| acute cold/restraint stress inhibits host resistance to listeria monocytogenes via beta1-adrenergic receptors. | we previously reported that acute cold/restraint stress (acrs) significantly inhibits host resistance to listeria monocytogenes (lm) in balb/c mice and that the sympathetic nervous system plays a major role in this inhibition. here, we have further investigated the involvement of adrenergic receptor (adr) subtypes. beta-adr antagonist propranolol, but not alpha-adr antagonist phentolamine significantly enhanced host resistance of acrs mice. pro-inflammatory cytokine (il-6, il-1beta, and tnfalpha ... | 2003 | 12676574 |
| alteration of pulmonary immunity to listeria monocytogenes by diesel exhaust particles (deps). ii. effects of deps on t-cell-mediated immune responses in rats. | previously, we showed that diesel exhaust particles (deps) suppressed pulmonary clearance of listeria monocytogenes (listeria) and inhibited the phagocytosis of alveolar macrophages and their response to listeria in the secretion of interleukin (il)-1 beta, tumor necrosis factor alpha, and il-12. in this report we examined the effects of deps and/or listeria on t-cell development and secretion of il-2, il-6, and interferon (ifn)-gamma. we exposed brown norway rats to clean air or deps at 50 or 1 ... | 2003 | 12676610 |
| role of sigmab in regulating the compatible solute uptake systems of listeria monocytogenes: osmotic induction of opuc is sigmab dependent. | the regulation of the compatible solute transport systems in listeria monocytogenes by the stress-inducible sigma factor sigma(b) was investigated. using wild-type strain 10403s and an otherwise isogenic strain carrying an in-frame deletion in sigb, we have examined the role of sigma(b) in regulating the ability of cells to utilize betaine and carnitine during growth under conditions of hyperosmotic stress. cells lacking sigma(b) were defective for the utilization of carnitine but retained the a ... | 2003 | 12676677 |
| selection and identification of a listeria monocytogenes target strain for pulsed electric field process optimization. | nine listeria monocytogenes strains were treated individually with a continuous pulsed electric field (pef) apparatus, and their sensitivities to the treatment were compared at 25 kv/cm. when cell suspensions of these strains in 0.1% nacl (ph 7.0) were treated at 23 degrees c for 144 micro s, inactivation ranged from 0.7 to 3.7 log(10) cfu/ml. inactivation by 72- micro s pef treatments at 37 degrees c ranged from 0.3 to 2.5 log(10) cfu/ml. l. monocytogenes osy-8578 was substantially more resista ... | 2003 | 12676704 |
| evidence on inhibition of listeria monocytogenes by divercin v41 action. | the aim of this study was to investigate the role of divercin v41 in inhibition and prevention of listeria monocytogenes. | 2003 | 12680940 |
| listeria monocytogenes isolates from invasive infections: variation of sero- and genotypes during an 11-year period in finland. | listeria monocytogenes strains that were isolated from 314 human listeriosis cases in finland during an 11-year period were analyzed by o:h serotyping and pulsed-field gel electrophoresis (pfge). serotyping divided the isolates into five serotypes, the most common being 1/2a (53%) and 4b (27%). during the study period, the number of cases caused by serotype 1/2a increased from 22% in 1990 to 67% in 2001, and those caused by serotype 4b decreased from 61 to 27%, respectively. pfge with restrictio ... | 2003 | 12682162 |
| the gp49b1 inhibitory receptor regulates the ifn-gamma responses of t cells and nk cells. | the magnitude and diversity of ag-specific t cell effector activity have been proposed to be controlled by an integration of positive signals transduced by the tcr and negative signals originating from inhibitory cell surface molecules. although the lectin family of nk cell-associated inhibitory receptors has been reported to regulate the function of murine ctls, gp49b1, the ig superfamily member is not known to be expressed on t cells. moreover, the consequences of the lack of an endogenously e ... | 2003 | 12682239 |
| role of heparan sulfate in interactions of listeria monocytogenes with enterocytes. | heparan sulfate is known to participate in binding a wide variety of microbes to mammalian cells, but few studies have focused on the enterocyte. normal human colonic and small intestinal enterocytes, and cultured ht-29 (but not caco-2) enterocytes, reacted prominently with antibodies specific for heparan sulfate and for the core protein of syndecan-1 (a heparan sulfate proteoglycan). the heparan sulfate analog, heparin, inhibited interactions of listeria monocytogenes (adherence and internaliza ... | 2003 | 12684756 |
| requirement for cd4 t cell help in generating functional cd8 t cell memory. | although primary cd8 responses to acute infections are independent of cd4 help, it is unknown whether a similar situation applies to secondary responses. we show that depletion of cd4 cells during the recall response has minimal effect, whereas depletion during the priming phase leads to reduced responses by memory cd8 cells to reinfection. memory cd8 cells generated in cd4+/+ mice responded normally when transferred into cd4-/- hosts, whereas memory cd8 cells generated in cd4-/- mice mounted de ... | 2003 | 12690201 |
| defective cd8 t cell memory following acute infection without cd4 t cell help. | the cd8+ cytotoxic t cell response to pathogens is thought to be cd4+ helper t cell independent because infectious agents provide their own inflammatory signals. mice that lack cd4+ t cells mount a primary cd8 response to listeria monocytogenes equal to that of wild-type mice and rapidly clear the infection. however, protective memory to a challenge is gradually lost in the former animals. memory cd8+ t cells from normal mice can respond rapidly, but memory cd8+ t cells that are generated withou ... | 2003 | 12690202 |
| adult community acquired bacterial meningitis in a singaporean teaching hospital. a seven-year overview (1993-2000). | the objective of this study is to describe the bacteriological, clinical and laboratory features of community acquired bacterial meningitis in adults admitted to a singapore tertiary-care hospital. | 2002 | 12693768 |
| detection of listeria monocytogenes in italian-style soft cheeses. | a rapid detection system specific for listeria monocytogenes and based on the polymerase chain reaction (pcr) was developed. | 2003 | 12694453 |
| effectiveness of electrolyzed acidic water in killing escherichia coli o157:h7, salmonella enteritidis, and listeria monocytogenes on the surfaces of tomatoes. | a study was conducted to evaluate the efficacy of electrolyzed acidic water, 200-ppm chlorine water, and sterile distilled water in killing escherichia coli o157:h7, salmonella, and listeria monocytogenes on the surfaces of spot-inoculated tomatoes. inoculated tomatoes were sprayed with electrolyzed acidic water, 200-ppm chlorine water, and sterile distilled water (control) and rubbed by hand for 40 s. populations of e. coli o157:h7, salmonella, and l. monocytogenes in the rinse water and in the ... | 2003 | 12696675 |
