Publications
| Title | Abstract | Year Filter | PMID(sorted descending) Filter |
|---|
| role of il-10 in a neonatal mouse listeriosis model. | this study was undertaken to test the hypothesis that altered il-10 production plays a role in the increased susceptibility of neonates to listeriosis. plasma il-10 levels were measured in neonatal and adult mice at various times after infection with listeria monocytogenes. relative to adults, neonatal mice had markedly increased il-10 levels early in the course of infection with listeria using a 90% lethal dose. higher neonatal il-10 responses were also observed after injecting adults and pups ... | 1999 | 10453021 |
| isolation of rifampin-resistant mutants of listeria monocytogenes and their characterization by rpob gene sequencing, temperature sensitivity for growth, and interaction with an epithelial cell line. | the sequence of the rpob gene from listeria monocytogenes was determined. rifampin-resistant (rif(r)) mutants arising from l. monocytogenes cultures exposed to rifampin were isolated, and by partial sequencing of their rpob genes, seven different point mutations affecting five different amino acids (473asp-->asn or gly, 479gly-->asp, 483his-->tyr or leu, 528ile-->phe, and 530ser-->tyr), which led to mics of 0.5 to 100 microg/ml for the organisms, were determined. these mutants showed various def ... | 1999 | 10449475 |
| interleukin-15 production at the early stage after oral infection with listeria monocytogenes in mice. | we previously reported that exogenous interleukin-15 (il-15) induces proliferation and activation of intestinal intraepithelial lymphocytes (i-iel) in naive mice. to investigate the ability of endogenous il-15 to stimulate i-iel in vivo, we monitored i-iel and intestinal epithelial cells (i-ec) in mice after an oral infection with listeria monocytogenes. although the populations of alphabeta and gammadelta i-iel were not significantly changed after the oral infection, the expression level of int ... | 1999 | 10447719 |
| evaluation of an rdna listeria probe for listeria monocytogenes typing. | a listeria monocytogenes dna fragment, identified as part of the 23s rrna gene and called b17, was used to type 266 l. monocytogenes strains and 43 strains of other listeria species. results were compared with those obtained: i) with pba2 (which consists of a 2.3 kb bacillus subtilis dna fragment encoding 16s rrna, inserted into the hindiii site of pbr322), a probe previously used for listeria and l. monocytogenes ribotyping, and ii) with dna macrorestriction profiles analysis. twenty profiles w ... | 1999 | 10440057 |
| the bvr locus of listeria monocytogenes mediates virulence gene repression by beta-glucosides. | the beta-glucoside cellobiose has been reported to specifically repress the prfa-dependent virulence genes hly and plca in listeria monocytogenes nctc 7973. this led to the hypothesis that beta-glucosides, sugars of plant origin, may act as signal molecules, preventing the expression of virulence genes if l. monocytogenes is living in its natural habitat (soil). in three other laboratory strains (egd, l028, and 10403s), however, the effect of cellobiose was not unique, and all fermentable carboh ... | 1999 | 10438775 |
| transposition of is1181 in the genomes of staphylococcus and listeria. | the recombinant plasmid pip1713 was constructed to analyse the transpositional activity of the insertion sequence is1181 in staphylococcus aureus rn4220, staphylococcus carnosus tm300 and listeria monocytogenes egd. this 11.3-kb plasmid contains two genetically different elements: (i) a pe194ts-derived replicon, the ermc gene of which confers resistance to erythromycin in gram-positive bacteria of several species, and (ii) a copy of is1181, cloned from s. aureus bm3121, in which the tetracycline ... | 1999 | 10436926 |
| molecular investigation of a listeriosis outbreak in goats caused by an unusual strain of listeria monocytogenes. | during a 16-month period, 10 goats with listeriosis were identified in 2 herds that shared 3 bucks, including 1 that died of listeriosis. using dna fingerprinting, we determined that a single genetically unique listeria monocytogenes strain had infected all goats from which isolates were available. all isolates were unable to metabolize rhamnose (rhamnose-negative), whereas as a species, l monocytogenes is considered to have a rhamnose-positive phenotype. therefore, these isolates would have bee ... | 1999 | 10434977 |
| the use of enterocin ccm 4231 in soy milk to control the growth of listeria monocytogenes and staphylococcus aureus. | the inhibitory effect of enterocin ccm 4231 (concentration 3200 au ml-1) was used to control the growth of listeria monocytogenes ohio and staphylococcus aureus in soy milk. the growth and bacteriocin (enterocin) production of producer strain ccm 4231 in soy milk was also checked. bacteriocin production by ccm 4231 strain in soy milk was first detected after 2 h from the beginning of cultivation (100 au ml-1). the stationary phase for ccm 4231 was reached after 6 h reaching 10.38 cfu ml-1 (log10 ... | 1999 | 10432598 |
| h2-m3-restricted t cells in bacterial infection: rapid primary but diminished memory responses. | major histocompatibility complex (mhc) class ib molecules have been implicated in cd8(+) t cell-mediated defenses against intracellular bacterial infection, but the relative importance of mhc class ib-restricted t cells in antimicrobial immunity is unknown. in this report, we use mhc tetramers to characterize t cell responses restricted by h2-m3, an mhc class ib molecule that selectively presents n-formyl peptides. we find that sizeable h2-m3-restricted t cell responses, occurring earlier than m ... | 1999 | 10432283 |
| a comparison of t cell memory against the same antigen induced by virus versus intracellular bacteria. | cytotoxic t cell (ctl) memory was analyzed after infection with lymphocytic choriomeningitis virus (lcmv) and recombinant listeria monocytogenes (rlm) expressing the complete nucleoprotein of lcmv (rlm-np(acta)) or only the immunodominant epitope of h-2(d) mice (rlm-np(118-126)). immunization with lcmv and rlm induced a long-lived increased ctl precursor (ctlp) frequency specific for the viral (np(118-126)) and for the bacterial (llo(91-99)) epitope, respectively. however, after infection with r ... | 1999 | 10430936 |
| listeria monocytogenes reinfection in a pregnant woman. | 1999 | 10430206 | |
| a quantitative approach for studying the effect of heat treatment conditions on resistance and recovery of bacillus cereus spores. | when a bacterial population undergoes an unfavourable transient increase in temperature, a death phase followed by a lag and growth phase are observed for the surviving and cultivable population. the lag phase is of great interest in regard to food safety, but for bacterial spores, very few studies have been carried out on the evolution of lag time versus heat treatment duration. the experiments monitored on spores of two strains of bacillus cereus showed a biphasic evolution of the lag time for ... | 1999 | 10426451 |
| production of listeriolysin o by listeria monocytogenes (scott a) under heat-shock conditions. | early stationary phase cells of listeria monocytogenes (scott a) were examined to determine the effect of heat-shock on the production of listeriolysin o (llo) during and after resuscitation at 37 degrees c. cells were subjected to a heat-shock at 48 degrees c for 1 h. intracellular and extracellular proteins of the heat-shocked cells were assayed for llo using a microtiter plate hemolysis assay and analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (sds-page) and immunoblotti ... | 1999 | 10426449 |
