| antibacterial efficacy of nisin, pediocin 34 and enterocin fh99 against listeria monocytogenes and cross resistance of its bacteriocin resistant variants to common food preservatives. | antilisterial efficiency of three bacteriocins, viz, nisin, pediocin 34 and enterocin fh99 was tested individually and in combination against listeria mononcytogenes atcc 53135. a greater antibacterial effect was observed when the bacteriocins were combined in pairs, indicating that the use of more than one lab bacteriocin in combination have a higher antibacterial action than when used individually. variants of listeria monocytogenes atcc 53135 resistant to nisin, pediocin 34 and enterocin fh99 ... | 2013 | 24159285 |
| formation of biofilm by listeria monocytogenes atcc 19112 at different incubation temperatures and concentrations of sodium chloride. | biofilm formation can lead to various consequences in the food processing line such as contamination and equipment breakdowns. since formation of biofilm can occur in various conditions; this study was carried out using l. monocytogenes atcc 19112 and its biofilm formation ability tested under various concentrations of sodium chloride and temperatures. cultures of l. monocytogenes atcc 19112 were placed in 96-well microtitre plate containing concentration of sodium chloride from 1-10% (w/v) and ... | 2013 | 24159283 |
| curcumin improves the therapeutic efficacy of listeria(at)-mage-b vaccine in correlation with improved t-cell responses in blood of a triple-negative breast cancer model 4t1. | success of cancer vaccination is strongly hampered by immune suppression in the tumor microenvironment (tme). interleukin (il)-6 is particularly and highly produced by triple-negative breast cancer (tnbc) cells, and has been considered as an important contributor to immune suppression in the tme. therefore, we hypothesized that il-6 reduction may improve efficacy of vaccination against tnbc cancer through improved t-cell responses. to prove this hypothesis, we investigated the effect of curcumin ... | 2013 | 24156030 |
| actin network disassembly powers dissemination of listeria monocytogenes. | several bacterial pathogens hijack the actin assembly machinery and display intracellular motility in the cytosol of infected cells. at the cell cortex, intracellular motility leads to bacterial dissemination through formation of plasma membrane protrusions that resolve into vacuoles in adjacent cells. here, we uncover a crucial role for actin network disassembly in dissemination of listeria monocytogenes. we found that defects in the disassembly machinery decreased the rate of actin tail turnov ... | 2014 | 24155331 |
| deficits in serum amyloid a contribute to increased neonatal mortality during murine listeriosis. | to understand the increased susceptibility of preterm neonates to infection. | 2013 | 24153400 |
| 'prevalence and antimicrobial susceptibility of listeria monocytogenes and methicillin-resistant staphylococcus aureus strains from raw meat and meat products in zaria, nigeria. | the bacterial genera listeria and staphylococcus have been frequently isolated from food products and are responsible for a number of animal and human diseases. the aim of the study was to simultaneously isolate and characterize l. monocytogenes and staphylococcus species from 300 samples of raw meat and meat products, to determine the susceptibility of the organisms to commonly used antimicrobial agents and to determine the presence of haemolysin a (hyl) virulence gene in l. monocytogenes and s ... | 2014 | 24151971 |
| listeria monocytogenes (lm)-llo immunotherapies reduce the immunosuppressive activity of myeloid-derived suppressor cells and regulatory t cells in the tumor microenvironment. | myeloid-derived suppressor cells (mdsc) and regulatory t cells (treg) are major components of the immune suppressive cells that potentially limit the effectiveness of an immunotherapy-based treatment. both of these suppressive cell types have been shown to expand in tumor models and promote t-cell dysfunction that in turn favors tumor progression. this study demonstrates that listeria monocytogenes (lm)-llo immunotherapies effect on the suppressive ability of mdsc and treg in the tumor microenvi ... | 2013 | 24145358 |
| in vitro and in vivo models to study human listeriosis: mind the gap. | listeria monocytogenes (lm) is the etiological agent of listeriosis, one of the deadliest human foodborne infections. lm is able to cross the intestinal, placental and blood-brain barriers, leading to septicemia, fetoplacental infection, meningitis and encephalitis. the intracellular life cycle of this facultative intracellular bacterium has been studied in detail in in vitro cell culture systems. lm enters in non-phagocytic cells in an inla-ecad and/or inb-met dependent manner. lm then escapes ... | 2013 | 24144539 |
| a non-catalytic histidine residue influences the function of the metalloprotease of listeria monocytogenes. | mpl, a thermolysin-like metalloprotease, and pc-plc, a phospholipase c, are synthesized as proenzymes by the intracellular bacterial pathogen listeria monocytogenes. during intracellular growth, l. monocytogenes is temporarily confined in a membrane-bound vacuole whose acidification leads to mpl autolysis and mpl-mediated cleavage of the pc-plc n-terminal propeptide. mpl maturation also leads to the secretion of both mpl and pc-plc across the bacterial cell wall. previously, we identified negati ... | 2014 | 24140648 |
| collaborative survey on the colonization of different types of cheese-processing facilities with listeria monocytogenes. | cross-contamination via equipment and the food-processing environment has been implicated as the main cause of listeria monocytogenes transmission. the aim of this study, therefore, was to determine the occurrence and potential persistence of l. monocytogenes in 19 european cheese-processing facilities. a sampling approach in 2007-2008 included, respectively, 11 and two industrial cheese producers in austria and the czech republic, as well as six irish on-farm cheese producers. from some of the ... | 2014 | 24138033 |
| genome sequences of listeria monocytogenes serotype 4b variant strains isolated from clinical and environmental sources. | listeria monocytogenes strains that show a novel pcr serotyping profile (ivb-v1) have been reported recently. here, we announce the draft genome sequences of five l. monocytogenes ivb-v1 strains isolated from the united states and australia that harbor a 6.3-kb dna cassette characteristic of serotype 1/2a strains. | 2013 | 24136844 |
| comparative proteomic analysis of listeria monocytogenes exposed to enterocin as-48 in planktonic and sessile states. | enterocin as-48 is a cyclic peptide of great interest for application in food preservation and sanitation. in the present study, the proteome response of listeria monocytogenes to purified enterocin as-48 was studied under two different conditions: planktonic cells and sessile cells grown on polystyrene plates. ten different proteins were differentially expressed in planktonic l. monocytogenes cells treated with 0.1 μg/ml enterocin as-48 compared to the untreated controls. overexpressed proteins ... | 2013 | 24135676 |
| challenges in listeriosis cluster and outbreak investigations, province of quebec, 1997-2011. | public health authorities place a high priority on investigating listeriosis outbreaks, and these epidemiological investigations remain challenging. some approaches have been described in the literature to address these challenges. this review of listeriosis clusters and outbreaks investigated in the province of quebec (quebec) highlights investigative approaches that contributed to identifying the source of these outbreaks. | 2014 | 24134667 |
