| minimal water activity levels for growth and survival of listeria monocytogenes and listeria innocua. | following initial range-finding experiments, total count determinations were used to determine minimal water activity (aw) levels for the growth and survival of listeria monocytogenes (l.m.) and l. innocua (l.i.). media containing three different humectants; nacl, sucrose or glycerol were used to determine minimal aw levels for growth in the above media which were 0.92, 0.92 and 0.90 respectively. the growth minima for l.i. were similar, or slightly higher than for l.m. in these media. survival ... | 1992 | 1457291 |
| development of a repair-enrichment broth for resuscitation of heat-injured listeria monocytogenes and listeria innocua. | the ability of the divalent cations magnesium, iron, calcium and manganese; yeast extract; pyruvate; catalase; and the carbohydrates glucose, lactose, sucrose, esculin, fructose, galactose, maltose, and mannose to facilitate repair of heat-injured listeria monocytogenes and listeria innocua was evaluated. listeria populations were injured by heating at 56 degrees c for 50 min. to determine the effects on repair, trypticase soy broth (tsb) was supplemented with each medium component to be evaluat ... | 1992 | 1531746 |
| phylogenetic analysis of the genus listeria based on reverse transcriptase sequencing of 16s rrna. | the phylogenetic interrelationships of members of the genus listeria were investigated by using reverse transcriptase sequencing of 16s rrna. the sequence data indicate that at the intrageneric level the genus listeria consists of the following two closely related but distinct lines of descent: (i) the listeria monocytogenes group of species (including listeria innocua, listeria ivanovii, listeria seeligeri, and listeria welshimeri) and (ii) the species listeria grayi and listeria murrayi. at th ... | 1991 | 1713054 |
| immunostimulatory effect of rothia dentocariosa in mice. | in mice killed rothia dentocariosa cells in doses of about 1.5 mg dry weight activated anti-infection immunity to listeria antigens and anti-tumour immunity to the ascitic form of mouse sarcoma s-180. their probable target site is the macrophage. the rothia-activated macrophages in human gingiva may take part in the pathogenesis of periodontal disease. three models were employed to verify the immunostimulating properties of preventively administered rothia dentocariosa bacterin-1) a spleen macro ... | 1991 | 1830743 |
| survival of listeria monocytogenes in egg washwater. | the viability of listeria monocytogenes strains scott a, 78-34, and 81-861 in artificial egg washwater at different temperatures and ph values was determined. after a 4-h incubation, less than a 1-log decrease in viability of strains scott a and 78-34 was found at 33 degrees c with alkaline detergent (ph 8.0-10.5); however, up to a 3-log decrease in viable numbers was found in neutral ph controls lacking detergent. at 42 degrees c, survival was generally poorer; complete loss of viability (great ... | 1991 | 1904755 |
| incidence of aeromonas and listeria spp. in red meat and milk samples in brisbane, australia. | a total of 150 samples, 50 each of beef, lamb and pork from 10 local retail stores in brisbane metropolitan area as well as 150 raw bovine bulk milk tank samples obtained from queensland united foods (quf), were examined for the presence of aeromonas and listeria spp. over a period of 1 year. different sets of enrichment and plating media were used to recover the organisms with subsequent identification using conventional biochemical and serotyping techniques. a total of 509 isolates consisting ... | 1991 | 1904764 |
| entry of l. monocytogenes into cells is mediated by internalin, a repeat protein reminiscent of surface antigens from gram-positive cocci. | we report the identification of a previously unknown gene, inla, which is necessary for the gram-positive intracellular pathogen listeria monocytogenes to invade cultured epithelial cells. the inla region was localized by transposon mutagenesis, cloned, and sequenced. inla was introduced into listeria innocua and shown to confer on this normally noninvasive species the ability to enter cells. sequencing of inla predicts an 80 kd protein, internalin. two-thirds of internalin is made up of two reg ... | 1991 | 1905979 |
| antagonistic effect of coryneform bacteria from red smear cheese against listeria species. | a total of 187 coryneform bacteria were isolated from red smear and screened for inhibitory effects against 16 strains of listeria species. culture filtrates from brevibacterium linens (16 strains), arthrobacter nicotianae (4 strains) and arthrobacter nucleogenes (3 strains) showed clear zones of inhibition. the antagonistic effect was seen against 26 to 87% of 91 listeria strains tested. a. nicotianae and a. nucleogenes were more effective against listeria innocua and listeria ivanovii than aga ... | 1991 | 1909545 |
| listeria isolations from feces of patients with diarrhea and from healthy food handlers. | a study was undertaken on the presence and frequency of listeria sp. in feces from 1,000 patients suffering from diarrheal diseases and from 2,000 healthy persons. furthermore, the feces of patients were examined for other well-documented enteropathogens such as campylobacter, salmonella, shigella, staphylococcus aureus, yersinia enterocolitica, protozoa and rotavirus as well as for organisms of questionable enteropathogenic potency such as fungi, i.e. candida. finally, in continuation of previo ... | 1990 | 2110118 |
| use of plasmid profiles and restriction endonuclease digest in environmental studies of listeria spp. from raw milk. | forty-eight isolates of listeria spp. (19 l. monocytogenes, 27 l. innocua, 2 l. welshimeri) from bulk raw milk were screened for plasmid dna. these isolates were collected over a period of 1 year. only l. innocua harboured plasmids (8/27 strains) which ranged in size 10-44 megadaltons. the plasmid bearing strains could be arranged into three groups 10 md, 44 md and 44 + 10 md. in two farms where listeria innocua were persistent in bulk raw milk different plasmids profiles were found (farm 1 and ... | 1990 | 2118791 |
| physiological studies on the growth and utilization of sugars by listeria species. | experiments, relevant to growth in milk, were done to delineate the aerobic and anaerobic growth of listeria species on selected sugars in several media. all species grew on glucose aerobically, forming lactic acid and (or) acetic acid. anaerobically, only lactic acid was formed; cell yields were 80% of those obtained aerobically. when incubated aerobically, small amounts (1.5 microns/ml) of isovaleric acid, 2-hydroxyisovaleric acid, and trace amounts of isobutyric acid were formed. these produc ... | 1989 | 2501014 |
| monoclonal antibody specific for listeria monocytogenes, listeria innocua, and listeria welshimeri. | eight hundred fifty-nine murine hybridomas were produced from eight fusions, and 27 were characterized for secretion of antibodies reactive to listeria monocytogenes. one monoclonal antibody (mab), p5c9, reacted with all test strains of l. monocytogenes (31 of 31), l. innocua (3 of 3), and l. welshimeri (1 of 1) but not with any strains of the other four listeria species or with any of 22 gram-positive or 11 gram-negative species of bacteria when tested in microtiter and dot blot enzyme immunoas ... | 1990 | 2116762 |
