Publications

TitleAbstractYear
Filter
PMID(sorted ascending)
Filter
fisetin inhibits listeria monocytogenes virulence by interfering with the oligomerization of listeriolysin o.listeriolysin o (llo), an essential virulence determinant of listeria monocytogenes, is a pore-forming toxin whose primary function is to facilitate cytosolic bacterial replication by breaching the phagosomal membranes, which is critical for the pathogen to evade host immune recognition. the critical role of llo in the virulence of l. monocytogenes renders it an ideal target for designing novel antivirulence therapeutics. we found that fisetin, a natural flavonoid without antimicrobial activity, ...201525231018
antimicrobial properties of nisin after glycation with lactose, maltodextrin and dextran and the thyme oil emulsions prepared thereof.to clarify the reported conflicting antimicrobial activities of nisin after glycation, nisin was glycated with lactose, maltodextrin, and dextran at 70 °c and 50% relative humidity for 1-24 h. nisin before and after glycation was studied for the first time to prepare thyme oil emulsions. the activity of glycated nisin and the thyme oil emulsions was tested in both tryptic soy broth (tsb) and 2% reduced fat milk. results showed that nisin glycated with a smaller saccharide for a longer duration h ...201425240139
listeria monocytogenes isolated from food samples from a romanian black market show distinct virulence profiles.listeria monocytogenes is a facultative intracellular foodborne pathogen responsible for listeriosis. in a recent study, in which we investigated neglected exogenous routes of transmission of foodborne pathogens into the european union, we have isolated 15 l. monocytogenes strains in food products, which were imported from the republic of moldavia to romania and illegally sold at a local market. the aim of this study was to characterize the subtype and virulence potential of these 15 l. monocyto ...201525241012
application of quantitative microbial risk assessment for selection of microbial reduction targets for hard surface disinfectants.this quantitative microbial risk assessment (qmra) included problem formulation for fomites and hazard identification for 7 microorganisms, including pathogenic escherichia coli and e coli 0157:h7, listeria monocytogenes, norovirus, pseudomonas spp, salmonella spp, and staphylococcus aureus. the goal was to address a risk-based process for choosing the log10 reduction recommendations, in contrast to the current us environmental protection agency requirements.201425241163
the global burden of listeriosis: a systematic review and meta-analysis.listeriosis, caused by listeria monocytogenes, is an important foodborne disease that can be difficult to control and commonly results in severe clinical outcomes. we aimed to provide the first estimates of global numbers of illnesses, deaths, and disability-adjusted life-years (dalys) due to listeriosis, by synthesising information and knowledge through a systematic review.201425241232
perinatal listeria monocytogenes susceptibility despite preconceptual priming and maintenance of pathogen-specific cd8(+) t cells during pregnancy.listeria monocytogenes (lm) is an intracellular bacterium with unique predisposition for systemic maternal infection during pregnancy and morbid consequences for the developing fetus. given the high mortality associated with prenatal lm infection, strategies for augmenting protective immunity during the exceedingly vulnerable period of pregnancy are urgently needed. herein, protection conferred by attenuated lm administered before pregnancy against subsequent virulent lm prenatal infection was e ...201425242275
the antimicrobial efficacy of lippia alba essential oil and its interaction with food ingredients.the objective of this study was to evaluate the antimicrobial potential of lippia alba essential oil (eola) and to investigate the effect of food ingredients on its efficacy. the antimicrobial potential of the oil was determined by the presence or absence of inhibition zones, minimum inhibitory concentration (mic) and minimum bactericidal concentration (mbc) against escherichia coli, listeria innocua, listeria monocytogenes, pseudomonas aeruginosa, salmonella choleraesuis and staphylococcus aure ...201425242961
microbiological aspects of the biofilm on wooden utensils used to make a brazilian artisanal cheese.the artisanal minas cheese is produced from raw cow's milk and wooden utensils were employed in its manufacture, which were replaced by other materials at the request of local laws. this substitution caused changes in the traditional characteristics of cheese. due to the absence of scientific studies indicating the microbial composition of biofilms formed on wooden forms, tables and shelves used in these cheese production, the present work evaluated the counts of staphylococcus aureus, escherich ...201425242963
retardation of listeria monocytogenes growth in mozzarella cheese using antimicrobial sachets containing rosemary oil and thyme oil.an antimicrobial sachet containing microcellular foam starch (mfs) with embedded rosemary oil and thyme oil was developed to reduce bacterial growth in shredded mozzarella cheese. the efficacy of the volatiles of oils at various concentrations in reducing listeria monocytogenes as well as the release of the oils from the mfs have been also determined in this study. the cheese, inoculated with a cocktail of 5 strains of l. monocytogenes (approximately 3 log cfu/g), was packaged in a nylon/evoh/pe ...201425243791
preparation of a porcine plasma protein composite film and its application.to use blood released from slaughtering houses, a porcine plasma protein (ppp)/nanoclay composite film was prepared. the tensile strength and elongation at break values of the ppp composite film with 5% nanoclay were 10.01 mpa and 6.55%, respectively. the ppp composite film containing 1% grapefruit seed extract (gse) was applied to pork meat, and the populations of inoculated escherichia coli o157:h7 and listeria monocytogenes in the pork meat packaged with the ppp composite film decreased by 0. ...201525248798
the adaptor asc exacerbates lethal listeria monocytogenes infection by mediating il-18 production in an inflammasome-dependent and -independent manner.listeria monocytogenes induces the formation of inflammasomes and subsequent caspase-1 activation, and the adaptor apoptosis-associated speck-like protein containing a card (asc) is crucial for this response. however, the role of asc in l. monocytogenes infection in vivo is unclear. in this study, we demonstrate that asc has a detrimental effect on host defense against l. monocytogenes infection at a lethal dose (10(6) cfu), but not at a sublethal dose (10(3) cfu). during lethal l. monocytogenes ...201425251560
[effect of ultra high pressure on cell membrane destruction and death of listeria monocytogenes].to study the effect of ultra high pressure (uhp) on the cell membrane of listeria monocytogenes.201425252455
antimicrobial properties of magnesium chloride at low ph in the presence of anionic bases.magnesium is an element essential for life and is found ubiquitously in all organisms. the different cations play important roles as enzymatic co-factors, as signaling molecules, and in stabilizing cellular components. it is not surprising that magnesium salts in microbiological experiments are typically associated with positive effects. in this study with listeria monocytogenes as a model organism, we focus however on the usefulness of magnesium (in form of mgcl2) as a stress enhancer. whereas ...201625252874
