| autolysis of listeria monocytogenes. | physiological conditions that could provide maximal rates of autolysis of listeria monocytogenes were examined. l. monocytogenes was found to be refractory to most treatments that promote rapid autolysis in other bacteria. best rates of autolysis were obtained after resuspending the cells in tris-hydrochloride buffer at 37 degrees c with the ph optimum at 8.0. autolysis was also efficiently promoted by the surfactant triton x-100. antibiotics that interfere with the biosynthesis of the cell wall ... | 1999 | 10581670 |
| osmoprotection of escherichia coli by peptone is mediated by the uptake and accumulation of free proline but not of proline-containing peptides. | the effect of meat peptone type i (sigma) on the growth of escherichia coli cells under hyperosmotic stress has been investigated. peptone is a complex mixture of peptides with a small content of free amino acids, which resembles nutrients found in natural environments. our data showed that peptone enhances the growth of e. coli cells in high-osmolarity medium to levels higher than those achieved with the main compatible solute in bacteria, glycine betaine. the mechanism of osmoprotection by pep ... | 1999 | 10583976 |
| listeria monocytogenes scott a: cell surface charge, hydrophobicity, and electron donor and acceptor characteristics under different environmental growth conditions. | we determined the variations in the surface physicochemical properties of listeria monocytogenes scott a cells that occurred under various environmental conditions. the surface charges, the hydrophobicities, and the electron donor and acceptor characteristics of l. monocytogenes scott a cells were compared after the organism was grown in different growth media and at different temperatures; to do this, we used microelectrophoresis and the microbial adhesion to solvents method. supplementing the ... | 1999 | 10583984 |
| agar underlay method for recovery of sublethally heat-injured bacteria. | a method of recovering sublethally heat-injured bacteria was developed. the procedure (termed the agar underlay method) uses a nonselective agar underlaid with a selective medium. in a two-chambered petri dish, the lutri plate (lp), a nonselective agar is inoculated with a population of sublethally heat-injured bacteria. after a 2-h repair incubation period, selective agar is added to the bottom chamber of the lp and incubated. by diffusing through the nonselective top agar, selective agents fro ... | 1999 | 10583985 |
| cloning, sequencing, and characterization of genomic subtracted sequences from listeria monocytogenes. | individual sequences of a genomic subtracted, pcr-amplified, mixed-sequence probe (gs probe) were cloned and sequenced. the gs probe differentiated restriction fragment length polymorphism patterns for listeria monocytogenes but did not hybridize with members of other bacterial genera. sequence analysis identified several l. monocytogenes sequences already present in the genbank database; the putative identities of other sequences were inferred from homology data, and still other sequences did n ... | 1999 | 10583999 |
| cytokine secretion by stimulated monocytes depends on the growth phase and heat treatment of bacteria: a comparative study between lactic acid bacteria and invasive pathogens. | the consumption of food containing lactic acid bacteria (lab) has been shown to exert immunomodulatory effects in humans. the specific cellular interaction of these bacteria with immuno-competent cells has not yet been fully understood. since the tnf-alpha secretion of stimulated monocytes is an important initial response to a bacterial challenge, we investigated the potential of lab originating from the human intestine or fermented food in comparison to the effect of invasive pathogens. the cha ... | 1999 | 10585139 |
| the adjacent flanking region plays a critical role in facilitating the presentation of the listeria monocytogenes product lema to h2 m3wt-restricted, peptide-specific murine cd8 cells. | mice infected with listeria monocytogenes (lm) generate cd8 effectors specific for f-migwii, the amino terminus of the bacterial product lema presented by the class ib mhc molecule h2 m3wt. lema has several distinctive properties: 1) it is readily presented as an exogenous ag in the absence of bacterial infection; 2) it is processed by a tap-independent pathway, which is sensitive to chloroquine, pepstatin, and brefeldin; and 3) the immunogenic portion of the molecule is extremely resistant to p ... | 1999 | 10586072 |
| cooperative symmetry-breaking by actin polymerization in a model for cell motility. | polymerizing networks of actin filaments are capable of exerting significant mechanical forces, used by eukaryotic cells and their prokaryotic pathogens to change shape or to move. here we show that small beads coated uniformly with a protein that catalyses actin polymerization are initially surrounded by symmetrical clouds of actin filaments. this symmetry is broken spontaneously, after which the beads undergo directional motion. we have developed a stochastic theory, in which each actin filame ... | 1999 | 10587645 |
| breaking through an actin cloud. | | 1999 | 10587655 |
| intracerebral activity of antibiotics against listeria monocytogenes during experimental rhombencephalitis. | we used a model of rhombencephalitis in gerbils to test the efficacy of various antibiotics against listeria monocytogenes. gerbils were inoculated in the middle ear with strain egd and treated subcutaneously with various antibiotics alone or in combination. we found that the most active antibiotics on intracerebral bacteria were amoxycillin, co-trimoxazole, rifampicin and imipenem. vancomycin, gentamicin and ciprofloxacin were weakly or not active. the combinations amoxycillin-co-trimoxazole, a ... | 1999 | 10588323 |
| control of early viral and bacterial distribution and disease by natural antibodies. | natural antibodies are often dismissed from immunological analysis as "background," but they may play an important role in conferring immunity against infections. in antibody-free mice infected with various viruses or with listeria monocytogenes, viral or bacterial titers in peripheral organs, including the kidney and brain, were 10 to 100 times greater than in antibody-competent mice (and enhanced their susceptibility to some infections), and titers in secondary lymphoid organs were 10 to 100 t ... | 1999 | 10591647 |
| interaction between the protein inlb of listeria monocytogenes and lipoteichoic acid: a novel mechanism of protein association at the surface of gram-positive bacteria. | inlb is a listeria monocytogenes protein that is sufficient to promote entry in a variety of mammalian cells. the last 232-amino-acid domain (csa) of inlb has been shown to mediate attachment on the listerial surface, although its sequence does not suggest any known mechanism of association to the bacterial surface. inlb is present both on the bacterial surface and in culture supernatants. as has been recently demonstrated, both forms of inlb, soluble and surface-bound, can trigger signalling in ... | 1999 | 10594817 |
