| various ready-to-eat products from retail stores linked to occurrence of diverse listeria monocytogenes and listeria spp. isolates. | listeriosis outbreaks have been associated with a variety of foods. this study investigated the prevalence and diversity of listeria monocytogenes and listeria spp. in ready-to-eat (rte) products and evaluated the performance of a rapid detection method, the 3m molecular detection assay for l. monocytogenes (mda-lm), for detection of l. monocytogenes. assay results were compared with those obtained using the u.s. food and drug administration standard culture method described in the bacteriologic ... | 2016 | 26818984 |
| assessment of listeria sp. interference using a molecular assay to detect listeria monocytogenes in food. | detection of listeria monocytogenes in food is currently based on enrichment methods. when l. monocytogenes is present with other listeria species in food, the species compete during the enrichment process. overgrowth competition of the nonpathogenic listeria species might result in false-negative results obtained with the current reference methods. this potential issue was noted when 50 food samples artificially spiked with l. monocytogenes were tested with a real-time pcr assay and canada's cu ... | 2016 | 26735040 |
| a dual microscopy-based assay to assess listeria monocytogenes cellular entry and vacuolar escape. | listeria monocytogenes is a gram-positive bacterium and a facultative intracellular pathogen that invades mammalian cells, disrupts its internalization vacuole, and proliferates in the host cell cytoplasm. here, we describe a novel image-based microscopy assay that allows discrimination between cellular entry and vacuolar escape, enabling high-content screening to identify factors specifically involved in these two steps. we first generated l. monocytogenes and listeria innocua strains expressin ... | 2015 | 26497455 |
| genome comparison of listeria monocytogenes serotype 4a strain hcc23 with selected lineage i and lineage ii l. monocytogenes strains and other listeria strains. | more than 98% of reported human listeriosis cases are caused by specific serotypes within genetic lineages i and ii. the genome sequence of listeria monocytogenes lineage iii strain hcc23 (serotype 4a) enables whole genomic comparisons across all three l. monocytogenes lineages. protein cluster analysis indicated that strain hcc23 has the most unique protein pairs with nonpathogenic species listeria innocua. orthology analysis of the genome sequences of representative strains from the three l. m ... | 2014 | 26484097 |
| use of a miniature laboratory fresh cheese model for investigating antimicrobial activities. | hispanic-style fresh cheeses, such as queso fresco, have relatively low salt content, high water activity, and near neutral ph, which predisposes them to growth of listeria monocytogenes. biosafety constraints limit the incorporation of l. monocytogenes into cheeses manufactured via traditional methods in challenge studies, so few have focused on in situ testing of novel antimicrobials in fresh cheeses. we have developed a modular, miniaturized laboratory-scale queso fresco model for testing the ... | 2015 | 26454301 |
| pulsed-light inactivation of pathogenic and spoilage bacteria on cheese surface. | cheese products are susceptible to postprocessing cross-contamination by bacterial surface contamination during slicing, handling, or packaging, which can lead to food safety issues and significant losses due to spoilage. this study examined the effectiveness of pulsed-light (pl) treatment on the inactivation of the spoilage microorganism pseudomonas fluorescens, the nonenterohemorrhagic escherichia coli atcc 25922 (nonpathogenic surrogate of escherichia coli o157:h7), and listeria innocua (nonp ... | 2015 | 26162787 |
| detection of listeria monocytogenes in ready-to-eat foods sampled from a catering service in apulia, italy. | listeria monocytogenes is currently considered a relevant emerging food-borne pathogen. in particular, the european centre for disease prevention and control (ecdc) illustrates its widespread presence in different foods. in the present article, l. monocytogenes prevalence was estimated in cooked ready-to-eat foods sampled from a catering service in a apulia city, southern italy. | 2015 | 26152545 |
| development of a new paenibacillin-producing strain and testing its usability in improving food safety. | a new bacterial strain that produces a bacteriocin (paenibacillin) without polymyxin was developed from paenibacillus polymyxa that co-produces the 2 antimicrobial agents. gamma radiation was used successfully to develop the new strain, p. polymyxa osy-hg. subsequently, we explored the feasibility of using food or food ingredients as growth media for the new strain. milk supported the growth of p. polymyxa osy-hg which produced up to 32 mg paenibacillin/l milk without polymyxin. fermentation cru ... | 2015 | 26073160 |
| two methods for increased specificity and sensitivity in loop-mediated isothermal amplification. | the technique of loop-mediated isothermal amplification (lamp) utilizes four (or six) primers targeting six (or eight) regions within a fairly small segment of a genome for amplification, with concentration higher than that used in traditional pcr methods. the high concentrations of primers used leads to an increased likelihood of non-specific amplification induced by primer dimers. in this study, a set of lamp primers were designed targeting the prfa gene sequence of listeria monocytogenes, and ... | 2015 | 25853320 |
| effectiveness of sanitizing products on controlling selected pathogen surrogates on retail deli slicers. | the objectives of this study were (i) to assess the efficacy of quaternary ammonium chloride-based wet foam (wf) and dry foam (df) sanitizer systems (600 ppm) for reducing listeria innocua (a nonpathogenic surrogate of listeria monocytogenes) or a 100.0 μg/ml rifampin-resistant salmonella typhimurium lt2 (a nonpathogenic surrogate of salmonella enterica serovar typhimurium) on niche and transfer point areas of an unwashed retail deli slicer as compared with traditional chlorine (cl(-)) treatment ... | 2015 | 25836395 |
| differentiation of different mixed listeria strains and also acid-injured, heat-injured, and repaired cells of listeria monocytogenes using fourier transform infrared spectroscopy. | fourier transform infrared (ft-ir) spectroscopy was used to differentiate mixed strains of listeria monocytogenes and mixed strains of l. monocytogenes and listeria innocua. ft-ir spectroscopy was also applied to investigate the hypothesis that heat-injured and acid-injured cells would return to their original physiological integrity following repair. thin smears of cells on infrared slides were prepared from cultures for mixed strains of l. monocytogenes, mixed strains of l. monocytogenes and l ... | 2015 | 25719878 |
| interaction with enzyme iibmpo (eiibmpo) and phosphorylation by phosphorylated eiibmpo exert antagonistic effects on the transcriptional activator manr of listeria monocytogenes. | listeriae take up glucose and mannose predominantly through a mannose class phosphoenolpyruvate:carbohydrate phosphotransferase system (pts(man)), whose three components are encoded by the manlmn genes. the expression of these genes is controlled by manr, a levr-type transcription activator containing two pts regulation domains (prds) and two pts-like domains (enzyme iia(man) [eiia(man)]- and eiib(gat)-like). we demonstrate here that in listeria monocytogenes, manr is activated via the phosphory ... | 2015 | 25691525 |
