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ultrastructure of rickettsia rickettsii actin tails and localization of cytoskeletal proteins.actin-based motility (abm) is a mechanism for intercellular spread that is utilized by vaccinia virus and the invasive bacteria within the genera rickettsia, listeria, and shigella. within the rickettsia, abm is confined to members of the spotted fever group (sfg), such as rickettsia rickettsii, the agent of rocky mountain spotted fever. infection by each agent induces the polymerization of host cell actin to form the typical f (filamentous)-actin comet tail. assembly of the actin tail propels t ...200010899876
critical role of neutrophils in eliminating listeria monocytogenes from the central nervous system during experimental murine listeriosis.neutrophils are the main inflammatory cell present in lesions involving the central nervous system (cns) during human and murine listeriosis. in this study, administration of the neutrophil-depleting monoclonal antibody rb6-8c5 during experimental murine listeriosis facilitated the multiplication of listeria monocytogenes in the cns. these data suggest that neutrophils play a key role in eliminating bacteria that gain access to the cns compartment. in addition, we provide evidence that their mig ...200010899890
humoral and cell-mediated immunity in mice with genetic deficiencies of prolactin, growth hormone, insulin-like growth factor-i, and thyroid hormone.prolactin (prl), growth hormone (gh), insulin-like growth factor-i (igf-i), and thyroid hormones have been proposed as critical immunoregulatory mediators, and their clinical use is being considered. the precise role played by each of these hormones in the generation of humoral and cell-mediated immune responses was assessed in a panel of mice with mutations that result in a selective reduction of prl, gh, igf-i, and/or thyroid hormone production. a surprising result, in view of previous studies ...200010900161
listeriosis in a raccoon dog (nyctereutes procyonoides) associated with canine distemper.a wild raccoon dog (nyctereutes procyonoides) that manifested severe illness and died was examined. necropsy revealed severe emaciation, systemic icterus and petechial hemorrhages on the mucous membranes. histopathologically, necroses were seen in the liver and brain stem associated with meningitis. eosinophilic intranuclear inclusion bodies were observed in the spleen and intestinal mucosa, and eosinophilic intracytoplasmic inclusion bodies were seen in transitional epithelium in the bladder. l ...200010907692
incidence of listeria monocytogenes in wild animals in japan.between 1991 and 1993, the intestinal contents and feces of wild animals in japan were examined for the presence of listeria. the wild animals examined included 623 mammals (11 species) and 996 birds (18 species). listeria species were isolated from 38 (6.1%) of the 623 mammalian samples and 133 (13.4%) of 996 bird samples. the highest incidence of listeria in the mammals was found in japanese monkeys (20.0%) and that in birds was found in crows (43.2%). the incidence of listeria in japanese mon ...200010907701
listeriolysin o as a reporter to identify constitutive and in vivo-inducible promoters in the pathogen listeria monocytogenes.listeria monocytogenes is a facultative intracellular gram-positive bacterium capable of growing in the cytoplasm of infected host cells. bacterial escape from the phagosomal vacuole of infected cells is mainly mediated by the pore-forming hemolysin listeriolysin o (llo) encoded by hly. llo-negative mutants of l. monocytogenes are avirulent in the mouse model. we have developed a genetic system with hly as a reporter gene allowing the identification of both constitutive and in vivo-inducible pro ...200010816469
interaction of listeria monocytogenes with human brain microvascular endothelial cells: an electron microscopic study.internalization of listeria monocytogenes into human brain microvascular endothelial cells (hbmec) has recently been demonstrated to be dependent upon the inlb gene. in the present scanning electron microscopic study we show that l. monocytogenes efficiently interacts with the surface of hbmec in an inlb-independent manner which is also different from invasion. the inlb-dependent invasion of hbmec by l. monocytogenes is accompanied by intracellular multiplication, movement, and production of bac ...200010816473
listeria monocytogenes-infected human dendritic cells: uptake and host cell response.dendritic cells (dcs) are potent antigen-presenting cells and play a crucial role in initiation and modulation of specific immune responses. various pathogens are able to persist inside dcs. however, internalization of the gram-positive bacterium listeria monocytogenes into human dcs has not yet been shown. in the present study, we demonstrate that human monocyte-derived immature dcs can efficiently phagocytose l. monocytogenes. this uptake is independent of listerial adhesion factors internalin ...200010816528
beta 2 integrins are involved in cytokine responses to whole gram-positive bacteria.proinflammatory cytokines have an important pathophysiologic role in septic shock. cd14 is involved in cytokine responses to a number of purified bacterial products, including lps. however, little is known of monocyte receptors involved in cytokine responses to whole bacteria. to identify these receptors, human monocytes were pretreated with different mabs and tnf-alpha was measured in culture supernatants after stimulation with whole heat-killed bacteria. human serum and anti-cd14 abs significa ...200010820267
yersinia enterocolitica-mediated translocation of defined fusion proteins to the cytosol of mammalian cells results in peptide-specific mhc class i-restricted antigen presentation.yersinia enterocolitica delivers a set of effector proteins [yersinia outer proteins (yop)] into the cytosol of target cells to modulate host cell signal transduction pathways required for the extracellular survival of the bacterium. secretion and subsequent translocation of yop across the eukaryotic cell membrane are achieved via a type iii secretion system. about 50 - 100 amino acids of the n terminus of yop are required for chaperone-directed secretion and translocation. in this study, it is ...200010820384
retinoid-mediated inhibition of interleukin-12 production in mouse macrophages suppresses th1 cytokine profile in cd4(+) t cells.interleukin-12 (il-12) plays a central role in the immune system by driving the immune response towards t helper 1 (th1) type responses characterized by high ifn-gamma and low il-4 production. in this study we investigated whether retinoid-mediated inhibition of interleukin-12 production in mouse macrophages could regulate cytokine profile of antigen (ag)-primed cd4(+) th cells. pretreatment with retinoids (9-cis-ra, all-trans-ra, ttnpb) significantly inhibited il-12 production by mouse macropha ...200010821786
