Publications

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[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
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
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
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 ...201525492235
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 ...201525535272
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 ...201525486917
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 ...201525569840
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 ...201525567129
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 ...201525565565
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 ...201525563498
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 ...201525562366
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 ...201525470339
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 ...201525521817
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 ...201525520148
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 ...201525500393
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 ...201525500391
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 ...201525500389
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 ...201525500386
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 ...201525498660
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 ...201525440316
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
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 ...201525475322
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) ...201525475314
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 ...201525475310
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- ...201525475266
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 ...201525516393
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 ...201525514674
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 ...201525460900
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 ...201525460122
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 ...201525450000
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 ...201525466888
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 ...201525466683
outbreak investigation identifies a single listeria monocytogenes strain in sheep with different clinical manifestations, soil and water.listeria (l.) monocytogenes causes orally acquired infections and is of major importance in ruminants. little is known about l. monocytogenes transmission between farm environment and ruminants. in order to determine potential sources of infection, we investigated the distribution of l. monocytogenes genetic subtypes in a sheep farm during a listeriosis outbreak by applying four subtyping methods (maldi-tof-ms, mlst, mlva and pfge). l. monocytogenes was isolated from a lamb with septicemia and f ...201525726302
comparative proteomic analysis of listeria monocytogenes atcc 7644 exposed to a sublethal concentration of nisin.listeria monocytogenes infections have been frequently reported in many food poisoning outbreaks around the world. in this work, the protein repertoires of l. monocytogenes atcc 7644 cells treated or not with a 10(-3)mg/ml nisin sublethal concentration, established by antimicrobial susceptibility tests, were analyzed by lc-ms/ms. overall, 179 proteins were identified, 9 of them more abundant in nisin-treated samples, and 4 more abundant in non-treated control samples. in nisin treated cells, pro ...201525724729
interaction of graphene family materials with listeria monocytogenes and salmonella enterica.graphene family materials have unique properties, which make them valuable for a range of applications. the antibacterial properties of graphene have been reported; however, findings have been contradictory. this study reports on the antimicrobial proprieties of three different graphene materials (pristine graphene (pg), graphene oxide (go), and reduced graphene oxide (rgo)) against the food-borne bacterial pathogens listeria monocytogenes and salmonella enterica. a high concentration (250 μg/ml ...201525685114
ultrasensitive detection and rapid identification of multiple foodborne pathogens with the naked eyes.in this study, a novel approach for ultrasensitive detection and rapid high-throughput identification of a panel of common foodborne pathogens with the naked eyes is presented. as a proof-of-concept application, a multiple pathogen analysis array is fabricated through immobilizing three specific polyt-capture probes which can respectively recognize rfbe gene (escherichia coli o157:h7), inva gene (salmonella enterica), inla gene (listeria monocytogenes) on the plastic substrates. pcr has been dev ...201525909338
surgical cytoreduction restores the antitumor efficacy of a listeria monocytogenes vaccine in malignant pleural mesothelioma.recent studies suggest that immunotherapy may offer a promising treatment strategy for early-stage malignant pleural mesothelioma (mpm), but advanced tumor burden may limit the efficacy of immunotherapy. therefore, we hypothesized that surgical cytoreduction could restore the efficacy of vaccine-based immunotherapy for mpm. we developed a murine model of mpm through transduction of a mesothelioma cell line with mesothelin. we used this model to evaluate the efficacy of a listeria monocytogenes v ...201525999306
