| carriage of four bacterial pathogens by beef cattle in northern ireland at time of slaughter. | to determine the prevalence of four bacterial zoonotic pathogens in beef cattle at time of slaughter in northern ireland (ni), in order to assess their potential for reducing beef safety. | 2007 | 17257247 |
| inhibition of listeria monocytogenes by freeze-dried piscicocin cs526 fermentate in food. | the effectiveness of freeze-dried powder, fermented with bacteriocin producing carnobacterium piscicola cs526, was evaluated for the inhibition of listeria monocytogenes in a food model. | 2007 | 17257251 |
| limitations in the use of drosophila melanogaster as a model host for gram-positive bacterial infection. | to examine sensitivities of various drosophila melanogaster strains towards human pathogenic and nonpathogenic gram-positive bacteria. | 2007 | 17257264 |
| a molecular beacon-based real time nasba assay for detection of listeria monocytogenes in food products: role of target mrna secondary structure on nasba design. | a molecular beacon-based real-time nasba (qnasba) assay for detection and identification of listeria monocytogenes has been developed. a correlation between targeting highly accessible mrna sequences and qnasba efficiency and sensitivity was demonstrated. the assay targets a sequence from the mrna transcript of the hly gene which is specific for this bacterium; and includes an internal amplification control to disclose failure of the reaction. it was fully selective and consistently detected dow ... | 2007 | 17258831 |
| identification of new noncoding rnas in listeria monocytogenes and prediction of mrna targets. | to identify noncoding rnas (ncrnas) in the pathogenic bacterium listeria monocytogenes, we analyzed the intergenic regions (igrs) of strain egd-e by in silico-based approaches. among the twelve ncrnas found, nine are novel and specific to the listeria genus, and two of these ncrnas are expressed in a growth-dependent manner. three of the ncrnas are transcribed in opposite direction to overlapping open reading frames (orfs), suggesting that they act as antisense on the corresponding mrnas. the ot ... | 2007 | 17259222 |
| piezotolerant small-colony variants with increased thermotolerance, antibiotic susceptibility, and low invasiveness in a clonal staphylococcus aureus population. | following a pressure treatment of a clonal staphylococcus aureus culture with 400 mpa for 30 min, piezotolerant variants were isolated. among 21 randomly selected survivors, 9 were piezotolerant and all formed small colonies on several agar media. the majority of the isolates showed increased thermotolerance, impaired growth, and reduced antibiotic resistance compared to the wild type. however, several nonpiezotolerant isolates also demonstrated impaired growth and the small-colony phenotype. in ... | 2007 | 17259364 |
| ischemic cerebral attacks due to a pseudo-aneurysm of the internal carotid artery with listeria monocytogenes. | | 2007 | 17260177 |
| in vitro and in vivo activities of pd 0305970 and pd 0326448, new bacterial gyrase/topoisomerase inhibitors with potent antibacterial activities versus multidrug-resistant gram-positive and fastidious organism groups. | pd 0305970 and pd 0326448 are new bacterial gyrase and topoisomerase inhibitors (quinazoline-2,4-diones) that possess outstanding in vitro and in vivo activities against a wide spectrum of bacterial species including quinolone- and multidrug-resistant gram-positive and fastidious organism groups. the respective mics (microg/ml) for pd 0305970 capable of inhibiting>or=90% of bacterial strains tested ranged from 0.125 to 0.5 versus staphylococci, 0.03 to 0.06 versus streptococci, 0.25 to 2 versus ... | 2007 | 17261623 |
| evaluation of housekeeping genes in listeria monocytogenes as potential internal control references for normalizing mrna expression levels in stress adaptation models using real-time pcr. | listeria monocytogenes is an important food-borne pathogen that can tolerate a wide range of stress conditions. however, its stress adaptation processes are still poorly understood. real-time-based quantitative rt-pcr (qrt-pcr) provides a tool to probe gene expression changes underlying stress adaptation. but, a limitation to study mrna levels by real-time qrt-pcr is that validated reference genes are required for normalization. such genes are currently lacking for experimental models that may b ... | 2007 | 17263845 |
| detection and survival of listeria monocytogenes in milk and dairy products. | detection of l. monocytogenes in raw and pasteurized milk, zabady, karish, domiati and romi cheeses were done in this study using direct and cold enrichment methods. out of 140 samples 3 samples were positive by cold enrichment and they were 2 of raw milk and one of domiati cheese. survival of l. monocytogenes was studied during heat treatment of milk by the sealed tube method of inactivation and it was found that l. monocytogenes inactivated completely at 60 degrees c for 15 minutes. there was ... | 1993 | 17265649 |
| biofilm formation by multidrug-resistant salmonella enterica serotype typhimurium phage type dt104 and other pathogens. | the biofilm-forming capability of salmonella enterica serotypes typhimurium and heidelberg, pseudomonas aeruginosa, listeria monocytogenes, escherichia coli o157:h7, klebsiella pneumoniae, and acinetobacter baumannii isolated from humans, animal farms, and retail meat products was evaluated by using a microplate assay. the tested bacterial species showed interstrain variation in their capabilities to form biofilms. strong biofilm-forming strains of s. enterica serotypes, e. coli o157: h7, p. aer ... | 2007 | 17265855 |
| recovery of salmonella, listeria monocytogenes, and mycobacterium bovis from cheese entering the united states through a noncommercial land port of entry. | a joint multiagency project was initiated in response to a salmonella outbreak in san diego county, california, in 2004. samples of cheese were collected during four 1-day operations at the san ysidro port of entry, along the united states-mexico border. surveyed participants were persons crossing the border as pedestrians or in vehicles who had a minimum of 2.27 kg of cheese, which may suggest a potential diversion to illegal marketing. in addition, data were collected about the cheese to ident ... | 2007 | 17265859 |
| rapid enrichment strategy for isolation of listeria from bovine hide, carcass, and meat samples. | since the outbreak of foodborne illness linked to escherichia coli o157:h7 bacteria in ground beef in the early 1980s, the beef processing industry has focused on increasing the safety of beef products by implementing procedures for surveying live cattle, carcasses, and beef products for bacterial pathogens. effective methods are in place for screening cattle and beef products for the presence of e. coli o157:h7 contamination, and recent work has established the acceptability of these methods fo ... | 2007 | 17265860 |
| protein variations in listeria monocytogenes exposed to sodium lactate, sodium diacetate, and their combination. | most studies of the effect of adverse conditions on survival of listeria monocytogenes have focused on stress caused by acid or sodium chloride. however, no information is available on resistance of this pathogen to stress caused by salts of organic acids. sodium lactate and sodium diacetate are generally recognized as safe substances and are approved as ingredients for use in foods. we evaluated antilisterial properties of each of these salts and the enhanced inhibition effected by their combin ... | 2007 | 17265861 |