| chitosan improves anti-biofilm efficacy of gentamicin through facilitating antibiotic penetration. | antibiotic overuse is one of the major drivers in the generation of antibiotic resistant "super bugs" that can potentially cause serious effects on health. in this study, we reported that the polycationic polysaccharide, chitosan could improve the efficacy of a given antibiotic (gentamicin) to combat bacterial biofilms, the universal lifestyle of microbes in the world. short- or long-term treatment with the mixture of chitosan and gentamicin resulted in the dispersal of listeria monocytogenes (l ... | 2014 | 25479075 |
| effect of listeria seeligeri or listeria welshimeri on listeria monocytogenes detection in and recovery from buffered listeria enrichment broth. | the presence of multiple species of listeria in regulated food products is not uncommon and can complicate the recovery of listeria monocytogenes particularly on a non-differentiating medium. the potential complications of listeria seeligeri and listeria welshimeri on the recovery of l. monocytogenes from inoculated food test samples using the u.s. food and drug administration's (fda) selective enrichment procedure was investigated. post-enrichment enumeration, in the absence of food product, in ... | 2015 | 25475325 |
| listeria monocytogenes and listeria spp. contamination patterns in retail delicatessen establishments in three u.s. states. | postprocessing contamination in processing plants has historically been a significant source of listeria monocytogenes in ready-to-eat delicatessen meats, and therefore a major cause of human listeriosis cases and outbreaks. recent risk assessments suggest that a majority of human listeriosis cases linked to consumption of contaminated deli meats may be due to l. monocytogenes contamination that occurs at the retail level. to better understand the ecology and transmission of listeria spp. in ret ... | 2014 | 25364927 |
| real-time pcr detection of listeria monocytogenes in infant formula and lettuce following macrophage-based isolation and enrichment. | to develop a rapid detection procedure for listeria monocytogenes in infant formula and lettuce using a macrophage-based enrichment protocol and real-time pcr. | 2015 | 25346434 |
| development of new multilocus variable number of tandem repeat analysis (mlva) for listeria innocua and its application in a food processing plant. | listeria innocua is an important hygiene indicator bacterium in food industries because it behaves similar to listeria monocytogenes, which is pathogenic to humans. pfge is often used to characterize bacterial strains and to track contamination source. however, because pfge is an expensive, complicated, time-consuming protocol, and poses difficulty in data sharing, development of a new typing method is necessary. mlva is a technique that identifies bacterial strains on the basis of the number of ... | 2014 | 25198191 |
| a novel model to assess the efficacy of steam surface pasteurization of cooked surimi gels inoculated with realistic levels of listeria innocua. | steam surface pasteurization is a promising decontamination technology for reducing pathogenic bacteria in different stages of food production. the effect of the artificial inoculation type and initial microbial load, however, has not been thoroughly assessed in the context of inactivation studies. in order to optimize the efficacy of the technology, the aim of this study was to design and validate a model system for steam surface pasteurization, assessing different inoculation methods and reali ... | 2014 | 25084647 |
| phenotypic and genotypic characterization of atypical listeria monocytogenes and listeria innocua isolated from swine slaughterhouses and meat markets. | in the last decade, atypical listeria monocytogenes and l. innocua strains have been detected in food and the environment. because of mutations in the major virulence genes, these strains have different virulence intensities in eukaryotic cells. in this study, we performed phenotypic and genotypic characterization of atypical l. monocytogenes and l. innocua isolates obtained from swine slaughterhouses and meat markets. forty strains were studied, including isolates of l. monocytogenes and l. inn ... | 2014 | 24987702 |
| antimicrobial resistance of listeria monocytogenes and listeria innocua from meat products and meat-processing environment. | a total of 336 listeria isolates from ready-to-eat (rte) meat products and meat-processing environments, consisting of 206 listeria monocytogenes, and 130 listeria innocua isolates, were characterized by disc diffusion assay and minimum inhibitory concentration (mic) values for antimicrobial susceptibility against twenty antimicrobials. resistance to one or two antimicrobials was observed in 71 l. monocytogenes isolates (34.5%), and 56 l. innocua isolates (43.1%). multidrug resistance was identi ... | 2014 | 24929718 |
| temperature effects on the antimicrobial efficacy of condensed smoke and lauric arginate against listeria and salmonella. | condensed smoke or liquid smoke (ls) and lauric arginate (lae) are antimicrobials used in food preservation. they have demonstrated abilities to reduce or inhibit pathogenic and spoilage organisms. few studies, however, have reported on the effectiveness of ls or lae over the range of temperatures typically encountered in food marketing channels. therefore, the effects of temperature on the antimicrobial properties of two commercial ls fractions, an ls derived from pecan shells, and lae against ... | 2014 | 24853515 |
| attachment of listeria innocua to polystyrene: effects of ionic strength and conditioning films from culture media and milk proteins. | it is recognized that bacterial adhesion usually occurs on conditioning films made of organic macromolecules absorbed to abiotic surfaces. the objectives of this study were to determine the extent to which milk protein-coated polystyrene (ps) pegs interfere with biofilm formation and the synergistic effect of this conditioning and hypertonic growth media on the bacterial adhesion and biofilm formation of listeria innocua, used as a nonpathogenic surrogate for listeria monocytogenes. ps pegs were ... | 2014 | 24674434 |
| atypical listeria innocua strains possess an intact lipi-3. | listeria monocytogenes is a food-borne pathogen which is the causative agent of listeriosis and can be divided into three evolutionary lineages i, ii and iii. while all strains possess the well established virulence factors associated with the listeria pathogenicity island i (lipi-1), lineage i strains also possess an additional pathogenicity island designated lipi-3 which encodes listeriolysin s (lls), a post-translationally modified cytolytic peptide. up until now, this pathogenicity island ha ... | 2014 | 24606727 |
| european validation of a real-time pcr-based method for detection of listeria monocytogenes in soft cheese. | the classical microbiological method for detection of listeria monocytogenes requires around 7 days for final confirmation, and due to perishable nature of rte food products, there is a clear need for an alternative methodology for detection of this pathogen. this study presents an international (at european level) iso 16140-based validation trial of a non-proprietary real-time pcr-based methodology that can generate final results in the following day of the analysis. this methodology is based o ... | 2014 | 24468028 |
| identification of six listeria species by real-time pcr assay. | the listeria genus comprises 10 recognized species. listeria monocytogenes causes listeriosis in humans and other animals primarily via contaminated food or animal feed. listeria ivanovii causes listeriosis in animals and on rare occasions in humans. the identification of nonpathogenic species of listeria in foods indicates that conditions exist that support the growth of pathogenic strains and is used to facilitate the implementation of control and prevention measures. this study shows the deve ... | 2014 | 24461044 |
