Publications
| Title | Abstract | Year(sorted ascending) Filter | PMID Filter |
|---|
| a gene-expression program reflecting the innate immune response of cultured intestinal epithelial cells to infection by listeria monocytogenes. | listeria monocytogenes is a gram-positive, facultative, intracellular bacterial pathogen found in soil, which occasionally causes serious food-borne disease in humans. the outcome of an infection is dependent on the state of the infected individual's immune system, neutrophils being key players in clearing the microorganism from the body. the first line of host defense, however, is the intestinal epithelium. | 2003 | 12537547 |
| a specific role for b cells in the generation of cd8 t cell memory by recombinant listeria monocytogenes. | in this study, we investigated whether b cells play a role in the induction and maintenance of cd8 t cell memory after immunization with an intracellular bacterium, listeria monocytogenes. our results show that b cells play a minimal role in the initial activation and ag-driven expansion of cd8 t lymphocytes. however, absence of b cells results in increased death of activated cd8 t cells during the contraction phase, leading to a lower level of ag-specific cd8 t cell memory. once memory is estab ... | 2003 | 12538706 |
| efficacy of ozone in killing listeria monocytogenes on alfalfa seeds and sprouts and effects on sensory quality of sprouts. | a study was done to determine the efficacy of aqueous ozone treatment in killing listeria monocytogenes on inoculated alfalfa seeds and sprouts. reductions in populations of naturally occurring aerobic microorganisms on sprouts and changes in the sensory quality of sprouts were also determined. the treatment (10 or 20 min) of seeds in water (4 degrees c) containing an initial concentration of 21.8 +/- 0.1 microg/ml of ozone failed to cause a significant (p < or = 0.05) reduction in populations o ... | 2003 | 12540180 |
| listeria monocytogenes contamination patterns for the smoked fish processing environment and for raw fish. | reliable data on the sources of listeria monocytogenes contamination in cold-smoked fish processing are crucial in designing effective intervention strategies. environmental samples (n = 512) and raw fish samples (n = 315) from two smoked fish processing facilities were screened for l. monocytogenes, and all isolates were subtyped by automated ribotyping to examine the relationship between l. monocytogenes contamination from raw materials and that from environmental sites. samples were collected ... | 2003 | 12540181 |
| effectiveness of trisodium phosphate against listeria monocytogenes on excised and nonexcised chicken skin. | the influence of sample type (i.e., excised versus nonexcised chicken skin) on the efficiency of trisodium phosphate (tsp) solutions in reducing listeria monocytogenes populations and inhibiting their growth during refrigerated storage was studied. whole chicken legs and excised chicken leg skin fragments inoculated with 10(8) cfu of l. monocytogenes per ml were dipped for 15 min in sterile tap water (control) or in a solution containing 8, 10, or 12% tsp. l. monocytogenes counts were determined ... | 2003 | 12540182 |
| a/j mice are susceptible and c57bl/6 mice are resistant to listeria monocytogenes infection by intragastric inoculation. | previous studies demonstrated that the innate resistance of mice to listeria monocytogenes infection by intravenous or intraperitoneal inoculation is regulated principally by the hc locus on mouse chromosome 2. the a/j and c57bl/6 mouse strains were identified as prototype l. monocytogenes-susceptible and -resistant strains, respectively. in the present study, we compared the relative susceptibilities of a/j and c57bl/6 mice to intragastric (i.g.) inoculation with l. monocytogenes. the results o ... | 2003 | 12540546 |
| efflux pump lde is associated with fluoroquinolone resistance in listeria monocytogenes. | five listeria monocytogenes isolates (clip 21369, clip 73298, clip 74811, clip 75679, and clip 79372) were found to be resistant to fluoroquinolones during the screening for antibiotic resistance of 488 l. monocytogenes isolates from human cases of listeriosis in france. on the basis of a fourfold or greater decrease in the ciprofloxacin mic in the presence of reserpine, fluoroquinolone resistance was attributed to active efflux of the drugs. the lde gene (listeria drug efflux; formerly lmo2741) ... | 2003 | 12543681 |
| measles virus infection results in suppression of both innate and adaptive immune responses to secondary bacterial infection. | among infectious agents, measles virus (mv) remains a scourge responsible for 1 million deaths per year and is a leading cause of childhood deaths in developing countries. although mv infection itself is not commonly lethal, mv-induced suppression of the immune system results in a greatly increased susceptibility to opportunistic bacterial infections that are largely responsible for the morbidity and mortality associated with this disease. despite its clinical importance, the underlying mechanis ... | 2003 | 12639986 |
| an improved selective isolation medium for the recovery of listeria monocytogenes from smoked fish. | the aim of this study was to improve the selective isolation of listeria monocytogenes from smoked haddock fillets. | 2003 | 12641717 |
| multi locus fingerprinting of listeria monocytogenes by sequence-specific labeling of dna probes combined with array hybridization. | we have developed an alternative multi locus sequence typing (mlst) approach that targets the variable genetic changes directly in a dna array format. our approach is based on dna array hybridization in combination with sequence-specific labeling of oligonucleotide probes. listeria monocytogenes was chosen for the development and evaluation of the assay. the genes hlya, iap, flaa, inla and acta were targeted. twenty-nine suitable probe regions were identified within these genes. the dna array re ... | 2003 | 12644221 |
