| the impact of nisin on sensitive and resistant mutants of listeria monocytogenes in cottage cheese. | listeria monocytogenes +ögadd1 and +ölisk mutants display enhanced and reduced sensitivity, respectively, to the food preservative nisin in laboratory media. however, the behaviour of these strains in a nisin-containing food has not been assessed. here we use cottage cheese as a model food to address this issue. | 2011 | 21435121 |
| comk prophage junction fragments as markers for listeria monocytogenes genotypes unique to individual meat and poultry processing plants and a model for rapid niche-specific adaptation, biofilm formation, and persistence. | different strains of listeria monocytogenes are well known to persist in individual food processing plants and to contaminate foods for many years; however, the specific genotypic and phenotypic mechanisms responsible for persistence of these unique strains remain largely unknown. based on sequences in comk prophage junction fragments, different strains of epidemic clones (ecs), which included ecii, eciii, and ecv, were identified and shown to be specific to individual meat and poultry processin ... | 2011 | 21441318 |
| increased in vitro adherence and on-farm persistence of predominant and persistent listeria monocytogenes strains in the milking system. | dairy farms are a reservoir for listeria monocytogenes, and the reduction of this pathogen at the farm level is important for reducing human exposure. the objectives of this research were to study the diversity of l. monocytogenes strains on a single dairy farm, assess strain dynamics within the farm, identify potential sources of l. monocytogenes in bulk tank milk and milk filters, and assess the adherence abilities of representative strains. a total of 248 l. monocytogenes isolates were analyz ... | 2011 | 21441322 |
| lipa, a tyrosine and lipid phosphatase involved in the virulence of listeria monocytogenes. | intracellular bacterial pathogens manipulate host cell functions by producing enzymes that stimulate or antagonize signal transduction. the listeria monocytogenes genome contains a gene, lmo1800, encoding a protein with a conserved motif of conventional tyrosine phosphatases. here, we report that the lmo1800-encoded protein lipa is secreted by listeria and displays tyrosine as well as lipid phosphatase activity in vitro. bacteria lacking lipa are severely attenuated in virulence in vivo, thus re ... | 2011 | 21444667 |
| inactivation of indicators and pathogens in cattle feedlot manures and compost as determined by molecular and culture assays. | accurate and conservative information about pathogen inactivation rates is needed as the basis for safe manure management on beef cattle feedlots. the survival of indicators and pathogens in faecal pen manure, stockpiled manure and manure compost was measured with autochthonous indicator bacteria (escherichia coli, clostridium perfringens, enterococci, total coliforms) and pathogens (listeria monocytogenes, campylobacter jejuni) using culture and/or real-time quantitative pcr (qpcr) methods. add ... | 2011 | 21446944 |
| il-6 induced by staphylococcus aureus infection prevents the induction of skin allograft acceptance in mice. | clinical correlations between bacterial infections and rejection suggest a hypothesis that innate immune stimulation by bacterial infections results in the production of inflammatory cytokine that facilitate bystander t-cell activation, increased alloreactivity and inhibition of tolerance induction. previous studies demonstrated that ifnß produced during an infection with a model bacterium, listeria monocytogenes, prevented the induction of transplantation tolerance in mice with anti-cd154 and d ... | 2011 | 21449942 |
| late hip arthroplasty infection caused by listeria monocytogenes in a non-immunocompromised patient. | prosthetic joint infections caused by listeria monocytogenes are uncommon. such infections usually occur in patients with malignant disease, diabetes mellitus, chronic kidney disease, or liver disease or in elderly or immunocompromised patients. | 2011 | 21453041 |
| dynamic imaging of the effector immune response to listeria infection in vivo. | host defense against the intracellular pathogen listeria monocytogenes (lm) requires innate and adaptive immunity. here, we directly imaged immune cell dynamics at lm foci established by dendritic cells in the subcapsular red pulp (scdc) using intravital microscopy. blood borne lm rapidly associated with scdc. myelomonocytic cells (mmc) swarmed around non-motile scdc forming foci from which blood flow was excluded. the depletion of scdc after foci were established resulted in a 10-fold reduction ... | 2011 | 21455492 |
| distinct responses of splenic dendritic cell subsets to infection with listeria monocytogenes: maturation phenotype, level of infection, and t cell priming capacity ex vivo. | to determine the relative contributions of dc subsets in the development of protective immunity to listeria monocytogenes we examined the relationship between maturation, bacterial burden, and t cell priming capacity of four well characterized subsets of splenic dc following infection with lm. cd8a(+), cd4(+), and cd8a(-)cd4(-) dc and the b220(+) plasmacytoid dc (pdc) were compared for abundance and costimulatory molecule expression at 24, 48, and 72h post i.v. infection. we further determined t ... | 2011 | 21457950 |
| the role of the ph conditions of growth on the bioadhesion of individual and lawns of pathogenic listeria monocytogenes cells. | the work of adhesion that governs the interactions between pathogenic listeria monocytogenes and silicon nitride in water was probed for individual cells using atomic force microscopy and for lawns of cells using contact angle measurements combined with a thermodynamic-based harmonic mean model. the work of adhesion was probed for cells cultured under variable ph conditions of growth that ranged from ph 5 to ph 9. our results indicated that l. monocytogenes cells survived and adapted well to the ... | 2011 | 21459385 |
| a contingency locus in prfa in a listeria monocytogenes subgroup allows reactivation of the prfa virulence regulator during infection in mice. | a nonhemolytic listeria monocytogenes strain isolated from a fish processing plant was avirulent in a plaque-forming assay and in a subcutaneous mouse virulence assay. however, it showed 60% lethality (9/15 mice) when 10? cfu were intraperitoneally injected into mice. hemolytic l. monocytogenes bacteria were recovered from liver and spleen of the deceased mice, and the pulsed-field gel electrophoresis patterns were indistinguishable for the nonhemolytic and the hemolytic isolates. sequencing of ... | 2011 | 21460116 |
| serving high-risk foods in a high-risk setting: survey of hospital food service practices after an outbreak of listeriosis in a hospital. | prepared ready-to-eat salads and ready-to-eat delicatessen-style meats present a high risk for listeria contamination. because no foodborne illness risk management guidelines exist specifically for us hospitals, a survey of new york city (nyc) hospitals was conducted to characterize policies and practices after a listeriosis outbreak occurred in a nyc hospital. | 2011 | 21460490 |
| antimicrobial activity of plant essential oils against bacterial and fungal species involved in food poisoning and/or food decay. | the currative properties of aromatic and medicinal plants have been recognized since ancient times and, more recently, the antimicrobial activity of plant essential oils has been used in several applications, including food preservation. the purpose of this study was to create directly comparable, quantitative data on the antimicrobial activity of some plant essential oils prepared in the national institute of research-development for chemistry and petrochemistry, bucharest to be used for the fu ... | 2010 | 21462837 |
