| contaminants in feed for food-producing animals. | outbreaks of bovine spongiform encephalopathy (bse) and food borne microbial infections, dioxin contaminated animal products, the presence of veterinary drug residues, microbial resistance to antibiotics, mycotoxins, agricultural and industrial chemicals, etc. are serious concerns for the food industry in many countries. since the direct links between feed safety and safety of foods of animal origin are obvious, feed production and manufacture should be considered as an integral part of the food ... | 2002 | 12189948 |
| extensive and preferential fas/fas ligand-dependent death of gammadelta t cells following infection with listeria monocytogenes. | in the spleens of mice infected intraperitoneally with the bacterium listeria monocytogenes, both alphabeta and gammadelta t cells became rapidly activated, followed by a massive apoptotic death response predominantly within the gammadelta population. the death response involved two major splenic gammadelta t-cell subsets and was fas/fas ligand (fas-l)-dependent. among t cells isolated from the listeria-infected spleen, fas-l was almost exclusively expressed in gammadelta t cells. gammadelta t c ... | 2002 | 12193224 |
| in vivo depletion of cd11c+ dendritic cells abrogates priming of cd8+ t cells by exogenous cell-associated antigens. | cytotoxic t lymphocytes (ctl) respond to antigenic peptides presented on mhc class i molecules. on most cells, these peptides are exclusively of endogenous, cytosolic origin. bone marrow-derived antigen-presenting cells, however, harbor a unique pathway for mhc i presentation of exogenous antigens. this mechanism permits cross-presentation of pathogen-infected cells and the priming of ctl responses against intracellular microbial infections. here, we report a novel diphtheria toxin-based system ... | 2002 | 12196292 |
| toll-like receptor 2-deficient mice are highly susceptible to streptococcus pneumoniae meningitis because of reduced bacterial clearing and enhanced inflammation. | toll-like receptor-2 (tlr2) mediates host responses to gram-positive bacterial wall components. tlr2 function was investigated in a murine streptococcus pneumoniae meningitis model in wild-type (wt) and tlr2-deficient (tlr2(-/-)) mice. tlr2(-/-) mice showed earlier time of death than wt mice (p<.02). plasma interleukin-6 levels and bacterial numbers in blood and peripheral organs were similar for both strains. with ceftriaxone therapy, none of the wt but 27% of the tlr2(-/-) mice died (p<.04). b ... | 2002 | 12198614 |
| environmental and physico-chemical factors induce vbnc state in listeria monocytogenes. | investigations of bacterial survival in natural environments have indicated that some organisms lose culturability on appropriate media under certain conditions and yet still exhibit signs of metabolic activity and thus viability. this reproducible loss of culturability in many bacterial species led to the description of a "viable but non culturable" (vbnc) state. the purpose of this article is to determine environmental and physico-chemical factors which induce the vbnc state in a food-borne pa ... | 2002 | 12199363 |
| rational design of dna sequence-based strategies for subtyping listeria monocytogenes. | the ability to differentiate bacteria beyond the species level is essential for identifying and tracking infectious disease outbreaks and to improve our knowledge of the population genetics, epidemiology, and ecology of bacterial pathogens. commonly used subtyping methods, such as serotyping, phage typing, ribotyping, and pulsed-field gel electrophoresis, can yield ambiguous results that are difficult to standardize and share among laboratories. dna sequence-based subtyping strategies can reduce ... | 2002 | 12202573 |
| participation of dnak in expression of genes involved in virulence of listeria monocytogenes. | dnak is required for adaptation to environmental stress and is also involved in bacterial growth under normal conditions. to examine whether dnak plays a role in the expression of genes related to pathogenicity of listeria monocytogenes, the transcription of flaa, iap and lmaa in a dnak mutant was analyzed. northern blot analysis showed that expression of flaa and lmaa mrnas was reduced in the dnak mutant, thy-lk1. a reporter assay revealed that transcription of lmab in the dnak mutant, lks01, c ... | 2002 | 12204374 |
| genetic characterization of the fusidic acid and cadmium resistance determinants of staphylococcus aureus plasmid pub101. | we report the cloning of the fusidic acid and cadmium resistance determinants from staphylococcus aureus plasmid pub101. the pub101 fusidic acid resistance determinant was located on a 2.9 kb hindiii fragment. sequencing of this fragment revealed three putative open reading frames (orfs) of 213 (far1), 152 (orf152) and 170 amino acids (orf170), which are flanked by the right-hand end of insertion sequence is431/257 (is431/257rh) and a partial orf. far1 and orf152 demonstrated homology with a chr ... | 2002 | 12205055 |
| anti-tumor necrosis factor therapy and listeria monocytogenes infection: report of two cases. | | 2002 | 12209538 |
| pulmonary microbial infection in mice: comparison of different application methods and correlation of bacterial numbers and histopathology. | many investigations have been performed in characterising experimental bacterial infections in the lung of mice using several pathogens. robust experimental pulmonary infection models require a reproducible method of application with defined numbers of pathogens to the respiratory tract without contaminating extrapulmonary tissues. at the same time trauma due to the experimental procedure should be kept to a minimum. so far several routes of administration have been used but a systematic compari ... | 2002 | 12211633 |
| growth and killing of a salmonella enterica serovar typhimurium sifa mutant strain in the cytosol of different host cell lines. | intracellular pathogens have developed different mechanisms which enable their survival and replication within the host cells. some survive and replicate within a membrane-bound vacuole modified by the bacteria to support microbial growth (e.g. salmonella enterica serovar typhimurium), whereas others escape from the vacuole into the host cell cytosol, where they proliferate (e.g. listeria monocytogenes). in this study a salmonella strain carrying a mutation in sifa which is released from the vac ... | 2002 | 12213917 |
| microbial composition, including the incidence of pathogens, of goat milk from the bergamo region of italy during a lactation year. | sixty samples of raw goat milk intended for caprino cheese-making were collected from ten farms in the bergamo area over a 6-month period. analyses of main microbial groups, somatic cell count (scc) and ph were performed to determine the effect of origin (farm) and lactation period (april - september) on microbial composition and the incidence of pathogens in milk. overall mean values were: standard plate count (spc), 5.0 x 10(4) cfu/ml; yeasts, 2.5 x 10(2) cfu/ml; coliforms, 91 x 10(2) cfu/ml; ... | 2002 | 12222800 |
