Publications
| Title | Abstract | Year(sorted ascending) Filter | PMID Filter |
|---|
| hybridoma ped-2e9 cells cultured under modified conditions can sensitively detect listeria monocytogenes and bacillus cereus. | lymphocyte origin hybridoma ped-2e9 cell-based cytotoxicity assay can detect virulent listeria or bacillus species, and its application in a cell-based biosensor for onsite use would be very attractive. however, maintaining enough viable cells on a sensor platform for a prolonged duration is a challenging task. in this study, key factors affecting the survival and growth of ped-2e9 cells under modified conditions were investigated. when the ped-2e9 cells were grown in media containing 5% fetal b ... | 2007 | 17043821 |
| optical forward-scattering for detection of listeria monocytogenes and other listeria species. | we demonstrate here the development of a non-invasive optical forward-scattering system, called 'scatterometer' for rapid identification of bacterial colonies. the system is based on the concept that variations in refractive indices and size, relative to the arrangement of cells in bacterial colonies growing on a semi-solid agar surface will generate different forward-scattering patterns. a 1.2-1.5mm colony size for a 1mm laser beam and brain heart infusion agar as substrate were used as fixed v ... | 2007 | 16949268 |
| inactivation of lgt allows systematic characterization of lipoproteins from listeria monocytogenes. | lipoprotein anchoring in bacteria is mediated by the prolipoprotein diacylglyceryl transferase (lgt), which catalyzes the transfer of a diacylglyceryl moiety to the prospective n-terminal cysteine of the mature lipoprotein. deletion of the lgt gene in the gram-positive pathogen listeria monocytogenes (i) impairs intracellular growth of the bacterium in different eukaryotic cell lines and (ii) leads to increased release of lipoproteins into the culture supernatant. comparative extracellular prote ... | 2007 | 17041050 |
| novel multiplex pcr approaches for the simultaneous detection of human pathogens: escherichia coli 0157:h7 and listeria monocytogenes. | escherichia coli 0157:h7 and listeria monocytogenes are the two most important food-borne human pathogens. to develop a single, rapid and sensitive pcr based test for simultaneous detection of both the organisms, flich7 and iap gene specific primers were used respectively for e. coli 0157:h7 and l. monocytogenes. initially, with equal quantities of purified genomic dnas of these organisms a multiplex pcr reaction was standardized to yield uniform amplification of both targets. although, this ass ... | 2007 | 16963139 |
| combined sigb allelic typing and multiplex pcr provide improved discriminatory power and reliability for listeria monocytogenes molecular serotyping. | conventional serotyping has traditionally been used to subtype listeria monocytogenes, but has several limitations, including low discriminatory power and poor reproducibility. molecular serotyping methods have been developed for l. monocytogenes, but generally show limited discriminatory power and high misclassification rates. we selected 157 listeria isolates to evaluate a combination of a previously described multiplex pcr assay and sigb allelic typing as an alternative molecular serotyping a ... | 2007 | 16887224 |
| evaluation of bbl chromagar listeria agar for the isolation and identification of listeria monocytogenes from food and environmental samples. | the performance of bbl chromagar listeria chromogenic agar for the detection of listeria monocytogenes was evaluated for its ability to isolate and identify l. monocytogenes from food and environmental samples. the medium was compared to non-chromogenic selective agars commonly used for listeria isolation: oxford, modified oxford, and palcam. bbl chromagar listeria had a sensitivity of 99% and 100% for the detection of l. monocytogenes from 200 natural and artificially inoculated food samples, r ... | 2007 | 16930751 |
| listeria: a foodborne pathogen that knows how to survive. | the foodborne pathogen listeria is the causative agent of listeriosis, a severe disease with high hospitalization and case fatality rates. listeria monocytogenes can survive and grow over a wide range of environmental conditions such as refrigeration temperatures, low ph and high salt concentration. this allows the pathogen to overcome food preservation and safety barriers, and pose a potential risk to human health. this review focuses on the key issues such as survival of the pathogen in advers ... | 2007 | 17010463 |
| characterization of listeria monocytogenes isolated from retail foods. | listeria monocytogenes isolates recovered from retail ready-to-eat (rte) meats, raw chickens and fresh produce were characterized by serogroup identification using pcr, genotyping using pulsed-field gel electrophoresis (pfge) and antimicrobial susceptibility testing. five l. monocytogenes serogroups were identified. of the 167 isolates 68 (41%) belonged to serogroup 1/2b, 3b; 53 (32%) belonged to serogroup 4b, 4d, 4e; 43 (26%) belonged to serogroup 1/2a, 3a; 2 (1.2%) belonged to serogroup 1/2c, ... | 2007 | 16996156 |
| screening antimicrobial activity of various extracts of artemisia dracunculus l. | the antimicrobial activities of chloroform, acetone and two different concentrations of methanol extracts of artemisia dracunculus l. were studied. these extracts were tested against nine bacteria and four yeasts strains by the disc diffusion method. the results indicated that the methanol extract of a. dracunculus is more effective against tested microorganisms than chloroform or acetone extracts. the chloroform and acetone extracts were inhibitory only towards pseudomonas aeruginosa (atcc 2785 ... | 2007 | 16986171 |
| pulsed electric fields cause bacterial envelopes permeabilization depending on the treatment intensity, the treatment medium ph and the microorganism investigated. | the relationship between membrane permeabilization and loss of viability by pulsed electric fields (pef) depending on the treatment intensity and the treatment media ph in two gram-positive (lactobacillus plantarum, listeria monocytogenes) and two gram-negative (escherichia coli, salmonella senftenberg 775w) bacterial species has been investigated. loss of membrane integrity was measured as increased uptake of the fluorescent dye propidium iodide (pi). non-permanent/reversible permeabilization w ... | 2007 | 16987561 |
| detection of multiple virulence-associated genes in listeria monocytogenes isolated from bovine mastitis cases. | clinical samples (n=725) were collected from bovines (n=243) which were positive for mastitis using the california mastitis test (cmt) and somatic cell count (scc). the clinical samples comprising blood (n=239), milk (n=243), and faecal swabs (n=243) were examined for the presence of pathogenic listeria spp. isolation of the pathogen was done using selective enrichment in university of vermont medium and plating onto dominguez-rodriguez isolation agar. confirmation of the isolates was based on b ... | 2007 | 16979771 |
| vaccination with recombinant fusion proteins incorporating toll-like receptor ligands induces rapid cellular and humoral immunity. | recognition of specific pathogen associated molecular patterns (pamps) is mediated primarily by members of the toll-like receptor (tlr) family. stimulation through these receptors results in quantitative and qualitative changes in antigen presentation and cellular activation, thereby linking innate and adaptive immunity. consequently, the incorporation of tlr-ligands into vaccines could result in more potent and efficacious vaccines. to test this hypothesis, we employed a recombinant fusion prot ... | 2007 | 16968658 |