| introduction of protein or dna delivered via recombinant salmonella typhimurium into the major histocompatibility complex class i presentation pathway of macrophages. | recombinant (r) salmonella typhimurium aroa strains which display the hen egg ovalbumin ova(257-264) peptide siinfekl in secreted form were constructed. in addition, attenuated rs. typhimurium pcdna-ova constructs harbouring a eukaryotic expression plasmid encoding complete ova were used to introduce the immunodominant ova(257-264) epitope into the major histocompatibility complex (mhc) class i presentation pathway. both modes of antigen delivery (dna and protein) by salmonella vaccine carriers ... | 1999 | 10594975 |
| [meningitis (ii)--acute bacterial meningitis]. | acute meningitis is a medical emergency, particularly in patients with rapidly progressing disease, mental status changes or neurological deficits. the majority of cases of bacterial meningitis are caused by a limited number of species, i.e. streptococcus pneumoniae, neisseria meningitis, listeria monocytogenes, group b streptococci (streptococcus agalactiae), haemophilus influenzae and enterobacteriaceae. many other pathogens can occasionally cause bacterial meningitis, often under special clin ... | 1999 | 10596276 |
| inhibition of listeriolysin o-induced hemolysis by bovine lactoferrin. | lactoferrin (lfr) plays an important role in the anti-microbial defense through iron binding, lipopolysaccharide binding and immunomodulation. in this study, we demonstrate that bovine lfr specifically inhibits the hemolytic activity of listeriolysin o (llo) produced by listeria monocytogenes. the hemolytic activity of llo was completely inhibited in the presence of bovine lfr that was highly purified on two cation-exchange columns, whereas that of streptolysin o or perfringolysin o was not inhi ... | 1999 | 10598021 |
| protective cultures inhibit growth of listeria monocytogenes and escherichia coli o157:h7 in cooked, sliced, vacuum- and gas-packaged meat. | contamination of cooked meat products with listeria monocytogenes poses a constant threat to the meat industry. the aim of this study was therefore to investigate the use of indigenous lactic acid bacteria (lab) as protective cultures in cooked meat products. cooked, sliced, vacuum- or gas-packaged ham and servelat sausage from nine meat factories in norway were inoculated with 10(3) cfu/g of a mixture of three rifampicin resistant (rif-mutant) strains of l. monocytogenes and stored at 8 degrees ... | 1999 | 10598113 |
| incidence of listeria monocytogenes in different types of meat products on the belgian retail market. | a survey was undertaken to determine the incidence and numbers of l. monocytogenes in a variety of meat products (cooked meat products, raw cured meat products (dried or not), mayonnaise based salads and prepared meals). as expected, raw cured meat products were significantly higher contaminated with l. monocytogenes than cooked meat products, 13.71% (113/824) and 4.90% (167/3405), respectively. also a larger proportion of raw cured meat product samples contained a high initial level of the path ... | 1999 | 10598117 |
| exposure to cigarette smoke impairs alveolar macrophage functions during halothane and isoflurane anesthesia in rats. | smoking alters numerous alveolar macrophage functions and is an important risk factor for postoperative pulmonary complications. the authors therefore tested the hypothesis that smoke exposure impairs antimicrobial and proinflammatory responses in alveolar macrophages during halothane and isoflurane anesthesia with mechanical ventilation. | 1999 | 10598627 |
| vaccination with heat-killed listeria as adjuvant reverses established allergen-induced airway hyperreactivity and inflammation: role of cd8+ t cells and il-18. | asthma is a respiratory disorder characterized by airway hyperreactivity (ahr) and inflammation and is associated with high serum ige and overproduction of il-4, il-5, and il-13 by allergen-specific th2 cells. our previous studies demonstrated that heat-killed listeria monocytogenes (hkl) as an adjuvant in immunotherapy successfully reversed ongoing ag-specific th2-dominated responses toward th1-dominated responses, but it was unclear if such immune modulation could reverse ongoing, established ... | 2000 | 10605015 |
| increasing the sensitivity of listeria monocytogenes assays: evaluation using elisa and amperometric detection. | an immunosensor for the detection of listeria monocytogenes was developed. elisa and amperometric studies were run in parallel to develop a more sensitive and rapid assay for the bacterium. conditions for the immunosensor were primarily characterised using elisa. a direct sandwich assay was employed and the affinities of two polyclonal (goat and rabbit) and one monoclonal (mouse) anti-l. monocytogenes antibodies were compared using this format. owing to low sensitivity being obtained with all an ... | 1999 | 10605890 |
| inhibition of listeria monocytogenes by in situ produced and semipurified bacteriocins of carnobacterium spp. on vacuum-packed, refrigerated cold-smoked salmon. | listeria monocytogenes inhibition by carnobacterium strains and crude bacteriocins on sterile and commercial vacuum-packed cold-smoked salmon stored at 4 degrees c and 8 degrees c was investigated. carnobacterium piscicola v1 was bactericidal against l. monocytogenes at the two temperatures, whereas carnobacterium divergens v41 presented a bacteriostatic effect. c. piscicola sf668 delayed l. monocytogenes growth at 8 degrees c and had a bacteriostatic effect at 4 degrees c. listeria growth was n ... | 1999 | 10606143 |
| good visual outcome after listeria monocytogenes endogenous endophthalmitis. | | 1999 | 10606462 |
| th1-biased immune responses induced by dna-based immunizations are mediated via action on professional antigen-presenting cells to up-regulate il-12 production. | the efficacy of dna-based immunization in conferring protective immunity against certain microbial pathogens including human immunodeficiency virus type 1 (hiv-1) has been described. the potential advantage of dna-based immunization over the traditional vaccines largely results from its capacity to efficiently induce th1-biased immune responses against an encoded antigen. we describe how th1-biased immune responses are induced by dna-based immunization, using a dna vaccine construct encoding hiv ... | 2000 | 10606974 |
| [pleural effusion due to listeria monocytogenes. a case report and review of the literature]. | the infection caused by listeria monocytogenes is a relatively common condition in immunosuppressed patients. the most frequent presentation in adults are sepsis and meningitis. pleural fluid infection due to this pathogen is a rare finding in the literature. most cases are found in immunosuppressed patients, particularly in those with haematologic malignancies. we report one case of pleural fluid infection due to listeria monocytogenes in a patient with hepatic cirrhosis (the third case in the ... | 1999 | 10609360 |
| mycobacterial infection of macrophages results in membrane-permeable phagosomes. | cell-mediated immunity is critical for host resistance to tuberculosis. t lymphocytes recognizing antigens presented by the major histocompatibility complex (mhc) class i and class ii molecules have been found to be necessary for control of mycobacterial infection. mice genetically deficient in the generation of mhc class i and class ia responses are susceptible to mycobacterial infection. although soluble protein antigens are generally presented by macrophages to t cells through mhc class ii mo ... | 1999 | 10611360 |