protective effect of a traditional japanese medicine, bu-zhong-yi-qi-tang (japanese name: hochu-ekki-to), on the restraint stress-induced susceptibility against listeria monocytogenes.in this study, the effect of traditional japanese (chinese) medicine, bu-zhong-yi-qi-tang (japanese name: hochu-ekki-to, hot), on the restraint stress treatment (rst)-induced susceptibility against listeria monocytogenes (l. monocytogenes) was examined. when rst was performed every day for 10 h from the day of infection, the bacterial numbers were increased at 3 and 5 days after the infection. oral pretreatment with hot for 7 days prevented such increases. pretreatment with hot prevented the sup ...200010822087
an outbreak of listeria monocytogenes serotype 3a infections from butter in finland.in february 1999, an outbreak of listeriosis caused by listeria monocytogenes serotype 3a occurred in finland. all isolates were identical. the outbreak strain was first isolated in 1997 in dairy butter. this dairy began delivery to a tertiary care hospital (tch) in june 1998. from june 1998 to april 1999, 25 case patients were identified (20 with sepsis, 4 with meningitis, and 1 with abscess; 6 patients died). patients with the outbreak strain were more likely to have been admitted to the tch t ...200010823797
a 9-month-old boy with fever and lethargy. 200010826077
antimicrobial effect of herb extracts against escherichia coli o157:h7, listeria monocytogenes, and salmonella typhimurium associated with beef.the effects of plant extracts against pathogenic bacteria in vitro are well known, yet few studies have addressed the effects of these compounds against pathogens associated with muscle foods. a series of experiments was conducted to determine the effectiveness of a commercially available, generally recognized as safe, herb extract dispersed in sodium citrate (protecta one) or sodium chloride (protecta two) against escherichia coli o157:h7, salmonella typhimurium, and listeria monocytogenes asso ...200010826716
fate of listeria monocytogenes, salmonella typhimurium dt104, and escherichia coli o157:h7 in labneh as a pre- and postfermentation contaminant.commercially pasteurized milk (approximately 2% milkfat) was heated at 85 to 87 degrees c/30 min, inoculated to contain 2,000 to 6,000 cfu/ml of listeria monocytogenes, salmonella typhimurium dt104, or escherichia coli o157:h7, cultured at 43 degrees c for 4 h with a 2.0% (wt/wt) commercial yogurt starter culture, stored 12 to 14 h at 6 degrees c, and centrifuged to obtain a labneh-like product. alternatively, traditional salted and unsalted labneh was prepared using a 3.0% (wt/wt) starter cultu ...200010826717
pathogenicity and production of virulence factors by listeria monocytogenes isolates from channel catfish.pathogenicity of four channel catfish listeria monocytogenes isolates (ccf1, ccf4, hcc7, and hcc23) was examined in a comparative manner with virulent type strains l. monocytogenes atcc 19115 and egd and avirulent type strain atcc 15313 in bdf and a/j mice. isolates hcc7 and ccf1 (both serovar 1) caused similar percent mortalities and 50% lethal concentration values when compared with virulent type strains and were therefore considered pathogenic. the presence of the virulence factors listerioly ...200010826718
temperature gradient gel electrophoresis of the amplified product of a small 16s rrna gene fragment for the identification of listeria species isolated from food.the development of a rapid method for the identification of listeria spp. is described. it is based on the polymerase chain reaction amplification of a small fragment from the 16s rrna gene followed by temperature gradient gel electrophoresis. forty-five strains of listeria spp. (listeria monocytogenes, listeria innocua, listeria ivanovii, listeria seeligeri, and listeria welshimeri) were used for the optimization of the protocol. no differences were observed between the results of the identific ...200010826726
inactivation of listeria monocytogenes scott a on artificially contaminated frankfurters by high-pressure processing.vacuum-packaged frankfurters, inoculated with 24-h cultures of listeria monocytogenes scott a (approximately 10(9) cfu/ml) by injection into the packages, were held at pressures of 300, 500, and 700 mpa for up to 9 min. l. monocytogenes were washed from the surface of the frankfurter and plated onto brain heart infusion agar. during the time to achieve 300, 500, and 700 mpa (come-up time), l. monocytogenes populations decreased by 1, >3, and >5 logs, respectively. additional inactivation of l. m ...200010826727
listeria monocytogenes as an alternative vaccine vector for hiv.the necessity for an hiv vaccine and a brief review of current strategies towards this aim are given here to set into context contemporary studies towards exploiting the bacterium listeria monocytogenes as an hiv vaccine vector. the cell biology and immunology of this unusual intracellular organism are also reviewed, in addition to its application to introducing viral antigens, including hiv antigens, to the immune system.200010912619
current status and future perspectives of dna vaccine delivery by attenuated intracellular bacteria.vaccination by intradermal or intramuscular injection of antigen-encoding plasmid-dna elicits strong cellular and humoral immune responses. professional antigen presenting cells (apc) seem to induce these responses, making it, therefore, desirable to deliver the plasmid molecules directly to these cells. the exploitation of attenuated intracellular bacteria as dna delivery vehicles makes the direct targeting of dna vaccine vectors to professional apc feasible.200010912622
antimicrobial activity of a 14-residue synthetic peptide against foodborne microorganisms.a chemically synthesized short-chain peptide composed of six leucine and eight lysine (6k8l) residues was demonstrated to be biocidal against several foodborne organisms including escherichia coli o157:h7, listeria monocytogenes, pseudomonas fluorescens, and kluyveromyces marxianus suspended in phosphate buffer at concentrations of 5 to 50 microg/ml. all strains were reduced by 3 log10 cfu/ml within 10 min at peptide concentrations of <10 microg/ml. the peptide reduced by 3 log10 cfu/ml e. coli ...200010914655
effectiveness of two cooking systems in destroying escherichia coli o157:h7 and listeria monocytogenes in ground beef patties.a rapid, high-temperature double-sided grilling-broiling (dgb) system was compared to a single-sided broiling (ssb) system for cooking of foodservice ground beef patties to reduce microbial numbers and maintain textural quality. patties (110 g) containing either escherichia coli o157:h7 or listeria monocytogenes (10(6-7) cfu/g) were cooked to target internal temperatures of 60 or 68 degrees c on each cooking system and immediately removed from the grills without the additional holding time at 60 ...200010914656
