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characterization of a potential listeria monocytogenes virulence factor associated with attachment to fresh produce.a study to determine the attachment of l. monocytogenes serotype 4b strain f2365 on vegetables and fruits was conducted. in an initial study, we screened 32 genes encoding surface proteins and lipases of the strain to find highly expressed genes on lettuce leaves. the results showed that transcription levels of lmof2365_0413, lmof2365_0498, lmof2365_0859, lmof2365_2052, and lmof2365_2812 were significantly upregulated on lettuce leaves. in silico analysis showed that lmof2365_0859 contains a put ...201323974144
transcription factor σb plays an important role in the production of extracellular membrane-derived vesicles in listeria monocytogenes.gram-negative bacteria produce extracellular outer membrane vesicles (omvs) that interact with host cells. unlike gram-negative bacteria, less is known about the production and role of extracellular membrane vesicles (mvs) in gram-positive bacteria. the food-borne pathogen listeria monocytogenes can survive under extreme environmental and energy stress conditions and the transcription factor σ(b) is involved in this survival ability. here, we first determined the production of mvs from l. monocy ...201323977379
clinical presentation of acute bacterial meningitis in qatar.to study the changes in the epidemiology of bacterial meningitis in the era of the hemophilus influenzae (h. influenzae) type b vaccine and pneumoccous resistance.200223978859
cerebellar abscess due to listeria monocytogenes.brain abscess due to listeria monocytogenes mainly involves the cerebral hemispheres. cerebellar abscess is an infrequent event, which could lead to rapid neurological deterioration if unrecognized. we present a case of multiple brain stem and cerebellar abscesses in a previously healthy individual exposed to unpasteurized milk. this is the 2nd case of cerebellar abscess due to listeria monocytogenes reported in the english literature. the diagnosis of listeria monocytogenes was made in the surg ...200223978925
cd38 controls the innate immune response against listeria monocytogenes.cd38, adenosine-5'-diphosphate-ribosyl cyclase 1, is a multifunctional enzyme, expressed on a wide variety of cell types. cd38 has been assigned diverse functions, including generation of calcium-mobilizing metabolites, cell activation, and chemotaxis. using a murine listeria monocytogenes infection model, we found that cd38 knockout (ko) mice were highly susceptible to infection. enhanced susceptibility was already evident within 3 days of infection, suggesting a function of cd38 in the innate ...201323980105
the transcription factor interferon regulatory factor 4 is required for the generation of protective effector cd8+ t cells.robust cytotoxic cd8(+) t-cell response is important for immunity to intracellular pathogens. here, we show that the transcription factor ifn regulatory factor 4 (irf4) is crucial for the protective cd8(+) t-cell response to the intracellular bacterium listeria monocytogenes. irf4-deficient (irf4(-/-)) mice could not clear l. monocytogenes infection and generated decreased numbers of l. monocytogenes-specific cd8(+) t cells with impaired effector phenotype and function. transfer of wild-type cd8 ...201323980171
colpoda secrete viable listeria monocytogenes within faecal pellets.transmission electron microscopy was used to demonstrate that co-cultures of the ciliate colpoda rr (an environmental isolate) and colpoda mls-5 (a food processing environment isolate) with the pathogenic listeria monocytogenes drdc8 resulted in secretion of faecal pellets containing intact drdc8 cells. a green fluorescent protein expressing variant of drdc8 was used in co-cultures to confirm that the pellet-associated bacterial cells were l. monocytogenes. viability was confirmed by plate count ...201423981071
development of a quaternized chitosan with enhanced antibacterial efficacy.the antibacterial activity of a water-soluble chitosan derivative prepared by chemical modification to quaternary ammonium compound n,n,n-trimethylchitosan (tc) was investigated against four selected waterborne pathogens: aeromonas hydrophila atcc 35654, yersinia enterocolitica atcc 9610, listeria monocytogenes atcc 19111 and escherichia coli o157:h7 atcc 32150. an inactivation of 4 log cfu/ml of all waterborne pathogens was noted for the quaternized chitosan as compared with chitosan over a sho ...201323981870
cpg oligodeoxynucleotide induces bone marrow precursor cells into myeloid-derived suppressor cells.dendritic cells (dcs) and myeloid-derived suppressor cells (mdscs) perform a number of functions in different immunological settings. in standard in vitro experiments, dcs are produced from mouse bone marrow (bm) cells in the presence of granulocyte-macrophage colony-stimulating factor (gm-csf) and il-4. our previous study demonstrated that bm precursor cells could differentiate into mdscs when co-cultured with poly (i:c). in the present study, bm precursor cells cultured in gm-csf and il-4 were ...201323982226
influence of freezing stress on morphological alteration and biofilm formation by listeria monocytogenes: relationship with cell surface hydrophobicity and membrane fluidity.the morphological changes and adhesive property of three listeria monocytogenes strains submitted to freezing stress (-20 °c) were studied. the atomic force micrographs showed a reduction in the cell size and an evolution to coccoid shape. the phenotypic slime production of l. monocytogenes and the expression of the adhesive gene were investigated before and after 10 months of incubation in salmon at -20°. our results showed that after ten months, stressed stains become more adherent and able to ...201323982847
role of flies as vectors of foodborne pathogens in rural areas.this study aims to evaluate flies as a vector for foodborne pathogens. for this purpose, several flies were collected from different sites from rural areas. these flies were then analyzed for the presence of enterobacteriaceae, escherichia coli, staphylococcus coagulase positive, and listeria monocytogenes. another aim of this study was to evaluate some virulence factors of the collected pathogens: susceptibility to some antibiotics and the presence of enterotoxigenic s. aureus. the results show ...201323984181
occurrence of genetic variants of listeria monocytogenes strains.isolates of listeria monocytogenes saved from outbreaks of listeriosis, cases of sporadic listeriosis, and similar events do not always belong to a solitary genetic variant. variants of the same strain may have evolved from a unique clone, and plasmid loss or gain and phage-mediated genetic changes are suggested as the main mechanism. some of these reports are summarized in this short communication.201323988078
development and characterization of essential oil component-based polymer films: a potential approach to reduce bacterial biofilm.the development of new polymeric materials aimed to control the bacterial biofilm appears to be an important practical approach. the goal of the present study was to prepare and characterize poly(ethylene-co-vinyl acetate) copolymer (eva) films containing citronellol, eugenol, and linalool and evaluate their efficiency on growth and biofilm formation of listeria monocytogenes, staphylococcus aureus, staphylococcus epidermidis, escherichia coli, and pseudomonas aeruginosa in monospecies and dual ...201323989976
