| listeria phage and phage tail induction triggered by components of bacterial growth media (phosphate, licl, nalidixic acid, and acriflavine). | the detection of listeria monocytogenes from food is currently carried out using a double enrichment. for the iso methodology, this double enrichment is performed using half-fraser and fraser broths, in which the overgrowth of l. innocua can occur in samples where both species are present. in this study, we analyzed the induction of phages and phage tails of listeria spp. in these media and in two brain heart infusion (bhi) broths (bhim [biomérieux] and bhik [biokar]) to identify putative effect ... | 2015 | 25595760 |
| complete genome sequence of listeria monocytogenes ntsn, a serovar 4b and animal source strain. | listeria monocytogenes is an important foodborne pathogen that causes infections in humans and animals and has a high mortality rate. the complete genome sequence of l. monocytogenes strain ntsn, a highly virulent and serovar 4b strain isolated from the brains of sheep in jiangsu province, china, is presented here. | 2015 | 25593254 |
| pathogen-expanded cd11b+ invariant nkt cells feedback inhibit t cell proliferation via membrane-bound tgf-β1. | natural killer t cells (nkt cells) are effector cells, but also regulator of immune response, which either promote or suppress immune response through production of different cytokines. however, the subsets of nkt cells with definite phenotype and regulatory function need to be further identified. furthermore, the mechanisms for nkt cells to regulate immune response remain to be fully elucidated. here we identified cd11b(+) invariant nkt (cd11b(+) inkt) cells as a new subset of regulatory nkt ce ... | 2015 | 25592391 |
| listeria arpj gene modifies t helper type 2 subset differentiation. | although the t-cell subset differentiation pathway has been characterized extensively from the view of host gene regulation, the effects of genes of the pathogen on t-cell subset differentiation during infection have yet to be elucidated. especially, the bacterial genes that are responsible for this shift have not yet been determined. | 2015 | 25589336 |
| listeria monocytogenes batch culture growth response to metabolic inhibitors. | in certain environments nutrient and energy sources available to microorganisms can be limited. foodborne pathogens must efficiently adapt in order to be successfully transmitted through the food chain to their hosts. for the intracellular foodborne pathogen listeria monocytogenes, little is known regarding its response to nutrient/energy-limiting conditions. the alternative stress responsive sigma factor σ(b) has been reported to contribute to survival under specific stresses. therefore, the ef ... | 2015 | 25587784 |
| genotypic analyses and virulence characterization of listeria monocytogenes isolates from crayfish (procambarus clarkii). | listeria monocytogenes is a foodborne pathogen that can cause invasive illness in humans and farm animals. it is frequently isolated from dairy products and poultry. however, there have been few literatures on the genetic diversity and virulence potential of l. monocytogenes from freshwater animal. thirty-nine l. monocytogenes strains from crayfish were isolated and identified in this study. molecular subtyping and polymorphism of each isolate were analyzed by multilocus sequence typing (mlst). ... | 2015 | 25586079 |
| safety and survival with gvax pancreas prime and listeria monocytogenes-expressing mesothelin (crs-207) boost vaccines for metastatic pancreatic cancer. | gvax pancreas, granulocyte-macrophage colony-stimulating factor-secreting allogeneic pancreatic tumor cells, induces t-cell immunity to cancer antigens, including mesothelin. gvax is administered with low-dose cyclophosphamide (cy) to inhibit regulatory t cells. crs-207, live-attenuated listeria monocytogenes-expressing mesothelin, induces innate and adaptive immunity. on the basis of preclinical synergy, we tested prime/boost vaccination with gvax and crs-207 in pancreatic adenocarcinoma. | 2015 | 25584002 |
| evaluation of aqueous and alcohol-based quaternary ammonium sanitizers for inactivating salmonella spp., escherichia coli o157:h7, and listeria monocytogenes on peanut and pistachio shells. | this study evaluated the efficacy of aqueous (aquat) and isopropyl alcohol-based quaternary ammonium (ipquat) sanitizers for reducing salmonella spp., escherichia coli o157:h7, or listeria monocytogenes populations on peanut and pistachio shell pieces. inoculated nutshells were mixed with quat sanitizers, water, or 70% ethanol and enumerated immediately or after incubation at 30 °c for 48 h. none of the treatments had any immediate effect on salmonella or e. coli o157:h7 populations on the peanu ... | 2015 | 25583342 |
| application of an oregano oil nanoemulsion to the control of foodborne bacteria on fresh lettuce. | although antimicrobial activities of plant essential oils are well documented, challenges remain as to their application in fresh produce due to the hydrophobic nature of essential oils. oregano oil nanoemulsions were formulated with a food-grade emulsifier and evaluated for their efficacy in inactivating the growth of foodborne bacteria on fresh lettuce. lettuce was artificially inoculated with listeria monocytogenes, salmonella typhimurium and escherichia coli o157:h7, followed by a one-minute ... | 2015 | 25583339 |
| listeria monocytogenes in retail delicatessens: an interagency risk assessment-model and baseline results. | the interagency risk assessment-listeria monocytogenes (lm) in retail delicatessens provides a scientific assessment of the risk of listeriosis associated with the consumption of ready-to-eat (rte) foods commonly prepared and sold in the delicatessen (deli) of a retail food store. the quantitative risk assessment (qra) model simulates the behavior of retail employees in a deli department and tracks the lm potentially present in this environment and in the food. bacterial growth, bacterial inacti ... | 2015 | 25581188 |
