Publications
| Title | Abstract | Year(sorted ascending) Filter | PMID Filter |
|---|
| validation of the usda/ars package rinse method for recovery of listeria monocytogenes from naturally contaminated, commercially prepared frankfurters. | the utility of the u.s. department of agriculture/agricultural research service (usda/ars) package rinse method for recovering listeria monocytogenes from the surface of contaminated foods was validated in comparison to the standard usda/food safety and inspection service (fsis) product composite enrichment method and two other methods using frankfurters from a lot with a known package prevalence rate of approximately 16% for this pathogen. one hundred packages from this batch of naturally conta ... | 2003 | 14572233 |
| dna vaccination protects mice against challenge with listeria monocytogenes expressing the hepatitis c virus ns3 protein. | the goal of this study was to develop a new surrogate challenge model for use in evaluating protective cell-mediated immune responses against hepatitis c virus (hcv) antigens. the use of recombinant listeria monocytogenes organisms which express hcv antigens provides novel tools with which to assay such in vivo protection, as expression of immunity against this hepatotropic bacterial pathogen is dependent on antigen-specific cd8(+) t lymphocytes. a plasmid dna vaccine encoding a ubiquitin-ns3 fu ... | 2003 | 14573658 |
| capg(-/-) mice have specific host defense defects that render them more susceptible than capg(+/+) mice to listeria monocytogenes infection but not to salmonella enterica serovar typhimurium infection. | loss of the actin filament capping protein capg has no apparent effect on the phenotype of mice maintained under sterile conditions; however, bone marrow-derived macrophages from capg(-/-) mice exhibited distinct motility defects. we examined the ability of capg(-/-) mice to clear two intracellular bacteria, listeria monocytogenes and salmonella enterica serovar typhimurium. the 50% lethal dose of listeria was 10-fold lower for capg(-/-) mice than for capg(+/+) mice (6 x 10(3) cfu for capg(-/-) ... | 2003 | 14573680 |
| cesrk, a two-component signal transduction system in listeria monocytogenes, responds to the presence of cell wall-acting antibiotics and affects beta-lactam resistance. | listeria monocytogenes is a food-borne pathogen that can cause a variety of illnesses ranging from gastroenteritis to life-threatening septicemia. the beta-lactam antibiotic ampicillin remains the drug of choice for the treatment of listeriosis. we have previously identified a response regulator of a putative two-component signal transduction system that plays a role in the virulence and ethanol tolerance of l. monocytogenes. here we present evidence that the response regulator, cesr, and a hist ... | 2003 | 14576097 |
| characterization and application of a listeria monocytogenes reactive monoclonal antibody c11e9 in a resonant mirror biosensor. | typical detection of listeria monocytogenes involves selective enrichment, isolation and biochemical testing. development of antibodies to listeria species has improved detection; however, most antibodies detect all species of listeria. a previously developed monoclonal antibody (mab)-c11e9 was examined for its reaction to 13 l. innocua and 40 l. monocytogenes strains representing all 13 serotypes by elisa. absorbance values for l. monocytogenes strains were 0.44-3.58 and for l. innocua 0.22-1.4 ... | 2003 | 14580886 |
| inhibition of listeria monocytogenes by bovicin hc5, a bacteriocin produced by streptococcus bovis hc5. | cattle can be infected with listeria monocytogenes by consuming contaminated plant materials, soil or silage, and farmers have sought ways of preventing this contamination. recent work indicated that streptococcus bovis hc5 produced a bacteriocin (bovicin hc5) that could inhibit a variety of gram-positive bacteria, and we examined the ability of bovicin hc5 to inhibit 10 strains of l. monocytogenes that had been isolated from plant materials, soil, silage and infected cattle. growth experiments ... | 2003 | 14580975 |
| antimicrobial resistance of listeria monocytogenes. | listeria monocytogenes is an opportunistic pathogen that causes rare but frequently fatal infections, termed listerioses. in general, strains of l. monocytogenes are susceptible to a wide range of antibiotics, except for the cephalosporins, fluorochinolones and fosfomycin (hof, 1991). the current therapy of choice is a combination of ampicillin and aminoglycoside, usually gentamicin (lorber, 1997). in cases when it is not possible to use a beta-lactam antibiotic, second-choice therapy involves t ... | 2003 | 14594399 |
| ampicillin resistance in listeria monocytogenes acquired as a result of transposon mutagenesis. | we have used plasmid pltv3, which carries transposon tn917, to obtain a series of mutants of listeria monocytogenes egd showing varied degrees of resistance to ampicillin and other beta-lactam antibiotics, including imipenem. in this paper we focus on the characteristics of two strains in which decreased susceptibility to ampicillin is accompanied by changes in the structure of the cell wall murein and cell-wall related changes of phenotype. | 2003 | 14594400 |
| wessex shopping basket survey - a structured approach to local food sampling. | the shopping basket approach to food sampling, in which ready-to-eat food items from a shopping list were sampled at premises chosen at random, was adopted by 15 environmental health departments in the wessex region. a total of 2037 samples were analysed over a 30-month period. the microbiological quality varied considerably between food categories, with gravy and stock samples giving the highest proportion of satisfactory results. sliced meats, cooked rice and sandwiches gave the poorest overal ... | 2003 | 14594701 |
| functionality of enterococci in dairy products. | enterococci have important implications in the dairy industry. they occur as nonstarter lactic acid bacteria (nslab) in a variety of cheeses, especially artisan cheeses produced in southern europe from raw or pasteurised milk, and in natural milk or whey starter cultures. they play an acknowledged role in the development of sensory characteristics during ripening of many cheeses and have been also used as components of cheese starter cultures. the positive influence of enterococci on cheese seem ... | 2003 | 14596993 |
| functionality of enterococci in meat products. | the presence of enterococci in meat fermentation is a constant as reported in the literature. despite the concern about pathogenicity of enterococci, recent studies point out that food and meat enterococci, especially enterococcus faecium have a much lower pathogenicity potential than clinical strains. enterococci possess a competitive advantage over other microbiota in meat fermentations, and many enterococci isolated from sausages have the ability to produce enterocins harbouring antimicrobial ... | 2003 | 14596994 |
| enterococcus faecium rzs c5, an interesting bacteriocin producer to be used as a co-culture in food fermentation. | enterocins, bacteriocins produced by enterococci, are gaining interest because of their industrial potential. due to its bacteriocin production, enterococcus faecium rzs c5, a natural cheese isolate, has a strong activity towards listeria monocytogenes. for this reason, the strain may be applicable as a bacteriocin-producing co-culture in food fermentation in order to reduce the risk on listeria outgrowth. the strain displays remarkable bacteriocin production kinetics. whereas most lactic acid b ... | 2003 | 14596995 |