| bacteriocin-like substance (bls) production in aeromonas hydrophila water isolates. | 30 aeromonas hydrophila water isolates were tested for bacteriocin-like substance (bls) production using a target panel of closely related microorganisms and other gram-positive and gram-negative bacteria, including food-borne pathogens. a. hydrophila showed antibacterial activity against one or more indicator microorganisms, but the activity emerged only with non-phylogenetically related genera or species. in particular all a. hydrophila showed antibacterial activity against one or more of the ... | 2003 | 12644237 |
| listeriosis: clinical presentation. | listeria monocytogenes is an uncommon cause of illness in the general population. however, this bacterium is an important cause of severe infections in neonates, pregnant women, the elderly, transplant recipients and other patients with impaired cell-mediated immunity. various clinical syndromes due to l. monocytogenes have been described such as sepsis, central nervous system infections, endocarditis, gastroenteritis and localized infections. a review of the clinical presentation of listeriosis ... | 2003 | 12648833 |
| murine model of pregnancy-associated listeria monocytogenes infection. | listeria monocytogenes has been recognized as a significant pathogen, occurring worldwide, capable of causing animal and human infections. in its most severe form, listeriosis is an invasive disease that affects immunocompromised patients. additionally, pregnant women represent a high-risk group for l. monocytogenes infection. abortion, stillbirth or severe neonatal infection can be the serious outcome of such an infection. in an experimental murine model of pregnancy-associated listeriosis we s ... | 2003 | 12648834 |
| listeria: growth, phenotypic differentiation and molecular microbiology. | the identification of listeria species is based on a limited number of biochemical markers, among which absence or presence of hemolysis and arylamidase are used to differentiate between l. monocytogenes and l. innocua. the camp (christie, atkins, munch-petersen) test must be interpreted with caution. chromogenic media are based on both the specific chromogenic detection of phosphatidylinositol phospholipase c and the xylose fermentation and give specific and direct identification of l. monocyto ... | 2003 | 12648835 |
| listeria monocytogenes: diagnostic problems. | the first isolation methods for the detection of listeria spp. were generally based on the direct culture of samples on simple agar media, but isolation of the pathogenic listeria monocytogenes was difficult. in time, new techniques were developed, based on a variety of selective and elective agents in isolation and enrichment media, which gained better and quicker results. current reference methods allow the recovery of l. monocytogenes from a variety of foods with relative ease. however, more ... | 2003 | 12648836 |
| history and epidemiology of listeriosis. | listeriae are used as a tool by different specialities in biomedical research. there are now at least four major fields of interest in listeria: (1). the role in medical microbiology: listeria monocytogenes causes severe diseases of men and animals and is difficult to treat; (2). the role in food microbiology: listeria is a food-borne pathogen and is found in various food items; (3). the role in cell biology: l. monocytogenes is a facultative intracellular parasite having an intense cross-talk a ... | 2003 | 12648837 |
| listeriosis: therapeutic options. | since overt listeriosis occurs mainly in immunocompromised persons it is quite consistent to try to restore the hampered defence system by supportive measurements. for direct antimicrobial treatment a series of different antibiotics is available, since listeria strains isolated from patients are in general susceptible to a wide range of antibiotics, except fosfomycin, quinolones and cephalosporins of the third generation, although a few exceptional strains exist. unfortunately, most antibiotics ... | 2003 | 12648838 |
| comparison of the genome sequences of listeria monocytogenes and listeria innocua: clues for evolution and pathogenicity. | listeria monocytogenes, an invasive opportunistic, food-borne pathogen, remains one of the leading causes of mortality from food-borne infections. the recently determined complete genome sequences of l. monocytogenes strain egde and of that of the closely related non-pathogenic species listeria innocua strain clip11262 enhance our knowledge of the genetic basis of the virulence of l. monocytogenes and advance our understanding of the evolution of these listeria species. both genomes encode a hig ... | 2003 | 12648839 |
| nucleic acid-based, cultivation-independent detection of listeria spp and genotypes of l monocytogenes. | based on comparative analysis of 16s rrna gene sequences, two oligonucleotide probes for in situ detection of all members of the genus listeria were designed. these probes allowed fast and reliable in situ detection of listeria spp. even in complex samples like raw milk. almost full-length iap (invasion-associated protein) gene sequences were determined for 69 listeria monocytogenes strains of all 13 known serotypes. a comparison of these sequences revealed that the l. monocytogenes strains can ... | 2003 | 12648840 |
| characterization of listeria monocytogenes recovered from 41 cases of sporadic listeriosis in austria by serotyping and pulsed-field gel electrophoresis. | 41 clinical listeria monocytogenes strains recovered from seven feto-maternal and 34 non-pregnancy associated cases of human listeriosis documented between 1997 and 2000 underwent serotyping and typing by pulsed-field gel electrophoresis (pfge) applying the enzymes asci, apai and smai. the pulsotypes of the clinical strains were compared to the pulsotypes of three l. monocytogenes strains isolated from healthy fecal carriers and nine reference strains isolated from seven outbreaks in europe and ... | 2003 | 12648841 |