| efficacy of a variety of disinfectants against listeria spp. | the efficacy of 14 disinfectants against listeria innocua and two strains of listeria monocytogenes in the presence of organic matter was studied. quantitative efficacy tests were used. many of the disinfectants tested were not as effective on listeria spp. when the test organisms were dried onto the surface of steel disks (carrier tests) as they were when the organisms were placed in suspension (suspension test). the presence of whole serum and milk (2% fat) further reduced the disinfectant cap ... | 1990 | 2106285 |
| [studies on the occurrence of listeria in cheese]. | various outbreaks of listeria registered in the usa and europe after eating cheese were the motive to investigate different cheese sorts of the gdr-production on the occurrence of listeria species. out of 100 samples of different cheese brands 11 curdled milk cheeses (11%) showed listeria innocua, an nonpathogenic listeria species. | 1991 | 2038861 |
| evaluation of hybridization characteristics of a cloned prf106 probe for listeria monocytogenes detection and development of a nonisotopic colony hybridization assay. | an internal fragment (prf106 fragment, ca. 500 bp) of a gene (msp) coding for a 60-kda protein of listeria monocytogenes serotype 1/2a was used to develop a screening method to discriminate between l. monocytogenes and avirulent listeria spp. on primary isolation plates. the l. monocytogenes-derived probe fragment of prf106 hybridized to a 13-kb fragment of l. monocytogenes and a 3-kb fragment of one cheese isolate strain of listeria seeligeri under stringent hybridization conditions (mean therm ... | 1991 | 1903627 |
| carriage of listeria monocytogenes and related species in pregnant and non-pregnant women in aberdeen, scotland. | the faecal, cervico-vaginal and oropharyngeal carriage of listeria species in 54 healthy pregnant women and 60 healthy non-pregnant women was investigated. samples were cold-enriched at 4 degrees c and subcultured on selective media containing acriflavin, nalidixic acid and potassium thiocyanate. listeria monocytogenes was isolated from the faeces of one pregnant woman (2%) and two non-pregnant women (3.4%). listeria innocua was isolated from the faeces of one pregnant woman (2%) and one non-pre ... | 1986 | 3093591 |
| taxonomy of the genus listeria by using multilocus enzyme electrophoresis. | seventy-three strains of the seven recognized listeria species were studied by performing a multilocus enzyme electrophoresis analysis of 18 enzyme loci. the mean number of alleles per locus was 9.5 and all of the loci were polymorphic. a total of 56 electrophoretic types were distinguished. cluster analysis of a matrix of the genetic distances between paired electrophoretic types revealed that there were six principal clusters at the species level (genetic distances between clusters greater tha ... | 1991 | 1899799 |
| sensitive and specific detection of listeria monocytogenes in milk and ground beef with the polymerase chain reaction. | a sensitive and specific method for detection of listeria monocytogenes in milk and ground-beef samples is described. it consists of culturing samples in listeria enrichment broth (leb) and subculturing them from leb to listeria plating media, followed by dna extraction and species-specific detection of the organism by using the polymerase chain reaction (pcr). in developing the l. monocytogenes pcr assay, five oligonucleotide primers complementary to the nucleotide sequence of the listeriolysin ... | 1991 | 1768130 |
| evaluation of an enzymatic method for fast identification of listeria spp. in cheese and meat products. | listeria-tek elisa was compared with conventional cultural procedure of fil/idf (federation international de laiterie/international dairy federation) modified by us. the elisa assay is able to detect listeria innocua, listeria monocytogenes, listeria murrayi and listeria welshimeri, after 48 h in artificially contaminated cheeses. no specific reactions, no false positive or negative were detected and the assay has a high correlation with the conventional method used in this research. we also ana ... | 1991 | 1750966 |
| development and characterization of a monoclonal antibody specific for listeria monocytogenes and listeria innocua. | balb/c mice were immunized with crude cell surface proteins of listeria monocytogenes v7. approximately 1,680 hybridomas were generated after two fusions, and the monoclone c11e9 was selected and used for further characterization. the monoclonal antibody (mab) produced by c11e9 was immunoglobulin subclass g2b with kappa light chains. dot and colony blot results indicated that mab c11e9 was reactive to all the l. monocytogenes (34 of 34) and listeria innocua (6 of 6) isolates without any cross-re ... | 1991 | 1715321 |
| phosphatidylinositol-specific phospholipase c activity as a marker to distinguish between pathogenic and nonpathogenic listeria species. | in this study, 468 listeria strains were checked for the presence of phosphatidylinositol-specific phospholipase c (pi-plc) activity by using a simple assay that consisted of overlaying colonies formed on agar plates with l-alpha-phosphatidylinositol as substrate. in this assay, pi-plc-active colonies show turbid halos around the colonies as a result of the release of insoluble diacylglycerol from the substrate. this activity was detected only in the pathogenic species listeria monocytogenes and ... | 1991 | 1662937 |
| monoclonal antibody specific for listeria monocytogenes associated with a 66-kilodalton cell surface antigen. | a monoclonal antibody (mab), em-7g1, specific for listeria monocytogenes was developed by using a previously developed mab, c11e9 (a. k. bhunia, p. h. ball, a. t. fuad, b. w. kurz, j. w. emerson, and m. g. johnson, infect. immun. 59:3176-3184, 1991), to mask epitopes shared by l. monocytogenes and listeria innocua in a 66-kda cell surface protein. mab em-7g1 was an immunoglobulin subclass g1 antibody with kappa light chains. this mab reacted with all 34 strains of l. monocytogenes tested and sho ... | 1992 | 1622267 |
| differentiation of listeria monocytogenes, listeria innocua, listeria ivanovii, and listeria seeligeri by pulsed-field gel electrophoresis. | clamped homogeneous electric field analysis of listeria dna with apai, asci, smai, or noti revealed species- and serotype-specific differences in genomic fingerprints. clamped homogeneous electric field analysis may prove useful, therefore, in epidemiologic studies. also, the summation of individually sized asci fragments of genomic dna from l. monocytogenes serotype 4b 101m and scott a indicated genome lengths of 2,925 and 3,046 kb, respectively. | 1992 | 1610193 |
| determination of virulence of different strains of listeria monocytogenes and listeria innocua by oral inoculation of pregnant mice. | a pregnant mouse model was developed to follow the course of infection after peroral inoculation with six different strains of listeria monocytogenes and one strain of listeria innocua. tissues were sampled and analyzed by microbiologic and histologic methods for 5 days postinoculation. in gnotobiotic pregnant balb/c mice, l. monocytogenes scott a (sa), serotype 4b, colonized the gastrointestinal tract, translocated to the livers and spleens of mice by day 1 postinoculation, and multiplied in th ... | 1992 | 1476441 |