| effect of acid adaptation on growth during storage at 10 degrees c and resistance to simulated gastric fluid of listeria monocytogenes inoculated onto bologna formulated with or without antimicrobials. | the fate of acid-adapted and nonadapted listeria monocytogenes inoculated onto bologna slices (formulated with or without antimicrobials) was examined during storage and after exposure to in vitro gastric challenge. bologna slices formulated with no antimicrobials (control), 3% sodium lactate (sl), or 1.8% sl plus 0.25% sodium diacetate (sd) were inoculated (2 log cfu/cm2) with a 10-strain composite of acid-adapted or nonadapted l. monocytogenes strains. growth or survival of the two inocula on ... | 2007 | 17265862 |
| modeling and predicting the growth boundary of listeria monocytogenes in lightly preserved seafood. | the antimicrobial effect of diacetate and lactate against listeria monocytogenes was evaluated in challenge tests with vacuum-packaged or modified atmosphere packaged (map) cold-smoked salmon, marinated salmon, cold-smoked greenland halibut, marinated greenland halibut, and gravad salmon. map cold-smoked salmon with the addition of 0.15% (wt/wt) diacetate prevented the growth of l. monocytogenes for more than 40 days at 8 degrees c, whereas the addition of 0.15% (wt/wt) diacetate reduced the gro ... | 2007 | 17265863 |
| efficacy of neutral electrolyzed water to inactivate escherichia coli, listeria monocytogenes, pseudomonas aeruginosa, and staphylococcus aureus on plastic and wooden kitchen cutting boards. | this study evaluated the efficacy of neutral electrolyzed water (new; 64.1 mg/liter of active chlorine) to reduce populations of escherichia coli, pseudomonas aeruginosa, staphylococcus aureus, and listeria monocytogenes on plastic and wooden kitchen cutting boards. its effectiveness was compared with that of a sodium hypochlorite solution (naclo; 62.3 mg/liter of active chlorine). inoculated portions of cutting boards were rinsed in either new or naclo solutions, or deionized water (control). p ... | 2007 | 17265867 |
| adhesive and chemokine stimulatory properties of potentially probiotic lactobacillus strains. | five lactobacillus plantarum strains and two lactobacillus johnsonii strains, stemming either from african traditionally fermented milk products or children's feces, were investigated for probiotic properties in vitro. the relationship between the hydrophobic-hydrophilic cell surface and adhesion ability to ht29 intestinal epithelial cells was investigated, and results indicated that especially the l. johnsonii strains, which exhibited both hydrophobic and hydrophilic surface characteristics, ad ... | 2007 | 17265871 |
| inhibition of listeria monocytogenes in turkey and pork-beef bologna by combinations of sorbate, benzoate, and propionate. | the control of listeria monocytogenes was evaluated with ready-to-eat uncured turkey and cured pork-beef bologna with combinations of benzoate, propionate, and sorbate. three treatments of each product type were formulated to include control with no antimycotic agents; a combination of 0.05% sodium benzoate and 0.05% sodium propionate; and a combination of 0.05% sodium benzoate and 0.05% potassium sorbate. ingredients were mixed, stuffed into fibrous, moisture-impermeable casings, cooked to an i ... | 2007 | 17265884 |
| heat shock protein gp96 is a master chaperone for toll-like receptors and is important in the innate function of macrophages. | gp96 is an endoplasmic reticulum chaperone for cell-surface toll-like receptors (tlrs). little is known about its roles in chaperoning other tlrs or in the biology of macrophage in vivo. we generated a macrophage-specific gp96-deficient mouse. despite normal development and activation by interferon-gamma, tumor necrosis factor-alpha, and interleukin-1beta, the mutant macrophages failed to respond to ligands of both cell-surface and intracellular tlrs including tlr2, tlr4, tlr5, tlr7, and tlr9. f ... | 2007 | 17275357 |
| imatinib mesylate inhibits antigen-specific memory cd8 t cell responses in vivo. | imatinib mesylate (im) is effective at inducing complete cytogenetic remission in patients with chronic myelogenous leukemia. because its influence on cd8 t cell responsiveness in vivo is unknown, we investigated the effects of im by analyzing the response of ot-1 cd8 t cells to listeria monocytogenes (lm) that express the cognate epitope ova(257-264) (lm-ova). in vitro, im had no effect on ag-specific expansion, cell division, cell cycle progression, or ifn-gamma expression in naive or memory o ... | 2007 | 17277106 |
| regulation of cd8+ t lymphocyte effector function and macrophage inflammatory cytokine production by retinoic acid receptor gamma. | vitamin a and its derivatives regulate a broad array of immune functions. the effects of these retinoids are mediated through members of retinoic acid receptors (rars) and retinoid x receptors. however, the role of individual retinoid receptors in the pleiotropic effects of retinoids remains unclear. to dissect the role of these receptors in the immune system, we analyzed immune cell development and function in mice conditionally lacking rargamma, the third member of the rar family. we show that ... | 2007 | 17277115 |
| rapid clonal expansion and prolonged maintenance of memory cd8+ t cells of the effector (cd44highcd62llow) and central (cd44highcd62lhigh) phenotype by an archaeosome adjuvant independent of tlr2. | vaccines capable of eliciting long-term t cell immunity are required for combating many diseases. live vectors can be unsafe whereas subunit vaccines often lack potency. we previously reported induction of cd8(+) t cells to ag entrapped in archaeal glycerolipid vesicles (archaeosomes). in this study, we evaluated the priming, phenotype, and functionality of the cd8(+) t cells induced after immunization of mice with ova-methanobrevibacter smithii archaeosomes (ms-ova). a single injection of ms-ov ... | 2007 | 17277146 |
| expression of the p60 autolysin enhances nk cell activation and is required for listeria monocytogenes expansion in ifn-gamma-responsive mice. | both peptidoglycan and muropeptides potently modulate inflammatory and innate immune responses. the secreted listeria monocytogenes p60 autolysin digests peptidoglycan and promotes bacterial infection in vivo. here, we report that p60 contributes to bacterial subversion of nk cell activation and innate ifn-gamma production. l. monocytogenes deficient for p60 (deltap60) competed well for expansion in mice doubly deficient for ifnar1 and ifn-gammar1 or singly deficient for ifn-gammar1, but not in ... | 2007 | 17277147 |
| use of high-affinity cell wall-binding domains of bacteriophage endolysins for immobilization and separation of bacterial cells. | immobilization and magnetic separation for specific enrichment of microbial cells, such as the pathogen listeria monocytogenes, depends on the availability of suitable affinity molecules. we report here a novel concept for the immobilization and separation of bacterial cells by replacing antibodies with cell wall-binding domains (cbds) of bacteriophage-encoded peptidoglycan hydrolases (endolysins). these polypeptide modules very specifically recognize and bind to ligands on the gram-positive cel ... | 2007 | 17277212 |