| tannin-rich pomegranate rind extracts reduce adhesion to and invasion of caco-2 cells by listeria monocytogenes and decrease its expression of virulence genes. | pomegranate rind is rich in tannins that have remarkable antimicrobial activities. this study aimed to evaluate the effects of a tannin-rich fraction from pomegranate rind (tfpr) on listeria monocytogenes virulence gene expression and on the pathogen's interaction with human epithelial cells. growth curves were monitored to determine the effect of tfpr on l. monocytogenes growth. the 3-(4,5-dimethylthiazol-2-yl)2,5-diphenyltetrazolium bromide and fluorescence staining assays were used to examine ... | 2015 | 25581187 |
| invading slugs (arion vulgaris) can be vectors for listeria monocytogenes. | listeriosis is a frequent silage-associated disease in ruminants. the slugs arion vulgaris are invaders in gardens, vegetable crops and meadows for silage production. field and laboratory studies were conducted to clarify whether slugs could host listeria monocytogenes and thereby constitute a threat to animal feed safety. | 2015 | 25580873 |
| comparison of five methods for direct extraction of surface proteins from listeria monocytogenes for proteomic analysis by orbitrap mass spectrometry. | extracts of surface proteins, with minimal artifacts from contaminating cytosolic components, are highly desirable for investigating surface factors involved in the attachment and formation of biofilms by bacteria that are problematic in commercial food processing facilities. in this study, we compared the protein profiles of the food pathogen, listeria monocytogenes, recovered after applying different surface protein extraction methods compiled from the literature: trypsin-enzymatic shaving wit ... | 2015 | 25578509 |
| liver-resident macrophage necroptosis orchestrates type 1 microbicidal inflammation and type-2-mediated tissue repair during bacterial infection. | kupffer cells, the phagocytes of fetal origin that line the liver sinusoids, are key contributors of host defense against enteroinvasive bacteria. here, we found that infection by listeria monocytogenes induced the early necroptotic death of kupffer cells, which was followed by monocyte recruitment and an anti-bacterial type 1 inflammatory response. kupffer cell death also triggered a type 2 response that involved the hepatocyte-derived alarmin interleukin-33 (il-33) and basophil-derived interle ... | 2015 | 25577440 |
| pulsed light treatment of different food types with a special focus on meat: a critical review. | today, the increasing demand for minimally processed foods that are at the same moment nutritious, organoleptically satisfactory, and free from microbial hazards challenges the research and development to establish alternative methods to reduce the level of bacterial contamination. as one of the recent emerging nonthermal methods, pulsed light (pl) constitutes a technology for the fast, mild, and residue-free surface decontamination of food and food contact materials in the processing environmen ... | 2016 | 25575192 |
| persistent and transient listeria monocytogenes strains from retail deli environments vary in their ability to adhere and form biofilms and rarely have inla premature stop codons. | based on recent risk assessments, up to 83% of listeriosis cases from deli meat in the united states are predicted to be from ready-to-eat deli meats contaminated during processing at retail grocery stores. listeria monocytogenes is known to use sanitizer tolerance and biofilm formation to survive, but interplay of these mechanisms along with virulence potential and persistence mechanisms specific to deli environments had yet to be elucidated. in this study, 442 isolates from food and nonfood co ... | 2015 | 25569840 |
| the tyrosine kinase itk suppresses cd8+ memory t cell development in response to bacterial infection. | vaccine efficacy depends on strong long-term development of immune memory and the formation of memory cd8(+) t cells is critical for recall responses to infection. upon antigen recognition by naïve t cells, the strength of the tcr signal influences the subsequent effector and memory cells differentiation. here, we have examined the role of itk, a tyrosine kinase critical for tcr signaling, in cd8(+) effector and memory t cell differentiation during listeria monocytogenes infection. we found that ... | 2015 | 25567129 |
| listeria monocytogenes has a functional chitinolytic system and an active lytic polysaccharide monooxygenase. | chitinases and chitin-active lytic polysaccharide monooxygenases (lpmos) are most commonly associated with chitin metabolism, but are also reported as virulence factors in pathogenic bacteria. listeria monocytogenes, a well-known virulent bacterium, possesses two chitinases (chia and chib) and a multi-modular lytic polysaccharide monooxygenase (lmlpmo10). these enzymes have been related to virulence and their role in chitin metabolism is poorly understood. it is thus of interest to functionally ... | 2015 | 25565565 |
| suppression of toll-like receptor-mediated innate immune responses at the ocular surface by the membrane-associated mucins muc1 and muc16. | membrane-associated mucins (mams) expressed on the ocular surface epithelium form a dense glycocalyx that is hypothesized to protect the cornea and conjunctiva from external insult. in this study, the hypothesis that the mams muc1 and muc16, expressed on the apical surface of the corneal epithelium, suppress toll-like receptor (tlr)-mediated innate immune responses was tested. using an in vitro model of corneal epithelial cells that are cultured to express mams, we show that reduced expression o ... | 2015 | 25563498 |
| investigating the therapeutic potential of herbal leads against drug resistant listeria monocytogenes by computational virtual screening and in vitro assays. | listeria monocytogenes, a gram-positive opportunistic food-borne pathogen, naturally resistant to many antibiotics and acquired resistance may be a concern in the nearer future. hence, there is a scope for screening of novel therapeutic agents and drug targets, toward the treatment of fatal listeria infections. the seca homologs, seca1 and seca2 are the essential components of the general secretion (sec) pathway, a specialised protein export system, present in l. monocytogenes. this study evalua ... | 2015 | 25562366 |
