| prostaglandin-mediated suppression of macrophage phagocytosis of listeria monocytogenes. | suppression of macrophage phagocytosis of listeria monocytogenes has been shown to be due to a low-molecular-weight component of spleen cell culture supernatant. the possibility that the factor could be a prostaglandin was investigated. when murine peritoneal macrophages were treated with prostaglandin e2 (pge2), l. monocytogenes was phagocytized at a rate comparable to that phagocytized when treated with a low-molecular-weight fraction of concanavalin a-generated spleen cell culture supernatant ... | 1987 | 3119229 |
| a murine macrophage cell line, immortalized by v-raf and v-myc oncogenes, exhibits normal macrophage functions. | in vitro immortalized cell lines with the morphology and phenotype of mature macrophages (m phi) have been generated by infecting freshly isolated bone marrow cells from c3h/hej mice with a recombinant retrovirus carrying v-raf and v-myc oncogenes. all of the clones obtained had m phi-like phenotypes, and one such clone, gg2ee, has been compared to normal m phi to ascertain the effects of immortalization on the expression of the biological functions of the lines. gg2ee cells expressed cytotoxic ... | 1987 | 3119352 |
| induction of interleukin 1 secretion and of tumoricidal activity in macrophages are not closely related phenomena. | rat bone marrow-derived mononuclear phagocytes (bmm phi), induced to differentiate in vitro and homogeneous with respect to the cell lineage, were interacted with various macrophage-activating agents. the effect of these agents on the secretion of interleukin 1 (il 1) activity and on the development of tumoricidal capacity was comparatively assessed. the findings show that il 1 secretion is considerably enhanced by macrophage-activating factor and by recombinant interferon-gamma but remained una ... | 1987 | 3119353 |
| [infection of the cns caused by listeria monocytogenes]. | this report examines two cases of infection of the central nervous system by listeria monocytogenes (l.m.). both cases show that listeriosis is not only a differential diagnosis of purulent meningitis, but can also be the cause of an isolated brain stem syndrome with normal cerebrospinal fluid cell count. the prognosis depends crucially on the early antibiotic therapy (ampicillin). the first patient was a chronic alcoholic. he died of fulminant septic shock and meningitis with brain stem encepha ... | 1987 | 3119467 |
| transfer of resistance to primary infection of listeria monocytogenes and early induction of delayed hypersensitivity by sera from l. monocytogenes-infected mice. | we found a new phenomenon which differs from previous reports on experimental listeriosis, that is, failure of passive transfer of serum from listeria monocytogenes-infected mice to convey resistance to the bacterium. transfer of immune serum from l. monocytogenes-infected mice markedly augmented resistance to the bacterium, and mechanisms of the transfer of l. monocytogenes-immune serum were investigated. transfer of immune serum prevented l. monocytogenes lethality. this effect of the immune s ... | 1987 | 3119497 |
| listeria monocytogenes--a current dilemma. | since 1985, listeria monocytogenes has gone from being an organism known to only a handful of microbiologists to being a fully recognized food-borne pathogen of concern. with nearly unprecedented speed and vigor, food processors, particularly in the dairy industry, and regulatory agencies have reacted in concert to resolve unanswered questions about listeria so as to assure the safety of the food supply. this report summarizes what has been learned and what is being done. | 1987 | 3119559 |
| inhibition of macrophage-mediated antigen presentation by hemolysin-producing listeria monocytogenes. | t lymphocytes and macrophages from listeria-infected mice were used to evaluate the processing and presentation of live listeria monocytogenes in vitro. antigen presentation to t cells was quantitated by interleukin-2 production. in contrast to inert antigens such as heat-killed listeria, live bacteria were processed and presented poorly. to evaluate the role of hemolysin (hly), we used isogenic pairs of hly+ and hly- listeria as antigens. in contrast to live hly- bacteria, which were presented ... | 1987 | 3119719 |
| t cell recognition of listeriolysin o is induced during infection with listeria monocytogenes. | during bacterial multiplication, listeria monocytogenes (strain egd) secretes sulfhydryl-dependent cytotoxin, termed listeriolysin o, a virulence factor presumable promoting intracellular growth of this ubiquitous pathogen. the role of this exotoxin in the process of t cell activation was studied in vivo during the course of an experimental infection in the mouse. by using highly purified listeriolysin o, it was found that infection with viable, replicative bacteria induced in vivo the emergence ... | 1987 | 3119720 |
| [an autopsy case of sepsis and meningitis due to listeria monocytogenes]. | | 1987 | 3119743 |
| [local epidemic of neonatal listeriosis in upper austria--report of 20 cases]. | in an 8 month period, 20 cases of listeriosis among neonates were seen in the federal district of upper austria. the majority of mothers reported influenza-like symptoms at the end of pregnancy. 19 cases were early-onset-infections, 6 infants developed meningitis. serotype 1/2a was isolated in 7 cases. all were of the same phage type. 15 neonates were successfully treated with aminopenicillin or penicillin. treatment with cephalosporin was ineffective. 4 mainly premature infants died, 1 was stil ... | 1987 | 3119914 |
| [obtaining dicloxacillin-resistant mutants in listeria monocytogenes]. | we obtained ten dicloxacillin resistant mutants from listeria monocytogenes atcc: 15313 (29-ccm-a: 454). none of the mutants could be differentiated from the parental strain (except for their increased resistance) neither using conventional biochemical assays nor by analysis of the electrophoretic pattern of their detergent-soluble proteins (figure 1). the wild type strain and some of these mutants were tolerant for dicloxacillin and/or penicillin g, but no rigorous correlation with each decreas ... | 1986 | 3120240 |