cutaneous listeriosis in a veterinarian with the evidence of zoonotic transmission--a case report.a case of listeria monocytogenes skin infection in a man is presented. a 54-year-old male veterinary practitioner developed pustular changes on the skin of arms and hands after assisting with the delivery of a stillborn calf. listeria monocytogenes was isolated from the skin lesions on the arms and from the bovine placenta. listeria monocytogenes isolates were serotyped and genotyped with pulsed-field gel electrophoresis (pfge) to confirm the suspected transmission of the pathogen from animal to ...201423992408
growth modeling of listeria monocytogenes in pasteurized liquid egg.the growth kinetics of listeria monocytogenes and natural flora in commercially produced pasteurized liquid egg was examined at 4.1 to 19.4°c, and a growth simulation model that can estimate the range of the number of l. monocytogenes bacteria was developed. the experimental kinetic data were fitted to the baranyi model, and growth parameters, such as maximum specific growth rate (μ(max)), maximum population density (n(max)), and lag time (λ), were estimated. as a result of estimating these para ...201323992499
inhibition of listeria monocytogenes in full- and low-sodium frankfurters at 4, 7, or 10°c using spray-dried mixtures of organic acid salts.in meat processing, powdered ingredients are preferred to liquids because of ease of handling, mixing, and storing. this study was conducted to assess listeria monocytogenes inhibition and the physicochemical and organoleptic characteristics of frankfurters that were prepared with organic acid salts as spray-dried powders (sodium lactate-sodium acetate, sodium lactate-sodium acetate-sodium diacetate, and potassium acetate-potassium diacetate) or liquids (sodium lactate, sodium lactate-sodium dia ...201323992500
effect of electropermeabilization by ohmic heating for inactivation of escherichia coli o157:h7, salmonella enterica serovar typhimurium, and listeria monocytogenes in buffered peptone water and apple juice.the effect of electric field-induced ohmic heating for inactivation of escherichia coli o157:h7, salmonella enterica serovar typhimurium, and listeria monocytogenes in buffered peptone water (bpw) (ph 7.2) and apple juice (ph 3.5; 11.8 °brix) was investigated in this study. bpw and apple juice were treated at different temperatures (55°c, 58°c, and 60°c) and for different times (0, 10, 20, 25, and 30 s) by ohmic heating compared with conventional heating. the electric field strength was fixed at ...201323995939
probable nosocomial transmission of listeriosis in neonates.listeria monocytogenes was isolated in two neonates born consecutively in the same hospital in france. the isolates had indistinguishable pulsed-field electrophoresis profiles. retrospective epidemiological investigations found no evidence of a food-borne or environmental source. infection control protocols and decontamination processes were in accordance with standard recommendations. the timing of onset of these infections within the same maternity unit, and the similarity of pulsed-field gel ...201324001996
synthesis and characterization of novel organocobaloximes as potential catecholase and antimicrobial activity agents.an asymmetric, potentially bidentate dioxime ligand (h₂l) was formed by condensation of 4-biphenylchloroglyoxime and napthyl-1-amine. two equivalents of h₂l were reacted with cocl₂  · 6h₂o under appropriate conditions with deprotonation of the dioxime ligand. a series of new organocobaloxime derivatives of the type [cor(hl)₂py], [corl₂pyb₂f₄], and [corl₂py(cu(phen))₂] (h₂l = 4-(napthyl-1-amino)biphenylglyoxime; phen = 1,10-phenathroline; r = izopropyl and benzyl; py = pyridine) were synthesized. ...201324003018
multistate outbreak of listeriosis associated with cantaloupe.although new pathogen-vehicle combinations are increasingly being identified in produce-related disease outbreaks, fresh produce is a rarely recognized vehicle for listeriosis. we investigated a nationwide listeriosis outbreak that occurred in the united states during 2011.201324004121
"epidemic clones" of listeria monocytogenes are widespread and ancient clonal groups.the food-borne pathogen listeria monocytogenes is genetically heterogeneous. although some clonal groups have been implicated in multiple outbreaks, there is currently no consensus on how "epidemic clones" should be defined. the objectives of this work were to compare the patterns of sequence diversity on two sets of genes that have been widely used to define l. monocytogenes clonal groups: multilocus sequence typing (mlst) and multi-virulence-locus sequence typing (mvlst). further, we evaluated ...201324006010
[rapid detection of listeria monocytogenes by immunomagnetic separation combined with selective medium].listeria monocytogenes is a pathogenic bacterium, therefore, it is essential for food safety monitoring to establish a rapid and specific detecting method. in this study, immunomagnetic beads and selective medium were combined to detect listeria monocytogenes at different concentrations (10(1)-10(5) cfu/ml). other three types of listeria spp., staphylococcus aureus and vibrio parahaemolyticus were also detected to conduct the cross-reaction analysis. meanwhile, contaminated milk samples were pre ...201324010365
characterization of carnobacterium maltaromaticum lma 28 for its positive technological role in soft cheese making.carnobacterium maltaromaticum is a lactic acid bacterium isolated from soft cheese. the objective of this work was to study its potential positive impact when used in cheese technology. phenotypic and genotypic characterization of six strains of c. maltaromaticum showed that they belong to different phylogenetic groups. although these strains lacked the ability to coagulate milk quickly, they were acidotolerant. they did not affect the coagulation capacity of starter lactic acid bacteria, lactoc ...201324010601
16s rrna partial gene sequencing for the differentiation and molecular subtyping of listeria species.use of 16s rrna partial gene sequencing within the regulatory workflow could greatly reduce the time and labor needed for confirmation and subtyping of listeria monocytogenes. the goal of this study was to build a 16s rrna partial gene reference library for listeria spp. and investigate the potential for 16s rrna molecular subtyping. a total of 86 isolates of listeria representing l. innocua, l. seeligeri, l. welshimeri, and l. monocytogenes were obtained for use in building the custom library. ...201324010602
use of marination for controlling salmonella enterica and listeria monocytogenes in raw beef.the effect of marination on the survival and growth of the pathogens salmonella enterica and listeria monocytogenes on beef pieces was investigated. five marinades were used: soy sauce base marinade without (sb) or with lactic acid (sbla), red wine base marinade without (wb) or with 0.5% v/v oregano essential oil (wbo), and sterile saline used as control (c). inoculated fresh beef pieces were marinated for 18 h at 5 °c, removed from the marinade and subjected to storage trials at 5 °c and 15 °c. ...201324010604
listeria monocytogenes and ready-to-eat seafood in spain: study of prevalence and temperatures at retail.the aim of this study was to obtain data from refrigerated ready-to-eat seafood products at retail in spain (young eels, crabstick and smoked salmon), regarding prevalence and levels of listeria monocytogenes, storage temperatures and the impact of transport conditions (type of bag) on the temperature of the product. the one-year surveillance period was carried out according to the ec regulation no. 2073/2005, taking 5 units/batch and analyzing 250 samples following iso 11290-1/a1 and iso 11290- ...201324010619