foodborne and waterborne pathogenic bacteria in selected organisation for economic cooperation and development (oecd) countries.the world ranking food safety performance reports by charlebois in 2008 and 2010 importantly stimulated international discussion and encouraged efforts to establish realistic international benchmarks for food safety performance among organisation for economic cooperation and development (oecd) countries. this paper presents the international incidence of 5 common foodborne pathogens and describes the challenges of comparing international data. data were compiled from surveillance authorities in ...201425257314
whole-genome sequence of listeria monocytogenes type strain 53 xxiii.listeria monocytogenes causes the food-borne illness listeriosis that primarily infects "vulnerable" groups (e.g., elderly adults, pregnant women, very young children, and the immunocompromised). we sequenced the genome of l. monocytogenes xxiii (atcc 15313) and assembled it into a single scaffold (three contigs) and deposited the annotated assembly into genbank as accession no. joox00000000.201425258271
adhesion of salmonella enteritidis and listeria monocytogenes on stainless steel welds.pathogenic microorganisms are able to adhere on equipment surfaces, being possible to contaminate food during processing. salmonella spp. and listeria monocytogenes are important pathogens that can be transmitted by food, causing severe foodborne diseases. most surfaces of food processing industry are made of stainless steel joined by welds. however currently, there are few studies evaluating the influence of welds in the microorganism's adhesion. therefore the purpose of the present study was t ...201425261827
bacteria detection based on the evolution of enzyme-generated volatile organic compounds: determination of listeria monocytogenes in milk samples.the rapid detection of listeria monocytogenes contamination in food is essential to prevent food-borne illness in humans. the aim of this study was to differentiate non-contaminated milk from milk contaminated with l. monocytogenes using enzyme substrates coupled with the analysis of volatile organic compounds (vocs). the method is based on the activity of β-glucosidase and hippuricase enzymes and the detection of a specific voc i.e. 2-nitrophenol and 3-fluoroaniline, respectively. vocs were ext ...201425263120
chaperone-mediated autophagy regulates t cell responses through targeted degradation of negative regulators of t cell activation.chaperone-mediated autophagy (cma) targets soluble proteins for lysosomal degradation. here we found that cma was activated in t cells in response to engagement of the t cell antigen receptor (tcr), which induced expression of the cma-related lysosomal receptor lamp-2a. in activated t cells, cma targeted the ubiquitin ligase itch and the calcineurin inhibitor rcan1 for degradation to maintain activation-induced responses. consequently, deletion of the gene encoding lamp-2a in t cells caused defi ...201425263126
selection of potential probiotic enterococcus faecium isolated from portuguese fermented food.four enterococcus faecium strains isolated from fermented products were evaluated for potential use as probiotic strains. in addition to efaafm gene, commonly found in e. faecium food isolates, none of the isolates possessed virulence genes and none had positive reactions for the production of tyramine, histamine, putrescine and cadaverine in the screening medium used. all of these four isolates proved to be resistant to 65 °c. e. faecium 119 did not show antimicrobial activity against any of th ...201425268323
σ(b) affects biofilm formation under the dual stress conditions imposed by adding salt and low temperature in listeria monocytogenes.the food-borne pathogenic bacteria listeria monocytogenes can form biofilms on various surfaces including food-processing equipment. biofilms offer survival benefits to the organisms entrapped against environmental insults. moreover, the σ(b) transcription factor of l. monocytogenes plays an important role in its survival under various stress conditions. in this study, we evaluated whether σ(b) contributes to biofilm formation when l. monocytogenes is grown under various temperatures and media. ...201425269605
application of high resolution pyrolysis gas chromatography/mass spectrometry (hrpgc/ms) for detecting listeria monocytogenes.the characteristic of listeria monocytogenes' pyrolysis product was found by fingerprint analysis of high resolution pyrolysis gas chromatography and mass spectrometry (hrpgc/ms), which hold a great potential to rapidly detect l. monocytogenes with the application of selected ion monitoring (sim). food products (beef and milk) contaminated by l. monocytogenes and uncontaminated were evaluated. the retention time of the characteristic peak of pyrolysis product was 19.056min, the ion of m/z were 5 ...201425270059
attachment of escherichia coli to listeria monocytogenes for pediocin-mediated killing.listeria phage endolysin cell wall-binding domain (cbd) from the listeria phage a500 was fused with flagellar subunit flic in escherichia coli, aiming at binding of e. coli cells to listeria cells, followed by enhanced killing of listeria by pediocin production. flic::cbd chimeric flagella were expressed and detected by western blot. however, only few chimeric flagella could be isolated from the recombinant cells compared with sufficient amount of wild-type flagella obtained from the host cells. ...201525270683
tsc1 promotes the differentiation of memory cd8+ t cells via orchestrating the transcriptional and metabolic programs.memory cd8(+) t cells are an essential component of protective immunity. signaling via mechanistic target of rapamycin (mtor) has been implicated in the regulation of the differentiation of effector and memory t cells. however, little is understood about the mechanisms that control mtor activity, or the effector pathways regulated by mtor. we describe here that tuberous sclerosis 1 (tsc1), a regulator of mtor signaling, plays a crucial role in promoting the differentiation and function of memory ...201425271321
rapid and sensitive detection of listeria monocytogenes by cross-priming amplification of lmo0733 gene.listeria monocytogenes is a food-borne pathogen that causes severe opportunistic infection in humans and animals. this study reports the development of single cross-priming amplification (s-cpa) and double cpa (d-cpa) assays targeting species-specific gene lmo0733 for identifying l. monocytogenes strains. the cpa assays were performed at a constant temperature 64 °c using seven specific primers and evaluated for specificity and sensitivity. the color change of positive amplification was directly ...201425273275
synergetic effect of combined fumaric acid and slightly acidic electrolysed water on the inactivation of food-borne pathogens and extending the shelf life of fresh beef.to evaluate synergetic effect of slight acidic electrolysed water (saew) and fumaric acid (fa) on inactivation of total viable count (tvc) and staphylococcus aureus, listeria monocytogenes, escherichia coli o157:h7 and salmonella typhimurium in fresh beef and to study shelf life and sensory quality of beef.201425273314