| hemolysin supports survival but not entry of the intracellular bacterium listeria monocytogenes. | the gram-positive bacterium listeria monocytogenes is a facultative intracellular pathogen. the only known property of l. monocytogenes which has been shown to be involved in virulence is a hemolysin, listeriolysin (j. l. gaillard, p. berche, and p. sansonetti, infect. immun. 52:50-55, 1986; s. kathariou, p. metz, h. hof, and w. goebel, j. bacteriol. 169:1291-1297, 1987). using our previously obtained transposon tn916-induced hemolysin-negative mutants of l. monocytogenes sv1/2a (mackaness strai ... | 1988 | 3121515 |
| pathogenicity test for listeria monocytogenes using immunocompromised mice. | the lethality of listeria isolates was determined with normal adult mice and mice that were immunocompromised by treatment with 20 mg of carrageenan per kg. the mean 50% lethal doses (ld50s) of the pathogenic isolates were significantly lower (alpha = 0.05) in the immunocompromised mice than in the untreated mice, with an average reduction of 5.8 log10 units. in contrast, the mean ld50s of the nonpathogenic isolates were lower in the immunocompromised mice by an average of only 0.4 log10 unit, a ... | 1987 | 3121665 |
| listeria monocytogenes atcc 35152 and nctc 7973 contain a nonhemolytic, nonvirulent variant. | listeria monocytogenes nctc 7973 and this same strain deposited as atcc 35152 contain two phenotypes: hemolytic virulent colonies and nonvirulent colonies that show no zones of hemolysis when streaked on heart infusion agar containing 5% rabbit blood. results of examinations of these virulent and nonvirulent strains by investigators at the centers for disease control, atlanta, ga., the pasteur institute, paris, france, and the university of würzburg, federal republic of germany, support the conc ... | 1987 | 3121669 |
| [congenital listeriosis]. | | 1987 | 3122163 |
| suppression of macrophage activation and t-lymphocyte function in hypoprolactinemic mice. | the effects of prolactin on lactation and reproductive organs are well known. however, the other possible target organs and physiological consequences of altered levels of circulating prolactin remain poorly understood. in this study, mice were treated with bromocryptine, a dopamine receptor agonist that inhibits pituitary prolactin secretion. bromocryptine treatment prevented t-cell-dependent induction of macrophage tumoricidal activity after the intraperitoneal injection of listeria monocytoge ... | 1988 | 3122324 |
| failure of recombinant murine gamma-interferon to cure chronic listerosis of nude, athymic mice. | the bacterial counts per spleen of athymic, nude mice chronically infected with listeria monocytogenes could not be reduced by treatment with high doses of recombinant murine gamma-interferon. | 1987 | 3122379 |
| effect of prompt inoculator on results of sceptor system minimal inhibitory concentration determinations for listeria monocytogenes. | the minimal inhibitory concentrations (mics) of eight antimicrobial agents were determined for each of 36 isolates of listeria monocytogenes with the sceptor system. two different inoculation procedures, the standard sceptor log-phase broth (lb) culture and the prompt inoculator (pi) (bauer-kirby type), were used. the pi mic/lb mic ratio (pi/lb ratio) was determined for each antimicrobial agent for each of the isolates. of the 217 on-scale pi/lb ratio results, all were within the expected range ... | 1988 | 3122704 |
| levels of listeria monocytogenes hemolysin are not directly proportional to virulence in experimental infections of mice. | the sulfhydryl-activated hemolysin of listeria monocytogenes has been implicated in the virulence of the bacteria. although loss of hemolytic activity by means of transposon mutagenesis is accompanied by loss of virulence in the mouse infection model, a direct relationship between in vitro production of hemolysin and virulence was not observed. noticeable deviations in the extent of hemolysin production appeared to leave virulence unaffected. | 1988 | 3123396 |
| the role of hepatic lectins and the activity of the mononuclear phagocyte system in systemic listeria monocytogenes infection in balb/c mice. | hepatic lectin blocking experiments with d-galactose in balb/c mice showed that parenchymal liver cells are obviously not involved in listeria monocytogenes infection (strain slcc 4013, 5 x 10(6) cells i.v.). using the bacterial immunomodifier propionibacterium avidum kp-40 the importance of an activated mononuclear phagocyte system in the early stage of listeria infection could be demonstrated. | 1988 | 3123903 |
| [fulminant hepatitis in listeria septicemia]. | we report on a 44-year-old male patient admitted with acute severe icteric hepatitis. listeria monocytogenes was isolated from blood cultures. the further course was complicated by meningitis and the patient finally died of multiorgan failure. autopsy revealed nodular cirrhosis of the liver with cholestatic hepatitis and focal subacute liver dystrophy, as well as granulating meningitis. the case is discussed in the context of five previously published observations on hepatitis due to listeria mo ... | 1987 | 3124266 |
| listeria monocytogenes: a foodborne pathogen. | listeriosis, caused by listeria monocytogenes, appears to be increasing in incidence worldwide. the disease is of great concern to the food industry. a recent outbreak in california was linked to the consumption of mexican-style soft cheese and involved more than 300 cases, 30% of which were fatal. l. monocytogenes can be found in a variety of dairy products, leafy vegetables, fish and meat products. it can grow in refrigerated foods and is more heat resistant than most vegetative microbes. the ... | 1988 | 3124948 |