| dna sequence heterogeneity in the gene encoding a 60-kilodalton extracellular protein of listeria monocytogenes and other listeria species. | chromosomal dna sequences from the 60 kilodalton protein gene of listeria monocytogenes, amplified by the polymerase chain reaction, were used for restriction fragment length polymorphism differentiation of l. monocytogenes serotypes and other listeria species. all 24 strains of l. monocytogenes examined produced an extracellular protein of molecular weight 60,000 (p60) as determined by western blot analysis. four of six other listeria species had a protein that cross-reacted to antibodies to p6 ... | 1992 | 1458376 |
| [the diagnosis of listeria encephalitis in ruminants using cultural and immunohistological techniques. i. comparison of different selective media and culture techniques for the detection of listeria from ruminant brains]. | the selective l-palcamy differential enrichment broth, the listeria enrichment broth of the international dairy federation, oxford listeria selective agar, and palcam listeria selective agar were comparatively examined in the cultural isolation of listeria spp. from ten ruminant brains. the l-palcamy medium proved to be superior to the idf broth in both selectivity and productivity for listeria spp. in the brain samples, which were also contaminated with other bacteria. the oxford and palcam aga ... | 1992 | 1414095 |
| neurotropic activity of a strain of listeria innocua in suckling mice. | | 1979 | 484104 |
| biological and immunological properties of avirulent strain of listeria innocua. | the strain isolated by dr. j. h. welshimer from plants has antigenic formula v (vi) ix; xv; xi; ab, c--serovar 6a, is non-haemolytic, produces lipase, and toxic factor ei, is avirulent for adult mice, but causes encephalitis in sucklings. in organs of intravenously injected mice the strain persists and multiplies for 1-3 weeks. the protective effect against listerial infections in mice of this strain administered 2-14 days before challenge is dose depending. after 3 weeks induces resistance of g ... | 1989 | 2631501 |
| impedimetric determination of activity of disinfectants and detergents on listeria: preliminary study. | the efficiency of several disinfectants or detergents against three strains of listeria monocytogenes, one strain of listeria innocua and two strains of streptococcus group d was tested in water as well as in the presence of milk, whey and salt by an impedimetric method using a bactometer m120. certain synergistic effects between active agents and matrix could be observed. differences in sensitivities were noticed amongst the tested strains. products containing iodine, peroxide or quaternary amm ... | 1989 | 2518386 |
| hemolytic phenomenons under the cultivation of listeria innocua. | it was proved that listeria innocua is able to hemolyze rabbit erythrocytes in blood agars when oxoid or difco nutrient agars are used as basic substrate. after 48 h incubation at 37 degrees c and a further 24 h at 4 degrees c the hemolytic effect was clearly expressed. the hot-cold incubation was inevitable. unlike the hemolytic effect of l. monocytogenes, the hemolytic phenomenon of l. innocua was not enhanced by the equi-factor. | 1983 | 6407238 |
| production of thiol-dependent haemolysins by listeria monocytogenes and related species. | twenty-six strains belonging to the five main species of the genus listeria were examined for production of thiol-dependent exotoxins. all strains of l. monocytogenes cultured in charcoal-treated broth secreted a haemolytic factor at a level ranging from 200 to 800 haemolytic units (hu) ml-1, except for the strain egd (1500 hu ml-1) and the type strain cip 82110t (10 hu ml-1). the haemolytic activity reached a maximum level by 8-10 h and then rapidly declined as soon as bacterial exponential gro ... | 1989 | 2516113 |
| cloning of a gene encoding a major secreted polypeptide of listeria monocytogenes and its potential use as a species-specific probe. | a gene, designated msp, that encodes a major secreted polypeptide with a molecular mass of approximately 60 kilodaltons (kda) was cloned from listeria monocytogenes 10403. dna hybridization analysis indicated that the msp gene was highly conserved among 15 independent l. monocytogenes isolates and that each of 5 isolates tested secreted a 60-kda polypeptide that was immunologically related to the msp gene product. dna sequences related to msp were not detected in any other listeria species or in ... | 1989 | 2508555 |
| characteristics of listeria strains, isolated from micromammalia in bulgaria. | 56 listeria strains isolated from the intestine contents of 13 species of micromammalia in bulgaria were studied. 10 of the strains belong to the serovars 1/2a, 4a, 4b and 5 of listeria monocytogenes and 44 of the strains belong to 10 antigenic variants of listeria innocua. according to their characteristics these strains could hardly cause diseases in humans or domestic animals. two strains have antigenic formulae o-v, vii, xiv and o-v, xiv and cannot be included in the existing classification. ... | 1981 | 6798107 |
| [listeriosis studies in game animals in tirol and in the steiermark (austria)]. | serological investigations were carried out on game for listeria monocytogenes. isolation attempts were also included. listeria monocytogenes and listeria innocua were isolated. | 1989 | 2501155 |
| taxonomy of the genus listeria. | according to dna homology values as well as to 16s rrna cataloguing results, the genus listeria presently contains two groups of closely related species: one is constitued by listeria gravi and listeria murrayi, the other by listeria monocytogenes, listeria ivanovii, listeria innocua, listeria welshimeri, and listeria seeligeri. among these seven species, only two are pathogenic for humans and animals: listeria monocytogenes and listeria ivanovii. listeria denitrificans was recently excluded fro ... | 1988 | 2458322 |
| the place of listeria among gram-positive bacteria. | the genus listeria, containing the species listeria monocytogenes, listeria innocua, listeria seeligeri, listeria welshimeri, listeria ivanovii, listeria grayi and listeria murrayi is a well circumscribed taxon. numerical taxonomic and chemical studies indicate a very close phenetic similarity to the genus brochothrix and a more distant, but close, similarity to a number of other genera such as lactobacillus, streptococcus, lactococcus, enterococcus, staphylococcus, kurthia and bacillus. recent ... | 1988 | 2458321 |
| effect of listeria infection on the allotransplantation reaction in cyclosporin a treated mice. | allogeneic reaction of listeria-infected balb/c mice to c3h skin graft was examined. the recipients were infected with listeria innocua and treated with cyclosporin a. listeria infection in the treated mice enhanced skin rejection reaction reduced by the immunosuppressor. | 1990 | 2264452 |
| characterization of diacetin b, a bacteriocin from lactococcus lactis subsp. lactis bv. diacetylactis ul720. | fourteen lactococcus lactis strains showing inhibitory activity against listeria innocua sicc 4202 were isolated from different french raw milks and raw milk cheeses and screened for bacteriocin production by the triple layer method under conditions that eliminate the effects of lactic acid and hydrogen peroxide. three bacteriocinogenic strains (two lactococcus lactis subsp. lactis bv. diacetylactis ul719 and ul720 and one lactococcus lactis subsp. lactis ul730) were selected for their high capa ... | 1995 | 7585360 |
