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impact of environmental factors on the culturability and viability of listeria monocytogenes under conditions encountered in food processing plants.the ability of listeria monocytogenes to adhere to and persist on surfaces for months or even years may be responsible for its transmission from contaminated surfaces to food products. hence the necessity to find effective means to prevent the establishment of l. monocytogenes in food processing environments. the aim of this study was to assess, through a fractional experimental design, the environmental factors that could affect the survival of l. monocytogenes cells on surfaces to thereby prev ...201728073080
listeria monocytogenes behaviour and quality attributes during sausage storage affected by sodium nitrite, sodium lactate and thyme essential oil.the effects of the addition of nitrite at 200 ppm (n), sodium lactate 1.5% (l) and thyme essential oil at 100 ppm (t1) on listeria monocytogenes behaviour and atpase activity inhibition were evaluated, as well as lipid oxidation through the quantification of malonaldehydes, in sausage stored at 8 ℃ for 41 days and at 30 ℃ for 14 days. the changes in the colour profile were performed during storage time at 8 ℃. quantitative descriptive sensory analyses were performed after two days at 4 ℃. at 8 ℃ ...201728068841
listeria monocytogenes circulating in rabbit meat products and slaughterhouses in italy: prevalence data and comparison among typing results.rabbit meat has outstanding dietetic and nutritional properties. however, few data on microbiological hazards associated with rabbit productions are available. in this study, the presence of listeria monocytogenes was determined in 430 rabbit carcasses, 256 rabbit meat cuts and products, and 599 environmental sponges collected from four italian rabbit slaughterhouses over a period of 1 year. prevalence of l. monocytogenes among the 1285 rabbit meat and environmental samples was 11%, with statist ...201728067541
acute fetal demise with first trimester maternal infection resulting from listeria monocytogenes in a nonhuman primate model.infection with listeria monocytogenes during pregnancy is associated with miscarriage, preterm birth, and neonatal complications, including sepsis and meningitis. while the risk of these conditions is thought to be greatest during the third trimester of pregnancy, the determinants of fetoplacental susceptibility to infection, the contribution of gestational age, and the in vivo progression of disease at the maternal-fetal interface are poorly understood. we developed a nonhuman primate model of ...201728223455
listeria monocytogenes in smoked salmon and other smoked fish at retail in italy: frequency of contamination and strain characterization in products from different manufacturers.seven hundred seventy-eight samples of packaged smoked fish (774 smoked salmon and 4 smoked swordfish) on sale in italy, from 50 different manufacturers located in 12 european union countries, were purchased from the italian market between may and december 2011. the surface temperatures of the samples on sale ranged from 0 to 13°c (3.4 ± 1.5°c, mean ± sd). six hundred eighty (87.4%) of 778 samples were stored at ≤4°c. one hundred fifty-seven samples (20.2%, 95% confidence interval 17.5 to 23.1%) ...201728221976
fate of listeria monocytogenes , pathogenic yersinia enterocolitica , and escherichia coli o157:h7 gfp(+) in ready-to-eat salad during cold storage: what is the risk to consumers?in this study, we investigated the fate of listeria monocytogenes , pathogenic yersinia enterocolitica , and escherichia coli o157:h7 gfp(+) inoculated in low numbers into ready-to-eat baby spinach and mixed-ingredient salad (baby spinach with chicken meat). samples were stored at recommended maximum refrigerator temperature (8°c in sweden) or at an abuse temperature (15°c) for up to 7 days. mixed-ingredient salad supported considerable growth when stored at 15°c during shelf life (3 days), with ...201728221975
microbial quality, safety, and pathogen detection by using quantitative pcr of raw salad vegetables sold in dhanbad city, india.consumption of ready-to-eat fresh vegetables has increased worldwide, with a consequent increase in outbreaks caused by foodborne pathogens. in the indian subcontinent, raw fresh vegetables are usually consumed without washing or other decontamination procedures, thereby leading to new food safety threats. in this study, the microbiological quality and pathogenic profile of raw salad vegetables was evaluated through standard protocols. in total, 480 samples (60 each of eight different salad vege ...201728221891
prediction of escherichia coli o157:h7, salmonella , and listeria monocytogenes growth in leafy greens without temperature control.a recent study by the centers for disease control and prevention reported that between 1998 and 2008, leafy greens outbreaks accounted for 22.3% of foodborne outbreaks in the united states. several studies on the growth of bacteria at different temperatures have been conducted; however, there is a need for the prediction of bacterial growth when leafy greens are transported without temperature control. food products, when taken out of refrigeration, undergo a temperature change, with the rate of ...201728221878
bacterial meningitis in alcoholic patients: a population-based prospective study.to study clinical features and outcome of community-acquired bacterial meningitis in alcoholic patients.201728065808
hospital-acquired listeriosis linked to a persistently contaminated milkshake machine.one case of hospital-acquired listeriosis was linked to milkshakes produced in a commercial-grade shake freezer machine. this machine was found to be contaminated with a strain of listeria monocytogenes epidemiologically and molecularly linked to a contaminated pasteurized, dairy-based ice cream product at the same hospital a year earlier, despite repeated cleaning and sanitizing. healthcare facilities should be aware of the potential for prolonged listeria contamination of food service equipmen ...201728065212
multistate outbreak of listeria monocytogenes infections linked to whole apples used in commercially produced, prepackaged caramel apples: united states, 2014-2015.whole apples have not been previously implicated in outbreaks of foodborne bacterial illness. we investigated a nationwide listeriosis outbreak associated with caramel apples. we defined an outbreak-associated case as an infection with one or both of two outbreak strains of listeria monocytogenes highly related by whole-genome multilocus sequence typing (wgmlst) from 1 october 2014 to 1 february 2015. single-interviewer open-ended interviews identified the source. outbreak-associated cases were ...201728065170