| factors affecting the performance of 5' nuclease pcr assays for listeria monocytogenes detection. | the design and operating parameters affecting the performance of 5' nuclease pcr (taqman) assays for the detection of listeria monocytogenes was investigated. a system previously developed and based on the hlya gene was used as a model [appl. environ. microbiol. 61 (1995) 3724]. a series of fluorogenic probes labeled with a reporter and a quencher dye was synthesized to explore the effect of probe position and sequence content on the efficiency of probe hydrolysis. in addition, a series of pcr p ... | 2002 | 12223296 |
| detection of escherichia coli o157:h7 using immunomagnetic separation and absorbance measurement. | an assay system for detection of escherichia coli o157:h7 was developed based on immunomagnetic separation of the target pathogen from samples and absorbance measurement of p-nitrophenol at 400 nm from p-nitrophenyl phosphate hydrolysis by alkaline phosphatase (ec 3.1.3.1) on the "sandwich" structure complexes (antibodies coated onto micromagnetic beads--e. coli o157:h7-antibodies conjugated with the enzyme) formed on the microbead surface. the effects of immunoreaction time, phosphate buffer co ... | 2002 | 12223297 |
| development of a microslide agglutination assay with the aid of an inexpensive projection microscope. | a microslide agglutination assay was developed involving the mixing of 2.5 microl each of antiserum and a cell suspension of listeria monocytogenes. cell agglutination in the final volume of 5.0 microl was visually observed at a direct magnification of 22 x on the projection screen of an inexpensive 20 us dollar projection microscope. the procedure has the advantage of increasing by a factor of 20 the number of agglutination assays that can be performed with a given volume of antiserum with the ... | 2002 | 12223305 |
| a predictive model that evaluates the effect of growth conditions on the thermal resistance of listeria monocytogenes. | a predictive model for listeria monocytogenes was developed using cells grown in different ph and milkfat levels before subsequent thermal inactivation in identical ph and milkfat conditions. inactivation of the cells used combinations of temperature (55, 60, 65 degrees c), ph (5.0, 6.0, 7.0), and milkfat (0%, 2.5%, 5.0%) in a complete 3 x 3 x 3 factorial design with each test done in triplicate. a modified gompertz equation was used to model nonlinear survival curves with the following three pa ... | 2002 | 12227642 |
| beneficial or deleterious effects of a preexisting hypersensitivity to bacterial components on the course and outcome of infection. | priming with heat-killed propionibacterium acnes enhances the sensitivity of mice to lipopolysaccharide (lps) and other biologically active bacterial components. we show that p. acnes priming has protective and deleterious effects on a subsequent serovar typhimurium infection. it may result in a complete protection or prolonged survival, or it may accelerate mortality of the infected mice, depending on the number of serovar typhimurium bacteria administered and on the degree of lps hypersensitiv ... | 2002 | 12228287 |
| the mycobacterium tuberculosis phagosome in human macrophages is isolated from the host cell cytoplasm. | knowledge of whether mycobacterium tuberculosis resides within a relatively impermeable membrane-bound vacuole or is free within the cytoplasm within its host cell is central to an understanding of the immunobiology of this intracellular parasite but is a matter of controversy. to explore this issue, we assessed the accessibility of medium-size protein molecules (fab fragments of 50,000 da) to m. tuberculosis within human macrophages. we infected the macrophages with wild-type or green fluoresce ... | 2002 | 12228310 |
| an rna thermosensor controls expression of virulence genes in listeria monocytogenes. | in listeria monocytogenes, virulence genes are maximally expressed at 37 degrees c, almost silent at 30 degrees c and controlled by prfa, a transcriptional activator whose expression is thermoregulated. here, we show that the untranslated mrna (utr) preceding prfa, forms a secondary structure, which masks the ribosome binding region. mutations predicted to destabilize this structure led to virulence gene expression and invasion of mammalian cells at 30 degrees c. chemical probing, native gel ele ... | 2002 | 12230973 |
| irradiation temperature influences product quality factors of frozen vegetables and radiation sensitivity of inoculated listeria monocytogenes. | four frozen vegetables (broccoli, corn, lima beans, and peas) were gamma irradiated at subfreezing temperatures ranging from -5 to -20 degrees c to determine (i) the radiation sensitivity of an inoculated outbreak strain of listeria monocytogenes (atcc 49594), (ii) the effect of changing irradiation conditions (i.e., temperature) on that sensitivity, and (iii) the effect of the recommended radiation dose on the texture and color of irradiated frozen vegetables. the amounts of radiation necessary ... | 2002 | 12233849 |
| control of listeria monocytogenes on turkey frankfurters by generally-recognized-as-safe preservatives. | generally-recognized-as-safe chemicals applied to the surfaces of turkey frankfurters were evaluated for their ability to reduce populations of or inhibit the growth of listeria monocytogenes. frankfurters were treated prior to inoculation by dipping for 1 min in a solution of one of four preservatives (sodium benzoate, sodium propionate, potassium sorbate, and sodium diacetate) at three different concentrations (15, 20, and 25% [wt/vol]), with < 0.3% of the preservative being present for each f ... | 2002 | 12233850 |
| detection of listeria monocytogenes in pigs and pork. | in this study, we surveyed hogs (n = 300) as well as pork products (ground pork and raw chitterlings) for listeria monocytogenes. pig specimens collected before (tonsil swabs) and after slaughter (tonsils, lymph nodes, carcass swabs, and rectal contents) were examined for l. monocytogenes by enrichment with conventional enrichment broths followed by subculturing to selective agar. a multiplex polymerase chain reaction assay targeting the highly conserved 16s rrna gene of the listeria species as ... | 2002 | 12233860 |
| ascopyrone p, a novel antibacterial derived from fungi. | to assess the antimicrobial efficacy of ascopyrone p (app), a secondary metabolite formed by the fungi anthracobia melaloma, plicaria anthracina, plic. leiocarpa and peziza petersi belonging to the order pezizales. | 2002 | 12234354 |
| critical roles of myeloid differentiation factor 88-dependent proinflammatory cytokine release in early phase clearance of listeria monocytogenes in mice. | listeria monocytogenes (lm), a facultative intracellular gram-positive bacterium, often causes lethal infection of the host. in this study we investigated the molecular mechanism underlying lm eradication in the early phase of infection. upon infection with lm, both il-12 and il-18 were produced, and then they synergistically induced ifn-gamma production, leading to normal lm clearance in the host. ifn-gamma knockout (ko) mice were highly susceptible to lm infection. il-12/il-18 double knockout ... | 2002 | 12244183 |
| myd88-dependent but toll-like receptor 2-independent innate immunity to listeria: no role for either in macrophage listericidal activity. | we have assessed the requirements for toll-like receptor (tlr) signaling in vivo during early infection with listeria monocytogenes. mice deficient for tlr2, a receptor required for the recognition of gram-positive peptidoglycan, showed equivalent listeria resistance to wild-type mice. however, mice deficient for myd88, an adaptor molecule used by all tlrs, showed profound susceptibility with 3-4 logs greater listeria burden and severe spleen and liver pathology at day 3 postinfection. listeria- ... | 2002 | 12244184 |
