under c. botulinum ntnh-gene promoter control. the plasmid also contained a c. botulinum botr/a gene, a positive transcriptional regulator of bota. the cytoplasmic fraction of the l. monocytogenes (pat-rl) strain was found to ...200111501674
sensitivity and specificity of the bax for screening/listeria monocytogenes assay: internal validation and independent laboratory study.in this study to certify the bax for screening/listeria monocytogenes assay (dupont qualicon, wilmington, de), an internal evaluation was conducted on 16 food types that were simultaneously analyzed with the bax system (bax), and the iso method for the detection of l. monocytogenes (iso). no statistically significant difference in performance between the bax and iso methods was observed. inclusivity/exclusivity testing showed that the bax system was able to detect 97 of 97 (100%) of l. monocytog ...200111501909
efficacies of abt-773, a new ketolide, against experimental bacterial infections.abt-773 is a novel ketolide effective against antibacterial-resistant respiratory tract pathogens. the pharmacokinetic profile of abt-773 was studied in rats and consisted of a mean peak concentration in plasma of 1.07 microg/ml and an area under the concentration-time curve (auc) of 12.03 microg. h/ml when the compound was delivered at a dose of 25 mg/kg of body weight. it concentrated in rat lung tissue, with a lung tissue-to-plasma ratio of 29 based on the auc. in acute systemic infections in ...200111502533
from the centers for disease control and prevention. outbreak of listeriosis associated with homemade mexican-style cheese--north carolina, october 2000-january 2001. 200111508310
development of a proposed standard method for assessing the efficacy of fresh produce sanitizers.a series of studies was done for the purpose of developing a proposed standard method to evaluate point-of-use home sanitizers for fresh produce. preliminary experiments were done to determine the survival of escherichia coli o157:h7, salmonella, and listeria monocytogenes after inoculation onto the surface of ripe tomatoes and drying for up to 24 h at 22 +/- 2 degrees c. within 2 h, the initial population (6.88 log10 cfu/tomato) of e. coli o157:h7 was reduced by approximately 3 log10, while red ...200111510643
analysis of native microflora and selection of strains antagonistic to human pathogens on fresh produce.the native microflora of three types of produce (green bell peppers, romaine lettuce, and prepeeled baby carrots) and two types of sprouting seeds (alfalfa and clover) were investigated. aerobic plate count (apc) for each produce or seed type as determined on pseudomonas agar f (paf) with incubation at 28 degrees c was in the range of 4 to 7 log cfu per g of tissue or seed. there was no significant difference (p > or = 0.05) in apc when the determinations were made with three agar media includin ...200111510644
pathogen testing of ready-to-eat meat and poultry products collected at federally inspected establishments in the united states, 1990 to 1999.the food safety and inspection service (fsis) conducted microbiological testing programs for ready-to-eat (rte) meat and poultry products produced at approximately 1,800 federally inspected establishments. all samples were collected at production facilities and not at retail. we report results here for the years 1990 through 1999. prevalence data for salmonella, listeria monocytogenes, escherichia coli o157:h7, or staphylococcal enterotoxins in nine different categories of rte meat and poultry p ...200111510658
home-style beef jerky: effect of four preparation methods on consumer acceptability and pathogen inactivation.the safety of homemade jerky continues to be questioned. producing a safe product that retains acceptable quality attributes is important. lethality of salmonella, escherichia coli o157:h7, and listeria monocytogenes as well as consumer acceptability and sensory attributes of jerky prepared by four methods were examined. preparation methods were drying marinated strips at 60 degrees c (representing a traditional method), boiling strips in marinade or heating in an oven to 71 degrees c prior to d ...200111510659
antibacterial activity in extracts of camellia japonica l. petals and its application to a model food system.the potential presence of naturally occurring antimicrobials in petals of camellia japonica l., a member of the tea family, was investigated against foodborne pathogens in microbiological media and food. petals of the camellia flower (c. japonica l.) were extracted with methanol and fractionated into basic, acidic, and neutral fractions. the acidic fraction (equivalent to 1.0 g of raw sample per disk) produced an inhibitory zone of 14 to 19 mm (diameter) in a disk assay against the pathogens sal ...200111510672
differential role of cytosolic phospholipase a2 in the invasion of brain microvascular endothelial cells by escherichia coli and listeria monocytogenes.invasion of brain microvascular endothelial cells (bmecs) is a key step in the pathogenesis of meningitis due to escherichia coli and listeria monocytogenes. although host cell actin cytoskeletal rearrangements are essential in bmec invasion by e. coli k1 and l. monocytogenes, the underlying signaling mechanisms remain unclear. this study demonstrates that host cell cytosolic phospholipase a2 (cpla2) contributes to e. coli k1 invasion of bmecs but not to l. monocytogenes invasion of bmecs. this ...200111517434
listeriosis: an emerging food-borne disease.listeriosis is a serious disease acquired by ingestion of foods contaminated with listeria monocytogenes. special populations at risk are individuals who are immunocompromised to some extent. the most common clinical findings include meningitis, septicemia, encephalitis, and intrauterine/cervical infections. food related listeriosis is an unusual occurrence but it is now being thought of as a new, and emergent illness. numerous types of food products have been implicated in listeriosis infection ...200111517630