| listeria monocytogenes survival of uv-c radiation is enhanced by presence of sodium chloride, organic food material and by bacterial biofilm formation. | the bactericidal effect on food processing surfaces of ceiling-mounted uv-c light (wavelength 254 nm) was determined in a fish smoke house after the routine cleaning and disinfection procedure. the total aerobic counts were reduced during uv-c light exposure (48 h) and the number of listeria monocytogenes positive samples went from 30 (of 68) before exposure to 8 (of 68). we therefore in a laboratory model determined the l. monocytogenes reduction kinetics by uv-c light with the purpose of evalu ... | 2011 | 21463911 |
| effect of recombinant divercin rv41, structural variants and the activators of potassium channels on listeria monocytogenes egde. | the effect of recombinant divercin rv41 (dvnrv41) and its structural variants on the k-channel formation was determined. the growth of listeria monocytogenes egde (sensitive phenotype) and its isogenic strain (resistant phenotype) was assessed in the presence of dvnrv41 combined or not with pinacidil, ns1619, cromakalim (as k-channel activators), iberiotoxin and glipizide (as k-channel blockers). the combined action of dvnrv41 and k activators permitted formation of atp-dependent pores. the comb ... | 2011 | 21468759 |
| splenic cd8α(+) dendritic cells undergo rapid programming by cytosolic bacteria and inflammation to induce protective cd8(+) t-cell memory. | memory cd8(+) t lymphocytes are critical effector cells of the adaptive immune system mediating long-lived pathogen-specific protective immunity. three signals - antigen, costimulation and inflammation - orchestrate optimal cd8(+) t-cell priming and differentiation into effector and memory cells and shape t-cell functional fate and ability to protect against challenge infections. while among the conventional spleen dcs (cdcs), the cd8α(+) but not the cd8α(-) cdcs most efficiently mediate cd8(+) ... | 2011 | 21469106 |
| increased apoptosis, curtailed expansion and incomplete differentiation of cd8(+) t cells combine to decrease clearance of l. monocytogenes in old mice. | aging is accompanied by altered immunity, resulting in a variable state of poorly understood immunodeficiency. while both the numbers and the functionality of naïve t cells are decreased by aging, the impact of these changes upon immune defense against bacterial pathogens in vivo remains understudied. using a model of listeria monocytogenes (lm), where the primary cd8(+) t-cell response is critically important for immune defense, we show that c57bl/6 (b6) mice exhibit an age-dependent reduction ... | 2011 | 21469120 |
| role of clic4 in the host innate responses to bacterial lipopolysaccharide. | chloride intracellular channel (clic) 4 has diverse functions in membrane trafficking, apoptosis, angiogenesis and cell differentiation. clic4 is abundantly expressed in macrophages, but its role in innate immune functions is unclear. here, we show that primary murine macrophages express increased amounts of clic4 after exposure to bacterial lipopolysaccharide (lps). endogenous clic4 level was significantly elevated in the brain, heart, lung, kidney, liver and spleen after lps injection of mice. ... | 2011 | 21469130 |
| identification of an n-terminal formylated, two-peptide bacteriocin from enterococcus faecalis 710c. | enterococcus faecalis 710c, isolated from beef product, has a broad antimicrobial activity spectrum against foodborne pathogens. two bacteriocins, enterocin 7a (ent7a) and enterocin 7b (ent7b), were purified from the culture supernatant of e. faecalis 710c and characterized using matrix-assisted laser desorption ionization-time-of-flight mass spectrometry and electrospray infusion tandem mass spectrometry analyses. these data and subsequent genetic analysis showed that ent7a and ent7b are produc ... | 2011 | 21469734 |
| characterization of the novel listeria monocytogenes pcr serogrouping profile ivb-v1. | the world health organization collaborating centre for listeria (whoccl) has developed in 2004 a multiplex pcr assay that separates the 4 major listeria monocytogenes serovars (1/2a, 1/2b, 1/2c, and 4b) into distinct pcr serogroups. a new pcr profile has been recently identified, constituted of amplified dna fragments of prs, orf2819, orf2110 and lmo0737. here we characterize 22 l. monocytogenes isolates of the whoccl collection with this pcr ivb variant 1 (ivb-v1) profile. the 22 isolates belon ... | 2011 | 21470706 |
| mekk3 regulates ifn-{gamma} production in t cells through the rac1/2-dependent mapk cascades. | mekk3 is a conserved ser/thr protein kinase belonging to the mapk kinase kinase (map3k) family. mekk3 is constitutively expressed in t cells, but its function in t cell immunity has not been fully elucidated. using mekk3 t cell conditional knockout (t-cko) mice, we show that mekk3 is required for t cell immunity in vivo. mekk3 t-cko mice had reduced t cell response to bacterial infection and were defective in clearing bacterial infections. the ag-induced cytokine production, especially ifn-γ pro ... | 2011 | 21471448 |
| outbreak of invasive listeriosis associated with the consumption of hog head cheese--louisiana, 2010. | during january-june 2010, a total of 14 cases of laboratory-confirmed invasive listeriosis were reported to the louisiana office of public health (oph). isolates of listeria monocytogenes from the blood samples of eight patients were identified as serotype 1/2a and had pulsed-field gel electrophoresis (pfge) pattern combinations that were indistinguishable from one another. the detection of this cluster prompted an investigation in coordination with cdc, the louisiana department of agriculture a ... | 2011 | 21471946 |
| behavior of salmonella typhimurium, staphylococcus aureus, listeria monocytogenes, and shigella flexneri and shigella sonnei during production of pulque, a traditional mexican beverage. | pulque is a typical fermented alcoholic beverage of central mexico, produced from the nectar of maguey agave plants. production systems are largely artisanal, with inadequate hygiene conditions and exposure to multiple contamination sources. no data exist on pulque microbiological safety and the behavior of pathogenic microorganisms in agave nectar and pulque. an initial trial was done of the behavior of salmonella typhimurium, staphylococcus aureus, listeria monocytogenes, and shigella flexneri ... | 2011 | 21477472 |
| radiation inactivation of foodborne pathogens on frozen seafood products. | foodborne illness due to consumption of contaminated seafood is, unfortunately, a regular occurrence in the united states. ionizing (gamma) radiation can effectively inactivate microorganisms and extend the shelf life of seafood. in this study, the ability of gamma irradiation to inactivate foodborne pathogens surface inoculated onto frozen seafood (scallops, lobster meat, blue crab, swordfish, octopus, and squid) was investigated. the radiation d(10)-values (the radiation dose needed to inactiv ... | 2011 | 21477481 |
| implications of the inability of listeria monocytogenes egd-e to grow anaerobically due to a deletion in the class iii nrdd ribonucleotide reductase for its use as a model laboratory strain. | listeria monocytogenes is a gram-positive facultative intracellular bacterium that causes life-threatening diseases in humans. it grows and survives in environments of low oxygen tension and under conditions of strict anaerobiosis. oxygen-limiting conditions may be an important factor in determining its pathogenicity. l. monocytogenes serovar 1/2a strain egd-e has been employed intensively to elucidate the mechanisms of intracellular multiplication and virulence. listeria possesses genes encodin ... | 2011 | 21478338 |