evaluation of the 3m™ molecular detection assay (mda) 2 - listeria monocytogenes for the detection of listeria monocytogenes in a variety of foods and select environmental surfaces: collaborative study, first action 2016.08.the 3m™ molecular detection assay (mda) 2 - listeria monocytogenes uses loop-mediated isothermal amplification of unique dna target sequences combined with bioluminescence to rapidly detect listeria monocytogenes in a broad range of food types and on environmental surfaces. using an unpaired study design, technicians from 13 laboratories located in the united states and canada compared the 3m mda 2 - listeria monocytogenes to the u.s. department of agriculture food safety inspection service micr ...201728059049
singleton sequence type 382, an emerging clonal group of listeria monocytogenes associated with three multistate outbreaks linked to contaminated stone fruit, caramel apples, and leafy green salad.three multistate outbreaks between 2014 and 2016, involving case patients in and outside the united states, were linked to stone fruit, caramel apples, and packaged leafy green salad contaminated with listeria monocytogenes singleton sequence type 382 (st382), a serotype ivb-v1 clone with limited genomic divergence. isolates from these outbreaks and other st382 isolates not associated with these outbreaks were analyzed by whole-genome sequencing (wgs) analysis. the primary differences among st38 ...201728053218
structural characterisation of the fatty acid biosynthesis enzyme fabf from the pathogen listeria monocytogenes.development of new antimicrobial agents is required against the causative agent for listeriosis, listeria monocytogenes, as the number of drug resistant strains continues to increase. a promising target is the β-ketoacyl-acyl carrier protein synthase fabf, which participates in the catalysis of fatty acid synthesis and elongation, and is required for the production of phospholipid membranes, lipoproteins, and lipopolysaccharides. in this study, we report the 1.35 å crystal structure of fabf from ...201728045020
detection of premature stop codons leading to truncated internalin a among food and clinical strains of listeria monocytogenes.listeria monocytogenes is a food-borne pathogen responsible for outbreaks and sporadic cases of listeriosis, a severe invasive disease. internalin a (inla) a protein encoded by inla has a key role in the mechanism of pathogenesis in l. monocytogenes infection, specifically in the invasion of human intestinal epithelial cells. studies on inla have shown that mutations leading to premature stop codons (pmscs) occur naturally and are associated with impaired virulence of l. monocytogenes strains. i ...201728040183
application of low frequency pulsed ohmic heating for inactivation of foodborne pathogens and ms-2 phage in buffered peptone water and tomato juice.the purpose of this study was to inactivate foodborne pathogens effectively by ohmic heating in buffered peptone water and tomato juice without causing electrode corrosion and quality degradation. escherichia coli o157:h7, salmonella typhimurium, and listeria monocytogenes were used as representative foodborne pathogens and ms-2 phage was used as a norovirus surrogate. buffered peptone water and tomato juice inoculated with pathogens were treated with pulsed ohmic heating at different frequencie ...201728040173
differential gene expression and filamentation of listeria monocytogenes 08-5923 exposed to sodium lactate and sodium diacetate.this study reports the gene expression and filamentation in listeria monocytogenes 08-5923 following exposure to food preservatives sodium lactate (nal) and sodium diacetate (sd). l. monocytogenes 08-5923 was challenged with a mixture of nal/sd, nal or sodium acetate at 37 °c in tryptic soy broth. in the initial study, l. monocytogenes 08-5923 was exposed to nal/sd for 24 h. the transcriptome was investigated by rna sequencing. a stress response network was discovered in l. monocytogenes 08-5923 ...201728040163
application of a 222-nm krypton-chlorine excilamp to control foodborne pathogens on sliced cheese surfaces and characterization of the bactericidal mechanisms.this study was conducted to investigate the basic spectral properties of a 222-nm krypton-chlorine (krcl) excilamp and its inactivation efficacy against major foodborne pathogens on solid media, as well as on sliced cheese compared to a conventional 254-nm low-pressure mercury (lp hg) lamp. selective media and sliced cheese inoculated with escherichia coli o157:h7, salmonella enterica serovar typhimurium, and listeria monocytogenes were irradiated with a krcl excilamp and a lp hg lamp at the sam ...201728039742
endoplasmic reticulum chaperone gp96 controls actomyosin dynamics and protects against pore-forming toxins.during infection, plasma membrane (pm) blebs protect host cells against bacterial pore-forming toxins (pfts), but were also proposed to promote pathogen dissemination. however, the details and impact of blebbing regulation during infection remained unclear. here, we identify the endoplasmic reticulum chaperone gp96 as a novel regulator of pft-induced blebbing. gp96 interacts with non-muscle myosin heavy chain iia (nmhciia) and controls its activity and remodelling, which is required for appropri ...201728039206
an effective counterselection system for listeria monocytogenes and its use to characterize the monocin genomic region of strain 10403s.construction of listeria monocytogenes mutants by allelic exchange has been laborious and time-consuming due to lack of proficient selection markers for the final recombination event, that is, a marker conveying substance sensitivity to the bacteria bearing it, enabling the exclusion of merodiploids and selection for plasmid loss. in order to address this issue, we engineered a counterselection marker based on a mutated phenylalanyl-trna synthetase gene (phes*). this mutation renders the phenyla ...201728039138
a rapid typing method for listeria monocytogenes based on high-throughput multilocus sequence typing (hi-mlst).listeria monocytogenes infects humans via food products, causing listeriosis. consequently, food companies pay meticulous attention to the risk of contamination of their products by this bacterium. while fragment analysis methods such as pulsed-field gel electrophoresis (pfge) are used to trace the sources of contamination for this bacterium, some drawbacks have been identified, namely the complexity of the methods and the difficulty of making data comparisons. as an alternative, multilocus sequ ...201728038334
sensitive detection of listeria monocytogenes based on highly efficient enrichment with vancomycin-conjugated brush-like magnetic nano-platforms.pathogens pose a significant threat to public health worldwide. despite many technological advances in the rapid diagnosis of pathogens, sensitive pathogen detection remains challenging because target pathogenic bacteria usually exist in complex samples at very low concentrations. here, the construction of multivalent brush-like magnetic nanoprobes and their application for the efficient enriching of pathogens are demonstrated. brush-like magnetic nanoprobes were constructed by modification with ...201728013018
