Publications
| Title | Abstract | Year Filter | PMID(sorted ascending) Filter |
|---|
| listeria species in raw and ready-to-eat foods from restaurants. | from september 1999 to march 2000, meat (pork, beef, and chicken), fish (salmon, hake, and sole), vegetable (lettuce and spinach), and spanish potato omelette samples obtained at restaurants were collected and tested for the occurrence of listeria spp. listeria monocytogenes was isolated from 3 (2.9%) out of 103 studied samples. other species isolated were listeria grayi (13.6%), listeria innocua (1.9%), listeria ivanovii (5.8%), listeria seeligeri (3.9%), and listeria welshimeri (1.9%). listeri ... | 2001 | 11307896 |
| incidence and characterization of listeria spp. from foods available in korea. | a total of 410 domestic korean food samples were analyzed for the presence of listeria spp. by the conventional u.s. department of agriculture protocol, and presumptive strains were identified by morphological, cultural and biochemical tests according to bergey's manual and confirmed by api-listeria kit. among the total 410 food samples, 46 samples (11.2%) were found to be contaminated with listeria species. among the 46 strains of listeria spp. isolates, 8 strains (17.42%) for listeria monocyto ... | 2001 | 11307897 |
| antibiotic resistance among listeria, including listeria monocytogenes, in retail foods. | in the past eight to 10 years, reports of antibiotic resistance in food-borne isolates in many countries have increased, and this work examined the susceptibility of 1001 food isolates of listeria species. | 2001 | 11309061 |
| thermal resistance of wild-type and antibiotic-resistant listeria monocytogenes in meat and potato substrates. | this study aimed to elucidate the relationship, if any, between the acquisition/possession of antibiotic resistance in strains of listeria monocytogenes and the resistance of such strains to heat stress. | 2001 | 11309067 |
| rapid detection of listeria monocytogenes in ham samples using immunomagnetic separation followed by polymerase chain reaction. | to develop a 24-h system for the detection of listeria monocytogenes in ham. | 2001 | 11309074 |
| a glutamate decarboxylase system protects listeria monocytogenes in gastric fluid. | we observed that glutamate greatly enhances the survival of listeria monocytogenes in gastric fluid, a phenomenon that is directly linked to glutamate decarboxylase activity (gad). glutamate-mediated acid tolerance has been associated in other intestinal genera with the gad system, in which glutamate is internalized and converted to gamma-aminobutyrate (consuming an intracellular proton) that is subsequently exchanged for another extracellular glutamate via a membrane-located antiporter. molecul ... | 2001 | 11309128 |
| contribution of mhc class i-dependent immune mechanisms induced by attenuated recombinant salmonella typhimurium secreting superoxide dismutase to protection against murine listeriosis. | a recombinant (r)salmonella typhimurium aroa strain secreting the naturally non-secreted superoxide dismutase (sod) of listeria monocytogenes controls murine listeriosis dependent on 'transporter associated with antigen processing' (tap)-mediated immune mechanisms. tap1-deficient mice (devoid of most cd8 t cells) vaccinated with this rsalmonella sods strain succumbed to lethal l. monocytogenes challenge, whereas c57bl/6 mice were protected by this vaccine. moreover, vaccination of h-2i-abeta-def ... | 2001 | 11312024 |
| characterisation of a listeria monocytogenes mutant deficient in d-arabitol fermentation. | we selected and analysed a tn917-lac listeria monocytogenes mutant deficient in d-arabitol fermentation. comparison of the 310-aa-long translated partial sequence of the disrupted gene with known proteins showed similarity with the phosphotransferase system galactitol-specific enzyme iic component of the alkaliphilic bacillus halodurans (50% identity) and of escherichia coli (36% identity). fermentation of 18 other carbohydrates was unimpaired, suggesting the specificity of this transmembrane pe ... | 2001 | 11316371 |
| comparison of logistic regression and linear regression in modeling percentage data. | percentage is widely used to describe different results in food microbiology, e.g., probability of microbial growth, percent inactivated, and percent of positive samples. four sets of percentage data, percent-growth-positive, germination extent, probability for one cell to grow, and maximum fraction of positive tubes, were obtained from our own experiments and the literature. these data were modeled using linear and logistic regression. five methods were used to compare the goodness of fit of th ... | 2001 | 11319091 |
| morphological and physiological characterization of listeria monocytogenes subjected to high hydrostatic pressure. | high hydrostatic pressure is a new food preservation technology known for its capacity to inactivate spoilage and pathogenic microorganisms. that inactivation is usually assessed by the number of colonies growing on solid media after treatment. under normal conditions the method does not permit recovery of damaged cells and may underestimate the number of cells that will remain viable and grow after a few days in high-pressure-processed foodstuffs. this study investigated the damage inflicted on ... | 2001 | 11319107 |
| comparative genetic characterization of listeria monocytogenes isolates from human and animal listeriosis cases. | listeria monocytogenes isolates from human sporadic and epidemic cases (n=119) and from animal cases (n=76) were characterized by automated ribotyping and pcr-restriction fragment length polymorphism (pcr-rflp) typing of the virulence genes acta and hly. this combination of typing methods differentiated 39 distinctive strains, each reflecting a unique combination of ribotypes, hly and acta alleles. simpson's index of discrimination indicated a high discriminatory ability of ribotyping for both a ... | 2001 | 11320113 |
| pulsenet standardized protocol for subtyping listeria monocytogenes by macrorestriction and pulsed-field gel electrophoresis. | pulsenet is a national network of pubic health and food regulatory laboratories established in the us to detect clusters of foodborne disease and respond quickly to foodborne outbreak investigations. pulsenet laboratories currently subtype escherichia coli o157:h7, non-typhoidal salmonella, and shigella isolates by a highly standardized 1-day pulsed-field gel electrophoresis (pfge), and exchange normalized dna "fingerprint" patterns via the internet. we describe a standardized molecular subtypin ... | 2001 | 11322701 |
| occurrence of listeria species in retail poultry meat and comparison of a cultural/immunoassay for their detection. | the prevalence of listeria spp. on the skin of a hundred fresh chicken carcasses purchased from 20 retail stores in león was investigated using the routine test procedure recommended by the united states department of agriculture (usda). palcam and modified oxford agar (mox) were used for isolation. listeria spp., listeria monocytogenes, l. innocua, l. welshimeri, l. grayi and l. ivanovii were present in 95%, 32%, 66%, 7%, 4% and 2% of the samples, respectively. next, an immunoassay test (lister ... | 2001 | 11322703 |