| [discrepant outcome of intrauterine listeria infection in dichorionic twins]. | background and case report: we report on a case of fetal listeriosis in a dichorionic twin pregnancy where both placentae, but only one of the twins were infected. while the firstborn child showed no infection and remained healthy until today, the other newborn had all clinical signs of granulomatosis infantiseptica and died despite of immediate resuscitation immediately after delivery. conclusions: this discrepant course with listeriosis in twins underlines, that fetal factors influence the cli ... | 1999 | 10612192 |
| surface interleukin-10 inhibits listericidal activity by primary macrophages. | interleukin-10 (il-10) down-regulates multiple functions of monocytes and macrophages, including the ability of macrophages to kill many intracellular microorganisms. the experiments presented here test the hypothesis that il-10 expressed on the cell surface inhibits the ability of primary mouse macrophages to kill the facultative, intracellular bacterium listeria monocytogenes. we show that, in contrast to macrophages from normal mice, both bone marrow-derived macrophages (bmdm) and thioglycoll ... | 1999 | 10614778 |
| identification and characterization of immunoglobulin g in blood as a major inhibitor of diagnostic pcr. | a major inhibitor of diagnostic pcr in human plasma was identified and the mechanism of inhibition was characterized. human blood was divided by centrifugation into buffy coat, plasma, platelets, and erythrocytes. all these blood fractions were found to be highly inhibitory to a standardized pcr mixture containing the thermostable dna polymerase amplitaq gold. pcr inhibitors in human plasma were purified by chromatographic procedures and were characterized by a process of elimination, so that th ... | 2000 | 10618113 |
| listeria monocytogenes acta protein interacts with phosphatidylinositol 4,5-bisphosphate in vitro. | the n-terminal region of the listeria monocytogenes acta protein, in conjunction with host cell factors, is sufficient for actin polymerization at the bacterial surface. previous data suggested that acta could protect barbed ends from capping proteins. we tested this hypothesis by actin polymerization experiments in the presence of the acta n-terminal fragment and capping protein. acta does not protect barbed ends from capping protein. in contrast, this polypeptide prevents pip(2) from inhibitin ... | 2000 | 10618167 |
| molecular grouping of listeria monocytogenes based on the sequence of the inib gene. | the major part of the gene inlb was sequenced in 24 strains of listeria monocytogenes belonging to serovars 1/2a, 1/2b, 1/2c, 3b and 4b. a phylogenetic analysis based on the inlb nucleotide sequences showed that strains of serovars 1/2a and 1/2c were closely related, as well as those of serovars 1/2b and 3b. strains sharing serovar 4b could be divided into two distinct groups. there were differences in amino-acid sequence between all serovars except between serovars 1/2b and 3b. differences in a ... | 2000 | 10628828 |
| comparative in vitro activity of moxifloxacin against gram-positive clinical isolates. | the in vitro activity of moxifloxacin was compared with that of 15 antibacterial agents against 513 gram-positive microorganisms. the mic(90) (mg/l) of moxifloxacin was 0.06 for quinolone-susceptible staphylococcus aureus and staphylococcus epidermidis, 0.12 for streptococcus pyogenes and streptococcus agalactiae; 0.25 for streptococcus pneumoniae, streptococcus mitis, streptococcus bovis, streptococcus anginosus and actinomyces pyogenes; 0.5 for streptococcus sanguis and listeria monocytogenes, ... | 2000 | 10629010 |
| electron paramagnetic resonance studies of the membrane fluidity of the foodborne pathogenic psychrotroph listeria monocytogenes. | listeria monocytogenes is a foodborne psychrotrophic pathogen that grows at refrigeration temperatures. previous studies of fatty acid profiles of wild-type and cold-sensitive, branched-chain fatty acid deficient mutants of l. monocytogenes suggest that the fatty acid 12-methyltetradecanoic (anteiso-c(15:0)) plays a critical role in low-temperature growth of l. monocytogenes, presumably by maintaining membrane fluidity. the fluidity of isolated cytoplasmic membranes of wild-type (slcc53 and 1040 ... | 2000 | 10631292 |
| molecular and cell biological aspects of infection by listeria monocytogenes. | bacterial pathogens have developed many subtle mechanisms to overcome and exploit cellular processes within the infected eukaryotic host cell. listeria monocytogenes, a facultative intracellular non-spore forming gram-positive pathogen, uses a number of strategies to ursurp and harness host cell processes to invade, proliferate, move intracellularly and effect cell-to-cell spread during the course of infection. in this review progress in elucidating mechanisms by which the bacteria recruit and u ... | 1999 | 10631564 |
| the mucosal phase of listeria infection. | listeria monocytogenes is an enteroinvasive bacterial pathogen of man and animals. listeriae have been shown capable of infecting the host by translocating from the intestinal lumen through peyer's patches (pp), however, results of experiments now indicate that these facultative intracellular parasites may also translocate through pp-independent routes. with regards to this, on occasion we observed that listeriae were absent from the pp of mice inoculated intragastrically with l. monocytogenes, ... | 1999 | 10631565 |
| early host-pathogen interactions in the liver and spleen during systemic murine listeriosis: an overview. | systemic listeriosis initiated by parenteral inoculation of mice with listeria monocytogenes has been used extensively as a model infection for studying mammalian host defense against intracellular bacterial pathogens in general. most effort has been expended on trying to understand the requirement for specific t cell-mediated immunity for combatting infection with this pathogen. by contrast, non-specific defenses have received much less attention. however, it is now obvious that these early inn ... | 1999 | 10631566 |
| immune reactions to listeria monocytogenes in the brain. | listeria monocytogenes (lm) is a common pathogen of cerebral infections. experimental studies in mice have revealed that epithelial cells of the choroid plexus, ependymal cells, macrophages/microglia, and neurons are the target cells of lm. for the intracerebral pathogenesis of lm cell-to-cell spread via phospholipase c was particularly important. however, phospholipase c-deficient lm were not completely attenuated and, therefore, other virulence factors may also contribute to the intracerebral ... | 1999 | 10631567 |
| a knockout approach to understanding cd8+ cell effector mechanisms in adaptive immunity to listeria monocytogenes. | in the described experimental approach, we use an attenuated lm strain to evoke lm specific cd8+ t cell responses. in this fashion, we can immunize immunocompromised gene knockout mice, that would succumb to low level infection with virulent lm. we then generate antigen matched, lm-specific cd8+ t cell lines from wild-type and gene knockout mice, and compare their capacity to provide immunity to lm infection in vivo. to date, our results demonstrate that cd8+ t cell-derived ifn-gamma and tnf are ... | 1999 | 10631568 |