| effect of citral and carvacrol on the susceptibility of listeria monocytogenes and listeria innocua to antibiotics. | the aim of this study was to evaluate the antibiotic susceptibility of listeria innocua (l. innocua) and listeria monocytogenes (l. monocytogenes) cells in the presence of citral and carvacrol at sublethal concentrations in an agar medium. the presence of terpenes in the l. monocytogenes and l. innocua culture medium provided a reduction in the minimal inhibitory concentration (mic) of all the antibiotics tested. these effects were dependent on the concentration of terpenes present in the cultur ... | 2014 | 24443987 |
| postenrichment population differentials using buffered listeria enrichment broth: implications of the presence of listeria innocua on listeria monocytogenes in food test samples. | the recovery of low levels of listeria monocytogenes from foods is complicated by the presence of competing microorganisms. nonpathogenic species of listeria pose a particular problem because variation in growth rate during the enrichment step can produce more colonies of these nontarget cells on selective and/or differential media, resulting in a preferential recovery of nonpathogens, especially listeria innocua. to gauge the extent of this statistical barrier to pathogen recovery, 10 isolates ... | 2013 | 24215687 |
| an allelopathy based model for the listeria overgrowth phenomenon. | in a standard procedure of food safety testing, the presence of the pathogenic bacterium listeria monocytogenes can be masked by non-pathogenic listeria. this phenomenon of listeria overgrowth is not well understood. we present a mathematical model for the growth of a mixed population of l. innocua and l. monocytogenes that includes competition for a common resource and allelopathic control of l. monocytogenes by l. innocua when this resource becomes limited, which has been suggested as one pote ... | 2014 | 24184260 |
| effects of antimicrobial coatings and cryogenic freezing on survival and growth of listeria innocua on frozen ready-to-eat shrimp during thawing. | foodborne pathogens such as listeria monocytogenes could pose a health risk on frozen ready-to-eat (rte) shrimp as the pathogen could grow following thawing. in this study, antimicrobial-coating treatments alone, or in combination with cryogenic freezing, were evaluated for their ability to inhibit the growth of listeria innocua, a surrogate for l. monocytogenes, on rte shrimp. cooked rte shrimp were inoculated with l. innocua at 3 population levels and treated with coating solutions consisting ... | 2013 | 23957407 |
| identification and evaluation of the probiotic potential of lactobacillus paraplantarum ft259, a bacteriocinogenic strain isolated from brazilian semi-hard artisanal cheese. | this study aimed to identify a bacteriocinogenic lactobacillus isolate (ft259) obtained from brazilian semi-hard minas type cheese and to evaluate its probiotic and antimicrobial potentials. the strain was identified by biochemical tests (at genus level), and by 16s rdna sequencing combined with reca gene amplification (for species). to determine the inhibitory spectrum towards food borne pathogens and lactic acid bacteria, the spot-on-the-lawn assay was carried out. moreover, the proteinaceous ... | 2013 | 23792229 |
| refined liquid smoke: a potential antilisterial additive to cold-smoked sockeye salmon (oncorhynchus nerka). | cold-smoked salmon (css) is a potentially hazardous ready-to-eat food product due to the high risk of contamination with listeria monocytogenes and lack of a listericidal step. we investigated the antilisterial property of liquid smokes (ls) against listeria innocua atcc 33090 (surrogate to l. monocytogenes) as a potential supplement to vacuum-packaged css. a full-strength ls (code 10-poly), and three commercially refined fractions (am-3, am-10, and 1291) having less color and flavor (lower cont ... | 2013 | 23643122 |
| characterization and antilisterial effect of phosphatidylcholine nanovesicles containing the antimicrobial peptide pediocin. | encapsulation may provide increased stability and antimicrobial efficiency to bacteriocins. in this work, the antilisterial peptide pediocin was encapsulated in nanovesicles prepared from partially purified soybean phosphatidylcholine. the maintenance of antimicrobial activity and properties of free and encapsulated pediocin was observed during 13 days at 4 °c, and after this period, the encapsulated pediocin retained 50 % its initial activity. the maintenance of the bioactive properties of free ... | 2013 | 26782604 |
| consumer method to control salmonella and listeria species in shrimp. | the purpose of this study was to determine whether the current consumer method of boiling shrimp until floating and pink in color is adequate for destroying listeria and salmonella. shrimp samples were submerged in bacterial suspensions of listeria and salmonella for 30 min and allowed to air dry for 1 h under a biosafety cabinet. color parameters were then measured with a spectrophotometer programmed with the cielab system. twenty-four shrimp samples were divided into groups (days 0, 1, or 2) a ... | 2013 | 23317857 |
| prevalence and antimicrobial resistance of listeria species isolated from different types of raw meat in iran. | listeria and particularly listeria monocytogenes are important foodborne pathogens that can cause listeriosis and severe complications in immunocompromised individuals, children, pregnant women, and the elderly. the objective of this study was to determine the prevalence of listeria spp. in raw meat in iran. from july 2010 to november 2011, a total of 1,107 samples of various raw meats were obtained from randomly selected retail butcher shops. the results of conventional bacteriologic and pcr me ... | 2012 | 23212021 |
| antimicrobial-resistant listeria species from retail meat in metro detroit. | a total of 138 listeria isolates from retail meat, including 58 listeria welshimeri, 44 listeria monocytogenes, and 36 listeria innocua isolates, were characterized by antimicrobial susceptibility tests against nine antimicrobials. in addition, the 44 l. monocytogenes isolates were analyzed by serotype identification using pcr and genotyping using pulsed-field gel electrophoresis. resistance to one or two antimicrobials was observed in 32 listeria isolates (23.2%). no multidrug resistance was id ... | 2012 | 23212009 |
| detection of virulence-associated genes and epidemic clone markers in listeria monocytogenes isolates from pdo gorgonzola cheese. | fifty-three listeria monocytogenes isolates obtained from gorgonzola cheese and previously characterized with biochemical typing, serotyping and pulsed field gel electrophoresis (pfge), were analyzed in this study. seven virulence-associated genes were selected (acta, inlc, inlj, plca, prfa, hlya and iap) and their presence was investigated using pcr. all virulence-associated genes were detected in 51 isolates. one isolate did not show amplification of the inlc gene and one other isolate, previo ... | 2012 | 23141648 |
| sensitivity to pulsed light technology of several spoilage and pathogenic bacteria isolated from fish products. | the effect of pulsed light (pl) on the inactivation of six fish spoilage bacteria (photobacterium phosphoreum, serratia liquefaciens, shewanella putrefaciens, brochothrix thermosphacta, pseudomonas group i, and pseudomonas groups iii and iv), six listeria monocytogenes isolates from fish products, and one strain of listeria innocua was evaluated. for all tested strains, grown at 4°c (temperature to process, store, and distribute convenient, lightly preserved fish products), the maximum detectabl ... | 2012 | 23127714 |