| repression of motility and flagellin production at 37 degrees c is stronger in listeria monocytogenes than in the nonpathogenic species listeria innocua. | listeria monocytogenes and listeria innocua differ markedly in virulence but are indistinguishable by classical taxonomic criteria. both species are actively motile and produce abundant flagellin at 22 degrees c. we have found, however, noticeable differences between l. monocytogenes and l. innocua in motility and flagellin production at 37 degrees c. at this temperature, l. monocytogenes strains were virtually nonmotile and produced little or no detectable flagellin, whereas strains of l. innoc ... | 1995 | 7641140 |
| activity and purification of linenscin oc2, an antibacterial substance produced by brevibacterium linens oc2, an orange cheese coryneform bacterium. | an orange cheese coryneform bacterium isolated from the surface of gruyère of comté and identified as brevibacterium linens produces an antimicrobial substance designated linenscin oc2. this compound inhibits gram-positive food-borne pathogens including staphylococcus aureus and listeria monocytogenes but is not active against gram-negative bacteria. linenscin oc2 caused viability loss and lysis of the test organism, listeria innocua. electron microscopy showed that linenscin oc2 induces protopl ... | 1995 | 7646021 |
| haematological reactions of rabbits infected intravenously with listeria strains of different virulence. | listeria strains of different virulence were injected intravenously into rabbits of both sexes (2-4 kg). the infectious dose was 10(8) cells/kg. blood samples were taken from the ear wein one day and immediately before the infection, then 3 h, 1, 2, 3, 6 and 10 days after it. total white blood cell counts and their changes were determined and the number of lysosomal granules in neutrophils were counted. a marked monocytic reaction was observed after the injection of virulent listeria monocytogen ... | 1990 | 2124767 |
| application of a statistical bootstrapping technique to calculate growth rate variance for modelling psychrotrophic pathogen growth. | the inherent variability or 'variance' of growth rate measurements is critical to the development of accurate predictive models in food microbiology. a large number of measurements are typically needed to estimate variance. to make these measurements requires a significant investment of time and effort. if a single growth rate determination is based on a series of independent measurements, then a statistical bootstrapping technique can be used to simulate multiple growth rate measurements from a ... | 1994 | 7703023 |
| incidence of antibiotic resistance in listeria species. | to define the prevalence of antibiotic resistance in listeria species pathogenic for humans and animals, 1100 isolates (60 from cases of listeriosis and 1040 from food and environment) collected worldwide were screened. of the 61 tetracycline- and minocycline-resistant strains (37 listeria monocytogenes), 57 harbored tet(m); 4 non-l. monocytogenes isolates contained tet(s). one listeria innocua isolate was also resistant to streptomycin and contained the tet(m) and aad6 genes. an l. monocytogene ... | 1995 | 7797931 |
| the occurrence of listeria monocytogenes in cheese from a manufacturer associated with a case of listeriosis. | a case of listeriosis was associated with the consumption of a soft cheese produced in england. goats cheese and other products from the same food manufacturer were examined for the presence of listeria over the following 11 months. listeria monocytogenes was isolated from 16 of 25 cheese samples on retail sale, 12 of 24 cheese samples obtained directly from the factory, and from shelving within the plant. phage-typing of 68 isolates of l. monocytogenes from cheese samples and the factory showed ... | 1990 | 2118796 |
| the use of the listeria monocytogenes dth gene for the detection of pathogenic biovars in food. | a gene probe encoding a listeria monocytogenes delayed type hypersensitivity factor (dth) was used for the detection of pathogenic biovars/serovars of the genus listeria isolated from soft cheese. a total of 187 strains, isolated by plating techniques, were screened. the probe reacted with all isolated serovars of l. monocytogenes (except one 4b strain) and did not react with any of the listeria innocua strains. using the mouse bio-assay, as described by kaufmann, a significant correlation was f ... | 1989 | 2631508 |
| serovars of listeria monocytogenes and listeria innocua from food. | the increase of listeriosis outbreaks in recent years has mainly been due to the consumption of contaminated dairy products. this prompted a revision of prevention and control measures. cheese and other foods (meat, poultry meat) were investigated. for isolation, samples were prepared and investigated according to the recommendations of the fda with some modifications including, in particular, sub-enrichment. suspicious colonies were tested biochemically followed by serological identification wi ... | 1989 | 2631511 |
| production of linnocuicina 819, a bacteriocin produced by listeria innocua. | we studied the reciprocal antagonistic properties of 14 listeria strains. listeria innocua 29-ccm-a 819 (cip 8011) produces a bacteriocin named linnocuicina 819. this substance is mainly released in the exponential phase of growth and was isolated from the supernatant of tpb cultures. thermal resistance and sensitivity to proteolytic enzymes was assayed. linnocuicina 819 has a bactericidal mode of action producing a lytic effect. | 1988 | 3050374 |
| vaccination against listeria infection in mice with a mutant strain of reduced virulence. | killed listeria monocytogenes (l.m.) or living listeria innocua, being unable to afford noticeable immunity against l.m. challenge in mice, the efficacy of a living strain of l.m. of reduced virulence was studied. this strain was obtained from a field strain of low virulence by successive mutations for streptomycin dependence, reversion to independence and resistance to erythromycin. its protective immunity was checked in mice against iv, sc and intra-gastric challenges. vaccinated mice were pro ... | 1986 | 3096187 |
| potential use of continuous cell lines to distinguish between pathogenic and nonpathogenic listeria spp. | continuous cell lines were tested for their potential use in distinguishing pathogenic from nonpathogenic listeria species. listeria monocytogenes and listeria ivanovii strains were lethal for mice, and culture filtrates were cytotoxic for cultured cells and hemolytic for sheep erythrocytes, while listeria innocua, listeria grayi, and listeria murrayi strains were negative in all three tests. the eight cell lines tested were all affected but varied in sensitivity, with the chinese hamster ovary ... | 1987 | 3114320 |
| in vitro model of penetration and intracellular growth of listeria monocytogenes in the human enterocyte-like cell line caco-2. | penetration and replication of listeria monocytogenes within intestinal epithelial cells were studied by infecting the human enterocyte-like cell line caco-2. entry was due to directed phagocytosis, as suggested by the inhibiting effect of cytochalasin d on bacterial entry and by electron microscopy showing bacteria inside membrane-limiting vacuoles at the early stage of infection. only bacteria from pathogenic species (l. monocytogenes and listeria ivanovii) were able to induce their own phagoc ... | 1987 | 3117693 |
