Publications

TitleAbstractYear
Filter
PMID(sorted ascending)
Filter
effect of ethylenediaminetetraacetate and lysozyme on the antimicrobial activity of ovotransferrin against listeria monocytogenes.this study evaluated the effect of edta and lysozyme on the antibacterial activities of activated ovotransferrin against 5 strains of listeria monocytogenes. first, a disc test was performed to screen the concentrations of edta or lysozyme that showed antibacterial activities in ovotransferrin (o) or ovotransferrin in 100 mm nahco3 (os) solution. turbidity and viability tests were conducted using o or os solution combined with either lysozyme (ol and osl) or edta (oe and ose). also, os combined ...200818648062
stable integration vector for nutrient broth-based selection of attenuated listeria monocytogenes strains with recombinant antigen expression.recombinant listeria monocytogenes strains induce strong cellular immune responses and may prove useful for antigen delivery for the vaccination of humans. however, the genetic systems currently available for the stable expression of recombinant antigens by l. monocytogenes rely on the use of antibiotic resistance genes. we report on a derivative, ppl2dalglna, of the listeria monocytogenes ppl2 integration vector that completely lacks drug resistance genes. the selectable markers in ppl2dalglna ...200818650400
pathogenesis of listeria-infected drosophila wntd mutants is associated with elevated levels of the novel immunity gene edin.drosophila melanogaster mount an effective innate immune response against invading microorganisms, but can eventually succumb to persistent pathogenic infections. understanding of this pathogenesis is limited, but it appears that host factors, induced by microbes, can have a direct cost to the host organism. mutations in wntd cause susceptibility to listeria monocytogenes infection, apparently through the derepression of toll-dorsal target genes, some of which are deleterious to survival. here, ...200818654628
in vitro inhibitory effect of cranberry (vaccinium macrocarpom ait.) juice on pathogenic microorganisms.the purpose of this study was to determine the inhibitory effects of cranberry juice on pathogenic microorganisms. the microorganisms analyzed were escherichia coli from patients with urinary infections, salmonella spp., listeria monocytogenes, pseudomonas aeruginosa, and staphylococcus aureus. the disc method was used to determine the sensitivity of bacteria to cranberry juice (cj, both concentrated and diluted). a lawn of 10(6) cfu/ml was grown on agar surfaces in petri dishes and on whatman d ...200818663959
nisin inducible production of listeriolysin o in lactococcus lactis nz9000.abstract:200818664263
the degu orphan response regulator of listeria monocytogenes autorepresses its own synthesis and is required for bacterial motility, virulence and biofilm formation.the gram-positive intracellular pathogen listeria monocytogenes is endowed with 17 sets of genes encoding two-component systems. l. monocytogenes is closely related to the gram-positive model bacterium bacillus subtilis, in which we have shown previously that the degs/degu system plays a central role in controlling stationary phase adaptive responses, including degradative enzyme synthesis and competence. although an orthologue of the degu response regulator is present in l. monocytogenes, the g ...200818667558
inactivation of listeria monocytogenes in brine and saline by alternating high-voltage pulsed current.the inactivating efficiency of alternating high-voltage pulsed (ahvp) current was investigated in brine (20 w/v% nacl) and saline (0.9 w/v% nacl) inoculated with 1x 10(7) cells/ml of listeria monocytogenes. ahvp current at 12 v with 1 pulse completely inactivated l. monocytogenes in brine within 3 ms, while the bacteria in saline were fully inactivated by 10-pulsed electric treatment at 12 v within the same time. electron microscopic observation demonstrated substantial structural damage of elec ...200818667856
ers a crp/fnr-like transcriptional regulator of enterococcus faecalis.ers has been identified in a recent study as a protein involved in the pathogenesis and the stress response of the lactic acid bacterium enterococcus faecalis, an opportunistic pathogen. in the e. faecalis sequenced genome, ers is annotated as a transcriptional regulator member of the crp/fnr family. this protein has been shown to be involved in the oxidative stress response as well as in the survival within macrophages. in the present study, we sum up the characteristics of ers and provide furt ...200918672305
transcriptome analysis of organisms with food safety relevance.transcriptome analysis using microarrays has become a powerful tool to better understand the process of disease and other complex biological processes such as food spoilage and biofilm formation. this review is divided into two basic sections: 1) a short history and description of microarrays and 2) a discussion of studies involving bacterial food safety pathogens that focused on whole genome transcript analysis. not included are the many studies using microarrays to identify, diagnose, or genet ...200818673071
[cryptococcosis].cryptococcus neoformans infection is an opportunistic infection affecting mainly patients lacking cell mediated immunity whose incidence has dramatically risen with the advent of hiv infection. this infection has rarely been reported in patients with humoral immunity deficiencies. we report two patients with cryptococcus neoformans infection with a fatal outcome: a man with disseminated criptococcosis leading to the diagnosis of aids; and a woman with stage iii- b k light chains multiple myeloma ...200818674423
liver invariant nkt cells and listeriosis.the invariant (i) nkt cells represent unique t lymphocytes expressing tcrvalpha14. although inkt cells have been regarded as t lymphocytes expressing nk1.1, they do not consistently express this marker. nk1.1 allows recognition of "missing-self" and thus controls inhibition/activation of inkt cells. it is thus tempting to assume that inkt cells participate in the regulation of host immune responses during microbial infection by controlling nk1.1 expression. these findings shed light on the uniqu ...200818674633
a novel prfa mutation that promotes listeria monocytogenes cytosol entry but reduces bacterial spread and cytotoxicity.listeria monocytogenes is an environmental bacterium that becomes a pathogen following ingestion by a mammalian host. the transition from environmental organism to pathogen requires significant changes in gene expression, including the increased expression of gene products that contribute to bacterial growth within host cells. prfa is an l. monocytogenes transcriptional regulator that becomes activated upon bacterial entry into mammalian cells and induces the expression of gene products required ...200818675335
towards on-site pathogen detection using antibody-based sensors.in this paper, the recent progress within biosensors for plant pathogen detection will be reviewed. bio-recognition layers on sensors can be designed in various ways, however the most popular approach is to immobilise antibodies for specific capture of analytes. focus will be put on antibody surface-immobilisation strategies as well as the use of antibodies in the widely used sensors, quartz crystal microbalance, surface plasmon resonance and cantilevers. we will describe the available data on a ...200818675543
