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investigating the therapeutic potential of herbal leads against drug resistant listeria monocytogenes by computational virtual screening and in vitro assays.listeria monocytogenes, a gram-positive opportunistic food-borne pathogen, naturally resistant to many antibiotics and acquired resistance may be a concern in the nearer future. hence, there is a scope for screening of novel therapeutic agents and drug targets, toward the treatment of fatal listeria infections. the seca homologs, seca1 and seca2 are the essential components of the general secretion (sec) pathway, a specialised protein export system, present in l. monocytogenes. this study evalua ...201525562366
a diverse range of bacterial and eukaryotic chitinases hydrolyzes the lacnac (galβ1-4glcnac) and lacdinac (galnacβ1-4glcnac) motifs found on vertebrate and insect cells.there is emerging evidence that chitinases have additional functions beyond degrading environmental chitin, such as involvement in innate and acquired immune responses, tissue remodeling, fibrosis, and serving as virulence factors of bacterial pathogens. we have recently shown that both the human chitotriosidase and a chitinase from salmonella enterica serovar typhimurium hydrolyze lacnac from galβ1-4glcnacβ-tetramethylrhodamine (lacnac-tmr (galβ1-4glcnacβ(ch2)8conh(ch2)2nhco-tmr)), a fluorescen ...201525561735
acipensins - novel antimicrobial peptides from leukocytes of the russian sturgeon acipenser gueldenstaedtii.antimicrobial peptides (amps) play an important role in the innate defense mechanisms in humans and animals. we have isolated and studied a set of antimicrobial peptides from leukocytes of the russian sturgeon acipenser gueldenstaedtii belonging to a subclass of chondrosteans, an ancient group of bony fish. structural analysis of the isolated peptides, designated as acipensins (ac), revealed in leukocytes of the russian sturgeon six novel peptides with molecular masses of 5336.2 da, 3803.0 da, 5 ...201425558400
[prosthetic hip infection due to listeria monocytogenes: review of the literature and case report].with the ageing of the population, articular prosthetic replacements are becoming more and more frequent. one of the most feared complications is prosthetic infection, mostly due to bacteria of the cutaneous flora. listeria monocytogenes is rarely the cause. this paper describes the management of a hip prosthetic infection due to listeria monocytogenes. the patient was cured with antimicrobial therapy and a two-stage exchange. this case report creates an opportunity to review the literature in t ...201425549378
detection of listeria monocytogenes with short peptide fragments from class iia bacteriocins as recognition elements.we employed a direct peptide-bacteria binding assay to screen peptide fragments for high and specific binding to listeria monocytogenes. peptides were screened from a peptide array library synthesized on cellulose membrane. twenty four peptide fragments (each a 14-mer) were derived from three potent anti-listerial peptides, leucocin a, pediocin pa1, and curvacin a, that belong to class iia bacteriocins. fragment leu10 (geafsagvhrlang), derived from the c-terminal region of leucocin a, displayed ...201525548942
exploring the diversity of listeria monocytogenes biofilm architecture by high-throughput confocal laser scanning microscopy and the predominance of the honeycomb-like morphotype.listeria monocytogenes is involved in food-borne illness with a high mortality rate. the persistence of the pathogen along the food chain can be associated with its ability to form biofilms on inert surfaces. while most of the phenotypes associated with biofilms are related to their spatial organization, most published data comparing biofilm formation by l. monocytogenes isolates are based on the quantitative crystal violet assay, which does not give access to structural information. using a hig ...201525548046
antimicrobial and mosquitocidal activity of microbial synthesized silver nanoparticles.microbial synthesis of nanoparticles is a green approach that interconnects nanotechnology and microbial biotechnology. here, we synthesized the silver nanoparticles (agnps) using bacterial strains of listeria monocytogenes, bacillus subtilius and streptomyces anulatus. we tested the efficacy of agnps against the larvae, pupae and adults of anopheles stephensi and culex quinquefasciatus. we have also investigated the antifungal activity of agnps against the soil keratinophilic fungus of chrysosp ...201525544704
deciphering host genotype-specific impacts on the metabolic fingerprint of listeria monocytogenes by ftir spectroscopy.bacterial pathogens are known for their wide range of strategies to specifically adapt to host environments and infection sites. an in-depth understanding of these adaptation mechanisms is crucial for the development of effective therapeutics and new prevention measures. in this study, we assessed the suitability of fourier transform infrared (ftir) spectroscopy for monitoring metabolic adaptations of the bacterial pathogen listeria monocytogenes to specific host genotypes and for exploring the ...201425541972
exploring the chicken embryo as a possible model for studying listeria monocytogenes pathogenicity.listeria monocytogenes is a bacterial pathogen capable of causing severe infections in humans, often with fatal outcomes. many different animal models exist to study l. monocytogenes pathogenicity, and we have investigated the chicken embryo as an infection model: what are the benefits and possible drawbacks? we have compared a defined wild-type strain with its isogenic strains lacking well-characterized virulence factors. our results show that wild-type l. monocytogenes, already at a relatively ...201425540772
whole-genome sequencing identifies an atypical listeria monocytogenes strain isolated from pet foods.four listeria isolates, including an atypical strain, were isolated from various pet foods and sequenced. we report here the draft genome sequences of these isolates and a comparative genomic analysis with a closely related human clinical isolate. an analysis of the atypical strain identified a frameshift mutation in the prfa gene.201425540336
intradermal administration of the type ii heat-labile enterotoxins lt-iib and lt-iic of enterotoxigenic escherichia coli enhances humoral and cd8+ t cell immunity to a co-administered antigen.vaccinations are extremely effective at combating infectious diseases. many conserved antigen (ag) targets, however, are poorly immunogenic. protein subunit vaccines frequently elicit only humoral immune responses and fail to confer protection against serious intracellular pathogens. these barriers to vaccine development are often overcome by the use of appropriate adjuvants. heat-labile enterotoxins (hlt) produced by enterotoxigenic strains of escherichia coli are potent adjuvants when administ ...201425536061
a prl mutation in secy suppresses secretion and virulence defects of listeria monocytogenes seca2 mutants.the bulk of bacterial protein secretion occurs through the conserved secy translocation channel that is powered by seca-dependent atp hydrolysis. many gram-positive bacteria, including the human pathogen listeria monocytogenes, possess an additional nonessential specialized atpase, seca2. seca2-dependent secretion is required for normal cell morphology and virulence in l. monocytogenes; however, the mechanism of export via this pathway is poorly understood. l. monocytogenes seca2 mutants form ro ...201525535272