| discriminating multi-species populations in biofilms with peptide nucleic acid fluorescence in situ hybridization (pna fish). | our current understanding of biofilms indicates that these structures are typically composed of many different microbial species. however, the lack of reliable techniques for the discrimination of each population has meant that studies focusing on multi-species biofilms are scarce and typically generate qualitative rather than quantitative data. | 2011 | 21479268 |
| acquired resistance to listeria monocytogenes during a secondary infection in a murine model fed dietary lipids. | objective: the ω-3 polyunsaturated fatty acids can suppress immune system functions. this property may cause adverse effects by impairing host resistance to infection. the present study focused on estimating the impact of different dietary lipids on the immune system of mice after a secondary infection with listeria monocytogenes. methods: balb/c mice were divided into five dietary groups of olive oil, fish oil, sunflower oil, high-oleic sunflower oil, or low fat that was administered for 8 wk. ... | 2011 | 21482069 |
| k+ efflux, is required for histone-h3 dephosphorylation by listeria llo and other pore forming toxins. | chromatin modification triggered by bacteria is a newly described mechanism by which pathogens impact host transcription. listeria monocytogenes dephosphorylates histone h3 through the action of listeriolysin o (llo), however, the underlying mechanism is unknown. here we show that an unrelated pore forming toxin, aeromonas aerolysin also provokes h3 dephosphorylation. as reported for aerolysin, we show that llo, and related toxins induce a pore-dependent k(+) efflux, and that this efflux is the ... | 2011 | 21482680 |
| green fluorescent protein labeling of listeria, salmonella, and escherichia coli o157:h7 for safety-related studies. | many food safety-related studies require tracking of introduced foodborne pathogens to monitor their fate in complex environments. the green fluorescent protein (gfp) gene (gfp) provides an easily detectable phenotype so has been used to label many microorganisms for ecological studies. the objectives of this study were to label major foodborne pathogens and related bacteria, including listeria monocytogenes, listeria innocua, salmonella, and escherichia coli o157:h7 strains, with gfp and charac ... | 2011 | 21483738 |
| the distribution of e-cadherin expression in listeric rhombencephalitis of ruminants indicates its involvement in listeria monocytogenes neuroinvasion. | aim: to investigate the expression of e-cadherin, a major host cell receptor for listeria monocytogenes (lm) internalin a, in the ruminant nervous system and its putative role in brainstem invasion and intracerebral spread of lm in the natural disease. methods: immunohistochemistry and double-immunofluorescence was performed on brains, cranial nerves and ganglia of ruminants with and without natural lm rhombencephalitis using antibodies against e-cadherin, pgp 9.5, mag and lm. results: in the ru ... | 2011 | 21486315 |
| purification and characterization of a new bacillus thuringiensis bacteriocin active against listeria monocytogenes, bacillus cereus and agrobacterium tumefaciens. | this study reports on the identification, characterization and purification of a new bacteriocin, named bacthuricin f103, from a bacillus thuringiensis strain bupm103. bacthuricin f103 production began in the early exponential phase and reached a maximum in the middle of the same phase. two chromatographic methods based on high performance liquid chromatography and fast protein liquid chromatography systems were used to purify bacthuricin f103. sodium dodecyl sulphate-polyacrylamide gel electrop ... | 2011 | 21487734 |
| spontaneous bacterial peritonitis caused by infection with listeria monocytogenes. | spontaneous bacterial peritonitis is a severe and life-threatening complication in patients with ascites caused by advanced liver disease. the organisms most commonly involved are coliform bacteria and third-generation cephalosporins are the empiric antibiotics of choice. this is an uncommon case of spontaneous bacterial peritonitis caused by listeria monocytogenes in a female patient with liver cirrhosis from autoimmune hepatitis. she did not improve with ceftriaxone and her course was complica ... | 2008 | 21490863 |
| neonatal listeria-meningitis in san luis, argentina: a three-case report. | between november 1996 and december 2006, two cases of early-onset and one case of late-onset neonatal listeriosis were reported in san luis, argentina. this article describes clinical and laboratory findings as well as treatment and outcome for newborns treated for listeria monocytogenes meningitis or septicaemia. in one of the newborns with early-onset listeriosis, meningitis led to important complications including hydrocephalus. the two other newborns showed complete recovery following adequa ... | 2011 | 21491067 |
| antimicrobial susceptibility of listeria monocytogenes food isolates from different cities in colombia. | abstract one hundred eight listeria monocytogenes food isolates from four cities in colombia and previously confirmed by multiplex polymerase chain reaction were characterized for antimicrobial susceptibility. isolates were evaluated against 17 antimicrobials contained in the microstrep plus(®)3 panel (microscan system). susceptibility found for ampicillin, amoxicillin/clavulanic acid, and chloramphenicol was 100%, whereas it was 98% for other antimicrobials such as trimethoprim/sulfamethoxazole ... | 2011 | 21492027 |
| production of ifn-β during listeria monocytogenes infection is restricted to monocyte/macrophage lineage. | the family of type i interferons (ifn), which consists of several ifn-α and one ifn-β, are produced not only after stimulation by viruses, but also after infection with non-viral pathogens. in the course of bacterial infections, these cytokines could be beneficial or detrimental. ifn-β is the primary member of type i ifn that initiates a cascade of ifn-α production. here we addressed the question which cells are responsible for ifn-β expression after infection with the intracellular pathogen lis ... | 2011 | 21494554 |
| antibacterial activity of egg yolk antibody (igy) against listeria monocytogenes and preliminary evaluation of its potential for food preservation. | background: egg yolk antibody (igy) is a unique type of immunoglobulin found in egg yolks, and many reports have described its ability to inhibit corresponding antigen bacteria. the objective of this study was to evaluate the antibacterial activity of igy specific to listeria monocytogenes, an important food pathogen to both humans and animals, as well as its potential use for food preservation. results: specific igy was generated by immunising leghorn chickens with whole cells of l. monocytogen ... | 2011 | 21495036 |
| the contribution of transcriptomic and proteomic analysis in elucidating stress adaptation responses of listeria monocytogenes. | abstract the foodborne transmission of listeria monocytogenes requires physiological adaptation to various conditions, including the cold, osmotic, heat, acid, alkaline, and oxidative stresses, associated with food hygiene, processing, and preservation measures. we review the current knowledge on the molecular stress adaptation responses in l. monocytogenes cells as revealed through transcriptome, proteome, genetic, and physiological analysis. the adaptation of l. monocytogenes to stress exposur ... | 2011 | 21495855 |
| interaction of acylated and substituted antimicrobial peptide analogs with phospholipid-polydiacetylene vesicles. correlation with their biological properties. | a series of peptide analogs based on region 6-22 of plantaricin 149 sequence were synthesized. the interaction between these analogs and phospholipid-polydiacetylene vesicles was investigated to evaluate the ability of the bioassay to detect differences in the interaction of the peptides with dipalmitoylphosphatidylglycerol and dipalmitoylphosphatidylcholine vesicles, associated with amino acid substitution and n-terminal conjugation of the sequences with short fatty acids (8 and 12 carbon atoms ... | 2011 | 21496212 |