| [abortifacient agents in the sow]. | abortion in sows may be complete, or much more often partial, since the average litter size is about 10. this review describes the clinical and serological findings, mode of transmission and recommended treatment for the most common parasitic, fungal, mycotoxin, deficient, and toxic causes of abortion in sows. the most likely possibilities in france are brucellosis, leptospirosis, aujeszky virus, mycotoxin, or dietary deficiencies. the bacterialtion in french sows are brucella species, leptospi ... | 1975 | 12308261 |
| multiple deletions of the osmolyte transporters betl, gbu, and opuc of listeria monocytogenes affect virulence and growth at high osmolarity. | the success of listeria monocytogenes as a food-borne pathogen owes much to its ability to survive a variety of stresses, both in the food environment and, after ingestion, within the animal host. growth at high salt concentrations is attributed mainly to the accumulation of organic solutes such as glycine betaine and carnitine. we characterized l. monocytogenes lo28 strains with single, double, and triple deletions in the osmolyte transport systems betl, gbu, and opuc. when single deletion muta ... | 2002 | 12324311 |
| glucose and nutrient concentrations affect the expression of a 104-kilodalton listeria adhesion protein in listeria monocytogenes. | growth media and environmental conditions influence the expression of adhesion and invasion proteins in listeria monocytogenes. here, the expression of the 104-kda listeria adhesion protein (lap) was studied in nutrient-rich media (trypticase soy broth [tsb] and brain heart infusion [bhi]), minimal medium (luria-bertani [lb]), or nutrient-deficient medium (peptone water [pw]) by immunoblotting, enzyme-linked immunosorbent assay (elisa), and immunoelectron microscopy. also, the effect of incorpor ... | 2002 | 12324334 |
| a pcr-based method for identification of lactobacilli at the genus level. | we developed a polymerase chain reaction (pcr)-based method for the identification of lactobacilli at the genus level. one specific primer, lblma1-rev, was designed by analysing similarities between the nucleotide sequence of the spacer between the 16s and 23s rrna genes in a number of lactobacillus strains. amplification with lblma1-rev and r16-1, a universal primer, generated a pcr product for 23 lactobacillus species. electrophoresis did not reveal any discrete bands when escherichia coli, la ... | 2002 | 12351242 |
| metastatic listeria monocytogenes infection of the peritoneum in mice with cyclosporine a-induced peritonitis. | inoculation of mice with listeria monocytogenes intragastrically or by parenteral routes has not been reported to cause peritonitis. in this study, however, severe listerial peritonitis was induced in mice infected subcutaneously and treated intraperitoneally with cyclosporin a (cs a) in an oil carrier. in both uninfected and listeria-infected mice, intraperitoneal administration of cs a consistently produced overexpression of p-selectin in the peritoneal microvasculature and pyogranulomatous in ... | 2002 | 12354529 |
| identification of bartonella bacilliformis genotypes and their relevance to epidemiological investigations of human bartonellosis. | genotypic diversity among 26 isolates of bartonella bacilliformis obtained from different areas of peru, and at different times, was assessed by comparison of dna sequences derived from 16s-23s ribosomal dna intergenic spacer regions (isr) and a citrate synthase gene (glta) fragment and by amplified fragment length polymorphism (aflp) analysis. glta comparison divided the isolates into two groups, whereas isr comparison revealed six sequences. aflp analysis using a selective primer delineated fi ... | 2002 | 12354853 |
| an outbreak of febrile gastroenteritis associated with delicatessen meat contaminated with listeria monocytogenes. | in june 2001, the los angeles county department of health services/public health conducted a cohort study of an outbreak of acute febrile gastroenteritis among 16 of 44 healthy attendees of a catered party. the median age of the attendees who became ill was 15.5 years. symptoms included body aches (in 88% of attendees), fever (81%), headache (81%), diarrhea (63%), and vomiting (56%). illness was associated with ingestion of precooked, sliced turkey (p=.000004). six stool specimens yielded lister ... | 2002 | 12355381 |
| contribution of cd8+ t cells to innate immunity: ifn-gamma secretion induced by il-12 and il-18. | the role of cd8+ t cells in adaptive immunity is well documented and involves numerous effector mechanisms including direct cytolysis of targets and secretion of cytokines. the role of cd8+ t cells in innate immunity has not been previously appreciated. using j774 macrophages infected in vitro with the intracellular bacterium, listeria monocytogenes (lm), we show that cd8+ t cells isolated from naïve c57bl/6 (b6) mice respond rapidly by secreting ifn-gamma. cd8+ t cells secreting ifn-gamma can a ... | 2002 | 12355433 |
| inactivation of listeria monocytogenes/flavobacterium spp. biofilms using chlorine: impact of substrate, ph, time and concentration. | to determine the effect of chlorine on mixed bacterial biofilms on stainless steel (ss) and conveyor belt surfaces. | 2002 | 12358696 |
| innate recognition of bacteria by a macrophage cytosolic surveillance pathway. | host recognition of bacterial pathogens is a critical component of the immune response. intracellular bacterial pathogens are able to evade the humoral immune system by residing within the host cell. here we show the existence of an innate host surveillance mechanism in macrophages that specifically distinguishes bacteria in the cytosol from bacteria in the vacuole. recognition of gram-positive and gram-negative bacterial products by this surveillance system results in transcription of the ifnb ... | 2002 | 12359878 |
| iron acquisition by gram-positive bacterial pathogens. | for the majority of bacterial pathogens, acquisition of iron from host proteins is a prerequisite for growth during infection. the mechanisms by which gram-negative bacteria obtain iron from host proteins have been well described, but only recently has substantial progress been made in identifying these mechanisms for gram-positive bacterial pathogens. this review provides an overview of the existing knowledge on the genetic basis of iron transport for important gram-positive pathogens. | 2002 | 12361915 |
| listeria monocytogenes demonstrated in cerebrospinal fluid in the absence of inflammatory cells: a case of fever and seizures in a 13-y-old boy. | | 2002 | 12374374 |
| inducible control of virulence gene expression in listeria monocytogenes: temporal requirement of listeriolysin o during intracellular infection. | we have constructed a lac repressor/operator-based system to tightly regulate expression of bacterial genes during intracellular infection by listeria monocytogenes. an l. monocytogenes strain was constructed in which expression of listeriolysin o was placed under the inducible control of an isopropyl-beta-d-thiogalactopyranoside (iptg)-dependent promoter. listeriolysin o (llo) is a pore-forming cytolysin that mediates lysis of l. monocytogenes-containing phagosomes. using hemolytic-activity ass ... | 2002 | 12374827 |