| mhc class jb-restricted cell responses to listeria monocytogenes infection. | murine infection with listeria monocytogenes induces cd8+ t cell responses specific for bacterial peptides that are presented on the infected cell surface by mhc class ia and mhc class ib molecules. we have used mhc tetramers to demonstrate that cd8+ t cells restricted by the h2-m3 mhc class ib molecules constitute a substantial portion of the t cell response to l. monocytogenes infection. the in vivo size and kinetics of mhc class ib-restricted t cell populations suggests that they play a promi ... | 1999 | 10631569 |
| the need for a novel generation of vaccines. | although empirical vaccine development was highly successful, it has now reached its limits. vaccines are only efficacious against those pathogens which are primarily controlled by antibodies. protection against many infectious agents, however, strongly depends on t lymphocytes. thus, novel vaccines have to stimulate the combination of t lymphocytes that is required for an optimum protective immune response. although identification of antigens remains crucial, novel vaccine design also needs to ... | 1999 | 10631576 |
| processing of listeria monocytogenes antigens and the in vivo t-cell response to bacterial infection. | presentation of antigens to t lymphocytes is a critical step in the clearance of pathogens from their hosts and in the establishment of protective immunity. several animal models have been developed to study this process, but few have been as informative as the murine immune response to listeria monocytogenes infection. herein we review the presentation of l. monocytogenes proteins by the mhc class i antigen-processing pathway and the in vivo t-cell response to these bacterial antigens. these st ... | 1999 | 10631945 |
| sequence variations within prfa dna binding sites and effects on listeria monocytogenes virulence gene expression. | reporter gene fusions were used to investigate the contributions of prfa dna binding sites to listeria monocytogenes virulence gene expression. our results suggest that the dna sequence of prfa binding sites determines the levels of expression of certain virulence genes, such as hly and mpl. other virulence genes, such as acta and plcb, may depend upon additional factors for full regulation of gene expression. | 2000 | 10633124 |
| listeria monocytogenes in pork slaughtering and cutting plants. use of rapd, pfge and pcr-rea for tracing and molecular epidemiology. | in order to determine the origin of pork cuts contamination by listeria monocytogenes, 287 isolates, collected from five french pork slaughtering and cutting plants, from live pigs to pork cuts, were characterised using three molecular typing methods: random amplification of polymorphic dna (rapd) carried out with five different primers, genomic macrorestriction using apai with pulsed-field gel electrophoresis (pfge) and a pcr-restriction enzyme analysis (pcr-rea) based on the polymorphism exist ... | 1999 | 10634704 |
| occurrence of nisin z production in lactococcus lactis bfe 1500 isolated from wara, a traditional nigerian cheese product. | screening for bacteriocin production of 500 strains of lactic acid bacteria (lab) from various african fermented foods resulted in the detection of a bacteriocin producing lactococcus lactis (bfe 1500) isolated from a dairy product called wara. the bacteriocin inhibited not only the closely related lab, but also strains of listeria monocytogenes, listeria innocua, clostridium butyricum, clostridium perfringens, bacillis cereus and staphylococcus aureus. it was heat stable even at autoclaving tem ... | 1999 | 10634705 |
| incidence and control of listeria monocytogenes in foods in denmark. | the danish regulatory policy on listeria monocytogenes in foods is based on the principles of haccp and was developed using a health risk assessment approach. the danish policy focuses examinations and criteria for l. monocytogenes in ready-to-eat foods and is based on a combination of inspection and product-testing. based on current epidemiological information from several countries, a concentration of l. monocytogenes not exceeding 100 cfu/g of food at the time of consumption, seems to be of l ... | 1999 | 10634710 |
| structure of the lnlb leucine-rich repeats, a domain that triggers host cell invasion by the bacterial pathogen l. monocytogenes. | the l. monocytogenes protein lnlb activates phosphoinositide 3-kinase and induces phagocytosis in several mammalian cell types. the 1.86 a resolution x-ray crystal structure of the leucine-rich repeat domain of lnlb that is both necessary and sufficient to induce phagocytosis is presented here. the structure supports a crucial role for calcium in host cell invasion by l. monocytogenes and supplies a rationale for its function. calciums are bound to the protein in an unusually exposed manner that ... | 1999 | 10635330 |
| pathogen-specific loss of host resistance in mice lacking the ifn-gamma-inducible gene igtp. | interferon-gamma (ifn-gamma) is critical for defense against pathogens, but the molecules that mediate its antimicrobial responses are largely unknown. igtp is the prototype for a family of ifn-gamma-regulated genes that encode 48-kda gtp-binding proteins that localize to the endoplasmic reticulum. we have generated igtp-deficient mice and found that, despite normal immune cell development and normal clearance of listeria monocytogenes and cytomegalovirus infections, the mice displayed a profoun ... | 2000 | 10639151 |
| mutants of listeria monocytogenes defective in in vitro invasion and cell-to-cell spreading still invade and proliferate in hepatocytes of neutropenic mice. | listeria monocytogenes mutants defective in the acta gene, the plcb gene, and the inla and inlb genes were less virulent when injected intravenously into balb/c mice. the growth of these strains as well as of the virulent wild-type strains was increased by treating mice with a neutrophil-specific depleting monoclonal antibody, rb6-8c5. histologic examination of the livers of the treated animals showed intrahepatocytic proliferation of the listeriae in all cases. our data show that more than one ... | 2000 | 10639462 |
| role of listeriolysin o in cell-to-cell spread of listeria monocytogenes. | listeria monocytogenes is a facultative intracellular bacterial pathogen that escapes from a host vacuolar compartment and grows rapidly in the cytosol. listeriolysin o (llo) is a secreted pore-forming protein essential for the escape of l. monocytogenes from the vacuole formed upon initial internalization. however, its role in intracellular growth and cell-to-cell spread events has not been testable by a genetic approach. in this study, purified six-his-tagged llo (hisllo) was noncovalently cou ... | 2000 | 10639481 |