quantifying listeria monocytogenes prevalence and concentration in minced pork meat and estimating performance of three culture media from presence/absence microbiological testing using a deterministic and stochastic approach.listeria monocytogenes poses a serious threat to public health, and the majority of cases of human listeriosis are associated with contaminated food. reliable microbiological testing is needed for effective pathogen control by food industry and competent authorities. the aims of this work were to estimate the prevalence and concentration of l. monocytogenes in minced pork meat by the application of a bayesian modeling approach, and also to determine the performance of three culture media commonl ...201324010622
efficacy of chlorine and peroxyacetic acid on reduction of natural microflora, escherichia coli o157:h7, listeria monocyotgenes and salmonella spp. on mung bean sprouts.sprouts-related outbreaks have risen due to increased raw sprouts consumption. to minimize such cases, chemical sanitations are applied. while chlorine is commonly used, concerns with its effectiveness and health implication have prompted researchers to seek alternatives. peroxyacetic acid (paa) has shown efficacy in inactivating foodborne pathogens on fresh vegetables, and hence could be considered as an alternative. thus, the objective of this study was to compare the efficacy of chlorine and ...201324010631
long-term consequences of foodborne infections.foodborne infections with campylobacter, e. coli o157:h7, listeria monocytogenes, salmonella, shigella, toxoplasma gondii, and other pathogens can result in long-term sequelae to numerous organ systems. these include irritable bowel syndrome, inflammatory bowel disease, reactive arthritis, hemolytic uremic syndrome, chronic kidney disease, guillain-barré syndrome, neurological disorders from acquired and congenital listeriosis and toxoplasmosis, and cognitive and developmental deficits due to di ...201324011832
in vitro evaluation of antimicrobial activities of various commercial essential oils, oleoresin and pure compounds against food pathogens and application in ham.the purpose of this research was to evaluate the application of commercially available essential oils (eos) and oleoresins to control bacterial pathogens for ready to eat food. in this study, sixty seven commercial eos, oleoresins (ors) and pure compounds were used to evaluate in vitro their antimicrobial activity against six food pathogens. these products were first screened for their antimicrobial activity using disk diffusion assay. forty one products were then chosen for further analysis to ...201424012976
listeria monocytogenes strains encoding premature stop codons in inla invade mice and guinea pig fetuses in orally dosed dams.listeria monocytogenes is an important food-borne bacterial pathogen and listeriosis can result in abortions in pregnant women. the bacterium can colonize food-processing environments, where specific molecular subtypes can persist for years. the purpose of this study was to determine the virulence potential of a group of food-processing persistent l. monocytogenes strains encoding a premature stop codon in inla (encoding internalin a) by using two orally dosed models, pregnant mice and pregnant ...201324014646
rhombencephalitis by listeria monocytogenes in a cirrhotic patient: a case report and literature review.we report a case of rhombencephalitis infection by listeria monocytogenes in a 66-year-old man with cirrhosis. the csf analysis indicated l. monocytogenes as the most likely pathogen. blood and csf culture were positive to l. monocytogenes and mri findings were suggestive of rhomboencephalitis. the treatment was started empirically and then modified when the culture results were available. the patient had a full clinical recovery without neurologic sequelae. clinicians should remember that l. mo ...201324018504
contamination of poultry products with listeria monocytogenes at poultry processing plants.this study aimed to confirm that poultry products packed at poultry processing plants have already been contaminated with listeria monocytogenes and that poultry products contaminated with l. monocytogenes are derived from broiler flocks infected with l. monocytogenes. l. monocytogenes was isolated from 16.8% (58/345) of chicken breast products and 2.3% (8/345) of chicken liver products. in contrast, l. monocytogenes was isolated from the pooled cecal content sample from only 1 (4%) of 25 flocks ...201424018827
effect of various conditions on inactivation of escherichia coli o157:h7, salmonella typhimurium, and listeria monocytogenes in fresh-cut lettuce using ultraviolet radiation.the effect of various conditions on inactivation of foodborne pathogens and quality of fresh-cut lettuce during ultraviolet (254 nm, uvc) radiation was investigated. lettuce was inoculated with a cocktail of escherichia coli o157:h7, salmonella typhimurium, and listeria monocytogenes and treated at different temperatures (4 and 25 °c), distances between sample and lamp (10 and 50 cm), type of exposure (illuminated from one or two sides), uv intensities (1.36 to 6.80 mw/cm²), and exposure times ( ...201324021819
characterisation of the transcriptomes of genetically diverse listeria monocytogenes exposed to hyperosmotic and low temperature conditions reveal global stress-adaptation mechanisms.the ability of listeria monocytogenes to adapt to various food and food- processing environments has been attributed to its robustness, persistence and prevalence in the food supply chain. to improve the present understanding of molecular mechanisms involved in hyperosmotic and low-temperature stress adaptation of l. monocytogenes, we undertook transcriptomics analysis on three strains adapted to sub-lethal levels of these stress stimuli and assessed functional gene response. adaptation to hyper ...201324023890
survival of foodborne pathogens on inshell walnuts.the survival of salmonella enterica enteritidis pt 30 or five-strain cocktails of s. enterica, escherichia coli o157:h7, and listeria monocytogenes was evaluated on inshell walnuts during storage. inshell walnuts were separately inoculated with an aqueous preparation of the pathogens at levels of 10 to 4 log cfu/nut, dried for 24 h, and then stored at either 4 °c or ambient conditions (23-25 °c, 25-35% relative humidity) for 3 weeks to more than 1 year. during the initial 24-h drying period, bac ...201324026009
antibacterial effect of light emitting diodes of visible wavelengths on selected foodborne pathogens at different illumination temperatures.the antibacterial effect of light emitting diodes (leds) in the visible region (461, 521 and 642 nm) of the electromagnetic spectrum was investigated on escherichia coli o157:h7, salmonella typhimurium, listeria monocytogenes and staphylococcus aureus. the irradiances of the 461, 521 and 642 nm leds were 22.1, 16 and 25.4 mw/cm², respectively. bacterial cultures suspended in tryptic soy broth were illuminated by 10-watt leds at a distance of 4.5 cm for 7.5h at 20, 15 and 10 °c. regardless of the ...201324026011