| actin-based motility of the intracellular pathogen listeria monocytogenes: assessing the inhibitory specificity of abm-1 peptide analogues. | actin-based motility motifs [abm-1 sequence = (d/e)fppppx(d/e), where x = p or t, and abm-2 sequence = xppppp, where x denotes g, a, l, p, and s] facilitate assembly of an activated motility complex. potent inhibition of intracellular motility of pathogens by abm-1 and abm-2 peptide analogues has served as a criterion for investigating actin-based motility. to assess the specificity of abm-1 peptide inhibitors, we microinjected proline-rich peptides into listeria-infected ptk2 host cells. use of ... | 1999 | 10425223 |
| codon optimization effect on translational efficiency of dna vaccine in mammalian cells: analysis of plasmid dna encoding a ctl epitope derived from microorganisms. | interspecific difference of codon usage is one of the major obstacles for effective induction of specific immune responses against bacteria and protozoa by dna immunization. using genes encoding major histocompatibility complex class i-restricted cytotoxic t-lymphocyte (ctl) epitopes, derived from an intracellular bacterium, listeria monocytogenes and a mouse malaria parasite, plasmodium yoelii, we report here that the codon optimization level of the genes is not precisely proportional to, but d ... | 1999 | 10425204 |
| listeriosis linked to retail outlets in hospitals--caution needed. | 1999 | 10422368 | |
| [a case of listeriosis revealed by voluminous cerebral abscesses]. | 1999 | 10422151 | |
| the arp2/3 complex is essential for the actin-based motility of listeria monocytogenes. | actin polymerisation is thought to drive the movement of eukaryotic cells and some intracellular pathogens such as listeria monocytogenes. the listeria surface protein acta synergises with recruited host proteins to induce actin polymerisation, propelling the bacterium through the host cytoplasm [1]. the arp2/3 complex is one recruited host factor [2] [3]; it is also believed to regulate actin dynamics in lamellipodia [4] [5]. the arp2/3 complex promotes actin filament nucleation in vitro, which ... | 1999 | 10421578 |
| foodborne infections during pregnancy. | the consequences of foodborne illness can be particularly devastating during pregnancy because both the woman and her fetus are at risk. escalated production of progesterone during pregnancy leads to down-regulation of cellular (cell-mediated) immune functions. many foodborne pathogens (and other pathogens) are intracellular pathogens, and infections caused by these pathogens are controlled by cell-mediated immunity. the pregnancy-induced decrease in cell-mediated immune functions leads to incre ... | 1999 | 10419281 |
| inactivation of listeria monocytogenes/pseudomonas biofilms by peracid sanitizers. | the ability of peracetic acid and peroctanoic acid sanitizers to inactivate mixed-culture biofilms of a pseudomonas sp. and listeria monocytogenes on stainless steel was investigated. types of biofilms tested included a 4-h attachment of the mixed-cell suspension and a 48-h biofilm of mixed culture formed in skim milk or tryptic soy broth. biofilm-containing coupons were immersed in solutions of hypochlorite, peracetic acid, and peroctanoic acid either with or without organic challenge. organic ... | 1999 | 10419269 |
| incidence of salmonella, campylobacter jejuni, campylobacter coli, and listeria monocytogenes in poultry carcasses and different types of poultry products for sale on the belgian retail market. | from january 1997 to may 1998, 772 samples of poultry carcasses and poultry products for sale on the retail market in belgium were analyzed for the presence of salmonella spp., salmonella enteritidis, campylobacter jejuni, c. coli, and listeria monocytogenes per 100 cm2 or 25 g. poultry samples were contaminated with salmonella (36.5%), c. jejuni and c. coli (28.5%), and l. monocytogenes (38.2%). in about 12.3% of the poultry samples, the l. monocytogenes contamination level exceeded 1 cfu per g ... | 1999 | 10419264 |
| rapid detection of escherichia coli o157:h7 in ground beef using a fiber-optic biosensor. | a portable fiber-optic biosensor was used to detect escherichia coli o157:h7 in seeded ground beef samples. the principle of the system is a sandwich immunoassay using cyanine 5 dye-labeled polyclonal anti-e. coli o157:h7 antibodies for generation of a specific fluorescent signal. signal acquisition is effected by launching light from a 635-nm diode laser into a dual tapered 600-microm silica fiber. fluorescent molecules within approximately 100 nm of the fiber surface are excited by the evanesc ... | 1999 | 10419260 |
| influence of soft rot bacteria on growth of listeria monocytogenes on potato tuber slices. | growth of listeria monocytogenes on potato tuber slices and its interaction with four representative species of soft rot bacteria (pseudomonas fluorescens, p. viridiflava, erwinia carotovora subsp. carotovora, and xanthomonas campestris) were investigated. when potato tuber slices were inoculated with one of two l. monocytogenes strains (scott a and atcc 15313), an increase in numbers of 3 to 4 logs per gram of tissue was observed with samples that were stored at 20 degrees c for 6 days. however ... | 1999 | 10419206 |
| growth control of listeria monocytogenes on cold-smoked salmon using a competitive lactic acid bacteria flora. | a lactobacillus sake strain lke5 and four strains of carnobacterium piscicola were evaluated as biopreservation cultures to control the growth of listeria monocytogenes on vacuum-packed, cold-smoked salmon stored at 5 degrees c. all five strains were antilisterial as live cultures in an agar diffusion assay. cell-free supernatants of two strains of c. piscicola and l. sake lke5 were also antilisterial because of the production of bacteriocins. the presence of high cell numbers of strains of c. p ... | 1999 | 10419205 |
| microbiological quality of retail imported unprepared whole lettuces: a phls food working group study. public health laboratory service. | a study of imported unprepared whole lettuces sampled from supermarkets, greengrocers, shops, and market stalls found that all were of acceptable microbiological quality. twenty-seven out of 151 (18%) imported lettuce samples had enterobacteriaceae levels of 10(4) cfu/g or more. however, these bacteria that constitute part of the natural microflora of unprepared vegetables may also be derived from the soil and/or by poor handling. the pathogens, salmonella spp., shigella spp., campylobacter spp. ... | 1999 | 10419203 |
| the actin-based motility of intracellular listeria monocytogenes is not controlled by small gtp-binding proteins of the rho- and ras-subfamilies. | in this study, we analyzed whether the actin-based motility of intracellular listeria monocytogenes is controlled by the small gtp-binding proteins of the rho- and ras-subfamilies. these signalling proteins are key regulatory elements in the control of actin dynamics and their activity is essential for the maintenance of most cellular microfilament structures. we used the clostridium difficile toxins tcdb-10463 and tcdb-1470 to specifically inactivate these gtp-binding proteins. treatment of euk ... | 1999 | 10418138 |