| diversity of listeria monocytogenes isolates from cold-smoked salmon produced in different smokehouses as assessed by random amplified polymorphic dna analyses. | one hundred and forty-eight listeria monocytogenes isolates originating from vacuum packed cold-smoked salmon produced in 10 different danish smokehouses were compared by random amplified polymorphic dna (rapd) profiling. a total of 16 different reproducible rapd profiles were obtained using a standardised rapd analysis by four primers separately. the grouping of the 148 strains was exactly the same for the four primers used. for a sub-set of 20 strains typed by pulsed field gel electrophoresis ... | 2001 | 11322704 |
| the innate immune response to bacterial flagellin is mediated by toll-like receptor 5. | the innate immune system recognizes pathogen-associated molecular patterns (pamps) that are expressed on infectious agents, but not on the host. toll-like receptors (tlrs) recognize pamps and mediate the production of cytokines necessary for the development of effective immunity. flagellin, a principal component of bacterial flagella, is a virulence factor that is recognized by the innate immune system in organisms as diverse as flies, plants and mammals. here we report that mammalian tlr5 recog ... | 2001 | 11323673 |
| the cd8 response on autopilot. | 2001 | 11323687 | |
| in vitro antibacterial activity of some aliphatic aldehydes from olea europaea l. | in the present paper we report the 'in vitro' activity of eight aliphatic long-chain aldehydes from olive flavor (hexanal, nonanal, (e)-2-hexenal, (e)-2-eptenal, (e)-2-octenal, (e)-2-nonenal, (e)-2-decenal and (e,e)-2,4-decadienal) against a number of standard and freshly isolated bacterial strains that may be causal agents of human intestinal and respiratory tract infections. the saturated aldehydes characterized in the present study do not exhibit significant antibacterial activity, while the ... | 2001 | 11325546 |
| mechanisms underlying antigen-specific cd8+ t cell homeostasis. | 2001 | 11326087 | |
| comparison of sludge and clinical isolates of listeria monocytogenes. | listeria monocytogenes strains isolated in the same geographical area from sewage sludge and from patients presenting with listeriosis were compared. | 2001 | 11328501 |
| [clinical and laboratory diagnosis of listeria monocytogenes on the basis of own investigations]. | the authors have described the issues surrounding listeria monocytogenes infection with reference to cases diagnosed and managed during the 5-year period (1995-2000) in the clinical department of neonatal pathology and intensive care of the national institute of mother and child in warsaw. four cases of congenital listeriosis have been diagnosed. some mothers presented with "flu-like" symptoms. all mothers delivered prematurely (29 hbd - 32 hbd). among the 4 infants the most common clinical feat ... | 2000 | 11328973 |
| uva exposure affects uvb and cis-urocanic acid-induced systemic suppression of immune responses in listeria monocytogenes-infected balb/c mice. | ultraviolet radiation can inhibit immune responses locally as well as systemically. such effects have been measured in animals and humans exposed to ultraviolet b (wavelength 280-315 nm) (uvb) and ultraviolet a (315-400 nm) (uva). the precise wavelength dependence is important for the identification of possible molecular targets and for assessments of risk of different artificial uv sources and solar uv. in such analyses, it is commonly assumed that radiation energy from each wavelength contribu ... | 2001 | 11332040 |
| evolution and function of the neisserial dam-replacing gene. | phase variation through slippage-like mechanisms involving homopolymeric tracts depends in part on the absence of dam-methylase in several pathogenic isolates of neisseria meningitidis. in dam-defective strains drg (dam-replacing gene), flanked by pseudo-transposable small repeated elements (sres), replaced dam. we demonstrate that drg encodes a restriction endonuclease (nmebii) that cleaves 5'-gmeatc-3'. drg is also present in 50% of neisseria lactamica strains, but in most of them it is inacti ... | 2001 | 11334887 |
| stimulation of myelopoiesis in listeria monocytogenes-infected mice by an aggregated polymer isolated from aspergillus oryzae. | in this work, we investigated the effects of the proteic aggregated polymer of magnesium ammonium phospholinoleate-palmitoleate anhydride (mapa) isolated from aspergillus oryzae on the growth and differentiation of bone marrow granulocyte-macrophage progenitor cells (cfu-gm) in listeriamonocytogenes-infected mice. a significant reduction in the cfu-gm number was observed in the initial phase of infection with a sublethal dose of listeria. treatment of mice with 0.5, 2.0 and 5.0 mg/kg mapa for 7 ... | 2001 | 11339624 |
| cutting edge: antigen-independent cd8 t cell proliferation. | recent analyses of cd8 t cell responses to listeria monocytogenes infection demonstrate that the duration of in vivo t cell proliferation is not determined by the amount or duration of ag presentation. however, the extent to which t lymphocytes are capable of proliferating in the absence of ag is unknown. herein we demonstrate that cd8 t lymphocytes undergo up to eight rounds of proliferation in the absence of ag following transient, 2.5-h in vitro antigenic stimulation. ag-independent expansion ... | 2001 | 11342598 |
| antibacterial mechanisms of the lower respiratory tract. i. immunoglobulin synthesis and secretion. | immunoglobulin synthesis and secretion have been studied in the rabbit lower respiratory tract, both in the normal state and after infection with diplococcus pneumoniae or listeria monocytogenes. in vitro synthesis of immunoglobulin and specific antibody was assessed by incorporation of 14c-labeled amino acids into protein. lower respiratory tract secretions and serum were analyzed for immunoglobulin and antibody against the infecting organism. normal respiratory tract produced small quantities ... | 1974 | 11344547 |
| leukocyte antimicrobial function in patients with leprosy. | patients with lepromatous leprosy are unresponsive to lepromin skin-test material and possess defective lymphocyte function in vitro, including impaired mitogenesis in response to antigens of mycobacterium leprae. it has been claimed that their macrophages cannot digest m. leprae in vitro; such a defect could explain both lepromin nonreactivity and impaired lymphocyte function on the basis of failure of the afferent limb of the immune response (i.e., defective macrophage "processing" of m. lepra ... | 1974 | 11344550 |
| two novel genes find and lind differentially expressed in deactivated and listeria-infected human macrophages. | deactivation of macrophage functions plays an important role in human infectious and inflammatory diseases. in this study, differential-display rt-pcr was used to analyze the gene expression of human mononuclear phagocytes deactivated with interleukin (il)-4, il-10, and dexamethasone (dex), in the absence and presence of infection with listeria monocytogenes (listeria). two novel differentially expressed mrna species were discovered: find (il-four induced) was upregulated with il-4 but down-regu ... | 2001 | 11345586 |