growth and survival of escherichia coli o157:h7 and listeria monocytogenes in egg products held at different temperatures.growth and survival of escherichia coli o157:h7 and listeria monocytogenes in steamed eggs and scrambled eggs held at different temperatures (5, 18, 22, 37, 55, and 60 degrees c) were investigated in the present study. among the holding temperatures tested, both pathogens multiplied best at 37 degrees c followed by 22, 18, and 5 degrees c. in general, e. coli o157:h7 grew better in the egg products than l. monocytogenes did at all the storage temperatures tested except at 5 degrees c. e. coli o1 ...200010914658
behavior of listeria monocytogenes in pasteurized milk during fermentation with lactic acid bacteria.the behavior of listeria monocytogenes in pasteurized milk during fermentation with starter and nonstarter lactic acid bacteria was investigated. pasteurized milk was co-inoculated with approximately 10(4) cfu/ml of l. monocytogenes and 10(6) cfu/ml of lactococcus lactis, lactococcus cremoris, lactobacillus plantarum, lactobacillus bulgaricus, or streptococcus thermophilus. inoculated milks were incubated at 30 degrees c or 37 degrees c for 24 to 72 h. listeria monocytogenes survived and also gr ...200010914660
use of capillary tubes and plate heat exchanger to validate u.s. department of agriculture pasteurization protocols for elimination of listeria monocytogenes in liquid egg products.d-values for a five-strain cocktail of listeria monocytogenes in five different liquid egg products (whole egg, egg yolk, egg white, egg yolk + 5% sucrose + 5% nacl, and egg yolk + 10% nacl) were determined using 100-microl capillary tubes. the egg products were inoculated with approximately 1 x 10(10) organisms/ml and heated in capillary tubes to temperatures ranging from 53 to 69 degrees c for various time intervals. using a pilot scale plate heat exchanger, the u.s. department of agriculture ...200010914661
natural variation in susceptibility of listeria strains to class iia bacteriocins.thirty-one listeria strains were tested for sensitivity to four class iia bacteriocins, namely, enterocin a, mesentericin y105, divercin v41, and pediocin ach, and to nisin a. class iia bacteriocins displayed surprisingly similar antimicrobial patterns ranging from highly susceptible to fully resistant strains, whereas nisin a showed a different pattern in which all listeria strains were inhibited. particularly, it was observed that the strain listeria monocytogenes v7 could not be inhibited by ...200010919390
optimization of green fluorescent protein expression vectors for in vitro and in vivo detection of listeria monocytogenes.the green fluorescent protein (gfp) of the jellyfish aequorea victoria is a useful reporter molecule for monitoring in vivo gene expression in eukaryotic and prokaryotic cells. we constructed a series of gfp vectors for in situ detection of the intracellular pathogen listeria monocytogenes. the gfp-mutl gene, which encodes a red-shifted gfp, was transcriptionally fused to a strong l. monocytogenes promoter and inserted into various escherichia coli-listeria shuttle vectors: i) the integrative mo ...200010919515
real-time measurements of the interaction between single cells of listeria monocytogenes and nisin on a solid surface.a method to obtain real-time measurements of the interactions between nisin and single cells of listeria monocytogenes on a solid surface was developed. this method was based on fluorescence ratio-imaging microscopy and measurements of changes in the intracellular ph (ph(i)) of carboxyfluorescein succinimidyl ester-stained cells during exposure to nisin. immobilized cells were placed in a chamber mounted on a microscope and attached to a high-precision peristaltic pump which allowed rapid change ...200010919824
a framework for interpreting the leucine-rich repeats of the listeria internalins.the surface protein inlb of the bacterial pathogen listeria monocytogenes is required for inducing phagocytosis in various nonphagocytic mammalian cell types in vitro. inlb causes tyrosine phosphorylation of host cell adaptor proteins, activation of phosphoinositide 3-kinase, and rearrangements of the actin cytoskeleton. these events lead to phagocytic uptake of the bacterium by the host cell. inlb belongs to the internalin family of listeria proteins, which also includes inla, another surface p ...200010922035
rapid molecular typing of listeria monocytogenes by pulsed-field gel electrophoresis.pulsed-field gel electrophoresis (pfge) is a highly discriminating tool for molecular typing, but the conventional pfge protocol is time consuming. this paper describes a rapid method of pfge for listeria monocytogenes that yields results within 2 days.200010924402
three regions within acta promote arp2/3 complex-mediated actin nucleation and listeria monocytogenes motility.the listeria monocytogenes acta protein induces actin-based motility by enhancing the actin nucleating activity of the host arp2/3 complex. using systematic truncation analysis, we identified a 136-residue nh(2)-terminal fragment that was fully active in stimulating nucleation in vitro. further deletion analysis demonstrated that this fragment contains three regions, which are important for nucleation and share functional and/or limited sequence similarity with host wasp family proteins: an acid ...200010931865
consumption of eicosapentaenoic acid and docosahexaenoic acid impair murine interleukin-12 and interferon-gamma production in vivo.in mice, individual dietary omega-3 polyunsaturated fatty acids n-3 (pufa) were found to be sufficient to effect the changes in circulating interleukin (il)-12 and interferon (ifn)-gamma levels that were previously seen in fish oil-fed mice. weanling female c3h mice were fed one of five experimental diets. all five diets met all known nutritional requirements for mice and differed only in the fat source. after 4 weeks, mice were challenged with live listeria monocytogenes or sterile pbs. twenty- ...200010944484
immunostimulatory dna sequences help to eradicate intracellular pathogens. 200010944809
activation of the innate immune system by cpg oligodeoxynucleotides: immunoprotective activity and safety. 200010944812
rapid detection of salmonella typhimurium in chicken carcass wash water using an immunoelectrochemical method.an immunoelectrochemical method coupled with immunomagnetic separation was developed for rapid detection of salmonella typhimurium in chicken carcass wash water. samples of chicken carcass wash water were inoculated with salmonella typhimurium at different cell numbers. possible nonspecified inhibitors in the wash water were minimized by filtration and centrifugation. an approximately 9.4% loss of salmonella cells was found after filtration (p < 0.01). the samples were mixed with anti-salmonella ...200010945578