inactivation dynamics of salmonella enterica, listeria monocytogenes, and escherichia coli o157:h7 in wash water during simulated chlorine depletion and replenishment processes.maintaining effective sanitizer concentration is of critical importance for preventing pathogen survival and transference during fresh-cut produce wash operation and for ensuring the safety of finished products. however, maintaining an adequate level of sanitizer in wash water can be challenging for processors due to the large organic load in the wash system. in this study, we investigated how the survival of human pathogens was affected by the dynamic changes in water quality during chlorine de ...201525998820
molecular epidemiology and genetic diversity of listeria monocytogenes isolates from a wide variety of ready-to-eat foods and their relationship to clinical strains from listeriosis outbreaks in chile.listeria monocytogenes is a pathogen transmitted through food that can cause severe infections in high-risk groups such as pregnant women, elderly, young children and immunocompromised individuals. it is a ubiquitous bacterium that can survive in harsh conditions, such as dry environments, at low temperatures, in brine conditions and at low ph values. it also has the capacity to form biofilms, which makes it particularly successful even in colonizing surfaces within food processing plants. this ...201525983727
hplc/ms analysis of polyphenols, antioxidant and antimicrobial activities of artabotrys hildebrandtii o. hffm. extracts.the purpose of this work was to evaluate chemical constituents, antioxidant and antimicrobial activities of artabotrys hildebrandtii, an endemic medicinal plant from madagascar. ethanol extracts from the leaves and stem bark were tested to evaluate dpph free radical scavenging, using butylated hydroxytoluene and quercetin as standard antioxidants. an high-performance liquid chromatography/mass spectrometry method was developed to investigate the presence of phenolic compounds in the studied samp ...201525679267
ph-responsive deoxyribonucleic acid capture/release by polydopamine functionalized magnetic nanoparticles.polydopamine functionalized magnetic nanoparticles (pda@fe3o4) were prepared and characterized by transmission electron microscopy, scanning electron microscopy, zeta potential and vibrating sample magnetometry. they were found to enable highly efficient capture of genomic deoxyribonucleic acid (dna). the adsorption capacity of pda@fe3o4 for genomic dna can reach 161 mg g(-1). the extraction protocol used aqueous solutions for dna binding to and releasing from the surface of the magnetic particl ...201525682426
protective dendritic cell responses against listeriosis induced by the short form of the deubiquitinating enzyme cyld are inhibited by full-length cyld.the deubiquitinating enzyme cyld is an important tumor suppressor and inhibitor of immune responses. in contrast to full-length cyld, the immunological function of the naturally occurring short splice variant of cyld (scyld) is insufficiently described. previously, we showed that dcs, which lack full-length cyld but express scyld, exhibit augmented nf-κb and dc activation. to explore the function of scyld in infection, we investigated whether dc-specific scyld regulates the pathogenesis of liste ...201525675948
a case report of listeria monocytogenes meningoencephalitis in general hospital "dr radivoj simonovir" sombor.listeria monocytogenes is one of the most common causes of bacterial central nervous system infections in adults. it often affects immunicompromised and elderly patients. even with appropriate antimicrobial treatment, mortality due to listeria monocytogenes meningoencephalitis is among the highest of all causes of bacterial central nervous system infections.201525675833
the clinical features, diagnosis, treatment, and prognosis of neuroinvasive listeriosis: a multinational study.the aim of this study was to determine the independent risk factors, morbidity, and mortality of central nervous system (cns) infections caused by listeria monocytogenes. we retrospectively evaluated 100 episodes of neuroinvasive listeriosis in a multinational study in 21 tertiary care hospitals of turkey, france, and italy from 1990 to 2014. the mean age of the patients was 57 years (range, 19-92 years), and 64% were males. the all-cause immunosuppression rate was 54 % (54/100). forty-nine (49 ...201525698311
molecular basis for the recognition of cyclic-di-amp by psta, a pii-like signal transduction protein.cyclic-di-amp (c-di-amp) is a broadly conserved bacterial second messenger that is of importance in bacterial physiology. the molecular receptors mediating the cellular responses to the c-di-amp signal are just beginning to be discovered. psta is a previously uncharacterized pii -like protein which has been identified as a c-di-amp receptor. psta is widely distributed and conserved among gram-positive bacteria in the phylum firmicutes. here, we report the biochemical, structural, and functional ...201525693966
