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effect of a matrix metalloproteinase inhibitor on host resistance against listeria monocytogenes infection.hydroxy acid-based matrix metalloproteinase (mmp) inhibitors have been shown to inhibit tumor infiltration and growth, endotoxin shock, and acute graft-versus-host disease. blockade of the release of soluble tumor necrosis factor-alpha (tnf-alpha) and cd95 ligand (cd95l; fasl) from cell-associated forms is reportedly involved in the mechanism of the drug effect. we investigated the effect of a mmp inhibitor, kb-r7785, on host resistance against listeria monocytogenes infection, in which tnf-alph ...200011064265
a pest-like sequence in listeriolysin o essential for listeria monocytogenes pathogenicity.establishment and maintenance of an intracellular niche are critical to the success of an intracellular pathogen. here, the pore-forming protein listeriolysin o (llo), secreted by listeria monocytogenes, was shown to contain a pest-like sequence (p, pro; e, glu; s, ser; t, thr) that is essential for the virulence and intracellular compartmentalization of this pathogen. mutants lacking the pest-like sequence entered the host cytosol but subsequently permeabilized and killed the host cell. llo lac ...200011062133
development of th1-type immune responses requires the type i cytokine receptor tccr.on antigen challenge, t-helper cells differentiate into two functionally distinct subsets, th1 and th2, characterized by the different effector cytokines that they secrete. th1 cells produce interleukin (il)-2, interferon-gamma (ifn-gamma) and lymphotoxin-beta, which mediate pro-inflammatory functions critical for the development of cell-mediated immune responses, whereas th2 cells secrete cytokines such as il-4, il-5 and il-10 that enhance humoral immunity. this process of t-helper cell differe ...200011057672
listeriosis in recipients of allogeneic bone marrow transplants from unrelated donors.two cases of listeriosis in patients submitted to matched unrelated donor bone marrow transplantation are reported. the patients developed listerial septicemia and listerial septicemia with meningitis and encephalitis 39 and 29 days after transplantation, respectively. including the present two cases, 19 listeria monocytogenes infections in related and unrelated donor allogeneic bone marrow transplant recipients have been reported to date. infection occurred earlier in unrelated donor transplant ...200011057507
low sensitivity of listeria monocytogenes to quaternary ammonium compounds.ninety-seven epidemiologically unrelated strains of listeria monocytogenes were investigated for their sensitivities to quaternary ammonium compounds (benzalkonium chloride and cetrimide). the mics for seven serogroup 1/2 strains were high. three came from the environment and four came from food; none were isolated from human or animal samples. all 97 strains carried the mdrl gene, which encodes a multidrug efflux pump, and the orfa gene, a putative transcriptional repressor of mdrl. the absence ...200011055967
growth limits of listeria monocytogenes as a function of temperature, ph, nacl, and lactic acid.models describing the limits of growth of pathogens under multiple constraints will aid management of the safety of foods which are sporadically contaminated with pathogens and for which subsequent growth of the pathogen would significantly increase the risk of food-borne illness. we modeled the effects of temperature, water activity, ph, and lactic acid levels on the growth of two strains of listeria monocytogenes in tryptone soya yeast extract broth. the results could be divided unambiguously ...200011055952
molecular epidemiological survey of listeria monocytogenes in seafoods and seafood-processing plants.to evaluate the role of seafoods in the epidemiology of human listeriosis and the role of the processing environment as a source of listeria monocytogenes in seafood products, 305 l. monocytogenes isolates were characterized by multilocus enzyme electrophoresis using 21 genetic loci and restriction enzyme analysis of total dna. forty-four isolates were recovered from patients in norway; 93 were isolated from seafoods, seafood-processing environments, and seawater from 55 different producers; and ...200011055923
identification and characterization of an atp binding cassette l-carnitine transporter in listeria monocytogenes.we identified an operon in listeria monocytogenes egd with high levels of sequence similarity to the operons encoding the opuc and opub compatible solute transporters from bacillus subtilis, which are members of the atp binding cassette (abc) substrate binding protein-dependent transporter superfamily. the operon, designated opuc, consists of four genes which are predicted to encode an atp binding protein (opuca), an extracellular substrate binding protein (opucc), and two membrane-associated pr ...200011055912
an elastic analysis of listeria monocytogenes propulsion.the bacterium listeria monocytogenes uses the energy of the actin polymerization to propel itself through infected tissues. in steady state, it continuously adds new polymerized filaments to its surface, pushing on its tail, which is made from previously cross-linked actin filaments. in this paper we introduce an elastic model to describe how the addition of actin filaments to the tail results in the propulsive force on the bacterium. filament growth on the bacterial surface produces stresses th ...200011053107
listeria and atypical presentations of listeria in the central nervous system.listeria monocytogenes infection of the central nervous system is often not recognized and treated appropriately in the crucial early stages of the disease. most consider patients with underlying disease or immunocompromised states to be at risk, although healthy individuals may present with a neurologic syndrome caused by l. monocytogenes. earlier suspicion and treatment remains our best means of reducing the morbidity and high mortality rate of this treatable disease. in addition to meningitis ...200011051300
kinetics of antibody production and clinical profiles of calves experimentally infected with listeria monocytogenes.clinical and serum antibody profiles were studied during oral listeria monocytogenes infection of calves. no clinical signs, except for pyrexia with mild diarrhoea and staggering gait, were observed in the infected calves. specific antibodies to listeriolysin o (llo) appeared as early as day 8 of an oral infection and peaked by days 16-32 of infection. antibodies to llo were observed to persist over the period of 126 days observed in the study. llo being a major virulence factor and capable of i ...200011048430
mhc class ib-restricted ctl provide protection against primary and secondary listeria monocytogenes infection.infection of b6 mice with the intracellular pathogen listeria monocytogenes (lm) results in the activation of cd8(+) t cells that respond to ag presented by both mhc class ia and class ib molecules. enzyme-linked immunospot analysis reveals that these ctl populations expand and contract at different times following a primary sublethal lm infection. between days 4 and 6 postinfection, class ib-restricted ctl exhibit a rapid proliferative response that is primarily h2-m3 restricted. the peak respo ...200011046052