| the smcl gene of listeria ivanovii encodes a sphingomyelinase c that mediates bacterial escape from the phagocytic vacuole. | the ruminant pathogen listeria ivanovii differs from listeria monocytogenes in that it causes strong, bizonal haemolysis and a characteristic shovel-shaped co-operative haemolytic ('camp-like') reaction with rhodococcus equi. we cloned the gene responsible for the differential haemolytic properties of l. ivanovii, smcl. it encodes a sphingomyelinase c (smase) highly similar (> 50% identity) to the smases from staphylococcus aureus (beta-toxin), bacillus cereus and leptospira interrogans. smcl wa ... | 1999 | 10417642 |
| dynamics of actin-based movement by rickettsia rickettsii in vero cells. | actin-based motility (abm) is a virulence mechanism exploited by invasive bacterial pathogens in the genera listeria, shigella, and rickettsia. due to experimental constraints imposed by the lack of genetic tools and their obligate intracellular nature, little is known about rickettsial abm relative to listeria and shigella abm systems. in this study, we directly compared the dynamics and behavior of abm of rickettsia rickettsii and listeria monocytogenes. a time-lapse video of moving intracellu ... | 1999 | 10417192 |
| plasma membrane expression of heat shock protein 60 in vivo in response to infection. | heat shock protein 60 (hsp60) is constitutively expressed in the mitochondria of eukaryotic cells. however, it has been identified in other subcellular compartments in several disease states and in transformed cells, and it is an immunogenic molecule in various infectious and autoimmune diseases. to better understand the factors that influence expression of hsp60 in normal cells in vivo, we analyzed its cellular and subcellular distribution in mice infected with the intracellular bacterium liste ... | 1999 | 10417191 |
| purification and properties of proline-rich antimicrobial peptides from sheep and goat leukocytes. | we purified three proline-rich antimicrobial peptides from elastase-treated extracts of sheep and goat leukocytes and subjected two of them, oabac5alpha and chbac5, to detailed analysis. oabac5alpha and chbac5 were homologous to each other and to bovine bac5. both exhibited potent, broad-spectrum antimicrobial activity under low-concentration salt conditions. while the peptides remained active against escherichia coli, pseudomonas aeruginosa, bacillus subtilis, and listeria monocytogenes in 100 ... | 1999 | 10417180 |
| listeriosis in a holstein cow. | bovine listeriosis is a sporadie bacterial infection most commonly manifested by encephalitis or meningoencephalitis in adult animals. cattle fed poorly fermented haylage or corn silage are at increased risk. mortality is high without early antibiotic and supportive therapy. listeria monocytogenes can affect many species and is a public health concern. | 1999 | 10416074 |
| th1 t cell responses to hiv-1 gag protein delivered by a listeria monocytogenes vaccine are similar to those induced by endogenous listerial antigens. | listeria monocytogenes is a facultative intracellular bacterium that lives and grows in the cytoplasm of the host cell. the hallmark of a listerial infection is a cell-mediated immune response to its own secreted virulence factors. thus, l. monocytogenes vaccines engineered to secrete hiv proteins may be ideal vectors for boosting cellular immune responses against hiv. using strains of l. monocytogenes that stably express and secrete hiv gag (lm-gag) to deliver this ag to the immune system, we h ... | 1999 | 10415046 |
| expression of l-selectin on th1 cells is regulated by il-12. | l-selectin has become established as a key molecule in the recirculation of naïve t cells from the blood to peripheral lymph nodes, yet little is known about its role in the migration of effector or memory cells. while differentiating naïve cd4+ t cells into th1 and th2 subsets in vitro, it was noted that l-selectin levels were maintained on the th1 subset of cells. the expression of l-selectin on the th1 cells appeared to be dependent on the presence of il-12. th2 cells, differentiated in the a ... | 1999 | 10415016 |
| polar lipids of four listeria species containing l-lysylcardiolipin, a novel lipid structure, and other unique phospholipids. | the membrane lipids of listeria innocua, listeria monocytogenes, listeria seeligeri and listeria welshimeri were fractionated on deae-cellulose and purified by chromatography on silica gel and/or preparative tlc. the lipid structures were elucidated by chemical and chromatographic means. the polar lipid composition of the four listeria species was similar. phospholipids predominated. they consisted of phosphatidylglycerol, l-lysylphosphatidylglycerol, cardiolipin [bis(phosphatidyl)glycerol] and ... | 1999 | 10408878 |
| oral administration of hot water extracts of chlorella vulgaris reduces ige production against milk casein in mice. | hot water extract of chlorella vulgaris (cve) is a biological response modifier (brm) which enhances resistance to listeria monocytogenes through augmentation of helper t cell type 1 (thl) responses producing gamma-interferon (gammaifn). we show here that oral administration of cve in mice suppressed the production of immunoglobulin (ig)e against casein antigen accompanied by increased gammaifn and il-12 mrna expression. oral administration of cve enhanced thl response to casein in the spleen of ... | 1999 | 10408628 |
| a single amino acid in e-cadherin responsible for host specificity towards the human pathogen listeria monocytogenes. | human e-cadherin promotes entry of the bacterial pathogen listeria monocytogenes into mammalian cells by interacting with internalin (inla), a bacterial surface protein. here we show that mouse e-cadherin, although very similar to human e-cadherin (85% identity), is not a receptor for internalin. by a series of domain-swapping and mutagenesis experiments, we identify pro16 of e-cadherin as a residue critical for specificity: a pro-->glu substitution in human e-cadherin totally abrogates interact ... | 1999 | 10406800 |
| high-performance liquid chromatography determination of residue levels on chicken carcasses treated with cetylpyridinium chloride. | cetylpyridinium chloride (cpc) has been found to be effective in reducing contamination of chicken carcasses from a variety of microorganisms, including escherichia coli o157:h7, salmonella typhimurium, campylobacter jejuni, aeromonas hydrophila, listeria monocytogenes, and staphylococcus aureus. a procedure has been developed to determine residue levels on chicken carcasses after cpc treatment. for the analysis, chicken carcasses were extracted with 95% ethanol. the cpc concentration in the ext ... | 1999 | 10406212 |
| repeated oral dosing with listeria monocytogenes in mice as a model of central nervous system listeriosis in man. | human listeriosis is a food-borne disease of immunosuppressed or previously healthy adults. the repeated oral administration of a sublethal dose (5x10(9)colony-forming units) of listeria monocytogenes for 7 or 10 consecutive days led to the development of severe central nervous system (cns) lesions in 25% of experimental mice. histopathological examination of the brain revealed rhombencephalitis and ventriculitis as two distinct inflammatory patterns, resembling those seen in human listeriosis. ... | 1999 | 10405304 |