| listeriosis: prevention and control. | | 1988 | 3124950 |
| a simple method for evaluation of delayed hypersensitivity in mice. | | 1987 | 3125573 |
| activity of new antimicrobial agents against listeria monocytogenes. | | 1987 | 3126061 |
| expression in escherichia coli and sequence analysis of the listeriolysin o determinant of listeria monocytogenes. | to evaluate the role of hemolysin production in the virulence of listeria monocytogenes, we have undertaken the analysis of the chromosomal region containing hlya, the gene coding for listeriolysin o. a recombinant cosmid, conferring a hemolytic phenotype to escherichia coli, was shown to express listeriolysin o, by immunoblotting with a specific antiserum against listeriolysin o. the presence of hlya on the cosmid was demonstrated by dna hybridization with a probe previously shown to contain pa ... | 1988 | 3126142 |
| survival of listeria monocytogenes in raw milk treated in a pilot plant size pasteurizer. | the survival of listeria monocytogenes in raw milk treated in a pilot plant size pasteurizer was investigated. raw milk was inoculated with different initial concentrations of l. monocytogenes and heated at temperatures ranging from 69 degrees to 73 degrees c. listerias were not isolated from any of the milk samples immediately after thermal treatment. they were isolated, however, from 46.6% of heated samples (none from samples heated at 73 degrees c) after variable periods at refrigeration temp ... | 1987 | 3126174 |
| [ruptured popliteal aneurysm caused by listeria monocytogenes]. | | 1988 | 3126250 |
| [infections by listeria monocytogenes. 15 years' experience]. | | 1987 | 3126377 |
| in vitro susceptibility of listeria monocytogenes isolated from human blood and cerebrospinal fluid. a material from the years 1958-1985. | the in vitro susceptibility of 156 strains of listeria monocytogenes isolated since 1958 from human cerebrospinal fluid or blood to twelve antibiotics was determined by an agar dilution technique. erythromycin (0.05), trimethoprim (0.2), netilmicin (0.2), and penicillin (0.2) were the most active drugs on weight basis (mic90 0.05-0.2 micrograms/ml). ampicillin and imipenem had mics for 90% of the strains of 0.4 micrograms/ml. ceftazidime was inactive (mic90 greater than 100 micrograms/ml). compa ... | 1988 | 3126784 |
| susceptibility of micro-organisms to active oxygen species: sensitivity to the xanthine-oxidase-mediated antimicrobial system. | xanthine oxidase with acetaldehyde as substrate (the xoa system) generated superoxide anion and hydrogen peroxide, but this system had only weak bactericidal activity. addition of fe2+ and edta to the xoa system (xoa-fe-edta system) increased bactericidal activity against staphylococcus aureus, escherichia coli, listeria monocytogenes and salmonella typhimurium, although both mycobacterium tuberculosis and candida albicans remained highly resistant. catalase (h2o2 scavenger) and mannitol (.oh sc ... | 1987 | 3127535 |
| relationship between the susceptibility of various bacteria to active oxygen species and to intracellular killing by macrophages. | the susceptibilities of six micro-organisms to active oxygen species generated in the xanthine oxidase-mediated bactericidal system were as follows: escherichia coli 81 greater than or equal to listeria monocytogenes egd greater than or equal to salmonella typhimurium hkb-1 greater than or equal to staphylococcus aureus smith much greater than mycobacterium tuberculosis h37rv approximately equal to candida albicans nih a207 (the last two organisms were essentially resistant to this system). the ... | 1987 | 3127536 |
| thermal inactivation of listeria monocytogenes within bovine milk phagocytes. | thermal resistance of intracellular and freely suspended listeria monocytogenes that was associated with a milkborne outbreak of listeriosis was studied by using the sealed tube and slug flow heat exchanger methods. test temperatures for the former method were 57.8, 62.8, 66.1, and 68.9 degrees c (136, 145, 151, and 156 degrees f, respectively); whereas those for the latter method were 66.1, 68.9, 71.7, and 74.4 degrees c (151, 156, 161, and 166 degrees f, respectively). the heating menstruum wa ... | 1988 | 3128163 |
| fate of listeria monocytogenes in tissues of experimentally infected cattle and in hard salami. | muscle, organ, and lymphoid tissues of four holstein cows experimentally inoculated (intravenously) with listeria monocytogenes were examined 2, 6, or 54 days postinoculation for the presence of the organism by direct plating and cold enrichment procedures. l. monocytogenes was isolated from 66% of the tissues sampled; 38% of the isolations were attributed to the use of cold enrichment. isolation of the organism from muscle tissue was possible only with animals inoculated 2 days before slaughter ... | 1988 | 3128165 |
| catalase and superoxide dismutase activities after heat injury of listeria monocytogenes. | four strains of listeria monocytogenes were examined for catalase (ca) and superoxide dismutase (sod) activities. the two strains having the highest ca activities (lcdc and scott a) also possessed the highest sod activities. the ca activity of heated cell extracts of all four strains examined decreased sharply between 55 and 60 degrees c. sod was more heat labile than ca. two l. monocytogenes strains demonstrated a decline in sod activity after heat treatment at 45 degrees c, whereas the other t ... | 1988 | 3128167 |
| immunomodulation of gvh reaction in mice by listeria monocytogenes. | in the first part of experiments the gvhr activity of the spleen cell suspensions from normal parental donors (balb/c) or infected with listeria monocytogenes was compared. gvhr was examined in (balb/c x akr) f1 mice. full suspensions from these donors or depleted of adherent cells or with addition of macrophages were studied. it has been proved that adherent cells population plays a significant role in the gvhr development. the addition of syngeneic macrophages from f1 hybrids results in a grea ... | 1987 | 3128245 |
