Publications

TitleAbstractYear(sorted descending)
Filter
PMID
Filter
inhibition of sortase a by chalcone prevents listeria monocytogenes infection.the critical role of sortase a in gram-positive bacterial pathogenicity makes this protein a good potential target for antimicrobial therapy. in this study, we report for the first time the crystal structure of listeria monocytogenes sortase a and identify the active sites that mediate its transpeptidase activity. we also used a sortase a (srta) enzyme activity inhibition assay, simulation, and isothermal titration calorimetry analysis to discover that chalcone, an agent with little anti-l. mono ...201626826492
listeria meningoencephalitis and anti-gq1b antibody syndrome.we report the first case of listeria monocytogenes meningoencephalitis associated with anti-gq1b antibody syndrome in an immunocompetent adult. a prompt diagnosis, made thanks to the multidisciplinary contribution, allowed a combined therapeutic approach leading to final favourable outcome, despite several intercurrent complications.201626825308
fresh produce-associated listeriosis outbreaks, sources of concern, teachable moments, and insights.foodborne transmission of listeria monocytogenes was first demonstrated through the investigation of the 1981 maritime provinces outbreak involving coleslaw. in the following two decades, most listeriosis outbreaks involved foods of animal origin, e.g., deli meats, hot dogs, and soft cheeses. l. monocytogenes serotype 4b, especially epidemic clones i, ii, and ia, were frequently implicated in these outbreaks. however, since 2008 several outbreaks have been linked to diverse types of fresh produc ...201626818997
antimicrobial activity of individual and combined essential oils against foodborne pathogenic bacteria.the antimicrobial activities of essential oils from mexican oregano (lippia berlandieri schauer), mustard (brassica nigra), and thyme (thymus vulgaris) were evaluated alone and in binary combinations against listeria monocytogenes, staphylococcus aureus, or salmonella enteritidis. chemical compositions of the essential oils were analyzed by gas chromatography-mass spectrometry. the mics of the evaluated essential oils ranged from 0.05 to 0.50% (vol/vol). mustard essential oil was the most effect ...201626818994
modeling the impact of ingoing sodium nitrite, sodium ascorbate, and residual nitrite concentrations on growth parameters of listeria monocytogenes in cooked, cured pork sausage.sodium nitrite has been identified as a key antimicrobial ingredient to control pathogens in ready-to-eat (rte) meat and poultry products, including listeria monocytogenes. this study was designed to more clearly elucidate the relationship between chemical factors (ingoing nitrite, ascorbate, and residual nitrite) and l. monocytogenes growth in rte meats. treatments of cooked, cured pork sausage (65% moisture, 1.8% salt, ph 6.6, and water activity 0.98) were based on response surface methodology ...201626818978
prosthetic knee joint infection due to listeria monocytogenes bacteremia in a diabetic female. 201626813571
[cabozantinib inhibits listeria monocytogenes infection in mice].to test the effect of the c-met inhibitor cabozantinib in inhibiting infections by listeria monocytogenes (lm) in mice.201626806739
effect of phytosanitary irradiation and methyl bromide fumigation on the physical, sensory, and microbiological quality of blueberries and sweet cherries.the objective of this study was to determine whether irradiation could serve as a suitable phytosanitary treatment alternative to methyl bromide (mb) fumigation for blueberries and sweet cherry and also to determine the effect of phytosanitary irradiation treatment on survival of salmonella spp. and listeria monocytogenes on these fruit. 'bluecrop' blueberries (vaccinium corymbosum) and 'sweetheart' cherries (prunus avium) were irradiated at 0.4 kgy or fumigated with methyl bromide and evaluated ...201626805024
community-acquired bacterial meningitis in adults with cancer or a history of cancer.to study the incidence, clinical presentation, causative bacteria, and outcome of community-acquired bacterial meningitis in adults with cancer.201626802096
draft genome sequence of a 94-year-old listeria monocytogenes isolate, slcc208.we report here the draft genome sequence of listeria monocytogenes strain slcc208 from seeliger's historical special listeria culture collection, initially cultured from a human case in france in 1921. this is, to our knowledge, the oldest l. monocytogenes isolate available and may be useful for comparative genomic studies of l. monocytogenes.201626798096
phenolic compounds, antioxidant, and antibacterial properties of pomace extracts from four virginia-grown grape varieties.grape pomace is a potential source of natural antioxidant and antimicrobial agents. phenolic compounds, antioxidant, and antibacterial properties of pomace extracts from four virginia-grown grape varieties were investigated. white grape pomaces had higher (p < 0.05) solvent extraction yield than red varieties. concentrations of total phenolic (tpc), total flavonoid (tfc), total anthocyanin (tac), tannins, condensed tannins (ct), as well as antioxidant capacities (dpph• and abts•+free radical sca ...201626788319
the incidence and distribution of listeria monocytogenes in ready-to-eat vegetables in south-western nigeria.the study investigated the incidence of listeria monocytogenes in ready-to-eat (rte) vegetables: (cucumber, cucumis sativas; cabbage, brassica olerecea; carrot, daucus carota; tomato, solanum lycopersicum; lettuce, lactuca sativa) in six states in south-western nigeria. a total of 555 composite samples were collected from 30 traditional markets within the states and only 244 l. monocytogenes species were isolated by standard methods. the incidence of l. monocytogenes was low and not statisticall ...201626788311
efficacy of activated alginate-based nanocomposite films to control listeria monocytogenes and spoilage flora in rainbow trout slice.essential oils of clove, coriander, caraway, marjoram, cinnamon, and cumin were tested for their antilisterial activity by application of agar diffusion assay (experiment 1). marjoram essential oil (meo) showed the highest inhibitory effect, followed by clove and cinnamon. subsequently, these essential oils were incorporated to alginate/clay nanocomposite films and antilisterial effectiveness of the films was studied in a model solid food system during 12 days at 10 °c (experiment 2). the result ...201626787971
perforin-2 protects host cells and mice by restricting the vacuole to cytosol transitioning of a bacterial pathogen.the host-encoded perforin-2 (encoded by the macrophage-expressed gene 1, mpeg1), which possesses a pore-forming macpf domain, reduces the viability of bacterial pathogens that reside within membrane-bound compartments. here, it is shown that perforin-2 also restricts the proliferation of the intracytosolic pathogen listeria monocytogenes within a few hours of systemic infection, the massive proliferation of l. monocytogenes in perforin-2(-/-)mice leads to a rapid appearance of acute disease symp ...201626831467