| recombinant vaccines based on translocated effector proteins of salmonella pathogenicity island 2. | attenuated live salmonella enterica are useful carriers for the delivery of heterologous antigens for vaccination. effector proteins translocated by type iii secretion systems (t3ss) of salmonella have been successfully utilized for antigen delivery. here we investigated the use of effector proteins of the t3ss encoded by salmonella pathogenicity island 2 (spi2). we observed that the effector protein ssef is suitable for delivery of various fusion proteins with heterologous antigens. the efficie ... | 2007 | 16887239 |
| antimicrobial activity of lysostaphin and a listeria monocytogenes bacteriophage endolysin produced and secreted by lactic acid bacteria. | the expression and secretion signals of the sep protein from lactobacillus fermentum br11 were used to direct export of two peptidoglycan hydrolases by lb. fermentum br11, lactobacillus rhamnosus gg, lactobacillus plantarum atcc 14917 and lactococcus lactis mg1363. the production levels, hydrolytic and bacteriocidal activities of the listeria monocytogenes bacteriophage n-acetylmuramoyl-l-alanine amidase endolysin ply511 and the glycylglycine endopeptidase lysostaphin were examined. buffering of ... | 2007 | 16490333 |
| cloning, sequencing and expression of a novel glutamate decarboxylase gene from a newly isolated lactic acid bacterium, lactobacillus brevis opk-3. | lactobacillus brevis opk-3, having 84.292 mg/l/h of gamma-aminobutyric acid (gaba) productivity, was isolated from kimchi, a traditional fermented food in korea. a core fragment of glutamate decarboxylase (gad) dna was isolated from the l. brevis opk-3, using primers based on two highly conserved regions of gad. a full-length gad (lbgad) clone was subsequently isolated through rapid amplification of cdna ends (race) pcr. nucleotide sequence analysis revealed that the open reading frame (orf) con ... | 2007 | 16500100 |
| fate of listeria spp. on parsley leaves grown in laboratory and field cultures. | to investigate the population dynamics of listeria monocytogenes and listeria innocua on the aerial surfaces of parsley. | 2007 | 17953592 |
| listeria monocytogenes in spontaneous abortions in humans and its detection by multiplex pcr. | to assess the extent of listeria monocytogenes in causation of human spontaneous abortions by isolation methods and pcr analysis for the presence of virulence-associated genes. | 2007 | 17953598 |
| identification of novel listeria monocytogenes secreted virulence factors following mutational activation of the central virulence regulator, prfa. | upon bacterial entry into the cytosol of infected mammalian host cells, the central virulence regulator prfa of listeria monocytogenes becomes activated and induces the expression of numerous factors which contribute to bacterial pathogenesis. the mechanism or signal by which prfa becomes activated during the course of infection has not yet been determined; however, several amino acid substitutions within prfa (known as prfa* mutations) that appear to lock the protein into a constitutively activ ... | 2007 | 17938228 |
| live attenuated listeria monocytogenes effectively treats hepatic colorectal cancer metastases and is strongly enhanced by depletion of regulatory t cells. | the liver represents a major and frequently sole site of metastases for many types of cancer, particularly gastrointestinal cancers. we showed previously that coadministration of an engineered hepatic-targeting listeria monocytogenes (lm) with a cancer vaccine enhanced the antitumor effect of vaccine-induced t cells selectively against hepatic metastases. here, we show that administration of multiple doses of lm, in the absence of vaccine, generates therapeutic responses against hepatic metastas ... | 2007 | 17942940 |
| protective effect of lactobacillus sakei 2a against experimental challenge with listeria monocytogenes in gnotobiotic mice. | lactobacillus sakei 2a isolated from sausage and presenting an in vitro antagonistic activity against listeria monocytogenes scott a was tested for a protective effect in mice experimentally challenged with the enterobacteria. | 2007 | 17944842 |
| rapid diagnosis of experimental meningitis by bacterial heat production in cerebrospinal fluid. | calorimetry is a nonspecific technique which allows direct measurement of heat generated by biological processes in the living cell. we evaluated the potential of calorimetry for rapid detection of bacterial growth in cerebrospinal fluid (csf) in a rat model of bacterial meningitis. | 2007 | 17927816 |
| rapid methods to assess sanitizing efficacy of benzalkonium chloride to listeria monocytogenes biofilms. | different methods were used to investigate biofilm growth including crystal violet staining, atp bioluminescence and total viable count. seven strains of listeria monocytogenes and 8 of their derivative strains were screened for their capacity to form biofilms. both adaptation to benzalkonium chloride (bc) and curing of plasmids did not significantly affect biofilm-forming ability. the strains of l. monocytogenes belonging to serotype 1 formed biofilms significantly better as compared to serotyp ... | 2007 | 17928079 |
| [first experience with detecting bacterial dna in the cerebrospinal fluid of patients with purulent meningitis using broad spectrum multiplex nested pcr]. | to propose and verify a pcr assay for detecting escherichia coli, haemophilus influenzae, listeria monocytogenes, staphylococcus species, streptococcus pneumoniae and neisseria meningitidis serogroups b and c in a single sample of the cerebrospinal fluid of patients with purulent meningitis. | 2007 | 17929222 |
| [viable but non-culturable form of bacteria]. | viable but non-culturable (vbnc) bacteria concept has been defined in 1982 when it has been shown that there exists bacteria whose metabolic activity continue and which can have the ability to reproduce in suitable conditions although they have lost their capability to reproduce in culture. recent studies have shown that most of the human pathogens (campylobacter spp., escherichia coli, francisella tularensis, helicobacter pylori, legionella pneumophila, listeria monocytogenes, mycobacterium tub ... | 2007 | 17933263 |
| enumeration of viable listeria monocytogenes cells by real-time pcr with propidium monoazide and ethidium monoazide in the presence of dead cells. | propidium monoazide (pma) and ethidium monoazide were used for enumeration of viable listeria monocytogenes cells in the presence of dead cells. pma had no antimicrobial effect on l. monocytogenes. viable cell counts were linearly related to real-time pcr threshold cycle values for pma-treated cells from planktonic and biofilm sources over a 4-log range. | 2007 | 17933922 |
| phenotypic and transcriptomic analyses demonstrate interactions between the transcriptional regulators ctsr and sigma b in listeria monocytogenes. | listeria monocytogenes sigma(b) positively regulates the transcription of class ii stress response genes; ctsr negatively regulates class iii stress response genes. to identify interactions between these two stress response systems, we constructed l. monocytogenes deltactsr and deltactsr deltasigb strains, as well as a deltactsr strain expressing ctsr in trans under the control of an iptg (isopropyl-beta-d-thiogalactopyranoside)-inducible promoter. these strains, along with a parent and a deltas ... | 2007 | 17933929 |