the detection of food soils and cells on stainless steel using industrial methods: uv illumination and atp bioluminescence.open food contact surfaces were subjected to organic soiling to provide a source for transfer of microbial cells. rapid industrial methods used for the detection of residual cells and soil e.g. atp (adenosine triphosphate) bioluminescence and an ultraviolet (uv) light detection method were assessed for their ability to detect organic soils, or organic soil-cell mix on surfaces. a range of soils (complex [meat extract, fish extract, cottage cheese extract]; oils [cholesterol, fish oil, mixed fatt ...200818678428
enumeration of cytotoxic cd8 t cells ex vivo during the response to listeria monocytogenes infection.cytotoxicity is a key effector function of cd8 t cells. however, what proportion of antigen-specific cd8 t cells in vivo exert cytotoxic activity during a functional cd8 t-cell response to infection still remains unknown. we used the lysispot assay to directly enumerate cytotoxic cd8 t cells from the spleen ex vivo during the immune response to infection with the intracellular bacterium listeria monocytogenes. we demonstrate that not all antigen-responsive gamma interferon (ifn-gamma)-secreting ...200818678661
neonatal meningoencephalitis caused by bacillus cereus.the classic organisms associated with central nervous system infection in the neonate are herpes simplex, listeria monocytogenes, escherichia coli, and streptococcus agalactiae; we describe an unusual case of neonatal meningoencephalitis caused by bacillus cereus.200818679155
decontamination of knives used in the meat industry: effect of different water temperature and treatment time combinations on the reduction of bacterial numbers on knife surfaces.previous regulations in australia and internationally required that knives used during the slaughter and dressing of carcasses be sanitized by brief submersion in water at 82 degrees c. many current international regulations allow science-based equivalent alternative procedures to be used. however, limited time-temperature data are available on the response of bacteria to hot-water treatment on knives. the present study was undertaken to determine the effect of combinations of time and temperatu ...200818680930
metabiotic effects of fusarium spp. on escherichia coli o157:h7 and listeria monocytogenes on raw portioned tomatoes.the metabiotic effects of fusarium proliferatum, f. avenaceum, and f. oxysporum on escherichia coli o157:h7 and listeria monocytogenes in fresh tomatoes were investigated. tomatoes were preinoculated with the molds and incubated at 15 degrees c for 7 days; then they were inoculated separately with the pathogens, packaged in air and modified atmosphere (5% o2, 30% co2, and 65% n2), and stored at 4, 8, and 12 degrees c for 9 days. the cell loads of pathogens and lactic acid bacteria and the ph wer ...200818680934
adhesion to and viability of listeria monocytogenes on food contact surfaces.listeria monocytogenes is an important pathogen responsible for major outbreaks associated with food products. adhesion to surfaces leads to significant modifications in cell physiology. the aim of this work was to determine the adhesion ability of 10 isolates of l. monocytogenes to eight materials commonly used in kitchens and to evaluate the viability of the adhered cells. the materials assayed were stainless steel 304, marble, granite, glass, polypropylene from a bowl and from a cutting board ...200818680936
inhibition of listeria monocytogenes growth in cured ready-to-eat meat products by use of sodium benzoate and sodium diacetate.the effect of sodium benzoate (0.08 to 0.25%) in combination with different concentrations of sodium diacetate (0.05 to 0.15%) and nacli (0.8 to 2%) and different finished product moisture (55 to 75%) on the growth of listeria monocytogenes in ready-to-eat meat products was evaluated using a central composite design over 18 weeks of storage at 4 degrees c. the effects of these factors on time to growth were analyzed using a time-to-failure regression method. all main effects were significant exc ...200818680937
antibacterial effects of long-chain polyphosphates on selected spoilage and pathogenic bacteria.the antimicrobial activities of four long-chain food-grade polyphosphates were studied at concentrations allowed in the food industry (<5,000 ppm) in defined basal media by determining the inhibition of growth of three gram-negative and four gram-positive spoilage and pathogenic bacteria. both generation time and lag phase of escherichia coli k-12, e. coli o157: h7, and salmonella typhimurium were increased with all of the polyphosphates tested. bacillus subtilis and staphylococcus aureus were m ...200818680939
role of sigma b factor in the alkaline tolerance response of listeria monocytogenes 10403s and cross-protection against subsequent ethanol and osmotic stress.many of the considerable abilities of listeria monocytogenes to persist and grow in a wide range of adverse environmental conditions are thought to be at least partly under the control of the alternative sigma factor (sigmab), encoded by the sigb gene. however, little is known about the role of this master regulon in the impressive ability of listeria to persist and grow under conditions of alkaline ph. in this study, northern blot analysis of parent listeria mrna revealed that alkali adaptation ...200818680951
funcat functional inference with belief propagation and feature integration.pairwise comparison of sequence data is intensively used for automated functional protein annotation, while graphical models emerge as promising candidates for an integration of various heterogeneous features. we designed a model, termed hrmn that integrates different genomic features and implemented a variant of belief propagation for functional annotation transfer. hrmn allows the assignment of multiple functional categories while avoiding common problems in annotation transfer from heterogene ...200818684672
probiotics protect mice against experimental infections.our group has concerned itself with the study of the effect of probiotics on the resistance to infections using experimental models. here, we will focus on evidence that the ufv-h2b20 strain of lactobacillus delbrueckii var. bulgaricus may be considered a probiotic and has protective effects on mice against a variety of bacterial infections.200818685501
linezolid activity against disseminated listeria monocytogenes meningitis and central nervous system abscesses: focus on early drug myelotoxicity.a very infrequent report of listeria monocytogenes meningitis and multiple subtentorial abscesses (cerebellar, bulbar, and pontine in location), occurred in an immunocompetent man, and is described and discussed on the ground of the most recent literature evidences regarding the frequency, presentation, and outcome of this disease. the possibility to resort to combination linezolid therapy in patients who appear to be not responsive to first-line treatment of cerebral abscess of definite origin, ...200718690960