uncovering listeria monocytogenes hypervirulence by harnessing its biodiversity.microbial pathogenesis studies are typically performed with reference strains, thereby overlooking within-species heterogeneity in microbial virulence. here we integrated human epidemiological and clinical data with bacterial population genomics to harness the biodiversity of the model foodborne pathogen listeria monocytogenes and decipher the basis of its neural and placental tropisms. taking advantage of the clonal structure of this bacterial species, we identify clones epidemiologically assoc ...201626829754
impact of different cell penetrating peptides on the efficacy of antisense therapeutics for targeting intracellular pathogens.there is a pressing need for novel and innovative therapeutic strategies to address infections caused by intracellular pathogens. peptide nucleic acids (pnas) present a novel method to target intracellular pathogens due to their unique mechanism of action and their ability to be conjugated to cell penetrating peptides (cpp) to overcome challenging delivery barriers. in this study, we targeted the rna polymerase α subunit (rpoa) using a pna that was covalently conjugated to five different cpps. c ...201626860980
control of relative air humidity as a potential means to improve hygiene on surfaces: a preliminary approach with listeria monocytogenes.relative air humidity fluctuations could potentially affect the development and persistence of pathogenic microorganisms in their environments. this study aimed to characterize the impact of relative air humidity (rh) variations on the survival of listeria monocytogenes, a bacterium persisting on food processing plant surfaces. to assess conditions leading to the lowest survival rate, four strains of l. monocytogenes (egde, ccl500, ccl128, and lo28) were exposed to different rh conditions (75%, ...201626840373
influence of probiotics, included in peanut butter, on the fate of selected salmonella and listeria strains under simulated gastrointestinal conditions.this study observed the behaviour of probiotics and selected bacterial pathogens co-inoculated into peanut butter during gastrointestinal simulation.201626836043
listeria monocytogenes endovascular graft infection.although best managed by surgical resection, we present a case of listeria monocytogenes endovascular graft infection alternatively treated with graft retention and antibiotic induction followed by a lifelong suppressive course. the epidemiological, pathological, and clinical features of this unique entity are reviewed.201626835477
listeria monocytogenes σh contributes to expression of competence genes and intracellular growth.the alternative sigma factor σ(h)has two functions in gram-positive bacteria: it regulates sporulation and the development of genetic competence. listeria monocytogenes is a nonsporulating species in which competence has not yet been detected. nevertheless, the main competence regulators and a series of orthologous genes that form the competence machinery are present in its genome; some of the competence genes play a role in optimal phagosomal escape. in this study, strains overexpressing σ(h) a ...201626833412
validation of the applied biosystems 7500 fast instrument for detection of listeria monocytogenes with the suretect listeria monocytogenes pcr assay.in 2013, the thermo scientific™ suretect™ listeria monocytogenes real-time pcr assay was certified by the aoac research institute (ri) performance tested methods(sm) program as a rapid method for the detection of l. monocytogenes from a wide range of food matrixes and surface samples. this report details the method modification studies undertaken to extend the analysis of this pcr assay to the applied biosystems™ 7500 fast pcr instrument and applied biosystems rapidfinder™ express 2.0 software a ...201627297838
identification of proteins derived from listeria monocytogenes inducing human dendritic cell maturation.dendritic cells (dcs) are potent antigen-presenting cells (apcs) that can promote antitumor immunity when pulsed with tumor antigens and then matured by stimulatory agents. despite apparent progress in dc-based cancer immunotherapy, some discrepancies were reported in generating potent dcs. listeria monocytogenes as an intracellular microorganism is able to effectively activate dcs through engaging pattern-recognition receptors (prrs). this study aimed to find the most potent components derived ...201626886282
antibacterial activity of aquatic gliding bacteria.the study aimed to screen and isolate strains of freshwater aquatic gliding bacteria, and to investigate their antibacterial activity against seven common pathogenic bacteria. submerged specimens were collected and isolated for aquatic gliding bacteria using four different isolation media (dw, ma, sap2, and vy/2). gliding bacteria identification was performed by 16s rrna gene sequencing and phylogenetic analysis. crude extracts were obtained by methanol extraction. antibacterial activity against ...201626885469
[clinical characteristics of 35 non-pregnant patients with listeria monocytogenes sepsis].to better understand the clinical characteristics and predisposing factors in non-pregnant patients with listeria monocytogenes (listeria) sepsis.201626875580
production of bacteriocin by virgibacillus salexigens isolated from "terasi": a traditionally fermented shrimp paste in indonesia.a natural antibacterial-substance-producing gram-positive bacterium was isolated from terasi shrimp paste, a popular fermented product in indonesia. this strain, a spore-forming and strictly aerobic bacterium, was identified as virgibacillus salexigens by 16s rrna gene sequence analysis. the antibacterial substance purified from the precipitated product in the culture supernatant of the strain using ammonium sulfate showed a broad inhibition spectrum against gram-positive bacteria, including a t ...201626873558
structural and biochemical insights into the peptidoglycan hydrolase domain of flgj from salmonella typhimurium.flgj is a glycoside hydrolase (gh) enzyme belonging to the carbohydrate active enzyme (cazy) family gh73. it facilitates passage of the bacterial flagellum through the peptidoglycan (pg) layer by cleaving the β-1,4 glycosidic bond between n-acetylglucosamine and n-acetylmuramic acid sugars that comprise the glycan strands of pg. here we describe the crystal structure of the gh domain of flgj from bacterial pathogen salmonella typhimurium (stflgj). interestingly, the active site of stflgj was blo ...201626871950
listeria monocytogenes wall teichoic acid decoration in virulence and cell-to-cell spread.wall teichoic acid (wta) comprises a class of glycopolymers covalently attached to the peptidoglycan of gram positive bacteria. in listeria monocytogenes, mutations that prevent addition of certain wta decorating sugars are attenuating. however, the steps required for decoration and the pathogenic process interrupted are not well described. we systematically examined the requirement for wta galactosylation in a mouse oral-virulent strain by first creating mutations in four genes whose products c ...201626871418