genome organization and the evolution of the virulence gene locus in listeria species.the chromosomal region of listeria monocytogenes harboring the gene cluster prfa-plca-hly-mpl-acta-plcb (virulence gene cluster; vgc) harbors virulence genes critical for the survival of the bacteria following infection. previous studies have implicated it as an ancestral pathogenicity island, derivatives of which are present in the species l. ivanovii and l. seeligeri, but absent in non-pathogenic species such as l. innocua. we cloned the corresponding region from l. innocua and l. welshimeri a ...200011045921
listeria monocytogenes contamination pattern in pig slaughterhouses.ten low-capacity slaughterhouses were examined for listeria by collecting a total of 373 samples, of which 50, 250, and 73 were taken from carcasses, pluck sets, and the slaughterhouse environment, respectively. six slaughterhouses and 9% of all samples were positive for listeria monocytogenes. of the samples taken from pluck sets, 9% were positive for l. monocytogenes, the highest prevalence occurring in tongue and tonsil samples, at 14% and 12%, respectively. six of 50 (12%) carcasses were con ...200011041148
comparison of the attachment of escherichia coli o157:h7, listeria monocytogenes, salmonella typhimurium, and pseudomonas fluorescens to lettuce leaves.attachment of escherichia coli o157:h7, listeria monocytogenes, salmonella typhimurium, and pseudomonas fluorescens on iceberg lettuce was evaluated by plate count and confocal scanning laser microscopy (cslm). attachment of each microorganism (approximately 10(8) cfu/ml) on the surface and the cut edge of lettuce leaves was determined. e. coli o157:h7 and l. monocytogenes attached preferentially to cut edges, while p. fluorescens attached preferentially to the intact surfaces. differences in at ...200011041147
antimicrobial effect of rosemary extracts.a rosemary extract commercially exploited (oxy'less) as an antioxidant of lipids in foods was dissolved in ethanol (100 mg/ml), and the solution was tested against foodborne microorganisms. for gram-positive bacteria, the mic of the ethanolic solution was 1% for leuconostoc mesenteroides, 0.5% for listeria monocytogenes, 0.5% for staphylococcus aureus, 0.13% for streptococcus mutans, and 0.06% for bacillus cereus. it slowed the growth of penicillium roquefortii and botrytis cinerea. up to 1% of ...200011041135
surface application of lysozyme, nisin, and edta to inhibit spoilage and pathogenic bacteria on ham and bologna.a study was conducted to determine if the effectiveness of an antimicrobial treatment for cooked ham and bologna would be increased or maintained when applied in a surface coating. cooked 10-g disks of ham and bologna sausage received one of three treatments: no coating (control), coating with 0.2 g of 7% (wt/vol) gelatin gel (gel-control), or coating with 0.2 g of 7% gelatin gel containing 25.5 g/liter of lysozyme-nisin (1:3) plus 25.5 g/liter of edta (gel-treated). the samples were then inocul ...200011041132
infection and immunity in chronic lymphocytic leukemia.patients having chronic lymphocytic leukemia (cll) are at increased risk for infectious morbidity and mortality. the predisposition to infections in cll patients has many components, including both immunodeficiency related to the leukemia itself (humoral and cellular immune dysfunction) and the results of cumulative immunosuppression related to cll treatment. the risk of infectious complications increases with the duration of cll, reflecting the natural history of the disease and the cumulative ...200011040852
[a diagnostic medium for arcanobacterium haemolyticum and other bacterial species reacting with hemolytic synergism to the equi-factor of rhodococcus equi].colonies of arcanobacterium haemolyticum on common blood agar can be easily overlooked. therefore a diagnostic medium was developed, on which a. haemolyticum colonies produce a conspicuous zone of complete hemolysis. the medium under question is blood agar prepared from the columbia blood agar base and 5% washed sheep erythrocytes sensitised with equi factor (ef) of rhodococcus equi. optimally, 10 activity units (au) of ef per 1 ml were used. ef was titrated on a non-nutrient medium consisting o ...200011040494
effect of enterocin crl35 on listeria monocytogenes cell membrane.the antimicrobial peptide enterocin crl35, a class ii bacteriocin, produces at high concentrations (8 microg ml(-1)) localized holes in the wall and cellular membrane of listeria monocytogenes, reflected in the efflux of macromolecules such as proteins and other ultraviolet-absorbing materials. at lower concentrations (0.5 microg ml(-1)), neither ultra structural changes nor macromolecules efflux were observed, however potassium and phosphate ions were released, dissipating the proton motive for ...200011040432
[listeria monocytogenes: a rare cause of pleurisy]. 200011039180
altered membrane trafficking in activated bone marrow-derived macrophages.activation of macrophages with interferon-gamma (ifn-gamma) and lipopolysaccharide (lps) leads to increased intracellular resistance to microbes and increased major histocompatibility complex class ii-restricted antigen presentation, processes that both use the vacuolar compartment. despite the requirement of the macrophage vacuolar compartment for microbicidal activities and antigen processing, the rates of endocytosis and membrane trafficking in activated macrophages are not clearly defined. i ...200011037969
partially tap-independent protection against listeria monocytogenes by h2-m3-restricted cd8+ t cells.effective protection against listeria monocytogenes requires ag-specific cd8(+) t cells. a substantial proportion of cd8(+) t cells activated during l. monocytogenes infection of c57bl/6 mice are restricted by the mhc class ib molecule h2-m3. in this study, an h2-m3-restricted cd8(+) t cell clone specific for a known h2-m3 epitope (fmigwii) was generated from l. monocytogenes-infected mice. the clone was cytotoxic, produced ifn-gamma, and could mediate strong protection against l. monocytogenes ...200011035099
requirements for bone marrow-derived antigen-presenting cells in priming cytotoxic t cell responses to intracellular pathogens.bone marrow (bm)-derived antigen-presenting cells (apcs) are potent stimulators of t cell immune responses. we investigated the requirements for antigen presentation by these cells in priming cytotoxic t lymphocyte (ctl) responses to intracellular bacterial and viral pathogens. [parent-->f(1)] radiation bm chimeras were constructed using c57bl/6 donors and (c57bl/6 x balb/c)f(1) recipients. infection of chimeric mice with either listeria monocytogenes or vaccinia virus expressing the nucleoprote ...200011034603
bifidobacterium strains from resident infant human gastrointestinal microflora exert antimicrobial activity.the gastrointestinal microflora exerts a barrier effect against enteropathogens. the aim of this study was to examine if bifidobacteria, a major species of the human colonic microflora, participates in the barrier effect by developing antimicrobial activity against enterovirulent bacteria.200011034580
interaction of listeria monocytogenes with the intestinal epithelium.listeria monocytogenes is a food-borne pathogen that must cross the intestinal epithelial barrier to reach its target organs. we have investigated the importance of m cells in translocation using an experimental mouse model and a novel, recently described in vitro coculture system that mimics the follicle-associated epithelium (fae). our data demonstrate that l. monocytogenes does not require, nor specifically use, m cells of the fae to cross the gut. we also show that bacterial translocation is ...200011034299