| viability of salmonella, escherichia coli o157:h7, and listeria monocytogenes in yellow fat spreads as affected by storage temperature. | a study was conducted to characterize the survival and inactivation kinetics of a five-serotype mixture of salmonella (6.23 to 6.55 log10 cfu per 3.5-ml or 4-g sample), a five-strain mixture of escherichia coli o157:h7 (5.36 to 6.14 log10 cfu per 3.5-ml or 4-g sample), and a six-strain mixture of listeria monocytogenes (5.91 to 6.18 log10 cfu per 3.5-ml or 4-g sample) inoculated into seven yellow fat spreads (one margarine, one butter-margarine blend, and five dairy and nondairy spreads and topp ... | 2003 | 12696676 |
| survey of listeria monocytogenes in ready-to-eat foods. | the purpose of this study was to develop data on the risk of listeriosis to support a science-based strategy for addressing listeria monocytogenes in foods in the united states. eight categories of ready-to-eat foods were collected over 14 to 23 months from retail markets at maryland and northern california foodnet sites. the product categories included luncheon meats, deli salads, fresh soft "hispanic-style" cheeses, bagged salads, blue-veined and soft mold-ripened cheeses, smoked seafood, and ... | 2003 | 12696677 |
| listeria monocytogenes: low levels equal low risk. | because of the public health significance of l. monocytogenes, u.s. regulatory agencies established a policy whereby ready-to-eat foods contaminated with the organism at a detectable level are deemed adulterated. this "zero tolerance" policy, however, makes no distinction between foods contaminated at high and low levels. we have reported elsewhere that a survey of over 31,000 ready-to-eat retail food samples, representing eight product categories, showed an overall prevalence rate of 1.82% for ... | 2003 | 12696678 |
| determination of thermal lethality of listeria monocytogenes in fully cooked chicken breast fillets and strips during postcook in-package pasteurization. | fully cooked chicken breast fillets and strips were surface inoculated with a cocktail of listeria monocytogenes culture. the inoculation level was 10(7) to 10(8) cfu/g meat. the inoculated products were vacuum packaged and pasteurized at 90 degrees c with a pilot-scale steam or hot water cooker. after heat treatment, the survivors of l. monocytogenes were enumerated. no significant difference was found on survivors of l. monocytogenes between steam- and hot water-treated products. to achieve a ... | 2003 | 12696679 |
| recovery rate of listeria monocytogenes from commercially prepared frankfurters during extended refrigerated storage. | to assess the prevalence of listeria monocytogenes in vacuum-sealed packages of frankfurters, about 33,000 packages (1 lb each) were obtained by a third-party contractor from 12 volunteer commercial manufacturers over a 2-year period. the 12 producers, each of which contributed about 2,700 packages of frankfurters from one production run, comprised 9 large and 3 small plants located in eight u.s. department of agriculture/food safety and inspection service (usda/fsis) districts in 10 states. fiv ... | 2003 | 12696680 |
| comparison of sodium hypochlorite-based foam and peroxyacetic acid-based fog sanitizing procedures in a salmon smokehouse: survival of the general microflora and listeria monocytogenes. | the effects of fog sanitization with peroxyacetic acid (hydrogen peroxide, peracetic acid, and acetic acid in combination) on general hygiene (aerobic plate count) and on listeria monocytogenes were assessed in a slicing area at a salmon smokehouse and compared with the effects of foam sanitization with sodium hypochlorite (routinely performed at the smokehouse). two hundred twenty-three environmental samples were collected with sponges and swabs after each of the sanitization procedures, and 68 ... | 2003 | 12696681 |
| immunostimulatory activity of aminoalkyl glucosaminide 4-phosphates (agps): induction of protective innate immune responses by rc-524 and rc-529. | earlier we showed that the structural requirements for adjuvanticity among the aminoalkyl glucosaminide 4-phosphate (agp) class of synthetic immunostimulants may be less strict than those for other endotoxic activities, including the induction of nitric oxide synthase in murine macrophages and cytokine production in human whole blood. the known role of nitric oxide and pro-inflammatory cytokines in the activation of host defenses against infection prompted us to examine the ability of certain ag ... | 2002 | 12697089 |
| influence of p-glycoprotein and mrp efflux pump inhibitors on the intracellular activity of azithromycin and ciprofloxacin in macrophages infected by listeria monocytogenes or staphylococcus aureus. | antibiotic efflux pumps expressed in eukaryotic cells can decrease the intracellular accumulation of the corresponding drugs and therefore impair their activity against intracellular bacteria. we have investigated whether verapamil (an inhibitor of p-glycoprotein) and gemfibrozil (an inhibitor of multidrug resistance proteins (mrp) and other organic anion transporters), can modulate the intracellular activity of azithromycin and ciprofloxacin against listeria monocytogenes and staphylococcus aur ... | 2003 | 12697643 |
| adhesive surface proteins of erysipelothrix rhusiopathiae bind to polystyrene, fibronectin, and type i and iv collagens. | erysipelothrix rhusiopathiae is a gram-positive bacterium that causes erysipelas in animals and erysipeloid in humans. we found two adhesive surface proteins of e. rhusiopathiae and determined the nucleotide sequences of the genes, which were colocalized and designated rspa and rspb. the two genes were present in all of the serovars of e. rhusiopathiae strains examined. the deduced rspa and rspb proteins contain the c-terminal anchoring motif, lpxtg, which is preceded by repeats of consensus ami ... | 2003 | 12700253 |
| the ysirk-g/s motif of staphylococcal protein a and its role in efficiency of signal peptide processing. | many surface proteins of pathogenic gram-positive bacteria are linked to the cell wall envelope by a mechanism requiring a c-terminal sorting signal with an lpxtg motif. surface proteins of streptococcus pneumoniae harbor another motif, ysirk-g/s, which is positioned within signal peptides. the signal peptides of some, but not all, of the 20 surface proteins of staphylococcus aureus carry a ysirk-g/s motif, whereas those of surface proteins of listeria monocytogenes and bacillus anthracis do not ... | 2003 | 12700270 |
| antimicrobial effects of garlic, clove and red hot chilli on listeria monocytogenes in broth model systems and soft cheese. | antimicrobial activity of 1% (w/v) fresh garlic, ground clove and red dried chilli on listeria monocytogenes was tested in broth systems at 37 degrees c and at 4 degrees c for 7 h. the initial cell concentration in the broth systems was between 2 x 10(6) and 4 x 10(6) cfu/ml. at 37 degrees c, growth to viable numbers of 3 x 10(8) cfu/ml in 7 h was measured. clove had bacteriocidal activity and reduced the count to 1 cfu/ml. garlic displayed bacteriostatic properties, and a count of 4 x 10(6) cfu ... | 2003 | 12701369 |
| maximizing efficacy and reducing the emergence of resistance. | an understanding of the pharmacokinetic and pharmacodynamic properties of antimicrobial agents enables better choices to be made in the clinical situation. the fluoroquinolones share several useful pharmacokinetic properties, such as good bioavailability (in most cases >85%) and the ability to penetrate and concentrate intracellularly, giving them activity against pathogens such as legionella pneumophila and listeria monocytogenes. nevertheless, there are some important differences between the f ... | 2003 | 12702702 |