| morphological changes in listeria monocytogenes subjected to sublethal alkaline stress. | scanning electron microscopy (sem) studies revealed that exposure to 4lethal alkaline stress induced statistically significant (p<0.05) changes in mean cell length, radius and volume in listeria monocytogenes and a derived sigma(b) deficient mutant. bacterial morphology was altered at ph values above 9.0, to include single filamentous or elongated chain forms. such filamentation and chain formation was observed in the parent strain and in the sigma(b) deficient strain, and in buffered and non-bu ... | 2007 | 17935812 |
| transcriptomic and phenotypic analyses suggest a network between the transcriptional regulators hrca and sigmab in listeria monocytogenes. | listeria monocytogenes hrca and ctsr negatively regulate class i and iii stress response genes, respectively, while sigma(b) positively regulates the transcription of class ii stress response genes. to define the hrca regulon and identify interactions between hrca, ctsr, and sigma(b), we characterized newly generated l. monocytogenes deltahrca, deltactsr deltahrca, and deltahrca deltasigb strains, along with previously described deltasigb, deltactsr, and deltactsr deltasigb strains, using phenot ... | 2007 | 17965207 |
| atmospheric plasma inactivation of foodborne pathogens on fresh produce surfaces. | a study was conducted to determine the effect of one atmosphere uniform glow discharge plasma (oaugdp) on inactivation of escherichia coli o157:h7, salmonella, and listeria monocytogenes on apples, cantaloupe, and lettuce, respectively. a five-strain mixture of cultured test organisms was washed, suspended in phosphate buffer, and spot inoculated onto produce (7 log cfu per sample). samples were exposed inside a chamber affixed to the oaugdp blower unit operated at a power of 9 kv and frequency ... | 2007 | 17969610 |
| effect of potassium lactate and a potassium lactate-sodium diacetate blend on listeria monocytogenes growth in modified atmosphere packaged sliced ham. | two commercially available organic acid salts, potassium lactate (purasal hipure p) and a potassium lactate-sodium diacetate blend (purasal opti. form pd 4), were assessed as potential inhibitors of listeria monocytogenes growth in modified atmosphere packaged (map) sliced ham in challenge studies. the influence of the initial inoculation level of l. monocytogenes (10(1) or 10(3) cfu g(-1)) and storage temperature (4 or 8 degrees c) was also examined. the addition of either organic acid salt to ... | 2007 | 17969611 |
| controlling listeria monocytogenes on sliced ham and turkey products using benzoate, propionate, and sorbate. | the objective of this study was to identify concentrations of sorbate, benzoate, and propionate that prevent the growth of listeria monocytogenes on sliced, cooked, uncured turkey breast and cured ham. sixteen test formulations plus a control formulation for each product type were manufactured to include potassium sorbate, sodium benzoate, or sodium propionate, used alone and combined (up to 0.3% [wt/wt]), or with sodium lactate-sodium diacetate combinations. products were inoculated with l. mon ... | 2007 | 17969612 |
| effect of packaging and storage temperature on the survival of listeria monocytogenes inoculated postprocessing on sliced salami. | the survival of postprocess listeria monocytogenes contamination on sliced salami, stored under the temperatures associated with retail and domestic storage, was investigated. sliced salami was inoculated with low and high concentrations of l. monocytogenes before being packaged under vacuum or air. survival of l. monocytogenes was determined after storage of sausages for 45 or 90 days for low or high sample inocula, respectively, at 5, 15, and 25 degrees c. all survival curves of l. monocytogen ... | 2007 | 17969613 |
| effect of salt, smoke compound, and storage temperature on the growth of listeria monocytogenes in simulated smoked salmon. | smoked salmon can be contaminated with listeria monocytogenes. it is important to identify the factors that are capable of controlling the growth of l. monocytogenes in smoked salmon so that control measures can be developed. the objective of this study was to determine the effect of salt, a smoke compound, storage temperature, and their interactions on l. monocytogenes in simulated smoked salmon. a six-strain mixture of l. monocytogenes (10(2) to 10(3) cfu/g) was inoculated into minced, cooked ... | 2007 | 17969614 |
| modeling the effect of storage atmosphere on growth-no growth interface of listeria monocytogenes as a function of temperature, sodium lactate, sodium diacetate, and nacl. | the effect of aerobic and anaerobic conditions on growth initiation by a 10-strain composite of listeria monocytogenes (10(4) cfu/ml) was evaluated in tryptic soy broth with 0.6% yeast extract (tsbye) as a function of 220 combinations of ph (3.82 to 7.42), sodium lactate (sl) (0 to 10%, vol/vol), and sodium diacetate (sd) (0 to 0.5%, wt/vol) at 10 or 30 degrees c (a slightly abusive and the optimal growth temperature, both above the growth limiting range of 0 to 3 degrees c for l. monocytogenes) ... | 2007 | 17969615 |
| antimicrobial susceptibility of listeria monocytogenes isolated from food and clinical cases in navarra, spain. | the susceptibility of 440 listeria monocytogenes strains isolated from food (n=401) and clinical cases (n=39) between 1995 and 2005 was determined by standard agar dilution and e-test methods. antimicrobial drugs currently used in veterinary and human therapy were tested, and they included penicillin g, ampicillin, cephalothin, gentamicin, chloramphenicol, tetracycline, doxycycline, trimethoprim, erythromycin, and clindamycin. the sensitivity of strains was established using clinical and laborat ... | 2007 | 17969626 |
| survey of temperature and consumption patterns of fresh-cut leafy green salads: risk factors for listeriosis. | increasing demand for fresh-cut or ready-to-eat fruits and vegetables, developed to meet the consumer need for quick and convenient products, has prompted extensive research into their microbiological quality, safety, processing, and packaging. the microbial ecology of listeria monocytogenes is recognized as a major safety concern for fresh-cut produce. a survey was performed to collect information on consumption patterns of fresh-cut leafy green salads and the temperature of domestic refrigerat ... | 2007 | 17969627 |
| detuning cd8 t cells: down-regulation of cd8 expression, tetramer binding, and response during ctl activation. | cd8 is critical for t cell recognition of peptide/class i major histocompatability complex ligands, yet is down-regulated during activation of cd8 t cells. we report that loss of cd8 expression early during in vivo responses to vaccinia virus or listeria monocytogenes (lm) correlates with decreased t cell staining with specific class i/peptide tetramers and reduced cd8 t cell sensitivity for antigen. loss of cd8 cell surface expression occurs despite sustained mrna expression, and cd8 levels ret ... | 2007 | 17954566 |
| prevalence of and risk factors for listeria species on dairy farms. | this cross-sectional study determined the prevalence of listeria spp. in bulk-tank milk on dairy farms in the region of galicia in northwest spain. the aim was to identify management practices associated with the presence of listeria spp. and possible effects on milk hygienic quality. a total of 98 farms was randomly selected on the basis of an expected prevalence of 6.5% for listeria monocytogenes from 20,107 dairy farms in the region. bulk-tank milk samples were obtained from 98 farms, fecal s ... | 2007 | 17954748 |
