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listeria monocytogenes peritonitis in an hivinfected patient.we report the first case of listeria monocytogenes peritoneal dialysis (pd) peritonitis in a human immunodeficiency virus-infected individual successfully treated with intraperitoneal ampicillin, without the need for catheter removal. suspicion of listerial infection in at-risk individuals is critical as empiric antimicrobial treatment for pd-associated infections may be ineffective against this organism.201627345188
antibiotic treatment and mortality in patients with listeria monocytogenes meningitis or bacteraemia.invasive listeria monocytogenes infections carry a high mortality despite antibiotic treatment. the rareness of the infection makes it difficult to improve antibiotic treatment through randomized clinical trials. this observational study investigated clinical features and outcome of invasive l. monocytogenes infections including the efficacy of empiric and definitive antibiotic therapies. demographic, clinical and biochemical findings, antibiotic treatment and 30-day mortality for all episodes o ...201627345176
multi-criteria framework as an innovative tradeoff approach to determine the shelf-life of high pressure-treated poultry.a multi-criteria framework combining safety, hygiene and sensorial quality was developed to investigate the possibility of extending the shelf-life and/or removing lactate by applying high hydrostatic pressure (hhp) in a ready-to-cook (rtc) poultry product. for this purpose, salmonella and listeria monocytogenes were considered as safety indicators and escherichia coli as hygienic indicator. predictive modeling was used to determine the influence of hhp and lactate concentration on microbial gro ...201627343425
modeling and validation of the ecological behavior of wild-type listeria monocytogenes and stress-resistant variants.listeria monocytogenes exhibits a heterogeneous response upon stress exposure which can be partially attributed to the presence of stable stress-resistant variants. this study aimed to evaluate the impact of the presence of stress-resistant variants of listeria monocytogenes and their corresponding trade-offs on population composition under different environmental conditions. a set of stress robustness and growth parameters of the wild type (wt) and an rpsu deletion variant was obtained and used ...201627342563
identification of surface protein biomarkers of listeria monocytogenes via bioinformatics and antibody-based protein detection tools.the gram-positive bacterium listeria monocytogenes causes a significant percentage of the fatalities among foodborne illnesses in humans. surface proteins specifically expressed in a wide range of l. monocytogenes serotypes under selective enrichment culture conditions could serve as potential biomarkers for detection and isolation of this pathogen via antibody-based methods. our study aimed to identify such biomarkers. interrogation of the l. monocytogenes serotype 4b strain f2365 genome identi ...201627342549
factors influencing the time between onset of illness and specimen collection in the diagnosis of non-pregnancy associated listeriosis in england and wales.listeriosis is an opportunistic bacterial infection caused by listeria monocytogenes and predominantly affects people who are immunocompromised. due to its severity and the population at risk, prompt clinical diagnosis and treatment of listeriosis is essential. a major step to making a clinical diagnosis is the collection of the appropriate specimen(s) for testing. this study explores factors that may influence the time between onset of illness and collection of specimen in order to inform clini ...201627341796
rna purification from intracellularly grown listeria monocytogenes in macrophage cells.analysis of the transcriptome of bacterial pathogens during mammalian infection is a valuable tool for studying genes and factors that mediate infection. however, isolating bacterial rna from infected cells or tissues is a challenging task, since mammalian rna mostly dominates the lysates of infected cells. here we describe an optimized method for rna isolation of listeria monocytogenes bacteria growing within bone marrow derived macrophage cells. upon infection, cells are mildly lysed and rapid ...201627341521
multicenter evaluation of biofire filmarray meningitis/encephalitis panel for detection of bacteria, viruses, and yeast in cerebrospinal fluid specimens.rapid diagnosis and treatment of infectious meningitis and encephalitis are critical to minimize morbidity and mortality. comprehensive testing of cerebrospinal fluid (csf) often includes gram stain, culture, antigen detection, and molecular methods, paired with chemical and cellular analyses. these methods may lack sensitivity or specificity, can take several days, and require significant volume for complete analysis. the filmarray meningitis/encephalitis (me) panel is a multiplexed in vitro di ...201627335149
is the lysm domain of l. monocytogenes p60 protein suitable for engineering a protein with high peptidoglycan binding affinity?lysin motif (lysm) is a highly conserved carbohydrate binding module that is widely present in proteins from both prokaryotes and eukaryotes. lysm domains from many lysm-containing proteins can be taken out of their natural context and retain their ability to bind peptidoglycan. therefore, lysm has enormous potential for applications in both industry and medicine. this potential has stimulated an intensive search for lysm modules with different evolutionary origins. the p60 protein (lm-p60) is a ...201627333274
physical and antimicrobial properties of cinnamon bark oil co-nanoemulsified by lauric arginate and tween 80.lauric arginate (lae) is a water-soluble cationic surfactant which has antimicrobial activity against a broad spectrum of foodborne pathogens. some spice essential oils are effective lipophilic antimicrobials. combining both antimicrobials may reduce their usage levels and possible negative sensory impacts when applied in complex food matrices. the objective of this study was to combine a nonionic surfactant (tween 80) with lae to form stable nanoemulsions with cinnamon bark essential oil (cbo) ...201627322724
broad substrate specificity of phosphotransbutyrylase from listeria monocytogenes: a potential participant in an alternative pathway for provision of acyl coa precursors for fatty acid biosynthesis.listeria monocytogenes, the causative organism of the serious food-borne disease listeriosis, has a membrane abundant in branched-chain fatty acids (bcfas). bcfas are normally biosynthesized from branched-chain amino acids via the activity of branched chain α-keto acid dehydrogenase (bkd), and disruption of this pathway results in reduced bcfa content in the membrane. short branched-chain carboxylic acids (bccas) added as media supplements result in incorporation of bcfas arising from the supple ...201627320015