| differences in gamma interferon production induced by listeriolysin o and ivanolysin o result in different levels of protective immunity in mice infected with listeria monocytogenes and listeria ivanovii. | two pathogenic species in the genus listeria, listeria monocytogenes and listeria ivanovii, are characterized by the production of hemolysins belonging to cholesterol-dependent cytolysins, listeriolysin o (llo) and ivanolysin o (ilo), respectively. llo, produced by l. monocytogenes, is able to induce gamma interferon (ifn-gamma) production and contributes to the generation of th1-dependent protective immunity. on the other hand, nothing is known about the role of ilo, produced by l. ivanovii, in ... | 2003 | 12704115 |
| viral infection results in massive cd8+ t cell expansion and mortality in vaccinated perforin-deficient mice. | perforin-mediated cytotoxicity is essential for clearance of primary lcmv infection. balb/c-perforin-deficient (pko) mice survived lcmv infection by deleting np(118)-specific cd8(+) t cells whereas vaccination of pko mice with listeria expressing np(118) generated a stable memory cd8(+) t cell population. however, >85% of vaccinated balb/c-pko mice died after lcmv infection. mortality was associated with enormous expansion of np(118)-specific cd8(+) t cells in both lymphoid and nonlymphoid tissu ... | 2003 | 12705850 |
| feedback regulation of pathogen-specific t cell priming. | mhc class i-restricted antigen presentation is an essential step in the priming of cd8 t lymphocytes during immune responses to infection. while microbial growth and clearance have been accurately measured in mammalian hosts, the duration of functional antigen presentation during infection remains undefined in vivo. herein we characterize the activation of naive and memory t cells at different times during bacterial infection. surprisingly, the host's ability to prime t cells is of much shorter ... | 2003 | 12705853 |
| hypovirulent listeria monocytogenes strains are less frequently recovered than virulent strains on palcam and rapid' l. mono media. | several selective media have been developed to detect listeria monocytogenes contaminated foodstuffs. polymyxin-acriflavine-licl-ceftazidime-aesculin-mannitol (palcam) and oxford media, required for the en iso method 11 290-1, are used for the detection of listeria spp. in 2 days based on the expression of esculinase activity. selective agar media such as rapid' l. mono and agar listeria according to ottaviani and agosti (aloa), based on the activity of phosphatidylinositol phospholipase c (pi-p ... | 2003 | 12706035 |
| leuconostoc carnosum 4010 has the potential for use as a protective culture for vacuum-packed meats: culture isolation, bacteriocin identification, and meat application experiments. | a new culture, leuconostoc carnosum 4010, for biopreservation of vacuum-packed meats is described. the culture originated from bacteriocin-producing lactic acid bacteria (lab) naturally present in vacuum-packed meat products. approximately, 72,000 colonies were isolated from 48 different vacuum-packed meat products and examined for antibacterial activity. bacteriocin-producing colonies were isolated from 46% of the packages examined. leuc. carnosum was the predominant bacteriocin-producing strai ... | 2003 | 12706038 |
| protection of interferon-gamma knockout mice against listeria monocytogenes challenge following intramuscular immunization with dna vaccines encoding listeriolysin o. | in this study we evaluated the efficacy of dna vaccination of ifn-gamma knockout (gko) mice against listeria monocytogenes, as these immunodeficient mice are highly susceptible to infection with low numbers of this intracellular bacterial pathogen. following intramuscular immunization of balb/c gko mice with plasmid dna constructs encoding recombinant forms of the l. monocytogenes hemolysin, listeriolysin o (llo), we detected the in vivo induction of a llo(91-99) peptide-specific, protective imm ... | 2003 | 12706703 |
| [current epidemiological and clinical features meningitis in a northern italian area] | objectives: to study etiological, epidemiological and clinical features of 97 cases of acute meningitis. methods: ninety-seven cases of acute meningitis were examined in adult hiv-negative patients admitted to the infectious diseases unit of the azienda ospedale-universita s. anna in ferrara. demographic, etiological, epidemiological and clinical data were analyzed. results: all cases were divided into two groups according to the macroscopic aspect of cerebrospinal fluid (csf): purulent csf (50 ... | 2000 | 12711895 |
| demonstration of labeless detection of food pathogens using electrochemical redox probe and screen printed gold electrodes. | the demonstration of a labeless immunosensor for the detection of pathogenic bacteria using screen printed gold electrodes (spges) and a potassium hexacyanoferrate(ii) redox probe is reported. gold electrodes were produced using screen printing and the gold surfaces were modified by a thiol based self assembled monolayer (sam) to facilitate antibody immobilisation. sams based on the use of thioctic acid (ta), mercaptopropionic acid (mpa) and mercaptoundecanoic acid (mua) were evaluated. followin ... | 2003 | 12713911 |
| intracellular activity of fosfomycin against two distinct enteropathogenic bacteria, salmonella enterica and listeria monocytogenes, alive inside host cells. | we studied the effect of fosfomycin (fom) on the intracellular growth of two different facultative intracellular bacteria, salmonella enterica serovar typhimurium and listeria monocytogenes, in an enterocyte-like cell line, caco-(2). these bacteria replicate in different compartments within the host cells; salmonella serovar typhimurium grow inside phagosomes, whereas l. monocytogenes escape the phagosomal environment and multiply in the cytosol of the host cells. at concentrations equal to 0.25 ... | 2003 | 12714811 |
| [neural listeriosis presenting as leptomeningitis: a case report]. | the listeria monocytogenes infection is rare and difficult to diagnosis. however, it is associated with a high mortality in adults. a case is presented of a 78-year-old woman with an immunological deficit following viral infection (herpes zoster). | 2002 | 12715698 |
| the bacteriocin piscicolin 126 retains antilisterial activity in vivo. | we have conducted a series of experiments to show that the bacteriocin piscicolin 126 (p126) retains antilisterial activity after injection into a mouse. | 2003 | 12716771 |
| low-level iron-dependent mutants of listeria monocytogenes and their virulence in macrophages. | listeria monocytogenes is an opportunistic intracellular pathogen capable of growth that requires iron for growth within phagocytic cells and virulence expression. in the presence of an appropriate concentration tropolone, an iron-chelating agent, growth of l. monocytogenes is completely inhibited. however, this inhibition can be relieved by addition of dopamine, norepinephrine, or ferric citrate. by selection on streptonigrin medium supplemented with tropolone and norepinephrine, we have obtain ... | 2003 | 12718395 |