| mouse ly49g2+ nk cells dominate early responses during both immune reconstitution and activation independent of mhc. | natural killer (nk) cell subsets can be defined by the differential expression of inhibitory receptors for major histocompatibility complex (mhc) class i molecules. early after congenic hematopoietic stem cell transplantation (hsct), we found that ly49g2(high) single-positive nk cells repopulated, displayed an activated phenotype and were highly cytolytic. over time, this subset was replaced with nk cells with a normal pattern of ly49 expression. treatment of mice with il-2 also resulted in the ... | 2011 | 21498673 |
| fibrocyte-like cells recruited to the spleen support innate and adaptive immune responses to acute injury or infection. | bone marrow (bm)-derived fibrocytes are a population of cd45(+) and collagen type i-expressing cells that migrate to the spleen and to target injured organs, such as skin, lungs, kidneys, and liver. while cd45(+)col(+) fibrocytes contribute to collagen deposition at the site of injury, the role of cd45(+)col(+) cells in spleen has not been elucidated. here, we demonstrate that hepatotoxic injury (ccl(4)), tgf-β1, lipopolysaccharide, or infection with listeria monocytogenes induce rapid recruitme ... | 2011 | 21499735 |
| indoleamine 2,3-dioxygenase-expressing myeloid dendritic cells and macrophages in infectious and noninfectious cutaneous granulomas. | background: the enzyme indoleamine 2,3-dioxygenase (ido) degrades the essential amino acid tryptophan, and this degradation is an immunosuppressive mechanism that is mainly used by antigen-presenting cells. ido-expressing dendritic cells and macrophages have previously been identified as components of lymph node granulomas after listeria monocytogenes infection. in this study we undertook an analysis of ido expression in granulomas of infectious and noninfectious origin in the human skin. method ... | 2011 | 21501890 |
| selective, α2β1 integrin-dependent secretion of il-6 by connective tissue mast cells. | mast cells, critical mediators of inflammation and anaphylaxis, are poised as one of the first lines of defense against external assault. mast cells release several classes of preformed and de novo synthesized mediators. cross-linking of the high-affinity fcεri results in degranulation and the release of preformed, proinflammatory mediators including histamine and serotonin. we previously demonstrated that mast cell activation by listeria monocytogenes requires the α2β1 integrin for rapid il-6 s ... | 2011 | 21502744 |
| antimicrobial susceptibilities of listeria monocytogenes human strains isolated from 1970 to 2008 in brazil. | listeria monocytogenes is the causative agent of listeriosis, a foodborne illness that affects mainly pregnant women, the elderly and immunocompromised patients. the primary treatment is a combination of ampicillin with an aminoglycoside, in addition to a second-choice drug represented by chloramphenicol, erythromycin, tetracycline and rifampicin. the aim of this study was to analyze the antimicrobial susceptibility profile of strains isolated from human sources in the last four decades. | 2011 | 21503548 |
| a role for septins in the interaction between the listeria monocytogenes invasion protein inlb and the met receptor. | septins are conserved gtpases that form filaments and are required for cell division. during interphase, septin filaments associate with cellular membrane and cytoskeleton networks, yet the functional significance of these associations have, to our knowledge, remained unknown. we recently discovered that different septins, sept2 and sept11, regulate the inlb-mediated entry of listeria monocytogenes into host cells. here we address the role of sept2 and sept11 in the inlb-met interactions underly ... | 2011 | 21504731 |
| disulfide reduction in the endocytic pathway: immunological functions of gamma-interferon-inducible lysosomal thiol reductase. | abstract gamma-interferon-inducible lysosomal thiol reductase (gilt) is constitutively expressed in most antigen presenting cells and is interferon γ inducible in other cell types via signal transducer and activator of transcription 1. normally, n- and c-terminal propeptides are cleaved in the early endosome, and the mature protein resides in late endosomes and lysosomes. correspondingly, gilt has maximal reductase activity at an acidic ph. monocyte differentiation via toll-like receptor 4 trigg ... | 2011 | 21506690 |
| risk evaluation and management to reaching a suggested fso in a steam meal. | steam meals are ready-to-eat meals composed of raw and semi-cooked ingredients, which get cooked while microwave heating. in this study, an indian style meal was selected, chicken tandoori, from two different producers. these meals were first evaluated with the risk ranger® to identify the main foodborne pathogens risks, which were listeria monocytogenes, salmonella typhimurium and bacillus cereus. thereafter, quantitative microbiology was applied using different models and verified with growth ... | 2011 | 21511122 |
| modeling microbial competition in food: application to the behavior of listeria monocytogenes and lactic acid flora in pork meat products. | competition between background microflora and microbial pathogens raises questions about the application of predictive microbiology in situ, i.e., in non-sterile naturally contaminated foods. in this article, we present a review of the models developed in predictive microbiology to describe interactions between microflora in foods, with a special focus on two approaches: one based on the jameson effect (simultaneous deceleration of all microbial populations) and one based on the lotka-volterra c ... | 2011 | 21511123 |
| individual cell lag time distributions of cronobacter (enterobacter sakazakii) and impact of pooling samples on its detection in powdered infant formula. | cells of six strains of cronobacter were subjected to dry stress and stored for 2.5 months at ambient temperature. the individual cell lag time distributions of recovered cells were characterized at 25 °c and 37 °c in non-selective broth. the individual cell lag times were deduced from the times taken by cultures from individual cells to reach an optical density threshold. in parallel, growth curves for each strain at high contamination levels were determined in the same growth conditions. in ge ... | 2011 | 21511124 |
| hierarchical bayesian analysis of censored microbiological contamination data for use in risk assessment and mitigation. | microbiological contamination data often is censored because of the presence of non-detects or because measurement outcomes are known only to be smaller than, greater than, or between certain boundary values imposed by the laboratory procedures. therefore, it is not straightforward to fit distributions that summarize contamination data for use in quantitative microbiological risk assessment, especially when variability and uncertainty are to be characterized separately. in this paper, distributi ... | 2011 | 21511131 |
| predictive microbiology models vs. modeling microbial growth within listeria monocytogenes risk assessment: what parameters matter and why. | predictive microbiology models are essential tools to model bacterial growth in quantitative microbial risk assessments. various predictive microbiology models and sets of parameters are available: it is of interest to understand the consequences of the choice of the growth model on the risk assessment outputs. thus, an exercise was conducted to explore the impact of the use of several published models to predict listeria monocytogenes growth during food storage in a product that permits growth. ... | 2011 | 21511132 |