| anti-listeria activity of poly(lactic acid)/sawdust particle biocomposite film impregnated with pediocin pa-1/ach and its use in raw sliced pork. | a novel poly(lactic acid) (pla)/sawdust particle (sp) biocomposite film with anti-listeria activity was developed by incorporation of pediocin pa-1/ach (ped) using diffusion coating method. sawdust particle played an important role in embedding pediocin into the hydrophobic pla film. the anti-listeria activity of the pla/sp biocomposite film incorporated with ped (pla/sp+ped) was detected, while no activity against the tested pathogen was observed for the control pla films (without sp and/or ped ... | 2013 | 24129155 |
| yersinia enterocolitica inhibits salmonella enterica serovar typhimurium and listeria monocytogenes cellular uptake. | yersinia enterocolitica biovar 1b employs two type three secretion systems (t3ss), ysa and ysc, which inject effector proteins into macrophages to prevent phagocytosis. conversely, salmonella enterica serovar typhimurium uses a t3ss encoded by salmonella pathogenicity island 1 (spi1) to actively invade cells that are normally nonphagocytic and a second t3ss encoded by spi2 to survive within macrophages. given the distinctly different outcomes that occur with regard to host cell uptake of s. typh ... | 2014 | 24126528 |
| efficacy of bacteriophage listex™p100 combined with chemical antimicrobials in reducing listeria monocytogenes in cooked turkey and roast beef. | the aim of this study was to verify the effectiveness of the commercially available anti-listeria phage preparation listex(™)p100 in reducing listeria monocytogenes on ready-to-eat (rte) roast beef and cooked turkey in the presence or absence of the chemical antimicrobials potassium lactate (pl) and sodium diacetate (sd). sliced rte meat cores at 4 and 10 °c were inoculated with cold-adapted l. monocytogenes to result in a surface contamination level of 10(3)cfu/cm(2). listex(tm)p100 was applied ... | 2013 | 24125778 |
| hiv-1 vaccine-specific responses induced by listeria vector vaccines are maintained in mice subsequently infected with a model helminth parasite, schistosoma mansoni. | in areas co-endemic for helminth parasites and hiv/aids, infants are often administered vaccines prior to infection with immune modulatory helminth parasites. systemic th2 biasing and immune suppression caused by helminth infection reduces cell-mediated responses to vaccines such as tetanus toxoid and bcg. therefore, we asked if infection with helminthes post-vaccination, alters already established vaccine induced immune responses. in our model, mice are vaccinated against hiv-1 gag using a list ... | 2013 | 24120546 |
| outbreak of listeria monocytogenes in an urban poultry flock. | listeria monocytogenes infection is most commonly recognized in ruminants, including cattle, sheep, and goats; but it is rarely diagnosed in poultry. this report describes an outbreak of l. monocytogenes in a backyard poultry flock. also, it points out the importance of collaboration between veterinarians and public health departments and the possible implications of zoonotic diseases. | 2013 | 24119838 |
| antilisterial activity of lactose monolaurate in milk, drinkable yogurt and cottage cheese. | lactose monolaurate (lml) was previously found to be an antimicrobial against listeria monocytogenes in culture medium at concentrations between 3 and 5 mg ml(-1) . in this study, the microbial inhibitory activity of lml in dairy products inoculated with a 5-strain cocktail of clinical isolates of l. monocytogenes was investigated. addition of lml at a concentration of 5 mg ml(-1) resulted in 4.4, 4.0 and 4.2 log reductions in 0.5% fat, 1% fat and 3.25% fat milks, respectively; 4.1, 4.4, and 3.5 ... | 2014 | 24117896 |
| microbial diversity and structure are drivers of the biological barrier effect against listeria monocytogenes in soil. | understanding the ecology of pathogenic organisms is important in order to monitor their transmission in the environment and the related health hazards. we investigated the relationship between soil microbial diversity and the barrier effect against listeria monocytogenes invasion. by using a dilution-to-extinction approach, we analysed the consequence of eroding microbial diversity on l. monocytogenes population dynamics under standardised conditions of abiotic parameters and microbial abundanc ... | 2013 | 24116193 |
| biotic and abiotic soil properties influence survival of listeria monocytogenes in soil. | listeria monocytogenes is a food-borne pathogen responsible for the potentially fatal disease listeriosis and terrestrial ecosystems have been hypothesized to be its natural reservoir. therefore, identifying the key edaphic factors that influence its survival in soil is critical. we measured the survival of l. monocytogenes in a set of 100 soil samples belonging to the french soil quality monitoring network. this soil collection is meant to be representative of the pedology and land use of the w ... | 2013 | 24116083 |
| survival of listeria monocytogenes during production and ripening of traditional turkish savak tulum cheese and in synthetic gastric fluid. | this study investigated the survival and acid tolerance of listeria monocytogenes during the 2-day processing stage and 90-day ripening of savak tulum cheese, a traditional cheese in turkey. experimental savak tulum cheese was produced from raw sheep's milk that was inoculated with a l. monocytogenes mixture consisting of five strains (average 7.0 log cfu/ml) and was ripened at 6°c for 90 days. microbiological and chemical analyses and acid exposure experiments in synthetic gastric fluid (sgf) ( ... | 2013 | 24112584 |
| listeria infection inhibits ige production in regional lymph nodes by suppressing chemotaxis of basophils to lymph nodes. | infection with listeria induces a dominant shift to the th1 immune response and inhibits the th2 response. papain is frequently utilized in animal models of allergies. papain administration induces chemotaxis of basophils to regional lymph nodes (lns) and production of interleukin (il)-4 by basophils, resulting in a th2-dominant status and increased ige production in lns. in this model, production of immunoglobulin (ig) e by ln cells is primarily controlled by il-4 produced by basophils. based o ... | 2013 | 24111499 |
| amythiamicin d and related thiopeptides as inhibitors of the bacterial elongation factor ef-tu: modification of the amino acid at carbon atom c2 of ring c dramatically influences activity. | three analogues of amythiamicin d, which differ in the substitution pattern at the methine group adjacent to c2 of the thiazole ring c, were prepared by de novo total synthesis. in amythiamicin d, this carbon atom is (s)-isopropyl substituted. two of the new analogues carry a hydroxymethyl in place of the isopropyl group, one at an s- (compound 3 a) and the other at an r-configured stereogenic center (3 b). the third analogue, 3 c, contains a benzyloxymethyl group at an s-configured stereogenic ... | 2013 | 24106106 |
| inactivation of the seca2 protein export pathway in listeria monocytogenes promotes cell aggregation, impacts biofilm architecture and induces biofilm formation in environmental condition. | listeria monocytogenes has a dichotomous lifestyle, existing as an ubiquitous saprophytic species and as an opportunistic intracellular pathogen. besides its capacity to grow in a wide range of environmental and stressful conditions, l. monocytogenes has the ability to adhere to and colonize surfaces. morphotype variation to elongated cells forming rough colonies has been reported for different clinical and environmental isolates, including biofilms. this cell differentiation is mainly attribute ... | 2014 | 24102749 |