| application of hexanal, e-2-hexenal, and hexyl acetate to improve the safety of fresh-sliced apples. | the aims of this work were to evaluate the effects of different concentrations of hexanal, (e)-2-hexenal, hexyl acetate, and their mixtures on the fate of pathogenic species such as escherichia coli, salmonella enteritidis, and listeria monocytogenes inoculated in model systems as well as the antimicrobial activity against the target species of the chosen molecules when added to the packaging atmosphere of inoculated fresh-sliced apples. the result obtained in this work pointed out the potential ... | 2003 | 12720377 |
| [listeriosis]. | | 2003 | 12722242 |
| modification of the signal sequence cleavage site of listeriolysin o does not affect protein secretion but impairs the virulence of listeria monocytogenes. | listeriolysin o (llo, hly-encoded), a major virulence factor secreted by the bacterial pathogen listeria monocytogenes, is synthesized as a precursor of 529 residues. to impair llo secretion, the four residues of the predicted signal sequence cleavage site (ea-kd) were deleted and the mutant llo protein was expressed in a hly-negative derivative of l. monocytogenes. unexpectedly, the mutant protein was secreted in normal amounts in the culture supernatant and was fully haemolytic. n-terminal seq ... | 2003 | 12724386 |
| antibody cocktail could cut risk of food poisoning. | | 2003 | 12726960 |
| effects of iron and oxygen species scavengers on listeria spp. chemiluminescence. | listeria monocytogenes and listeria innocua are able, under certain conditions, to produce chemiluminescence (cl), which is amplified by luminol. kinetic studies of cl by l. monocytogenes and l. innocua show a close parallelism between cl and growth curves during the exponential phase, with a maximum of cl reached just before entrance of bacteria into the stationary phase. cl is tightly correlated with the release of oxygen compounds. the reactive oxygen species scavengers tryptophan, mannitol, ... | 2003 | 12727229 |
| bactericidal effect of tio2 photocatalyst on selected food-borne pathogenic bacteria. | titanium dioxide (tio(2)) photocatalysts have attracted great attention as a material for photocatalytic sterilization in the food and environmental industry. this research aimed to design a new photobioreactor and its application to sterilize selected food borne pathogenic bacteria, salmonella choleraesuis subsp., vibrio parahaemolyticus, and listeria monocytogenes. the photocatalytic reaction was carried out with various tio(2) concentrations and ultraviolet (uv) illumination time. a feasible ... | 2003 | 12729712 |
| role of listeria monocytogenes sigma(b) in survival of lethal acidic conditions and in the acquired acid tolerance response. | the food-borne pathogen listeria monocytogenes can acquire enhanced resistance to lethal acid conditions through multiple mechanisms. we investigated contributions of the stress-responsive alternative sigma factor, sigma(b), which is encoded by sigb, to growth phase-dependent acid resistance (ar) and to the adaptive acid tolerance response in l. monocytogenes. at various points throughout growth, we compared the relative survival of l. monocytogenes wild-type and deltasigb strains that had been ... | 2003 | 12732538 |
| antimicrobial effects of mustard flour and acetic acid against escherichia coli o157:h7, listeria monocytogenes, and salmonella enterica serovar typhimurium. | this study was designed to investigate the individual and combined effects of mustard flour and acetic acid in the inactivation of food-borne pathogenic bacteria stored at 5 and 22 degrees c. samples were prepared to achieve various concentrations by the addition of acetic acid (0, 0.5, or 1%) along with mustard flour (0, 10, or 20%) and 2% sodium chloride (fixed amount). acid-adapted three-strain mixtures of escherichia coli o157:h7, listeria monocytogenes, and salmonella enterica serovar typhi ... | 2003 | 12732572 |
| an improved cloning vector for construction of gene replacements in listeria monocytogenes. | listeria monocytogenes is a gram-positive, facultative intracellular bacterium implicated in severe food-borne illness (listeriosis) in humans. the construction of well-defined gene replacements in the genome of l. monocytogenes has been instrumental to several genetic studies of the virulence and other attributes of the organism. construction of such mutations by currently available procedures, however, tends to be labor intensive, and gene replacement mutants are sometimes difficult to recover ... | 2003 | 12732583 |
| the role of the sigb gene in the general stress response of listeria monocytogenes varies between a strain of serotype 1/2a and a strain of serotype 4c. | the ability of listeria monocytogenes to resist many adverse environmental conditions has been attributed in part to activation of the alternative sigma factor sigma(b), encoded by the sigb gene. the ability of this pathogen to survive and grow under stress conditions varies between strains within the species. the current study was undertaken to determine whether the role played by the sigb gene in the stress response varies among strains of different serotypes. null mutations were generated in ... | 2003 | 12732955 |
| identification and characteristics of nisin z-producing lactococcus lactis subsp. lactis isolated from kimchi. | we isolated bacteriocin-producing lactococcus lactis subsp. lactis from kimchi. the bacteriocin inhibited strains of clostridium perfringens, c. difficile, listeria monocytogenes, vancomycin-resistant enterococcus, and one out of four methicillin-resistant staphylococcus aureus strains, as well as some closely related lactic acid bacteria. in tricine-sds-page, the bacteriocin migrated with an apparent molecular weight of about 4 kda to the same location as nisin a and crude nisin z. the gene enc ... | 2003 | 12732968 |
| regulation of cd8+ t cells undergoing primary and secondary responses to infection in the same host. | naive ag-specific cd8(+) t cells expand, contract, and become memory cells after infection and/or vaccination. memory cd8(+) t cells provide faster, more effective secondary responses against repeated exposure to the same pathogen. using an adoptive transfer system with low numbers of trackable nontransgenic memory cd8(+) t cells, we showed that secondary responses can be comprised of both primary (naive) and secondary (memory) cd8(+) t cells after bacterial (listeria monocytogenes) and/or viral ... | 2003 | 12734336 |
| the induction of hiv gag-specific cd8+ t cells in the spleen and gut-associated lymphoid tissue by parenteral or mucosal immunization with recombinant listeria monocytogenes hiv gag. | the induction of mucosal immunity is crucial in controlling viral replication during hiv infection. in this study we compare the ability of a recombinant listeria monocytogenes that expresses and secretes the hiv ag gag to induce cd8(+) t cells against this ag in the spleen, mesenteric lymph nodes, and peyer's patches and the ability to provide effector gag-specific cd8(+) t cells to the lamina propria after i.v., oral, or rectal administration of the vaccine. the levels of ag-specific cd8(+)-ac ... | 2003 | 12734365 |