| effects of chlorella vulgaris extract on cytokines production in listeria monocytogenes infected mice. | in this study, we have investigated the effects of the unicellular-green-algae chlorella vulgaris on the production of inf-gamma, il-2, il-4 and il-10 in normal and listeria monocytogenes infected mice. our results demonstrated that in normal/non infected mice, cve administration produced no effects in the levels of all cytokines studied. however, listeria monocytogenes infection enhanced the production of inf-gamma and il-2 at 48 and 72 h after the bacteria inoculation. interestingly, the treat ... | 2002 | 12375742 |
| a recombinant e. coli vaccine to promote mhc class i-dependent antigen presentation: application to cancer immunotherapy. | we have examined the potential of recombinant escherichia coli expressing listeriolysin o (llo) to deliver tumour antigens to dendritic cells (dcs) for cancer immunotherapy. using ova as a model tumour antigen, we have shown in murine dcs that e. coli expressing cytoplasmic llo and ova proteins can deliver the ova k(b)-restricted epitope siinfekl for mhc class i presentation. in contrast, when e. coli expressing ova alone were used, mhc class ii presentation of the ova 323-339 i-a(b)-restricted ... | 2002 | 12378408 |
| listeric infections in humans and animals in the indian subcontinent: a review. | listeriosis is an important bacterial zoonosis caused by the intracellular pathogen listeria monocytogenes. the disease has been reported in animals from the indian subcontinent, usually in the form of sporadic cases but occasionally as outbreaks. cases of listeriosis arise mainly from the ingestion of contaminated food. listeriosis has been reported to cause encephalitis, abortion, mastitis, repeat breeding and endometriosis in animals. listeric infections occur in children and women with a poo ... | 2002 | 12379055 |
| oral cancer, fever of unknown origin, and listeriosis. | listeriosis is a rare cause of fever of unknown origin in patients with oral cancer. we report two patients who, because of pain and discomfort, ate large quantities of soft cheeses; this caused listeriosis and fever. both cases responded to high doses of amoxycillin. | 2002 | 12379195 |
| bactericidal activities of plant essential oils and some of their isolated constituents against campylobacter jejuni, escherichia coli, listeria monocytogenes, and salmonella enterica. | an improved method of sample preparation was used in a microplate assay to evaluate the bactericidal activity levels of 96 essential oils and 23 oil compounds against campylobacter jejuni, escherichia coli o157:h7, listeria monocytogenes, and salmonella enterica obtained from food and clinical sources. bactericidal activity (ba50) was defined as the percentage of the sample in the assay mixture that resulted in a 50% decrease in cfu relative to a buffer control. twenty-seven oils and 12 compound ... | 2002 | 12380738 |
| effect of superatmospheric oxygen packaging on sensorial quality, spoilage, and listeria monocytogenes and aeromonas caviae growth in fresh processed mixed salads. | atmospheres with o2 levels higher than 70 kpa have recently been suggested as an innovation to modified atmosphere packaging (map) for fresh processed vegetables to maintain sensory quality and safety. in the present work, mixed vegetable salad collected from a commercial processing plant and stored with the map technique was studied. two gas mixtures were actively generated by using an initial o2 concentration of 95 kpa and combined with two plastic films. the low-barrier film permeability for ... | 2002 | 12380740 |
| molecular characterization of listeria monocytogenes isolated from a poultry further processing facility and from fully cooked product. | this study was undertaken to explore environmental sources of listeria monocytogenes in a commercial chicken further processing facility and to compare the isolates obtained from this facility with others obtained from fully cooked product. in a survey conducted at the processing facility, 40 environmental sites (encompassing two production lines and representing areas in which raw and cooked products are processed) were cultured for l. monocytogenes. the resulting isolates were subjected to mol ... | 2002 | 12380741 |
| effects of pulsed electric field processing and storage on the quality and stability of single-strength orange juice. | the effects of pulsed electric field (pef) processing on microorganisms in orange juice and on the flavor and color of the juice during storage for 112 days at 4 and 22 degrees c were investigated. single-strength orange juice was pef processed at an electric field strength of 35 kv/cm for 59 micros and placed into sterilized glass bottles in a sanitary glove box. pef-processed orange juice was microbiologically stable at 4 and 22 degrees c for 112 days. pef processing resulted in significant in ... | 2002 | 12380749 |
| inactivation of listeria monocytogenes scott a 49594 in apple juice supplemented with cinnamon. | normal (ph 3.7) and adjusted (ph 5.0) pasteurized apple juice containing cinnamon (0, 0.1, 0.2, and 0.3%) was inoculated with listeria monocytogenes scott a 49594 at 10(4) cfu/ml and stored at 5 and 20 degrees c for 7 days. counts on tryptic soy agar (tsa), modified oxford (mox) medium, and thin agar layer (tal) were determined at 1 h and 1, 3, and 7 days. the tal method (mox medium overlaid with tsa) was used for the recovery of injured cells. in apple juice, both at normal and adjusted ph, wit ... | 2002 | 12380758 |
| caring for a patient with listeria endocarditis: use of antibiotic desensitization. | occurrence of listeria endocarditis is rare, and the mortality rate is high, 100% in untreated cases. the use of antibiotics, specifically ampicillin, is considered a first-line treatment. coadministration of ampicillin and gentamicin provides a synergistic effect in killing the bacteria. antibiotics are among the most common causes of hypersensitivity reactions. of all antibiotics, penicillin is the one that most often causes a reaction. skin testing adds time until treatment, and all patients ... | 2002 | 12382616 |
| preservation and fermentation: past, present and future. | preservation of food and beverages resulting from fermentation has been an effective form of extending the shelf-life of foods for millennia. traditionally, foods were preserved through naturally occurring fermentations, however, modern large scale production generally now exploits the use of defined strain starter systems to ensure consistency and quality in the final product. this review will mainly focus on the use of lactic acid bacteria (lab) for food improvement, given their extensive appl ... | 2002 | 12382680 |
| physiological damages of listeria monocytogenes treated by high hydrostatic pressure. | high hydrostatic pressure is a new food preservation technology known for its capacity to inactivate spoilage and pathogenic microorganisms. this study investigated the damages inflicted on listeria monocytogenes cells treated by high pressure for 10 min at 400 mpa in ph 5.6 citrate buffer. under these conditions, no cell growth occurred after 48 h on plate count agar. scanning electron microscopy (sem) revealed that cellular morphology was not really affected. measuring propidium iodide (pi) st ... | 2002 | 12382684 |