| mouse macrophages stimulated by recombinant gamma interferon to kill tumor cells are not bactericidal for the facultative intracellular bacterium listeria monocytogenes. | data presented here demonstrate that recombinant gamma interferon (rifn-gamma) activated a single population of 10% fetal calf serum-elicited mouse peritoneal exudate cells to express tumoricidal activity but not bactericidal activity for the facultative intracellular bacterium listeria monocytogenes. fetal calf serum-elicited cells incubated with rifn-gamma phagocytosed listeriae normally, suggesting that their inability to kill this bacterium is not because they cannot phagocytose it. data als ... | 1988 | 3128484 |
| [listeriosis]. | | 1988 | 3128855 |
| particulate antigens may be reprocessed after initial phagocytosis for presentation to t cells in vivo. | macrophages were pulsed with listeria monocytogenes antigens by intraperitoneal injection prior to harvesting and thoroughly washing the cells. the pulsed macrophages were injected into the feet of listeria-immune or naive mice to elicit a delayed hypersensitivity reaction. where soluble listeria antigen was used, presentation by donor macrophages to host t cells required identity within the i region of the h-2 complex. however, presentation of alcohol-killed listeria organisms or of a living, t ... | 1987 | 3129365 |
| an in vitro model for toxoplasma infection in man. interaction between cd4+ monoclonal t cells and macrophages results in killing of trophozoites. | the cell interactions that take place between toxoplasma gondii trophozoites and the human immune system have been investigated by using an in vitro model of infection. pbmc were co-cultured with live, appropriately attenuated, trophozoites. when cells from immune (seropositive) donors were used, a proliferative response was observed. at the same time, the proliferating t cells proved capable of controlling the growth of live trophozoites. by contrast, cells from seronegative donors failed to mo ... | 1988 | 3129496 |
| cloned listeria monocytogenes specific non-mhc-restricted lyt-2+ t cells with cytolytic and protective activity. | mice were infected with listeria monocytogenes and lyt-2+ t cell clones capable of lysing ag-primed bone marrow macrophages were established. in accordance with earlier findings obtained at the population level, some t cell clones were identified which lysed bone marrow macrophages of different mhc type provided the relevant ag was present. this unusual target cell recognition was further analyzed using a t3+, l3t4-, lyt-2+, f23+, kj16+ t cell clone, designated l-28. target cell lysis by this cl ... | 1988 | 3129513 |
| antigen-specific production of colony-stimulating factors by listeria monocytogenes-immune, l3t4-positive cells. | we investigated production of colony-stimulating factors by listeria monocytogenes-immune spleen cells. levels of total colony-stimulating factors in supernatants from antigen-stimulated immune cells were increased two- to fourfold over those in supernatants from nonimmune cells. immune supernatants primarily induced formation of granulocyte colonies, whereas nonimmune supernatants induced formation of macrophage colonies. immune supernatants had two- to 10-fold higher levels of macrophage colon ... | 1988 | 3129523 |
| listeria encephalitis with intermittent symptoms and serological diagnosis. | | 1988 | 3129540 |
| [listeria monocytogenes in food. a review]. | listeriosis as a foodborne disease made european headlines in the autumn of 1987. some years earlier, the usa were alarmed by the presence of listeria monocytogenes in a large number of dairy products. following recent outbreaks, this paper deals with pathogenesis, isolation, epidemiology and distribution of listeria monocytogenes in food. its reactions in food (e.g. growth, survival, thermal inactivation) under various circumstances is described. | 1988 | 3129821 |
| [listeria mastitis in cattle]. | cases of human infection caused by listeria and resulting from the consumption of dairy produce contaminated by listeria are referred to in the literature. a case of mastitis in cattle, caused by listeria monocytogenes type 1/2a, is reported. the result of treatment of the infected quarters with penicillin was not satisfactory so far. several cases of short-lived excretion of listeria bacteria in the milk and carriers not showing any symptoms are referred to in the literature, whereas cases of p ... | 1988 | 3129822 |
| [cardiotocography practice. case 15]. | | 1988 | 3129884 |
| proposed changes in interpretive criteria and potency of ampicillin and ampicillin-sulbactam disks for susceptibility tests. | the accuracy of disk susceptibility tests with ampicillin and ampicillin-sulbactam was not improved when the amount of ampicillin was increased from 10 to 20 or 30 micrograms per disk. for testing members of the family enterobacteriaceae, ampicillin disk tests correlated better with broth microdilution tests when the zone size standards were altered from greater than or equal to 14 greater than or equal to 17 mm for susceptible and from less than or equal to 11 to less than or equal to 13 mm for ... | 1988 | 3130390 |
| recurrence of listeria monocytogenes meningitis. | a case of listeria monocytogenes meningitis in a 3-year-old boy which relapsed after chloramphenicol treatment is described. the patient was subsequently successfully treated with ampicillin and gentamicin and made a complete recovery. in vitro studies confirmed the inadequacy of chloramphenicol therapy. the value of combination therapy, as evidenced by chessboard and killing-curve techniques with the strain, is discussed. | 1988 | 3130425 |
| [the present status of listeriosis--a review]. | | 1988 | 3130834 |