| design of challenge testing experiments to assess the variability of listeria monocytogenes growth in foods. | the assessment of the evolution of micro-organisms naturally contaminating food must take into account the variability of biological factors, food characteristics and storage conditions. a research project involving eight french laboratories was conducted to quantify the variability of growth parameters of listeria monocytogenes obtained by challenge testing in five food products. the residual variability corresponded to a coefficient of variation (cv) of approximately 20% for the growth rate (μ ... | 2011 | 21511135 |
| use of global sensitivity analysis in quantitative microbial risk assessment: application to the evaluation of a biological time temperature integrator as a quality and safety indicator for cold smoked salmon. | the aim of this study was to apply a global sensitivity analysis (sa) method in model simplification and to evaluate (eo)®, a biological time temperature integrator (tti) as a quality and safety indicator for cold smoked salmon (css). models were thus developed to predict the evolutions of listeria monocytogenes and the indigenous food flora in css and to predict ttis endpoint. a global sa was then applied on the three models to identify the less important factors and simplify the models accordi ... | 2011 | 21511136 |
| a new mechanistic growth model for simultaneous determination of lag phase duration and exponential growth rate and a new bĕlehdrádek-type model for evaluating the effect of temperature on growth rate. | a new mechanistic growth model was developed to describe microbial growth under isothermal conditions. the new mathematical model was derived from the basic observation of bacterial growth that may include lag, exponential, and stationary phases. with this model, the lag phase duration and exponential growth rate of a growth curve were simultaneously determined by nonlinear regression. the new model was validated using listeria monocytogenes and escherichia coli o157:h7 in broth or meat. statist ... | 2011 | 21511137 |
| model for listeria monocytogenes inactivation on dry-cured ham by high hydrostatic pressure processing. | the aim of the work was to develop and validate a model of the inactivation of listeria monocytogenes on dry-cured ham by high hydrostatic pressure (hhp) processing, as a function of the technological parameters: intensity, length and fluid temperature. dry-cured ham inoculated with l. monocytogenes was treated at different hhp conditions (at 347-852 mpa; for 2.3 to 15.75 min; at 7.6 to 24.4 °c) following a central composite design. bacterial inactivation was assessed in terms of logarithmic red ... | 2011 | 21511142 |
| listeriosis in human pregnancy: a systematic review. | abstract listeria is commonly found in processed and prepared foods and listeriosis is associated with high morbidity and mortality. preventative measures are well prescribed and monitoring and voluntary recall of contaminated products has resulted in a 44% reduction in the prevalence of perinatal listeriosis in the usa. pregnant women are at high risk for listeriosis, but symptoms are non-specific and diagnosis is difficult. the intracellular life-cycle of listeria protects the bacterium from h ... | 2011 | 21517700 |
| quantification of cell infection caused by listeria monocytogenes invasion. | listeria monocytogenes causes a life-threatening food-borne disease known as listeriosis. elderly, immunocompromised, and pregnant women are primarily the victims of this facultative intracellular gram-positive pathogen. since the bacteria survive intracellularly within the human host cells they are protected against the immune system and poorly accessed by many antibiotics. in order to screen pharmaceutical substances for their ability to interfere with the infection, persistence and release of ... | 2011 | 21527293 |
| fly immunity: recognition of pathogens and induction of immune responses. | despite the lack of adaptive immunity based on gene rearrangement such as that in higher vertebrates, flies are able to defend themselves from a wide array of pathogens using multiple innate immune responses whose molecular mechanisms are strikingly similar to those of the innate immune responses of other multicellular organisms, including humans. invading pathogens passing through the epithelial barriers, the first line of self-defense, are detected by pattern recognition receptors that identif ... | 2010 | 21528700 |
| prevalence of listeria monocytogenes in raw meats marketed in bangkok and characterization of the isolates by phenotypic and molecular methods. | listeria monocytogenes causes listeriosis characterized by septicaemia, encephalitis, and abortion or stillbirth. regular monitoring of its prevalence in food and characterization of its phenotypes and genotypes are necessary for disease surveillance and tracing the epidemic outbreaks. in this study, the prevalence of l. monocytogenes in raw meats marketed in bangkok was 15.4%. the bacteria isolated from meat were serotyped and genotyped using enterobacterial repetitive intergenic consensus-poly ... | 2011 | 21528788 |
| towards a synthetic chloroplast. | the evolution of eukaryotic cells is widely agreed to have proceeded through a series of endosymbiotic events between larger cells and proteobacteria or cyanobacteria, leading to the formation of mitochondria or chloroplasts, respectively. engineered endosymbiotic relationships between different species of cells are a valuable tool for synthetic biology, where engineered pathways based on two species could take advantage of the unique abilities of each mutualistic partner. | 2011 | 21533097 |
| a small rna controls expression of the chitinase chia in listeria monocytogenes. | in recent years, more than 60 small rnas (srnas) have been identified in the gram-positive human pathogen listeria monocytogenes, but their putative roles and mechanisms of action remain largely unknown. the srna lhra was recently shown to be a post-transcriptional regulator of a single gene, lmo0850, which encodes a small protein of unknown function. lhra controls the translation and degradation of the lmo0850 mrna by an antisense mechanism, and it depends on the rna chaperone hfq for efficient ... | 2011 | 21533114 |
| impaired cellular responses to cytosolic dna or infection with listeria monocytogenes and vaccinia virus in the absence of the murine lgp2 protein. | innate immune signaling is crucial for detection of and the initial response to microbial pathogens. evidence is provided indicating that lgp2, a dexh box domain protein related to the rna recognition receptors rig-i and mda5, participates in the cellular response to cytosolic double-stranded dna (dsdna). analysis of embryonic fibroblasts and macrophages from mice harboring targeted disruption in the lgp2 gene reveals that lgp2 can act as a positive regulator of type i ifn and anti-microbial gen ... | 2011 | 21533147 |
| expression and activity of a novel cathelicidin from domestic cats. | cathelicidins are small cationic antimicrobial peptides found in many species including primates, mammals, marsupials, birds and even more primitive vertebrates, such as the hagfish. some animals encode multiple cathelicidins in their genome, whereas others have only one. this report identifies and characterizes feline cathelicidin (fecath) as the sole cathelicidin in domestic cats (felis catus). expression of fecath is predominantly found in the bone marrow, with lower levels of expression in t ... | 2011 | 21533281 |
| synthesis, antimicrobial activity and cytotoxicity of novel oxadiazole derivatives. | in the present study, 5-substituted-1,3,4-oxadiazolin-2-thiones (1a-b) were synthesized via the ring closure reactions of appropriate acid hydrazides with carbon disulphide. n-(benzothiazol-2-yl)-2-[[5-substituted-1,3,4-oxadiazol-2-yl]sulfanyl]acetamide derivatives (3a-j) were obtained by the nucleophilic substitution reactions of 5-substituted-1,3,4-oxadiazolin-2-thiones (1a-b) with n-(benzothiazol-2-yl)-2-chloroacetamides. the chemical structures of the compounds were elucidated by ir, (1)h nm ... | 2011 | 21534862 |