| phagocytosis and clearance of apoptotic cells is mediated by mer. | apoptosis is fundamental to the development and maintenance of animal tissues and the immune system. rapid clearance of apoptotic cells by macrophages is important to inhibit inflammation and autoimmune responses against intracellular antigens. here we report a new function for mer, a member of the axl/mer/tyro3 receptor tyrosine kinase family. mer(kd) mice with a cytoplasmic truncation of mer had macrophages deficient in the clearance of apoptotic thymocytes. this was corrected in chimaeric mic ... | 2001 | 11346799 |
| evaluation of the bacteriological quality of ice cream sold at san jose, costa rica. | the presence of total and fecal coliforms, e. coli, listeria sp and salmonella sp. was evaluated in 65 samples of both commercial and homemade ice cream. 37.1% of homemade ice cream and 20% of commercial ice cream did not fulfill the international standard for total coliforms. at the same time 82.9% of home made samples and 56.7% of commercial ones presented fecal coliforms. e. coli was found in 51.4% of home made samples and 26.7% of commercial ones. sixteen listeria sp. isolates were obtained, ... | 2000 | 11347303 |
| evaluation of surface contamination and the presence of listeria monocytogenes in fish processing factories. | the main objective of this study was to determine the level of surface contamination in fish processing factories and the presence of listeria in the factory environment and products. another objective was evaluation of the different hygiene-monitoring methods. total aerobic heterotrophic and enterobacteria, yeast and mold samples were collected and atp levels measured in 28 factories. the number of well or adequately washed and disinfected factories was small (2 of 28), in terms of total aerobi ... | 2001 | 11347992 |
| enhanced inhibition of listeria monocytogenes and salmonella enteritidis in meat by combinations of sodium lactate and diacetate. | the antimicrobial activities of sodium lactate (sl) and sodium acetate (sa) are well documented, but there is limited information on the effect of their combination or of the combination of sl and sodium diacetate (sda) on survival and growth of listeria monocytogenes and salmonellae in meat. effects of sl (1.8 and 2.5%), sda (0.1 and 0.2%), or sa (0.2%) and their combinations on the behavior of l monocytogenes and salmonella enterica serovar enteritidis were investigated in sterile comminuted b ... | 2001 | 11347993 |
| random amplified polymorphic dna typing applied to the study of cross-contamination by listeria monocytogenes in processed food products. | the presence of listeria spp. was investigated in 369 samples of cooked meat products and 52 of smoked salmon. incidences of 17.6% for cooked meat and 38.5% for smoked salmon samples were found. all listeria monocytogenes isolates (34 from meat products and 16 from smoked salmon) were typed serologically and by random amplified polymorphic dna (rapd) typing using primers hlwl74 (5'-acgtatctgc-3'), hlwl85 (5'-acaactgctc-3'), and omp-01 (5'-gti'ggtggct-3'). strains from cooked meat products were c ... | 2001 | 11348007 |
| effects of epiphytic enterobacteriaceae and pseudomonads on the growth of listeria monocytogenes in model media. | four enterobacteriaceae (enterobacter agglomerans and rhanella aquatilis) and six pseudomonads (pseudomonas fluorescens, pseudomonas chlororaphis, pseudomonas putida) isolated from minimally processed green endive were coinoculated at 10 degrees c with listeria monocytogenes in a minimal medium. pseudomonads did not modify the growth of l. monocytogenes, whereas enterobacteriaceae reduced its maximal population by 2 to 3 log cfu/ml. the same effect was observed in a diluted yeast extract medium ... | 2001 | 11348008 |
| immunization of mice with lipopeptide antigens encapsulated in novel liposomes prepared from the polar lipids of various archaeobacteria elicits rapid and prolonged specific protective immunity against infection with the facultative intracellular pathogen, listeria monocytogenes. | protective immunity to intracellular bacterial pathogens usually requires the participation of specific cd8+ t cells. natural exposure of the host to sublethal infection, or vaccination with attenuated live vaccines are the most effective means of eliciting prolonged protective cell-mediated immunity against this class of pathogens. the ability to replace these immunization strategies with defined sub-unit vaccines would represent a major advance for clinical vaccinology. the present study exami ... | 2001 | 11348718 |
| gut colonization of mice with acta-negative mutant of listeria monocytogenes can stimulate a humoral mucosal immune response. | we used listeria monocytogenes, a gram-positive, facultative intracellular bacterium, to study the gut mucosal immune responses following oral infection. we employed a germfree (gf) mouse model to try to accentuate the development of a humoral mucosal immune response in the gut, and we used oral colonization with one of the mutants, acta-negative (deltaacta) l. monocytogenes, to restrict infection largely to the gut. the deltaacta mutant was able to colonize the intestinal mucosa of formerly gf ... | 2001 | 11349011 |
| calprotectin expression inhibits bacterial binding to mucosal epithelial cells. | squamous mucosal epithelial cells constitutively express calprotectin in the cytoplasm. to study how this antimicrobial protein complex confers epithelial resistance to invading bacteria, an epithelial cell line was stably transfected to express the calprotectin complex. cells expressing calprotectin resist invasion by listeria monocytogenes and salmonella enterica serovar typhimurium. calprotectin expression was accompanied by altered actin organization, increased alpha3 integrin expression, an ... | 2001 | 11349032 |
| characterization of the groesl operon in listeria monocytogenes: utilization of two reporter systems (gfp and hly) for evaluating in vivo expression. | the ability of intracellular pathogens to sense and adapt to the hostile environment of the host is an important factor governing virulence. we have sequenced the operon encoding the major heat shock proteins groes and groel in the gram-positive food-borne pathogen listeria monocytogenes. the operon has a conserved orientation in the order groes groel. upstream of groes and in the opposite orientation is a gene encoding a homologue of the bacillus subtilis protein ydil, while downstream of groel ... | 2001 | 11349060 |
