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characteristics of microbial biofilm on wooden vats ('gerles') in pdo salers cheese.the purpose of this study was to characterize microbial biofilms from 'gerles' (wooden vats for making pdo salers cheese) and identify their role in milk inoculation and in preventing pathogen development. gerles from ten farms producing pdo salers cheese were subjected to microbial analysis during at least 4 periods spread over two years. they were distinguished by their levels of lactobacillus (between 4.50 and 6.01 log cfu/cm(2)), gram negative bacteria (between 1.45 and 4.56 log cfu/cm(2)), ...201222483401
differential expression of virulence and stress fitness genes during interaction between listeria monocytogenes and bifidobacterium longum.bifidobacterium is well known to have an inhibitory effect on the survival, growth, and proliferation of various foodborne pathogens, but the mechanism of the molecular action of b. longum in blocking the invasion of listeria monocytogenes is not yet well defined. in the present study, following rna extraction and cdna synthesis, differential expression of virulence and stress fitness genes in l. monocytogenes and b. longum was determined by real-time pcr. the results indicate that l. monocytoge ...201222484935
insight into the prevalence and distribution of microbial contamination to evaluate water management in the fresh produce processing industry.this study provided insight into the degree of microbial contamination in the processing chain of prepacked (bagged) lettuce in two belgian fresh-cut produce processing companies. the pathogens salmonella and listeria monocytogenes were not detected. total psychrotrophic aerobic bacterial counts (tpacs) in water samples, fresh produce, and environmental samples suggested that the tpac is not a good indicator of overall quality and best manufacturing practices during production and processing. be ...201222488054
heat shock and cold shock treatments affect the survival of listeria monocytogenes and salmonella typhimurium exposed to disinfectants.the foodborne pathogens listeria monocytogenes and salmonella typhimurium were subjected to heat shock at 48°c for 10 and 30 min, respectively, and then cold shocked at 15°c for 3 h. the effect of these shocks on the viability of test organisms exposed to chlorine dioxide and quaternary ammonium compounds was then determined. after exposure to the disinfectants, the viable population of each test organism, regardless of heat shock or cold shock treatment, decreased as the exposure period was ext ...201222488057
microbiological performance of a food safety management system in a food service operation.the microbiological performance of a food safety management system in a food service operation was measured using a microbiological assessment scheme as a vertical sampling plan throughout the production process, from raw materials to final product. the assessment scheme can give insight into the microbiological contamination and the variability of a production process and pinpoint bottlenecks in the food safety management system. three production processes were evaluated: a high-risk sandwich p ...201222488059
effect of anolyte on background microflora, salmonella, and listeria monocytogenes on catfish fillets.near-neutral electrolyzed water (anolyte), having a ph of 6.0 to 6.5 ± 0.02, oxidation reduction potential of greater than 700 mv, and a residual chlorine level of 10 to 200 ppm, was reported to have a potential use to decontaminate food surfaces. an electrolyzing cell was developed that is capable of producing neutral electrolyzed water containing a chlorine level of greater than 700 ppm in the form of hypochlorous acid (anolyte). anolyte with a chlorine level of 300 ppm was used to determine i ...201222488069
biologic therapy and risk of infection.biologic compounds are being used more frequently to treat a multitude of systemic inflammatory conditions. these novel compounds are composed of antibodies or other peptides that act through one of three mechanisms: inhibiting inflammatory cytokine signaling (typically tumor necrosis factor or tnf), inhibiting t-cell activation, or depleting b-cells. the increase in use and ever expanding list of new immune modulating therapies make knowledge of the infectious complications associated with immu ...201222491803
hmgr, a key enzyme in the mevalonate pathway for isoprenoid biosynthesis, is essential for growth of listeria monocytogenes egde.isoprenoids may be synthesized via one of two pathways, the classical mevalonate pathway or the alternative 2-c-methyl-d-erythritol 4-phosphate (mep) pathway. while the majority of bacteria utilize a single pathway for isoprenoid biosynthesis, listeria monocytogenes is unusual in possessing the complete set of genes for both pathways. here, we utilized new molecular tools to create precise gene deletions in selected genes encoding enzymes of both pathways, gcpe, lytb (encoding proteins in the me ...201222504435
bactericidal antibiotics do not appear to cause oxidative stress in listeria monocytogenes.oxidative stress can be an important contributor to the lethal effect of bactericidal antibiotics in some bacteria, such as escherichia coli and staphylococcus aureus. thus, despite the different target-specific actions of bactericidal antibiotics, they have a common mechanism leading to bacterial self-destruction by internal production of hydroxyl radicals. the purpose of the present study was to determine if a similar mechanism is involved in antibiotic killing of the infectious human pathogen ...201222504823
structural analysis of a 3-deoxy-d-arabino-heptulosonate 7-phosphate synthase with an n-terminal chorismate mutase-like regulatory domain.3-deoxy-d-arabino-heptulosonate 7-phosphate synthase (dahps) catalyzes the first step in the biosynthesis of a number of aromatic metabolites. likely because this reaction is situated at a pivotal biosynthetic gateway, several dahps classes distinguished by distinct mechanisms of allosteric regulation have independently evolved. one class of dahpss contains a regulatory domain with sequence homology to chorismate mutase-an enzyme further downstream of dahps that catalyzes the first committed ste ...201222505283
purification, crystallization and preliminary crystallographic studies of a pacl homologue from listeria monocytogenes.ca(2+)-atpases are members of a large family of membrane proteins that maintain the selective movement of cations across biological membranes. a putative listeria monocytogenes ca(2+)-atpase (lmo0818) was crystallized in an unknown functional state. the crystal belonged to space group p2(1)2(1)2(1) and a complete data set was collected to 3.2 å resolution. the molecular-replacement solution obtained revealed that lmo0818 is likely to adopt an e2-like state mimicking the phosphorylated intermedia ...201222505411
purine biosynthesis mutants (pura and purb) of serotype 4b listeria monocytogenes are severely attenuated for systemic infection in intragastrically inoculated a/j mice.in this study, we demonstrate that pura and purb transposon mutants of serotype 4b listeria monocytogenes were severely impaired in their ability to colonize the gastrointestinal tract and cause systemic infection of the spleen, liver, and gallbladder following intragastric inoculation of a/j mice. the mutant strains were also impaired in their ability to multiply within caco-2 human intestinal epithelial cells. neither mutant was affected in resistance to synthetic gastric fluid (ph 4.5). these ...201222506772