| effect of temperature and growth media on the attachment of listeria monocytogenes to stainless steel. | listeria monocytogenes atcc 19111 cultivated in nutrient-rich medium (brain heart infusion, bhi) or starved in minimal medium (10% filter sterilized pond water and 90% sterilized distilled water) were investigated for their initial attachment to austenitic stainless steel no. 4 with satin finish at 4 degrees c, 20 degrees c, 30 degrees c, 37 degrees c, or 42 degrees c. a droplet (10 microl) containing approximately 10(7) cfu/ml of l. monocytogenes suspended in bhi or minimal medium was placed on ... | 2007 | 17959265 |
| antibacterial effect of five zingiberaceae essential oils. | essential oil obtained by hydrodistillation and two different solvent extractions (petroleum ether and ethanol) from five zingiberaceae species: ginger (zingiber officinale roscoe.), galanga (alpinia galanga sw.), turmeric (curcuma longa l.), kaempferia (boesenbergia pandurata holtt.) and bastard cardamom (amomum xanthioides wall.) was characterized. volatile components of all extracts were analyzed by gas chromatography-mass spectrometry (gc-ms). the major components of ginger, turmeric, galang ... | 2007 | 17960105 |
| unique functions of splenic cd8alpha+ dendritic cells during infection with intracellular pathogens. | deciphering the prerequisites for the induction of protective cytotoxic t cell responses is essential for future development of more effective cd8(+) t cell-based vaccines against infectious diseases and cancer. since crucial events for cd8(+) t cell priming and differentiation occur during the first contacts of naïve t cells with distinct antigen-presenting cells (apcs), the identification and therapeutic targeting of these 'master' apcs has become a major quest in the field. a decade ago, dend ... | 2007 | 17964665 |
| miniature protein ligands for evh1 domains: interplay between affinity, specificity, and cell motility. | dynamic rearrangements of the actin cytoskeleton power cell motility in contexts ranging from intracellular microbial pathogenesis to axon guidance. the ena/vasp family proteins-mena, vasp, and evl-are believed to control cell motility by serving as a direct link between signaling events and the actin cytoskeleton. it has previously been reported that a novel miniature protein, pgolemi, binds with high affinity to the evh1 domain of mena (mena1-112) but not to those of vasp (vasp1-115) or evl (e ... | 2007 | 17973491 |
| induction of suicidal erythrocyte death by listeriolysin from listeria monocytogenes. | listeriolysin, the secreted cytolysin of the facultative intracellular bacterium listeria monocytogenes, is its major virulence factor. previously, non-lytic concentrations of listeriolysin were shown to induce ca2+-permeable nonselective cation channels in human embryonic kidney cells. in erythrocytes, ca2+ entry is followed by activation of k+ channels resulting in k+-exit as well as by membrane scrambling resulting in phosphatidylserine exposure at the cell surface. phosphatidylserine-exposin ... | 2007 | 17975307 |
| memory phenotype cd8+ t cells with innate function selectively develop in the absence of active itk. | t cells with a memory-like phenotype and possessing innate immune function have been previously identified as cd8(+)cd44(hi) cells. these cells rapidly secrete ifn-gamma upon stimulation with il-12/il-18 and are involved in innate responses to infection with listeria monocytogenes. the signals regulating these cells are unclear. the tec kinase itk regulates t cell activation and we report here that a majority of the cd8(+) t cells in itk null mice have a phenotype of cd44(hi) similar to memory-l ... | 2007 | 17724684 |
| toward an improved laboratory definition of listeria monocytogenes virulence. | listeria monocytogenes is an opportunistic foodborne pathogen that encompasses a diversity of strains with varied virulence. the ability to rapidly determine the pathogenic potential of l. monocytogenes strains is integral to the control and prevention campaign against listeriosis. early methods for assessing l. monocytogenes virulence include in vivo bioassays and in vitro cell assays. while in vivo bioassays provide a measurement of all virulence determinants of l. monocytogenes, they are not ... | 2007 | 17727992 |
| immunization with dendritic cells loaded with alpha-galactosylceramide at priming phase, but not at boosting phase, enhances cytotoxic t lymphocyte activity against infection by intracellular bacteria. | we evaluated the effect of immunization with dendritic cells (dcs) pulsed with alpha-galactosylceramide (alphagalcer) and listeriolysin o (llo) 91-99 peptide, a dominant cytotoxic t lymphocyte (ctl) epitope of listeria monocytogenes by observing the responses of specific cd8(+) t cells and in vivo ctl activity. dcs were pulsed with various combinations of alphagalcer and llo91-99 peptide and administered to balb/c mice. immunization with dcs pulsed with alphagalcer and llo91-99 at priming phase ... | 2007 | 17760876 |
| immunodominant tuberculosis cd8 antigens preferentially restricted by hla-b. | cd8(+) t cells are essential for host defense to intracellular bacterial pathogens such as mycobacterium tuberculosis (mtb), salmonella species, and listeria monocytogenes, yet the repertoire and dominance pattern of human cd8 antigens for these pathogens remains poorly characterized. tuberculosis (tb), the disease caused by mtb infection, remains one of the leading causes of infectious morbidity and mortality worldwide and is the most frequent opportunistic infection in individuals with hiv/aid ... | 2007 | 17892322 |
| evaluation of indirect and avidin-biotin enzyme linked immunosorbent assays for detection of anti-listeriolysin o antibodies in bovine milk samples. | listeria monocytogenes is a foodborne pathogen that causes a wide spectrum of diseases in humans and animals. enzyme linked immunosorbent assays (elisa) [indirect and avidin-biotin (a-b)] for detecting l. monocytogenes antibodies in bovine milk samples (n = 2060) were standardized and evaluated by comparison with bacteriological examination. the tests were standardized by checker board titration. highly purified listeriolysin o (llo) was used as an antigen. receiver operating characteristic (roc ... | 2007 | 17894640 |
| improved solubilization of surface proteins from listeria monocytogenes for 2-de. | solubilization of bacterial surface (cell wall and membrane-associated) proteins for 2-de is challenging, particularly in the case of gram-positive bacteria. this is primarily due to strong protein association with the cell wall peptidoglycan and protein hydrophobicity. we solubilized surface proteins for 2-de from the gram-positive pathogen listeria monocytogenes using mutanolysin, which digests cell wall peptidoglycan, and one of three different mixtures of zwitterionic detergent and chaotrope ... | 2007 | 17922522 |
| lpla1-dependent utilization of host lipoyl peptides enables listeria cytosolic growth and virulence. | the bacterial pathogen listeria monocytogenes replicates within the cytosol of mammalian cells. mechanisms by which the bacterium exploits the host cytosolic environment for essential nutrients are poorly defined. l. monocytogenes is a lipoate auxotroph and must scavenge this critical cofactor, using lipoate ligases to facilitate attachment of the lipoyl moiety to metabolic enzyme complexes. although the l. monocytogenes genome encodes two putative lipoate ligases, lpla1 and lpla2, intracellular ... | 2007 | 17908209 |
| conjugal transfer of plasmid r6k gamma ori minireplicon derivatives from escherichia coli to various genera of pathogenic bacteria. | three r6k-derived gamma ori minireplicons were successfully transferred by conjugation from escherichia coli to several species of pathogenic bacteria. the pfl129 replicon encodes the wild-type initiation replication protein pi, while plasmids pfl130 and pag101 encode mutant forms of the pi protein conferring the plasmid copy-up phenotype. plasmids could be transferred to all recipient species tested, although high efficiency conjugal transfer was only obtained with genera of the enterobacteriac ... | 2007 | 17909888 |
