Publications

TitleAbstractYear(sorted descending)
Filter
PMID
Filter
nonviable bacterial antigens administered with il-12 generate antigen-specific t cell responses and protective immunity against listeria monocytogenes.the development of effective vaccine strategies for intracellular pathogens, including bacteria, viruses, and parasites, is one of the major frontiers of scientific research. for the studies described here, the murine model of listeria infection was used to evaluate the adjuvant effects of il-12 when used as an immunization component. these studies revealed that typically nonimmunogenic doses of heat-killed listeria monocytogenes, or soluble listerial ag preparations, elicit intense th1-type lis ...19957594484
high level monocyte chemoattractant protein-1 expression in transgenic mice increases their susceptibility to intracellular pathogens.we have constructed transgenic mice in which the mouse mammary tumor virus long terminal repeat controls the expression of murine monocyte chemoattractant protein-1 (mcp-1). several independently derived lines of transgenic mice constitutively expressed mcp-1 protein in a variety of organs. protein extracts from these organs had substantial in vitro monocyte chemoattractant activity that was neutralized by an anti-mcp-1 ab, indicating that transgenic mcp-1 protein is biologically active. however ...19957594486
listeriolysin is processed efficiently into an mhc class i-associated epitope in listeria monocytogenes-infected cells.listeria monocytogenes is an intracellular pathogen that enters the cytoplasm of infected cells by secreting listeriolysin (llo), a protein that destroys the phagosomal membrane. in infected mice, llo is a major ag detected by protective, mhc class i-restricted ctls. although the role of llo in pathogenesis and host immunity is well established, its rate of intracellular synthesis has yet to be determined. herein we show that cytosolic l. monocytogenes secrete llo at a relatively low rate of app ...19957594534
il-1 beta is required for il-12 to induce production of ifn-gamma by nk cells. a role for il-1 beta in the t cell-independent mechanism of resistance against intracellular pathogens.mice with the severe combined immunodeficiency (scid) possess an ifn-gamma-dependent mechanism of resistance to the intracellular pathogens toxoplasma gondii and listeria monocytogenes that is dependent on il-12-induced production of ifn-gamma by nk cells. in this report we demonstrate that il-1 beta is required for il-12 to stimulate production of ifn-gamma by nk cells, and that il-1 is important in il-12-mediated resistance to t. gondii in vivo. stimulation of scid mouse splenocytes with tachy ...19957594594
mechanisms of t cell epitope immunodominance analyzed in murine listeriosis.we demonstrate conclusively that the bacterial exotoxin listeriolysin o (llo) is a target ag for eliciting cd4+ t cell responses following infection with listeria monocytogenes. the minimal i-ek-restricted immunodominant cd4+ t cell epitope was identified as peptide 215-226 (p215-226). most llo-specific t cell hybridomas recognized p203-226, p208-226, p215-226, and p215-234, although each exhibited a characteristic pattern of preferential reactivity. one hybridoma (iiic5) reacted to p203-226 but ...19957594595
experimental listeria meningoencephalitis. macrophage inflammatory protein-1 alpha and -2 are produced intrathecally and mediate chemotactic activity in cerebrospinal fluid of infected mice.in bacterial meningitis, the recruitment of leukocytes across the blood-brain barrier into the central nervous system may be crucial for both elimination of pathogens and tissue injury. in addition to bacterial cell wall products, host factors including chemokines may lead to accumulation of phagocytes within the central nervous system. as shown by northern analysis, brains of mice infected intracerebrally with listeria monocytogenes (lm) express mrna for three chemokines, the macrophage inflamm ...19957594596
flexor tenosynovitis in the hand. an unusual aetiology.we report an unusual case of tenosynovitis in the hand. a female farm worker aged 66 developed swelling of the middle and little fingers. extensive synovectomy of the flexor tendon sheaths was performed, and the synovitis was found to be due to listeria monocytogenes, which is unusual in this area. treatment with amoxycillin and gentamicin for 10 days was replaced by trimethoprim-sulfamethoxazole for 3 weeks. there was no recurrence of infection 3 months after surgery, and flexion and extension ...19957594995
differential regulation of tnf-alpha production by listeriolysin-producing versus nonproducing strains of listeria monocytogenes.only listeria monocytogenes that produce listeriolysin o (llo) elicit protective immunity. given the importance of tumor necrosis factor alpha (tnf-alpha) in anti-listeria immunity, we have investigated tnf-alpha production by macrophages after they ingested live llo-producing compared to llo-non-producing bacteria. we used two genetically engineered strains of listeria that differed only in their ability (ly+) or inability (ly-) to produce llo. ly+ and ly- caused the same kinetics of increased ...19957595057
the effect of various bacteria and sera on functional activity of mouse macrophages.the study has been performed to compare the ability of mouse peritoneal macrophages to ingest various types (catalase positive and negative) of bacteria and compared the influence of various sera on intracellular killing of escherichia coli c (e. coli c). among the tested microbes only e. coli c was ingested very luxuriantly and other organisms were taken up luxuriantly and moderately by mouse peritoneal resident macrophages (rmqs). broad difference of ingestion was found even within the same ge ...19957595973
the changing face of neonatal septicaemia.a prospective study was undertaken over a 1-year period in northern jordan to determine the incidence, causes and characteristics of neonatal septicaemia which is a major cause of mortality and morbidity in newborns. the study identified 47 septicaemic neonates, representing an incidence of 2.3/1000 live births. respiratory distress and hyperbilirubinaemia were the prominent presenting clinical findings. gram-negative organisms were cultured from 46 neonates with klebsiella species, accounting f ...19957598444
contamination pattern of listeria monocytogenes and other listeria spp. in a salmon slaughterhouse and smoked salmon processing plant.a smoked salmon processing plant including a smokehouse and a slaughterhouse was examined for the occurrence of listeria monocytogenes and other listeria spp. from a total of 475 samples the overall frequency of l. monocytogenes was 16%, while other listeria spp. were found in 22% of the samples. l. monocytogenes was most often detected in samples from the smokehouse, where 29% of the environmental and 26% of the fish samples during processing contained the bacteria. 17% of the fish raw material ...19957599028