| cd8 t cell immunome analysis of listeria monocytogenes. | the identification of t cell epitopes is crucial for the understanding of the host response during infections with pathogenic microorganisms. generally, the identification of relevant t cell responses is based on the analysis of t cell lines propagated in vitro. we used an ex vivo approach for the analysis of the cd8 t cell response against listeria monocytogenes that is based upon the fractionation of naturally processed antigenic peptides and subsequent analysis with t cells in an enzyme-linke ... | 2003 | 12648842 |
| tailoring host immune responses to listeria by manipulation of virulence genes -- the interface between innate and acquired immunity. | although attenuated strains of microbial pathogens have triggered vaccine development from its origin, the role of virulence factors in determining host immunity has remained largely unexplored. using the murine listeriosis model, we investigated whether the induction and expansion of protective and inflammatory t cell responses may be modified by selective manipulation of virulence genes. we intentionally deleted specific genes of listeria monocytogenes, including those encoding the positive re ... | 2003 | 12648843 |
| production of il-12 and il-18 in human dendritic cells upon infection by listeria monocytogenes. | dendritic cells (dcs) are major antigen-presenting cells of the immune system, which need to be activated in order to initiate an immune response. here, we describe the immunostimulatory effects on human monocyte-derived dcs observed upon infection with listeria monocytogenes or after treatment with listerial lipoteichoic acid (lta) and lipopolysaccharide (lps), respectively. all stimuli caused upregulation of costimulatory molecules, induced t-cell proliferative responses and secretion of cytok ... | 2003 | 12648844 |
| quantitative risk assessment of listeria monocytogenes in ready-to-eat foods: the fao/who approach. | quantitative microbiological risk assessment is a very new and unique scientific approach able to link, for the first time, data from food (in the farm-to-fork continuum) and the various data on human disease to provide a clear estimation of the impact of contaminated food on human public health. the food and agriculture organization of the united nations (fao) and the world health organization (who) have recently launched risk assessment studies of a number of pathogen-food commodity combinatio ... | 2003 | 12648845 |
| efficiency of high pressure treatment for destruction of listeria monocytogenes in fruit juices. | the objective of this study was to compare high pressure resistance of listeria monocytogenes strains at 25 degrees c and 50 degrees c at 350 mpa and to use high pressure (250 mpa and 350 mpa) at 30 degrees c and 40 degrees c for the inactivation of the relatively most pressure resistant strain inoculated in pasteurized apple, apricot, cherry and orange juices. l. monocytogenes ca was found to be the relatively most pressure resistant strain and increasing pressurization from 250 mpa to 350 mpa ... | 2003 | 12648846 |
| occurrence of listeria sp and l monocytogenes in sewage sludge used for land application: effect of dewatering, liming and storage in tank on survival of listeria species. | the application of sewage sludge to agricultural land is widely used in france. to determine the impact of sludge treatments, concentrations of listeria sp., listeria monocytogenes and faecal indicators were monitored in five types of sludge from three sewage treatment plants in angers (france) and its suburbs over a 1-year period. on the whole, bacteria were reduced in numbers through sludge treatments. apart from liming, which leads to reduced levels of bacteria below detection limits, other s ... | 2003 | 12648847 |
| high-level expression of the listeria monocytogenes listeriolysin o in escherichia coli and preliminary characterization of the purified protein. | listeriolysin o (llo) is a cholesterol-binding sulfhydryl-activated hemolysin encoded by listeria monocytogenes hlya gene. after analyzing the nucleotide coding sequence of this gene from the atcc 9525 l. monocytogenes strain, we cloned it in a pet vector for expression in escherichia coli. thanks to the optimization of the induction protocol, we achieved a high-level llo synthesis (about 10% of total cell proteins) in hemolytically active form. the expressed hemolysin was then purified to homog ... | 2003 | 12651110 |
| the use of nasba for the detection of microbial pathogens in food and environmental samples. | the isothermal amplification method nucleic acid sequence-based amplification (nasba), which amplifies rna, has been reported as useful for the detection of microbial pathogens in food and environmental samples. methods have been published for campylobacter spp., listeria monocytogenes and salmonella enterica ser. enteritidis in various foods and for cryptosporidium parvum in water. both 16s rrna and various mrnas have been used as target molecules for detection; the latter may have advantages i ... | 2003 | 12654488 |
| detection of bacterial pathogens in environmental samples using dna microarrays. | polymerase chain reaction (pcr) is an important tool for pathogen detection, but historically, it has not been possible to accurately identify pcr products without sequencing, southern blots, or dot-blots. microarrays can be coupled with pcr where they serve as a set of parallel dot-blots to enhance product detection and identification. microarrays are composed of many discretely located probes on a solid substrate such as glass. each probe is composed of a sequence that is complimentary to a pa ... | 2003 | 12654494 |