estimating the diagnostic accuracy of three culture-dependent methods for the listeria monocytogenes detection from a bayesian perspective.the objective of this study was to estimate the test accuracy measures (classification probabilities [cps], predictive values [pvs], likelihood ratios [lrs] and area under receiving operating characteristic curve [auc]) of three different culture-dependent methods, commonly used during routine analysis for the detection of the foodborne pathogen listeria monocytogenes, from a bayesian perspective. data from a previous study by andritsos et al. (2010) were used to define measures of accuracy for ...201222507629
the cultivation of the mushroom agaricus bisporus (champignon): micro-organisms and preservability.cultivation of agaricus bisporus mushrooms requires the use of substrates that are potentially dangerous from the microbiological point of view, such as chicken and horse manure. microorganisms can pose risks to consumers and workers, and generate lower profits. packaging of fresh mushrooms with impermeable films is used to extend their shelf life but creates anaerobic and humidity conditions that could favour the growth of microorganisms such as listeria monocytogenes and clostridium botulinum. ...201122508614
listeria monocytogenes strain-specific impairment of the tetr regulator underlies the drastic increase in cyclic di-amp secretion and beta interferon-inducing ability.among a number of laboratory strains of listeria monocytogenes used in experimental infection, strain lo28 is highly capable of inducing robust beta interferon (ifn-β) production in infected macrophages. in this study, we investigated the molecular mechanism of the ifn-β-inducing ability of lo28 by comparing it with that of strain egd, a low-ifn-β-inducing strain. it was found that lo28 secretes a large amount of ifn-β-inducing factor, which turned out to be cyclic di-amp. the secretion of cycli ...201222508860
[microbiological characterisation of listeria monocytogenes isolates from human cases in andalusia].the aim of this study was to perform a retrospective study by genotyping 154 isolates from human listeriosis cases occurred in the region of andalusia (southern spain) in the period 2005-2009.201222513092
re-evaluation of the significance of penicillin binding protein 3 in the susceptibility of listeria monocytogenes to β-lactam antibiotics.penicillin binding protein 3 (pbp3) of l. monocytogenes has long been thought of as the primary lethal target for β-lactam antibiotics due to the excellent correlation between the mics of different β-lactams and their affinity for this protein. the gene encoding pbp3 has not yet been directly identified in this gram-positive bacterium, but based on in silico analysis, this protein is likely to be encoded by lmo1438. however, studies examining the effects of mutations in genes encoding known and ...201222513233
bacterial peritonitis caused by listeria monocytogenes: case report and review of the literature.although listeria monocytogenes has been isolated from the gastrointestinal tract, it is an infrequent cause of bacterial peritonitis. since 1963 only 23 cases of peritonitis caused by listeria have been reported. this report describes another case in a patient with cirrhosis and chronic renal failure and presents a review of the literature. most (16) of the previous cases were cirrhotic while six were undergoing chronic ambulatory peritoneal dialysis. eight patients were on immunosuppressive th ...199622514418
[not available].to review the epidemiology, risk factors, clinical features and outcomes of listeria monocytogenes infection in the eastern townships of quebec, a retrospective study was completed over the period 1976 to 1995. cases were identified from positive cultures and diagnosis given by the infectious diseases service of the centre hospitalier universitaire de sherbrooke, sherbrooke, quebec. a total of 12 cases were in the study. septicemia not related to pregnancy (four of 12) and meningitis (six of 12) ...199722514474
rhomboencephalitis caused by listeria monocytogenes.listerial rhomboencephalitis is a rare, devastating treatable disease. a previously well 72-year-old man presented with a one-week history of fever and headache. four days before admission he developed right facial numbness and ataxia. diagnosis and treatment are described, including the relevant clinical, laboratory and radiological findings.199722514485
development of sandwich enzyme-linked immunosorbent assay for the detection of cronobacter muytjensii (formerly called enterobacter sakazakii).this study aimed to produce a polyclonal antibody against cronobacter muytjensii (c. muytjensii, formerly called enterobacter sakazakii) and to develop an immunoassay for its detection. the optimum production of rabbit anti-c. muytjensii immunoglobulin g (igg) and chicken anti-c. muytjensii igy was reached in weeks 8 and 9, respectively. purification of rabbit anti-c. muytjensii igg from immunized rabbit sera was accomplished using the caprylic acid and ammonium sulfate precipitation method. as ...201222519814
listeria fleischmannii sp. nov., isolated from cheese.a study was performed on three isolates (lu2006-1(t), lu2006-2 and lu2006-3), which were sampled independently from cheese in western switzerland in 2006, as well as a fourth isolate (a11-3426), which was detected in 2011, using a polyphasic approach. the isolates could all be assigned to the genus listeria but not to any known species. phenotypic and chemotaxonomic data were compatible with the genus listeria and phylogenetic analysis based on 16s rrna gene sequences confirmed that the closest ...201322523164
variability of rna quality extracted from biofilms of foodborne pathogens using different kits impacts mrna quantification by qpcr.the biofilm formation by foodborne pathogens is known to increase the problem related with surface disinfection procedure in the food processing environment and consequent transmission of these pathogens into the population. messenger rna has been increasingly used to understand the action and the consequences of disinfectants in the virulence on such biofilms. rna quality is an important requirement for any rna-based analysis since the quality can impair the mrna quantification. therefore, we e ...201222526569
carbon catabolite control is important for listeria monocytogenes biofilm formation in response to nutrient availability.the foodborne pathogen listeria monocytogenes has the ability to develop biofilm in food-processing environment, which becomes a major concern for the food safety. the biofilm formation is strongly influenced by the availability of nutrients and environmental conditions, and particularly enhanced in poor minimal essential medium (mem) containing glucose rather than in rich brain heart infusion (bhi) broth. to gain better insight into the conserved protein expression profile in these biofilms, th ...201222526570