control of listeria monocytogenes in the delicatessen industries: the lessons of a listeriosis outbreak in france.during a recent outbreak of foodborne listeriosis which occurred in france in 1992, investigations were carried out in order to identify the plants associated with the production of contaminated products. these investigations were made in six 'suspect' delicatessen plants following the first epidemiological investigations, and in one 'control plant'. the first visits were made during working operations. two hundred and seventy samples were taken ('environmental' swabs, air samples, products), wi ...19957599032
[foodborne listeria monocytogenes and their rapid determination]. 19957600891
synthesis and evaluation of a non-radioactive gene probe for the detection of c.perfringens alpha toxin.the synthesis and evaluation of a non-radioactive hybridization probe is described, specific detecting the clostridium perfringens alphatoxin gene (plc) by colony blot hybridization assay. a vector free digoxigenin-dutp-labelled probe was generated by polymerase chain reaction (pcr) targeting the cloned plc gene of c.perfringens strain atcc 13124. in a colony blot hybridization assay 296 strains of c.perfringens were tested for plc. none of the strains failed in hybridization. presence of plc wa ...19957603469
multi-centre collaborative study for the in vitro evaluation of new macrolides dirithromycin and erythromycylamine. australian group for antimicrobial resistance (agar).a national study was conducted to determine the in vitro activity of 2 newer macrolides, dirithromycin and erythromycylamine compared with that of erythromycin, tetracycline and penicillin. nineteen major teaching hospitals participated in the study. minimal inhibitory concentrations (mics) were determined by agar dilution, mostly using iso-sensitest agar and an inoculum of 10(4) cells per spot. 2284 clinically significant strains were isolated in late 1991 and early 1992, comprising 1736 gram-p ...19957603759
shigella flexneri surface protein icsa is sufficient to direct actin-based motility.shigella flexneri is a gram-negative bacterial pathogen that can grow directly in the cytoplasm of infected host cells and uses a form of actin-based motility for intra- and intercellular spread. moving intracellular bacteria are associated with a polarized "comet tail" composed of actin filaments. icsa, a 120-kda outer membrane protein necessary for actin-based motility, is located at a single pole on the surface of the organism, at the junction with the actin tail. here, we demonstrate that st ...19957604035
analysis of the interrelationship between il-12, tnf-alpha, and ifn-gamma production during murine listeriosis.il-12, a recently described cytokine, is an important mediator in the early production of ifn-gamma during infection. to evaluate the timing of il-12 production, and its relationship to tnf-alpha, and ifn-gamma production during primary murine listeriosis, we measured cytokine mrna and protein levels in c57b1/6 mice infected intravenously with listeria monocytogenes (lm). il-12 is a disulfide-linked heterodimer containing two chains (designated p35 and p40); however, bioactive cytokine productio ...19957606797
analysis of heat and cold shock proteins in listeria by two-dimensional electrophoresis.the proteins induced by heat and cold shock in listeria monocytogenes (pathogenic for humans) and l. innocua (nonpathogenic) strains were analyzed by two-dimensional (2-d) electrophoresis with the help of a computerized 2-d gel analysis system. heat (49 degrees c) and cold (4 degrees c) shock repressed roughly half the number of proteins synthesized at normal temperature (25 degrees c) and decreased the level of numerous other proteins. conversely, the synthesis of a great number of proteins was ...19957607179
effects of leflunomide on the course of listeriosis in mice. short communication.the intensity of an infection with listeria monocytogenes depends on the immunological stab1p4f the body. impairment of the specific or unspecific defence can lead to severe and partly fatal complications such as meningitis or septicaemia. in a normal defence situation affected individuals are often not diagnosed because the infection appears as an unspecific indisposition. the new immunomodulator leflunomide (n-(4-trifluoro-methyl-phenyl)-5-methyl-isoxazol-4-carboxamide, cas 75706-12-6, hwa 486 ...19957612063
antibiotic therapy for listeria monocytogenes bacteremia.listeria monocytogenes has been recognized as an important pathogen in immunocompromised patients, but it has been rarely reported in taiwan. we reviewed 13 cases of l. monocytogenes bacteremia at national taiwan university hospital over a 12-year period. all of the patients had underlying diseases. fever was the most common presenting symptom, and neurologic signs were found in 6 patients. most of the patients received penicillin g, ampicillin or piperacillin with an aminoglycoside. corticoster ...19957613229
antimicrobial chemotherapy of human infection due to listeria monocytogenes.listeriosis is an uncommon infection, but when it occurs it carries a high mortality rate. early diagnosis is essential and thereafter appropriate antimicrobial chemotherapy. ampicillin or penicillin plus gentamicin remains the treatment of choice for most manifestations of listeriosis, and adequate doses must be given, i.e. greater than 6g/day of ampicillin or penicillin. co-trimoxazole appears to be an excellent alternative agent with good penetration into the cerebrospinal fluid. vancomycin i ...19957614955
fatal pericarditis due to listeria monocytogenes. 19957614972
effects of essential oil from mint (mentha piperita) on salmonella enteritidis and listeria monocytogenes in model food systems at 4 degrees and 10 degrees c.the effect of mint (mentha piperita) essential oil (0.5, 1.0, 1.5 and 2.0%, v/w) on salmonella enteritidis and listeria monocytogenes in a culture medium and three model foods; tzatziki (ph 4.5), taramosalata (ph 5.0) and pâté (ph 6.8), inoculated at 10(7) cfu g-1, at 4 degrees and 10 degrees c for ca 1 week was studied. in the culture medium supplemented with the essential oil, no growth was observed over 2 d at 30 degrees c determined by a conductance method with a malthus 2000 growth analyser ...19957615414
growth of food-borne pathogenic bacteria in oil-in-water emulsions: i--methods for investigating the form of growth.methods are presented for investigating the site and form of growth of bacteria in model oil-in-water emulsions and in dairy cream. following growth of the bacteria, the continuous aqueous phase is gelled using agarose and the oil phase removed using a mixture of chloroform and methanol. using this method, the authors have found that listeria monocytogenes, salmonella typhimurium and yersinia enterocolitica grow in the form of colonies in concentrated oil-in-water emulsions. colonies of l. monoc ...19957615415