| quantitative, multiplexed detection of bacterial pathogens: dna and protein applications of the luminex labmap system. | escherichia coli, salmonella, listeria monocytogenes and campylobacter jejuni are bacterial pathogens commonly implicated in foodborne illnesses. generally used detection methods (i.e., culture, biochemical testing, elisa and nucleic acid amplification) can be laborious, time-consuming and require multiple tests to detect all of the pathogens. our objective was to develop rapid assays to simultaneously detect these four organisms through the presence of antigen or dna using the luminex labmap sy ... | 2003 | 12654495 |
| activities of abt-773 against listeria monocytogenes and coryneform bacteria of clinical interest. | the in vitro activities of abt-773 were evaluated against 15 listeria monocytogenes strains and 196 coryneform bacteria isolated from clinical samples. one hundred percent of the l. monocytogenes strains were inhibited by </=0.015 micro g of abt-773/ml. mics of abt-773 ( micro g/ml) at which 50% of the isolates tested were inhibited (mic(50)s) and mic(90)s for other organisms were 0.125 and 0.5 (corynebacterium amycolatum), 1 and >32 (corynebacterium jeikeium), 0.03 and >32 (corynebacterium minu ... | 2003 | 12654678 |
| activity of beta-lactams (ampicillin, meropenem), gentamicin, azithromycin and moxifloxacin against intracellular listeria monocytogenes in a 24 h thp-1 human macrophage model. | 2003 | 12654747 | |
| induction of protective immunity to listeria monocytogenes with dendritic cells retrovirally transduced with a cytotoxic t lymphocyte epitope minigene. | in the present study, we developed a cytotoxic t lymphocyte (ctl) epitope minigene-transduced dendritic cell (dc)-based vaccine against listeria monocytogenes. murine bone marrow-derived dcs were retrovirally transduced with a minigene for listeriolysin o (llo) 91-99, a dominant ctl epitope of l. monocytogenes, and were injected into balb/c mice intravenously. we found that the dc vaccine was capable of generating peptide-specific cd8+ t cells exhibiting llo 91-99-specific cytotoxic activity and ... | 2003 | 12654788 |
| functional regulation of the listeria monocytogenes bacteriophage a118 holin by an intragenic inhibitor lacking the first transmembrane domain. | we have dissected the functional properties of the holin encoded by listeria monocytogenes bacteriophage a118. native hol118 was cloned into lambdadeltasthf, devoid of the s holin, and tested in an e. coli background. surprisingly, it caused very late cell lysis, beginning at 80 min after induction. immunological analyses demonstrated that hol118 appears in the cytoplasmic membrane shortly after infection. the hol118 gene features a dual start motif similar to lambda s. therefore, different n-te ... | 2003 | 12657053 |
| probing polymerization forces by using actin-propelled lipid vesicles. | actin polymerization provides a powerful propulsion force for numerous types of cell motility. although tremendous progress has been made in identifying the biochemical components necessary for actin-based motility, the precise biophysical mechanisms of force generation remain unclear. to probe the polymerization forces quantitatively, we introduce an experimental system in which lipid vesicles coated with the listeria monocytogenes virulence factor acta are propelled by actin polymerization. th ... | 2003 | 12657740 |
| the sigmae regulon and the identification of additional sporulation genes in bacillus subtilis. | we report the identification and characterization on a genome-wide basis of genes under the control of the developmental transcription factor sigma(e) in bacillus subtilis. the sigma(e) factor governs gene expression in the larger of the two cellular compartments (the mother cell) created by polar division during the developmental process of sporulation. using transcriptional profiling and bioinformatics we show that 253 genes (organized in 157 operons) appear to be controlled by sigma(e). among ... | 2003 | 12662922 |
| mapping quantitative trait loci in the case of a spike in the phenotype distribution. | a common departure from the usual normality assumption in qtl mapping concerns a spike in the phenotype distribution. for example, in measurements of tumor mass, some individuals may exhibit no tumors; in measurements of time to death after a bacterial infection, some individuals may recover from the infection and fail to die. if an appreciable portion of individuals share a common phenotype value (generally either the minimum or the maximum observed phenotype), the standard approach to qtl mapp ... | 2003 | 12663553 |
| rapidly enlarging iliac aneurysm secondary to listeria monocytogenes infection: a case report. | infected aneurysms caused by listeria monocytogenes are rare. worldwide, 16 cases have been reported, none in the iliac system. the authors report the case of an 80-year-old man being followed for small aortic and right common iliac artery (rcia) aneurysms who presented with progressive gastrointestinal symptoms. serial computed tomography demonstrated a 200% increase in rcia diameter with development of infection over 1 month. right axillobifemoral bypass and aneurysm resection were performed. ... | 2003 | 12669148 |
| dietary fish oil impairs primary host resistance against listeria monocytogenes more than the immunological memory response. | the primary objective of this study was to determine whether dietary (n-3) polyunsaturated fatty acids (pufa) impair the ability of mice to generate an immunological memory response against the bacterial pathogen, listeria monocytogenes. weanling balb/c female mice were fed for 28 d one of two semipurified high fat diets containing either lard or refined menhaden fish oil, rich in long-chain (n-3) pufa. mice were immunized with 10(4) or 10(3) colony forming units (cfu) bacteria. thirty-five days ... | 2003 | 12672937 |
| 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 |