| determination of natural resistance of mice fed dietary lipids to experimental infection induced by listeria monocytogenes. | current understanding based on the effect of dietary lipid manipulation upon immune system function indicates that fatty acids are involved in the modulation of the immune response through different and complex pathways. reduction of several immune parameters by fatty acid action may be applied in the treatment of diseases characterised by an overactivation of the immune system. as a consequence, a reduction of host resistance against infectious agents has been reported in animals fed dietary li ... | 2000 | 10640607 |
| bactericidal activity of isothiocyanate against pathogens on fresh produce. | the bactericidal activity of allyl and methyl isothiocyanate (aitc and mitc) was tested with a rifampicin-resistant strain of salmonella montevideo and streptomycin-resistant strains of escherichia coil o157:h7 and listeria monocytogenes scott a. iceberg lettuce inoculated with high (10(7) to 10(8) cfu/g) and low (10(3) to 10(4) cfu/g) concentrations of bacterial pathogens was treated with aitc and mitc in sealed containers at 4 degrees c for 4 days. aitc showed stronger bactericidal activity th ... | 2000 | 10643765 |
| survival of listeria monocytogenes scott a on vacuum-packaged raw beef treated with polylactic acid, lactic acid, and nisin. | low-molecular-weight polylactic acid (lmw-pla) and lactic acid (la) were used to inhibit growth of listeria monocytogenes scott a on vacuum-packaged beef. nisin was also used simultaneously as an additional hurdle to the growth of this pathogen. inoculated beef cubes were immersed in a solution of 2% lmw-pla, 2% la, 400 iu/ml of nisin, or combinations of each acid and nisin for 5 min and drip-dried for 15 min. the cubes were then vacuum-packaged and stored at 4 degrees c for up to 42 days. surfa ... | 2000 | 10643784 |
| suppression of lymphoproliferation by alveolar macrophages in the guinea pig. | the relationship between alveolar macrophages (am) and lymphocytes may be important in the early establishment of infection with mycobacterium tuberculosis. am in several species have been shown to suppress lymphoproliferation by producing inhibitors that include nitric oxide (no). | 1998 | 10645450 |
| p45, an extracellular 45 kda protein of listeria monocytogenes with similarity to protein p60 and exhibiting peptidoglycan lytic activity. | a monoclonal antibody obtained by immunization of mice with heat-killed cells of listeria monocytogenes serotype 4d showed reactivity towards a protein (p45) from l. monocytogenes with an apparent molecular mass of 45 kda. this protein was detected in the culture supernatant and at the cell surface of l. monocytogenes. proteins cross-reacting with the monoclonal antibody were present in all listeria strains investigated, except l. grayi. the structural gene was cloned in escherichia coli and seq ... | 2000 | 10648100 |
| synergistic effects of nisin and thymol on antimicrobial activities in listeria monocytogenes and bacillus subtilis. | nisin z and thymol were tested, alone and in combination, for antibacterial activity against listeria monocytogenes atcc 7644 and bacillus subtilis atcc 33712. the antibacterial effect of nisin z, produced by lactococcus lactis ke3 isolated from the traditional moroccan fermented milk, was greatly potentiated by sub-inhibitory concentrations of thymol in both bacterial strains. our data showed that the concentration of nisin required for effective control of food-borne pathogenic bacteria could ... | 2000 | 10650225 |
| ph-regulated activation and release of a bacteria-associated phospholipase c during intracellular infection by listeria monocytogenes. | listeria monocytogenes grows in the cytosol of mammalian cells and spreads from cell to cell without exiting the intracellular milieu. during cell-cell spread, bacteria become transiently entrapped in double-membrane vacuoles. escape from these vacuoles is mediated in part by a bacterial phospholipase c (pc-plc), whose activation requires cleavage of an n-terminal peptide. pc-plc activation occurs in the acidified vacuolar environment. in this study, the ph-dependent mechanism of pc-plc activati ... | 2000 | 10652090 |
| generalized transduction of serotype 1/2 and serotype 4b strains of listeria monocytogenes. | this is the first report of generalized transduction in the gram-positive, food-borne pathogen listeria monocytogenes. bacteriophages were isolated from the environment and from lysogens, or were obtained from other laboratories. of the 59 bacteriophages tested, 34 proved to be capable of transduction. we exploited the ability of l. monocytogenes to grow at room temperature and isolated bacteriophages that were incapable of growth at 37 degrees c. transductions at this temperature therefore elim ... | 2000 | 10652092 |
| complete nucleotide sequence, molecular analysis and genome structure of bacteriophage a118 of listeria monocytogenes: implications for phage evolution. | a118 is a temperate phage isolated from listeria monocytogenes. in this study, we report the entire nucleotide sequence and structural analysis of its 40 834 bp dna. electron microscopic and enzymatic analyses revealed that the a118 genome is a linear, circularly permuted, terminally redundant collection of double-stranded dna molecules. no evidence for cohesive ends or for a terminase recognition (pac) site could be obtained, suggesting that a118 viral dna is packaged via a headful mechanism. p ... | 2000 | 10652093 |
| recent advances with recombinant bacterial vaccine vectors. | bacille calmette-guerin (bcg), listeria monocytogenes, salmonellae and shigellae have shown promise as vaccine vectors in experimental animal models. although disappointing results in humans and non-human primates stalled the development of this vaccination strategy, interest in this approach was reinvigorated recently by the development of bacterial dna-vaccine-vectors. the purpose of this review is to highlight the strengths and weaknesses of bacterial vaccine vectors, and to discuss the futur ... | 2000 | 10652479 |
| carbon dioxide and nisin act synergistically on listeria monocytogenes. | this paper examines the synergistic action of carbon dioxide and nisin on listeria monocytogenes scott a wild-type and nisin-resistant (nis(r)) cells grown in broth at 4 degrees c. carbon dioxide extended the lag phase and decreased the specific growth rate of both strains, but to a greater degree in the nis(r) cells. wild-type cells grown in 100% co(2) were two to five times longer than cells grown in air. nisin (2.5 microg/ml) did not decrease the viability of nis(r) cells but for wild-type ce ... | 2000 | 10653749 |
| effect of flagella on initial attachment of listeria monocytogenes to stainless steel. | at 22 degrees c a flagellin mutant of listeria monocytogenes was found to attach to stainless steel at levels 10-fold lower than wild-type cells, even under conditions preventing active motility. at 37 degrees c, when flagella are not produced, attachment of both strains was identical. therefore, flagella per se facilitate the early stage of attachment. | 2000 | 10653766 |
| reconstitution of listeria motility: implications for the mechanism of force transduction. | listeria monocytogenes and some other infectious bacteria polymerize their host cell's actin into tails that propel the bacteria through the cytoplasm. here we show that reconstitution of this behavior in simpler media resolves two aspects of the mechanism of force transduction. first, since dilute reconstitution media have no cytoskeleton, we consider what keeps the tail from being pushed backward rather than the bacterium being propelled forward. the dependence of the partitioning of motion on ... | 2000 | 10656971 |