| gene fragments distinguishing an epidemic-associated strain from a virulent prototype strain of listeria monocytogenes belong to a distinct functional subset of genes and partially cross-hybridize with other listeria species. | most major food-borne outbreaks of listeriosis in europe and in the united states have been caused by genetically closely related listeria monocytogenes strains of serotype 4b. in order to assess whether genomic loci exist that could underlie this increased epidemic potential, we subtracted the genome of the virulent prototype l. monocytogenes strain egd from a prototype epidemic strain. a total of 39 dna fragments corresponding to 20% of an estimated total of 150 to 190 kb of differential genom ... | 2001 | 11349066 |
| nitric oxide is protective in listeric meningoencephalitis of rats. | the bacterium listeria monocytogenes causes meningoencephalitis in humans. in rodents, listeriosis is associated with granulomatous lesions in the liver and the spleen, but not with meningoencephalitis. here, infant rats were infected intracisternally to generate experimental listeric meningoencephalitis. dose-dependent effects of intracisternal inoculation with l. monocytogenes on survival and activity were noted; 10(4) l. monocytogenes organisms induced a self-limiting brain infection. bacteri ... | 2001 | 11349080 |
| gp96-peptide vaccination of mice against intracellular bacteria. | this work demonstrates that gp96 preparations isolated from cells infected with intracellular bacteria induce cytotoxic t-lymphocyte responses and confer protection. our findings extend previous reports on the immunogenicity of gp96-associated peptides to antigens derived from intracellular bacteria. immunization with gp96 may therefore represent a promising vaccination strategy against bacterial pathogens. | 2001 | 11349093 |
| [genetic mechanisms of listeria monocytogenes virulence]. | current data on genetic determinants of virulence in listeria monocytogenes and on factors affecting their expression are reviewed. the role of the prfa protein, the only known transcriptional regulator that directly affects virulence gene expression and mechanisms responsible for the activity and/or concentration of this protein in the cell are considered. detailed information of outer signals modulating the level of virulence factor expression is provided. data that favor the involvement of au ... | 2001 | 11357361 |
| listeriolysin--a useful cytolysin. | 2001 | 11357827 | |
| the act operon controls the level and time of c-signal production for myxococcus xanthus development. | the c-signal is a morphogen that controls the assembly of fruiting bodies and the differentiation of myxospores. production of this signal, which is encoded by the csga gene, is regulated by the act operon of four genes that are co-transcribed from the same start site. the act a and act b genes regulate the maximum level of the c-signal, which never rises above one-quarter of the maximum wild-type level of csga protein in null mutants of either gene. the act a and act b mutants have the same dev ... | 2001 | 11359579 |
| effect of silica inhalation on the pulmonary clearance of a bacterial pathogen in fischer 344 rats. | silica inhalation predisposes workers to bacterial infection and impairments in pulmonary defense function. in this study, we evaluated the effect of pre-exposure to silica on lung defense mechanisms by use of a rat pulmonary listeria monocytogenes infection model. male fischer 344 rats were exposed by inhalation to filtered air or silica (15 mg/m3 x 6 h/day x 5 days/wk). after 21 or 59 days of silica exposure, the rats were inoculated intratracheally with 5 x 10(3) l. monocytogenes. at 0 (nonin ... | 2000 | 11361057 |
| poppers: more evidence of suppressed immunity. | evidence from studies in mice shows that exposure to isobutyl nitrite suppresses the immune system. this immune suppression allows for bacterial growth in the lungs and livers of infected mice and can inhibit the ability of mediastinal lymph nodes to respond to antigen-specific stimulation. the mechanism for immune suppression may be a reduction in cd4+ and cd8+ t cell populations in the mediastinal lymph nodes following pulmonary infection with listeria monocytogenes. | 1999 | 11366577 |
| searching for the holy grail: hiv vaccine development in the new millennium. | many reasons for the difficulty in developing an hiv vaccine were discussed at the 5th national symposium on basic aspects of vaccines. the april 1999 conference was attended by nearly 200 researchers. speakers included dr. neal nathanson of the national institutes of health (nih), who called hiv "particularly insidious." topics included envelope glycoproteins; enhancing ctl responses; soluble cd40 ligand trimer and its effect on growth of antigen-specific t cells; responses of immunized monkeys ... | 1999 | 11367310 |
| intracellular antibody neutralizes listeria growth. | we previously reported that treatment of mice with a neutralizing mab against listeriolysin o (llo), the pore-forming toxin of listeria monocytogenes, provided resistance to this intracellular bacterium. we evaluated whether anti-llo mab would affect listeria handling by macrophages, essential cells in listeria resistance. macrophages infected in the presence of anti-llo mab showed a marked reduction in intracellular listeria growth, with a concomitant block in llo-dependent listeria passage fro ... | 2001 | 11371353 |
| influence of the natural microbial flora on the acid tolerance response of listeria monocytogenes in a model system of fresh meat decontamination fluids. | depending on its composition and metabolic activity, the natural flora that may be established in a meat plant environment can affect the survival, growth, and acid tolerance response (atr) of bacterial pathogens present in the same niche. to investigate this hypothesis, changes in populations and atr of inoculated (10(5) cfu/ml) listeria monocytogenes were evaluated at 35 degrees c in water (10 or 85 degrees c) or acidic (2% lactic or acetic acid) washings of beef with or without prior filter s ... | 2001 | 11375145 |
| survival and heat resistance of listeria monocytogenes after exposure to alkali and chlorine. | a strain of listeria monocytogenes isolated from a drain in a food-processing plant was demonstrated, by determination of d values, to be more resistant to the lethal effect of heat at 56 or 59 degrees c following incubation for 45 min in tryptose phosphate broth (tpb) at ph 12.0 than to that of incubation for the same time in tpb at ph 7.3. cells survived for at least 6 days when they were suspended in tpb at phs 9.0, 10.0, and 11.0 and stored at 4 or 21 degrees c. cells of l. monocytogenes inc ... | 2001 | 11375163 |
| identification and disruption of the proba locus in listeria monocytogenes: role of proline biosynthesis in salt tolerance and murine infection. | intracellular accumulation of the amino acid proline has previously been linked to the salt tolerance and virulence potential of a number of bacteria. taking advantage of the proba mutant escherichia coli csh26, we identified a listerial proba operon coding for enzymes functionally similar to the glutamyl kinase (gk) and glutamylphosphate reductase (gpr) enzyme complex which catalyzes the first and second steps of proline biosynthesis in e. coli. the first gene of the operon, prob, is predicted ... | 2001 | 11375165 |