| kinetics of biofilm formation and desiccation survival of listeria monocytogenes in single and dual species biofilms with pseudomonas fluorescens, serratia proteamaculans or shewanella baltica on food-grade stainless steel surfaces. | this study investigated the dynamics of static biofilm formation (100% rh, 15 °c, 48-72 h) and desiccation survival (43% rh, 15 °c, 21 days) of listeria monocytogenes, in dual species biofilms with the common spoilage bacteria, pseudomonas fluorescens, serratia proteamaculans and shewanella baltica, on the surface of food grade stainless steel. the gram-negative bacteria reduced the maximum biofilm population of l. monocytogenes in dual species biofilms and increased its inactivation during desi ... | 2013 | 24102145 |
| influence of temperature on acid-stress adaptation in listeria monocytogenes. | our findings show that temperature plays a significant role in the induction of acid-stress adaptation in listeria monocytogenes, and two distinct patterns were observed: (1) presence of sublethal acid at 37°c or 22°c significantly induced acid-stress adaptation; and (2) presence of sublethal acid at 4°c did not induce any acid-stress adaptation. both patterns were confirmed by two experimental models: (1) l. monocytogenes cells were first grown at 37°c and then exposed to sublethal acid at 37°c ... | 2014 | 24102079 |
| central nervous system infection by listeria monocytogenes in patients with systemic lupus erythematosus: analysis of 26 cases, including the report of a new case. | infections in patients with systemic lupus erythematosus cause significant morbidity. infection due to listeria monocytogenes (lm) is considered an opportunistic disease, and has been published on rare occasions in patients with sle. | 2013 | 24094430 |
| coadministration of polyinosinic:polycytidylic acid and immunostimulatory complexes modifies antigen processing in dendritic cell subsets and enhances hiv gag-specific t cell immunity. | currently approved adjuvants induce protective ab responses but are more limited for generating cellular immunity. in this study, we assessed the effect of combining two adjuvants with distinct mechanisms of action on their ability to prime t cells: the tlr3 ligand, polyinosinic:polycytidylic acid (poly i:c), and immunostimulatory complexes (iscoms). each adjuvant was administered alone or together with hiv gag protein (gag), and the magnitude, quality, and phenotype of gag-specific t cell respo ... | 2013 | 24089189 |
| imaging inlc secretion to investigate cellular infection by the bacterial pathogen listeria monocytogenes. | bacterial intracellular pathogens can be conceived as molecular tools to dissect cellular signaling cascades due to their capacity to exquisitely manipulate and subvert cell functions which are required for the infection of host target tissues. among these bacterial pathogens, listeria monocytogenes is a gram positive microorganism that has been used as a paradigm for intracellular parasitism in the characterization of cellular immune responses, and which has played instrumental roles in the dis ... | 2013 | 24084755 |
| daptomycin activity against uncommonly isolated streptococcal and other gram-positive species groups. | a total of 1,356 clinical isolates were tested against daptomycin by broth microdilution methods. daptomycin was active against seven groups of viridans group streptococci (mic50 and mic90 values ranging from ≤0.06 and ≤0.06 μg/ml [streptococcus bovis and streptococcus dysgalactiae] to 0.5 and 1 μg/ml [streptococcus mitis, streptococcus oralis, and streptococcus parasanguinis], respectively), beta-hemolytic streptococci serogroups c, f, and g (mic50 and mic90, ≤0.06 to 0.25 and 0.12 to 0.25 μg/m ... | 2013 | 24080651 |
| detection of listeria monocytogenes from selective enrichment broth using maldi-tof mass spectrometry. | conventional methods used for primary detection of listeria monocytogenes from foods and subsequent confirmation of presumptive positive samples involve prolonged incubation and biochemical testing which generally require four to five days to obtain a result. in the current study, a simple and rapid proteomics-based maldi-tof ms approach was developed to detect l. monocytogenes directly from selective enrichment broths. milk samples spiked with single species and multiple species cultures were i ... | 2014 | 24080423 |
| infective rhomboencephalitis and inverted takotsubo: neurogenic-stunned myocardium or myocarditis? | here we originally describe the clinical scenario of a young immune-competent patient affected by acute rhomboencephalitis with severe parenchymal edema and acute hydrocephalus who developed sudden life-threatening cardiac derangement. hemodynamic and perfusion parameters revealed cardiogenic shock, so intensive circulatory support with epinephrine infusion and intra-aortic balloon pump was needed to restore organ perfusion. transesophageal echocardiographic examination showed severe left ventri ... | 2014 | 24079984 |
| risk factors associated with salmonella and listeria monocytogenes contamination of produce fields. | identification of management practices associated with preharvest pathogen contamination of produce fields is crucial to the development of effective good agricultural practices (gaps). a cross-sectional study was conducted to (i) determine management practices associated with a salmonella- or listeria monocytogenes-positive field and (ii) quantify the frequency of these pathogens in irrigation and nonirrigation water sources. over 5 weeks, 21 produce farms in new york state were visited. field- ... | 2013 | 24077713 |
| evaluation of immunochromatography for the rapid and specific identification of listeria monocytogenes from food. | to rapidly, simply and specifically detect and identify listeria monocytogenes from food samples, an immunochromatographic assay, based on gold-labeled monoclonal antibodies directed against an antigen common to all serovars of l. monocytogenes, was used. all strains of l. monocytogenes serovars showed a positive reaction to the assay, but all other gram positive and negative bacteria did not. the detection limit of the assay was in the order of 10(6) cfu/ml in fluid medium. the assay could simp ... | 2013 | 24077539 |
| differential roles of klf4 in the development and differentiation of cd8+ t cells. | the transcription factor krüppel-like factor 4 (klf4) can activate or repress gene expression in a cell-context dependent manner. we have previously shown that klf4 inhibits the proliferation of naïve cd8(+) t cells in vitro downstream of the transcription factor elf4. in this work, we describe a novel role of klf4 in the differentiation of cd8(+) t cells upon infection. loss of klf4 had minimal effect on thymic t cell development and distribution of mature t cells in the spleen, blood, and lymp ... | 2017 | 24075846 |
| listeria monocytogenes strains isolated from dry milk samples in mexico: occurrence and antibiotic sensitivity. | dry milk is a particular concern in mexico, as approximately 150,000 metric tons of dry milk are imported every year at a cost of around $250 million. dry milk is used to make many products, most of which are dairy products widely distributed among the population covered by welfare programs. the purpose of the study described in this article was to determine the presence of listeria spp. in imported dry milk samples in mexico, and to determine the sensitivity of the listeria monocytogenes isolat ... | 2013 | 24073487 |