thermal inactivation and sublethal injury kinetics of salmonella enterica and listeria monocytogenes in broth versus agar surface.the objective of the present study was to compare the thermal inactivation and sublethal injury kinetics of salmonella enterica and listeria monocytogenes in broth (suspended cells) and on solid surface (agar-seeded cells). a 3-strain cocktail of s. enterica or l. monocytogenes inoculated in broth or on agar was subjected to heating in a water bath at various set temperatures (55.0, 57.5 and 60.0°c for s. enterica and 60.0, 62.5 and 65°c for l. monocytogenes). the occurrence of sublethally injur ...201728011300
growth, viability and architecture of biofilms of listeria monocytogenes formed on abiotic surfaces.the pathogenic bacterium listeria monocytogenes can persist in food processing plants for many years, even when appropriate hygienic measures are in place, with potential for contaminating ready-to-eat products and, its ability to form biofilms on abiotic surfaces certainly contributes for the environmental persistence. in this research, l. monocytogenes was grown in biofilms up 8 days attached to stainless steel and glass surfaces, contributing for advancing the knowledge on architecture of mat ...201728237677
surface-enhanced raman spectroscopy introduced into the international standard organization (iso) regulations as an alternative method for detection and identification of pathogens in the food industry.we show that surface-enhanced raman spectroscopy (sers) coupled with principal component analysis (pca) can serve as a fast, reliable, and easy method for detection and identification of food-borne bacteria, namely salmonella spp., listeria monocytogenes, and cronobacter spp., in different types of food matrices (salmon, eggs, powdered infant formula milk, mixed herbs, respectively). the main aim of this work was to introduce the sers technique into three iso (6579:2002; 11290-1:1996/a1:2004; 22 ...201728004171
insight into the genome of brochothrix thermosphacta, a problematic meat spoilage bacterium.brochothrix thermosphacta is a dominant but poorly studied meat spoilage organism. it is a close relative of the foodborne pathogen listeria monocytogenes, and brochothrix constitutes the second genus in the listeriaceae family. here, the genomes of 12 b. thermosphacta strains were sequenced, assembled into draft genomes, characterized, and compared with the genomes of brochothrix campestris and l. monocytogenes phenotypic properties including biogenic amine production and antibiotic and heavy m ...201727986732
novel cadmium resistance determinant in listeria monocytogenes.listeria monocytogenes is a foodborne pathogen that can cause severe disease (listeriosis) in susceptible individuals. it is ubiquitous in the environment and often exhibits resistance to heavy metals. one of the determinants that enables listeria to tolerate exposure to cadmium is the cadac efflux system, with cada being a p-type atpase. three different cada genes (designated cada1 to cada3) were previously characterized in l. monocytogenes a novel putative cadmium resistance gene (cada4) was r ...201727986731
production of bacterial ghosts from gram-positive pathogen listeria monocytogenes.the gram-positive bacterium listeria monocytogenes is a ubiquitous intracellular pathogen, which has been implicated within the past decade as the causative organism in several outbreaks of foodborne disease. bacterial ghosts (bgs) are nonliving and vacant cell envelopes of bacteria generated by releasing the bacterial cytoplasm through a channel in the cell envelope. this study attempted to produce gram-positive pathogenic l. monocytogenes ghosts (lmgs) with simple chemicals.201727982711
polyethylene oxide (peo)-hyaluronic acid (ha) nanofibers with kanamycin inhibits the growth of listeria monocytogenes.listeria monocytogenes is well known to cause prosthetic joint infections in immunocompromised patients. in this study, polyethylene oxide (peo) nanofibers, containing kanamycin and hyaluronic acid (ha), were prepared by electrospinning at a constant electric field of 10kv. peo nanofibers spun with 0.2% (w/v) ha and 1% (w/v) kanamycin had a smooth, bead-free structure at 30-35% relative humidity. the average diameter of the nanofibers was 83±20nm. attenuated total reflectance (atr)-fourier trans ...201727960136
utilization of multiple substrates by butyrate kinase from listeria monocytogenes.listeria monocytogenes, the causative agent of listeriosis, can build up to dangerous levels in refrigerated foods potentially leading to expensive product recalls. an important aspect of the bacterium's growth at low temperatures is its ability to increase the branched-chain fatty acid anteiso c15:0 content of its membrane at lower growth temperatures, which imparts greater membrane fluidity. mutants in the branched-chain α-keto dehydrogenase (bkd) complex are deficient in branched-chain fatty ...201727940001
molecular identification and functional delineation of a glutathione reductase homolog from disk abalone (haliotis discus discus): insights as a potent player in host antioxidant defense.glutathione reductase (gsr) is an enzyme that catalyzes the biochemical conversion of oxidized glutathione (gssg) into the reduced form (gsh). since the ratio between the two forms of glutathione (gsh/gssg) is important for the optimal function of gsh to act as an antioxidant against h2o2, the contribution of gsr as an enzymatic regulatory agent to maintain the proper ratio is essential. abalones are marine mollusks that frequently encounter environmental factors that can trigger the overproduct ...201727919756
tracking listeria monocytogenes contamination and virulence-associated characteristics in the ready-to-eat meat-based food products industry according to the hygiene level.listeria monocytogenes isolates collected from final products and food contact surfaces of 10 ready-to-eat meat-based food products (rtemp) producing industries were analyzed to relate their virulence-associated characteristics and genetic profiles with the hygiene assessment of those industries. together with sample collection, an audit was performed to evaluate the implemented food safety management system and to investigate the specific audit requisites more associated to the occurrence of th ...201727919005
assessing vacuolar escape of listeria monocytogenes.listeria monocytogenes is a bacterial pathogen which invades and multiplies within non-professional phagocytes. signaling cascades involved in cellular entry have been extensively analyzed, but the events leading to vacuolar escape remain less clear. in this chapter, we detail a microscopy fret-based assay which allows quantitatively measuring l. monocytogenes infection and escape from its internalization vacuole, as well as a correlative light/electron microscopy method to investigate the morph ...201727914079