| the lymphotoxin beta receptor is critically involved in controlling infections with the intracellular pathogens mycobacterium tuberculosis and listeria monocytogenes. | containment of intracellularly viable microorganisms requires an intricate cooperation between macrophages and t cells, the most potent mediators known to date being ifn-gamma and tnf. to identify novel mechanisms involved in combating intracellular infections, experiments were performed in mice with selective defects in the lymphotoxin (lt)/lt beta r pathway. when mice deficient in lt alpha or lt beta were challenged intranasally with mycobacterium tuberculosis, they showed a significant increa ... | 2003 | 12734369 |
| neutrophilia in lfa-1-deficient mice confers resistance to listeriosis: possible contribution of granulocyte-colony-stimulating factor and il-17. | lfa-1 (cd11a/cd18) plays a crucial role in various inflammatory responses. in this study, we show that lfa-1(-/-) mice are far more resistant to listeria monocytogenes infection than lfa-1(+/-) mice. consistent with this, we found the following: 1) the numbers of granulocytes infiltrating the liver were markedly higher in lfa-1(-/-) mice than in lfa-1(+/-) mice, 2) increased antilisterial resistance in lfa-1(-/-) mice was abrogated by depletion of granulocytes, and 3) the numbers of granulocytes ... | 2003 | 12734371 |
| a listeria adhesion protein-deficient listeria monocytogenes strain shows reduced adhesion primarily to intestinal cell lines. | listeria monocytogenes adheres and penetrates intestinal cell linings for systemic infection. a 104-kda listeria adhesion protein (lap) from l. monocytogenes was previously demonstrated to be responsible for adhesion to intestinal enterocyte-like caco-2 cells. we investigated the adhesion and invasion characteristics of a lap-deficient mutant l. monocytogenes strain (a572) to various human intestinal and non-intestinal cell lines to assess the possible target host cells. among the intestinal cel ... | 2003 | 12736821 |
| listeria monocytogenes and inflammatory bowel disease: detection of listeria species in intestinal mucosal biopsies by real-time pcr. | | 2003 | 12737451 |
| compression forces generated by actin comet tails on lipid vesicles. | polymerizing networks of actin filaments generate force for a variety of movements in living cells, including protrusion of filopodia and lamellipodia, intra- and intercellular motility of certain bacterial and viral pathogens, and motility of endocytic vesicles and other membrane-bound organelles. during actin-based motility, coexisting populations of actin filaments exert both pushing and retarding forces on the moving cargo. to examine the distribution and magnitude of forces generated by act ... | 2003 | 12738883 |
| bioprotectives and probiotics for dry sausages. | the microbial stability of dry sausages is determined by the combination and timing of different factors referred to as the hurdle-concept. however, the hurdles present in dry sausage are not sufficient to prevent the survival of listeria monocytogenes or enterohemorrhagic escherichia coli o157:h7. recently bioprotective lactic acid bacteria, which in addition to the production of antimicrobial lactic acid, have been found to contribute to the safety of the dry sausage by producing antimicrobial ... | 2003 | 12745229 |
| susceptibility of listeria monocytogenes isolated from food in italy to antibiotics. | the susceptibility of 148 strains of listeria monocytogenes isolated from food to antibiotics currently used in veterinary and human therapy was determined by standard agar dilution and disk diffusion methods. the antibiotics included amikacin, amoxicillin, cefazolin, chloramphenicol, erythromycin, flumequine, fosfomycin, gentamicin, kanamycin, lincomycin, oxytetracycline, rifampicin, spiramycin, streptomycin, tetracycline, tobramycin and vancomycin. soussy's breakpoints and mic(50)-mic(90) valu ... | 2003 | 12745237 |
| comparison of recovery methods for freeze-injured listeria monocytogenes, salmonella typhimurium, and campylobacter coli in cell suspensions and associated with pork surfaces. | cells injured as a result of freezing, heating, and acidification treatments may not grow during conventional microbiological procedures owing to the presence of selective agents, compounds, or dyes in the media, impairing the cell's ability to repair itself and grow. injured cells can be recovered by combining selective and nonselective media into a single system. with such combinations, the diffusion of the selective compounds or dyes is controlled, allowing for the resuscitation of injured ce ... | 2003 | 12747688 |
| predictive model for the combined effect of temperature, sodium lactate, and sodium diacetate on the heat resistance of listeria monocytogenes in beef. | the effects of heating temperature (60 to 73.9 degrees c), sodium lactate (nal; 0.0 to 4.8% [wt/wt]), and/or sodium diacetate (sda; 0.0 to 0.25% [wt/wt]) and of the interactions of these factors on the heat resistance of a five-strain mixture of listeria monocytogenes in 75% lean ground beef were examined. thermal death times for l. monocytogenes in filtered stomacher bags in a circulating water bath were determined. the recovery medium was tryptic soy agar supplemented with 0.6% yeast extract a ... | 2003 | 12747689 |
| reducing levels of listeria monocytogenes contamination on raw salmon with acidified sodium chlorite. | the antimicrobial activity of acidified sodium chlorite (asc) against listeria monocytogenes in salmon was studied. raw salmon (whole fish and fillets) inoculated with l. monocytogenes (10(3) cfu/cm2 or 10(4) cfu/g) were washed with asc solution (50 ppm) for 1 min and stored at -18 degrees c for 1 month (whole salmon) or in ice for 7 days (fillets). l. monocytogenes populations were determined for whole salmon after frozen storage and for fillets on days 1, 3, 5, and 7 of storage. a wash with as ... | 2003 | 12747690 |
| gamma irradiation of fine-emulsion sausage containing sodium diacetate. | listeria monocytogenes, a psychrotrophic foodborne pathogen, is a frequent postprocess contaminant of ready-to-eat (rte) meat products, including frankfurters and bologna. ionizing radiation can eliminate l. monocytogenes from rte meats. sodium diacetate (sda) incorporated into fine-emulsion sausages inhibits the growth of l. monocytogenes. irradiation of l. monocytogenes suspended in sda solutions resulted in synergistic reductions of the microorganism. l. monocytogenes populations were reduced ... | 2003 | 12747691 |
| impact of ph enhancement on populations of salmonella, listeria monocytogenes, and escherichia coli o157:h7 in boneless lean beef trimmings. | boneless lean beef trimmings were inoculated with multiple strains of salmonellae, listeria monocytogenes, and escherichia coli o157:h7 at levels of ca. 6 log10 cfu/g. ph enhancement with ammonia gas was then used to increase the ph of the trimmings to ca. 9.6. the product was then frozen, chipped, and compressed into blocks. ph enhancement reduced the populations of salmonellae, l. monocytogenes, and e. coli o157:h7 by approximately 4, 3, and 1 log10 cycles, respectively. after the product had ... | 2003 | 12747699 |