lactococcus lactis-expressing listeriolysin o (llo) provides protection and specific cd8(+) t cells against listeria monocytogenes in the murine infection model.lactococcus lactis has previously been proposed as a vaccine platform for the safe delivery of heterologous antigens. here we utilized l. lactis as a live vector for expression of listeriolysin o (llo), a major listeria monocytogenes antigen and virulence factor. a variety of plasmid constructs were designed to permit either constitutive or nisin-inducible expression of secreted or non-secreted llo in l. lactis. recombinant strains were subsequently tested in a murine model for vaccination effic ...200818691625
enhanced gene delivery using disulfide-crosslinked low molecular weight polyethylenimine with listeriolysin o-polyethylenimine disulfide conjugate.one of the most important requirements for non-viral gene delivery systems is the ability to mediate high levels of gene expression with low toxicity. after the dna/vector complexes are taken up by cells through endocytosis, dna is typically contained within the endocytic compartments and rapidly degraded due to the low ph and hydrolytic enzymes within endosomes and lysosomes, limiting its accessibility to the cytosol and ultimately to the nucleus. in this study, the endosomolytic protein lister ...200818692533
biodiversity of the microbial community in a spanish farmhouse cheese as revealed by culture-dependent and culture-independent methods.the microbial diversity within alberquilla cheese, made from a spontaneously fermented mixture of raw goats' and sheep's milk in the alpujarra mountains (granada, south-east spain), has been studied by the classical culturing method and also by molecular analysis of community dna. a collection of 206 isolates was obtained from the cheese on different selective/differential media, which were then re-grouped to 52 after randomly amplified polymorphic dna (rapd)-pcr analyses. isolates on man-rogosa ...200818692931
the actin propulsive machinery: the proteome of listeria monocytogenes tails.actin-based comet tails produced by listeria monocytogenes are considered as representative models for cellular force-producing machineries crucial for cell migration. we here present a proteomic picture of these tails formed in extracts from brain and platelets. this provides a comprehensive view, revealing high molecular complexity and novel host cell proteins as tail components, and suggests the participation of specific multicomponent regulatory complexes. this work forms a new basis to expa ...200818694727
a high-throughput comparison of recombinant gene expression parameters for e. coli-mediated gene transfer to p388d1 macrophage cells.escherichia coli strain bl21(de3) was tested as a delivery vector for gene transfer to a murine p388d1 macrophage cell line using a 96-well high-throughput assay. five recombinant strains of e. coli were compared to identify the effect recombinant listeriolysin o (llo) and associated gene expression parameters had on final delivery of a luciferase reporter gene. listeriolysin o, native to listeria monocytogenes and used here in an effort to improve final gene delivery, was expressed from plasmid ...200818694790
chronic type a aortic dissection associated with listeria monocytogenes infection.a previously healthy 77-year-old woman with a 4-week history of back pain and fever was admitted to our hospital for chronic type a aortic dissection. the aortic arch was enlarged to 7.5 cm in diameter, and the large dissecting aortic aneurysm involved all three branches of the aortic arch and compressed the trachea. laboratory tests showed an increased c-reactive protein level (10.5 mg/dl). blood cultures performed upon admission were negative. progression of the symptoms suggested the possibil ...200818696209
anti-inflammatory, gastroprotective, free-radical-scavenging, and antimicrobial activities of hawthorn berries ethanol extract.hawthorn [crataegus monogyna jacq. and crataegus oxyacantha l.; sin. crataegus laevigata (poiret) dc., rosaceae] leaves, flowers, and berries are used in traditional medicine in the treatment of chronic heart failure, high blood pressure, arrhythmia, and various digestive ailments, as well as geriatric and antiarteriosclerosis remedies. according to european pharmacopoeia 6.0, hawthorn berries consist of the dried false fruits of these two species or their mixture. the present study was carried ...200818698794
genome-wide analyses reveal lineage specific contributions of positive selection and recombination to the evolution of listeria monocytogenes.the genus listeria includes two closely related pathogenic and non-pathogenic species, l. monocytogenes and l. innocua. l. monocytogenes is an opportunistic human foodborne and animal pathogen that includes two common lineages. while lineage i is more commonly found among human listeriosis cases, lineage ii appears to be overrepresented among isolates from foods and environmental sources. this study used the genome sequences for one l. innocua strain and four l. monocytogenes strains representin ...200818700032
mode of action of antimicrobial peptide p45 on listeria monocytogenes.the mode of action of an antimicrobial peptide produced by bacillus sp. p45 isolated from the intestine of the amazonian basin fish piaractus mesopotamicus was investigated. the antimicrobial peptide was purified from culture supernatants by precipitation with ammonium sulfate and gel filtration chromatography. the peptide has an ec(50) of 300 au (activity units) ml(-1) and kills all viable cells of listeria monocytogenes with a concentration of 800 au ml(-1). a decrease in od was observed when ...200818702075
[study by multiplex pcr of listeria monocytogenes serotypes isolated in argentine].a multiplex pcr assay, recently validated to characterize the serotypes of listeria monocytogenes was evaluated in comparison to conventional serotyping. three hundred forty two l. monocytogenes strains isolated from human, food, animal and environmental sources during the 1992-2005 period were assayed. the concordance between the two methods for serotypes 1/2a, 1/2b and 1/2c was 100%, whereas for serotype 4b it was 98%. serotyping is a useful tool for first line strain differentiation during ep ...200818705488
risk factors associated with the presence of viable listeria monocytogenes in bulk tank milk from us dairies.the objective of the study was to screen a large number of herd management practices and herd characteristics from us dairies to identify herd-level risk factors associated with the presence of listeria monocytogenes in bulk tank milk (btm). a total of 71 variables was univariately evaluated for their association with the presence of l. monocytogenes in btm. results from the univariate analysis indicated that using automatic take offs and having an open herd management increased the risk of btm ...200918705657
effectiveness of chitosan-coated plastic films incorporating antimicrobials in inhibition of listeria monocytogenes on cold-smoked salmon.the objective of this study was to evaluate the efficacy of chitosan-coated plastic films incorporating five generally recognized as safe (gras) antimicrobials (nisin, sodium lactate (sl), sodium diacetate (sd), potassium sorbate (ps) and sodium benzoate (sb)) against listeria monocytogenes on cold-smoked salmon. salmon samples were surface-inoculated with a five-strain cocktail of l. monocytogenes and packaged in chitosan-coated plastic films containing 500 iu/cm(2) of nisin, 9 mg/cm(2) of sl, ...200818707789