| the effect of micro-architectural structure of cabbage substratum and or background bacterial flora on the growth of listeria monocytogenes. | the effect of micro-architectural structure of cabbage (brassica oleracea var. capitata l.) substratum and or background bacterial flora on the growth of listeria monocytogenes as a function of incubation temperature was investigated. a cocktail mixture of pseudomonas fluorescens, pantoea agglomerans and lactobacillus plantarum was constituted to a population density of approximately 5 log cfu/ml in order to pseudo-simulate background bacterial flora of fresh-cut cabbage. this mixture was co-ino ... | 2007 | 17910986 |
| the c/ebp beta isoform 34-kda lap is responsible for nf-il-6-mediated gene induction in activated macrophages, but is not essential for intracellular bacteria killing. | the c/ebpb gene is translated into three different protein isoforms, two transcriptional activating proteins (38-kda full and 34-kda liver-enriched transcriptional activation protein (lap)) and one transcriptional inhibitory protein, by alternative use of different aug initiation codons within the same open reading frame. the isoform 34-kda lap is thought to be the most transcriptionally active form of c/ebpbeta in macrophages. to assess the function of the 34-kda lap in vivo, we generated knock ... | 2007 | 17911624 |
| antimicrobial activity of extracts of the lichen parmelia sulcata and its salazinic acid constituent. | the antimicrobial activity of the acetone, chloroform, diethyl ether, methanol, and petroleum ether extracts of the lichen parmelia sulcata and its salazinic acid constituent have been screened against twenty eight food-borne bacteria and fungi. all of the extracts with the exception of the petroleum ether extract showed antimicrobial activity against aeromonas hydrophila, bacillus cereus, bacillus subtilis, listeria monocytogenes, proteus vulgaris, yersinia enterocolitica, staphylococcus aureus ... | 2007 | 17913083 |
| pre-existing anti-salmonella vector immunity prevents the development of protective antigen-specific cd8 t-cell frequencies against murine listeriosis. | our laboratory has focused its research on the use of the type iii secretion system of salmonella enterica serovar typhimurium to translocate heterologous antigens directly into the cytosol of antigen-presenting cells. we have previously reported that the single oral immunization of mice with a recombinant salmonella aroa/sptp mutant strain expressing the translocated yersinia outer protein e fused to the immunodominant antigen p60 from listeria monocytogenes in a type iii-mediated fashion resul ... | 2007 | 17913544 |
| protein kinase c delta is essential for optimal macrophage-mediated phagosomal containment of listeria monocytogenes. | activation of macrophages and subsequent "killing" effector functions against infectious pathogens are essential for the establishment of protective immunity. nf-il6 is a transcription factor downstream of ifn-gamma and tnf in the macrophage activation pathway required for bacterial killing. comparison of microarray expression profiles of listeria monocytogenes (lm)-infected macrophages from wt and nf-il6-deficient mice enabled us to identify candidate genes downstream of nf-il6 involved in the ... | 2007 | 17913887 |
| a novel real-time pcr-based method for the detection of listeria monocytogenes in food. | a new real-time pcr-based method was developed for the detection of listeria monocytogenes in food. | 2007 | 17916129 |
| in situ imaging of the endogenous cd8 t cell response to infection. | mounting a protective immune response is critically dependent on the orchestrated movement of cells within lymphoid organs. we report here the visualization, using major histocompatability complex class i tetramers, of the cd8-positive (cd8) t cell response in the spleens of mice to listeria monocytogenes infection. a multistage pathway was revealed that included initial activation at the borders of the b and t cell zones followed by cluster formation with antigenpresenting cells leading to cd8 ... | 2007 | 17916739 |
| impact of lymphocyte apoptosis on the innate immune stages of infection. | infection of mice with listeria monocytogenes has led to a puzzling observation: mice deficient in lymphocytes are more resistant during the early innate immune response. this is counterintuitive, because mice deficient in the adaptive immune response are unable to clear the infection and eventually die. this work will highlight some of our recent work on listeria induced apoptosis and its immunological consequences. we show that listeria produces a toxin, listeriolysin o (llo), which causes apo ... | 2007 | 17917040 |
| in silico and in vitro characterization of mgbp4 splice variants. | in a systematic approach to identify interferon-gamma (ifn-gamma)-regulated host effector molecules, we found several members of the 65 kda guanylate-binding proteins (gbps) highly upregulated. during extensive characterization of these guanosine triphosphatases (gtpases), we identified discrepancies between the cloned and published sequences of the murine gtpase mgbp4. two splice variants of mgbp4 could be detected. one variant led to a premature stop codon after 312 bp. the second variant resu ... | 2007 | 17919070 |
| the listeria monocytogenes homolog of the escherichia coli era gene is involved in adhesion to inert surfaces. | two transposon-insertional mutants of listeria monocytogenes showing smaller viable surface-attached cell populations after disinfection with n,n-didecyl-n,n-dimethylammonium chloride were identified. in both mutants, transposon tn917-lac was found to be inserted into the same gene, lmo1462, which is homologous to the essential escherichia coli era gene. both l. monocytogenes lmo1462-disrupted mutants displayed lower growth rates, as was also shown for several e. coli era mutants, and the lmo146 ... | 2007 | 17921262 |
| studies probe microbes in raw milk, swine. | 2007 | 17895451 | |
| differential effect of listeria monocytogenes infection on cytokine production and cytotoxicity of cd8 t cells. | bacterial infection induces a shift to type 1 cd4 t cell subset in an infected host and this shift is important for protection of the host from disease development. many researchers think that the shift is antigen-dependent, but we previously demonstrated an initial induction step for cd4 t cell subsets during listeria monocytogenes (lm) infection is antigen-independent. although listeria is a tlr2 ligand, the immune system of the lm-infected host responded to the pathogen to induce expression o ... | 2007 | 17895607 |
| viable but non-culturable listeria monocytogenes on parsley leaves and absence of recovery to a culturable state. | to investigate the presence of viable but non-culturable listeria monocytogenes during survival on parsley leaves under low relative humidity (rh) and to evaluate the ability of l. monocytogenes to recover from vbnc to culturable state under satured humidity. | 2007 | 17897231 |
| long-term analysis of listeria monocytogenes vaginal carriage frequency in belgrade, serbia (short communication). | in order to gain insight into the frequency of l. monocytogenes vaginal carriage among women of reproductive age in belgrade, serbia, we conducted the long-term investigation (january 1992 through august 2006) described herein. the study population of 958 women included 799 patients with spontaneous abortion and 159 patients with infertility. a low rate of l. monocytogenes vaginal carriage of 0.1% was established, since only one strain was recovered from vaginal swab of a woman with spontaneous ... | 2007 | 17899798 |