short communication: inhibitory activities of the lantibiotic nisin combined with phenolic compounds against staphylococcus aureus and listeria monocytogenes in cow milk.we aimed to investigate the antibacterial activities of carvacrol, thymol, eugenol, cinnamaldehyde, and lantibiotic nisin against standard bacterial strains of the milk pathogens staphylococcus aureus atcc 25923 and listeria monocytogenes atcc 15313 in cow milk. the minimum inhibitory concentrations (mic) of these substances were recorded. the synergistic effects were also assessed in culture medium (time kill curve) and in a food model (cow milk) during the storage period (4 °c for 6 d) after i ...201626774728
effectiveness of superheated steam for inactivation of escherichia coli o157:h7, salmonella typhimurium, salmonella enteritidis phage type 30, and listeria monocytogenes on almonds and pistachios.this study was undertaken to evaluate the effectiveness of superheated steam (shs) on the inactivation of escherichia coli o157:h7, salmonella typhimurium, salmonella enteritidis phage type (pt) 30 and listeria monocytogenes on almonds and in-shell pistachios and to determine the effect of superheated steam heating on quality by measuring color and texture changes. almonds and in-shell pistachios inoculated with four foodborne pathogens were treated with saturated steam (ss) at 100 °c and shs at ...201626773253
too much of a good thing: regulated depletion of c-di-amp in the bacterial cytoplasm.bacteria that synthesize c-di-amp also encode several mechanisms for controlling c-di-amp levels within the cytoplasm. one major class of phosphodiesterases comprises gdpp and dhhp homologs, which degrade c-di-amp into the linear molecule 5'-papa or amp by the dhh-dhha1 domain. the other major class comprises pgph homologs, which degrade c-di-amp by the hd domain. both gdpp and pgph harbor sensory domains, likely to regulate c-di-amp hydrolysis activity in response to signal input. as another po ...201626773214
impact of pathogen population heterogeneity and stress-resistant variants on food safety.this review elucidates the state-of-the-art knowledge about pathogen population heterogeneity and describes the genotypic and phenotypic analyses of persister subpopulations and stress-resistant variants. the molecular mechanisms underlying the generation of persister phenotypes and genetic variants are identified. zooming in on listeria monocytogenes, a comparative whole-genome sequence analysis of wild types and variants that enabled the identification of mutations in variants obtained after a ...201626772414
reductions in neonatal listeriosis: "collateral benefit" of group b streptococcal prophylaxis?we tested the hypothesis that declines in listeria monocytogenes in infants are related to declines in rates of early-onset group b streptococcus (gbs) infections associated with widespread prophylaxis using agents with listeria activity.201626772166
splenic leukocytes traffic to the thyroid and produce a novel tshβ isoform during acute listeria monocytogenes infection in mice.the thyroid stimulating hormone beta-subunit (tshβ) with tshα form a glycoprotein hormone that is produced by the anterior pituitary in the hypothalamus-pituitary-thyroid (hpt) axis. although tshβ has been known for many years to be made by cells of the immune system, the role of immune system tsh has remained unclear. recent studies demonstrated that cells of the immune system produce a novel splice variant isoform of tshβ (tshβv), but little if any native tshβ. here, we show that within three ...201626771831
genome sequence of listeria monocytogenes strain f6540 (sequence type 360) collected from food samples in ontario, canada.comparative genomic analysis between pathogenic and nonpathogenic listeria monocytogenes strains provides a good model for studying the virulence of this organism. here, we report the genome sequence of the nonpathogenic l. monocytogenes strain f6540 (sequence type 360) identified specifically in food samples in ontario, canada, in 2010.201626769922
molecular serogrouping of listeria monocytogenes from brazil using pcr.we assessed the serotype distribution of listeria monocytogenes isolates from clinical, beef, and environment samples using two pcr-based protocols for serogrouping. a panel of 134 isolates (22 clinical samples, 79 samples of beef cuts, and 33 samples from the beef processing environment) were subjected to conventional serology and identified as serotypes 1/2a (n = 12), 1/2b (n = 21), 1/2c (n = 71), and 4b (n = 30). isolates from clinical samples were predominantly serotype 4b, and the most prev ...201626735041
antimicrobial activities, toxicity and phenolic composition of asphodeline anatolica e. tuzlaci leaf extracts from turkey.the antimicrobial activity of acetone, methanol and aqueous extracts of asphodeline anatolica e. tuzlaci leaves was evaluated against american type culture collection, food and clinical isolates (listeria monocytogenes and staphylococcus aureus including methicillin-resistant strains-mrsa). biofilm formation, toxicity and characterisation of the polyphenolic content were analysed. the acetone extract demonstrated a higher antibacterial activity against s. aureus including mrsa strains, l. monocy ...201626727992
the role of listeria monocytogenes cell wall surface anchor protein lapb in virulence, adherence, and intracellular replication.lmof2365_2117 is a listeria monocytogenes putative cell wall surface anchor protein with a conserved domain found in collagen binding proteins. we constructed a deletion mutation in lmof2365_2117 in serotype 4b strain f2365, evaluated its virulence, and determined its ability to adhere and invade colonic epithelial cells and macrophages. in a/j mice, colonization of liver was significantly higher for f2365 than for f2365δ2117. the ability of f2365δ2117 to adhere to caco-2 cells was significantly ...201626724740
differential internalin a levels in biofilms of listeria monocytogenes grown on different surfaces and nutrient conditions.listeria monoctyogenes is a foodborne pathogen containing the surface protein, internalin a (inla). the expression of this protein permits the invasion of l. monocytogenes into intestinal epithelial cells expressing the receptor e-cadherin, thus crossing the intestinal barrier and resulting in listerosis. the main aim of this work was to investigate inla levels in different l. monocytogenes strains in both planktonic and sessile states using an anti-inla antibody. biofilms were grown in high and ...201626724402
effect of peracetic acid on biofilms formed by staphylococcus aureus and listeria monocytogenes isolated from dairy plants.this research investigated the removal of adherent cells of 4 strains of staphylococcus aureus and 1 listeria monocytogenes strain (previously isolated from dairy plants) from polystyrene microtiter plates using peracetic acid (paa, 0.5%) for 15, 30, 60, and 120 s, and the inactivation of biofilms formed by those strains on stainless steel coupons using the same treatment times. in the microtiter plates, paa removed all s. aureus at 15 s compared with control (no paa treatment). however, l. mono ...201626723125