| from pasteur to probiotics: a historical overview of cheese and microbes. | cheese is a food which has been produced for centuries. while cheese was originally developed as a product which extended the shelf life of milk, over time distinct cheese varieties arose, being shaped by geographic, climate, cultural, and economic factors. global demand for artisan cheeses is creating new economic opportunities. consumers seeking distinctive products with regional flavor, or terroir, are becoming connoisseurs of hand-crafted cheeses with distinctive tastes and character. these ... | 2013 | 26184821 |
| pulsed-field gel electrophoresis proficiency testing trials: toward european harmonization of the typing of food and clinical strains of listeria monocytogenes. | the european union reference laboratory for listeria monocytogenes (eurl for lm) coordinates a european network of 35 national reference laboratories (nrls), most of which perform food, environmental, and veterinary lm strain surveillance in their respective countries. the eurl activities resulted in the recent creation of a database (eurl lm db). typing and related epidemiological data submitted to the eurl lm db will be collected and shared by all the nrls. for a given nrl, the only criterion ... | 2013 | 24066940 |
| roles of a novel crp/fnr family transcription factor lmo0753 in soil survival, biofilm production and surface attachment to fresh produce of listeria monocytogenes. | listeria monocytogenes is a foodborne bacterial pathogen and the causative agent of an infectious disease, listeriosis. l. monocytogenes is ubiquitous in nature and has the ability to persist in food processing environments for extended periods of time by forming biofilms and resisting industrial sanitization. human listeriosis outbreaks are commonly linked to contaminated dairy products, ready-to-eat meats, and in recent years, fresh produce such as lettuce and cantaloupes. we identified a puta ... | 2013 | 24066185 |
| survival of bactericidal antibiotic treatment by a persister subpopulation of listeria monocytogenes. | listeria monocytogenes can cause the serious infection listeriosis, which despite antibiotic treatment has a high mortality. understanding the response of l. monocytogenes to antibiotic exposure is therefore important to ensure treatment success. some bacteria survive antibiotic treatment by formation of persisters, which are a dormant antibiotic-tolerant subpopulation. the purpose of this study was to determine whether l. monocytogenes can form persisters and how bacterial physiology affects th ... | 2013 | 24056460 |
| listeria monocytogenes multidrug resistance transporters and cyclic di-amp, which contribute to type i interferon induction, play a role in cell wall stress. | the intracellular bacterial pathogen listeria monocytogenes activates a robust type i interferon response upon infection. this response is partially dependent on the multidrug resistance (mdr) transporter mdrm and relies on cyclic-di-amp (c-di-amp) secretion, yet the functions of mdrm and cyclic-di-amp that lead to this response are unknown. here we report that it is not mdrm alone but a cohort of mdr transporters that together contribute to type i interferon induction during infection. in a sea ... | 2013 | 24056102 |
| superior induction and maintenance of protective cd8 t cells in mice infected with mouse cytomegalovirus vector expressing rae-1γ. | due to a unique pattern of cd8 t-cell response induced by cytomegaloviruses (cmvs), live attenuated cmvs are attractive candidates for vaccine vectors for a number of clinically relevant infections and tumors. nkg2d is one of the most important activating nk cell receptors that plays a role in costimulation of cd8 t cells. here we demonstrate that the expression of cd8 t-cell epitope of listeria monocytogenes by a recombinant mouse cmv (mcmv) expressing the nkg2d ligand retinoic acid early-induc ... | 2013 | 24052528 |
| isolation and quantification of highly acid resistant variants of listeria monocytogenes. | heterogeneity in stress response of bacteria is one of the biggest challenges posed by minimal processing, which aims at finding the balance between microbiologically stable foods while maintaining the characteristics of fresh products. in this study, exposure of listeria monocytogenes lo28 to acid stress, which can be encountered in the food processing environment as well as in the human body upon ingestion, led to inactivation kinetics showing considerable tailing, which was described by a bip ... | 2013 | 24051176 |
| listeria monocytogenes brain abscess: two cases and review of the literature. | listeria monocytogenes is a gram-positive bacillus that exhibits predilection to infect the central nervous system in immunocompromised individuals; the most common manifestations are meningitis and rhombencephalitis. listerial brain abscesses are rare. we report here two brain abscess cases caused by l. monocytogenes in patients receiving immunosuppressive agents. the first patient presented with left hemiparesis mimicking stroke and the second patient presented with neurological symptoms witho ... | 2013 | 24050079 |
| identifying the initiating events of anti-listeria responses using mice with conditional loss of ifn-γ receptor subunit 1 (ifngr1). | although ifn-γ is required for resolution of listeria monocytogenes infection, the identities of the ifn-γ-responsive cells that initiate the process remain unclear. we addressed this question using novel mice with conditional loss of ifn-γr (ifngr1). itgax-cre(+)ifngr1(f/f) mice with selective ifn-γ unresponsiveness in cd8α(+) dendritic cells displayed increased susceptibility to infection. this phenotype was due to the inability of ifn-γ-unresponsive cd8α(+) dendritic cells to produce the init ... | 2013 | 24048899 |
| cutting edge: tlr signaling licenses irak1 for rapid activation of the nlrp3 inflammasome. | activation of the nlrp3 inflammasome by diverse stimuli requires a priming signal from tlrs and an activation signal from purinergic receptors or pore-forming toxins. in this study, we demonstrate, through detailed analysis of nlrp3 activation in macrophages deficient in key downstream tlr signaling molecules, that myd88 is required for an immediate early phase, whereas toll/il-1r domain-containing adapter inducing ifn-β is required for a subsequent intermediate phase of posttranslational nlrp3 ... | 2013 | 24043892 |
| adenovirus-based vaccine against listeria monocytogenes: extending the concept of invariant chain linkage. | the use of replication-deficient adenoviruses as vehicles for transfer of foreign genes offers many advantages in a vaccine setting, eliciting strong cellular immune responses involving both cd8(+) and cd4(+) t cells. further improving the immunogenicity, tethering of the inserted target ag to mhc class ii-associated invariant chain (ii) greatly enhances both the presentation of most target ags, as well as overall protection against viral infection, such as lymphocytic choriomeningitis virus (lc ... | 2013 | 24043891 |
| atypical mitochondrial fission upon bacterial infection. | we recently showed that infection by listeria monocytogenes causes mitochondrial network fragmentation through the secreted pore-forming toxin listeriolysin o (llo). here, we examine factors involved in canonical fusion and fission. strikingly, llo-induced mitochondrial fragmentation does not require the traditional fission machinery, as drp1 oligomers are absent from fragmented mitochondria following listeria infection or llo treatment, as the dynamin-like protein 1 (drp1) receptor mff is rapid ... | 2013 | 24043775 |
| fetal bacterial infections in antepartum stillbirth: a case series. | this study aims to assess the frequency of fetal bacterial infections in stillbirth (sb) and to evaluate the best samples for the diagnosis of infection-related sb. | 2013 | 24041816 |