| elucidation of listeria monocytogenes contamination routes in cold-smoked salmon processing plants detected by dna-based typing methods. | the contamination routes of listeria monocytogenes in cold-smoked salmon processing plants were investigated by analyzing 3,585 samples from products (produced in 1995, 1996, 1998, and 1999) and processing environments (samples obtained in 1998 and 1999) of two danish smokehouses. the level of product contamination in plant i varied from 31 to 85%, and no l. monocytogenes was found on raw fish (30 fish were sampled). in plant ii, the levels of both raw fish and product contamination varied from ... | 2001 | 11375167 |
| analysis of the role of opuc, an osmolyte transport system, in salt tolerance and virulence potential of listeria monocytogenes. | the success of listeria monocytogenes as a food-borne pathogen owes much to its ability to survive a variety of stresses, both in the external environment prior to ingestion and subsequently within the animal host. growth at high salt concentrations and low temperatures is attributed mainly to the accumulation of organic solutes such as glycine betaine and carnitine. we utilized a novel system for generating chromosomal mutations (based on a lactococcal pwvo1-derived ori(+) repa(-) vector, pori1 ... | 2001 | 11375182 |
| mechanism of actin-based motility. | spatially controlled polymerization of actin is at the origin of cell motility and is responsible for the formation of cellular protrusions like lamellipodia. the pathogens listeria monocytogenes and shigella flexneri, which undergo actin-based propulsion, are acknowledged models of the leading edge of lamellipodia. actin-based motility of the bacteria or of functionalized microspheres can be reconstituted in vitro from only five pure proteins. movement results from the regulated site-directed t ... | 2001 | 11379633 |
| pulsenet: the molecular subtyping network for foodborne bacterial disease surveillance, united states. | pulsenet, the national molecular subtyping network for foodborne disease surveillance, was established by the centers for disease control and prevention and several state health department laboratories to facilitate subtyping bacterial foodborne pathogens for epidemiologic purposes. pulsenet, which began in 1996 with 10 laboratories typing a single pathogen (escherichia coli o157:h7), now includes 46 state and 2 local public health laboratories and the food safety laboratories of the u.s. food a ... | 2001 | 11384513 |
| immunology. brief encounter. | 2001 | 11385554 | |
| microbiology. cracking listeria's password. | 2001 | 11387462 | |
| a transgenic model for listeriosis: role of internalin in crossing the intestinal barrier. | listeria monocytogenes is responsible for severe food-borne infections, but the mechanisms by which bacteria cross the intestinal barrier are unknown. listeria monocytogenes expresses a surface protein, internalin, that interacts with a host receptor, e-cadherin, to promote entry into human epithelial cells. murine e-cadherin, in contrast to guinea pig e-cadherin, does not interact with internalin, excluding the mouse as a model for addressing internalin function in vivo. in guinea pigs and tran ... | 2001 | 11387478 |
| analysis of sigma(54)-dependent genes in enterococcus faecalis: a mannose pts permease (eii(man)) is involved in sensitivity to a bacteriocin, mesentericin y105. | the sigma(54) rna polymerase subunit has a prominent role in susceptibility of listeria monocytogenes and enterococcus faecalis to mesentericin y105, a class iia bacteriocin. consequently, sigma(54)-dependent genes as well as specific activators also required for expression of these genes were sought. five putative sigma(54)-associated activators were detected in the genome of e. faecalis v583, and all but one could activate the transcription of permease genes belonging to sugar phosphotransfera ... | 2001 | 11390688 |
| [isolation of pathogenic bacteria in pasteurized type c milk sold in recife city, pernambuco, brazil]. | in order to improve information about the microbiological quality of the milk commercially available in the city of recife, 250 samples of pasteurized type-c milk and 50 samples of raw milk were analyzed for yersinia enterocolitica and listeria monocytogenes and verify the possible occurrence of yersinia enterocolitica and listeria monocytogenes. these bacteria can develop in refrigeration temperatures and are responsible for food-born diseases. neither y. enterocolitica nor l. monocytogenes wer ... | 2001 | 11391438 |
| listeria monocytogenes lineage group classification by mama-pcr of the listeriolysin gene. | nucleotide sequence differences within several virulence genes, including the listeriolysin o (hly) gene, are associated with three evolutionary lineage groups of listeria monocytogenes. because the ability of l. monocytogenes to cause disease may vary by evolutionary lineage group, rapid discrimination among the three lineage types may be important for estimating pathogenic potential. a mismatch amplification mutation assay (mama) was developed and used to rapidly screen and characterize l. mon ... | 2001 | 11391477 |
| can food-related environmental factors induce different behaviour in two key serovars, 4b and 1/2a, of listeria monocytogenes? | listeria monocytogenes isolates (81 in total; 42 isolated from cases of human listeriosis: 39 isolated from food), belonging to serovars 1/2a or 4b, were studied for any group differences between serovars to selected factors associated with foods (two bacteriocins and mild heat treatment), growth kinetics at 37 degrees c and pathogenicity for chick embryos. the isolates were tested for sensitivity to two bacteriocins at 4 degrees c and 37 degrees c, and were tested for the remaining parameters b ... | 2001 | 11393689 |
| diesel exhaust particles suppress macrophage function and slow the pulmonary clearance of listeria monocytogenes in rats. | in this study, we tested the hypothesis that exposure to diesel exhaust particles (dep) may increase susceptibility of the host to pulmonary infection. male sprague-dawley rats received a single dose of dep (5 mg/kg), carbon black (cb, 5 mg/kg), or saline intratracheally. three days later, the rats were inoculated intratracheally with approximately 5,000 listeria monocytogenes and sacrificed at 3, 5, and 7 days postinfection, and we determined the number of viable listeria in the left lobe of lu ... | 2001 | 11401764 |
| endogenous interleukin-10 is required for prevention of a hyperinflammatory intracerebral immune response in listeria monocytogenes meningoencephalitis. | to analyze the role of interleukin-10 (il-10) in bacterial cerebral infections, we studied cerebral listeriosis in il-10-deficient (il-10(-/-)) and wild-type (wt) mice, the latter of which express high levels of il-10 in both primary and secondary cerebral listeriosis. il-10(-/-) mice succumbed to primary as well as secondary listeriosis, whereas wt mice were significantly protected from secondary listeriosis by prior intraperitoneal immunization with listeria monocytogenes. meningoencephalitis ... | 2001 | 11402000 |
