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involvement of the cell envelope of listeria monocytogenes in the acquisition of nisin resistance.the involvement of the cell wall in the acquisition of nisin resistance by listeria monocytogenes f6861 and its nisin-resistant mutant was investigated. results indicated that without a cell wall, the acquired nisin resistance of the mutant was lost. cell surface hydrophobicity was shown to correlate with nisin sensitivity; the wild type strain being more hydrophobic than its mutant. the possible role of s-layer proteins in nisin resistance was investigated. examination of strains by freeze-etch ...19968760323
metabolic activities of listeria monocytogenes in the presence of sodium propionate, acetate, lactate and citrate.the effects of sodium propionate, acetate, lactate and citrate on cell proliferation, glucose and oxygen consumption, and atp production in listeria monocytogenes were investigated in growing and resting cells. media ph was 6.7-6.8. growth inhibition increased while glucose consumption continued in the presence of > or = 1% propionate, > or = 3% acetate and > or = 5% lactate in broth during incubation at 35 degrees c, indicating that glucose consumption was uncoupled from cell proliferation. ace ...19968760324
risk assessment of uvb effects on resistance to infectious diseases.the aim of this study was to develop a quantitative risk assessment of lowered resistance to infections in humans due to (solar) ultraviolet b (uvb) exposure. we followed the steps for risk assessment as defined by the u.s. national academy of sciences: (1) hazard identification, (2) dose-response assessment, (3) exposure assessment, and (4) risk characterization. for step 1, the suppressory effects of uvb radiation on the immune system have been reviewed, supplemented with new data, and analyze ...19968760567
[mri and listeria monocytogenes rhombencephalitis].rhombencephalitidis is a serious form of brainstem inflammation, difficult to diagnose on the basis of clinical and laboratory findings alone. we describe the mr appearance of 3 cases of listeria monocytogenes rhombencephalitidis and correlate the findings with clinical information. mr imaging is crucial for early diagnosis of this illness: patchy signal hyperintensity throughout the medulla and cerebellar peduncles on t2 weighted images, always in association with a hypointense dot; numerous ga ...19968760616
occurrence of listeria species in prepacked retail sandwiches.a survey of 725 prepacked sandwiches was conducted examining for the presence on enrichment, and by plate count, of listeria species. sandwiches were found to contain listeria sp. more frequently than their component foods. chicken, beef and bacon fillings were associated with more frequent isolation. salad also was associated with more frequent isolation, but the increase was not significant. on enrichment, over 15% of sandwiches contained listeria species. l. innocua and l. monocytogenes were ...19968760954
transcriptional activation of virulence genes in wild-type strains of listeria monocytogenes in response to a change in the extracellular medium composition.a panel of 103 listeria monocytogenes strains of different origins was examined for haemolysin and lecithinase production in brain-heart infusion (bhi). three distinct phenotypes were observed. phenotype 1 was characterized by low to undetectable levels of expression and was exhibited by almost all strains tested. phenotype 2 expressed high levels of haemolysin and lecithinase and was displayed by five strains: one (p14-a) was a spontaneous mutant derived from a type 1 isolate (p14); the four ot ...19968763623
regulation of virulence gene expression in pathogenic listeria.dynamic interactions between host and pathogen are characteristic of infections caused by intracellular bacteria. this has favoured the evolution of highly effective control systems by which these pathogens regulate the expression of different virulence factors during sequential steps of the infection process. in the case of the facultative intracellular bacterium listeria monocytogenes, these steps involve internalization by eukaryotic cells, lysis of the resulting phagosome, replication as wel ...19968767706
the molecular mechanisms of actin-based intracellular motility by listeria monocytogenes.a key virulence trait of bacteria and viruses that multiply in the cytoplasm of the infected cell is their ability to direct movement intracellularly and to spread from cell-to-cell. intracellular movement is effected by harnessing components of the host microfilament system. this mode of locomotion by intracytoplasmic parasites has recently gained much interest as a model to examine microfilament assembly and function. of the intracellular bacteria employing association with the host cytoskelet ...19968767707
the pathogenesis of infection by listeria monocytogenes.listeria monocytogenes is a gram-positive bacterium responsible for severe infections in human and a large variety of animal species. it is a facultative intracellular pathogen which invades macrophages and most tissue cells of infected hosts where it can proliferate. the molecular basis of this intracellular parasitism has been to a large extent elucidated. the virulence factors, including internalin, listeriolysin o, phospholipases and a bacterial surface protein, acta, are encoded by chromoso ...19968767708
comparison of the antimicrobial activity of deactivated human macrophages challenged with aspergillus fumigatus and listeria monocytogenes.the anticonidial activity of human monocytes deactivated by cytokines interleukin (il)-4 and il-10 and the hormone dexamethasone was studied and compared with antilisterial activity. dexamethasone had the largest effect on the anticonidial activity and suppressed germination-inhibiting activity and elimination of ingested spores by macrophages more than the cytokines did. maximally active concentrations of il-10 had a similar but significantly smaller deactivating effect. il-4, in contrast to il ...19968769631
[the immunogenic and protective properties of the cell wall proteins of listeria monocytogenes].two protein antigens with molecular weights of 58 kd (antigen lm58) and 79/39 kd (antigen lm79/ 39) were isolated from listeria monocytogenes cell wall. only lm79/39 was shown to protect mice from l. monocytogenes infection, increasing their ld50 and survival time. the protective activity of lm79/39 correlated (r = 0.64) with its mitogenic properties and its capacity for activating the production of interleukin-1- and interleukin-2-like factors. more over lm79/ 39 induced more strong than lm58 s ...19968771731