molecular analysis of the iap gene of listeria monocytogenes isolated from cheeses in rio grande do sul, brazil.the polymorphic region sequences in the iap gene were analyzed in 25 strains of listeria monocytogenes isolated from cheeses in the state of rio grande do sul, and compared with reference strains. this investigation distinguished two clusters of l. monocytogenes: i (20 strains) and ii (5 strains).200824031198
epidemiological survey of listeria monocytogenes in a gravlax salmon processing line.listeria monocytogenes is a cause of concern to food industries, mainly for those producing ready-to-eat (rte) products. this microorganism can survive processing steps such as curing and cold smoking and is capable of growing under refrigeration temperatures. its presence in rte fish products with extended shelf life may be a risk to the susceptible population. one example of such a product is gravlax salmon; a refrigerated fish product not exposed to listericidal processes and was the subject ...200824031233
behaviour of l. monocytogenes in sliced, vacuum-packed mortadella.this study evaluated the growth of naturally occurring l. monocytogenes in sliced, vacuum-packed mortadella samples during storage at 5°c until the expiration date. tukey's test indicated that counts of l. monocytogenes on 0, 10, 20, 30 and 40 days of storage were significantly different (p<0.05), indicating growth during shelf life. in three trials, the mean increase was 1.72 log cycles. vacuum packing and storage under refrigeration were not effective in controlling the growth of l. monocytoge ...200824031257
quantitative evaluation of listeria monocytogenes in fresh and processed surubim fish (pseudoplatystoma sp).l. monocytogenes is a foodborne psychrotrophic bacterial pathogen of special importance for minimally processed foods. in this work, it was enumerated in samples of surubim fish by mpn technique. the population of l. monocytogenes was estimated as < 0.012 mpn/cm(2) in fresh and < 0.03 mpn/g in minimally processed fish.200824031260
characterization of listeria monocytogenes isolated from a fresh mixed sausage processing line in pelotas-rs by pfge.listeria monocytogenes is a bacterium capable to adhere to the surfaces of equipment and utensils and subsequently form biofilms. it can to persist in the food processing environmental for extended periods of time being able to contaminate the final product. the aim of this study was to trace the contamination route of l. monocytogenes on a fresh mixed sausage processing line, from raw material to the final product. the isolates obtained were characterized by serotyping and molecular typing by p ...200924031402
potential of chitosan from mucor rouxxi ucp064 as alternative natural compound to inhibit listeria monocytogenes.listeria monocytogenes is widely distributed in nature and the infection listeriosis is recognized as a potential threat for human health because of its mortality rate. the objective of this study was to evaluate the growth profile and chitosan production by mucor rouxxi ucp 064 grown in yam bean (pachyrhizus erosus l. urban) medium. it was also to assess the anti-l. monocytogenes efficacy of the obtained chitosan. higher values of biomass of m. rouxxi (16.9 g.l(-1)) and best yield of chitosan ( ...200924031403
antibacterial and antioxidant activities of acid and bile resistant strains of lactobacillus fermentum isolated from miang.miang is a kind of traditional fermented tea leaves, widely consumed in northern thailand as a snack. it contains several kinds of lactobacilli spp. the aim of this study was to isolate strains of lactobacillus fermentum from miang and to investigate their antibacterial and antioxidant activities. the agar spot and well assays were used for determination of antibacterial power. the antibacterial mechanism was investigated by cell morphologic change under scanning electron microscope (sem). antio ...200924031422
antimicrobial activity of enterococcus faecium fair-e 198 against gram-positive pathogens.this study investigated the antimicrobial activity of enterococcus faecium fair-e 198 against bacillus cereus, listeria monocytogenes and staphylococcus aureus. using the critical-dilution method, the bacteriocin produced by e. faecium fair-e 198 inhibited all l. monocytogenes strains evaluated (1,600 to 19,200 au ml(-1)). however, none of the b. cereus and s. aureus strains investigated were inhibited. the maximum activity of this bacteriocin (800 au ml(-1)) was observed in mrs broth, while the ...201024031466
biofilm formation by listeria monocytogenes on stainless steel surface and biotransfer potential.an experimental model was proposed to study biofilm formation by listeria monocytogenes atcc 19117 on aisi 304 (#4) stainless steel surface and biotransfer potential during this process. in this model, biofilm formation was conducted on the surface of stainless steel coupons, set on a stainless steel base with 4 divisions, each one supporting 21 coupons. trypic soy broth was used as bacterial growth substrate, with incubation at 37 °c and stirring of 50 rpm. the number of adhered cells was deter ...201024031469
production of bacteriocin-like substances by lactic acid bacteria isolated from regional ovine cheese.lactic acid bacteria (lab) were isolated from ovine milk and cheeses manufactured in the south region of brazil. among 112 bacterial isolates investigated, 59 were chosen through a screening for lab. among these 59 strains of lab, 21% showed antimicrobial, proteolytic and lipolytic activities. based on this screening, lactobacillus plantarum lcn 17 and lactobacillus rhamnosus lcn 43 were selected and tested for the production of bacteriocin-like substances (bls). the bls produced by both isolate ...201024031581
quantification of biofilm production on polystyrene by listeria, escherichia coli and staphylococcus aureus isolated from a poultry slaughterhouse.this study assessed biofilm formation on polystyrene by staphylococcus aureus, listeria monocytogenes, l. welshimeri and escherichia coli, isolated from a slaughtering plant, grown on tryptic soy broth (tsb) using different glucose concentrations. the tested bacteria produced biofilm in at least one of the concentrations used, and some of them were strong biofilm producers.201024031590
expression of virulence genes by listeria monocytogenes j0161 in natural environment.majority of studies concerning the gene expression of listeria monocytogenes have been done on pure culture states. our objective was to study l.monocytogenes in a co-cultured state and to understand if microbes in their natural state of existence are different in their expression than that of the purely cultured lab grown forms. for a long period discussions have been on the expression of prfa, (which is a virulence gene regulator) in a mammalian host and its role in causing the switch from a s ...201224031897
activity of disinfectants against foodborne pathogens in suspension and adhered to stainless steel surfaces.the purpose of this study was to investigate and compare the efficacy of various disinfectants on planktonic cells and biofilm cells of listeria monocytogenes, staphylococcus aureus and escherichia coli. numbers of viable biofilm cells decreased after treatment with all tested disinfectants (iodine, biguanide, quaternary ammonium compounds, peracetic acid and sodium hypochlorite). sodium hypochlorite was the most effective disinfectant against biofilm cells, while biguanide was the least effecti ...201224031935