| variation in the infectivity of listeria monocytogenes isolates following intragastric inoculation of mice. | the infectivities of 66 listeria monocytogenes isolates were assessed by intragastric inoculation of mice. eight were poorly infective. serovars 4b and 1/2 were more infective than serovars 3 and 4nonb. a noninfective isolate was cleared more rapidly from the cecum than were infective isolates, suggesting that survival in the gut may relate to infectivity. | 2001 | 11402011 |
| inactivation of escherichia coli o1 57:h7, listeria monocytogenes, and lactobacillus leichmannii by combinations of ozone and pulsed electric field. | pulsed electric field (pef) and ozone technologies are nonthermal processing methods with potential applications in the food industry. this research was performed to explore the potential synergy between ozone and pef treatments against selected foodborne bacteria. cells of lactobacillus leichmannii atcc 4797, escherichia coli o157:h7 atcc 35150, and listeria monocytogenes scott a were suspended in 0.1% nacl and treated with ozone, pef, and ozone plus pee cells were treated with 0.25 to 1.00 mic ... | 2001 | 11403125 |
| evaluation of a polymerase chain reaction-based system for detection of salmonella enteritidis, escherichia coli o157:h7, listeria spp., and listeria monocytogenes on fresh fruits and vegetables. | a polymerase chain reaction (pcr)-based detection system, bax, was evaluated for its sensitivity in detecting salmonella enteritidis, escherichia coli o157:h7, listeria sp., and listeria monocytogenes on fresh produce. fifteen different types of produce (alfalfa sprouts, green peppers, parsley, white cabbage, radishes, onions, carrots, mushrooms, leaf lettuce, tomatoes, strawberries, cantaloupe, mango, apples, and oranges) were inoculated, in separate studies, with salmonella enteritidis, e. col ... | 2001 | 11403127 |
| validation of a 5-log10 reduction of listeria monocytogenes following simulated commercial processing of lebanon bologna in a model system. | recently, numerous product recalls and one devastating outbreak that claimed 21 lives were attributed to listeria monocytogenes in ready-to-eat meat products. consequently, the food safety and inspection service published a federal register notice requiring manufacturers of ready-to-eat meat and poultry products to reassess their hazard analysis and critical control point plans for these products as specified in 9 cfr 417.4(a). lebanon bologna is a moist, fermented ready-to-eat sausage. because ... | 2001 | 11403142 |
| antimicrobial effects of corn zein films impregnated with nisin, lauric acid, and edta. | bacterial growth during food transport and storage is a problem that may be addressed with packaging materials that release antimicrobials during food contact. in a series of five experiments, edta, lauric acid (la), nisin, and combinations of the three antimicrobial agents were incorporated into a corn zein film and exposed to broth cultures of listeria monocytogenes and salmonella enteritidis for 48 h (sampled at 2, 4, 8, 12, 24, and 48 h). four experiments used starting cultures of 10(8) cfu/ ... | 2001 | 11403145 |
| subtraction hybridization in microplates: an improved method to generate strain-specific pcr primers. | an improved subtraction hybridization technique was developed and evaluated. the hybridization is performed in a microplate with the subtractor-dna immobilized in the plate while the probe-dna is in solution. after hybridization the probe-specific dna can easily be removed from the microwell and submitted to further analysis. this new technique has been successfully applied to generate several strain-specific pcr-primers for lactococcus lactis subsp. lactis, pediococcus spec., saccharomyces spec ... | 2001 | 11403389 |
| intracellular bacteria as targets and carriers for vaccination. | in this review we discuss intracellular bacteria as targets and carriers for vaccines. for clarity and ease of comprehension, we focus on three microbes, mycobacterium tuberculosis, listeria monocytogenes and salmonella, with an emphasis on tuberculosis, one of the leading causes of death from infectious disease. novel vaccination strategies against these pathogens are currently being considered. one approach favors the use of live attenuated vaccines and vaccine carrier strains thereof, either ... | 2001 | 11405217 |
| bacteria-mediated transfer of eukaryotic expression plasmids into mammalian host cells. | invasive intracellular bacteria are able to transfer eukaryotic expression plasmids into mammalian host cells in vitro and in vivo. this can be used to induce immune responses toward protein antigens encoded by the plasmid or to complement genetic defects. plasmid transfer takes place when the recombinant bacterium dies within the host cell, either due to metabolic attenuation or induction of autolysis. alternatively, antibiotics can be used and spontaneous transfer has also been observed, indic ... | 2001 | 11405218 |
| [what is your diagnosis? basal meningitis and rhombencephalitis. blood culture positive for listeria monocytogenes]. | 2001 | 11407238 | |
| comparative in vitro activity of abt-773, a novel antibacterial ketolide. | the in vitro activities of abt-773, erythromycin, clarithromycin, and azithromycin were compared. abt-773 was the most active compound against macrolide-susceptible streptococcus pneumoniae, streptococcus pyogenes, staphylococcus aureus, staphylococcus epidermidis, listeria monocytogenes, and enterococcus spp. and multidrug-resistant streptococcus pneumoniae. it also had good activity against gram-negative and atypical respiratory tract pathogens and helicobacter pylori. | 2001 | 11408246 |
| a simple chemiluminescence-based method for rapid enumeration of listeria spp. microcolonies. | listeria monocytogenes is capable, under certain conditions, of producing chemiluminescence which is amplified by luminol. this property was used to detect and count microcolonies of listeria spp. in a few hours, without the use of a microscope. | 2001 | 11412329 |
| comparison of selective and non-selective enrichment media in the detection of listeria monocytogenes from meat containing listeria innocua. | this study investigated whether the higher incidence of recovery from meat of listeria innocua compared with l. monocytogenes could be due to the laboratory media used, leading to an artificially lower detection of the pathogenic species, l. monocytogenes. | 2001 | 11412330 |
| listeria monocytogenes adheres to many materials found in food-processing environments. | to investigate the adhesion of listeria monocytogenes 10403s to 17 different, food-use approved materials representing metals, rubbers and polymers. | 2001 | 11412331 |
| influence of strain and trisodium phosphate concentration on growth parameters of listeria monocytogenes in vitro. | the present study was conducted to determine the influence of strain and trisodium phosphate (tsp) concentration in the growth of listeria monocytogenes in vitro. | 2001 | 11412357 |