host endoplasmic reticulum copii proteins control cell-to-cell spread of the bacterial pathogen listeria monocytogenes.listeria monocytogenes is a food-borne pathogen that uses actin-dependent motility to spread between human cells. cell-to-cell spread involves the formation by motile bacteria of plasma membrane-derived structures termed 'protrusions'. in cultured enterocytes, the secreted listeria protein inlc promotes protrusion formation by binding and inhibiting the human scaffolding protein tuba. here we demonstrate that protrusions are controlled by human copii components that direct trafficking from the e ...201525529574
isolation of listeria monocytogenes from milks used for iranian traditional cheese in lighvan cheese factories.traditional lighvan cheese is a semi-hard cheese which has a popular market in iran and neighboring countries. the aim of this study was evaluating the contamination of milks used for lighvan cheese making with listeria monocytogenes. raw milk samples were randomly collected from different cheese producing factories (sampling carried out from large milk tanks used cheese making in factories). isolation of l. monocytogenes was performed according to iso 11290 and biochemical tests were done to id ...201425528910
the microbiological quality of ready-to-eat salads in turkey: a focus on salmonella spp. and listeria monocytogenes.the microbiological safety of ready-to-eat (rte) foods is of special concern as they are not exposed to further processing before consumption. in the present study, listeria monocytogenes and salmonella spp. were isolated from 15(6%) and 21(8%) samples respectively out of 261 rte foods commercialized in turkey. escherichia coli was present in 10(4%) samples analyzed. psychrotrophic aerobic populations >6logcfu/g were found in 36 (14%) of the samples, while total coliforms were detected in 155 (5 ...201525528536
design and characterization of novel recombinant listeriolysin o-protamine fusion proteins for enhanced gene delivery.to improve the efficiency of gene delivery for effective gene therapy, it is essential that the vector carries functional components that can promote overcoming barriers in various steps leading to the transport of dna from extracellular to ultimately nuclear compartment. in this study, we designed genetically engineered fusion proteins as a platform to incorporate multiple functionalities in one chimeric protein. prototypes of such a chimera tested here contain two domains: one that binds to dn ...201525521817
schistosoma mansoni soluble egg antigens enhance t cell responses to a newly identified hiv-1 gag h-2b epitope.schistosome infection induces significant t helper type 2 (th2) and anti-inflammatory immune responses and has been shown to negatively impact vaccine efficacy. our goal was to determine if the administration of schistosome soluble egg antigens (sea) would negatively influence the induction of cytotoxic t lymphocyte (ctl) and th1-type t cell responses to an hiv candidate vaccine in the th1-biased c57bl/6 mouse strain. initial experiments failed, as we were unable to detect any response to the de ...201525520148
identification of listeria monocytogenes determinants required for biofilm formation.listeria monocytogenes is a gram-positive, food-borne pathogen of humans and animals. l. monocytogenes is considered to be a potential public health risk by the u.s. food and drug administration (fda), as this bacterium can easily contaminate ready-to-eat (rte) foods and cause an invasive, life-threatening disease (listeriosis). bacteria can adhere and grow on multiple surfaces and persist within biofilms in food processing plants, providing resistance to sanitizers and other antimicrobial agent ...201425517120
attached and planktonic listeria monocytogenes global proteomic responses and associated influence of strain genetics and temperature.contamination of industrial and domestic food usage environments by the attachement of bacterial food-borne pathogen listeria monocytogenes has public health and economic implications. comprehensive proteomics experiments using label-free liquid chromatography/tandem mass spectrometry were used to compare the proteomes of two different l. monocytogenes strains (siliken_1/2c and f2365_4b), which show very different capacities to attach to surfaces. growth temperature and strain type were highly i ...201525516393
inactivation of pathogenic listeria monocytogenes in raw milk by high hydrostatic pressure.the aim of this work was to investigate the mechanisms underlying the inactivation of listeria monocytogenes in raw milk under high hydrostatic pressure (hhp). the results showed that a 450-mpa treatment for 5 min could completely eliminate 10⁸ colony-forming units/ml of viable bacteria, as indicted by increased uptake of propidium iodide. morphological damage to the cell wall, cell membrane, and cytoplasmic components by hhp treatments was observed on scanning and transmission electron microgra ...201525514674
proteomic differences between listeria monocytogenes isolates from food and clinical environments.listeria monocytogenes is an organism associated with a wide range of foods. it causes listeriosis, a severe illness that mainly affects people with weakened immune systems. proteomic profiles of three different l. monocytogenes isolates were studied using 1d sds page, 2de and mass spectrometry. the protein banding patterns generated by 1d sds page of three strains of l. monocytogenes were found to be similar. visual observations from 2de gel maps revealed that certain spots appeared to have int ...201425513735
ruptured thoracic aortic aneurysm infected with listeria monocytogenes: a case report and a review of literature.a 75-year-old male with a history of alcoholic liver cirrhosis, sigmoid colon cancer, and metastatic liver cancer was admitted to our institution with a complaint of a prickly feeling in his chest. on admission, a chest radiograph revealed a normal cardio-thoracic ratio of 47%. echocardiography revealed pericardial effusion and blood chemical analyses revealed elevated c-reactive protein levels (14.7 mg/dl). on day 3, chest radiography revealed cardiomegaly with a cardio-thoracic ratio of 58% an ...201325512697
development and validation of a stochastic model for potential growth of listeria monocytogenes in naturally contaminated lightly preserved seafood.a new stochastic model for the simultaneous growth of listeria monocytogenes and lactic acid bacteria (lab) was developed and validated on data from naturally contaminated samples of cold-smoked greenland halibut (csgh) and cold-smoked salmon (css). during industrial processing these samples were added acetic and/or lactic acids. the stochastic model was developed from an existing deterministic model including the effect of 12 environmental parameters and microbial interaction (o. mejlholm and p ...201525500393
modeling transfer of escherichia coli o157:h7 and listeria monocytogenes during preparation of fresh-cut salads: impact of cutting and shredding practices.cutting and shredding of leafy vegetables increases the risk of cross contamination in household settings. the distribution of escherichia coli o157:h7 and listeria monocytogenes transfer rates (tr) between cutting knives and lettuce leaves was investigated and a semi-mechanistic model describing the bacterial transfer during consecutive cuts of leafy vegetables was developed. for both pathogens the distribution of log10trs from lettuce to knife was towards low values. conversely log10trs from k ...201525500391
investigating boundaries of survival, growth and expression of genes associated with stress and virulence of listeria monocytogenes in response to acid and osmotic stress.the objective of this study was to correlate the relative transcription of listeria monocytogenes (strains c5, 6179) stress- (gad2, sigb) and virulence- (prfa) associated genes following habituation at twenty-five ph (4.8, 5.0, 5.2, 5.5, 6.4) and nacl (2, 4, 6, 8, 10% w/v) combinations at 7 °c, with the survival against subsequent exposure to severe acid stress (ph 2.0 at 37 °c). our findings pointed out the inter-strain variation governing growth inhibiting conditions (ph ≤5.0 and nacl ≥6%), wh ...201525500389