| molecular characterization of listeria monocytogenes isolated from fresh seafood samples in iran. | among all species of listeria, listeria monocytogenes (l. monocytogenes) is a major pathogenic microorganism of humans and animals and l. ivanovii is rarely pathogenic for humans. the objective of this study was to isolate and characterize listeria species and to determine the frequencies of virulence genes in l. monocytogenes serotypes in fresh fish, shrimp, crab and lobster in isfahan and shahrekord, iran. | 2013 | 24033984 |
| inhibition of listeria monocytogenes in minas frescal cheese by free and nanovesicle-encapsulated nisin. | the effectiveness of free and nanovesicle-encapsulated nisin to control listeria monocytogenes in minas frescal cheese was investigated. commercial nisin was encapsulated into liposomes of partially purified soy lecithin. free (0.1 mg/ml and 0.25 mg/ml) and nanovesicle-encapsulated nisin (0.25 mg/ml) were applied onto the surface of cheese samples, and l. monocytogenes was inoculated before incubation at 6-8°c for 28 days. a bactericidal effect was observed with 0.25 mg/ml free nisin; a bacterio ... | 2012 | 24031971 |
| antibacterial effect of light emitting diodes of visible wavelengths on selected foodborne pathogens at different illumination temperatures. | the antibacterial effect of light emitting diodes (leds) in the visible region (461, 521 and 642 nm) of the electromagnetic spectrum was investigated on escherichia coli o157:h7, salmonella typhimurium, listeria monocytogenes and staphylococcus aureus. the irradiances of the 461, 521 and 642 nm leds were 22.1, 16 and 25.4 mw/cm², respectively. bacterial cultures suspended in tryptic soy broth were illuminated by 10-watt leds at a distance of 4.5 cm for 7.5h at 20, 15 and 10 °c. regardless of the ... | 2013 | 24026011 |
| survival of foodborne pathogens on inshell walnuts. | the survival of salmonella enterica enteritidis pt 30 or five-strain cocktails of s. enterica, escherichia coli o157:h7, and listeria monocytogenes was evaluated on inshell walnuts during storage. inshell walnuts were separately inoculated with an aqueous preparation of the pathogens at levels of 10 to 4 log cfu/nut, dried for 24 h, and then stored at either 4 °c or ambient conditions (23-25 °c, 25-35% relative humidity) for 3 weeks to more than 1 year. during the initial 24-h drying period, bac ... | 2013 | 24026009 |
| effect of various conditions on inactivation of escherichia coli o157:h7, salmonella typhimurium, and listeria monocytogenes in fresh-cut lettuce using ultraviolet radiation. | the effect of various conditions on inactivation of foodborne pathogens and quality of fresh-cut lettuce during ultraviolet (254 nm, uvc) radiation was investigated. lettuce was inoculated with a cocktail of escherichia coli o157:h7, salmonella typhimurium, and listeria monocytogenes and treated at different temperatures (4 and 25 °c), distances between sample and lamp (10 and 50 cm), type of exposure (illuminated from one or two sides), uv intensities (1.36 to 6.80 mw/cm²), and exposure times ( ... | 2013 | 24021819 |
| contamination of poultry products with listeria monocytogenes at poultry processing plants. | this study aimed to confirm that poultry products packed at poultry processing plants have already been contaminated with listeria monocytogenes and that poultry products contaminated with l. monocytogenes are derived from broiler flocks infected with l. monocytogenes. l. monocytogenes was isolated from 16.8% (58/345) of chicken breast products and 2.3% (8/345) of chicken liver products. in contrast, l. monocytogenes was isolated from the pooled cecal content sample from only 1 (4%) of 25 flocks ... | 2014 | 24018827 |
| rhombencephalitis by listeria monocytogenes in a cirrhotic patient: a case report and literature review. | we report a case of rhombencephalitis infection by listeria monocytogenes in a 66-year-old man with cirrhosis. the csf analysis indicated l. monocytogenes as the most likely pathogen. blood and csf culture were positive to l. monocytogenes and mri findings were suggestive of rhomboencephalitis. the treatment was started empirically and then modified when the culture results were available. the patient had a full clinical recovery without neurologic sequelae. clinicians should remember that l. mo ... | 2013 | 24018504 |
| listeria monocytogenes strains encoding premature stop codons in inla invade mice and guinea pig fetuses in orally dosed dams. | listeria monocytogenes is an important food-borne bacterial pathogen and listeriosis can result in abortions in pregnant women. the bacterium can colonize food-processing environments, where specific molecular subtypes can persist for years. the purpose of this study was to determine the virulence potential of a group of food-processing persistent l. monocytogenes strains encoding a premature stop codon in inla (encoding internalin a) by using two orally dosed models, pregnant mice and pregnant ... | 2013 | 24014646 |
| in vitro evaluation of antimicrobial activities of various commercial essential oils, oleoresin and pure compounds against food pathogens and application in ham. | the purpose of this research was to evaluate the application of commercially available essential oils (eos) and oleoresins to control bacterial pathogens for ready to eat food. in this study, sixty seven commercial eos, oleoresins (ors) and pure compounds were used to evaluate in vitro their antimicrobial activity against six food pathogens. these products were first screened for their antimicrobial activity using disk diffusion assay. forty one products were then chosen for further analysis to ... | 2014 | 24012976 |
| efficacy of chlorine and peroxyacetic acid on reduction of natural microflora, escherichia coli o157:h7, listeria monocyotgenes and salmonella spp. on mung bean sprouts. | sprouts-related outbreaks have risen due to increased raw sprouts consumption. to minimize such cases, chemical sanitations are applied. while chlorine is commonly used, concerns with its effectiveness and health implication have prompted researchers to seek alternatives. peroxyacetic acid (paa) has shown efficacy in inactivating foodborne pathogens on fresh vegetables, and hence could be considered as an alternative. thus, the objective of this study was to compare the efficacy of chlorine and ... | 2013 | 24010631 |
| quantifying listeria monocytogenes prevalence and concentration in minced pork meat and estimating performance of three culture media from presence/absence microbiological testing using a deterministic and stochastic approach. | listeria monocytogenes poses a serious threat to public health, and the majority of cases of human listeriosis are associated with contaminated food. reliable microbiological testing is needed for effective pathogen control by food industry and competent authorities. the aims of this work were to estimate the prevalence and concentration of l. monocytogenes in minced pork meat by the application of a bayesian modeling approach, and also to determine the performance of three culture media commonl ... | 2013 | 24010622 |
| listeria monocytogenes and ready-to-eat seafood in spain: study of prevalence and temperatures at retail. | the aim of this study was to obtain data from refrigerated ready-to-eat seafood products at retail in spain (young eels, crabstick and smoked salmon), regarding prevalence and levels of listeria monocytogenes, storage temperatures and the impact of transport conditions (type of bag) on the temperature of the product. the one-year surveillance period was carried out according to the ec regulation no. 2073/2005, taking 5 units/batch and analyzing 250 samples following iso 11290-1/a1 and iso 11290- ... | 2013 | 24010619 |