rapid and visual detection of listeria monocytogenes based on nanoparticle cluster catalyzed signal amplification.foodborne pathogens pose a significant threat to human health worldwide. the identification of foodborne pathogens needs to be rapid, accurate and convenient. here, we constructed a nanoparticle cluster (npc) catalyzed signal amplification biosensor for foodborne pathogens visual detection. in this work, vancomycin (van), a glycopeptide antibiotic for gram-positive bacteria, was used as the first molecular recognition agent to capture listeria monocytogenes (l. monocytogenes). fe3o4 npc modified ...201627318103
adiponectin enhances antibacterial activity of hematopoietic cells by suppressing bone marrow inflammation.obesity has been shown to increase the morbidity of infections, however, the underlying mechanisms remain largely unknown. here we demonstrate that obesity caused adiponectin deficiency in the bone marrow (bm), which led to an inflamed bm characterized by increased tumor necrosis factor (tnf) production from bone marrow macrophages. hematopoietic stem and progenitor cells (hspcs) chronically exposed to excessive tnf in obese marrow aberrantly expressed cytokine signaling suppressor socs3, impair ...201627317261
listeria monocytogenes dna glycosylase adlp affects flagellar motility, biofilm formation, virulence, and stress responses.the temperature-dependent alteration of flagellar motility gene expression is critical for the foodborne pathogen listeria monocytogenes to respond to a changing environment. in this study, a genetic determinant, l. monocytogenes f2365_0220 (lmof2365_0220), encoding a putative protein that is structurally similar to the bacillus cereus alkyl base dna glycosylase (alkd), was identified. this determinant was involved in the transcriptional repression of flagellar motility genes and was named adlp ...201627316964
biological activities of aerial parts extracts of euphorbia characias.the aim of the present study was to evaluate antioxidant, antimicrobial, anti-hiv, and cholinesterase inhibitory activities of aqueous and alcoholic extracts from leaves, stems, and flowers of euphorbia characias. the extracts showed a high antioxidant activity and were a good source of total polyphenols and flavonoids. ethanolic extracts from leaves and flowers displayed the highest inhibitory activity against acetylcholinesterase and butyrylcholinesterase, showing potential properties against ...201627314007
a case of leukocytoclastic vasculitis caused by listeria monocytogenes bacteremia.importance. infections can cause leukocytoclastic vasculitis. observations. we report the case of a patient with a left ventricular assist device who presented with acute kidney injury and biopsy proven leukocytoclastic vasculitis. blood cultures grew listeria monocytogenes. the patient's rash improved with treatment of the underlying listeria infection. conclusion. clinicians should be aware that there are a number of broad categories of disease associated with the histologic finding of vasculi ...201627313916
viable bacterial population and persistence of foodborne pathogens on the pear carpoplane.knowledge on the culturable bacteria and foodborne pathogen presence on pears is important for understanding the impact of postharvest practices on food safety assurance. pear fruit bacteria were investigated from the point of harvest, following chlorine drenching and after controlled atmosphere (ca) storage to assess the impact on natural bacterial populations and potential foodborne pathogens.201727300139
validation of the applied biosystems 7500 fast instrument for detection of listeria monocytogenes with the suretect listeria monocytogenes pcr assay.in 2013, the thermo scientific™ suretect™ listeria monocytogenes real-time pcr assay was certified by the aoac research institute (ri) performance tested methods(sm) program as a rapid method for the detection of l. monocytogenes from a wide range of food matrixes and surface samples. this report details the method modification studies undertaken to extend the analysis of this pcr assay to the applied biosystems™ 7500 fast pcr instrument and applied biosystems rapidfinder™ express 2.0 software a ...201627297838
inhibition of multidrug resistant listeria monocytogenes by peptides isolated from combinatorial phage display libraries.the aim of the study was to isolate and characterize novel antimicrobial peptides from peptide phage library with antimicrobial activity against multidrug resistant listeria monocytogenes. combinatorial phage-display library was used to affinity select peptides binding to the cell surface of multidrug resistant l. monocytogenes. after several rounds of affinity selection followed by sequencing, three peptides were revealed as the most promising candidates. peptide l2 exhibited features common to ...201727296960
foodborne bacterial pathogens in retail prepacked ready-to-eat mixed ingredient salads.prepacked ready-to-eat mixed ingredient salads (rte salads) are readily available whole meals that include a variety of ingredients such as raw vegetables, cooked meat, and pasta. as part of a trend toward healthy convenience foods, rte salads have become an increasingly popular product among consumers. however, data on the incidence of foodborne pathogens in rte salads are scarce. in this study, the microbiological safety of 141 rte salads containing chicken, ham, or smoked salmon was investiga ...201627296602
a rapid multiplex real-time pcr high-resolution melt curve assay for the simultaneous detection of bacillus cereus, listeria monocytogenes, and staphylococcus aureus in food.three important foodborne pathogens, bacillus cereus, listeria monocytogenes, and staphylococcus aureus, are of great concern for food safety. they may also coexist in food matrices and, in the case of b. cereus and s. aureus, the resulting illnesses can resemble each other owing to similar symptoms. therefore, their simultaneous detection may have advantages in terms of cost savings and rapidity. given this context, a rapid multiplex real-time pcr high-resolution melt curve assay for the simult ...201627296430
use of whole genome sequencing and patient interviews to link a case of sporadic listeriosis to consumption of prepackaged lettuce.we report on a case of listeriosis in a patient who probably consumed a prepackaged romaine lettuce-containing product recalled for listeria monocytogenes contamination. although definitive epidemiological information demonstrating exposure to the specific recalled product was lacking, the patient reported consumption of a prepackaged romaine lettuce-containing product of either the recalled brand or a different brand. a multinational investigation found that patient and food isolates from the r ...201627296429
assessment of the microbiological quality of meat pies from retail sale in england 2013.outbreaks of foodborne illness caused by bacillus cereus and listeria monocytogenes in england associated with meat pie consumption were detected in 2012. to obtain baseline data for pies unrelated to outbreaks, 862 samples of ready-to-eat meat pies were collected at retail or from catering facilities in england in 2013 and examined to enumerate food-poisoning bacteria and indicator organisms using organization for standardization (iso) methods for listeria spp. including l. monocytogenes (iso 1 ...201627296425