| community-acquired listeria monocytogenes meningitis in adults. | | 2007 | 17278080 |
| immunostimulatory rna is a potent inducer of antigen-specific cytotoxic and humoral immune response in vivo. | single-stranded rna stimulates immune cells and induces the secretion of pro-inflammatory cytokines and type i ifn. as adjuvant rna can induce a t(h)2 type of humoral response, however, its potency in the induction of cytotoxic t cells in vivo has not been analyzed. here we show that immunization with the antigen ovalbumin (ova) and the adjuvant phosphodiester rna complexed to the cationic lipid n-[1-(2,3-dioleoyloxy)propyl]-n,n,n-trimethylammonium methylsulfate (dotap) induced a toll-like recep ... | 2007 | 17289655 |
| [determination of the minimum enrichment time for the qualitative detection of listeria monocytogenes in minced pork meat using multiplex-pcr, microarray and elisa]. | a qualitative detection of listeria monocytogenes was performed in spiked minced pork meat using elisa, multiplex-pcr, microarray and cultural reference method. minced pork meat in batches of 10 or 25 g was spiked with 25 cfu listeria monocytogenes per gram and incubated in selective enrichment solutions. during enrichment samples were collected continiously and a listeria monocytogenes-elisa, a multiplex-pcr with electrophoretical detection (listeria duplex) and a pcr with detection by microarr ... | 2007 | 17290946 |
| priming of cd8+ t cell responses by pathogens typically depends on cd70-mediated interactions with dendritic cells. | the cd27/cd70-interaction has been shown to provide a costimulatory and survival signal for t cells in vitro and in vivo. recently, cd70 expression by dc was found to be important for the priming of cd8+ t cells. we show here that blocking cd70 interactions has a significant impact on priming of cd8+ t cell responses by vaccinia virus (vv), listeria monocytogenes and vesicular stomatitis virus (vsv) in mice. however, the priming of specific cd8+ t cells upon infection with lymphocytic choriomeni ... | 2007 | 17295392 |
| [expression of acta gene of listeria monocytogenes in escherichia coli and preparation of acta monoclonal antibodies]. | the acta gene was amplified from lm-4 strain of listeria monocytogenes serotype 1/2a by pcr and inserted into t vector. sequencing showed acta gene was 1833bp long and nucleotide homology was 100% compared with acta gene of listeria monocytogenes egd strain in genbank. the cloned acta gene was then inserted into prokaryotic expression vector pgex-6p-1 and pet respectively. the predicted fusion protein was detected by sds-page after iptg induction of recombinant bacteria. the fusion protein expre ... | 2006 | 17302169 |
| characterization of rela and cody mutants of listeria monocytogenes: identification of the cody regulon and its role in virulence. | listeria monocytogenes is a gram-positive intracellular parasite and the causative organism of human listeriosis. in this article we demonstrate that l. monocytogenes encodes a functional member of the cody family of global regulatory proteins that is responsive to both gtp and branched chain amino acids. by transcript analyses we identified the cody regulon in l. monocytogenes and demonstrated that it comprises genes involved in amino acid metabolism, nitrogen assimilation as well as genes invo ... | 2007 | 17302820 |
| [bacterial meningitis in denmark 2002-2003. a nation-wide laboratory-based registration]. | notification of bacterial meningitis (bm) is likely to be incomplete, and a recent danish study indicated that unbalanced notification may bias expected aetiology of bm. therefore the danish bacterial meningitis group initiated a national registration of culture-positive bm. | 2007 | 17303030 |
| identification and molecular characterization of listeria monocytogenes isolated in raw milk in the region of algiers (algeria). | listeria monocytogenes was isolated from raw milk, whey and curdled milk produced and collected in the region of algiers and blida between september 2003 and july 2004. four out of 153 (2.61%) farm milk samples and 6 out of 80 (7.50%) tankers' samples tested positive for l. monocytogenes. all samples of whey and curdled milk (n=12) tested negative for l. monocytogenes, but 2 of 22 (9%) samples of whey were contaminated by l. innocua. l. monocytogenes isolates were grouped by a multiplex pcr assa ... | 2007 | 17303276 |
| investigation of the mechanism of binding between internalin b and heparin using surface plasmon resonance. | listeria monocytogenes, a food-borne pathogen that infects immunocompromised patients, enters and proliferates within mammalian cells by taking advantage of host cell machinery. while entry into macrophages and other phagocytic cells occurs constitutively, intracellular invasion of nonphagocytic cells, such as epithelial and endothelial cells, occurs through induced phagocytosis. invasion of these nonphagocytic cell types is under the control of the secreted l. monocytogenes protein internalin b ... | 2007 | 17305366 |
| application of single strand conformation polymorphism --pcr method for distinguishing cheese bacterial communities that inhibit listeria monocytogenes. | the aim of this study was to compare the microbial communities of different cheeses where listeria monocytogenes either grew or did not grow. for this purpose, (i) isolates from the most inhibitory cheese ecosystem were identified and their ability to produce anti-listeria substances was determined, (ii) bacterial communities of cheeses with and without l. monocytogenes growth were compared using the single strand conformation polymorphism method. the study showed sscp to be an effective tool fo ... | 2007 | 17306399 |
| modelling the bacterial survival/death interface induced by high pressure processing. | the survival/death interface model was developed for prediction of inactivation of listeria monocytogenes by high pressure processing (hpp). the model was derived from data sets comprising 360 combinations of environmental factors such as pressure (200, 300 400, and 500 mpa), pressure-holding time (1, 3, 5, 10, 20, 30 min), ph (3, 4, 5, 6, 7), and inoculum level (3, 5, 7 log(10) cfu/ml). the determination of survival/death of l. monocytogenes after hpp was confirmed by the presence/absence of co ... | 2007 | 17307266 |
| a mariner-based transposition system for listeria monocytogenes. | in this study, we developed a new mariner-based transposition system for listeria monocytogenes. the mariner-based system has a high rate of transposition and a low rate of plasmid retention, and transposition is very random, making it an ideal tool for high-throughput transposon mutagenesis in l. monocytogenes. | 2007 | 17308180 |
| the synergistic effect of nisin and lactoferrin on the inhibition of listeria monocytogenes and escherichia coli o157:h7. | the goal of this study was to determine whether nisin and lactoferrin would act synergistically to inhibit the growth of listeria monocytogenes and escherichia coli o157:h7. | 2007 | 17309501 |