detection of listeria monocytogenes in food samples in avezzano, sulmona and castel di sangro (province of l'aquila, abruzzo, italy) between 2000-2009.the retrospective study of the results of the analysed samples is a fundamental tool for the identification of major risk related to food and for planning future monitoring activities. the evaluation of the quality of data collected may also allow for estimating the effectiveness of the controls so to improve their efficacy. in this article, the authors evaluated the results of tests for the detection of listeria monocytogenes performed by the istituto zooprofilattico sperimentale dell'abruzzo e ...201425273959
a novel function of interferon regulatory factor-1: inhibition of th2 cells by down-regulating the il4 gene during listeria infection.infection with certain pathogens induces a shift of the th subset balance to a th1 dominant state. this, in turn, results in the suppression of th2 responses. we focused on the involvement of interferon regulatory factor-1 (irf-1) in the suppression of th2 cells during listeria infection. we found that the inhibition of il-4 production by th2 cells is mediated by a soluble factor (lmsn) produced by listeria-infected antigen-presenting cells. the inhibition is not observed with t cells from irf1 ...201525280793
phosphotransferase system-dependent extracellular growth of listeria monocytogenes is regulated by alternative sigma factors σl and σh.alternative sigma (σ) factors and phosphotransferase systems (ptss) play pivotal roles in the environmental adaptation and virulence of listeria monocytogenes. the growth of the l. monocytogenes parent strain 10403s and 15 isogenic alternative σ factor mutants was assessed in defined minimal medium (dm) with pts-dependent or non-pts-dependent carbon sources at 25°c or 37°c. overall, our results suggested that the regulatory effect of alternative σ factors on the growth of l. monocytogenes is dep ...201425281379
the diaphanous-related formins promote protrusion formation and cell-to-cell spread of listeria monocytogenes.the gram-positive bacterium listeria monocytogenes is a facultative intracellular pathogen whose virulence depends on its ability to spread from cell to cell within an infected host. although the actin-related protein 2/3 (arp2/3) complex is necessary and sufficient for listeria actin tail assembly, previous studies suggest that other actin polymerization factors, such as formins, may participate in protrusion formation. here, we show that arp2/3 localized to only a minor portion of the protrusi ...201525281757
antioxidant and antibacterial activities of exopolysaccharides from bifidobacterium bifidum wbin03 and lactobacillus plantarum r315.the objective of this study was to investigate the antioxidant and antibacterial activities of exopolysaccharide (eps) from bifidobacterium bifidum wbin03 (b-eps) and lactobacillus plantarum r315 (l-eps). the 1,1-diphenyl-2-picrylhydrazyl (dpph)-radical scavenging, hydroxyl radical-scavenging, and superoxide radical-scavenging abilities were measured to evaluate antioxidant activity. inhibition of erythrocyte hemolysis and lipid peroxidation was also measured. both b-eps and l-eps had strong sca ...201425282420
modeling the effects of temperature, sodium chloride, and green tea and their interactions on the thermal inactivation of listeria monocytogenes in turkey.the interactive effects of heating temperature (55 to 65°c), sodium chloride (nacl; 0 to 2%), and green tea 60% polyphenol extract (gtpe; 0 to 3%) on the heat resistance of a five-strain mixture of listeria monocytogenes in ground turkey were determined. thermal death times were quantified in bags that were submerged in a circulating water bath set at 55, 57, 60, 63, and 65°c. the recovery medium was tryptic soy agar supplemented with 0.6% yeast extract and 1% sodium pyruvate. d-values were anal ...201425285486
decontamination of hard cheeses by pulsed uv light.cheese is a ready-to-eat food that may be contaminated on the surface by undesirable spoilage and pathogenic microorganisms during production, packaging, and postpackaging processes. penicillium roqueforti is commonly found on cheese surfaces at refrigeration temperatures and is one of the most common spoilage fungal species. consumption of cheese contaminated with listeria monocytogenes can result in foodborne listeriosis. therefore, cheese should be decontaminated at postprocessing stages. pul ...201425285489
effect of gamma radiation on the reduction of salmonella strains, listeria monocytogenes, and shiga toxin-producing escherichia coli and sensory evaluation of minimally processed spinach (tetragonia expansa).this study evaluated the effects of irradiation on the reduction of shiga toxin-producing escherichia coli (stec), salmonella strains, and listeria monocytogenes, as well as on the sensory characteristics of minimally processed spinach. spinach samples were inoculated with a cocktail of three strains each of stec, salmonella strains, and l. monocytogenes, separately, and were exposed to gamma radiation doses of 0, 0.2, 0.4, 0.6, 0.8, and 1.0 kgy. samples that were exposed to 0.0, 1.0, and 1.5 kg ...201425285495
inhibition of listeria monocytogenes in deli-style turkey breast formulated with cultured celery powder and/or cultured sugar-vinegar blend during storage at 4°c.fermentation-derived nitrite (no2) from vegetable sources is increasingly used as a "clean label" alternative to conventional nano2. previous results suggested that processed meats cured with no2 derived from a "natural" source had lower antimicrobial activity than did meats produced with chemical nano2; however, the differences were likely due to no2 concentration rather than source. the objective of this study was to compare the antilisterial properties of traditional and clean label alternati ...201425285499
detection of very long antisense transcripts by whole transcriptome rna-seq analysis of listeria monocytogenes by semiconductor sequencing technology.the gram-positive bacterium listeria monocytogenes is the causative agent of listeriosis, a severe food-borne infection characterised by abortion, septicaemia, or meningoencephalitis. l. monocytogenes causes outbreaks of febrile gastroenteritis and accounts for community-acquired bacterial meningitis in humans. listeriosis has one of the highest mortality rates (up to 30%) of all food-borne infections. this human pathogenic bacterium is an important model organism for biomedical research to inve ...201425286309
are inflammatory phagocytes responsible for resistance to facultative intracellular bacteria?at least 38 deaths from listeriosis in the united states in recent months have drawn attention to how little we know about resistance to facultative intracellular bacteria. much more is known about resistance to obligate intracellular parasites. macrophages, activated by t cell-derived macrophage activating factors (maf), are able to kill obligate intracellular parasites and tumor cells(1-10) including leishmania, certain trypanosomes, toxoplasma, the obligate intracellular bacterium rickettsia, ...198625289573