listeria monocytogenes exopolysaccharide: origin, structure, biosynthetic machinery and c-di-gmp-dependent regulation.elevated levels of the second messenger c-di-gmp activate biosynthesis of an unknown exopolysaccharide (eps) in the food-borne pathogen listeria monocytogenes. this eps strongly protects cells against disinfectants and desiccation, indicating its potential significance for listerial persistence in the environment and for food safety. we analyzed the potential phylogenetic origin of this eps, determined its complete structure, characterized genes involved in its biosynthesis and hydrolysis and id ...201525662512
evaluation of transcription levels of inla, inlb, hly, bsh and prfa genes in listeria monocytogenes strains using quantitative reverse-transcription pcr and ability of invasion into human caco-2 cells.listeria monocytogenes virulence depends on the activity of well-characterized virulence factors. in this study, transcription levels of inla, inlb, hly, bsh and prfa genes in l. monocytogenes strains, and the ability of invasion into caco-2 cells were investigated. serotyping, multiplex-pcr for serovar identification and restriction fragment analysis of inla were performed. transcription levels and invasiveness were evaluated by quantitative reverse-transcription pcr and by in vitro assays, res ...201525673285
mir-182 is largely dispensable for adaptive immunity: lack of correlation between expression and function.microrna (mir)-mediated regulation of protein abundance is a pervasive mechanism of directing cellular processes. the well-studied and abundant mir-182 has previously been implicated in many aspects of t cell function, dna repair, and cancer. in this study, we show that mir-182 is the most highly induced mir in b cells undergoing class-switch recombination. to elucidate the requirement of mir-182 in lymphocyte function, we extensively characterized mice with a targeted deletion of mir182. we sho ...201525672759
organelle targeting during bacterial infection: insights from listeria.listeria monocytogenes, a facultative intracellular bacterium responsible for severe foodborne infections, is now recognized as a multifaceted model in infection biology. comprehensive studies of the molecular and cellular basis of the infection have unraveled how the bacterium crosses the intestinal and feto-placental barriers, invades several cell types in which it multiplies and moves, and spreads from cell to cell. interestingly, although listeria does not actively invade host cell organelle ...201525670529
listeria monocytogenes varies among strains to maintain intracellular ph homeostasis under stresses by different acids as analyzed by a high-throughput microplate-based fluorometry.listeria monocytogenes, a food-borne pathogen, has the capacity to maintain intracellular ph (phi) homeostasis in acidic environments, but the underlying mechanisms remain elusive. here, we report a simple microplate-based fluorescent method to determine phi of listerial cells that were prelabeled with the fluorescent dye carboxyfluorescein diacetate n-succinimidyl ester and subjected to acid stress. we found that l. monocytogenes responds differently among strains toward organic and inorganic a ...201525667585
the class ii phosphatidylinositol 3-phosphate kinase pik3c2a promotes shigella flexneri dissemination through formation of vacuole-like protrusions.intracellular pathogens such as shigella flexneri and listeria monocytogenes achieve dissemination in the intestinal epithelium by displaying actin-based motility in the cytosol of infected cells. as they reach the cell periphery, motile bacteria form plasma membrane protrusions that resolve into vacuoles in adjacent cells, through a poorly understood mechanism. here, we report on the role of the class ii phosphatidylinositol 3-phosphate kinase pik3c2a in s. flexneri dissemination. time-lapse mi ...201525667265
previous physicochemical stress exposures influence subsequent resistance of escherichia coli o157:h7, salmonella enterica, and listeria monocytogenes to ultraviolet-c in coconut liquid endosperm beverage.this study investigated the influences of prior exposures to common physicochemical stresses encountered by microorganisms in food and food processing ecologies such as acidity, desiccation, and their combinations, on their subsequent susceptibility towards uv-c treatment in coconut liquid endosperm beverage. cocktails of escherichia coli o157:h7, salmonella enterica, and listeria monocytogenes were separately subjected to gradually acidifying environment (final ph 4.46), exposed to abrupt desic ...201525723813
type i interferons in infectious disease.type i interferons (ifns) have diverse effects on innate and adaptive immune cells during infection with viruses, bacteria, parasites and fungi, directly and/or indirectly through the induction of other mediators. type i ifns are important for host defence against viruses. however, recently, they have been shown to cause immunopathology in some acute viral infections, such as influenza virus infection. conversely, they can lead to immunosuppression during chronic viral infections, such as lympho ...201525614319
risk-based control of food-borne pathogens listeria monocytogenes and salmonella enterica in the italian fermented sausages cacciatore and felino.fermentation is the most important killing step during production of fermented meats to eliminate food-borne pathogens. the objective was to evaluate whether the food-borne pathogens listeria monocytogenes and salmonella enterica may survive during the production of two italian fermented sausages. sausage batter was inoculated with five strains of l. monocytogenes or s. enterica (ca. 10(5)-10(6) cfu/g) and their kinetic behavior was monitored during production. both pathogens survived relatively ...201525612557