comparison of individual-based modeling and population approaches for prediction of foodborne pathogens growth.individual-based modeling (ibm) approach combined with the microenvironment modeling of vacuum-packed cold-smoked salmon was more effective to describe the variability of the growth of a few listeria monocytogenes cells contaminating irradiated salmon slices than the traditional population models. the ibm approach was particularly relevant to predict the absence of growth in 25% (5 among 20) of artificially contaminated cold-smoked salmon samples stored at 8 °c. these results confirmed similar o ...201525500386
preparation, characterization, and antimicrobial activity of chitin nanofibrils reinforced carrageenan nanocomposite films.present study illustrates the preparation of chitin nanofibrils (cnf) reinforced carrageenan nanocomposite films by the solution-casting technique. cnf was prepared by acid hydrolysis of chitin, followed by high speed homogenization and sonication. ftir result demonstrated that the chemical structure of chitin had not changed after acid hydrolysis. however, the crystalinity of cnf was found to be higher than chitin. the crystallite size of chitin and cnf was 4.73 and 6.27 nm, respectively. the c ...201525498660
antimicrobial activity of hop extracts against foodborne pathogens for meat applications.the objective of this study was the fundamental investigation of the antimicrobial efficiency of various hop extracts against selected foodborne pathogens in vitro, as well as their activity against listeria monocytogenes in a model meat marinade and on marinated pork tenderloins.201525494620
the cyclic antibacterial peptide enterocin as-48: isolation, mode of action, and possible food applications.enterocin as-48 is a circular bacteriocin produced by enterococcus. it contains a 70 amino acid-residue chain circularized by a head-to-tail peptide bond. the conformation of enterocin as-48 is arranged into five alpha-helices with a compact globular structure. enterocin as-48 has a wide inhibitory spectrum on gram-positive bacteria. sensitivity of gram-negative bacteria increases in combination with outer-membrane permeabilizing treatments. eukaryotic cells are bacteriocin-resistant. this catio ...201425493478
essential oils from herbs against foodborne pathogens in chicken sausage.consumption of chicken meat and its products, especially sausage, have increased in recent years. however, this product is susceptible to microbial contamination during manufacturing, which compromises its shelf life. the flavoring and preservative activities of essential oils (eo) have been recognized and the application of these antimicrobial agents as natural active compounds in food preservation has shown promise. the aim of this study was to evaluate the effect of ocimum basilicum and origa ...201525492235
genetic distance in the whole-genome perspective on listeria monocytogenes strains f2-382 and nihs-28 that show similar subtyping results.genome subtyping approaches could provide useful epidemiological information regarding food pathogens. however, the full genomic diversity of strains that show similar subtyping results has not yet been completely explored. most subtyping methods are based on the differences of only a portion of the genome. we investigated two draft genome sequences of listeria monocytogenes strain f2-382 and nihs-28, which have been identified as closely related strains by subtyping (identical multi-virulence-l ...201425492229
potentially probiotic and bioprotective lactic acid bacteria starter cultures antagonise the listeria monocytogenes adhesion to ht29 colonocyte-like cells.the capability of five lactic acid bacteria (lab) to counteract the adhesion of listeria monocytogenes to the epithelial intestinal cell line ht29 was studied. the highest adhesion ability to ht29 was achieved by the intestinal strain lactobacillus rhamnosus ctc1679, followed by the meat-derived strains lactobacillus sakei ctc494 and enterococcus faecium ctc8005. surprisingly, the meat strains showed significantly better adhesion to ht29 than two faecal isolates of lactobacillus casei and even s ...201525488261
a novel method to detect listeria monocytogenes via superparamagnetic lateral flow immunoassay.a novel strip test system combining immunomagnetic separation with lateral flow immunoassay (lfia) was established for the accurate detection of listeria monocytogenes. in this system, a pair of matched monoclonal antibodies was used to construct a sandwich immunoassay, in which superparamagnetic particles were coupled with one of the antibodies as a labeled antibody to capture the target bacteria, while the other antibody was immobilized on the detection zone. after a 20-min reaction, the strip ...201525486917
regulation of autophagy by e3 ubiquitin ligase rnf216 through becn1 ubiquitination.autophagy is an evolutionarily conserved biological process involved in an array of physiological and pathological events. without proper control, autophagy contributes to various disorders, including cancer and autoimmune and inflammatory diseases. it is therefore of vital importance that autophagy is under careful balance. thus, additional regulators undoubtedly deepen our understanding of the working network, and provide potential therapeutic targets for disorders. in this study, we found tha ...201425484083
adxs-hpv: a therapeutic listeria vaccination targeting cervical cancers expressing the hpv e7 antigen.listeria monocytogenes is a bacterium that can be genetically modified to express fusion proteins with antigens specific to certain cancer models. this technology has been harnessed to develop adxs11-001, a vaccine that aims to elicit an immune response against human papillomavirus (hpv) oncoprotein e7.  pre-clinical studies assessing the efficacy of recombinant listeria vaccination targeting this same oncoprotein have consistently demonstrated successful reduction of in vivo tumor burden among ...201425483687
comparison of three bacillus amyloliquefaciens strains growth behaviour and evaluation of the spoilage risk during bread shelf-life.this study aims at the characterisation of growth behaviour of three strains of bacillus amyloliquefaciens, isolated from ropy bread (atcc8473), wheat grain (ispa-s109.3) and semolina (ispa-n9.1) to estimate rope spoilage risk in pan bread during shelf-life using the sym'previus tool. cardinal values and growth/no growth boundaries were determined in broth, while artificial spore inoculations were performed in dough for various pan bread recipes to compare experimental counts with in silico grow ...201525481056
association of histophilus somni with spontaneous abortions in dairy cattle herds from brazil.this study investigated the participation of infectious agents in spontaneous abortions and reproductive problems at eight dairy cattle herds from three geographical regions of brazil. fourteen aborted fetuses and the organ sections of one cow with history of repeated abortions were received for pathological evaluations and molecular diagnostics. pcr/rt-pcr assays targeted specific genes of abortifacient agents of cattle: bovine viral diarrhea virus (bvdv), bovine herpesvirus 1 (bohv-1), listeri ...201525480485