| multiple cerebral abscesses because of listeria monocytogenes: three case reports and a literature review of supratentorial listerial brain abscess(es). | central nervous system involvement often follows bacteremia because of listeria monocytogenes. meningitis is clinically the most common manifestation, while brain abscess occurs in about 1% of patients. brain abscess is usually solitary but in recent years, probably in part because of the availability of computerized tomography and magnetic resonance imaging, several reports have described two or more separate supratentorial abscesses. | 2003 | 12748019 |
| syringomyelia following listeria meningoencephalitis: report of a case. | a case of symptomatic syringomyelia which appeared six years after listeria meningoencephalitis is described. chronic spinal arachnoiditis, as shown by standard mri and dynamic phase contrast (pc) cine-mri, may occur after spinal infection and is likely the cause of syringomyelia. to our knowledge, there are no previous reports of delayed spinal complications following listeria monocytogenes infection. the possibility of developing syringomyelia should be always considered in any patient with a ... | 2003 | 12754657 |
| actin-based motility as a self-organized system: mechanism and reconstitution in vitro. | site-directed actin polymerisation in response to signalling is responsible for the formation of cell protrusions. these elementary 'actin-based motility processes' are involved in cell locomotion, cell metastasis, organ morphogenesis and microbial pathogenesis. we have reconstituted actin-based propulsive movement of particles of various sizes and geometries (rods, microspheres) in a minimum motility medium containing five pure proteins. the atp-supported treadmilling of actin filaments, regula ... | 2003 | 12754935 |
| intestinal m cells and their role in bacterial infection. | m cells are located in the epithelia overlying mucosa-associated lymphoid tissues such as peyer's patches where they function as the antigen sampling cells of the mucosal immune system. paradoxically, some pathogens exploit m cells as a route of invasion. here we review our current knowledge of intestinal m cells with particular emphasis on the mechanisms underlying bacterial infection of these atypical epithelial cells. | 2003 | 12755364 |
| experimental validation of low virulence in field strains of listeria monocytogenes. | several reports have described listeria monocytogenes strains which were nonpathogenic or weakly pathogenic, but little is known about these low-virulence strains. we found that 9 field l. monocytogenes strains were hypovirulent and 17 were avirulent, based on the number of mice contaminated and the colonization of their spleens after subcutaneous inoculation. all these strains possessed the known virulence genes. we have now assessed the low virulence of these strains in other assays before det ... | 2003 | 12761127 |
| attenuated yersinia pseudotuberculosis carrier vaccine for simultaneous antigen-specific cd4 and cd8 t-cell induction. | yersinia pseudotuberculosis employs a type iii secretion system for targeting of several virulence factors directly to the cytosol of eukaryotic cells. this protein translocation mechanism mediates the ability of yersinia to resist phagocytosis and is required for sustained extracellular bacterial replication. in the present study, the yersinia outer protein e (yope) was used as a carrier molecule for type iii-dependent secretion and translocation of listeriolysin o (llo) from listeria monocytog ... | 2003 | 12761131 |
| deletion of the gene encoding p60 in listeria monocytogenes leads to abnormal cell division and loss of actin-based motility. | protein p60 encoded by the iap gene is regarded as an essential gene product of listeria monocytogenes. here we report, however, the successful construction of a viable iap deletion mutant of l. monocytogenes egd. the mutant, which produces no p60, shows abnormal septum formation and tends to form short filaments and hooked forms during logarithmic growth. these abnormal bacterial cells break into almost normal sized single bacteria in the late-stationary-growth phase. the iap mutant is strongly ... | 2003 | 12761132 |
| listeriolysin o-mediated calcium influx potentiates entry of listeria monocytogenes into the human hep-2 epithelial cell line. | to investigate factors which modulate the entry of listeria monocytogenes into mammalian cells, we have analyzed the role of ca(2+). we show that l. monocytogenes induced ca(2+) transients into the human hep-2 epithelial cell line. the nonpathogenic species l. innocua or a l. monocytogenes mutant strain defective in listeriolysin o (llo) production was unable to induce these calcium fluxes. addition of plasma membrane calcium channel antagonists or chelation of extracellular calcium markedly red ... | 2003 | 12761148 |
| growth and survival of selected pathogens in margarine-style table spreads. | although margarine-style table spreads can have a ph above 4.6 and a water activity greater than 0.85, there is some question if such products can support the growth of pathogenic bacteria. the objective of this study was to evaluate the growth and survival of staphylococcus aureus, listeria monocytogenes, escherichia coli o157:h7, and salmonella typhi in 60-percent- and 70-percent-vegetable-oil, margarine-style, water-in-oil-emulsion table spreads stored at different temperatures. samples of 25 ... | 2003 | 12762119 |
| induction of immune responses by attenuated isogenic mutant strains of listeria monocytogenes. | we have generated isogenic listeria monocytogenes mutant strains to study the induction of protective immunity in mice. these strains harbored either a specific deletion within the actin nucleator (acta) and/or have multiple deletions within the acta and phospholipase b (plcb) genes. in comparison to the wild type parental l. monocytogenes egde strains, the mutant strains were extremely low in virulence and were rapidly eliminated by the host during the first days of infection. nevertheless, a s ... | 2003 | 12763691 |
| methodologies for the characterization of microbes in industrial environments: a review. | there is growing interest in research and development to develop novel tools to study, detect, and characterize microbes and their communities in industrial environments. however, knowledge about their validity in practical industrial use is still scarce. this review describes the advantages and limitations of traditional and molecular methods used for biofilm and/or planktonic cell studies, especially those performed with listeria monocytogenes, bacillus cereus, and/or clostridium perfringens. ... | 2003 | 12764674 |
| anti-oxidant properties of n-acetyl-l-cysteine do not improve the immune resistance of mice fed dietary lipids to listeria monocytogenes infection. | current knowledge of the potential effects that several dietary lipids exert on immune functions indicates that these substances participate actively in the modulation of immune system by which they contribute to the improvement of the conditions of patients suffering from inflammatory disorders. however, long-chain n-3 polyunsaturated fatty acids induce an immunosuppressive status that leads to a reduction of the host natural resistance to infectious agents as well as to an enhancement of oxida ... | 2003 | 12765672 |