| effectiveness of trisodium phosphate, acidified sodium chlorite, citric acid, and peroxyacids against pathogenic bacteria on poultry during refrigerated storage. | the effects of dipping treatments (15 min) in potable water or in solutions (wt/vol) of 12% trisodium phosphate (tsp), 1,200 ppm acidified sodium chlorite (asc), 2% citric acid (ca), and 220 ppm peroxyacids (pa) on inoculated pathogenic bacteria (listeria monocytogenes, staphylococcus aureus, bacillus cereus, salmonella enteritidis, escherichia coli, and yersinia enterocolitica) and skin ph were investigated throughout storage of chicken legs (days 0, 1, 3, and 5) at 3 +/- 1 degrees c. all chemi ... | 2007 | 17900083 |
| survival of escherichia coli o157:h7, salmonella, and listeria monocytogenes in cranberry juice concentrates at different obrix levels. | survival of escherichia coli o157:h7, salmonella, and listeria monocytogenes was evaluated in cranberry juice concentrates to determine if a 5-log reduction could be achieved without any other treatment. inactivation at 0 degrees c in concentrates with different obrix levels was determined for a five-strain composite of the individual pathogens in two physiological states. in concentrates at 18 to 46 obrix (ph 2.2 to 2.5), all three pathogens (stationary-phase or acid-adapted cells) showed at le ... | 2007 | 17900084 |
| efficacy of chlorine dioxide gas sachets for enhancing the microbiological quality and safety of blueberries. | in response to increasingly stringent microbial specifications being imposed by purchasers of frozen blueberries, chlorine dioxide (clo2) gas generated by a dry chemical sachet was assessed for inactivation of listeria monocytogenes, salmonella spp., and escherichia coli o157:h7 as well as five yeasts and molds known for blueberry spoilage. fresh blueberry samples (100 g) were separately inoculated with cocktails of l. monocytogenes, salmonella, e. coli o157:h7 (three strains each), or yeasts an ... | 2007 | 17900086 |
| performance of a growth-no growth model for listeria monocytogenes developed for mayonnaise-based salads: influence of strain variability, food matrix, inoculation level, and presence of sorbic and benzoic acid. | a previously developed growth-no growth model for listeria monocytogenes, based on nutrient broth data and describing the influence of water activity (a(w)), ph, and acetic acid concentrations, was validated (i) for a variety of l. monocytogenes strains and (ii) in a laboratory-made, mayonnaise-based surimi salad (as an example of a mayonnaise-based salad). in these challenge tests, the influence of the inoculation level was tested as well. also, the influence of chemical preservatives on the gr ... | 2007 | 17900091 |
| low temperature and binding to food components inhibit the antibacterial activity of carvacrol against listeria monocytogenes in steak tartare. | carvacrol is a major component of thyme and oregano essential oils and has potential uses as a food preservative. the effect of carvacrol on the growth of listeria monocytogenes was investigated in vitro and in steak tartare. carvacrol had strong antilisterial activity in growth medium (mic = 1.6 mm), but no effect was observed when carvacrol was tested in steak tartare. there were two reasons for this reduced activity: the antilisterial activity of carvacrol was strongly reduced at lower temper ... | 2007 | 17900092 |
| a review of the incidence and transmission of listeria monocytogenes in ready-to-eat products in retail and food service environments. | contamination of ready-to-eat products with listeria monocytogenes may occur at several stages before consumption. accessibility to the public and relatively limited control interventions at retail and food service establishments (compared with the processing sector of the food industry) and the lack of a specific regulatory framework increase the likelihood of introduction of this pathogen into some foods in these establishments. this review is a compilation of available information on the inci ... | 2007 | 17900099 |
| use of the cd107 mobilization assay reveals that cytotoxic t lymphocytes with novel mhc-ib restriction are activated during listeria monocytogenes infection. | detection of cytotoxic activity by pathogen-specific t cells of unknown antigenic specificity is difficult due to the limitations of using infected cells, instead of peptide-pulsed cells, as targets. we report here that the recently described cd107 mobilization assay readily allowed for the ex vivo detection of cytotoxic t lymphocytes (ctl) with a novel mhc-ib restriction that specifically recognized listeria monocytogenes-infected macrophages. the cd107 mobilization assay is likely to be a usef ... | 2007 | 17900608 |
| predictive modelling of the recovery of listeria monocytogenes on sliced cooked ham after high pressure processing. | this study examined bacterial recovery on sliced cooked ham that was inoculated with listeria monocytogenes, treated by high pressure processing (hpp) and then stored at 10 degrees c for 70 days. the number of l. monocytogenes on the ham inoculated with 5 log(10) cfu/g was initially reduced by hpp at 500 mpa for 10 min to below the detectable level (10 cfu/g). however, the bacterial count gradually increased during storage, and exceeded the initial inoculum level at the end of the 70-day period, ... | 2007 | 17900728 |
| [rhombencephalitis due to listeria monocytogenes]. | a 37-year-old man presented with acute dizziness, nausea, headache and fever. later on, he developed diplopia, swallowing difficulties, numbness and ataxia. mri on day 6 showed hypo-intense, contrast-enhancing lesions on ti-weighted scans in the brainstem and cerebellum. cerebrospinal fluid (csf) findings on day 6 included pleiocytosis, a mildly-elevated protein level and mildly-decreased glucose level. csf and blood cultures were initially negative for both bacteria and viruses. acute dissemina ... | 2007 | 17902563 |
| the effect of disease activity on leptin, leptin receptor and suppressor of cytokine signalling-3 expression in relapsing-remitting multiple sclerosis. | in this study we observed higher serum leptin levels in relapsing-remitting multiple sclerosis (rrms) patients during remission than in controls. the expression of leptin receptor (obr) was higher in cd8+ t cells and monocytes from rrms patients in relapse than in patients in remission and in controls. relapsing patients showed high levels of pstat3 and low expression of socs3 and leptin administration induced an up-regulation of pstat3 only in monocytes from patients in relapse. our data sugges ... | 2007 | 17904647 |
| improving gastric transit, gastrointestinal persistence and therapeutic efficacy of the probiotic strain bifidobacterium breve ucc2003. | given the increasing commercial and clinical relevance of probiotic cultures, improving their stress tolerance profile and ability to overcome the physiological defences of the host is an important biological goal. in order to reach the gastrointestinal tract in sufficient numbers to exert a therapeutic effect, probiotic bacteria must resist the deleterious actions of low ph, elevated osmolarity and bile salts. cloning the listerial betaine uptake system, betl, into the probiotic strain bifidoba ... | 2007 | 17906153 |