| mycobacterium marinum escapes from phagosomes and is propelled by actin-based motility. | mycobacteria are responsible for a number of human and animal diseases and are classical intracellular pathogens, living inside macrophages rather than as free-living organisms during infection. numerous intracellular pathogens, including listeria monocytogenes, shigella flexneri, and rickettsia rickettsii, exploit the host cytoskeleton by using actin-based motility for cell to cell spread during infection. here we show that mycobacterium marinum, a natural pathogen of fish and frogs and an occa ... | 2003 | 14597736 |
| incidence of listeria monocytogenes in food and environmental samples in italy between 1990 and 1999: serotype distribution in food, environmental and clinical samples. | we report the findings of the study of 4185 food samples and 958 environmental samples collected in italy in the period 1990-1999 and tested for the presence of listeria monocytogenes. the strains isolated were biochemically and serologically characterised. we found a fairly high percentage of l. monocytogenes contamination in food (12.8%), whereas the level of contamination was lower in the environment (environment and work surfaces in food processing plants) (6.1%). serotyping showed a prevale ... | 2003 | 14598931 |
| sigma(b)-dependent expression patterns of compatible solute transporter genes opuca and lmo1421 and the conjugated bile salt hydrolase gene bsh in listeria monocytogenes. | listeria monocytogenes is a food-borne pathogen that can persist and grow under a wide variety of environmental conditions including low ph and high osmolarity. the alternative sigma factor sigma(b) contributes to l. monocytogenes survival under extreme conditions. the purpose of this study was to identify and confirm specific sigma(b)-dependent genes in l. monocytogenes and to characterize their expression patterns under various stress conditions. opuca, lmo1421 and bsh were identified as putat ... | 2003 | 14600237 |
| the role of dietary vitamin e in experimental listeria monocytogenes infections in turkeys. | the current study was designed to determine if dietary vitamin e influenced either the gut clearance or levels of peripheral blood cd4+ and cd8+ t lymphocytes in adult turkeys experimentally infected with listeria monocytogenes. turkeys were fed vitamin e (0, 100, or 200 iu) from day of hatch to time of necropsy. after 6 wk on the experimental diet, turkeys were orally inoculated with l. monocytogenes (approximately 10(9) cfu). to monitor infection status, cloacal swabs were taken on selected da ... | 2003 | 14601733 |
| rapid identification of listeria species by using restriction fragment length polymorphism of pcr-amplified 23s rrna gene fragments. | a molecular method based on restriction fragment length polymorphism (rflp) of pcr-amplified fragments of the 23s rrna gene was designed to rapidly identify listeria strains to the species level. two fragments (s1, 460 bp, and s2, 890 bp) were amplified from boiled dna. s2 was cut with the restriction enzymes xmni or cfoi and, if needed, s1 was digested by either alui or clai. this method was first optimized with six reference strains and then applied to 182 isolates collected from effluents of ... | 2003 | 14602590 |
| assessment of photodynamic destruction of escherichia coli o157:h7 and listeria monocytogenes by using atp bioluminescence. | antimicrobial photodynamic therapy was shown to be effective against a wide range of bacterial cells, as well as for fungi, yeasts, and viruses. it was shown previously that photodestruction of yeast cells treated with photosensitizers resulted in cell destruction and leakage of atp. three photosensitizers were used in this study: tetra(n-methyl-4-pyridyl)porphine tetratosylate salt (tmpyp), toluidine blue o (tbo), and methylene blue trihydrate (mb). a microdilution method was used to determine ... | 2003 | 14602591 |
| development of a synthetic minimal medium for listeria monocytogenes. | a defined solid and liquid minimal medium, htm, which contained methionine and cysteine as the sole amino acids, was developed for listeria monocytogenes. complex broth-grown l. monocytogenes had to adapt to htm by inducing amino acid biosyntheis. htm is the simplest minimal medium available for growth of l. monocytogenes. | 2003 | 14602660 |
| first documented outbreak of listeria monocytogenes in quebec, 2002. | 2003 | 14603730 | |
| isolation of bartonella washoensis from a dog with mitral valve endocarditis. | we report the first documented case of bartonella washoensis bacteremia in a dog with mitral valve endocarditis. b. washoensis was isolated in 1995 from a human patient with cardiac disease. the main reservoir species appears to be ground squirrels (spermophilus beecheyi) in the western united states. based on echocardiographic findings, a diagnosis of infective vegetative valvular mitral endocarditis was made in a spayed 12-year-old female doberman pinscher. a year prior to presentation, the re ... | 2003 | 14605197 |
| identification of foodborne bacteria by infrared spectroscopy using cellular fatty acid methyl esters. | identification of bacterial species by profiling fatty acid methyl esters (fames) has commonly been carried out by using a 20-min capillary gas chromatographic procedure followed by library matching of fame profiles using commercial midi databases and proprietary pattern recognition software. fast gc (5 min) fame procedures and mass spectrometric methodologies that require no lipid separation have also been reported. in this study, bacterial identification based on the rapid (2 min) infrared mea ... | 2003 | 14607413 |
| comparison of a cultural method with listerscreen plus rapid'l.mono or pcr-elisa methods for the enumeration of l. monocytogenes in naturally contaminated sewage sludge. | cultural methods used to count listeria monocytogenes in sewage sludge are laborious and time consuming, and alternative methods are needed to reduce analysis time and improve detection limits. in this study, a survey of l. monocytogenes in sewage sludge is presented with a comparative study between a cultural method and immunomagnetic separation using a listerscreen test followed by identification of l. monocytogenes with rapid'l.mono agar or pcr-elisa. these two alternative methods improved th ... | 2003 | 14607419 |
| localized reactive oxygen and nitrogen intermediates inhibit escape of listeria monocytogenes from vacuoles in activated macrophages. | listeria monocytogenes (lm) evades being killed after phagocytosis by macrophages by escaping from vacuoles into cytoplasm. activated macrophages are listericidal, in part because they can retain lm in vacuoles. this study examined the contribution of reactive oxygen intermediates (roi) and reactive nitrogen intermediates (rni) to the inhibition of lm escape from vacuoles. lm escaped from vacuoles of nonactivated macrophages within 30 min of infection. macrophages activated with ifn-gamma, lps, ... | 2003 | 14607950 |
| increased cd8+ t cell memory to concurrent infection at the expense of increased erosion of pre-existing memory: the paradoxical role of il-15. | the use of cytokines during vaccination, particularly il-15, is being considered due to the unique ability of il-15 to enhance the proliferation of memory cd8(+) t cells. however, as homeostatic mechanisms limit excessive lymphocyte expansion, we addressed the consequences of this enhancement of t cell memory by il-15. infection of mice with either recombinant mycobacterium bovis (bcg) expressing il-15 (bcg-il-15) or bcg and purified il-15 resulted in an increased cd44, il-2rbeta expression and ... | 2003 | 14607951 |