| human heat-shock protein 60 receptor-coated paramagnetic beads show improved capture of listeria monocytogenes in the presence of other listeria in food. | aims: to investigate the suitability of human hsp60, a receptor for listeria adhesion protein (lap), on paramagnetic beads (pmb) to capture listeria monocytogenes from food in the presence of other listeria to facilitate rapid and specific detection of this pathogen. methods and results: commercially available streptavidin-coated pmbs were linked with biotinylated hsp60 (pmb-hsp60), and the bacterial capture efficiency from pure culture and meat samples was determined. capture rate was also co ... | 2011 | 21535331 |
| evaluation of antibacterial activity of 3-butenyl, 4-pentenyl, 2-phenylethyl, and benzyl isothiocyanate in brassica vegetables. | this study investigated antibacterial activities of 4 isothiocyanates (3-butenyl, 4-phentenyl, 2-phenylethyl, and benzyl isothiocyanate) against 4 gram-positive bacteria (bacillus cereus, bacillus subtilis, listeria monocytogenes, and staphylococcus aureus) and 7 gram-negative bacteria (aeromonas hydrophila, pseudomonas aeruginosa, salmonella choleaesuis, salmonella enterica, serratia marcescens, shigella sonnei, and vibrio parahaemolyticus) by an agar disc diffusion assay. benzyl isothiocyanate ... | 2010 | 21535549 |
| synergic antimicrobial activity of lysozyme, nisin, and edta against listeria monocytogenes in ostrich meat patties. | synergic antimicrobial activity of lysozyme (250 ppm), nisin (250 ppm), and disodium ethylenediamine tetraacetic acid (edta) (20 mm) against listeria monocytogenes and meat-borne spoilage bacteria in ostrich patties packaged in air and vacuum was studied. the antimicrobial treatment decreased the l. monocytogenes population in ostrich patties below the official limit of the european union (<2 log cfu/g). the total viable counts for the treated samples (air and vacuum) showed a reduction of 1 log ... | 2010 | 21535551 |
| antilisterial activity and consumer acceptance of irradiated chicken breast meat vacuum-infused with grape seed and green tea extracts and tartaric acid. | contamination of poultry with pathogenic bacteria contributes to human foodborne disease, causes damage to industry brand names, and has a significant economic impact on the food industry in the form of both damage to industry brand names and losses associated with recalls. irradiation is a safe and effective means of decontaminating poultry products, but the maximum dose strengths allowed negatively impact poultry sensory quality characteristics. the 1st objective of this study was to investiga ... | 2010 | 21535556 |
| inhibition of listeria monocytogenes by food antimicrobials applied singly and in combination. | combining food antimicrobials can enhance inhibition of listeria monocytogenes in ready-to-eat (rte) meats. a broth dilution assay was used to compare the inhibition of l. monocytogenes resulting from exposure to nisin, acidic calcium sulfate, ɛ-poly-l-lysine, and lauric arginate ester applied singly and in combination. minimum inhibitory concentrations (mics) were the lowest concentrations of single antimicrobials producing inhibition following 24 h incubation at 35 °c. minimum bactericidal con ... | 2010 | 21535610 |
| effect of nacl on the biofilm formation by foodborne pathogens. | this study was designed to evaluate the effect of nacl on the biofilm formation of listeria monocytogenes, staphylococcus aureus, shigella boydii, and salmonella typhimurium. the biofilm cells were cultured in media containing different nacl concentrations (0% to 10%) for 10 d of incubation at 37 °c using a 24-well polystyrene microtiter plate, collected by swabbing methods, and enumerated using plate count method. the attachment and detachment kinetic patterns were estimated according to the mo ... | 2010 | 21535614 |
| characterization and antimicrobial activity of sweetpotato starch-based edible film containing origanum (thymus capitatus) oil. | the objectives of this research were to characterize the mechanical and barrier properties of sweetpotato starch (sps)-based film (spsf) and to investigate the antimicrobial activity of spsf containing origanum oil (og) against foodborne pathogenic bacteria. the spsf was fabricated with the sps extracted from commercial sweetpotato roots. tensile strength (ts), percent elongation at break (e), and water vapor permeability (wvp) were determined to characterize the spsf fabricated with selected sp ... | 2011 | 21535647 |
| control of listeria monocytogenes on cold-smoked salmon using chitosan-based antimicrobial coatings and films. | the relatively high incidence of listeria monocytogenes in ready-to-eat (rte) products such as cold-smoked salmon is of serious concern. the objective of this study was to evaluate the efficacy of chitosan-based edible coatings and films incorporating 3 generally recognized as safe (gras) antimicrobials, sodium lactate (sl), sodium diacetate (sd), and potassium sorbate (ps), against l. monocytogenes on cold-smoked salmon. salmon samples were surface-inoculated with a 5-strain cocktail of listeri ... | 2011 | 21535689 |
| antimicrobial activity of plant extracts against salmonella typhimurium, escherichia coli o157:h7, and listeria monocytogenes on fresh lettuce. | plant extracts have been found to be effective in reducing microorganisms. this study evaluated antimicrobial activity of 12 plant extracts against salmonella typhimurium, escherichia coli o157:h7, and listeria monocytogenes by using a disk diffusion assay, and syzygium aromaticum (clove) showed the highest inhibitory effect. to investigate the efficacy of clove extract that inactivates pathogens on lettuce, inoculated lettuce with s. typhimurium, e. coli o157:h7, and l. monocytogenes was treate ... | 2011 | 21535692 |
| inappropriate use of d-values for determining biocidal activity of various antimicrobials. | the objective of this study was to investigate the application of established d-value calculations to survival curves for various bacteria using the following antimicrobials: acidified sodium chlorite, triclosan, octanoic acid, and sodium hydroxide. d-values can be calculated in 3 ways, a linear regression, an endpoint calculation, or an average of multiple endpoint calculations. the assumption made in calculating a d-value is that the rate of kill follows 1st-order kinetics under specified trea ... | 2011 | 21535698 |
| antibacterial activities of blueberry and muscadine phenolic extracts. | phenolics are one category of phyto-antimicrobials that refer to the antimicrobial substances extracted from plant sources. this study was undertaken to determine the influence of blueberry and muscadine phenolic extracts on the growths of 2 important foodborne bacterial pathogens, salmonella enteritidis and listeria monocytogenes. cells of s. enteritidis (n = 4) or l. monocytogenes (n = 4) strains were inoculated (3 log cfu/ml) into tryptic soy broth (tsb) supplemented with 46.25 ppm of muscadi ... | 2011 | 21535771 |
| kinetics and mechanism of bacterial inactivation by ultrasound waves and sonoprotective effect of milk components. | inactivation of escherichia coli and listeria monocytogenes were investigated in buffer and milk upon treatment with ultrasound waves (usw). in addition, sonoprotective effect of milk components and ultrasound-induced changes in bacterial cells were investigated using scanning electron microscopy (sem). bacterial cells were added to phosphate buffer, whole milk, skim milk, or simulated milk ultrafiltrate (smuf). to determine the sonoprotective effect of milk components, lactose (5%), casein (3%) ... | 2011 | 21535773 |