| antimicrobial activity of the essential oil of calamintha nepeta and its constituent pulegone against bacteria and fungi. | the chemical composition of the essential oil of calamintha nepeta and its antimicrobial activity against listeria monocytogenes, bacillus cereus, salmonella veneziana, s. paratyphi b. s. typhimurium, fusarium moniliforme, botrytis cinerea, aspergillus niger and pyricularia oryzae have been studied. moreover the main constituents of the oil (limonene, menthone, pulegone, menthol) have been tested against the same microorganisms. only pulegone showed antimicrobial activity, particularly against a ... | 1999 | 10404547 |
| in-vitro activity of levofloxacin, ofloxacin and d-ofloxacin against coryneform bacteria and listeria monocytogenes. | the objective of this study was to evaluate the in-vitro activity of levofloxacin, ofloxacin and d-ofloxacin compared with ciprofloxacin, norfloxacin and sparfloxacin against coryneform bacteria and listeria monocytogenes isolated from clinical samples. the following organisms (and number of strains) were studied: corynebacterium jeikeium (20), corynebacterium urealyticum (20), corynebacterium minutissimum (20), corynebacterium striatum (20), corynebacterium amycolatum (30), brevibacterium spp. ... | 1999 | 10404334 |
| the bacteriology of neonatal septicaemia in ile-ife, nigeria. | the incidence of septicaemia among neonates categorized as being at high risk was 55 per cent in ile-ife, nigeria. gram-positive organisms, specifically staphylococcus aureus, were predominant (33.8 per cent) among bacteria cultured from proven cases of septicaemia. other coagulase-negative staphylococci also contributed 21 per cent, with staphylococcus epidermidis occurring in 5 per cent of the isolates. listeria monocytogenes was cultured from 8.4 per cent of septic neonates. pseudomonas aerug ... | 1999 | 10401192 |
| the use of dummy data points when fitting bacterial growth curves. | we consider the problem of fitting mathematical models for bacterial growth and decline to experimental data. using models which represent the phases of the growth and decline cycle in a piecewise manner, we describe how least-squares fitting can lead to potentially misleading parameter estimates. we show how these difficulties can be overcome by extending a data set to include hypothetical observations (dummy data points) which reflect biological beliefs, and the resulting stabilization of para ... | 1999 | 10399311 |
| comparative study on the in vitro antibacterial activity of australian tea tree oil, cajuput oil, niaouli oil, manuka oil, kanuka oil, and eucalyptus oil. | to compare the antibacterial activity of the australian tea tree oil (tto) with various other medicinally and commercially important essential myrtaceous oils (cajuput oil, niaouli oil, kanuka oil, manuka oil, and eucalyptus oil) the essential oils were first analysed by gc-ms and then tested against various bacteria using a broth microdilution method. the highest activity was obtained by tto, with mic values of 0.25% for enterobacter aerogenes, escherichia coli, klebsiella pneumoniae, proteus m ... | 1999 | 10399193 |
| inhibition of salmonella typhimurium in the chicken intestinal tract by a transformed avirulent avian escherichia coli. | an avirulent, wild-type avian escherichia coli (e. coli av) was electrotransformed with a plasmid coding for the production of microcin 24 (pgob18) and was designated e. coli avgob18. the transformant inhibited the growth of seven serotypes of salmonella commonly associated with colonization and contamination of poultry products and seven strains of e. coli o157:h7 in the in vitro colicin/microcin assay. the transformant did not inhibit the replication of multiple isolates of listeria monocytoge ... | 1999 | 10396637 |
| impaired cytokine signaling in mice lacking the il-1 receptor-associated kinase. | stimulation of the type 1 il-1r (il-1r1) and the il-18r by their cognate ligands induces recruitment of the il-1r-associated kinase (irak). activation of irak leads in turn to nuclear translocation of nf-kappab, which directs expression of innate and adaptive immune response genes. to study irak function in cytokine signaling, we generated cells and mice lacking the irak protein. irak-deficient fibroblasts show diminished activation of nf-kappab when stimulated with il-1. immune effector cells w ... | 1999 | 10395695 |
| immune system development and function in prolactin receptor-deficient mice. | prolactin (prl) is the primary lactogenic pituitary hormone that plays an essential role in many aspects of reproduction, from fertilization to mammary gland development and maternal behavior. prl has also been reported to play a role in immunoregulation. because initial observations indicated that hypophysectomized rats present abnormalities of the immune system, including increased thymic atrophy and lymphopenia, a number of studies have focused on the potential immunomodulatory roles of prl. ... | 1999 | 10395643 |
| high intake of milk fat inhibits intestinal colonization of listeria but not of salmonella in rats. | during fat digestion, fatty acids and monoglycerides are liberated in the gastrointestinal tract. generally, these lipids are potent inhibitors of gram-positive bacteria in vitro but have less effect on gram-negative microbes. considering this, we hypothesized that increased intake of bovine milk fat would result in enhanced gastrointestinal killing of listeria monocytogenes (gram-positive) but have little effect on infection with salmonella enteritidis (gram-negative) in rats. to test this, rat ... | 1999 | 10395602 |
| megakaryocyte hyperplasia and enhanced agonist-induced platelet activation in vasodilator-stimulated phosphoprotein knockout mice. | vasodilator-stimulated phosphoprotein (vasp), a substrate of camp- and cgmp-dependent protein kinases, is associated with focal adhesions, cell-cell contacts, microfilaments, and highly dynamic membrane regions. vasp, which is expressed in most cell types and in particularly high levels in human platelets, binds to profilin, zyxin, vinculin, f-actin, and the listeria monocytogenes surface protein acta. vasp is a member of the enabled (ena)/vasp protein family and is thought to be involved in act ... | 1999 | 10393958 |
| the development of bactericidal yeast strains by expressing the pediococcus acidilactici pediocin gene (peda) in saccharomyces cerevisiae. | the excessive use of sulphur dioxide and other chemical preservatives in wine, beer and other fermented food and beverage products to prevent the growth of unwanted microbes holds various disadvantages for the quality of the end-products and is confronted by mounting consumer resistance. the objective of this study was to investigate the feasibility of controlling spoilage bacteria during yeast-based fermentations by engineering bactericidal strains of saccharomyces cerevisiae. to test this nove ... | 1999 | 10392443 |
| comparative efficacies of antibiotics in a rat model of meningoencephalitis due to listeria monocytogenes. | the antibacterial activities of amoxicillin-gentamicin, trovafloxacin, trimethoprim-sulfamethoxazole (tmp-smx) and the combination of trovafloxacin with tmp-smx were compared in a model of meningoencephalitis due to listeria monocytogenes in infant rats. at 22 h after intracisternal infection, the cerebrospinal fluid was cultured to document meningitis, and the treatment was started. treatment was instituted for 48 h, and efficacy was evaluated 24 h after administration of the last dose. all tes ... | 1999 | 10390217 |