the profilin:actin complex localizes to sites of dynamic actin polymerization at the leading edge of migrating cells and pathogen-induced actin tails.a unique set of affinity-purified anti-profilin and anti-actin antibodies generated against a covalently coupled version of the profilin:actin complex was used to assess the distribution of profilin and non-filamentous actin in mouse melanoma cells. in agreement with the profilin:actin complex being the principal source of actin for filament formation, we observed extensive co-distribution of both antibody preparations with vasodilator-stimulated phosphoprotein (vasp) and the p34 subunit of the ...200818707793
functional whole-colony screening method to identify antimicrobial peptides.a high throughput method for screening cdna libraries has been developed to identify putative antimicrobial peptides (amps). it is based on a rapid dye inclusion assay for assessing antagonism of bacterial viability. colonies are grown on a membrane on a permissive medium until full colony size is reached. the membrane, supporting the array of colonies, is transferred onto an inductive medium containing a vital dye. upon expression of any antagonizing peptides, the cell membrane becomes compromi ...200818708097
listeria monocytogenes infection in pregnant guinea pigs is associated with maternal liver necrosis, a decrease in maternal serum tnf-alpha concentrations, and an increase in placental apoptosis.stillbirths and spontaneous abortions can result when pregnant women are exposed to the food borne pathogen, listeria monocytogenes. fetuses and neonates account for one-third of the 2500 cases annually. the objectives were to determine the dose dependent trends of immunological and pathological effects in pregnant guinea pigs after infection with l. monocytogenes. timed pregnant guinea pigs were treated on gestation day (gd) 35 with doses of 10(4) to 10(8) colony forming units (cfus) and sacrif ...200818708136
colorimetric assay for biofilms in wet processing conditions.controlling bacterial biofilms is necessary for food safety and industrial processing in clean room environments. our goal was to develop a method to quantitatively measure biofilm produced by pathogens under wet poultry production and processing conditions. stainless steel and glass coupons were incubated in aqueous media containing reduced nutrients and exposed to listeria monocytogenes under static temperature and humidity conditions. samples were measured separately by biofilm assay and viab ...200818712536
differential regulation of listeria monocytogenes internalin and internalin-like genes by sigmab and prfa as revealed by subgenomic microarray analyses.the listeria monocytogenes genome contains more than 20 genes that encode cell surface-associated internalins. to determine the contributions of the alternative sigma factor sigma(b) and the virulence gene regulator prfa to internalin gene expression, a subgenomic microarray was designed to contain two probes for each of 24 internalin-like genes identified in the l. monocytogenes 10403s genome. competitive microarray hybridization was performed on rna extracted from (i) the 10403s parent strain ...200818713061
impact of compounding error on strategies for subtyping pathogenic bacteria.comparative-omics will identify a multitude of markers that can be used for intraspecific discrimination between strains of bacteria. it seems intuitive that with this plethora of markers we can construct higher resolution subtyping assays using discrete markers to define strain "barcodes." unfortunately, with each new marker added to an assay, overall assay robustness declines because errors are compounded exponentially. for example, the difference in accuracy of strain classification for an as ...200818713065
the growth limits of a large number of listeria monocytogenes strains at combinations of stresses show serotype--and niche-specific traits.the aim of this study was to associate the growth limits of listeria monocytogenes during exposure to combined stresses with specific serotypes or origins of isolation, and identify potential genetic markers.200818713284
il-17a produced by gammadelta t cells plays a critical role in innate immunity against listeria monocytogenes infection in the liver.il-17a is originally identified as a proinflammatory cytokine that induces neutrophils. although il-17a production by cd4(+) th17 t cells is well documented, it is not clear whether il-17a is produced and participates in the innate immune response against infections. in the present report, we demonstrate that il-17a is expressed in the liver of mice infected with listeria monocytogenes from an early stage of infection. il-17a is important in protective immunity at an early stage of listerial inf ...200818714018
tio2 nanowire bundle microelectrode based impedance immunosensor for rapid and sensitive detection of listeria monocytogenes.a novel tio 2 nanowire bundle microelectrode based immunosensor was demonstrated as a more sensitive, specific, and rapid technology for detection of listeria monocytogenes. tio 2 nanowire bundle was prepared through a hydrothermal reaction of alkali with tio 2 powder and connected to gold microelectrodes with mask welding. monoclonal antibodies were immobilized on the surface of a tio 2 nanowire bundle to specifically capture l. monocytogenes. impedance change caused by the nanowire-antibody-ba ...200818715043
inhibition of vancomycin and high-level aminoglycoside-resistant enterococci strains and listeria monocytogenes by bacteriocin-like substance produced by enterococcus faecium e86.three hundred and thirty nine lactic bacteria strains isolated from food samples were screened for antimicrobial activity. only one strain isolated from meat pie and identified as enterococcus faecium produced a bacteriocin-like inhibitory substance (blis) showing activity against enterococcus, leuconostoc, lactobacillus, listeria, corynebacterium and staphylococcus aureus. the blis produced was resistant to acid and alkali treatment and 121 masculinec for 15 min. the addition of blis in bhi con ...200818716832
assessment of the stability of cell-surface components of microorganisms by maldi-tof-ms following preservation on lenticule discs.strains representing the species campylobacter coli, escherichia coli, listeria monocytogenes, pseudomonas aeruginosa, salmonella enterica, and staphylococcus aureus were randomly selected to assess the consistency of cells preserved on lenticule discs to those archived in traditional freeze-dried ampoules. each matched pair was cultured using identical conditions and analysed by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (ms) to profile the surface-associated m ...200818717884