| eta-1 (osteopontin): an early component of type-1 (cell-mediated) immunity. | cell-mediated (type-1) immunity is necessary for immune protection against most intracellular pathogens and, when excessive, can mediate organ-specific autoimmune destruction. mice deficient in eta-1 (also called osteopontin) gene expression have severely impaired type-1 immunity to viral infection [herpes simplex virus-type 1 (kos strain)] and bacterial infection (listeria monocytogenes) and do not develop sarcoid-type granulomas. interleukin-12 (il-12) and interferon-gamma production is dimini ... | 2000 | 10657301 |
| human toll-like receptor 2 mediates monocyte activation by listeria monocytogenes, but not by group b streptococci or lipopolysaccharide. | human toll like receptor (tlr) 2 has been implicated as a signaling receptor for lps from gram-negative bacteria and cell wall components from gram-positive organisms. in this study, we investigated whether tlr2 can signal cell activation by the heat-killed group b streptococci type iii (gbs) and listeria monocytogenes (hklm). hklm, but not gbs, showed a time- and dose-dependent activation of chinese hamster ovary cells transfected with human tlr2, as measured by translocation of nf-kappab and i ... | 2000 | 10657659 |
| expression and use of the green fluorescent protein as a reporter system in legionella pneumophila. | the gene encoding the green fluorescent protein (gfp) was used as a reporter gene in legionella pneumophila. to analyze gfp expression in legionella, transcriptional fusions of gfp with the legionella-specific mip (macrophage infectivity potentiator) promoter (p(mip)) and the sod (superoxide dismutase) promoter (p(sod)) derived from listeria monocytogenes were constructed. following transformation into the virulent l. pneumophila strain jr 32, strong gfp-mediated fluorescence was detected with b ... | 2000 | 10660067 |
| physical and metabolic causes of sub-lethal damage in listeria monocytogenes after long-term chilled storage at 4 degrees c. | cells of listeria monocytogenes display sub-lethal injury when subjected to long-term chill-storage in a nutrient-poor environment. the physical and metabolic causes of sub-lethal injury to two meat (l61 and l62) and two clinical (l98 and l99) l. monocytogenes strains chill-stored (4 degrees c) for 4 weeks in phosphate-buffered saline at ph 7.0 and ph 5.5, and ph 5.5 in the presence of 0.3% potassium sorbate, were characterized. causes of sub-lethal injury were determined by examining changes in ... | 1999 | 10664914 |
| simple method to observe the adaptive response of listeria monocytogenes in food. | a simple, novel method for determining stress-adaptive response of listeria monocytogenes in food systems is presented. the method involves plating samples on listeria-selective agar (lsa) acidified to ph 5.25 with incubation at 36 degrees c for 60 h to detect acid adaptation and plating on lsa with 70 gl-1 nacl and incubation at 7 degrees c for 7 d to detect cold-osmotic adaptation. adapted cells produced larger colonies (> 1 mm) under these conditions than unadapted cells. scot a (97%) and bri ... | 1999 | 10664977 |
| rapid detection of listeria monocytogenes by pcr-elisa. | a rapid detection system specific for listeria monocytogenes based upon the polymerase chain reaction was developed. the specificity of the primers and the probe annealing to the coding region of the mpl gene proved positive with the dna from a total of 103 l. monocytogenes strains, while dna from another 73 listeria and non-listeria strains tested negative. to facilitate detection with large numbers of samples, a microtitre plate assay was established with biotinylated probes. use of a standard ... | 1999 | 10664986 |
| rapid neutrophil response controls fast-replicating intracellular bacteria but not slow-replicating mycobacterium tuberculosis. | being one of the first cells to invade the site of infection, neutrophils play an important role in the control of various bacterial and viral infections. in the present work, the contribution of neutrophils to the control of infection with different intracellular bacteria was investigated. mice were treated with the neutrophil-depleting monoclonal antibody rb6-8c5, and the time course of infection in treated and untreated mice was compared by using intracellular bacterial species and strains va ... | 2000 | 10669354 |
| recombinant human interleukin-11 has anti-inflammatory actions yet does not exacerbate systemic listeria infection. | to determine whether recombinant human (rh) interleukin (il)-11 disrupts the clearance of microbial pathogens, mice were challenged with listeria monocytogenes after receiving high-dose rhil-11, anti-tumor necrosis factor (tnf) monoclonal antibody (mab), anti-il-11 mab, or saline control. the ld50 was not affected by rhil-11 but was 10-fold lower in the anti-tnf mab group (p<.001). plasma il-6, il-1beta, and tnf-alpha levels were not different between rhil-11-treated animals and the control grou ... | 2000 | 10669370 |
| transient expression of bacterial gene fragments in eukaryotic cells: implications for cd8(+) t cell epitope analysis. | cd8(+) t cells are potent effectors of acquired immunity against some viruses and intracellular bacterial pathogens. antigens recognized by cd8(+) t cells are small, 8-9 amino acid peptides derived from proteins produced by the pathogen. these peptides are presented by mhc class i molecules on the surface of the infected cell. when characterizing the cd8(+) t cell response to a bacterial or viral pathogen, it is often necessary to express an antigenic protein in a eukaryotic host cell that is ca ... | 2000 | 10669778 |
| disease patterns in field and bank vole populations during a cyclic decline in central finland. | declining field vole (microtus agrestis) and bank vole (clethrionomys glareolus) populations were sampled (117 field voles and 34 bank voles) in south-central finland during the winter of 1988-89. the last surviving field voles were caught in april and bank voles in february. a subsample (16) of the april field voles were taken live to the laboratory for immunosuppression. the histopathology of the main internal organs and the presence of aerobic bacteria and certain parasites were studied. in t ... | 2000 | 10670697 |
| listeria monocytogenes in renal transplant recipients. | five cases of listeria monocytogenes bacteremia were observed from april to december 1985, among renal transplant recipients from the same hospital in são paulo, brazil. the patients were adults (mean age: 40.6 years), and the basic complaint was fever, with no report of meningeal syndrome. laboratory tests revealed the presence of two serovars, (1/2)a and 4b, which were classified into three lysotypes. the four strains of serovar 4b showed the same antibiotype, with resistance to cefoxitin, cli ... | 1999 | 10671292 |