growth of food-borne pathogenic bacteria in oil-in-water emulsions: ii--effect of emulsion structure on growth parameters and form of growth.the growth rates and yields of listeria monocytogenes and yersinia enterocolitica were determined in liquid culture media, and in model oil-in-water emulsions that contained 30, 70 or 83% (v/v) hexadecane. in emulsions with a mean droplet size of 2 microns containing 83% (v/v) hexadecane, the growth of both organisms resulted in decreased yields. additionally, in these emulsions adjusted to ph 5.0 or 4.4 the growth rate of l. monocytogenes was significantly less than in other model systems which ...19957615416
factors affecting the growth of listeria monocytogenes on minimally processed fresh endive.the influence of various factors on the fate of listeria monocytogenes on cut leaves of broad-leaved endive has been studied. factors considered were temperature, characteristics of the leaves (age, quantity and quality of the epiphytic microflora) and characteristics of the l. monocytogenes inoculum (concentration, strain). the increases in numbers of l. monocytogenes were lower than those of the aerobic mesophilic microflora at 3 degrees, 6 degrees, 10 degrees and 20 degrees c. doubling times ...19957615420
actin-based movement of listeria monocytogenes: actin assembly results from the local maintenance of uncapped filament barbed ends at the bacterium surface.the thermodynamic basis for actin-based motility of listeria monocytogenes has been investigated using cytoplasmic extracts of xenopus eggs, initially developed by theriot et al. (theriot, j. a., j. rosenblatt, d. a. portnoy, p. j. goldschmidt-clermont, and t. j. mitchison. 1994. cell. 76:505-517) as an in vitro cell-free system. a large proportion (75%) of actin was found unpolymerized in the extracts. the amount of unassembled actin (12 microm) is accounted for by the sequestering functions of ...19957615635
comparison of e-test with broth microdilution and disk diffusion for susceptibility testing of coryneform bacteria.the susceptibilities of 135 coryneform bacteria isolated from clinical samples to ampicillin (amp), cephalothin (cr), cefoxitin (fox), cefotaxime (ctx), erythromycin (e), ciprofloxacin (cip), tetracycline (te), amikacin (ak), vancomycin (va), and rifampin (r) were determined by disk diffusion, broth microdilution, and the e-test. the following species (number of isolates in parentheses) were included: corynebacterium urealyticum (30), corynebacterium minutissimum (20), coryneform cdc group anf-1 ...19957615748
listeria monocytogenes infections: laboratory investigation of an unexpected increase in incidence.listeria monocytogenes is a facultative intracellular pathogen causing mainly meningitis and septicemia in immunocompromised hosts. from july 1988 through december 1989, 16 patients at the mount sinai hospital were diagnosed as having listeriosis shortly after admission, 14 within a one-year period (july 1988-july 1989). because this incidence was almost double the incidence in previous years (< 8 annually), an epidemiologic and microbiologic investigation was undertaken to determine a potential ...19957616977
growth of untreated and radiation-damaged listeria as affected by environmental factors.the growth of untreated listeria monocytogenes 4ab no. 10 and that of the surviving fraction of its population treated with 0.8 kgy gamma rays was investigated in a microtitreplate system at incubation temperatures between 3 degrees c and 35 degrees c in tryptic phosphate broth (tpb) or brain heart infusion broth (bhib) media containing nacl between 0.25 to 16.75% (w/v), and acidified with citrate-phosphate buffers to ph values between 4.63 and 7.06. the initial viable count was 3 x 10(3)/ml. ti ...19957620808
specific immunity to listeria monocytogenes in the absence of ifn gamma.cytokine and cytokine receptor gene knockout mice provide powerful experimental systems to characterize the functions of these molecules in resistance to infectious disease. such mice may also provide unique models of immune deficiency to learn whether manipulation of the immune response can overcome the specific dysfunction. we demonstrate that resistance of ifn gamma gene knockout (gko-/-) mice to the intracellular bacterium listeria monocytogenes is severely impaired compared with wild-type m ...19957621071
resistance to fever induction and impaired acute-phase response in interleukin-1 beta-deficient mice.we used gene targeting in embryonic stem cells to introduce an il-1 beta null allele in mice. the il-1 beta-deficient mice develop normally and are apparently healthy and fertile. the il-1 beta null mice responded normally in models of contact and delayed-type hypersensitivity or following bacterial endotoxin lps-induced inflammation. the il-1 beta-deficient mice showed equivalent resistance to listeria monocytogenes compared with wild-type controls. in contrast, when challenged with turpentine, ...19957621081
early appearance of t cell receptor alpha beta + cd4- cd8- t cells with a skewed variable region repertoire after infection with listeria monocytogenes.we found that the number of t cell receptor (tcr) alpha beta + cd4- cd8- t cells increased in the peritoneal cavity on day 5 after an intraperitoneal infection with listeria monocytogenes strain egd together with tcr gamma delta + cd4- cd8- t cells. thereafter, the tcr alpha beta + cd4- cd8- t cells decreased to a normal level by day 14. the tcr alpha beta + cd4- cd8- t cells showed an activated t cell phenotype (l-selectin cd44 +) and expressed cd45/b220 and interleukin-2 receptor beta, but did ...19957621874
suppression of cytokines in mice by protein a-v antigen fusion peptide and restoration of synthesis by active immunization.it is established that an approximately 70-kb lcr plasmid enables yersinia pestis, the causative agent of bubonic plague, to multiply in focal necrotic lesions within visceral organs of mice by preventing net synthesis of the cytokines tumor necrosis factor alpha (tnf-alpha) and gamma interferon (ifn-gamma), thereby minimizing inflammation (lcr+). rabbit antiserum raised against cloned staphylococcal protein a-v antigen fusion peptide (pav) is known to passively immunize mice against 10 minimum ...19957622225
delivery of class i and class ii mhc-restricted t-cell epitopes of listeriolysin of listeria monocytogenes by attenuated salmonella.using a salmonella vaccine-listeria infection model of intracellular infection, we studied the capacity of an attenuated strain of salmonella carrying t-cell epitopes of listeriolysin (llo) of l. monocytogenes to elicit epitope-specific t-cell responses. class ii (llo 215-226) or class i (llo 91-99) mhc-restricted t-cell epitopes of llo were inserted within a central, hypervariable domain of the flagellin protein of an attenuated delta aroa salmonella dublin strain. t cells from listeria-immuniz ...19957625107