comparison of different reducing agents for enhanced detection of heat-injured listeria monocytogenes.the effect of different reducing agents (l-cysteine, oxyrase, and enterococcus faecium) and their combinations on the detection of heat-injured (62.8 degrees c, 7.5 min or 10 min) listeria monocytogenes was examined. the incorporation of l-cysteine (0.5 g/liter) yielded higher percentage detection than any of the other reducing agents (p < 0.05). the combination of oxyrase (10 u/ml) and e. faecium (10(3) cfu/ml) synergistically enhanced the detection of l. monocytogenes heat-injured for 10 min a ...200010945581
feasibility of a defined microflora challenge method for evaluating the efficacy of foodborne listeria monocytogenes selective enrichments.comparison of isolation methods for microbial pathogens is complicated by the variable interference caused by the competitive microflora present in test samples such as foods. in principle, using measured amounts of a standard competitor in a defined surrogate food matrix might control the effect of variable interference. this possibility was investigated using listeria monocytogenes and enrichment broths belonging to the acriflavine-nalidixate selective agent class. triplicate test sample sets ...200010945582
high-pressure processing applied to cooked sausages: bacterial populations during chilled storage.vacuum-packaged cooked sausages were pressurized at 500 mpa for 5 or 15 min at mild temperature (65 degrees c) and later stored at 2 and 8 degrees c for 18 weeks. counts of aerobic mesophiles and psychrotrophs, lactic acid bacteria, enterobacteria, baird-parker microbiota, and listeria spp. were determined 1 day and 3, 6, 9, 12, 15, and 18 weeks after treatment and compared with those of cooked sausages treated at 80 to 85 degrees c for 40 min. pressurization generated reductions of about 4 log ...200010945586
recalls of foods and cosmetics due to microbial contamination reported to the u.s. food and drug administration.in the u.s., food product recalls serve as an important intervention in stemming the consumption of food products contaminated with infectious disease agents. we summarize the number and nature of foods and cosmetics recalled as a result of microbial contamination reported to the u.s. food and drug administration (fda) for the period 1 october 1993 through 30 september 1998. during this period, microbial contamination of food and cosmetic products was the leading cause for recalls, accounting fo ...200010945589
microbiological safety of mayonnaise, salad dressings, and sauces produced in the united states: a review.the literature on the death and survival of foodborne pathogens in commercial mayonnaise, dressing, and sauces was reviewed and statistically analyzed with emphasis on salmonella, escherichia coli o157:h7, and listeria monocytogenes. the absence of reports of foodborne illness associated directly with the consumption of commercially prepared acidic dressings and sauces is evidence of their safety. salmonella, e. coli o157:h7, e. coli, l. monocytogenes, staphylococcus aureus, and yersinia enteroc ...200010945595
cytokine profile and natural killer cell activity in listeria monocytogenes infected mice treated orally with petiveria alliacea extract.in this work, we investigated the effects of petiveria alliacea extract on the production of th1-type and th2-type cytokines and on nk cells activity in normal and listeria monocytogenes infected mice. our results demonstrated that in normal/non-infected mice p. alliacea administration led to increased levels of interleukin-2 (il-2). the infection alone enhanced inf-gamma levels and nk cell activity at 48 and 72 hours of infection. the treatment with five consecutive doses of 1000 mg/kg/day of p ...200010946828
evaluation of the impact of short-term temperature abuse on the microbiology and shelf life of a model ready-to-use vegetable combination product.the growth dynamics of indigenous aerobic mesophilic populations (amp), lactic acid bacteria (lab) and inoculated (listeria spp.) microbial populations on cooked and fresh vegetable products, packaged as separate entities and in combination, subjected to temperature fluctuation, were assessed. microbial proliferation was temperature and product dependent, being most pronounced at 12 degrees c in all products with maximum growth rates of 0.140, 0.175 and 0.126 log10 cfu/g per h being identified f ...200010946838
prevalence and contamination levels of listeria monocytogenes in retail foods in japan.retail foods in japan were surveyed for the presence and contamination levels of l. monocytogenes. it was isolated from 12.2, 20.6, 37.0 and 25.0% of 41 minced beef, 34 minced pork, 46 minced chicken and 16 minced pork-beef mixture samples, respectively. mpn values were higher than 100/g in five (10.9%) minced chicken samples, but lower than 100/g in all minced beef, pork and pork-beef mixture samples. the organism was also isolated from 5.4% of the 92 smoked salmon samples at mpn values lower t ...200010946841
induction of interleukin-4 (il-4) by legionella pneumophila infection in balb/c mice and regulation of tumor necrosis factor alpha, il-6, and il-1beta.infection of balb/c mice with a sublethal concentration of legionella pneumophila causes an acute disease that is resolved by innate immune responses. the infection also initiates the development of adaptive th1 responses that protect the mice from challenge infections. to study the early responses, cytokines induced during the first 24 h after infection were examined. in the serum, interleukin-12 (il-12) was detectable by 3 h and peaked at 10 h, while gamma interferon was discernible by 5 h and ...200010948149
interleukin-1 signaling is essential for host defense during murine pulmonary tuberculosis.interleukin (il)-1 signaling is required for the containment of infections with intracellular microorganisms, such as listeria monocytogenes and leishmania major. to determine the role of il-1 in the host response to tuberculosis, we infected il-1 type i receptor-deficient (il-1r(-/-)) mice, in which il-1 does not exert effects, with mycobacterium tuberculosis. il-1r(-/-) mice were more susceptible to pulmonary tuberculosis, as reflected by an increased mortality and an enhanced mycobacterial ou ...200010950787
antibodies to the junctional adhesion molecule cause disruption of endothelial cells and do not prevent leukocyte influx into the meninges after viral or bacterial infection.a hallmark of infectious meningitis is the invasion of leukocytes into the subarachnoid space. in experimental meningitis triggered by tumor necrosis factor-alpha and interleukin-1beta, the interaction of leukocytes with endothelial cells and the subsequent migration of the cells through the vessel wall can be inhibited by an antibody to the junctional adhesion molecule (jam). in contrast to the cytokine-induced meningitis model, anti-jam antibodies failed to prevent leukocyte influx into the ce ...200010950802