[the regulation of sigmab activity and its role in some gram-positive food-borne pathogens--a review].the alternative sigma factor sigmab modulates the stress response of several gram-positive bacteria. not only does sigmab play a prominent role in sporulation in the gram-positive model organism bacillus subtilis, but it also contributes both directly and indirectly to bacterial virulence in the food-borne human pathogens bacillus cereus, listeria monocytogenes and staphylococcus aureus. as sigmab has been shown to regulate expression of both virulence and virulence-associated genes, it indicate ...200818720853
inactivation kinetics of inoculated escherichia coli o157:h7, listeria monocytogenes and salmonella poona on whole cantaloupe by chlorine dioxide gas.the objectives of this study were to examine inactivation kinetics of inoculated escherichia coli o157:h7, listeria monocytogenes and salmonella poona inoculated onto whole cantaloupe and treated with clo(2) gas at different concentrations (0.5, 1.0, 1.5, 3.0 and 5.0 mg l(-1)) for different times (0, 2.0, 4.0, 6.0, 8.0 and 10.0 min). the effect of clo(2) gas on the quality and shelf life of whole cantaloupe was also evaluated during storage at 22 degrees c for 12 days. a 100 microl inoculation o ...200818721673
effect of combining nisin and/or lysozyme with in-package pasteurization for control of listeria monocytogenes in ready-to-eat turkey bologna during refrigerated storage.this study investigated the efficacy of in-package pasteurization combined with pre-surface application of nisin and/or lysozyme to reduce and prevent the subsequent recovery and growth of listeria monocytogenes during refrigerated storage on the surface of low-fat turkey bologna. sterile bologna samples were treated with solutions of nisin (2 mg/ml=5000 au/ml), lysozyme (10 mg/ml=80 au/ml) and a mixture of nisin and lysozyme (2 mg nisin+10mg lysozyme/ml) before in-package pasteurization at 65 d ...200818721674
effect of poultry decontaminants concentration on growth kinetics for pathogenic and spoilage bacteria.various chemical compounds are currently under review for final approval as poultry decontaminants in the european union (eu). concentration is among the factors considered by the eu authorities in the evaluation of these treatments. the aim of this research was to compare the growth parameters for pathogenic and spoilage bacteria in presence of high and low concentrations of poultry decontaminants to assess whether such treatments could involve a potential sanitary risk for consumers. growth cu ...200818721678
listeria monocytogenes sclerokeratitis: a case report and literature review.to report a case of listeria monocytogenes sclerokeratitis and to review the literature.200818724160
microbial quality of raw aquacultured fish fillets procured from internet and local retail markets.the microbial quality of raw fillets of aquacultured catfish, salmon, tilapia, and trout was evaluated. a total of 272 fillets from nine local and nine internet retail markets were tested. mean values were 5.7 log cfu/g for total aerobic mesophiles, 6.3 log cfu/g for psychrotrophs, and 1.9 log most probable number (mpn) per gram for coliforms. differences in these microbial levels between the two kinds of markets and among the four types of fish were not significant (p > 0.05), except that inter ...200818724746
survival of listeria monocytogenes strains in a dry sausage model.the survival of five inoculated listeria monocytogenes strains (dcs 31, dcs 184, at3e, ht4e, and hr5e) was studied in dry fermented sausages prepared using two different starter cultures (starter a and b) with or without a protective lactobacillus plantarum dden 2205 strain. l. monocytogenes was detected throughout ripening in every sausage sample in which the l. plantarum dden 2205 strain had not been used. the use of either starter a, with a high concentration of protective culture, or starter ...200818724747
comparison of the stress response of listeria monocytogenes strains with sprout colonization.twenty-nine strains of the foodborne pathogen listeria monocytogenes were tested for their ability to colonize alfalfa, radish, and broccoli sprouts and their capacity to withstand acid and oxidative stress, two stresses common to the sprouting environment. wide variation in the ability of different strains to colonize alfalfa sprouts were confirmed, but the variations among radish and broccoli sprouts were not as large. with a few exceptions, strains that were poor colonizers of alfalfa tended ...200818724748
60-day aging requirement does not ensure safety of surface-mold-ripened soft cheeses manufactured from raw or pasteurized milk when listeria monocytogenes is introduced as a postprocessing contaminant.because of renewed interest in specialty cheeses, artisan and farmstead producers are manufacturing surface-mold-ripened soft cheeses from raw milk, using the 60-day holding standard (21 cfr 133.182) to achieve safety. this study compared the growth potential of listeria monocytogenes on cheeses manufactured from raw or pasteurized milk and held for > 60 days at 4 degrees c. final cheeses were within federal standards of identity for soft ripened cheese, with low moisture targets to facilitate t ...200818724749
low incidence of foodborne pathogens of concern in raw milk utilized for farmstead cheese production.overall milk quality and prevalence of four target pathogens in raw milk destined for farmstead cheesemaking was examined. raw milk samples were collected weekly from june to september 2006 from 11 farmstead cheese operations manufacturing raw milk cheese from cow's, goat's, and sheep's milk. samples were screened for listeria monocytogenes, staphylococcus aureus, salmonella, and escherichia coli o157:h7 both quantitatively (direct plating) and qualitatively (pcr). overall, 96.8% of samples had ...200818724751
effects of high pressure, subzero temperature, and ph on survival of listeria monocytogenes in buffer and smoked salmon.high pressure processing is a novel food preservation technology, applied for over 15 years in the food industry to inactivate spoilage and pathogenic microorganisms. many studies have shown the differential resistance of bacterial cells to high pressure. listeria monocytogenes is a bacterium able to grow at refrigerated temperature and to survive for a long time in minimally processed foods such as raw smoked fish. the freezing process does not cause significant decline of l. monocytogenes. the ...200818724755
cold atmospheric plasma disinfection of cut fruit surfaces contaminated with migrating microorganisms.the efficacy of cold atmospheric gas plasmas against escherichia coli type 1, saccharomyces cerevisiae, gluconobacter liquefaciens, and listeria monocytogenes scott a was examined on inoculated membrane filters and inoculated fruit surfaces. inoculated samples were exposed to a cold atmospheric plasma plume generated by an ac voltage of 8 kv at 30 khz. the cold atmospheric plasma used in this study was very efficient in reducing the microbial load on the surfaces of filter membranes. however, it ...200818724756
antimicrobial activity of extracts of edible wild and cultivated mushrooms against foodborne bacterial strains.the antimicrobial activity of aqueous, methanol, hexane, and ethyl acetate extracts from edible wild and cultivated mushrooms against nine foodborne pathogenic bacterial strains (escherichia coli o157:h7, salmonella enteritidis, shigella sonnei, vibrio parahaemolyticus, yersinia enterocolitica, bacillus cereus, clostridium perfringens, listeria monocytogenes, and staphylococcus aureus) was screened with a disk diffusion assay. twenty-nine of the 48 species tested had antimicrobial activity. meth ...200818724768