[characteristics of listeria monocytogenes strains isolated in russia and their typing using pulse electrophoresis].on the basis of specially developed scheme for the isolation of listeria strains comprising 2 enrichment stages and the use of growth inhibitors, 128 l. monocytogenes cultures were isolated from clinical material, foodstuffs and sewage water. highly virulent l.monocytogenes strains isolated from clinical material belonged to serovar 4b (54%) and 1/2a (38%), while those isolated from foodstuffs and sewage water belonged to 4b (74%). the restriction analysis of the chromosomal dna of the isolated ...19968771733
listeria monocytogenes endocarditis in a patient with an aortic prosthetic valve.patients with prosthetic cardiac valves have an increased risk of developing bacterial endocarditis. the causative micro-organism in bacterial endocarditis may be a guide to the portal of entry. in this case report, we describe a patient with a prosthetic cardiac valve who suffered from recurrent endocarditis with different micro-organisms from the gastrointestinal tract.19968775747
applications of the bacteriocin, nisin.nisin was first introduced commercially as a food preservative in the uk approximately 30 years ago. first established use was as a preservative in processed cheese products and since then numerous other applications in foods and beverages have been identified. it is currently recognised as a safe food preservative in approximately 50 countries. the established uses of nisin as a preservative in processed cheese, various pasteurised dairy products, and canned vegetables will be briefly reviewed. ...19968775979
a comparative study of unpassaged and animal passaged cultures of listeria monocytogenes in rabbits.variants of a parent culture of listeria monocytogenes were prepared by passaging it several times through rabbits. the resulting isolates (v1 to v6) were investigated and compared with the parent culture with particular emphasis on their phenotypic characters and their pathogenicity for rabbits. the variants maintained the morphological, cultural, biochemical and serological features of the parent strain. although no significant decrease was noted in the total extracellular protein produced, 10 ...19968779534
comparative analysis of 16s and 23s rrna sequences of listeria species.in order to establish the taxonomic value of 16s rrna and 23s rrna for distinguishing listeria species, the complete 23s rrna sequences for all listeria species were determined by using the type strains. we designed and experimentally validated a universal 23s rrna sequencing method, which included pcr amplification of the rdna gene and direct cycle sequencing of the amplicon with eubacterial primers. the results of our sequence comparison indicated that the genus listeria can be divided into tw ...19968782674
taxonomic note: a proposal for reviewing the interpretation of the camp reaction between listeria monocytogenes and rhodococcus equi.the discrepancies between the current description of the camp test between listeria monocytogenes and rhodococcus equi in the latest edition of bergey's manual of determinative bacteriology (l. monocytogenes is described as camp test negative with r. equi) and routine findings (positive reactions are usually described in many laboratories) make it advisable to review the current interpretation of the camp test to avoid confusion among people working in microbiological laboratories. overall, 98.4 ...19968782698
diversity of the polar lipids of the food-borne pathogen listeria monocytogenes.listeria monocytogenes is a gram-positive bacterium that can adapt to high salinity and cold. because the membrane lipids may play a role in its survival and adaptation, we have examined the polar lipids of l. monocytogenes. extraction of total lipids from l. monocytogenes yielded 7 +/- 1 mg/ml wet cells. polar lipids represented 64% of total lipids and contained 9% lipid-phosphorus. polar lipids were separated into 14 components by two-dimensional thin-layer chromatography. eight components (88 ...19968784744
[antimicrobial activities of meropenem against clinically isolated strains. the result against strains isolated from blood and cerebrospinal fluid].in order to evaluate the antimicrobial activity of meropenem (mepm), minimum inhibitory concentrations (mics) of mepm and control drugs were determined against clinical isolates from blood and cerebrospinal fluid that were obtained from january, 1993 to december, 1994. the results are summarized as follows; 1. the mic-range, 50% mic (mic50) and 90% mic (mic90) of mepm were equal to those of imipenem (ipm) and panipenem (papm) against streptococcus pneumoniae including benzylpenicillin (pcg)-inse ...19968786628
investigation of the effect of combined variations in temperature, ph, and nacl concentration on nisin inhibition of listeria monocytogenes and staphylococcus aureus.gradient plates were used to investigate the effects of varying temperature, ph, and sodium chloride (nacl) concentration on nisin inhibition of staphylococcus aureus and listeria monocytogenes, nisin was incorporated into the plates of 0, 50, 100, 250, and 500 iu ml -1. gradients of ph (3.7 to 7.92) at right angles to nacl concentration (2.1 to 7% [wt/vol]) were used for the plates, which were incubated at 20, 25, 30 and 35 degrees c. growth on the plates were recorded by eye and by image analy ...19968787399
functional t cell subsets in mycobacterial and listerial infections: lessons from other intracellular pathogens. 19968791719
activation of natural killer cells by heat-killed listeria monocytogenes requires additional signals from lymphoid cells.regulatory and protective functions have been attributed to murine natural killer (nk) cells in a number of infectious diseases including listeriosis. we have developed an in vitro model to study parameters underlying the activation of naive nk cells using heat-killed listeria monocytogenes (hkl) as stimulator. independent from expression of the cell surface marker nk1.1, nk cells lysed yac-1 cells after in vitro stimulation with hkl or hkl + interleukin (il)-2, but not medium or il-2 alone. in ...19968793563
a single substitution in the putative helix-turn-helix motif of the pleiotropic activator prfa attenuates listeria monocytogenes virulence.prfa, the regulator of virulence-gene expression in the pathogenic bacterium listeria monocytogenes, displays sequence similarity to members of the cap-fnr family of transcriptional regulators. to test the functional significance of this similarity, we constructed and analysed substitutions of two amino acids of prfa predicted to contact dna, i.e. ser-184 and ser-183. substitution of ser-184 by ala reduced dna binding and virulence-gene activation, and attenuated the virulence in a mouse model o ...19968793875