| generation of airborne listeria innocua from model floor drains. | listeria monocytogenes can colonize floor drains in poultry processing and further processing facilities, remaining present even after cleaning and disinfection. therefore, during wash down, workers exercise caution to avoid spraying hoses directly into drains in an effort to prevent the escape and transfer of drain microflora to food contact surfaces. the objective of this study was to examine the extent to which an inadvertent water spray into a colonized floor drain can cause the spread of ai ... | 2012 | 22980019 |
| growth kinetics of listeria isolated from salmon and salmon processing environment: single strains versus cocktails. | the growth dynamics of listeria monocytogenes strains isolated from salmon or a salmon processing environment and two reference listeria innocua strains were investigated at refrigerated and close-to-optimal growth temperatures. estimates for the growth rates and the lag-phase duration at 4, 8, 12, and 30°c were obtained for optical density measurements by using different growth parameter estimation methods, i.e., the serial dilution (sd) method and the relative rate to detection (rrd) method. b ... | 2012 | 22980005 |
| high-pressure processing inactivates listeria innocua yet compromises queso fresco crumbling properties. | the objective of this study was to determine the effectiveness of high-pressure processing to inactivate listeria innocua (a listeria monocytogenes surrogate) in queso fresco, and to study the effects of the high-pressure treatment on cheese-crumbling properties. queso fresco was made with pasteurized, homogenized milk, lactic acid bacterial starter culture, chymosin, and flake salt. cheeses were pressed (0.1 mpa) for 1h before crumbling and inoculation with a cocktail of 3 strains of l. innocua ... | 2012 | 22916889 |
| listeria monocytogenes and hemolytic listeria innocua in poultry. | listeria monocytogenes is a ubiquitous, saprophytic, gram-positive bacterium and occasional food-borne pathogen, often associated with ready-to-eat meat products. because of the increased consumer interest in organic, all natural, and free range poultry products, it is important to understand l. monocytogenes in the context of such systems. pasture-reared poultry were surveyed over the course of two 8-wk rearing periods. cecal, soil, and grass samples were collected for listeria isolation and ch ... | 2012 | 22912449 |
| comparative transcriptomics of pathogenic and non-pathogenic listeria species. | listeria monocytogenes is a human, food-borne pathogen. genomic comparisons between l. monocytogenes and listeria innocua, a closely related non-pathogenic species, were pivotal in the identification of protein-coding genes essential for virulence. however, no comprehensive comparison has focused on the non-coding genome. we used strand-specific cdna sequencing to produce genome-wide transcription start site maps for both organisms, and developed a publicly available integrative browser to visua ... | 2012 | 22617957 |
| a review of the ecology, genomics, and stress response of listeria innocua and listeria monocytogenes. | listeria monocytogenes is a gram-positive foodborne pathogen responsible for a severe disease occurring in immuno-compromised populations. foodborne illness caused by l. monocytogenes is a serious public health concern because of the high associated mortality. study of the closely related, but nonpathogenic listeria innocua has accounted for a better understanding of the behavior of l. monocytogenes in environments beyond the laboratory. traditionally, the ecological co-habitation, genomic synte ... | 2012 | 22591342 |
| protective immunity to listeria monocytogenes infection mediated by recombinant listeria innocua harboring the vgc locus. | in this study we propose a novel bacterial vaccine strategy where non-pathogenic bacteria are complemented with traits desirable for the induction of protective immunity. to illustrate the proof of principle of this novel vaccination strategy, we use the model organism of intracellular immunity listeria. we introduced a, low copy number bac-plasmid harbouring the virulence gene cluster (vgc) of l. monocytogenes (lm) into the non-pathogenic l. innocua (l.inn) strain and examined for its ability t ... | 2012 | 22536395 |
| characterization of atypical listeria innocua isolated from swine slaughterhouses and meat markets. | atypical listeria innocua strains presenting phenotypic characteristics similar to those of listeria monocytogenes were recently isolated from food and the environment. these isolates also tested positive for virulence genes specific to l. monocytogenes. here we report the isolation of atypical hemolytic l. innocua strains from the environment of pork processing plants in brazil. the strains were positive for l. monocytogenes virulence genes hly, inla and inlb by pcr and presented genotypic simi ... | 2012 | 22426248 |
| occurrence and characterization of listeria spp. in ready-to-eat retail foods from vancouver, british columbia. | the occurrence of listeria spp. and listeria monocytogenes in retail rte meat and fish products in vancouver, british columbia (b.c.) was investigated. to assess potential consumer health risk, recovered l. monocytogenes isolates were subjected to genotypic and phenotypic characterization. conventional methods were used to recover listeria spp. from deli meat (n = 40) and fish (n = 40) samples collected from 17 stores. listeria spp. were recovered only from fish samples (20%); 5% harboured liste ... | 2012 | 22365350 |
| listeria ivanovii infection in mice: restricted to the liver and lung with limited replication in the spleen. | listeria monocytogenes (lm) vectors have shown much promise in delivery of viral and tumor antigens for the development of vaccines. l. ivanovii (li) is a closely related bacterium with a similar intracellular life cycle that may offer advantages over lm because it is not a human pathogen, but can infect other animal species. recent studies show that recombinant li expressing mycobacterium tuberculosis antigens is effective in inducing protective immunity in mouse models, demonstrating the poten ... | 2016 | 27375558 |
| phytochemical characterization of veronica officinalis l., v. teucrium l. and v. orchidea crantz from romania and their antioxidant and antimicrobial properties. | aerial parts of veronica species are used in romanian traditional medicine for the treatment of various conditions like kidney diseases, cough, and catarrh, and are known for their wound-healing properties. in the present study, the phenolic and sterolic content and the antioxidant and antimicrobial activities of three veronica species (plantaginaceae), v. officinalis l., v. teucrium l. and v. orchidea crantz, were studied. the identification and quantification of several phenolic compounds and ... | 2015 | 26404257 |
| magnetic bead based immuno-detection of listeria monocytogenes and listeria ivanovii from infant formula and leafy green vegetables using the bio-plex suspension array system. | listeriosis, a disease contracted via the consumption of foods contaminated with pathogenic listeria species, can produce severe symptoms and high mortality in susceptible people and animals. the development of molecular methods and immuno-based techniques for detection of pathogenic listeria in foods has been challenging due to the presence of assay inhibiting food components. in this study, we utilize a macrophage cell culture system for the isolation and enrichment of listeria monocytogenes a ... | 2015 | 25475329 |