| separation of listeria from cheese and enrichment media using antibody-coated microbeads and centrifugation. | an immunoseparation system for the separation of listeria from enriched cheese samples was developed. the system utilizes polystyrene microbeads (3.8 microm in diameter) coated with covalently bound anti-listeria genus-specific antibody. the beads were incubated with cheese enriched in half-fraser broth and the bead-bacterial complex was separated by centrifugation at 110 g then spread on selective agar plates. although cross-reactivity with certain gram-positive bacteria (staphylococcus saproph ... | 2001 | 11412914 |
| evaluation of enhanced haemolysis agar for detection of listeria spp. and l. monocytogenes from production lines of fresh to cold-smoked fish. | enhanced haemolysis agar (eha) was compared to the two conventional listeria isolation agars oxford and palcam for its ability to detect listeria spp. from production lines of fresh to cold-smoked fish. the ability of eha for distinguishing l. monocytogenes colonies from other listeria spp. was also evaluated.a total of 243 fish and environmental samples were analysed. overall, 42 samples were found to contain listeria spp. only 34 samples were positive simultaneously by the three plating media. ... | 2001 | 11412926 |
| functional dichotomy in natural killer cell signaling: vav1-dependent and -independent mechanisms. | the product of the protooncogene vav1 participates in multiple signaling pathways and is a critical regulator of antigen-receptor signaling in b and t lymphocytes, but its role during in vivo natural killer (nk) cell differentiation is not known. here we have studied nk cell development in vav1-/- mice and found that, in contrast to t and nk-t cells, the absolute numbers of phenotypically mature nk cells were not reduced. vav1-/- mice produced normal amounts of interferon (ifn)-gamma in response ... | 2001 | 11413196 |
| gc1q-r/p33, a member of a new class of multifunctional and multicompartmental cellular proteins, is involved in inflammation and infection. | human gc1q-r (p33, p32, c1qbp, tap) is a ubiquitously expressed, multiligand-binding, multicompartmental cellular protein involved in various ligand-mediated cellular responses. although expressed on the surface of cells, an intriguing feature of the membrane-associated form of gc1q-r is that its translated amino acid sequence does not predict the presence of either a sequence motif compatible with a transmembrane segment or a consensus site for a glycosylphosphatidylinositol anchor. moreover, t ... | 2001 | 11414365 |
| protection against murine listeriosis by oral vaccination with recombinant salmonella expressing hybrid yersinia type iii proteins. | in the present study, we have investigated the possibility to engage the yersinia outer protein e (yope) as a carrier molecule for heterologous ag delivery by the type iii secretion system of salmonella typhimurium. defined secretion and translocation domains of yope were fused to the immunodominant t cell ags listeriolysin o and p60 of listeria monocytogenes. in vitro experiments showed that s. typhimurium allows secretion and translocation of large hybrid yope proteins in a type iii-dependent ... | 2001 | 11418671 |
| recurrent listeria monocytogenes infection: relapse or reinfection with a unique strain confirmed by molecular subtyping. | we report a case of recurrent listeriosis for which molecular subtyping by automated ribotyping and pulsed-field gel electrophoresis confirmed either relapse of infection or reinfection due to a common source almost 9 months after initial infection due to a unique listeria monocytogenes strain in a patient with colorectal cancer. this case report illustrates the potential use of molecular subtyping to further understand the pathogenesis and epidemiology of listeriosis and the potential for relap ... | 2001 | 11418887 |
| biological response modifier activity of an exopolysaccharide from paenibacillus jamilae cp-7. | an extracellular polysaccharide was purified from culture supernatants of paenibacillus jamilae cp-7, a gram-positive bacillus that was isolated from compost prepared with olive mill wastewaters. the extracellular polysaccharide was produced under aerobic conditions in a medium containing olive mill wastewaters (80% [vol/vol]). this exopolymer had a low level of acute toxicity when it is administered to balb/c mice by the intraperitoneal route. interesting immunomodulatory effects were detected ... | 2001 | 11427415 |
| correlations between molecular subtyping and serotyping of listeria monocytogenes. | to define relationships between listeria monocytogenes genetic lineages, ribotypes, and serotypes, 235 l. monocytogenes isolates were characterized by serotyping and automated ecori ribotyping. genetic lineage predicted the following serovar clusters: lineage i, comprising serotypes 1/2b, 3b, 3c, and 4b; lineage ii, comprising serotypes 1/2a, 1/2c, and 3a; and lineage iii, comprising serotypes 4a and 4c. some ecori ribotypes contained multiple serotypes; a subset of these isolates was further di ... | 2001 | 11427601 |
| endophthalmitis caused by listeria monocytogenes. | listeria monocytogenes was isolated from the aqueous chamber of an immunodepressed patient with acute hypertensive uveitis, who developed a dark hypopyon and pigment dispersion. no extraocular septic focus was found. treatment was successful with intravitreal vancomycin, anterior chamber irrigation with vancomycin, orally administered ciprofloxacin, and topical fortified vancomycin. | 2001 | 11427612 |
| industrial application of an antilisterial strain of lactobacillus sakei as a protective culture and its effect on the sensory acceptability of cooked, sliced, vacuum-packaged meats. | the application of a protective lactic acid bacterium (lab) during the commercial production of cooked meat products is described. the lab, a strain of lactobacillus sakei, was previously isolated from cooked ham and inhibited growth of listeria monocytogenes and escherichia coli o157:h7 in this product. l. sakei was applied to the cooked products at a concentration of 10(5)-10(6) cfu/g immediately before slicing and vacuum-packaging using a hand-operated spraying bottle. the lab strain inhibite ... | 2001 | 11428578 |
| effects of sodium lactate and other additives in a cooked ham product on sensory quality and development of a strain of lactobacillus curvatus and listeria monocytogenes. | cooked cured ham products were produced according to a standard recipe for cooked ham with various levels of sodium lactate, sodium diacetate or buffered sodium citrate. they were compared with a reference ham product with respect to sensory quality and growth of lactobacillus curvatus and listeria monocytogenes. for this, a part of the products was sensory analysed directly after preparation. another part of the cooked ham products was minced and homogeneously inoculated with l. curvatus (10(4) ... | 2001 | 11428579 |