clinical, pathological, and genetic characterization of listeria monocytogenes causing sepsis and necrotizing typhlocolitis and hepatitis in a foal.listeria monocytogenes was isolated from the blood, lungs, and liver of a 5-week-old american quarter horse filly that presented with a 2-day history of fever, lethargy, ataxia, and seizure activity. the foal was born on a well-managed breeding facility to a multiparous mare with no periparturient complications. at 8 hr of age, the foal had an adequate passive transfer of immunity (immunoglobulin g > 2,000 mg/dl). since the time of birth, the foal reportedly had mild, intermittent diarrhea that ...201222529130
what do we do about listeria monocytogenes? 199122529716
prevention of foodborne listeriosis.listeria monocytogenes is a gram-positive, rod-shaped bacterium which, although recognized in the medical literature as an opportunistic pathogen for the past 60 years, has only recently gained prominence as an important foodborne pathogen. factors which make this organism unique among foodborne pathogens include its ability both to survive in foods under a variety of adverse conditions and to grow at low refrigeration temperatures. the organism is very widespread in the environment and can be f ...199122529720
bacterial meningitis in hiv-infected patients: case reports and review of the literature.meningitis is not an uncommon complication of the acquired immune deficiency syndrome. purulent meningitis is not a well recognized infection in human immunodeficiency virus (hiv) positive patients. three cases of bacterial meningitis caused by streptococcus pneumoniae, neisseria meningitidis and listeria monocytogenes are presented. these cases illustrate that common community organisms may present in hiv positive patients. an acquired b cell defect may predispose to bacterial infections respon ...199222529735
evaluation of food protective property of five natural products using fresh-cut apple slice model.the present study evaluated the antioxidant (aa), antimicrobial and preservation effects of five plant derived natural products viz., rosmarinic acid (ra), p-coumaric acid (pca), trans-cinnamic acid (tca), hydroxyphenyllactic acid (hpa) and caffeic acid (ca) along with synthetic compounds (ascorbic acid, gallic acid, citric acid and bha) on fresh cut apple slices. antimicrobial efficacy of these compounds against bacillus licheniformis, pseudomonas vulgaris, shigella boydii, salmonella typhi, st ...201222530437
factors affecting quality and safety of fresh-cut produce.the quality of fresh-cut fruit and vegetable products includes a combination of attributes, such as appearance, texture, and flavor, as well as nutritional and safety aspects that determine their value to the consumer. nutritionally, fruit and vegetables represent a good source of vitamins, minerals, and dietary fiber, and fresh-cut produce satisfies consumer demand for freshly prepared, convenient, healthy food. however, fresh-cut produce deteriorates faster than corresponding intact produce, a ...201222530712
first study on antimicriobial activity and synergy between isothiocyanates and antibiotics against selected gram-negative and gram-positive pathogenic bacteria from clinical and animal source.the emergence of new diseases and the resurgence of several infections that were controlled in the past, associated with recent increase of bacterial resistance have created the necessity for more studies towards to the development of new antimicrobials and new treatment strategies. the aim of the present study was to evaluate the in vitro synergy between different classes of important glucosinolates hydrolysis products-isothiocyanates with antibiotics (gentamycin and vancomycin), against import ...201222530889
comparative genomics and transcriptomics of lineages i, ii, and iii strains of listeria monocytogenes.listeria monocytogenes is a food-borne pathogen that causes infections with a high-mortality rate and has served as an invaluable model for intracellular parasitism. here, we report complete genome sequences for two l. monocytogenes strains belonging to serotype 4a (l99) and 4b (clip80459), and transcriptomes of representative strains from lineages i, ii, and iii, thereby permitting in-depth comparison of genome- and transcriptome -based data from three lineages of l. monocytogenes. lineage iii, ...201222530965
antilisterial activity of nisin-like bacteriocin-producing lactococcus lactis subsp. lactis isolated from traditional sardinian dairy products.with the aim of selecting lab strains with antilisterial activity to be used as protective cultures to enhance the safety of dairy products, the antimicrobial properties of 117 lactococcus lactis subsp. lactis isolated from artisanal sardinian dairy products were evaluated, and six strains were found to produce bacteriocin-like substances. the capacity of these strains to antagonize listeria monocytogenes during cocultivation in skimmed milk was evaluated, showing a reduction of l. monocytogenes ...201222536018
single-cell growth probability of listeria monocytogenes at suboptimal temperature, ph, and water activity.the single-cell growth probability of listeria monocytogenes was characterized in tryptone soy broth supplemented with 0.6% yeast extract at temperature ranging from 5 to 25°c, ph ranging from 4.4 to 6.5, and water activity ranging from 0.919 to 0.989. growth was monitored visually in 96-microwell plates and the growth probability was deduced from concentrations estimated with the mpn calculation. models were proposed to describe the increase of the probability from 0 to 1 with increasing values ...201222536203
protective immunity to listeria monocytogenes infection mediated by recombinant listeria innocua harboring the vgc locus.in this study we propose a novel bacterial vaccine strategy where non-pathogenic bacteria are complemented with traits desirable for the induction of protective immunity. to illustrate the proof of principle of this novel vaccination strategy, we use the model organism of intracellular immunity listeria. we introduced a, low copy number bac-plasmid harbouring the virulence gene cluster (vgc) of l. monocytogenes (lm) into the non-pathogenic l. innocua (l.inn) strain and examined for its ability t ...201222536395
comparative spatiotemporal analysis of the intrathecal immune response in natural listeric rhombencephalitis of cattle and small ruminants.this study examined the spatiotemporal immune response in listeric rhombencephalitis of ruminants in situ. our data support the view that astrocytes facilitate the containment of infectious lesions. results on the natural disease recapitulate observations in experimental rodent models and suggest that the mounted adaptive lymphocytic response of ruminants is effective in eliminating listeria monocytogenes (lm). however, our data indicate earlier participation of the adaptive immune response, a s ...201222537479
immunohistochemical search for viral and bacterial antigens in crohn's disease.recent studies show that diseased intestinal tissues of patients with crohn's disease (cd) contain obstructed lymphatics, granulomas, and tertiary lymphoid organs, representing responses to persistent antigen.201322537638