effect of inoculum size, bacterial species, type of surfaces and contact time to the transfer of foodborne pathogens from inoculated to non-inoculated beef fillets via food processing surfaces.the objective of the present study was to determine the factors affecting the transfer of foodborne pathogens from inoculated beef fillets to non-inoculated ones, through food processing surfaces. three different levels of inoculation of beef fillets surface were prepared: a high one of approximately 10(7) cfu/cm(2), a medium one of 10(5) cfu/cm(2) and a low one of 10(3) cfu/cm(2), using mixed-strains of listeria monocytogenes, or salmonella enterica typhimurium, or escherichia coli o157:h7. the ...201727889165
exposure to minimally processed pear and melon during shelf life could modify the pathogenic potential of listeria monocytogenes.survival and virulence of foodborne pathogens can be influenced by environmental factors such as the intrinsic properties of food as well as the extrinsic properties that contribute to food shelf life (e.g., temperature and gas atmosphere). the direct contribution of food matrix characteristics on the survival of l. monocytogenes during fresh-cut fruit shelf life is not very well understood. in addition, the gastrointestinal tract is the primary route of listeriosis infection and penetration of ...201727889159
fat and fibre interfere with the dramatic effect that nanoemulsified d-limonene has on the heat resistance of listeria monocytogenes.the application of d-limonene in form of nanoemulsion has been proved to reduce dramatically the thermal resistance of listeria monocytogenes in culture media. the present research shows very promising results on the application in food products. the thermal resistance of l. monocytogenes was reduced 90 times when 0.5 mm nanoemulsified d-limonene was added to apple juice. this is the biggest reduction in the heat resistance of a microorganism caused by an antimicrobial described ever. however, n ...201727889158
inhibition of listeriolysin o oligomerization by lutein prevents listeria monocytogenes infection.the foodborne pathogenic bacterial species listeria monocytogenes (l. monocytogenes) has caused incalculable damages to public health, and its successful infection requires various virulence factors, including listeriolysin o (llo). by forming pores in phagosomal membranes and even in some organelles, llo plays an indispensable role in the ability of l. monocytogenes to escape from host immune attacks. because of its critical role, llo offers an appropriate therapeutic target against l. monocyto ...201727884571
antimicrobial activity and bioguided fractionation of rumex tingitanus extracts for meat preservation.this study was undertaken to investigate the antibacterial and antifungal activities of rumex tingitanus leaves extracts as well as the identification of bioactive components and their performance in meat preservation. total phenolics and flavonoids showed the highest content of phenolics and flavonoids in the ethyl acetate fraction (rt etoacf). for antimicrobial efficacy, leaves extract and derived fraction were tested for their capacity to inhibit bacterial and fungal proliferation in vitro an ...201727883958
characteristics of volatile organic compounds produced from five pathogenic bacteria by headspace-solid phase micro-extraction/gas chromatography-mass spectrometry.the characteristics of volatile compounds from five different bacterial species, escherichia coli o157:h7, salmonella enteritidis, shigella flexneri, staphylococcus aureus, and listeria monocytogenes, growing, respectively, in trypticase soy broth were monitored by headspace solid-phase micro-extraction/gas chromatography-mass spectrometry. the results showed that most volatile organic compounds (vocs) of five pathogens started to increase after the sixth to tenth hour. methyl ketones and long c ...201727874211
inhibitory activity of avocado seed fatty acid derivatives (acetogenins) against listeria monocytogenes.high standards regarding listeria monocytogenes control and consumer demands for food products without synthetic additives represent a challenge to food industry. we determined the antilisterial properties of an enriched acetogenin extract (eae) from avocado seed, compared it to two commercial antimicrobials (one enriched in avocado acetogenins), and tested purified molecules. acetogenin composition in pulp and seed of hass avocado was quantified. eae were obtained by two sequential centrifuge p ...201727871119
benzalkonium tolerance genes and outcome in listeria monocytogenes meningitis.listeria monocytogenes is a food-borne pathogen that can cause meningitis. the listerial genotype st6 has been linked to increasing rates of unfavourable outcome over time. we investigated listerial genetic variation and the relation with clinical outcome in meningitis.201727998823
microbial counts of mealworm larvae (tenebrio molitor) and crickets (acheta domesticus and gryllodes sigillatus) from different rearing companies and different production batches.the rising interest in insects for human consumption and the changing regulations in europe require a profound insight into the food safety of insects reared and sold in western society. the microbial quality of edible insects has only been studied occasionally. this study aimed at generating an overview of intrinsic parameters (ph, water activity and moisture content) and microbial quality of fresh mealworm larvae and crickets for several rearing companies and for several batches per rearer. in ...201727863329
study of the antibacterial activity of electro-activated solutions of salts of weak organic acids on salmonella enterica, staphylococcus aureus and listeria monocytogenes.this work assessed the antibacterial activity of electro-activated solutions of salts of weak organic acids (potassium acetate, potassium citrate and calcium lactate) on salmonella enterica, staphylococcus aureus and listeria monocytogenes. this activity was compared in terms of minimal inhibitory (bactericidal) concentration to the effect of commercial acetic, citric and lactic acid at equivalent titratable acidity. staining live/dead baclight method was used to consider physiological state of ...201727838894
listeria monocytogenes-induced cell death inhibits the generation of cell-mediated immunity.the influence of cell death on adaptive immunity has been studied for decades. despite these efforts, the intricacies of how various cell death pathways shape immune responses in the context of infection remain unclear, particularly with regard to more recently discovered pathways such as pyroptosis. the emergence of listeria monocytogenes as a promising immunotherapeutic platform demands a thorough understanding of how cell death induced in the context of infection influences the generation of ...201727821585