| microcalorimetric investigations on listeria. | sixty-one listeria strains--listeria monocytogenes (35 strains), listeria ivanovii (8), listeria innocua (7), listeria welshimeri (6) and listeria seeligeri (5)--were tested microcalorimetrically for their heat production upon growth in columbia broth. listeria ivanovii and listeria seeligeri displayed different and quite characteristic thermograms. listeria welshimeri, listeria innocua and all but one of the listeria monocytogenes strains showed similar microcalorimetric curves, which differed ... | 1988 | 3134766 |
| antilisterial activity by enterococci in a model predicting the temperature evolution of taleggio, an italian soft cheese. | enterococcus ssp. produced broad-spectrum bacteriocins, which were active against listeria innocua and listeria monocytogenes. inhibition of l. innocua in milk by different starter cultures was evaluated. milk was inoculated with a conventional starter (streptococcus salivarius ssp. thermophilus and lactobacillus delbrueckii ssp. bulgaricus mixed cultures) as a sole starter or in combination with inhibitory starter cultures (enterococcus ssp., bacteriocin-producing strains). tests were performed ... | 1994 | 8046062 |
| cytokine gene expression in mice at an early stage of infection with various strains of listeria spp. differing in virulence. | by using reverse transcription-pcr, cytokine gene expression was examined in mice 24 h after infection with various strains of listeria spp. differing in virulence as determined by in vivo growth and 50% lethal dose values. all the virulent strains of listeria monocytogenes induced the expression of mrnas specific for interleukin-1 alpha (il-1 alpha), gamma interferon (ifn-gamma), and tumor necrosis factor alpha (tnf-alpha) in the spleen of mice, while an l. monocytogenes strain incapable of pro ... | 1994 | 8063381 |
| the presence of listeria spp. in raw milk in ontario. | raw milk samples from bulk tanks in ontario were analyzed for the presence of listeria species. the overall incidence of listeria species in raw milk was 12.4%. listeria innocua was most frequently isolated and was found in 9.7% (43/445) of the raw milk samples, while l. monocytogenes and l. welshimeri were each found in 1.3% (6/445) of the samples. no other species of listeria was found. of five regions in ontario that were examined, the eastern region had a significantly higher incidence rate ... | 1988 | 3135930 |
| histomorphology of experimental listeriosis. | this paper is a survey of the histomorphology of experimental listeriosis based on cooperative studies performed within the past ten years. the influence of various parameters of the infectious agent (pathogenic listeria monocytogenes serovar 4b, nonpathogenic listeria innocua serovar 6b etc.) as well as of the host (euthymic nmri-mice conditioned with dextran sulfate 500 or cyclosporin a, athymic nude mice etc.) on the course, morphology and outcome of the listeria infection was investigated. f ... | 1988 | 3138181 |
| pathogenicity of listeria monocytogenes in comparison to other listeria species. | in different mouse models the pathogenicity of various strains of listeria monocytogenes and of other listeria spp. was evaluated. although quantitative differences of virulence among strains of l. monocytogenes are found, all isolates have to be regarded pathogenic unless essential virulence factors, such as protein composition of the cell wall or hemolysin production, are lacking. besides l. monocytogenes, only listeria ivanovii is able to multiply in the murine host, though definitely to a le ... | 1988 | 3138187 |
| hemolysin from listeria--biochemistry, genetics and function in pathogenesis. | thiol-activated hemolysins (listeriolysins) from listeria monocytogenes (sv4b) and listeria ivanovii were purified to homogeneity. the n-terminal amino acid sequences of the 58 kda listeriolysin of l. ivanovii and of a 24 kda protein which may represent the camp-factor of l. ivanovii were determined. antibodies raised against the l. ivanovii listeriolysin and anti-streptolysin o antibodies were used in western blot analyses to detect listeriolysin(s) in virulent and avirulent listeria strains. i ... | 1988 | 3138189 |
| [the detection of listeria monocytogenes and listeria innocua in cheese]. | | 1988 | 3143352 |
| genetic basis of tetracycline resistance in food-borne isolates of listeria innocua. | eleven of 12 tetracycline-resistant listeria innocua strains, isolated from chicken or turkey frankfurters and mozzarella cheese, were shown to carry dna sequences which hybridized with the tet m probe; of these, two strains also hybridized with tet k. the remaining strain hybridized with the tet k probe only. the tet m determinant appeared to be located on the chromosome; in one case, it was transferable by conjugation to recipients listeria monocytogenes, listeria ivanovii, and enterococcus fa ... | 1993 | 8434927 |
| course of infection and development of immunity in experimental infection of mice with listeria serotypes. | nmri mice were experimentally infected with listeria monocytogenes serotypes 1/2b, 3a, 4b, and 4d and listeria innocua serotype 6b by different means. the course of infection was monitored, using bacteriological and histological methods. the following typical features of experimental infection with the various l. monocytogenes and l. innocua serotypes were observed. (i) on the basis of the mean lethal dose, l. monocytogenes 4b, 4d, and 1/2b proved to be mouse pathogenic, although to different de ... | 1983 | 6406363 |
| [hemolytic effect of listeria innocua on sheep erythrocytes]. | the influence of culture medium composition on hemolytic effects produced by listeria innocua on sheep blood agar has been investigated. neither alpha- nor beta-hemolysis could be observed around l. innocua colonies grown on sheep erythrocyte agar lacking glucose. however, green zones of hemolytic phenomena were observed around colonies grown on such agar which contained 0,6% (w/v) glucose. by using l. innocua cell suspensions and culture filtrates this glucose-associated hemolysis only occurred ... | 1984 | 6485632 |
| a proposed nonpathogenic biological indicator for thermal inactivation of listeria monocytogenes. | listeria innocua m1 was developed as a thermal processing indicator organism for l. monocytogenes by selection of a rifampin- and streptomycin-resistant mutant. zetad values were 5.6 and 5.8 degrees c, and d (68 degrees c) values were 3.8 and 4.9 s for l. monocytogenes and l. innocua, respectively, in skim milk. the advantages of easy selection, similar heat resistance, and nonpathogenicity make l. innocua m1 appropriate for challenge studies designed to evaluate process lethality with respect t ... | 1993 | 8489233 |
| broad host range of streptococcal macrolide resistance plasmids. | four macrolide-lincosamide-streptogramin b resistance plasmids transferred into 13 recipients belonging to streptococcus, staphylococcus, and listeria genera. the plasmids were stably maintained in all new hosts except streptococcus sanguis, streptococcus pneumoniae, staphylococcus aureus, and listeria innocua and were identical to those found in the corresponding donor strains. | 1984 | 6712204 |