primary and secondary immune responses to listeria monocytogenes.recent studies have revealed the complexity of cytokine and cellular interactions required for resistance to primary listeria monocytogenes infection and have illustrated that resistance to secondary infection may occur through multiple pathways. analyses of listeria epitope generation and the specificity of protective cd8(+) t cells have suggested that future research should focus on secreted protein antigens in specific resistance to infection and have increased our understanding of listeria a ...19968794012
role of osmolytes in adaptation of osmotically stressed and chill-stressed listeria monocytogenes grown in liquid media and on processed meat surfaces.listeria monocytogenes is a food-borne pathogen that is widely distributed in nature and is found in many kinds of fresh and processed foods. the pervasiveness of this organism is due, in part, to its ability to tolerate environments with elevated osmolarity and reduced temperatures. previously, we showed that l. monocytogenes adapts to osmotic and chill stress by transporting the osmolyte glycine betaine from the environment and accumulating it intracellularly (r. ko, l. t. smith, and g. m. smi ...19968795194
acid adaptation of listeria monocytogenes can enhance survival in acidic foods and during milk fermentation.we have previously shown that tolerance to severe acid stress (ph 3.5) can be induced in listeria monocytogenes following a 1-h adaptation to mild acid (ph 5.5), a phenomenon termed the acid tolerance response (atr) (b. o'driscoll, c. g. m. gahan, and c. hill, appl. environ. microbiol. 62:1693-1698, 1966). in an attempt to determine the industrial significance of the atr, we have examined the survival of adapted and nonadapted cells in a variety of acidic foods. acid adaptation enhanced the surv ...19968795199
the particular behaviour of listeria monocytogenes under sub-optimal conditions.listeria monocytogenes is a ubiquitous pathogenic microorganism which has been described as growing at temperatures of interest to food production and especially at low temperatures (-2 degrees to 8 degrees c) in storage process. however, the general relationship between the maximum specific growth rate, mumax and temperature has not often been studied for l. monocytogenes in the whole temperature range from minimal to maximal growth temperature. a global analysis of this relationship for temper ...19968796423
production and characterization of enterocin 900, a bacteriocin produced by enterococcus faecium bfe 900 from black olives.enterococcus faecium bfe 900 isolated from black olives produced a bacteriocin termed enterocin 900, which was antagonistic towards lactobacillus sake, clostridium butyricum, enterococci as well as listeria spp. including listeria monocytogenes. enterocin 900 was inactivated by pepsin, alpha-chymotrypsin, proteinase k and trypsin but not by catalase, alpha-amylase, or other non-proteolytic enzymes tested. the bacteriocin was heat stable, retaining activity after heating at 121 degrees c for 15 m ...19968796427
control of listeria monocytogenes in ground beef by 'lactocin 705', a bacteriocin produced by lactobacillus casei crl 705).the effectiveness of lactobacillus casei crl 705 as well as that of lactocin 705, the associated bacteriocin produced, in reducing population levels and growth of listeria monocytogenes in sterile and non-sterile ground beef was studied. predetermined numbers of l. monocytogenes and concentrations of lactocin 705 were added to the meat slurries. listeria in the bacteriocin-treated and control samples during incubation at 20 degrees c were enumerated as cfu on bacto blood agar base. results indic ...19968796440
effect of monolaurin and lactic acid on listeria monocytogenes attached to catfish fillets.the purpose of this study was to determine the effects of monolaurin and lactic acid, singly or combined, on listeria monocytogenes attached to catfish fillets. skinless catfish fillets were inoculated with l. monocytogenes and dip treated in monolaurin and/or lactic acid solution for various time periods. results showed that monolaurin up to 400 micrograms/ml had no influence on counts. conversely, lactic acid-treated fillets had reduced counts compared to controls. dipping in 0.85, 1.70, or 2. ...19968796441
cerebritis due to listeria monocytogenes: ct and mr findings.infections by listeria monocytogenes are uncommon, with cerebritis being even rarer. we present three cases of cerebritis which occurred during an outbreak of listeriosis. the ct and mr findings at diagnosis and during follow-up are described. predominant deep white matter lesions with nodular and ring enhancement were seen. the mr yielded a higher resolution of the lesions than ct.19968797977
use of aqueous two-phase systems in sample preparation for polymerase chain reaction-based detection of microorganisms.an aqueous two-phase system, consisting of poly(ethylene glycol) (peg) and dextran, was employed to separate polymerase chain reaction (pcr)-inhibitory substances from bacterial cells. the pcr inhibition of four soft cheeses was examined and three of them were found to be strongly pcr-inhibitory. extraction of the pcr-inhibitory soft cheeses inoculated with listeria monocytogenes in an aqueous two-phase system containing 8% (w/w) peg 4000 and 8% (w/w) dextran 500, was found to lower the pcr dete ...19968798894
listeria monocytogenes meningitis complicated by symptomatic spinal subarachnoid cysts.we report the case of a man who developed signs of compression of the spinal cord in the dorsal region over a year after treatment of listeria monocytogenes meningitis. he proved to have mild hydrocephalus and a number of subarachnoid pouches compressing the upper dorsal cord. insertion of a ventriculo-peritoneal shunt caused clinical improvement. we believe that this was caused by relief of tension in the spinal cysts rather than any reduction in ventricular size.19968799548
prevalence of salmonella, listeria monocytogenes, campylobacter spp., yersinia enterocolitica and cryptosporidium spp. in bulk milk, cows' faeces and effluents of dairy farms in trinidad.the prevalence of listeria, salmonella, campylobacter, yersinia and cryptosporidium species in bulk milk, faeces of dairy cows and effluents of milking parlours from dairy farms in trinidad was investigated. of the 177 bulk milk samples studied, 3 (1.7%), 3 (1.7%) and 2 (1.1%) were positive for l. monocytogenes, salmonella spp. and y. enterocolitica, respectively, but were all negative for campylobacter and cryptosporidium species. from 333 faecal samples tested, l. monocytogenes, campylobacter ...19969239938