| factors influencing in vitro killing of bacteria by hemocytes of the eastern oyster (crassostrea virginica). | a tetrazolium dye reduction assay was used to study factors governing the killing of bacteria by oyster hemocytes. in vitro tests were performed on bacterial strains by using hemocytes from oysters collected from the same location in winter and summer. vibrio parahaemolyticus strains, altered in motility or colonial morphology (opaque and translucent), and listeria monocytogenes mutants lacking catalase, superoxide dismutase, hemolysin, and phospholipase activities were examined in winter and su ... | 1999 | 10388697 |
| production of monoclonal antibodies to listeria monocytogenes and their application to determine the virulence of isolates from channel catfish. | we produced monoclonal antibodies (mabs) to the extracellular proteins of listeria monocytogenes egd grown in chelex-treated improved minimal medium. ten of the positive hybridomas generated were chosen for further characterization. seven of the mabs reacted with a protein having a molecular mass of 60 kda. these mabs inhibited listeriolysin (llo)-mediated hemolysis, and two of them were specific for llo and none of the other thiol-activated toxins tested. in an enzyme-linked immunosorbent assay ... | 1999 | 10388671 |
| apoptosis of caco-2 intestinal cells invaded by listeria monocytogenes: protective effect of lactoferrin. | the apoptosis of infected hepatocytes is a critical step in nonspecific defense against listeria monocytogenes infection. we have observed that infection by l. monocytogenes in enterocyte-like cells (caco-2) results in apoptosis. however, a large fraction of infected intestinal epithelial cells escape from cellular condensation and fragmentation, typical of programmed cell death, and become necrotic. the balance between apoptosis and necrosis seems to be influenced by the number of internalized ... | 1999 | 10388533 |
| characterization, production, and purification of leucocin h, a two-peptide bacteriocin from leuconostoc mf215b. | leuconostoc mf215b was found to produce a two-peptide bacteriocin referred to as leucocin h. the two peptides were termed leucocin halpha and leucocin hbeta. when acting together, they inhibit, among others, listeria monocytogenes, bacillus cereus, and clostridium perfringens. production of leucocin h in growth medium takes place at temperatures down to 6 degrees c and at ph below 7. the highest activity of leucocin h in growth medium was demonstrated in the late exponential growth phase. the ba ... | 1999 | 10387116 |
| physical and genetic map of the listeria monocytogenes egd serotype 1/2a chromosome. | listeria monocytogenes is a facultative intracellular pathogen responsible for both invasive and non-invasive food-borne illness in animals and humans. in this study, macrorestriction analysis following pulsed-field gel electrophoresis was used to show that listeria monocytogenes serovar 1/2a strain egd has a single chromosome containing eight noti fragments of 1100, 850, 365, 320, 275, 40, 30 and 20 kb in size and 11 asci fragments of 860, 470, 410, 360, 320, 250, 110, 80, 50, 30 and 20 kb. the ... | 1999 | 10386380 |
| genetic immunization of mice against listeria monocytogenes using plasmid dna encoding listeriolysin o. | the development of protective immunity against many intracellular bacterial pathogens commonly requires sublethal infection with viable forms of the bacteria. such infection results in the in vivo activation of specific cell-mediated immune responses, and both cd4+ and cd8+ t lymphocytes may function in the induction of this protective immunity. in rodent models of experimental infection with listeria monocytogenes, the expression of protective immunity can be mediated solely by the immune cd8+ ... | 1999 | 10384131 |
| the role of b cells in the establishment of t cell response in mice infected with an intracellular bacteria, listeria monocytogenes. | to clarify the role of b cells in the establishment of t cell response against intracellular bacteria, b-cell-deficient (mumt-/-) mice were infected with an intracellular bacteria, listeria monocytogenes, and t cell response against the bacteria was analyzed. on day 6 of primary listeria infection, spleen t cells of the mumt-/- mice showed significantly lower levels of proliferative response and ifn-gamma production than those of normal infected mice after in vitro stimulation with listerial ant ... | 1999 | 10383820 |
| acid adaptation of listeria monocytogenes strains does not offer cross-protection against an activated lactoperoxidase system. | listeria monocytogenes has been implicated in foodborne illness outbreaks involving several types of cheeses made from acidified milk. acid shock response (asr) and acid tolerance response (atr) could be possible reasons for its survival. the asr and atr of three strains of l. monocytogenes (v7, v37, and ca) in skim milk acidified to ph 4.0 and 3.5 with lactic acid and held at 32 degrees c were studied. studies were also done to determine if acid adaptation of the organism enhanced survival in t ... | 1999 | 10382659 |
| defining the growth/no-growth interface for listeria monocytogenes in mexican-style cheese based on salt, ph, and moisture content. | the objective of this study was to define combinations of ph, salt, and moisture that produce growth, stasis, or inactivation of listeria monocytogenes in mexican-style cheese. a soft, directly acidified, rennet-coagulated, fresh cheese similar to mexican-style cheese was produced. the cheese was subsequently altered in composition as required by the experimental protocol. a factorial design with four moisture contents (42, 50, 55, and 60%), four salt concentrations (2.0, 4.0, 6.0, and 8.0% wt/w ... | 1999 | 10382647 |
| differential immune responses in mice with left- and right-turning preference. | humoral and cell-mediated immune responses of inbred balb/c male mice were assayed for differential reactivities associated with behavioral sidedness, which was evaluated by spontaneous rotational behavior in a circular cage model system. mice with left-turning preference had lower in vivo primary igm and igg anti-keyhole limpet hemocyanin (klh) antibody responses, delayed-type hypersensitivity (dth) responses, and host-resistance against the intracellular bacteria, listeria monocytogenes, than ... | 1999 | 10378880 |
| interleukin 12-dependent interferon gamma production by cd8alpha+ lymphoid dendritic cells. | we investigated the role of antigen-presenting cells in early interferon (ifn)-gamma production in normal and recombinase activating gene 2-deficient (rag-2(-/-)) mice in response to listeria monocytogenes (lm) infection and interleukin (il)-12 administration. levels of serum ifn-gamma in rag-2(-/-) mice were comparable to those of normal mice upon either lm infection or il-12 injection. depletion of natural killer (nk) cells by administration of anti-asialogm1 antibodies had little effect on if ... | 1999 | 10377194 |
| dissemination of listeria monocytogenes by infected phagocytes. | in vitro data suggest that blood-borne listeria monocytogenes organisms enter the central nervous system (cns) by direct invasion of endothelial cells or by cell-to-cell spread from infected phagocytes to endothelial cells. however, a role for infected phagocytes in neuroinvasion and dissemination of l. monocytogenes in vivo has not been confirmed experimentally. experiments described here tested whether l. monocytogenes-infected peripheral blood leukocytes (pbl) circulated in bacteremic mice an ... | 1999 | 10377133 |