| isolation of bacteriophages from listeria monocytogenes serovar 5 and listeria innocua. | 11 new bacteriophages, 3 from listeria monocytogenes serovar 5 and 8 from listeria innocua were isolated from lysogenic strains without induction. phagovar determinations were carried out with these phages and 12 other isolated from l. monocytogenes serovars 1/2 and 4b. 76% of the 142 strains from different serovars tested gave a lytic pattern. the new phage set increased the percentage of determinable l. innocua strains to 61.7%. different phage patterns underline the distinction between l. mon ... | 1982 | 6808789 |
| transferable erythromycin resistance in listeria spp. isolated from food. | an erythromycin-resistant (emr) listeria innocua and an emr listeria monocytogenes isolate both carried ermc genes, which code for rrna methylases. the ermc genes were transferable by conjugation to recipient l. monocytogenes, listeria ivanovii, and enterococcus faecalis but did not appear to be associated with conjugative plasmids. | 1996 | 8572704 |
| effect of cyclosporine a (csa), cyclophosphamide (cy) and azathioprine (aza) on the survival of listeria innocua in mice. | immunosuppressors reducing the defensive mechanisms of the organism make favourable conditions for the development of different infections, particularly for intracellular facultative bacteria such as listeria. in this paper, the effects of different doses of cyclosporine a (csa), cyclophosphamide (cy) and azathioprine (aza) on the survival of listeria innocua, a nonpathogenic strain, in the peritoneal cavity and spleen of balb/c mice, were investigated. it was found that csa and aza, applied on ... | 1994 | 7487366 |
| comparison of the incidence of listeria on equipment versus environmental sites within dairy processing plants. | this study was undertaken to compare the incidence of listeria contamination of processing equipment with that of the general dairy processing environment. a total of 378 sponge samples obtained from 21 dairy plants were analyzed for listeria using three different enrichment media. use of extended microbiological analysis allowed us to identify 26 listeria positive sites which would have not been identified had a single test format been employed. eighty (80) of 378 sites (21.2%) were identified ... | 1995 | 7488532 |
| listeria innocua isolated from a case of ovine meningoencephalitis. | this paper reports a naturally occurring case of meningoencephalitis associated with listeria innocua in a polled-dorset ewe. the ewe was one of a housed group of twenty-five, fed ad lib. on wrapped baled silage. l. innocua was isolated after one week from cold enrichment culture of brain and pituitary tissue. its identity was confirmed by conventional biochemical tests, api listeria (biomerieux uk ltd), the absence of hly and prfa genes using pcr assay and sequencing two variable regions of 16s ... | 1994 | 7533963 |
| modelling growth rates of listeria innocua as a function of lactate concentration. | the effect of sodium lactate (nal) concentration on growth of listeria innocua in a yeast-extract/peptone broth at ph 5.5, 6.0, 6.5 and 7.0 at 4, 10, 20 and 30 degrees c was modelled with the modified gompertz model. nacl was used as a reference to distinguish between the water activity effect and the specific inhibitory effect of nal. minimum inhibitory concentrations (mic) of nacl appeared to be significantly higher than mic values of nal, indicating that nal had a specific inhibitory effect o ... | 1994 | 7703006 |
| in vitro conjugative transfer of vana vancomycin resistance between enterococci and listeriae of different species. | in a study designed to gain data on the in vitro transferability of vancomycin resistance from enterococci of the vana phenotype to listeriae of different species, three clinical enterococcus isolates-enterococcus faecium ls10, enterococcus faecalis ls4, and enterococcus faecalis a3208, all harboring a plasmid that strongly hybridized with a vana probe-were used as donors in transfer experiments. strains of five listeria species were used as recipients. from enterococcus faecium ls10, glycopepti ... | 1996 | 8641304 |
| incidence of listeria spp. in vegetables in kuala lumpur. | from april 1992 to september 1992, 280 samples of 10 different fresh vegetables, bought from four different market outlets in kuala lumpur were examined for the presence of listeria spp. most of the market produce were locally grown with the exception of carrots. the isolation procedure was based on the food & drug administration method (modified) used for the detection of listeria spp. isolation media used were listeria selective medium and licl- phenylethanol-moxalactam agars. the identificati ... | 1994 | 7845269 |
| thermotolerance of meat spoilage lactic acid bacteria and their inactivation in vacuum-packaged vienna sausages. | heat resistance of three meat spoilage lactic acid bacteria was determined in vitro. d-values at 57, 60 and 63 degrees c were 52.9, 39.3 and 32.5 s for lactobacillus sake, 34.9, 31.3 and 20.2 s for leuconostoc mesenteroides and 22.5, 15.6 and 14.4 s for lactobacillus curvatus, respectively. the three lactic acid bacteria were heat sensitive, as one log reductions in numbers were achieved at 57 degrees c in less than 60 s. z-values could not be accurately determined as d-values did not change by ... | 1996 | 8722187 |
| comparison of the infectivity of isolates of listeria monocytogenes following intragastric and intravenous inoculation in mice. | the infectivity of 19 haemolytic isolates of listeria monocytogenes from different sources (clinical and environmental) and representative isolates from listeria ivanovii and listeria innocua was compared following intragastric (i.g.) and intravenous (i.v.) inoculation in immunocompetent male balb/c mice. there was marked variation in the infectivity of the different isolates by either route but when isolates were ranked in descending order by spleen count, following i.g. administration, the str ... | 1996 | 8737494 |
| study of the prevalence of listeria spp. in surface water. | the quantity of listeria species was determined in 49 samples of various types of water (river, brackish water, urban wastewater). twenty nine strains of listeria were isolated. these were mainly identified as listeria monocytogenes (72,4%), but listeria innocua, listeria grayi, listeria ivanohovii and listeria welshimeri were also present. with the exception of water taken from the estuary, 74.4% of samples contained listeria in mean concentrations of between 2 mpn/100 ml and 1320 mpn/100 ml in ... | 1994 | 7848499 |
| interactions with lectins and agglutination profiles of clinical, food, and environmental isolates of listeria. | on the basis of preliminary trials with 14 collection strains of listeria, five lectins (canavalia ensiformis, concanavalin a; griffonia simplicifolia lectin i; helix pomatia agglutinin; ricinus communis agglutinin; and triticum vulgaris wheat germ agglutinin) were selected to set up a microtiter agglutination assay. the lectin agglutination profiles of 174 clinical, food, and environmental strains of listeria monocytogenes, listeria innocua, and listeria seeligeri were investigated. data on the ... | 1994 | 7883879 |
| antibacterial activity of 7-aminocholesterol, a new sterol. | a new sterol, 7-aminocholesterol, which inhibits growth of saccharomyces cerevisiae, also displayed antibiotic activity against gram-positive bacteria. the 50% growth inhibitory concentration against strains of listeria innocua, l. monocytogenes, staphylococcus aureus, enterococcus hirae and bacillus cereus was 3 microm. | 1995 | 7896083 |