| listeria monocytogenes tricuspid valve endocarditis with septic pulmonary emboli in a liver transplant recipient. | listeria monocytogenes has long been known as a pathogen of immunocompromised hosts, including solid organ and bone marrow transplant recipients. its principal manifestations include bacteremia and meningitis. endocarditis due to listeria is far less common and in general affects the left side of the heart. we here report an unusual case of listeria tricuspid valve endocarditis and septic pulmonary emboli in a sulfa-intolerant liver transplant recipient with a history of relapsing cytomegaloviru ... | 1999 | 11428999 |
| infections of the central nervous system in transplant recipients. | central nervous system (cns) infections, accounting for 4-29% of cns lesions in transplant recipients, are a significant post-transplant complication. focal cns infectious lesions or brain abscesses have been documented in 0.36-1% of the transplant recipients. mycelial fungi, particularly aspergillus, are by far the most frequent etiologies of post-transplant brain abscesses. bacteria, with the exception of nocardia, are rarely associated with brain abscesses in transplant recipients. time of on ... | 2000 | 11429020 |
| the acid-stress response in lactobacillus sanfranciscensis cb1. | lactobacillus sanfranciscensis cb1, an important sourdough lactic acid bacterium, can withstand low ph after initial exposure to sublethal acidic conditions. the sensitivity to low ph varied according to the type of acid used. treatment of lb: sanfranciscensis cb1 with chloramphenicol during acid adaptation almost completely eliminated the protective effect, suggesting that induction of protein synthesis was required for the acid-tolerance response. two constitutively acid-tolerant mutants, cb1- ... | 2001 | 11429463 |
| listeria pathogenesis and molecular virulence determinants. | the gram-positive bacterium listeria monocytogenes is the causative agent of listeriosis, a highly fatal opportunistic foodborne infection. pregnant women, neonates, the elderly, and debilitated or immunocompromised patients in general are predominantly affected, although the disease can also develop in normal individuals. clinical manifestations of invasive listeriosis are usually severe and include abortion, sepsis, and meningoencephalitis. listeriosis can also manifest as a febrile gastroente ... | 2001 | 11432815 |
| [cerebromeningeal listeriosis associated with a cytolytic hepatitis. first case report in senegal]. | hepatitis due to listeria monocytogenes is uncommon in adults. this report describes the first case observed in senegal. the patient was a 73-year old man presenting listeria-related hepatitis presumably secondary to low-grade meningeal encephalitis. treatment using ampicillin was unsuccessful and the patient died four days after hospitalization. the authors note that the incidence of adult listeriosis has risen constantly for the past twenty years in relation with alcohol abuse, cirrhosis, diab ... | 2000 | 11436588 |
| regulation of virulence genes in listeria. | as in all pathogenic bacteria, virulence of the facultative intracellular listeria species is a multifactorial trait. the expression of the bacterial genes involved in the different steps of the infectious process--invasion, intracellular multiplication and spreading--is temporally and spatially controlled, thus ensuring the presence of the respective gene products at the right moment and place. so far, one network which is involved in the regulation of listerial virulence, the prfa regulon, has ... | 2001 | 11437337 |
| cervical lymphadenitis--a rare case of focal listeriosis. | cervical lymphadenopathy is a condition with a broad differential diagnosis. malignant tumors, allergic reactions, autoimmune diseases as well as various infectious agents can be the cause. we report the case of a 75-year-old man who had a cervical lymphadenopathy without symptoms of infection. the draining lymph nodes were excised. histology revealed a granulomatous abscess and culture yielded pure growth of listeria monocytogenes. because food is occasionally contaminated with l. monocytogenes ... | 2001 | 11440390 |
| cutting edge: ifn-inducible elr- cxc chemokines display defensin-like antimicrobial activity. | recent reports highlighted the chemotactic activities of antimicrobial peptide defensins whose structure, charge, and size resemble chemokines. by assaying representative members of the four known families of chemokines we explored the obverse: whether some chemokines exert antimicrobial activity. in a radial diffusion assay, only recombinant monokine induced by ifn-gamma (mig/cxcl9), ifn-gamma-inducible protein of 10 kda (ip-10/cxcl10), and ifn-inducible t cell alpha chemoattractant (i-tac/cxcl ... | 2001 | 11441062 |
| spontaneous nisin-resistant listeria monocytogenes mutants with increased expression of a putative penicillin-binding protein and their sensitivity to various antibiotics. | a concern regarding the use of bacteriocins, as for example the lantibiotic nisin, for biopreservation of certain food products is the possibility of resistance development and potential cross-resistance to antibiotics in the target organism. the genetic basis for nisin resistance development is as yet unknown. we analyzed changes in gene expression following nisin resistance development in listeria monocytogenes 412 by restriction fragment differential display. the mutant had increased expressi ... | 2001 | 11442339 |
| listeria monocytogenes: a continuing challenge. | as a leading cause of death from a foodborne pathogen, listeria monocytogenes continues to cause sporadic cases and outbreaks of illness. the most recent of these outbreaks in the united states involved consumption of hot dogs, with 101 cases of illness and 21 deaths reported to the centers for disease control and prevention for the years 1998-1999. epidemiologic analysis determined that contamination levels in hot dogs were remarkably low (0.3 cfu [colony-forming units] l monocytogenes serotype ... | 2001 | 11444596 |
| identification and characterization of a novel secreted immunoglobulin binding protein from group a streptococcus. | immunoglobulin binding proteins are one of several pathogenicity factors which have been associated with invasive disease caused by group a streptococci. the surface-bound m and m-like proteins of streptococcus pyogenes are the most characterized of these immunoglobulin binding proteins, and in most cases they bind only a single antibody class. here we report the identification of a novel non-m-type secreted protein, designated siba (for secreted immunoglobulin binding protein from group a strep ... | 2001 | 11447160 |
| stress-induced clpp serine protease of listeria monocytogenes is essential for induction of listeriolysin o-dependent protective immunity. | the stress-induced protease clpp is required for virulence of the facultative intracellular pathogen listeria monocytogenes. we previously found that in the absence of clpp, the virulence of this pathogen was strongly reduced, mainly due to the decreased production of functional listeriolysin o (llo), a major immunodominant virulence factor promoting intracellular growth. in this work, a clpp deletion mutant of l. monocytogenes was used to study the generation of anti-listeria protective immunit ... | 2001 | 11447171 |