behavior of escherichia coli o157:h7 and listeria monocytogenes during fermentation and storage of camel yogurt.in addition to its nutritional and therapeutic properties, camel milk has the ability to suppress the growth of a wide range of foodborne pathogens, but there is a lack of information regarding the behavior of these pathogens in products such as yogurt produced from camel milk. the objective of the current study was to investigate the behavior of listeria monocytogenes and escherichia coli o157:h7 during manufacture and storage of camel yogurt. camel milk inoculated with l. monocytogenes and e. ...201626723116
pregnancy vaccination with gold glyco-nanoparticles carrying listeria monocytogenes peptides protects against listeriosis and brain- and cutaneous-associated morbidities.listeriosis is a fatal infection for fetuses and newborns with two clinical main morbidities in the neonatal period, meningitis and diffused cutaneous lesions. in this study, we vaccinated pregnant females with two gold glyconanoparticles (gnp) loaded with two peptides, listeriolysin peptide 91-99 (llo91-99) or glyceraldehyde-3-phosphate dehydrogenase 1-22 peptide (gapdh1-22). neonates born to vaccinated mothers were free of bacteria and healthy, while non-vaccinated mice presented clear brain a ...201628335280
multiplex pcr for simultaneous identification of e. coli o157:h7, salmonella spp. and l. monocytogenes in food.the rapid detection of pathogens in food is becoming increasingly critical for ensuring the safety of consumers, since the majority of food-borne illnesses and deaths are caused by pathogenic bacteria. hence, rapid, sensitive, inexpensive and convenient approaches to detect food-borne pathogenic bacteria is essential in controlling food safety. in this study, a multiplex pcr assay for the rapid and simultaneous detection of escherichia coli o157:h7, salmonella spp. and listeria monocytogenes was ...201628330283
creative lysins: listeria and the engineering of antimicrobial enzymes.cell wall lytic enzymes have been of increasing interest as antimicrobials for targeting gram-positive spoilage and pathogenic bacteria, largely due to the development of strains resistant to antibiotics and bacteriophage therapy. such lysins show considerable promise against listeria monocytogenes, a primary concern in food-processing environments, but there is room for improvement via protein engineering. advances in antilisterial applications could benefit from recent developments in lysin bi ...201626710271
microbial inactivation kinetics and mechanisms of carbon-doped tio2 (c-tio2) under visible light.in this study, titanium dioxide nanoparticles doped with carbon (c-tio2) were synthesized by means of sol-gel methods, and the synthesis was verified by means of x-ray photoelectron spectroscopy. the nanoparticles' photocatalytic disinfection activity of listeria monocytogenes was tested under uv and visible light. the observed inactivation levels for 150min of visible light exposure with and without uv cutoff filters were 2.10 and 2.45 log, respectively. we also found that traditional reactive ...201626705890
two listeria monocytogenes pseudo-outbreaks caused by contaminated laboratory culture media.listeriosis is a serious foodborne infection that disproportionately affects elderly adults, pregnant women, newborns, and immunocompromised individuals. diagnosis is made by culturing listeria monocytogenes from sterile body fluids or from products of conception. this report describes the investigations of two listeriosis pseudo-outbreaks caused by contaminated laboratory media made from sheep blood.201626699704
enteric listeriosis in grazing steers supplemented with spoiled silage.an outbreak of enteric listeriosis in steers that were fed spoiled silage is reported. the outbreak started 2 days after ~200 animals in a single paddock were given a supplement of spoiled silage. forty animals (20%) were affected, and 13 (6.5%) died over a period of 10 days. affected animals were recumbent, depressed, and had diarrhea with mucus and fibrin. gross and microscopic findings in 3 animals that were subjected to autopsy included excess peritoneal fluid, congestion and edema of abomas ...201626699524
effect of hops beta acids on the survival of unstressed- or acid-stress-adapted-listeria monocytogenes and on the quality and sensory attributes of commercially cured ham slices.this study evaluated the antilisterial activity of hops beta acids (hba) and their impact on the quality and sensory attributes of ham. commercially cured ham slices were inoculated with unstressed- and acid-stress-adapted (asa)-l. monocytogenes (2.2 to 2.5 log cfu/cm(2) ), followed by no dipping (control), dipping in deionized (di) water, or dipping in a 0.11% hba solution. this was followed by vacuum or aerobic packaging and storage (7.2 °c, 35 or 20 d). samples were taken periodically during ...201626748557
use of a novel medium, the polymyxin ceftazidime oxford medium, for isolation of listeria monocytogenes from raw or non-pasteurized foods.polymyxin ceftazidime oxford medium (pcom), a novel selective and differential plating medium for listeria monocytogenes was compared with modified oxford agar (mox) for efficacy to isolate l. monocytogenes and other listeria spp. naturally present in non-pasteurized mexican-style cheese (n = 50), non-pasteurized fresh squeezed orange juice (n = 50), raw beef chunks (n = 36), and fresh cabbage (n = 125). samples were collected from retail markets and farms in mexico and tested following the us d ...201626742621
survival mechanism of escherichia coli o157:h7 against combined treatment with acetic acid and sodium chloride.the combination of salt and acid is commonly used in the production of many foods, including pickles and fermented foods. however, in our previous studies, the addition of salt significantly reduced the inhibitory effect of acetic acid on escherichia coli o157:h7 in laboratory media and pickled cucumbers. therefore, this study was conducted to determine the mechanism by which salt confers resistance against acetic acid in e. coli o157:h7. the addition of high concentrations (up to 9% or 15% [w/v ...201626742620
effect of sanitizer combined with steam heating on the inactivation of foodborne pathogens in a biofilm on stainless steel.the combined effect of chemical sanitizers including sodium hypochlorite, hydrogen peroxide, iodophor, and benzalkonium chloride with steam heating on the inactivation of biofilms formed by escherichia coli o157:h7, salmonella typhimurium, and listeria monocytogenes on stainless steel was investigated. six day old biofilms, comprised of a mixture of three strains each of three foodborne pathogens, were produced on stainless steel coupons at 25 °c and treated with each sanitizer alone (for 5, 15, ...201626742615