| phosphatidylinositol-specific phospholipase c from listeria monocytogenes contributes to intracellular survival and growth of listeria innocua. | listeria monocytogenes is a facultative intracellular organism that is capable of replicating within macrophage and macrophage-like cells. the species secretes a phosphatidylinositol-specific phospholipase c (pi-plc) encoded by the plca gene. a plca gene from l. monocytogenes was cloned downstream of a gram-positive promoter in the plasmid pws2-2. to determine what effect plca would have on intracellular survival when introduced into listeria innocua, a species that does not growth intracellular ... | 1994 | 7927757 |
| purification, partial characterisation and mode of action of enterococcin efs2, an antilisterial bacteriocin produced by a strain of enterococcus faecalis isolated from a cheese. | enterococcus faecalis strain efs2, isolated from the surface of a traditional cheese, produced a bacteriocin active against gram-positive bacteria including listeria spp. and some staphylococcus aureus strains. the bacteriocin, named enterococcin efs2, has been purified to homogeneity by ammonium sulphate precipitation and reversed-phase high performance liquid chromatography (rp-hplc). the molecular weight was determined by mass spectrometry to be 7149.6. the amino acid composition of enterococ ... | 1996 | 8854179 |
| induction of phagocytic behaviour in human epithelial cells by escherichia coli cytotoxic necrotizing factor type 1. | cytotoxic necrotizing factor type 1 (cnf1) from strains of pathogenic escherichia coli induces in human epithelial hep-2 cells, a profound reorganization of the actin cytoskeleton into prominent stress fibres and membrane ruffles. we report here that this process is associated with induction of phagocytic-like activity. cnf1-treated cells acquired the ability to ingest latex beads as well as non-invasive bacteria such as listeria innocua, which were taken as a model system. uptake of bacteria wa ... | 1993 | 7934938 |
| host cell responses to listeria monocytogenes infection include differential transcription of host stress genes involved in signal transduction. | we examined the effect of listeria monocytogenes infection of j774 macrophage-like mouse cells on induction of several stress genes, including genes for heat shock proteins (hsps) and a protein-tyrosine phosphatase (ptp), to understand the host response in various steps of the bacterial invasion process. exposure to wild-type l. monocytogenes strain egd elicited an early induction of hsp70 mrna with a corresponding early appearance of hsp70 protein. cytochalasin d pretreatment prevented the indu ... | 1994 | 8022799 |
| ultrastructural study of listeria monocytogenes entry into cultured human colonic epithelial cells. | evidence that listeria monocytogenes enters caco-2 cells through the apical surface is presented. attachment of bacteria to host cells seems to induce modifications of microvilli which are either in direct contact with the bacterial surface or in close vicinity, resulting in the formation of lamellipodia involved in the cellular uptake of the bacteria. such modifications are not induced by l. monocytogenes slcc 53, which carries a deletion in the prfa gene, although attachment of this mutant to ... | 1994 | 8039928 |
| isolation from food sources, of lactic acid bacteria that produced antimicrobials. | the potential of lactic acid bacteria, isolated from a variety of foods, to inhibit indicators representative of spoilage and pathogenic bacteria associated with food products was examined. fruit and vegetables were a poor source of lactic acid bacteria but large numbers were readily isolated on mrs agar from cheese, milk and meat samples. approximately 1000 isolates from each of the food samples were examined by the deferred antagonism procedure to determine their ability to inhibit staphylococ ... | 1994 | 8144413 |
| interaction of listeria species with human cell monolayers. | in foodborne listeriosis, the first step of infection must be attachment to, and invasion of, the gastrointestinal epithelium by virulent listeria monocytogenes. virulence factors affecting this invasion are only now being determined. we examined the interaction of l. monocytogenes, serotypes 4b and 1/2a strains with "smooth" and "rough" characteristics. in addition, flagellated and non-flagellated isogenic strains altered by transposon mutagenesis were examined to study the effect of flagellae ... | 1994 | 8174317 |
| [protective action of anti-listeria igg]. | it was found that single injection into mice of 70 micrograms igg against listeria innocua protected them against lethal action of virulent cell of l. monocytogenes, if antibodies were injected 1-3 weeks before infection. immune igg did not exert the protective effect when injected one day before infection. mice t lymphocytes receiving immune igg three weeks before infection, exhibited increased ability to direct interactions (cluster formation) with dendritic cells presenting listeria antigen ( ... | 1993 | 8231444 |
| lactate and acetate production in listeria innocua. | listeria innocua nctc 11289 was grown aerobically in continuous culture in defined media at 30 degrees c. both acetate and lactate were produced, the proportion of acetate decreased with increasing dilution rate. enzymatic analysis showed lactate dehydrogenase was activated 10-fold by fructose-1, 6-bisphosphate. the presence of phosphate acetyltransferase and acetate kinase but not pyruvate oxidase was detected, suggesting the sequential action of phosphate acetyltransferase and acetate kinase t ... | 1996 | 8987454 |
| distribution of listeria spp. in confectioners' pastries from western france: comparison of enrichment methods. | three hundred samples of pastry from 100 different suppliers in western france, including butter-cream, whipped dairy cream and custard filled cakes from each supplier, were collected and tested for the occurrence of listeria spp. in 25 g samples. listeria spp. were detected in 21.7% of he samples: listeria monocytogenes in 13.7%, listeria innocua in 10% and listeria seeligeri in 2.3%. thirteen samples were contaminated with two species simultaneously. the frequency of contaminated samples was n ... | 1993 | 8347428 |
| dna fragments from regions involved in surface antigen expression specifically identify listeria monocytogenes serovar 4 and a subset thereof: cluster iib (serotypes 4b, 4d, and 4e). | listeria monocytogenes serotype 4b has frequently been implicated in sporadic as well as epidemic listeriosis. on the basis of pulsed-field fingerprinting, serotype 4b strains, along with strains of serotypes 4d and 4e, constitute one genomic cluster (iib). we have identified two genomic regions essential for the expression of surface antigens which previously were shown to be specific to cluster iib strains. a dna probe of 1.1 kb derived from one of the regions (probe 1) hybridized only with st ... | 1997 | 9055423 |
| optical dna-dna homology in the genus listeria. | twenty-three strains of the seven recognized listeria species were studied by using dna-dna optical hybridization. the level of error in the data was low. our results supported the results of rocourt et al. (j. rocourt, f. grimont, p. a. d. grimont, and h. p. r. seeliger, curr. microbiol. 7:383-388, 1982), although there was some overlap between listeria monocytogenes and listeria innocua. we suggest that there may be more than one cluster in the species l. monocytogenes or the species may form ... | 1993 | 8427807 |