| beta-casein-derived peptides, produced by bacteria, stimulate cancer cell invasion and motility. | in colon cancer, enteric bacteria and dietary factors are major determinants of the microenvironment but their effect on cellular invasion is not known. we therefore incubated human hct-8/e11 colon cancer cells with bacteria or bacterial conditioned medium on top of collagen type i gels. listeria monocytogenes stimulate cellular invasion through the formation of a soluble motility-promoting factor, identified as a 13mer beta-casein-derived peptide (hkempfpkypvep). the peptide is formed through t ... | 2003 | 14609961 |
| delivery of macromolecules into cytosol using liposomes containing hemolysin. | 2003 | 14610821 | |
| characterization of virulent and avirulent listeria monocytogenes strains by pcr amplification of putative transcriptional regulator and internalin genes. | listeria monocytogenes is an opportunistic bacterial pathogen that is an important cause of human food-borne illness worldwide. however, l. monocytogenes strains demonstrate considerable variation in pathogenic potential. in this report, virulent and avirulent l. monocytogenes isolates were compared by using a comparative screening strategy. two clones were identified that contained dna that was only present in virulent l. monocytogenes strains. pcr primers were designed for three genes from the ... | 2003 | 14614064 |
| [effect of transferrin on the expression of virulence factors in listeria monocytogenes strains]. | iron is an essential element for the great majority of microorganisms, which developed transport systems for iron acquisition, because during the colonization and invasion processes the microorganisms encounter iron-limiting conditions. the bacterial genes implicated in the iron transport and those codifying for other virulence factors are simultaneously depressed. the purpose of this study was to investigate the role of transferrin on the virulence factors expression in food isolated listeria m ... | 2003 | 15341331 |
| foodborne enteric infections. | foodborne infections are estimated to affect one in four americans each year. most these (67%) are caused by the norwalk-like viruses, but campylobacter and nontyphoidal salmonellae together account for about one fourth of cases of illness in which a pathogen can be detected. less common bacterial infections, such as with listeria monocytogenes and the shiga toxin-producing escherichia coli, cause fewer infections but are important because of their severe complications or high mortality rate, or ... | 2003 | 15699888 |
| [listeria disease. the first 2 cases reported at the principal hospital of dakar]. | infection disease due to listeria monocytogenes, which is a ubiquitous positive gram bacillus to the essentially alimentary transmission, listeriosis happens on patients presenting an immunodeficiency. the authors report the two first cases of listeriosis diagnosed at hopital principal de dakar. the first case was observed on a 73 years old man, hospitalised for a feverish coma scored at 9 using glasgow scale, with neither meningitis syndrome, nor sign of neurological localisation. the analysis ... | 2003 | 15776652 |
| left thalamo-peduncular abscess caused by listeria monocytogenes in a homeless patient. | 2003 | 14962707 | |
| [microbiological study of the meals served in school lunch rooms on the island of tenerife, spain]. | school lunchrooms and catered meals are of major importance from the public health standpoint. this study is aimed at evaluating the microbiological quality of the meals served in school lunchrooms for the purpose of ascertaining whether it is suitable or, to the contrary, the intake thereof may involve a serious health problem for this high-risk group. | 2003 | 14965066 |
| [construction and verification of the effectiveness of pmbl: a cloning vector of exported proteins encoding genes]. | the beta-lactamase was used as the reporter of expression and transmembrane secretion in this paper. a fragment of amp resistance gene encoding the mature part of beta-lactamase (delta p delta sp amp, i.e. without promoter and signal peptide coding sequences) was amplified from puc18 vector. the upstream primer has bglii, bcli, bamhi in three reading frame respectively, in order to in frame fuse and express target genes together with the downstream reporter in finally constructed vector. meanwhi ... | 2003 | 14682241 |
| pathology of listerial encephalitis in chickens in japan. | neural signs (torticollis, drowsiness) and mortality were observed in five chickens of a native chicken flock (reared for meat) that included 450 male birds on a farm that had 2300 native chickens and 1120 layers. histologic lesions were observed in the medulla oblongata, optic lobe, cerebellum, and spinal cord of the affected birds. the lesions, which were most severe in the medulla oblongata, were massive abscesses with rarefaction (demyelination and malacia) of the parenchyma with gram-positi ... | 2003 | 14709003 |
| emerging food pathogens and bacterial toxins. | many different foodborne diseases have been described. for example, shigella bacteria, hepatitis a virus and norwalk virus were shown as a unwashed hands microorganisms, but pathogen campylobacter and escherichia coli were named as raw and undercooked meat and poultry or raw milk and untreated water born bacteria. however, two of them: listeria monocytogenes and yersinia enterocolitica are known as growing at refrigerator temperatures. essential virulence determinants of listeria monocytogenes p ... | 2003 | 15058810 |
| [monitoring of a haccp (hazard analysis critical control point) plan for listeria monocytogenes control]. | the monitoring of a haccp (hazard analysis critical control point) plan for the listeria monocytogenes control in the cooked and frozen meat section of a thermo-processing meat plant was evaluated. seventy "non-product-contact" surface samples and fourteen finished product samples were examined. thirty eight positive sites for the presence of listeria sp. were obtained. twenty-two isolates were identified as l. monocytogenes, two as l. seeligeri and fourteen as l. innocua. non isolates were obta ... | 2003 | 14976876 |
| detection and characterization of enterocins from enterococcus sp. | examination of 90 isolates of enterococcus sp. revealed production of enterocin by two isolates of e. faecalis which was inhibitory to listeria monocytogenes. two isolates of e. gallinarum produced enterocin active against staphylococcus aureus. none of the isolates antagonized salmonella enteritidis. the enterocins of e. faecalis isolates were inactivated by alpha-chymotrypsin but not by trypsin and papain, while those of e. gallinarum were resistant to all the three enzymes. enterocins produce ... | 2003 | 15266908 |
| [lysteria monocytogenes in samples of swines sent to the human alimentary chain]. | animal food-stuffs are known to be potential vehicles of listeria monocytogenes. the contamination can be caused from processing or enviromental sources and from infected animals. this hypothesis has been checked in the present work. the authors found that 13.2% of 189 swines were carriers of listeria monocytogenes, the microrganism was isolated from salivary glands, mesenterial gangles and tonsils. the authors suggest some preventive intervention to reduce both the environmental circulation of ... | 2003 | 14969312 |