| antimicrobial efficacy of a silver-zeolite matrix coating on stainless steel. | a silver- and zinc-containing zeolite matrix (agion) used as a coating for stainless steel was tested for antimicrobial efficacy against escherichia coli 25922, staphylococcus aureus 25923, pseudomonas aeruginosa 27853, and listeria monocytogenes 7644. assays were performed on flat coupon surfaces and in formed steel cups. agion reduced microbial colony-forming units when compared to uncoated steel surfaces under all conditions tested. percent reductions ranged from 84.536 to 99.999 after 4 h ex ... | 2003 | 12612784 |
| febrile gastroenteritis after eating on-farm manufactured fresh cheese--an outbreak of listeriosis? | an outbreak of febrile gastroenteritis affected consumers of on-farm manufactured dairy products from a summer farm in sweden. symptoms included diarrhoea, fever, stomach cramps and vomiting in 88, 60, 54 and 21% of cases identified. the median incubation period was 31 h. a cohort study with 33 consumers showed an attack rate of 52% and an association between the total amount of product eaten and illness (p=0.07). twenty-seven of 32 (84%) stool samples cultured for listeria monocytogenes tested ... | 2003 | 12613748 |
| il-13 effector functions. | il-13 was first recognized for its effects on b cells and monocytes, where it upregulated class ii expression, promoted ige class switching and inhibited inflammatory cytokine production. it was also thought to be functionally redundant with il-4. however, studies conducted with knockout mice, neutralizing antibodies, and novel antagonists demonstrate that il-13 possesses several unique effector functions that distinguish it from il-4. resistance to most gastrointestinal nematodes is mediated by ... | 2003 | 12615888 |
| flt3 ligand-treated neonatal mice have increased innate immunity against intracellular pathogens and efficiently control virus infections. | flt-3 ligand (fl), a hematopoetic growth factor, increases the number of dendritic cells (dcs), b cells, and natural killer cells in adult mice but the effect in neonates was unknown. we show that fl treatment of newborn mice induced a >100-fold increase in the innate resistance against infection with herpes simplex virus type 1 and listeria monocytogenes. this resistance required interferon (ifn)-alpha/beta for viral and interleukin (il)-12 for bacterial infections. long-term survival after vir ... | 2003 | 12615899 |
| effect of lactational exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin on the susceptibility to listeria infection. | we studied the effect of lactational exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin (tcdd) on the susceptibility to listeria infection of offspring in c57bl /6ncji mice. the offspring were nursed by tcdd-treated dams and exposed to tcdd from birth to weaning via milk. the exposure had little effect on the weights of immune organs and the spleen or the thymus cell population in the dams and offspring, but it enhanced the production of tumor necrosis factor alpha (tnf-alpha) and interferon gamma ... | 2003 | 12619678 |
| kdpe and a putative rsbq homologue contribute to growth of listeria monocytogenes at high osmolarity and low temperature. | the kdp locus of listeria monocytogenes encodes products with homology to structural proteins of a high-affinity potassium uptake system and to a two-component signal transduction system commonly involved in controlling gene expression. we have investigated the role of kdpe, encoding the transcriptional response regulator, as well as of the downstream gene, orfx, in adaptation of l. monocytogenes egd to nacl and low temperature. when grown in chemically defined medium the addition of nacl to 2% ... | 2003 | 12620626 |
| a pediocin-producing lactobacillus plantarum strain inhibits listeria monocytogenes in a multispecies cheese surface microbial ripening consortium. | the growth of listeria monocytogenes wslc 1364, originating from a cheese-borne outbreak, was examined in the presence and in the absence of a pediocin ach-producing lactobacillus plantarum strain on red smear cheese. nearly complete inhibition was observed at 10(2) cfu of l. monocytogenes per ml of salt brine solution, while contamination with listeria mutants resistant to pediocin resulted in high cell counts of the pathogen on the cheese surface. the inhibition was due to pediocin ach added t ... | 2003 | 12620882 |
| transcriptome analysis of listeria monocytogenes identifies three groups of genes differently regulated by prfa. | prfa is the major regulator of listeria virulence gene expression. this protein is a member of the crp/fnr family of transcription regulators. to gain a deeper understanding of the prfa regulon, we constructed a whole-genome array based on the complete genome sequence of listeria monocytogenes strain egde and evaluated the expression profiles of the wild-type egde and a prfa-deleted mutant (egde delta prfa). both strains were grown at 37 degrees c in brain-heart infusion broth (bhi) and bhi supp ... | 2003 | 12622816 |
| use of listeriolysin o and internalin a in a seroepidemiological study of listeriosis in swiss dairy cows. | recombinant listeriolysin o and internalin a were used as antigens in an enzyme-linked immunosorbent assay (elisa) for the specific detection of anti-listeria monocytogenes antibodies in cattle. the results showed sensitivities and specificities of 82 and 92%, respectively, for the listeriolysin o elisa, and 100 and 90%, respectively, for the internalin a elisa, respectively. the test may be useful for the confirmation of listeria-related abortions and mastitis but does not seem to be indicated ... | 2003 | 12624029 |