expression of listeria monocytogenes key virulence genes during growth in liquid medium, on rocket and melon at 4, 10 and 30 °c.the aim of the present study was to assess the expression of key virulence genes, during growth of a listeria monocytogenes isolate in liquid medium, on melon and rocket at different temperatures and time. for that purpose, bhi broth, rocket and melon were inoculated at 7.0-7.5 log cfu ml(-1) or g(-1)and stored at 4, 10 and 30 °c. sampling took place upon inoculation and after 0.5, 6 and 24 h of incubation. the rna was stabilized and the expression of hly, plca, plcb, sigb, inla, inlb, inlc, inl ...201626742611
tracking foodborne pathogenic bacteria in raw and ready-to-eat food illegally sold at the eastern eu border.food illegally brought into the european union, mainly in the personal luggage of travelers, represents a potential threat to consumers' health. the aim of this study was to investigate the presence of five pathogens in food brought into the european union by moldavian citizens as personal goods and illegally sold in romania in the vicinity of the border. the occurrence of staphylococcus aureus and listeria monocytogenes was 7.5% and 8%, while campylobacter spp., escherichia coli o157:h7, and sa ...201626741503
xcr1+ dendritic cells promote memory cd8+ t cell recall upon secondary infections with listeria monocytogenes or certain viruses.naive cd8(+) t cell priming during tumor development or many primary infections requires cross-presentation by xcr1(+) dendritic cells (dcs). memory cd8(+) t lymphocytes (mctls) harbor a lower activation threshold as compared with naive cells. however, whether their recall responses depend on xcr1(+) dcs is unknown. by using a new mouse model allowing fluorescent tracking and conditional depletion of xcr1(+) dcs, we demonstrate a differential requirement of these cells for mctl recall during sec ...201626694969
cutting edge: novel tmem173 allele reveals importance of sting n terminus in trafficking and type i ifn production.with the stimulator of ifn genes (sting) c terminus being extensively studied, the role of the n-terminal domain (ntd) of sting remains an important subject of investigation. in this article, we identify novel mutations in ntd of sting of the molf strain in response to hsv and listeria monocytogenes both in vitro and in vivo. these mutations are responsible for low levels of ifn-β caused by failure of molf sting to translocate from the endoplasmic reticulum. these data provide evidence that the ...201626685207
inactivation kinetics of listeria monocytogenes and salmonella enterica serovar typhimurium on fresh-cut bell pepper treated with slightly acidic electrolyzed water combined with ultrasound and mild heat.the goal of this study was to enhance the antimicrobial effect of slightly acidic electrolyzed water (saew) through addition of synergistic treatment with ultrasound (us) and mild heat treatment in order to improve the microbial safety of fresh-cut bell pepper. to evaluate the synergistic effects, the weibull model was used to mathematically measure the effectiveness of the individual and combined treatments against listeria monocytogenes and salmonella typhimurium on the pepper. the combined tr ...201626678144
the challenge of enumerating listeria monocytogenes in food.listeria monocytogenes is recognised as a serious foodborne pathogen in humans. however, food products are usually contaminated at low levels (i.e. <100 cfu/g) and there is still no adequate enumeration method for testing food. much research has been carried out to improve listeria enumeration methods, leading to several proposed alternative methods such as the most probable number technique, molecular-based methods and bacterial cell concentration techniques. here, we catalogue the current know ...201626678141
development of a model describing the inhibitory effect of selected preservatives on the growth of listeria monocytogenes in a meat model system.the objective of this study was to evaluate the impact of seven independent factors consisting of sodium nitrite, ph, sodium chloride, sodium acetate, sodium lactate syrup, calcium propionate and a blend of nisin and hop alpha acids on the growth rate of listeria monocytogenes in ham as a model of ready-to-eat (rte) meat products. a central composite consisted of seven factors mentioned above was designed and the response surface methodology was applied for creating a mathematic model to predict ...201626678138
detection of virulence genes and growth potential in listeria monocytogenes strains isolated from ricotta salata cheese.ricotta salata is a traditional ripened and salted whey cheese made in sardinia (italy) from sheep's milk. this product is catalogued as ready-to-eat food (rte) since it is not submitted to any further treatment before consumption. thus, foodborne pathogens, such as listeria monocytogenes, can represent a health risk for consumers. in september 2012, the fda ordered the recall of several batches of ricotta salata imported from italy linked to 22 cases of listeriosis in the united states. this st ...201626666835
long-term exposure to high levels of decabrominated diphenyl ether inhibits cd4 t-cell functions in c57bl/6 mice.in recent years, the adverse health effects of decabrominated diphenyl ether (bde-209) have raised more concerns as a growing number of studies reported its persistence in the environment and abundance in the human population, especially in occupational environmental compartments and exposed personnel. this study applies our previous animal model simulating occupational exposure to bde-209 to investigate its potential adverse effects on cd4 t cells. female c57bl/6 mice were orally gavaged with b ...201626682527
restraining of reactive oxygen species promotes invasion of listeria monocytogenes into glia cells.listeria monocytogenes is a foodborne pathogen that could cause severe infection in the central nervous system of humans and animals. however, the molecular mechanism of the pathogenesis is not fundamentally assessed. this study aimed to analyze the role of reactive oxygen species (ros) in l. monocytogenes during its invasion into glia cells. the ros level in l. monocytogenes was manipulated using nad(p)h oxidase inhibitor diphenyleneiodonium chloride (dpi) and ros scavenger n-acetyl cysteine (n ...201626635415
listeria infected pseudoaneurysm of the superficial femoral artery.we present a unique case of listeria-infected pseudoaneurysm of the superficial femoral artery. listeria monocytogenes, a gram positive, intracellular bacterium, is widespread in the environment. the manifestation of infection in humans ranges from mild gastroenteritis to life-threatening listeriosis. the incidence in the healthy population is low (0.7 per 100,000) but rises sharply in pregnancy, the immunocompromised and patients with malignancy. listeria rarely causes mycotic aneurysm formatio ...201626620380
systemic listeriosis following vaccination with the attenuated listeria monocytogenes therapeutic vaccine, adxs11-001. 201626618528