| biohazards and ecotoxicological considerations of landspreading of spent compost wastes. | spent mushroom compost (smc) is a major waste of the mushroom industry with low economic value. smc arises after mushroom production in phase ii compost (piic), predominantly comprising straw and chicken litter as principal raw ingredients. the majority of smc waste is disposed off by application to agricultural land. it is an attractive proposition for utilising smc as soil inorganic fertiliser supplementation. however, there is limited data available as to the consequences of this method of di ... | 2003 | 15151327 |
| [presence of escherichia coli o157:h7, listeria monocytogenes and salmonella spp. in food from animal origin in costa rica]. | the presence of escherichia coli o157:h7, listeria monocytogenes and salmonella spp was analyzed in two kinds of food from animal origin in costa rica. 100 samples of non pasteurized milk, from the principal producing zones of the country, and 100 samples of chicken giblets, purchased in retail markets, were analyzed according to the methodology described by food and drug administration, 1995. escherichia coli o157:h7 was analyzed in both kinds of food, while l. monocytogenes was evaluated in ra ... | 2003 | 15125081 |
| t cell reactivity to listeria monocytogenes amongst us. | in the last two decades, listeriosis, caused by the intracellular pathogen listeria monocytogenes, became one of the most concerning food-born infections. although it had been known before as an infectious disease of limited importance, listeriosis was brought into attention of scientists due to the frequent outbreaks recently reported. despite the major progress made towards understanding the mechanisms of virulence of l. monocytogenes, our current knowledge into the process of listeria-associa ... | 2003 | 16008146 |
| the effects of sodium lactate and starter cultures on ph, lactic acid bacteria, listeria monocytogenes and salmonella spp. levels in pure chicken dry fermented sausage. | two starter cultures (a and b) and seven sodium lactate concentrations were evaluated for chicken raw dry-fermented sausage processing. starter culture b contained more lactic acid bacteria and less staphylococci than starter a. their effects on acidification and inhibition of pathogens (listeria monocytogenes and salmonella spp.) were monitored. starter culture b grew faster and was less inhibited by sodium lactate, thus inducting a faster and more important ph drop into the sausages. with lowe ... | 2003 | 22063699 |
| evaluation of sodium lactate as a replacement for conventional chemical preservatives in comminuted sausages inoculated with listeria monocytogenes. | sodium lactate (sl) as a potential replacer for potassium sorbate (ps) or sodium benzoate (sb) in comminuted sausages was evaluated. sausages manufactured with 3.3% sl were compared with a control and 0.05 or 0.1% of ps and sb with regard to its influence on changes of chemical composition, physico-chemical and textural properties, and the growth of inoculated listeria monocytogenes (lm) stored at 4 °c for up to 8 weeks. the sausages contained 62-64% moisture, 15-17% fat and 12-14% protein with ... | 2003 | 22063246 |
| characterization of lactic acid bacteria isolated from a greek dry-fermented sausage in respect of their technological and probiotic properties. | a total of 147 lactic acid bacteria was isolated from two types of naturally fermented dry sausages at four different stages of the ripening process studied in order to select the most suitable strains according to their technological characteristics including probiotic properties and antimicrobial activity against food-borne pathogens. identification of the isolates revealed that 90% were lactobacilli, 4% enterococci, 3% pediococcus sp. and sporadic isolates of weissella viridescens, leuconosto ... | 2003 | 22063449 |
| effect of citric acid on the radiation resistance of listeria monocytogenes and frankfurter quality factors. | listeria monocytogenes is a common contaminant of ready-to-eat meat products, including frankfurters. ionizing (gamma) radiation can eliminate l. monocytogenes from frankfurters. citric acid (ca) is an antioxidant synergist and anti-microbial agent that can be applied to the surfaces of cured meat products prior to packaging. the effect of ca on the radiation resistance of l. monocytogenes that was surface-inoculated onto frankfurters was determined. the d(10) values, the radiation doses require ... | 2003 | 22062395 |
| antioxidant and antimicrobial effects of four garlic-derived organosulfur compounds in ground beef. | the antioxidant and antimicrobial protection of diallyl sulfide (das), diallyl disulfide (dads), s-ethyl cysteine (sec), n-acetyl cysteine (nac) in ground beef against discoloration, lipid oxidation and microbial contamination were studied. the exogenous addition of these garlic-derived organosulfur compounds significantly delayed both oxymyoglobin and lipid oxidations (p<0.05). the antioxidant protection from these organosulfur compounds was dose-dependent (p<0.05), and showed significantly gre ... | 2003 | 22061980 |
| behaviour of listeria monocytogenes in raw sausages (merguez) in presence of a bacteriocin-producing lactococcal strain as a protective culture. | the effectiveness of a bacteriocin produced by lactococcus lactis subsp. lactis m in reducing population level and growth of listeria monocytogenes atcc 7644 in fermented merguez sausage was examined. two different formulas (with or without added nitrites) were assayed and predetermined numbers of listeria (ca 10(6) cfu g(-1)) were added to sausage mixture. the effect of in situ production of the bacteriocin by lactococcus lactis m on listeria monocytogenes atcc 7644 during fermentation and stor ... | 2003 | 22062517 |
| evaluation of the potential of meat born lactic acid bacteria for use as protective cultures in the biopreservation of cooked meat products. | in this study, 97 lactic acid bacteria were subjected to a step-by-step screening and characterisation to search for potential protective cultures to be used in the cooked cured meat industry. strains were first tested on their homofermentative and psychrotrophic character and salt tolerance. secondly, the antibacterial capacities towards listeria monocytogenes, leuconostoc mesenteroides, leuconostoc carnosum and brochotrix thermosphacta were determined in an agar spot test. finally, 12 selected ... | 2003 | 24757784 |
| listeria monocytogenes and inflammatory bowel diseasedetection of listeria species in intestinal mucosal biopsies by real-time pcr. | 2003 | 28248597 | |
| [prokaryotic expression and bioactivity of the listeria monocytogenes listeriolysin o]. | to express the listeria monocytogenes hly gene in escherichia coli and study its primary biological characteristics, hly gene without signal peptide sequence was amplified from listeria monocytogenes serotype 4b by pcr and inserted into t-easy vector. sequencing showed this hly gene was 1518 bp and nucleotide homology was more than 99.8% compared with three listeria monocytogenes hly genes in genbank. the cloned hly gene was then inserted into prokaryotic expression vector pgex-6p-1 and transfor ... | 2004 | 16110954 |
| murein-hydrolyzing activity of flagellin flaa of listeria monocytogenes. | in this preliminary report we show that a 29 kda surface protein of listeria monocytogenes egd removed from cells with 4 m licl has peptidoglycan (murein) hydrolyzing activity, as revealed by zymographic analysis using bacillus subtilis murein and heat-killed micrococcus luteus cells casted in the gel. following two-dimensional electrophoresis, the protein was electroblotted to pvdf membrane and its identity (flaa) was revealed by sequencing. peptidoglycan hydrolysing activity of flaa purified b ... | 2004 | 15790072 |