ultrastructural localization of acid phosphatase in some bacteria, after treatment with lubrol w1.the ultracytochemical localization of acid phosphatase from some bacteria (listeria monocytogenes, salmonella typhimurium, pseudomonas pseudomallei and pseudomonas aeruginosa) was dependent on the changes in the lipoprotein content of the membranes as a result of the action of the lubrol w1.19969178530
identification of listeria species by a semi-nested polymerase chain reaction.three primers derived from the lap gene were used to distinguish listeria monocytogenes from l.innocua and other listeria species. l. monocytogenes and l. innocua yielded a pcr product of 600 and 300 bp, respectively, whereas a typical pattern of three amplimers was observed with l. ivanovii, l. seeligeri and l. welshimeri.19969157490
expression of listeriolysin o by intracellular listeria monocytogenes following infection of lipopolysaccharide-treated or untreated j774.1 macrophage-like cells.listeria monocytogenes replicates in a phagocytic cell following escape into the host cytoplasm. listeriolysin o, secreted by l. monocytogenes, which belongs to the thiol-activated hemolysin family, is known to play an important role in the escape of the bacterium into the host cytoplasm. in this study, we demonstrated that expression of listeriolysin o by infecting l. monocytogenes was lightly induced in j774.1 macrophage-like cells pretreated with lipopolysaccharide, although the growth of the ...19969116638
involvement of various combinations of endogenous inflammatory cytokines in listeria monocytogenes-induced expression of inducible nitric oxide synthase in mice.using a in vitro infection of spleen cells with listeria monocytogenes, the relationship between endogenous cytokines and the expression of inducible nitric oxide synthase (inos) was examined. when all interferon (ifn)-gamma, tumor necrosis factor (tnf)-alpha and interleukin (il)-1 alpha, or the combination of ifn-gamma with either tnf-alpha or il-1 alpha were neutralized by antibodies, there was a significant reduction of inos expression and nitrite production in culture. however, there was no ...19969116644
the protective role of endogenous cytokines in host resistance against an intragastric infection with listeria monocytogenes in mice.it has been demonstrated that endogenous cytokines including gamma-interferon (ifn-gamma), tumour necrosis factor-alpha (tnf-alpha), and interleukin-6 (il-6) play a protective role but that il-4 plays a detrimental role in systemic listeria monocytogenes infection in mice. the diverse roles of il-10 have been reported in antilisterial resistance. in this paper, we studied the role of endogenous cytokines in host resistance against an intragastric infection with l. monocytogenes in mice. the expr ...19969116648
development of a predictive model for growth of listeria monocytogenes in a skim milk medium and validation studies in a range of dairy products.a predictive model based on growth of listeria monocytogenes in milk is described. the main aim of this work was to generate a predictive model in milk acidified with lactic acid to mimic conditions found in a range of dairy products. a complete factorial design was employed to determine the effects of ph (4.5-7.5), temperature (3-35 degrees c) and salt concentration (0-8%) on growth of the organism. there were 210 design points and growth curves were individually fitted for the gompertz functio ...19969072528
bovine mastitis caused by listeria monocytogenes: kinetics of antibody responses in serum and milk after experimental infection.the kinetics of antibodies in serum and milk directed against proteins from listeria monocytogenes were studied using 4 lactating cows after infection was experimentally induced in the udder with four strains of serotypes 4b or 1/2a. antibodies (igg and iga) in samples of composite quarter milk and serum of the cow were measured by indirect elisa. microtiter plates were coated with proteins obtained from the culture supernatant of l. monocytogenes 4b. after challenge, an igg response in serum an ...19969029357
catalase-negative listeria monocytogenes causing lethal sepsis and meningitis in an adult hematologic patient. 19969031886
[central nervous system infections in patients with malignant diseases].infections of the nervous system remain a significant source of morbidity and mortality in patients with cancer. this paper reviews the main pathogens and emphasizes some of the principles of diagnosis and management of nervous system infections in cancer patients. due to immunosuppression, diagnosis is more difficult in this group, secondary to the multitude of potential pathogens, and often by their atypical presentations. fever or headache are often the only symptoms. clinical history and gen ...19969033951
th0-like cd4+ t cells protect mice with murine retrovirus-induced immunodeficiency syndrome (maids) against co-infection with listeria monocytogenes.we examined the host defence mechanism against infection with listeria monocytogenes, a facultative intracellular bacterium, in mice with murine acquired immunodeficiency syndrome (maids) caused by lp-bm5 murine leukaemia virus (mulv) infection. although lp-bm5 mulv infection in c57bl/6 mice leads to a stage of immunodeficiency characterized by severe compromise of cell-mediated immunity, the mice with established maids infected with lp-bm5 8 weeks previously, showed resistance to an intraperito ...19969014817
[acute bacterial meningitis in adults]. 19969019208
antimicrobial effects of oligoamines.twenty-four oligoamines belonging to six (1-6) structurally different types were tested in vitro for their antibacterial activity against 14 different bacterial species comprising a total of 187 strains. ten compounds were able to inhibit growth of at least one strain at concentrations < or = 10 mumol/l. for three compounds, minimum inhibitory concentrations for some strains were even below 1 mumol/l. clear structure-activity relationships showed that the inhibitory effect depended on the bridge ...19969005815
superinfection by listeria monocytogenes of cultured human enterocyte-like cells infected with poliovirus or rotavirus.a mixed infection with either rotavirus or poliovirus and listeria monocytogenes was analysed in caco-2 cells, a tumour-derived cell line, highly susceptible to these pathogens. the multiplication of these pathogens, whose usual site of entry and/or replication is the intestine, was also followed by electron microscopy. results obtained showed an increase of l. monocytogenes internalisation in cells infected with rotavirus, whereas the preinfection with poliovirus had only a slight interfering e ...19969007817