| [prosthetic hip infection due to listeria monocytogenes: review of the literature and case report]. | with the ageing of the population, articular prosthetic replacements are becoming more and more frequent. one of the most feared complications is prosthetic infection, mostly due to bacteria of the cutaneous flora. listeria monocytogenes is rarely the cause. this paper describes the management of a hip prosthetic infection due to listeria monocytogenes. the patient was cured with antimicrobial therapy and a two-stage exchange. this case report creates an opportunity to review the literature in t ... | 2014 | 25549378 |
| exploring specific primers targeted against different genes for a multiplex pcr for detection of listeria monocytogenes. | the efficacy of six different sets of primers targeted against 16s rrna and virulence genes such as 'iap', 'hly' and 'prf' was evaluated in separate pcr assays. the primer pairs targeted against 16s rrna resulted into amplification of 1.2 kb pcr product. however, sets of primers targeted against different regions of 'iap' produced 371 and 660 bp pcr products, respectively. the primer pair targeted against 'prf' gene could produce 508 bp product. three primer pairs targeted against different regi ... | 2015 | 28324291 |
| chosen quality parameters of pork sausage produced without curing mixture. | the aim of this study was to determine the influence of the dried celeriac juice addition, as a nitrogenous compounds sources, on the quality of the experimental pork sausage. | 2017 | 28068026 |
| effect of lemongrass essential oil vapors on microbial dynamics and listeria monocytogenes survival on rocket and melon stored under different packaging conditions and temperatures. | the aim of the present study was to examine the effect of lemongrass essential oil vapors on the dynamics of surface microbiota and l. monocytogenes growth on rocket and melon under different packaging conditions and storage temperature. for that purpose, rocket and melon were placed on expanded polystyrene (eps) trays, sprayed with l. monocytogenes to a population of 4.5-5.0 log cfu·g(-1), packaged using microperforated oriented polypropylene (opp) film in either air or microperforated active m ... | 2015 | 27682104 |
| fumaric acid and slightly acidic electrolyzed water inactivate gram positive and gram negative foodborne pathogens. | sanitizing effectiveness of slightly acidic electrolyzed water (saew) and fumaric acid (fa) at different dipping temperatures (25-60 °c), times (1-5 min), and concentrations (5-30 ppm for saew and 0.125%-0.5% for fa) on pure cultures of two gram positive pathogens staphylococcus aureus (sa) and listeria monocytogenes (lm) and two gram negative pathogens escherichia coli o157:h7 (ec) and salmonella typhimurium (st) was evaluated. fa (0.25%) showed the strongest sanitizing effect, demonstrating co ... | 2015 | 27682077 |
| identification of multiple bacteriocins in enterococcus spp. using an enterococcus-specific bacteriocin pcr array. | twenty-two bacteriocin-producing enterococcus isolates obtained from food and animal sources, and demonstrating activity against listeria monocytogenes, were screened for bacteriocin-related genes using a bacteriocin pcr array based on known enterococcal bacteriocin gene sequences in the ncbi genbank database. the 22 bacteriocin-positive (bac+) enterococci included en. durans (1), en. faecalis (4), en. faecium (12), en. hirae (3), and en. thailandicus (2). enterocin a (enta), enterocins mr10a an ... | 2015 | 27682075 |
| exploring the diversity of listeria monocytogenes biofilm architecture by high-throughput confocal laser scanning microscopy and the predominance of the honeycomb-like morphotype. | listeria monocytogenes is involved in food-borne illness with a high mortality rate. the persistence of the pathogen along the food chain can be associated with its ability to form biofilms on inert surfaces. while most of the phenotypes associated with biofilms are related to their spatial organization, most published data comparing biofilm formation by l. monocytogenes isolates are based on the quantitative crystal violet assay, which does not give access to structural information. using a hig ... | 2015 | 25548046 |
| antimicrobial and mosquitocidal activity of microbial synthesized silver nanoparticles. | microbial synthesis of nanoparticles is a green approach that interconnects nanotechnology and microbial biotechnology. here, we synthesized the silver nanoparticles (agnps) using bacterial strains of listeria monocytogenes, bacillus subtilius and streptomyces anulatus. we tested the efficacy of agnps against the larvae, pupae and adults of anopheles stephensi and culex quinquefasciatus. we have also investigated the antifungal activity of agnps against the soil keratinophilic fungus of chrysosp ... | 2015 | 25544704 |
| whole-genome sequencing identifies an atypical listeria monocytogenes strain isolated from pet foods. | four listeria isolates, including an atypical strain, were isolated from various pet foods and sequenced. we report here the draft genome sequences of these isolates and a comparative genomic analysis with a closely related human clinical isolate. an analysis of the atypical strain identified a frameshift mutation in the prfa gene. | 2014 | 25540336 |
| a prl mutation in secy suppresses secretion and virulence defects of listeria monocytogenes seca2 mutants. | the bulk of bacterial protein secretion occurs through the conserved secy translocation channel that is powered by seca-dependent atp hydrolysis. many gram-positive bacteria, including the human pathogen listeria monocytogenes, possess an additional nonessential specialized atpase, seca2. seca2-dependent secretion is required for normal cell morphology and virulence in l. monocytogenes; however, the mechanism of export via this pathway is poorly understood. l. monocytogenes seca2 mutants form ro ... | 2015 | 25535272 |
| isolation of listeria monocytogenes from milks used for iranian traditional cheese in lighvan cheese factories. | traditional lighvan cheese is a semi-hard cheese which has a popular market in iran and neighboring countries. the aim of this study was evaluating the contamination of milks used for lighvan cheese making with listeria monocytogenes. raw milk samples were randomly collected from different cheese producing factories (sampling carried out from large milk tanks used cheese making in factories). isolation of l. monocytogenes was performed according to iso 11290 and biochemical tests were done to id ... | 2014 | 25528910 |