chitosan improves anti-biofilm efficacy of gentamicin through facilitating antibiotic penetration.antibiotic overuse is one of the major drivers in the generation of antibiotic resistant "super bugs" that can potentially cause serious effects on health. in this study, we reported that the polycationic polysaccharide, chitosan could improve the efficacy of a given antibiotic (gentamicin) to combat bacterial biofilms, the universal lifestyle of microbes in the world. short- or long-term treatment with the mixture of chitosan and gentamicin resulted in the dispersal of listeria monocytogenes (l ...201425479075
bacteriocinogenic lactococcus lactis subsp. lactis df04mi isolated from goat milk: evaluation of the probiotic potential.lactic acid bacteria capable of producing bacteriocins and presenting probiotic potential open innovative technological applications in the dairy industry. in this study, a bacteriocinogenic strain (lactococcus lactis subsp. lactis df4mi) was isolated from goat milk, and studied for its probiotic potential. lc. lactis df4mi was resistant to acidic ph and oxbile, presented co-aggregation with listeria monocytogenes, and was not affected by several drugs from different generic groups, being sensit ...201425477942
characterization of bacteriocin like inhibitory substance produced by a new strain brevibacillus borstelensis ag1 isolated from 'marcha'.in the present study, a bacterium isolated from marcha- a herbal cake used as traditional starter culture to ferment local wine in north east india, was evaluated for bacteriocin like inhibitory substance production and was tested against six food borne/spoilage causing pathogens viz. listeria monocytogenes mtcc 839, bacillus subtilis mtcc 121, clostridium perfringens mtcc 450, staphylococcus aureus, lactobacillus plantarum and leuconostoc mesenteroides mtcc 107 by using bit/disc method followed ...201425477937
complete genome sequence of listeria monocytogenes lm60, a strain with an enhanced cold adaptation capacity.the complete genome sequence of listeria monocytogenes lm60, a fast cold-adapting serotype 1/2a human isolate, is presented.201425477407
metal ion homeostasis in listeria monocytogenes and importance in host-pathogen interactions.listeria monocytogenes is responsible for one of the most life-threatening food-borne infections and the leading cause of food-poisoning associated deaths in the uk. infection may be of the unborn/newly born infant where disease may manifest as listeric abortion, stillbirth or late-onset neonatal listeriosis, while in adults, infection usually affects the central nervous system causing meningitis. crucial to the survival of l. monocytogenes, both inside and outside the host, is its ability to ac ...201425476765
magnetic bead based immuno-detection of listeria monocytogenes and listeria ivanovii from infant formula and leafy green vegetables using the bio-plex suspension array system.listeriosis, a disease contracted via the consumption of foods contaminated with pathogenic listeria species, can produce severe symptoms and high mortality in susceptible people and animals. the development of molecular methods and immuno-based techniques for detection of pathogenic listeria in foods has been challenging due to the presence of assay inhibiting food components. in this study, we utilize a macrophage cell culture system for the isolation and enrichment of listeria monocytogenes a ...201525475329
effect of listeria seeligeri or listeria welshimeri on listeria monocytogenes detection in and recovery from buffered listeria enrichment broth.the presence of multiple species of listeria in regulated food products is not uncommon and can complicate the recovery of listeria monocytogenes particularly on a non-differentiating medium. the potential complications of listeria seeligeri and listeria welshimeri on the recovery of l. monocytogenes from inoculated food test samples using the u.s. food and drug administration's (fda) selective enrichment procedure was investigated. post-enrichment enumeration, in the absence of food product, in ...201525475325
synergistic effect of gamma (γ)-irradiation and microencapsulated antimicrobials against listeria monocytogenes on ready-to-eat (rte) meat.oregano essential oil (origanum compactum; 250 μg/ml), cinnamon essential oil (cinnamomum cassia; 250 μg/ml) and nisin (16 μg/ml) were used alone or in combination to evaluate their efficiency to inhibit the growth of listeria monocytogenes on rte ham. microencapsulation of the antimicrobial formulations was done to verify the potential effect of the polymer to protect the antimicrobial efficiency during storage. combined treatments of antimicrobial formulation with γ-irradiation were done to ve ...201525475322
role of sigb and osmolytes in desiccation survival of listeria monocytogenes in simulated food soils on the surface of food grade stainless steel.this research aimed to determine whether the sigb (σ(b)) regulon and osmolytes impact the survival of the foodborne pathogen, listeria monocytogenes, during desiccation in simulated food soils with varying salt and nutrient contents on food grade stainless steel (ss) surfaces. l. monocytogenes 568 (lm568, serotype 1/2a), its isogenic sigb mutant (δsigb) and the back-complemented δsigb were desiccated in bhi, tsb with 1% glucose (tsb-glu), peptone physiological saline (pps) and minimal media (mm) ...201525475314
differential gene expression profiling of listeria monocytogenes in cacciatore and felino salami to reveal potential stress resistance biomarkers.the current study reports a) the in situ transcriptional profiles of listeria monocytogenes in response to fermented sausage stress and b) an approach in which in situ rt-qpcr data have been combined with advanced statistical techniques to discover potential stress resistance or cell viability biomarkers. gene expression profiling of the pathogen has been investigated using rt-qpcr to understand how l. monocytogenes responds to the conditions encountered during the fermentation and ripening of s ...201525475310
inactivation kinetics of foodborne pathogens by uv-c radiation and its subsequent growth in fresh-cut kailan-hybrid broccoli.the inactivation of escherichia coli, s. enteritidis and listeria monocytogenes after uv-c radiation with 0, 2.5, 5, 7.5, 10 and 15 kj uv-c m(-2) on fresh-cut kailan-hybrid broccoli was explored. inactivation did not follow linear kinetics. hence, it was modelled by using the weibull distribution function, obtaining adjusted r(2) values higher than 94%, indicative of the accuracy of the model to the experimental data. the uv-c doses needed to reduce 1 log cycle the e. coli, s. enteritidis and l. ...201525475295
improving safety of salami by application of bacteriocins produced by an autochthonous lactobacillus curvatus isolate.the aims of this study were to isolate lab with anti-listeria activity from salami samples, characterize the bacteriocin/s produced by selected isolates, semi-purify them and evaluate their effectiveness for the control of listeria monocytogenes during manufacturing of salami in a pilot scale. two isolates (differentiated by rapd-pcr) presented activity against 22 out of 23 l. monocytogenes strains for bacteriocin mbsa2, while the bacteriocin mbsa3 inhibited all 23 strains in addition to several ...201525475294
environmental and biological factors influencing the uv-c resistance of listeria monocytogenes.in this investigation, the effect of microbiological factors (strain, growth phase, exposition to sublethal stresses, and photorepair ability), treatment medium characteristics (ph, water activity, and absorption coefficient), and processing parameters (dose and temperature) on the uv resistance of listeria monocytogenes was studied. the dose to inactivate 99.99% of the initial population of the five strains tested ranged from 21.84 j/ml (stcc 5672) to 14.66 j/ml (stcc 4031). the uv inactivation ...201525475293