| effectiveness of cell-adsorbed bacteriocin produced by lactobacillus curvatus cwbi-b28 and selected essential oils to control listeria monocytogenes in pork meat during cold storage. | to study the effectiveness of a combination of cell-adsorbed bacteriocin (cab; a suspension of producer cells on which maximum bacteriocin has been immobilized by ph adjustments) of a lactobacillus curvatus strain with oregano or savory essential oil to control listeria monocytogenes in pork meat at 4 degrees c. | 2007 | 17309503 |
| characteristics of bacteriocin-like inhibitory substances from dochi-isolated enterococcus faecium d081821 and d081833. | to characterize bacteriocin-like inhibitory substances (blis) from two dochi-isolated enterococcus faecium. | 2007 | 17309511 |
| effect of nacl and kcl on fate and growth/no growth interfaces of listeria monocytogenes scott a at different ph and nisin concentrations. | the fate of listeria monocytogenes scott a, was studied in broth, at different a(w)s (by adding nacl or kcl from 0.0 to 1.4 mol l(-1)), phs (from 4.0 to 7.3 by adding lactic acid), and nisin concentrations (from 0 to 100 iu ml(-1)). | 2007 | 17309630 |
| targeting of antigen to dendritic cells with poly(gamma-glutamic acid) nanoparticles induces antigen-specific humoral and cellular immunity. | nanoparticles are considered to be efficient tools for inducing potent immune responses by an ag carrier. in this study, we examined the effect of ag-carrying biodegradable poly(gamma-glutamic acid) (gamma-pga) nanoparticles (nps) on the induction of immune responses in mice. the nps were efficiently taken up by dendritic cells (dcs) and subsequently localized in the lysosomal compartments. gamma-pga nps strongly induced cytokine production, up-regulation of costimulatory molecules, and the enha ... | 2007 | 17312143 |
| interleukin-1 receptor type 1 is essential for control of cerebral but not systemic listeriosis. | listeria monocytogenes may infect the central nervous system and several peripheral organs. to explore the function of il-1 receptor type 1 (il-1r1) in cerebral versus systemic listeriosis, il-1r1(-/-) and wild-type mice were infected either intracerebrally or intraperitoneally with l. monocytogenes. after intracerebral infection with various numbers of attenuated listeria, il-1r1(-/-) mice succumbed due to an insufficient control of intracerebral listeria, whereas all wild-type mice survived, e ... | 2007 | 17322383 |
| immunoediting sculpts tumor epitopes during immunotherapy. | immunoediting of tumor-associated antigens occurs in response to immune pressure. we show that the mutation of residues within epitopes of her-2/neu leads to the outgrowth of autochthonous tumors after immunizing her-2/neu transgenic mice with listeria monocytogenes therapeutic vaccines expressing fragments of her-2/neu. three of these vaccines target the extracellular domain (lmllo-ec1, lmllo-ec2, and lmllo-ec3), and two of these vaccines target the intracellular domain (lm-llo-ic1 and lm-llo-i ... | 2007 | 17332314 |
| asymmetric t lymphocyte division in the initiation of adaptive immune responses. | a hallmark of mammalian immunity is the heterogeneity of cell fate that exists among pathogen-experienced lymphocytes. we show that a dividing t lymphocyte initially responding to a microbe exhibits unequal partitioning of proteins that mediate signaling, cell fate specification, and asymmetric cell division. asymmetric segregation of determinants appears to be coordinated by prolonged interaction between the t cell and its antigen-presenting cell before division. additionally, the first two dau ... | 2007 | 17332376 |
| listeria--review of epidemiology and pathogenesis. | listeria monocytogenes (commonly called listeria) is a gram-positive facultatively intracellular foodborne pathogen often found in food and elsewhere in nature. it can cause a rare but serious disease called listeriosis, especially among pregnant women, the elderly or individuals with a weakened immune system. in serious cases, it can lead to brain infection and even death. listeria is more likely to cause death than other bacteria that cause food poisoning. in fact, 20 to 30% of food borne list ... | 2007 | 17332901 |
| a p60 mutant of listeria monocytogenes is impaired in its ability to cause infection in intragastrically inoculated mice. | a spontaneous p60 mutant of listeria monocytogenes was less able to cause systemic infection in a/j mice, following intragastric inoculation, than the parental wild type strain (slcc 5764, serotype 1/2a). significantly fewer cfu were recovered from internal organs (spleen, liver, gall bladder) and from the cecum of mice inoculated intragastrically with the p60 mutant than mice inoculated with wild type l. monocytogenes. the p60 mutant also exhibited a diminished ability to invade and multiply wi ... | 2007 | 17336491 |
| quantification of gene expression of listeria monocytogenes by real-time reverse transcription pcr: optimization, evaluation and pitfalls. | in the current study, various steps in the real-time reverse transcription pcr (real-time rt-pcr) method for determination of rna expression levels starting from different numbers of listeria monocytogenes cells were evaluated and optimized. our results showed that the rna isolation method as well as the cdna synthesis may influence the sensitivity of the procedure. for high bacterial cell numbers (10(9) bacterial cells), the rnaqueous kit and the rneasy mini kit were equally useful, whereas for ... | 2007 | 17337308 |
| occurrence and persistence of listeria spp. in the environment of ewe and cow's milk cheese dairies in portugal unveiled by an integrated analysis of identification, typing and spatial-temporal mapping along production cycle. | eight dairies, located in two distant geographic regions of portugal, were screened along the production cycle in order to evaluate the presence and distribution of listeria spp. in their environment. three dairies in each region were positive for the presence of listeriae and 213 isolates were obtained. based on an integrated analysis of rapd fingerprints with three primers, molecular identification and genomic typing of isolates was performed followed by spatial and temporal mapping on dairy p ... | 2007 | 17337311 |
| the alternative sigma factor sigma b and the virulence gene regulator prfa both regulate transcription of listeria monocytogenes internalins. | some listeria monocytogenes internalins are recognized as contributing to invasion of mammalian tissue culture cells. while prfa is well established as a positive regulator of l. monocytogenes virulence gene expression, the stress-responsive sigma(b) has been recognized only recently as contributing to expression of virulence genes, including some that encode internalins. to measure the relative contributions of prfa and sigma(b) to internalin gene transcription, we used reverse transcription-pc ... | 2007 | 17337550 |
| temperature-dependent expression of listeria monocytogenes internalin and internalin-like genes suggests functional diversity of these proteins among the listeriae. | the listeria monocytogenes genome contains genes encoding several internalins and internalin-like proteins. as l. monocytogenes is present in many environments and can infect numerous, diverse host species, the environmental temperature was hypothesized to be a signal that might affect internalin gene transcription. a subgenomic microarray was used to investigate temperature-dependent transcription of 24 members of the internalin gene family in l. monocytogenes 10403s. the levels of internalin g ... | 2007 | 17337561 |