| antimicrobial susceptibilities of listeria monocytogenes strains isolated from 2000 to 2002 in poland. | minimal inhibitory concentration (mic) of ampicillin, penicillin, gentamicin, erythromycin, clarithromycin, sulfisoxazole and trimethoprim for 73 listeria monocytogenes isolates from clinical material samples, food and environment was determined using broth microdilution method. with exception of the sulfonamide all antibacterial agents were active against all tested strains. resistance to sulfisoxazole (mic > or = 512 microg/ml) was detected in case of 30.1% of isolates including 5 of 14 human ... | 2004 | 15790078 |
| methods for the isolation and identification of listeria spp. and listeria monocytogenes: a review. | listeria monocytogenes is an important food-borne pathogen and is widely tested for in food, environmental and clinical samples. identification traditionally involved culture methods based on selective enrichment and plating followed by the characterization of listeria spp. based on colony morphology, sugar fermentation and haemolytic properties. these methods are the gold standard; but they are lengthy and may not be suitable for testing of foods with short shelf lives. as a result more rapid t ... | 2004 | 16219509 |
| the cost and benefit of listeria monocytogenes food safety measures. | the objectives of this study were to evaluate economic techniques used to determine the cost and benefit of listeria monocytogenes control and to estimate the economic optimum of l. monocytogenes food safety measures. the level of food safety measures is optimal if marginal benefit and marginal cost equate. estimates of benefit and cost of l. monocytogenes food safety measures, from available published literature, are derived from different methods of economic analysis (willingness to pay, cost ... | 2004 | 15969324 |
| evaluation of universal pre-enrichment broth for isolation of salmonella spp., escherichia coli o157:h7, and listeria monocytogenes from dairy farm environmental samples. | use of universal pre-enrichment broth (upb) as a primary enrichment medium for detection of salmonella spp., escherichia coli o157:h7, and listeria monocytogenes from dairy farm environmental samples was evaluated. there were no differences in bacterial growth between upb and selective primary enrichment broths for each pathogen inoculated individually or in combination at 10(1) and 10(2) colony forming units/ml. in addition, no differences were observed when upb and selective primary enrichment ... | 2004 | 15992260 |
| detection of sorbitol-negative and sorbitol-positive shiga toxin-producing escherichia coli, listeria monocytogenes, campylobacter jejuni, and salmonella spp. in dairy farm environmental samples. | six visits were conducted to four dairy farms to collect swab, liquid, and solid dairy farm environmental samples (165 to 180/farm; 15 sample types). the objective of the study was to determine on-farm sources of campylobacter jejuni, salmonella spp., listeria monocytogenes, and shiga toxin-producing escherichia coli (stec), which might serve as reservoirs for transmission of pathogens. samples were analyzed using mostly u.s. food and drug administration's bacteriological analytical manual proto ... | 2004 | 15992268 |
| causes behind a human cheese-borne outbreak of gastrointestinal listeriosis. | in a previous paper, we reported an outbreak of gastrointestinal listeriosis due to consumption of fresh cheese made from raw milk and manufactured on a summer farm. the aim of the present study was to investigate why the cheese harbored listeria monocytogenes. to our knowledge, this is the first documented outbreak of listeriosis caused by raw milk cheese where the human epidemic strain has been cultured from a dairy animal, whose milk has been used for cheese production. the conditions on a su ... | 2004 | 15992274 |
| accelerating bacterial identification by infrared spectroscopy by employing microarray deposition of microorganisms. | a microarray method for the deposition of bacteria onto an agar slide was developed to accelerate the formation of microcolonies. representative microarrays each consisting of 40 micro-spots of five replicates of eight foodborne bacteria (yersinia enterocolitica, staphylococcus aureus, salmonella typhimurium, listeria monocytogenes, enterobacter cloacae, citrobacter freundii, klebsiella pneumoniae, and escherichia coli) were printed on a brain heart infusion (bhi) agar slide using a contact micr ... | 2004 | 15992277 |
| detection of escherichia coli o157:h7 and listeria monocytogenes in beef products by real-time polymerase chain reaction. | rapid methods for the detection of escherichia coli o157:h7 and listeria monocytogenes in food products are important to the food industry and for public health. conventional microbiological methods and newly developed molecular-based techniques such as polymerase chain reaction (pcr)-based methods are time consuming. in this study, a faster method based on utilization of a hybridization probe with real-time pcr, was developed and applied for detection of e. coli o157:h7 and l. monocytogenes fro ... | 2004 | 15992285 |
| methods to determine the growth domain in a multidimensional environmental space. | data from a database on microbial responses to the food environment (combase, see www.combase.cc) were used to study the boundary of growth several pathogens (aeromonas hydrophila, escherichia coli, listeria monocytogenes, yersinia enterocolitica). two methods were used to evaluate the growth/no growth interface. the first one is an application of the minimum convex polyhedron (mcp) introduced by baranyi et al. [baranyi, j., ross, t., mcmeekin, t., roberts, t.a., 1996. the effect of parameterisa ... | 2004 | 15854687 |
| a quasi-chemical model for the growth and death of microorganisms in foods by non-thermal and high-pressure processing. | predictive microbial models generally rely on the growth of bacteria in laboratory broth to approximate the microbial growth kinetics expected to take place in actual foods under identical environmental conditions. sigmoidal functions such as the gompertz or logistics equation accurately model the typical microbial growth curve from the lag to the stationary phase and provide the mathematical basis for estimating parameters such as the maximum growth rate (mgr). stationary phase data can begin t ... | 2004 | 15854689 |
| modelling the individual cell lag phase: effect of temperature and ph on the individual cell lag distribution of listeria monocytogenes. | the individual-based approach of the lag phase is gaining interest, especially for pathogens that initially contaminate food products in low amounts. in this paper, the effect of temperature (30, 10, 7, 4 and 2 degrees c) and ph (7.4, 6.1, 5.5, 5.0, 4.7 and 4.4) on the individual cell lag phase of listeria monocytogenes was examined in a factorial design, using od measurements. individual lag phases of about 100 individual cells per condition were examined and calculated using a linear extrapola ... | 2004 | 15854691 |