heat resistance and growth of salmonella enteritidis, listeria monocytogenes and aeromonas hydrophila in whole liquid egg.salmonella enteritidis atcc,13067, listeria monocytogenes atcc,19116 and aeromonas hydrophila atcc,7965 strains were evaluated for growth and thermal resistance in liquid whole egg (lwe). each strain grew well in lwe at temperatures between 4 and 30 degrees c, except s. enteritidis which grew weakly at 4 and 10 degrees c. maximum populations for each strain increased with increasing growth temperature. the thermal destruction of each strain was determined in six liquid products. the egg products ...200111518391
[less frequent etiology in uveitis].this material intends to present three clinical observations regarding the uveitis etiology, that is represented by the association of some etiological factors less known: toxoplasma gondii, listeria monocytogenes, leptospira icterohaemorrhagiae. the uveitis described here have been severe in the fast evolution and with trends of reappearence. this work demonstrates that the strict etiological antibacteria and antiparasite therapy is not enough and only corticotherapy is able to fight against th ...200111519339
tnf-alpha hyper-responses to gram-negative and gram-positive bacteria in propionibacterium acnes primed or salmonella typhimurium infected mice.ifn-gamma-dependent hypersensitivity to lps is inducible in mice by infection or pre-treatment with killed bacteria. hypersensitive mice exhibit enhanced inflammatory responses to lps, including the overproduction of tnf-alpha. using lps(n) balb/c and lps(d) balb/c/l mice, primed with propionibacterium acnes or infected with salmonella typhimurium, we show that concurrently to hypersensitivity to lps, a hypersensitivity to other constituents of killed gram-negative or gram-positive bacteria and ...200111521096
calcitermin, a novel antimicrobial peptide isolated from human airway secretions.the human airways are protected from pathogenic colonization by a blanket of fluid impregnated with innate antimicrobial effector molecules. among several previously uncharacterized components, we isolated a peptide that had activity primarily targeting gram-negative bacteria. we named the peptide 'calcitermin' since its amino acid sequence and mass were equivalent to the 15 c-terminal residues of the s100 protein, calgranulin c. the antimicrobial activity of calcitermin was enhanced in acidic b ...200111522286
identification of a new plasmid-encoded sec-dependent bacteriocin produced by listeria innocua 743.listeria innocua 743 produces an inhibitory activity demonstrating broad-spectrum inhibition of listeria monocytogenes isolates. gel-electrophoretic analysis of culture supernatants indicated that two inhibitors with different molecular weights were produced by this strain. insertion of tn917 into a 2.9 kb plasmid (phc743) generated mutants with either an impaired ability or a loss in ability to produce one of the inhibitors. sequence analysis of the transposon insertion regions revealed the pre ...200111526003
farm-management and milking practices associated with the presence of listeria monocytogenes in new york state dairy herds.knowledge of the relationship between dairy herd management and milking practices with the occurrence of listeria monocytogenes on dairy farms might assist in the development of intervention strategies aimed at eliminating this organism at the pre-harvest dairy-food-production level. this paper represents a first step towards that goal. we carried out a cross-sectional study to identify farm factors that were associated with isolation of l. monocytogenes from on-farm in-line milk-filters. data o ...200111530195
molecular characterisation of aureocin a70, a multi-peptide bacteriocin isolated from staphylococcus aureus.staphylococcus aureus a70 produces a heat-stable bacteriocin designated aureocin a70. aureocin a70 is encoded within a mobilisable 8 kb plasmid, prj6, and is active against listeria monocytogenes. experiments of transposition mutagenesis and gene cloning had shown that aureocin a70 production and immunity were associated with the hindiii-a and b fragments of prj6. therefore, a 6332 bp region of the plasmid, encompassing both these fragments, was sequenced using a concatenation dna sequencing pro ...200111531330
[listeria monocytogenes meningitis in a patient with hiv infection and cytomegalovirus infection after colonoscopy]. 200111534435
effect of exposure to diesel exhaust particles on the susceptibility of the lung to infection.there are at least three mechanisms by which alveolar macrophages play a critical role in protecting the lung from bacterial or viral infections: production of inflammatory cytokines that recruit and activate lung phagocytes, production of antimicrobial reactive oxidant species, and production of interferon (an antiviral agent). in this article we summarize data concerning the effect of exposure to diesel exhaust particles on these alveolar macrophage functions and the role of adsorbed organic c ...200111544172
positive selection of mutations leading to loss or reduction of transcriptional activity of prfa, the central regulator of listeria monocytogenes virulence.transcription factor prfa controls the expression of virulence genes essential for listeria monocytogenes pathogenesis. to gain insight into the structure-function relationship of prfa, we devised a positive-selection system to isolate mutations reducing or abolishing transcriptional activity. the system is based on the observation that the listerial iap gene, encoding the p60 protein, is lethal if overexpressed in bacillus subtilis. a plasmid in which the iap gene is placed under the control of ...200111544218
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