impedimetric characterization of adsorption of listeria monocytogenes on the surface of an aluminum-based immunosensor.the impedimetric characteristics of an immunosensor depend on the electrical properties of an immunosensor substrate. the impedimetric characteristics of an immunosensor compared with adsorption of listeria monocytogenes were investigated on an aluminum surface insulated with an electrically resistive aluminum oxide layer. antibody for l. monocytogenes (anti-l. monocytogenes) was immobilized on an aluminum surface that was insulated with a native air-formed aluminum oxide layer. the resistance o ...201425296910
the c5a anaphylatoxin receptor (c5ar1) protects against listeria monocytogenes infection by inhibiting type 1 ifn expression.listeria monocytogenes is a major cause of mortality resulting from food poisoning in the united states. in mice, c5 has been genetically linked to host resistance to listeriosis. despite this genetic association, it remains poorly understood how c5 and its activation products, c5a and c5b, confer host protection to this gram-positive intracellular bacterium. in this article, we show in a systemic infection model that the major receptor for c5a, c5ar1, is required for a normal robust host immune ...201425297874
pregnancy-related listeriosis in france, 1984 to 2011, with a focus on 606 cases from 1999 to 2011.this study describes trends in the incidence of pregnancy-related listeriosis in france between 1984 and 2011, and presents the major characteristics of 606 cases reported between 1999 and 2011 to the french institute for public health surveillance through the mandatory notification system. the incidence of pregnancy-related listeriosis decreased by a factor of 12 from 1984 to 2011. this reduction was a result of progressive implementation of specific listeria monocytogenes control measures in f ...201425306879
type i interferons in bacterial infections: taming of myeloid cells and possible implications for autoimmunity.type i interferons (ifns) were first described for their ability to protect the host from viral infections and may also have beneficial effects under specific conditions within some bacterial infections. yet, these pleiotropic cytokines are now known to exacerbate infections by numerous life-threatening bacteria, including the intracellular pathogens listeria monocytogenes and mycobacterium tuberculosis. the evidence that such detrimental effects occur during bacterial infections in both animals ...201425309533
assessment of the contamination potentials of some foodborne bacteria in biofilms for food products.to assess biofilms formed by different bacterial strains on glass slides, and changes in biofilm mass and biofilm-associated cell populations after brief contacts between biofilms and either media agar or food products.201425312128
the listeria monocytogenes transposon tn6188 provides increased tolerance to various quaternary ammonium compounds and ethidium bromide.tolerance of the foodborne pathogen listeria monocytogenes to sublethal concentrations of disinfectants has been frequently reported. particularly, quaternary ammonium compounds (qacs) such as benzalkonium chloride (bc) are often used in disinfectants and also as antiseptics in food industry and hospitals. recently, we described tn6188, a novel transposon in l. monocytogenes harbouring the transporter qach, a molecular mechanism leading to increased tolerance to bc. in this study, we investigate ...201425312720
direct incorporation of the nkt-cell activator α-galactosylceramide into a recombinant listeria monocytogenes improves breast cancer vaccine efficacy.immune suppression in the tumour microenvironment remains a major limitation to successful immunotherapy of cancer. in the current study, we analysed whether the natural killer t cell-activating glycolipid α-galactosylceramide could overcome immune suppression and improve vaccination against metastatic breast cancer.201425314062
novel mechanism of hemin capture by hbp2, the hemoglobin-binding hemophore from listeria monocytogenes.iron is an essential nutrient that is required for the growth of the bacterial pathogen listeria monocytogenes. in cell cultures, this microbe secretes hemin/hemoglobin-binding protein 2 (hbp2; lmo2185) protein, which has been proposed to function as a hemophore that scavenges heme from the environment. based on its primary sequence, hbp2 contains three near transporter (neat) domains of unknown function. here we show that each of these domains mediates high affinity binding to ferric heme (hemi ...201425315777
listeria monocytogenes-associated biliary tract infections: a study of 12 consecutive cases and review.at present, little is known regarding listeria monocytogenes-associated biliary tract infection, a rare form of listeriosis.in this article, we will study 12 culture-proven cases reported to the french national reference center for listeria from 1996 to 2013 and review the 8 previously published cases.twenty cases were studied: 17 cholecystitis, 2 cholangitis, and 1 biliary cyst infection. half were men with a median age of 69 years (32-85). comorbidities were present in 80%, including cirrhosis ...201425319439
purification and characterization of bacteriocin produced by lactobacillus brevis un isolated from dhulliachar: a traditional food product of north east india.a bacteriocin producing strain lactobacillus brevis un isolated from dulliachar-a salted pickle and identified by biochemical and molecular methods. l. brevis un was found to produce bacteriocin with broad spectrum activity against spoilage causing/food borne pathogens viz. l. monocytogenes, c. perfringens, s. aureus, l. mesenteroides, l. plantarum and b. cereus. bacteriocin production was optimized through classical one variable at a time method. the isolate showed maximum bacteriocin productio ...201325320420
bacillus spp. isolated from the conjunctiva and their potential antimicrobial activity against other eye pathogens.in this study, we attempted to screen and investigate antibacterial activity of bacillus species, which were isolated from conjunctiva, against other eyes pathogens.201425320585
lmo0171, a novel internalin-like protein, determines cell morphology of listeria monocytogenes and its ability to invade human cell lines.internalins comprise a class of listeria monocytogenes proteins responsible for activation of signalling pathways leading to phagocytic uptake of the bacterium by the host cell. in this paper, a possible role of lmo0171-a new member of the internalin family was investigated. disruption of the lmo0171 gene resulted in important cell morphology alterations along with a decrease in the ability to invade three eukaryotic cell lines, that is int407, hep-2 and hela and diminished adhesion efficiency t ...201525323012
drastic therapy for listerial brain abscess involving combined hyperbaric oxygen therapy and antimicrobial agents.listeria monocytogenes (l. monocytogenes) is a rare causative pathogen of brain abscess that is often found in immunocompromised patients. although patients with supratentorial listerial abscesses showed a longer survival with surgical drainage, the standard therapy for patients with subtentorial lesions has not been established.201425324887
current status of antisense rna-mediated gene regulation in listeria monocytogenes.listeria monocytogenes is a gram-positive human-pathogen bacterium that served as an experimental model for investigating fundamental processes of adaptive immunity and virulence. recent novel technologies allowed the identification of several hundred non-coding rnas (ncrnas) in the listeria genome and provided insight into an unexpected complex transcriptional machinery. in this review, we discuss ncrnas that are encoded on the opposite strand of the target gene and are therefore termed antisen ...201425325017