| biofilms of listeria monocytogenes produced at 12 ° c either in pure culture or in co-culture with pseudomonas aeruginosa showed reduced susceptibility to sanitizers. | the biofilm-forming ability of 21 listeria monocytogenes isolates, previously pulsotyped and corresponding to 16 strains, from different origins was evaluated using the calgary biofilm device, at 37 °c. biofilms of 4 selected strains were also produced either on pure cultures or on co-cultures with pseudomonas aeruginosa (pao1), at 12 °c and at 37 °c. for these biofilms, the minimum biofilm eradication concentrations (mbecs) of 4 commercial dairy sanitizers (1 alkyl amine acetate based-t99, 2 ch ... | 2011 | 21535778 |
| physical and antibacterial properties of edible films formulated with apple skin polyphenols. | fruit and vegetable skins have polyphenolic compounds, terpenes, and phenols with antimicrobial and antioxidant activity. these flavoring plant essential oil components are generally regarded as safe. edible films made from fruits or vegetables containing apple skin polyphenols have the potential to be used commercially to protect food against contamination by pathogenic bacteria. the main objective of this study was to evaluate physical properties as well as antimicrobial activities against lis ... | 2011 | 21535779 |
| preparation and characterization of agar/clay nanocomposite films: the effect of clay type. | agar-based nanocomposite films with different types of nanoclays, such as cloisite na(+), cloisite 30b, and cloisite 20a, were prepared using a solvent casting method, and their tensile, water vapor barrier, and antimicrobial properties were tested. tensile strength (ts), elongation at break (e), and water vapor permeability (wvp) of control agar film were 29.7 ± 1.7 mpa, 45.3 ± 9.6%, and (2.22 ± 0.19) × 10(-9) g·m/m(2)·s·pa, respectively. all the film properties tested, including transmittance, ... | 2011 | 21535851 |
| tnf-a production and apoptosis in hepatocytes after listeria monocytogenes and salmonella typhimurium invasion. | invasion of hepatocytes by listeria monocytogenes (lm) and salmonella typhimurium (st) can stimulate tumor necrosis factor alpha (tnf-α) release and induce apoptosis. in this study, we compared the behavior of hepatocytes invaded by three l. monocytogenes serotypes (lm-4a, lm-4b and lm-1/2a) and by st to understand which bacterium is more effective in the infectious process. we quantified tnf-α release by elisa, apoptosis rates by annexin v (early apoptosis) and tunel (late apoptosis) techniques ... | 2011 | 21537759 |
| generation of a listeria vaccine strain by enhanced caspase-1 activation. | the immunostimulatory properties conferred by vaccine adjuvants require caspase-1 for processing of il-1â and il-18. caspase-1 is activated in response to a breach of the cytosolic compartment by microbes and the process is initiated by intracellular pattern recognition receptors within inflammasomes. listeria monocytogenes is detected in the cytosol by the nlrc4, nlrp3 and aim2 inflammasomes. nlrc4 is activated by flagellin, and l. monocytogenes evades nlrc4 by repressing flagellin expression. ... | 2011 | 21538346 |
| toxicological evaluation of lung responses after intratracheal exposure to non-dispersed titanium dioxide nanorods. | fine- and coarse-sized titanium dioxide (tio(2)) particles are considered to be relatively inert when inhaled. the goal of this study was to assess potential lung toxicity associated with well-characterized, non-dispersed rutile tio(2) nanorods (10 × 40 nm). in vitro bioreactivity of tio(2) nanorods was determined by electron spin resonance (esr) to measure free radical production. to assess pulmonary effects in vivo, sprague-dawley rats were intratracheally instilled with saline, silica, or tio ... | 2011 | 21541881 |
| early gene response of human brain microvascular endothelial cells to listeria monocytogenes infection. | the gene expression of human brain microvascular endothelial cells (hbmec) in response to 4 h of infection by listeria monocytogenes was analyzed. four hours after infection, the expression of 456 genes of hbmec had changed (p < 0.05). we noted that many active genes were involved in the formyl-methionyl-leucyl-phenylalanine pathway in infected hbmec. in the upregulated genes, mrna levels of interleukin-8 and interleukin-15 in infected cells increased according to microarray and real-time revers ... | 2011 | 21542783 |
| the novel listeria monocytogenes bile sensor brta controls expression of the cholic acid efflux pump mdrt. | mammalian bile has potent anti-microbial activity, yet bacterial pathogens of the gastrointestinal tract and hepatobiliary system nonetheless persist and replicate within bile-rich environments. listeria monocytogenes, a gram-positive pathogen, encounters bile at three stages throughout its infectious cycle in vivo: in the gut during initial infection, in the liver where it replicates robustly and in the gallbladder, from which it can return to the intestine and thence to the environment. the me ... | 2011 | 21542862 |
| effects of probiotic fermentation on the enhancement of biological and pharmacological activities of codonopsis lanceolata extracted by high pressure treatment. | this study was designed to evaluate the enhancement of antioxidant, antimicrobial, enzymatic, cytotoxic, and cognitive activities of codonopsis lanceolata extracted by high pressure treatment followed by probiotic fermentation. dried c. lanceolata samples were subjected to 400mpa for 20min and then fermented with bifidobacterium longum b6 (hpe-blf) and lactobacillus rhamnosus (hpe-lrf) at 37°c for 7days. compared to conventional extraction (ce-nf, 6.69mg gae/g), the phenol amounts of hpe-blf and ... | 2011 | 21543255 |
| functional analysis of the listeria monocytogenes secretion chaperone prsa2 and its multiple contributions to bacterial virulence. | as an organism that has evolved to live in environments ranging from soil to the cytosol of mammalian cells, listeria monocytogenes must regulate the secretion and activity of protein products that promote survival within these habitats. the post-translocation chaperone prsa2 has been adapted to assist in the folding and activity of l. monocytogenes secreted proteins required for bacterial replication within host cells. here we present the first structure/function investigation of the contributi ... | 2011 | 21545417 |
| sortase independent and dependent systems for acquisition of haem and haemoglobin in listeria monocytogenes. | we studied three fur-regulated systems of listeria monocytogenes: the srtb region, that encodes sortase-anchored proteins and a putative abc transporter, and the fhu and hup operons, that produce putative abc transporters for ferric hydroxamates and haemin (hn)/haemoglobin (hb) respectively. deletion of lmo2185 in the srtb region reduced listerial [(59) fe]-hn transport, and purified lmo2185 bound [(59) fe]-hn (k(d) = 12 nm), leading to its designation as a hn/hb binding protein (hbp2). purifie ... | 2011 | 21545655 |
| biofilm formation and adherence characteristics of an elizabethkingia meningoseptica isolate from oreochromis mossambicus. | abstract: background: elizabethkingia spp. are opportunistic pathogens often found associated with intravascular device-related bacteraemias and ventilator-associated pneumonia. their ability to exist as biofilm structures has been alluded to but not extensively investigated. methods: the ability of elizabethkingia meningoseptica isolate ch2b from freshwater tilapia (oreochromis mossambicus) and e. meningoseptica strain nctc 10016t to adhere to abiotic surfaces was investigated using microtiter ... | 2011 | 21545730 |