[liver abscess due to listeria monocytogenes]. 201322537897
development and optimization of an egfp-based reporter for measuring the general stress response in listeria monocytogenes.a characteristic of the food-borne pathogen listeria monocytogenes is its tolerance to the harsh conditions found both in minimally processed foods and the human gastrointestinal tract. this trait is partly under the control of the alternative sigma factor sigma b (σ(b)). to study the mechanisms that trigger the activation of σ(b) , and hence the development of stress tolerance, we have developed a fluorescent reporter fusion that allows the real-time activity of σ(b) to be monitored. the report ...201522539028
multidrug-resistant bacterial infection in solid organ transplant recipients.the most frequent complication from infection after solid organ transplantation is bacterial infection. this complication is more frequent in organ transplantation involving the abdominal cavity, such as liver or pancreas transplantation, and less frequent in heart transplant recipients. the sources, clinical characteristics, antibiotic resistance and clinical outcomes vary according to the time of onset after transplantation. most bacterial infections during the first month post-transplantation ...201222542034
nitric oxide increases susceptibility of toll-like receptor-activated macrophages to spreading listeria monocytogenes.toll-like receptor (tlr) stimulation activates macrophages to resist intracellular pathogens. yet, the intracellular bacterium listeria monocytogenes (lm) causes lethal infections in spite of innate immune cell activation. lm uses direct cell-cell spread to disseminate within its host. here, we have shown that tlr-activated macrophages killed cell-free lm but failed to prevent infection by spreading lm. instead, tlr signals increased the efficiency of lm spread from "donor" to "recipient" macrop ...201222542147
development of leprosy in a patient with rheumatoid arthritis during treatment with etanercept: a case report.rheumatoid arthritis (ra) is a chronic, systemic inflammatory disorder. there is a clear association between some disease-modifying drugs used to treat ra and infection. the introduction of the anti-tumor necrosis factor (tnf) therapies has improved the outcome of severe ra. the tnf-antagonism may increase susceptibility to granulomatous pathogens such as mycobacterium tuberculosis, listeria monocytogenes, and histoplasma capsulatum.201222542278
[listeria monocytogenes and herpes simplex type 1, associated in a meningoencephalitis episode in an immunodepressed patient]. 201222542878
listeria weihenstephanensis sp. nov., isolated from the water plant lemna trisulca taken from a freshwater pond.the phylogenetic position and phenotypic characteristics of two non-spore-forming bacilli similar to members of the genus listeria were studied. the gram-reaction-positive, slightly motile, facultatively anaerobic strains were isolated from the water plant lemna trisulca sampled from a freshwater pond in bavaria, germany. although no identification was possible employing the api listeria test (biomérieux), 16s rrna sequence analysis confirmed a close phylogenetic similarity to listeria rocourtia ...201322544790
invasive escherichia coli vaccines expressing brucella melitensis outer membrane proteins 31 or 16 or periplasmic protein bp26 confer protection in mice challenged with b. melitensis.because of the serious economic and medical consequences of brucellosis, efforts are to prevent infection of domestic animals through vaccines. many disadvantages are associated with the current brucella melitensis rev.1 vaccine prompting development of alternative vaccines and delivery. escherichia coli (dh5α) was engineered to express a plasmid containing the inv gene from yersinia pseudotuberculosis and the hly gene from listeria monocytogenes. these recombinant invasive e. coli expressing b. ...201222546330
sanitation of selected ready-to-eat intermediate-moisture foods of animal origin by e-beam irradiation.to optimize the sanitation treatment of ready-to-eat (rte) intermediate-moisture foods (imf), the behavior of listeria monocytogenes scott a (cip 103575), l. innocua (ntc 11288), salmonella enterica serovar typhimurium (cect 443), and escherichia coli o157:h7 (cect 4972) following treatment with electron-beam irradiation has been studied. as food matrixes, three rte vacuum-packed products (iberian dry-cured ham, dry beef [cecina], and smoked tuna) were used. although an irradiation treatment is ...201222551071
prevalence and risk factors for listeria monocytogenes in broiler flocks in shiraz, southern iran.listeria monocytogenes has been identified as an important foodborne pathogen in recent years. in humans, it most commonly affects pregnant women, neonates, children, elderly people, and persons with a suppressed immune system. it could contaminate both raw and cooked meat and poultry products. studies regarding prevalence and risk factors of l. monocytogenes in broilers flocks are limited. therefore, the present study was conducted to determine the prevalence and risk factors for l. monocytogen ...201222551072
effect of liposome-encapsulated nisin and bacteriocin-like substance p34 on listeria monocytogenes growth in minas frescal cheese.the efficacy of liposome-encapsulated nisin and bacteriocin-like substance (bls) p34 to control growth of listeria monocytogenes in minas frescal cheese was investigated. nisin and bls p34 were encapsulated in partially purified soybean phosphatidylcholine (pc-1) and pc-1-cholesterol (7:3) liposomes. pc-1 nanovesicles were previously characterized. pc-1-cholesterol encapsulated nisin and bls p34 presented, respectively, 218 nm and 158 nm diameters, zeta potential of -64 mv and -53 mv, and entrap ...201222554928
signature tagged mutagenesis in the functional genetic analysis of gastrointestinal pathogens.signature tagged mutagenesis is a genetic approach that was developed to identify novel bacterial virulence factors. it is a negative selection method in which unique identification tags allow analysis of pools of mutants in mixed populations. the approach is particularly well suited to functional genetic analysis of the gastrointestinal phase of infection in foodborne pathogens and has the capacity to guide the development of novel vaccines and therapeutics. in this review we outline the techni ...201222555467
isolation of a bacteriocin-producing lactococcus lactis and application of its bacteriocin to manage spoilage bacteria in high-value marine fish under different storage temperatures.the bacteriocins of lactic acid bacteria have considerable potential for biopreservation. the lactococcus lactis strain psy2 (genbank account no. jf703669) isolated from the surface of marine perch perca flavescens produced antibacterial activity against pathogenic and spoilage-causing gram-positive and gram-negative bacteria viz. arthrobacter sp., acinetobacter sp., bacillus subtilis, escherichia coli, listeria monocytogenes, pseudomonas aeruginosa and staphylococcus aureus and possessed broad ...201222555500