bacteriophage amplification assay for detection of listeria spp. using virucidal laser treatment.a protocol for the bacteriophage amplification technique was developed for quantitative detection of viable listeria monocytogenes cells using the a511 listeriophage with plaque formation as the end-point assay. laser and toluidine blue o (tbo) were employed as selective virucidal treatment for destruction of exogenous bacteriophage. laser and tbo can bring a total reduction in titer phage (ca. 10(8) pfu/ml) without affecting the viability of l. monocytogenes cells. artificially inoculated skimm ...201224031937
inhibition of listeria monocytogenes in minas frescal cheese by free and nanovesicle-encapsulated nisin.the effectiveness of free and nanovesicle-encapsulated nisin to control listeria monocytogenes in minas frescal cheese was investigated. commercial nisin was encapsulated into liposomes of partially purified soy lecithin. free (0.1 mg/ml and 0.25 mg/ml) and nanovesicle-encapsulated nisin (0.25 mg/ml) were applied onto the surface of cheese samples, and l. monocytogenes was inoculated before incubation at 6-8°c for 28 days. a bactericidal effect was observed with 0.25 mg/ml free nisin; a bacterio ...201224031971
molecular characterization of listeria monocytogenes isolated from fresh seafood samples in iran.among all species of listeria, listeria monocytogenes (l. monocytogenes) is a major pathogenic microorganism of humans and animals and l. ivanovii is rarely pathogenic for humans. the objective of this study was to isolate and characterize listeria species and to determine the frequencies of virulence genes in l. monocytogenes serotypes in fresh fish, shrimp, crab and lobster in isfahan and shahrekord, iran.201324033984
antibacterial and antifungal activity of photoactivated zno nanoparticles in suspension.antibacterial activity of photoactivated zinc oxide nanoparticles (zno nps) against human pathogens escherichia coli o157:h7, listeria monocytogenes atcl3c 7644 and plant pathogen botrytis cinerea was investigated. data indicate that photoactivated (λ = 400 nm) zno nps at concentration 1 × 10(-3)m and incubation time 60 min reduced population of both bacteria by 7 log (cfu/ml). clear dependence of antimicrobial properties of zno nps on used concentration and incubation time was found. scanning e ...201324035847
clay mineral type effect on bacterial enteropathogen survival in soil.enteropathogens released into the environment can represent a serious risk to public health. soil clay content has long been known to have an important effect on enteropathogen survival in soil, generally enhancing survival. however, clay mineral composition in soils varies, and different clay minerals have specific physiochemical properties that would be expected to impact differentially on survival. this work investigated the effect of clay materials, with a predominance of a particular minera ...201424035982
microbiological quality of ready-to-eat salads: an underestimated vehicle of bacteria and clinically relevant antibiotic resistance genes.the increase demand for fresh vegetables is causing an expansion of the market for minimally processed vegetables along with new recognized food safety problems. to gain further insight on this topic we analyzed the microbiological quality of portuguese ready-to-eat salads (rts) and their role in the spread of bacteria carrying acquired antibiotic resistance genes, food products scarcely considered in surveillance studies. a total of 50 rts (7 brands; split or mixed leaves, carrot, corn) were co ...201324036261
phage display-derived binders able to distinguish listeria monocytogenes from other listeria species.the objective of this study was to produce phage display-derived binders with the ability to distinguish listeria monocytogenes from other listeria spp., which may have potential utility to enhance detection of listeria monocytogenes. to obtain binders with the desired binding specificity a series of surface and solution phage-display biopannings were performed. initially, three rounds of surface biopanning against gamma-irradiated l. monocytogenes serovar 4b cells were performed followed by an ...201324040227
fetal bacterial infections in antepartum stillbirth: a case series.this study aims to assess the frequency of fetal bacterial infections in stillbirth (sb) and to evaluate the best samples for the diagnosis of infection-related sb.201324041816
atypical mitochondrial fission upon bacterial infection.we recently showed that infection by listeria monocytogenes causes mitochondrial network fragmentation through the secreted pore-forming toxin listeriolysin o (llo). here, we examine factors involved in canonical fusion and fission. strikingly, llo-induced mitochondrial fragmentation does not require the traditional fission machinery, as drp1 oligomers are absent from fragmented mitochondria following listeria infection or llo treatment, as the dynamin-like protein 1 (drp1) receptor mff is rapid ...201324043775
adenovirus-based vaccine against listeria monocytogenes: extending the concept of invariant chain linkage.the use of replication-deficient adenoviruses as vehicles for transfer of foreign genes offers many advantages in a vaccine setting, eliciting strong cellular immune responses involving both cd8(+) and cd4(+) t cells. further improving the immunogenicity, tethering of the inserted target ag to mhc class ii-associated invariant chain (ii) greatly enhances both the presentation of most target ags, as well as overall protection against viral infection, such as lymphocytic choriomeningitis virus (lc ...201324043891
cutting edge: tlr signaling licenses irak1 for rapid activation of the nlrp3 inflammasome.activation of the nlrp3 inflammasome by diverse stimuli requires a priming signal from tlrs and an activation signal from purinergic receptors or pore-forming toxins. in this study, we demonstrate, through detailed analysis of nlrp3 activation in macrophages deficient in key downstream tlr signaling molecules, that myd88 is required for an immediate early phase, whereas toll/il-1r domain-containing adapter inducing ifn-β is required for a subsequent intermediate phase of posttranslational nlrp3 ...201324043892
identifying the initiating events of anti-listeria responses using mice with conditional loss of ifn-γ receptor subunit 1 (ifngr1).although ifn-γ is required for resolution of listeria monocytogenes infection, the identities of the ifn-γ-responsive cells that initiate the process remain unclear. we addressed this question using novel mice with conditional loss of ifn-γr (ifngr1). itgax-cre(+)ifngr1(f/f) mice with selective ifn-γ unresponsiveness in cd8α(+) dendritic cells displayed increased susceptibility to infection. this phenotype was due to the inability of ifn-γ-unresponsive cd8α(+) dendritic cells to produce the init ...201324048899
immunomodulatory effects of danshen (salvia miltiorrhiza) in balb/c mice.danshen, the root and rhizome of salvia miltiorrhiza bge, a traditional chinese medicine, especially for cardiovascular and cerebrovascular diseases, has unique immunomodulatory effects. danshen is capable of anti-inflammation and antiallergy, which are immunosuppressive activities, whereas it is also able to promote immunity against cancer, viruses, and bacteria. most previous reports were performed with use of a purified compound or compounds of danshen. since there are more than twenty active ...201224049654