estimating bacterial pathogen levels in new zealand bulk tank milk.zoonotic bacteria such as campylobacter, listeria, and shiga toxin-producing escherichia coli have been found in bulk tank milk in many countries, and the consumption of raw milk has been implicated in outbreaks of disease in new zealand. fecal contamination at milking is probably the most common source of pathogenic bacteria in bulk tank milk. raw milk was collected from 80 new zealand dairy farms during 2011 and 2012 and tested periodically for campylobacter, e. coli o157, listeria monocytogen ...201627296424
transfer of pathogens from cantaloupe rind to preparation surfaces and edible tissue as a function of cutting method.whole and cut cantaloupes have been implicated as vehicles in foodborne illness outbreaks of norovirus, salmonellosis, and listeriosis. preparation methods that minimize pathogen transfer from external surfaces to the edible tissue are needed. two preparation methods were compared for the transfer of listeria monocytogenes, salmonella enterica serovar typhimurium lt2, murine norovirus, and tulane virus from inoculated cantaloupe rinds to edible tissue and preparation surfaces. for the first meth ...201627296423
capacity of listeria monocytogenes strains from the 2011 cantaloupe outbreak to adhere, survive, and grow on cantaloupe.the 2011 listeriosis outbreak attributed to whole cantaloupe involved several genetically distinct strains of serotypes 1/2a and 1/2b that had not been previously reported in invasive listeriosis outbreaks. here we investigated the potential of strains from the 2011 cantaloupe outbreak to adhere, survive, and grow on cantaloupe rind and flesh and in juice extracted from cantaloupe at different temperatures (4, 8, and 25°c). all strains were able to adhere and grow, with ∼10-fold increases after ...201627296422
an outbreak of human listeriosis in england between 2010 and 2012 associated with the consumption of pork pies.an outbreak of listeriosis in england affecting 14 people between 2010 and 2012 and linked to the consumption of pork pies was investigated. all 14 individuals were older than 55 years, 12 were men, and 10 reported the presence of an underlying condition. all were resident in or had visited either of two english regions and were infected with the same strain of listeria monocytogenes. in interviews with 12 patients, 9 reported eating pork pies, and individuals that consumed pork pies were signif ...201627296419
fate of listeria monocytogenes in fresh apples and caramel apples.an outbreak of listeriosis in late 2014 and early 2015 associated with caramel apples led to questions about how this product became a vector for listeria monocytogenes. this investigation aimed to determine information about the survival and growth of l. monocytogenes in both fresh apples and caramel apples, specifically examining the effects of site and level of inoculation, inoculum drying conditions, and storage temperature. at a high inoculation level (7 log cfu per apple), l. monocytogenes ...201627296414
bacterial manipulation of nk cell regulatory activity increases susceptibility to listeria monocytogenes infection.natural killer (nk) cells produce interferon (ifn)-γ and thus have been suggested to promote type i immunity during bacterial infections. yet, listeria monocytogenes (lm) and some other pathogens encode proteins that cause increased nk cell activation. here, we show that stimulation of nk cell activation increases susceptibility during lm infection despite and independent from robust nk cell production of ifnγ. the increased susceptibility correlated with il-10 production by responding nk cells. ...201627295349
proteomic analysis of egg white heparin-binding proteins: towards the identification of natural antibacterial molecules.the chicken egg resists most environmental microbes suggesting that it potentially contains efficient antimicrobial molecules. considering that some heparin-binding proteins in mammals are antibacterial, we investigated the presence and the antimicrobial activity of heparin-binding proteins from chicken egg white. mass spectrometry analysis of the proteins recovered after heparin-affinity chromatography, revealed 20 proteins, including known antimicrobial proteins (avidin, lysozyme, tenp, ovalbu ...201627294500
antimicrobial activity of croton macrostachyus stem bark extracts against several human pathogenic bacteria.in kenya, leaves and roots from croton macrostachyus are used as a traditional medicine for infectious diseases such as typhoid and measles, but reports on possible antimicrobial activity of stem bark do not exist. in this study, the antibacterial and antifungal effects of methanol, ethyl acetate and butanol extracts, and purified lupeol of c. macrostachyus stem bark were determined against important human gram-negative pathogens escherichia coli, salmonella typhi, klebsiella pneumoniae, and ent ...201627293897
innovative bionanocomposite films of edible proteins containing liposome-encapsulated nisin and halloysite nanoclay.films and coatings based on natural polymers have gained increased interest for food packaging applications. in this work, halloysite and phosphatidylcholine liposomes encapsulating nisin were used to develop nanocomposite films of gelatin and casein. liposomes prepared with either soybean lecithin or phospholipon(®) showed particle size ranging from 124 to 178nm and high entrapment efficiency (94-100%). considering their stability, phospholipon(®) liposomes with 1.0mg/ml nisin were selected for ...201627289315
coliform detection in cheese is associated with specific cheese characteristics, but no association was found with pathogen detection.coliform detection in finished products, including cheese, has traditionally been used to indicate whether a given product has been manufactured under unsanitary conditions. as our understanding of the diversity of coliforms has improved, it is necessary to assess whether coliforms are a good indicator organism and whether coliform detection in cheese is associated with the presence of pathogens. the objective of this study was (1) to evaluate cheese available on the market for presence of colif ...201627289158
whole genome sequence-based serogrouping of listeria monocytogenes isolates.whole genome sequencing (wgs) is currently becoming the method of choice for characterization of listeria monocytogenes isolates in national reference laboratories (nrls). wgs is superior with regards to accuracy, resolution and analysis speed in comparison to several other methods including serotyping, pcr, pulsed field gel electrophoresis (pfge), multilocus sequence typing (mlst), multilocus variable number tandem repeat analysis (mlva), and multivirulence-locus sequence typing (mvlst), which ...201627288594
propagation method for persistent high yield of diverse listeria phages on permissive hosts at refrigeration temperatures.the efficient production of a high concentration of bacteriophage in large volumes has been a limiting factor in the exploration of the true potential of these organisms for biotechnology, agriculture and medicine. traditional methods focus on generating small volumes of highly concentrated samples as the end product of extensive mechanical and osmotic processing. to function at an industrial scale mandates extensive investment in infrastructure and input materials not feasible for many smaller ...201627287043