pregnancy related listeriosis: treatment and control.listeriosis during pregnancy usually presents as an unremarkable febrile illness in the mother but can be fatal for the fetus and newborn. reliable laboratory testing for early diagnosis is lacking. serological antibody tests and bacteriological stool tests are not helpful since listeria-specific antibodies and stool cultures yielding the organism can be found in healthy pregnant women. because early diagnosis is difficult, diagnosis is usually made by culturing the pathogen from blood, cerebros ...201525604158
proteome mining for drug target identification in listeria monocytogenes strain egd-e and structure-based virtual screening of a candidate drug target penicillin binding protein 4.we used a combination of in-silico approaches to identify 168 promising drug targets in the proteome of a multidrug-resistant listeria monocytogenes strain; of these, one (pbp4) was particularly promising. virtual screening using it, followed by reverse docking, revealed four compounds namely nci524121, cap332797, nci524136 and zinc00518462 as good multi-target leads.201525601791
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 ...201525595760
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.201525593254
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 ...201525592391
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.201525589336
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 ...201525587784
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.201525580873
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 ...201525578509
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 ...201525577440
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 ...201527682077
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 ...201527682075
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 ...201525475293
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 ...201525475279
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 ...201525475291
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 ...201525548046
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 ...201525544704
plasmid-borne cadmium resistant determinants are associated with the susceptibility of listeria monocytogenes to bacteriophage.listeria monocytogenes is an intracellular pathogen causing gastroenteritis, central nervous system infections and abortions. chromosomal virulence determinants have been extensively investigated. however, the function of genes encoded by plasmids in l. monocytogenes has not been fully understood. in this study, we determined the prevalence and molecular profile of plasmids in food isolates of l. monocytogenes and examined the contribution of four plasmid-borne cadmium-resistant genes to the sus ...201525721472
whole-genome sequences of 12 clinical strains of listeria monocytogenes.listeria monocytogenes is a foodborne pathogen of global concern due to the high mortality rate among immunocompromised patients. whole-genome sequences of 12 strains of l. monocytogenes from humans were reported. the availability of these genomes should provide useful information on the evolutionary history and genetic diversity of l. monocytogenes.201525720683
seek and destroy process: listeria monocytogenes process controls in the ready-to-eat meat and poultry industry.the majority of human listeriosis cases appear to be caused by consumption of ready-to-eat (rte) foods contaminated at the time of consumption with high levels of listeria monocytogenes. although strategies to prevent growth of l. monocytogenes in rte products are critical for reducing the incidence of human listeriosis, control of postprocessing environmental contamination of rte meat and poultry products is an essential component of a comprehensive l. monocytogenes intervention and control pro ...201525710164
assessing the survival of listeria monocytogenes in a domestic freezer by analyzing subsequent growth at 30°c using a novel reference method.listeria monocytogenes is a serious pathogen capable of extensive survival under frozen storage. using optical density and multiple initial inocula in multiple identically prepared microtiter plates, the effect of storage time at -22°c on the subsequent growth at 30°c of the organism when defrosted was studied using a technique that compared the growth (through time to detection) of a test plate (previously frozen) with that of an identically prepared control plate, analyzed at the start of the ...201525710150
survival of salmonella, escherichia coli o157:h7, and listeria monocytogenes on raw peanut and pecan kernels stored at -24, 4, and 22°c.cocktails of lawn-collected cells were used to determine the survival of salmonella, escherichia coli o157:h7, and listeria monocytogenes on the surface of raw peanut and pecan kernels. kernels were inoculated with mixtures of four to five strains at 3 or 6 log cfu/g, dried at room temperature, and then stored at -24 ± 1, 4 ± 2, and 22 ± 1°c for 28 or 365 days. in most cases, rates of decline of the pathogens did not differ significantly between the two inoculum concentrations in the 28-day stud ...201525710147