listeria monocytogenes brain abscess: two cases and review of the literature.listeria monocytogenes is a gram-positive bacillus that exhibits predilection to infect the central nervous system in immunocompromised individuals; the most common manifestations are meningitis and rhombencephalitis. listerial brain abscesses are rare. we report here two brain abscess cases caused by l. monocytogenes in patients receiving immunosuppressive agents. the first patient presented with left hemiparesis mimicking stroke and the second patient presented with neurological symptoms witho ...201324050079
isolation and quantification of highly acid resistant variants of listeria monocytogenes.heterogeneity in stress response of bacteria is one of the biggest challenges posed by minimal processing, which aims at finding the balance between microbiologically stable foods while maintaining the characteristics of fresh products. in this study, exposure of listeria monocytogenes lo28 to acid stress, which can be encountered in the food processing environment as well as in the human body upon ingestion, led to inactivation kinetics showing considerable tailing, which was described by a bip ...201324051176
superior induction and maintenance of protective cd8 t cells in mice infected with mouse cytomegalovirus vector expressing rae-1γ.due to a unique pattern of cd8 t-cell response induced by cytomegaloviruses (cmvs), live attenuated cmvs are attractive candidates for vaccine vectors for a number of clinically relevant infections and tumors. nkg2d is one of the most important activating nk cell receptors that plays a role in costimulation of cd8 t cells. here we demonstrate that the expression of cd8 t-cell epitope of listeria monocytogenes by a recombinant mouse cmv (mcmv) expressing the nkg2d ligand retinoic acid early-induc ...201324052528
membrane chaperone secdf plays a role in the secretion of listeria monocytogenes major virulence factors.listeria monocytogenes is a gram-positive human intracellular pathogen that infects diverse mammalian cells. upon invasion, l. monocytogenes secretes multiple virulence factors that target host cellular processes and promote infection. it has been presumed, but was not empirically established, that the sec translocation system is the primary mediator of this secretion. here, we validate an important role for secdf, a component of the sec system, in the secretion of several critical l. monocytoge ...201324056100
listeria monocytogenes multidrug resistance transporters and cyclic di-amp, which contribute to type i interferon induction, play a role in cell wall stress.the intracellular bacterial pathogen listeria monocytogenes activates a robust type i interferon response upon infection. this response is partially dependent on the multidrug resistance (mdr) transporter mdrm and relies on cyclic-di-amp (c-di-amp) secretion, yet the functions of mdrm and cyclic-di-amp that lead to this response are unknown. here we report that it is not mdrm alone but a cohort of mdr transporters that together contribute to type i interferon induction during infection. in a sea ...201324056102
survival of bactericidal antibiotic treatment by a persister subpopulation of listeria monocytogenes.listeria monocytogenes can cause the serious infection listeriosis, which despite antibiotic treatment has a high mortality. understanding the response of l. monocytogenes to antibiotic exposure is therefore important to ensure treatment success. some bacteria survive antibiotic treatment by formation of persisters, which are a dormant antibiotic-tolerant subpopulation. the purpose of this study was to determine whether l. monocytogenes can form persisters and how bacterial physiology affects th ...201324056460
nsd1 mitigates caspase-1 activation by listeriolysin o in macrophages.mammals and plants share pathogen-sensing systems named nod-like receptors (nlrs). some nlrs form the inflammasome, a protein scaffold that regulates the secretion of interleukin (il)-1β and il-18 by cleaving catalytically inactive substrates into mature cytokines. here, we show an immune conservation between plant and mammalian nlrs and demonstrate that the murine nuclear receptor binding set domain protein 1 (nsd1), a protein that bears similarity to the nlr regulator enhanced downy mildew 2 ( ...201324058709
roles of a novel crp/fnr family transcription factor lmo0753 in soil survival, biofilm production and surface attachment to fresh produce of listeria monocytogenes.listeria monocytogenes is a foodborne bacterial pathogen and the causative agent of an infectious disease, listeriosis. l. monocytogenes is ubiquitous in nature and has the ability to persist in food processing environments for extended periods of time by forming biofilms and resisting industrial sanitization. human listeriosis outbreaks are commonly linked to contaminated dairy products, ready-to-eat meats, and in recent years, fresh produce such as lettuce and cantaloupes. we identified a puta ...201324066185
pulsed-field gel electrophoresis proficiency testing trials: toward european harmonization of the typing of food and clinical strains of listeria monocytogenes.the european union reference laboratory for listeria monocytogenes (eurl for lm) coordinates a european network of 35 national reference laboratories (nrls), most of which perform food, environmental, and veterinary lm strain surveillance in their respective countries. the eurl activities resulted in the recent creation of a database (eurl lm db). typing and related epidemiological data submitted to the eurl lm db will be collected and shared by all the nrls. for a given nrl, the only criterion ...201324066940
epstein barr virus-induced 3 (ebi3) together with il-12 negatively regulates t helper 17-mediated immunity to listeria monocytogenes infection.although the protective functions by t helper 17 (th17) cytokines against extracellular bacterial and fungal infection have been well documented, their importance against intracellular bacterial infection remains unclear. here, we investigated the contribution of th17 responses to host defense against intracellular bacteria listeria monocytogenes and found that th17 cell generation was suppressed in this model. unexpectedly, mice lacking both p35 and ebi3 cleared l. monocytogenes as efficiently ...201324068935
a mariner transposon-based signature-tagged mutagenesis system for the analysis of oral infection by listeria monocytogenes.listeria monocytogenes is a gram-positive foodborne pathogen and the causative agent of listerosis a disease that manifests predominately as meningitis in the non-pregnant individual or infection of the fetus and spontaneous abortion in pregnant women. common-source outbreaks of foodborne listeriosis are associated with significant morbidity and mortality. however, relatively little is known concerning the mechanisms that govern infection via the oral route. in order to aid functional genetic an ...201324069416
listeria monocytogenes strains isolated from dry milk samples in mexico: occurrence and antibiotic sensitivity.dry milk is a particular concern in mexico, as approximately 150,000 metric tons of dry milk are imported every year at a cost of around $250 million. dry milk is used to make many products, most of which are dairy products widely distributed among the population covered by welfare programs. the purpose of the study described in this article was to determine the presence of listeria spp. in imported dry milk samples in mexico, and to determine the sensitivity of the listeria monocytogenes isolat ...201324073487