an invertebrate signal transducer and activator of transcription 5 (stat5) ortholog from the disk abalone, haliotis discus discus: genomic structure, early developmental expression, and immune responses to bacterial and viral stresses.signal transducer and activator of transcription (stat) family members are key signaling molecules that transduce cellular responses from the cell membrane to the nucleus upon janus kinase (jak) activation. although seven stat members have been reported in mammals, very limited information on stat genes in molluscans is available. in this study, we identified and characterized a stat paralog that is homologous to stat5 from the disk abalone, haliotis discus discus, and designated as abstat5. com ...201626616564
microbial dynamics in mixed culture biofilms of bacteria surviving sanitation of conveyor belts in salmon-processing plants.the microbiota surviving sanitation of salmon-processing conveyor belts was identified and its growth dynamics further investigated in a model mimicking processing surfaces in such plants.201626613979
extending rad tag analysis to microbial ecology: a comparison between multilocus sequence typing and 2b-rad to investigate listeria monocytogenes genetic structure.the advent of next-generation sequencing (ngs) has dramatically changed bacterial typing technologies, increasing our ability to differentiate bacterial isolates. despite it is now possible to sequence a bacterial genome in a few days and at reasonable costs, most genetic analyses do not require whole-genome sequencing, which also remains impractical for large population samples due to the cost of individual library preparation and bioinformatics. more traditional sequencing approaches, however, ...201626613186
effect of salt types and concentrations on the high-pressure inactivation of listeria monocytogenes in ground chicken.national and international health agencies have recommended a significant reduction in daily intake of sodium by reducing the amount of nacl in foods, specifically processed meats. however, sodium reduction could increase the risk of survival and growth of spoilage and pathogenic microorganisms on these products. therefore, alternate processing technologies to improve safety of sodium reduced foods are necessary. this study examined the effects of three different salt types and concentrations on ...201626613161
inhibition mechanism of listeria monocytogenes by a bioprotective bacteria lactococcus piscium cncm i-4031.listeria monocytogenes is a pathogenic gram positive bacterium and the etiologic agent of listeriosis, a severe food-borne disease. lactococcus piscium cncm i-4031 has the capacity to prevent the growth of l. monocytogenes in contaminated peeled and cooked shrimp. to investigate the inhibititory mechanism, a chemically defined medium (msma) based on shrimp composition and reproducing the inhibition observed in shrimp was developed. in co-culture at 26 °c, l. monocytogenes was reduced by 3-4 log ...201626611171
prospective whole-genome sequencing enhances national surveillance of listeria monocytogenes.whole-genome sequencing (wgs) has emerged as a powerful tool for comparing bacterial isolates in outbreak detection and investigation. here we demonstrate that wgs performed prospectively for national epidemiologic surveillance of listeria monocytogenes has the capacity to be superior to our current approaches using pulsed-field gel electrophoresis (pfge), multilocus sequence typing (mlst), multilocus variable-number tandem-repeat analysis (mlva), binary typing, and serotyping. initially 423 l. ...201626607978
teichoic acid is the major polysaccharide present in the listeria monocytogenes biofilm matrix.the aim of this study was to characterize the listeria monocytogenes biofilm and particularly the nature of the carbohydrates in the biofilm extracellular matrix and culture supernatant versus to cell wall carbohydrates. listeria monocytogenes serotype 1/2a and 4b strains were able to form complex biofilms embedded in an extracellular matrix. the soluble carbohydrates from biofilm extracellular matrix and culture supernatant were identified as teichoic acids, structurally identical to cell wall ...201626626878
dynamics of listeria monocytogenes colonisation in a newly-opened meat processing facility.this study determined the colonisation scenario of listeria monocytogenes in a newly-opened ready-to-eat meat processing facility using a combination of classical microbiology and molecular biology techniques. samples (n=183), including food contact surfaces, non-food contact surfaces, raw materials and food samples, collected on four sampling occasions, were analysed for l. monocytogenes by the iso 11290:1996 standard method and by real-time pcr applied to the second enrichment broth from the i ...201626599913
collapsin response mediator protein-1 regulates arp2/3-dependent actin assembly.listeria monocytogenes is a bacterial parasite that uses host proteins to assemble an arp2/3-dependent actin comet tail to power its movement through the host cell. initiation of comet tail assembly is more efficient in cytosol than it is under defined conditions, indicating that unknown factors contribute to the reaction. we therefore fractionated cytosol and identified crmp-1 as a factor that facilitates arp2/3-dependent listeria actin cloud formation in the presence of arp2/3 and actin alone. ...201626598519
exoproteome analysis reveals higher abundance of proteins linked to alkaline stress in persistent listeria monocytogenes strains.the foodborne pathogen listeria monocytogenes, responsible for listeriosis a rare but severe infection disease, can survive in the food processing environment for month or even years. so-called persistent l. monocytogenes strains greatly increase the risk of (re)contamination of food products, and are therefore a great challenge for food safety. however, our understanding of the mechanism underlying persistence is still fragmented. in this study we compared the exoproteome of three persistent st ...201626594790
adam17 controls il-6 signaling by cleavage of the murine il-6rα from the cell surface of leukocytes during inflammatory responses.the cytokine il-6 is part of a regulatory signaling network that controls immune responses. il-6 binds either to the membrane-bound il-6 receptor-α (classic signaling) or to the soluble il-6 receptor-α (trans-signaling) to initiate signal transduction via gp130 activation. because classic and trans-signaling of il-6 fulfill different tasks during immune responses, controlled shedding of the membrane-bound il-6 receptor-α from the surface of immune cells can be considered a central regulator of i ...201626561568
structure of the bacterial cell division determinant gpsb and its interaction with penicillin-binding proteins.each bacterium has to co-ordinate its growth with division to ensure genetic stability of the population. consequently, cell division and growth are tightly regulated phenomena, albeit different bacteria utilise one of several alternative regulatory mechanisms to maintain control. here we consider gpsb, which is linked to cell growth and division in gram-positive bacteria. δgpsb mutants of the human pathogen listeria monocytogenes show severe lysis, division and growth defects due to distortions ...201626575090