[listeria monocytogenes: a dangerous pathogen used as a vector for the new generation of vaccines].listeria monocytogenes (lm) has become a major pathogen of human foodborne illnesses eliciting meningitis, peritonitis, and abortions with a mortality rate of about 30%. during the course of the disease, lm infects a variety of tissues and cell types due to its capacity to induce its own phagocytosis even into non-phagocytic cells. for over 35 years lm continues to serve as a model to define general paradigms of immunology in this review we focus on the clinical characteristics of listeriosis, o ...200011033885
effect of selenium deficiency on the development of central nervous system lesions in murine listeriosis.the effect of selenium (se) deficiency, produced by feeding a se-deficient diet, on the development of central nervous system (cns) lesions was studied in mice infected with listeria monocytogenes, administered in drinking water for 1 or 7 days in a daily dose of 10(9)organisms, or for 7 days in a daily dose of 10(7). se-deficient mice differed from se-normal controls in developing cns lesions significantly more frequently. moreover, regardless of se status, mice receiving repeated doses of 10(9 ...200011032662
gut feelings: enteropathogenic e. coli (epec) interactions with the host.enteropathogenic escherichia coli (epec) is a gram-negative bacterial pathogen that adheres to human intestinal epithelial cells, resulting in watery, persistent diarrhea. it subverts the host cell cytoskeleton, causing a rearrangement of cytoskeletal components into a characteristic pedestal structure underneath adherent bacteria. in contrast to other intracellular pathogens that affect the actin cytoskeleton from inside the host cytoplasm, epec remains extracellular and transmits signals throu ...200011031234
ciboulot regulates actin assembly during drosophila brain metamorphosis.a dynamic actin cytoskeleton is essential for the remodeling of cell shape during development, but the specific roles of many actin partners remain unclear. here we characterize a novel actin binding protein, ciboulot (cib), which plays a major role in axonal growth during drosophila brain metamorphosis. loss of cib function leads to axonal growth defects in the central brain, while overexpression of the gene during development leads to overgrown projections. the cib protein displays strong sequ ...200011030623
activation of the arp2/3 complex by the listeria acta protein. acta binds two actin monomers and three subunits of the arp2/3 complex.acta is a bacterially encoded protein that enables listeria monocytogenes to hijack the host cell actin cytoskeleton. it promotes arp2/3-dependent actin nucleation, but its interactions with cellular components of the nucleation machinery are not well understood. here we show that two domains of acta (residues 85-104 and 121-138) with sequence similarity to wasp homology 2 domains bind two actin monomers with submicromolar affinity. acta binds arp2/3 with a k(d) of 0.6 microm and competes for bi ...200111029465
a sheep in wolf's clothing: listeria innocua strains with teichoic acid-associated surface antigens and genes characteristic of listeria monocytogenes serogroup 4.listeria monocytogenes serotype 4b has been implicated in numerous food-borne epidemics and in a substantial fraction of sporadic listeriosis. a unique lineage of the nonpathogenic species listeria innocua was found to express teichoic acid-associated surface antigens that were otherwise expressed only by l. monocytogenes of serotype 4b and the rare serotypes 4d and 4e. these l. innocua strains were also found to harbor sequences homologous to the gene gtca, which has been shown to be essential ...200011029438
control of foodborne pathogens during sufu fermentation and aging.control of the foodborne pathogens escherichia coli o157:h7, salmonella typhimurium, staphylococcus aureus, and listeria monocytogenes during sufu fermentation was evaluated. before fermentation, pathogens were inoculated onto tofu (substrate for sufu) at 5 log cfu/g or 3 log cfu/g, and starter culture (actinomucor elegans) was inoculated at 3 log cfu/g. after 2 days of fermentation at 30 degrees c, the four pathogens reached 7 to 9 log cfu/g, and the mold count reached 6 to 7 log cfu/g. after f ...200011029011
synergistic inhibition of listeria monocytogenes on cold-smoked rainbow trout by nisin and sodium lactate.the inhibition of listeria monocytogenes and mesophilic aerobic bacteria in cold-smoked rainbow trout by nisin, sodium lactate or their combination was studied. nisin (4000-6000 iu/ml), sodium lactate (60%) or their combination (1:1) were injected into rainbow trout at an industrial scale before the smoking process, or injected into the finished smoked product. both types of fish samples were smoked, sliced and vacuum-packed according to normal practice in the plant. packages were opened and l. ...200011028960
maillard reaction causes suppression of virulence gene expression in listeria monocytogenes.many environmental signals affect the expression of virulence genes of the food borne pathogen listeria monocytogenes. in addition media composition has been shown to suppress levels of haemolytic activity. using a pr(plca)::luxab reporter gene fusion it was observed that the heat processing of media also reduces the level of virulence gene expression in l. monocytogenes without affecting its growth. physicochemical factors that are considered to enhance the maillard reaction were also found to ...200011028958
application of polynomial models to predict growth of mixed cultures of pseudomonas spp. and listeria in meat.three models for one rapid and one slow growing strain of pseudomonas fragi and one slow growing strain of p. fluorescens were developed in a meat broth; they were designed to take account of variations in growth and to provide a growth response interval. these models, and another for listeria monocytogenes (lm14 model), were used to predict the growth of spoilage pseudomonas spp. and pathogenic listeria in meat products. the pseudomonas and listeria models provided satisfactory predictions conc ...200011028957
neurolisteriosis presenting as recurrent transient ischemic attacks.an elderly man experienced recurrent transient episodes of right arm weakness and expressive aphasia. he was initially treated with aspirin and then with coumadin. thirteen days after initial presentation, he became febrile and had signs of meningitis. the illness progressed relentlessly to death 9 weeks after admission to the hospital. necropsy showed prominent meningitis with vasculitis extending into the left frontal lobe. polymerase chain reaction identified the organism as listeria monocyto ...200011026451
induction of human immunodeficiency virus (hiv)-specific cd8 t-cell responses by listeria monocytogenes and a hyperattenuated listeria strain engineered to express hiv antigens.induction of cell-mediated immunity may be essential for an effective aids vaccine. listeria monocytogenes is an attractive bacterial vector to elicit t-cell immunity to human immunodeficiency virus (hiv) because it specifically infects monocytes, key antigen-presenting cells, and because natural infection originates at the mucosa. immunization with recombinant l. monocytogenes has been shown to protect mice from lymphocytic choriomeningitis virus, influenza virus, and tumor inoculation. l. mono ...200011024127