listeria monocytogenes--which of your patients is not at risk?listeria monocytogenes is an environmental bacterium that is capable of causing infection (known as listeriosis) in vulnerable people who generally acquire the organism following the ingestion of contaminated foods. pregnant women are a particular risk group, as listeriosis in pregnancy is associated with an increased risk of spontaneous abortion, stillbirth, neonatal septicaemia and meningitis. the immunocompromised, and people over the age of 65 to 70 are also at increased risk of listeriosis. ...200818727264
genetic dissection of host resistance to mycobacterium tuberculosis: the sst1 locus and the ipr1 gene.genetic variation of the host significantly contributes to dramatic differences in the outcomes of natural infection with virulent mycobacterium tuberculosis (mtb) in humans, as well as in experimental animal models. host resistance to tuberculosis is a complex multifactorial genetic trait in which many genetic polymorphisms contribute to the phenotype, while their individual contributions are influenced by gene-gene and gene-environment interactions. the most epidemiologically significant form ...200818727490
mage-b vaccine delivered by recombinant listeria monocytogenes is highly effective against breast cancer metastases.new therapies are needed that target breast cancer metastases. in previous studies, we have shown that vaccination with pcdna3.1-mage-b dna vaccine is effective against breast cancer metastases. in the study presented here, we have further enhanced the efficacy of mage-b vaccination through the improved delivery of the vaccine using recombinant listeria monocytogenes (lm). three overlapping fragments of mage-b as well as the complete protein-encoding region of mage-b have been expressed as a fus ...200818728665
horizontal gene transfers link a human mrsa pathogen to contagious bovine mastitis bacteria.acquisition of virulence factors and antibiotic resistance by many clinically important bacteria can be traced to horizontal gene transfer (hgt) between related or evolutionarily distant microflora. comparative genomic analysis has become an important tool for identifying hgt dna in emerging pathogens. we have adapted the multi-genome alignment tool evoprinter to facilitate discovery of hgt dna sequences within bacterial genomes and within their mobile genetic elements.200818728754
animal models of listeria infection.listeria monocytogenes is an intracellular foodborne pathogen that causes listeriosis, an infection characterized by gastroenteritis, meningitis, encephalitis, and maternofetal infections in humans. l. monocytogenes enters the host via contaminated foods, invades the small intestine, translocates to mesenteric lymph nodes, and spreads to the liver, spleen, brain and, in pregnant women, the fetoplacental unit. many pathogenicity tests for studying l. monocytogenes have been developed, including t ...200818729060
persistent fever, mediastinal mass in a 5-year-old boy. 200818751568
bacterial meningitis and sigmoid diverticulitis caused by listeria monocytogenes. 200818751639
decreasing listeriosis mortality in the united states, 1990-2005.listeria monocytogenes is among the most virulent foodborne pathogens, with 20% of clinical infections resulting in death. to explore listeriosis-associated mortality in the united states and to evaluate prevention efforts, we reviewed vital records over a 16-year period to assess demographic, temporal, and seasonal trends.200818752441
different contamination patterns of lineage i and ii strains of listeria monocytogenes in a spanish broiler abattoir.the purpose of this study was to determine whether genetically similar or diverse strains of listeria monocytogenes colonize the environment and carcasses in a single spanish broiler abattoir over time. the study was composed of 5 surveys over a 1.5-yr period and included the monitoring of cleaning and disinfection procedures. overall, a total of 212 samples were tested for the presence of l. monocytogenes, and 31% of the samples were found to be positive. listeria monocytogenes was isolated fro ...200818753457
non-classical use of clathrin during bacterial infections.how invasive bacteria exploit mammalian host cell components to induce their entry into cells has received a lot of attention in the last two decades. model organisms have emerged and helped understanding the various mechanisms that are used. among those, listeria monocytogenes is one of the most documented organisms. it enters into cells via two bacterial proteins, internalin (also called inla) and inlb, which interact with cell surface receptors, e-cadherin and the hepatocyte growth factor rec ...200818755008
impact of bacterial stress and biofilm-forming ability on transfer of surface-dried listeria monocytogenes during slicing of delicatessen meats.listeria monocytogenes contamination of delicatessen slicer blades can lead to cross-contamination of luncheon meats. a cocktail of 3 strong or 3 weak biofilm-forming strains of l. monocytogenes suspended in turkey slurry was used to inoculate stainless steel delicatessen slicer blades at a level of 6 log cfu/blade. the cocktails were used with or without injury (cold-shocked at 4 degrees c for 2 h, or chlorine-injured at 100 ppm for 1 min). inoculated blades were held at 22 degrees c/78+/-2% re ...200818755520
effects of pulsed electric fields on pathogenic microorganisms of major concern in fluid foods: a review.pathogenic microorganisms such as escherichia coli o157:h7, salmonella spp., listeria monocytogenes, bacillus cereus, staphylococcus aureus, yersinia enterocolitica, and campylobacter jejuni have been implicated in foodborne diseases and outbreaks worldwide. these bacteria have been associated with the consumption of fresh fruit juices, milk, and dairy products, which are foodstuff, highly demanded by consumers in retails and supermarkets. nowadays, consumers require high quality, fresh-like, an ...200818756397
characterization of linear forms of the circular enterocin as-48 obtained by limited proteolysis.as-48 is a 70-residue circular peptide from enterococcus faecalis with a broad antibacterial activity. here, we produced by limited proteolysis a protein species carrying a single nicking and fragments of 55 and 38 residues. nicked as-48 showed a lower helicity by far-ultraviolet circular dichroism and a reduced stability to thermal denaturation, but it was active against the sensitive bacteria assayed. the fragments also partly retained the biological activity of the intact protein. these resul ...200818760277
bacterial entry to the splenic white pulp initiates antigen presentation to cd8+ t cells.the spleen plays an important role in host-protective responses to bacteria. however, the cellular dynamics that lead to pathogen-specific immunity remain poorly understood. here we examined listeria monocytogenes (lm) infection in the mouse spleen via in situ fluorescence microscopy. we found that the redistribution of lm from the marginal zone (mz) to the periarteriolar lymphoid sheath (pals) was inhibited by pertussis toxin and required the presence of cd11c(+) cells. as early as 9 hr after i ...200818760639