| cd2+ and the n-terminal metal-binding domain protect the putative membranous cpc motif of the cd2+-atpase of listeria monocytogenes. | cada, the cd(2+)-atpase of listeria monocytogenes, contains four cysteine residues: two in the ctnc (cys-thr-asn-cys) sequence in the cytoplasmic metal-binding domain (mbd), and two in the cpc (cys-pro-cys) sequence in the membrane domain. taking advantage of deltambd, a truncated version of cada that lacks the mbd but which still acts as a functional cd(2+)-atpase [bal, mintz, guillain and catty (2001) febs lett. 506, 249-252], we analysed the role of the membrane cysteine residues (studied usi ... | 2003 | 12383056 |
| the icest1 element of streptococcus thermophilus belongs to a large family of integrative and conjugative elements that exchange modules and change their specificity of integration. | the 34,734-bp element icest1 from streptococcus thermophilus cnrz368 is site-specifically integrated into the 3(') end of the gene fda. icest1 encodes integrative functions and putative transfer functions. six proteins of the putative conjugative system of icest1 are related to those encoded by the conjugative transposon tn916 from enterococcus faecalis. a comparison of these proteins with those encoded by the complete or partial genome sequences of various low g+c bacteria including bacillus su ... | 2002 | 12383726 |
| nod/scid/gamma(c)(null) mouse: an excellent recipient mouse model for engraftment of human cells. | to establish a more appropriate animal recipient for xenotransplantation, nod/scid/gamma(c)(null) mice double homozygous for the severe combined immunodeficiency (scid) mutation and interleukin-2rgamma (il-2rgamma) allelic mutation (gamma(c)(null)) were generated by 8 backcross matings of c57bl/6j-gamma(c)(null) mice and nod/shi-scid mice. when human cd34+ cells from umbilical cord blood were transplanted into this strain, the engraftment rate in the peripheral circulation, spleen, and bone marr ... | 2002 | 12384415 |
| residual oil fly ash increases the susceptibility to infection and severely damages the lungs after pulmonary challenge with a bacterial pathogen. | inhalation of residual oil fly ash (rofa), a component of ambient particulate matter, has been shown to increase pulmonary morbidity and impair lung defense mechanisms in exposed workers. our objective was to evaluate the effect of rofa preexposure on lung defense and injury after pulmonary challenge with a bacterial pathogen. male sprague-dawley rats were dosed intratracheally at day 0 with saline (control) or rofa (0.2 or 1 mg/100 g body weight). three days later, a low (5 x 10(3)) or high (5 ... | 2002 | 12388840 |
| listeria infection during pregnancy: a 10 year experience. | although listeria monocytogenes is widely distributed in nature, it rarely causes clinical infection in previously healthy people. this microorganism, however, may cause severe invasive disease in pregnant women and newborns. | 2002 | 12389339 |
| series of incidents of listeria monocytogenes non-invasive febrile gastroenteritis involving ready-to-eat meats. | a series of cases and outbreaks of febrile noninvasive gastrointestinal disease involving 31 identified cases was investigated in terms of the numbers and types of listeria monocytogenes present in the suspect foods (ready-to-eat meats) and clinical samples from cases. | 2002 | 12390491 |
| inactivation of the f4/80 glycoprotein in the mouse germ line. | macrophages play a crucial role in the defense against pathogens. distinct macrophage populations can be defined by the expression of restricted cell surface proteins. resident tissue macrophages, encompassing kupffer cells of the liver and red pulp macrophages of the spleen, characteristically express the f4/80 molecule, a cell surface glycoprotein related to the seven transmembrane-spanning family of hormone receptors. in this study, gene targeting was used to simultaneously inactivate the f4/ ... | 2002 | 12391169 |
| quantitation of cd8+ t cell expansion, memory, and protective immunity after immunization with peptide-coated dendritic cells. | dendritic cells (dcs) are potent apcs for naive cd8(+) t cells and are being investigated as vaccine delivery vehicles. in this study, we examine the cd8(+) t cell response to defined peptides from listeria monocytogenes (lm), lymphocytic choriomeningitis virus, and murine cmv coated singly and in combination onto mature bone marrow-derived dcs (bmdcs). we show that immunization of mice with 2 x 10(5) mature bmdcs coated with multiple mhc class i peptides generates a significant ag-specific cd8( ... | 2002 | 12391206 |
| perforin-mediated ctl cytolysis counteracts direct cell-cell spread of listeria monocytogenes. | the immune system has evolved various effector cells and functions to combat diverse infectious agents equipped with different virulence strategies. cd8 t cells play a critical role in protective immunity to listeria monocytogenes (lm), a bacterium that grows within the host cell cytosol and spreads directly into neighboring cells. the importance of cd8 t cells during lm infection is currently attributed to the cytosolic niche of this organism, which allows it to evade many aspects of immune sur ... | 2002 | 12391238 |
| antibacterial activity of pepsin-digested lactoferrin on foodborne pathogens in buffered broth systems and ultra-high temperature milk with edta. | to evaluate the antimicrobial activity in peptone yeast extract glucose (pyg) broth and ultra-high temperature (uht) milk of bovine lactoferrin hydrolysate (lfh) with pepsin against the foodborne pathogens salmonella stanley, escherichia coli, listeria monocytogenes and staphylococcus aureus. | 2002 | 12392532 |
| interaction of human hematopoietic stem cells with bacterial pathogens. | primitive hematopoietic stem cells (hscs) in the bone marrow are rare pluripotent cells with the capacity to give rise to all lineages of blood cells. during commitment, progenitor cells are composed mainly of cells with the potential for differentiation into 1 or 2 lineages. this commitment involves the acquisition of specific growth factor receptors and the loss of others. viral and bacterial infections may lead to profound disturbance of hematopoiesis, which is possibly due to different susce ... | 2002 | 12393678 |
| a proteomic analysis of the salt stress response of listeria monocytogenes. | protein variations in listeria monocytogenes were analyzed by 2-d electrophoresis. bacteria were grown either in a rich medium or in a chemically defined medium. three proteins, which are more expressed in the chemically defined medium than in the rich medium, were identified by mass spectrometry. they are closely related to appa, ctc and yvyd. after an osmotic shock, according to the medium and the nacl concentration, the synthesis rate (p<0.05) of 59 proteins is altered by salinity. half of th ... | 2002 | 12399033 |
| effects of pregnancy-associated listeria monocytogenes infection: necrotizing hepatitis due to impaired maternal immune response and significantly increased abortion rate. | the impact of l. monocytogenes infection on maternal immune responses as well as on the outcome of pregnancy was studied in a murine model of pregnancy-associated listeriosis. mice infected i.v. with l. monocytogenes at day 15 of pregnancy showed a significantly impaired bacterial elimination, which resulted in a severe necrotizing hemorrhagic hepatitis. the aggravated course of the infection could be attributed to a suppressed transcription and production of anti-listerial, pro-inflammatory cyt ... | 2002 | 12404062 |