| ribotype analysis of strain distribution in listeria monocytogenes. | changes in the temporal and spatial patterns of strain distribution for the foodborne pathogen listeria monocytogenes were studied by ribotyping using the qualicon riboprinter system. ribotype patterns were obtained by using the restriction enzymes ecori and pvuii for 72 isolates of l. monocytogenes recovered from smoked salmon samples over a period of 3 years. each pattern was classified both by comparison to a pattern library and by comparison among the 72 isolate patterns. eleven ecori-based ... | 2000 | 10678421 |
| incidence and characterization of listeria monocytogenes from domestic and imported foods in korea. | a total of 1,537 domestic and imported food products were examined for the incidence of listeria monocytogenes between 1993 and 1997 in korea. l. monocytogenes was detected using the u.s. department of agriculture isolation method. isolated l. monocytogenes was confirmed by polymerase chain reaction with hly1 and hly2 primers designed from the listeriolysin o. overall, 122 samples (7.9%) contained l. monocytogenes. the rate of isolation was 4.3% for beef, 19.1% for pork, 30.2% for chicken, 1.2% ... | 2000 | 10678422 |
| listeria monocytogenes as a short-lived delivery system for the induction of type 1 cell-mediated immunity against the p36/lack antigen of leishmania major. | listeria monocytogenes has been used as an experimental live vector for the induction of cd8-mediated immune responses in various viral and tumoral experimental models. susceptibility of balb/c mice to leishmania major infection has been correlated to the preferential development of th2 cd4 t cells through an early production of interleukin 4 (il-4) by a restricted population of cd4 t cells which react to a single parasite antigen, lack (stands for leishmania homologue of receptors for activated ... | 2000 | 10678966 |
| interaction between burkholderia pseudomallei and acanthamoeba species results in coiling phagocytosis, endamebic bacterial survival, and escape. | burkholderia pseudomallei causes melioidosis, a potentially fatal disease whose clinical outcomes include rapid-onset septicemia and relapsing and delayed-onset infections. like other facultative intracellular bacterial pathogens, b. pseudomallei is capable of survival in human phagocytic cells, but unlike mycobacteria, listeria monocytogenes, and salmonella serovar typhimurium, the species has not been reported to survive as an endosymbiont in free-living amebae. we investigated the consequence ... | 2000 | 10678988 |
| novel approaches to monitor bacterial gene expression in infected tissue and host. | elucidating the complex and dynamic host-microbe interactions during infection requires, among other things, detailed knowledge of microbial gene expression in vivo. recently, advances in fluorescence and bioluminescence detection techniques, as well as recombinase-based in vivo expression technology, have rendered monitoring virulence gene expression in vivo a feasible task. these techniques have been adapted by several laboratories to study the spatial and temporal patterns of virulence gene e ... | 2000 | 10679414 |
| bacterial replication in the host cell cytosol. | intracellular bacteria in mammalian host cells can either live in a membrane-bound vacuole modified to support bacterial growth, or escape from the primary phagosome into the host cell cytoplasm. phagosomal escape is best studied in listeria monocytogenes in which a pore-forming cytolysin and two phospholipases are involved in the lysis of the phagosomal membrane. the mechanisms of and requirements for cytoplasmic growth are less clear but there is growing evidence that proficient replication of ... | 2000 | 10679420 |
| [direct gram staining of blood culture sample enabled the early diagnosis of brain abscess due to listeria monocytogenes]. | a 58 year old woman had a long history of immunocompromised state. since age 28 she had multiple endocrine neoplasm type 2a: her thyroid gland and bilateral adrenal glands were removed because of pheochromocytoma and thyroid medullary carcinoma. corticosteroid and levothyroxine were supplemented. at age 57 she was afflicted with systemic lupus erythematodes and nephrotic syndrome. prednisolone therapy was started. two months later she developed fever, lethergy, headache and left hemiparesis. mri ... | 1999 | 10689944 |
| high seropositivity against listeriolysin o in humans. | | 1999 | 10690251 |
| rat dorsal root ganglia neurons as a model for listeria monocytogenes infections in culture. | neurotropism of listeria monocytogenes was studied in rat dorsal root ganglia (drg) and hippocampal neurons in culture. using a system in which the drg neurons can grow relatively free from other cells, it was observed that such drg neurons, in contrast to hippocampal neurons, can be effectively infected by l. monocytogenes. the bacteria aligned along drg axons, but not along hippocampal neurites. a mutant deficient in internalin, a protein required for entry into e-cadherin-expressing cells, di ... | 1999 | 10691089 |
| ctsr controls class iii heat shock gene expression in the human pathogen listeria monocytogenes. | stress proteins play an important role in virulence, yet little is known about the regulation of stress response in pathogens. in the facultative intracellular pathogen listeria monocytogenes, the clp atpases, including clpc, clpp and clpe, are required for stress survival and intracellular growth. the first gene of the clpc operon of l. monocytogenes encodes a homologue of the bacillus subtilis ctsr repressor of stress response genes. an l. monocytogenes ctsr-deleted mutant displayed enhanced s ... | 2000 | 10692157 |
| growing an actin gel on spherical surfaces. | inspired by the motility of the bacteria listeria monocytogenes, we have experimentally studied the growth of an actin gel around spherical beads grafted with acta, a protein known to be the promoter of bacteria movement. on acta-grafted beads f-actin is formed in a spherical manner, whereas on the bacteria a "comet-like" tail of f-actin is produced. we show experimentally that the stationary thickness of the gel depends on the radius of the beads. moreover, the actin gel is not formed if the ac ... | 2000 | 10692348 |
| rapid determination of listeria monocytogenes by automated enzyme-linked immunoassay and nonradioactive dna probe. | a rapid and reliable analytical method was developed to detect and confirm the presence of listeria monocytogenes in raw and partially processed foods. forty-nine food samples (25 mixed cut vegetable salad, 12 smoked salmon, and 12 sterile smoked salmon) were individually inoculated with high levels [10-100 colony forming units (cfu)/25 g sample] and low levels (1-10 cfu/25 g sample) of l. monocytogenes, and were screened using the vitek immuno diagnostic assay (vidas) listeria monocytogenes (vi ... | 2000 | 10693007 |
| cell adhesion molecules in the pathogenesis of and host defence against microbial infection. | eukaryotic cell adhesion molecules (cams) are used by various cells and extracellular molecules in host defence against infection. they are involved in many processes including recognition by circulating phagocytes of a site of inflammation, transmigration through the endothelial barrier, diapedesis through basement membrane and extracellular matrix, and release of effector mechanisms at the infected site. cams involved in leucocyte-endothelial cell interaction include the selectins, integrins, ... | 1999 | 10694943 |