risk assessment of human listeriosis from semisoft cheeses made from raw sheep's milk in lazio and tuscany (italy).semisoft cheese made from raw sheep's milk is traditionally and economically important in southern europe. however, raw milk cheese is also a known vehicle of human listeriosis and contamination of sheep cheese with listeria monocytogenes has been reported. in the present study, we have developed and applied a quantitative risk assessment model, based on available evidence and challenge testing, to estimate risk of invasive listeriosis due to consumption of an artisanal sheep cheese made with ra ...201627285819
new antimicrobial peptides against foodborne pathogens: from in silico design to experimental evidence.recently there has been growing interest in the discovery of new antimicrobial agents to increase safety and shelf-life of food products. here, we developed an innovative approach by introducing the concept that mitochondrial targeting peptides (mtp) can interact and disrupt bacterial membranes, acting as antimicrobial agents. as proof-of-principle, we used a multidisciplinary strategy by combining in silico predictions, docking simulations and antimicrobial assays, to identify two peptides, mtp ...201627283665
sharing is caring: international sharing of data enhances genomic surveillance of listeria monocytogenes. 201627282712
the effect of oxygen on bile resistance in listeria monocytogenes.listeria monocytogenes is a gram-positive facultative anaerobe that is the causative agent of the disease listeriosis. the infectious ability of this bacterium is dependent upon resistance to stressors encountered within the gastrointestinal tract, including bile. previous studies have indicated bile salt hydrolase activity increases under anaerobic conditions, suggesting anaerobic conditions influence stress responses. therefore, the goal of this study was to determine if reduced oxygen availab ...201627274623
listeriosis downregulates hepatic cytochrome p450 enzymes in sublethal murine infection.listeria monocytogenes (lm) can cross the intestinal barrier in humans and then disseminates into different organs. invasion of the liver occurs even in sublethal infections, however, knowledge of affected physiological processes is scarce. this study employed a sublethal murine infection model to investigate liver responses systematically by proteomics.201627273978
erosion of transplantation tolerance after infection.recent clinical studies suggest that operational allograft tolerance can be persistent, but long-term surviving allografts can be rejected in a subset of patients, sometimes after episodes of infection. in this study, we examined the impact of listeria monocytogenes (lm) infection on the quality of tolerance in a mouse model of heart allograft transplantation. lm infection induced full rejection in 40% of tolerant recipients, with the remaining experiencing a rejection crisis or no palpable chan ...201727273890
presence of a widely disseminated listeria monocytogenes serotype 4b clone in india. 201627273224
antimicrobial activity of serbian propolis evaluated by means of mic, hptlc, bioautography and chemometrics.new information has come to light about the biological activity of propolis and the quality of natural products which requires a rapid and reliable assessment method such as high performance thin-layer chromatography (hptlc) fingerprinting. this study investigates chromatographic and chemometric approaches for determining the antimicrobial activity of propolis of serbian origin against various bacterial species. a linear multivariate calibration technique, using partial least squares, was used t ...201627272728
antioxidant, antibacterial, and antiproliferative activities of free and bound phenolics from peel and flesh of fuji apple.this study was conducted to investigate the antioxidant, antibacterial, and antiproliferative activities of flesh free (ff), flesh bound (fb), peel free (pf), and peel bound (pb) phenolics from fuji apple. the pb, which had highest total phenolic contents (126.15 ± 2.41 mg/100 g wet weight) and lowest total carbohydrate contents (34.68 ± 2.78 mg/100 g wet weight), showed the strongest 2,2'-azinobis-(3-ethylbenthiazoline-6-sulphonate) (abts) radical scavenging activity (ec50 = 0.36 ± 0.02 mg/ml), ...201627272442
cd8(+) t cells specific to a single yersinia pseudotuberculosis epitope restrict bacterial replication in the liver but fail to provide sterilizing immunity.cd8(+) t cells use contact-dependent cytolysis of target cells to protect the host against intracellular pathogens. we have previously shown that cd8(+) t cells and perforin are required to protect against the extracellular pathogen yersinia pseudotuberculosis. here we establish an experimental system where cd8(+) t cells specific to a single model antigen are the only memory response present at time of challenge. using mice immunized with a vaccine strain of listeria monocytogenes that expresse ...201627268148
hybrid antifouling and antimicrobial coatings prepared by electroless co-deposition of fluoropolymer and cationic silica nanoparticles on stainless steel: efficacy against listeria monocytogenes.controlling formation, establishment, and proliferation of microbial biofilms on surfaces is critical for ensuring public safety. herein, we report on the synthesis of antimicrobial nanoparticles and their co-deposition along with fluorinated nanoparticles during electroless nickel plating of stainless steel. plating bath composition is optimized to ensure sufficiently low surface energy to resist fouling and microbial adhesion as well as to exert significant (>99.99% reduction) antimicrobial ac ...201627268033
comorbidities and factors associated with central nervous system infections and death in non-perinatal listeriosis: a clinical case series.listeriosis is a rare disease caused by the bacterium listeria monocytogenes and mainly affects at risk people. listeriosis can lead to sepsis, central nervous system (cns) infections and death. the objectives of this study were to describe and quantify comorbidities and neurological sequelae underlying non-perinatal listeriosis cases and to describe the factors associated with death and cns infections in non-perinatal listeriosis.201627267465
inhibitory effect of liposome-entrapped lemongrass oil on the growth of listeria monocytogenes in cheese.listeria monocytogenes infection in dairy products is of mounting public concern. to inhibit bacterial growth, we engineered stimuli-responsive liposomes containing lemongrass oil for this study. the controlled release of liposome-entrapped lemongrass oil is triggered by listerolysin o, secreted by l. monocytogenes. we investigated the antibiotic activities of lemongrass oil liposomes against l. monocytogenes in cheese. we also assessed their possible effects on the quality of the cheese. liposo ...201627265173
infective endocarditis due to listeria monocytogenes: a report of 4 patients. 201627262490
the impact of oxygen on bacterial enteric pathogens.bacterial enteric pathogens are responsible for a tremendous amount of foodborne illnesses every year through the consumption of contaminated food products. during their transit from contaminated food sources to the host gastrointestinal tract, these pathogens are exposed and must adapt to fluctuating oxygen levels to successfully colonize the host and cause diseases. however, the majority of enteric infection research has been conducted under aerobic conditions. to raise awareness of the import ...201627261784