| design and characterization of novel recombinant listeriolysin o-protamine fusion proteins for enhanced gene delivery. | to improve the efficiency of gene delivery for effective gene therapy, it is essential that the vector carries functional components that can promote overcoming barriers in various steps leading to the transport of dna from extracellular to ultimately nuclear compartment. in this study, we designed genetically engineered fusion proteins as a platform to incorporate multiple functionalities in one chimeric protein. prototypes of such a chimera tested here contain two domains: one that binds to dn ... | 2015 | 25521817 |
| schistosoma mansoni soluble egg antigens enhance t cell responses to a newly identified hiv-1 gag h-2b epitope. | schistosome infection induces significant t helper type 2 (th2) and anti-inflammatory immune responses and has been shown to negatively impact vaccine efficacy. our goal was to determine if the administration of schistosome soluble egg antigens (sea) would negatively influence the induction of cytotoxic t lymphocyte (ctl) and th1-type t cell responses to an hiv candidate vaccine in the th1-biased c57bl/6 mouse strain. initial experiments failed, as we were unable to detect any response to the de ... | 2015 | 25520148 |
| identification of listeria monocytogenes determinants required for biofilm formation. | listeria monocytogenes is a gram-positive, food-borne pathogen of humans and animals. l. monocytogenes is considered to be a potential public health risk by the u.s. food and drug administration (fda), as this bacterium can easily contaminate ready-to-eat (rte) foods and cause an invasive, life-threatening disease (listeriosis). bacteria can adhere and grow on multiple surfaces and persist within biofilms in food processing plants, providing resistance to sanitizers and other antimicrobial agent ... | 2014 | 25517120 |
| attached and planktonic listeria monocytogenes global proteomic responses and associated influence of strain genetics and temperature. | contamination of industrial and domestic food usage environments by the attachement of bacterial food-borne pathogen listeria monocytogenes has public health and economic implications. comprehensive proteomics experiments using label-free liquid chromatography/tandem mass spectrometry were used to compare the proteomes of two different l. monocytogenes strains (siliken_1/2c and f2365_4b), which show very different capacities to attach to surfaces. growth temperature and strain type were highly i ... | 2015 | 25516393 |
| inactivation of pathogenic listeria monocytogenes in raw milk by high hydrostatic pressure. | the aim of this work was to investigate the mechanisms underlying the inactivation of listeria monocytogenes in raw milk under high hydrostatic pressure (hhp). the results showed that a 450-mpa treatment for 5 min could completely eliminate 10⁸ colony-forming units/ml of viable bacteria, as indicted by increased uptake of propidium iodide. morphological damage to the cell wall, cell membrane, and cytoplasmic components by hhp treatments was observed on scanning and transmission electron microgra ... | 2015 | 25514674 |
| proteomic differences between listeria monocytogenes isolates from food and clinical environments. | listeria monocytogenes is an organism associated with a wide range of foods. it causes listeriosis, a severe illness that mainly affects people with weakened immune systems. proteomic profiles of three different l. monocytogenes isolates were studied using 1d sds page, 2de and mass spectrometry. the protein banding patterns generated by 1d sds page of three strains of l. monocytogenes were found to be similar. visual observations from 2de gel maps revealed that certain spots appeared to have int ... | 2014 | 25513735 |
| development and validation of a stochastic model for potential growth of listeria monocytogenes in naturally contaminated lightly preserved seafood. | a new stochastic model for the simultaneous growth of listeria monocytogenes and lactic acid bacteria (lab) was developed and validated on data from naturally contaminated samples of cold-smoked greenland halibut (csgh) and cold-smoked salmon (css). during industrial processing these samples were added acetic and/or lactic acids. the stochastic model was developed from an existing deterministic model including the effect of 12 environmental parameters and microbial interaction (o. mejlholm and p ... | 2015 | 25500393 |
| modeling transfer of escherichia coli o157:h7 and listeria monocytogenes during preparation of fresh-cut salads: impact of cutting and shredding practices. | cutting and shredding of leafy vegetables increases the risk of cross contamination in household settings. the distribution of escherichia coli o157:h7 and listeria monocytogenes transfer rates (tr) between cutting knives and lettuce leaves was investigated and a semi-mechanistic model describing the bacterial transfer during consecutive cuts of leafy vegetables was developed. for both pathogens the distribution of log10trs from lettuce to knife was towards low values. conversely log10trs from k ... | 2015 | 25500391 |
| investigating boundaries of survival, growth and expression of genes associated with stress and virulence of listeria monocytogenes in response to acid and osmotic stress. | the objective of this study was to correlate the relative transcription of listeria monocytogenes (strains c5, 6179) stress- (gad2, sigb) and virulence- (prfa) associated genes following habituation at twenty-five ph (4.8, 5.0, 5.2, 5.5, 6.4) and nacl (2, 4, 6, 8, 10% w/v) combinations at 7 °c, with the survival against subsequent exposure to severe acid stress (ph 2.0 at 37 °c). our findings pointed out the inter-strain variation governing growth inhibiting conditions (ph ≤5.0 and nacl ≥6%), wh ... | 2015 | 25500389 |