| engineered recombinant peanut protein and heat-killed listeria monocytogenes coadministration protects against peanut-induced anaphylaxis in a murine model. | peanut allergy (pna) is the major cause of fatal and near-fatal anaphylactic reactions to foods. traditional immunotherapy using peanut (pn) protein is not an option for pna therapy because of the high incidence of adverse reactions. we investigated the effects of s.c. injections of engineered (modified) recombinant pn proteins and heat-killed listeria monocytogenes (hklm) as an adjuvant on anaphylactic reactions in a mouse model of pn allergy. pn-allergic c3h/hej mice were treated s.c. with a m ... | 2003 | 12626588 |
| autolytic activity and pediocin-induced lysis in pediococcus acidilactici and pediococcus pentosaceus strains. | to evaluate the autolytic phenotype of pediococcus acidilactici and p. pentosaceus, the peptidoglycan hydrolases content and the effect of pediocin ach/pa-1 and autolysins on cell lysis. | 2003 | 12631191 |
| molecular epidemiological survey of listeria monocytogenes in broilers and poultry products. | to investigate the prevalence of listeria monocytogenes in poultry products, and to elucidate whether poultry products may be linked to listeriosis cases. a further goal was to identify contamination routes for l. monocytogenes to broiler carcasses. | 2003 | 12631199 |
| subtyping listeria monocytogenes through the combined analyses of genotype and expression of the hlya virulence determinant. | a major challenge for listeria monocytogenes diagnostics is that this bacterium is ubiquitous in the environment, and that only a small fraction of the lineages are potential human pathogens. the aim of this work was to obtain a better subtyping of l. monocytogenes through utilization of combined analyses of genotype and the expression of the virulence determinant hlya. | 2003 | 12631208 |
| can cold cuts kill? | 2003 | 12632673 | |
| capacity of ivanolysin o to replace listeriolysin o in phagosomal escape and in vivo survival of listeria monocytogenes. | listeriolysin o (llo, hly-encoded) is a major virulence factor secreted by the pathogen listeria monocytogenes. the amino acid sequence of llo shows a high degree of similarity with that of ivanolysin o (ilo), the cytolysin secreted by the ruminant pathogen listeria ivanovii. here, it was tested whether ilo could functionally replace llo by expressing the gene encoding ilo under the control of the hly promoter, in an hly-deleted strain of l. monocytogenes. it is shown that ilo allows efficient p ... | 2003 | 12634330 |
| meconium enhances the growth of perinatal bacterial pathogens. | to demonstrate the effects of meconium on growth of bacterial pathogens, which are common causes of intra-amniotic infection and neonatal sepsis. | 2003 | 12634904 |
| impact of microbial ecology of meat and poultry products on predictions from exposure assessment scenarios for refrigerated storage. | a novel extension of traditional growth models for exposure assessment of food-borne microbial pathogens was developed to address the complex interactions of competing microbial populations in foods. scenarios were designed for baseline refrigeration and mild abuse of servings of chicken broiler and ground beef our approach employed high-quality data for microbiology of foods at production, refrigerated storage temperatures, and growth kinetics of microbial populations in culture media. simple p ... | 2003 | 12635734 |
| viability of clostridium perfringens, escherichia coli, and listeria monocytogenes surviving mild heat or aqueous ozone treatment on beef followed by heat, alkali, or salt stress. | the threat of pathogen survival following ozone treatment of meat necessitates careful evaluation of the microorganisms surviving under such circumstances. the objective of this study was to determine whether sublethal aqueous ozone treatment (3 ppm of o3 for 5 min) of microorganisms on beef surfaces would result in increased or decreased survival with respect to subsequent heat, alkali, or nacl stress. a mild heat treatment (55 degrees c for 30 min) was used for comparison. reductions in three- ... | 2003 | 12636289 |
| a novel method for the reduction of numbers of listeria monocytogenes cells by freezing in combination with an essential oil in bacteriological media. | the use of multiple freeze (-20 degrees c)-thaw cycles in combination with isoeugenol and polysorbate 80 was investigated as a method for the reduction of numbers of listeria monocytogenes cells in a bacteriological medium. three freeze (1 h, -20 degrees c)-thaw cycles in the presence of isoeugenol at concentrations of 0, 100, and 300 ppm resulted in average l. monocytogenes reductions of 0.69, 2.65, and 3.3 log10 mpn (most probable number) per ml, respectively. increasing the number of freeze-t ... | 2003 | 12636290 |
| microbiological study of ready-to-eat salad vegetables from retail establishments uncovers a national outbreak of salmonellosis. | the increasing availability of bagged prepared salad vegetables reflects consumer demand for fresh, healthy, convenient, and additive-free foods that are safe and nutritious. during may and june 2001 a study of retail bagged prepared ready-to-eat salad vegetables was undertaken to determine the microbiological quality of these vegetables. examination of the salad vegetables revealed that the vast majority (3,826 of 3,852 samples; 99.3%) were of satisfactory or acceptable microbiological quality ... | 2003 | 12636292 |
| detection of listeria monocytogenes in salmon using the probelia polymerase chain reaction system. | a validation was conducted on the performance of a commercially available polymerase chain reaction (pcr) kit (probelia) in comparison with international organization for standardization (iso) method 11290-1 (adopted as an australian new zealand standard method, as/nzs 1766.2.16.1:1998) for the detection of listeria monocytogenes in salmon samples. the validation was conducted following the guidelines of an australian new zealand standard (guide to determining the equivalence of food microbiolog ... | 2003 | 12636297 |