| modelling the effect of a temperature shift on the lag phase duration of listeria monocytogenes. | the aim of this work is to study and model the effect of a temperature shift on h(0), the product of the growth rate by the lag phase duration (mulambda). our work is based on the data of whiting and bagi [int. j. food microbiol. 73 (2002) 291], who studied the influence of both the pre-incubation temperature (t(prior)) and the growth temperature (t(growth)) on lambda values of listeria monocytogenes. we introduce a new model to describe the evolution of the parameter h(0) as a function of t(pri ... | 2004 | 15854694 |
| temperature effect on bacterial growth rate: quantitative microbiology approach including cardinal values and variability estimates to perform growth simulations on/in food. | temperature effect on growth rates of listeria monocytogenes, salmonella, escherichia coli, clostridium perfringens and bacillus cereus, was studied. growth rates were obtained in laboratory medium by using a binary dilutions method in which 15 optical density curves were generated to determine one mu value. the temperature was in the range from 2 to 48 degrees c, depending on the bacterial species. data were analysed after a square root transformation. no large difference between the strains of ... | 2004 | 15854703 |
| comparing predicting models for heat inactivation of listeria monocytogenes and pseudomonas aeruginosa at different ph. | under the same experimental conditions it has been demonstrated that whereas survival curves of listeria monocytogenes in the range of temperatures from 54 to 62 degrees c followed a first-order kinetic, those of pseudomonas aeruginosa in the range of temperatures from 50 to 56 degrees c were not linear showing a shoulder followed by a linear region. the first order kinetic model did not describe survival curves of p. aeruginosa. a model based on the weibull distribution (log(10)(n(t)/n(0))=(1/- ... | 2004 | 15854706 |
| development of a safety monitoring and assurance system for chilled food products. | the principles of a novel chill chain management policy, coded safety monitoring and assurance system (smas) for the optimisation of the distribution of chilled food products within the chill chain are developed. in this system, a new approach based on actual risk evaluation at important points of the chill chain is used in order to promote products to the next stage of distribution. this evaluation based on product's time-temperature history, variation in product's characteristics (e.g. a(w), p ... | 2004 | 15854710 |
| cd1d-independent regulation of nkt cell migration and cytokine production upon listeria monocytogenes infection. | natural killer t (nkt) cells are a unique t-cell population that is positively selected by cd1d-expressing cells. in this study, we examined the kinetics of conventional cd4+tcrbeta+ and cd4-tcrbeta+ cells along with various nkt cell populations from wt and cd1d ko mice after oral listeria monocytogenes (lm) infection at different time points in tissue compartments. we found that cd4+tcrbeta+ cells expressing nk1.1+ (nkt) were constitutively expressed in the lung of both strains of mice, but dis ... | 2004 | 15922714 |
| a stochastic analysis of a brownian ratchet model for actin-based motility. | in recent single-particle tracking (spt) measurements on listeria monocytogenes motility in cells [kuo and mcgrath (2000)], the actin-based stochastic dynamics of the bacterium movement has been analyzed statistically in terms of the mean-square displacement (msd) of the trajectory. we present a stochastic analysis of a simplified polymerization brownian ratchet (br) model in which motions are limited by the bacterium movement. analytical results are obtained and statistical data analyses are in ... | 2004 | 16783923 |
| coinfection with listeria monocytogenes potentlxtes the response of balb/c mice against leishmania major. | protection against l. major is dependent on the stimulation of an anti-leishmanial t helper1 (th1) response and the production of interferon (ifn)-y. balb/c mice develop a th2 response and fatal infection with leishmania major. strategies that boost il-12 production have shown to be protective. the innate response to listeria monocytogenes is associated with il-12 production. the co-infection of balb/c mice with l. monocytogenes attenuates the course of l. major infection. lesion sizes were smal ... | 2004 | 15125539 |
| increased atpase activity is responsible for acid sensitivity of nisin-resistant listeria monocytogenes atcc 700302. | the growth of the foodborne pathogen listeria monocytogenes can be controlled by nisin, an antimicrobial peptide. a spontaneous mutant of l. monocytogenes shows both resistance to nisin and increased acid sensitivity compared to the wild type. changes in the cell membrane correlated with nisin resistance, but the mechanism for acid sensitivity appears unrelated. when hydrochloric or lactic acid is added to cultures, intracellular atp levels drop significantly in the mutant (p < 0.01) compared to ... | 2004 | 15128523 |
| molecular and physiological analysis of the role of osmolyte transporters betl, gbu, and opuc in growth of listeria monocytogenes at low temperatures. | listeria monocytogenes is a ubiquitous food-borne pathogen found widely distributed in nature as well as an undesirable contaminant in a variety of fresh and processed foods. this ubiquity can be at least partly explained by the ability of the organism to grow at high osmolarity and reduced temperatures, a consequence of its ability to accumulate osmo- and cryoprotective compounds termed osmolytes. single and multiple deletions of the known osmolyte transporters betl, gbu, and opuc significantly ... | 2004 | 15128551 |
| osmotic stress leads to decreased intracellular ph of listeria monocytogenes as determined by fluorescence ratio-imaging microscopy. | intracellular ph (ph(i)) of listeria monocytogenes was determined after exposure to nacl or sorbitol in liquid and solid media (agar). both compounds decreased ph(i), and recovery on solid medium was impaired compared to that in liquid medium. n,n'-dicyclohexylcarbodiimide abolished ph(i) recovery, and lowering a(w) with glycerol showed no effect on ph(i). | 2004 | 15128587 |
| the ability of two listeria monocytogenes vaccines targeting human papillomavirus-16 e7 to induce an antitumor response correlates with myeloid dendritic cell function. | previous work from our laboratory has shown that lm-llo-e7 induces complete regression of approximately 75% of established tc-1 tumors, whereas lm-e7 only slows the growth of such tumors. in this study, we examine the effects of lm-llo-e7 vs lm-e7 on apcs. we hypothesize that the difference in antitumor efficacy of the two vaccines is due to the ability of each of these vectors to render immature dendritic cells (dcs) effective apcs in terms of mhc class ii or costimulatory molecule expression. ... | 2004 | 15128786 |
| global analysis of gene expression in an rpon mutant of listeria monocytogenes. | the role of the alternative sigma(54) factor, encoded by the rpon gene, was investigated in listeria monocytogenes by comparing the global gene expression of the wild-type egde strain and an rpon mutant. gene expression, using whole-genome macroarrays, and protein content, using two-dimensional gel electrophoresis, were analysed. seventy-seven genes and nine proteins, whose expression was modulated in the rpon mutant as compared to the wild-type strain, were identified. most of the modifications ... | 2004 | 15133119 |