| occurrence of microorganisms of public health and spoilage significance in fruit juices sold in retail markets in greece. | fruit juices are an important part of the modern diet in many countries. however, few data are available concerning the microbiological quality of the fruit juices sold in greece. using standard microbiological procedures, we conducted a bacteriological survey of commercially sold, pasteurized, shelf-stable fruit juices from retail markets. a total of 120 samples of fruit juices sold in various retail markets were examined for their bacteriological quality. the ph of the tested juices was 2.4-4. ... | 2011 | 21545842 |
| prevalence of salmonella enterica, listeria monocytogenes, and escherichia coli virulence factors in bulk tank milk and in-line filters from u.s. dairies. | the zoonotic bacteria salmonella enterica, listeria monocytogenes, and escherichia coli are known to infect dairy cows while not always causing clinical signs of disease. these pathogens are sometimes found in raw milk, and human disease outbreaks due to these organisms have been associated with the consumption of raw milk or raw milk products. bulk tank milk (btm) samples (536) and in-line milk filters (519) collected from dairy farms across the united states during the national animal health m ... | 2011 | 21549046 |
| prevalence of salmonella spp. and listeria monocytogenes at small-scale spanish factories producing traditional fermented sausages. | the manufacturing of fermented sausages is subject to natural contamination processes that can potentially carry foodborne pathogens along the process chain and result in contamination of the final product. the aim of this study was to evaluate the occurrence of salmonella spp. and listeria monocytogenes at different sampling points during the manufacturing process of fuet, a type of traditional fermented sausage, at 10 small-scale spanish factories. the presence of both pathogens was studied in ... | 2011 | 21549053 |
| incidence of listeria monocytogenes in cheese manufacturing plants from the northeast region of são paulo, brazil. | the incidence of listeria monocytogenes in three cheese manufacturing plants from the northeastern region of são paulo, brazil, was evaluated from october 2008 to september 2009. l. monocytogenes was found in samples from two plants, at percentages of 13.3% (n = 128) and 9.6% (n = 114). samples of raw and pasteurized milk, water, and minas frescal cheese were negative for l. monocytogenes, although the pathogen was isolated from the surface of prato cheese and in brine from one of the plants eva ... | 2011 | 21549054 |
| transcriptional analysis of disk abalone (haliotis discus discus) antioxidant enzymes against marine bacteria and virus challenge. | diverse antioxidant enzymes are essential for marine organisms to overcome oxidative stress as well as for the fine-tuning of immune reactions through activating different signal transduction pathways. this study describes the transcriptional analysis of antioxidant enzymes of disk abalone by challenging with bacteria (vibrio alginolyticus, vibrio parahemolyticus, and listeria monocytogenes) and viral hemorrhagic septicemia virus (vhsv). upon bacteria and vhsv challenge, manganese superoxide dis ... | 2011 | 21549200 |
| do leafy green vegetables and their ready-to-eat [rte] salads carry a risk of foodborne pathogens? | over the past 10 years, there is an increasing demand for leafy green vegetables and their ready-to-eat (rte) salads since people changed their eating habits because of healthier lifestyle interest. nevertheless fresh leafy green vegetables and their rte salads are recognized as a source of food poisoning outbreaks in many parts of the world. however, this increased proportion of outbreaks cannot be completely explained by increased consumption and enhanced surveillance of them. both in europe a ... | 2011 | 21549216 |
| effect of several map compositions on the microbiological and sensory properties of graviera cheese. | the shelf life of graviera cheese, a full fat cheese produced in heraklion (crete greece), was investigated. graviera cheese was stored at 4°c for up to 90 days in polyamide packages under three different modified atmosphere compositions. control cheeses were packaged in air whereas map mixtures were map(1): 40% co(2)/55% n(2)/5% o(2), map(2): 60% co(2)/40% n(2) and map(3): 50% co(2)/50% n(2). sampling of product was carried out every 10 days to investigate its sensory quality and microbiologica ... | 2011 | 21549849 |
| multiple-locus variable number of tandem repeat analysis (mlva) of listeria monocytogenes directly in food samples. | listeria monocytogenes is the etiologic agent of listeriosis responsible for severe and fatal infections in humans. listeria contamination occurs quite often in a wide range of foods due to its ubiquitous nature. isolates need to be characterized to a strain level for accurate diagnosis of listeria infection, epidemiological studies, investigation of outbreaks and effective prevention and control of food-borne listeriosis. the purpose of this research was to evaluate the multiple-locus variable ... | 2011 | 21550679 |
| a family of ifn-gamma-inducible 65-kd gtpases protects against bacterial infection. | immune interferon gamma (ifn-γ) is essential for mammalian host defense against intracellular pathogens. ifn-γ induces nearly 2000 host genes, yet few have any assigned function. here, we examined a complete mouse 65-kilodalton (kd) guanylate-binding protein (gbp) gene family as part of a 43-member ifn-γ-inducible guanosine triphosphatase (gtpase) superfamily in mouse and human genomes. family-wide loss-of-function analysis found that at least four gbps--gbp1, gbp6, gbp7, and gbp10--conferred ce ... | 2011 | 21551061 |
| genome sequences of listeria monocytogenes strains j1816 and j1-220 associated with human outbreaks. | listeria monocytogenes has caused numerous human outbreaks. here we report draft genomes of l. monocytogenes j1816 and j1-220, which belongs to the epidemic clone ii and epidemic clone iv, respectively. whole genome sequence analysis of these strains provides a tool for studying the short-term evolution of these epidemic clones. | 2011 | 21551300 |
| infrared and raman spectroscopic studies of the antimicrobial effects of garlic concentrates and diallyl constituents on foodborne pathogens. | the antimicrobial effects of garlic (allium sativum) extract (25, 50, 75, 100, and 200 μl/ml) and diallyl sulfide (5, 10, and 20 μm) on listeria monocytogenes and escherichia coli o157:h7 cultivated in tryptic soy broth at 4, 22, and 35 °c for up to 7 days were investigated. l. monocytogenes was more resistant to garlic extract and diallyl compounds treatment than e. coli o157:h7. fourier transform infrared (ft-ir) spectroscopy indicated that diallyl constituents contributed more to the antimicr ... | 2011 | 21553849 |
| antibacterial peptides derived from caprine whey proteins, by digestion with human gastrointestinal juice. | peptides in caprine whey were identified after in vitro digestion with human gastrointestinal enzymes in order to determine their antibacterial effect. the digestion was performed in two continuing steps using human gastric juice (ph 2·5) and human duodenal juice (ph 8) at 37°c. after digestion the hydrolysate was fractionated and 106 peptides were identified. from these results, twenty-two peptides, located in the protein molecules, were synthesised and antibacterial activity examined. strong a ... | 2011 | 21554806 |
| interplay between cd8α dendritic cells and monocytes in response to listeria monocytogenes infection attenuates t cell responses. | during the course of a microbial infection, different antigen presenting cells (apcs) are exposed and contribute to the ensuing immune response. cd8α(+) dendritic cells (dcs) are an important coordinator of early immune responses to the intracellular bacteria listeria monocytogenes (lm) and are crucial for cd8(+) t cell immunity. in this study, we examine the contribution of different primary apcs to inducing immune responses against lm. we find that cd8α(+) dcs are the most susceptible to infec ... | 2011 | 21559416 |