| in vivo-activated mononuclear phagocytes and protective immunity to chlamydiae in mice. | peritoneal macrophages (m phi s) collected from chlamydia psittaci 6bc-immune mice after intraperitoneal challenge with 10(6) 6bc (immune-boosted [ib] m phi s) were compared by various functional criteria with other in vivo- and in vitro-activated m phi populations. while casein-, protease peptone-, and thioglycolate (thio)-elicited m phi s were equally susceptible to in vitro infection with 6bc, ib m phi s did not support chlamydial growth and m phi s from mycobacterium tuberculosis bcg- or lis ... | 1988 | 3131246 |
| [listeriosis of the central nervous system in children beyond the neonatal period]. | observations on three children with neurolisteriosis (one case of meningitis, two cases of meningoencephalitis, each serovar 4 b), show that even after the neonatal period, listeriosis must not be ignored in the process of diagnosis and therapy. it is the bacteriological examination of the cerebrospinal fluid, together with the blood culture, and not clinical symptoms and serology that guarantee a timely diagnosis and therapy (ampicillin and gentamicin). | 1988 | 3131787 |
| [congenital listeriosis]. | | 1987 | 3131937 |
| an outbreak of meningo-encephalitis in fallow deer caused by listeria monocytogenes. | an outbreak of listeric meningo-encephalitis occurred in a population of 1800 fallow deer (dama dama) in a park during the winter and early spring of 1985 to 1986. listeriosis was diagnosed in 41 of 42 fallow deer that showed the typical central nervous system signs of circling disease or were found dead. the diagnosis was verified by bacteriological examination of the brains of 35 animals. in five of the seven remaining cases listeriosis was diagnosed by histological examination, and in one ani ... | 1988 | 3131946 |
| vaccination with a listeria strain of reduced virulence against experimental listeria abortion in goats. | a live listeria monocytogenes strain of reduced virulence, strain aer, obtained by three successive mutations in regard to streptomycin and erythromycin, was used as vaccine on goats in two successive experiments. animals were vaccinated either once or twice by subcutaneous route with doses varying from 6 x 10(8) to 1.5 x 10(10) cfu. no side effect was observed, except in one goat, vaccinated as pregnant, that aborted and from which the vaccinal strain was reisolated. the goats were challenged b ... | 1987 | 3132075 |
| susceptibility of listeria strains to imipenem, by species, serotype and origin. | | 1988 | 3132444 |
| listeria monocytogenes chorioamnionitis and preterm labor. | two cases of listeria monocytogenes chorioamnionitis in association with preterm labor are presented. the pathogenicity and the recommended treatments of listeriosis in regard to the pregnancy outcomes of our patients are discussed. | 1988 | 3132932 |
| false-positive agglutinations with listeria monocytogenes using a commercial kit for lancefield grouping of beta-haemolytic streptococci. | | 1988 | 3134222 |
| historical perspectives on methodology to detect listeria monocytogenes. | while recognized as a causative agent of illness in animals and humans for some time, the foodborne role of listeria monocytogenes is a new and emerging one. this review briefly summarizes the historical developments in methodology used to detect the presence of l. monocytogenes. although clinical procedures exist, these procedures do not consider isolation of listeria from heavily contaminated environments. federal agencies such as the u.s. food and drug administration and the u.s. department o ... | 1988 | 3134334 |
| direct plating technique for enumeration of listeria monocytogenes in foods. | the advantages and disadvantages of various techniques for detecting and enumerating listeria monocytogenes in foods are reviewed, and results from a study designed to compare 14 direct plating media for their suitability to recover uninjured cells of l. monocytogenes from 4 foods are summarized. mcbride listeria agar (mla), gum base nalidixic acid tryptone soy agar (gbntsa), modified despierres agar (mda), and modified mla (mmla) performed best for recovering all inoculum populations from milk ... | 1988 | 3134335 |
| listeria methods development research at the eastern regional research center, u.s. department of agriculture. | listeria methods research at the u.s. department of agriculture, eastern regional research center, has concentrated on 2 areas during the past year. the first was development of techniques for assessing isolation methods for their ability to detect sublethally stressed cells. it appears that a number of widely used media do not accurately detect listeria that have been injured by thermal processing or acidification. the second was development of improved plating media. one, modified vogel-johnso ... | 1988 | 3134336 |
| flow cytometry for automated analysis of milk containing listeria monocytogenes. | this paper describes the application of flow cytometry to the analysis of milk for the presence of listeria monocytogenes. a total of 939 raw milk samples from 54 farms were analyzed for the presence of l. monocytogenes by cold enrichment vs flow cytometry, which incorporated a selective enrichment step. analyzed samples consisted of milk from individual farm bulk tanks; string samples which represented milk from 25 to 40 cows; and combination samples representing milk from 200 cows. raw milk sa ... | 1988 | 3134337 |
| isolation and identification of listeria monocytogenes in dairy products. | after an outbreak of listeriosis in massachusetts in 1983, the ability of listeria monocytogenes to survive in raw and pasteurized milk was investigated. an enrichment broth (eb) containing acriflavine, nalidixic acid, and cycloheximide was used to eliminate overgrowth of the culture by competing organisms, and a modification of mcbride's agar (mma) was used as the isolation medium. the culture was incubated 24 h at 30 degrees c. to isolate listeria from soft cheese, the incubation period was le ... | 1988 | 3134338 |