| evaluation of the anti-listeria potentials of some plant-derived triterpenes. | listeriosis is a fatal disease caused by pathogenic listeria bacteria and it is most prevalent in immune-compromised individuals. the increase in numbers of immune-compromised individuals against a background of listeria antibiotic resistance, limits listeriosis treatment options. this therefore calls for research into substitute treatments, of which, medicinal plants derived compounds offer a viable alternative. | 2014 | 25056181 |
| extraction, antioxidant and antilisterial activities of polysaccharides from the flower of viper's bugloss. | the objective of the present research was to investigate the effect of microwave-assisted extraction (mae) conditions on the extraction yield, antioxidant properties and antilisterial activities of the polysaccharides from the flowers of viper's bugloss (echium vulgare l.). the four extraction variables, time (40-100min), microwave power (200-800w), temperature (30-70°c), and the ratio of water to raw material (10-70), were optimized using response surface methodology. the experimental data were ... | 2014 | 24950309 |
| listeria ivanovii atcc 19119 strain behaviour is modulated by iron and acid stress. | it has been suggested that the rarity of human listeriosis due to listeria ivanovii reflects not only host tropism factors but also the rare occurrence of this species in the environment, compared with listeria monocytogenes. in the present study we evaluate the effects on the reference strain l. ivanovii atcc 19119 behaviour of two combined stresses, low iron availability and acid environment, that bacteria can encounter in the passage from saprophytic life to the host. in these conditions, l. ... | 2014 | 24929719 |
| genome sequences of three frequently used listeria monocytogenes and listeria ivanovii strains. | we present the complete de novo assembled genome sequences of listeria monocytogenes strains wslc 1001 (atcc 19112) and wslc 1042 (atcc 23074) and listeria ivanovii wslc 3009, three strains frequently used for the propagation and study of bacteriophages because they are presumed to be free of inducible prophages. | 2014 | 24786957 |
| prevalence, pathogenic capability, virulence genes, biofilm formation, and antibiotic resistance of listeria in goat and sheep milk confirms need of hygienic milking conditions. | goat and sheep milk is consumed by human populations throughout the world; as a result, it has been proposed as an alternative, nutrient-rich milk to feed infants allergic to cow's milk. unfortunately, potentially harmful bacteria have not been thoroughly tested in goat or sheep milk. listeria monocytogenes is a harmful bacterium that causes adverse health effects if ingested by humans. the purpose of this study was to estimate the prevalence and characterize the phenotype, genotype, virulence f ... | 2014 | 24548157 |
| stability and inhibitory activity of pediocin pa-1 against listeria sp. in simulated physiological conditions of the human terminal ileum. | listeria monocytogenes is responsible for severe foodborne infections, which can be life-threatening especially for infants and elderly populations. the emergence of antibiotic-resistant pathogens has stimulated the search for new strategies, such as the use of bacteriocins, to prevent or cure foodborne infectious diseases in the intestine. in this study, we evaluated the efficacy of the bacteriocin pediocin pa-1 from pediococcus acidilactici ul5 to inhibit listeria ivanovii, used as a surrogate ... | 2012 | 26782185 |
| peptide nucleic acid fluorescence in situ hybridization for identification of listeria genus, listeria monocytogenes and listeria ivanovii. | a fluorescent in situ hybridization (fish) method in conjunction with fluorescin-labeled peptide nucleic acid (pna) probes (pna-fish) for detection of listeria species was developed. in silico analysis showed that three pna probes lis-16s-1, lm-16s-2 and liv-16s-5 were suitable for specific identification of listeria genus, listeria monocytogenes and listeria ivanovii, respectively. these probes were experimentally verified by their reactivity against 19 strains of six listeria species (excludin ... | 2012 | 22633537 |
| comparative phenotypic and genotypic analysis of swiss and finnish listeria monocytogenes isolates with respect to benzalkonium chloride resistance. | reduced susceptibility of listeria monocytogenes to benzalkonium chloride (bc), a quaternary ammonium compound widely used in food processing and hospital environments, is a growing public health and food safety concern. the minimal inhibitory concentration of bc on 392 l. monocytogenes strains from switzerland (ch) and finland (fin) was determined. within this strain collection, benzalkonium chloride resistance was observed in 12.3% (24/195) of swiss and 10.6% (21/197) of finnish strains. in bo ... | 2017 | 28386248 |
| local outbreak of listeria monocytogenes serotype 4b sequence type 6 due to contaminated meat pâté. | in january and february 2016, five cases of confirmed and two cases of probable infection due to listeria monocytogenes serotype 4b, sequence type (st) 6 belonging to a single pulsed-field gel electrophoresis pulsotype pattern were registered in a region of southern switzerland. l. monocytogenes was detected in blood samples (four cases) and pleural fluid (one case). furthermore, l. monocytogenes 4b st6 was detected in a stool sample of an asymptomatic person exposed to a common food. forthwith, ... | 2017 | 28379731 |
| listeriolysin s is a streptolysin s-like virulence factor that targets exclusively prokaryotic cells in vivo. | streptolysin s (sls)-like virulence factors from clinically relevant gram-positive pathogens have been proposed to behave as potent cytotoxins, playing key roles in tissue infection. listeriolysin s (lls) is an sls-like hemolysin/bacteriocin present among listeria monocytogenes strains responsible for human listeriosis outbreaks. as lls cytotoxic activity has been associated with virulence, we investigated the lls-specific contribution to host tissue infection. surprisingly, we first show that l ... | 2017 | 28377528 |
| listeria monocytogenes infection associated with alemtuzumab - - a case for better preventive strategies. | the mortality of septicaemia, meningitis and encephalitis caused by listeria monocytogenes is 20-40%. twenty-one cases of invasive listeriosis associated with alemtuzumab, including at least 16 in patients with multiple sclerosis, have been published or reported to the world health organization case safety reports database. three cases were fatal, including at least one patient treated for multiple sclerosis in 2016. | 2017 | 28376817 |
| whey protein isolate/cellulose nanofibre/tio2 nanoparticle/rosemary essential oil nanocomposite film: its effect on microbial and sensory quality of lamb meat and growth of common foodborne pathogenic bacteria during refrigeration. | the use of biodegradable nanocomposite films in active packaging is of great importance since they can have a controlled release of antimicrobial compounds. this study was conducted to evaluate the efficacy of whey protein isolate (wpi)/cellulose nanofibre (cnf) nanocomposite films containing 1.0% (w/w) titanium dioxide (tio2) and 2.0% (w/v) rosemary essential oil (reo) in preserving the microbial and sensory quality of lamb meat during the storage at 4±1°c. initially, the best concentration of ... | 2017 | 28376399 |