inactivation of listeria monocytogenes atcc 7644 on fresh-cut tomato using nisin in combinations with organic salts.the inhibition of listeria monocytogenes atcc 7644 on fresh-cut tomato was investigated using nisin alone, and in combinations with organic salts. nisin at a concentration of 5000ui/ml was introduced alone or in combination with an organic salt (sodium citrate or sodium acetate each at 3 and 5g/100ml each) on fresh-cut tomato previously inoculated with 10(8)cfu/ml of l. monocytogenes atcc 7644. chlorine at 200ppm was used as a control. the inoculated samples were incubated at different temperatu ...201727261167
survival and metabolic activity of listeria monocytogenes on ready-to-eat roast beef stored at 4 °c.three brands of commercial roast beef were purchased and artificially inoculated with a 5-strain listeria monocytogenes cocktail at 2 inoculation levels (approximately 3 and 6 log cfu/g). although all 3 brands contained sodium diacetate and sodium lactate, inoculated listeria cocktail survived for 16 d in all 3 brands; significant increases in l. monocytogenes numbers were seen on inoculated brand b roast beef on days 12 and 16. numbers of l. monocytogenes increased to 4.14 log cfu/g for the 3 l ...201627258789
antimicrobial and physicochemical characterization of biodegradable, nitric oxide-releasing nanocellulose-chitosan packaging membranes.biodegradable composite membranes with antimicrobial properties consisting of nanocellulose fibrils (cnfs), chitosan, and s-nitroso-n-acetyl-d-penicillamine (snap) were developed and tested for food packaging applications. as a nitric oxide donor, snap was encapsulated into completely dispersed chitosan in 100 ml of 0.1 n acetic acid and was thoroughly mixed with cnfs to produce a composite membrane. the fabricated membranes had a uniform dispersion of chitosan and snap within the cnfs, which wa ...201627258235
subunit arrangement in gpsb, a regulator of cell wall biosynthesis.gpsb, a key regulator of cell division in gram-positive bacteria, interacts with a key peptidoglycan synthase at the cell division septum, the penicillin binding protein pbp1 (a.k.a. pona). bacillus subtilis gpsb has been reported to interact with other components of the cell division machinery, including ezra, mrec, and prkc. in this study, we report an analysis of the arrangement of subunits in listeria monocytogenes gpsb by small-angle x-ray scattering. the resulting model has an elongated sh ...201627257764
bacterial quality and safety of packaged fresh leafy vegetables at the retail level in finland.consumption of packaged fresh leafy vegetables, which are convenient ready-to-eat products, has increased during the last decade. the number of foodborne outbreaks associated with these products has concurrently increased. in our study, (1) label information, (2) o2/co2 composition, (3) bacterial quality and (4) safety of 100 fresh leafy vegetables at the retail level were studied in finland during 2013. bacterial quality was studied using aerobic bacteria (ab) and coliform bacteria (cb) counts, ...201627257744
draft genome sequences of listeria monocytogenes serotype 4b strains 944 and 2993 and serotype 1/2c strains 198 and 2932.listeria monocytogenes is a foodborne pathogen and the causative agent of listeriosis among humans and animals. the draft genome sequences of l. monocytogenes serotype 4b strains 944 and 2993 and serotype 1/2c strains 198 and 2932 are reported here.201627257200
rab32/38 and the xenophagic restriction of intracellular bacteria replication.rab gtpases' subversion by intracellular pathogens during infection has been extensively documented. recent findings have implicated a key intracellular bacterial restriction/containment function for rab32/38 in salmonella species in macrophages and listeria monocytogenes in dendritic cells. rab32/38 aids the phagolysosome maturation, and mediates a parallel xenophagy mechanism by engaging prohibitins.201627256464
listeriosis: is it a rare disease in thailand?the prevalence of listeria monocytogenes infection has been characterized as rare in thailand. within one month, 3 cases of listeriosis were seen at vachira phuket hospital in phuket, thailand. two cases were neonates with septicemia, of which one made an uneventful recovery and the other expired. the third case was an eleven-year-old boy with meningitis who also succumbed to his illness. all isolated l. monocytogenes were sensitive to ampicillin. an outbreak investigation revealed no l. monocyt ...201627249907
recovery and growth potential of listeria monocytogenes in temperature abused milkshakes prepared from naturally contaminated ice cream linked to a listeriosis outbreak.the recovery and growth potential of listeria monocytogenes was evaluated in three flavors of milkshakes (vanilla, strawberry, and chocolate) that were prepared from naturally contaminated ice cream linked to a listeriosis outbreak in the u.s. in 2015, and were subsequently held at room temperature for 14 h. the average lag phase duration of l. monocytogenes was 9.05 h; the average generation time was 1.67 h; and the average population level increase per sample at 14 h was 1.14 log cfu/g. milksh ...201627242775
comparative resistance of bacterial foodborne pathogens to non-thermal technologies for food preservation.in this paper the resistance of bacterial foodborne pathogens to manosonication (ms), pulsed electric fields (pefs), high hydrostatic pressure (hhp), and uv-light (uv) is reviewed and compared. the influence of different factors on the resistance of bacterial foodborne pathogens to these technologies is also compared and discussed. only results obtained under harmonized experimental conditions have been considered. this has allowed us to establish meaningful comparisons and draw significant conc ...201627242749
microbial safety and overall quality of cantaloupe fresh-cut pieces prepared from whole fruit after wet steam treatment.fresh-cut cantaloupes have been associated with outbreaks of salmonellosis. minimally processed fresh-cut fruits have a limited shelf life because of deterioration caused by spoilage microflora and physiological processes. the objectives of this study were to use a wet steam process to 1) reduce indigenous spoilage microflora and inoculated populations of salmonella, escherichia coli o157:h7 and listeria monocytogenes on the surface of cantaloupes, and 2) reduce the populations counts in cantalo ...201627240141
isolation and characterization of a broad spectrum bacteriocin from bacillus amyloliquefaciens rx7.we isolated a bacillus strain, rx7, with inhibitory activity against listeria monocytogenes from soil and identified it as bacillus amyloliquefaciens based on 16s rrna gene sequencing. the inhibitory activity was stable over a wide range of ph and was fully retained after 30 min at 80°c, after which it decreased gradually at higher temperatures. the activity was sensitive to the proteolytic action of α-chymotrypsin, proteinase-k, and trypsin, indicating its proteinaceous nature. this bacteriocin ...201627239477