cloning, sequencing and characterisation of a listeria monocytogenes gene encoding a fibronectin-binding protein.listeria monocytogenes is a gram-positive, non-sporulating food-borne pathogen of man and animals that is able to invade many eukaryotic cells. l. monocytogenes possesses several proteins that bind fibronectin. in this study, an l. monocytogenes dna library in puc19 was screened with fibronectin and a gene encoding a 24.6-kda fibronectin-binding protein (fbp) was isolated and sequenced. transcripts of the fbp gene were found in wild-type, in deltaprfa, and prfa-s183a strains, despite the presenc ...200011023185
comparison between the growth of yersinia enterocolitica, listeria monocytogenes, escherichia coli o157:h7 and salmonella spp. in ground beef packed by three commercially used packaging techniques.growth of the pathogens yersinia enterocolitica, listeria monocytogenes, escherichia coli o157:h7 and strains of salmonella were compared in ground beef packed in modified atmospheres of 60% co2/40% n2/0.4% co (high co2/low co mixture), 70% o2/30% co2 (high o2 mixture) and in chub packs (stuffed in plastic casings). the ground beef was inoculated with rifampicin-resistant or nalidixic acid/streptomycin-resistant strains of the pathogens (final concentration 10(2) - 10(3) bacteria/g) and stored a ...200011020041
structural model requirements to describe microbial inactivation during a mild heat treatment.the classical concept of d and z values, established for sterilisation processes, is unable to deal with the typical non-loglinear behaviour of survivor curves occurring during the mild heat treatment of sous vide or cook-chill food products. structural model requirements are formulated, eliminating immediately some candidate model types. promising modelling approaches are thoroughly analysed and, if applicable, adapted to the specific needs: two models developed by casolari (1988), the inactiva ...200011020040
predictions of growth for listeria monocytogenes and salmonella during fluctuating temperature.we studied the predictive performance of a dynamic modelling approach, combined with predictions from the food micromodel software, applied to the growth of listeria monocytogenes and salmonella in pasteurised milk, chicken liver pâté and minced chicken, under constant as well as fluctuating temperatures. we found that, in general, the accuracy of a prediction under fluctuation temperature was similar to that under constant temperature. generally, there was a good agreement between predictions a ...200011020037
polymerase chain reaction for the laboratory diagnosis of aseptic meningitis and encephalitis.a protocol for testing cerebrospinal fluid specimens using a range of pcr assays for the diagnosis of central nervous system infection was developed and used to test prospectively 383 specimens. pcr assays were used for the detection of adenovirus, borrelia burgdorferi, enteroviruses, epstein barr virus, cytomegalovirus, herpes simplex virus, human herpes virus type 6, jc virus, leptospira interrogans, listeria monocytogenes, lymphocytic choriomeningitis virus, measles virus, mumps virus, mycoba ...200011018820
foodborne listeriosis.listeria monocytogenes emerged as an important foodborne pathogen in the latter part of the 20th century. clinical syndromes caused by this microorganism include sepsis in the immunocompromised patient, meningoencephalitis in infants and adults, and febrile gastroenteritis. focal infections at other sites are less frequent. listeria species are commonly found in raw and unprocessed food products. major outbreaks of listeriosis, with high morbidity and mortality, have been caused by a variety of ...200011017828
analysis of the role of betl in contributing to the growth and survival of listeria monocytogenes lo28.survival of the food-borne pathogen listeria monocytogenes in environments of elevated osmolarity and reduced temperature is attributed, at least in part, to the accumulation of the trimethylammonium compound glycine betaine. previously we identified betl, a gene encoding the secondary glycine betaine transporter betl, which we linked to the salt tolerance of listeria. in this report, we demonstrate that betl, preceded by a consensus sigmab-dependent promoter, is regulated by osmotic up-shock, a ...200011016615
new developments in chromogenic and fluorogenic culture media.this review describes some recent developments in chromogenic and fluorogenic culture media in microbiological diagnostic. the detection of beta-d-glucuronidase (gud) activity for enumeration of escherichia coli is well known. e. coli o157:h7 strains are usually gud-negative and do not ferment sorbitol. these characteristics are used in selective media for these organisms and new chromogenic media are available. some of the new chromogenic media make the salmonella diagnostic easier and faster. ...200011016610
analysis of the role of the listeria monocytogenes f0f1 -atpase operon in the acid tolerance response.as little is known about the genes involved in the induction of an acid tolerance response in listeria monocytogenes, the role of the f0f1-atpase was analyzed as a consequence of its role in the acid tolerance of a number of other bacteria and its conserved nature. it was found that acid adapted cells treated with n,n'-dicyclohexylcarbodiimide (dccd) exhibited greatly enhanced sensitivity to low ph stress. degenerate primers were designed to amplify and sequence a portion of the atpd gene. subse ...200011016603
interferon gamma signaling alters the function of t helper type 1 cells.one mechanism regulating the ability of different subsets of t helper (th) cells to respond to cytokines is the differential expression of cytokine receptors. for example, th2 cells express both chains of the interferon gamma receptor (ifn-gammar), whereas th1 cells do not express the second chain of the ifn-gammar (ifn-gammar2) and are therefore unresponsive to ifn-gamma. to determine whether the regulation of ifn-gammar2 expression, and therefore ifn-gamma responsiveness, is important for the ...200011015439
absence of serotype-specific surface antigen and altered teichoic acid glycosylation among epidemic-associated strains of listeria monocytogenes.outbreaks of food-borne listeriosis have often involved strains of serotype 4b. examination of multiple isolates from three different outbreaks revealed that ca. 11 to 29% of each epidemic population consisted of strains which were negative with the serotype-specific monoclonal antibody c74.22, lacked galactose from the teichoic acid of the cell wall, and were resistant to the serotype 4b-specific phage 2671.200011015420
subchronic silica exposure enhances respiratory defense mechanisms and the pulmonary clearance of listeria monocytogenes in rats.both listeria monocytogenes infection and silica exposure have been shown to significantly alter immune responses. in this study, we evaluated the effect of preexposure to silica on lung defense mechanisms using a rat pulmonary l. monocytogenes infection model. male sprague-dawley rats were instilled intratracheally with saline (vehicle control) or silica using either an acute treatment regimen (5 mg/kg; 3 days) or a subchronic treatment protocol (80 mg/kg; 35 days). at 3 or 35 days after silica ...200011015141