| use of marination for controlling salmonella enterica and listeria monocytogenes in raw beef. | the effect of marination on the survival and growth of the pathogens salmonella enterica and listeria monocytogenes on beef pieces was investigated. five marinades were used: soy sauce base marinade without (sb) or with lactic acid (sbla), red wine base marinade without (wb) or with 0.5% v/v oregano essential oil (wbo), and sterile saline used as control (c). inoculated fresh beef pieces were marinated for 18 h at 5 °c, removed from the marinade and subjected to storage trials at 5 °c and 15 °c. ... | 2013 | 24010604 |
| 16s rrna partial gene sequencing for the differentiation and molecular subtyping of listeria species. | use of 16s rrna partial gene sequencing within the regulatory workflow could greatly reduce the time and labor needed for confirmation and subtyping of listeria monocytogenes. the goal of this study was to build a 16s rrna partial gene reference library for listeria spp. and investigate the potential for 16s rrna molecular subtyping. a total of 86 isolates of listeria representing l. innocua, l. seeligeri, l. welshimeri, and l. monocytogenes were obtained for use in building the custom library. ... | 2013 | 24010602 |
| [rapid detection of listeria monocytogenes by immunomagnetic separation combined with selective medium]. | listeria monocytogenes is a pathogenic bacterium, therefore, it is essential for food safety monitoring to establish a rapid and specific detecting method. in this study, immunomagnetic beads and selective medium were combined to detect listeria monocytogenes at different concentrations (10(1)-10(5) cfu/ml). other three types of listeria spp., staphylococcus aureus and vibrio parahaemolyticus were also detected to conduct the cross-reaction analysis. meanwhile, contaminated milk samples were pre ... | 2013 | 24010365 |
| "epidemic clones" of listeria monocytogenes are widespread and ancient clonal groups. | the food-borne pathogen listeria monocytogenes is genetically heterogeneous. although some clonal groups have been implicated in multiple outbreaks, there is currently no consensus on how "epidemic clones" should be defined. the objectives of this work were to compare the patterns of sequence diversity on two sets of genes that have been widely used to define l. monocytogenes clonal groups: multilocus sequence typing (mlst) and multi-virulence-locus sequence typing (mvlst). further, we evaluated ... | 2013 | 24006010 |
| multistate outbreak of listeriosis associated with cantaloupe. | although new pathogen-vehicle combinations are increasingly being identified in produce-related disease outbreaks, fresh produce is a rarely recognized vehicle for listeriosis. we investigated a nationwide listeriosis outbreak that occurred in the united states during 2011. | 2013 | 24004121 |
| probable nosocomial transmission of listeriosis in neonates. | listeria monocytogenes was isolated in two neonates born consecutively in the same hospital in france. the isolates had indistinguishable pulsed-field electrophoresis profiles. retrospective epidemiological investigations found no evidence of a food-borne or environmental source. infection control protocols and decontamination processes were in accordance with standard recommendations. the timing of onset of these infections within the same maternity unit, and the similarity of pulsed-field gel ... | 2013 | 24001996 |
| effect of electropermeabilization by ohmic heating for inactivation of escherichia coli o157:h7, salmonella enterica serovar typhimurium, and listeria monocytogenes in buffered peptone water and apple juice. | the effect of electric field-induced ohmic heating for inactivation of escherichia coli o157:h7, salmonella enterica serovar typhimurium, and listeria monocytogenes in buffered peptone water (bpw) (ph 7.2) and apple juice (ph 3.5; 11.8 °brix) was investigated in this study. bpw and apple juice were treated at different temperatures (55°c, 58°c, and 60°c) and for different times (0, 10, 20, 25, and 30 s) by ohmic heating compared with conventional heating. the electric field strength was fixed at ... | 2013 | 23995939 |
| inhibition of listeria monocytogenes in full- and low-sodium frankfurters at 4, 7, or 10°c using spray-dried mixtures of organic acid salts. | in meat processing, powdered ingredients are preferred to liquids because of ease of handling, mixing, and storing. this study was conducted to assess listeria monocytogenes inhibition and the physicochemical and organoleptic characteristics of frankfurters that were prepared with organic acid salts as spray-dried powders (sodium lactate-sodium acetate, sodium lactate-sodium acetate-sodium diacetate, and potassium acetate-potassium diacetate) or liquids (sodium lactate, sodium lactate-sodium dia ... | 2013 | 23992500 |
| growth modeling of listeria monocytogenes in pasteurized liquid egg. | the growth kinetics of listeria monocytogenes and natural flora in commercially produced pasteurized liquid egg was examined at 4.1 to 19.4°c, and a growth simulation model that can estimate the range of the number of l. monocytogenes bacteria was developed. the experimental kinetic data were fitted to the baranyi model, and growth parameters, such as maximum specific growth rate (μ(max)), maximum population density (n(max)), and lag time (λ), were estimated. as a result of estimating these para ... | 2013 | 23992499 |
| cutaneous listeriosis in a veterinarian with the evidence of zoonotic transmission--a case report. | a case of listeria monocytogenes skin infection in a man is presented. a 54-year-old male veterinary practitioner developed pustular changes on the skin of arms and hands after assisting with the delivery of a stillborn calf. listeria monocytogenes was isolated from the skin lesions on the arms and from the bovine placenta. listeria monocytogenes isolates were serotyped and genotyped with pulsed-field gel electrophoresis (pfge) to confirm the suspected transmission of the pathogen from animal to ... | 2014 | 23992408 |
| extent and mode of action of cationic legume proteins against listeria monocytogenes and salmonella enteritidis. | the methylated soybean protein and methylated chickpea protein (msp and mcp) with isoelectric points around pi 8 were prepared by esterifying 83 % of their free carboxyl groups and tested for their interactions with listeria monocytogenes and salmonella enteritidis. the two substances exhibited a concentration-dependent inhibitory action against the two studied bacteria with a minimum inhibitory concentration of about 100 μg/ml. the ic50 % of the two proteins against l. monocytogenes (17 μg/ml) ... | 2013 | 26782988 |
| effect of bacteriocins and conditions that mimic food and digestive tract on biofilm formation, in vitro invasion of eukaryotic cells and internalin gene expression by listeria monocytogenes. | in this report, listeria monocytogenes isolates were evaluated for their ability to form biofilms, for adhesion/invasion of eukaryotic cells and for differential expression of internalin a (inl a) gene, which is related to virulence potential. the presence of bacteriocins of lactic acid bacteria and incubation at 5 °c were the main factors that influenced biofilm formation by l. monocytogenes, in comparison with bhi (control). in general, adhesion and invasion of caco-2 cells were significantly ... | 2013 | 26782984 |