an updated model of cell-mediated immunity--listeriosis: clinical and research aspects.listeria monocytogenes causes sepsis and meningitis in immunocompromised hosts and a devastating maternal/fetal infection in pregnant women. in recent years a more benign gastroenteritis in normal hosts has been described. listeria has been increasingly identified as a food-borne pathogen, and large-scale contamination of processed foods with resulting outbreaks has occurred in recent years, possibly as a result of consolidation of the food industry. experimental listeriosis in mice has proven t ...200010951886
mutations of arginine residues within the 146-kkrrk-150 motif of the acta protein of listeria monocytogenes abolish intracellular motility by interfering with the recruitment of the arp2/3 complex.the recruitment of actin to the surface of intracellular listeria monocytogenes and subsequent tail formation is dependent on the expression of the bacterial surface protein acta. of the different functional domains of acta identified thus far, the n-terminal region is absolutely required for actin filament recruitment and intracellular motility. mutational analysis of this domain which abolished actin recruitment by intracellular listeria monocytogenes identified two arginine residues within th ...200010954425
[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 ...200011436588
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 ...200011429020
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, ...200011347303
[listeriosis: an infrequent infection in patients with hiv].although resistance to listeria monocytogenes infection requires intact t-cell mediated immunity, listeriosis is an infrequent problem in patients with hiv infection and only about 50 patients have been reported to date. only two patients with hiv and l. monocytogenes have been attended in our hospital since the beginning of aids epidemic in 1981. case 1: a man with hiv and 364 cd4+ cells/mm3 presented fever and occipital headache. the cerebral scan was normal and l. monocytogenes grew in licuor ...200011213581
[autoregulation of expression of secreted proteins in listeria monocytogenes].the spectrum of proteins secreted by l. monocytogenes greatly depends on the composition of the cultivation medium. the introduction of activated charcoal (ac) into brain heart infusion (bhi) leads to the secretion of a number of additional proteins with mol.wt. ranging between 20 and 100 kd, whose production is not observed in pure bhi. the effect depends on the absorption capacity of ac: when adsorption capacity is reduced due to a decrease in the concentration of ac or its preliminary saturat ...200011220960
[immunity in listeriosis].in this review modern concepts on the formation of specific immunity to listeriosis are presented. numerous data indicate that in listeria monocytogenes virulence and the capacity for inducing specific protection is ensured by the protein listeriolysin o. the importance of gamma-interferon, tumor necrosis factor alpha, interleukin 12 and other mediators in ensuring the differentiation of (cd4(+) t-cells into th1-helpers and cytotoxic t-lymphocytes in animals infected with l. monocytogenes is des ...200011220980
fresh ideas for food safety. 200011221672
interactions between listeriae and lectins.interactions between members of the genus listeria and lectins are described. l. monocytogenes was shown to be heterogenous with respect to agglutination by lectins. l. monocytogenes serotype 4b had a pattern of lectin binding distinct from the other listeriae. titration of the listeriae with lectins proved to be useful in further distinguishing serotype 4b. the results show that lectins may provide useful probes as diagnostic reagents for listeriae.200011845476
listeria monocytogenes septic arthritis in an immunocompetent adult. 199911856258
[pathogenic gene analysis of listeria isolated from foods].in 1996-1997, listeria in foods from 12 provinces of china were detected by using the national standard examination method gb 4789.30-94 (routine traditional methods). twenty four strains listeria monocytogenes and 141 strains listeria were identified by biochemical procedures and animal toxicity experiment. polymerase chain reaction(pcr) was used to amplify two specific dna fragments(719 bp and 446 bp) of listeriolysin o and internalin genes with two pairs of primer--hly1-2 and inl1-2, respecti ...199911938989
[investigation on the contamination of listeria monocytogenes in seven kinds of foods].an examination on 3746 samples of 7 kinds of foods from 12 provinces of china for the detection of listeria monocytogenes (lm) was carried out in 1996-1997. the detected rates of lm in commercial cold drinks, raw meat, sterilized milk products, cooked meat products, raw milk and aquatic products were 1.39%, 1.53%, 0.52%, 0.47%, 0.72% and 0.19% respectively. the result showed that lm present in the contaminated foods in a potential hazardous factor of foodborne disease.199911938995
spread of antibiotic resistance with food-borne pathogens.this short review summarizes data on antibiotic resistance profiles of common food-borne pathogens like salmonella sp., escherichia coli, campylobacter sp., listeria monocytogenes, clostridium perfringens, staphylococcus aureus, and coagulase-negative staphylococci. as a flashlight on the literature of the last few years, it provides ample evidence that antibiotic resistance traits have entered the microflora of farm animals and the food produced from them. molecular analysis of the resistance g ...199911212335
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 ...199911428999
[listeria monocytogenes--the bacterium, mode of transmission and relation to food consumption]. 199910955096
[the influence of antibiotics on phagocytic and bacteriocidal activity of rabbit peritoneal macrophages stimulated by filtrates of cultured t-lymphocytes].the aim of the study was to determine the influence of twelve antibacterial antibiotics (various concentrations) on the activation of rabbit peritoneal macrophages. macrophages were stimulated by filtrates of culture of lymphocytes t obtained from ova immunized rabbits. phagocytic activity and intracellular killing against listeria monocytogenes were tested by fluorescence method. penicillin g (0.4-50 mg/l), erythromycin and lincomycin (2.5-40 mg/l) used at all concentrations, were not exerting ...199910803270
[the effect of selected antibacterial antibiotics on production of interferon gamma (ifn-g) by mouse t lymphocytes stimulated by listeria monocytogenes].the aim of the study was to determine the influence of certain antibiotics on the production of ifn-gamma by mouse lymphocytes t after four days incubation with listeria monocytogenes. the level of mouse ifn-gamma was determined by elisa method (inter test-gamma mouse ifn-gamma kit, genzyme). the strongest immunosuppression effect was demonstrated using rifampicin (39 ng/ml ifn-gamma) (control: 123 +/- 29 ng/ml ifn-gamma, p < 0.05). lower immunosuppression effects were observed also with cephrad ...199910803271