il-37 impairs host resistance to listeria infection by suppressing macrophage function.listeria monocytogenes is a gram-positive intracellular bacterium that was transmitted through contaminated food and causes sepsis and even death. il-37 has been described as an important anti-inflammatory factor, but little is known about the function of il-37 in host defense against liseria monocytogenes (lm) infection. in mice model of systemic infection, we found that mice treated with il-37 were more sensitive to lm infection compared with pbs-treated mice. this reduced resistance to lm in ...201727816450
short communication: investigation into mycobacterium avium ssp. paratuberculosis in pasteurized milk in italy.this study investigated the presence of viable mycobacterium avium ssp. paratuberculosis (map) in pasteurized milk produced by italian industrial dairy plants to verify the prediction of a previously performed risk assessment. the study analyzed 160 one-liter bottles of pasteurized milk from 2 dairy plants located in 2 different regions. traditional cultural protocols were applied to 500ml of pasteurized milk for each sample. the investigation focused also on the pasteurization parameters and da ...201727816242
outbreaks and factors influencing microbiological contamination of fresh produce.fresh fruits and vegetables are nutritionally well-recognised as healthy components in diets. the microbiological foodborne outbreaks associated with the consumption of fresh produce have been increasing. salmonella spp., escherichia coli o157:h7, staphylococcus aureus, campylobacter spp. and listeria monocytogenes are the most common pathogens that contaminate fresh produce. this review discusses recent foodborne outbreaks linked to fresh produce, factors that affect microbiological contaminati ...201727807844
listeria infections of the eye.the bacterium listeria monocytogenes resides originally in the environment. infections of the eye have been induced experimentally; for example, in rabbits and guinea pigs. natural ocular infections occur in various animals; in most instances, they are induced exogenously; for example, by contaminated silage affecting primarily the conjunctiva, cornea, or the anterior chamber. sporadic infections as well as outbreaks have been described. in humans, besides exogenous infections, endogenous infect ...201727791252
lineage ii (serovar 1/2a and 1/2c) human listeria monocytogenes pulsed-field gel electrophoresis types divided into pfge groups using the band patterns below 145.5 kb.among 504 clinical lineage ii isolates of listeria monocytogenes isolated during 1958-2010 in sweden, 119 pulsed-field gel electrophoresis (pfge) types (asci) have been identified based on the number and distribution of all banding patterns in each dna profile. in this study, these types were further divided into pfge groups based on the configuration of small bands with sizes <145.5 kb. the 504 isolates included 483 serovar 1/2a isolates distributed into 114 pfge types and 21 serovar 1/2c isola ...201727860487
tolerance to quaternary ammonium compound disinfectants may enhance growth of listeria monocytogenes in the food industry.the antibacterial effect of disinfectants is crucial for the control of listeria monocytogenes in food processing environments. tolerance of l. monocytogenes to sublethal levels of disinfectants based on quaternary ammonium compounds (qac) is conferred by the resistance determinants qach and bcrabc. the presence and distribution of these genes have been anticipated to have a role in the survival and growth of l. monocytogenes in food processing environments where qac based disinfectants are in c ...201727810443
suppressor mutations linking gpsb with the first committed step of peptidoglycan biosynthesis in listeria monocytogenes.the cell division protein gpsb is a regulator of the penicillin binding protein a1 (pbp a1) in the gram-positive human pathogen listeria monocytogenes penicillin binding proteins mediate the last two steps of peptidoglycan biosynthesis as they polymerize and cross-link peptidoglycan strands, the main components of the bacterial cell wall. it is not known what other processes are controlled by gpsb. l. monocytogenes gpsb mutants are unable to grow at 42°c, but we observed that spontaneous suppres ...201727795316
acta of listeria monocytogenes and its manifold activities as an important listerial virulence factor.listeria monocytogenes is a ubiquitously occurring gram-positive bacterium in the environment that causes listeriosis, one of the deadliest foodborne infections known today. it is a versatile facultative intracellular pathogen capable of growth within the host's cytosolic compartment. following entry into the host cell, l. monocytogenes escapes from vacuolar compartments to the cytosol, where the bacterium begins a remarkable journey within the host cytoplasm, culminating in bacterial spread fro ...201727726006
genetic subtyping of listeria monocytogenes via multiple-locus sequence typing using iap, sigb and acta.pulse field gel electrophoresis (pfge) is widely used for listeriosis surveillance. although this technique is effective for epidemiology, the data among laboratories are inconsistent. we previously reported a method for listeria monocytogenes subtyping combined with sequence analysis of partial iap and whole genome restriction fragment length polymorphism (rflp) using xbai, clai (baniii) and psti. however, distinguishing subtypes was challenging, because the output comprised complicated fragmen ...201727725353
preparation and characterization of agar-based nanocomposite films reinforced with bimetallic (ag-cu) alloy nanoparticles.agar-based active nanocomposite films were prepared by incorporating silver-copper (ag-cu) alloy nanoparticles (nps) (0.5-4wt%) into glycerol plasticized agar solution. thermo-mechanical, morphological, structural, and optical properties of the nanocomposite films were characterized by texture analyzer, differential scanning calorimetry (dsc), scanning electron microscope (sem), x-ray diffraction (xrd), fourier transforms infrared (ftir) spectroscopy, and surface color measurement. tensile stren ...201727702525
molecular analysis of the role of osmolyte transporters opuca and betl in listeria monocytogenes after cold and freezing stress.listeria monocytogenes is a food-borne pathogen of humans and other animals. the striking ability to survive several stresses usually used for food preservation makes l. monocytogenes one of the biggest concerns to the food industry. this ubiquity can be partly explained by the ability of the organism to grow and persist at very low temperatures, a consequence of its ability to accumulate cryoprotective compound called osmolytes. a quantitative rt-pcr assay was used to measure mrna transcript ac ...201727695911