treatment strategies for central nervous system infections: an update.central nervous system infection continues to be an important cause of mortality and morbidity worldwide. our incomplete knowledge on the pathogenesis of how meningitis-causing pathogens cause cns infection and emergence of antimicrobial resistance has contributed to the mortality and morbidity. an early empiric antibiotic treatment is critical for the management of patients with bacterial meningitis, but early recognition of bacterial meningitis continues to be a challenge.201525328149
synthesis, characterization and antibacterial activity of biodegradable films prepared from schiff bases of zein.pure zein is known to be very hydrophobic, but is still inappropriate for coating and film applications because of their brittle nature. in an attempt to improve the flexibility and the antimicrobial activity of these coatings and films, chemical modification of zein through forming schiff bases with different phenolic aldhydes was tried. influence of this modifications on mechanical, topographical, wetting properties and antimicrobial activity of zein films were evaluated. the chemical structur ...201425328181
salmonella enterica serovar enteritidis and listeria monocytogenes in mango (mangifera indica l.) pulp: growth, survival and cross-contamination.this study examined the ability of salmonella enterica serovar enteritidis and listeria monocytogenes to grow or survive in mango pulp stored at -20°c, 4°c, 10°c and 25°c, as well as to cross-contaminate mangoes by means of a knife contaminated with different levels of these pathogens.201425328926
[immunomodulatory role of dietary lipids in an immunosuppressed mouse model and infected with listeria monocytogenes].dietary fatty acids immunomodulatory capacity in immunosuppression conditions may differ according to the type of fatty acid present in the diet.201425335671
species-specific engagement of human nucleotide oligomerization domain 2 (nod)2 and toll-like receptor (tlr) signalling upon intracellular bacterial infection: role of crohn's associated nod2 gene variants.recognition of bacterial peptidoglycan-derived muramyl-dipeptide (mdp) by nucleotide oligomerization domain 2 (nod2) induces crucial innate immune responses. most bacteria carry the n-acetylated form of mdp (a-mdp) in their cell membranes, whereas n-glycolyl mdp (g-mdp) is typical for mycobacteria. experimental murine studies have reported g-mdp to have a greater nod2-stimulating capacity than a-mdp. as nod2 polymorphisms are associated with crohn's disease (cd), a link has been suggested betwee ...201525335775
of microspheres and microbes: a double-hit strategy for cancer immunotherapy.efficient immunotherapy relies on the rapid generation of elevated amounts of cancer-specific t lymphocytes. we have recently demonstrated that both rapid and potent tumor-targeting immune responses can be induced with a heterologous prime-boost regimen consisting of poly-lactic co-glycolic acid (plga) microsphere-based immunization followed by listeria monocytogenes infection.201425340000
foodborne illness, australia, circa 2000 and circa 2010.foodborne disease is a major public health problem worldwide. to examine changes in foodborne illness in australia, we estimated the incidence, hospitalizations, and deaths attributed to contaminated food circa 2010 and recalculated estimates from circa 2000. approximately 25% of gastroenteritis cases were caused by contaminated food; to account for uncertainty we used simulation techniques to estimate 90% credible intervals. we estimate that circa 2010, 4.1 million foodborne gastroenteritis cas ...201425340705
bacterial and cellular rnas at work during listeria infection.listeria monocytogenes is an intracellular pathogen that can enter and invade host cells. in the course of its infection, rna-mediated regulatory mechanisms provide a fast and versatile response for both the bacterium and the host. they regulate a variety of processes, such as environment sensing and virulence in pathogenic bacteria, as well as development, cellular differentiation, metabolism and immune responses in eukaryotic cells. the aim of this article is to summarize first the rna-mediate ...201425340833
listeria monocytogenes dampens the dna damage response.the dna damage response (ddr) is an essential signaling pathway that detects dna lesions, which constantly occur upon either endogenous or exogenous assaults, and maintains genetic integrity. an infection by an invading pathogen is one such assault, but how bacteria impact the cellular ddr is poorly documented. here, we report that infection with listeria monocytogenes induces host dna breaks. strikingly, the signature response to these breaks is only moderately activated. we uncover the role of ...201425340842
detection and identification of six foodborne bacteria by two-tube multiplex real time pcr and melting curve analysis.this study is aimed to develop a two-tube melting curve-based multiplex real time pcr assay (mcmrt-pcr) for the simultaneous detection of six common foodborne pathogenic bacteria (diarrhoeagenic escherichia coli, salmonella, and shigella in tube 1, staphylococcus aureus, vibrio parahaemolyticus, and listeria monocytogenes in tube 2).201425341812
copsin, a novel peptide-based fungal antibiotic interfering with the peptidoglycan synthesis.fungi and bacteria compete with an arsenal of secreted molecules for their ecological niche. this repertoire represents a rich and inexhaustible source for antibiotics and fungicides. antimicrobial peptides are an emerging class of fungal defense molecules that are promising candidates for pharmaceutical applications. based on a co-cultivation system, we studied the interaction of the coprophilous basidiomycete coprinopsis cinerea with different bacterial species and identified a novel defensin, ...201425342741
real-time pcr detection of listeria monocytogenes in infant formula and lettuce following macrophage-based isolation and enrichment.to develop a rapid detection procedure for listeria monocytogenes in infant formula and lettuce using a macrophage-based enrichment protocol and real-time pcr.201525346434
an essential role of a ferritin-like protein in acid stress tolerance of listeria monocytogenes.the expression of ten genes of listeria monocytogenes previously identified as penicillin g-inducible was transcriptionally analyzed in the presence of 0.5 m kcl, ph 5.0 and 42 °c. this study revealed that all the genes are upregulated by osmotic stress, seven by acid stress and four by temperature stress conditions. the contribution of a gene encoding a ferritin-like protein (fri), a two-component phosphate-response regulator (phop) and an arac/xyls family transcription regulator (axyr) to temp ...201525352185
listeria infection in chinese pregnant women and neonates from shandong.this study aims to investigate the characters of pregnant women and neonates with listeria monocytogenes infections (l. monocytogenes) in shandong of china.201425356132