| the molecular mechanisms that control function and death of effector cd4+ t cells. | this review features two areas of our research interests. first, our laboratory is interested in elucidating the molecular mechanisms that control generation, effector function, and fate of th1 cells during inflammatory responses. we have been particularly interested in the role of the growth arrest and dna damage-inducible protein 45 (gadd45) gene family in th1-mediated immune responses. we and others have shown that, in th1 cells, gadd45b and gadd45g are induced by tcr signaling or il-12 and i ... | 2006 | 17337788 |
| neonatal listeriosis. | in western developed countries, listeria monocytogenesis not an uncommon pathogen in neonates. however, neonatal listeriosis has rarely been reported in taiwan. we describe two cases collected from a single medical institute between 1990 and 2005. case 1 was a male premature baby weighing 1558 g with a gestational age of 31 weeks whose mother had fever with chills 3 days prior to delivery. generalized maculopapular rash was found after delivery and subtle seizure developed. both blood and cerebr ... | 2007 | 17339161 |
| induction of protective immunity to listeria monocytogenes in neonates. | neonates suffer unduly from infections and also respond suboptimally to most commonly used vaccines. however, a cd8 t cell response can be elicited in neonates if the ag is introduced into the cytoplasm of apcs. listeria monocytogenes (lm) targets the cytoplasm of apc and is a strong cd8 and cd4 th1-promoting vaccine vehicle in adult mice. we hypothesized that an attenuated strain of lm would be safe and induce long-lasting protective immunity, even in neonates. we found that neonatal mice immun ... | 2007 | 17339467 |
| effects of heat-degraded sugars on survival and growth of vibrio parahaemolyticus and other bacteria. | we studied the effects of autoclaved (121 degrees c, 15 min) sugar solutions on the survival and growth of vibrio parahaemolyticus and other bacteria. the growth and survival of v. parahaemolyticus in luria-bertani media and phosphate buffer, respectively, were inhibited by the addition of d-glucose autoclaved in ph 8.0 phosphate buffer. the bactericidal effect of autoclaved d-glucose was very small when autoclaved in ph 7.0 phosphate buffer, but larger effects were observed when autoclaved in t ... | 2007 | 17340871 |
| fate of listeria monocytogenes in commercial ham, formulated with or without antimicrobials, under conditions simulating contamination in the processing or retail environment and during home storage. | commercial cured ham formulated with or without potassium lactate and sodium diacetate was inoculated with listeria monocytogenes and stored to simulate conditions of processing, retail, and home storage. the ham was sliced, inoculated with a 10-strain composite of l. monocytogenes (1 to 2 log cfu/cm2), vacuum packaged, and stored at 4 degrees c to simulate contamination following lethality treatment at processing (first shelf life). after 10, 20, 35, and 60 days of storage, packages were opened ... | 2007 | 17340872 |
| effect of inhibitory liquid smoke fractions on listeria monocytogenes during long-term storage of frankfurters. | listeria monocytogenes is a potential health hazard that sometimes finds harborage in facilities that manufacture ready-to-eat meats, including frankfurters. our objectives were to examine the effect of select liquid smoke extracts on control of l. monocytogenes on frankfurters. frankfurters were either obtained locally at retail (containing lactate-diacetate) or manufactured for us in-house or by a local processor (without added lactate-diacetate). in challenge studies of retail franks containi ... | 2007 | 17340873 |
| use of octanoic acid as a postlethality treatment to reduce listeria monocytogenes on ready-to-eat meat and poultry products. | the antilisterial efficacy and organoleptic impact of an octanoic acid (oa)-based treatment for ready-to-eat (rte) meat and poultry products were investigated. whole-muscle and comminuted rte products were inoculated with a five-strain mixture of listeria monocytogenes. the oa treatments were applied to the surface of rte products by dispensing a specific volume of solution directly into the final package prior to vacuum sealing. once sealed, the vacuum-packaged rte products containing oa were i ... | 2007 | 17340874 |
| influence of salt, smoke, and high pressure on growth of listeria monocytogenes and spoilage microflora in cold-smoked dolphinfish (coryphaena hippurus). | the effects of different salting and smoking conditions on the growth of listeria monocytogenes in cold-smoked dolphinfish (coryphaena hippurus) fillets were evaluated. high concentrations of phenol (72.47 ppm) and salt (3.25%) in muscle inhibited l. monocytogenes growth in smoked fish stored at 20 degrees c for 4 days. the antibacterial effect of high pressure in cold-smoked dolphinfish during long-term chilled (5 degrees c) storage was evaluated in fillets prepared according to two different s ... | 2007 | 17340875 |
| listeria monocytogenes f2365 carries several authentic mutations potentially leading to truncated gene products, including inlb, and demonstrates atypical phenotypic characteristics. | searches of the genome annotation of listeria monocytogenes f2365, an isolate from the 1985 listeriosis epidemic in california, showed that this strain carries 20 authentic mutations resulting in premature stop codons, including a nonsense mutation in inlb. here we showed that l. monocytogenes f2365 demonstrates atypical virulence-associated characteristics, including significantly (p < 0.05) reduced invasion efficiency in caco-2 cells as compared with a closely related lineage i serotype 4b str ... | 2007 | 17340887 |
| bacteria-eating virus approved as food additive. | not all viruses harm people. the food and drug administration has approved a mixture of viruses as a food additive to protect people. the additive can be used in processing plants for spraying onto ready-to-eat meat and poultry products to protect consumers from the potentially life-threatening bacterium listeria monocytogenes (l. monocytogenes). | 2007 | 17342833 |
| localization of protein kinase c epsilon to macrophage vacuoles perforated by listeria monocytogenes cytolysin. | three proteins secreted by listeria monocytogenes facilitate escape from macrophage vacuoles: the cholesterol-dependent cytolysin listeriolysin o (llo), a phosphoinositide-specific phospholipase c (pi-plc) and a broad-range phospholipase c (pc-plc). llo and pi-plc can activate several members of the protein kinase c (pkc) family during infection. pkcepsilon is a novel pkc that contributes to macrophage activation, defence against bacterial infection, and phagocytosis; however, a role for pkcepsi ... | 2007 | 17346313 |