foodborne listeria monocytogenes: a real challenge in quality control.listeria monocytogenes is a foodborne pathogen, and the detection and differentiation of this bacterium from the nonpathogenic listeria species are of great importance to the food industry. differentiation of listeria species is very difficult, even with the sophisticated maldi-tof ms technique because of the close genetic relationship of the species and the usual gene transfer. the present paper emphasizes the difficulties of the differentiation through the standardized detection and confirmati ...201627239376
virulence factors and resistance to antimicrobials in listeria monocytogenes serotype 1/2c isolated from food.the aim of this study was to assess the potential risk posed to the human population by the presence of listeria monocytogenes serotype 1/2c in food based on the characterization of virulence factors of listeria involved in the invasion of host cells and sensitivity to antimicrobial agents.201627238881
anti-biofilm and sporicidal activity of peptides based on wheat puroindoline and barley hordoindoline proteins.the broad-spectrum activity of antimicrobial peptides (amps) and low probability of development of host resistance make them excellent candidates as novel bio-control agents. a number of amps are found to be cationic, and a small proportion of these are tryptophan-rich. the puroindolines (pin) are small, basic proteins found in wheat grains with proposed roles in biotic defence of seeds and seedlings. synthetic peptides based on their unique tryptophan-rich domain (trd) display antimicrobial pro ...201627238815
antimicrobial activity of chitosan coatings and films against listeria monocytogenes on black radish.the antibacterial activity of chitosan coatings prepared with acetic or lactic acid, as well as of composite chitosan-gelatin films prepared with essential oils, was evaluated in fresh shredded black radish samples inoculated with listeria monocytogenes atcc 19115 and l. monocytogenes atcc 19112 during seven days of storage at 4°c. the chitosan coating prepared with acetic acid showed the most effective antibacterial activity. all tested formulations of chitosan films exhibited strong antimicrob ...201727237426
microbiology of cooked and dried edible mediterranean field crickets (gryllus bimaculatus) and superworms (zophobas atratus) submitted to four different heating treatments.to increase the shelf life of edible insects, modern techniques (e.g. freeze-drying) add to the traditional methods (degutting, boiling, sun-drying or roasting). however, microorganisms become inactivated rather than being killed, and when rehydrated, many return to vegetative stadia. crickets (gryllus bimaculatus) and superworms (zophobas atratus) were submitted to four different drying techniques (t1 = 10' cooking, 24 h drying at 60℃; t2 = 10' cooking, 24 h drying at 80℃; t3 = 30' cooking, 12  ...201727235993
latex protein extracts from calotropis procera with immunomodulatory properties protect against experimental infections with listeria monocytogenes.the latex from the medicinal plant calotropis procera is often used in folk medicine against infectious and inflammatory diseases.201627235713
population genetic structure of listeria monocytogenes strains as determined by pulsed-field gel electrophoresis and multilocus sequence typing.listeria monocytogenes is a ubiquitous bacterium that may cause the foodborne illness listeriosis. only a small amount of data about the population genetic structure of strains isolated from food is available. this study aimed to provide an accurate view of the l. monocytogenes food strain population in france. from 1999 to 2014, 1,894 l. monocytogenes strains were isolated from food at the french national reference laboratory for l. monocytogenes and classified according to the five risk food m ...201627235443
inhibitory effect of zataria multiflora boiss. essential oil, alone and in combination with monolaurin, on listeria monocytogenes.listeria monocytogenes is one of the major causes of infections in developing countries. in this study, chemical composition and anti-listerial effect of the essential oil of zataria multiflora boiss. alone and in combination with monolaurin were evaluated at different ph values (5, 6, and 7) and temperatures (5 ˚c and 30 ˚c). chemical composition of zataria multiflora boiss. essential oil was evaluated by gas chromatography-mass spectrometry (gc-ms) analysis. minimum inhibitory concentration (m ...201627226881
the antimicrobial peptide aureocin a53 as an alternative agent for biopreservation of dairy products.the aim of this study was to investigate the potential of aureocin a53, a staphylococcal antimicrobial peptide, for improving food safety.201627225974
brain abscesses due to listeria monocytogenes after rituximab therapy. 201627219320
listeria monocytogenes septicemia in an immunocompromised dog.an 11-year-old, male castrated, boston terrier was presented to the north carolina state university college of veterinary medicine small animal emergency service with a 2-day history of progressive ataxia, left-sided head tilt, and anorexia. the dog had previously been diagnosed with chronic lymphoid leukemia and suspected immune-mediated destruction of his bone marrow precursor cells, possibly due to therapy with immunosuppressive dosages of prednisone and azathioprine. during the physical exam ...201627218230
purification of plasmodium sporozoites enhances parasite-specific cd8+ t cell responses.malaria infection caused by plasmodium parasites continues to cause enormous morbidity and mortality in areas where it is endemic, and there is no licensed vaccine capable of inducing sterile protection. hyperimmunization with attenuated whole sporozoites can induce sterile protective immune responses targeting preerythrocytic antigens. most animal models of hyperimmunization rely on sporozoites dissected from mosquito salivary glands and injected without further purification. in balb/c mice, re ...201627217420
inactivation of listeria monocytogenes, salmonella spp. and escherichia coli o157:h7 on cantaloupes by octenidine dihydrochloride.the efficacy of a new generation disinfectant, octenidine dihydrochloride (oh), as wash and coating treatments for reducing listeria monocytogenes (lm), salmonella spp. (sal), and escherichia coli o157:h7 (ec) on cantaloupe was investigated. cantaloupe rind plugs inoculated separately with the three bacterial species (∼8 log cfu/cm(2)) were washed for 1, 3, 5 min at 25 °c in water, or chlorine (200 ppm), ethanol (1%), oh (0.01, 0.05, 0.1%) and surviving populations were measured after treatment. ...201627217367
physio-chemical, microbiological properties of tempoyak and molecular characterisation of lactic acid bacteria isolated from tempoyak.this study aims to determine physio-chemical properties of tempoyak, characterise the various indigenous species of lactic acid bacteria (lab) present at different stages of fermentation and also to determine the survival of selected foodborne pathogens in tempoyak. the predominant microorganisms present in tempoyak were lab (8.88-10.42 log cfu/g). fructobacillus durionis and lactobacillus plantarum were the dominant members of lab. other lab species detected for the first time in tempoyak were ...201627217364