mitogen-activated protein kinases are required for effective infection of human choroid plexus epithelial cells by listeria monocytogenes.listeria monocytogenes, a gram-positive bacterium, can cause meningitis after invading the human central nervous system. the blood-cerebrospinal fluid barrier (bcsfb), located at the epithelium of the choroid plexus, is a possible entry site for l. monocytogenes into the brain, and in vitro l. monocytogenes invades human choroid plexus epithelial papilloma (hibcpp) cells. although host cell signal transduction subsequent to infection by l. monocytogenes has been investigated, the role of mitogen ...201727671041
effect of vitamin a on listeria monocytogenes infection in a silkworm model.insect infection models have been used increasingly to study various pathogenic agents in evaluations of pathogenicity and drug efficacy. in this study, we demonstrated that larvae of the silkworm bombyx mori are useful for studying listeria monocytogenes infections in insects. infection with the l. monocytogenes wild-type strain induced silkworm death. infection by a listeriolysin o (llo) deletion mutant also induced silkworm death, but the bacterial numbers in silkworms were lower than those o ...201727669511
impact of starch-based emulsions on the antibacterial efficacies of nisin and thymol in cantaloupe juice.the use of antimicrobial compounds to prevent foodborne pathogens from contaminating fresh-cut produce has received broad attentions; however, the applications of these compounds are hindered by their rapid depletion in foods. to prolong their efficacies, the use of delivery systems is essential. in this study, oil-in-water emulsions formed using starch octenyl succinate (starch-os) were used to stabilize nisin and thymol in cantaloupe juice-containing fluid. listeria monocytogenes v7 and salmon ...201727664621
comparative evaluation of direct plating and most probable number for enumeration of low levels of listeria monocytogenes in naturally contaminated ice cream products.a precise and accurate method for enumeration of low level of listeria monocytogenes in foods is critical to a variety of studies. in this study, paired comparison of most probable number (mpn) and direct plating enumeration of l. monocytogenes was conducted on a total of 1730 outbreak-associated ice cream samples that were naturally contaminated with low level of l. monocytogenes. mpn was performed on all 1730 samples. direct plating was performed on all samples using the rapid'l.mono (rlm) aga ...201727741432
effects of low nano2 and nacl concentrations on listeria monocytogenes growth in emulsion-type sausage.the objective of this study was to evaluate the effect of combinations of nano2 and nacl concentrations on listeria monocytogenes (l. monocytogenes) growth in emulsion-type sausage.201727739291
alteration of epithelial cell lysosomal integrity induced by bacterial cholesterol-dependent cytolysins.bacterial pathogens can interfere during infection with host cell organelles, such as mitochondria, the endoplasmic reticulum-golgi system or nuclei. as important cellular functions are often compartmentalized in these organelles, their targeting allows pathogens to manipulate key host functions during infection. here, we identify lysosomes as a new class of organelles targeted by the pathogenic bacterium listeria monocytogenes. we demonstrate that extracellular listeria, via secretion of the po ...201727739224
combination of cymbopogon citratus and allium cepa essential oils increased antibacterial activity in leafy vegetables.cymbopogon citratus and allium cepa essential oils (eos) are rich in terpenes and sulfur compounds respectively, both with antibacterial activity and different cell targets, supporting the idea that their combination can increase their efficacy.201727611358
the diverse family of arp2/3 complexes.the arp2/3 complex has so far been considered to be a single seven-subunit protein complex required for actin nucleation and actin filament polymerization in diverse critical cellular functions including phagocytosis, vesicular trafficking and lamellipodia extension. the arp2/3 complex is also exploited by bacterial pathogens and viruses during cellular infectious processes. recent studies suggest that some subunits of the complex are dispensable in specific cellular contexts, pointing to the ex ...201727595492
pyelonephritis with bacteremia caused by listeria monocytogenes: a case report.listeria monocytogenes is a well-known cause of meningitis, colitis, and bacteremia; however, obstructive pyelonephritis caused by l. monocytogenes has never been reported. we herein report on a 90-year-old japanese woman with obstructive pyelonephritis and bacteremia due to uterus carcinoma invading the ureter. she was admitted to our hospital complaining of fever and chills, and her physical examination revealed left costovertebral angle tenderness. computed tomography showed hydronephrosis an ...201727600175
type i interferon promotes cell-to-cell spread of listeria monocytogenes.type i interferons (ifns) play a critical role in antiviral immune responses, but can be deleterious to the host during some bacterial infections. listeria monocytogenes (lm) induces a type i ifn response by activating cytosolic antiviral surveillance pathways. this is beneficial to the bacteria as mice lacking the type i ifn receptor (ifnar1(-/-) ) are resistant to systemic infection by lm. the mechanisms by which type i ifns promote lm infection are unclear. here, we show that ifnar1 is requir ...201727582004
impact of food model (micro)structure on the microbial inactivation efficacy of cold atmospheric plasma.the large potential of cold atmospheric plasma (cap) for food decontamination has recently been recognized. room-temperature gas plasmas can decontaminate foods without causing undesired changes. this innovative technology is a promising alternative for treating fresh produce. however, more fundamental studies are needed before its application in the food industry. the impact of the food structure on cap decontamination efficacy of salmonella typhimurium and listeria monocytogenes was studied. c ...201727507138
listeria rhombencephalitis mimicking a demyelinating event in an immunocompetent young patient.listeriosis caused by listeria monocytogenes (lm) is a potentially lethal foodborne infection of the central nervous system (cns) and the third most common cause of bacterial meningitis. foods most commonly implicated are soft cheeses, raw or ready-to-eat meat and pre-processed foods. the incubation time is between 11 and 70 days. rarely lm rhombencephalitis (re) can occur, which typically has a biphasic course with non- specific prodromal symptoms like fever, malaise, fatigue, headache, nausea ...201727430683
c-met inhibitors are potential novel therapeutic agents against listeria monocytogenes infection through blocking the bacteria entry into nonphagocytic cells.high lethality of infections caused by listeria monocytogenes still remains a major clinical problem in spite of their susceptibility to a wide spectrum of antibiotics. the refractoriness towards treatment is primarily due to its amazing capacity to invade non-phagocytic cells and replicate there in, imparting the dual protection from immune response and antimicrobials. therefore, generating new anti-infective drugs against intracellular infections has emerged as an urgent issue in the therapeut ...201727572078