study on carvacrol and cinnamaldehyde polymeric films: mechanical properties, release kinetics and antibacterial and antibiofilm activities.polyethylene-co-vinylacetate (eva) films with different concentrations (3.5 wt% and 7 wt%) of essential oil constituents, carvacrol or cinnamaldehyde, were prepared and characterized by mechanical, antibacterial and antibiofilm properties. the incorporation of the compounds into copolymer films affected their elastic modulus, tensile stress and elongation at break. carvacrol and cinnamaldehyde act as plasticizers which reduce the intermolecular forces of polymer chains, thus improving the flexib ...201222555914
risk-based sampling plan to control listeria monocytogenes in a hospital food service operation. 201222558755
effects of x-ray treatments on pathogenic bacteria, inherent microflora, color, and firmness on whole cantaloupe.inactivation of inoculated escherichia coli o157:h7, listeria monocytogenes, salmonella enterica and shigella flexneri on whole cantaloupes using x-ray at different doses (0.1, 0.5, 1.0, 1.5, and 2.0 kgy) was studied. the effect of x-ray on quality parameters (color and texture) of untreated and treated whole cantaloupes was instrumentally determined. the effect of x-ray on microflora counts (mesophilic counts, psychrotrophic counts and yeast and mold counts) of untreated and treated whole canta ...201222560020
adaptor protein-3 in dendritic cells facilitates phagosomal toll-like receptor signaling and antigen presentation to cd4(+) t cells.effective major histocompatibility complex-ii (mhc-ii) antigen presentation from phagocytosed particles requires phagosome-intrinsic toll-like receptor (tlr) signaling, but the molecular mechanisms underlying tlr delivery to phagosomes and how signaling regulates antigen presentation are incompletely understood. we show a requirement in dendritic cells (dcs) for adaptor protein-3 (ap-3) in efficient tlr recruitment to phagosomes and mhc-ii presentation of antigens internalized by phagocytosis bu ...201222560444
growth potential of salmonella spp. and listeria monocytogenes in nine types of ready-to-eat vegetables stored at variable temperature conditions during shelf-life.growth potential (δ) is defined as the difference between the population of a microorganism at the end of shelf-life of specific food and its initial population. the determination of δ of salmonella and listeria monocytogenes in rte vegetables can be very useful to determine likely threats to food safety. however, little is known on the behavior of these microorganisms in several rte vegetables. therefore, the aim of this study was to determine the δ of both pathogens in nine different types of ...201222561064
genetic organization of ascb-dape internalin cluster serves as a potential marker for listeria monocytogenes sublineages iia, iib, and iic.listeria monocytogenes is an important foodborne pathogen that comprises four genetic lineages: i, ii, iii, and iv. of these, lineage ii is frequently recovered from foods and environments and responsible for the increasing incidence of human listeriosis. in this study, the phylogenetic structure of lineage ii was determined through sequencing analysis of the ascb-dape internalin cluster. fifteen sequence types proposed by multilocus sequence typing based on nine housekeeping genes were grouped ...201222561849
inhibition of calpain blocks the phagosomal escape of listeria monocytogenes.listeria monocytogenes is a gram-positive facultative intracellular bacterium responsible for the food borne infection listeriosis, affecting principally the immunocompromised, the old, neonates and pregnant women. following invasion l. monocytogenes escapes the phagosome and replicates in the cytoplasm. phagosome escape is central to l. monocytogenes virulence and is required for initiating innate host-defence responses such as the secretion of the cytokine interleukin-1. phagosome escape of l. ...201222563421
antimicrobial activities of therapeutic herbal plants against listeria monocytogenes and the herbal plant cytotoxicity on caco-2 cell.this study investigated the antimicrobial effect of various therapeutic herbal plants on listeria monocytogenes, and their cytotoxicity effect on mammalian cells.201222563627
genes encoding putative dead-box rna helicases in listeria monocytogenes egd-e are needed for growth and motility at 3°c.quantitative rt-pcr revealed that transcripts of all four putative dead-box rna helicase genes of the psychrotrophic pathogen listeria monocytogenes egd-e are found at higher levels in organisms grown at 3°c than at 37°c. at 3°c, growth of the three corresponding gene deletion mutants δlmo0866, δlmo1450 and δlmo1722 was clearly restricted. the minimum growth temperatures of the three mutants were also higher than that of the wild-type egd-e. in addition to inability to grow at 3°c, growth of δlm ...201222564273
effect of brine marination on survival and growth of spoilage and pathogenic bacteria during processing and subsequent storage of ready-to-eat shrimp (pandalus borealis).the effect of brine marination at chill temperatures on survival and growth of spoilage and pathogenic bacteria during processing and subsequent storage of ready-to-eat cold water shrimp was studied. survival and growth of lactobacillus sakei, listeria monocytogenes, salmonella, staphylococcus aureus and vibrio parahaemolyticus were examined. the effect of brine composition and ph was determined in 12 screening experiments without addition of shrimp. sixteen challenge tests with shrimp were then ...201222564452
prevalence and distribution of listeria monocytogenes serotypes and pulsotypes in sows and fattening pigs in farrow-to-finish farms (france, 2008).this study was undertaken to acquire new data on the prevalence of listeria monocytogenes in sows and fattening pigs in farrow-to-finish pig farms, and to analyze distribution of serotypes and genotypes of the bacterium within farms. detection of l. monocytogenes was carried out on 730 pooled feces samples from sows in 73 pig farms and on 172 pooled feces samples from fattening pigs in 43 of these farms. isolates were serotyped and typed by pulsed-field gel electrophoresis. for sows, 46% of the ...201222564938
growth of listeria monocytogenes in different retail delicatessen meats during simulated home storage.delicatessen meats are reported to be the leading vehicle of foodborne listeriosis in the united states. listeria monocytogenes can reach high numbers in these products during storage, and the growth rate is largely dictated by product formulation and storage temperature. to assess the impact of product age on listeria growth, five commercial brands each of cured and uncured turkey breast, ham, and roast beef (three lots per brand) were sliced (approximately 25 g per slice) at the beginning of t ...201222564939
global gene expression of listeria monocytogenes to salt stress.outbreaks of listeriosis caused by the ingestion of listeria-contaminated ready-to-eat foods have been reported worldwide. many ready-to-eat foods, such as deli meat products, contain high amounts of salt, which can disrupt the maintenance of osmotic balance within bacterial cells. to understand how listeria monocytogenes adapts to salt stress, we examined the growth and global gene expression profiles of l. monocytogenes strain f2365 under salt stress using oligonucleotide probe-based dna array ...201222564940