estimation of listeria monocytogenes and escherichia coli o157:h7 prevalence and levels in naturally contaminated rocket and cucumber samples by deterministic and stochastic approaches.the aims of the present study were to determine the prevalence and levels of listeria monocytogenes and escherichia coli o157:h7 in rocket and cucumber samples by deterministic (estimation of a single value) and stochastic (estimation of a range of values) approaches. in parallel, the chromogenic media commonly used for the recovery of these microorganisms were evaluated and compared, and the efficiency of an enzyme-linked immunosorbent assay (elisa)-based protocol was validated. l. monocytogene ...201525710146
g0s2 modulates homeostatic proliferation of naïve cd8⁺ t cells and inhibits oxidative phosphorylation in mitochondria.since its discovery, diverse functions have been attributed to the g0/g1 switch gene 2 (g0s2), from lipid metabolism to control of cell proliferation. our group showed for the first time that g0s2 promotes quiescence in hematopoietic stem cells by interacting with and retaining nucleolin around the nucleus. herein, we report the role of g0s2 in the differentiation and function of cd8(+) t cells examined in mice with an embryonic deletion of the g0s2 gene. g0s2 expression in naïve cd8(+) t cells ...201525666096
efficacies of nisin a and nisin v semipurified preparations alone and in combination with plant essential oils for controlling listeria monocytogenes.the food-borne pathogenic bacterium listeria is known for relatively low morbidity and high mortality rates, reaching up to 25 to 30%. listeria is a hardy organism, and its control in foods represents a significant challenge. many naturally occurring compounds, including the bacteriocin nisin and a number of plant essential oils, have been widely studied and are reported to be effective as antimicrobial agents against spoilage and pathogenic microorganisms. the aim of this study was to investiga ...201525662980
characterization of polar lipids of listeria monocytogenes by hcd and low-energy cad linear ion-trap mass spectrometry with electrospray ionization.listeria monocytogenes (l. monocytogenes) is a facultative, gram-positive, food-borne bacterium, which causes serious infections. although it is known that lipids play important roles in the survival of listeria, the detailed structures of these lipids have not been established. in this contribution, we described linear ion-trap multiple-stage mass spectrometric approaches with high-resolution mass spectrometry toward complete structural analysis including the identities of the fatty acid substi ...201525656850
listeria monocytogenes as a cause of spontaneous bacterial peritonitis: a rare entity.listeria is an uncommon cause of spontaneous bacterial peritonitis (sbp) in the united states. listeria should be suspected as a cause of sbp when the patient has diphtheria-like organisms on ascitic/blood cultures, iron overload/hemochromatosis, exposure to farm animals, or poor response to empiric therapy within 48-72 h. diagnosis of sbp is made if the ascitic fluid shows polymorphonuclear cell count >250 cells/mm(3) without an intra-abdominal source of infection. ampicillin with or without an ...201525656671
src-dependent tyrosine phosphorylation of non-muscle myosin heavy chain-iia restricts listeria monocytogenes cellular infection.bacterial pathogens often interfere with host tyrosine phosphorylation cascades to control host responses and cause infection. given the role of tyrosine phosphorylation events in different human infections and our previous results showing the activation of the tyrosine kinase src upon incubation of cells with listeria monocytogenes, we searched for novel host proteins undergoing tyrosine phosphorylation upon l. monocytogenes infection. we identify the heavy chain of the non-muscle myosin iia (n ...201525635050
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 ...201525581188
septicemic listeriosis in wild hares from saskatchewan, canada.the bacterium listeria monocytogenes causes disease in a wide variety of mammals including rabbits and hares. we describe naturally acquired metritis and septicemic listeriosis in wild female hares from saskatchewan, canada. between april 2012 and july 2013, two white-tailed jackrabbits (lepus townsendii) and a snowshoe hare (lepus americanus) were presented to the veterinary medical centre at the western college of veterinary medicine, saskatoon, saskatchewan, canada with nonspecific neurologic ...201525647601
contribution of the multiple type i signal peptidases to the secretome of listeria monocytogenes: deciphering their specificity for secreted exoproteins by exoproteomic analysis.as commonly seen in monoderm bacteria, listeria monocytogenes possesses multiple membrane-bound signal peptidases of type i (spases i) called sipx, sipy and sipz. in order to decipher their respective contribution in an integrated and global view, the complement of the secretome corresponding to the exoproteome was resolved by two-dimensional gel electrophoresis (2-de). this was performed for l. monocytogenes sipx(-), sipy(-), sipz(-) single mutants, as well as for δsipxy and δsipyz double mutan ...201525637307