| apoptosis and loss of virus-specific cd8+ t-cell memory. | cd8(+) t-cell memory to viruses is stable in the absence but volatile in the presence of other infections. apoptotic events that occur early in acute infections delete pre-existing memory t cells, leaving the host with reduced memory (except for cross-reactive responses) to previously encountered viruses. apoptotic events also silence the acute immune response, leaving the host with a residual population of memory t cells. persistent infections can induce apoptotic deletions of memory t cells th ... | 2004 | 15134774 |
| the role of cd1d in the immune response against listeria infection. | to address the role of cd1d in mucosal immune regulation in bacterial infection, we infected cd1d ko mice with listeria monocytogenes (lm). a higher systemic bacterial burden associated with inflammatory lymphocytic infiltrations within the intestine was found in cd1d ko compared with wild type (wt) mice. lm induced strong ifn-gamma mrna expression in the liver of wt and the intestine of cd1d ko mice, thus demonstrating the dual, opposing immune activities of ifn-gamma in lm infection that is de ... | 2004 | 15135293 |
| screening of glutamate decarboxylase activity and bile salt resistance of human asymptomatic carriage, clinical, food, and environmental isolates of listeria monocytogenes. | following consumption, stomach acidity is the first major barrier encountered by the food-borne pathogen listeria monocytogenes. analysis of low ph sensitivity and glutamate decarboxylase (gad) acid resistance system of 14 isolates of l. monocytogenes carried asymptomatically by humans showed that levels of gad activity were subjected to strain variation. similar variations were observed for strains responsible for 18 cases of listeriosis, whereas in comparison, 13 strains isolated from food and ... | 2004 | 15135585 |
| overview of listeria monocytogenes contamination in japan. | listeriosis is a relatively rare foodborne illness but can be life threatening with high fatality rates. in japan, the incidence of listeriosis has been very low for the past 40 years compared with that of western europe and north america. we hypothesized that less listeria monocytogenes contamination in japanese foods would be related to the lower incidence in japan. for this purpose, we collected data of japanese foods contaminated with l. monocytogenes, mainly from japanese-written reports, a ... | 2004 | 15135952 |
| use of monoclonal antibodies that recognize p60 for identification of listeria monocytogenes. | listeria monocytogenes causes major food-borne outbreaks of disease worldwide. specific identification of this microorganism is of utmost importance to public health and industry. listeria species are known to secrete a 60-kda protein collectively termed p60, which is encoded by the iap (invasion-associated protein) gene and secreted in large quantities into the growth media. p60 is a highly immunogenic murein hydrolase that is essential for cell division. due to these properties, p60 is an idea ... | 2004 | 15138168 |
| potential therapeutic applications of recombinant, invasive e. coli. | an invasive escherichia coli expressing the inv gene from yersinia pseudotuberculosis was used as a vector for protein delivery to mammalian epithelial cells. upon incubation with beta1-integrin-expressing mammalian cells, the bacteria are internalized, allowing bacteria-encoded proteins to function from within the mammalian cell. these bacteria are eventually processed in the host phagosome where they are destroyed. expression of listeriolysin o from listeria monocytogenes in the bacterium and ... | 2004 | 15141160 |
| meropenem therapy failure in listeria monocytogenes infection. | listeria monocytogenes is highly susceptible to meropenem in vitro, but data on the efficacy of meropenem in clinical cases of listeriosis are scarce. described here is the case of a child with aplastic anemia who acquired nosocomial listeriosis and failed to respond to initial meropenem therapy. resolution of fever was not noted after 5 days of therapy with meropenem and, more importantly, clinical worsening was observed during this period. the patient began to improve after ampicillin was intr ... | 2004 | 15141335 |
| studies of listeria monocytogenes-antibody binding using electro-orientation. | an electro-optical (eo) approach has been used for studies of listeria monocytogenes-antibody binding. the eo analyzer, which has been developed at the state research center for applied microbiology, obolensk, was used as a basic instrument for eo measurements. ac electro-kinetic effects depend on dielectric properties of bioparticles, their composition, morphology, the medium, and the frequency of applied electrical field. electro-orientational spectra were used for discrimination of bacteria b ... | 2004 | 15142611 |
| a molecular marker for evaluating the pathogenic potential of foodborne listeria monocytogenes. | internalin mediates entry of listeria monocytogenes into some human cultured cell lines and crossing of the intestinal barrier in transgenic mice expressing its receptor, human e-cadherin, in enterocytes. the relevance of these findings for humans is challenged by the observation that some l. monocytogenes isolates express a truncated nonfunctional form of internalin. | 2004 | 15143478 |
| impairment of growth of listeria monocytogenes in thp-1 macrophages by granulocyte macrophage colony-stimulating factor: release of tumor necrosis factor-alpha and nitric oxide. | listeria monocytogenes tends to survive in phagocytes. granulocyte macrophage colony-stimulating factor (gm-csf) protects mice against l. monocytogenes infection, and mice knocked out for the gm-csf gene are more susceptible to these infections. | 2004 | 15143479 |
| mode of action of lactococcin r produced by lactococcus lactis r. | we investigated the mode of action and factors affecting adsorption of lactoccocin r produced by lactococcus lactis r. it was found that lactococcin r adsorbed to all gram-positive but not to the gram-negative bacteria tested and its adsorption was dependent on ph. it was observed that the binding of lactococcin r was prevented by anions of several salts (cl-, po4(-3)) and lipoteichoic acid. pretreatments of sensitive cells and cell walls with detergents, organic solvents or enzymes did not redu ... | 2004 | 15146973 |
| inverted pathogenicity: the use of pathogen-specific molecular mechanisms for prevention or therapy of disease. | the term "inverted pathogenicity" stands for the exploitation of microbial toxins, virulence factors and cellular mechanisms for preventive or therapeutic purposes. this mini-review will focus on the major pathogenicity concept of salmonella and yersinia and how to use its underlying molecular principle for the development of a novel vaccination strategy. both bacterial species employ a type iii secretion system which mediates secretion and direct delivery (translocation) of antihost factors int ... | 2004 | 15149032 |
| the rna-binding protein hfq of listeria monocytogenes: role in stress tolerance and virulence. | in gram-negative bacteria, the rna-binding protein hfq has emerged as an important regulatory factor in a variety of physiological processes, including stress resistance and virulence. in escherichia coli, hfq modulates the stability or the translation of mrnas and interacts with numerous small regulatory rnas. here, we studied the role of hfq in the stress tolerance and virulence of the gram-positive food-borne human pathogen listeria monocytogenes. we present evidence that hfq is involved in t ... | 2004 | 15150220 |