| improved luciferase tagging system for listeria monocytogenes allows real-time monitoring in vivo and in vitro. | an improved system for luciferase tagging listeria monocytogenes was developed by constructing a highly active, constitutive promoter. this construct gave 100-fold-higher activity in broth than any native promoter tested and allowed for imaging of lux-tagged l. monocytogenes in food products, during murine infections, and in tumor targeting studies. | 2007 | 17351089 |
| effect of a previous heat shock on the thermal resistance of listeria monocytogenes and pseudomonas aeruginosa at different phs. | in this work we study the effect of heat shocks of various durations up to 60 min, at different temperatures between 35 and 45 degrees c, in media of ph 4.0, 5.5 and 7.4 on the heat resistance of listeria monocytogenes and pseudomonas aeruginosa. the pattern of survival curves after heat treatment did not change with the application of a previous heat shock. however, the kinetics of inactivation was different for the two microorganisms studied. whereas the inactivation of l. monocytogenes was si ... | 2007 | 17355896 |
| 3,4-dichloropropionaniline suppresses normal macrophage function. | macrophages are a critical part of the innate immune response and natural surveillance mechanisms. as such, proper macrophage function is crucial for engulfing bacterial pathogens through phagocytosis and destroying them by generation of reactive oxygen species (ros) and reactive nitrogen species (rns). the production of a number of cytokines by macrophages, such as tumor necrosis factor-alpha (tnf-alpha), interleukin (il)-1beta, and il-6, plays an important role in the initiation of the acquire ... | 2007 | 17355946 |
| sterol and ph interdependence in the binding, oligomerization, and pore formation of listeriolysin o. | listeriolysin o (llo) is the most important virulence factor of the intracellular pathogen listeria monocytogenes. its main task is to enable escape of bacteria from the phagosomal vacuole into the cytoplasm. llo belongs to the cholesterol-dependent cytolysin (cdc) family but differs from other members, as it exhibits optimal activity at low ph. its pore forming ability at higher ph values has been largely disregarded in listeria pathogenesis. here we show that high cholesterol concentrations in ... | 2007 | 17358050 |
| interactions between the environmental pathogen listeria monocytogenes and a free-living protozoan (acanthamoeba castellanii). | listeria monocytogenes can cause severe disease in animal hosts, but it has no recognized animal host reservoir. we tested the hypothesis that l. monocytogenes retains virulence traits to survive predation by amoebae and that listeriolysin o plays a crucial role in this process. co-culturing of l. monocytogenes and acanthamoeba castellanii demonstrated that l. monocytogenes does not actively kill amoebae, but in the presence of amoebae, high bacterial population densities can be maintained over ... | 2007 | 17359263 |
| survey on the listeria contamination of ready-to-eat food products and household environments in vienna, austria. | qualitative and quantitative contamination of ready-to-eat food-stuffs with the pathogen listeria monocytogenes was studied in 1586 samples collected from 103 supermarkets (n = 946) and 61 households (n = 640) in vienna, austria. seventeen groups of ready-to-eat foods were classified into three risk categories for contamination (cp1-cp3). three to four samples were randomly collected at the retail level from each cp. regarding the households, the sampling procedure was started with food items of ... | 2007 | 17359442 |
| an evaluation of the neonatal immune system using a listeria infection model. | t helper 1 (th1)/t helper 2 (th2)-biased cytokine regulation may be another reason that neonates are much more susceptible to infectious disease than are adults. | 2007 | 17361091 |
| modeling individual cell lag time distributions for listeria monocytogenes. | the food industry faces two paradoxical demands: on the one hand, foods need to be microbiologically safe for consumption and on the other hand, consumers want fresh, minimally processed foods. to meet these demands, more insight into the mechanisms of microbial growth is needed, which includes, among others, the microbial lag phase. this is the time needed by bacterial cells to adapt to a new environment (for example, after food product contamination) before starting an exponential growth regim ... | 2007 | 17362412 |
| behavior of listeria monocytogenes at 7 degrees c in commercial turkey breast, with or without antimicrobials, after simulated contamination for manufacturing, retail and consumer settings. | uncured turkey breast, commercially available with or without a mixture of potassium lactate and sodium diacetate, was sliced, inoculated with a 10-strain composite of listeria monocytogenes, vacuum-packaged, and stored at 4 degrees c, to simulate contamination after a lethal processing step at the plant. at 5, 15, 25 and 50 days of storage, packages were opened, slices were tested, and bags with remaining slices were reclosed with rubber bands; this simulated home use of plant-sliced and -packa ... | 2007 | 17367676 |
| growth characteristics of listeria monocytogenes, listeria welshimeri and listeria innocua strains in broth cultures and a sliced bologna-type product at 4 and 7 degrees c. | the growth characteristics of meat processing plant-derived field strains of listeria monocytogenes, l. welshimeri and l. innocua were analyzed. the strains were inoculated in bhi broth cultures and incubated at 4 and 7 degrees c. growth curves were determined by colony counting for 28 days. significant variations were detected in the growth properties of these field-derived strains. in particular some of the l. monocytogenes strains displayed better cold stress tolerance. these discrepancies in ... | 2007 | 17367677 |
| product unit neural network models for predicting the growth limits of listeria monocytogenes. | a new approach to predict the growth/no growth interface of listeria monocytogenes as a function of storage temperature, ph, citric acid (ca) and ascorbic acid (aa) is presented. a linear logistic regression procedure was performed and a non-linear model was obtained by adding new variables by means of a neural network model based on product units (punn). the classification efficiency of the training data set and the generalization data of the new logistic regression punn model (lrpu) were compa ... | 2007 | 17367678 |
| major role of levofloxacin in the treatment of a case of listeria monocytogenes meningitis. | we report a case of acute bacterial meningitis due to listeria monocytogenes whose successful treatment was mainly attributable to high-dose levofloxacin therapy (500 mg iv bid). this supports the hypothesis that levofloxacin may be an effective option for the treatment of listerial meningitis. | 2007 | 17368798 |
| [evaluation of api coryne system, version 2.0, for diphteroid gram-positive rods identification with clinical relevance]. | the ability of the api coryne system, version 2.0, to identify 178 strains of gram-positive rods was evaluated. seventy eight isolates belonged to genus corynebacterium and one hundred to related genera, all strains were isolated from clinical samples at the laboratory of bacteriology, hospital de clínicas josé de san martin (uba) between 1995 and 2004. the isolates were identified according to von graevenitz and funke's scheme. one hundred and sixty two out of 178 strains (91%) were correctly i ... | 2006 | 17370571 |