interactions of high hydrostatic pressure, pressurization temperature and ph on death and injury of pressure-resistant and pressure-sensitive strains of foodborne pathogens.the objective of this study is to determine the interactions between high hydrostatic pressure, pressurization temperature, time and ph during pressurization on death and injury of pressure-resistant and pressure-sensitive strains of four foodborne pathogens: staphylococcus aureus 485 and 765, listeria ,monocytogenes ca and oh2, escherichia coli o157:h7 933 and 931, salmonella enteritidis fda and salmonella typhimurium e21274. among these strains s. aureus 485, l. monocytogenes ca, e. coli o157: ...200011014520
the contribution of both oxygen and nitrogen intermediates to the intracellular killing mechanisms of c1q-opsonized listeria monocytogenes by the macrophage-like ic-21 cell line.listeria monocytogenes is a facultative intracellular pathogen which is internalized by host mammalian cells upon binding to their surface. further listerial growth occurs in the cytosol after escape from the phagosomal-endosomal compartment. we have previously reported that c1q is able to potentiate l. monocytogenes phagocytosis upon bacterial opsonization by ingestion through c1q-binding structures. in this report, we analysed the post-phagocytic events upon internalization of c1q-opsonized l. ...200011012757
improved template preparation for pcr-based assays for detection of food-borne bacterial pathogens.shigella flexneri, salmonella enterica serotype typhimurium, and listeria monocytogenes were applied to fta filters, and the filters were used directly as templates to demonstrate their sensitivity and applicability in pcr-based detection assays. with pure cultures, the sensitivities of detection by fta filter-based pcr were 30 to 50 and 200 cfu for the gram-negative enterics and listeria, respectively. different numbers of s. flexneri cells were used in controlled contamination experiments with ...200011010913
cold shock and its effect on ribosomes and thermal tolerance in listeria monocytogenes.differential scanning calorimetry (dsc) and fatty acid analysis were used to determine how cold shocking reduces the thermal stability of listeria monocytogenes. additionally, antibiotics that can elicit production of cold or heat shock proteins were used to determine the effect of translation blockage on ribosome thermal stability. fatty acid profiles showed no significant variations as a result of cold shock, indicating that changes in membrane fatty acids were not responsible for the cold sho ...200011010881
cold shock induction of thermal sensitivity in listeria monocytogenes.cold shock at 0 to 15 degrees c for 1 to 3 h increased the thermal sensitivity of listeria monocytogenes. in a model broth system, thermal death time at 60 degrees c was reduced by up to 45% after l. monocytogenes scott a was cold shocked for 3 h. the duration of the cold shock affected thermal tolerance more than did the magnitude of the temperature downshift. the z values were 8.8 degrees c for controls and 7.7 degrees c for cold-shocked cells. the d values of cold-shocked cells did not return ...200011010880
use of two-dimensional electrophoresis to study differential protein expression in divercin v41-resistant and wild-type strains of listeria monocytogenes.the use of bacteriocins from food-grade lactic acid bacteria to fight against the food-borne pathogen listeria monocytogenes has been gaining interest. however, the emergence of resistant cells is frequently reported when listeria is exposed to such antibacterials. a two-dimensional electrophoresis study of whole-cell protein expression of listeria monocytogenes variants sensitive or resistant to the action of a bacteriocin produced by carnobacterium divergens v41, divercin v41, is reported in t ...200011010876
application of 5'-nuclease pcr for quantitative detection of listeria monocytogenes in pure cultures, water, skim milk, and unpasteurized whole milk.pcr techniques have significantly improved the detection and identification of bacterial pathogens. countless adaptations and applications have been described, including quantitative pcr and the latest innovation, real-time pcr. in real-time pcr, e.g., the 5'-nuclease chemistry renders the automated and direct detection and quantification of pcr products possible (p. m. holland et al., proc. natl. acad. sci. usa 88:7276-7280, 1991). we present an assay for the quantitative detection of listeria ...200011010869
interleukin-18 (il-18) and infectious diseases, with special emphasis on diseases induced by intracellular pathogens.interleukin-18 (il-18) is a novel cytokine mainly produced by activated macrophages. il-18 was originally called interferon-gamma inducing factor, due to its action in inducing ifn-gamma secretion from th1 cells, nk cells and nkt cells. it has been reported that il-18 may play important roles in various diseases including cancer and infectious diseases. this review deals with the roles of il-18 in infectious diseases, with special emphasis on il-18 in infectious diseases caused by intracellular ...200011008115
bacterial penetration across the blood-brain barrier during the development of neonatal meningitis.bacterial pathogens may breach the blood-brain barrier (bbb) and invade the central nervous system through paracellular and/or transcellular mechanisms. transcellular penetration, e.g., transcytosis across the bbb has been demonstrated for escherichia coli k1, group b streptococcus, listeria monocytogenes, citrobacter freundii and streptococcus pneumonia strains. genes contributing to invasion of brain microvascular endothelial cells include e. coli k1 genes ompa, ibea, ibeb, and yijp. understan ...200011008113
identification in listeria monocytogenes of meca, a homologue of the bacillus subtilis competence regulatory protein.we identified in listeria monocytogenes a gene encoding a protein homologous to meca, a regulatory protein acting with clpc and comk in the competence pathway of bacillus subtilis. in l. monocytogenes, meca is involved, along with clpc and clpp, in the downregulation of a 64-kda secreted protein. in b. subtilis, the meca protein of l. monocytogenes behaves as a regulatory protein, controlling the transcription of comk and comg. complete or disrupted comk homologues were also found in l. monocyto ...200011004200
cloning, sequence analysis, and expression of lactobacillus casei phage pl-1 lysis genes.the genes encoding the host cell wall-lytic proteins were searched in the genome dna of phage pl-1 active against lactobacillus casei atcc 27092 by comparing the amino acid sequences with those of others using a computer software of the ddbj data base. the gene regions found were cloned into e. coli by inserting pcr-amplified dna fragments into the ecori site of puc 19, and the nucleotide sequences were determined. one of the orfs (hol) consisted of 270 bp encoding 90 amino acids. the hol produc ...200011003466
delivery of protein antigens and dna by virulence-attenuated strains of salmonella typhimurium and listeria monocytogenes.two different plasmid-vector systems were developed which allow the efficient production and presentation of protein antigens in antigen-presenting cells (apc) by means of virulence-attenuated bacteria. the first antigen-delivery system is based on the secretion machinery of the escherichia coli hemolysin (hlya-type i secretion system), which transports proteins, possessing the specific hlya secretion signal (hlya(s)) at the c-terminus, across both membranes of gram-negative bacteria. this syste ...200011000455