| development of usda-fsis method for isolation of listeria monocytogenes from raw meat and poultry. | a method was developed specifically to detect naturally occurring listeria monocytogenes in meat because the traditional cold enrichment procedure was extremely slow and other procedures were ineffective. this method could identify beta-hemolytic listeria colonies in 3-4 days. the use of a 2-stage enrichment, highly selective lpm agar, and a thin-layer horse blood agar plate for the detection of beta-hemolytic listeria isolates are the important steps of this method. l. monocytogenes was recover ... | 1988 | 3134339 |
| evaluation of enrichment and plating media for isolating listeria monocytogenes. | we compared selective enrichment broths used by the u.s. food and drug administration (fda) and the u.s. department of agriculture (usda), food safety and inspection service, for their efficiency in the quantitative recovery of listeria monocytogenes from a naturally contaminated brie cheese that was obtained as part of an epidemic investigation. quantitative recovery of listeria in fda broth (greater than 2.4 x 10(5) colony forming units/ml) was significantly better than recovery in usda broth ... | 1988 | 3134340 |
| identification and enumeration of beta-hemolytic listeria monocytogenes in naturally contaminated dairy products. | a dna probe was used to identify hemolytic listeria monocytogenes in naturally contaminated dairy products: unpasteurized milk, ricotta cheese, and imported semisoft cheeses. of 34 milk samples, 12 were suspected to contain hemolytic l. monocytogenes; 1 contained greater than 6000 viable organisms/g. the ricotta cheese, although temperature-abused, had a titer of 3.6 x 10(6) beta-hemolytic l. monocytogenes cells/g, whereas the semisoft cheeses reached a maximum of 5.6 x 10(6) cells/g. pure cultu ... | 1988 | 3134341 |
| industry perspectives on listeria monocytogenes. | industry concerns and our ongoing research on listeria are discussed in this report. topics include sampling for analysis; sanitizers and their use in manufacturing facilities; precautions on use of the fda method for listeria; use of the vitek gram positive identification card; and a brief discussion on findings of listeria in environmental samples taken from the same site at the same time of year in 1986 and 1987. | 1988 | 3134342 |
| anti-listeria monocytogenes immunity in mu-suppressed mice: a comparison of treatment with conventional hyperimmune rabbit anti-mouse igm and affinity-purified, monoclonal rat anti-mouse igm. | the capacity of anti-igm treated, b-cell-depleted mice to control infection by listeria monocytogenes was evaluated. suppression was achieved with a hyperimmune rabbit anti-mouse-igm antiserum (irs), with affinity-purified irs (irp), or with an affinity-purified, monoclonal, rat anti-mouse-igm antibody (lo-mm-9). b-cell depletion in specifically treated mice was judged to be complete by the following criteria: absence of significant response to a b-cell mitogen lipopolysaccharide, absence of b-c ... | 1988 | 3134601 |
| 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 |
| necrotizing ring ulcer of the cornea caused by exogenous listeria monocytogenes serotype iv b infection. | | 1988 | 3134816 |
| the effects of allyl isovalerate on the hematopoietic and immunologic systems in rodents. | female b6c3f1 mice plus male and female fischer 344/n rats were gavaged with allyl isovalerate (aiv) in corn oil at 0, 31, 62, or 125 (mice) and 0, 31, 62, 125, or 250 (rats) mg/kg body weight for five daily exposures per week for a 2-week period. hematologic, immunologic, and histopathologic studies were performed 48 to 72 hr following the final treatment. aiv exposure had no effect on hematology or bone marrow cellularity in mice or rats. aiv exposure at 250 mg/kg was toxic to rats causing red ... | 1988 | 3135219 |
| evaluation of anti-listeria monocytogenes antibodies by elisa. | a new elisa test using the purified listeria monocytogenes-derived antigen lm 84 ag is described together with its application in the diagnosis of listeriosis. fifty-seven human sera were titrated by the elisa and the complement fixation method and compared for specificity and sensitivity. the problem of possible cross-reactions with other antigens is discussed. | 1986 | 3135221 |
| prevention by gamma interferon of fatal infection with listeria monocytogenes in mice treated with cyclosporin a. | the significance of interferons (ifns) induced by listeria monocytogenes in the antilisterial defense mechanism was studied in mice. cyclosporin a (csa) had no effect on ifn-alpha production that was induced in the bloodstream after intravenous infection of mice with l. monocytogenes, whereas ifn-gamma that was induced in the bloodstreams of control mice 6 h after stimulation with specific antigen in the late phase of infection was suppressed in csa-treated mice, depending on the dose of the dru ... | 1988 | 3135267 |
| induction of immunity with avirulent listeria monocytogenes 19113 depends on bacterial replication. | events necessary for triggering the cell-mediated response to intracellular parasites are poorly understood. here we show that extremely high doses of avirulent listeria monocytogenes 19113 (greater than 10(9] induce a modest and short-lived state of resistance in balb/c mice. induction of this protective state could not be achieved with nonviable bacteria and was blocked by inhibiting replication of viable l. monocytogenes 19113 through antibiotic treatment. the immune response was antigen spec ... | 1988 | 3135271 |
| induction of tumor necrosis factor, ifn-gamma, and acute lethality in mice by toxic and non-toxic forms of lipid a. | the effect of the i.v. administration of endotoxin (lps), diphosphoryl lipid a, and the non-toxic derivative monophosphoryl lipid a (mpl), on the production of serum cachectin (tnf), ifn-gamma, and the appearance of endotoxin shock have been measured in mice primed with listeria monocytogenes. all three of the lipid a varieties induced the production of tnf in a dose-dependent manner. although comparable peak levels of tnf were produced (5 x 10(5) to 1 x 10(6) u/ml), treatments with lps or dipho ... | 1988 | 3135314 |