the listeria small rna rli27 regulates a cell wall protein inside eukaryotic cells by targeting a long 5'-utr variant.listeria monocytogenes is a bacterial pathogen whose genome encodes many cell wall proteins that bind covalently to peptidoglycan. some members of this protein family have a key role in virulence, and recent studies show that some of these, such as lmo0514, are upregulated in bacteria that colonize eukaryotic cells. the regulatory mechanisms that lead to these changes in cell wall proteins remain poorly characterized. here we studied the regulation responsible for increased lmo0514 protein level ...201425356775
genetic and phenotypic characterization of listeria monocytogenes from human clinical cases that occurred in portugal between 2008 and 2012.listeria monocytogenes infection (listeriosis) is an uncommon but severe foodborne illness that affects mainly individuals with recognized underlying conditions: the elderly, immunocompromised individuals, and pregnant women and their fetuses. the aim of this study was to obtain epidemiological data on cases of listeriosis occurring in portugal from 2008 through 2012, collected in hospitals on a voluntary basis. l. monocytogenes isolates were characterized by genoserotyping by multiplex polymera ...201425361468
[determination of the antimicrobial capacity of green tea (camellia sinensis) against the potentially pathogenic microorganisms escherichia coli, salmonella enterica, staphylococcus aureus, listeria monocytogenes, candida albicans and aspergillus niger].many studies can be found in scientific literature demonstrating the antimicrobial capacity of different herbs, including green tea. never-theless, many results are divergent or cannot be compared. several green tea formulations may be found in market, but there is scarce or non-information about its activity. in this work, the potential antimicrobial effect of 50 samples of dry green tea and in 10% infusion against escherichia coli, salmonella enterica, listeria monocytogenes, staphylococcus au ...201325362825
microbiological profile and incidence of salmonella and listeria monocytogenes on hydroponic bell peppers and greenhouse cultivation environment.the aim of this study was to generate information regarding the microbiological profile, including salmonella and listeria monocytogenes incidence, of hydroponically grown bell peppers and materials associated with their production in greenhouses located in mexico. samples of coconut fiber (24), knives (30), drippers (20), conveyor belts (161), pepper transportation wagons (30), air (178), water (16), nutrient solution for plant irrigation (78), and bell pepper fruits (528) were collected during ...201425364924
inactivation of pathogens during aerobic composting of fresh and aged dairy manure and different carbon amendments.two separate studies were conducted to address the condition and the type of feedstocks used during composting of dairy manure. in each study, physical (temperature), chemical (ammonia, volatile acids, and ph), and biological (salmonella, listeria monocytogenes, and escherichia coli o157:h7) parameters were monitored during composting in bioreactors to assess the degree to which they were affected by the experimental variables and, ultimately, the ability of the chemical and physical parameters ...201425364925
geographical and meteorological factors associated with isolation of listeria species in new york state produce production and natural environments.listeria species have been isolated from diverse environments, often at considerable prevalence, and are known to persist in food processing facilities. the presence of listeria spp. has been suggested to be a marker for listeria monocytogenes contamination. therefore, a study was conducted to (i) determine the prevalence and diversity of listeria spp. in produce production and natural environments and (ii) identify geographical and/or meteorological factors that affect the isolation of listeria ...201425364926
listeria monocytogenes and listeria spp. contamination patterns in retail delicatessen establishments in three u.s. states.postprocessing contamination in processing plants has historically been a significant source of listeria monocytogenes in ready-to-eat delicatessen meats, and therefore a major cause of human listeriosis cases and outbreaks. recent risk assessments suggest that a majority of human listeriosis cases linked to consumption of contaminated deli meats may be due to l. monocytogenes contamination that occurs at the retail level. to better understand the ecology and transmission of listeria spp. in ret ...201425364927
visualization of granzyme b-expressing cd8 t cells during primary and secondary immune responses to listeria monocytogenes.cd8 t cells contribute to long-term protection against listeria monocytogenes infection by differentiating into memory t cells. these rapidly respond to antigen or inflammation upon secondary infection. in this study we used cd8 t cells from ot1 mice and cd4 t cells from ot2 mice expressing a fluorescent chimeric granzyme (gzmb-tom) protein to monitor the primary response to infection with ovalbumin-expressing l. monocytogenes (lm-ova). we show that, unlike poorly responding cd4 t cells, cd8 t c ...201525367158
bacteriocin protein bacl1 of enterococcus faecalis targets cell division loci and specifically recognizes l-ala2-cross-bridged peptidoglycan.bacteriocin 41 (bac41) is produced from clinical isolates of enterococcus faecalis and consists of two extracellular proteins, bacl1 and baca. we previously reported that bacl1 protein (595 amino acids, 64.5 kda) is a bacteriolytic peptidoglycan d-isoglutamyl-l-lysine endopeptidase that induces cell lysis of e. faecalis when an accessory factor, baca, is copresent. however, the target of bacl1 remains unknown. in this study, we investigated the targeting specificity of bacl1. fluorescence micros ...201525368300
in situ proteolysis, crystallization and preliminary x-ray diffraction analysis of a vhh that binds listeria internalin b.the variable region of camelid heavy-chain antibodies produces the smallest known antibody fragment with antigen-binding capability (a vhh). the vhh r303 binds internalin b (inlb), a virulence factor expressed by the pathogen listeria monocytogenes. inlb is critical for initiation of listeria infection, as it binds a receptor (c-met) on epithelial cells, triggering the entry of bacteria into host cells. inlb is surface-exposed and is required for virulence, hence a vhh targeting inlb has potenti ...201425372824
attenuated listeria monocytogenes vectors overcome suppressive plasma factors during hiv infection to stimulate myeloid dendritic cells to promote adaptive immunity and reactivation of latent virus.hiv-1 infection is characterized by myeloid dendritic cell (dc) dysfunction, which blunts the responsiveness to vaccine adjuvants. we previously showed that nonviral factors in hiv-seropositive plasma are partially responsible for mediating this immune suppression. in this study we investigated recombinant listeria monocytogenes (lm) vectors, which naturally infect and potently activate dcs from seronegative donors, as a means to overcome dc dysfunction associated with hiv infection. monocyte-de ...201525376024