[spontaneous bacterial peritonitis due to listeria monocytogenes].we present a case of spontaneous bacterial peritonitis (sbp) caused by listeria monocytogenes in a patient previously diagnosed as alcoholic liver cirrhosis. the clinical presentation, biochemical data and outcome of the patient are compared with those of cases of sbp caused by listeria monocytogenes in patients with cirrhosis published in the spanish and english literature. twelve out of 20 cases described in the literature were published by spanish authors. this greater proportion could be rel ...19957626303
bovine mastitis caused by listeria monocytogenes: characteristics of natural and experimental infections.experimental mastitis induced with a single intramammary injection of listeria monocytogenes was compared with two naturally occurring cases. four strains of l. monocytogenes, two of serotype 1/2a and two of serotype 4b were used for the experimental infections and two diametrically opposed quarters of four cows were inoculated with 300 cfu. bacteriological examination and somatic cell counts of quarter foremilk samples were performed weekly for at least 6 months after challenge. all the inocula ...19957629852
bacterial infection of the testis leading to autoaggressive immunity triggers apparently opposed responses of alpha beta and gamma delta t cells.the mechanisms that lead to the breakdown of self-tolerance and testis-specific immune reactivity in the murine orchitis model are understood only in part. we investigated the histopathologic and immunologic consequences of a unilateral bacterial (listeria monocytogenes) infection of the testis. both infected and contralateral sides of this bilateral organ suffered severe inflammatory responses despite a conspicuous absence of bacteria in the contralateral tissue. also, in both testicles, t cell ...19957636256
listeria septicemia complicating bone marrow transplantation for diamond-blackfan syndrome.infection with listeria monocytogenes is uncommon in patients receiving cytotoxic chemotherapy, and is even rarer among recipients of bone marrow transplantation. hemosiderosis, either idiopathic or caused by transfusion, appears to be another risk factor. we report a 3-year-old chinese girl with transfusion-dependent diamond-blackfan syndrome who had l. monocytogenes septicemia when she received an allogeneic bone marrow transplantation. she was treated successfully with intravenous ampicillin. ...19957640184
repression of motility and flagellin production at 37 degrees c is stronger in listeria monocytogenes than in the nonpathogenic species listeria innocua.listeria monocytogenes and listeria innocua differ markedly in virulence but are indistinguishable by classical taxonomic criteria. both species are actively motile and produce abundant flagellin at 22 degrees c. we have found, however, noticeable differences between l. monocytogenes and l. innocua in motility and flagellin production at 37 degrees c. at this temperature, l. monocytogenes strains were virtually nonmotile and produced little or no detectable flagellin, whereas strains of l. innoc ...19957641140
interaction of listeria monocytogenes with mouse dendritic cells.in this study, the interaction of murine dendritic cells with listeria monocytogenes was investigated. dendritic cells are efficient antigen-presenting cells, play a key role in the immune response, and are capable of migrating over substantial distances between sites of infection and lymphoid tissues. l. monocytogenes egd invaded dendritic cells, escaped from phagosomes into the cytoplasm, and there directed actin nucleation, polymerization, and polarization in a typical fashion, thereby achiev ...19957642305
activity and purification of linenscin oc2, an antibacterial substance produced by brevibacterium linens oc2, an orange cheese coryneform bacterium.an orange cheese coryneform bacterium isolated from the surface of gruyère of comté and identified as brevibacterium linens produces an antimicrobial substance designated linenscin oc2. this compound inhibits gram-positive food-borne pathogens including staphylococcus aureus and listeria monocytogenes but is not active against gram-negative bacteria. linenscin oc2 caused viability loss and lysis of the test organism, listeria innocua. electron microscopy showed that linenscin oc2 induces protopl ...19957646021
adhesion of listeria monocytogenes to silica surfaces after sequential and competitive adsorption of bovine serum albumin and beta-lactoglobulin.adsorbed bovine serum albumin was resistant to exchange with beta-lactoglobulin, and when albumin was adsorbed from a mixture, its surface concentration increased with time. the passivating character of adsorbed albumin and its resistance to desorption were consistent with the level of listeria monocytogenes adhesion evoked by albumin-containing protein films.19957646040
immunochemical detection methods for salmonella spp., escherichia coli o157:h7, and listeria monocytogenes in foods.immunochemical assays should prove to be a significant improvement over standard culture methods for the detection of foodborne pathogens. these techniques take advantage of the specificity and sensitivity of the antibody/antigen reaction for analyte detection. elisa is the most useful form of immunochemical method for the detection of foodborne pathogens in the food-processing setting, based on their simplicity and ability to analyze large numbers of samples at a time. concerns with immunochemi ...19957652195
identification and classification of listeria by two-dimensional protein mapping.the cellular proteins of 29 listeria strains belonging to different species and serotypes were analysed by two-dimensional (2-d) electrophoresis with the help of a computerized 2-d gel analysis system. the protein patterns were similar among strains within a listeria species, but were different from one species to another. the comparative analysis of these protein maps enabled us to find specific proteins and to determine the genetic relatedness among listeria spp. strains. the cluster analysis ...19957652208
laboratory data which differentiate meropenem and imipenem.meropenem and imipenem are carbapenems which are distinguishable from all other currently available beta-lactam antibiotics by breadth of antibacterial spectrum and stability to beta-lactamases, but can be differentiated one from another. meropenem is relatively stable to human renal dehydropeptidase-i (dhp-i); it does not require to be co-administered with cilastatin and consequently, unlike imipenem, will be administered as a single agent. in vitro both meropenem and imipenem are active agains ...19957652504
[the isolation and partial characterization of the cell wall proteins of listeria monocytogenes].the preparative scheme for the purification of proteins with molecular weights of 39 and 79 kd, obtained from l. monocytogenes membrane fractions, has been developed. this technology included the cultivation of bacteria in heart-brain broth, isolation of bacterial membranes, the extraction of their components with triton-x-100 and chromatography on superose columns. the purified proteins have been shown to form structures with a molecular weight of 500-100 kd and pl 4.7 in water solutions.19957653127