predictive risk factors for listeria monocytogenes meningitis compared to pneumococcal meningitis: a multicenter case-control study.various immunocompromised conditions increase the risk of meningitis caused by listeria monocytogenes. however, the relative importance of these risk factors has not been well established. we determined the risk factors that predict meningitis due to l. monocytogenes compared to that caused by streptococcus pneumoniae.201727541039
listeria monocytogenes induces mast cell extracellular traps.mast cells play an essential role in different immunological phenomena including allergy and infectious diseases. several bacteria induce mast cell activation leading to degranulation and the production of several cytokines and chemokines. however, mast cells also have different microbicidal activities such as phagocytosis and the release of dna with embedded granular proteins known as mast cell extracellular traps (mcets). although previous reports indicate that extracellular bacteria are able ...201727520114
nitrite formation from vegetable sources and its use as a preservative in cooked sausage.due to the potential health risk associated with nitrites, nitrite alternatives from natural sources in meat products have been investigated. we compared the nitrate contents of young radish, lettuce and commercial vegetable powder (cabbage and chinese cabbage). we also investigated the effect of incubation time and salt addition on vegetable nitrite formation from vegetable sources. the antioxidant and antimicrobial effects of vegetable nitrite in cooked sausage were also compared with sodium n ...201727469979
mycotic abdominal aortic aneurysm due to listeria monocytogenes. 201727469417
differentiation of distinct long-lived memory cd4 t cells in intestinal tissues after oral listeria monocytogenes infection.mucosal antigen-specific cd4 t-cell responses to intestinal pathogens remain incompletely understood. here we examined the cd4 t-cell response after oral infection with an internalin a 'murinized' listeria monocytogenes (lm). oral lm infection induced a robust endogenous listeriolysin o (llo)-specific cd4 t-cell response with distinct phenotypic and functional characteristics in the intestine. circulating llo-specific cd4 t cells transiently expressed the 'gut-homing' integrin α4β7 and accumulat ...201727461178
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
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
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
effect of fermented soybean products intake on the overall immune safety and function in mice.various functional activities have been reported for the fermented soybean products doenjang (dj) and cheonggukjang (cgj), although no systemic investigations of their immune functions have been conducted to date. we examined the effects of an experimental diet of dj, cgj, or a mixture of unfermented raw material for 4 weeks on overall immunity and immune safety in mice. no significant alterations were observed in peripheral or splenic immune cells among groups. enhanced splenic natural killer c ...201727030201
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
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
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
listeria monocytogenes cholecystitis in an immunocompetent patient. 201726826779
linezolid and dexamethasone experience in a serious case of listeria rhombencephalitis.listeria rhombencephalitis is a rare cause of brain stem encephalitis. we report a case with a history of immunosupressive therapy due to takayasu's arteritis that was treated with corticosteroids and linezolid for listeria rhombencephalitis. a 63-year-old woman was admitted to the hospital with fever, headache, nausea, and vomiting. the patient's body temperature was 38°c, and she had a stiff neck. listeria monocytogenes was isolated from the cerebrospinal fluid (csf), and penicillin g and gent ...201726860968
validation of the ansr(®) listeria monocytogenes method for detection of listeria monocytogenes in selected food and environmental samples.work was conducted to validate performance of the ansr(®) for listeria monocytogenes method in selected food and environmental matrixes. this dna-based assay involves amplification of nucleic acid via an isothermal reaction based on nicking enzyme amplification technology. following single-step sample enrichment for 16-24 h for most matrixes, the assay is completed in 40 min using only simple instrumentation. when 50 distinct strains of l. monocytogenes were tested for inclusivity, 48 produced p ...201726833248
a case report of listeria monocytogenes abscesses presenting as cortically predominant ring-enhancing lesions.listeria monocytogenes, a common cause of bacterial meningitis, rarely involves the central nervous system (cns) in the form of multiple cerebral ring-enhancing lesions.201726034484
fournier's gangrene caused by listeria monocytogenes as the primary organism.a 70-year-old man with a history of tongue cancer presented with fournier's gangrene caused by listeria monocytogenes serotype 4b. surgical debridement revealed undiagnosed rectal adenocarcinoma. the patient did not have an apparent dietary or travel history but reported daily consumption of sashimi (raw fish). old age and immunodeficiency due to rectal adenocarcinoma may have supported the direct invasion of l monocytogenes from the tumour. the present article describes the first reported case ...201725798155
[listeriosis in mexico: clinical and epidemiological importance].listeriosis is caused by listeria monocytogenes, an important food-borne disease due to its clinical forms, high mortality rate, and the economic impact in both clinical and food production industries. in mexico, the lack of epidemiological surveillance systems leads to the need of accurate data on the incidence of listeriosis and its association with food-borne disease. in this paper, we present data about the presence of this bacterium in food, reports related to clinical cases of listeriosis, ...201725604418
chosen quality parameters of pork sausage produced without curing mixture.the aim of this study was to determine the influence of the dried celeriac juice addition, as a nitrogenous compounds sources, on the quality of the experimental pork sausage.201728068026
[listeria monocytogenes and its relationship with non-biological therapy in inflammatory bowel disease]. 201725138387