[listeria monocytogenes incidence and evaluation of the sanitary quality of filleted fresh fish from the metropolitan area of san josé].fish constitutes a very important part of human diet due to its protein content. the poor commercialization system existing in costa rica for this product causes an important secondary contamination that may include microorganisms such as fecal coliforms, staphylococcus aureus and even pathogens such as listeria monocytogenes. there is a lack of recent information about the microbiological quality of the fish that arrives to the metropolitan area of san josé, costa rica, so the aim of this work ...199910883301
intracellular growth of listeria monocytogenes insertional mutant deprived of protein p60.the study of the mutant strain described here demonstrates that several characteristics contribute to maximal virulence of pathogenic strains of l. monocytogenes. the invasion levels of l. monocytogenes jb1115, a p60-deficient strain, were the same as for the parent strain l. monocytogenes 1043s in j774 macrophage-like cells. the invasion level of listeria strains in int407 cells was 100 times lower than in j774 cells. in epithelial int407 cells, the time of division of p60- strain l. monocytoge ...199910756716
effect of benzylpenicillin on murein biosynthesis, turnover and structure in listeria monocytogenes cells.the action of beta-lactam antibiotics such as ampicillin and benzylpenicillin on cells of listeria monocytogenes appears to be bacteriostatic. however, after approximately two hours in the presence of 10 x mic of benzylpenicillin the cells begin to rapidly lose viability without undergoing lysis. in this report we present the results of studies on the biosynthesis of murein in l. monocytogenes cells during the first 120 min of their exposure to benzylpenicillin as measured by the continuous and ...199910756717
the interaction of intestinal epithelial cells and intraepithelial lymphocytes in host defense.intestinal intraepithelial lymphocytes (i-iel) are located at the basolateral surfaces of intestinal epithelial cells (i-ec) and play important roles in the homeostasis of intestinal microenvironment. i-iel comprise unique t cell populations including cd4-cd8alphaalpha+ t cells expressing t cell receptor (tcr)alphabeta or tcrgammadelta and cd4+ cd8alphaalpha+ t cells expressing tcr alphabeta. we show here that cd4+ cd8alphaalpha+ i-iel belongs to th1 type t cells capable of responding to self-mh ...199910741862
listeria monocytogenes subtypes associated with mortality among fallow deer (dama dama).different subtypes of listeria monocytogenes were isolated from various animal and environmental samples during an episode of increased mortality on a fallow deer (dama dama) farm. during a 4-wk period, six fallow deer died, including four does, one fawn, and one adult buck. prior to death, one of the does had exhibited central nervous system signs characteristic of listeriosis. postmortem examination of the six deer showed no histologic changes typical of listeriosis, although inflammatory chan ...199910749443
pregnancy-associated glycoprotein levels in pregnant goats inoculated with toxoplasma gondii or listeria monocytogenes: a retrospective study.the pregnancy-associated glycoprotein (pag) concentration profiles of goats that had been experimentally inoculated with either toxoplasma gondii or listeria monocytogenes are described. all goats were examined regularly by ultrasonography. in t. gondii-infected females (n = 5), a slow decrease of pag was observed throughout a period of 55 to 74 d after inoculation. afterwards, the goats either aborted (n = 4) or kidded 1 dead and 1 weak fetus (n = 1). in l. monocytogenes-infected females (n = 8 ...199910735115
efficiency of four secondary enrichment protocols in differentiation and isolation of listeria spp. and listeria monocytogenes from smoked fish processing chains.four secondary enrichment protocols (conventional methods: uvm ii, fraser 24 h and fraser 48 h: impedimetric method: listeria electrical detection medium) were studied for their ability to isolate listeria spp. and listeria monocytogenes from fish and environmental samples collected along the processing chain of cold-smoked fish. from all methods, listeria spp. and l. monocytogenes were respectively present in 56 and 34 of 315 samples analysed. fraser broth incubated for 48 h gave the fewest fal ...199910733247
cell adhesion molecules in the pathogenesis of and host defence against microbial infection.eukaryotic cell adhesion molecules (cams) are used by various cells and extracellular molecules in host defence against infection. they are involved in many processes including recognition by circulating phagocytes of a site of inflammation, transmigration through the endothelial barrier, diapedesis through basement membrane and extracellular matrix, and release of effector mechanisms at the infected site. cams involved in leucocyte-endothelial cell interaction include the selectins, integrins, ...199910694943
[direct gram staining of blood culture sample enabled the early diagnosis of brain abscess due to listeria monocytogenes].a 58 year old woman had a long history of immunocompromised state. since age 28 she had multiple endocrine neoplasm type 2a: her thyroid gland and bilateral adrenal glands were removed because of pheochromocytoma and thyroid medullary carcinoma. corticosteroid and levothyroxine were supplemented. at age 57 she was afflicted with systemic lupus erythematodes and nephrotic syndrome. prednisolone therapy was started. two months later she developed fever, lethergy, headache and left hemiparesis. mri ...199910689944
high seropositivity against listeriolysin o in humans. 199910690251
rat dorsal root ganglia neurons as a model for listeria monocytogenes infections in culture.neurotropism of listeria monocytogenes was studied in rat dorsal root ganglia (drg) and hippocampal neurons in culture. using a system in which the drg neurons can grow relatively free from other cells, it was observed that such drg neurons, in contrast to hippocampal neurons, can be effectively infected by l. monocytogenes. the bacteria aligned along drg axons, but not along hippocampal neurites. a mutant deficient in internalin, a protein required for entry into e-cadherin-expressing cells, di ...199910691089
validation of predictive models describing the growth of listeria monocytogenes.in this study, predictions for growth rate of listeria on food products were evaluated by both general applicable models and specific growth models. literature values, obtained from a large number of publications, for growth rates in/on a variety of foods were compared by graphical and mathematical analysis with predictions given by various models. apart for the great advantage of being generally applicable, the general models performed best. however, only small differences between the various m ...199910728614