| comparison of individual-based modeling and population approaches for prediction of foodborne pathogens growth. | individual-based modeling (ibm) approach combined with the microenvironment modeling of vacuum-packed cold-smoked salmon was more effective to describe the variability of the growth of a few listeria monocytogenes cells contaminating irradiated salmon slices than the traditional population models. the ibm approach was particularly relevant to predict the absence of growth in 25% (5 among 20) of artificially contaminated cold-smoked salmon samples stored at 8 °c. these results confirmed similar o ... | 2015 | 25500386 |
| preparation, characterization, and antimicrobial activity of chitin nanofibrils reinforced carrageenan nanocomposite films. | present study illustrates the preparation of chitin nanofibrils (cnf) reinforced carrageenan nanocomposite films by the solution-casting technique. cnf was prepared by acid hydrolysis of chitin, followed by high speed homogenization and sonication. ftir result demonstrated that the chemical structure of chitin had not changed after acid hydrolysis. however, the crystalinity of cnf was found to be higher than chitin. the crystallite size of chitin and cnf was 4.73 and 6.27 nm, respectively. the c ... | 2015 | 25498660 |
| essential oils from herbs against foodborne pathogens in chicken sausage. | consumption of chicken meat and its products, especially sausage, have increased in recent years. however, this product is susceptible to microbial contamination during manufacturing, which compromises its shelf life. the flavoring and preservative activities of essential oils (eo) have been recognized and the application of these antimicrobial agents as natural active compounds in food preservation has shown promise. the aim of this study was to evaluate the effect of ocimum basilicum and origa ... | 2015 | 25492235 |
| genetic distance in the whole-genome perspective on listeria monocytogenes strains f2-382 and nihs-28 that show similar subtyping results. | genome subtyping approaches could provide useful epidemiological information regarding food pathogens. however, the full genomic diversity of strains that show similar subtyping results has not yet been completely explored. most subtyping methods are based on the differences of only a portion of the genome. we investigated two draft genome sequences of listeria monocytogenes strain f2-382 and nihs-28, which have been identified as closely related strains by subtyping (identical multi-virulence-l ... | 2014 | 25492229 |
| a novel method to detect listeria monocytogenes via superparamagnetic lateral flow immunoassay. | a novel strip test system combining immunomagnetic separation with lateral flow immunoassay (lfia) was established for the accurate detection of listeria monocytogenes. in this system, a pair of matched monoclonal antibodies was used to construct a sandwich immunoassay, in which superparamagnetic particles were coupled with one of the antibodies as a labeled antibody to capture the target bacteria, while the other antibody was immobilized on the detection zone. after a 20-min reaction, the strip ... | 2015 | 25486917 |
| microbiological challenge testing for listeria monocytogenes in ready-to-eat food: a practical approach. | food business operators (fbos) are the primary responsible for the safety of food they place on the market. the definition and validation of the product's shelf-life is an essential part for ensuring microbiological safety of food and health of consumers. in the frame of the regulation (ec) no 2073/2005 on microbiological criteria for foodstuffs, fbos shall conduct shelf-life studies in order to assure that their food does not exceed the food safety criteria throughout the defined shelf-life. in ... | 2014 | 27800369 |
| regulation of autophagy by e3 ubiquitin ligase rnf216 through becn1 ubiquitination. | autophagy is an evolutionarily conserved biological process involved in an array of physiological and pathological events. without proper control, autophagy contributes to various disorders, including cancer and autoimmune and inflammatory diseases. it is therefore of vital importance that autophagy is under careful balance. thus, additional regulators undoubtedly deepen our understanding of the working network, and provide potential therapeutic targets for disorders. in this study, we found tha ... | 2014 | 25484083 |
| complete genome sequence of listeria monocytogenes lm60, a strain with an enhanced cold adaptation capacity. | the complete genome sequence of listeria monocytogenes lm60, a fast cold-adapting serotype 1/2a human isolate, is presented. | 2014 | 25477407 |
| metal ion homeostasis in listeria monocytogenes and importance in host-pathogen interactions. | listeria monocytogenes is responsible for one of the most life-threatening food-borne infections and the leading cause of food-poisoning associated deaths in the uk. infection may be of the unborn/newly born infant where disease may manifest as listeric abortion, stillbirth or late-onset neonatal listeriosis, while in adults, infection usually affects the central nervous system causing meningitis. crucial to the survival of l. monocytogenes, both inside and outside the host, is its ability to ac ... | 2014 | 25476765 |
| synergistic effect of gamma (γ)-irradiation and microencapsulated antimicrobials against listeria monocytogenes on ready-to-eat (rte) meat. | oregano essential oil (origanum compactum; 250 μg/ml), cinnamon essential oil (cinnamomum cassia; 250 μg/ml) and nisin (16 μg/ml) were used alone or in combination to evaluate their efficiency to inhibit the growth of listeria monocytogenes on rte ham. microencapsulation of the antimicrobial formulations was done to verify the potential effect of the polymer to protect the antimicrobial efficiency during storage. combined treatments of antimicrobial formulation with γ-irradiation were done to ve ... | 2015 | 25475322 |
| role of sigb and osmolytes in desiccation survival of listeria monocytogenes in simulated food soils on the surface of food grade stainless steel. | this research aimed to determine whether the sigb (σ(b)) regulon and osmolytes impact the survival of the foodborne pathogen, listeria monocytogenes, during desiccation in simulated food soils with varying salt and nutrient contents on food grade stainless steel (ss) surfaces. l. monocytogenes 568 (lm568, serotype 1/2a), its isogenic sigb mutant (δsigb) and the back-complemented δsigb were desiccated in bhi, tsb with 1% glucose (tsb-glu), peptone physiological saline (pps) and minimal media (mm) ... | 2015 | 25475314 |