comparative genomics of the late gene cluster from lactobacillus phages.three prophage sequences were identified in the lactobacillus johnsoni strain ncc533. prophage lj965 predicted a gene map very similar to those of pac-site streptococcus thermophilus phages over its dna packaging and head and tail morphogenesis modules. sequence similarity linked the putative dna packaging and head morphogenesis genes at the protein level. prophage lj965/s. thermophilus phage sfi11/lactococcus lactis phage tp901-1 on one hand and lactobacillus delbrueckii phage ll-h/lactobacillu ...200010998330
insertional knock-out of protein translocation systems common for yersinia enterocolitica and listeria monocytogenes.to carry out efficient insertional mutagenesis in listeria monocytogenes and to facilitate the characterisation of disrupted genes, a novel derivative of plasmid pacyc 184 was constructed, pliv vira3, carrying a fragment from the vira region of the of y. enterocolitica plasmid pyve 0:9. after transformation of this plasmid into l. monocytogenes it was possible to select for its integration into the host dna at 42 degrees c. insertional mutants of l. monocytogenes obtained by using pliv vector co ...200010997489
vidas enzyme-linked immunoflourescent assay for detection of listeria in foods: collaborative study.the vidas lis method and the traditional culture methods for detection of listeria species in food were evaluated in a multilaboratory comparative study. the 6 foods tested were either naturally contaminated or inoculated with 3 different concentrations of listeria. results for each food and each contamination level with the vidas lis method were as good as or better than those obtained with the traditional culture method. of 1558 samples tested, 935 were positive: 839 by the vidas method and 80 ...200010995115
presence of bacterial 16s ribosomal rna gene segments in human intestinal lymph follicles.there is currently no information regarding microbial agents inside the intestinal lymph follicles.200010994621
activation of host phospholipases c and d in macrophages after infection with listeria monocytogenes.infection of the j774 murine macrophage-derived cell line with listeria monocytogenes results in several elevations of intracellular calcium during the first 15 min of infection. these appear to result from the actions of secreted bacterial proteins, including phosphatidylinositol-specific phospholipase c (pi-plc), a broad-range phospholipase c, and listeriolysin o (llo) (s. j. wadsworth and h. goldfine, infect. immun. 67:1770-1778, 1999). we have measured hydrolysis of host pi and the activatio ...200010992479
dual epitope recognition by the vasp evh1 domain modulates polyproline ligand specificity and binding affinity.the ena-vasp family of proteins act as molecular adaptors linking the cytoskeletal system to signal transduction pathways. their n-terminal evh1 domains use groups of exposed aromatic residues to specifically recognize 'fpppp' motifs found in the mammalian zyxin and vinculin proteins, and acta protein of the intracellular bacterium listeria monocytogenes. here, evidence is provided that the affinities of these evh1-peptide interactions are strongly dependent on the recognition of residues flanki ...200010990454
[prevention of listeria infections].listeriosis is a rare but very serious foodborne disease. the non-contamination of food products is the best prevention of listeriosis. in spite of notable efforts to improve the microbiologic quality of food products through surveillance and control of food contaminations, the prevention has still to be based upon the information of consumers. this information can take different forms. when a food product is found to be contaminated with listeria monocytogenes, if the withdrawal of this product ...200010989539
[epidemiology of human listeria infections in france].human listeriosis is a relatively rare but serious disease with case fatality rates between 20 and 30%. the majority of patients who have listeriosis present with meningitis or septicaemia. listeriosis during pregnancy can lead to a congenital infection, neonatal sepsis and meningitis or foetal death. the main mode of transmission is through contaminated foods. the infection usually occurs sporadically but small outbreaks and even large epidemics have occurred in a large number of industrialised ...200010989536
myosin light chain kinase plays an essential role in s. flexneri dissemination.shigella flexneri, the causitive agent of bacillary dysentery, has been shown to disseminate in colonic epithelial cells via protrusions that extend from infected cells and are endocytosed by adjacent cells. this phenomenon occurs in the region of the eukaryotic cell's adherens junctions and is inhibited by pharmacological reagents or host cell mutations that completely disrupt the junctional complex. in this study, inhibitors of the myosin light chain kinase (mlck) were shown to dramatically de ...200010984429
use of oleic acid to reduce the population of the bacterial flora of poultry skin.the effect of oleic acid on native bacterial flora of poultry skin was examined. skin from commercial broiler carcasses was washed once or twice in solutions of 0, 2, 4, 6, 8, or 10% (wt/vol) oleic acid and rinsed in peptone water. aerobic bacteria, enterobacteriaceae, campylobacter, and enterococci in the rinsates were enumerated. significantly fewer aerobic bacteria, enterobacteriaceae, campylobacter, and enterococci were recovered from rinsates of skin washed in oleic acid than from control s ...200010983807
incidence and seasonal variation of listeria species in bulk tank goat's milk.four hundred and fifty raw goat's milk samples obtained from the bulk tanks of 39 goat farms were analyzed for listeria spp. over a 1-year period. modified versions of the u.s. department of agriculture food safety and inspection service (usda-fsis) and food and drug administration (fda) protocols were used for recovery of listeria. overall, 35 (7.8%) samples yielded listeria spp. with listeria monocytogenes identified in 17 of the 35 (3.8%) listeria-positive samples. listeria innocua was detect ...200010983794
persistent listeria monocytogenes strains show enhanced adherence to food contact surface after short contact times.adherence of 3 persistent and 14 nonpersistent listeria monocytogenes strains to stainless steel surfaces after short and long contact times was investigated. l. monocytogenes strains were obtained from poultry plants and an ice cream plant throughout several years. adherence tests were performed in tryptic soy broth at 25 degrees c for 1, 2, and 72 h. test surfaces were rinsed after the contact time, and attached cells were stained with acridine orange and enumerated with an epifluorescence mic ...200010983793
the main cold shock protein of listeria monocytogenes belongs to the family of ferritin-like proteins.the transfer of the food-borne pathogen listeria monocytogenes from 30 to 5 degrees c was characterized by the sharp induction of a low molecular mass protein. this major cold shock protein has an isoelectric point at ph 5.1 and a molecular mass of about 18 kda, as observed on two-dimensional gel electrophoresis (2-de) pattern. its n-terminal sequence, obtained from the 2-de spot, shared a complete sequence identity with a listeria innocua non-heme iron-binding ferritin. the purification of thes ...200010981685