| contamination by salmonella spp., campylobacter spp. and listeria spp. of most popular chicken- and pork-sausages sold in reunion island. | one of the most popular meat products of the local "cuisine" is sausage composed with 100% chicken or 100% pork. in this study, we aimed to determine the presence of salmonella spp., campylobacter spp. and listeria spp. in chicken- and pork-sausages, quantify salmonella spp. population and identify the factors that could be associated with contamination in the outlets. two hundred and three batches of pork and chicken sausages were randomly collected from 67 local outlets (supermarkets, grocerie ... | 2017 | 28371717 |
| the prevalence of listeria monocytogenes and staphylococcus aureus and their virulence genes in bulk tank milk in kosovo. | milk is considered to be a healthy, nutritious food product. microbiological quality is an important aspect in evaluating the quality of milk. | 2017 | 28368859 |
| listeria monocytogenes cadc regulates cadmium efflux and fine-tunes lipoprotein localization to escape the host immune response and promote infection. | listeria monocytogenes (lm) is a major intracellular human foodborne bacterial pathogen. we previously revealed lm-cadc as highly expressed during mouse infection. here we show that lm-cadc is a sequence-specific, dna-binding and cadmium-dependent regulator of cada, an efflux pump conferring cadmium resistance. cadc, but not cada, is required for lm infection in vivo. interestingly, cadc also directly represses lspb, a gene encoding a lipoprotein signal peptidase whose expression appears detrime ... | 2017 | 28368435 |
| listeria monocytogenes: a rare cause of endophthalmitis, a case report. | listeria monocytogenes is a known cause of gastroenteritis. invasive disease can follow bacteremia causing meningoencephalitis, endocarditis and spontaneous miscarriages in immunocompromised patients and pregnant women respectively. we present the first case in england of endogenous endophthalmitis caused by l. monocytogenes following acute gastroenteritis in an immunocompetent host. a 50-year-old south asian female presented with acute painful unilateral visual loss occurring shortly after an e ... | 2017 | 28367407 |
| comparative effects of untreated and 3-methacryloxypropyltrimethoxysilane treated zno nanoparticle reinforcement on properties of polylactide-based nanocomposite films. | polylactide (pla) nanocomposites characterized by antimicrobial properties are gaining increasing attention for food packaging. in this contribution, the pla based nanocomposite films with multifunctional end-use properties were achieved by incorporating zno nanoparticles (nps) [untreated: zno(ut) and 3-methacryloxypropyltrimethoxysilane treated: zno(st)] into polymer matrix via solvent casting method. the zno(st) prevented the degradation of pla at higher temperature and improved the mechanical ... | 2017 | 28366847 |
| a type i ifn-dependent dna damage response regulates the genetic program and inflammasome activation in macrophages. | macrophages produce genotoxic agents, such as reactive oxygen and nitrogen species, that kill invading pathogens. here we show that these agents activate the dna damage response (ddr) kinases atm and dna-pkcs through the generation of double stranded breaks (dsbs) in murine macrophage genomic dna. in contrast to other cell types, initiation of this ddr depends on signaling from the type i interferon receptor. once activated, atm and dna-pkcs regulate a genetic program with diverse immune functio ... | 2017 | 28362262 |
| peritonitis as the first presentation of disseminated listeriosis in a patient on peritoneal dialysis-a case report. | infections with listeria monocytogenes are uncommon but serious, with mortality rate approaching 30% in cases of systemic involvement despite first-line therapy. they are usually caused by ingestion of contaminated foods, but spontaneous infections have also been described. listeria monocytogenes is a rare cause of peritonitis, and most of the published cases are in patients with cirrhosis and ascites. there are a few reported cases of listeria peritonitis associated with peritoneal dialysis (pd ... | 2017 | 28360372 |
| corrigendum: uncovering listeria monocytogenes hypervirulence by harnessing its biodiversity. | | 2017 | 28358126 |
| stochastic and differential activation of σ(b) and prfa in listeria monocytogenes at the single cell level under different environmental stress conditions. | during host infection, the foodborne pathogen listeria monocytogenes must sense and respond to rapidly changing environmental conditions. two transcriptional regulators, the alternative sigma factor b (σ(b)) and the positive regulatory factor a (prfa), are key contributors to the transcriptomic responses that enable bacterial survival in the host gastrointestinal tract and invasion of host duodenal cells. increases in temperature and osmolarity induce activity of these proteins; such conditions ... | 2017 | 28352251 |
| ngmaster:in silico multi-antigen sequence typing for neisseria gonorrhoeae. | whole-genome sequencing (wgs) provides the highest resolution analysis for comparison of bacterial isolates in public health microbiology. however, although increasingly being used routinely for some pathogens such as listeria monocytogenes and salmonella enterica, the use of wgs is still limited for other organisms, such as neisseria gonorrhoeae. multi-antigen sequence typing (ng-mast) is the most widely performed typing method for epidemiological surveillance of gonorrhoea. here, we present ng ... | 2016 | 28348871 |
| successful treatment of listeria monocytogenes prosthetic valve endocarditis using rifampicin and benzylpenicillin in combination with valve replacement. | introduction.listeria monocytogenes is an uncommon cause of prosthetic valve endocarditis (pve). recommended antimicrobial therapy typically includes intravenous β-lactams with or without synergistic aminoglycosides. in vitro studies have previously identified antagonism when rifampicin has been used in combination with β-lactams. however, in vivo data of rifampicin use are limited despite its enhanced anti-biofilm activity. case presentation. a 63-year-old male presented with fever and back pai ... | 2017 | 28348807 |
| stevia rebaudiana bertoni effect on the hemolytic potential of listeria monocytogenes. | the effect of stevia rebaudiana bertoni on the hemolytic potential of listeria monocytogenes was studied by means of the assessment of the listeriolysin o (llo) production. the three factors under study, stevia concentration in the range [0-2.5] % (w/v), incubation temperature (10 and 37°c), and exposure time (0-65h) significantly affected (p≤0.05) the hemolytic activity of l. monocytogenes. results showed that at the lower incubation temperature the hemolytic potential of the bacterium was sign ... | 2017 | 28346877 |
| antimicrobial medium- and long-chain free fatty acids prevent prfa-dependent activation of virulence genes in listeria monocytogenes. | the foodborne pathogen listeria monocytogenes is the causative agent of the invasive disease listeriosis. infection by l. monocytogenes involves bacterial crossing of the intestinal barrier and intracellular replication in a variety of host cells. the prfa protein is the master regulator of virulence factors required for bacterial entry, intracellular replication and cell-to-cell spread. prfa-dependent activation of virulence genes occurs primarily in the blood and during intracellular infection ... | 2017 | 28344104 |
| membrane fatty acid composition as a determinant of listeria monocytogenes sensitivity to trans-cinnamaldehyde. | trans-cinnamaldehyde, the major compound of cinnamon essential oil, is a potentially interesting natural antimicrobial food preservative. although a number of studies have addressed its mode of action, the factors that determine bacterial sensitivity or tolerance to trans-cinnamaldehyde are poorly understood. we report the detailed characterization of a listeria monocytogenes scott a trans-cinnamaldehyde hypersensitive mutant defective in ilve, which catalyzes the reversible transamination of br ... | 2017 | 28342836 |