behavior of listeria monocytogenes in mozzarella cheese in presence of lactococcus lactis.the behavior of listeria monocytogenes (scott a) on fully processed italian mozzarella cheese was examined in presence and in absence of bacteriocins produced by lactococcus lactis ssp. lactis strains (dip 15 and dip 16). these strains, isolated from raw milk, produced heat stable bacteriocins that were inactivated by pronase, alpha- chymotrypsin and proteinase k, but not by pepsin, trypsin and catalase. the addition of crude bacteriocins to the growing culture of listeria monocytogenes resulted ...19957654515
a rapid general method for the identification of pcr products using a fibre-optic biosensor and its application to the detection of listeria.a 200-mer fragment of the flaa gene from listeria monocytogenes was amplified using the polymerase chain reaction (pcr) incorporating biotin- and fluorescein amadite (fam-)labelled primers. methods are described for isolating the single stranded fam-labelled 200-mer. a central portion of this 200-mer was successfully hybridized onto a complementary sequence coated onto a fibre optic biosensor. advantages in the specificity and speed of this approach compared to standard agarose gel electrophores ...19957662336
culture media and methods for the isolation of listeria monocytogenes.the recovery of low numbers of listeria monocytogenes from foods and environmental samples requires the use of enrichment cultures followed by selective plating and, where injured organisms are likely to be present, a pre-enrichment step. the development of selective and enrichment media for l. monocytogenes is traced and currently used media are discussed. comparisons of media and methods for the culture of l. monocytogenes are reported but no single method can be recommended for all situations ...19957662515
systemic immunization induces protective cd4+ and cd8+ t cell-mediated immune responses in murine listeria monocytogenes meningoencephalitis.the immune mechanisms underlying immunization-induced protection of mice from lethal central nervous system (cns) listeriosis were evaluated by immunohistochemistry, flow cytometry of leukocytes isolated from the brain, reverse transcription-polymerase chain reaction analysis of intracerebral (i.c.) tumor-necrosis factor-alpha, interferon-gamma, interleukin (il)-2, il-1 beta, il-10, granulocyte/macrophage colony-stimulating factor, and inducible nitric oxide synthase mrna expression, and t cell ...19957664800
transgenic mice expressing high levels of soluble tnf-r1 fusion protein are protected from lethal septic shock and cerebral malaria, and are highly sensitive to listeria monocytogenes and leishmania major infections.mice bearing a transgene coding for a soluble tumor necrosis factor receptor type 1 (tnfr1)-fcigg3 fusion protein and placed under the control of the alpha-1-antitrypsin gene promoter were generated. depending on the mouse line, blood levels of the protein ranged from 25 ng/ml to over 100 micrograms/ml; this level of expression was most often transmitted to the transgene-bearing progeny as a relatively stable feature. high-expressor mice were completely resistant to lipopolysaccharide-induced sh ...19957664802
[studies on the occurrence of listeria monocytogenes in fecal samples of domestic and companion animals].listeria (l.) monocytogenes was isolated from 33.3% fecal samples of 138 cattle (29 strains serovar 1/2b, 10 strains serovar 1/2a, 7 strains serovar 4ab), from 8% fecal samples of 100 hens (5 strains serovar 1/2b, 1 strain serovar 1/2a, 4ab and 4b each), from 8% fecal samples of 100 sheep (6 strains serovar 1/2a, 1 strain serovar 1/2b and 4ab each), from 5.9% fecal samples of 34 pigs (2 strains serovar 4ab), from 4.8% fecal samples of 400 horses (7 strains serovar 1/2a, 6 strains serovar 1/2b an ...19959376045
comparison of different selective methods for detection of listeria species in surface water.tests were carried out to evaluate the efficiency of various combinations of selective enrichment and plating techniques using pure cultures of listeria monocytogenes, listeria seeligeri and listeria innocua in suspension and samples of surface water. the best yields for the various listeria spp. were obtained after a single passage in leb (oxoid) or leb buffered (oxoid) and after using palcam and oxford agar (oxoid). palcam agar was, however, shown to be the most efficient means of detecting th ...19959353532
bacterial complications of transplantation: diagnosis and treatment.bacterial complications develop mainly after transplantation during the period before engraftment takes place. wound infections, urinary tract infection and pneumonia are the commonest complications of solid organ transplantation and generally involve gram-negative bacilli and staphylococcus aureus. however, gram-positive cocci will predominate when selective oral antimicrobial prophylaxis is given as is frequently the case in bone marrow transplant recipients. oromucositis, induced by total bod ...19958601544
live recombinant listeria monocytogenes as an immunotherapeutic agent for experimental tumors. 19958800833
accumulation of activated lymphocytes in liver of listeria factor ei treated rabbits.factor ei isolated from listeria monocytogenes caused in rabbits 1 d after intravenous administration activation of peripheral blood lymphocytes in terms of rrna biosynthesis. increase of the number of these active lymphocytes was observed not only in peripheral blood, but also in spleen, lung, kidney, and liver. when the number of lymphocytes was related to the amount of the organ tissue cells, the increment appeared significant only in the liver where the number of active lymphocytes exceeded ...19958768256
the unrelated surface proteins acta of listeria monocytogenes and icsa of shigella flexneri are sufficient to confer actin-based motility on listeria innocua and escherichia coli respectively.listeria monocytogenes and shigella flexneri are two unrelated facultative intracellular pathogens which spread from cell to cell by using a similar mode of intracellular movement based on continuous actin assembly at one pole of the bacterium. this process requires the asymmetrical expression of the acta surface protein in l. monocytogenes and the icsa (virg) surface protein in s. flexneri. acta and icsa share no sequence homology. to assess the role of the two proteins in the generation of act ...19958748026
the amino-terminal part of acta is critical for the actin-based motility of listeria monocytogenes; the central proline-rich region acts as a stimulator.the intracellular bacterial pathogen listeria monocytogenes moves inside the host-cell cytoplasm propelled by continuous actin assembly at one pole of the bacterium. this process requires expression of the bacterial surface protein acta. recently, in order to identify the regions of acta which are required for actin assembly, we and others have expressed different domains of acta by transfection in eukaryotic cells. as this type of approach cannot address the role of acta in the actin-driven bac ...19958748027