| potential role of the epec translocated intimin receptor (tir) in host apoptotic events. | apoptosis, or programmed cell death, is a well-ordered process that allows damaged or diseased cells to be removed from an organism without severe inflammatory reactions. multiple factors, including microbial infection, can induce programmed death and trigger reactions in both host and microbial cellular pathways. whereas an ultimate outcome is host cell death, these apoptotic triggering mechanisms may also facilitate microbial spread and prolong infection. to gain a better understanding of the ... | 2003 | 12766478 |
| recombinant e. coli efficiently delivers antigen and maturation signals to human dendritic cells: presentation of mart1 to cd8+ t cells. | the generation of tumour-specific cytotoxic t-lymphocyte (ctl) responses is the primary focus in the design of immunotherapeutic cancer vaccines. we have recently demonstrated generation of ovalbumin (ova)-specific ctls and tumour-protection in a murine tumour model using vaccination with dendritic cells (dcs) pulsed with e. coli expressing listeriolysin o (llo) and ova as a model antigen. in this system paraformaldehyde fixation of e. coli/llo provided an additional safety feature without compr ... | 2003 | 12767067 |
| immune changes during acute cold/restraint stress-induced inhibition of host resistance to listeria. | experiments were conducted to delineate the cellular changes modulated by acute cold/restraint stress (acrs), a physical and psychological stressor, in response to a listeria monocytogenes(lm) infection. in addition to wild type (wt) balb/c mice, cd4-deficient (cd4-/-) balb/c mice, which have no effective adaptive immunity, were used to determine the involvement of adaptive versus innate immunity. acrs-induced suppression of host resistance to lm was not observed in cd4-/- mice, suggesting the i ... | 2003 | 12773754 |
| a crucial role for profilin-actin in the intracellular motility of listeria monocytogenes. | we have examined the effect of covalently crosslinked profilin-actin (pxa), which closely matches the biochemical properties of ordinary profilin-actin and interferes with actin polymerization in vitro and in vivo, on listeria monocytogenes motility. pxa caused a marked reduction in bacterial motility, which was accompanied by the detachment of bacterial tails. the effect of pxa was dependent on its binding to proline-rich sequences, as shown by the inability of ph133sxa, which cannot interact w ... | 2003 | 12776739 |
| t cells bite the hand that feeds them. | | 2003 | 12778158 |
| molecular subtyping to detect human listeriosis clusters. | we analyzed the diversity (simpson's index, d) and distribution of listeria monocytogenes in human listeriosis cases in new york state (excluding new york city) from november 1996 to june 2000 by using automated ribotyping and pulsed-field gel electrophoresis (pfge). we applied a scan statistic (p<or=0.05) to detect listeriosis clusters caused by a specific listeria monocytogenes subtype. among 131 human isolates, 34 (d=0.923) ribotypes and 74 (d=0.975) pfge types were found. nine (31% of cases) ... | 2003 | 12781006 |
| protective effects of chlorella vulgaris in lead-exposed mice infected with listeria monocytogenes. | chlorella vulgaris extract (cve) was examined for its chelating effects on the myelosuppression induced by lead in listeria monocytogenes-infected mice. the reduction in the number of bone marrow granulocyte-macrophage progenitors (cfu-gm) observed after the infection was more severe in the groups previously exposed to lead. extramedullar hematopoiesis, which was drastically increased after the infection, was not altered by the presence of lead. treatment with cve, given simultaneously or follow ... | 2003 | 12781705 |
| the effect of growth atmosphere on the ability of listeria monocytogenes to survive exposure to acid, proteolytic enzymes and bile salts. | four isolates of listeria monocytogenes from food, human and environmental sources were grown separately in broth (ph 6.0 at 8 degrees c) under atmospheres of air, 100% n(2), 40% co(2):60% n(2) or 100% co(2). exponential and stationary phase cells were harvested to determine if growth atmosphere and growth phase influenced this pathogen's ability to survive exposure to an acid environment coupled with proteolytic enzymes, and the activity of bile salts. in general, isolates were more resistant t ... | 2003 | 12781937 |
| stress response of listeria monocytogenes isolated from cheese and other foods. | the responses to ph and sodium chloride of four strains of listeria monocytogenes isolated from portuguese cheese, with a sodium chloride concentration of about 2% (w/v) and a ph value from 5.1 to 6.2, were studied. two isolates from meat and two clinical isolates related to food-borne listeriosis, in which the implicated food product had about 2-3.5% (w/v) sodium chloride, also were studied. the effect of temperature on ph and sodium chloride sensitivity was also determined. the results show th ... | 2003 | 12781943 |
| simultaneous detection of escherichia coli o157:h7, listeria monocytogenes and salmonella strains by real-time pcr. | a protocol enabling simultaneous detection of escherichia coli o157:h7, listeria monocytogenes and salmonella strains was devised and evaluated using artificially contaminated fresh produce. association of official analytical chemists (aoac)-approved polymerase chain reaction (pcr) detection methods for three human pathogens were modified to enable simultaneous and real-time detection with high throughput capability. the method includes a melting-curve analysis of pcr products, which serves as c ... | 2003 | 12781944 |
| effects of a bacteriocin-like inhibitory substance from carnobacterium piscicola against human and salmon isolates of listeria monocytogenes. | the aim of this study was to characterize the antagonism of a bacteriocin-like inhibitory substance (blis) produced by carnobacterium piscicola l103 against listeria monocytogenes strains isolated from salmon and human samples. the inhibitory effect of the blis was evaluated in tryptic soy agar (tsa) during different growth phases of l. monocytogenes at 5 degrees c, using the well diffusion method. also, the type of inhibition, either bacteriostatic or bactericidal of the blis in tryptic soy bro ... | 2003 | 12781946 |
| rapid enumeration of listeria monocytogenes in milk using competitive pcr. | competitive polymerase chain reaction (cpcr) was used to develop a direct enumeration method of listeria monocytogenes in milk. sterile milk was artificially inoculated with l. monocytogenes and dna was extracted using guanidine thiocyanate/phenol/chloroform, followed by pcr. several primers for l. monocytogenes hlya gene were tested for specific detection and dg69/dg74 primer set was selected. the primer set produced a 636-bp band from l. monocytogenes, but no band appeared from the other six l ... | 2003 | 12781957 |
| haemolysin a and listeriolysin--two vaccine delivery tools for the induction of cell-mediated immunity. | haemolysin a of escherichia coli and listeriolysin of listeria monocytogenes represent important bacterial virulence factors. while such cytolysins are usually the reason for morbidity and even mortality, vaccine researchers have turned haemolysin a and listeriolysin into tools for vaccine delivery. both cytolysins have found widespread application in vaccine research and are highly suitable for the elicitation of cell-mediated immunity. in this paper, we will review vaccine delivery mediated by ... | 2003 | 12782050 |