| occurrence of genetic variants of listeria monocytogenes strains. | isolates of listeria monocytogenes saved from outbreaks of listeriosis, cases of sporadic listeriosis, and similar events do not always belong to a solitary genetic variant. variants of the same strain may have evolved from a unique clone, and plasmid loss or gain and phage-mediated genetic changes are suggested as the main mechanism. some of these reports are summarized in this short communication. | 2013 | 23988078 |
| influence of freezing stress on morphological alteration and biofilm formation by listeria monocytogenes: relationship with cell surface hydrophobicity and membrane fluidity. | the morphological changes and adhesive property of three listeria monocytogenes strains submitted to freezing stress (-20 °c) were studied. the atomic force micrographs showed a reduction in the cell size and an evolution to coccoid shape. the phenotypic slime production of l. monocytogenes and the expression of the adhesive gene were investigated before and after 10 months of incubation in salmon at -20°. our results showed that after ten months, stressed stains become more adherent and able to ... | 2013 | 23982847 |
| cpg oligodeoxynucleotide induces bone marrow precursor cells into myeloid-derived suppressor cells. | dendritic cells (dcs) and myeloid-derived suppressor cells (mdscs) perform a number of functions in different immunological settings. in standard in vitro experiments, dcs are produced from mouse bone marrow (bm) cells in the presence of granulocyte-macrophage colony-stimulating factor (gm-csf) and il-4. our previous study demonstrated that bm precursor cells could differentiate into mdscs when co-cultured with poly (i:c). in the present study, bm precursor cells cultured in gm-csf and il-4 were ... | 2013 | 23982226 |
| colpoda secrete viable listeria monocytogenes within faecal pellets. | transmission electron microscopy was used to demonstrate that co-cultures of the ciliate colpoda rr (an environmental isolate) and colpoda mls-5 (a food processing environment isolate) with the pathogenic listeria monocytogenes drdc8 resulted in secretion of faecal pellets containing intact drdc8 cells. a green fluorescent protein expressing variant of drdc8 was used in co-cultures to confirm that the pellet-associated bacterial cells were l. monocytogenes. viability was confirmed by plate count ... | 2014 | 23981071 |
| the transcription factor interferon regulatory factor 4 is required for the generation of protective effector cd8+ t cells. | robust cytotoxic cd8(+) t-cell response is important for immunity to intracellular pathogens. here, we show that the transcription factor ifn regulatory factor 4 (irf4) is crucial for the protective cd8(+) t-cell response to the intracellular bacterium listeria monocytogenes. irf4-deficient (irf4(-/-)) mice could not clear l. monocytogenes infection and generated decreased numbers of l. monocytogenes-specific cd8(+) t cells with impaired effector phenotype and function. transfer of wild-type cd8 ... | 2013 | 23980171 |
| cd38 controls the innate immune response against listeria monocytogenes. | cd38, adenosine-5'-diphosphate-ribosyl cyclase 1, is a multifunctional enzyme, expressed on a wide variety of cell types. cd38 has been assigned diverse functions, including generation of calcium-mobilizing metabolites, cell activation, and chemotaxis. using a murine listeria monocytogenes infection model, we found that cd38 knockout (ko) mice were highly susceptible to infection. enhanced susceptibility was already evident within 3 days of infection, suggesting a function of cd38 in the innate ... | 2013 | 23980105 |
| transcription factor σb plays an important role in the production of extracellular membrane-derived vesicles in listeria monocytogenes. | gram-negative bacteria produce extracellular outer membrane vesicles (omvs) that interact with host cells. unlike gram-negative bacteria, less is known about the production and role of extracellular membrane vesicles (mvs) in gram-positive bacteria. the food-borne pathogen listeria monocytogenes can survive under extreme environmental and energy stress conditions and the transcription factor σ(b) is involved in this survival ability. here, we first determined the production of mvs from l. monocy ... | 2013 | 23977379 |
| characterization of a potential listeria monocytogenes virulence factor associated with attachment to fresh produce. | a study to determine the attachment of l. monocytogenes serotype 4b strain f2365 on vegetables and fruits was conducted. in an initial study, we screened 32 genes encoding surface proteins and lipases of the strain to find highly expressed genes on lettuce leaves. the results showed that transcription levels of lmof2365_0413, lmof2365_0498, lmof2365_0859, lmof2365_2052, and lmof2365_2812 were significantly upregulated on lettuce leaves. in silico analysis showed that lmof2365_0859 contains a put ... | 2013 | 23974144 |
| the effect of ph and nitrite concentration on the antimicrobial impact of celery juice concentrate compared with conventional sodium nitrite on listeria monocytogenes. | the objectives of this study were to evaluate the impact of ph and nitrite from celery juice concentrate (cj) on the growth of listeria monocytogenes in broth and on ham slices, and to evaluate the impact of ph and nitrite from cj on quality attributes of the ham. the ph of both broth and ham were increased by the addition of cj. the cj was less effective than conventional nitrite at 100 mg/kg nitrite in broth, but in ham, the cj treatments at both 100 and 200 mg/kg resulted in growth of l. mono ... | 2014 | 23973624 |
| circadian gene bmal1 regulates diurnal oscillations of ly6c(hi) inflammatory monocytes. | circadian clocks have evolved to regulate physiologic and behavioral rhythms in anticipation of changes in the environment. although the molecular clock is present in innate immune cells, its role in monocyte homeostasis remains unknown. here, we report that ly6c(hi) inflammatory monocytes exhibit diurnal variation, which controls their trafficking to sites of inflammation. this cyclic pattern of trafficking confers protection against listeria monocytogenes and is regulated by the repressive act ... | 2013 | 23970558 |
| proteomic identification of listeria monocytogenes surface-associated proteins. | this study aimed to identify proteins exposed on the surface of listeria monocytogenes cells for diagnostic reagent development. brief trypsin treatment of l. monocytogenes cells followed by peptide separation and identification by nano-lc and online-ms/ms was performed. in parallel, as a negative control, proteins secreted into the digest buffer as well as proteins from cell lysis were identified. one hundred and seventy-four proteins were identified in at least two of three trials in either th ... | 2013 | 23970489 |
| extrauterine listeriosis in the gravid mouse influences embryonic growth and development. | gravid mice and other rodents inoculated with listeria monocytogenes typically fail to clear an intrauterine infection and either succumb or expel their intrauterine contents. we took advantage of this property to investigate the effects of an extrauterine infection on parameters of pregnancy success. pregnant mice were selected for our study if they showed no clinical signs of listeriosis following oral inoculation at 7.5 gestational days (gd), and had no detectable intrauterine colony forming ... | 2013 | 23967322 |
| cutaneous listeriosis. | cutaneous infections due to listeria monocytogenes are rare. typically, infections manifest as nonpainful, nonpruritic, self-limited, localized, papulopustular or vesiculopustular eruptions in healthy persons. most cases follow direct inoculation of the skin in veterinarians or farmers who have exposure to animal products of conception. less commonly, skin lesions may arise from hematogenous dissemination in compromised hosts with invasive disease. here, we report the first case in a gardener th ... | 2013 | 23966491 |