| listeriosis and recurrent abortion in a renal transplant recipient. | a 29-year-old farmer's wife had received a kidney from her brother (of identical hla type) at the age of 22 years. she was afterwards immunosuppressed with prednisolone and azathioprine. her first pregnancy had been uneventful but the second and third had terminated spontaneously at 15 and 24 weeks gestation respectively. following the third pregnancy, listeria monocytogenes (serotype 4) was grown from the fetus, the placenta and maternal blood. over the next 18 months, antibody titres which wer ... | 1988 | 3135336 |
| 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 |
| rhabdomyolysis and acute renal failure associated with listeria meningitis. | | 1988 | 3136213 |
| growth of mycobacterium avium in activated macrophages harvested from inbred mice with differing innate susceptibilities to mycobacterial infection. | the growth of mycobacterium avium in macrophages obtained from mycobacterium bovis bcg-infected mice was compared with that in macrophages from uninfected mice. bcg vaccination resulted in substantial macrophage activation, measured as increased acid phosphatase and superoxide anion production, as well as enhanced leishmanicidal activity. however, the activated macrophages were only able to reduce the rate of intracellular growth by listeria monocytogenes and m. avium in vivo and did not express ... | 1988 | 3137164 |
| intracellular interference with antigen presentation. | murine peritoneal macrophages were cultured with heat-killed listeria monocytogenes organisms and then with the protein hen egg white lysozyme. hen egg lysozyme is well known to need intracellular processing for presentation to t cells. the presentation to t cells of lysozyme was affected despite no reduction in the amount taken up or catabolized by the macrophage. this interference with ag presentation was not found if the macrophages were cultured with lysozyme before the listeria pulse. the i ... | 1988 | 3137257 |
| epidemic listeriosis associated with mexican-style cheese. | in los angeles county, california, 142 cases of human listeriosis were reported from january 1 through august 15, 1985. ninety-three cases (65.5 percent) occurred in pregnant women or their offspring, and 49 (34.5 percent) in nonpregnant adults. there were 48 deaths: 20 fetuses, 10 neonates, and 18 nonpregnant adults. of the nonpregnant adults, 98 percent (48 of 49) had a known predisposing condition. eighty-seven percent (81 of 93) of the maternal/neonatal cases were hispanic. of the listeria m ... | 1988 | 3137471 |
| listeria monocytogenes isolated from soft cheese. | | 1988 | 3137717 |
| evaluation of selective direct plating media for their suitability to recover uninjured, heat-injured, and freeze-injured listeria monocytogenes from foods. | six direct plating media were evaluated for their suitability to recover uninjured, heat-injured, and freeze-injured cells of four strains of listeria monocytogenes from four foods. cells were inoculated into foods to achieve ca. 10(2) to 10(3), 10(4) to 10(5), or 10(5) to 10(6) viable cells per ml or g (low, medium, and high populations, respectively). no appreciable differences in recovery of the four test strains within a treatment were observed. generally, recovery on all test media was simi ... | 1988 | 3137864 |
| monoclonal antibodies which identify a genus-specific listeria antigen. | fifteen murine monoclonal antibodies (mabs) which react specifically with a protein antigen found in all species of listeria were developed and characterized. these mabs were tested extensively by both enzyme-linked immunosorbent assay and western blot (immunoblot) analyses for cross-reaction with non-listeria organisms, such as staphylococcus, streptococcus, citrobacter, pseudomonas, and salmonella species, and were found to be nonreactive. the genus-specific antigen was identified as a heat-st ... | 1988 | 3137865 |
| increased bactericidal macrophage activity induced by immunological stimuli is dependent on interferon (ifn)-gamma. interference of anti-ifn-gamma but not anti-ifn-alpha/beta with modulation of macrophage activity caused by lymphocytic choriomeningitis virus infection or systemic graft-vs.-host reactions. | during generalized immune responses such as the acute phase of graft-vs.-host reaction (gvhr) or many systemic viral infections the macrophage-monocyte system of mice is activated as demonstrated by their increased bactericidal capacity against listeria monocytogenes. to study the effect of interferon (ifn)-gamma in maintainance of macrophage activity, lymphocytic choriomeningitis virus (lcmv) primed c57bl/6 mice or (c57bl/10 x b10.br) f1 mice undergoing a gvhr were treated with polyclonal speci ... | 1988 | 3138138 |
| endogenous tumor necrosis factor (cachectin) is essential to host resistance against listeria monocytogenes infection. | during a sublethal murine infection with listeria monocytogenes cells, tumor necrosis factor (tnf) activity was detectable in neither sera nor spleen homogenates at any stage of the infection when a bioassay with l-929 cells (less than 4 u/ml) was used. however, injecting the mice with an immunoglobulin fraction obtained from a rabbit hyperimmunized with recombinant murine tnf-alpha resulted in acceleration of listeriosis. when 1 mg of anti-tnf antibody was injected per mouse, all the mice died ... | 1988 | 3138177 |
| 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 |
| alteration of non-specific resistance to infection with listeria monocytogenes. | the experimental infection of murine hosts with listeria monocytogenes is often used as a model for cell-mediated immunity. however, the natural immunity or non-specific resistance to listeriosis can be influenced by the parasite itself and also by a wide array of endogenous and exogenous host factors. the most important host factor in inbred mouse strains is their genetically determined susceptibility or resistance to listeria monocytogenes. secondly, the age of the mice is crucial for the outc ... | 1988 | 3138182 |