pigmented hypopyon in association with listeria monocytogenes endopthalmitis: an interesting case report following refractive surgery procedure with literature review.listeria monocytogenes is an aerobic, motile, gram positive bacillus recognized as an intercellular pathogen in human where it most frequently affects neonates, pregnant women, elderly patients, and immunosuppressed individuals as well as healthy persons. ocular listeriosis is rare, most frequently in the form of conjunctivitis, but has been also shown to cause rarely endophthalmitis with pigmented hypopyon and elevated intraocular pressure such as in our case.201724669144
differential roles of klf4 in the development and differentiation of cd8+ t cells.the transcription factor krüppel-like factor 4 (klf4) can activate or repress gene expression in a cell-context dependent manner. we have previously shown that klf4 inhibits the proliferation of naïve cd8(+) t cells in vitro downstream of the transcription factor elf4. in this work, we describe a novel role of klf4 in the differentiation of cd8(+) t cells upon infection. loss of klf4 had minimal effect on thymic t cell development and distribution of mature t cells in the spleen, blood, and lymp ...201724075846
listeria monocytogenes-induced endogenous endophthalmitis in an otherwise healthy.purpose listeria monocytogenes is a rare cause of endogenous endophthalmitis. to date 15 cases have been published in the literature. all eyes showed similar clinical features and profound visual loss mainly due to delayed diagnosis.201728226136
pathological findings in the red fox (vulpes vulpes), stone marten (martes foina) and raccoon dog (nyctereutes procyonoides), with special emphasis on infectious and zoonotic agents in northern germany.anthropogenic landscape changes contributed to the reduction of availability of habitats to wild animals. hence, the presence of wild terrestrial carnivores in urban and peri-urban sites has increased considerably over the years implying an increased risk of interspecies spillover of infectious diseases and the transmission of zoonoses. the present study provides a detailed characterisation of the health status of the red fox (vulpes vulpes), stone marten (martes foina) and raccoon dog (nyctereu ...201728399176
pregnancy-related listeriosis.about one in seven cases of listeriosis occurs in pregnant women, and, although listeriosis is rare, it is the third leading cause of death from food-borne infections. pregnancy-related listeriosis increases the risk for fetal and neonatal mortality by approximately 21%. during pregnancy, infections are more likely to occur in the third trimester (66%) than the first trimester (3%). however, fetal and neonatal adverse effects are less common as gestational age increases or with older gestational ...201728398675
impact of acanthamoeba cysts on stress resistance of salmonella enterica serovar typhimurium, yersinia enterocolitica 4/o:3, listeria monocytogenes 1/2a, and escherichia coli o:26.the formation of robust resting cysts enables acanthamoeba to resist harsh environmental conditions. this study investigated to what extent these cysts are resistant to physical and chemical stresses as applied in food industry cleaning and disinfection procedures. moreover, it was assessed whether certain intracystic meat-borne bacterial pathogens are more stress resistant than free-living bacterial monocultures and if intracystic passage and subsequent association with trophozoites induces cro ...201728526786
uv-curable contact active benzophenone terminated quaternary ammonium antimicrobials for applications in polymer plastics and related devices.a series of uv active benzophenone ([c6h5coc6h4-o-(ch2)n-n+me2r][x-], 4: r = c12h25, n = 3, x- = br- , 5a-c: r = c18h37, n = 3, x- = cl-, br-, i-; 6a-c: r = c18h37, n = 4, x- = cl-, br-, i- ; 7a-c: r = c18h37, n = 6, x- = cl-, br-, i-) terminated c12 and c18 quaternary ammonium salts (qacs) were prepared by thermal or microwave driven menshutkin protocols of the appropriate benzophenone alkyl halide (1a-c, 2a-c, 3a-c) with the corresponding dodecyl- or octadecyl n,n-dimethylamine. all new compou ...201728777541
diversity of endophytic bacteria in a fern species dryopteris uniformis (makino) makino and evaluation of their antibacterial potential against five foodborne pathogenic bacteria.the fern plant dryopteris uniformis has traditionally been used in herbal medicine and possesses many biological activities. this study was conducted to explore the endophytic bacterial diversity associated with d. uniformis and evaluate their antibacterial potential against foodborne pathogenic bacteria (fpb). among 51 isolated endophytic bacteria (eb), 26 eb were selected based on their morphological characteristics and identified by 16s rrna gene analysis. the distribution of eb was diverse i ...201728418717
molecular characterization of gluten hydrolysing bacillus sp. and their efficacy and biotherapeutic potential as probiotics using caco-2 cell line.to isolate and characterize indigenous gluten hydrolysing bacteria from wheat sourdough and curd samples and further evaluation of their probiotic potentiality.201728637081
chemical constituents of helichrysum italicum (roth) g. don essential oil and their antimicrobial activity against gram-positive and gram-negative bacteria, filamentous fungi and candida albicans.the aerial parts of helichrysum italicum (roth) g. don were subjected to hydrodistillation to obtain essential oils which had been analyzed by gas chromatography and gas chromatography coupled with mass spectrometry and tested for antimicrobial activity against 12 bacteria, two yeasts and four fungi by agar diffusion method. the essential oil yielded 0.44% (v/w) and 67 compounds accounting for 99.24% of the oil were identified with a high content of oxygenated sesquiterpenes (61.42%). the most o ...201728725151
development and characterization of bioactive edible films from spider crab (maja crispata) chitosan incorporated with spirulina extract.active food packaging films based on crab chitosan and spirulina extract (se) were developed. the effects of the se incorporation at different levels on physical (color, opacity water vapor and oxygen permeability) and mechanical (tensile strength and elongation at break) properties of chitosan films were investigated. ftir was carried out to observe the potential modifications of the chitosan films when incorporated with se. the obtained results suggested that incorporation of se into chitosan ...201728705500
identification and growth optimization of a marine bacillus dk1-sa11 having potential of producing broad spectrum antimicrobial compounds.control of harmful bacteria in food, aquaculture, pharmaceuticals, agriculture, hospitals and recreation water pools are of great global concern. marine bacteria are an enormous source of bio-controlling agents. the aim of this study was to identify and optimize the growth conditions including effect of different biotic and abiotic factors on antimicrobial activity of strain dk1-sa11 isolated from qingdao bay of china yellow sea. microscopic characterization, api® 20e and 50 chb kit base carbohy ...201728653930
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