intestinal expression of fas and fas ligand is upregulated by bacterial signaling through tlr4 and tlr5, with activation of fas modulating intestinal tlr-mediated inflammation.tlrs play an important role in mediating intestinal inflammation and homeostasis. fas is best studied in terms of its function in apoptosis, but recent studies demonstrate that fas signaling may mediate additional functions such as inflammation. the role of fas, and the fas ligand (fasl), in the intestine is poorly understood. the aim of this study was to evaluate potential cross-talk between tlrs and fas/fasl system in intestinal epithelial cells (iecs). iecs were stimulated with tlr ligands, a ...201425378591
aerobic bacterial microbiota isolated from the cloaca of the european pond turtle (emys orbicularis) in poland.we conducted a comparative analysis of the aerobic cloacal bacteria of european pond turtles (emys orbicularis) living in their natural environment and juvenile turtles reared under controlled conditions in a breeding center. we included 130 turtles in the study. the aerobic bacteria isolated from the cloaca of the juvenile turtles were less diverse and more prevalent than the bacteria isolated from free-living adults. we isolated 17 bacterial species from juvenile captive turtles, among which t ...201525380369
spontaneous bacterial peritonitis caused by listeria monocytogenes associated with ascitic fluid lymphocytosis: a case report and review of current empiric therapy.spontaneous bacterial peritonitis (sbp) is a potentially deadly complication of ascites. we describe a case of sbp caused by listeria monocytogenes in a patient with alcoholic cirrhosis. this was associated with the unusual finding of ascitic fluid lymphocytosis, which previously had only been associated with tuberculoid or malignant ascites. given increasing rates of cefotaxime-resistant sbp alongside the possibility of listeriosis, the use of cefotaxime as first-line therapy in sbp should be r ...201325383227
quantitative proteome analyses identify prfa-responsive proteins and phosphoproteins in listeria monocytogenes.protein phosphorylation is a major mechanism of signal transduction in bacteria. here, we analyzed the proteome and phosphoproteome of a wild-type strain of the food-borne pathogen listeria monocytogenes that was grown in either chemically defined medium or rich medium containing glucose. we then compared these results with those obtained from an isogenic prfa* mutant that produced a constitutively active form of prfa, the main transcriptional activator of virulence genes. in the prfa* mutant gr ...201425383790
listeria monocytogenes panophthalmitis: a novel strain follows a virulent course.to describe the findings and clinical course of a case of listeria endophthalmitis as it progressed to panophthalmitis despite vitrectomy and intravitreal and systemic antibiotic therapy.201325383817
divergent evolution of the activity and regulation of the glutamate decarboxylase systems in listeria monocytogenes egd-e and 10403s: roles in virulence and acid tolerance.the glutamate decarboxylase (gad) system has been shown to be important for the survival of listeria monocytogenes in low ph environments. the bacterium can use this faculty to maintain ph homeostasis under acidic conditions. the accepted model for the gad system proposes that the antiport of glutamate into the bacterial cell in exchange for γ-aminobutyric acid (gaba) is coupled to an intracellular decarboxylation reaction of glutamate into gaba that consumes protons and therefore facilitates ph ...201425386947
the antimicrobial activity of liquidambar orientalis mill. against food pathogens and antioxidant capacity of leaf extracts.medicinal plants are an important source of substances which are claimed to induce antimicrobial, antimutagenic and antioxidant effects. many plants have been used due to their antimicrobial treatments. antimicrobial and antioxidant activities of l. orientalis have not been reported to the present day. the aim of this work was to investigate of the antimicrobial and antioxidant potentials of different extracts from l. orientalis.201425395700
multivariate analysis reveals differences in biofilm formation capacity among listeria monocytogenes lineages.biofilm formation capacity evaluated under identical conditions differs among listeria monocytogenes lineages. the approach of using one set of factors or one variable at a time fails to explain why some lineages are more prevalent than others in certain environments. this study proposes the use of multivariate analysis to compare biofilm formation by various strains and describes the ecological niches of l. monocytogenes lineages. nutrient availability, temperature, ph and water activity (aw) a ...201425397897
depletion of autophagy-related genes atg3 and atg5 in tenebrio molitor leads to decreased survivability against an intracellular pathogen, listeria monocytogenes.macroautophagy (autophagy) is an evolutionarily conserved catabolic process involved in physiological and developmental processes including cell survival, death, and innate immunity. homologues of most of 36 originally discovered autophagy-related (atg) genes in yeast have been characterized in higher eukaryotes including insects. in this study, the homologues of atg3 (tmatg3) and atg5 (tmatg5) were isolated from the coleopteran beetle, tenebrio molitor by expressed sequence tag and rnaseq appro ...201525403020
analysis of carbon substrates used by listeria monocytogenes during growth in j774a.1 macrophages suggests a bipartite intracellular metabolism.intracellular bacterial pathogens (ibps) are dependent on various nutrients provided by the host cells. different strategies may therefore be necessary to adapt the intracellular metabolism of ibps to the host cells. the specific carbon sources, the catabolic pathways participating in their degradation, and the biosynthetic performances of ibps are still poorly understood. in this report, we have exploited the technique of (13)c-isotopologue profiling to further study the carbon metabolism of li ...201425405102
prevalence and populations of listeria monocytogenes in meat products retailed in sao paulo, brazil.this study evaluated the prevalence of the populations and serotypes of listeria monocytogenes in 552 refrigerated samples of ground beef, chicken leg, hot dog, and pork sausage collected in supermarkets in the city of sao paulo, sp, brazil, between may 2008 and july 2009. the supermarkets were selected after stratification by geographical region and by random draw. tests for presence and enumeration of l. monocytogenes were based on iso 11290-1:1996/amd.1:2004 and iso 11290-2:1998 methods, resp ...201425407460
acute prostatitis probably due to listeria monocytogenes in an hiv-infected patient.we report a unique case of acute bacterial prostatitis probably caused by listeria monocytogenes in an hiv-infected patient. for the best of our knowledge, this is the first case reported of a patient with this association. our case illustrates the protean clinical presentations that l. monocytogenes infections may adopt, particularly in immunocompromised patients.201525411351
committee opinion no. 614: management of pregnant women with presumptive exposure to listeria monocytogenes.listeriosis is predominantly a foodborne illness, with sporadic and outbreak-related cases tied to consumption of food contaminated with listeria (listeria monocytogenes). the incidence of listeriosis associated with pregnancy is approximately 13 times higher than in the general population. maternal infection may present as a nonspecific, flu-like illness with fever, myalgia, backache, and headache, often preceded by diarrhea or other gastrointestinal symptoms. however, fetal and neonatal infect ...201425411758