chemical composition and bioactivity of essential oils of hypericum helianthemoides, hypericum perforatum and hypericum scabrum.a number hypericum species are well known for their therapeutic efficacy and use in traditional medicine. the various species of hypericum have been traditionally used for the treatment of wounds, eczema, burns, trauma, rheumatism, neuralgia, gastroenteritis, ulcers, hysteria, bedwetting and depression.201424073965
differential roles of klf4 in the development and differentiation of cd8+ t cells.the transcription factor krüppel-like factor 4 (klf4) can activate or repress gene expression in a cell-context dependent manner. we have previously shown that klf4 inhibits the proliferation of naïve cd8(+) t cells in vitro downstream of the transcription factor elf4. in this work, we describe a novel role of klf4 in the differentiation of cd8(+) t cells upon infection. loss of klf4 had minimal effect on thymic t cell development and distribution of mature t cells in the spleen, blood, and lymp ...201724075846
evaluation of immunochromatography for the rapid and specific identification of listeria monocytogenes from food.to rapidly, simply and specifically detect and identify listeria monocytogenes from food samples, an immunochromatographic assay, based on gold-labeled monoclonal antibodies directed against an antigen common to all serovars of l. monocytogenes, was used. all strains of l. monocytogenes serovars showed a positive reaction to the assay, but all other gram positive and negative bacteria did not. the detection limit of the assay was in the order of 10(6) cfu/ml in fluid medium. the assay could simp ...201324077539
[a case of spontaneous bacterial peritonitis caused by listeria monocytogenes].spontaneous bacterial peritonitis (sbp) is a life-threatening complication in patients with ascites caused by advanced liver disease. while gram negative bacteria, such as escherichia coli and klebsiella pneumonia are the common pathogens, listeria monocytogenes has been recognized as a very rare pathogen. empirical treatment with third generation cephalosporins does not provide adequate antibiotics coverage against l. monocytogenes. diagnosis is often delayed as it requires confirmation from as ...201324077630
risk factors associated with salmonella and listeria monocytogenes contamination of produce fields.identification of management practices associated with preharvest pathogen contamination of produce fields is crucial to the development of effective good agricultural practices (gaps). a cross-sectional study was conducted to (i) determine management practices associated with a salmonella- or listeria monocytogenes-positive field and (ii) quantify the frequency of these pathogens in irrigation and nonirrigation water sources. over 5 weeks, 21 produce farms in new york state were visited. field- ...201324077713
infective rhomboencephalitis and inverted takotsubo: neurogenic-stunned myocardium or myocarditis?here we originally describe the clinical scenario of a young immune-competent patient affected by acute rhomboencephalitis with severe parenchymal edema and acute hydrocephalus who developed sudden life-threatening cardiac derangement. hemodynamic and perfusion parameters revealed cardiogenic shock, so intensive circulatory support with epinephrine infusion and intra-aortic balloon pump was needed to restore organ perfusion. transesophageal echocardiographic examination showed severe left ventri ...201424079984
detection of listeria monocytogenes from selective enrichment broth using maldi-tof mass spectrometry.conventional methods used for primary detection of listeria monocytogenes from foods and subsequent confirmation of presumptive positive samples involve prolonged incubation and biochemical testing which generally require four to five days to obtain a result. in the current study, a simple and rapid proteomics-based maldi-tof ms approach was developed to detect l. monocytogenes directly from selective enrichment broths. milk samples spiked with single species and multiple species cultures were i ...201424080423
daptomycin activity against uncommonly isolated streptococcal and other gram-positive species groups.a total of 1,356 clinical isolates were tested against daptomycin by broth microdilution methods. daptomycin was active against seven groups of viridans group streptococci (mic50 and mic90 values ranging from ≤0.06 and ≤0.06 μg/ml [streptococcus bovis and streptococcus dysgalactiae] to 0.5 and 1 μg/ml [streptococcus mitis, streptococcus oralis, and streptococcus parasanguinis], respectively), beta-hemolytic streptococci serogroups c, f, and g (mic50 and mic90, ≤0.06 to 0.25 and 0.12 to 0.25 μg/m ...201324080651
interferon γ-induced intratumoral expression of cxcl9 alters the local distribution of t cells following immunotherapy with listeria monocytogenes.the ability of listeria monocytogenes-based anticancer vaccines to induce tumor regression depends on the responsiveness of malignant cells to interferon γ (ifnγ). inhibition of ifnγ limits the recruitment of t cells to the tumors of vaccinated mice. we hypothesized that vaccination with immunotherapeutic l. monocytogenes induces the ifnγ-dependent production of chemokines that regulate the migration of tumor-infiltrating t cells. to gain further insights into this issue, we examined the chemoki ...201324083082
imaging inlc secretion to investigate cellular infection by the bacterial pathogen listeria monocytogenes.bacterial intracellular pathogens can be conceived as molecular tools to dissect cellular signaling cascades due to their capacity to exquisitely manipulate and subvert cell functions which are required for the infection of host target tissues. among these bacterial pathogens, listeria monocytogenes is a gram positive microorganism that has been used as a paradigm for intracellular parasitism in the characterization of cellular immune responses, and which has played instrumental roles in the dis ...201324084755
simvastatin enhances protection against listeria monocytogenes infection in mice by counteracting listeria-induced phagosomal escape.statins are well-known cholesterol lowering drugs targeting hmg-coa-reductase, reducing the risk of coronary disorders and hypercholesterolemia. statins are also involved in immunomodulation, which might influence the outcome of bacterial infection. hence, a possible effect of statin treatment on listeriosis was explored in mice. statin treatment prior to subsequent l. monocytogenes infection strikingly reduced bacterial burden in liver and spleen (up to 100-fold) and reduced histopathological l ...201324086542
coadministration of polyinosinic:polycytidylic acid and immunostimulatory complexes modifies antigen processing in dendritic cell subsets and enhances hiv gag-specific t cell immunity.currently approved adjuvants induce protective ab responses but are more limited for generating cellular immunity. in this study, we assessed the effect of combining two adjuvants with distinct mechanisms of action on their ability to prime t cells: the tlr3 ligand, polyinosinic:polycytidylic acid (poly i:c), and immunostimulatory complexes (iscoms). each adjuvant was administered alone or together with hiv gag protein (gag), and the magnitude, quality, and phenotype of gag-specific t cell respo ...201324089189