| evaluation and interlaboratory validation of a selective agar for phosphatidylinositol-specific phospholipase c activity using a chromogenic substrate to detect listeria monocytogenes from foods. | phosphatidylinositol-specific phospholipase c (pi-plc) activity is a potential virulence factor and is exhibited only by the listeria species listeria monocytogenes and listeria ivanovii. a chromogenic substrate for the direct detection of pi-plc activity is available in a new medium (bcm l. monocytogenes plating agar). the use of a chromogenic substrate offers a mechanism with which to directly screen for l. monocytogenes and l. ivanovii other than the esculin used in oxford (oxf) and palcam (p ... | 2003 | 12636298 |
| rapid detection of escherichia coli o157:h7 inoculated in ground beef, chicken carcass, and lettuce samples with an immunomagnetic chemiluminescence fiber-optic biosensor. | a biosensor was evaluated with regard to its usefulness in the rapid detection of escherichia coli o157:h7 inoculated in ground beef, chicken carcass, and romaine lettuce samples. the biosensor consisted of a chemiluminescence reaction cell, a fiber-optic light guide, and a luminometer linked to a personal computer in conjunction with immunomagnetic separation. the samples inoculated with e. coli o157:h7 were first centrifuged and suspended in buffered peptone water and then incubated with anti- ... | 2003 | 12636312 |
| 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 |
| discrimination among listeria monocytogenes isolates using a mixed genome dna microarray. | listeria monocytogenes can cause serious illness in humans, usually following the ingestion of contaminated food. epidemiologic investigation requires identification of specific isolates, usually done by a combination of serotyping and subtyping using pulsed-field gel electrophoresis (pfge). dna microarrays provide a new format to resolve genetic differences among isolates and, unlike pfge, to identify specific genes associated with the infecting pathogen. a 585 probe, mixed genome microarray wa ... | 2003 | 12554104 |
| enhancing the immunogenicity of bioengineered listeria monocytogenes by passaging through live animal hosts. | bioengineered listeria monocytogenes can be used as a recombinant bacterial vaccine vector for the induction of strong cell-mediated immunity to passenger antigens. listeria loses virulence after undergoing bioengineering techniques, thus decreasing its efficacy as a vaccine vector. we addressed this problem by examining the virulence, and the ability to induce cd8(+) t-cells, of listeria monocytogenes vaccine strains before and after passaging through mice. we found that two in vivo passages ar ... | 2003 | 12559797 |
| antibacterial activity of peptides derived from envelope glycoproteins of hiv-1. | recent reports have highlighted the anti-hiv-1 activities of defensins, whose structure and charge resemble portions of the hiv-1 transmembrane envelope glycoprotein gp41. the current report explores the obverse, whether peptides derived from hiv-1 envelope glycoproteins can exert antimicrobial activity. fifteen-residue peptides spanning the entire sequence of hiv-1(mn) gp120 and gp41 were subjected to radial diffusion assays against laboratory strains of escherichia coli and listeria monocytoge ... | 2003 | 12560103 |
| lineage relationship and protective immunity of memory cd8 t cell subsets. | memory cd8 t cells can be divided into two subsets, central (t(cm)) and effector (t(em)), but their lineage relationships and their ability to persist and confer protective immunity are not well understood. our results show that t(cm) have a greater capacity than t(em) to persist in vivo and are more efficient in mediating protective immunity because of their increased proliferative potential. we also demonstrate that, following antigen clearance, t(em) convert to t(cm) and that the duration of ... | 2003 | 12563257 |
| bad bugs: good for cancer therapy? | components of listeria and escherichia coli have been used to prime the immune system in a novel approach to fighting cancer. | 2003 | 12565001 |
| growths kinetics comparison of clinical and seafood listeria monocytogenes isolates in acid and osmotic environment. | comparison of pathogenic bacterial strains of clinical origin with strains of the same species isolated from the environment may be a valuable tool for microbial risk assessment, especially for foodborne pathogens. thus, a number of listeria monocytogenes strains responsible for human cases of listeriosis, in relation to the consumption of contaminated seafood, have been compared with "natural" l. monocytogenes strains isolated from similar seafood products. complete factorial designs were used ... | 2003 | 12568752 |
| three transporters mediate uptake of glycine betaine and carnitine by listeria monocytogenes in response to hyperosmotic stress. | the uptake and accumulation of the potent osmolytes glycine betaine and carnitine enable the food-borne pathogen listeria monocytogenes to proliferate in environments of elevated osmotic stress, often rendering salt-based food preservation inadequate. to date, three osmolyte transport systems are known to operate in l. monocytogenes: glycine betaine porter i (betl), glycine betaine porter ii (gbu), and a carnitine transporter opuc. we investigated the specificity of each transporter towards each ... | 2003 | 12571024 |
| detection of listeria monocytogenes from a model food by fluorescence resonance energy transfer-based pcr with an asymmetric fluorogenic probe set. | it has been shown that fluorescence resonance energy transfer (fret)-based pcr, including the taqman assay and molecular beacons, has potential for rapid detection of pathogens. in these promising real-time detection assays a single internal oligonucleotide probe labeled on both the 5' (reporter) and 3' (quencher) ends is used for selective generation of fluorescence. in this paper, we describe the use of a previously reported novel probe design for fret-based pcr detection of listeria monocytog ... | 2003 | 12571032 |