effects of irradiation dose and o(2) and co(2) concentrations in packages on foodborne pathogenic bacteria and quality of ready-to-cook seasoned ground beef product (meatball) during refrigerated storage.combined effects of gamma irradiation and concentrations of o(2) (0, 5, 21%) and co(2) (0, 50%) on survival of escherichia coli o157:h7, salmonella enteritidis, listeria monocytogenes, lipid oxidation, and color changes in ready-to-cook seasoned ground beef (meatball) during refrigerated storage were investigated. ground beef seasoned with mixed spices was packaged in varying o(2) and co(2) levels and irradiated at 2 and 4 kgy. irradiation (4 kgy) caused about 6 log inactivation of the inoculate ...201222566763
innate ifn-γ-producing cells in the spleen of mice early after listeria monocytogenes infection: importance of microenvironment of the cells involved in the production of innate ifn-γ.production of innate interferon-γ (ifn-γ) is a crucial step in immunological defense against bacteria. however, there is little information regarding cellular mechanisms underlying ifn-γ production in vivo early after bacterial infection. here we analyze innate ifn-γ production in the spleen of mice early after listeria monocytogenes (lm) infection ex vivo by flow-cytometry and in situ by immunohistochemistry, and compare them with the ifn-γ-producing cells reported previously in our in vitro co ...201122566816
prevalence and antibiotic resistance of campylobacter, salmonella, and l. monocytogenes in ducks: a review.campylobacter, salmonella, and listeria monocytogenes are important bacterial pathogens associated with gastroenteritis. the consumption of poultry meat and their products is considered as a major and leading source of human infection. while surveys of chicken meat and products, and its association with foodborne pathogens are widely available, such information on ducks is scarce. this survey examines the prevalence and antibiotic resistance of campylobacter, salmonella and l. monocytogenes isol ...201222571641
invasive listeriosis in the foodborne diseases active surveillance network (foodnet), 2004-2009: further targeted prevention needed for higher-risk groups.listeriosis can cause severe disease, especially in fetuses, neonates, older adults, and persons with certain immunocompromising and chronic conditions. we summarize us population-based surveillance data for invasive listeriosis from 2004 through 2009.201222572660
estimates of enteric illness attributable to contact with animals and their environments in the united states.contact with animals and their environment is an important, and often preventable, route of transmission for enteric pathogens. this study estimated the annual burden of illness attributable to animal contact for 7 groups of pathogens: campylobacter species, cryptosporidium species, shiga toxin-producing escherichia coli (stec) o157, stec non-o157, listeria monocytogenes, nontyphoidal salmonella species, and yersinia enterocolitica.201222572672
fusion of the fc part of human igg1 to cd14 enhances its binding to gram-negative bacteria and mediates phagocytosis by fc receptors of neutrophils.microbial resistance to antimicrobial drugs is promoting a search for new antimicrobial agents that target highly conservative structures of pathogens. human cd14 - a known pattern recognition receptor (prr) which recognizes multiple ligands from different microbes might be a worthy candidate. the aim of our work was to create a cd14/fc dimer protein and evaluate its whole bacteria binding and opsonizing capabilities. fusion of cd14 with the fragment crystallisable (fc) part of human igg1 could ...201222575527
precise detection of l. monocytogenes hitting its highly conserved region possessing several specific antibody binding sites.listeria monocytogenes, a facultative intracellular fast-growing gram-positive food-borne pathogen, can infect immunocompromised individuals leading to meningitis, meningoencephalitis and septicaemias. from the pool of virulence factors of the organism, acta, a membrane protein, has a critical role in the life cycle of l. monocytogenes. high mortality rate of listeriosis necessitates a sensitive and rapid diagnostic test for precise identification of l. monocytogenes. we used bioinformatic tools ...201222575546
ciap1 and ciap2 limit macrophage necroptosis by inhibiting rip1 and rip3 activation.cellular inhibitor of apoptosis proteins (ciaps) have emerged as important anti-cell death mediators, particularly in cancer. although they are known to be expressed in immune tissue, their specific immune function remains unclear. we observed that degradation of ciaps with smac mimetic (sm) results in death of primary bone-marrow-derived macrophages. sm-induced death of macrophages occurred by programmed necrosis (necroptosis), which was dependent on tnf receptor expression. consistent with nec ...201222576661
high-intensity 405 nm light inactivation of listeria monocytogenes.the antimicrobial properties of light is an area of increasing interest. this study investigates the sensitivity of the significant foodborne pathogen listeria monocytogenes to selected wavelengths of visible light. results demonstrate that exposure to wavelength region 400-450 nm, at sufficiently high dose levels (750 j cm(-2)), induced complete inactivation of a 5 log(10) population. exposure to wavelengths longer than 450 nm did not cause significant inactivation. analysis of 10 nm bandwidths ...201222582879
essential oil of the leaves of eugenia uniflora l.: antioxidant and antimicrobial properties.essential oil (eo) of the leaves of eugenia uniflora l. (brazilian cherry tree) was evaluated for its antioxidant, antibacterial and antifungal properties. the acute toxicity of the eo administered by oral route was also evaluated in mice. the eo exhibited antioxidant activity in the dpph, abts and frap assays and reduced lipid peroxidation in the kidney of mice. the eo also showed antimicrobial activity against two important pathogenic bacteria, staphylococcus aureus and listeria monocytogenes, ...201222583648
a review of the ecology, genomics, and stress response of listeria innocua and listeria monocytogenes.listeria monocytogenes is a gram-positive foodborne pathogen responsible for a severe disease occurring in immuno-compromised populations. foodborne illness caused by l. monocytogenes is a serious public health concern because of the high associated mortality. study of the closely related, but nonpathogenic listeria innocua has accounted for a better understanding of the behavior of l. monocytogenes in environments beyond the laboratory. traditionally, the ecological co-habitation, genomic synte ...201222591342
clinical development of listeria monocytogenes-based immunotherapies.active immunotherapy targeting dendritic cells (dcs) has shown great promise in preclinical models and in human clinical trials for the treatment of malignant disease. sipuleucel-t (provenge, dendreon, seattle, wa), which consists of antigen-loaded dendritic cells (dcs), recently became the first targeted therapeutic cancer vaccine to be approved by the us food and drug administration (fda). however, ex vivo therapies such as provenge have practical limitations and elicit an immune response with ...201222595054