occurrence of listeria and listeriosis in hungary.listeriosis is a rare human disease in hungary. the number of cases is slowly increasing. only sporadic events have been observed but the occurrence of epidemic listeriosis may be supposed. the listeria monocytogenes (in abbreviation: l. m.) transmitter role of food in human infections has not yet been verified. the epidemiological character of animal listeriosis is different. healthy carriers can be found among both humans and animals. foodstuffs of animal as well as plant origin may be contami ...19969055453
down-regulation of listeria monocytogenes-specific th1 cytokine response by treatment of mice with goat antibody to mouse igd.injection of goat anti-mouse igd antibody (g alpha m igd) to mice has been shown to induce polyclonal igg1 and ige production by b cells and il-4 production by goat ig-specific t cells. surface igd crosslinking also activates function of b cells as antigen presenting cells. although the g alpha m igd treatment is a well established system for regulation of immune response against antigens that bind to b cell receptor, we found that the g alpha m igd treatment also influences immune response agai ...19969061384
[clinical characteristics and epidemiologic study of a listeriosis outbreak in grand canary].background and methods: human infections caused by listeria monocytogenes often present as sporadic cases without any epidemiological relationship among them; however they also appear as outbreaks that are usually detected by an increase in the number of cases diagnosed by hospitals of the geographic area. between december 1991 and may 1993, twenty four cases of listeriosis were detected in three hospitals of las palmas de gran canaria; and they were classified as an outbreak. our report describ ...19968991435
protective immunity to listeria monocytogenes elicited by immunization with heat-killed listeria and il-12. potential mechanism of il-12 adjuvanticity.the results presented here demonstrate the striking potentiating effects of il-12 when it is combined with listerial immunogens. although hklm alone does not elicit strong t-cell responses, the results presented here demonstrate that the combination of hklm and il-12 elicited vigorous listeria-specific th1-type t-cell responses when administered intraperitoneally. the intensity of these responses, as well as the cytokine profiles of the listeria-specific peritoneal t cells and macrophages, was r ...19968993364
impact of in vitro fatty acid uptake on nitric oxide production and antilisterial activity of wehi-3 cells. 19968993386
vasp interaction with vinculin: a recurring theme of interactions with proline-rich motifs.vasp (vasodilator-stimulated phosphoprotein), a protein associated with microfilaments at cellular contact sites, has been identified as a ligand for profilin and zyxin, two proteins also involved in microfilament dynamics and organization at these regions. here, we report that vasp also directly binds to vinculin, another component of adherens junctions. competition experiments with a vinculin-derived peptide showed that a proline-rich motif, located in the hinge region that connects vinculin's ...19968980130
e-cadherin is the receptor for internalin, a surface protein required for entry of l. monocytogenes into epithelial cells.we report the first identification of a cellular receptor mediating entry of a gram-positive bacterium into nonphagocytotic cells. by an affinity chromatography approach, we identified e-cadherin as the ligand for internalin, an l. monocytogenes protein essential for entry into epithelial cells. expression of the chicken homolog of e-cadherin (l-cam) in transfected fibroblasts dramatically increases entry of l. monocytogenes and promotes that of a recombinant l. innocua strain expressing interna ...19968601315
[spontaneous listeria monocytogenes peritoneal infection complicating hepatic transplantation].the incidence of listeriosis is increased in immunosuppressed patients. we report a case of spontaneous bacterial peritonitis with bacteraemia caused by listeria monocytogenes in a 47-year old woman with liver transplantation. complete recovery was achieved after amoxicillin and amikacin therapy. high doses of corticosteroids and okt3 monoclonal therapy may have favoured the occurrence of infection. in liver transplant recipients, regular stool screening could be proposed, and trimethoprim-sulfa ...19968977820
[taxonomy of the listeria genus and typing of l. monocytogenes].the genus listeria contains six species (l. monocytogenes, l. innocua, l. ivanovii, l. seeligeri, l. welshimeri and l. grayi) among which only l. monocytogenes can cause infections in humans. typing of l. monocytogenes includes phenotypic methods, serotyping and phage-typing, and molecular methods, mainly ribotyping, multilocus enzyme analysis, dna micro- and macrorestriction analysis and rapd (random amplified polymorphic dna).19968977897
listeria monocytogenes--aspects of pathogenicity.the genus listeria includes different species of ubiquitary present gram-positive rod shaped bacteria. the species listeria monocytogenes causes severe diseases like meningitis and meningoencephalitis in humans. additional groups of syndromes associated with this microorganism are the listeriosis of the pregnant woman, mostly appearing as an abortion or septic premature birth and the meningitis of the newborn. transmission of listeria may occur on the oral route due to infected food like raw mil ...19968977899
pathogenesis and immunology of listeria monocytogenes.listeriosis is primarily a foodborne disease and the pathogenesis of infection is determined by passage of the organism from the gastrointestinal lumen to the reticuloendothelial cells of the liver and spleen. subsequent invasive events such as sepsis and meningitis develop. the immune response to listeria is characterized by early macrophage mediated killing followed by the development of a brisk cell mediated immune response. humoral immunity appears to play no role in infection in the protect ...19968977900
[resistance of listeria monocytogenes to physical exposure].the resistance of listeria monocytogenes to physical processing, particularly heat resistance and radioresistance, is widely dependent on the method involved, the physiological state of the strain used, and, obviously, the substrate in which the organism is. htst pasteurization of milk would allow at least 11 decimal reductions of the potentially present population of l. monocytogenes, and then greatly minimizes the risks of survival of the organism. on the other hand, high and low pasteurizatio ...19968977902
[incidence of listeria in food].it is only recently that the role of food in the appearance of human listeriosis has been shown up. however, the increasing number of studies made, up to date, don't let us appreciate the influence of listeria, and more particularly listeria monocytogenes, in a somehow satisfying way. the problems set by the evaluation of this incidence are called up firstly, and afterwards the data concerning different food-stuffs (meat and meat products, milk and milk products, sea foods, vegetal products) are ...19968977903