| the heat-shock response of listeria monocytogenes comprises genes involved in heat shock, cell division, cell wall synthesis, and the sos response. | the food-borne pathogen listeria monocytogenes has the ability to survive extreme environmental conditions due to an extensive interacting network of stress responses. it is able to grow and survive at relatively high temperatures in comparison with other non-sporulating food-borne pathogens. to investigate the heat-shock response of l. monocytogenes, whole-genome expression profiles of cells that were grown at 37 degrees c and exposed to 48 degrees c were examined using dna microarrays. transcr ... | 2007 | 17906156 |
| subtractive screening for probiotic properties of lactobacillus species from the human gastrointestinal tract in the search for new probiotics. | in the search for new probiotics, 61 lactobacillus spp. isolates, belonging to 12 species and isolated as dominant lactic acid bacteria from the feces of healthy humans, were subjected to a subtractive system of in vitro analyses, which included desirable and undesirable traits. twenty-four isolates were able to grow in 2% bovine bile, of which 13 grew in acidified broth at ph 3.5 in acidified cysteine-containing mrs broth. intrinsic resistance to certain antimicrobial agents (cefoxitin, metroni ... | 2007 | 17995611 |
| antimicrobial activity of epsilon-polylysine against escherichia coli o157:h7, salmonella typhimurium, and listeria monocytogenes in various food extracts. | this study compared the antimicrobial effects of epsilon-polylysine (epsilon-pl) against escherichia coli o157:h7, salmonella typhimurium, and listeria monocytogenes in 6 food extracts and in broth. the food extracts (10% (w/w) in distilled water) evaluated were fat-free and whole fat milk, beef, bologna, rice, and vegetables (50:50 ratio of broccoli and cauliflower). epsilon-pl was tested at 0.005% and 0.02% (w/v) against e. coli o157:h7 and l. monocytogenes, and 0.02% and 0.04% (w/v) against s ... | 2007 | 17995614 |
| modeling the lag phase and growth rate of listeria monocytogenes in ground ham containing sodium lactate and sodium diacetate at various storage temperatures. | refrigerated ready-to-eat (rte) meats contaminated with listeria monocytogenes were implicated in several listeriosis outbreaks. lactate and diacetate have been shown to control l. monocytogenes in rte meats. the objective of this study was to examine and model the effect of lactate (1.0% to 4.2%) and diacetate (0.05% to 0.2%) in ground ham on the lag phase duration (lpd, h) and growth rate (gr, log cfu/h) of l. monocytogenes at a range of temperatures (0 to 45 degrees c). a 6-strain mixture of ... | 2007 | 17995648 |
| impact of nitrite on detection of listeria monocytogenes in selected ready-to-eat (rte) meat and seafood products. | the impact of sodium nitrite (nano2) on detection and recovery of listeria monocytogenes from select ready-to-eat (rte) foods including smoked salmon, smoked ham, beef frankfurters, and beef bologna was assessed. nitrite-containing (nc; 100 to 200 ppm nano2) or nitrite-free (nf) foods were inoculated with a 5-strain cocktail of l. monocytogenes by immersion into butterfield's buffer solution containing 5.4 to 7.4 x 10(3) l. monocytogenes per milliliter. inoculated products were vacuum-packaged a ... | 2007 | 17995651 |
| characterization and selection of autochthonous lactic acid bacteria isolated from traditional iberian dry-fermented salchichón and chorizo sausages. | a total of 192 lactic acid bacteria were isolated from 2 types of naturally fermented dry sausages at 3 different stages of the ripening process in order to select the most suitable strains as starter cultures in dry-cured sausage manufacture according to their technological characteristics such as glucose fermentation, lactic and acetic acid production, and proteolytic, lipolytic, and antimicrobial activities. identification of the isolates revealed that 31.2% were pediococcus pentosaceus, 26.9 ... | 2007 | 17995686 |
| recipes for antimicrobial wine marinades against bacillus cereus, escherichia coli o157:h7, listeria monocytogenes, and salmonella enterica. | we have evaluated bactericidal activities against bacillus cereus, escherichia coli o157:h7, listeria monocytogenes, and salmonella enterica of several antimicrobial wine recipes, each consisting of red or white wine extracts of oregano leaves with added garlic juice and oregano oil. dose-response plots were used to determine the percentage of the recipes that resulted in a 50% decrease in colony-forming units (cfu) at 60 min (ba(50)). studies designed to optimize antibacterial activities of the ... | 2007 | 17995688 |
| effect of ph on the antimicrobial activity and oxidative stability of oil-in-water emulsions containing caffeic acid. | antioxidant properties in food are dependent on various parameters. these include the ph value and interactions with food components, including proteins or metal ions. food components affect antioxidant stability and also influence the properties of microorganisms and their viability. this paper describes an investigation of the effect of ph on the antioxidant and antibacterial properties of caffeic acid in different media. the ph values studied, using an oil-in-water emulsion as model system, w ... | 2007 | 17995712 |
| numerical analysis of survival of listeria monocytogenes during in-package pasteurization of frankfurters by hot water immersion. | the objective of this research was to develop and validate a more accurate method to analyze and calculate the inactivation of listeria monocytogenes in frankfurter packages during postlethality hot water immersion heating and the subsequent cooling processes. finite difference analysis with implicit scheme was used to simulate the heat transfer process during in-package pasteurization of frankfurters. a volumetrically distributed simulation method was developed to calculate the lethality of the ... | 2007 | 17995728 |
| effect of water phase salt content and storage temperature on listeria monocytogenes survival in chum salmon (oncorhynchus keta) roe and caviar (ikura). | salmon caviar, or ikura, is a ready-to-eat food prepared by curing the salmon roe in a brine solution. other seasonings or flavorants may be added, depending upon the characteristics of the product desired. listeria monocytogenes growth is a potential risk, since it can grow at high salt concentrations (>10%) and in some products at temperatures as low as 3 degrees c. ikura was prepared from chum salmon (oncorhynchus keta) roe by adding food-grade nacl to yield water phase salt contents (wps) of ... | 2007 | 17995738 |
| uncertainty in thermal process calculations due to variability in first-order and weibull kinetic parameters. | alternatives to first-order model of death kinetics of microorganisms have been proposed as improvements in the calculation of lethality for a thermal process. although such models can potentially improve predictions for many situations, this article tries to answer the question of whether the added complexities of these models are a worthwhile investment once we include the effect of uncertainties in various microbiological and process parameters. monte carlo technique is used to include variab ... | 2007 | 17995767 |
| inactivation of shigella boydii 18 idph and listeria monocytogenes scott a with power ultrasound at different acoustic energy densities and temperatures. | the effect of acoustic energy density (aed) on inactivation of shigella boydii 18 idph and listeria monocytogenes scott a in a cell suspension was studied at sublethal temperatures and at aeds of 0.49, 0.85, and 1.43 w/ml. the effect of temperature on ultrasonic inactivation of l. monocytogenes scott a at 35, 50, and 65 degrees c was examined at an aed of 1.43 w/ml. increasing aed increased the rate of inactivation for both s. boydii and l. monocytogenes. the destruction of s. boydii and l. mono ... | 2007 | 17995776 |