minimal inhibitory concentrations of undissociated lactic, acetic, citric and propionic acid for listeria monocytogenes under conditions relevant to cheese.minimal inhibitory concentrations (mics) of undissociated lactic acid were determined for six different listeria monocytogenes strains at 30 °c and in a ph range of 4.2-5.8. small increments in ph and acid concentrations were used to accurately establish the growth/no growth limits of l. monocytogenes for these acids. the mics of undissociated lactic acid in the ph range of 5.2-5.8 were generally higher than at ph 4.6 for the different l. monocytogenes strains. the average mic of undissociated l ...201627217360
validation of a predictive model coupling gas transfer and microbial growth in fresh food packed under modified atmosphere.predicting microbial safety of fresh products in modified atmosphere packaging implies to take into account the dynamic of o2, co2 and n2 exchanges in the system and its effect on microbial growth. in this paper a mechanistic model coupling gas transfer and predictive microbiology was validated using dedicated challenge-tests performed on poultry meat, fresh salmon and processed cheese, inoculated with either listeria monocytogenes or pseudomonas fluorescens and packed in commercially used packa ...201627217358
rna- and protein-mediated control of listeria monocytogenes virulence gene expression.the model opportunistic pathogen listeria monocytogenes has been the object of extensive research, aiming at understanding its ability to colonize diverse environmental niches and animal hosts. bacterial transcriptomes in various conditions reflect this efficient adaptability. we review here our current knowledge of the mechanisms allowing l. monocytogenes to respond to environmental changes and trigger pathogenicity, with a special focus on rna-mediated control of gene expression. we highlight ...201627217337
evaluation of technological properties of enterococcus faecium cect 8849, a strain isolated from human milk, for the dairy industry.in this work, a variety of biochemical properties of enterococcus faecium cect 8849, which had been isolated from breast milk, were analyzed. its acidifying capacity and proteolytic activity were low but, in contrast, remarkable peptidase and esterase activities were observed. ethanol and 3-hydroxy-2-butanone were the most abundant volatile compounds found in experimental model cheese manufactured with e. faecium cect 8849. this strain inhibited the growth of several listeria monocytogenes and l ...201627216614
memory cd8(+) t cells require increased concentrations of acetate induced by stress for optimal function.how systemic metabolic alterations during acute infections impact immune cell function remains poorly understood. we found that acetate accumulates in the serum within hours of systemic bacterial infections and that these increased acetate concentrations are required for optimal memory cd8(+) t cell function in vitro and in vivo. mechanistically, upon uptake by memory cd8(+) t cells, stress levels of acetate expanded the cellular acetyl-coenzyme a pool via atp citrate lyase and promoted acetylat ...201627212436
shedding light on betl*: ppl2-lux mediated real-time analysis of betl* expression in listeria monocytogenes.we propose a mechanism of action for the betl* mutation which is based on dna topology. removing a single thymine residue from the betl σ(a) promoter's -10 and -35 spacer results in a 'twist'-mediated activation of transcription which accounts for the osmotolerance phenotype observed for strains expressing betl*.201627212260
detection, identification, and typing of listeria species from baled silages fed to dairy cows.anaerobiosis, critical for successful ensilage, constitutes a challenge in baled silages. the loss of complete anaerobiosis causes aerobic deterioration and silages undergo dry matter and nutrient losses, pathogen growth, and mycotoxin production. silage may represent an ideal substrate for listeria monocytogenes, a pathogen of primary concern in several cheeses. the aim of this research was to investigate the occurrence of listeria in baled silage fed to cows producing milk for a protected desi ...201627209131
effect of acidic electrolyzed water-induced bacterial inhibition and injury in live clam (venerupis philippinarum) and mussel (mytilus edulis).the effect of acidic electrolyzed water (aew) on inactivating escherichia coli o104:h4, listeria monocytogenes, aeromonas hydrophila, vibrio parahaemolyticus and campylobacter jejuni in laboratory contaminated live clam (venerupis philippinarum) and mussel (mytilus edulis) was investigated. the initial levels of bacterial contamination were: in clam 4.9 to 5.7log10cfu/g, and in mussel 5.1 to 5.5log10cfu/g. two types of aew were used for treatment time intervals of 1 and 2h: strong (saew) with an ...201627208583
loss of sigb in listeria monocytogenes strains egd-e and 10403s confers hyperresistance to hydrogen peroxide in stationary phase under aerobic conditions.sigb is the main stress gene regulator in listeria monocytogenes affecting the expression of more than 150 genes and thus contributing to multiple-stress resistance. despite its clear role in most stresses, its role in oxidative stress is uncertain, as results accompanying the loss of sigb range from hyperresistance to hypersensitivity. previously, these differences have been attributed to strain variation. in this study, we show conclusively that unlike for all other stresses, loss of sigb resu ...201627208116
potential impact of the resistance to quaternary ammonium disinfectants on the persistence of listeria monocytogenes in food processing environments.the persistence of certain strains of listeria monocytogenes, even after the food processing environment has been cleaned and disinfected, suggests that this may be related to phenomena that reduce the concentration of the disinfectants to subinhibitory levels. this includes (i) the existence of environmental niches or reservoirs that are difficult for disinfectants to reach, (ii) microorganisms that form biofilms and create microenvironments in which adequate concentrations of disinfectants can ...201627199964
temperature significantly affects the plaquing and adsorption efficiencies of listeria phages.listeria-infecting phages are currently being used to control and detect the important foodborne pathogen listeria monocytogenes; however, the influence of environmental conditions on the interactions between l. monocytogenes and its phages has not been explored in depth. here, we examined the infective potential of four listeria phages (two each from the p70-like and p100-like phages of listeria) against five strains of l. monocytogenes (representing serotypes 1/2a, 1/2b, 4a, and 4b) grown unde ...201627199957
comparison of surface proteomes of adherence variants of listeria monocytogenes using lc-ms/ms for identification of potential surface adhesins.the ability of listeria monocytogenes to adhere and form biofilms leads to persistence in food processing plants and food-associated listeriosis. the role of specific surface proteins as adhesins to attach listeria cells to various contact surfaces has not been well characterized to date. in prior research comparing different methods for surface protein extraction, the ghost urea method revealed cleaner protein content as verified by the least cytoplasmic protein detected in surface extracts usi ...201627196934