| [foodborne listeria monocytogenes: are all the isolates equally virulent?]. | listeria monocytogenes is a foodborne human pathogen responsible for invasive infections presenting overall a high mortality. despite the ubiquity of the microorganism, the actual disease rate is quite low and the disease is most often associated with an underlying predisposition. foodborne and environmental isolates were traditionally considered of similar pathogenicity compared to clinical isolates. but the analysis of mutations in the genes encoding specific virulence factors (internalin, hem ... | 2006 | 17370579 |
| outbreak of listeriosis in the czech republic, late 2006--preliminary report. | | 2007 | 17370949 |
| functional plasticity in memory t helper cell responses. | following activation, naive cd4+ th cells can differentiate to selectively produce either the th1 lineage-specific cytokine ifn-gamma or the th2 cytokine il-4 and, in so doing, lose the capacity to produce cytokines of the alternative lineage. lineage commitment of murine cd4+ t cells has largely been considered to be absolute with little flexibility to produce cytokines of the opposing lineage. in this study, we demonstrate that cells within th2 memory populations can produce ifn-gamma if react ... | 2007 | 17371962 |
| nk dendritic cells are innate immune responders to listeria monocytogenes infection. | nk dendritic cells (nkdc) are recently described immunologic cells that possess both lytic and ag-presenting function and produce prolific quantities of ifn-gamma. the role of nkdc in innate immunity to bacterial infection is unknown. because ifn-gamma is important in the immune response to listeria monocytogenes (lm), we hypothesized that nkdc play a critical role during lm infection in mice. we found that lm increased the frequency and activation state of nkdc in vivo. using in vivo intracellu ... | 2007 | 17371998 |
| tyk2 signaling in host environment plays an important role in contraction of antigen-specific cd8+ t cells following a microbial infection. | tyrosine kinase 2 (tyk2), a member of jak signal transducer family contributes to the signals triggered by il-12 for ifn-gamma production. to elucidate potential roles of tyk2 in generation and maintenance of ag-specific cd8+ t cells, we followed the fate of ova-specific cd8+ t cells in tyk2-deficient (-/-) mice after infection with recombinant listeria monocytogenes expressing ova (rlm-ova). results showed that the numbers of ova(257-264)/k(b) tetramer-positive cd8+ t cells in tyk2(-/-) mice we ... | 2007 | 17372006 |
| il-12 and type-i ifn synergize for ifn-gamma production by cd4 t cells, whereas neither are required for ifn-gamma production by cd8 t cells after listeria monocytogenes infection. | differentiation of ag-specific t cells into ifn-gamma producers is essential for protective immunity to intracellular pathogens. in addition to stimulation through the tcr and costimulatory molecules, ifn-gamma production is thought to require other inflammatory cytokines. two such inflammatory cytokines are il-12 and type i ifn (ifn-i); both can play a role in priming naive t cells to produce ifn-gamma in vitro. however, their role in priming ag-specific t cells for ifn-gamma production during ... | 2007 | 17372008 |
| quantitative recovery of listeria monocytogenes and select salmonella serotypes from environmental sample media. | environmental sampling has become increasingly important in the food industry for monitoring the presence of specific pathogens such as listeria monocytogenes and salmonella enterica. several microbiological media are available for storage and transport of environmental samples from the processing plant to the test laboratory. in this study, we quantified the survival of l. monocytogenes, s. typhimurium, s. enteritidis, and s. typhi in environmental sampling media over several time and temperatu ... | 2007 | 17373457 |
| inactivation of foodborne pathogens using a one atmosphere uniform glow discharge plasma. | this study was conducted to determine the efficacy of a one atmosphere uniform glow discharge plasma (oaugdp) for inactivation of foodborne pathogens and to evaluate the influence of growth temperature, ph, and culture age on their inactivation. escherichia coli o157:h7, listeria monocytogenes, staphylococcus aureus, bacillus cereus, salmonella enteritidis, vibrio parahaemolyticus, yersinia enterocolitica, and shigella flexneri were evaluated. three-strain mixtures of each bacterium were inocula ... | 2007 | 17378708 |
| evaluation of the pathogenicity of listeria spp. in caenorhabditis elegans. | caenorhabditis has proven to be a useful model for studying host-pathogen interactions as well as the ability of nematodes to serve as vectors for the dispersal of foodborne pathogens. in this study, we evaluated whether c. elegans can serve as a host for listeria spp. while there was an effect of growth media on c. elegans killing, c. elegans exposed to l. monocytogenes and l. innocua pregrown in luria-bertani medium showed reduced survival when compared to nonpathogenic e. coli op50, while l. ... | 2007 | 17378710 |
| development of listeria monocytogenes-specific immunomagnetic beads using a single-chain antibody fragment. | a method for coupling single-chain antibody fragments (scfvs) to immunomagnetic beads (imbs) was developed and evaluated using scfvs specific for listeria monocytogenes. a plasmid vector, pbad380, was constructed that allowed the expression of histidine-tagged biotinylated scfvs in escherichia coli. the gene encoding a scfv specific for l. monocytogenes was cloned into pbad380 and the 6-histidine-tagged biotinylated anti-l. monocytogenes scfvs were coupled to streptavidin-coated imbs. the abilit ... | 2007 | 17378711 |
| influence of immunomodulation on the development of listeria monocytogenes infection in aged guinea pigs. | we investigated the impact of immunomodulation on the development of listeriosis within an aged population of guinea pigs after an intragastric challenge with listeria monocytogenes. supplementation with vitamin e for 35 days significantly increased the level of cytotoxic t cells (cd8(+)), while treatment with cyclosporin a resulted in a 25% decrease of cd8(+) t cells. in the animals receiving the low dose (10(2) cfu) of l. monocytogenes, 50% of the control-group animals became infected. only 22 ... | 2007 | 17378902 |
| a naturally occurring mutation k220t in the pleiotropic activator prfa of listeria monocytogenes results in a loss of virulence due to decreasing dna-binding affinity. | the sequencing of prfa, encoding the transcriptional regulator of virulence genes, in 26 low-virulence field listeria monocytogenes strains showed that eight strains exhibited the same single amino-acid substitution: prfak220t. these strains exhibited no expression of prfa-regulated proteins and thus no virulence. this substitution inactivated prfa, since expression of the prfak220t mutant gene in an egddeltaprfa strain did not restore the haemolytic and phosphatidylcholine phospholipase c activ ... | 2007 | 17379709 |