| comparison of responsiveness to the monocytosis-producing activity of listeria monocytogenes in mice genetically susceptible or resistant to listeriosis. | injection of a monocytosis producing activity (mpa) from listeria monocytogenes caused a dose-dependent elevation in numbers of macrophage colony forming units (cfu-m) in bone marrow and in peripheral blood. the increase could be seen as early as 8 h after injection of mpa and persisted until 72 h after injection. serum from mpa-treated animals, capable of inducing monocytosis, also caused an elevation in numbers of cfu-m. the effect of mpa on cfu-m numbers in peripheral blood was measured in in ... | 1988 | 3138183 |
| the role of t cell subpopulations in cell mediated immunity to facultative intracellular bacteria. | this brief review summarizes the experimental data which underly the classic concept of antibacterial cell mediated immunity and will integrate recent developments focusing on results obtained by in vivo studies in the model of rodent listeriosis. | 1988 | 3138184 |
| listeria monocytogenes specific t-cell lines and clones. | evidence is summarized to suggest that both cd4 and cd8 t cells and both helper and cytolytic t cell functions are involved in protective immunity to infection with the intracellular bacterium, listeria monocytogenes. this suggestion is based on the following findings obtained with t cell lines and clones from l. monocytogenes infected mice: l3t4+ (cd4) t cells produce multiple lymphokines after antigen stimulation in vitro; lyt2+ (cd8) t cells lyse l. monocytogenes primed macrophages; l3t4+ (cd ... | 1988 | 3138185 |
| roles of factor increasing monocytopoiesis (fim) and macrophage activation in host resistance to listeria monocytogenes. | the present contribution concerns two aspects of host resistance in overcoming an infection with listeria monocytogenes. one of these aspects is the regulation of monocyte production by the factor increasing monocytopoiesis (fim), a macrophage-derived factor. listeria-resistant (c57bl/10 mice and listeria-sensitive cba mice produce and secrete similar amounts of fim in response to an inflammation induced by soluble listeria antigen. however, monocyte precursors in the bone marrow of listeria-res ... | 1988 | 3138186 |
| 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 |
| invasiveness and intracellular growth of listeria monocytogenes. | listeria monocytogenes is an invasive bacterial pathogen capable of multiplying inside many host cells, including macrophages, enterocytes and hepatocytes. there is evidence to believe that secretion of listeriolysin o, an sh-activated exotoxin, is crucial for bacterial growth in host tissues. this exotoxin is stimulated in iron-deprived medium and mostly active at low ph (5.5). electron microscopic studies showed that intracellular bacteria rapidly disrupt the vacuole membrane of phagosomes and ... | 1988 | 3138188 |
| 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 |
| liposome-encapsulated ampicillin against listeria monocytogenes in vivo and in vitro. | in an experimental infection caused by listeria monocytogenes in mice a considerable enhancement (90-fold) of the therapeutic activity of ampicillin resulting from liposomal encapsulation was observed. the mechanism by which liposomes improved the therapeutic index of ampicillin in this infection appeared to be an increased delivery of the antibiotic to the site of infection, i.e. the liver and spleen. substantial amounts of liposomal ampicillin were recovered from isolated kupffer cells, the ta ... | 1988 | 3138190 |
| therapy of experimental listeriosis--an evaluation of different antibiotics. | the therapeutic activities of various antibiotics were evaluated in two murine models, i.e. the infection of normal mice as well as of nude mice. coumermycin and rifampicin were the most active drugs, since not only inhibition of multiplication but also rapid elimination of listeria monocytogenes could be achieved in normal and immunocompromised animals. ampicillin was the most active beta-lactam antibiotic followed by azlocillin. the other beta-lactam antibiotics were definitely less active. th ... | 1988 | 3138191 |
| listeria and listeriosis. rothenburg, west germany, april 29-30, 1987. proceedings. | | 1988 | 3138192 |
| listeriosis--history and actual developments. | although apparently observed before, the history of listeriosis dates back approximately 60 years. first known as a cause of epidemics and sporadic cases in some 50 species of animals, the disease appears now with increased frequency among human populations at risk. the causative agent listeria monocytogenes is primarily a psychrophilic soil-borne bacterium with a wide pathogenic potential thus provoking primarily septicemia, meningitis and intrauterine infections. recent observations indicate c ... | 1988 | 3138193 |
| [studies of the effect of antimicrobials encapsulated in liposomes in the treatment of experimental infection due to legionella pneumophila and listeria monocytogenes]. | | 1988 | 3138320 |
| generation of listeria monocytogenes-specific t cells mediating delayed footpad reaction and protection in neonatally thymectomized mice but not in nude mice. | neonatally thymectomized (ntx) mice, sham-operated control mice and congenitally athymic nude mice were immunized with viable listeria monocytogenes and their spleen cells examined for the capacity to transfer both delayed footpad reaction and protection against challenge at the site of local transfer. cells from immune ntx mice conferred significant degrees of delayed footpad reaction and protection comparable to sham mice, while cells from immune nude (nu/nu) mice did not. this ability was com ... | 1988 | 3138516 |