| listeriosis: recognizing it, treating it, preventing it. | listeria monocytogenes has become a major pathogen in foodborne illness. it most often affects patients who are pregnant, at the extremes of life, or immunocompromised in some way. a variety of clinical manifestations are possible, but bacteremia and meningitis are most common. this article reviews the epidemiology, microbiology, populations at risk, clinical manifestations, treatment, and prevention of listeriosis. | 1999 | 10375847 |
| pulsed high electric field causes 'all or nothing' membrane damage in listeria monocytogenes and salmonella typhimurium, but membrane h+-atpase is not a primary target. | salmonella typhimurium (cra 1005) was more sensitive than listeria monocytogenes (nctc 11994) to pulsed high electric field (phef) treatment in distilled water (10, 15 and 20 kv/cm), 10 mm tris-maleate buffer, ph 7.4 (15 kv/cm) and model beef broth (0.75%, w/v; 15 kv/cm). sublethal injury could not be detected using a selective medium plating technique, indicating that bacterial inactivation by phef may be an 'all or nothing' event. phef-induced membrane permeabilisation resulted in an increase ... | 1999 | 10375130 |
| molecular epidemiology of an outbreak of febrile gastroenteritis caused by listeria monocytogenes in cold-smoked rainbow trout. | febrile gastroenteritis in five healthy persons was associated with the consumption of vacuum-packed cold-smoked rainbow trout containing listeria monocytogenes. l. monocytogenes isolates from the incriminated fish product lot and the stool samples were all of serotype 1/2a and were indistinguishable by pulsed-field gel electrophoresis employing asci and smai. | 1999 | 10364616 |
| endogenous cytokines during a lethal 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 protective roles but that il-4 and il-10 play detrimental roles in nonlethal listeria monocytogenes infection in mice. in this paper, we studied the roles of endogenous cytokines in a lethal infection with l. monocytogenes in mice. tnf-alpha and il-6 titres in the bloodstreams, spleens and livers paralleled bacterial numbers in the org ... | 1999 | 10361718 |
| the ketolide antibiotic hmr 3647, a candidate substance for the treatment of systemic and intracerebral infections with listeria monocytogenes. | hmr 3647 is a novel macrolide derivative with a broad spectrum of activity against grampositive bacteria and some fastiduous gramnegative bacteria, anaerobes and toxoplasma gondii. in this work, its activity against the facultatively intracellular bacterium, listeria monocytogenes, was examined in vitro, in tissue culture and in animal models of systemic and intracerebral infection and compared with that of erythromycin. all strains of l. monocytogenes were susceptible to the substance, with min ... | 1999 | 10360316 |
| the listeria monocytogenes protein inlb is an agonist of mammalian phosphoinositide 3-kinase. | the gram-positive pathogen listeria monocytogenes induces its own internalization into some non-phagocytic mammalian cells by stimulating host tyrosine phosphorylation, phosphoinositide (pi) 3-kinase activity, and rearrangements in the actin cytoskeleton. entry into many cultured cell lines is mediated by the bacterial protein inlb. here we investigate the role of inlb in regulating mammalian signal transduction and cytoskeletal structure. treatment of vero cells with purified inlb caused rapid ... | 1999 | 10358053 |
| bacterial infections in infants 60 days and younger: epidemiology, resistance, and implications for treatment. | to establish what might be more optimal initial antibiotic therapy for suspected invasive bacterial infections in infants 60 days or younger who are evaluated in the emergency department (ed). | 1999 | 10357302 |
| occurrence and typing of listeria monocytogenes strains in retail vacuum-packed fish products and in a production plant. | one hundred and ten samples of ready-to-eat, vacuum-packed, smoked and cold-salted fish products were collected from retail outlets in southern finland during 1996 for examination of the occurrence and level of listeria monocytogenes. the samples originated from 12 producers. positive samples with levels exceeding 100 cfu/g were encountered mainly in one of the producers (no. 8). therefore, 200 samples from the plant and the products of this producer were studied during august-september 1996 and ... | 1999 | 10357279 |
| a model based on absorbance data on the growth rate of listeria monocytogenes and including the effects of ph, nacl, na-lactate and na-acetate. | a mathematical model was developed for predicting the growth of l. monocytogenes at 9 degrees c in the presence of 70 ppm sodium nitrite, and at different levels of ph (5.5-6.5), sodium chloride (1.0-4.0%), sodium lactate (0-0.5%) and sodium acetate (0-0.6%). collection of the growth data was done using absorbance measurements in broth cultures and the absorbance measurement was evaluated. the model was compared to the food micromodel, and against the growth of l. monocytogenes in a vacuum-packe ... | 1999 | 10357278 |
| analysis of the bacterial surface ripening flora of german and french smeared cheeses with respect to their anti-listerial potential. | the anti-listerial potential of 19 different french smeared cheese bacterial consortia was analyzed semi-quantitatively. comparison of the total viable cell count to the direct microscopic count yielded no indication that non-culturable bacteria contribute significantly to the undefined, complex ripening floras. from 2613 isolates, 48 showed clear inhibition of one or more listeria monocytogenes strains on solid medium, while only three isolates excreted an anti-listerial, soluble substance when ... | 1999 | 10357277 |
| inhibition of listeria monocytogenes by carnobacterium spp. strains in a simulated cold smoked fish system stored at 4 degrees c. | preservation of smoked salmon from bacterial spoilage, and especially from listeria monocytogenes by bacteriocin producers is a promising challenge. over a hundred lactic acid bacteria, isolated from commercial vacuum packaged cold smoked salmon, were screened for their antagonistic activity against l. innocua. twenty-two strains were able to produce bacteriocin-like proteinaceous substances. these strains were characterized physiologically and biochemically as carnobacterium strains. three diff ... | 1999 | 10357271 |
| antigen secreted from noncytosolic listeria monocytogenes is processed by the classical mhc class i processing pathway. | intracellular bacteria can reside in a vacuolar compartment, or they can escape the vacuole and become free living in the cytoplasm. the presentation of ag by class i mhc molecules has been defined primarily for ag present in the cytoplasm. it was therefore thought that ags from bacteria that remain in a vacuole would not be presented by mhc class i molecules. although some studies have provided data to support this idea, it is not necessarily true for all intracellular bacteria. for example, we ... | 1999 | 10352246 |
| conjugative mobilization of the rolling-circle plasmid pip823 from listeria monocytogenes bm4293 among gram-positive and gram-negative bacteria. | we determined the sequence and genetic organization of plasmid pip823, which contains the dfrd gene; dfrd confers high-level trimethoprim resistance to listeria monocytogenes bm4293 by synthesis of dihydrofolate reductase type s2. pip823 possessed all the features of the pub110/pc194 plasmid family, whose members replicate by the rolling-circle mechanism. the rep gene encoded a protein identical to repu, the protein required for initiation of the replication of plasmids ptb913 from a thermophili ... | 1999 | 10348847 |