| molecular characterization of the fur protein of listeria monocytogenes. | iron is essential for the survival of almost all organisms, although excess iron can result in the generation of free radicals which are toxic to cells. to avoid the toxic effects of free radicals, the concentration of intracellular iron is generally regulated by the ferric uptake regulator fur in bacteria. the 150 aa fur orf from listeria monocytogenes was cloned into prseta, and the his-tagged fusion protein was purified by nickel affinity column chromatography. dna binding activity of this pr ... | 2007 | 17379719 |
| immunology. asymmetry and immune memory. | | 2007 | 17379796 |
| antimicrobial activity of bacillus subtilis and bacillus pumilus during the fermentation of african locust bean (parkia biglobosa) for soumbala production. | to examine predominant isolates of bacillus subtilis and b. pumilus isolated from soumbala for their antimicrobial activity against indicator microorganisms as micrococcus luteus, staphyloccocus aureus, bacillus cereus, enterococus facium, listeria monocytogenes, escherichia coli, salmonella typhimurium, shigella dysenteriae, yersinia enterocolitica, aspergillus ochraceus and penicillium roqueforti. | 2007 | 17381739 |
| role of caspase-8 in hepatocyte response to infection and injury in mice. | caspase-8 has been implicated in signaling for apoptotic cell death and for certain nonapoptotic functions. however, knowledge of actual physiological or pathophysiological processes to which this enzyme contributes is lacking. using a mouse model and employing the conditional knockout approach to delete the caspase-8 gene specifically in the liver, we found that caspase-8 deficiency in hepatocytes facilitates infection of the liver by listeria monocytogenes, attenuates the hepatocyte proliferat ... | 2007 | 17385212 |
| rapid detection of escherichia coli o157:h7 spiked into food matrices. | food poisoning causes untold discomfort to many people each year. one of the primary culprits in food poisoning is escherichia coli o157:h7. while most cases cause intestinal discomfort, up to 7% of the incidences lead to a severe complication called hemolytic uremic syndrome which may be fatal. the traditional method for detection of e. coli o157:h7 in cases of food poisoning is to culture the food matrices and/or human stool. additional performance-based antibody methods are also being used. t ... | 2007 | 17386586 |
| axonal transport of listeria monocytogenes and nerve-cell-induced bacterial killing. | listeria monocytogenes (l. monocytogenes) can cause fatal brainstem encephalitis in both sheep and humans. here we review evidence that the bacteria can be incorporated into axons following a primary cycle of replication in macrophages/dendritic cells after subcutaneous injection in projection areas of peripheral neurons. the molecular mechanisms for the rocketing of l. monocytogenes in the cytosol by asymmetric cometic tails and the utility of this phenomenon for bacterial migration intraaxonal ... | 2007 | 17387705 |
| isolation and molecular characterization of antibiotic-resistant lactic acid bacteria from poultry and swine meat products. | the transfer via the food chain from animals to humans of microbes that are resistant to antimicrobial agents is of increasing concern. to determine the contributions of nonpathogenic microflora to the occurrence and spread of antibiotic resistance (ar) genes in the food chain, 123 lactic acid bacteria were isolated from 29 samples of raw and processed pork and chicken meat products that had previously tested positive for one or more ar genes that encode clinically relevant ars: tet(m), tet(o), ... | 2007 | 17388042 |
| distribution of epidemic clonal genetic markers among listeria monocytogenes 4b isolates. | recent genome sequencing of isolates of listeria monocytogenes serotype 4b implicated in some major outbreaks of foodborne listeriosis has revealed unique genetic markers in these isolates. the isolates were grouped into two distinct epidemic clones, eci and ecii. in the present study, selected eci- and ecii-specific genetic markers were detected in 16 and 15 of 89 l. monocytogenes 4b isolates, respectively. the eci markers were found in 6 of 34 clinical isolates, 9 of 50 food isolates, and 1 of ... | 2007 | 17388044 |
| sodium chloride enhances adherence and aggregation and strain variation influences invasiveness of listeria monocytogenes strains. | some subtypes of listeria monocytogenes can persist in the food-processing industry, but the reasons for such persistence are not known. in the present study, 10 strains of l. monocytogenes representing known persistent randomly amplified polymorphic dna (rapd) types from fish processing plants were compared to eight strains of different rapd type and origin (clinical, food, and animal). all 18 strains of l. monocytogenes had similar growth patterns at different temperatures (5 or 37 degrees c) ... | 2007 | 17388046 |
| evaluation of the transfer of listeria monocytogenes from stainless steel and high-density polyethylene to bologna and american cheese. | the objective of this study was to determine the factors involved in the transfer of listeria monocytogenes from surfaces to foods. we evaluated the influence of surface type (stainless steel and high-density polyethylene), inoculation method (biofilm growth and attached cells), hydration level (visibly dry and wet), and food type (bologna and american cheese). each experiment included all 16 combinations and was repeated 11 times. a four-strain cocktail of l. monocytogenes was used to inoculate ... | 2007 | 17388047 |
| quantitative effect of refrigerated storage time on the enumeration of campylobacter, listeria, and salmonella on artificially inoculated raw chicken meat. | active monitoring of pathogens on retail foods has been recommended and implemented in a number of developed countries. because only a portion of retail food is contaminated with pathogens, a cost-effective and informative surveillance program at the retail level often involves a two-stage approach of initial presence-absence analysis and subsequent pathogen enumeration in any positive samples. most-probable-number (mpn) methods are more resource intensive and therefore used only for samples con ... | 2007 | 17388068 |
| modeling the growth of listeria monocytogenes in pasteurized white asparagus. | growth of listeria monocytogenes in pasteurized white asparagus was monitored at different storage temperatures (4, 10, 20, and 30 degrees c). among the main microbial kinetic parameters, growth rate (mu) per hour was calculated at each temperature using the baranyi-roberts model. l. monocytogenes was able to grow at all temperatures, although at 4 degrees c only a slight increment of the microbial population was observed (approximately 1 log cfu/g) after 300 h of storage. subsequently, two diff ... | 2007 | 17388071 |
| ultrasonic cleaning of conveyor belt materials using listeria monocytogenes as a model organism. | persistent listeria monocytogenes contamination of food industry equipment is a difficult problem to solve. ultrasonic cleaning offers new possibilities for cleaning conveyors and other equipment that are not easy to clean. ultrasonic cleaning was tested on three conveyor belt materials: polypropylene, acetal, and stainless steel (cold-rolled, aisi 304). cleaning efficiency was tested at two temperatures (30 and 45 degrees c) and two cleaning times (30 and 60 s) with two cleaning detergents (koh ... | 2007 | 17388072 |