| differential gene expression profiling of listeria monocytogenes in cacciatore and felino salami to reveal potential stress resistance biomarkers. | the current study reports a) the in situ transcriptional profiles of listeria monocytogenes in response to fermented sausage stress and b) an approach in which in situ rt-qpcr data have been combined with advanced statistical techniques to discover potential stress resistance or cell viability biomarkers. gene expression profiling of the pathogen has been investigated using rt-qpcr to understand how l. monocytogenes responds to the conditions encountered during the fermentation and ripening of s ... | 2015 | 25475310 |
| environmental and biological factors influencing the uv-c resistance of listeria monocytogenes. | in this investigation, the effect of microbiological factors (strain, growth phase, exposition to sublethal stresses, and photorepair ability), treatment medium characteristics (ph, water activity, and absorption coefficient), and processing parameters (dose and temperature) on the uv resistance of listeria monocytogenes was studied. the dose to inactivate 99.99% of the initial population of the five strains tested ranged from 21.84 j/ml (stcc 5672) to 14.66 j/ml (stcc 4031). the uv inactivation ... | 2015 | 25475293 |
| effect of quantity of food residues on resistance to desiccation of food-related pathogens adhered to a stainless steel surface. | in order to study the effect of food residues on the survival of food-borne pathogens, salmonella typhimurium, staphylococcus aureus, and listeria monocytogenes were subjected to drying conditions in the presence of small amounts of food such as carrot juice, aqueous solution of nori, milk, and soy-milk. after drying for 2 h at room temperature in the absence of food residue, cell counts of s. typhimurium, s. aureus, and l. monocytogenes decreased from 8 to 3, 6, and 5 log cfu/dish, respectively ... | 2015 | 25475291 |
| effects of osmotic pressure, acid, or cold stresses on antibiotic susceptibility of listeria monocytogenes. | prevalence of antibiotic resistance of listeria monocytogenes isolated from a variety of foods has increased in many countries. l. monocytogenes has many physiological adaptations that enable survival under a wide range of environmental stresses. the objective of this study was to evaluate effects of osmotic (2, 4, 6, 12% nac), ph (6, 5.5, 5.0) and cold (4 °c) stresses on susceptibility of three isolates of l. monocytogenes towards different antibiotics. the minimal inhibitory concentrations (mi ... | 2015 | 25475279 |
| flexible thin-layer dielectric barrier discharge plasma treatment of pork butt and beef loin: effects on pathogen inactivation and meat-quality attributes. | the effects of a flexible thin-layer dielectric barrier discharge (dbd) plasma system using a sealed package on microbial inactivation and quality attributes of fresh pork and beef were tested. following a 10-min treatment, the microbial-load reductions of listeria monocytogenes, escherichia coli o157:h7, and salmonella typhimurium were 2.04, 2.54, and 2.68 log cfu/g in pork-butt samples and 1.90, 2.57, and 2.58 log cfu/g in beef-loin samples, respectively. colorimetric analysis showed that dbd- ... | 2015 | 25475266 |
| influence of temperature, glucose, and iron on sinigrin degradation by salmonella and listeria monocytogenes. | factors, including ph, temperature, glucose concentration, and iron compounds, affect the activity of plant myrosinase and, consequently, endogenous glucosinolate degradation. these factors also may affect glucosinolate degradation by bacterial myrosinase. therefore, this study examined the effect of temperature (4 to 21°c), glucose (0.05 to 1.0%), and iron (10 mm ferrous or ferric) on sinigrin degradation by salmonella or listeria monocytogenes cocktails in mueller-hinton broth and the effect o ... | 2014 | 25474062 |
| controlling attachment and growth of listeria monocytogenes in polyvinyl chloride model floor drains using a peroxide chemical, chitosan-arginine, or heat. | listeria monocytogenes can colonize a poultry processing plant as a resident in floor drains. limiting growth and attachment to drain surfaces may help lessen the potential for cross-contamination of product. the objective of this study was to compare a hydrogen peroxide-peroxyacetic acid-based chemical to chitosan-arginine or heat to prevent attachment of or destroy existing l. monocytogenes on the inner surface of model floor drains. l. monocytogenes was introduced to result in about 10(9) pla ... | 2014 | 25474061 |
| analysis of listeria monocytogenes strain distribution in a pork slaughter and cutting plant in the province of quebec. | following the 2008 canadian listeriosis outbreak associated with ready-to-eat (rte) meat products, regulations on the presence of listeria monocytogenes in rte food production facilities were modified by health canada, confirming the need to control this pathogen, not only in the final product but also in the plant environment. information on the occurrence of this microorganism during the early steps of production, such as the slaughtering process and in the cutting area, is scarce in canada. i ... | 2014 | 25474060 |
| listeria monocytogenes serotype prevalence and biodiversity in diverse food products. | the aim of this study was to assess serotype prevalence and biodiversity of listeria monocytogenes strains isolated from diverse food products, i.e., minced pork, fruits, and vegetables. three hundred twenty-six samples previously purchased from supermarkets and street markets within the athens area were studied for l. monocytogenes prevalence. a total of 121 strains were isolated from the 36 samples that were positive for l. monocytogenes. serotyping was performed with multiplex pcr, and biodiv ... | 2014 | 25474059 |