behaviour of listeria spp. in naturally contaminated chorizo (spanish fermented sausage).counts of listeria spp. were determined during the manufacture and drying of 21 lots of five chorizo varieties produced by three different manufacturers. presumptive listeria were not isolated from any of the batches produced in a large factory (f3) using starter, sorbate and controlled ripening at high temperatures. initial levels in factory 1 (f1), with no starter added, but controlled ripening at low temperatures, were ca 3.5 log10 cfu/g while those in factory 2 (f2), with no starter added an ...199910728617
listeria monocytogenes in renal transplant recipients.five cases of listeria monocytogenes bacteremia were observed from april to december 1985, among renal transplant recipients from the same hospital in são paulo, brazil. the patients were adults (mean age: 40.6 years), and the basic complaint was fever, with no report of meningeal syndrome. laboratory tests revealed the presence of two serovars, (1/2)a and 4b, which were classified into three lysotypes. the four strains of serovar 4b showed the same antibiotype, with resistance to cefoxitin, cli ...199910671292
physical and metabolic causes of sub-lethal damage in listeria monocytogenes after long-term chilled storage at 4 degrees c.cells of listeria monocytogenes display sub-lethal injury when subjected to long-term chill-storage in a nutrient-poor environment. the physical and metabolic causes of sub-lethal injury to two meat (l61 and l62) and two clinical (l98 and l99) l. monocytogenes strains chill-stored (4 degrees c) for 4 weeks in phosphate-buffered saline at ph 7.0 and ph 5.5, and ph 5.5 in the presence of 0.3% potassium sorbate, were characterized. causes of sub-lethal injury were determined by examining changes in ...199910664914
simple method to observe the adaptive response of listeria monocytogenes in food.a simple, novel method for determining stress-adaptive response of listeria monocytogenes in food systems is presented. the method involves plating samples on listeria-selective agar (lsa) acidified to ph 5.25 with incubation at 36 degrees c for 60 h to detect acid adaptation and plating on lsa with 70 gl-1 nacl and incubation at 7 degrees c for 7 d to detect cold-osmotic adaptation. adapted cells produced larger colonies (> 1 mm) under these conditions than unadapted cells. scot a (97%) and bri ...199910664977
rapid detection of listeria monocytogenes by pcr-elisa.a rapid detection system specific for listeria monocytogenes based upon the polymerase chain reaction was developed. the specificity of the primers and the probe annealing to the coding region of the mpl gene proved positive with the dna from a total of 103 l. monocytogenes strains, while dna from another 73 listeria and non-listeria strains tested negative. to facilitate detection with large numbers of samples, a microtitre plate assay was established with biotinylated probes. use of a standard ...199910664986
listeria monocytogenes in pork slaughtering and cutting plants. use of rapd, pfge and pcr-rea for tracing and molecular epidemiology.in order to determine the origin of pork cuts contamination by listeria monocytogenes, 287 isolates, collected from five french pork slaughtering and cutting plants, from live pigs to pork cuts, were characterised using three molecular typing methods: random amplification of polymorphic dna (rapd) carried out with five different primers, genomic macrorestriction using apai with pulsed-field gel electrophoresis (pfge) and a pcr-restriction enzyme analysis (pcr-rea) based on the polymorphism exist ...199910634704
occurrence of nisin z production in lactococcus lactis bfe 1500 isolated from wara, a traditional nigerian cheese product.screening for bacteriocin production of 500 strains of lactic acid bacteria (lab) from various african fermented foods resulted in the detection of a bacteriocin producing lactococcus lactis (bfe 1500) isolated from a dairy product called wara. the bacteriocin inhibited not only the closely related lab, but also strains of listeria monocytogenes, listeria innocua, clostridium butyricum, clostridium perfringens, bacillis cereus and staphylococcus aureus. it was heat stable even at autoclaving tem ...199910634705
incidence and control of listeria monocytogenes in foods in denmark.the danish regulatory policy on listeria monocytogenes in foods is based on the principles of haccp and was developed using a health risk assessment approach. the danish policy focuses examinations and criteria for l. monocytogenes in ready-to-eat foods and is based on a combination of inspection and product-testing. based on current epidemiological information from several countries, a concentration of l. monocytogenes not exceeding 100 cfu/g of food at the time of consumption, seems to be of l ...199910634710
structure of the lnlb leucine-rich repeats, a domain that triggers host cell invasion by the bacterial pathogen l. monocytogenes.the l. monocytogenes protein lnlb activates phosphoinositide 3-kinase and induces phagocytosis in several mammalian cell types. the 1.86 a resolution x-ray crystal structure of the leucine-rich repeat domain of lnlb that is both necessary and sufficient to induce phagocytosis is presented here. the structure supports a crucial role for calcium in host cell invasion by l. monocytogenes and supplies a rationale for its function. calciums are bound to the protein in an unusually exposed manner that ...199910635330
[pleural effusion due to listeria monocytogenes. a case report and review of the literature].the infection caused by listeria monocytogenes is a relatively common condition in immunosuppressed patients. the most frequent presentation in adults are sepsis and meningitis. pleural fluid infection due to this pathogen is a rare finding in the literature. most cases are found in immunosuppressed patients, particularly in those with haematologic malignancies. we report one case of pleural fluid infection due to listeria monocytogenes in a patient with hepatic cirrhosis (the third case in the ...199910609360
mycobacterial infection of macrophages results in membrane-permeable phagosomes.cell-mediated immunity is critical for host resistance to tuberculosis. t lymphocytes recognizing antigens presented by the major histocompatibility complex (mhc) class i and class ii molecules have been found to be necessary for control of mycobacterial infection. mice genetically deficient in the generation of mhc class i and class ia responses are susceptible to mycobacterial infection. although soluble protein antigens are generally presented by macrophages to t cells through mhc class ii mo ...199910611360
[discrepant outcome of intrauterine listeria infection in dichorionic twins].background and case report: we report on a case of fetal listeriosis in a dichorionic twin pregnancy where both placentae, but only one of the twins were infected. while the firstborn child showed no infection and remained healthy until today, the other newborn had all clinical signs of granulomatosis infantiseptica and died despite of immediate resuscitation immediately after delivery. conclusions: this discrepant course with listeriosis in twins underlines, that fetal factors influence the cli ...199910612192