effect of quantity of food residues on resistance to desiccation of food-related pathogens adhered to a stainless steel surface.in order to study the effect of food residues on the survival of food-borne pathogens, salmonella typhimurium, staphylococcus aureus, and listeria monocytogenes were subjected to drying conditions in the presence of small amounts of food such as carrot juice, aqueous solution of nori, milk, and soy-milk. after drying for 2 h at room temperature in the absence of food residue, cell counts of s. typhimurium, s. aureus, and l. monocytogenes decreased from 8 to 3, 6, and 5 log cfu/dish, respectively ...201525475291
effects of osmotic pressure, acid, or cold stresses on antibiotic susceptibility of listeria monocytogenes.prevalence of antibiotic resistance of listeria monocytogenes isolated from a variety of foods has increased in many countries. l. monocytogenes has many physiological adaptations that enable survival under a wide range of environmental stresses. the objective of this study was to evaluate effects of osmotic (2, 4, 6, 12% nac), ph (6, 5.5, 5.0) and cold (4 °c) stresses on susceptibility of three isolates of l. monocytogenes towards different antibiotics. the minimal inhibitory concentrations (mi ...201525475279
flexible thin-layer dielectric barrier discharge plasma treatment of pork butt and beef loin: effects on pathogen inactivation and meat-quality attributes.the effects of a flexible thin-layer dielectric barrier discharge (dbd) plasma system using a sealed package on microbial inactivation and quality attributes of fresh pork and beef were tested. following a 10-min treatment, the microbial-load reductions of listeria monocytogenes, escherichia coli o157:h7, and salmonella typhimurium were 2.04, 2.54, and 2.68 log cfu/g in pork-butt samples and 1.90, 2.57, and 2.58 log cfu/g in beef-loin samples, respectively. colorimetric analysis showed that dbd- ...201525475266
evaluation of pathogen inactivation on sliced cheese induced by encapsulated atmospheric pressure dielectric barrier discharge plasma.pathogen inactivation induced by atmospheric pressure dielectric barrier discharge (dbd) (250 w, 15 khz, air discharge) produced in a rectangular plastic container and the effect of post-treatment storage time on inactivation were evaluated using agar plates and cheese slices. when agar plates were treated with plasma, populations of escherichia coli, salmonella typhimurium, and listeria monocytogenes showed 3.57, 6.69, and 6.53 decimal reductions at 60 s, 45 s, and 7 min, respectively. when the ...201525475265
modelling and predicting the simultaneous growth of listeria monocytogenes and psychrotolerant lactic acid bacteria in processed seafood and mayonnaise-based seafood salads.a new combined model for listeria monocytogenes and psychrotolerant lactobacillus spp. was constructed and evaluated for processed seafood and mayonnaise-based seafood salads. the new model was constructed by combining existing cardinal parameter models for l. monocytogenes and lactobacillus spp. using the classical jameson effect to model microbial interaction. maximum population density (mpd) values of l. monocytogenes were accurately predicted in processed seafood with a known initial cell co ...201525475260
influence of temperature, glucose, and iron on sinigrin degradation by salmonella and listeria monocytogenes.factors, including ph, temperature, glucose concentration, and iron compounds, affect the activity of plant myrosinase and, consequently, endogenous glucosinolate degradation. these factors also may affect glucosinolate degradation by bacterial myrosinase. therefore, this study examined the effect of temperature (4 to 21°c), glucose (0.05 to 1.0%), and iron (10 mm ferrous or ferric) on sinigrin degradation by salmonella or listeria monocytogenes cocktails in mueller-hinton broth and the effect o ...201425474062
controlling attachment and growth of listeria monocytogenes in polyvinyl chloride model floor drains using a peroxide chemical, chitosan-arginine, or heat.listeria monocytogenes can colonize a poultry processing plant as a resident in floor drains. limiting growth and attachment to drain surfaces may help lessen the potential for cross-contamination of product. the objective of this study was to compare a hydrogen peroxide-peroxyacetic acid-based chemical to chitosan-arginine or heat to prevent attachment of or destroy existing l. monocytogenes on the inner surface of model floor drains. l. monocytogenes was introduced to result in about 10(9) pla ...201425474061
analysis of listeria monocytogenes strain distribution in a pork slaughter and cutting plant in the province of quebec.following the 2008 canadian listeriosis outbreak associated with ready-to-eat (rte) meat products, regulations on the presence of listeria monocytogenes in rte food production facilities were modified by health canada, confirming the need to control this pathogen, not only in the final product but also in the plant environment. information on the occurrence of this microorganism during the early steps of production, such as the slaughtering process and in the cutting area, is scarce in canada. i ...201425474060
listeria monocytogenes serotype prevalence and biodiversity in diverse food products.the aim of this study was to assess serotype prevalence and biodiversity of listeria monocytogenes strains isolated from diverse food products, i.e., minced pork, fruits, and vegetables. three hundred twenty-six samples previously purchased from supermarkets and street markets within the athens area were studied for l. monocytogenes prevalence. a total of 121 strains were isolated from the 36 samples that were positive for l. monocytogenes. serotyping was performed with multiplex pcr, and biodiv ...201425474059
microbiological quality of seasoned roasted laver and potential hazard control in a real processing line.microbiological quality of laver, one of the edible seaweeds, has not been reported in a real processing line. laver or supplements were collected from six manufacturers (a to f) to assess potential microbiological hazards and the critical control points in commercial processing lines. aerobic plate counts (apc), coliform counts, bacillus cereus, staphylococcus aureus, and vibrio parahaemolyticus were enumerated, and the presence of b. cereus, listeria monocytogenes, salmonella, s. aureus, and v ...201425474052
effect of white mustard essential oil on the growth of foodborne pathogens and spoilage microorganisms and the effect of food components on its efficacy.antimicrobial preservative compounds are added to foods to target specific pathogens and spoilage organisms. white mustard essential oil (wmeo) is an extract that contains 4-hydroxybenzyl isothiocyanate, a compound which has been demonstrated to have antimicrobial activity in limited studies. the objective of this research was to determine the in vitro antimicrobial activity of wmeo against gram-positive and gram-negative spoilage and pathogenic bacteria and determine the effect of food componen ...201425474051
inactivation of listeria monocytogenes by disinfectants and bacteriophages in suspension and stainless steel carrier tests.to simulate food contact surfaces with pits or cracks, stainless steel plates with grooves (depths between 0.2 and 5 mm) were constructed. these plates were artificially contaminated with listeria monocytogenes in clean conditions, with organic soiling, or after 14 days of biofilm formation after which inactivation of the pathogen by suma tab d4 (sodium dichloroisocyanurate, 240 and 300 mg/liter), suma bac d10 (quaternary ammonium compound, 740 mg/liter), and bacteriophage suspension (listex p10 ...201425474045