| inactivation of listeria monocytogenes by disinfectants and bacteriophages in suspension and stainless steel carrier tests. | to simulate food contact surfaces with pits or cracks, stainless steel plates with grooves (depths between 0.2 and 5 mm) were constructed. these plates were artificially contaminated with listeria monocytogenes in clean conditions, with organic soiling, or after 14 days of biofilm formation after which inactivation of the pathogen by suma tab d4 (sodium dichloroisocyanurate, 240 and 300 mg/liter), suma bac d10 (quaternary ammonium compound, 740 mg/liter), and bacteriophage suspension (listex p10 ... | 2014 | 25474045 |
| simultaneous construction of pcr-dgge-based predictive models of listeria monocytogenes and vibrio parahaemolyticus on cooked shrimps. | the aim of this study was to simultaneously construct pcr-dgge-based predictive models of listeria monocytogenes and vibrio parahaemolyticus on cooked shrimps at 4 and 10°c. calibration curves were established to correlate peak density of dgge bands with microbial counts. microbial counts derived from pcr-dgge and plate methods were fitted by baranyi model to obtain molecular and traditional predictive models. for l. monocytogenes, growing at 4 and 10°c, molecular predictive models were construc ... | 2015 | 25470339 |
| cxcr3 expression defines a novel subset of innate cd8+ t cells that enhance immunity against bacterial infection and cancer upon stimulation with il-15. | innate cd8(+) t cells are a heterogeneous population with developmental pathways distinct from conventional cd8(+) t cells. however, their biology, classification, and functions remain incompletely understood. we recently demonstrated the existence of a novel population of chemokine (c-x-c motif) receptor 3 (cxcr3)-positive innate cd8(+) t cells. here, we investigated the functional properties of this subset and identified effector molecules and pathways which mediate their function. adoptive tr ... | 2015 | 25466888 |
| microbiological detection of bacteria in animal products seized in baggage of international air passengers to brazil. | airline travel favours the transmission of diseases, given the short time it takes to travel long distances. in this study, animal products without health certificates seized in international air passengers' baggage at guarulhos (gru) and galeão (gig) airports in brazil underwent a microbiological evaluation. analyses (1610) were carried out on 322 seizures to test for the presence of total and thermotolerant coliforms, as well as staphylococcus aureus counts and the presence of listeria monocyt ... | 2015 | 25466683 |
| quantifying variability on thermal resistance of listeria monocytogenes. | knowledge of the impact of strain variability and growth history on thermal resistance is needed to provide a realistic prediction and an adequate design of thermal treatments. in the present study, apart from quantifying strain variability on thermal resistance of listeria monocytogenes, also biological variability and experimental variability were determined to prioritize their importance. experimental variability was defined as the repeatability of parallel experimental replicates and biologi ... | 2015 | 25462932 |
| identification of non-listeria spp. bacterial isolates yielding a β-d-glucosidase-positive phenotype on agar listeria according to ottaviani and agosti (aloa). | agar listeria according to ottaviani and agosti (aloa) is the mandatory medium used for the detection and enumeration of listeria monocytogenes in foods according to the official international organization for standardization (iso) methods. on aloa, listeria spp. appear as bluish-green colonies due to the production of β-d-glucosidase, an enzyme that cleaves 5-bromo-4-chloro-3-indolyl-β-d-glucopyranoside, a chromogenic substrate included in the formulation of the medium. the present work reports ... | 2015 | 25462931 |
| gold nanoparticle-based dynamic light scattering immunoassay for ultrasensitive detection of listeria monocytogenes in lettuces. | gold nanoparticle (gnp)-based dynamic light scattering (dls) assay has been widely used for sensitive detection of small analytes based on analyte binding-induced gnp aggregation. however, the use of this new method to detect large biological objectives, such as pathogenic bacteria, has not been reported. this study is the first to describe a homogeneous gnp-based dls immunoassay for ultrasensitive detection of listeria monocytogenes. compared with small analytes, l. monocytogenes has a larger s ... | 2015 | 25460900 |
| estimating the non-thermal inactivation of listeria monocytogenes in fermented sausages relative to temperature, ph and water activity. | data relative to in situ listeria monocytogenes inactivation in fermented sausages were collected from 13 individual studies found in the literature. inactivation rates were extrapolated and used to develop a predictive model to evaluate the relative effects of ph, water activity (a(w)) and temperature on l. monocytogenes fate during fermentation and ripening. temperature explained ca. 60% of the data variability, while ph and a(w) only a small part. temperature alone may not be sufficient to ca ... | 2015 | 25460122 |
| identification and molecular characterization of pathogenic bacteria in foods confiscated from non-eu flights passengers at one spanish airport. | two hundred food samples of animal origin confiscated from passengers arriving on flights from non-european countries at the international airport of bilbao (spain) were tested for the presence of four main bacterial foodborne pathogens (campylobacter spp., escherichia coli o157:h7, listeria monocytogenes and salmonella spp.) during 2012 and 2013. overall, 20 samples were positive for l. monocytogenes (10%) and 11 for salmonella spp. (5.5%), whereas campylobacter spp. and e. coli o157:h7 were no ... | 2015 | 25454793 |
| enhanced transport of nanocage stabilized pure nanodrug across intestinal epithelial barrier mimicking listeria monocytogenes. | ligand grafted nanoparticles have been shown to enhance drug transport across epithelium barrier and are expected to improve drug delivery. however, grafting of these ligands to the surface of pure nanodrug, i.e., nanocrystals (ncs), is a critical challenge due to the shedding of ligands along with the stabilizer upon high dilution or dissolving of the drug. herein, a non-sheddable nanocage-like stabilizer was designed by covalent cross-linking of poly(acrylic acid)-b-poly(methyl acrylate) on dr ... | 2015 | 25453961 |