splenectomy alters distribution and turnover but not numbers or protective capacity of de novo generated memory cd8 t-cells.the spleen is a highly compartmentalized lymphoid organ that allows for efficient antigen presentation and activation of immune responses. additionally, the spleen itself functions to remove senescent red blood cells, filter bacteria, and sequester platelets. splenectomy, commonly performed after blunt force trauma or splenomegaly, has been shown to increase risk of certain bacterial and parasitic infections years after removal of the spleen. although previous studies report defects in memory b- ...201425414706
the agr communication system provides a benefit to the populations of listeria monocytogenes in soil.in this study, we investigated whether the agr communication system of the pathogenic bacterium listeria monocytogenes was involved in adaptation and competitiveness in soil. alteration of the ability to communicate, either by deletion of the gene coding the response regulator agra (response-negative mutant) or the signal pro-peptide agrd (signal-negative mutant), did not affect population dynamics in soil that had been sterilized but survival was altered in biotic soil suggesting that the agr s ...201425414837
[99mtc]annexin v-128 spect monitoring of splenic and disseminated listeriosis in mice: a model of imaging sepsis.here, we evaluate [(99m)tc]annexin v-128, an in vivo marker of apoptosis, for single photon emission computed tomography (spect) imaging of localization and antibiotic treatment of disseminated bacterial infection, using a well-described mouse model that employs bioluminescent listeria monocytogenes.201525416406
role of the twin-arginine translocase (tat) system in iron uptake in listeria monocytogenes.the twin-arginine translocase (tat) complex is a unique system that translocates folded proteins across the cytoplasmic membrane. in this study, the tat transporter system in listeria monocytogenes was characterized to determine the role of tat in the iron uptake pathway. a putative tatac operon, containing conserved fur-binding sequences in the promoter region, has been predicted to encode tat-translocase components. another operon, fepcab, with a putative fur-binding sequence in the promoter, ...201525416690
two outbreaks of listeria monocytogenes infection, northern spain.in the province of gipuzkoa, spain (≈700,000 inhabitants), 7-12 episodes of human listeriosis were recorded annually during 2009-2012. however, during january 2013-february 2014, 27 episodes were detected, including 11 pregnancy-associated cases. fifteen cases in 2 epidemiologically unrelated outbreaks were caused by a rare type of listeria monocytogenes, sequence type 87 serotype 1/2b.201425418800
the listeria monocytogenes hibernation-promoting factor is required for the formation of 100s ribosomes, optimal fitness, and pathogenesis.during exposure to certain stresses, bacteria dimerize pairs of 70s ribosomes into translationally silent 100s particles in a process called ribosome hibernation. although the biological roles of ribosome hibernation are not completely understood, this process appears to represent a conserved and adaptive response that contributes to optimal survival during stress and post-exponential-phase growth. hibernating ribosomes are formed by the activity of one or more highly conserved proteins; gammapr ...201525422304
cytomegalovirus generates long-lived antigen-specific nk cells with diminished bystander activation to heterologous infection.natural killer (nk) cells play a key role in the host response to cytomegalovirus (cmv) and can mediate an enhanced response to secondary challenge with cmv. we assessed the ability of mouse cmv (mcmv)-induced memory ly49h(+) nk cells to respond to challenges with influenza, an acute viral infection localized to the lung, and listeria monocytogenes, a systemic bacterial infection. mcmv-memory nk cells did not display enhanced activation or proliferation after infection with influenza or listeria ...201425422494
discrete and overlapping functions of peptidoglycan synthases in growth, cell division and virulence of listeria monocytogenes.upon ingestion of contaminated food, listeria monocytogenes can cause serious infections in humans that are normally treated with β-lactam antibiotics. these target listeria's five high molecular weight penicillin-binding proteins (hmw pbps), which are required for peptidoglycan biosynthesis. the two bi-functional class a hmw pbps pbp a1 and pbp a2 have transglycosylase and transpeptidase domains catalyzing glycan chain polymerization and peptide cross-linking, respectively, whereas the three cl ...201525424554
production of antibacterial bombyx mori cecropin a in mealworm-pathogenic beauveria bassiana erl1170.efforts are underway to produce antimicrobial peptides in yellow mealworms (tenebrio molitor), which can be developed as more effective and safer animal feed additives. in this work, we expressed bombyx mori (bm) cecropin-a in mealworms by the infection of transformed entomopathogenic beauveria bassiana erl1170. the active domain of bm cecropin a gene was tagged with a signal sequence of b. bassiana for extracellular secretion, and the fragment was inserted into erl1170 by the restriction enzyme ...201525429897
[sausage-related listeria monocytogenes infection].infection with listeria monocytogenes is rare and mainly seen in immunosuppressed patients. infection with l. monocytogenes has a mortality rate of 30%. we present a case report of l. monocytogenes bacteraemia and endocarditis in a 70-year-old man with several co-morbidities and following four major surgical procedures. this illustrates the findings and characteristics in one of the 16 patients who died in 2013 and 2014 this summer due to sausage-related l. monocytogenes infection.201425430580
the metabolic regulator cody links listeria monocytogenes metabolism to virulence by directly activating the virulence regulatory gene prfa.metabolic adaptations are critical to the ability of bacterial pathogens to grow within host cells and are normally preceded by sensing of host-specific metabolic signals, which in turn can influence the pathogen's virulence state. previously, we reported that the intracellular bacterial pathogen listeria monocytogenes responds to low availability of branched-chain amino acids (bcaas) within mammalian cells by up-regulating both bcaa biosynthesis and virulence genes. the induction of virulence g ...201425430920
evaluation of dna extraction methods for pcr-based detection of listeria monocytogenes from vegetables.epidemiological data indicate that raw vegetables are associated with outbreaks of listeria monocytogenes. therefore, there is a demand for the availability of rapid and sensitive methods, such as pcr assays, for the detection and accurate discrimination of l. monocytogenes. however, the efficiency of pcr methods can be negatively affected by inhibitory compounds commonly found in vegetable matrices that may cause false-negative results. therefore, the sample processing and dna isolation steps m ...201525431169
Refresh
firstprev
...141142143144145146147148149150...
nextlast
Displaying items 14601 - 14700 of 16792