[enterocin-35, a bacteriocin with activity against listeria monocytogenes. possible use in the food industry].the in vitro inhibitory activity of enterocin-35 produced by enterococcus faecium crl 35, was studied against listeria monocytogenes, isolated from seafoods. optimal growth conditions of the enterocin-35 producing strain, for higher bacteriocin production and improve the extraction and purification of these peptides, were applied. a crude extract of enterocin-35 was assayed in a frozen seafood artificially contaminated with listeria monocytogenes isolate, simulating at laboratory scale an eventu ...199910979837
etiologic spectrum and pattern of antimicrobial drug susceptibility in bacterial meningitis in sokoto, nigeria.etiologic agents of meningitis were prospectively investigated among patients admitted to usman danfodio university teaching hospital, sokoto. of 1097 cerebrospinal fluid (csf) samples submitted to the microbiology laboratory from various wards of the hospital, 289 (26%) were microscopically, culturally and/or serologically proven to be bacterial meningitis. the etiologic spectrum was as follows: neisseria meningitidis (61%), streptococcus pneumoniae (18%), haemophilus influenzae (10%), staphylo ...200010976835
regulation of growth inhibition at high temperature, autolysis, transformation and adherence in streptococcus pneumoniae by clpc.the clpc atpase is a subfamily of hsp100/clp molecular chaperones-regulators of proteolysis. by screening a library of loss of function mutants for the ability to survive treatment with penicillin, we identified the gene clpc. the corresponding protein was identified as a clpc atpase, sharing strong peptide sequence identity with clpc of bacillus subtilis, listeria monocytogenes and lactococcus lactis. northern blot experiments showed that expression of clpc was induced in response to high tempe ...200010972795
selective amplification of bacterial rna: use of a dna primer containing mismatched bases near its 3' terminus to reduce false-positive signals.a reverse transcription pcr (rt-pcr) method designed to reduce false-positive results due to the co-amplification of contaminating genomic dna is reported. feasibility of the method was evaluated using 16s rrna sequences specific to bacillus cereus. a dna oligonucleotide primer, consisting of 22-bases containing three consecutive mismatched bases near its 3' terminus (primer b16rt), was used for reverse transcription and in subsequent cdna amplification. specific rrna was reverse transcribed at ...200010972726
a small outbreak of listeriosis potentially linked to the consumption of imitation crab meat.a small outbreak of listeriosis involving two previously healthy adults occurred in ontario. food samples obtained from the refrigerator of the patients included imitation crab meat, canned black olives, macaroni and vegetable salad, spaghetti sauce with meatballs, mayonnaise and water. all of the samples except the water contained listeria monocytogenes. the three most heavily contaminated samples were the imitation crab meat, the olives and the salad which contained 2.1 x 109, 1.1 x 107 and 1. ...200010972708
combined action of s-carvone and mild heat treatment on listeria monocytogenes scott a.the combined action of the plant-derived volatile, s-carvone, and mild heat treatment on the food-borne pathogen, listeria monocytogenes, was evaluated. the viability of exponential phase cultures grown at 8 degrees c could be reduced by 1.3 log units after exposure to s-carvone (5 mmol l-1) for 30 min at 45 degrees c, while individual treatment with s-carvone or exposure to 45 degrees c for 30 min did not result in a loss in viability. other plant-derived volatiles, namely carvacrol, cinnamalde ...200010971762
the effect of culture growth phase on induction of the heat shock response in yersinia enterocolitica and listeria monocytogenes.the effect of culture growth phase on induction of the heat shock response in yersinia enterocolitica and listeria monocytogenes, was examined. exponential or stationary preconditioned cultures were heat shocked and survivor numbers estimated using selective and overlay/resuscitation recovery techniques. the results indicate that prior heat shock induced increased heat resistance in both micro-organisms to higher heat treatments. heat-shocked cells of each micro-organism were able to survive muc ...200010971751
acid tolerance in listeria monocytogenes influences invasiveness of enterocyte-like cells and macrophage-like cells.clinical and food listeria monocytogenes isolates, pre-exposed to mild acidic conditions, were able to readily develop acid tolerance, irrespective of their origin. we attempted to investigate the influence of acid tolerance mechanisms, either constitutive or induced, on the invasive behaviour of this facultative food-borne pathogen. entry efficiency and intracellular growth of acid-tolerant strains were evaluated in in vitro cell models capable to mimic in vivo target cells, such as enterocytes ...200010968945
listeria monocytogenes in faeces from clinically healthy dairy cows in sweden.faecal samples from 102 clinically healthy dairy cows, representing 34 farms in the swedish province of uppsala, were analysed for the presence of listeria spp. using an enrichment procedure. listeria monocytogenes was isolated from six (6%) and l. innocua from 2 (2%) cows. from each of the 6 samples positive for l. monocytogenes, 5 isolates were further characterised by restriction enzyme analysis using the 3 enzymes apa i, sma i, and asc i, followed by pulsed-field gel electrophoresis. three o ...200010965567
a role for alpha-and beta-catenins in bacterial uptake.interaction of internalin with e-cadherin promotes entry of listeria monocytogenes into human epithelial cells. this process requires actin cytoskeleton rearrangements. here we show, by using a series of stably transfected cell lines expressing e-cadherin variants, that the ectodomain of e-cadherin is sufficient for bacterial adherence and that the intracytoplasmic domain is required for entry. the critical cytoplasmic region was further mapped to the beta-catenin binding domain. because beta-ca ...200010963665
[neurological complications of renal transplant].advances in surgical procedures and new immunosuppressor therapies have improved the outcome of renal grafts. however, these changes have been accompanied by infectious, neoplastic and neurologic complications. the purpose of this study was to determine the incidence of neurologic complications among 542 patients receiving a renal transplant (from living or cadaveric donors) at cemic between 1970 and 1996. neurologic complications occurred in 43 patients (8%) as follows: 8 meningitis (1.5%), 8 a ...200010962803
trimethoprim-sulfamethoxazole salvage for refractory listeriosis during maintenance chemotherapy for acute lymphoblastic leukemia.a 5-year-old boy with acute lymphoblastic leukemia (all) and intolerance to oral trimethoprim-sulfamethoxazole (tmp/smx) had listeria monocytogenes bacteremia and meningitis develop during maintenance chemotherapy. despite prompt administration of iv amoxicillin/gentamicin and microbiologic clearance of the bloodstream, the patient had no response to therapy after a course of 7 days. intravenous tmp/smx (10 mg/kg per day of tmp) was added to the antibiotic regimen after desensitization. fever an ...200010959905