| critical role of the n-terminal residues of listeriolysin o in phagosomal escape and virulence of listeria monocytogenes. | a putative pest sequence was recently identified close to the n-terminus of listeriolysin o (llo), a major virulence factor secreted by the pathogenic listeria monocytogenes. the deletion of this motif did not affect the secretion and haemolytic activity of llo, but abolished bacterial virulence. here, we first tested whether the replacement of the pest motif of llo by two different sequences, with either a very high or no pest score, would affect phagosomal escape, protein stability and, ultima ... | 2002 | 12406215 |
| membranes of class iia bacteriocin-resistant listeria monocytogenes cells contain increased levels of desaturated and short-acyl-chain phosphatidylglycerols. | a major concern in the use of class iia bacteriocins as food preservatives is the well-documented resistance development in target listeria strains. we studied the relationship between leucocin a, a class iia bacteriocin, and the composition of the major phospholipid, phosphatidylglycerol (pg), in membranes of both sensitive and resistant l. monocytogenes strains. two wild-type strains, l. monocytogenes b73 and 412, two spontaneous mutants of l. monocytogenes b73 with intermediate resistance to ... | 2002 | 12406708 |
| postadaptational resistance to benzalkonium chloride and subsequent physicochemical modifications of listeria monocytogenes. | many studies have demonstrated that bacteria, including listeria monocytogenes, are capable of adapting to disinfectants used in industrial settings after prolonged exposure to sublethal concentrations. however, the consequent alterations of the cell surface due to sanitizer adaptation of this pathogen are not fully understood. two resistant and four sensitive l. monocytogenes strains from different sources were progressively subcultured with increasing sublethal concentrations of a surfactant, ... | 2002 | 12406712 |
| gbu glycine betaine porter and carnitine uptake in osmotically stressed listeria monocytogenes cells. | the food-borne pathogen listeria monocytogenes grows actively under high-salt conditions by accumulating compatible solutes such as glycine betaine and carnitine from the medium. we report here that the dominant transport system for glycine betaine uptake, the gbu porter, may act as a secondary uptake system for carnitine, with a k(m) of 4 mm for carnitine uptake and measurable uptake at carnitine concentrations as low as 10 microm. this porter has a k(m) for glycine betaine uptake of about 6 mi ... | 2002 | 12406761 |
| in vitro and in vivo invasiveness of different pulsed-field gel electrophoresis types of listeria monocytogenes. | the virulence of different pulsed-field gel electrophoresis (pfge) types of listeria monocytogenes was examined by monitoring their ability to invade caco-2 cells. strains belonging to seven different pfge types originating from both foods and humans were included. no significant differences in invasiveness were detected between strains isolated from humans and those isolated from food. strains belonging to pfge type 1 expressed a significantly lower ability to invade cells compared to strains b ... | 2002 | 12406767 |
| a regulatory role for suppressor of cytokine signaling-1 in t(h) polarization in vivo. | suppressor of cytokine signaling (socs)-1 is an inhibitory molecule for jak, and its deficiency in mice leads to lymphocyte-dependent multi-organ disease and perinatal death. crossing of socs-1(-/-) mice on an ifn-gamma(-/-), stat1(-/-) and stat6(-/-) background revealed that the fatal disease of socs-1(-/-) mice is also dependent on ifn-gamma/stat1 and il-4/stat6 signaling pathways. since ifn-gamma and il-4 are representative t(h)1 and t(h)2 cytokines respectively, here we investigated the role ... | 2002 | 12407025 |
| multimethod assessment of commercial nisin preparations. | nisin is a gras preservative effective against several gram-positive organisms including listeria monocytogenes. commercial preparations are usually fermentation products containing 2.5% pure nisin along with insoluble material which, in this study, was found to influence the quantification and activity of nisin under different conditions. commercially available samples of nisin were tested for efficacy using various methods, such as well diffusion, time to turbidity, and gus (where a reporter c ... | 2002 | 12407455 |
| measuring the immeasurable. | many bacterial pathogens turn on virulence genes at host body temperature. in the september 6, 2002, issue of cell, johansson et al. show that the listeria monocytogenes thermosensor is an rna structure in the 5' untranslated region of the mrna for the virulence-activating transcription factor prfa. the stem-loop structure blocks translation initiation at 30 degrees c but melts away at 37 degrees c. | 2002 | 12408812 |
| gw domains of the listeria monocytogenes invasion protein inlb are sh3-like and mediate binding to host ligands. | inlb, a surface-localized protein of listeria monocytogenes, induces phagocytosis in non-phagocytic mammalian cells by activating met, a receptor tyrosine kinase. inlb also binds glycosaminoglycans and the protein gc1q-r, two additional host ligands implicated in invasion. we present the structure of inlb, revealing a highly elongated molecule with leucine-rich repeats that bind met at one end, and gw domains that dissociably bind the bacterial surface at the other. surprisingly, the gw domains ... | 2002 | 12411480 |
| immune response overview. | a short synopsis of the history of identification of the protective cellular immune response to brucella is given along with indication of the current major research focuses in this area. finally, critical areas of research for the future are suggested. | 2002 | 12414156 |
| compromised peripheral immunity of mice injected intrastriatally with six-hydroxydopamine. | intracisternal or intracerebroventricular administration of six-hydroxydopamine (6-ohda), which results in decreased norepinephrine (ne) and dopamine (da) levels throughout the brain, causes impaired peripheral immunity. however, in vivo immunocompetence following selective striatal depletion of da by 6-ohda has not been investigated. thus, we sought to determine whether striatal da depletion compromises host resistance to listeria monocytogenes (lm) and impairs the immune response to keyhole li ... | 2002 | 12417443 |
| alteration of pulmonary immunity to listeria monocytogenes by diesel exhaust particles (deps). i. effects of deps on early pulmonary responses. | it has been hypothesized that diesel exhaust particles (deps) aggravate pulmonary bacterial infection by both innate and cell-mediated immune mechanisms. to test this hypothesis, we investigated the effects of dep exposure on the functions of alveolar macrophages (ams) and lymphocytes from lung-draining lymph nodes using a rat listeria monocytogenes infection model. in the present study, we focused on the effects of dep exposure on am functions, including phagocytic activity and secretion of pro ... | 2002 | 12417481 |
| bacterial growth in the cytosol: lessons from listeria. | | 2002 | 12419611 |