[listeria monocytogenes meningitis. description of a clinically significant case].meningitis caused by listeria monocytogenes is a rare affection: it develops from close contagion as professional illness (veterinarians, butchers) or in newborns by infected mothers; in indirect way for ingestion of contaminated food in subjects at high risk: elderly, immunosuppressed patients, alcoholics, diabetics. clinically it is not diversified from the other bacterial meningitises. in this paper we present a case of listeria monocytogenes meningitis in an adult female, without a sure occa ...19958684674
the cell biology of infection by intracellular bacterial pathogens.listeria monocytogenes and shigella flexneri are unrelated bacterial pathogens that have independently evolved similar strategies of survival within an infected host animal. bacteria coming into contact with the surface of an epithelial cell induce cytoskeletal rearrangements resulting in phagocytosis. they then secrete enzymes that degrade the phagosomal membrane, releasing the bacteria into the host cytoplasm. intracytoplasmic bacteria move rapidly, in association with a "comet tail" made up o ...19958689557
[the mechanism of induction and expression of protective immunity with special reference to the role of cytokines].the mechanism of induction of protective t cells mediating the anti-tuberculous immunity is not well elucidated. using viable and killed cells of mycobacterium bovis bcg and listeria monocytogenes, which differ in the ability to induce specific protection in mice, we have found that the difference is mainly due to the different ability to induce several cytokines especially ifn-rho not due to the difference in antigenic property. it was shown that the induction of protective t cells is highly de ...19958656590
listeria rhombencephalitis: report of two cases with early diagnosis and favourable outcome.we present 2 cases of listeria monocytogenes rhombencephalitis (l-re), both affecting previously healthy adult men. each of them developed a diphasic syndrome first characterized by fever, nausea and headache, followed, in a second phase, by severe brain stem dysfunction at the level of the pons, with meningism, multiple cranial nerve palsies, ataxia, and, in one case, seizures. the early examination of the cerebrospinal fluid (csf) demonstrated the presence of gram-positive bacilli whose typica ...19958599906
interleukin-4-producing cd4+ nk1.1+ tcr alpha/beta intermediate liver lymphocytes are down-regulated by listeria monocytogenes.experimental infection of mice with the intracellular bacterium, listeria monocytogenes, provides a paragon model for immune defence dominated by t helper type 1 (th1) responses. potent production of interleukin (il)-12 by infected macrophages is considered the determining factor in th1 cell development. in contrast, it is assumed that il-4 producers remain virtually unstimulated in listeriosis. in the liver, the major target organ of listeriosis, an unusual t lymphocyte population exists with t ...19958566018
an iron-dependent mutant of listeria monocytogenes of attenuated virulence.a bank of tn917-insertional mutants from the facultative intracellular pathogen listeria monocytogenes was screened by an original method based on bacterial growth on synthetic medium under iron-limiting conditions. one mutant, whose in vitro growth in synthetic medium was specifically dependent upon the availability of iron in its environment, was isolated and characterized. the insertional event occurred in a non-coding region, upstream of a rrn operon and located within a 1100-kb noti fragmen ...19958566716
stimulation of protective cd8+ t lymphocytes by vaccination with nonliving bacteria.infectious diseases caused by intracellular microbes are responsible for major health problems, and satisfactory control will ultimately depend on efficient vaccination strategies. the general assumption is that activation of protective immune responses against intracellular microbes dominated by cd8+ t cells are achieved only by live vaccines. in contrast, we here demonstrate stimulation of protective immunity in mice against the intracellular pathogen listeria monocytogenes by vaccination with ...19958618907
peripheral blood gamma delta t cells in human listeriosis.a phenotypical analysis carried out by direct immunofluorescence and two-colour cytofluorometry showed that the number of lymphocytes bearing the gamma delta t-cell receptor heterodimer was increased in the blood of eight children with listeria monocytogenes infection, mainly due to an expansion of cells identified by monoclonal antibodies which recognize v delta 2 gene products. these findings are further evidence that gamma delta t cells are in some way involved in the immune response directed ...19958645966
listeria monocytogenes arthritis of several joints.a patient with rheumatoid arthritis (ra) developed an infection caused by listeria monocytogenes in her left knee and both shoulder joints. the clinical presentation of the disease was rather indolent with relatively moderate joint symptoms. moreover, the synovial fluid sample was only slightly turbid with a white blood cell count of 23.5 x 10(9)/1. as compared to the earlier reported cases of l. monocytogenes septic arthritis, our patient is unique because she had infection in several joints. t ...19958610227
asymmetric distribution of the listeria monocytogenes acta protein is required and sufficient to direct actin-based motility.listeria monocytogenes is a gram-positive facultative intracytoplasmic bacterial pathogen that exhibits rapid actin-based motility in eukaryotic cells and in cell-free cytoplasmic extracts. the protein product of the acta gene is required for bacterial movement and is normally expressed in a polarized fashion on the bacterial surface. here we demonstrate that the acta protein is sufficient to direct motility in the absence of other l. monocytogenes gene products, and that polarized localization ...19958596443
frozen stored murine hybridoma cells can be used to determine the virulence of listeria monocytogenes.murine hybridoma cells, designated ped-2e9, when stored up to 60 days at -196 degrees c or up to 48 days at -80 degrees c, gave results equivalent to those for freshly grown murine hybridoma cells in an in vitro pathogenicity assay of listeria species. thus, laboratories do not need to have their own tissue culture facilities to maintain the hybridoma cells for the assay described.19958586737
[a new case of arterial listeria infection].listeria monocytogenes arterial infections are uncommon and usually occur on aneurysms of previously operated arteries, classically in very young and very old or immunodepressed subjects. peroperative samples for bacteriology should always be taken as antibiotics generally used in vascular surgery are ineffective against listeria. we report a case of a patient who underwent emergency surgery. bacteriologic analysis of the thrombus revealed listeria inoculation which was eradicated by adapted ant ...19958586958