| seven die in french listeria outbreak. | | 2000 | 10698871 |
| bacterial pore-forming hemolysins and their use in the cytosolic delivery of macromolecules. | advances in our understanding of fundamental cell biological processes have facilitated an expansion of therapeutic approaches to altering cellular physiology and phenotype. as many of these methods involve macromolecular agents that act on targets within the nucleus or cytoplasm, achieving their full potential ultimately requires the efficient delivery of these agents across the cell membrane barrier into the cytosol. various strategies have been employed to enhance cytosolic delivery. these in ... | 2000 | 10699316 |
| advantage of gene gun-mediated over intramuscular inoculation of plasmid dna vaccine in reproducible induction of specific immune responses. | utilizing a plasmid dna encoding a single cytotoxic t lymphocyte (ctl) epitope and that encoding ovalbumin (ova), we compared the reproducibility in the induction of immune responses by gene gun and intramuscular immunization. as compared to intramuscular inoculation, gene gun dna immunization appeared to bring about highly reproducible and reliable results in the induction of specific ctl and ifn-gamma production to the ctl epitope and production of anti-ova igg. the results obtained by intramu ... | 2000 | 10699319 |
| evaluation of mini-vidas rapid test for detection of listeria monocytogenes from production lines of fresh to cold-smoked fish. | this study was conducted to evaluate the efficacy of the mini-vidas listeria monocytogenes (lmo) system (biomérieux vitek, inc., missouri, usa) for detection of l. monocytogenes in environmental and fish samples from three portuguese cold-smoking plants and from their fresh fish suppliers. mini-vidas-lmo is a fully automated system that uses fluorescent elfa (enzyme linked fluorescent assay) technology for detection of listeria monocytogenes antigens in food. it can be a rapid screening method a ... | 2000 | 10699670 |
| cloning, sequencing, and transcriptional analysis of the dnak heat shock operon of listeria monocytogenes. | the complete dnak operon of listeria monocytogenes was isolated by chromosome walking using the previously cloned dnak gene as a probe. molecular analysis of the locus identified 6 genes in the order hrca, grpe, dnak, dnaj, orf35, and orf29. primer extension analysis revealed 3 transcription start sites-s1, s2, and s3-upstream of the hrca, grpe, and dnaj, respectively. the transcription from s1 was heat inducible. analysis of the sequences revealed the consensus promoter sequences of gram-positi ... | 2000 | 10701836 |
| [changes in the virulence factor expression level in listeria monocytogenes under various environmental conditions]. | effects of chelators chelex-100 and activated charcoal on the production of proteins responsible for virulence of listeria monocytogenes, facultative intracellular parasite were studied. bivalent cation chelator chelex-100 stimulates the production of only thiol-dependent hemolysin listeriolysin o. the presence of activated charcoal, a nonspecific chelator, in culture medium stimulated the expression of listeriolysin o and other main virulence factors by increasing the level of their transcripti ... | 2000 | 10702985 |
| [listeriosis: an old or a current health problem?]. | | 2000 | 10703069 |
| erratum: volume 45, number 1, january 2000 | the legend to the issue's cover figure was incorrectly printed. it should have read: cover micrograph: actin-comet tails induced by the bacterial pathogen listeria monocytogenes. vero cells were infected by listeria monoctyogenes. after fixation, cells were labeled with fitc-phalloidin (green) and anti-listeria antibodies (red). photo courtesy of inigo lasa and pascale cossart. | 2000 | 10706779 |
| genes for the synthesis of the osmoprotectant glycine betaine from choline in the moderately halophilic bacterium halomonas elongata dsm 3043, usa. | the genes involved in the oxidative pathway of choline to glycine betaine in the moderate halophile halomonas elongata dsm 3043 were isolated by functional complementation of an escherichia coli strain defective in glycine betaine synthesis. the cloned region was able to mediate the oxidation of choline to glycine betaine in e. coli, but not the transport of choline, indicating that the gene(s) involved in choline transport are not clustered with the glycine betaine synthesis genes. nucleotide s ... | 2000 | 10708384 |
| human toll-like receptors 2 and 4 are targets for deactivation of mononuclear phagocytes by interleukin-4. | | 2000 | 10709778 |
| does administration of infliximab increase susceptibility to listeriosis? | | 2000 | 10710107 |
| infections and intoxications associated with animal feed and forage which may present a hazard to human health. | animal feed or forage may be the source of a limited number of infections for farm animals that could lead to human illness. likely organisms include salmonella enterica, toxoplasma gondii, trichinella spiralis and possibly the agent of bovine spongiform encephalopathy. the risk to human health from other infectious agents which may contaminate either feed or forage appear to be either negligible, e.g. bacillus anthracis and mycobacterium bovis, or non-existent, e.g. clostridium botulinum toxin ... | 2000 | 10712800 |
| single-strand conformation polymorphisms in the hly gene and polymerase chain reaction analysis of a repeat region in the iap gene to identify and type listeria monocytogenes. | two novel methods that allow the powerful identification of listeria monocytogenes by polymerase chain reaction (pcr) and simultaneous differentiation by special electrophoresis formats are described. the first method involves a pcr-driven single-strand conformation polymorphism (sscp-pcr) assay using a portion of the noncoding region of the hlv gene. the assay was evaluated with 120 genetically distinct l. monocytogenes strains of either foodborne or clinical origin. distribution of listerial s ... | 2000 | 10716561 |
| rapid polymerase chain reaction/dna probe membrane-based assay for the detection of listeria and listeria monocytogenes in food. | we describe the development of polymerase chain reaction (pcr)/dna probe membrane-based colorimetric assays for the detection and identification of listeria and l. monocytogenes. pcr primers designed from the 16s to 23s rrna intergenic spacer region amplified products that were reverse hybridized to membrane-bound oligonucleotide probes specific for listeria and l. monocytogenes with a detection limit of 1 to 10 cfu/25 ml in inoculated raw and pasteurized milk samples. these qualitative assays h ... | 2000 | 10716562 |
| development and evaluation of a 24-hour method for the detection and quantification of listeria monocytogenes in meat products. | a 24-h filter monitor-based test, listeria-select, has been developed to quantify listeria monocytogenes organisms in meat samples with a sensitivity of < or = 1.0 cfu/g. the technique comprises a filter monitor-based system and a colony lift immunoassay to identify and enumerate the target organism. meat homogenates were centrifuged and the eluate was filtered to trap and immobilize the microorganisms on the filter. fraser broth was then added to the filter apparatus to allow the organisms to b ... | 2000 | 10716564 |