functional characterization of the infection-inducible peptide edin in drosophila melanogaster.drosophila is a well-established model organism for studying innate immunity because of its high resistance against microbial infections and lack of adaptive immunity. in addition, the immune signaling cascades found in drosophila are evolutionarily conserved. upon infection, activation of the immune signaling pathways, toll and imd, leads to the expression of multiple immune response genes, such as the antimicrobial peptides (amps). previously, we identified an uncharacterized gene edin among t ...201222606343
bayesian inference for quantifying listeria monocytogenes prevalence and concentration in minced pork meat from presence/absence microbiological testing.the purpose of this work was to estimate the prevalence and concentration of listeria monocytogenes in minced pork meat by the application of a bayesian modeling approach. samples (n = 100) collected from local markets were tested for l. monocytogenes using in parallel the palcam, aloa and rapid'l.mono selective media. presence of the pathogen was confirmed through biochemical and molecular tests. independent experiments (n = 10) for validation purposes were performed. no l. monocytogenes was en ...201222608217
survey of raw milk cheeses for microbiological quality and prevalence of foodborne pathogens.cheese may be manufactured in the united states using raw milk, provided the cheese is aged for at least 60 days at temperatures not less than 35°f (1.7°c). there is now increased concern among regulators regarding the safety of raw milk cheese due to the potential ability of foodborne pathogens to survive the manufacturing and aging processes. in this study, 41 raw milk cheeses were obtained from retail specialty shops, farmers' markets, and on-line sources. the cheeses were then analyzed for t ...201222608218
prevalence, characterization and sources of listeria monocytogenes in blue crab (callinectus sapidus) meat and blue crab processing plants.seven blue crab processing plants were sampled to determine the prevalence and sources of listeria spp. and listeria monocytogenes for two years (2006-2007). a total of 488 raw crabs, 624 cooked crab meat (crab meat) and 624 environmental samples were tested by standard methods. presumptive listeria spp. were isolated from 19.5% of raw crabs, 10.8% of crab meat, and 69.5% of environmental samples. l. monocytogenes was isolated from 4.5% of raw crabs, 0.2% of crab meat, and 2.1% of environmental ...201222608232
plant-derived antimicrobials reduce listeria monocytogenes virulence factors in vitro, and down-regulate expression of virulence genes.listeria monocytogenes (lm) is a major foodborne pathogen causing septicemia, meningitis and death in humans. lm infection is preceded by its attachment to and invasion of human intestinal epithelium followed by systemic spread. the major virulence factors in lm include motility, hemolysin and lecithinase production. reducing lm attachment to and invasion of host tissue and production of virulence factors could potentially control listeriosis in humans. this study investigated the efficacy of su ...201222608657
screening and in situ synthesis using crystals of a nad kinase lead to a potent antistaphylococcal compound.making new ligands for a given protein by in situ ligation of building blocks (or fragments) is an attractive method. however, it suffers from inherent limitations, such as the limited number of available chemical reactions and the low information content of usual chemical library deconvolution. here, we describe a focused screening of adenosine derivatives using x-ray crystallography. we discovered an unexpected and biocompatible chemical reactivity and have simultaneously identified the mode o ...201222608967
notch-rbp-j signaling regulates the transcription factor irf8 to promote inflammatory macrophage polarization.emerging concepts suggest that the functional phenotype of macrophages is regulated by transcription factors that define alternative activation states. we found that rbp-j, the main nuclear transducer of signaling via notch receptors, augmented toll-like receptor 4 (tlr4)-induced expression of key mediators of classically activated m1 macrophages and thus of innate immune responses to listeria monocytogenes. notch-rbp-j signaling controlled expression of the transcription factor irf8 that induce ...201222610140
therapeutic live vaccines as a potential anticancer strategy.the design of efficient cancer treatments is one of the major challenges of medical science. therapeutic vaccines of cancer have been emerged as an attractive approach for their capacity of breaking the immune tolerance and invoking long-term immune response targeting cancer cells without autoimmunity. an efficient antigen delivery system is the key issue of developing an effective cancer vaccine. in this regard, live vaccination strategies including various live bacterial and viral vectors have ...201222610886
listeria monocytogenes growth dynamics on produce: a review of the available data for predictive modeling.several listeriosis outbreaks have been linked to the consumption of fresh or processed produce in recent years. one major determinant of the listeriosis risk is the ability of a food to support growth of listeria monocytogenes during storage. however, data regarding the ability to support growth of l. monocytogenes are scarce or nonexisting for many produce commodities. here we synthesize the available data regarding growth behavior of l. monocytogenes on produce, compare the growth data with l ...201222612229
cellular pharmacokinetics and intracellular activity against listeria monocytogenes and staphylococcus aureus of chemically modified and nanoencapsulated gentamicin.the aim of this study was to investigate different hydrophobic gentamicin formulations [gentamicin-bis(2-ethylhexyl) sulfosuccinate (gen-aot), microstructured gen-aot (pca gen-aot) and gen-aot-loaded poly(lactide-co-glycolide) acid (plga) nanoparticles (nps)] in view of improving its therapeutic index against intracellular bacteria. the intracellular accumulation, subcellular distribution and intracellular activity of gen-aot and nps in different monocytic-macrophagic cell lines were studied.201222615297
comparative transcriptomics of pathogenic and non-pathogenic listeria species.listeria monocytogenes is a human, food-borne pathogen. genomic comparisons between l. monocytogenes and listeria innocua, a closely related non-pathogenic species, were pivotal in the identification of protein-coding genes essential for virulence. however, no comprehensive comparison has focused on the non-coding genome. we used strand-specific cdna sequencing to produce genome-wide transcription start site maps for both organisms, and developed a publicly available integrative browser to visua ...201222617957
antimicrobial activity of wild mushroom extracts against clinical isolates resistant to different antibiotics.this work aimed to screen the antimicrobial activity of aqueous methanolic extracts of 13 mushroom species, collected in bragança, against several clinical isolates obtained in hospital center of trás-os-montes and alto douro, portugal.201222621239