| gut symbiotic microbes imprint intestinal immune cells with the innate receptor slamf4 which contributes to gut immune protection against enteric pathogens. | interactions between host immune cells and gut microbiota are crucial for the integrity and function of the intestine. how these interactions regulate immune cell responses in the intestine remains a major gap in the field. | 2017 | 28341747 |
| genotypes associated with listeria monocytogenes isolates displaying impaired or enhanced tolerances to cold, salt, acid, or desiccation stress. | the human pathogen listeria monocytogenes is a large concern in the food industry where its continuous detection in food products has caused a string of recalls in north america and europe. most recognized for its ability to grow in foods during refrigerated storage, l. monocytogenes can also tolerate several other food-related stresses with some strains possessing higher levels of tolerances than others. the objective of this study was to use a combination of phenotypic analyses and whole genom ... | 2017 | 28337186 |
| listeria monocytogenes endophthalmitis after intermediate uveitis and ppv for retinal detachment. | | 2017 | 28329887 |
| sensing of bacterial cyclic dinucleotides by the oxidoreductase recon promotes nf-κb activation and shapes a proinflammatory antibacterial state. | bacterial and host cyclic dinucleotides (cdns) mediate cytosolic immune responses through the sting signaling pathway, although evidence suggests that alternative pathways exist. we used cdn-conjugated beads to biochemically isolate host receptors for bacterial cdns, and we identified the oxidoreductase recon. high-affinity cdn binding inhibited recon enzyme activity by simultaneously blocking the substrate and cosubstrate sites, as revealed by structural analyses. during bacterial infection of ... | 2017 | 28329705 |
| listeria monocytogenes cadc regulates cadmium efflux and fine-tunes lipoprotein localization to escape the host immune response and promote infection. | listeria monocytogenes (lm) is a major intracellular human foodborne bacterial pathogen. we previously revealed lm-cadc as highly expressed during mouse infection. here we show that lm-cadc is a sequence-specific, dna-binding and cadmium-dependent regulator of cada, an efflux pump conferring cadmium resistance. cadc, but not cada, is required for lm infection in vivo. interestingly, cadc also directly represses lspb, a gene encoding a lipoprotein signal peptidase whose expression appears detrime ... | 2017 | 28329127 |
| suspected giant cell aortitis : from multiple aortic structural damage to fatal listeria sepsi. a case report. | giant cell arteritis ( gca) is an inflammatory vasculopathy affecting large and middle-sized vessels , specifically cranial arteries derived from carotid artery. isolated extracranial vessel involvement can occur. interest in extravascular manifestations is recently increasing because of diffusion of sensitive and specific imaging tools such as 18fdg pet tc . patients have an increased relative risk of severe infection. listeria monocytogenes infection risk is increased, and vascular system invo ... | 2017 | 28323232 |
| impairment of the class iia bacteriocin receptor function and membrane structural changes are associated to enterocin crl35 high resistance in listeria monocytogenes. | enterocin crl35 is a class iia bacteriocin with anti-listeria activity. resistance to these peptides has been associated with either the downregulation of the receptor expression or changes in the membrane and cell walls. the scope of the present work was to characterize enterocin crl35 resistant listeria strains with mics more than 10,000 times higher than the mic of the wt sensitive strain. | 2017 | 28323072 |
| listeria monocytogenes meningitis preceded by acute cholangitis. | listeria monocytogenes is a well-known cause of meningitis in immunocompromised patients. this organism has a growing significance for community-acquired meningitis, which should have ampicillin added to the usual regimen. we describe a case of l. monocytogenes meningitis preceded by cholangitis. this case suggests gastrointestinal symptoms preceding meningitis may be a clue of listeriosis. it is important for physicians to consider l. monocytogenes as a cause of bacterial meningitis in patients ... | 2017 | 28320704 |
| efficacy of a sonicating swab for removal and capture of listeria monocytogenes in biofilm on stainless steel. | listeria monocytogenes is of great concern in food processing facilities because it persists in biofilms, potentiating biotransfer. stainless steel is commonly used for food contact surfaces and transport containers. l. monocytogenes biofilm on stainless steel served as a model system for surface sampling to test the performance of a sonicating swab in comparison to a standard cotton swab. swab performance and consistency were determined using total viable counts. stainless steel coupons sampled ... | 2017 | 28314729 |
| bacterial detection using peptide-based platform and impedance spectroscopy. | antimicrobial peptides have the ability to function as bio-recognition elements in the detection of bacteria. for instance, we showed that leucocin a, an antimicrobial peptide from class iia bacteriocins, binds gram-positive listeria monocytogenes with higher affinity than other gram-positive bacteria like s. aureus, l. innocua, and e. faecalis. the binding was detected using impedance spectroscopy when leucocin a immobilized on impedance electrodes binds bacteria from a sample. here we highligh ... | 2017 | 28299684 |
| anti-listeria activity of lactic acid bacteria in two traditional sicilian cheeses. | listeria monocytogenes is a pathogen frequently found in dairy products, and its growth is difficult to control. bacteriocin-like inhibitory substances (blis), produced by lactic acid bacteria (lab), having proven in vitro anti-listeria activity, could provide an innovative approach to control l. monocytogenes; however, this application needs to be evaluated in vivo. in this study, twenty lab strains isolated from different sicilian dairy environments were tested for control of growth of l. mono ... | 2017 | 28299290 |
| biofilm-producing ability of listeria monocytogenes isolates from brazilian cheese processing plants. | the persistence of listeria monocytogenes in food industry environments has been associated to the ability of specific isolates to produce biofilms. this study aimed to evaluate the biofilm production of 85 l. monocytogenes strains previously isolated from samples of cheese, brine and the environment of two cheese processing plants located in são paulo, brazil. the l. monocytogenes isolates belonged to serotypes 4b, 1/2b and 1/2c, yielded 30 different pulsotypes by pulsed-field gel electrophores ... | 2017 | 28290331 |
| metabolic determinants in listeria monocytogenes anaerobic listeriolysin o production. | listeria monocytogenes is a human pathogen and a facultative anaerobe. to better understand how anaerobic growth affects l. monocytogenes pathogenesis, we first showed that anaerobic growth led to decreased growth and changes in surface morphology. moreover, compared to aerobically grown bacteria, anaerobically grown l. monocytogenes established higher level of invasion but decreased intracellular growth and actin polymerization in cultured cells. the production of listeriolysin o (llo) was sign ... | 2017 | 28289786 |