nisin-activated hydrophobic and hydrophilic surfaces: assessment of peptide adsorption and antibacterial activity against some food pathogens.an effective antimicrobial packaging or food contact surface should be able to kill or inhibit micro-organisms that cause food-borne illnesses. setting up such systems, by nisin adsorption on hydrophilic and hydrophobic surfaces, is still a matter of debate. for this purpose, nisin was adsorbed on two types of low-density polyethylene: the hydrophobic native film and the hydrophilic acrylic acid-treated surface. the antibacterial activity was compared for those two films and it was highly depend ...201324092009
central nervous system infection by listeria monocytogenes in patients with systemic lupus erythematosus: analysis of 26 cases, including the report of a new case.infections in patients with systemic lupus erythematosus cause significant morbidity. infection due to listeria monocytogenes (lm) is considered an opportunistic disease, and has been published on rare occasions in patients with sle.201324094430
tn6188 - a novel transposon in listeria monocytogenes responsible for tolerance to benzalkonium chloride.controlling the food-borne pathogen listeria (l.) monocytogenes is of great importance from a food safety perspective, and thus for human health. the consequences of failures in this regard have been exemplified by recent large listeriosis outbreaks in the usa and europe. it is thus particularly notable that tolerance to quaternary ammonium compounds such as benzalkonium chloride (bc) has been observed in many l. monocytogenes strains. however, the molecular determinants and mechanisms of bc tol ...201324098567
influence of temperature on acid-stress adaptation in listeria monocytogenes.our findings show that temperature plays a significant role in the induction of acid-stress adaptation in listeria monocytogenes, and two distinct patterns were observed: (1) presence of sublethal acid at 37°c or 22°c significantly induced acid-stress adaptation; and (2) presence of sublethal acid at 4°c did not induce any acid-stress adaptation. both patterns were confirmed by two experimental models: (1) l. monocytogenes cells were first grown at 37°c and then exposed to sublethal acid at 37°c ...201424102079
kinetics of biofilm formation and desiccation survival of listeria monocytogenes in single and dual species biofilms with pseudomonas fluorescens, serratia proteamaculans or shewanella baltica on food-grade stainless steel surfaces.this study investigated the dynamics of static biofilm formation (100% rh, 15 °c, 48-72 h) and desiccation survival (43% rh, 15 °c, 21 days) of listeria monocytogenes, in dual species biofilms with the common spoilage bacteria, pseudomonas fluorescens, serratia proteamaculans and shewanella baltica, on the surface of food grade stainless steel. the gram-negative bacteria reduced the maximum biofilm population of l. monocytogenes in dual species biofilms and increased its inactivation during desi ...201324102145
inactivation of the seca2 protein export pathway in listeria monocytogenes promotes cell aggregation, impacts biofilm architecture and induces biofilm formation in environmental condition.listeria monocytogenes has a dichotomous lifestyle, existing as an ubiquitous saprophytic species and as an opportunistic intracellular pathogen. besides its capacity to grow in a wide range of environmental and stressful conditions, l. monocytogenes has the ability to adhere to and colonize surfaces. morphotype variation to elongated cells forming rough colonies has been reported for different clinical and environmental isolates, including biofilms. this cell differentiation is mainly attribute ...201424102749
amythiamicin d and related thiopeptides as inhibitors of the bacterial elongation factor ef-tu: modification of the amino acid at carbon atom c2 of ring c dramatically influences activity.three analogues of amythiamicin d, which differ in the substitution pattern at the methine group adjacent to c2 of the thiazole ring c, were prepared by de novo total synthesis. in amythiamicin d, this carbon atom is (s)-isopropyl substituted. two of the new analogues carry a hydroxymethyl in place of the isopropyl group, one at an s- (compound 3 a) and the other at an r-configured stereogenic center (3 b). the third analogue, 3 c, contains a benzyloxymethyl group at an s-configured stereogenic ...201324106106
listeria monocytogenes meningitis in adults: the czech republic experience.listeria monocytogenes (lm) is currently the third most frequent pathogen of bacterial meningitis in adults.201324106719
listeria infection inhibits ige production in regional lymph nodes by suppressing chemotaxis of basophils to lymph nodes.infection with listeria induces a dominant shift to the th1 immune response and inhibits the th2 response. papain is frequently utilized in animal models of allergies. papain administration induces chemotaxis of basophils to regional lymph nodes (lns) and production of interleukin (il)-4 by basophils, resulting in a th2-dominant status and increased ige production in lns. in this model, production of immunoglobulin (ig) e by ln cells is primarily controlled by il-4 produced by basophils. based o ...201324111499
survival of listeria monocytogenes during production and ripening of traditional turkish savak tulum cheese and in synthetic gastric fluid.this study investigated the survival and acid tolerance of listeria monocytogenes during the 2-day processing stage and 90-day ripening of savak tulum cheese, a traditional cheese in turkey. experimental savak tulum cheese was produced from raw sheep's milk that was inoculated with a l. monocytogenes mixture consisting of five strains (average 7.0 log cfu/ml) and was ripened at 6°c for 90 days. microbiological and chemical analyses and acid exposure experiments in synthetic gastric fluid (sgf) ( ...201324112584
biotic and abiotic soil properties influence survival of listeria monocytogenes in soil.listeria monocytogenes is a food-borne pathogen responsible for the potentially fatal disease listeriosis and terrestrial ecosystems have been hypothesized to be its natural reservoir. therefore, identifying the key edaphic factors that influence its survival in soil is critical. we measured the survival of l. monocytogenes in a set of 100 soil samples belonging to the french soil quality monitoring network. this soil collection is meant to be representative of the pedology and land use of the w ...201324116083
microbial diversity and structure are drivers of the biological barrier effect against listeria monocytogenes in soil.understanding the ecology of pathogenic organisms is important in order to monitor their transmission in the environment and the related health hazards. we investigated the relationship between soil microbial diversity and the barrier effect against listeria monocytogenes invasion. by using a dilution-to-extinction approach, we analysed the consequence of eroding microbial diversity on l. monocytogenes population dynamics under standardised conditions of abiotic parameters and microbial abundanc ...201324116193
antilisterial activity of lactose monolaurate in milk, drinkable yogurt and cottage cheese.lactose monolaurate (lml) was previously found to be an antimicrobial against listeria monocytogenes in culture medium at concentrations between 3 and 5 mg ml(-1) . in this study, the microbial inhibitory activity of lml in dairy products inoculated with a 5-strain cocktail of clinical isolates of l. monocytogenes was investigated. addition of lml at a concentration of 5 mg ml(-1) resulted in 4.4, 4.0 and 4.2 log reductions in 0.5% fat, 1% fat and 3.25% fat milks, respectively; 4.1, 4.4, and 3.5 ...201424117896
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