| listeria monocytogenes infection as a complication of treatment with tumor necrosis factor alpha-neutralizing agents. | tumor necrosis factor alpha (tnfalpha) has been implicated in the pathogenesis of certain inflammatory diseases. two tnfalpha-neutralizing agents are licensed in the us. infliximab is licensed for the treatment of crohn's disease (cd) and, when used with methotrexate, for the treatment of rheumatoid arthritis (ra). etanercept is licensed for the treatment of ra, including juvenile ra, and, more recently, was licensed for the treatment of psoriatic arthritis. because of the potential for decrease ... | 2003 | 12571839 |
| serotyping of listeria monocytogenes by enzyme-linked immunosorbent assay and identification of mixed-serotype cultures by colony immunoblotting. | routine analysis of listeria monocytogenes by serotyping using traditional agglutination methods is limited in use because of the expense and limited availability of commercially prepared antisera and intra- and interlaboratory discrepancies arising from differences in antiserum preparation and visual determination of agglutination. we have adapted a commercially available set of l. monocytogenes antisera to an enzyme-linked immunosorbent assay (elisa) format for high-throughput, low-cost seroty ... | 2003 | 12574247 |
| mixed-genome microarrays reveal multiple serotype and lineage-specific differences among strains of listeria monocytogenes. | epidemiological studies and analysis of putative virulence genes have shown that listeria monocytogenes has diverged into several phylogenetic divisions. we hypothesize that similar divergence has occurred for many genes that influence niche-specific fitness and virulence and that identifying these differences may offer new opportunities for the detection, treatment, and control of this important pathogen. to explore this issue further, we developed a microarray composed of fragmented dna taken ... | 2003 | 12574259 |
| bartonella strains from ground squirrels are identical to bartonella washoensis isolated from a human patient. | the most likely animal source of a human case of cardiac disease in washoe county, nev., was identified by comparison of dna sequences of three genes (citrate synthase glta, 60-kda heat shock protein gene groel, and 16s rrna gene) of bartonella washoensis cultured from the human patient in question and of bartonella isolates obtained from the following nevada rodents: peromyscus maniculatus (17 isolates), tamias minimus (11 isolates), spermophilus lateralis (3 isolates), and spermophilus beechey ... | 2003 | 12574261 |
| development of a multilocus sequence typing method for analysis of listeria monocytogenes clones. | this study is a first step in the development of multilocus sequence typing (mlst) method for listeria monocytogenes. nine housekeeping genes were analyzed in a set of 62 strains isolated from different sources and geographic locations in spain. these strains were previously characterized by pulsed-field gel electrophoresis (pfge). because of low diversity, two loci were discarded from the study. the sequence analysis of the seven remaining genes showed 29 different allelic combinations, with 22 ... | 2003 | 12574278 |
| preferential survival of cd8 t and nk cells expressing high levels of cd94. | the qa-1(b)/qdm tetramer binds to cd94/nkg2 receptors expressed at high levels on approximately 50% of murine nk cells. although very few cd8 t cells from naive mice express cd94/nkg2 receptors, approximately 50% of cd8 t cells taken from mice undergoing a secondary response against listeria monocytogenes (lm) are cd94(high) and bind the tetramer. although cd94(int) nk cells do not bind the tetramer, cd94(int) cd8 t cells do, and this binding is dependent on the cd8 coreceptor. we found that the ... | 2003 | 12574337 |
| h2-m3-restricted memory t cells: persistence and activation without expansion. | h2-m3-restricted t cells respond more rapidly to primary listeria monocytogenes infection than conventional mhc class ia-restricted t cells. reinfection with l. monocytogenes, while inducing explosive proliferation of h2-k(d)-restricted t cells, does not stimulate significant expansion of h2-m3-restricted ctl. these disparate responses to reinfection are apparent within 5 days of primary l. monocytogenes infection. however, h2-m3-restricted memory t cells are generated, and are indistinguishable ... | 2003 | 12574352 |
| role of cd4 t cell help and costimulation in cd8 t cell responses during listeria monocytogenes infection. | cd4 t cells are known to assist the cd8 t cell response by activating apc via cd40-cd40 ligand (l) interactions. however, recent data have shown that bacterial products can directly activate apc through toll-like receptors, resulting in up-regulation of costimulatory molecules necessary for the efficient priming of naive t cells. it remains unclear what role cd4 t cell help and various costimulation pathways play in the development of cd8 t cell responses during bacterial infection. in this stud ... | 2003 | 12574376 |
| negative regulation of prfa, the key activator of listeria monocytogenes virulence gene expression, is dispensable for bacterial pathogenesis. | listeria monocytogenes is a facultative intracellular bacterial pathogen that regulates the expression of virulence-associated gene products in response to specific host cell compartment environments. the prfa protein of l. monocytogenes functions as a key regulatory factor required for the differential expression of bacterial virulence gene products within infected host cells. prfa both positively and negatively regulates its own expression, and while prfa positive regulation is required for ce ... | 2003 | 12576585 |
| 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 |