| the anti-invasive effect of bovine lactoferrin requires an interaction with surface proteins of listeria monocytogenes. | the anti-invasive effect of bovine lactoferrin (blf) and of bovine transferrin (btf) towards l. monocytogenes, an intracellular facultative food-borne pathogen, was assayed in the enterocyte-like cell line caco-2. when 0.5 mg/ml blf were added during the infection time or preincubated with bacteria the number of internalized bacteria was noticeably decreased whereas blf was ineffective when preincubated with the enterocytes or added post infection. btf was deprived of any effect. results from di ... | 1999 | 12783644 |
| occurrence of listeria spp. in captive antelope herds and their environment. | two juvenile scimitar-horned oryx (oryx dammah) at the wild animal park planckendael died from acute septicemia caused by listeria monocytogenes serovar 4b. subsequently, listeria spp. were isolated from the feces, food, and environment of seven antelope species and examined using a two-stage enrichment procedure in fraser broth, followed by isolation on palcam agar. a total of 40/170 samples (23.5%) was positive for listeria spp. no organisms were cultured in 83/170 samples (48.8%), and 47 samp ... | 2001 | 12785709 |
| identification of listeria monocytogenes genes involved in salt and alkaline-ph tolerance. | the capacity of listeria monocytogenes to tolerate salt and alkaline stresses is of particular importance, as this pathogen is often exposed to such environments during food processing and food preservation. we screened a library of tn917-lacz insertional mutants in order to identify genes involved in salt and/or alkaline tolerance. we isolated six mutants sensitive to salt stress and 12 mutants sensitive to salt and alkaline stresses. the position of the insertion of the transposon was located ... | 2003 | 12788708 |
| development of a listeria monocytogenes egde partial proteome reference map and comparison with the protein profiles of food isolates. | a partially annotated proteome reference map of the food pathogen listeria monocytogenes was developed for exponentially growing cells under standardized, optimal conditions by using the sequenced strain egde (serotype 1/2a) as a model organism. the map was developed by using a reproducible total protein extraction and two-dimensional (2-d) polyacrylamide gel electrophoresis analysis procedure, and it contained 33 identified proteins representing the four main protein functional classes. in orde ... | 2003 | 12788738 |
| adhesion, invasion, and translocation characteristics of listeria monocytogenes serotypes in caco-2 cell and mouse models. | adhesion is a crucial first step in listeria monocytogenes pathogenesis. in this study, we examined how the adhesion properties of serotypes correlate with their invasion efficiencies in a cell culture model (caco-2) and in a mouse model. adhesion characteristics of all 13 serotypes of l. monocytogenes (25 strains) were analyzed, which yielded three distinct groups (p < 0.05) with high-, medium-, and low-level-adhesion profiles. the efficiency of these strains in invading the caco-2 cell line wa ... | 2003 | 12788773 |
| generation of food-grade lactococcal starters which produce the lantibiotics lacticin 3147 and lacticin 481. | transconjugant lactococcal starters which produce both lantibiotics lacticin 3147 and lacticin 481 were generated via conjugation of large bacteriocin-encoding plasmids. a representative of one of the resultant strains proved more effective at killing lactobacillus fermentum and inhibiting the growth of listeria monocytogenes lo28h than either of the single bacteriocin-producing parental strains, demonstrating the potential of these transconjugants as protection cultures for food safety applicat ... | 2003 | 12788782 |
| aromatic amino acids at the surface of inlb are essential for host cell invasion by listeria monocytogenes. | the surface protein inlb of the pathogen listeria monocytogenes promotes invasion of this bacterium into host cells by binding to and activating the receptor tyrosine kinase met. the curved leucine-rich repeat (lrr) domain of inlb, which is essential for this process, contains a string of five surface-exposed aromatic amino acid residues positioned along its concave face. here, we show that the replacement of four of these residues (f104, w124, y170 or y214) by serine leads to a complete loss of ... | 2003 | 12791136 |
| isolation of listeria monocytogenes mutants with high-level in vitro expression of host cytosol-induced gene products. | the facultative intracellular bacterial pathogen listeria monocytogenes dramatically increases the expression of several key virulence factors upon entry into the host cell cytosol. acta, the protein product of which is required for cell-to-cell spread of the bacterium, is expressed at low to undetectable levels in vitro and increases in expression more than 200-fold after l. monocytogenes escape from the phagosome. to identify bacterial factors that participate in the intracellular induction of ... | 2003 | 12791137 |
| report of an additional case of anti-tumor necrosis factor therapy and listeria monocytogenes infection: comment on the letter by glück et al. | | 2003 | 12794847 |
| heterogeneity of virulence-related properties in listeria monocytogenes strains isolated from patients with haematological malignancies. | listeria monocytogenes is an intracellular foodborne pathogen of humans and animals for which there are indications of virulence differences among strains. various virulence properties related to different phases of infection process were investigated in l. monocytogenes strains isolated from patients affected by haematological malignancies. in these isolates, besides to the clinical history, we analysed the haemolysin production, the survival to acidic ph, the ability to enter and proliferate i ... | 2003 | 12797902 |
| il-12-assisted immunization generates cd4+ t cell-mediated immunity to listeria monocytogenes. | mice infected with virulent listeria monocytogenes develop long-lived acquired immunity. we previously reported that acquired immunity to listeria could also be elicited by immunizing mice with non-viable listeria or listerial proteins/peptides in combination with il-12. here we show that this il-12-assisted immunization strategy was effective in class i but not in class ii mhc-deficient mice, suggesting that antigen-specific cd4(+) t cells are selectively generated using this adjuvant system. w ... | 2003 | 12798303 |
| membrane filter (pore size, 0.22-0.45 micro m; thickness, 150 micro m) passing-through activity of pseudomonas aeruginosa and other bacterial species with indigenous infiltration ability. | bacteria growing on mf-millipore filters (thickness, 150 micro m) passed through the underlying membrane by their infiltration activity. bacillus subtilis, staphylococcus aureus, klebsiella pneumoniae, and escherichia coli passed through a 0.45- micro m pore size filter within 48-96 h. pseudomonas aeruginosa, serratia marcescens, and listeria monocytogenes passed through a 0.3- micro m pore size filter. p. aeruginosa passed through a 0.22- micro m pore size filter. the membranes which allowed pa ... | 2003 | 12798998 |
| a branched chain fatty acid promotes cold adaptation in bacteria. | | 2003 | 12799482 |