| nisin and alta 2341 inhibit the growth of listeria monocytogenes on smoked salmon packaged under vacuum or 100% co2. | the effects of nisin and alta 2341 on the growth of listeria monocytogenes were assessed on smoked salmon packaged under vacuum or 100% co2. smoked salmon slices (ph 6.3) were inoculated with a cocktail of seven l. monocytogenes isolates at a level of approximately 2.5 log10 colony forming units (cfu) g-1. after inoculation, the surface of the smoked salmon slices was treated with either nisin (400 or 1250 iu g-1) or alta 2341 (0.1 or 1%). the smoked salmon was packaged and stored at 4 degrees c ... | 1999 | 10347892 |
| isolation, partial purification and characterization of a bacteriocin produced by a newly isolated bacillus subtilis strain. | a wild type micro-organism producing antibacterial substances has been isolated from a chinese fermented soybean seasoning and identified as bacillus subtilis. a crude antibacterial preparation (cabp) was obtained by ammonium sulphate precipitation. isoelectric focusing assay revealed at least four antimicrobial components in the cabp. however, in sds-page analysis, only one peptide band displayed antimicrobial activity against pathogenic bacillus cereus and listeria monocytogenes. this inhibito ... | 1999 | 10347890 |
| synergistic effect of heat and sodium lactate on the thermal resistance of yersinia enterocolitica and listeria monocytogenes in minced beef. | the effect of sodium lactate (nal) (0, 2.4 or 4.8%), in heating and recovery media, on yersinia enterocolitica and listeria monocytogenes numbers recovered from minced beef heated at 55 degrees c, was examined. survivors were enumerated on selective media at ph 5.7/7.4 (y. enterocolitica) or ph 5.7/7.2 (l. monocytogenes). recovery of the organisms depended on the ph and nal levels in the recovery medium. the heat resistance of y. enterocolitica (p < 0.001) and l. monocytogenes (p < 0.01) decreas ... | 1999 | 10347886 |
| influence of temperature and growth phase on expression of a 104-kilodalton listeria adhesion protein in listeria monocytogenes. | interaction of listeria monocytogenes with mammalian intestinal cells is believed to be an important first step in listeria pathogenesis. transposon (tn916) mutagenesis provided strong evidence that a 104-kda surface protein, designated the listeria adhesion protein (lap), was involved in adherence of l. monocytogenes to a human enterocyte-like caco-2 cell line (v. pandiripally, d. westbrook, g. sunki, and a. bhunia, j. med. microbiol. 48:117-124, 1999). in this study, expression of lap in l. mo ... | 1999 | 10347076 |
| live virulent rhodococcus equi, rather than killed or avirulent, elicits protective immunity to r. equi infection in mice. | mice inoculated intravenously with a sublethal dose of live virulent rhodococcus equi atcc 33701 that contained an 85-kb virulence plasmid were immune to a lethal intravenous challenge of atcc 33701. this immunity depended upon the dose of immunization and developed rapidly: mice primed with 10(5) live atcc 33701 eliminated the challenged bacteria more rapidly than mice primed with doses ranging from 10(2) to 10(4) bacteria, and mice given 10(5) live atcc 33701 intravenously withstood the lethal ... | 1999 | 10340706 |
| acid-adapted listeria monocytogenes displays enhanced tolerance against the lantibiotics nisin and lacticin 3147. | log-phase listeria monocytogenes cells become tolerant to a variety of environmental stresses following acid adaptation at ph 5.5. we demonstrated that adapted cells also exhibit increased tolerance to nisin and, to a lesser extent, lacticin 3147. at nisin concentrations of 100 and 200 iu/ml the survival of acid-adapted cells was approximately 10-fold greater than nonadapted cells. however, acid adaptation had only a moderate effect on the tolerance of l. monocytogenes to lacticin 3147, a phenom ... | 1999 | 10340677 |
| microbial, physical, and chemical quality of packaged ice in florida. | in a statewide survey, ice samples purchased at retail were evaluated for labeling information and microbiological, chemical, and physical quality. only 11% of bags from on-premises manual facilities, compared to 79% for off-premises mechanical facilities, had appropriate label information. one ice sample exceeded the state regulatory limit for aerobic plate count (apc) (<500 cfu/ml). yeasts and molds were detected in 12% of the samples. no listeria monocytogenes were found in any of the samples ... | 1999 | 10340675 |
| application of high hydrostatic pressure to eliminate listeria monocytogenes from fresh pork sausage. | ground pork patties were inoculated separately with 10(9) cfu/g each of three strains of listeria monocytogenes obtained from the national animal disease center (nadc). inoculated patties were packaged under vacuum and treated at 414 megapascals (60,000 lb/in2) for up to 60 min by high hydrostatic pressure (hhp). survivors were determined by surface plating onto modified oxford agar and trypticase soy agar with yeast extract, as well as by the most probable number method using listeria enrichmen ... | 1999 | 10340668 |
| identification of a new locus in listeria monocytogenes involved in cellobiose-dependent repression of hly expression. | expression of the prfa-controlled virulence gene hly (encoding the pore-forming cytolysin listeriolysin) is down-regulated by readily metabolized carbon sources in listeria monocytogenes. we isolated a tn917-insertional mutant of l. monocytogenes (strain lo28), which expressed a hemolytic phenotype in the presence of cellobiose. using hly fusions to luxaluxb genes, we show that hly expression was derepressed in the presence of cellobiose at the transcriptional level. surprisingly, hly expression ... | 1999 | 10339818 |
| the wiskott-aldrich syndrome protein directs actin-based motility by stimulating actin nucleation with the arp2/3 complex. | actin polymerization at the cell cortex is thought to provide the driving force for aspects of cell-shape change and locomotion. to coordinate cellular movements, the initiation of actin polymerization is tightly regulated, both spatially and temporally. the wiskott-aldrich syndrome protein (wasp), encoded by the gene that is mutated in the immunodeficiency disorder wiskott-aldrich syndrome [1], has been implicated in the control of actin polymerization in cells [2] [3] [4] [5]. the arp2/3 compl ... | 1999 | 10339430 |
| porcine epithelial beta-defensin 1 is expressed in the dorsal tongue at antimicrobial concentrations. | epithelial cells and phagocytes contain antimicrobial polypeptides that participate in innate host defense. a recently cloned porcine beta-defensin, pbd-1, was detected by northern organ blots exclusively in the tongue epithelium. we generated recombinant pbd-1 peptide by using a baculovirus-insect cell expression system and obtained two forms (pbd-142 and pbd-138), which differed by n-terminal truncation. only pbd-142 was found in scrapings of the surface of the dorsal tongue or the buccal muco ... | 1999 | 10338529 |
| presence of eubacteria in biopsies from crohn's disease inflammatory lesions as determined by 16s rrna gene-based pcr. | the aim of this study was to search for putative microbial agents in crohn's disease (cd) tissues by bacterial broad-range 16s rdna pcr combined with genus- and species-specific dna hybridisation analysis. biopsies taken both surgically and endoscopically from the terminal ileum of 11 cd patients and 11 control patients were investigated. significant amounts of eubacteria were demonstrated in biopsies taken endoscopically from both affected and unaffected individuals; the biopsies taken at surge ... | 1999 | 10334593 |