up-regulation of cyld enhances listeria monocytogenes induced apoptosis in thp-1 cells.listeria monocytogenes (lm), a facultative anaerobic gram-positive bacterium, causes listeriosis. immune cell apoptosis is considered to be one pathogenic factor for listeriosis. as a deubiquitinase, cyld is an important regulator both in innate immune response and apoptosis by negatively modulating nf-κb pathway. however the role of cyld in lm induced apoptosis remains unclear. here we found that cyld is significantly up-regulated in macrophages upon its infection. there is a moderate decrease ...201626545866
multiplex pcr serogrouping of listeria monocytogenes isolated in japan.pcr serogrouping methods were used to examine strains of l. monocytogenes isolated in japan. among 187 strains, 99.5% were classified into 4 pcr serogroups corresponding to conventional serotypes. only one isolate had a new pcr profile, which may be a variant of serogroup ivb.201626537550
tracing sources of listeria contamination in traditional italian cheese associated with a us outbreak: investigations in italy.in 2012 a us multistate outbreak of listeriosis was linked to ricotta salata imported from italy, made from pasteurized sheep's milk. sampling activities were conducted in italy to trace the source of listeria monocytogenes contamination. the cheese that caused the outbreak was produced in a plant in apulia that processed semi-finished cheeses supplied by five plants in sardinia. during an 'emergency sampling', 179 (23·6%) out of 758 end-products tested positive for l. monocytogenes, with concen ...201626522501
effect of x-ray treatments on escherichia coli o157:h7, listeria monocytogenes, shigella flexneri, salmonella enterica and inherent microbiota on whole mangoes.the aims of this investigation were to; (i) study the effect of x-ray treatments in reducing escherichia coli o157:h7, listeria monocytogenes, salmonella enterica and shigella flexneri on whole mangoes, and (ii) study the effect of x-ray treatments on microflora counts (mesophilic counts, psychrotrophic counts and yeast and mould counts) of whole mangoes during storage at ambient temperature (22°c) for 30 days. a mixture of three strains of each test organism was spot inoculated (100 μl; approx. ...201626518738
listeria monocytogenes isolates from food and food environment harbouring tetm and ermb resistance genes.listeria monocytogenes is a foodborne pathogen that has become an important cause of human and animal diseases worldwide. the purpose of this study was to evaluate the serotypes, virulence potential, antimicrobial resistance profile, and genetic relationships of 50 l. monocytogenes isolates from food and food environment in southern brazil. in this study, the majority of l. monocytogenes isolates belonged to the serotypes 1/2b (42%) and 4b (26%), which are the main serotypes associated with huma ...201626518475
efflux pump-mediated benzalkonium chloride resistance in listeria monocytogenes isolated from retail food.in this study, efflux pump-mediated benzalkonium chloride (bc) resistance, including plasmid-encoded (qac protein family and bcrabc) and chromosome-borne efflux pumps, was investigated in listeria monocytogenes from retail food in china. among the 59 l. monocytogenes strains, 13 (22.0%) strains were resistant to bc. the pcr results showed that bcrabc was harbored by 2 of 13 bc resistant strains. however, none of the qac genes were detected among the 59 strains. the bcrabc was absent in both of t ...201626513255
the intrinsic cephalosporin resistome of listeria monocytogenes in the context of stress response, gene regulation, pathogenesis and therapeutics.intrinsic resistance to antibiotics is a serious therapeutic problem in the case of many bacterial species. the gram-positive human pathogen listeria monocytogenes is intrinsically resistant to broad spectrum cephalosporin antibiotics, which are commonly used in therapy of bacterial infections. besides three penicillin-binding proteins the intrinsic cephalosporin resistome of l. monocytogenes includes multidrug resistance transporter transporters, proteins involved in peptidoglycan biosynthesis ...201626509460
enhanced antimicrobial effect of organic acid washing against foodborne pathogens on broccoli by vacuum impregnation.this study was undertaken to evaluate the effect of vacuum impregnation applied to the washing process for removal of salmonella typhimurium and listeria monocytogenes from broccoli surfaces. broccoli was inoculated with the two foodborne pathogens and treated with simple dipping washing or with vacuum impregnation in 2% malic acid for 5, 10, 20, or 30 min. there were two methods of vacuum impregnation: continuous and intermittent. after 30 min of 101.3 kpa (=14.7 psi, simple dipping), 61.3 kpa ...201626496412
ring-enhancing brain lesions: listeria monocytogenes abscesses. 201626494469
outbreak of hospital-acquired gastroenteritis and invasive infection caused by listeria monocytogenes, finland, 2012.during one week in july 2012, two patients from the same ward at the municipal hospital in vaasa, finland, were diagnosed with septicaemia caused by listeria monocytogenes. an outbreak investigation revealed eight concomitant cases of febrile gastroenteritis caused by l. monocytogenes on the same ward. median age of the cases was 82 years and median incubation time for listerial gastroenteritis was 21 h (range 9-107). an additional 10 cases of invasive listeriosis caused by the same outbreak str ...201626493730
systemic tolerance mediated by melanoma brain tumors is reversible by radiotherapy and vaccination.immune responses to antigens originating in the central nervous system (cns) are generally attenuated, as collateral damage can have devastating consequences. the significance of this finding for the efficacy of tumor-targeted immunotherapies is largely unknown.201626490306
synergism between carvacrol or thymol increases the antimicrobial efficacy of soy sauce with no sensory impact.here, we examined the antimicrobial effects of soy sauce containing essential oils (eos) against escherichia coli o157:h7, salmonella typhimurium, and listeria monocytogenes at 22°c and 4°c. to screen a variety of combined effects, soy sauce was mixed with six different eos (carvacrol, thymol, eugenol, trans-cinnamaldehyde, β-resorcylic acid, and vanillin), each at a concentration of 1mm for 10 min. none of the oils showed bactericidal activity when used alone. soy sauce combined with carvacrol ...201626490647
virus recovering from strawberries: evaluation of a skimmed milk organic flocculation method for assessment of microbiological contamination.skimmed milk organic flocculation method was adapted, optimized and compared with polyethylene glycol (peg) precipitation and filtration methods for recovering viruses from a strawberry matrix. spiking experiments with norovirus genogroup ii genotype 4 (nov gii.4) and murine norovirus 1 (mnv-1) demonstrated that the organic flocculation method associated with a glycine elution buffer, filter bag and cetyltrimethylammonium bromide (ctab) showed a recovery percentage of 2.5 and 32 times higher tha ...201626476572