surface interleukin-10 inhibits listericidal activity by primary macrophages.interleukin-10 (il-10) down-regulates multiple functions of monocytes and macrophages, including the ability of macrophages to kill many intracellular microorganisms. the experiments presented here test the hypothesis that il-10 expressed on the cell surface inhibits the ability of primary mouse macrophages to kill the facultative, intracellular bacterium listeria monocytogenes. we show that, in contrast to macrophages from normal mice, both bone marrow-derived macrophages (bmdm) and thioglycoll ...199910614778
molecular and cell biological aspects of infection by listeria monocytogenes.bacterial pathogens have developed many subtle mechanisms to overcome and exploit cellular processes within the infected eukaryotic host cell. listeria monocytogenes, a facultative intracellular non-spore forming gram-positive pathogen, uses a number of strategies to ursurp and harness host cell processes to invade, proliferate, move intracellularly and effect cell-to-cell spread during the course of infection. in this review progress in elucidating mechanisms by which the bacteria recruit and u ...199910631564
the mucosal phase of listeria infection.listeria monocytogenes is an enteroinvasive bacterial pathogen of man and animals. listeriae have been shown capable of infecting the host by translocating from the intestinal lumen through peyer's patches (pp), however, results of experiments now indicate that these facultative intracellular parasites may also translocate through pp-independent routes. with regards to this, on occasion we observed that listeriae were absent from the pp of mice inoculated intragastrically with l. monocytogenes, ...199910631565
early host-pathogen interactions in the liver and spleen during systemic murine listeriosis: an overview.systemic listeriosis initiated by parenteral inoculation of mice with listeria monocytogenes has been used extensively as a model infection for studying mammalian host defense against intracellular bacterial pathogens in general. most effort has been expended on trying to understand the requirement for specific t cell-mediated immunity for combatting infection with this pathogen. by contrast, non-specific defenses have received much less attention. however, it is now obvious that these early inn ...199910631566
immune reactions to listeria monocytogenes in the brain.listeria monocytogenes (lm) is a common pathogen of cerebral infections. experimental studies in mice have revealed that epithelial cells of the choroid plexus, ependymal cells, macrophages/microglia, and neurons are the target cells of lm. for the intracerebral pathogenesis of lm cell-to-cell spread via phospholipase c was particularly important. however, phospholipase c-deficient lm were not completely attenuated and, therefore, other virulence factors may also contribute to the intracerebral ...199910631567
a knockout approach to understanding cd8+ cell effector mechanisms in adaptive immunity to listeria monocytogenes.in the described experimental approach, we use an attenuated lm strain to evoke lm specific cd8+ t cell responses. in this fashion, we can immunize immunocompromised gene knockout mice, that would succumb to low level infection with virulent lm. we then generate antigen matched, lm-specific cd8+ t cell lines from wild-type and gene knockout mice, and compare their capacity to provide immunity to lm infection in vivo. to date, our results demonstrate that cd8+ t cell-derived ifn-gamma and tnf are ...199910631568
mhc class jb-restricted cell responses to listeria monocytogenes infection.murine infection with listeria monocytogenes induces cd8+ t cell responses specific for bacterial peptides that are presented on the infected cell surface by mhc class ia and mhc class ib molecules. we have used mhc tetramers to demonstrate that cd8+ t cells restricted by the h2-m3 mhc class ib molecules constitute a substantial portion of the t cell response to l. monocytogenes infection. the in vivo size and kinetics of mhc class ib-restricted t cell populations suggests that they play a promi ...199910631569
the need for a novel generation of vaccines.although empirical vaccine development was highly successful, it has now reached its limits. vaccines are only efficacious against those pathogens which are primarily controlled by antibodies. protection against many infectious agents, however, strongly depends on t lymphocytes. thus, novel vaccines have to stimulate the combination of t lymphocytes that is required for an optimum protective immune response. although identification of antigens remains crucial, novel vaccine design also needs to ...199910631576
processing of listeria monocytogenes antigens and the in vivo t-cell response to bacterial infection.presentation of antigens to t lymphocytes is a critical step in the clearance of pathogens from their hosts and in the establishment of protective immunity. several animal models have been developed to study this process, but few have been as informative as the murine immune response to listeria monocytogenes infection. herein we review the presentation of l. monocytogenes proteins by the mhc class i antigen-processing pathway and the in vivo t-cell response to these bacterial antigens. these st ...199910631945
increasing the sensitivity of listeria monocytogenes assays: evaluation using elisa and amperometric detection.an immunosensor for the detection of listeria monocytogenes was developed. elisa and amperometric studies were run in parallel to develop a more sensitive and rapid assay for the bacterium. conditions for the immunosensor were primarily characterised using elisa. a direct sandwich assay was employed and the affinities of two polyclonal (goat and rabbit) and one monoclonal (mouse) anti-l. monocytogenes antibodies were compared using this format. owing to low sensitivity being obtained with all an ...199910605890
inhibition of listeria monocytogenes by in situ produced and semipurified bacteriocins of carnobacterium spp. on vacuum-packed, refrigerated cold-smoked salmon.listeria monocytogenes inhibition by carnobacterium strains and crude bacteriocins on sterile and commercial vacuum-packed cold-smoked salmon stored at 4 degrees c and 8 degrees c was investigated. carnobacterium piscicola v1 was bactericidal against l. monocytogenes at the two temperatures, whereas carnobacterium divergens v41 presented a bacteriostatic effect. c. piscicola sf668 delayed l. monocytogenes growth at 8 degrees c and had a bacteriostatic effect at 4 degrees c. listeria growth was n ...199910606143
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