| suspension of thymic emigration promotes the maintenance of antigen-specific memory t cells and the recall responses. | thymic involution is evolutionarily conserved and occurs early in life. however, the physiological significance remains elusive of this seemingly detrimental process. the present study investigated the potential impact of altered thymic output on t cell memory using ovalbumin (ova) expressed by listeria monocytogenes as a model antigen. suspension of thymic emigration by thymectomy was shown to lead to a marked increase in the frequency and total number of ova-specific memory t cells. in contras ... | 2014 | 25450389 |
| high affinity anti-internalin b vhh antibody fragments isolated from naturally and artificially immunized repertoires. | the need for rapid and easy technologies for the detection of food-borne and environmental pathogens is essential for safeguarding the health of populations. furthermore, distribution of tainted food and water can have consequences which can affect whole economies. antibodies and antibody fragments have been historically used in detection platforms due to their antigen specificity and robust physicochemical properties. in this study, we report the isolation and characterization of antibody fragm ... | 2015 | 25450000 |
| comparative analysis of crispr loci in different listeria monocytogenes lineages. | listeria monocytogenes, an important food-borne pathogen, causes high mortality rate of listeriosis. pan-genomic comparisons revealed the species genome of l. monocytogenes is highly stable but not completely clonal. the population structure of this species displays at least four evolutionary lineages (i-iv). isolates of different lineages displayed distinct genetic, phenotypic and ecologic characteristics, which appear to affect their ability to be transmitted through foods and to cause human d ... | 2014 | 25445602 |
| the roles of noncoding rna rli60 in regulating the virulence of listeria monocytogenes. | listeria monocytogenes (lm) is an important zoonotic foodborne pathogen. noncoding rna (ncrna) has an important role in regulating its virulence. as a member of ncrna, however, the function of rli60 in regulating lm virulence remain unclear. the aim of this study was to investigate the role of rli60 in regulating lm virulence. | 2016 | 25442865 |
| transcriptional response of selected genes of salmonella enterica serovar typhimurium biofilm cells during inactivation by superheated steam. | superheated steam (shs), produced by the addition of heat to saturated steam (ss) at the same pressure, has great advantages over conventional heat sterilization due to its high temperature and accelerated drying rate. we previously demonstrated that treatment with shs at 200°c for 10 sec inactivated escherichia coli o157:h7, salmonella typhimurium, and listeria monocytogenes biofilm cells on the surface of stainless steel to below the detection limit. however, bacteria withstanding heat stress ... | 2015 | 25440555 |
| fast and discriminative cosyps detection system of viable salmonella spp. and listeria spp. in carcass swab samples. | in this study, the complete cosyps path food workflow including all steps, namely swab sample enrichment, sybr®green qpcr detection of salmonella spp. and listeria spp., isolation and confirmation of the detected strain, was validated on beef carcass swabs. to perform the validation, the results of the complete workflow were compared, according to the iso 16140:2003, with the iso reference methods for detection, isolation and confirmation of listeria monocytogenes and salmonella spp. the results ... | 2015 | 25440553 |
| subversion of the cytoskeleton by intracellular bacteria: lessons from listeria, salmonella and vibrio. | entry into host cells and intracellular persistence by invasive bacteria are tightly coupled to the ability of the bacterium to disrupt the eukaryotic cytoskeletal machinery. herein we review the main strategies used by three intracellular pathogens to harness key modulators of the cytoskeleton. two of these bacteria, namely listeria monocytogenes and salmonella enterica serovar typhimurium, exhibit quite distinct intracellular lifestyles and therefore provide a comprehensive panel for the under ... | 2015 | 25440316 |
| 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 ... | 2015 | 25431169 |
| [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. | 2014 | 25430580 |
| 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 ... | 2015 | 25424554 |
| 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 ... | 2015 | 25422304 |
| 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. | 2014 | 25418800 |
| 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, ... | 2015 | 25416690 |
| [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. | 2015 | 25416406 |
| 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- ... | 2014 | 25414706 |
| 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 ... | 2014 | 25411758 |
| 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. | 2015 | 25411351 |
| 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 ... | 2014 | 25407460 |
| 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 ... | 2014 | 25405102 |
| 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 ... | 2015 | 25403020 |
| 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 ... | 2014 | 25397897 |
| 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. | 2014 | 25395700 |
| 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 ... | 2014 | 25383790 |
| 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 ... | 2014 | 25378591 |
| 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 ... | 2014 | 25372824 |
| 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 ... | 2015 | 25367158 |
| 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 ... | 2014 | 25364926 |
| 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 ... | 2014 | 25364925 |
| 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 ... | 2014 | 25361468 |
| 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 ... | 2014 | 25356775 |