| polyphenol oxidase activity as a potential intrinsic index of adequate thermal pasteurization of apple cider. | in response to increasing concerns about microbial safety of apple cider, the u.s. food and drug administration has mandated treatment of cider sufficient for a 5-log reduction of the target pathogen. pasteurization has been suggested as the treatment most likely to achieve a 5-log reduction, with escherichia coli o157:h7 as the target pathogen. regulators and processors need a reliable method for verifying pasteurization, and apple cider polyphenol oxidase (ppo) activity was studied as a potent ... | 2004 | 15151226 |
| effectiveness of acidic calcium sulfate with propionic and lactic acid and lactates as postprocessing dipping solutions to control listeria monocytogenes on frankfurters with or without potassium lactate and stored vacuum packaged at 4.5 degrees c. | the safety of ready-to-eat meat products such as frankfurters can be enhanced by treating with approved antimicrobial substances to control the growth of listeria monocytogenes. we evaluated the effectiveness of acidic calcium sulfate with propionic and lactic acid, potassium lactate, or lactic acid postprocessing dipping solutions to control l. monocytogenes inoculated (ca. 10(8) cfu/ml) onto the surface of frankfurters with or without potassium lactate and stored in vacuum packages at 4.5 degr ... | 2004 | 15151227 |
| encapsulation of nisin and lysozyme in liposomes enhances efficacy against listeria monocytogenes. | the efficacy and stability against listeria monocytogenes of nisin and lysozyme encapsulated in phospholipid liposomes was evaluated. antimicrobial-containing liposomes were prepared by hydrating dried lipids with buffer containing nisin, nisin plus the fluorescence probe calcein, or calcein and lysozyme. mixtures were then centrifuged and sonicated, and encapsulated liposomes were collected using size-exclusion chromatography. antimicrobial concentration in liposomes was determined by bicinchon ... | 2004 | 15151228 |
| isolation, identification, and selection of lactic acid bacteria from alfalfa sprouts for competitive inhibition of foodborne pathogens. | several studies have investigated the control of pathogens on alfalfa sprouts, and some treatments have been shown to be effective in reducing pathogen populations. however, control methods investigated thus far only provide pathogen control at a given point in the sprouting process and can affect germination. competitive inhibition of pathogens with lactic acid bacteria might provide pathogen control throughout the sprouting process and up to consumption. the purpose of this study was to isolat ... | 2004 | 15151232 |
| molecular weight of chitosan influences antimicrobial activity in oil-in-water emulsions. | the objective of this study was to evaluate the antimicrobial efficiency of chitosans in oil-in-water emulsions. model emulsions were prepared with 20% corn oil, 1.5% tween 20, 1.5% trypticase soy broth, 0.58% acetic acid, and chitosan polysaccharide or chitosan oligosaccharide in concentrations of 0, 0.1, 0.2, 0.5, and 0.7%. a control containing hcl was included to determine the role of acetic acid in the overall antibacterial activity. the ph of samples and controls was adjusted to 4.5. emulsi ... | 2004 | 15151233 |
| sensitization of gram-negative and gram-positive bacteria to jenseniin g by sublethal injury. | jenseniin g, a bacteriocin produced by propionibacterium thoenii p126, is active against related propionibacteria and some lactic acid bacteria and is sporostatic to botulinal spores. the objective of this study was to evaluate the effects of sublethal stress on jenseniin g activity. bacillus cereus, enterococcus faecalis, escherichia coli, listeria monocytogenes, salmonella typhimurium, shigella flexneri, staphylococcus aureus, and yersinia enterocolitica were subjected to temperature, acid, an ... | 2004 | 15151241 |
| inactivation of pathogenic bacteria by cucumber volatiles (e,z)-2,6-nonadienal and (e)-2-nonenal. | the effects of (e,z)-2,6-nonadienal (nde) and (e)-2-nonenal (ne) on bacillus cereus, escherichia coli o157:h7, listeria monocytogenes, and salmonella typhimurium were investigated. a suspension of each organism of 6 to 9 log cfu/ml was incubated for 1 h at 37 degrees c in brain heart infusion solution that contained 0 to 500 or 1,000 ppm of nde or ne. depending on concentration, exposure to either nde or ne caused a reduction in cfu of each organism. treatment with 250 and 500 ppm nde completely ... | 2004 | 15151242 |
| evaluation of nisin-coated cellulose casings for the control of listeria monocytogenes inoculated onto the surface of commercially prepared frankfurters. | commercially prepared frankfurters were formulated with and without approximately 1.4% potassium lactate and 0.1% sodium diacetate and were subsequently processed in cellulose casings coated with and without nisin (approximately 50,000 iu per square inch of internal surface area) to control the outgrowth of listeria monocytogenes during refrigerated storage. the frankfurters were inoculated with approximately 5 log cfu per package of a five-strain mixture of l. monocytogenes and then vacuum seal ... | 2004 | 15151243 |
| prevalence and growth of listeria on naturally contaminated smoked salmon over 28 days of storage at 4 degrees c. | only limited data are available on the growth characteristics of listeria in naturally contaminated ready-to-eat foods. to evaluate listeria contamination patterns and growth in smoked salmon, 72 smoked salmon product samples from two processing plants were tested for listeria spp. and l. monocytogenes. samples were divided into four approximately equal portions: one portion was tested on receipt, and the other three were vacuum sealed and stored at 4 degrees c for 7, 14, and 28 days. listeria t ... | 2004 | 15151244 |
| role of flagellin and the two-component chea/chey system of listeria monocytogenes in host cell invasion and virulence. | the flagellum protein flagellin of listeria monocytogenes is encoded by the flaa gene. immediately downstream of flaa, two genes, chey and chea, encoding products with homology to chemotaxis proteins of other bacteria, are located. in this study we constructed deletion mutants with mutations in flaa. chey, and chea to elucidate their role in the biology of infection with l. monocytogenes. the deltachey, deltachea, and double-mutant deltacheya mutants, but not deltaflaa mutant, were motile in liq ... | 2004 | 15155625 |
| cpg oligodeoxynucleotides improve the survival of pregnant and fetal mice following listeria monocytogenes infection. | listeria infection during pregnancy can cause the death of both mother and fetus. previous studies established that immunostimulatory cpg oligodeoxynucleotides (odn) increase the resistance of healthy adult mice to many infectious pathogens, including listeria monocytogenes. this study examines whether the innate immune response elicited by cpg odn can reduce the susceptibility of pregnant mice to lethal listeria challenge. the results indicate that cpg odn treatment significantly improves mater ... | 2004 | 15155663 |
| purification of bacteriocins produced by lactic acid bacteria. | bacteriocins are antibacterial substances of a proteinaceous nature that are produced by different bacterial species. lactic acid bacteria (lab) produce biologically active peptides or protein complexes that display a bactericidal mode of action almost exclusively toward gram-positive bacteria and particularly toward closely related species. generally they are active against food spoilage and foodborne pathogenic microorganisms including bacillus cereus, clostridium perfringens, staphylococcus a ... | 2004 | 15156043 |