rapid diagnosis of bacterial meningitis by a seminested pcr strategy.a polymerase chain reaction (pcr) based diagnostic assay has been developed for the simultaneous detection in cerebrospinal fluid (csf) of neisseria meningitidis, haemophilus influenzae, streptococcus pneumoniae, streptococcus agalactiae, listeria monocytogenes and bacteria in general. in the present communication we describe the design of primers for s. pneumoniae, s. agalactiae, and l. monocytogenes, and a general pcr protocol for the assay. the diagnostic outcome is presented for a small coll ...19958588152
the use of pcr ribotyping for typing strains of listeria spp.the potential of pcr ribotyping for discriminating between and within various species of listeria, as well as strains of listeria monocytogenes was examined. in total, 49 strains of listeria monocytogenes and 12 isolates of listeria spp. were analyzed. the genomic dna isolated from these strains was subjected to pcr amplification in the regions between 16s and 5s rrna. amplifications were performed with both low and high concentrations of taq polymerase. length polymorphisms in the amplified dna ...19958861851
[water disinfection: comparative activities of ozone and chlorine on a wide spectrum of bacteria].ozone and chlorine are agents that disinfect by destroying, neutralizing or inhibiting the growth of pathogenic microorganisms. the treatment of drinking water with ozone has shown to be more efficient against spores of bacillus subtilis. it was observed that the ozone already in dose of 0.35 mg/l produced the reduction of at least 5 log in populations of approximately 1 x 10(6) cells/ml of escherichia coli, vibrio cholerae, salmonella typhi, yersinia enterocolitica, pseudomonas aeruginosa, aero ...19958850129
[survival of listeria monocytogenes in milk fermented with a starter culture for making yogurt].the purpose of this research was to determine the survival of listeria monocytogenes in sterile skim milk during the fermentation with a yogurt starter culture and during storage at refrigeration temperature. sterile skim milk was inoculated with 10(3), 10(5) and 10(7) cfu/ml of l. monocytogenes and with 10(6) cfu of lactic acid bacteria. inoculated milks were fermented for 8 h at 42 degrees c, followed by refrigeration at 4 degrees c. samples were taken at 2 h intervals during fermentation and ...19958850344
activity of ci-960 alone and in combination with amoxycillin against listeria monocytogenes, and comparison with other quinolones.in-vitro activity of ci-960 against seven strains of listeria monocytogenes was compared to that of other fluoroquinolones. mics/mbcs were: ciprofloxacin and sparfloxacin: 0.5-2/1-4 mg/l;pd 131628: 0.125-0.5/0.25-2 mg/l; ci-960: 0.06-0.25/0.25-0.5 mg/l. at 4 h, ci-960 (4 x mic) reduced the inoculum (log10 cfu) by 2.88 +/- 0.61 compared with 1.78 +/- 0.48 for ciprofloxacin, 1.5 +/- 0.46 for sparfloxacin, and 1.35 +/- 0.47 for pd 131628 (p < 0.05). at 24 h, the bactericidal effects were similar (- ...19958830017
modulation of dna topology by flar, a new gene from listeria monocytogenes.we report the identification of a previously unknown listeria monocytogenes gene, flar, which modulates dna topology. through the analysis of a tn917 non-motile mutant, losc1, in which production of flagellin was abolished, we have identified a bacterial component involved in gene regulation. the transposon had inserted in flar, an open reading frame of 531 bp, followed by a second open reading frame of 1252 bp in reverse orientation. on the l. monocytogenes physical map, flar was located in a d ...19958825084
simultaneous detection of listeria spp. and listeria monocytogenes by reverse hybridization with 16s-23s rrna spacer probes.enzymatic amplification results showed that listeria species have at least two 16s-23s rrna spacer regions of different lengths. these spacer regions of l. monocytogenes, l. ivanovii and l. seeligeri were cloned after enzymatic amplification. sequence analysis of the inserts revealed two spacers of 245-246 bp and 496-498 bp, respectively, of which the latter included trna(ala) and trna(ile) genes. one listeria spp.-specific probe, lis-icg4, was deduced from the 245-bp spacer and a l. monocytogen ...19958808313
[hepatic listeriosis]. 19958749431
growth/survival of psychrotrophic pathogens on meat packaged under modified atmospheres. 19958750668
physiology of the osmotic stress response in microorganisms. 19958750669
acid adaptation and food poisoning microorganisms. 19958750670
membranes as a target for stress adaptation. 19958750671
probes and polymerase chain reaction for detection of food-borne bacterial pathogens.dna-hybridization and the polymerase chain reaction (pcr) are techniques commonly used to detect pathogenic bacteria. in this paper, the use of these techniques for detection of salmonella, e. coli, v. cholerae, non-o1 vibrio, yersinia enterocolitica, campylobacter, listeria monocytogenes, staphylococcus aureus, bacillus cereus, clostridium perfringens, and c. botulinum is reviewed with emphasis on application in food microbiology. in food control, dna-techniques have most often been used in a ' ...19958751091
the loss of contact inhibition and anchorage-dependent growth are key steps in the acquisition of listeria monocytogenes susceptibility phenotype by non-phagocytic cells.we have previously demonstrated that intestinal and kidney finite cell lines were resistant to l monocytogenes invasion (ie allowed low bacterial entry and no intracellular multiplication) in contrast to the continuous cell lines which were susceptible to listeria invasion (ie allowed high bacterial entry and intracellular multiplication) (velge et al (1994a) med microbial immunol 183, 145). the aim of this study was to discover whether epigenetic or genetic cellular modifications could convert ...19958882519
expression of an adenovirally encoded lymphotoxin-beta inhibitor prevents clearance of listeria monocytogenes in mice.the lymphotoxin (lt)-beta heterotrimer was recently identified as a molecule containing lt-alpha subunits, tethered to the cell through non-covalent association with an integral plasma membrane protein, derived from the lt-beta gene. since knockout mutations of the lt-alpha gene yield animals that lack lymph nodes, whereas animals lacking either or both of the receptors for tumor necrosis factor (tnf) and lt-alpha homotrimers have normal lymph nodes, it has been inferred that the association bet ...19958867668
differential induction of il12 synthesis by mycobacterium bovis bcg and listeria monocytogenes. 19958839156