| [isolation of micro-organisms of the species listeria from raw milk intended for human consumption]. | refrigerated mixtures of raw milk provided by a dairy which was supplied by farms from west and central spain were tested for the presence of listeria microorganisms. a total of 95 samples were taken at regular intervals over a 16-month period. listeria grayi was isolated from 89.5% of the samples, listeria monocytogenes s. str. from 45.3%, listeria innocua from 15.8%, listeria welshimeri from 3.1%, and listeria seeligeri from 1.05%. listeria ivanovii, listeria murrayi, and listeria denitrifican ... | 1985 | 4063881 |
| [nonpathogenic listeriae: l. innocua sp. n. (seeliger et schoofs, 1977) (author's transl)]. | in connexion with the separation of listeria innocua (seeliger and schoofs, 1977) from listeria monocytogenes (murray et at., pirie, 1940), resulting epidemiological and epizootological problems are discussed. l. innocua is apathogenic when conventional experimental models for testing listeria monocytogenes are used. under special conditions, i.e. use of suckling mice, strain welshimer of l. innocua produced localized encephalitis (patoĉka et al., 1979). the peculiarities of l. innocua justify f ... | 1981 | 6171948 |
| selective diagnostic medium for pathogenic listeria spp. | pathogenic listeria serovars produced hemolysis on agars containing 5% rabbit erythrocytes and 10 micrograms of acriflavin, 40 micrograms of nalidixic acid, and 7.5 activity units of equi factor per ml. apathogenic listeria innocua was nonhemolytic on this medium. | 1983 | 6361058 |
| bactericidal activity of disinfectants on listeria. | the bactericidal activity on listeria spp. of nine disinfectants used in the food industry was studied by previously published methods. the disinfectants were diluted to the test concentration in sterile standard hard water. various types of chemical agents were evaluated, including phenolic compounds, alcohols, quaternary ammonium compounds, surface-active agents, aldehydes and disochlorine tablets. the following strains isolated from cheese were studied: listeria innocua, l. welshimeri, l. mon ... | 1993 | 8486555 |
| characterization of listeria strains isolated from soft cheese. | three soft cheeses were exposed to quantitative analysis for listeria and found to contain a large number of listeria. thirty-five of the listeria strains isolated from the three cheeses were characterized by use of biochemical tests, serotyping, phagetyping and dna restriction enzyme analysis. seven isolates were identified as listeria innocua and 28 as listeria monocytogenes. two to four different clones of l. monocytogenes could be identified from each cheese. in contrast, only one clone coul ... | 1993 | 8494682 |
| [phosphatidylinositol specific phospholipase c (pi-plc) in differentiation of listeria monocytogenes and listeria innocua]. | listeria strains were investigated as regard: the production of pi-plc and lecytinase, haemolytic and camp activity survival in mouse tissues. although all the examined l. monocytogenes strains produced pi-plc, they showed a very different activity of this enzyme. it was surprising that one of the four l. innocua strains demonstrated a weak activity of pi-plc. l. monocytogenes bacteria with strong pi-plc activity survived in mouse spleens for a much longer period of time than l. monocytogenes mi ... | 1995 | 8523967 |
| antibacterial and hemolytic activities of linenscin oc2, a hydrophobic substance produced by brevibacterium linens oc2. | linenscin oc2 is an antibacterial substance produced by the orange cheese coryneform bacterium brevibacterium linens oc2. it inhibits the growth of gram-positive bacteria but it is inactive against gram-negative bacteria. the intact outer membrane of gram-negative bacteria was shown to be an effective permeability barrier against linenscin oc2. at high dosage the effect of linenscin oc2 was bacteriolytic on listeria innocua. bacteriostasis was observed at low dosage and peptidoglycan biosynthesi ... | 1997 | 9271855 |
| comparison of different selective methods for detection of listeria species in surface water. | tests were carried out to evaluate the efficiency of various combinations of selective enrichment and plating techniques using pure cultures of listeria monocytogenes, listeria seeligeri and listeria innocua in suspension and samples of surface water. the best yields for the various listeria spp. were obtained after a single passage in leb (oxoid) or leb buffered (oxoid) and after using palcam and oxford agar (oxoid). palcam agar was, however, shown to be the most efficient means of detecting th ... | 1995 | 9353532 |
| comprehensive study of the intestinal stage of listeriosis in a rat ligated ileal loop system. | the intestinal stage of listeriosis was studied in a rat ligated ileal loop system. listeria monocytogenes translocated to deep organs with similar efficiencies after inoculation of loops with or without peyer's patches. bacterial seeding of deep organs was demonstrated as early as 15 min after inoculation. it was dose dependent and nonspecific, as the delta inlab, the delta hly, and the delta acta l. monocytogenes mutants and the nonpathogenic species, listeria innocua, translocated similarly t ... | 1998 | 9453636 |
| predictive modelling of inactivation of listeria spp. in bovine milk during high-temperature short-time pasteurization. | a linear model was derived to describe the thermal inactivation of listeria innocua in bovine whole milk in a high-temperature short-time pilot scale pasteurizer. integrated lethal effect, or pasteurization effect (pe), was obtained by converting times at different temperatures in the various sections of the pasteurizer to the equivalent time at the reference temperature (72 degrees c). pe was then related by a simple linear function to the log10 of the % viable counts with a power transformatio ... | 1998 | 9553795 |
| characterization of plasmids from listeria monocytogenes and listeria innocua strains isolated from short-ripened cheeses. | the plasmid content of 30 isolates of listeria monocytogenes and 18 isolates of listeria innocua obtained from short-ripened cheeses was analysed. the isolates of l. monocytogenes serogroup 1 harboured a single plasmid, plm33 (33.2 kbp), whereas the serogroup 4 isolates did not contain plasmids. one group of l. innocua strains harboured the plasmid pli71 (71 kbp) and another one contained two plasmids: pli59 (59.5 kbp) and pli56 (56.5 kbp). these plasmid groups were in accordance with clusters p ... | 1998 | 9553802 |
| genomic subtraction in combination with pcr for enrichment of listeria monocytogenes-specific sequences. | genomic dna from listeria innocua and listeria ivanovii was used in subtractive hybridization with dna from listeria monocytogenes involving two amplification strategies. subtraction was accomplished by labelling the subtracting dna with biotin and removal after liquid hybridization with tester dna (l. monocytogenes) by reaction with streptavidin and phenol extraction. in one strategy, l. monocytogenes dna was poly(a)-tailed with terminal transferase and amplified asymmetrically after subtractio ... | 1995 | 8579987 |