update and actual trends on bacterial infections following liver transplantation.recent advances in effective antimicrobial prophylactic strategies have led to a decline in the incidence of opportunistic infections in liver transplant recipients. however, morbidity and mortality due to infectious diseases remain as major problems. bacterial infections occurring early after transplant are mainly related to the technical aspects of the procedure. by contrast, after the first postoperative days and beyond, the nature and variety of infectious complications change. opportunistic ...200818763277
central nervous system infection with listeria monocytogenes.the foodborne pathogen listeria monocytogenes has a particular tropism for the central nervous system and can produce infection in the meninges and brain substance. well-recognized clinical syndromes include meningitis, brain abscess, rhombencephalitis, and spinal cord abscess; simultaneous infection of the meninges and brain is common. although it is an uncommon cause of infection in the population at large, l. monocytogenes is an important cause of central nervous system infection in those wit ...200818765103
analysis of the isoprenoid biosynthesis pathways in listeria monocytogenes reveals a role for the alternative 2-c-methyl-d-erythritol 4-phosphate pathway in murine infection.most bacteria synthesize isoprenoids through one of two essential pathways which provide the basic building block, isopentyl diphosphate (ipp): either the classical mevalonate pathway or the alternative non-mevalonate 2-c-methyl-d-erythritol 4-phosphate (mep) pathway. however, postgenomic analyses of the listeria monocytogenes genome revealed that this pathogen possesses the genetic capacity to produce the complete set of enzymes involved in both pathways. the nonpathogenic species listeria inno ...200818765739
gammadeltat cell-mediated regulation of chemokine producing macrophages during listeria monocytogenes infection-induced inflammation.infection of gammadeltat cell-deficient (tcrdelta-/-) mice with the intracellular bacterium listeria monocytogenes (lm) results in an exacerbated inflammatory response characterized by the accumulation of activated macrophages and necrotic liver lesions. here we investigated whether changes in chemokine production by lm-elicited macrophages contribute to this abnormal inflammatory response. in response to lm infection, activated macrophages accumulate in the primary sites of infection in tcrdelt ...200818767021
promises and challenges for the development of listeria monocytogenes-based immunotherapies.active immunotherapy has shown great promise in preclinical models for the treatment of infectious and malignant disease. yet, these promising results have not translated into approved therapies. one of the major deficits of active immunotherapies tested to date in advanced clinical studies has been their inability to stimulate both arms of the immune system appropriately. the interest in using recombinant bacteria as vaccine vectors for active immunotherapy derives in part from their ability to ...200818767955
neonatal listeriosis in taiwan, 1990-2007.listeria monocytogenes is an important pathogen in neonates in western countries, with a fatality rate of 20-30%. there is limited information on neonatal listeriosis in eastern countries. the purpose of this study was to delineate the occurrence and clinical picture of neonatal listeriosis in taiwan.200918768340
high sensitivity of intestinal cd8+ t cells to nucleotides indicates p2x7 as a regulator for intestinal t cell responses.the purinoreceptor p2x7 is expressed on subsets of t cells and mediates responses of these cells to extracellular nucleotides such as atp or nad(+). we identified p2x7 as a molecule highly up-regulated on conventional cd8alphabeta(+) and unconventional cd8alphaalpha(+) t cells of the intestinal epithelium of mice. in contrast, cd8(+) t cells derived from spleen, mesenteric lymph nodes, and liver expressed only marginal levels of p2x7. however, p2x7 was highly up-regulated on cd8(+) t cells from ...200818768840
cross-tolerization between nod1 and nod2 signaling results in reduced refractoriness to bacterial infection in nod2-deficient macrophages.nod2 is an intracellular innate immune receptor that plays a role in host defense and susceptibility to inflammatory disease. we show in this study that macrophages rendered refractory to tlr4 and nod2 signaling by exposure to lps and muramyl dipeptide (mdp) exhibit impaired tnf-alpha and il-6 production in response to pathogenic listeria monocytogenes and yersinia pseudotuberculosis as well as commensal bacteria including escherichia coli and bacteroides fragilis. surprisingly, nod2 deficiency ...200818768892
induction of autophagy via innate bacterial recognition.macroautophagy (referred to hereafter as autophagy) functions not only in self-digestion, but also in the killing and degradation of infectious pathogens in in vitro-cultured cells. based on genetic manipulations of both the host, drosophila and pathogen, listeria monocytogenes, we recently reported that l. monocytogenes-induced autophagy is dependent on the recognition of the pathogen by the drosophila pattern recognition protein, pgrp-le. autophagy and pgrp-le are crucial for inhibition of the ...200818769162
xiap regulates cytosol-specific innate immunity to listeria infection.the inhibitor of apoptosis protein (iap) family has been implicated in immune regulation, but the mechanisms by which iap proteins contribute to immunity are incompletely understood. we show here that x-linked iap (xiap) is required for innate immune control of listeria monocytogenes infection. mice deficient in xiap had a higher bacterial burden 48 h after infection than wild-type littermates, and exhibited substantially decreased survival. xiap enhanced nf-kappab activation upon l. monocytogen ...200818769721
tissue culture cell assays used to analyze listeria monocytogenes.this unit describes tissue culture cell assays for analysis of the ability of listeria monocytogenes to cause intracellular infection. it includes methods for evaluating the organism's ability to invade its host, to escape the primary vacuole formed upon invasion of host cells, to multiply within the cytosol of its host, and to spread from cell to cell without exiting the intracellular milieu. each step can be evaluated quantitatively and qualitatively.200618770595
bacterial infection alters the kinetics and function of inkt cell responses.cd1d-restricted valpha14 invariant nkt cells (inkt) are innate-like, immunoregulatory lymphocytes that play critical roles in autoimmunity, tumor surveillance, and infectious disease. although inkt cells are activated during microbial infection, the impacts of infection on the function of inkt cells have not been fully characterized. using a listeria monocytogenes (lm) infection model, we found that inkt cells failed to expand after infection, resulting in prolonged loss in the spleen, in contra ...200818772281