simplified purification of listeria monocytogenes listeriolysin o and preliminary application in the enzyme-linked immunosorbent assay (elisa).a simplified procedure was developed for purification of listeriolysin o (llo) of listeria monocytogenes, consisting of hydroxylapatite adsorption chromatography followed by sepharose s ion exchange chromatography. the llo (58 kda) appeared pure in terms of sodium dodecylsulfate polyacrylamide electrophoresis and immunoblots with polyclonal rabbit immune sera. the purified llo could be stored at -65 degrees c for 1 year without loss of immunoreactivity. similarly, flat-bottom microtiter strips f ...19959810643
correlation between production of listeriolysin o by variants of listeria monocytogenes and their virulence for rabbits.l. monocytogenes serovar 1/2a nctc 7973 was passaged through rabbits and the severity of infection at each passage was determined by counting viable bacteria from infested organs and recording the time of death. a comparative evaluation of the levels of hemolysin produced in vitro by the original and six variant cultures (v1-v6) was done by determination of hemolytic units (chu). while virulence of the cultures enhanced at each passage (2.2 x 10(9) cfu/g of the spleen for v6 as compared to 5.0 x ...19959810660
[ecological and food safety considerations about products of vegetable origin].media have paid much attention in recent years to emerging microbiological problems in foods of plant origin. the potential for contamination of fruits and vegetables is high because of the wide variety of conditions to which produce is exposed during growth, harvest, processing and distribution. these considerations acquire great significance in the current scenario of the new processing techniques that offer attributes of convenience and fresh-likeness in response to changes in consumption pat ...19948984963
ventriculoperitoneal shunt infection due to listeria monocytogenes. 19947677812
incidence of listeria monocytogenes in pasteurized ice cream and soft cheese in costa rica, 1992. 19947480942
interactions with lectins and agglutination profiles of clinical, food, and environmental isolates of listeria.on the basis of preliminary trials with 14 collection strains of listeria, five lectins (canavalia ensiformis, concanavalin a; griffonia simplicifolia lectin i; helix pomatia agglutinin; ricinus communis agglutinin; and triticum vulgaris wheat germ agglutinin) were selected to set up a microtiter agglutination assay. the lectin agglutination profiles of 174 clinical, food, and environmental strains of listeria monocytogenes, listeria innocua, and listeria seeligeri were investigated. data on the ...19947883879
comparison of ribotyping and multilocus enzyme electrophoresis for subtyping of listeria monocytogenes isolates.ribotyping was compared with multilocus enzyme electrophoresis (mee) for subtyping 305 listeria monocytogenes isolates from clinical and nonclinical sources. for ribotyping, ecori-restricted genomic dna fragments of l. monocytogenes strains were separated by agarose gel electrophoresis, and southern blots were probed with a cloned escherichia coli rrnb operon (plasmid pkk3535) labeled with digoxigenin. the l. monocytogenes isolates were divided into 28 distinct ribotypes, while mee analysis divi ...19947883880
[the mixotrophy of pathogenic bacteria].this work deals with materials on the utilization of carbon dioxide and hydrogen from gas-air mixture by yersinia pseudotuberculosis and listeria monocytogenes in the process of their cultivation in hirsch's mineral medium. as follows from the data presented in these materials, the above-mentioned bacterial species are heterotrophic when the infectious process is reproduced in the body of warm-blooded animals and chemolithoautotrophic under the conditions of their life in environmental objects. ...19947879477
growth of listeria monocytogenes on vacuum-packed cooked meats: effects of ph, aw, nitrite and ascorbate.slices of cooked meats were inoculated with listeria monocytogenes strain murray b, vacuum-packed and stored at either 0 or 5 degrees c. decreases in ph (6.9-5.9) and aw (0.993-0.960; adjusted with sodium chloride) of the cooked meats increased the lag time and reduced the growth rate at 5 degrees c. the type of meat (beef, pork, chicken or turkey) had no effect on the growth of the organism after allowance was made for ph. sodium tripolyphosphate (0.3%) increased growth by increasing the ph of ...19947873338
estimation of bacterial growth rates from turbidimetric and viable count data.the relationship between maximum specific growth rates (mu max) determined from viable counts and turbidimetric measurements for a range of bacterial species is examined in order to assess the potential of turbidimetric methods in predictive microbiology. two methods for the estimation of mu max from turbidimetric data are presented. one is based on absorbance and the other on transmittance measurements. both are compared to estimates obtained by viable count methods. calibration factors, a func ...19947873339
naturally occurring virulence-attenuated isolates of listeria monocytogenes capable of inducing long term protection against infection by virulent strains of homologous and heterologous serotypes.experimental infections of mice with strains of listeria spp. isolated from contaminated food sources allowed discrimination of strains into those either exhibiting high, attenuated or low virulence. compared to the highly virulent l. monocytogenes strain egd, an attenuated strain such as l99 persisted for shorter times (5 versus 10 days) in the infected host. using a tissue culture cell model of infection, we found that, although strain l99 was capable of accumulating actin like its virulent co ...19947874073
evidence that gamma delta t cells play a limited role in resistance to murine listeriosis.a role for alpha beta and gamma delta t cells in protection against primary and secondary infection with listeria monocytogenes was studied. the results show that mice depleted of either gamma delta t cells with 3a10 monoclonal antibody (mab), or alpha beta t cells with anti-cd4 plus anti-cd8 mab, or both types of t cells, remained capable of controlling listeria multiplication during the first 4 days of primary sublethal infection. moreover, mice depleted of either or both types of t cells also ...19947875733
exploitation of microfilament proteins by listeria monocytogenes: microvillus-like composition of the comet tails and vectorial spreading in polarized epithelial sheets.effective cell-to-cell spreading of the facultative intracellular pathogen listeria monocytogenes requires the interaction between bacteria and the microfilament system of the host cell. by recruiting actin filaments into a 'comet tail' localized at one pole of the bacterial cell wall, listeria become mobile and propel themselves through the cytoplasm. they create protrusions at the plasma membrane that can invaginate adjacent cells. in this work, we have analysed the structural composition of l ...19947876360
Refresh
firstprev
...121122123124125126127128129130...
nextlast
Displaying items 12301 - 12400 of 16792