| [antimicrobial resistance of listeria monocytogenes strains of human and food origin in the czech republic]. | to assess the incidence of antimicrobial resistance of l. monocytogenes strains isolated from humans and foods in the czech republic in the period of 2001 to 2012. | 2013 | 23965810 |
| wall teichoic acid structure governs horizontal gene transfer between major bacterial pathogens. | mobile genetic elements (mges) encoding virulence and resistance genes are widespread in bacterial pathogens, but it has remained unclear how they occasionally jump to new host species. staphylococcus aureus clones exchange mges such as s. aureus pathogenicity islands (sapis) with high frequency via helper phages. here we report that the s. aureus st395 lineage is refractory to horizontal gene transfer (hgt) with typical s. aureus but exchanges sapis with other species and genera including staph ... | 2013 | 23965785 |
| identification and expression analysis of a novel r-type lectin from the coleopteran beetle, tenebrio molitor. | we have identified novel ricin-type (r-type) lectin by sequencing of random clones from cdna library of the coleopteran beetle, tenebrio molitor. the cdna sequence is comprised of 495 bp encoding a protein of 164 amino acid residues and shows 49% identity with galectin of tribolium castaneum. bioinformatics analysis shows that the amino acid residues from 35 to 162 belong to ricin-type beta-trefoil structure. the transcript was significantly upregulated after early hours of injection with peptid ... | 2013 | 23962621 |
| structure of internalin inlk from the human pathogen listeria monocytogenes. | listeria monocytogenes is a human pathogen that employs a wide variety of virulence factors in order to adhere to, invade, and replicate within target cells. internalins play key roles in processes ranging from adhesion to receptor recognition and are thus essential for infection. recently, inlk, a surface-associated internalin, was shown to be involved in listeria's ability to escape from autophagy by recruitment of the major vault protein (mvp) to the bacterial surface. here, we report the str ... | 2013 | 23958637 |
| characteristics of three listeriaphages isolated from new zealand seafood environments. | to isolate and characterize listeriaphages from seafood environments. methods and | 2013 | 23957554 |
| subtyping of a large collection of historical listeria monocytogenes strains from ontario, canada, by an improved multilocus variable-number tandem-repeat analysis (mlva). | listeria monocytogenes is responsible for severe and often fatal food-borne infections in humans. a collection of 2,421 l. monocytogenes isolates originating from ontario's food chain between 1993 and 2010, along with ontario clinical isolates collected from 2004 to 2010, was characterized using an improved multilocus variable-number tandem-repeat analysis (mlva). the mlva method was established based on eight primer pairs targeting seven variable-number tandem-repeat (vntr) loci in two 4-plex f ... | 2013 | 23956391 |
| cold shock proteins contribute to the regulation of listeriolysin o production in listeria monocytogenes. | cold shock proteins (csps) are multifunctional nucleic acid binding proteins used to regulate a wide range of gene expression responses in bacteria. we report here that csps regulate the production of the pore-forming cytolysin listeriolysin (llo) and hemolysis phenotypes in listeria monocytogenes. a triple csp gene deletion mutant incapable of producing any csps, as well as double csp gene deletion mutants only producing either cspa or cspd, caused less hemolysis and produced lower llo concentr ... | 2013 | 23952475 |
| pulsed-field gel electrophoresis proficiency testing trials: toward european harmonization of the typing of food and clinical strains of listeria monocytogenes. | abstract the european union reference laboratory for listeria monocytogenes (eurl for lm) coordinates a european network of 35 national reference laboratories (nrls), most of which perform food, environmental, and veterinary lm strain surveillance in their respective countries. the eurl activities resulted in the recent creation of a database (eurl lm db). typing and related epidemiological data submitted to the eurl lm db will be collected and shared by all the nrls. for a given nrl, the only c ... | 2013 | 23952473 |
| fusidic acid is an effective treatment against toxoplasma gondii and listeria monocytogenes in vitro, but not in mice. | fusidic acid is a bacteriostatic antibiotic that inhibits the growth of bacteria by preventing the release of translation elongation factor g (ef-g) from the ribosome. the apicomplexan parasite toxoplasma gondii has an orthologue of bacterial ef-g that can complement bacteria and is necessary for parasite virulence. fusidic acid has been shown to be effective in tissue culture against the related pathogen plasmodium falciparum, and current drug treatments against t. gondii are limited. we theref ... | 2013 | 23949312 |
| sensitive colorimetric detection of listeria monocytogenes based on isothermal gene amplification and unmodified gold nanoparticles. | listeria monocytogenes (l. monocytogenes), one of most problematic food-borne bacteria, is mainly transmitted through the food chain and may cause listeriosis. therefore, the development of rapid and sensitive l. monocytogenes detection technique has become an urgent task. in this study, we proposed a method using hyperbranching rolling circle amplification (hrca) combined with gold nanoparticle (gnp) based colorimetric strategy to offer an isothermal, highly sensitive and specific assay for the ... | 2013 | 23948710 |
| nucleic acid aptamers for capture and detection of listeria spp. | the purpose of this study was to identify biotinylated single-stranded (ss) dna aptamers with binding specificity to listeria and use these for capture and subsequent qpcr detection of the organism. for aptamer selection, selex (systematic evolution of ligands by exponential enrichment) was applied to a biotin-labeled ssdna combinatorial library. after multiple rounds of selection and counter-selection, aptamers separated, sequenced, and characterized by flow cytometry showed binding affinities ... | 2013 | 23942378 |
| attachment of bacterial pathogens to a bacterial cellulose-derived plant cell wall model: a proof of concept. | this study aimed to establish, as a proof of concept, whether bacterial cellulose (bc)-derived plant cell wall models could be used to investigate foodborne bacterial pathogen attachment. attachment of two strains each of salmonella enterica and listeria monocytogenes to four bc-derived plant cell wall models (namely, bc, bc-pectin [bcp], bc-xyloglucan [bcx], and bc-pectin-xyloglucan [bcpx]) was investigated. chemical analysis indicated that the bcpx composite (31% cellulose, 45.6% pectin, 23.4% ... | 2013 | 23941519 |
| the ido1-induced kynurenines play a major role in the antimicrobial effect of human myeloid cells against listeria monocytogenes. | induction of indoleamine 2,3-dioxygenase (ido1) is an established cellular response to infection with numerous pathogens. several mechanisms, such as ido1-mediated tryptophan (trp) depletion, but also accumulation of trp catabolites, have been associated with the antimicrobial effects of ido(+) cells. recent findings of ido1 as an immunoinhibitory and signaling molecule extended these previous observations. using infection of professional phagocytes with listeria monocytogenes (l.m.) as a model, ... | 2014 | 23940074 |