| use of automated ribotyping of austrian listeria monocytogenes isolates to support epidemiological typing. | we used automated ribotyping on the riboprinter microbial characterization system to study the epidemiology of listeriosis in western austria over the period 1988-1996. thirty-six isolates containing three serotypes were included in this collection. each of the 16 ribotype groupings (ribogroups) produced in this study contained a single serotype. isolates collected from within a single food factory environment all grouped into unique ribogroups. one factory contained isolates showing two unique ... | 1999 | 10333075 |
| [identification of listeria monocytogenes by pcr method]. | to establish a rapid, sensitive and specific polymerase chain reaction (pcr) method for detection of listeria monocytogenes (lm). | 1998 | 10322746 |
| peptidoglycan hydrolase lytf plays a role in cell separation with cwlf during vegetative growth of bacillus subtilis. | peptidoglycan hydrolase, lytf (cwle), was determined to be identical to yhdd (deduced cell wall binding protein) by zymography after insertional inactivation of the yhdd gene. yhdd exhibits high sequence similarity with cwlf (papq, lyte) and p60 of listeria monocytogenes. the n-terminal region of yhdd has a signal sequence followed by five tandem repeated regions containing polyserine residues. the c-terminal region corresponds to the catalytic domain, because a truncated protein without the n-t ... | 1999 | 10322020 |
| clpe, a novel type of hsp100 atpase, is part of the ctsr heat shock regulon of bacillus subtilis. | clp atpases, which include the ubiquitous hsp100 family, are classified according to their structural features and sequence similarities. during the course of the bacillus subtilis genome sequencing project, we identified a gene encoding a new member of the hsp100 family. we designated this protein clpe, as it is the prototype of a novel subfamily among the clp atpases, and have identified homologues in several bacteria, including listeria monocytogenes, enterococcus faecalis, streptococcus pyog ... | 1999 | 10320580 |
| a comparative study of the actin-based motilities of the pathogenic bacteria listeria monocytogenes, shigella flexneri and rickettsia conorii. | listeria monocytogenes, shigella flexneri, and rickettsia conorii are three bacterial pathogens that are able to polymerize actin into 'comet tail' structures and move within the cytosol of infected cells. the actin-based motilities of l. monocytogenes and s. flexneri are known to require the bacterial proteins acta and icsa, respectively, and several mammalian cytoskeleton proteins including the arp2/3 complex and vasp (vasodilator-stimulated phosphoprotein) for l. monocytogenes and vinculin an ... | 1999 | 10318762 |
| characteristics of induction of virulence factor expression by activated charcoal in listeria monocytogenes. | activated charcoal has been previously shown to induce in vitro expression of virulence factors by listeria monocytogenes. in trying to elucidate the nature of the charcoal action, we found that the treatment of brain heart infusion medium with activated charcoal followed by charcoal removal does not result in an increase of virulence factor expression. at the same time, the addition of fresh charcoal to the charcoal-treated medium induces expression, suggesting that the effect of activated char ... | 1999 | 10234832 |
| characterisation of a new operon encoding a zur-like protein and an associated abc zinc permease in listeria monocytogenes. | metal ions uptake is mainly studied for iron, as it has often been implicated in bacterial virulence. although listeria monocytogenes virulence is expected to be controlled by the iron availability, little is known about such an uptake and its regulation. we describe the analysis of the first operon involved in metal ions uptake in l. monocytogenes. its three orfs encode respectively (1) an abc protein, likely implicated in zinc uptake, (2) a hydrophobic membrane protein, generally associated wi ... | 1999 | 10234828 |
| the protective role of t-cell receptor vgamma1+ t cells in primary infection with listeria monocytogenes. | we have previously reported that the t-cell receptor (tcr) gamma delta+ t cells increase in mice infected with an intracellular bacteria listeria monocytogenes, and the cells predominantly express vdelta6 and vgamma1 genes. in this study, we used a monoclonal antibody (mab) specific to tcr vgamma1 to estimate the frequency of vgamma1+ t cells and we discuss their significance in protection against l. monocytogenes. the spleen, liver and peritoneal exudate cells from mice intraperitoneally infect ... | 1999 | 10233675 |
| listeria monocytogenes-induced endogenous endophthalmitis in an otherwise healthy individual: rapid pcr-diagnosis as the basis for effective treatment. | listeria monocytogenes is a rare cause of endogenous endophthalmitis. to date 15 cases have been published in the literature. all eyes showed similar clinical features and profound visual loss mainly due to delayed diagnosis. | 1999 | 10230593 |
| response to listeria monocytogenes in mice lacking mhc class ia molecules. | mhc class ia-deficient mice (h2 kb-/- db-/-) inoculated with the intracellular pathogen listeria monocytogenes (lm) displayed a three- to fourfold expansion of splenic cd8+ t cells 6 days following infection. culture of these spleen cells in vitro gave rise to ctl that recognized lm-infected target cells and were restricted by the class ib molecules, qa1b and m3. exposure of target cells to heat-killed lm (hklm) rather than live bacteria did not result in ctl-mediated lysis. target cells pulsed ... | 1999 | 10228021 |
| cd8+ t cells are a biologically relevant source of macrophage inflammatory protein-1 alpha in vivo. | chemokines are small proteins that direct the migration of leukocytes to inflammatory foci. many cell types, including macrophages, fibroblasts, endothelial cells, and lymphocytes, produce chemokines in vitro, but biologically relevant sources of chemokines in vivo have not been well characterized. to investigate the pertinent sources of macrophage inflammatory protein-1 alpha (mip-1 alpha) in vivo, we used mip-1 alpha-deficient (mip-1 alpha-/-) mice as donors and as recipients in adoptive trans ... | 1999 | 10228020 |
| detection of salmonella spp. and listeria monocytogenes in suspended organic waste by nucleic acid extraction and pcr. | a nucleic acid-based method for the detection of the bacterial pathogens salmonella spp. and listeria monocytogenes in biological waste was developed. the detection limits were less than 10 cells per ml of biological waste. the method does not include a phenol extraction step and can be easily performed in 1 to 2 days. | 1999 | 10224026 |
| detection of viable listeria monocytogenes with a 5' nuclease pcr assay. | a 5' nuclease assay has been developed to detect viable listeria monocytogenes. the assay targets the hemolysin a (hlya) transcript, which is found only in l. monocytogenes. the single-tube, reverse transcriptase (rt), fluorogenic probe-based assay was formatted by using tth dna polymerase whose activity was modulated by using the manganese-chelating morpholinepropanesulfonic acid (mops) buffer. this assay was quantitative over a 3-log-unit range of template concentrations when tested with an in ... | 1999 | 10224010 |