novel polymer anchored cr(iii) schiff base complexes: synthesis, characterization and antimicrobial properties.new polymer-bound schiff bases and cr(iii) complexes have been synthesized by the reaction of 4-benzyloxybenzaldehyde, polymer-bound with 2-aminophenol, 2-amino-4-chlorophenol and 2-amino-4-methylphenol. the structure of polymeric-schiff bases and their cr(iii) complexes have been characterized by elemental analyses, magnetic measurements, ir, uv-vis, tg-dta and (1)h-nmr. all these compounds have also been investigated for antibacterial activity by the well-diffusion method against staphylococcu ...201222622060
listeria monocytogenes sepsis in ulcerative colitis. 201222622754
listeria infection in patients on anti-tnf treatment: report of two cases and review of the literature.listeria monocytogenes is an aerobic gram positive intracellular bacillus, predominantly affecting pregnant women, immunocompromised patients and old individuals. invasive listeriosis, meningitis and meningoencephalitis, bacteraemia with or without joint, eye or heart focalization are clinical manifestations of the disease. anti-tnf-α drugs blocking the host's response against various microorganisms, particularly intracellular agents like listeria monocytogenes, increase the risk of disease. we ...201322626505
lack of pparγ in myeloid cells confers resistance to listeria monocytogenes infection.the peroxisomal proliferator-activated receptor γ (pparγ) is a nuclear receptor that controls inflammation and immunity. innate immune defense against bacterial infection appears to be compromised by pparγ. the relevance of pparγ in myeloid cells, that organize anti-bacterial immunity, for the outcome of immune responses against intracellular bacteria such as listeria monocytogenes in vivo is unknown. we found that listeria monocytogenes infection of macrophages rapidly led to increased expressi ...201222629382
listeria monocytogenes: no spreading without no.in infectious disease immunology, inducible nitric oxide (no) synthase-derived no is believed to function primarily as an antimicrobial and immunoregulatory molecule. in this issue of immunity, cole et al. (2012) show that no helps the intracellular bacteria listeria monocytogenes to spread.201222633455
development of antimicrobial films for microbiological control of packaged salad.the aim of the present work was to characterize the antimicrobial efficiency of films consisting of pp/evoh structures with oregano essential oil and citral. both substances are known for their antimicrobial activity based on their interaction with the cell membrane. the films developed were used to pack minimally processed salads, combining modified atmosphere technology to extend shelf-life and active packaging technology to reduce possible microbiological risks. the antimicrobial activity of ...201222633535
peptide nucleic acid fluorescence in situ hybridization for identification of listeria genus, listeria monocytogenes and listeria ivanovii.a fluorescent in situ hybridization (fish) method in conjunction with fluorescin-labeled peptide nucleic acid (pna) probes (pna-fish) for detection of listeria species was developed. in silico analysis showed that three pna probes lis-16s-1, lm-16s-2 and liv-16s-5 were suitable for specific identification of listeria genus, listeria monocytogenes and listeria ivanovii, respectively. these probes were experimentally verified by their reactivity against 19 strains of six listeria species (excludin ...201222633537
influence of flow direction and flow rate on the initial adhesion of seven listeria monocytogenes strains to fine polished stainless steel.the effects of flow direction and shear stress on the adhesion of different strains of listeria monocytogenes to fine polished stainless steel under liquid flow conditions were investigated. furthermore, the relationship between cell surface properties and cell size and the initial adhesion rate (iar) was studied. a method, including fluorescence microscopy and a flow perfusion system, was developed and used to examine the real-time initial cell adhesion of different l. monocytogenes species in ...201222633798
heat resistance of listeria monocytogenes in semi-skim milk supplemented with vanillin.the kinetics of destruction of listeria monocytogenes scott a in semi-skim milk heated at 55, 58, 60 and 62°c without and with addition of 900, 1400 and 1800 ppm of vanillin was studied. survival curves displayed an initial shoulder phase followed by an accelerating killing phase. addition of vanillin to semi-skim milk heated between 55 and 62°c reduced the heat resistance of l. monocytogenes, effect that was more evident at the lowest temperatures. two kinetic inactivation models were used to f ...201222633800
bilateral anterior uveitis in a patient with bacterial meningitis.we report a case of bilateral iridocyclitis accompanied by bacterial meningitis in an immunocompetent patient. case report. a 48 year-old healthy female visited our hospital with strong headache, fever, bilateral hyperemia, and blurred vision in both eyes. a slit-lamp examination revealed moderate cells and flare in the anterior chamber of both eyes, with fine keratoprecipitates. there were no obvious inflammatory changes in the vitreous, retina, and optic disc of both eyes. elevation of periphe ...201222638923
antimicrobial food packaging film based on the release of lae from evoh.the aim of this work was to develop antimicrobial films for active packaging applications containing the natural antimicrobial compound lae (lauramide arginine ethyl ester) in evoh copolymers with different mol % ethylene contents (i.e. evoh-29 and evoh-44). evoh-29 and evoh-44 films were made by casting and incorporating 0.25%, 1%, 5%, and 10% lae in the film forming solution (w/w with respect to polymer weight). previously, the minimum inhibitory concentration (mic) and the minimum bactericida ...201222640726
combined immunotherapy with listeria monocytogenes-based psa vaccine and radiation therapy leads to a therapeutic response in a murine model of prostate cancer.radiation therapy (rt) is an integral part of prostate cancer treatment across all stages and risk groups. immunotherapy using a live, attenuated, listeria monocytogenes-based vaccines have been shown previously to be highly efficient in stimulating anti-tumor responses to impact on the growth of established tumors in different tumor models. here, we evaluated the combination of rt and immunotherapy using listeria monocytogenes-based vaccine (adxs31-142) in a mouse model of prostate cancer. mice ...201222644735
distinct cd4+ helper t cells involved in primary and secondary responses to infection.helper t cells are critical for protective immunity, cd8(+) t-cell memory, and cd4(+) recall responses, but whether the same or distinct cd4(+) t cells are involved in these responses has not been established. here we describe two cd4(+) t cells, llo118 and llo56, specific for an immunodominant listeria monocytogenes epitope, with dramatically different responses to primary and secondary infection. comparing in vivo responses, llo118 t cells proliferate more strongly to primary infection, wherea ...201222645349
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