[prevention of listeria monocytogenes contamination on dairy farms and in the cheese industry].listeria monocytogenes remains a pathogen bacteria the prevention of which, in food products, stays delicate. a complete organization, from the farmer's production to the industry and the consumer is necessary to eliminate listeria in a type of food product. listeria monocytogenes is susceptible of contaminate raw milk. the silage may be a major source of the occurrence of listeria monocytogenes in raw milk. in this case, the contamination sources in a dairy farm and the good hygienic practices ...19968977904
esculetin antagonizes iron-chelating agents and increases the virulence of listeria monocytogenes.iron is an essential compound for the growth and virulence of listeria monocytogenes. in extracellular environments, iron often requires a siderophore to be acquired by microorganisms. although it does not produce siderophores, l. monocytogenes can use some exogenous bacterial or fungal siderophores as well as a number of animal or plant o-diphenol compounds to overcome growth inhibition by the iron-chelating agents tropolone and 8-hydroxyquinoline. esculin, a plant glycoside, can be hydrolysed ...19969296102
[presence of listeria spp. in vegetables]. 19969244463
[role of starlings in the diffusion of listeria monocytogenes and listeria spp]. 19969244465
class ib mhc products in host immunity against listeria monocytogenes. 19969127884
[presence of listeria monocytogenes and listeria spp. in various kinds of food]. 19969312234
[listeriosis in a rabbitry].an enzootic of listeriosis in a rabbitry is reported. listeria monocytogenes serotype 1/2a was isolated from the organs of a doe, which had died of septic metritits. from aborted fetuses of two other does listeria monocytogenes serotype 1/2b and 4b were cultured, respectively. in feed samples of the rabbitry listeria monocytogenes strains of the serotypes 1/2b and 4b besides the apathogenic listeria species listeria seeligeri and listeria innocua were detected. serological studies with agglutina ...19969081819
[listeria in plants: an experimental study of its colonization, numbers and variability].the possibility for listeria monocytogenes to penetrate into plants from the soil via the root system was experimentally proved. listeria were shown to continuously persist for 30 days (the term of observation) in the vegetative organs of wheat (roots, stems and leaves). the concentration of listeria was 10(9) cfu/g in the environment (soil extract) and the roots of wheat, 10(6)-10(7) cfu/g in stems, 10(8)-10(9) cfu/g in leaves. six days later the dissociation of colonies in the s-form into smal ...19969082711
[presence of various pathogenic microorganisms in fresh vegetables in costa rica].this study reports the occurrence of some pathogenic microorganisms in vegetable consumed on a daily basis by costa ricans. cryptosporidium sp. oocysts were found in 5.2% (4/80) of cilantro leaves, in 8.7% (7/80) of cilantro roots and 2.5% of lettuce samples. a 1.2% (1/80) incidence was found in other vegetables samples (carrot, cucumber, radish and tomatoe). oocysts of this parasite were absent in cabbage. giardia intestinalis was only detected in 5.2% (4/80) of cilantro leaves and in 2.5% (2/ ...19969429609
il-15 is a novel growth factor for murine gamma delta t cells induced by salmonella infection.we have previously shown evidence for the early recruitment of gamma delta t cells during the disease course of primary infections with listeria monocytogenes or salmonella choleraesuis in mice. since gamma delta t cells at this stage of the disease do not produce il-2, the growth factor for the gamma delta t cells remains unknown. il-15 is a novel cytokine that uses beta- and gamma-chain of il-2r for signal transduction, and is produced by activated monocytes/macrophages. in this study, we inve ...19968543818
listeria monocytogenes induces apoptosis of infected hepatocytes.infection with blood-borne listeria monocytogenes results in their early uptake by the liver. foci of hepatocytes become heavily infected and develop into microabscesses. infection results in apoptosis of the hepatocytes. this is particularly evident in the edge of the microabscess, where hepatocytes are not yet destroyed by the neutrophil. it is also apparent when neutrophils are depleted from the circulation. infection of hepatocytes in culture induces their death by apoptosis with the release ...19968543820
two listeria monocytogenes ctl epitopes are processed from the same antigen with different efficiencies.listeria monocytogenes is an intracellular bacterium that elicits mhc class i-restricted ctl in infected mice. a major ctl specificity is the nonamer peptide p60 217-225, which is derived from the bacterial murein hydrolase p60 and presented by the h-2kd mhc class i molecule. in this report, we identify a second h-2kd presented peptide, encompassing residues 449-457 of p60, that is detected by l. monocytogenes-specific ctl. both p60-derived ctl epitopes are good competitors for h-2kd binding and ...19968543821
influence of beta 2-microglobulin expression on gamma interferon secretion and target cell lysis by intraepithelial lymphocytes during intestinal listeria monocytogenes infection.numerous microbial pathogens, including listeria monocytogenes, enter the host through the intestine. although relatively little is known about the biological functions of intestinal intraepithelial lymphocytes (i-iel), they are generally considered a first line of defense against intestinal infections. in the mouse, the vast majority of i-iel express the cd8 coreceptor either as a cd8 alpha/alpha homodimer or as a cd8 alpha/beta heterodimer. the cd8 receptor of t-cell receptor tcr gamma/delta i ...19968550209
listeriolysin is a potent inducer of the phosphatidylinositol response and lipid mediator generation in human endothelial cells.the impact of listeria monocytogenes listeriolysin o (llo) secretion on phosphoinositide metabolism and mediator (platelet-activating factor and prostaglandin i2) generation was investigated in human umbilical vein endothelial cells. wild-type l. monocytogenes, purified llo, and an l. innocua strain engineered to secrete llo all elicited a strong response, whereas mutant strains defective in llo production were ineffective. thus, human umbilical vein endothelial cell stimulation by listeriae is ...19968550226