glycidol modulation of the immune responses in female b6c3f1 mice.the immunotoxic potential of glycidol was evaluated in female b6c3f1 mice using a battery of functional assays and three host resistance models. glycidol was administered to the animals by oral gavage as a solution in sterile distilled water daily for 14 days at doses of 25, 125 and 250 mg/kg. in tier i, we observed that glycidol exposure produced a dose-related decrease in splenocyte igm antibody-forming cell response to sheep red blood cells (srbc); the spleen natural killer (nk) cell activity ...200010959546
[listeria monocytogenes infections--ten years' experience].7 cases of listeriosis were diagnosed here between 1988-1997 (6 in last 3 years), or 2.94/100,000 admissions. 2 elderly patients suffered from meningitis and 2 pregnant women presented with premature contractions, 1 of whom delivered a premature, infected baby. 2 other patients had fever and gastroenteritis. listeria monocytogenes was isolated from blood in 4, csf in 2 and the placenta in 1. it was isolated from those with bacterial meningitis. all patients recovered. both increased awareness fo ...199910959337
application of a chromogenic medium and the pcr method for the rapid confirmation of l. monocytogenes in foodstuffs.detection of listeria monocytogenes in foodstuffs by conventional cultivation methods carried out according to en iso guidelines is rather time-consuming. therefore, two alternative methods were applied for rapid confirmation of l. monocytogenes in foodstuffs. inoculum from liquid selective broth was plated on palcam and oxford agar and on chromogenic agar medium rapid l. mono. suspect colonies from palcam were confirmed according to en iso standards and by the multiplex pcr method. in total, 99 ...200010958972
interactions between listeria monocytogenes and host mammalian cells.bacterial pathogens have developed a variety of strategies to induce their own internalization into mammalian cells which are normally nonphagocytic. the gram-positive bacterium listeria monocytogenes enters into many cultured cell types using two bacterial surface proteins, inla (internalin) and inlb. in both cases, entry takes place after engagement of a receptor and induction of a series of signaling events.200010955961
[listeria monocytogenes--the bacterium, mode of transmission and relation to food consumption]. 199910955096
mutations of arginine residues within the 146-kkrrk-150 motif of the acta protein of listeria monocytogenes abolish intracellular motility by interfering with the recruitment of the arp2/3 complex.the recruitment of actin to the surface of intracellular listeria monocytogenes and subsequent tail formation is dependent on the expression of the bacterial surface protein acta. of the different functional domains of acta identified thus far, the n-terminal region is absolutely required for actin filament recruitment and intracellular motility. mutational analysis of this domain which abolished actin recruitment by intracellular listeria monocytogenes identified two arginine residues within th ...200010954425
an updated model of cell-mediated immunity--listeriosis: clinical and research aspects.listeria monocytogenes causes sepsis and meningitis in immunocompromised hosts and a devastating maternal/fetal infection in pregnant women. in recent years a more benign gastroenteritis in normal hosts has been described. listeria has been increasingly identified as a food-borne pathogen, and large-scale contamination of processed foods with resulting outbreaks has occurred in recent years, possibly as a result of consolidation of the food industry. experimental listeriosis in mice has proven t ...200010951886
antibodies to the junctional adhesion molecule cause disruption of endothelial cells and do not prevent leukocyte influx into the meninges after viral or bacterial infection.a hallmark of infectious meningitis is the invasion of leukocytes into the subarachnoid space. in experimental meningitis triggered by tumor necrosis factor-alpha and interleukin-1beta, the interaction of leukocytes with endothelial cells and the subsequent migration of the cells through the vessel wall can be inhibited by an antibody to the junctional adhesion molecule (jam). in contrast to the cytokine-induced meningitis model, anti-jam antibodies failed to prevent leukocyte influx into the ce ...200010950802
interleukin-1 signaling is essential for host defense during murine pulmonary tuberculosis.interleukin (il)-1 signaling is required for the containment of infections with intracellular microorganisms, such as listeria monocytogenes and leishmania major. to determine the role of il-1 in the host response to tuberculosis, we infected il-1 type i receptor-deficient (il-1r(-/-)) mice, in which il-1 does not exert effects, with mycobacterium tuberculosis. il-1r(-/-) mice were more susceptible to pulmonary tuberculosis, as reflected by an increased mortality and an enhanced mycobacterial ou ...200010950787
induction of interleukin-4 (il-4) by legionella pneumophila infection in balb/c mice and regulation of tumor necrosis factor alpha, il-6, and il-1beta.infection of balb/c mice with a sublethal concentration of legionella pneumophila causes an acute disease that is resolved by innate immune responses. the infection also initiates the development of adaptive th1 responses that protect the mice from challenge infections. to study the early responses, cytokines induced during the first 24 h after infection were examined. in the serum, interleukin-12 (il-12) was detectable by 3 h and peaked at 10 h, while gamma interferon was discernible by 5 h and ...200010948149
prevalence and contamination levels of listeria monocytogenes in retail foods in japan.retail foods in japan were surveyed for the presence and contamination levels of l. monocytogenes. it was isolated from 12.2, 20.6, 37.0 and 25.0% of 41 minced beef, 34 minced pork, 46 minced chicken and 16 minced pork-beef mixture samples, respectively. mpn values were higher than 100/g in five (10.9%) minced chicken samples, but lower than 100/g in all minced beef, pork and pork-beef mixture samples. the organism was also isolated from 5.4% of the 92 smoked salmon samples at mpn values lower t ...200010946841
evaluation of the impact of short-term temperature abuse on the microbiology and shelf life of a model ready-to-use vegetable combination product.the growth dynamics of indigenous aerobic mesophilic populations (amp), lactic acid bacteria (lab) and inoculated (listeria spp.) microbial populations on cooked and fresh vegetable products, packaged as separate entities and in combination, subjected to temperature fluctuation, were assessed. microbial proliferation was temperature and product dependent, being most pronounced at 12 degrees c in all products with maximum growth rates of 0.140, 0.175 and 0.126 log10 cfu/g per h being identified f ...200010946838
cytokine profile and natural killer cell activity in listeria monocytogenes infected mice treated orally with petiveria alliacea extract.in this work, we investigated the effects of petiveria alliacea extract on the production of th1-type and th2-type cytokines and on nk cells activity in normal and listeria monocytogenes infected mice. our results demonstrated that in normal/non-infected mice p. alliacea administration led to increased levels of interleukin-2 (il-2). the infection alone enhanced inf-gamma levels and nk cell activity at 48 and 72 hours of infection. the treatment with five consecutive doses of 1000 mg/kg/day of p ...200010946828
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