| amplified fragment length polymorphism (aflp) analysis of listeria monocytogenes. | an agarose gel based single enzyme aflp method using ecor1 digestion of listeria monocytogenes dna was developed for epidemiological typing. the method was evaluated with 84 l. monocytogenes cultures, and results were compared with those obtained with serotyping, phage-typing and cadmium and arsenic resistance typing. the aflp method was reproducible and 14 different banding patterns comprising between five and eight dna fragments were produced. all except two of the aflp patterns were serorype ... | 2002 | 12421084 |
| genetically-modified-animal models for human infections: the listeria paradigm. | several human pathogens exhibit a restricted host-tropism, relying on the species-specific interaction of microbial ligand(s) with host receptor(s). this specificity accounts for some of the difficulties in modeling human infections in animals. the discovery of l. monocytogenes host-specificity and elucidation of the underlying mechanism has led to the generation of transgenic mice expressing one of its human receptors, e-cadherin. this model is presented here as a paradigm of a genetically-modi ... | 2002 | 12421688 |
| nonsecreted bacterial proteins induce recall cd8 t cell responses but do not serve as protective antigens. | secreted or nonsecreted ag expressed by recombinant listeria monocytogenes can prime cd8 t cells. however, ag-specific memory cd8 t cells confer protection against bacteria secreting ag, but not against bacteria expressing the nonsecreted form of the same ag. this dichotomy may be explained by a long-standing hypothesis that nonsecreted ags are less effective than secreted ags at inducing a protective immune response at the onset of infection. we tested this hypothesis by examining whether these ... | 2002 | 12421961 |
| inducible costimulator protein controls the protective t cell response against listeria monocytogenes. | the inducible costimulator protein (icos) was recently identified as a costimulatory molecule for t cells. here we analyze the role of icos for the acquired immune response of mice against the intracellular bacterium listeria monocytogenes. during oral l. monocytogenes infection, low levels of icos expression were detected by extracellular and intracellular ab staining of listeria-specific cd4(+) and cd8(+) t cells. blocking of icos signaling with a soluble icos-ig fusion protein markedly impair ... | 2002 | 12421962 |
| endosomal/lysosomal targeting of a single helper t-cell epitope of an intracellular bacterium by dna immunisation induces a specific t-cell subset and partial protective immunity in vivo. | we evaluated here the effect of the intracellular targeting of a helper t-cell (th) epitope, literiolysin o 215-226 derived from listeria monocytogenes, on induction of a specific th by gene gun immunisation. immunisation of c3h/he mice with pe215lamp plasmid encoding the th epitope fused with the endosomal/lysosomal targeting signal of lysosome-associated membrane protein (lamp)-1 gave the epitope-specific proliferative responses of cd4(+) t lymphocytes. in addition, specific interferon-gamma p ... | 2002 | 12423758 |
| antibacterial activity of extracts from some edible plants commonly consumed in asia. | extracts of edible plants (26 species) from china, japan, thailand and yemen were screened for their antibacterial activity against bacillus cereus, staphylococcus aureus, listeria monocytogenes, escherichia coli and salmonella infantis. buffered methanol (80% methanol and 20% pbs) and acetone extracted inhibitory substances against tested bacteria from 16 plants, as revealed by the disc assay. the minimum inhibitory concentrations (mics) of extracts determined by the agar dilution method ranged ... | 2003 | 12423924 |
| interactive inhibition of meat spoilage and pathogenic bacteria by lysozyme, nisin and edta in the presence of nitrite and sodium chloride at 24 degrees c. | to develop a nisin- and lysozyme-based antimicrobial treatment for use with processed ham and bologna, in vitro experiments were conducted to determine whether inhibition enhancing interactions occur between the antimicrobials lysozyme, chrisin (a commercial nisin preparation), edta, nacl and nano(2). inhibitory interactions were observed between a number of agents when used against specific pathogenic and spoilage bacteria. the observed interactions included lysozyme with edta (enterococcus fae ... | 2003 | 12423927 |
| strategy of escherichia coli for crossing the blood-brain barrier. | a major contributing factor to high mortality and morbidity associated with bacterial meningitis is the incomplete understanding of the pathogenesis of this disease: it is unclear how circulating bacteria cross the blood-brain barrier (bbb). recent studies with escherichia coli k1 show that successful traversal of the bbb requires a high degree of bacteremia, invasion of brain microvascular endothelial cells (bmec), host cell actin cytoskeleton rearrangements and related signaling pathways, and ... | 2002 | 12424701 |
| listeria monocytogenes-induced monomicrobial non-neutrocytic bacterascites. | spontaneous bacterial peritonitis (sbp) is a common complication in patients with cirrhosis of the liver. the organisms most commonly involved in this infection are gram-negative bacteria like escherichia coli and klebsiella pneumoniae, and gram-positive bacteria like streptococcus pneumoniae and staphylococcus aureus. listeria monocytogenes is an uncommon gram-positive bacillus implicated in infections in neonates, pregnant females, the elderly, and immunocompromised patients. listeria monocyto ... | 2002 | 12425510 |
| trends in indigenous foodborne disease and deaths, england and wales: 1992 to 2000. | commitment to food safety is evidenced by high profile governmental initiatives around the globe. to measure progress towards targets, policy makers need to know the baseline from which they started. | 2002 | 12427786 |
| calcinated calcium killing of escherichia coli o157:h7, salmonella, and listeria monocytogenes on the surface of tomatoes. | this study was conducted to evaluate the efficacy of calcinated calcium, 200 ppm chlorine water (1% active chlorine), and sterile distilled water in killing escherichia coli o157:h7, salmonella, and listeria monocytogenes on the surfaces of spot-inoculated tomatoes. inoculated tomatoes were sprayed with calcinated calcium, chlorinated water, or sterile distilled water (control) and hand rubbed for 30 s. populations of e coli o157:h7, salmonella, and l. monocytogenes in the rinse water and in the ... | 2002 | 12430690 |
| biofilm formation by acid-adapted and nonadapted listeria monocytogenes in fresh beef decontamination washings and its subsequent inactivation with sanitizers. | the antimicrobial effects of sodium hypochlorite (sh, 200 ppm, at an adjusted ph of 6.80 +/- 0.20 and at an unadjusted ph of 10.35 +/- 0.25), quaternary ammonium compound (ph 10.20 +/- 0.12, 200 ppm), and peroxyacetic acid (paa, ph 3.45 +/- 0.20, 150 ppm) on previously acid-adapted or nonadapted listeria monocytogenes inoculated (10(5) cfu/ml) into beef decontamination water washings were evaluated. the effects of the sanitizers on suspended cells (planktonic or deattached) and on cells attached ... | 2002 | 12430692 |