pfge standard operating procedures for listeria monocytogenes: harmonizing the typing of food and clinical strains in europe.listeria monocytogenes is a foodborne pathogen responsible for a severe disease known as listeriosis. the european centre for disease prevention and control (ecdc) coordinates a network of national public health laboratories (nphls) in charge of typing clinical strains. in food, it is the european union reference laboratory for l. monocytogenes (eurl lm), which manages a network of national reference laboratories (nrls). a pulsed-field gel electrophoresis (pfge) standard operating procedure (eur ...201525658711
whole-genome sequence of listeria monocytogenes strains from clinical and environmental samples from varanasi, india.we present here the whole-genome sequences of listeria monocytogenes from ganges river water, agricultural soil, and human clinical samples from varanasi, india, which will be used for a comparative analysis.201525657276
draft genome sequence of listeria monocytogenes lm201, isolated from foodstuff.listeria monocytogenes is a facultative intracellular foodborne pathogen that can cause listeriosis in humans and animals. l. monocytogenes lm201 was isolated from foodstuff. the draft genome sequence of strain lm201 provides the genetic basis for the application of this strain in biotechnological vaccine production.201525657267
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). ...201525586079
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.201525584002
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 ...201525583342
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 ...201525583339
microfluidic filtration and extraction of pathogens from food samples by hydrodynamic focusing and inertial lateral migration.detecting pathogenic bacteria in food or other biological samples with lab-on-a-chip (loc) devices requires several sample preparation steps prior to analysis which commonly involves cleaning complex sample matrices of large debris. this often underestimated step is important to prevent these larger particles from clogging devices and to preserve initial concentrations when loc techniques are used to concentrate or isolate smaller target microorganisms for downstream analysis. in this context, w ...201525653055
synergy among thymol, eugenol, berberine, cinnamaldehyde and streptomycin against planktonic and biofilm-associated food-borne pathogens.essential oils have been found to exert antibacterial, antifungal, spasmolytic, and antiplasmodial activity and therapeutic effect in cancer treatment. in this study, the antibacterial activities of four main essential oils' components (thymol (thy), eugenol (eug), berberine (ber), and cinnamaldehyde (cin)) were evaluated against two food-borne pathogens, listeria monocytogenes and salmonella typhimurium, either alone or in combination with streptomycin. checkerboard assay demonstrated that thy ...201525661823
a gold glyco-nanoparticle carrying a listeriolysin o peptide and formulated with advax™ delta inulin adjuvant induces robust t-cell protection against listeria infection.in the search for an effective vaccine against the human pathogen, listeria monocytogenes (listeria), gold glyconanoparticles (gnp) loaded with a listeriolysin o peptide llo91-99 (gnp-llo) were used to immunise mice, initially using a dendritic cell (dc) vaccine approach, but subsequently using a standard parenteral immunisation approach. to enhance vaccine immunogenicity a novel polysaccharide adjuvant based on delta inulin (advax™) was also co-formulated with the gnp vaccine. confirming previo ...201525659269
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 ...201525581187
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 ...201527682104
structure and mechanism of the caseinolytic protease clpp1/2 heterocomplex from listeria monocytogenes.listeria monocytogenes is a devastating bacterial pathogen. its virulence and intracellular stress tolerance are supported by caseinolytic protease p (clpp), an enzyme that is conserved among bacteria. l. monocytogenes expresses two clpp isoforms that are only distantly related by sequence and differ in catalysis, oligomerization, active-site composition, and n-terminal interaction sites for associated aaa(+) chaperones. the crystal structure of the clpp1/2 heterocomplex from l. monocytogenes wa ...201525630955
empirical antibiotic cover for listeria monocytogenes infection beyond the neonatal period: a time for change? 201525628458
shelf life determination of sliced portuguese traditional blood sausage--morcela de arroz de monchique through microbiological challenge and consumer test.morcela de arroz (ma) is a ready-to-eat blood and rice cooked sausage produced with pork, blood, rice, and seasonings, stuffed in natural casing and cooked above 90 °c/30 min. it is commercialized whole, not packed, with a restricted shelf life (1 wk/0 to 5 °c). the objective of this work was to establish sliced ma shelf life considering both the behavior of l. monocytogenes through a microbiological challenge test (mct) and the consumer acceptability of ma stored: vacuum packed (vp), modified a ...201525627176
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