| a 2-step cooking method of searing and hot water pasteurization to maximize the safety of refrigerated, vacuum packaged, chicken breast meat. | americans consume almost 40 kg per capita of chicken each year. increasing consumption of chicken surpassed pork in 1982 and beef in 1992. the objectives of this study were to examine the effectiveness of a novel, 2-step cooking method of grilling, slicing, vacuum packaging, and hot water pasteurization to inhibit the growth of listeria monocytogenes in chicken breast meat. because this study required the use of pilot plant scale pasteurization equipment, listeria innocua m1, a nonpathogen with ... | 2007 | 17995778 |
| inhibition of foodborne pathogens by native microflora recovered from fresh peeled baby carrot and propagated in cultures. | the inhibitory effect of fresh peeled baby carrot and associated microflora on the viability and growth of listeria monocytogenes, yersinia enterocolitica, salmonella enterica, escherichia coli o157:h7, and pseudomonas marginalis was investigated. the population of viable l. monocytogenes was reduced by more than 2 logs following the dipping of sliced baby carrots in the bacterial suspension for 2 min. however, other pathogens subjected to the same treatment showed no reduction in the population ... | 2007 | 17995781 |
| thermal inactivation of escherichia coli o157:h7, salmonella, and listeria monocytogenes in breaded pork patties. | decimal reduction times (d-values) and thermal resistance constants (z-values) for 3 foodborne pathogenic bacteria in formulated ready-to-eat breaded pork patties were determined with thermal inactivation studies. meat samples, inoculated with escherichia coli o157:h7, salmonella, and listeria monocytogenes cultures or uninoculated controls, were packaged in sterile bags, immersed in circulated water bath, and held at 55, 57.5, 60, 62.5, 65, 67.5, and 70 degrees c for different durations of time ... | 2007 | 17995843 |
| invasiveness and intracellular growth of multidrug-resistant salmonella and other pathogens in caco-2 cells. | the increase of multidrug-resistant pathogens of human and animal origins is a major public health concern. for a better understanding of the health consequences of multidrug-resistant bacteria transmitted from animal products to humans, the host interaction of zoonotic salmonella isolates along with other pathogenic and commensal bacteria was evaluated using a human intestinal caco-2 cell system. multidrug-resistant s. agona, s. heidelberg, and s. typhimurium possessed plasmid-mediated class 1 ... | 2007 | 17995846 |
| characterization of new hybridoma clones producing monoclonal antibodies reactive against both live and heat-killed listeria monocytogenes. | the objective of this study is to develop high affinity monoclonal antibody (mab) probes recognizing all major serotypes of listeria monocytogenes cells. from 500 candidate hybridoma clones, 2 new monoclonal antibody-producing hybridomas were selected and evaluated. mabs 22d10 and 24f6 reacted strongly with live cells of most serotypes of l. monocytogenes except 4c and 4e and with some l. innocua strains; mab 22d10 reacted strongly with both live and heat-killed cells (100 degrees c for 20 min) ... | 2007 | 17995886 |
| searching for new mathematical growth model approaches for listeria monocytogenes. | different secondary modeling approaches for the estimation of listeria monocytogenes growth rate as a function of temperature (4 to 30 degrees c), citric acid (0% to 0.4% w/v), and ascorbic acid (0% to 0.4% w/v) are presented. response surface (rs) and square-root (sr) models are proposed together with different artificial neural networks (ann) based on product functions units (pu), sigmoidal functions units (su), and a novel approach based on the use of hybrid functions units (psu), which resul ... | 2007 | 17995887 |
| effectiveness of potassium lactate and sodium diacetate in combination with irradiation to control listeria monocytogenes on frankfurters. | the use of antimicrobial ingredients in combination with irradiation is an effective antilisterial intervention strategy for ready-to-eat meat products. microbial safety was evaluated for frankfurters formulated with 0% or 3% added potassium lactate/sodium diacetate solution and inoculated with listeria monocytogenes before or after treatment with irradiation (0, 1.8, or 2.6 kgy). frankfurters were stored aerobically or vacuum packaged and l. monocytogenes counts and apcs were determined while r ... | 2007 | 17995888 |
| progression of pulmonary tuberculosis and efficiency of bacillus calmette-guérin vaccination are genetically controlled via a common sst1-mediated mechanism of innate immunity. | using a mouse model for genetic analysis of host resistance to virulent mycobacterium tuberculosis, we have identified a genetic locus sst1 on mouse chromosome 1, which controls progression of pulmonary tuberculosis. in vitro, this locus had an effect on macrophage-mediated control of two intracellular bacterial pathogens, m. tuberculosis and listeria monocytogenes. in this report, we investigated a specific function of the sst1 locus in antituberculosis immunity in vivo, especially its role in ... | 2007 | 17982083 |
| the aryl hydrocarbon receptor is required for optimal resistance to listeria monocytogenes infection in mice. | the aryl hydrocarbon receptor (ahr) is part of a powerful signaling system that is triggered by xenobiotic agents such as polychlorinated hydrocarbons and polycyclic aromatic hydrocarbons. although activation of the ahr by 2,3,7,8-tetrachlorodibenzo-p-dioxin or certain polycyclic aromatic hydrocarbons can lead to immunosuppression, there is also increasing evidence that the ahr regulates certain normal developmental processes. in this study, we asked whether the ahr plays a role in host resistan ... | 2007 | 17982086 |
| an itam-signaling pathway controls cross-presentation of particulate but not soluble antigens in dendritic cells. | dendritic cells (dc) possess a unique capacity for presenting exogenous antigen on major histocompatibility class i, a process that is referred to as cross-presentation, which serves a critical role in microbial and tumor immunity. during cross-presentation, antigens derived from pathogen-infected or tumor cells are internalized and processed by dcs for presentation to cytotoxic t lymphocytes (ctls). we demonstrate that a signaling pathway initiated by the immunoreceptor tyrosine-based activatio ... | 2007 | 17984307 |
| isolation of listeria monocytogenes from the skin of slaughtered beef cattle. | we attempted to isolate listeria monocytogenes from skin, contents of large intestines and carcasses of cattle introduced to a slaughterhouse in order to identify source of contamination for this pathogen. sixty skin samples, 60 samples of the contents of large intestines and 30 carcass samples were colleted in june, august and november 2003 for use in this study. listeria spp. and l. monocytogenes were isolated from 30 (50%) and 3 (5%) of the cattle skin samples, respectively. however, no liste ... | 2007 | 17984598 |
| listeriosis in a cockatiel (nymphicus hollandicus). | listeriosis was diagnosed in a 4-yr-old female cockatiel (nymphicus hollandicus) that died after exhibiting clinical signs that included a fluffed-up appearance, weakness, and loss of weight of several days duration. grossly, the bird was moderately emaciated, and the liver and spleen were enlarged. microscopically, there was mild-to-moderate inflammation associated with rod-shaped, gram-positive bacteria in the liver, spleen, kidneys, adrenal glands, bone marrow, and esophagus. listeria monocyt ... | 2007 | 17992946 |