detection and characterization by differential pcr of host eukaryotic cell genes differentially transcribed following uptake of intracellular bacteria.host eukaryotic cell genes that are differentially transcribed after phagocytosis of various pathogenic and nonpathogenic bacterial cells were identified by a differential pcr (dpcr) system. this dpcr procedure favors detection and isolation of host genes affected at the transcriptional level by selecting for poly(a) tails but differs substantially from reverse transcription-pcr. several unidentified macrophage gene fragments from genes that were either transcriptionally activated or downregulat ...19968557379
macrophages have cell surface il-10 that regulates macrophage bactericidal activity.il-10, which is secreted by multiple cell types, has regulatory effects on macrophages, including decreasing their ability to kill some microorganisms. the experiments presented here test the hypothesis that endogenous il-10 inhibits the ability of macrophages to kill the facultative intracellular bacterium, listeria monocytogenes. we show that the nonbactericidal macrophage hybrid, h36.12j (12j), can kill listeria after incubation for 3 days with anti-il-10 mab. il-10 was not detected in 12j ma ...19968557991
intracerebral targets and immunomodulation of murine listeria monocytogenes meningoencephalitis.in humans, infection with listeria monocytogenes (l. monocytogenes) can severely affect the central nervous system (cns). in the present study we have employed a murine model of cns listeriosis to characterize the intracerebral distribution of l. monocytogenes. following intracerebral application of a low dose of l. monocytogenes (serovar 1/2a, egd strain) a severe fatal leptomeningitis, ventriculitis, and encephalitis developed. listeria were detectable both intracellularly in different cell ty ...19968558168
ctl epitope generation is tightly linked to cellular proteolysis of a listeria monocytogenes antigen.listeria monocytogenes is a pathogenic intracellular bacterium that secretes proteins into the cytosol of host cells. a major secreted protein, p60, is processed by the host cell into the nonamer peptides p60 217-225 and p60 449-457, which are presented to ctl by h-2kd mhc class i molecules. herein, we use two membrane permeable peptide aldehyde protease inhibitors, llnl and z-llf, to inhibit cytosolic proteolysis in l. monocytogenes-infected cells. these inhibitors, which have been shown to inh ...19968568253
transferable erythromycin resistance in listeria spp. isolated from food.an erythromycin-resistant (emr) listeria innocua and an emr listeria monocytogenes isolate both carried ermc genes, which code for rrna methylases. the ermc genes were transferable by conjugation to recipient l. monocytogenes, listeria ivanovii, and enterococcus faecalis but did not appear to be associated with conjugative plasmids.19968572704
aerobic and anaerobic metabolism of listeria monocytogenes in defined glucose medium.a defined medium with glucose as the carbon source was used to quantitatively determine the metabolic end products produced by listeria monocytogenes under aerobic and anaerobic conditions. of 10 strains tested, all produced acetoin under aerobic conditions but not anaerobic conditions. percent carbon recoveries of end products, typified by strain f5069, were as follows: lactate, 28%; acetate, 23%; and acetoin, 26% for aerobic growth and lactate, 79%; acetate, 2%; formate, 5.4%; ethanol, 7.8%; a ...19968572709
sequestration of inhaled particulate antigens by lung phagocytes. a mechanism for the effective inhibition of pulmonary cell-mediated immunity.dendritic cells (dcs) have emerged as the dominant antigen-presenting cells (apcs) of the lung, playing a vital role in the induction of cell-mediated immunity to inhaled antigens. we have previously demonstrated that an airway challenge with the soluble antigen hen egg lysozyme yields rapid acquisition of specific antigen-presenting cell activity by purified pulmonary dcs and a cell-mediated immune response in the lung upon secondary challenge. to examine how a particulate antigen leads to a ce ...19968579128
effect of benzylpenicillin on the viability and osmotic sensitivity of listeria monocytogenes.growth in the presence of 100 ppm benzylpenicillin (bp) for 2 h failed to result in a detectable reduction in cfu. cells grown and incubated for 24 h in 0, 1, 10 and 100 ppm bp underwent reductions in cfu of 0%, 0%, 90% and 99% respectively of maximum cfu values.19968588882
effects of benzylpenicillin on glucose utilization, macromolecule synthesis and cell wall proteins of listeria monocytogenes.when growing cells were incubated in the presence of 100 ppm benzylpenicillin (bp) for 30 min and then harvested for metabolic studies, the initial rate of glucose utilization by resting cells was reduced by 19.6% compared to control cells, whereas the rates of protein, dna and rna synthesis were reduced by 40.7%, 55.0% and 87.5% respectively. growth in the presence of 100 ppm bp for 2 h was found to result in a marked depletion of cell wall proteins.19968588883
a comparison between starch and polyacrylamide gels for the analysis of listeria monocytogenes using multilocus enzyme electrophoresis.forty-seven listeria monocytogenes isolates were analysed using multilocus enzyme electrophoresis in two laboratories. both assayed for the same six enzymes, but one used a starch gel method and the other polyacrylamide gels. the starch gel method distinguished six electrophoretic types whereas the polyacrylamide gel method produced 17 different electrophoretic types. the polyacrylamide gel method was more discriminatory than the starch gel method.19968588884
subinhibitory concentrations of beta-lactams and other cell-wall antibiotics inhibit listeriolysin production by listeria monocytogenes.in the present study we tested the ability of beta-lactam antibiotics and other cell-wall antibiotics to inhibit the production of listeriolysin which is the main virulence factor of l. monocytogenes. the amount of listeriolysin produced was measured in the supernatants with a sensitive hemolysin assay and as beta-galactosidase expression from the listeriolysin promoter. when tested in concentrations that did not affect growth of the bacteria, all beta-lactam antibiotics and all other cell-wall ...199618611740
dna extraction and pcr methods for the detection of listeria monocytogenes in cold-smoked salmon.protocols for the specific detection of listeria monocytogenes in cold-smoked salmon were developed. pcr was used as the method of detection. inhibitors of pcr present in the food samples were removed by ether extraction or column purification, or their effect was overcome by the use of tween 20 as an enhancer. these protocols are many times more rapid than conventional detection methodologies and also have the potential for automation.199616535272