| prevalence of listeria monocytogenes during production and postharvest processing of cabbage. | from november 1999 to may 2000, analyses of 425 cabbage, 205 water, and 225 environmental sponge samples from four cabbage farms with packing sheds and from two packing sheds in the rio grande valley and uvalde, tex., were conducted to determine whether listeria monocytogenes was present. samples were tested by the food and drug administration method for the isolation of listeria spp., and confirmed isolates were dna fingerprinted by repetitive-element sequence-based polymerase chain reaction (r ... | 2002 | 12430693 |
| detection of listeria in crawfish processing plants and in raw, whole crawfish and processed crawfish (procambarus spp.). | the foodborne pathogen listeria monocytogenes represents a major concern to the food industry and particularly to producers of ready-to-eat (rte) foods because of the severity of human listeriosis infections and because of the ubiquitous nature of this organism. although several studies on the prevalence and sources of l monocytogenes in various rte seafoods have been conducted, limited information is available on the presence and potential sources of this organism in rte crawfish products. we t ... | 2002 | 12430694 |
| effect of gamma irradiation on listeria monocytogenes in frozen, artificially contaminated sandwiches. | gamma irradiation has been shown to effectively control l monocytogenes in uncooked meats but has not been extensively studied in ready-to-eat foods. the presence of listeria in ready-to-eat foods is often due to postprocess contamination by organisms in the food-manufacturing environment. because gamma irradiation is applied after products are packaged, the treated foods are protected from environmental recontamination. currently, a petition to allow gamma irradiation of ready-to-eat foods is u ... | 2002 | 12430695 |
| behavior of listeria monocytogenes in avocado pulp and processed guacamole. | the potential ability of listeria monocytogenes to grow or survive in avocado pulp (ap) and processed guacamole (pg) stored at 22, 4 to 7, and -18 degrees c was studied. both products were obtained from a factory in michoacan, mexico. pg consisted of ap mixed with dehydrated vegetables, antioxidants, and preservatives. populations of l monocytogenes in ap stored at 22 degrees c increased from 2 to 6 and 9 log cfu/g after 24 and 48 h, respectively. at 4 to 7 degrees c, the growth rate of l monocy ... | 2002 | 12430696 |
| antioxidant power, lipid oxidation, color, and viability of listeria monocytogenes in beef bologna treated with gamma radiation and containing various levels of glucose. | ionizing radiation can be used to pasteurize ready-to-eat (rte) meat products. thermal processing of rte meats that contain dextrose results in the production of antioxidants that may interfere with ionizing radiation pasteurization of rte meat products. beef bologna was manufactured with dextrose concentrations of 0, 2, 4, 6, and 8%. antioxidant activity, as measured by the ferric reducing antioxidant power assay, increased with dextrose concentration but was unaffected by ionizing radiation. l ... | 2002 | 12430697 |
| antimicrobial resistance of listeria monocytogenes isolated from various cabbage farms and packing sheds in texas. | twenty-one isolates of listeria monocytogenes from cabbage, environmental, and water samples were evaluated for antimicrobial resistance by the disk diffusion method. ninety-five percent (20 of 21) of the isolates tested were resistant to two or more antimicrobial agents. this finding is significant, since multiresistant strains of listeria spp. are not commonly found in nature. eighty-five percent (17 of 20) of the multiresistant strains were resistant to penicillin, and the remaining multiresi ... | 2002 | 12430706 |
| magnetized carbonyl iron and insoluble zirconium hydroxide mixture facilitates bacterial concentration and separation from nonfat dry milk. | a mixture of magnetized carbonyl iron and insoluble zirconium hydroxide was investigated for its ability to concentrate various foodborne pathogens from 25-ml samples of reconstituted nonfat dry milk. each sample was artificially contaminated with 10(3) to 10(6) cfu/25 ml of representative foodborne pathogens (salmonella enterica serovar enteritidis, listeria monocytogenes, and bacillus cereus spores) and processed for bacterial concentration with high-speed centrifugation for the primary concen ... | 2002 | 12430708 |
| listeria monocytogenes virulence and pathogenicity, a food safety perspective. | several virulence factors of listeria monocytogenes have been identified and extensively characterized at the molecular and cell biologic levels, including the hemolysin (listeriolysin o), two distinct phospholipases, a protein (acta), several internalins, and others. their study has yielded an impressive amount of information on the mechanisms employed by this facultative intracellular pathogen to interact with mammalian host cells, escape the host cell's killing mechanisms, and spread from one ... | 2002 | 12430709 |
| estimation of low bacterial concentration: listeria monocytogenes in raw milk. | a time-series bacteriological analysis has been carried out on milk collected on farms from 1997 to 2001 by a plant producing raw milk soft cheese, with the purpose of assessing the time course of the presence/absence of listeria monocytogenes. a standard data collection procedure was used, in which farms were tested on a monthly or biweekly basis and 2-3 days after the detection of milk tanker contamination. this procedure yielded low figures for contamination frequencies. the average value and ... | 2003 | 12430767 |
| [genome analysis and primer sets determination for listeria species detection and gene typing]. | computer analysis of listeria genome isolates of sequences from embl, genbank, ddbj data bases has been made. variable and highly conservative (homology degree is 90-100% for all known isolates) genes loci iap and listeriolysin (cytolysin) gene locuses have been determined. primer sets for detection and differentiation of listeria species by polymerase chain reaction (pcr) were designed by computer and following thermodynamic analysis. primer sets can provide detection of listeria monocytogenes, ... | 2002 | 12436870 |
| outbreak of listeriosis--northeastern united states, 2002. | a multistate outbreak of listeria monocytogenes infections with 46 culture-confirmed cases, seven deaths, and three stillbirths or miscarriages in eight states has been linked to eating sliceable turkey deli meat. cases have been reported from pennsylvania (14 cases), new york (11 in new york city and seven in other locations), new jersey (five), delaware (four), maryland (two), connecticut (one), massachusetts (one), and michigan (one). culture dates ranged from july 18 to september 30, 2002; c ... | 2002 | 12437035 |
| typing of food-borne listeria monocytogenes by the optimized repetitive extragenic palindrome-based polymerase chain reaction. | the repetitive extragenic palindrome-based polymerase chain reaction was optimized for typing listeria monocytogenes by 1) using the qlaamp method to increase the reproducibility of dna isolation, 2) running pcr with three different dna concentrations in parallel, 3) using antibody-protected therrnostable dna polymerase to reduce non-specific priming, and 4) using an improved temperature programme to increase the amplification yield. when applied to 42 l. monocytogenes strains isolated from food ... | 2002 | 12437224 |