presence of a widely disseminated listeria monocytogenes serotype 4b clone in india. 201627273224
cd8(+) t cells specific to a single yersinia pseudotuberculosis epitope restrict bacterial replication in the liver but fail to provide sterilizing immunity.cd8(+) t cells use contact-dependent cytolysis of target cells to protect the host against intracellular pathogens. we have previously shown that cd8(+) t cells and perforin are required to protect against the extracellular pathogen yersinia pseudotuberculosis. here we establish an experimental system where cd8(+) t cells specific to a single model antigen are the only memory response present at time of challenge. using mice immunized with a vaccine strain of listeria monocytogenes that expresse ...201627268148
hybrid antifouling and antimicrobial coatings prepared by electroless co-deposition of fluoropolymer and cationic silica nanoparticles on stainless steel: efficacy against listeria monocytogenes.controlling formation, establishment, and proliferation of microbial biofilms on surfaces is critical for ensuring public safety. herein, we report on the synthesis of antimicrobial nanoparticles and their co-deposition along with fluorinated nanoparticles during electroless nickel plating of stainless steel. plating bath composition is optimized to ensure sufficiently low surface energy to resist fouling and microbial adhesion as well as to exert significant (>99.99% reduction) antimicrobial ac ...201627268033
comorbidities and factors associated with central nervous system infections and death in non-perinatal listeriosis: a clinical case series.listeriosis is a rare disease caused by the bacterium listeria monocytogenes and mainly affects at risk people. listeriosis can lead to sepsis, central nervous system (cns) infections and death. the objectives of this study were to describe and quantify comorbidities and neurological sequelae underlying non-perinatal listeriosis cases and to describe the factors associated with death and cns infections in non-perinatal listeriosis.201627267465
inhibitory effect of liposome-entrapped lemongrass oil on the growth of listeria monocytogenes in cheese.listeria monocytogenes infection in dairy products is of mounting public concern. to inhibit bacterial growth, we engineered stimuli-responsive liposomes containing lemongrass oil for this study. the controlled release of liposome-entrapped lemongrass oil is triggered by listerolysin o, secreted by l. monocytogenes. we investigated the antibiotic activities of lemongrass oil liposomes against l. monocytogenes in cheese. we also assessed their possible effects on the quality of the cheese. liposo ...201627265173
infective endocarditis due to listeria monocytogenes: a report of 4 patients. 201627262490
antimicrobial eugenol nanoemulsion prepared by gum arabic and lecithin and evaluation of drying technologies.the purpose of present work was to develop eugenol oil nanoemulsions using gum arabic and lecithin as food grade natural emulsifiers, and study their antimicrobial activity. in addition, our study also evaluated different drying techniques (spray drying and freeze drying) on the morphology and redispersibility of nanoemulsion powders. the optimal fabrication method, physicochemical and structural characterization, stability, and antimicrobial activity were investigated. results showed that nanoe ...201626902894
towards lag phase of microbial populations at growth-limiting conditions: the role of the variability in the growth limits of individual cells.the water activity (aw) growth limits of unheated and heat stressed listeria monocytogenes individual cells were studied. the aw limits varied from 0.940 to 0.997 and 0.951 to 0.997 for unheated and heat stressed cells, respectively. due to the above variability a decrease in aw results in the presence of a non-growing fraction in the population leading to an additional pseudo-lag in population growth. in this case the total apparent lag of the population is the sum of the physiological lag of t ...201626900994
genes involved in listeria monocytogenes biofilm formation at a simulated food processing plant temperature of 15 °c.listeria monocytogenes is a pathogenic foodborne bacterium whose persistence in food processing environments is in part attributed to its biofilm formation. most biofilm studies have been carried out at 30-37 °c rather than at temperatures found in the food processing plants (i.e., 10-20 °c). the objective of the present study was to mine for novel genes that contribute to l. monocytogenes biofilm formation at 15 °c using the random insertional mutagenesis approach. a library of 11,024 l. monocy ...201626900648
genotypic and antimicrobial characterization of pathogenic bacteria at different stages of cattle slaughtering in southern brazil.meat can be contaminated in different stages of the slaughtering process and the identification of these stages is the starting point to implement adequate control measures. the objectives of this study were to assess the presence of pathogenic microorganisms in cattle carcasses, to identify the most important contamination points of the slaughtering process, and to evaluate the possible risk factors related to them in a cattle slaughterhouse. to this aim, 108 cattle carcasses were sampled at th ...201626896744
type i ifn does not promote susceptibility to foodborne listeria monocytogenes.type i ifn (ifn-α/β) is thought to enhance growth of the foodborne intracellular pathogen listeria monocytogenes by promoting mechanisms that dampen innate immunity to infection. however, the type i ifn response has been studied primarily using methods that bypass the stomach and, therefore, fail to replicate the natural course of l. monocytogenes infection. in this study, we compared i.v. and foodborne transmission of l. monocytogenes in mice lacking the common type i ifn receptor (ifnar1(-/-)) ...201626895837
systems level analyses reveal multiple regulatory activities of cody controlling metabolism, motility and virulence in listeria monocytogenes.bacteria sense and respond to many environmental cues, rewiring their regulatory network to facilitate adaptation to new conditions/niches. global transcription factors that co-regulate multiple pathways simultaneously are essential to this regulatory rewiring. cody is one such global regulator, controlling expression of both metabolic and virulence genes in gram-positive bacteria. branch chained amino acids (bcaas) serve as a ligand for cody and modulate its activity. classically, cody was cons ...201626895237
erratum for henke et al., listeria monocytogenes spreads within the brain by actin-based intra-axonal migration. 201626912561
Refresh
firstprev
12345678910...
nextlast
Displaying items 601 - 700 of 16792