use of molecular typing methods to trace the dissemination of listeria monocytogenes in a shrimp processing plant.volume 62, no. 2, p. 705, column 2, line 5 from bottom: "neutralized with chlorine" should read "chlorine neutralized by the addition of 5 ml of a 1% solution of sodium thiosulfate." page 706, table 1, footnote b: footnote b should read "the designation in parentheses is the area or type of sample collected as indicated in table 3." page 709, tables 3 and 4: tables 3 and 4 should read as shown below. [this corrects the article on p. 705 in vol. 62.].199616535326
actin-based bacterial motility: towards a definition of the minimal requirements.at the border line between microbiology and cell biology, the spectacular capacity o f some intracellular bacterial pathogens, including listeria monocytogenes, shigella flexneri and several rickettsias, to use actin polymerization as a driving force for intracellular movement, cell-to-cell spreading and dissemination within the infected tissue is being increasingly studied. now that it is possible to manipulate the bacterial surface proteins involved in this process - acta o f l. monocytogenes ...199615157487
activity in vitro of 22 antimicrobial agents against clinical isolates of listeria monocytogenes. 199611866814
multiresistant strain of listeria monocytogenes in greece. 199611866815
disk diffusion, agar dilution and the e-test for susceptibility testing of corynebacterium jeikeium.objective: the susceptibilities to penicillin, tetracycline, erythromycin, gentamicin, vancomycin and teicoplanin of 58 strains of corynebacterium jeikeium were assessed by disk diffusion and agar dilution reference methods. methods: zone sizes and minimal inhibitory concentrations (mic) by agar dilution were interpreted using the ranges in the nccls tables for organisms other than haemophilus, neisseria gonorrhoeae, and streptococcus pneumoniae. results: by agar dilution, 14%, 88%, 17% and 26% ...199611866845
prevalence of listeria monocytogenes and other listerias in italian-made soft cheeses.the frequency of l. monocytogenes and other listerias was determined in different types of italian-made soft cheeses purchased from retail outlets (shops and supermarkets) located in different areas and different towns of central italy. of the 164 examined samples, eight proved to be positive for l. monocytogenes (4.9%), seven strains belonged to serotype 1, and one strain to serotype 4. thirty-six samples were positive for the presence of other listeria species (22%); of these, l. innocua was p ...19969353545
bacteriocins for control of listeria spp. in food.foodborne outbreaks of listeriosis caused by listeria monocytogenes have contributed to public consciousness about bacterial pathogens involved with foodborne disease. major concerns with l. monocytogenes are its high mortality rate, wide distribution on raw products, growth at low temperatures, and its ability to establish itself in various food-processing environments. these concerns have prompted the examination of novel approaches, including the use of antimicrobial peptides, or bacteriocins ...199628384026
bacterial peritonitis caused by listeria monocytogenes: case report and review of the literature.although listeria monocytogenes has been isolated from the gastrointestinal tract, it is an infrequent cause of bacterial peritonitis. since 1963 only 23 cases of peritonitis caused by listeria have been reported. this report describes another case in a patient with cirrhosis and chronic renal failure and presents a review of the literature. most (16) of the previous cases were cirrhotic while six were undergoing chronic ambulatory peritoneal dialysis. eight patients were on immunosuppressive th ...199622514418
interruption of microbial cycles in farm animals from farm to table.the fact that only slight problems are posed by salmonella, campylobacter and escherichia coli o157 in mammalian farm animals in norway, is undoubtedly due in large degree to the agricultural set-up with small farms and small herds, allowing a good overview of the situation at any time. other factors are the very limited import of breeding animals and food products of animal origin, microbiological control of animal feed, and favourable geographical and climatic conditions. however, the norwegia ...199622060640
[acute bacterial meningitis in adults, a 20 year overview.]introduction: although acute bacterial meningitis is most common among children, the disease nevertheless poses serious problems in the adult population. however, most clinical overviews of the disease have either focused on children or all age groups combined. subjects and methods: information on all patients 5=16 years of age diagnosed in iceland during the years 1975-1994 was collected from patient records from 10 hospitals and the records of the dept. of microbiology at the university hospit ...199520065460
listeria monocytogenes infections.this article reviews current information regarding human infection with listeria monocytogenes. significant advances have occurred in regard to our knowledge of the epidemiology, pathogenesis, immunology, and treatment of this disease which was formerly believed to be of importance mainly to veterinarians. it remains a cause of high mortality in the many different groups of compromised hosts it infects unless diagnosis and treatment are rapidly established.199510829842
incidence of listeria spp. and listeria monocytogenes in a poultry processing environment and in poultry products and their rapid confirmation by multiplex pcr.volume 60, no. 12, p. 4602: fig. 1 should appear as shown below. fig. 1. incidence of l. monocytogenes and other listeria spp. in a poultry processing environment and in raw and cooked poultry products from march to september 1992. (a) raw (r) and cooked (c) areas within the processing environment. (b) raw and cooked poultry products. (box), l. monocytogenes; (box), listeria spp. (not l. monocytogenes); (symbl), no listeria spp. [this corrects the article on p. 4600 in vol. 60.].199516534947
vector plasmid for insertional mutagenesis and directional cloning in listeria spp. 19958588903
listeriosis in bone marrow transplant recipients: incidence, clinical features, and treatment.cultures of blood and/or cerebrospinal fluid from four of 1,013 bone marrow transplant recipients treated at our center between january 1972 and april 1994 were positive for listeria monocytogenes. the overall occurrence of listeriosis was 0.39 case per 100 transplantations. allograft recipients had received prior treatment with parenteral methylprednisolone, thus supporting an association between listeriosis and corticosteroids. treatment with parenteral ampicillin (200 mg/[kg.d]) and gentamici ...19958589157
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