antimicrobial efficacy and in vivo toxicity studies of a quaternized biopolymeric flocculant.this study evaluated the antibacterial spectrum and safety of a chemically modified biopolymeric flocculant (tmb) against waterborne pathogens. the biopolymer previously characterized as polysaccharide with flocculating activity is produced extracellularly by the bacterium klebsiella terrigena. the amino sugars on the polymer were chemically modified by quaternization, which resulted in n,n,n trimethyl biopolymer (tmb). quaternization was effective in imparting biocidal activity to tmb against f ...201425473973
antimicrobial activities of commercial essential oils and their components against food-borne pathogens and food spoilage bacteria.this study was undertaken to determine the in vitro antimicrobial activities of 15 commercial essential oils and their main components in order to pre-select candidates for potential application in highly perishable food preservation. the antibacterial effects against food-borne pathogenic bacteria (listeria monocytogenes, salmonella typhimurium, and enterohemorrhagic escherichia coli o157:h7) and food spoilage bacteria (brochothrix thermosphacta and pseudomonas fluorescens) were tested using pa ...201425473498
simultaneous construction of pcr-dgge-based predictive models of listeria monocytogenes and vibrio parahaemolyticus on cooked shrimps.the aim of this study was to simultaneously construct pcr-dgge-based predictive models of listeria monocytogenes and vibrio parahaemolyticus on cooked shrimps at 4 and 10°c. calibration curves were established to correlate peak density of dgge bands with microbial counts. microbial counts derived from pcr-dgge and plate methods were fitted by baranyi model to obtain molecular and traditional predictive models. for l. monocytogenes, growing at 4 and 10°c, molecular predictive models were construc ...201525470339
chemical composition, antibacterial and antioxidant activities of six essentials oils from the alliaceae family.six essential oils (eos) from the alliaceae family, namely garlic (allium sativum), onion (allium cepa), leek (allium porrum), chinese chive (allium tuberosum), shallot (allium ascalonicum) and chive (allium schoenoprasum) were characterized by gc and gc-ms and evaluated for their functional food properties. antibacterial properties were tested on five food-borne pathogens: two gram-positive staphylococcus aureus (atcc 25923), listeria monocytogenes (atcc 19115) and three gram-negative salmonell ...201425470273
cxcr3 expression defines a novel subset of innate cd8+ t cells that enhance immunity against bacterial infection and cancer upon stimulation with il-15.innate cd8(+) t cells are a heterogeneous population with developmental pathways distinct from conventional cd8(+) t cells. however, their biology, classification, and functions remain incompletely understood. we recently demonstrated the existence of a novel population of chemokine (c-x-c motif) receptor 3 (cxcr3)-positive innate cd8(+) t cells. here, we investigated the functional properties of this subset and identified effector molecules and pathways which mediate their function. adoptive tr ...201525466888
microbiological detection of bacteria in animal products seized in baggage of international air passengers to brazil.airline travel favours the transmission of diseases, given the short time it takes to travel long distances. in this study, animal products without health certificates seized in international air passengers' baggage at guarulhos (gru) and galeão (gig) airports in brazil underwent a microbiological evaluation. analyses (1610) were carried out on 322 seizures to test for the presence of total and thermotolerant coliforms, as well as staphylococcus aureus counts and the presence of listeria monocyt ...201525466683
uncommon manifestations of listeria monocytogenes infection.listeria monocytogenes causes gastroenteritis, meningitis and bacteraemia in immunocompromised, pregnant patients, the elderly as well in immunocompetent patients. focal infections with this organism are uncommon, especially in sporadic (non-outbreak) setting, require high index of suspicion and are challenging to diagnose. we present 3 cases of listeria monocytogenes presenting as focal infections to our hospitals, all of which are the first reported cases from australia.201425466213
the influence of the cell free solution of lactic acid bacteria on tyramine production by food borne-pathogens in tyrosine decarboxylase broth.the function of cell-free solutions (cfss) of lactic acid bacteria (lab) on tyramine and other biogenic amine production by different food borne-pathogens (fbps) was investigated in tyrosine decarboxylase broth (tdb) using hplc. cell free solutions were prepared from four lab strains. two different concentrations which were 50% (5 ml cfs+5 ml medium/1:1) and 25% (2.5 ml cfs+7.5 ml medium/1:3) cfs and the control without cfs were prepared. both concentration of cfs of streptococcus thermophilus a ...201525465993
quantifying variability on thermal resistance of listeria monocytogenes.knowledge of the impact of strain variability and growth history on thermal resistance is needed to provide a realistic prediction and an adequate design of thermal treatments. in the present study, apart from quantifying strain variability on thermal resistance of listeria monocytogenes, also biological variability and experimental variability were determined to prioritize their importance. experimental variability was defined as the repeatability of parallel experimental replicates and biologi ...201525462932
identification of non-listeria spp. bacterial isolates yielding a β-d-glucosidase-positive phenotype on agar listeria according to ottaviani and agosti (aloa).agar listeria according to ottaviani and agosti (aloa) is the mandatory medium used for the detection and enumeration of listeria monocytogenes in foods according to the official international organization for standardization (iso) methods. on aloa, listeria spp. appear as bluish-green colonies due to the production of β-d-glucosidase, an enzyme that cleaves 5-bromo-4-chloro-3-indolyl-β-d-glucopyranoside, a chromogenic substrate included in the formulation of the medium. the present work reports ...201525462931
effect of packaging technology on microbiological and sensory quality of a cooked blood sausage, morcela de arroz, from monchique region of portugal.morcela de arroz (ma), a popular portuguese blood sausage, with high ph and water activity (aw), is traditionally commercialized without preservatives and unpacked. this study evaluated the best packaging solution to extend ma shelf life stored at 4±1°c for 44days: without packaging (wp), vacuum (vp) and modified atmosphere packaging (map) (80% co2; 20% n2). mesophilic (mtvc), psychrotrophic (ptvc), lactic acid bacteria (lab), pseudomonads, molds and yeasts, enterobacteriaceae, listeria monocyto ...201525462380
prevalence and predictors of bacterial meningitis in young infants with fever without a source.classical criteria differ when performing cerebrospinal fluid (csf) analysis in infants younger than 90 days with fever without a source (fws). our objectives were to analyze the prevalence and microbiology of bacterial meningitis in this group and its prevalence in relation to clinical and laboratory risk factors.201525461476
gold nanoparticle-based dynamic light scattering immunoassay for ultrasensitive detection of listeria monocytogenes in lettuces.gold nanoparticle (gnp)-based dynamic light scattering (dls) assay has been widely used for sensitive detection of small analytes based on analyte binding-induced gnp aggregation. however, the use of this new method to detect large biological objectives, such as pathogenic bacteria, has not been reported. this study is the first to describe a homogeneous gnp-based dls immunoassay for ultrasensitive detection of listeria monocytogenes. compared with small analytes, l. monocytogenes has a larger s ...201525460900