| control of recombination directionality by the listeria phage a118 protein gp44 and the coiled-coil motif of its serine integrase. | the serine integrase of phage a118 catalyzes integrative recombination between attp on the phage and a specific attb locus on the chromosome of listeriamonocytogenes but is unable to promote excisive recombination between the hybrid attl and attr sites found on the integrated prophage without assistance from a recombination directionality factor (rdf). we have identified and characterized the phage-encoded rdf, gp44, which activates the a118 integrase for excision and inhibits integration. gp44 ... | 2017 | 28289084 |
| listeria monocytogenes ability to survive desiccation: influence of serotype, origin, virulence, and genotype. | listeria monocytogenes, a bacterium that is responsible for listeriosis, is a very diverse species. desiccation resistance has been rarely studied in l. monocytogenes, although it is a stress that is largely encountered by this microorganism in food-processing environments and that could be managed to prevent its presence. the objective of this study was to evaluate the resistance of 30 l. monocytogenes strains to moderate desiccation (75% relative humidity) and evaluate the correlation of such ... | 2017 | 28288399 |
| intractable neck pain in an oncologic palliative care setting: is cancer always the answer? | refractory pain is a common manifestation in an oncologic palliative care setting and represents a major challenge for health care professionals involved in care provision. the underlying neoplasm and its dissemination are the foremost pathophysiologic mechanism for the development of pain in patients with advanced cancer. nonetheless, other etiologies such as trauma and infections need to be considered by clinicians in this particular care setting. the authors present the case of a patient with ... | 2017 | 28287358 |
| efficient control of chronic lcmv infection by a cd4 t cell epitope-based heterologous prime-boost vaccination in a murine model. | cd4(+) t cells are essential for sustaining cd8(+) t cell responses during a chronic infection. the adoptive transfer of virus-specific cd4(+) t cells has been shown to efficiently rescue exhausted cd8(+) t cells. however, the question of whether endogenous virus-specific cd4(+) t cell responses can be enhanced by certain vaccination strategies and subsequently reinvigorate exhausted cd8(+) t cells remains unexplored. in this study, we developed a cd4(+) t cell epitope-based heterologous prime-b ... | 2017 | 28287115 |
| teriyaki sauce with carvacrol or thymol effectively controls escherichia coli o157:h7, listeria monocytogenes, salmonella typhimurium, and indigenous flora in marinated beef and marinade. | an effective bactericidal cold-marinating method for beef products is described, exploiting the synergism between soy sauce and natural compounds (carvacrol, cv or thymol, tm) to reduce microbiological risks. beef slices inoculated with escherichia coli o157:h7, listeria monocytogenes, and salmonella typhimurium (3.1-3.5logcfu/g) were marinated in a teriyaki sauce with or without cv and tm (0.3 and 0.5%). after 1, 3, and 7days at 4°c, indigenous microflora population, color, lipid oxidation, mar ... | 2017 | 28285115 |
| listeria monocytogenes in fresh produce: outbreaks, prevalence and contamination levels. | listeria monocytogenes, a member of the genus listeria, is widely distributed in agricultural environments, such as soil, manure and water. this organism is a recognized foodborne pathogenic bacterium that causes many diseases, from mild gastroenteritis to severe blood and/or central nervous system infections, as well as abortion in pregnant women. generally, processed ready-to-eat and cold-stored meat and dairy products are considered high-risk foods for l. monocytogenes infections that cause h ... | 2017 | 28282938 |
| the complement anaphylatoxins c5a and c3a suppress ifn-β production in response to listeria monocytogenes by inhibition of the cyclic dinucleotide-activated cytosolic surveillance pathway. | listeria monocytogenes is an intracellular gram-positive bacterium that induces expression of type i ifns (ifn-α/ifn-β) during infection. these cytokines are detrimental to the host during infection by priming leukocytes to undergo l. monocytogenes-mediated apoptosis. our previous studies showed that c5ar1(-/-) and c3ar(-/-) mice are highly susceptible to l. monocytogenes infection as a result of increased ifn-β-mediated apoptosis of major leukocyte cell populations, including cd4(+) and cd8(+) ... | 2017 | 28275134 |
| virulence genes and genetic relationship of l. monocytogenes isolated from human and food sources in brazil. | the herein presented assay provided a bacteriological and molecular characterization of 100 samples of l. monocytogenes isolated from human (43) and food (57) sources, from several regions of brazil, and collected between 1975 and 2013. antigenic characterization defined 49% of serotype 4b samples, followed by 28% of serotype 1/2b, 14% of serotype 1/2c, 8% of serotype 1/2a, and 1% of serotype 3b. both type of samples from human and food origin express the same serotype distribution. multiplex pc ... | 2017 | 28274807 |
| inactivation of listeria monocytogenes on frozen red raspberries by using uv-c light. | in this study, the efficacy of uv-c treatment was determined on the reduction of foodborne pathogens on artificially contaminated frozen food surfaces. at first, the uv-c inactivation rates on 100 μl of the respective cocktails of escherichia coli o157:h7, salmonella , and listeria monocytogenes covered underneath 0.5-cm-thick ice were examined. simultaneously, the energy percentage of uv-c transmitted through the ice was determined. the experiments showed that more than 65% of the uv-c light en ... | 2017 | 28272923 |
| genetic characterization of listeria monocytogenes isolates from industrial and retail ready-to-eat meat-based foods and their relationship with clinical strains from human listeriosis in portugal. | listeria monocytogenes isolates (n = 81) recovered from ready-to-eat meat-based food products (rtemp) collected in industrial processing plants and retail establishments were genetically characterized for comparison with those from human clinical cases of listeriosis (n = 49). the aim was to assess rtemp as a possible food source for human infection. l. monocytogenes was detected in 12.5% of the rtemp samples, and in some cases, counts were above the european food safety criteria. all isolates w ... | 2017 | 28272920 |
| in situ generation of chlorine dioxide for surface decontamination of produce. | fresh fruits and vegetables are frequently contaminated with bacterial pathogens and implicated in foodborne illnesses. the objective of this study was to develop a unique surface decontamination method for produce using sodium chlorite and an acid in a sequential treatment. the surfaces of cantaloupe rinds, peels of cucumbers, stem scars of grape tomatoes, and leaves of baby spinach were inoculated with salmonella or listeria monocytogenes at 5 to 6 log cfu/g, submerged in 1.6 to 4% sodium chlo ... | 2017 | 28272919 |
| listeria monocytogenes internalizes in romaine lettuce grown in greenhouse conditions. | listeria monocytogenes has been implicated in a number of outbreaks involving fresh produce, including an outbreak in 2016 resulting from contaminated packaged salads. the persistence and internalization potential of l. monocytogenes in romaine lettuce was evaluated, and the persistence of two l. monocytogenes strains was assessed on three romaine lettuce cultivars. seeds were germinated, and plants grown in three soil types (i.e., standard potting mix, autoclaved potting mix, and top soil) and ... | 2017 | 28271926 |