a new perspective on listeria monocytogenes evolution.listeria monocytogenes is a model organism for cellular microbiology and host-pathogen interaction studies and an important food-borne pathogen widespread in the environment, thus representing an attractive model to study the evolution of virulence. the phylogenetic structure of l. monocytogenes was determined by sequencing internal portions of seven housekeeping genes (3,288 nucleotides) in 360 representative isolates. fifty-eight of the 126 disclosed sequence types were grouped into seven well ...200818773117
xbp1 links er stress to intestinal inflammation and confers genetic risk for human inflammatory bowel disease.inflammatory bowel disease (ibd) has been attributed to aberrant mucosal immunity to the intestinal microbiota. the transcription factor xbp1, a key component of the endoplasmic reticulum (er) stress response, is required for development and maintenance of secretory cells and linked to jnk activation. we hypothesized that a stressful environmental milieu in a rapidly proliferating tissue might instigate a proinflammatory response. we report that xbp1 deletion in intestinal epithelial cells (iecs ...200818775308
listeria monocytogenes, a unique model in infection biology: an overview.this review rather than covering the whole field intends to highlight recent findings on the listeria monocytogenes infectious process or some listeria specific traits, place them within the framework of well-established data, and demonstrate how this gram-positive bacterium has, in two decades, emerged as a multifaceted paradigm. indeed, the cell biology of the infectious process has been deciphered in great detail and provided insights in both the way bacterial pathogen manipulate the host and ...200818775788
modelling the competitive growth between listeria monocytogenes and biofilm microflora of smear cheese wooden shelves.the aim of this study was to investigate the mechanism of the observed inhibition of listeria monocytogenes by the natural biofilm microflora (bm) on wooden shelves used in the ripening of a soft and smear cheese. for this, bm was harvested and we conducted a series of experiments in which two strains of l. monocytogenes were co-cultured with bm on glass fiber filters deposited on model cheeses. compared to monoculture, l. monocytogenes growth rate in co-culture was not reduced but the growth of ...200818778863
temperature governs the inactivation rate of vegetative bacteria under growth-preventing conditions.novel studies, in combination with a meta-analysis of available data, were undertaken to explore the kinetics of non-thermal inactivation of escherichia coli with particular attention to inactivation in fermented meats and including analogous broth-based model systems. the analyses were based on rates of inactivation and specifically investigated the influence of temperature, ph and water activity at levels that alone, or in combination, prevented growth. when independently-derived inactivation ...200818778864
[spontaneus abortion caused by listeria monocytogenes--report of three cases].this paper describes three cases of spontaneous abortion caused by listeria monocytogenes which were diagnosed during the outbreak of listeriosis in late 2006. both clinical and morphological features were highly consistent. the abortion between 19 and 20 weeks of gestation was preceded by high maternal fever. the fetal disease was miliary widespread with involvement of adrenals, liver and lungs in particular. there was always present a pustular rash. histological examination of the placentas re ...200818783138
ceramide in bacterial infections and cystic fibrosis.ceramide is formed by the activity of sphingomyelinases, by degradation of complex sphingolipids, reverse ceramidase activity or de novo synthesized. the formation of ceramide within biological membranes results in the formation of large ceramide-enriched membrane domains. these domains serve the spatial and temporal organization of receptors and signaling molecules. the acid sphingomyelinase-ceramide system plays an important role in the infection of mammalian host cells with bacterial pathogen ...200818783339
[molecular typing of listeria monocytogenes isolated from foodstuff in guangdong province by pulsed-field gel electrophoresis].to establish molecular typing of listeria monocytogenes isolates by pulsed-field gel electrophoresis (pfge) for studying the epidemiologic characteristics of listeria monocytogenes isolated from foodstuff in guangdong province and to build up pfge typing database of listeria monocytogenes isolates for identifying the infectious resource of the outbreaks and other epidemiologic investigation.200818785476
cloning, sequencing and analysis of dnak -dnaj gene cluster of bacillus megaterium.the dna fragment of heat shock genes (hrca-grpe-dnak-dnaj) containing complete hrca-grpe-dnak operon and the transcription unit of dnaj was cloned, sequensed and analyzed from bacillus megaterium rf5. the sequence of hrca, grpe and dnaj were first time reported, and their coding products exibit 60%, 63% and 81% of identities to the homologs of b. subtilis. a sigmaa-type promoter of gram-positive bacteria (pa1) and a terminator were located upstream of the hrca and downstream of dnak, and a contr ...200818785662
listeriosis: a primer. 200818787096
listeriolysin s, a novel peptide haemolysin associated with a subset of lineage i listeria monocytogenes.streptolysin s (sls) is a bacteriocin-like haemolytic and cytotoxic virulence factor that plays a key role in the virulence of group a streptococcus (gas), the causative agent of pharyngitis, impetigo, necrotizing fasciitis and streptococcal toxic shock syndrome. although it has long been thought that sls and related peptides are produced by gas and related streptococci only, there is evidence to suggest that a number of the most notorious gram-positive pathogenic bacteria, including listeria mo ...200818787690
host ranges of listeria-specific bacteriophages from the turkey processing plant environment in the united states.even though at least 400 listeria phages have been isolated from various sources, limited information is available on phages from the food processing plant environment. phages in the processing plant environment may play critical roles in determining the listeria population that becomes established in the plant. in this study, we pursued the isolation of listeria-specific phages from environmental samples from four turkey processing plants in the united states. these environmental samples were a ...200818791016
inla premature stop codons are common among listeria monocytogenes isolates from foods and yield virulence-attenuated strains that confer protection against fully virulent strains.previous studies showed that a considerable proportion of listeria monocytogenes isolates obtained from foods carry a premature stop codon (pmsc) mutation in inla that leads to production of a truncated and secreted inla. to further elucidate the role these mutations play in virulence of l. monocytogenes, we created isogenic mutants, including (i) natural isolates where an inla pmsc was reverted to a wild-type inla allele (without a pmsc) and (ii) natural isolates where a pmsc mutation was intro ...200818791029
Refresh
firstprev
...101102103104105106107108109110...
nextlast
Displaying items 10501 - 10600 of 16792