estimating the non-thermal inactivation of listeria monocytogenes in fermented sausages relative to temperature, ph and water activity.data relative to in situ listeria monocytogenes inactivation in fermented sausages were collected from 13 individual studies found in the literature. inactivation rates were extrapolated and used to develop a predictive model to evaluate the relative effects of ph, water activity (a(w)) and temperature on l. monocytogenes fate during fermentation and ripening. temperature explained ca. 60% of the data variability, while ph and a(w) only a small part. temperature alone may not be sufficient to ca ...201525460122
bioprocess development for the production of sonorensin by bacillus sonorensis mt93 and its application as a food preservative.media composition and environmental conditions were optimized using statistical tools, plackett burman design and response surface methodology, to maximize the yield of a bacteriocin, named as sonorensin, from a new marine isolate bacillus sonorensis mt93 showing broad spectrum of antimicrobial activity. under optimized conditions, mt93 produced 15-fold higher yield of sonorensin compared to that under initial fermentation conditions. as oxygen supply is a critical parameter controlling growth a ...201525459843
identification and molecular characterization of pathogenic bacteria in foods confiscated from non-eu flights passengers at one spanish airport.two hundred food samples of animal origin confiscated from passengers arriving on flights from non-european countries at the international airport of bilbao (spain) were tested for the presence of four main bacterial foodborne pathogens (campylobacter spp., escherichia coli o157:h7, listeria monocytogenes and salmonella spp.) during 2012 and 2013. overall, 20 samples were positive for l. monocytogenes (10%) and 11 for salmonella spp. (5.5%), whereas campylobacter spp. and e. coli o157:h7 were no ...201525454793
enhanced transport of nanocage stabilized pure nanodrug across intestinal epithelial barrier mimicking listeria monocytogenes.ligand grafted nanoparticles have been shown to enhance drug transport across epithelium barrier and are expected to improve drug delivery. however, grafting of these ligands to the surface of pure nanodrug, i.e., nanocrystals (ncs), is a critical challenge due to the shedding of ligands along with the stabilizer upon high dilution or dissolving of the drug. herein, a non-sheddable nanocage-like stabilizer was designed by covalent cross-linking of poly(acrylic acid)-b-poly(methyl acrylate) on dr ...201525453961
immobilization of proteases on chitosan for the development of films with anti-biofilm properties.bacterial resistance due to biofilm formation-particularly staphylococci biofilms-is associated with multiple problems in medical settings where biofilms can colonize medical indwelling devices and cause nosocomial infections. it was against this backdrop that we explored the anti-biofilm activities of a set of proteases against biofilm formation by staphylococcus aureus, listeria monocytogenes and pseudomonas aeruginosa. the selected screened enzymes were immobilized on chitosan to obtain films ...201525451753
antimicrobial effects of short chained imidazolium-based ionic liquids—influence of anion chaotropicity.ionic liquids (ils), a new solvent class composed solely of ions, have already found their way into numerous chemical and biochemical applications. due to their unique properties and wide application range, research utilizing this new technology for biotechnological applications is steadily increasing. however, progress is hampered by lack of toxicological data, especially concerning il anions and their general underlying toxicity mechanisms. the present study investigated for the first time the ...201525450920
synthesis, antibacterial, antioxidant activity and qsar studies of novel 2-arylidenehydrazinyl-4-arylthiazole analogues.a novel series of 2-arylidenehydrazinyl-4-arylthiazole analogues (3a-p) was designed and synthesized in excellent yields using a rapid, simple, efficient methodology. sixteen novel compounds were screened for in vitro antimicrobial activities against eleven bacteria, namely, staphylococcus aureus, listeria monocytogenes, enterococcus faecalis, bacillus subtilis, klebsiella pneumonia, citrobacter freundii, cronobacter sakazakii, salmonella enteritidis, escherichia coli, yersinia pestis, and pseud ...201425450634
suspension of thymic emigration promotes the maintenance of antigen-specific memory t cells and the recall responses.thymic involution is evolutionarily conserved and occurs early in life. however, the physiological significance remains elusive of this seemingly detrimental process. the present study investigated the potential impact of altered thymic output on t cell memory using ovalbumin (ova) expressed by listeria monocytogenes as a model antigen. suspension of thymic emigration by thymectomy was shown to lead to a marked increase in the frequency and total number of ova-specific memory t cells. in contras ...201425450389
high affinity anti-internalin b vhh antibody fragments isolated from naturally and artificially immunized repertoires.the need for rapid and easy technologies for the detection of food-borne and environmental pathogens is essential for safeguarding the health of populations. furthermore, distribution of tainted food and water can have consequences which can affect whole economies. antibodies and antibody fragments have been historically used in detection platforms due to their antigen specificity and robust physicochemical properties. in this study, we report the isolation and characterization of antibody fragm ...201525450000
comparative analysis of crispr loci in different listeria monocytogenes lineages.listeria monocytogenes, an important food-borne pathogen, causes high mortality rate of listeriosis. pan-genomic comparisons revealed the species genome of l. monocytogenes is highly stable but not completely clonal. the population structure of this species displays at least four evolutionary lineages (i-iv). isolates of different lineages displayed distinct genetic, phenotypic and ecologic characteristics, which appear to affect their ability to be transmitted through foods and to cause human d ...201425445602
the roles of noncoding rna rli60 in regulating the virulence of listeria monocytogenes.listeria monocytogenes (lm) is an important zoonotic foodborne pathogen. noncoding rna (ncrna) has an important role in regulating its virulence. as a member of ncrna, however, the function of rli60 in regulating lm virulence remain unclear. the aim of this study was to investigate the role of rli60 in regulating lm virulence.201625442865
brazilian fruit pulps as functional foods and additives: evaluation of bioactive compounds.eight tropical fruit pulps from brazil were simultaneously characterised in terms of their antioxidant and antimicrobial properties. antioxidant activity was screened by dpph radical scavenging activity (126-3987 mg te/100g dw) and ferric reduction activity power (368-20819 mg aae/100g dw), and complemented with total phenolic content (329-12466 mg gae/100g dw) and total flavonoid content measurements (46-672 mg ee /100g dw), whereas antimicrobial activity was tested against the most frequently ...201525442579
antibacterial activity and genotypic-phenotypic characteristics of bacteriocin-producing bacillus subtilis kku213: potential as a probiotic strain.the antimicrobial activity and probiotic properties of bacillus subtilis strain kku213, isolated from local soil, were investigated. the cell-free supernatant (cfs) of a kku213 culture containing crude bacteriocins exhibited inhibitory effects on gram-positive bacteria, including bacillus cereus, listeria monocytogenes, micrococcus luteus, and staphylococcus aureus. the antibacterial activity of the cfs precipitated with 40% ammonium sulfate (as) remained even after treatment at 60 and 100 °c, a ...201525440998