application of electron-beam irradiation combined with aging for improvement of microbiological and physicochemical quality of beef loin.the combined effects of irradiation and aging temperature on the microbial and chemical quality of beef loin were investigated. the samples were vacuum-packaged, irradiated at 0 or 2 kgy using electron-beam (eb), and stored for 10 d at different aging temperatures (2, 14, or 25℃). the microbial growth, shear values, meat color, and nucleotide-related flavor compounds of the samples were analyzed. the irradiation effect on inactivation of foodborne pathogens was also investigated. the population ...201627194930
mode of action of leucocin k7 produced by leuconostoc mesenteroides k7 against listeria monocytogenes and its potential in milk preservation.to investigate the mode of action of leucocin k7 against listeria monocytogenes and to assess its inhibitory effect on lis. monocytogenes in refrigerated milk.201627193759
atf3 provides protection from staphylococcus aureus and listeria monocytogenes infections. 201627190243
control of listeria monocytogenes biofilms on industrial surfaces by the bacteriocin-producing lactobacillus sakei crl1862.the effect of the bacteriocin-producing lactobacillus sakei crl1862 and its bacteriocin in the control of listeria biofilm formation on industrial surfaces at 10°c was investigated. a screening among different listeria species was performed allowing selecting l. monocytogenes fbunt for its use as a biofilm producer on stainless steel (ss) and polytetrafluoroe-thylene (ptfe) surfaces. three conditions were simulated to evaluate the ability of the bacteriocinogenic strain to displace, exclude and ...201627190146
identification of a lipoteichoic acid glycosyltransferase enzyme reveals that gw-domain-containing proteins can be retained in the cell wall of listeria monocytogenes in the absence of lipoteichoic acid or its modifications.listeria monocytogenes is a foodborne gram-positive bacterial pathogen, and many of its virulence factors are either secreted proteins or proteins covalently or noncovalently attached to the cell wall. previous work has indicated that noncovalently attached proteins with gw (glycine-tryptophan) domains are retained in the cell wall by binding to the cell wall polymer lipoteichoic acid (lta). lta is a glycerol phosphate polymer, which is modified in l. monocytogenes with galactose and d-alanine r ...201627185829
effects of chitin nano-whiskers on the antibacterial and physicochemical properties of maize starch films.we investigated the effects of chitin nano-whiskers (cnws) on the antibacterial and physiochemical properties of maize starch-based films. the microstructures, crystalline structures, and thermal, mechanical and barrier properties of the nanocomposite films were characterized by using transmission electron microscopy, x-ray diffraction analysis, thermogravimetric, differential scanning calorimeter, and texture profile analysis. the tensile strength of the maize starch films increased from 1.64mp ...201627178943
predicting the kinetics of listeria monocytogenes and yersinia enterocolitica under dynamic growth/death-inducing conditions, in italian style fresh sausage.traditional italian pork products can be consumed after variable drying periods, where the temporal decrease of water activity spans from optimal to inactivating values. this makes it necessary to a) consider the bias factor when applying culture-medium-based predictive models to sausage; b) apply the dynamic version (described by differential equations) of those models; c) combine growth and death models in a continuous way, including the highly uncertain growth/no growth range separating the t ...201727178365
bacillus licheniformis contains two more perr-like proteins in addition to perr, fur, and zur orthologues.the ferric uptake regulator (fur) family proteins include sensors of fe (fur), zn (zur), and peroxide (perr). among fur family proteins, fur and zur are ubiquitous in most prokaryotic organisms, whereas perr exists mainly in gram positive bacteria as a functional homologue of oxyr. gram positive bacteria such as bacillus subtilis, listeria monocytogenes and staphylococcus aureus encode three fur family proteins: fur, zur, and perr. in this study, we identified five fur family proteins from b. li ...201627176811
inactivation of salmonella, listeria monocytogenes and enterococcus faecium nrrl b-2354 in a selection of low moisture foods.the aims of this study were to obtain data on survival and heat resistance of cocktails of salmonella, listeria monocytogenes and the surrogate enterococcus faecium (nrrl b-2354) in four low moisture foods (confectionery formulation, chicken meat powder, pet food and savoury seasoning) during storage before processing. inoculated samples were stored at 16°c and cell viability examined at day 0, 3, 7 and 21. at each time point, the heat resistance at 80°c was determined. the purpose was to determ ...201627174678
lactococcus piscium: a psychrotrophic lactic acid bacterium with bioprotective or spoilage activity in food-a review.the genus lactococcus comprises 12 species, some known for decades and others more recently described. lactococcus piscium, isolated in 1990 from rainbow trout, is a psychrotrophic lactic acid bacterium, probably disregarded because most of the strains are unable to grow at 30°c. during the last 10 years, this species has been isolated from a large variety of food: meat, seafood and vegetables, mostly packed under vacuum (vp) or modified atmosphere (map) and stored at chilled temperature. recent ...201627172050
free-living species of carnivorous mammals in poland: red fox, beech marten, and raccoon as a potential reservoir of salmonella, yersinia, listeria spp. and coagulase-positive staphylococcus.the objective of the study was to examine a population of free-living carnivorous mammals most commonly found in poland (red fox, beech marten, and raccoon) for the occurrence of bacteria that are potentially pathogenic for humans and other animal species and to determine their virulence potential (the presence of selected virulence genes). from the total pool of isolates obtained (n = 328), we selected 90 belonging to species that pose the greatest potential threat to human health: salmonella s ...201627171434
a rare case of listeriosis, acute cholecystitis and multiple myeloma.listeria monocytogenes (lm) is an aerobic, motile, intracellular gram-positive bacterium. most invasive systemic infections caused by lm are commonly seen in patients at both extremes of age, during pregnancy or in immunocompromised hosts. common clinical manifestations of lm infection in immunocompromised adults are bacteremia, infections of central nervous system, such as meningitis, and self-limiting febrile gastroenteritis. focal infections of listeria are rare, especially cholecystitis, wit ...201627170703
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