transcriptional response of selected genes of salmonella enterica serovar typhimurium biofilm cells during inactivation by superheated steam.superheated steam (shs), produced by the addition of heat to saturated steam (ss) at the same pressure, has great advantages over conventional heat sterilization due to its high temperature and accelerated drying rate. we previously demonstrated that treatment with shs at 200°c for 10 sec inactivated escherichia coli o157:h7, salmonella typhimurium, and listeria monocytogenes biofilm cells on the surface of stainless steel to below the detection limit. however, bacteria withstanding heat stress ...201525440555
fast and discriminative cosyps detection system of viable salmonella spp. and listeria spp. in carcass swab samples.in this study, the complete cosyps path food workflow including all steps, namely swab sample enrichment, sybr®green qpcr detection of salmonella spp. and listeria spp., isolation and confirmation of the detected strain, was validated on beef carcass swabs. to perform the validation, the results of the complete workflow were compared, according to the iso 16140:2003, with the iso reference methods for detection, isolation and confirmation of listeria monocytogenes and salmonella spp. the results ...201525440553
subversion of the cytoskeleton by intracellular bacteria: lessons from listeria, salmonella and vibrio.entry into host cells and intracellular persistence by invasive bacteria are tightly coupled to the ability of the bacterium to disrupt the eukaryotic cytoskeletal machinery. herein we review the main strategies used by three intracellular pathogens to harness key modulators of the cytoskeleton. two of these bacteria, namely listeria monocytogenes and salmonella enterica serovar typhimurium, exhibit quite distinct intracellular lifestyles and therefore provide a comprehensive panel for the under ...201525440316
application of dna aptamers and quantum dots to lateral flow test strips for detection of foodborne pathogens with improved sensitivity versus colloidal gold.preliminary studies aimed at improving the sensitivity of foodborne pathogen detection via lateral flow (lf) test strips by use of high affinity dna aptamers for capture and reporter functions when coupled to red-emitting quantum dots (qdot 655) are reported. a variety of dna aptamers developed against escherichia coli, listeria monocytogenes, and salmonella enterica were paired in capture and reporter combinations to determine which yielded the strongest detection of their cognate bacteria usin ...201425437803
evaluation of dna extraction methods for pcr-based detection of listeria monocytogenes from vegetables.epidemiological data indicate that raw vegetables are associated with outbreaks of listeria monocytogenes. therefore, there is a demand for the availability of rapid and sensitive methods, such as pcr assays, for the detection and accurate discrimination of l. monocytogenes. however, the efficiency of pcr methods can be negatively affected by inhibitory compounds commonly found in vegetable matrices that may cause false-negative results. therefore, the sample processing and dna isolation steps m ...201525431169
the metabolic regulator cody links listeria monocytogenes metabolism to virulence by directly activating the virulence regulatory gene prfa.metabolic adaptations are critical to the ability of bacterial pathogens to grow within host cells and are normally preceded by sensing of host-specific metabolic signals, which in turn can influence the pathogen's virulence state. previously, we reported that the intracellular bacterial pathogen listeria monocytogenes responds to low availability of branched-chain amino acids (bcaas) within mammalian cells by up-regulating both bcaa biosynthesis and virulence genes. the induction of virulence g ...201425430920
[sausage-related listeria monocytogenes infection].infection with listeria monocytogenes is rare and mainly seen in immunosuppressed patients. infection with l. monocytogenes has a mortality rate of 30%. we present a case report of l. monocytogenes bacteraemia and endocarditis in a 70-year-old man with several co-morbidities and following four major surgical procedures. this illustrates the findings and characteristics in one of the 16 patients who died in 2013 and 2014 this summer due to sausage-related l. monocytogenes infection.201425430580
production of antibacterial bombyx mori cecropin a in mealworm-pathogenic beauveria bassiana erl1170.efforts are underway to produce antimicrobial peptides in yellow mealworms (tenebrio molitor), which can be developed as more effective and safer animal feed additives. in this work, we expressed bombyx mori (bm) cecropin-a in mealworms by the infection of transformed entomopathogenic beauveria bassiana erl1170. the active domain of bm cecropin a gene was tagged with a signal sequence of b. bassiana for extracellular secretion, and the fragment was inserted into erl1170 by the restriction enzyme ...201525429897
discrete and overlapping functions of peptidoglycan synthases in growth, cell division and virulence of listeria monocytogenes.upon ingestion of contaminated food, listeria monocytogenes can cause serious infections in humans that are normally treated with β-lactam antibiotics. these target listeria's five high molecular weight penicillin-binding proteins (hmw pbps), which are required for peptidoglycan biosynthesis. the two bi-functional class a hmw pbps pbp a1 and pbp a2 have transglycosylase and transpeptidase domains catalyzing glycan chain polymerization and peptide cross-linking, respectively, whereas the three cl ...201525424554
cytomegalovirus generates long-lived antigen-specific nk cells with diminished bystander activation to heterologous infection.natural killer (nk) cells play a key role in the host response to cytomegalovirus (cmv) and can mediate an enhanced response to secondary challenge with cmv. we assessed the ability of mouse cmv (mcmv)-induced memory ly49h(+) nk cells to respond to challenges with influenza, an acute viral infection localized to the lung, and listeria monocytogenes, a systemic bacterial infection. mcmv-memory nk cells did not display enhanced activation or proliferation after infection with influenza or listeria ...201425422494
the listeria monocytogenes hibernation-promoting factor is required for the formation of 100s ribosomes, optimal fitness, and pathogenesis.during exposure to certain stresses, bacteria dimerize pairs of 70s ribosomes into translationally silent 100s particles in a process called ribosome hibernation. although the biological roles of ribosome hibernation are not completely understood, this process appears to represent a conserved and adaptive response that contributes to optimal survival during stress and post-exponential-phase growth. hibernating ribosomes are formed by the activity of one or more highly conserved proteins; gammapr ...201525422304
two outbreaks of listeria monocytogenes infection, northern spain.in the province of gipuzkoa, spain (≈700,000 inhabitants), 7-12 episodes of human listeriosis were recorded annually during 2009-2012. however, during january 2013-february 2014, 27 episodes were detected, including 11 pregnancy-associated cases. fifteen cases in 2 epidemiologically unrelated outbreaks were caused by a rare type of listeria monocytogenes, sequence type 87 serotype 1/2b.201425418800
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